Usami, Kiyoaki; Sakamoto, Kenji; Yokota, Junichiro; Uehara, Yoichi; Ushioda, Sukekatsu
2008-12-01
We have investigated the pretilt angle of liquid crystal (LC) molecules induced by photoaligned films of a series of polyimides. The polyimides were random copolymers synthesized from pyromellitic dianhydride and a mixture of 4,4'-diaminoazobenzene and 4-[4'-propylbi(cyclohexan)-4-yl]phenyl 3,5-diaminobenzoate (PBCP-DABA). PBCP-DABA is a diamine to introduce a side-chain structure into polyimide. We found that the pretilt angle of LC molecules can be controlled from 0° to 90° by varying the molar fraction (x) of PBCP-DABA from 0 to 0.5. Defect-free uniform LC alignment was observed for x ≤0.125 and x ≥0.3, but threadlike textures appeared for 0.15≤x≤0.25. Since the interaction between the polyimide backbone structure and the LC molecule may be blocked by relatively dense side-chains, the appearance of threadlike texture is tentatively attributed to weak azimuthal anchoring strength of the photoaligned polyimide films with x ≥0.15.
Directional Wide-Angle Range Finder (DWARF)
National Aeronautics and Space Administration — The proposed innovation, the Directional Wide-Angle Range Finder (DWARF) is the creation of a laser range-finder with a wide field-of-view (FOV) and a directional...
Hybrid Projectile Body Angle Estimation for Selectable Range Increase
Gioia, Christopher J.
A Hybrid Projectile (HP) is a tube launched munition that transforms into a gliding UAV, and is currently being researched at West Virginia University. A simple launch timer was first envisioned to control the transformation point in order to achieve maximum distance. However, this timer would need to be reprogrammed for any distance less than maximum range due to the nominal time to deployment varying with launch angle. A method was sought for automatic wing deployment that would not require reprogramming the round. A body angle estimation system was used to estimate the pitch of the HP relative to the Earth to determine when the HP is properly oriented for the designed glide slope angle. It was also necessary to filter out noise from a simulated inertial measurement unit (IMU), GPS receiver, and magnetometer. An Extended Kalman Filter (EKF) was chosen to estimate the Euler angles, position and velocity of the HP while an algorithm determined when to deploy the wings. A parametric study was done to verify the optimum deployment condition using a Simulink aerodynamic model. Because range is directly related to launch angle, various launch angles were simulated in the model. By fixing the glide slope angle to -10° as a deployment condition for all launch angles, the range differed only by a maximum of 6.1% from the maximum possible range. Based on these findings, the body angle deployment condition provides the most flexible option to maintain maximum distance without the need of reprogramming. Position and velocity estimates were also determined from the EKF using the GPS measurements. Simulations showed that the EKF estimates exhibited low root mean squared error values, corresponding to less than 3% of the total position values. Because the HP was in flight for less than a minute in this experiment, the drift encountered was acceptable.
Test technology on divergence angle of laser range finder based on CCD imaging fusion
Shi, Sheng-bing; Chen, Zhen-xing; Lv, Yao
2016-09-01
Laser range finder has been equipped with all kinds of weapons, such as tank, ship, plane and so on, is important component of fire control system. Divergence angle is important performance and incarnation of horizontal resolving power for laser range finder, is necessary appraised test item in appraisal test. In this paper, based on high accuracy test on divergence angle of laser range finder, divergence angle test system is designed based on CCD imaging, divergence angle of laser range finder is acquired through fusion technology for different attenuation imaging, problem that CCD characteristic influences divergence angle test is solved.
Ranges of the least uncomfortable joint angles for assessing automotive driving posture.
Peng, Junfeng; Wang, Xuguang; Denninger, Lisa
2017-05-01
Few investigations have been performed on how the ranges of preferred angles should be used for vehicle interior discomfort evaluation. This study investigated the ranges of the least uncomfortable joint angles considering both inter-individual and intra-individual variability. The driving postures of sixty-one subjects were collected using two multi-adjustable vehicle mock-ups under four test conditions by gradually adding the number of control parameters (constraints), from the "least-constrained" driving condition to the configurations close to currently existing vehicles. With help of subjective discomfort evaluation, the intra-and inter-individual variation ranges of least uncomfortable postural angles were quantified. Results show that intra-individual variation ranges of postural angles were much smaller than those of inter-individual variation as expected. An individual may not feel comfortable throughout the whole range of comfortable angles from all participants. Possible relationships between perceived discomfort and ranges of inter and inter individual variations in least uncomfortable angles were explored, suggesting that the inter ranges could be used to detect potential problems of postural discomfort and the intra ranges could be considered as optimum ranges. A three color model, based on the intra-and inter-individual variability ranges of comfortable driving postures, was proposed for ergonomics assessment of a vehicle configuration. Copyright © 2017 Elsevier Ltd. All rights reserved.
Using a grating analyser for SEMSANS investigations in the very small angle range
International Nuclear Information System (INIS)
Strobl, M.; Wieder, F.; Duif, C.P.; Hilger, A.; Kardjilov, N.; Manke, I.; Bouwman, W.G.
2012-01-01
Spin-echo modulation small-angle neutron scattering (SEMSANS) is based on the detection of spatial beam modulation, which is induced by triangular spin echo precession regions and subsequent spin analyses. In order to detect such signal and exploit it for small angle scattering investigations neutron detection with sub-millimeter spatial resolution is required. Here an approach is reported where instead of a position sensitive detector an absorption grating is used to analyze the beam modulation stepwise. The spin-echo length scan in this case is performed by varying the sample-to-detector distance. The real space correlation functions of reference sample structures in the range 10 2 nm, i.e. giving rise to small-angle scattering in the very small-angle range, are recorded and analyzed successfully.
Lepage, Benoit; Painchaud-April, Guillaume
2017-02-01
As seamless tube manufacturers push quality requirements for their products, automated phased array Rotating Tube Inspection Systems (RTIS) are now required to provide continuous NDE detection performances over a wide angular range of oblique flaws. One major impact of this new reality is a paradigm shift for the calibration method use. This change is driven by the requirement to meet homogeneous detection over broad oblique flaw angle intervals, whereas standard practice only requires calibration at specific discrete angles. This paper presents an innovative method specifically designed to obtain high productivity and homogeneous inspection measurements over an oblique flaw range extending from -45 to 45 degrees. Experimental results from the application of the method on various tubes presenting multiple artificial flaws support the quantitative performance evaluation.
A Lead Angle Control for HB-Type Stepping Motor in the Constant Voltage Range
Okumatsu, Yoshihiro; Kawamura, Atsuo
Stepping motors are generally used as a positioning servo in the OA (Office Automation) and FA (Factory Automation) system because the construction cost is very low and the construction of system is very easy. Since they are generally driven by an open loop controller, the response of stepping motors is oscillatory and it is possible to be out of drive. Therefore they are driven by a closed loop controller in the special system, which requires the high reliability and stability. The lead angle control is used as a closed loop controller of stepping motors because an applied voltage amplitude is not able to be controlled. However a closed loop control of stepping motors is hardly used at present. This paper presents the lead angle control based on the vector control in the constant voltage drive range for 2 phases HB type stepping motors. In the constant voltage range, since the HB type stepping motor is modeled as a surface permanent magnet motor, the motor torque is controlled by the q-axis current. The d-axis current is calculated by the voltage limit condition because of the constant voltage amplitude operation. The control performances are examined by the simulations and experimental results.
The Influence of Long-Range Surface Forces on the Contact Angle of Nanometric Droplets and Bubbles.
Stocco, Antonio; Möhwald, Helmuth
2015-11-03
For a droplet or a bubble of dimensions below 100 nm, long-range surface forces such as long-range van der Waals forces can compete with capillarity, which leads to a size dependence of the contact angle. This is discussed in this work, where we also show that the effect cannot simply be described by a normalized line tension. We calculate interfacial profiles for typical values of van der Waals forces and discuss the role of long-range surface forces on the contact angle of nanobubbles and nanodrops.
Long range correlations and folding angle with applications to Î±-helical proteins
Krokhotin, Andrey; Nicolis, Stam; Niemi, Antti J.
2014-03-01
The conformational complexity of chain-like macromolecules such as proteins and other linear polymers is much larger than that of point-like atoms and molecules. Unlike particles, chains can bend, twist, and even become knotted. Thus chains might also display a much richer phase structure. Unfortunately, it is not very easy to characterize the phase of a long chain. Essentially, the only known attribute is the radius of gyration. The way how it changes when the degree of polymerization becomes different, and how it evolves when the ambient temperature and solvent properties change, is commonly used to disclose the phase. But in any finite length chain there are corrections to scaling that complicate the detailed analysis of the phase structure. Here we introduce a quantity that we call the folding angle to identify and scrutinize the phase structure, as a complement to the radius of gyration. We argue for a mean-field level relationship between the folding angle and the scaling exponent in the radius of gyration. We then estimate the value of the folding angle in the case of crystallographic α-helical protein structures in the Protein Data Bank. We also show how the experimental value of the folding angle can be obtained computationally, using a semiclassical Born-Oppenheimer description of α-helical chiral chains.
Architecture of a low-angle normal fault zone, southern Basin and Range (SE California)
Goyette, J. A.; John, B. E.; Campbell-Stone, E.; Stunitz, H.; Heilbronner, R.; Pec, M.
2009-12-01
Exposures of the denuded Cenozoic detachment fault system in the southern Sacramento Mountains (SE California) delimit the architecture of a regional low-angle normal fault, and highlight the evolution of these enigmatic faults. The fault was initiated ~23 Ma in quartzo-feldspathic basement gneiss and granitoids at a low-angle (2km, and amplitudes up to 100m. These corrugations are continuous along their hinges for up to 3.6 km. Damage zone fracture intensity varies both laterally, and perpendicular to the fault plane (over an area of 25km2), decreasing with depth in the footwall, and varies as a function of lithology and proximity to corrugation walls. Deformation is concentrated into narrow damage zones (100m) are found in areas where low-fracture intensity horses are corralled by sub-horizontal zones of cataclasite (up to 8m) and thick zones of epidote (up to 20cm) and silica-rich alteration (up to 1m). Sub-vertical shear and extension fractures, and sub-horizontal shear fractures/zones dominate the NE side of the core complex. In all cases, sub-vertical fractures verge into or are truncated by low-angle fractures that dominate the top of the damage zone. These low-angle fractures have an antithetic dip to the detachment fault plane. Some sub-vertical fractures become curviplanar close to the fault, where they are folded into parallelism with the sub-horizontal fault surface in the direction of transport. These field data, corroborated by ongoing microstructural analyses, indicate fault activity at a low angle accommodated by a variety of deformation mechanisms dependent on lithology, timing, fluid flow, and fault morphology.
Density model for medium range order in amorphous materials: application to small angle scattering
International Nuclear Information System (INIS)
Boucher, B.; Tournarie, M.; Chieux, P.; Convert, P.
1983-06-01
We consider a family of randomly spaced parallel planes, each plane dressed with a density function, h(x), where x is the distance from the plane. An expression for the volume scattering power from a system of N such families with random orientations in space is derived from Fourier transform of h(x), which can subsequently be determined from experimental observations. This density model is used to interpret the small angle neutron scattering (SANS) results for the amorphous alloy TbCusub(3.54)
Wei, Xian-Zhao; Xu, Xi-Ming; Wang, Fei; Li, Ming; Wang, Zi-Min
2015-09-05
A quantitative and accurate measurement of the range of hip joint flexion (RHF) is necessarily required in the evaluation of disordered or artificial hip joint function. This study aimed to assess a novel method to measure RHF more accurately and objectively. Lateral radiographs were taken of 31 supine men with hip joints extended or flexed. Relevant angles were measured directly from the radiographs. The change in the sacrofemoral angle (SFA) (the angle formed between the axis of the femur and the line tangent to the upper endplate of S1) from hip joint extension to hip joint flexion, was proposed as the RHF. The validity of this method was assessed via concomitant measurements of changes in the femur-horizontal angle (between the axis of the femur and the horizontal line) and the sacrum-horizontal angle (SHA) (between the line tangent to the upper endplate of S1 and the horizontal line), the difference of which should equal the change in the SFA. The mean change in the SFA was 112.5 ± 7.4°, and was independent of participant age, height, weight, or body mass index. The mean changes in the femur-horizontal and SHAs were 123.0 ± 6.4° and 11.4 ± 3.0°, respectively. This confirmed that the change of SFA between hip joint extension and hip joint flexion was equal to the difference between the changes in the femur-horizontal and SHAs. Using the SFA, to evaluate RHF could prevent compromised measurements due to the movements of pelvis and lumbar spine during hip flexion, and is, therefore, a more accurate and objective method with reasonable reliability and validity.
Directory of Open Access Journals (Sweden)
Petr V. Konarev
2015-05-01
Full Text Available Small-angle X-ray and neutron scattering (SAXS and SANS experiments on solutions provide rapidly decaying scattering curves, often with a poor signal-to-noise ratio, especially at higher angles. On modern instruments, the noise is partially compensated for by oversampling, thanks to the fact that the angular increment in the data is small compared with that needed to describe adequately the local behaviour and features of the scattering curve. Given a (noisy experimental data set, an important question arises as to which part of the data still contains useful information and should be taken into account for the interpretation and model building. Here, it is demonstrated that, for monodisperse systems, the useful experimental data range is defined by the number of meaningful Shannon channels that can be determined from the data set. An algorithm to determine this number and thus the data range is developed, and it is tested on a number of simulated data sets with various noise levels and with different degrees of oversampling, corresponding to typical SAXS/SANS experiments. The method is implemented in a computer program and examples of its application to analyse the experimental data recorded under various conditions are presented. The program can be employed to discard experimental data containing no useful information in automated pipelines, in modelling procedures, and for data deposition or publication. The software is freely accessible to academic users.
Konarev, Petr V; Svergun, Dmitri I
2015-05-01
Small-angle X-ray and neutron scattering (SAXS and SANS) experiments on solutions provide rapidly decaying scattering curves, often with a poor signal-to-noise ratio, especially at higher angles. On modern instruments, the noise is partially compensated for by oversampling, thanks to the fact that the angular increment in the data is small compared with that needed to describe adequately the local behaviour and features of the scattering curve. Given a (noisy) experimental data set, an important question arises as to which part of the data still contains useful information and should be taken into account for the interpretation and model building. Here, it is demonstrated that, for monodisperse systems, the useful experimental data range is defined by the number of meaningful Shannon channels that can be determined from the data set. An algorithm to determine this number and thus the data range is developed, and it is tested on a number of simulated data sets with various noise levels and with different degrees of oversampling, corresponding to typical SAXS/SANS experiments. The method is implemented in a computer program and examples of its application to analyse the experimental data recorded under various conditions are presented. The program can be employed to discard experimental data containing no useful information in automated pipelines, in modelling procedures, and for data deposition or publication. The software is freely accessible to academic users.
Cabido, Christian E T; Bergamini, Juliana C; Andrade, André G P; Lima, Fernando V; Menzel, Hans J; Chagas, Mauro H
2014-04-01
The aim of the present study was to compare the acute effects of constant torque (CT) and constant angle (CA) stretching exercises on the maximum range of motion (ROMmax), passive stiffness (PS), and ROM corresponding to the first sensation of tightness in the posterior thigh (FSTROM). Twenty-three sedentary men (age, 19-33 years) went through 1 familiarization session and afterward proceeded randomly to both CA and CT treatment stretching conditions, on separate days. An isokinetic dynamometer was used to analyze hamstring muscles during passive knee extension. The subjects performed 4 stretches of 30 seconds each with a 15-second interval between them. In the CA stretching, the subject reached a certain ROM (95% of ROMmax), and the angle was kept constant. However, in the CT stretching exercise, the volunteer reached a certain resistance torque (corresponding to 95% of ROMmax) and it was kept constant. The results showed an increase in ROMmax for both CA and CT (p stretch may be explained by greater changes in the biomechanical properties of the muscle-tendon unit and stretch tolerance, as indicated by the results of PS and FSTROM.
Comparing the range of μ and β angles in 6-17-year-old children of Isfahan with normal occlusion
Directory of Open Access Journals (Sweden)
Saeed Sadeghian
2014-01-01
Full Text Available Background: Linear and angular measurements such as A point, nasion, B point (ANB angle and Wits appraisal index are not accurate enough to evaluate sagittal relationship of the jaws. The aim of this study was to evaluate and compare the range of μ and β angles in 6-17-year-old children of Isfahan, having normal occlusion. Materials and Methods: This was an analytical descriptive study. For this study, 235 cephalometric radiographs of patients who didn′t receive orthodontics treatments and based on 13 indexes had normal occlusion, were selected. After tracing of cephalograms, ANB angle, Wits appraisal index, μ angle (resulted from the intersection of AB line and perpendicular line from point A to mandibular plane and β angle (resulted from the intersection of AB line and perpendicular line from point A on CB line were measured. Data was analyzed by t-test, ANOVA and Pierson-Spearman correlation coefficient (P < 0.05. Results: Mean value of μ and β angles were 17.34 ± 3.47 and 31.7 ± 3.31 and ranged from 8-27 to 21.5-39 respectively. According to t-test, there was a significant difference between two sex groups for μ angle (P = 0.02; however, it was not significant for β angle. According to Spearman correlation coefficient, there was no significant difference between age and μ angle; however, β angle was directly and significantly related to age (r = 0.435. There was significant and reverse relationship between μ and β angles with ANB angle and Wits appraisal index. Conclusion: μ and β angles are reliable and can be used to evaluate the anterior-posterior relationship of the jaws.
Comparing the range of μ and β angles in 6-17-year-old children of Isfahan with normal occlusion.
Sadeghian, Saeed; Hajiahmadi, Maryam; Khorrami, Ladan; Moshkelgosha, Hadi
2014-01-01
Linear and angular measurements such as A point, nasion, B point (ANB) angle and Wits appraisal index are not accurate enough to evaluate sagittal relationship of the jaws. The aim of this study was to evaluate and compare the range of μ and β angles in 6-17-year-old children of Isfahan, having normal occlusion. This was an analytical descriptive study. For this study, 235 cephalometric radiographs of patients who didn't receive orthodontics treatments and based on 13 indexes had normal occlusion, were selected. After tracing of cephalograms, ANB angle, Wits appraisal index, μ angle (resulted from the intersection of AB line and perpendicular line from point A to mandibular plane) and β angle (resulted from the intersection of AB line and perpendicular line from point A on CB line) were measured. Data was analyzed by t-test, ANOVA and Pierson-Spearman correlation coefficient (P < 0.05). Mean value of μ and β angles were 17.34 ± 3.47 and 31.7 ± 3.31 and ranged from 8-27 to 21.5-39 respectively. According to t-test, there was a significant difference between two sex groups for μ angle (P = 0.02); however, it was not significant for β angle. According to Spearman correlation coefficient, there was no significant difference between age and μ angle; however, β angle was directly and significantly related to age (r = 0.435). There was significant and reverse relationship between μ and β angles with ANB angle and Wits appraisal index. μ and β angles are reliable and can be used to evaluate the anterior-posterior relationship of the jaws.
Stone, Christopher; Williams, Derrick; Price, Jeremy
2016-01-01
The Extended Q-range Small-angle Neutron Scattering Diffractometer (EQ-SANS) instrument at the spallation neutron source (SNS), Oak Ridge, Tennessee, incorporates a 69 m 3 detector vessel with a vacuum system which required an upgrade with respect to performance, ease of operation, and maintenance. The upgrade focused on improving pumping performance as well as optimizing system design to minimize opportunity for operational error. This upgrade provided the following practical contributions: •Reduced time required to evacuate from atmospheric pressure to 2 mTorr from 500 to 1000 min to 60-70 min•Provided turn-key automated control with a multi-faceted interlock for personnel and machine safety.
Fujii, Hirofumi; Hara, Kazuhiko; Hayashi, Kohei; Kakuno, Hidekazu; Kodama, Hideyo; Nagamine, Kanetada; Sato, Kazuyuki; Sato, Kotaro; Kim, Shin-Hong; Suzuki, Atsuto; Takahashi, Kazuki; Takasaki, Fumihiko
2017-12-01
We have measured the cosmic muon flux in the zenith angle range {technique called muon radiography, where the mass distribution inside a large object is investigated from the cosmic muon distribution measured behind the object.
Sissay, Adonay; Abanador, Paul; Mauger, François; Gaarde, Mette; Schafer, Kenneth J; Lopata, Kenneth
2016-09-07
Strong-field ionization and the resulting electronic dynamics are important for a range of processes such as high harmonic generation, photodamage, charge resonance enhanced ionization, and ionization-triggered charge migration. Modeling ionization dynamics in molecular systems from first-principles can be challenging due to the large spatial extent of the wavefunction which stresses the accuracy of basis sets, and the intense fields which require non-perturbative time-dependent electronic structure methods. In this paper, we develop a time-dependent density functional theory approach which uses a Gaussian-type orbital (GTO) basis set to capture strong-field ionization rates and dynamics in atoms and small molecules. This involves propagating the electronic density matrix in time with a time-dependent laser potential and a spatial non-Hermitian complex absorbing potential which is projected onto an atom-centered basis set to remove ionized charge from the simulation. For the density functional theory (DFT) functional we use a tuned range-separated functional LC-PBE*, which has the correct asymptotic 1/r form of the potential and a reduced delocalization error compared to traditional DFT functionals. Ionization rates are computed for hydrogen, molecular nitrogen, and iodoacetylene under various field frequencies, intensities, and polarizations (angle-dependent ionization), and the results are shown to quantitatively agree with time-dependent Schrödinger equation and strong-field approximation calculations. This tuned DFT with GTO method opens the door to predictive all-electron time-dependent density functional theory simulations of ionization and ionization-triggered dynamics in molecular systems using tuned range-separated hybrid functionals.
Short-range order in Fe-based metallic glasses: Wide-angle X-ray scattering studies
International Nuclear Information System (INIS)
Babilas, Rafał; Hawełek, Łukasz; Burian, Andrzej
2014-01-01
The local atomic structure of the Fe 80 B 20 , Fe 70 Nb 10 B 20 and Fe 62 Nb 8 B 30 glasses prepared in the form of ribbons has been studied by wide-angle X-ray scattering. Structural information about the amorphous ribbons has been derived from analysis of the radial distribution functions using the least-squares curve-fitting method. The obtained structural parameters indicate that Fe–Fe, Fe–B, Fe–Nb and Nb–B contributions are involved in the near-neighbor coordination spheres. The possible similarities of the local atomic arrangement in the investigated glasses and the crystalline Fe 3 B, Fe 23 B 6 and bcc Fe structures are also discussed. - Graphical abstract: Pair distribution functions (a) and best-fit model and experimental radial distribution functions for Fe 80 B 20 (b), Fe 70 Nb 10 B 20 (c) and Fe 62 Nb 8 B 30 (d) metallic glasses. - Highlights: • The short-range ordering in the Fe-based metallic glasses is presented. • The results of RDF function have been analyzed using the least-squares method. • The Fe–Fe, Fe–B, Fe–Nb or Nb–B contributions are involved in coordination spheres. • The structural unit is distorted triangular prism containing B, Fe or Nb atoms. • Similarities of atomic arrangement in glassy and crystalline structures are discussed
Digital Repository Service at National Institute of Oceanography (India)
Barros, E.A. de; Dantas, J.L.D.; Pascoal, A.M.; Desa, E.S.
to be no- ticed at the sideslip angle of 15 and reaches its maximum when sideslip reaches 25 . However, the corresponding correction angle never exceeds 2.5 . The total lateral force and yaw moment coefficients are cal- culated summing up algebraically body...
Elastic scattering of 7Li + 27Al at several angles in the 7-11 MeV energy range
International Nuclear Information System (INIS)
Abriola, D.; Carnelli, P.; Arazi, A.; Figueira, J.M.; Capurro, O.A.; Cardona, M.A.; Fernandez Niello, J.O.; Hojman, D.; Fimiani, L.; Grinberg, P.; Martinez Heimann, D.; Marti, G.V.; Negri, A.E.; Pacheco, A.J.
2010-01-01
Elastic cross sections for the 7 Li + 27 Al system were measured at laboratory energies between 7 and 11 MeV in steps of 0.25 MeV, and angles between 135 o and 170 o in steps of 5 o . Excitation functions for the elastic scattering were measured using an array of eight Si surface-barrier detectors whereas a solid-state telescope was used to estimate and subtract background from other reactions. Contamination from α particles arising from the 7 Li breakup process at E lab ≥ 10 MeV makes the use of these energies inadvisable for RBS applications. The present results are compared with previous data obtained at 165 o (E lab ≤ 6 MeV), 140 o and 170 o (E lab ≤ 8 MeV). The experimental data were analyzed in terms of the Optical Model. Two different energy-independent potentials were found. These optical potentials allow an interpolation with physical meaning to other energies and scattering angles. The experimental cross sections will be uploaded to the IBANDL database.
Energy Technology Data Exchange (ETDEWEB)
Montgomerie, Bjoern
2004-06-01
For wind turbine and propeller performance calculations aerodynamic data, valid for several radial stations along the blade, are used. For wind turbines the data must be valid for the 360 degree angle of attack range. The reason is that all kinds of abnormal conditions must be analysed especially during the design of the turbine. Frequently aerodynamic data are available from wind tunnel tests where the angle of attack range is from say -5 to +20 degrees. This report describes a method to extend such data to be valid for {+-} 180 degrees. Previously the extension of data has been very approximate following the whim of the moment with the analyst. Furthermore, the Himmelskamp effect at the root and tip effects are treated in the complete method.
Usami, Kiyoaki; Sakamoto, Kenji
2011-08-01
We have succeeded in controlling the pretilt angle of liquid crystal (LC) molecules over the whole range of 0 to 90° by using photo-aligned blend films of two azobenzene-containing polyimides (Azo-PIs) with and without side-chains. The Azo-PIs were synthesized from pyromellitic dianhydride and a mixture of 4,4'-diaminoazobenzene and 4-(4'-propylbi(cyclohexan)-4-yl)phenyl 3,5-diaminobenzoate (PBCP-DABA). PBCP-DABA is a diamine to introduce a side-chain structure into the polyimide. Defect-free uniform LC alignment was obtained in the pretilt angle (θp) ranges of θp ≤ 11° and θp ≥ 78°. Previously, we reported that the pretilt angle can be controlled using pure photo-aligned films of Azo-PIs with different molar fractions of PBCP-DABA. For the pure photo-aligned films, the defect-free pretilt angle ranges were θp < 5° and θp ≥ 85°. These results suggest that the azimuthal anchoring strength of the blend Azo-PI film is stronger than that of the pure films of Azo-PIs with side-chains, at least for the pretilt angle range from 5 to 11°. We found that the defect-free pretilt angle range can be extended by using the blend Azo-PI films instead of the pure Azo-PI films.
International Nuclear Information System (INIS)
Petrascu, M.; Bordeanu, C.; Isbasescu, A.; Mihai, I.; Giurgiu, M.
1997-01-01
Recently, an inclusive fusion experiment of 9,11 Li projectiles with Si targets, in the energy range (9.5 - 25) AMeV has been performed at Riken Ring Cyclotron-Japan using, for the detection of the fusion products, an ionization chamber, MUSIC, built in NIPNE-HH, Bucharest. In this experiment, the contribution of elastic and inelastic scattering, at forward detection angles is eliminated through the experimental set-up. For a clear investigation of the fusion process, the estimation of elastic and inelastic scattering at backward angles, between 80 angle - 180 angle was considered necessary. This estimation was made by the coupled channels computer code ECIS. ECIS is an iterative method, the first iteration of this procedure being DWBA. In the analysis of elastic and inelastic scattering of 9,11 Li projectile on Si target we assumed that the incident 9 Li and 11 Li waves are diffracted by an optical potential with an Woods-Saxon geometry. The adopted optical potential is given. For the depth of the real and imaginary volume terms we used values dependent on projectile energy and target mass number. These values have been chosen in good agreement with a semi-microscopic model with a double-folding potential. The set of optical parameters selected for the system 9,11 Li (13 AMeV) + Si is given. The presence of neutron halo of 11 Li nucleus was taken into account by using adjusted values for the parameters r R and a R . The 28 Si nucleus is considered a rigid rotor, including the couplings involving the ground state and a first to excited states. The quadrupole deformation parameter was β 2 = - 0.24. The results for the scattering of 11 Li projectile on Si target at 13 AMeV energy are given with the parameters R match , I and J max taken from the Monte Carlo simulations with PACE code. We found that the contribution of elastic and inelastic scattering for background angles, between 80 angle - 180 angle is under 2%. The contribution of a inelastic scattering taken
X-Band high range resolution radar measurements of sea surface forward scatter at low grazing angles
CSIR Research Space (South Africa)
Smit, JC
2008-05-01
Full Text Available Radar measurements of a radar calibration sphere test target suspended in sea surface multipath propagation conditions are reported. Wideband measurements together with high range resolution (HRR) processing were employed to resolve the direct...
Belfiori, F.; Rossum, W. van; Hoogeboom, P.
2014-01-01
A coherent two-dimensional (2D) multiple signal classification (MUSIC) processing for the simultaneous estimation of angular and range target positions has been presented. A 2D spatial smoothing technique is also introduced to cope with the coherent behaviour of the received echoes, which may result
International Nuclear Information System (INIS)
Reininger, Ruben; Castro, A.R.B. de
2005-01-01
We give a unified discussion of two different approaches to the design of grazing incidence monochromators with a variable line spacing (VLS) grating for soft X-ray undulator sources. Neither one uses an entrance slit and both work with a fixed position exit slit. In one approach, being constructed at LNLS and designed for the energy range 100< E<1000eV, the choice of the VLS parameters allows for the operation at a variable c-value with a single plane grating and little sacrifice in the maximum resolving power. In this case source size limited resolving power of circa 40000 is expected at 100eV. In the second approach, for the storage ring in Wisconsin, two gratings covering the energy range 40< E<1500eV are used, one capable of delivering a resolving power larger than 20000 at 860eV and the other lower resolving power but much higher flux
Long, S. P.; Walker, J. P.
2016-12-01
Documenting the range of styles of normal faulting is fundamental to understanding how the crust responds during extension. Here, we discuss field relationships that constrain the geometry and kinematic development of a system of W-vergent, upper-crustal detachment faults in the Grant Range in eastern Nevada. The faults exhibit brecciation and stratigraphic cutoff angles of 5-15° at all structural levels, deform a 10 km-thick section of Paleozoic and Paleogene rocks, and exhume a `core' of greenschist-facies Cambrian rocks and Cretaceous granite. The oldest faults are cut by a 29 Ma dike, and the highest fault cuts 32 Ma volcanic rocks that restore to a paleo-depth of 1 km. The fault system is folded across an anticlinal culmination, which grew during extension, as indicated by progressively increasing interlimb angles and incision in the axial zone. The eastern limb consists of an imbricate stack of faults that were emplaced from bottom-to-top. In the western limb, several faults exhibit apparent thrust relationships. Retro-deformation of folding and minimal structural relief and angularity across a Paleogene unconformity indicate that the faults were active at ≤15° angles. Retro-deformation of offset indicates ≥49 km (98%) extension. We propose a model of stationary, sustained isostatic uplift and incision at the culmination axis (a `fixed hinge'), with back-rotation and excision up-dip of the axis producing bottom-to-top growth of the imbricate stack, and excision down-dip of the axis yielding apparent thrust relationships. Initiation of extension, bracketed between 32-29 Ma, was coeval with the sweep of ignimbrite magmatism through this region. Therefore, the Grant Range can be placed in the temporal context of the episode of Paleogene, core complex-dominated extension within the retroarc plateau. Low-angle faulting is interpreted to have been favored by rotation of the upper-crustal stress field as a result of shear traction imparted by lower
Nostell, Per; Roos, Arne; Rönnow, Daniel
1999-05-01
A multipurpose instrument for the measurement of reflectance and transmittance versus angle of incidence for both specular and diffuse samples in the solar wavelength range has been constructed and evaluated. The instrument operates in the single-beam mode and uses a common light source for three experimental setups. Two integrating spheres, 20 cm in diameter, are used for diffuse transmittance and reflectance measurements. The transmittance sphere can be turned around an axis through the sample to vary the angle of incidence. The reflectance sphere uses a center mounted sample and a special feature is the position of the detector, which is mounted on the sample holder at the center of the sphere. This way the detector always sees the same part of the sphere wall and no light can reach the detector directly from the sample. The third setup is an absolute instrument for specular samples. It uses a small averaging sphere as a detector. The detector is mounted on an arm which rotates around the center of the sample, and it can thus pick up both the reflected and transmitted beams including all multiply reflected components. The averaging sphere detector is insensitive to small side shifts of the detected beams and no multiple reflections between detector and optical system occur. In this report a number of calibration procedures are presented for the three experimental setups and models for the calculation of correct transmittance and reflectance values from measured data are presented. It is shown that for integrating sphere measurements, the geometry of the sphere and the diffusivity of the sample as well as the sphere wall reflectance and port losses are important factors that influence the result. For the center mounted configuration these factors are particularly important and special emphasis is given to the evaluation of the reflectance sphere model. All three instrument setups are calibrated using certified reference materials and nonscattering mirrors and
International Nuclear Information System (INIS)
Jal, J.F.; Chieux, P.; Dupuy, J.
1978-01-01
The correlation lengths for concentration fluctuations have been investigated by small-angle neutron scattering as a function of temperature and concentration for the solutions of potassium in potassium bromide. The fluctuations were found to be essentially located above the liquid miscibility gap. The temperature dependence of the fluctuations on the liquid-liquid critical isochore gives lattice-gas-type critical indices. (Auth.)
Energy Technology Data Exchange (ETDEWEB)
Nagata, Kohki, E-mail: nagata.koki@iri-tokyo.jp [Tokyo Metropolitan Industrial Technology Research Institute, 2-4-10 Aomi, Koto-ku, Tokyo 135-0064 (Japan); School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Ogura, Atsushi [School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Hirosawa, Ichiro [Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Suwa, Tomoyuki; Teramoto, Akinobu; Ohmi, Tadahiro [New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aramakiazaaoba, Aoba-ku, Sendai, Miyagi 980-8579 (Japan)
2016-04-21
The effects of the fabrication process conditions on the microstructure of silicon dioxide thin films of <10 nm thickness are presented. The microstructure was investigated using grazing-incidence wide and small-angle X-ray scattering methods with synchrotron radiation. The combination of a high brilliance light source and grazing incident configuration enabled the observation of very weak diffuse X-ray scattering from SiO{sub 2} thin films. The results revealed different microstructures, which were dependent on oxidizing species or temperature. The micro-level properties differed from bulk properties reported in the previous literature. It was indicated that these differences originate from inner stress. The detailed structure in an amorphous thin film was not revealed owing to detection difficulties.
Jauernik, Stephan; Hein, Petra; Gurgel, Max; Falke, Julian; Bauer, Michael
2018-03-01
Laser-based angle-resolved photoelectron spectroscopy is performed on tin-phthalocyanine (SnPc) adsorbed on silver Ag(111). Upon adsorption of SnPc, strongly dispersing bands are observed which are identified as secondary Mahan cones formed by surface umklapp processes acting on photoelectrons from the silver substrate as they transit through the ordered adsorbate layer. We show that the photoemission data carry quantitative structural information on the adsorbate layer similar to what can be obtained from a conventional low-energy electron diffraction (LEED) study. More specifically, we compare photoemission data and LEED data probing an incommensurate-to-commensurate structural phase transition of the adsorbate layer. Based on our results we propose that Mahan-cone spectroscopy operated in a pump-probe configuration can be used in the future to probe structural dynamics at surfaces with a temporal resolution in the sub-100-fs regime.
International Nuclear Information System (INIS)
Marklund, T.
1978-01-01
The most commonly used methods of assessing the scoliotic deviation measure angles that are not clearly defined in relation to the anatomy of the patient. In order to give an anatomic basis for such measurements it is proposed to define the scoliotic deviation as the deviation the vertebral column makes with the sagittal plane. Both the Cobb and the Ferguson angles may be based on this definition. The present methods of measurement are then attempts to measure these angles. If the plane of these angles is parallel to the film, the measurement will be correct. Errors in the measurements may be incurred by the projection. A hypothetical projection, called a 'rectified orthogonal projection', is presented, which correctly represents all scoliotic angles in accordance with these principles. It can be constructed in practice with the aid of a computer and by performing measurements on two projections of the vertebral column; a scoliotic curve can be represented independent of the kyphosis and lordosis. (Auth.)
Energy Technology Data Exchange (ETDEWEB)
Ridier, Karl; Gillon, Béatrice; André, Gilles; Chaboussant, Grégory, E-mail: gregory.chaboussant@cea.fr [Laboratoire Léon Brillouin, UMR12 CEA-CNRS, 91191 Gif-sur-Yvette (France); Catala, Laure; Mazérat, Sandra; Mallah, Talal [Institut de Chimie Moléculaire et des Matériaux d' Orsay, CNRS, Université Paris-Sud, 91405 Orsay (France)
2015-09-21
Prussian blue analogues magnetic nanoparticles (of radius R{sub 0} = 2.4–8.6 nm) embedded in PVP (polyvinylpyrrolidone) or CTA{sup +} (cetyltrimethylammonium) matrices have been studied using neutron diffraction and small angle neutron scattering (SANS) at several concentrations. For the most diluted particles in neutral PVP, the SANS signal is fully accounted for by a “single-particle” spherical form factor with no structural correlations between the nanoparticles and with radii comparable to those inferred from neutron diffraction. For higher concentration in PVP, structural correlations modify the SANS signal with the appearance of a structure factor peak, which is described using an effective “mean-field” model. A new length scale R{sup * }≈ 3R{sub 0}, corresponding to an effective repulsive interaction radius, is evidenced in PVP samples. In CTA{sup +}, electrostatic interactions play a crucial role and lead to a dense layer of CTA{sup +} around the nanoparticles, which considerably alter the SANS patterns as compared to PVP. The SANS data of nanoparticles in CTA{sup +} are best described by a core-shell model without visible inter-particle structure factor.
Ridier, Karl; Gillon, Béatrice; André, Gilles; Chaboussant, Grégory; Catala, Laure; Mazérat, Sandra; Mallah, Talal
2015-09-01
Prussian blue analogues magnetic nanoparticles (of radius R0 = 2.4-8.6 nm) embedded in PVP (polyvinylpyrrolidone) or CTA+ (cetyltrimethylammonium) matrices have been studied using neutron diffraction and small angle neutron scattering (SANS) at several concentrations. For the most diluted particles in neutral PVP, the SANS signal is fully accounted for by a "single-particle" spherical form factor with no structural correlations between the nanoparticles and with radii comparable to those inferred from neutron diffraction. For higher concentration in PVP, structural correlations modify the SANS signal with the appearance of a structure factor peak, which is described using an effective "mean-field" model. A new length scale R* ≈ 3R0, corresponding to an effective repulsive interaction radius, is evidenced in PVP samples. In CTA+, electrostatic interactions play a crucial role and lead to a dense layer of CTA+ around the nanoparticles, which considerably alter the SANS patterns as compared to PVP. The SANS data of nanoparticles in CTA+ are best described by a core-shell model without visible inter-particle structure factor.
International Nuclear Information System (INIS)
Ridier, Karl; Gillon, Béatrice; André, Gilles; Chaboussant, Grégory; Catala, Laure; Mazérat, Sandra; Mallah, Talal
2015-01-01
Prussian blue analogues magnetic nanoparticles (of radius R 0 = 2.4–8.6 nm) embedded in PVP (polyvinylpyrrolidone) or CTA + (cetyltrimethylammonium) matrices have been studied using neutron diffraction and small angle neutron scattering (SANS) at several concentrations. For the most diluted particles in neutral PVP, the SANS signal is fully accounted for by a “single-particle” spherical form factor with no structural correlations between the nanoparticles and with radii comparable to those inferred from neutron diffraction. For higher concentration in PVP, structural correlations modify the SANS signal with the appearance of a structure factor peak, which is described using an effective “mean-field” model. A new length scale R * ≈ 3R 0 , corresponding to an effective repulsive interaction radius, is evidenced in PVP samples. In CTA + , electrostatic interactions play a crucial role and lead to a dense layer of CTA + around the nanoparticles, which considerably alter the SANS patterns as compared to PVP. The SANS data of nanoparticles in CTA + are best described by a core-shell model without visible inter-particle structure factor
International Nuclear Information System (INIS)
Durwen, E.J.
1980-04-01
The differential cross section of the reaction γp->π + n was increased in 6 excitation curves at pion laboratory angles from thetasub(lab)sup(π) = 35 0 to 85 0 in 10 0 -steps. The γ-energy range extended from 0.3 GeV at thetasub(lab) = 35 0 to an angle-dependent maximum value which lied between 0.77 GeV at thetasub(lab)sup(π) = 35 0 and 1.94 GeV thetasub(lab)sup(π) = 85 0 . The 705 measuring points are part of a comprehensive measuring program of this laboratory which has the aim of the establishment of a complete, consistent high precision data set for the differential cross sections of the π + photoproduction in the resonance region. (orig./HSI) [de
International Nuclear Information System (INIS)
Carnelli, P. F. F.; Arazi, A.; Cardona, M. A.; Figueira, J. M.; Hojman, D.; Martinez Heimann, D.; Negri, A. E.; Pacheco, A. J.; Abriola, D.; Capurro, O. A.; Fimiani, L.; Grinberg, P.; Marti, G. V.; Fernandez Niello, J. O.
2010-01-01
We have measured elastic excitation functions for the 7 Li+ 27 Al system, in an energy range close to its Coulomb barrier (E lab = 8.4 MeV) in steps of 0.25 MeV. For this purpose, an array of eight surface-barrier detectors was used. To get an insight on the background composition (mainly α particles), a telescope-detector was used for atomic-number identification. Identical measurements for the 6 Li+ 27 Al system are planned for the near future.
Small angle neutron scattering
International Nuclear Information System (INIS)
Gupta, Sanjay
1982-01-01
The technique of small angle neutron scattering was first used in Germany less than two decades ago. Since then it has developed very rapidly, and today it is regarded as one of the most powerful techniques in materials, chemical and biological research. During the last decade the combination of high flux reactors and sophisticated instrumentation has revolutionized the technique. This paper endeavours to present a brief but comprehensive review of small angle scattering of neutrons and its applications in solid state research. The domain in which small angle neutron scattering is particularly useful is delineated and some of the methods used in the analysis of data are discussed with special emphasis on recent developments. Typical small angle neutron scattering cameras are described. Finally some experimental results on heterogeneities in metallic systems (both static and dynamic studies), radiation damage in materials, superconductivity, magnetic materials and the technologically very important area of non-destructive testing are reviewed in order to illustrate the wide range of applicability of this technique to problems in solid state research. (author)
Energy Technology Data Exchange (ETDEWEB)
Bordenave-Montesquieu, D.; Nouet, P.; Boutonnet, A.; Bergnes, C.; Dagnac, R.
1987-09-14
Elastic and inelastic cross sections, differential in energy loss and scattering angle, have been determined from the energy loss spectra of 1.5 - 25 keV He/sup +/ scattered from atomic hydrogen at scattering angles from 5'-2/sup 0/ (laboratory frame). The experimental results compare favourably with the experimental and theoretical data obtained at low incident energies by other authors, but for the higher energies, the present results exhibit a strong disagreement with many of the reported calculations.
Solid angles III. The role of conformers in solid angle calculations
CSIR Research Space (South Africa)
White, D
1995-06-14
Full Text Available The values of the solid angles Omega for a range of commonly encountered ligands in organometallic chemistry (phosphines, phosphites, amines, arsines and cyclopentadienyl rings) have been determined. The solid angles were derived from a single...
Critical angle laser refractometer
International Nuclear Information System (INIS)
Castrejon-Pita, J.R.; Morales, A.; Castrejon-Garcia, R.
2006-01-01
A simple laser refractometer based on the detection of the critical angle for liquids is presented. The calibrated refractometer presents up to 0.000 11 of uncertainty when the refractive index is in the range between 1.300 00 and 1.340 00. The experimental setup is easy to construct and the material needed is available at most optics laboratories. The calibration method is simple and can be used in other devices. The refractive index measurements in aqueous solutions of sodium chloride were carried out to test the device and a linear dependence between the refractive index and the salt concentration was found
Tiny incident light angle sensor
Mitrenga, D.; Schädel, M.; Winzer, A. T.; Völlmeke, S.; Preuß, K. D.; Freitag, J.; Brodersen, O.
2017-05-01
A novel device for detecting the intensity and the angles of incoming light is presented. The silicon chip with 1 mm edge length comprises a segmented photo diode with four active areas within the inclined surfaces of a deep etched cavity. Simple signal difference analysis of these signals allow for accurate azimuth and inclination measurement in the range of 0 to 360° and 0 to 55°, respectively. Using an artificial neural network (ANN) calibration strategy the operation range of inclination can be increased up to 85° with typical angle errors below 2°. In this report we present details on design, fabrication, signal analysis and calibration strategies.
Directory of Open Access Journals (Sweden)
Francisco José Berral de la Rosa
2009-01-01
force with low release angles. The objective of this work is to asses if, with an appropriate training, it is possible to condition the athletes to exert more force at bigger release angles, improving considerably the range of the shot put. A research has been carried out with 12 inexperienced throwers. In the pre-test they threw the same medicinal ball 30 times over a range of release angles from 25º to 45º. After a period of four weeks of training, focused on increasing progressively the release angle, a post-test, similar to the initial one, was carried out. All of the throws were filmed and a 2-D video analysis with the best throw of each thrower in both tests was made. There were significant differences in the average values of release speed,release angle and total range between the pre-test and the post-test. The significant differences in the average release angle with which the throwers obtained their best range show that the period of training made the throwers develop more force at bigger release angles.Key words: shot-put; release speed; initial height; release angle; flight distance; optimal angle.
Federal Laboratory Consortium — Description:The FTA32 goniometer provides video-based contact angle and surface tension measurement. Contact angles are measured by fitting a mathematical expression...
Individualized optimal release angles in discus throwing.
Leigh, Steve; Liu, Hui; Hubbard, Mont; Yu, Bing
2010-02-10
The purpose of this study was to determine individualized optimal release angles for elite discus throwers. Three-dimensional coordinate data were obtained for at least 10 competitive trials for each subject. Regression relationships between release speed and release angle, and between aerodynamic distance and release angle were determined for each subject. These relationships were linear with subject-specific characteristics. The subject-specific relationships between release speed and release angle may be due to subjects' technical and physical characteristics. The subject-specific relationships between aerodynamic distance and release angle may be due to interactions between the release angle, the angle of attack, and the aerodynamic distance. Optimal release angles were estimated for each subject using the regression relationships and equations of projectile motion. The estimated optimal release angle was different for different subjects, and ranged from 35 degrees to 44 degrees . The results of this study demonstrate that the optimal release angle for discus throwing is thrower-specific. The release angles used by elite discus throwers in competition are not necessarily optimal for all discus throwers, or even themselves. The results of this study provide significant information for understanding the biomechanics of discus throwing techniques. Copyright 2009 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Harsh Bhagvatiprasad Dave
2015-01-01
Full Text Available Aim: The purpose of this study was to establish a new cephalometric measurement, named the Harsh Bhagvatiprasad Nita angle (HBN, to assess the sagittal jaw relationship with accuracy and reproducibility. Materials and Methods: Three hundred pretreatment lateral cephalograms (100 each of Class I, II, and III were taken from the Department of Orthodontics and Dentofacial Orthopedics of Rajasthan Dental College and Hospital, Jaipur (Rajasthan and were subdivided into skeletal Class I, II, and III based on ANB, Wits appraisal, and Beta angle. This angle uses 3 skeletal landmarks the "C" (apparent axis of the condyle, "M" (midpoint of the premaxilla, and "G" (center of the largest circle that is tangent to the internal inferior, anterior, and posterior surfaces of the mandibular symphysis. Results: The result of the mean and standard deviation for the HBN angle were calculated in all three skeletal groups. After using one-way analysis of variance and post-hoc multiple comparisons by using Tukey′s honestly significant difference, homogeneous subsets, receiver operating characteristics (ROC curve - to differentiate Class II with Class I, ROC curve - to differentiate Class III with Class I, Reliability analysis with interclass correlation of HBN angle with other angles, we obtained results that showed that a patient with a HBN angle 40° and 46° can be considered to have a Class I skeletal pattern. Conclusions: A new angle, the HBN angle, was developed as a diagnostic aid to evaluate the sagittal jaw relationship more consistently. HBN angle 40° and 46° can be considered to have a Class I skeletal pattern, a more acute HBN angle indicates a Class II skeletal pattern, and a more obtuse HBN angle indicates a Class III skeletal pattern.
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…
International Nuclear Information System (INIS)
Cook, G.O. Jr.; Knight, L.
1979-07-01
The question of optimal projection angles has recently become of interest in the field of reconstruction from projections. Here, studies are concentrated on the n x n pixel space, where literative algorithms such as ART and direct matrix techniques due to Katz are considered. The best angles are determined in a Gauss--Markov statistical sense as well as with respect to a function-theoretical error bound. The possibility of making photon intensity a function of angle is also examined. Finally, the best angles to use in an ART-like algorithm are studied. A certain set of unequally spaced angles was found to be preferred in several contexts. 15 figures, 6 tables
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.
DEFF Research Database (Denmark)
Risager, Morten S.; Södergren, Carl Anders
2017-01-01
It is well known that the angles in a lattice acting on hyperbolic n -space become equidistributed. In this paper we determine a formula for the pair correlation density for angles in such hyperbolic lattices. Using this formula we determine, among other things, the asymptotic behavior of the den......It is well known that the angles in a lattice acting on hyperbolic n -space become equidistributed. In this paper we determine a formula for the pair correlation density for angles in such hyperbolic lattices. Using this formula we determine, among other things, the asymptotic behavior...... of the density function in both the small and large variable limits. This extends earlier results by Boca, Pasol, Popa and Zaharescu and Kelmer and Kontorovich in dimension 2 to general dimension n . Our proofs use the decay of matrix coefficients together with a number of careful estimates, and lead...
Small angle neutron scattering
Directory of Open Access Journals (Sweden)
Cousin Fabrice
2015-01-01
Full Text Available 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
Using Digital Technology to See Angles from Different Angles. Part 2: Openings and Turns
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…
Paddle Angle and Ball Spin in Table Tennis
Directory of Open Access Journals (Sweden)
Binvant Broca
2017-01-01
Full Text Available The relationship between the impact angle of a table tennis ball with respect to the paddle and angular velocity of the ball leaving the paddle was investigated. A table tennis ball was dropped onto a paddle oriented at impact angles ranging from 10° to 80°. It was found that the sine of the impact angle is proportional to the angular velocity of the ball as it leaves the paddle for all impact angles tested.
LHC Report: playing with angles
Mike Lamont for the LHC team
2016-01-01
Ready (after a machine development period), steady (running), go (for a special run)! The crossing angles are an essential feature of the machine set-up. They have to be big enough to reduce the long-range beam-beam effect. The LHC has recently enjoyed a period of steady running and managed to set a new record for “Maximum Stable Luminosity Delivered in 7 days” of 3.29 fb-1 between 29 August and 4 September. The number of bunches per beam remains pegged at 2220 because of the limitations imposed by the SPS beam dump. The bunch population is also somewhat reduced due to outgassing near one of the injection kickers at point 8. Both limitations will be addressed during the year-end technical stop, opening the way for increased performance in 2017. On 10 and 11 September, a two day machine development (MD) period took place. The MD programme included a look at the possibility of reducing the crossing angle at the high-luminosity interaction points. The crossing angles are an ess...
Light Scattering at Various Angles
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
Angle comparison using an autocollimator
Geckeler, Ralf D.; Just, Andreas; Vasilev, Valentin; Prieto, Emilio; Dvorácek, František; Zelenika, Slobodan; Przybylska, Joanna; Duta, Alexandru; Victorov, Ilya; Pisani, Marco; Saraiva, Fernanda; Salgado, Jose-Antonio; Gao, Sitian; Anusorn, Tonmueanwai; Leng Tan, Siew; Cox, Peter; Watanabe, Tsukasa; Lewis, Andrew; Chaudhary, K. P.; Thalmann, Ruedi; Banreti, Edit; Nurul, Alfiyati; Fira, Roman; Yandayan, Tanfer; Chekirda, Konstantin; Bergmans, Rob; Lassila, Antti
2018-01-01
Autocollimators are versatile optical devices for the contactless measurement of the tilt angles of reflecting surfaces. An international key comparison (KC) on autocollimator calibration, EURAMET.L-K3.2009, was initiated by the European Association of National Metrology Institutes (EURAMET) to provide information on the capabilities in this field. The Physikalisch-Technische Bundesanstalt (PTB) acted as the pilot laboratory, with a total of 25 international participants from EURAMET and from the Asia Pacific Metrology Programme (APMP) providing measurements. This KC was the first one to utilise a high-resolution electronic autocollimator as a standard. In contrast to KCs in angle metrology which usually involve the full plane angle, it focused on relatively small angular ranges (+/-10 arcsec and +/-1000 arcsec) and step sizes (10 arcsec and 0.1 arcsec, respectively). This document represents the approved final report on the results of the KC. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
African Journals Online (AJOL)
there is a build up of pressure due to poor outflow of aqueous humor. The outflow obstruction could occur at the trabecular meshwork of the anterior chamber angle or subsequently in the episcleral vein due to raised venous pressure. Such build up of pressure results in glaucoma . Elevated intraocular pressure remains the ...
DEFF Research Database (Denmark)
Miles, James Edward; Frederiksen, Jane V.; Jensen, Bente Rona
2012-01-01
: Pelvic limbs from red foxes (Vulpes vulpes). METHODS: Q angles were measured on hip dysplasia (HD) and whole limb (WL) view radiographs of each limb between the acetabular rim, mid-point (Q1: patellar center, Q2: femoral trochlea), and tibial tuberosity. Errors of 0.5-2.0 mm at measurement landmarks...
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 9. At Right Angles. Shailesh A Shirali. Information and Announcements Volume 17 Issue 9 September 2012 pp 920-920. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/017/09/0920-0920 ...
DEFF Research Database (Denmark)
Morgan, Jeannie; Lynnerup, Niels; Hoppa, R.D.
2013-01-01
This article presents the results of a validation study of a previously published method of sex determination from the temporal bone. The purpose of this study was to evaluate the lateral angle method for the internal acoustic canal for accurately determining the sex of human skeletal remains usi...... method appears to be of minimal practical use in forensic anthropology and archeology....
Neutron small angle scattering
International Nuclear Information System (INIS)
Ibel, K.
1975-01-01
The neutron small-angle scattering system at the High-Flux Reactor in Grenoble consists of three major parts: the supply of cold neutrons via bent neutron guides; the small angle camera D11; and the data handling facilities. The camera D11 has an overall length of 80 m. The effective length of the camera is variable. The length of the collimator before the fixed sample position can be reduced by movable neutron guides; the secondary flight path of 40 m full length contains detector sites in various positions. Thus, a large domain of momentum transfers can be exploited. Scattering angles between 5.10 -4 and 0.5 rad and neutron wavelengths from 0.2 to 2.0 nm are available with the same instrument and the same relative resolution. A large-area position-sensitive detector is used which allows simultaneous recording of intensities scattered into different angles; it is a multiwire proportional chamber. 3808 elements of 1 cm 2 are arranged in a two-dimensional matrix. Future development comprises an increase of the limit in the count rate due to the electronic interface between the detector and on-line computer, actually at 5.10 4 per sec. by one order of magnitude
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 9. At Right Angles. Shailesh A Shirali. Information and Announcements Volume 17 Issue 9 September 2012 pp 920-920. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/017/09/0920-0920 ...
Scattering angle-based filtering via extension in velocity
Kazei, Vladimir
2016-09-06
The scattering angle between the source and receiver wavefields can be utilized in full-waveform inversion (FWI) and in reverse-time migration (RTM) for regularization and quality control or to remove low frequency artifacts. The access to the scattering angle information is costly as the relation between local image features and scattering angles has non-stationary nature. For the purpose of a more efficient scattering angle information extraction, we develop techniques that utilize the simplicity of the scattering angle based filters for constantvelocity background models. We split the background velocity model into several domains with different velocity ranges, generating an
Relationship between the angle of repose and angle of internal ...
African Journals Online (AJOL)
Abstract. Click on the link to view the abstract. Keywords: Angle of repose, angle of internal friction, granular materials, triaxial compression machine, moisture content. Tanzania J. Agric. Sc. (1998) Vol.1 No.2, 187-194 ...
A small angle neutron scattering study
Indian Academy of Sciences (India)
Nanocrystalline nickel oxide powders were calcined at 300, 600 and 900°C and pore structure evolution was followed by small angle neutron scattering (SANS). Pore size distributions at two widely separated size ranges have been revealed. Shrinkage of larger-sized pore with reduction in polydispersity has been observed ...
Scaling of misorientation angle distributions
DEFF Research Database (Denmark)
Hughes, D.A.; Chrzan, D.C.; Liu, Q.
1998-01-01
The measurement of misorientation angle distributions following different amounts of deformation in cold-rolled aluminum and nickel and compressed stainless steel is reported. The sealing of the dislocation cell boundary misorientation angle distributions is studied. Surprisingly, the distributio...
Angle performance on optima MDxt
Energy Technology Data Exchange (ETDEWEB)
David, Jonathan; Kamenitsa, Dennis [Axcelis Technologies, Inc., 108 Cherry Hill Dr, Beverly, MA 01915 (United States)
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}).
Variable angle correlation spectroscopy
International Nuclear Information System (INIS)
Lee, Y.K.; Lawrence Berkeley Lab., CA
1994-05-01
In this dissertation, a novel nuclear magnetic resonance (NMR) technique, variable angle correlation spectroscopy (VACSY) is described and demonstrated with 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
Variable angle correlation spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Lee, Young Kyo [Univ. of California, Berkeley, CA (United States)
1994-05-01
In this dissertation, a novel nuclear magnetic resonance (NMR) technique, variable angle correlation spectroscopy (VACSY) is described and demonstrated with ^{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.
Small angle neutron scattering
International Nuclear Information System (INIS)
Dasannacharya, B.A.; Goyal, P.S.
1997-01-01
Small angle neutron scattering (SANS) is one of the most popular neutron scattering technique both for the basic research and as a tool in the hands of applied scientist. SANS is used for studying the structure of a material on a length scale of 10 - 1000 A. SANS is a diffraction experiment that involves scattering of a monocromatic beam of neutrons in order to obtain structural information about macromolecules and heterogeneities. This paper will discuss the design of SANS spectrometers with a special emphasis on the instruments which are better suited for medium flux reactors. The design of several different types of SANS spectrometers will be given. The optimization procedures and appropriate modifications to suit the budget and the space will be discussed. As an example, the design of a SANS spectrometer at CIRUS reactor Trombay will be given. (author)
A heterodyne interferometer for angle metrology
International Nuclear Information System (INIS)
Hahn, Inseob; Weilert, M.; Wang, X.; Goullioud, R.
2010-01-01
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/√(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 μrad rms, respectively.
Investigation of Polarimetric SAR Data Acquired at Multiple Incidence Angles
DEFF Research Database (Denmark)
Svendsen, Morten Thougaard; Skriver, Henning; Thomsen, A.
1998-01-01
The dependence of different polarimetric parameters on the incidence angles in the range of 30° to 60° is investigated for a number of different crops using airborne SAR data. The purpose of the investigation is to determine the effect of the variation of incidence angle within a SAR image when...
Normal values of knee angle, intercondylar and intermalleolar ...
African Journals Online (AJOL)
There is little data on the range of variation of knee angle, intermalleolar and intercondylar distances in African children. Such measurements are needed to assist determining whether a child legs are normal or not. Knee angle intermalleolar and intercondylar distances were measured in 2166 Nigerian children aged one ...
Solar electricity potentials and optimal angles for mounting solar ...
African Journals Online (AJOL)
The need for harnessing solar energy using solar panels mounted at optimal inclination angles in the six geopolitical zones of Nigeria is presented. The optimal angle for mounting solar panels as presented by Photovoltaic Geographic Information System (PVGIS) ranges from 11º to 14º in the Southern zone and 13º to 16º ...
Generalization of the Euler Angles
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.
Angle Performance on Optima XE
International Nuclear Information System (INIS)
David, Jonathan; Satoh, Shu
2011-01-01
Angle control on high energy implanters is important due to shrinking device dimensions, and sensitivity to channeling at high beam energies. On Optima XE, beam-to-wafer angles are controlled in both the horizontal and vertical directions. In the horizontal direction, the beam angle is measured through a series of narrow slits, and any angle adjustment is made by steering the beam with the corrector magnet. 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 during implant.Using a sensitive channeling condition, we were able to quantify the angle repeatability of Optima XE. By quantifying the sheet resistance sensitivity to both horizontal and vertical angle variation, the total angle variation was calculated as 0.04 deg. (1σ). Implants were run over a five week period, with all of the wafers selected from a single boule, in order to control for any crystal cut variation.
Relationship between the Angle of Repose and Angle of Internal ...
African Journals Online (AJOL)
ghum and rice. The angles have a big influence on the design offlow and storage structures of ... the angles of internal friction for the same grains and same moisture contents. The data ob- tained were fed into SAS statistical software for step-wise regression analysis. A model of the ..... tion, Application and Validation of En-.
Directory of Open Access Journals (Sweden)
Alexander V. Perig
2017-11-01
Full Text Available Minimization of the dead zone (DZA in the process of material forming is a materials science problem. Geometric and kinematic approaches to the minimization of the DZA during Equal Channel Angular Extrusion (ECAE have been proposed, developed, analyzed, and documented. The present article is focused on a 2D Computational Fluid Dynamics (CFD description of the kinematic effects of punch shape geometry and inlet (IDW and outlet (ODW die wall motion on the DZA during ECAE of Viscous Incompressible Continuum (VIC through a Segal 2θ-die for a range of channel angles 60° ≤ 2θ ≤ 135°. Due attention has been given to the independent alternating transport motions of the IDW and ODW. Punch shape geometry and the kinematic modes of IDW and ODW motions for DZA minimization have been determined with a numerical solution of the boundary value problem for the Navier-Stokes equations in curl transfer form for VIC. Experimental verification was accomplished with an introduction of initial circular gridlines-based physical simulation techniques. For the first time, experimental verification of CFD-derived results was made through an additional superposition of empirically-derived digital photos with deformed elliptical gridlines in the channel intersection deformation zones and correspondent 2D numerical plots with CFD-derived flow lines and full flow velocities. An empirical DZA localization was experimentally determined as the location of minimally-deformed near circular markers. The computational DZA localization was numerically determined as a flow-lines-free zone (the first hypothesis or as a zone with near-zero values of full flow velocities (the second hypothesis. The relative DZA was estimated as a ratio of the measured DZA with respect to the area of the deformation zone in the channel intersection region. A good agreement was obtained between DZA values obtained with the first hypothesis and experimental results.
Positron Emission Mammography with Multiple Angle Acquisition
Energy Technology Data Exchange (ETDEWEB)
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.
Positron Emission Mammography with Multiple Angle Acquisition
Energy Technology Data Exchange (ETDEWEB)
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.
Measurement of the angle gamma
International Nuclear Information System (INIS)
Aleksan, R.; Sphicas, P.; Massachusetts Inst. of Tech., Cambridge, MA
1993-12-01
The angle γ as defined in the Wolfenstein approximation is not completely out of reach of current or proposed dedicated B experiments. This work represents but a first step in the direction of extracting the third angle of the unitarity triangle by study the feasibility of using new decay modes in a hadronic machine. (A.B.). 11 refs., 1 fig., 7 tabs
Nucleation of small angle boundaries
CSIR Research Space (South Africa)
Nabarro, FRN
1996-12-01
Full Text Available 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...
Chan, Amanda C Y; Morrison, Devlin G; Nguyen, Duc V; Hill, Douglas L; Parent, Eric; Lou, Edmond H M
2014-05-01
A reliability analysis of Cobb angle, vertebral rotation (VR), and spinous process angle (SPA) measurements in adolescent idiopathic scoliosis. To determine the intra- and interobserver reliability of semi-automated digital radiograph measurements. Cobb angle measurements on posteroanterior radiographs are commonly used to determine the severity of scoliosis. Vertebral rotation helps assess scoliosis 3-dimensionally and has a role in predicting curve progression. Recent studies have shown that the spinous process angle is a useful parameter in assessing scoliosis when using ultrasound imaging. Because the reliability of SPA measurements on radiographs has yet to be determined, it is important to compare the reliability of these 3 parameters (Cobb angle, VR, and SPA) using a computer assisted semi-automated method. Sixty posteroanterior radiographs of patients with adolescent idiopathic scoliosis were obtained and measured twice by 3 observers who were blinded to their previous measurements, using an in-house developed program. Measurements were obtained using a semi-automated method to minimize variability resulting from observer reliability. The intra- and interobserver reliabilities were analyzed using intra-class correlation coefficients (ICCs) as well as Bland-Altman's bias and limits of agreement. Over 350 (intra) and 90 (inter) sets of curves with an average Cobb angle of 26° ± 9° (range, 10° to 44°) were compared for each parameter. Intra-observer reliabilities for each parameter were excellent (ICC [2,1] , .82; 1.00), with mean absolute differences under 3° between most measurements. Interobserver reliability (ICC [2,1] , .72; .95) was mostly good to excellent, with mean absolute differences ranging from 2.0° to 5.6°. Both the intra- and interobserver assessment of the Cobb, VR, and SPA from the semi-automated measurements had clinically acceptable reliability ranges and may be considered for clinical implementation. Additional studies will be
Yao, Bao-qun; Wu, Ling-ling; Zhang, Chun; Wang, Xin
2009-03-01
To investigate the frequency of appositional angle closure and related anatomic characteristics in fellow eyes of Chinese subjects with acute primary angle closure (APAC) after laser peripheral iridotomy (LPI). Cross-sectional study. Consecutive subjects with APAC presenting from April 2006 to September 2006 at the Glaucoma Service of Peking University Eye Center, Peking University Third Hospital. Under dark conditions, fellow eyes were divided into 2 groups based on the detection of appositional angle closure by ultrasound biomicroscopy (UBM). For all subjects, UBM parameters were measured to evaluate the different anatomic features between the 2 groups. Darkroom provocative tests (DRPTs) and gonioscopy were performed to investigate the relationship between angle closure and intraocular pressure. Central anterior chamber depth (ACD); angle opening distance(500) (AOD(500)); angle recess area(750) (ARA(750)); trabecular-iris angle (T-I angle); trabecular-ciliary process distance (TCPD); peripheral iris thickness (IT(1)); iris-zonule distance (IZD); and the position of the iris insertion. Thirty-four post-LPI fellow eyes of 34 patients with APAC (8 men, 26 women; mean +/- standard deviation age 66.3+/-7.2 years, range 54-83) were included. Peripheral anterior synechiae (PAS) were not observed in any subject. Appositional angle closure was observed in at least 1 quadrant in 13 (38.2%) of the 34 patients. Compared with eyes without appositional closure, eyes with appositional closure showed significantly lower AOD(500), ARA(750), and T-I angle in 4 quadrants; shorter TCPD in the inferior and temporal quadrants; and thicker IT(1) in the superior and nasal quadrants (PAPAC showed appositional angle closure after LPI. The anatomic findings indicate a narrower angle, a more anterior position of the ciliary body, and a thicker peripheral iris in fellow eyes of APAC after LPI may be associated with an increased risk for progressive angle closure.
A Novel Monopulse Angle Estimation Method for Wideband LFM Radars
Directory of Open Access Journals (Sweden)
Yi-Xiong Zhang
2016-06-01
Full Text Available Traditional monopulse angle estimations are mainly based on phase comparison and amplitude comparison methods, which are commonly adopted in narrowband radars. In modern radar systems, wideband radars are becoming more and more important, while the angle estimation for wideband signals is little studied in previous works. As noise in wideband radars has larger bandwidth than narrowband radars, the challenge lies in the accumulation of energy from the high resolution range profile (HRRP of monopulse. In wideband radars, linear frequency modulated (LFM signals are frequently utilized. In this paper, we investigate the monopulse angle estimation problem for wideband LFM signals. To accumulate the energy of the received echo signals from different scatterers of a target, we propose utilizing a cross-correlation operation, which can achieve a good performance in low signal-to-noise ratio (SNR conditions. In the proposed algorithm, the problem of angle estimation is converted to estimating the frequency of the cross-correlation function (CCF. Experimental results demonstrate the similar performance of the proposed algorithm compared with the traditional amplitude comparison method. It means that the proposed method for angle estimation can be adopted. When adopting the proposed method, future radars may only need wideband signals for both tracking and imaging, which can greatly increase the data rate and strengthen the capability of anti-jamming. More importantly, the estimated angle will not become ambiguous under an arbitrary angle, which can significantly extend the estimated angle range in wideband radars.
Multi-Angle Snowflake Camera Instrument Handbook
Energy Technology Data Exchange (ETDEWEB)
Stuefer, Martin [Univ. of Alaska, Fairbanks, AK (United States); Bailey, J. [Univ. of Alaska, Fairbanks, AK (United States)
2016-07-01
The Multi-Angle Snowflake Camera (MASC) takes 9- to 37-micron resolution stereographic photographs of free-falling hydrometers from three angles, while simultaneously measuring their fall speed. Information about hydrometeor size, shape orientation, and aspect ratio is derived from MASC photographs. The instrument consists of three commercial cameras separated by angles of 36º. Each camera field of view is aligned to have a common single focus point about 10 cm distant from the cameras. Two near-infrared emitter pairs are aligned with the camera’s field of view within a 10-angular ring and detect hydrometeor passage, with the lower emitters configured to trigger the MASC cameras. The sensitive IR motion sensors are designed to filter out slow variations in ambient light. Fall speed is derived from successive triggers along the fall path. The camera exposure times are extremely short, in the range of 1/25,000th of a second, enabling the MASC to capture snowflake sizes ranging from 30 micrometers to 3 cm.
Introduction to small-angle scattering
International Nuclear Information System (INIS)
Gilbert, E.
2003-01-01
Full text: Small angle neutron and X-ray scattering (SANS and SAXS) are ideal tools for studying the structure of materials in the size range between 10 and 1000 Angstrom. While imaging methods such as transmission electron microscopy (TEM) also have this capability, they provide images in real space, for instance individual grains in a nanocrystalline material. SANS and SAXS, on the other hand, provide (generally) a non-destructive method yielding structural information averaged over all grains with high statistical accuracy due to averaging over the whole sample volume. The use of neutrons and X-rays is also implicitly complementary due to their sensitivity to either nuclear or electron density respectively. This provides several further advantages over real-space techniques such as isotopic sensitivity and contrast variation. In this talk, I will provide an introduction to the technique with a minimum number of equations, emphasising what structural information may be obtained from small-angle scattering
Observations at large zenith angles
Schroeder, F
2000-01-01
Cherenkov telescope observations at zenith angles >70 deg. are capable of providing large collection areas for high energy gamma-induced air showers. In order to provide a full Monte Carlo simulation of the large zenith angle observations the air shower simulation code CORSIKA was modified to treat particles in a curved geometry. First results of studies with the stand alone telescope HEGRA CT1 are presented.
Simulation of Canopy Leaf Inclination Angle in Rice
Directory of Open Access Journals (Sweden)
Xiao-cui ZHANG
2013-11-01
Full Text Available A leaf inclination angle distribution model, which is applicable to simulate leaf inclination angle distribution in six heights of layered canopy at different growth stages, was established by component factors affecting plant type in rice. The accuracy of the simulation results was validated by measured values from a field experiment. The coefficient of determination (R2 and the root mean square error (RMSE between the simulated and measured values were 0.9472 and 3.93%, respectively. The simulation results showed that the distribution of leaf inclination angles differed among the three plant types. The leaf inclination angles were larger in the compact variety Liangyoupeijiu with erect leaves than in the loose variety Shanyou 63 with droopy leaves and the intermediate variety Liangyou Y06. The leaf inclination angles were distributed in the lower range in Shanyou 63, which matched up with field measurements. The distribution of leaf inclination angles in the same variety changed throughout the seven growth stages. The leaf inclination angles enlarged gradually from transplanting to booting. During the post-booting period, the leaf inclination angle increased in Shanyou 63 and Liangyou Y06, but changed little in Liangyoupeijiu. At every growth stage of each variety, canopy leaf inclination angle distribution on the six heights of canopy layers was variable. As canopy height increased, the layered leaf area index (LAI decreased in all the three plant types. However, while the leaf inclination angles showed little change in Liangyoupeijiu, they became larger in Shanyou 63 but smaller in Liangyou Y06. The simulation results used in the constructed model were very similar to the actual measurement values. The model provides a method for estimating canopy leaf inclination angle distribution in rice production.
EFFECT OF SWEEP ANGLE ON THE VORTICAL FLOW OVER DELTA WINGS AT AN ANGLE OF ATTACK OF 10°
Directory of Open Access Journals (Sweden)
JAMES BRETT
2014-12-01
Full Text Available CFD simulations have been used to analyse the vortical flows over sharp edged delta wings with differing sweep angles under subsonic conditions at an angle of attack of 10°. RANS simulations were validated against experimental data for a 65° sweep wing, with a flat cross-section, and the steadiness of the flow field was assessed by comparing the results against unsteady URANS and DES simulations. To assess the effect of sweep angle on the flow field, a range of sweep angles from 65° to 43° were simulated. For moderate sweep wings the primary vortex was observed to detach from the leading edge, undergoing vortex breakdown, and a weaker, replacement, "shadow" vortex was formed. The shadow vortex was observed for sweep angles of 50° and less, and resulted in reduced lift production near the wing tips loss of the stronger primary vortex.
The Influence of Face Angle and Club Path on the Resultant Launch Angle of a Golf Ball
Directory of Open Access Journals (Sweden)
Paul Wood
2018-02-01
Full Text Available A two-part experimental study was conducted in order to better understand how the delivered face angle and club path of a golf club influences the initial launch direction of a golf ball for various club types. A robust understanding of how these parameters influence the ball direction has implications for both coaches and club designers. The first study used a large sample of golfers hitting shots with different clubs. Initial ball direction was measured with a Foresight Sports camera system, while club delivery parameters were recorded with a Vicon motion capture system. The second study used a golf robot and Vision Research camera to measure club and ball parameters. Results from these experiments show that the launch direction fell closer to face angle than club path. The percent toward the face angle ranged from 61% to 83%, where 100% designates a launch angle entirely toward the face angle.
Steric Nature of the Bite Angle. A Closer and a Broader Look
van Zeist, W.-J.; Bickelhaupt, F.M.
2011-01-01
The bite angle (ligand-metal-ligand angle) is known to greatly influence the activity of catalytically active transition-metal complexes towards bond activation. Here, we have computationally explored how and why the bite angle has such effects in a wide range of prototypical C-X bonds and palladium
Control of Angular Intervals for Angle-Multiplexed Holographic Memory
Kinoshita, Nobuhiro; Muroi, Tetsuhiko; Ishii, Norihiko; Kamijo, Koji; Shimidzu, Naoki
2009-03-01
In angle-multiplexed holographic memory, the full width at half maximum of the Bragg selectivity curves is dependent on the angle formed between the medium and incident laser beams. This indicates the possibility of high density and high multiplexing number by varying the angular intervals between adjacent holograms. We propose an angular interval scheduling for closely stacking holograms into medium even when the angle range is limited. We obtained bit error rates of the order of 10-4 under the following conditions: medium thickness of 1 mm, laser beam wavelength of 532 nm, and angular multiplexing number of 300.
Large angle tracking and high discriminating tracking in nuclear emulsion
International Nuclear Information System (INIS)
Matsuo, Tomokazu; Shibuya, Hiroshi; Ogawa, Satoru; Fukuda, Tsutomu; Mikado, Shoji
2015-01-01
Nuclear emulsion is a high resolution and re-analyzable detector. Conventional “Track Selector” which have angle acceptance |tan θ|<0.6 are widely used to find tracks in emulsion. We made a new track selector “Fine Track Selector” (FTS) which has large angle acceptance and high discriminating ability. The FTS reduces fake tracks using new algorithms, navigation etc. FTS also keeps finding efficiency of tracks around 90% in an angle range of |tan θ| < 3.5. FTS was applied to the τ candidate in OPERA and no additional tracks found. FTS will be useful to our new J-PARC emulsion experiment.
Effects of slant angle and illumination angle on MTF estimations
CSIR Research Space (South Africa)
Vhengani, LM
2012-07-01
Full Text Available angle d(?) was not constant. It was also noted that the iris of the imaging system was in most cases adjusted during initial setups of each measurements. After each measurement, the knife-edge target was replaced with the ISO 12233 MTF target (shown....085 0.09 0.095 K:\\Working Folder\\Project_On_orbit MTF\\edgetargets\\MTF_Lab_Measurements _20120302_Edge Slant Angle (degrees) Ny qu ist MT F (c yc le/p ixe l) Data Regression -18 -16 -14 -12 -10 -8 -6 -4 -2 0.05 0.055 0.06 0...
Detection of Contact Binaries Using Sparse High Phase Angle Lightcurves
Lacerda, Pedro
2007-01-01
We show that candidate contact binary asteroids can be efficiently identified from sparsely sampled photometry taken at phase angles >60deg. At high phase angle, close/contact binary systems produce distinctive lightcurves that spend most of the time at maximum or minimum (typically >1mag apart) brightness with relatively fast transitions between the two. This means that a few (~5) sparse observations will suffice to measure the large range of variation and identify candidate contact binary s...
Pair creation at large inherent angles
International Nuclear Information System (INIS)
Chen, P.; Tauchi, T.; Schroeder, D.V.
1992-01-01
In the next-generation linear colliders, the low-energy e + e - pairs created during the collision of high-energy e + e - beams would cause potential deleterious background problems to the detectors. At low collider energies, the pairs are made essentially by the incoherent process, where the pair is created by the interaction of beamstrahlung photons on the individual particles in the oncoming beam. This problem was first identified by Zolotarev, et al. At energies where the beamstrahlung parameter Υ lies approximately in the range 0.6 approx-lt Υ approx-lt 100, pair creation from the beamstrahlung photons is dominated by a coherent process, first noted by Chen. The seriousness of this pair creation problem lies in the transverse momenta that the pair particles carry when leaving the interaction point (IP) with large angles. Since the central issue is the transverse momentum for particles with large angles, the authors notice that there is another source for it. Namely, when the pair particles are created at low energies, the intrinsic angles of these pairs when produced may already be large. In this paper they reinvestigate the problem, following essentially the same equivalent photon approach, but with changes in specific details including the virtual photon spectrum. In addition, various assumptions are made more explicit. The formulas derived are then applied to the collider parameters designed by Palmer
Head flexion angle while using a smartphone.
Lee, Sojeong; Kang, Hwayeong; Shin, Gwanseob
2015-01-01
Repetitive or prolonged head flexion posture while using a smartphone is known as one of risk factors for pain symptoms in the neck. To quantitatively assess the amount and range of head flexion of smartphone users, head forward flexion angle was measured from 18 participants when they were conducing three common smartphone tasks (text messaging, web browsing, video watching) while sitting and standing in a laboratory setting. It was found that participants maintained head flexion of 33-45° (50th percentile angle) from vertical when using the smartphone. The head flexion angle was significantly larger (p smartphone, could be a main contributing factor to the occurrence of neck pain of heavy smartphone users. Practitioner Summary: In this laboratory study, the severity of head flexion of smartphone users was quantitatively evaluated when conducting text messaging, web browsing and video watching while sitting and standing. Study results indicate that text messaging while sitting caused the largest head flexion than that of other task conditions.
Spin Valve Systems for Angle Sensor Applications
Johnson, Andrew
2004-01-01
A contact-less sensor with the ability to measure over a 360° range has been long sought after in the automotive industry. Such a sensor could be realized by utilizing the angle dependence of the Giant Magneto Resistance (GMR) Effect in a special type of magnetic multilayer called a spin valve arranged in a wheatstone bridge circuit [Spo96]. A spin valve consists of two ferromagnetic layers separated by nonmagnetic spacer layer where the magnetization of one of the ferromagnetic layers is pin...
Frequency scaling for angle gathers
Zuberi, M. A H
2014-01-01
Angle gathers provide an extra dimension to analyze the velocity after migration. Space-shift and time shift-imaging conditions are two methods used to obtain angle gathers, but both are reasonably expensive. By scaling the time-lag axis of the time-shifted images, the computational cost of the time shift imaging condition can be considerably reduced. In imaging and more so Full waveform inversion, frequencydomain Helmholtz solvers are used more often to solve for the wavefields than conventional time domain extrapolators. In such cases, we do not need to extend the image, instead we scale the frequency axis of the frequency domain image to obtain the angle gathers more efficiently. Application on synthetic data demonstrate such features.
Patient-specific rhytidectomy: finding the angle of maximal rejuvenation.
Jacono, Andrew A; Ransom, Evan R
2012-09-01
Rhytidectomy is fundamentally an operation of tissue release and resuspension, although the manner and direction of suspension are subject to perpetual debate. The authors describe a method for identifying the angle of maximal rejuvenation during rhytidectomy and quantify the resulting angle and its relationship to patient age. Patients were prospectively enrolled; demographic data, history, and operative details were recorded. Rhytidectomies were performed by the senior author (AAJ). After complete elevation, the face-lift flap was rotated in a medially-based arc (0-90°) while attention was given to the submental area, jawline, and midface. The angle of maximal rejuvenation for each hemiface was identified as described, and the flap was resuspended. During redraping, measurements of vertical and horizontal skin excess were recorded in situ. The resulting angle of lift was then calculated for each hemiface using trigonometry. Symmetry between sides was determined, and the effect of patient age on this angle was assessed. Three hundred hemifaces were operated (147 women; 3 men). Mean age was 60 years (range, 37-80 years). Mean resulting angle for the cohort was 60° from horizontal (range, 46-77°). This was inversely correlated with patient age (r = -.3). Younger patients (<50 years, 64°) had a significantly more vertical angle than older patients (≥70 years, 56°; P < .0002). No significant intersubject difference was found between hemifaces (P = .53). The authors present a method for identifying the angle of maximal rejuvenation during rhytidectomy. This angle was more superior than posterior in all cases and is intimately related to patient age. Lasting results demand a detailed anatomical understanding and strict attention to the direction and degree of laxity.
Temperature dependence of Brewster's angle.
Guo, Wei
2018-01-01
In this work, a dielectric at a finite temperature is modeled as an ensemble of identical atoms moving randomly around where they are trapped. Light reflection from the dielectric is then discussed in terms of atomic radiation. Specific calculation demonstrates that because of the atoms' thermal motion, Brewster's angle is, in principle, temperature-dependent, and the dependence is weak in the low-temperature limit. What is also found is that the Brewster's angle is nothing but a result of destructive superposition of electromagnetic radiation from the atoms.
Angle independent velocity spectrum determination
DEFF Research Database (Denmark)
2014-01-01
An ultrasound imaging system (100) includes a transducer array (102) that emits an ultrasound beam and produces at least one transverse pulse-echo field that oscillates in a direction transverse to the emitted ultrasound beam and that receive echoes produced in response thereto and a spectral vel...... velocity estimator (110) that determines a velocity spectrum for flowing structure, which flows at an angle of 90 degrees and flows at angles less than 90 degrees with respect to the emitted ultrasound beam, based on the received echoes....
A Hitch Angle Measurement Device
National Research Council Canada - National Science Library
Von
1998-01-01
As part of a project to demonstrate that an unmanned ground vehicle (UGV) could remotely back up with a trailer, a simple proof-of-concept device was designed to measure the angle between a high-mobility multipurpose wheeled vehicle (HMMWV...
Determination of the Contact Angle Based on the Casimir Effect
Mazuruk, Konstantin; Volz, Martin P.
2015-01-01
On a macroscopic scale, a nonreactive liquid partially covering a homogeneous solid surface will intersect the solid at an angle called the contact angle. For molten metals and semiconductors, the contact angle is materially dependent upon both the solid and liquid and typical values fall in the range 80-170 deg, depending on the crucible material. On a microscopic scale, there does not exist a precise and sharp contact angle but rather the liquid and solid surfaces merge smoothly and continuously. Consider the example of the so called detached Bridgman crystal growth process. In this technique, a small gap is formed between the growing crystal and the crucible. At the crystal/melt interface, a meniscus ring is formed. Its width can be in the range of a few micrometers, approaching a microscopic scale. It then becomes questionable to describe the shape of this meniscus by the contact angle. A more advanced treatment of the interface is needed and here we propose such a refined model. The interaction of the liquid surface with the solid can be calculated by considering two forces: a short-range repulsive force and a longer range (up to a few micrometers) Casimir or van der Waals force.
Exclusive Backward-Angle Omega Meson Electroproduction
Energy Technology Data Exchange (ETDEWEB)
Wenliang, Li [Univ. of Regina, Regina, SK (Canada)
2017-10-01
photoproduction data. Through comparison of our σ_{T} data with the prediction of the Transition Distribution Amplitude (TDA) model, and signs of σ_{T} dominance, promising indications of the applicability of the TDA factorization are demonstrated at a much lower Q^{2} value than its preferred range of Q^{2} > 10 GeV^{2}. These studies have opened a new means to study the transition of the nucleon wavefunction through backward-angle experimental observables.
Effect of Angle of Attack on Slope Climbing Performance
Creager, Colin M.; Jones, Lucas; Smith, Lauren M.
2017-01-01
Ascending steep slopes is often a very difficult challenge for off-road vehicles, whether on Earth or on extraterrestrial bodies. This challenge is even greater if the surface consists of loose granular soil that does not provide much shear strength. This study investigated how the path at which a vehicle traverses a slope, specifically the angle that it is commanded to drive relative to the base of the hill (the angle of attack), can affect its performance. A vehicle was driven in loose sand at slope angles up to 15 degrees and angles of attack ranging from 10 to 90 degrees. A novel photogrammetry technique was implemented to both track vehicle motion and create a three-dimensional profile of the terrain. This allowed for true wheel sinkage measurements. The study showed that though low angles of attack result in lower wheel slip and sinkage, the efficiency of the vehicles uphill motion increased at higher angles of attack. For slopes up to 15 degrees, a 90 degree angle of attack provided the greatest likelihood of successful ascent.
Angle-resolved photoemission extended fine structure
International Nuclear Information System (INIS)
Barton, J.J.
1985-03-01
Measurements of the Angle-Resolved Photoemission Extended Fine Structure (ARPEFS) from the S(1s) core level of a c(2 x 2)S/Ni(001) are analyzed to determine the spacing between the S overlayer and the first and second Ni layers. ARPEFS is a type of photoelectron diffraction measurement in which the photoelectron kinetic energy is swept typically from 100 to 600 eV. By using this wide range of intermediate energies we add high precision and theoretical simplification to the advantages of the photoelectron diffraction technique for determining surface structures. We report developments in the theory of photoelectron scattering in the intermediate energy range, measurement of the experimental photoemission spectra, their reduction to ARPEFS, and the surface structure determination from the ARPEFS by combined Fourier and multiple-scattering analyses. 202 refs., 67 figs., 2 tabs
Transmission-type angle deviation microscopy
International Nuclear Information System (INIS)
Chiu, M.-H.; Lai, C.-W.; Tan, C.-T.; Lai, C.-F.
2008-01-01
We present a new microscopy technique that we call transmission angle deviation microscopy (TADM). It is based on common-path heterodyne interferometry and geometrical optics. An ultrahigh sensitivity surface plasmon resonance (SPR) angular sensor is used to expand dynamic measurement ranges and to improve the axial resolution in three-dimensional optical microscopy. When transmitted light is incident upon a specimen, the beam converges or diverges because of refractive and/or surface height variations. Advantages include high axial resolution (∼32 nm), nondestructive and noncontact measurement, and larger measurement ranges (± 80 μm) for a numerical aperture of 0.21in a transparent measurement medium. The technique can be used without conductivity and pretreatment
Can orbital angle morphology distinguish dogs from wolves?
Janssens, Luc; Spanoghe, Inge; Miller, Rebecca; Van Dongen, Stefan
For more than a century, the orbital angle has been studied by many authors to distinguish dog skulls from their progenitor, the wolf. In early studies, the angle was reported to be different between dogs (49°-55°) and wolves (39°-46°). This clear difference was, however, questioned in a more recent Scandinavian study that shows some overlap. It is clear that in all studies several methodological issues were unexplored or unclear and that group sizes and the variety of breeds and wolf subspecies were small. Archaeological dog skulls had also not been studied. Our goal was to test larger and more varied groups and add archaeological samples as they are an evolutionary stage between wolves and modern dogs. We also tested the influence of measuring methods, intra- and inter-reliability, angle symmetry, the influence of variations in skull position and the possibility of measuring and comparing this angle on 3D CT scan images. Our results indicate that there is about 50 % overlap between the angle range in wolves and modern dogs. However, skulls with a very narrow orbital angle were only found in wolves and those with a very wide angle only in dogs. Archaeological dogs have a mean angle very close to the one of the wolves. Symmetry is highest in wolves and lowest in archaeological dogs. The measuring method is very reliable, for both inter- and intra-reliability (0.99-0.97), and most skull position changes have no statistical influence on the angle measured. Three-dimensional CT scan images can be used to measure OA, but the angles differ from direct measuring and cannot be used for comparison. Evolutionary changes in dog skulls responsible for the wider OA compared to wolf skulls are mainly the lateralisation of the zygomatic process of the frontal bone. Our conclusion is that the orbital angle can be used as an additional morphological measuring method to discern wolves from recent and archaeological dogs. Angles above 60° are certainly from recent dogs. Angles
Lewis, Christina M; Hurley, Samuel A; Meyerand, M Elizabeth; Koay, Cheng Guan
2016-09-01
Define criteria for selection of optimal flip angle sets for T1 estimation and evaluate effects on T1 mapping. Flip angle sets for spoiled gradient echo-based T1 mapping were selected by minimizing T1 estimate variance weighted by the joint density of M0 and T1 in an initial acquisition. The effect of optimized flip angle selection on T1 estimate error was measured using simulations and experimental data in the human and rat brain. For two-point acquisitions, optimized angle sets were similar to those proposed by other groups and, therefore, performed similarly. For multipoint acquisitions, optimal angle sets for T1 mapping in the brain consisted of a repetition of two angles. Implementation of optimal angles reduced T1 estimate variance by 30-40% compared with a multipoint acquisition using a range of angles. Performance of the optimal angle set was equivalent to that of a repetition of the two-angle set selected using criteria proposed by other researchers. Repetition of two carefully selected flip angles notably improves the precision of resulting T1 estimates compared with acquisitions using a range of flip angles. This work provides a flexible and widely applicable optimization method of particular use for those who repeatedly perform T1 estimation. Magn Reson Med 76:792-802, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.
A New Method to Calibrate Attachment Angles of Data Loggers in Swimming Sharks
Directory of Open Access Journals (Sweden)
Shizuka Kawatsu
2010-01-01
Full Text Available Recently, animal-borne accelerometers have been used to record the pitch angle of aquatic animals during swimming. When evaluating pitch angle, it is necessary to consider a discrepancy between the angle of an accelerometer and the long axis of an animal. In this study, we attached accelerometers to 17 free-ranging scalloped hammerhead shark (Sphyrna lewini pups from Kaneohe Bay, Hawaii. Although there are methods to calibrate attachment angles of accelerometers, we confirmed that previous methods were not applicable for hammerhead pups. According to raw data, some sharks ascended with a negative angle, which differs from tank observations of captive sharks. In turn, we developed a new method to account for this discrepancy in swimming sharks by estimating the attachment angle from the relationship between vertical speed (m/s and pitch angle obtained by each accelerometer. The new method can be utilized for field observation of a wide range of species.
New Light Source Setup for Angle Resolved Light Absorption measurement of PV samples
DEFF Research Database (Denmark)
Amdemeskel, Mekbib Wubishet; Poulsen, Peter Behrensdorff; Thorsteinsson, Sune
Here, we introduce measurements of angle resolved light absorption by PV cells, using broadband laser driven white light source with a bright, stable, broad spectral range and well collimated light.......Here, we introduce measurements of angle resolved light absorption by PV cells, using broadband laser driven white light source with a bright, stable, broad spectral range and well collimated light....
New Light Source Setup for Angle Resolved Light Absorption measurement of PV sample
DEFF Research Database (Denmark)
Amdemeskel, Mekbib Wubishet; Poulsen, Peter Behrensdorff; Thorsteinsson, Sune
Here, we introduce measurements of angle resolved light absorption by PV cells, using broadband laser driven white light source with a bright, stable, broad spectral range and well collimated light.......Here, we introduce measurements of angle resolved light absorption by PV cells, using broadband laser driven white light source with a bright, stable, broad spectral range and well collimated light....
Small angle x-ray scattering and its applications
International Nuclear Information System (INIS)
Buckely, C.E.
2002-01-01
Full text: Small angle X-ray scattering is an excellent technique to characterise inhomogeneities in materials in the size range from 1 nm - several hundred nm. Ultra small angle X-ray scattering has extended this size range out to 20 μm. SAXS is due to the electron density difference between the matrix and the inhomogeneity. SAXS and small angle neutron scattering have been successfully used to characterise colloidal particles in solution, colloidal powders, macromolecules, glasses and a wide range of solids such as metals, alloys, and natural and synthetic high polymers. Small angle scattering and complementary techniques, such as transmission and scanning electron microscopy are a powerful combination for the investigation of submicron particles. This talk will introduce the small angle scattering technique and its applications, and will also describe the new Nanostar SAXS instrument in the Department of Applied Physics at Curtin University that has been purchased through a 2001 Australian Research Council research infrastructure and equipment fund (2001 ARC RIEF) grant. Copyright (2002) Australian X-ray Analytical Association Inc
Measurement of the angle gamma
International Nuclear Information System (INIS)
Aleksan, R.; Kayser, B.; Sphicas, P.
1993-01-01
The angle γ at least as defined in the Wolfenstein approximation is not completely out of reach of current or proposed dedicated B experiments. This conclusion certainly depends crucially on the assumed trigger and tagging efficiencies and also on the expected backgrounds. The work summarized here represents but a first step in the direction of extracting the third angle of the unitarity triangle. The theoretical developments during the workshop have resulted in a clearer understanding of the quantities studied. On the experimental side, new decay modes (i.e. in addition to the traditional ρK s decay) have resulted in expections for observing CP violation in B s decays which are not unreasonable. It is conceivable that a dedicated B experiment can probe a fundamental aspect of the Standard Model, the CKM matrix, in multiple ways. In the process, new physics can appear anywhere along the line
Contact angles on stretched solids
Mensink, Liz; Snoeijer, Jacco
2017-11-01
The surface energy of solid interfaces plays a central role in wetting, as they dictate the liquid contact angle. Yet, it has been challenging to measure the solid surface energies independently, without making use of Young's law. Here we present Molecular Dynamics (MD) simulations by which we measure the surface properties for all interfaces, including the solids. We observe change in contact angles upon stretching the solid substrates, showing that the surface energy is actually strain dependent. This is clear evidence of the so-called Shuttleworth effect, making it necessary to distinguish surface energy from surface tension. We discuss how this effect gives rise to a new class of elasto-capillary phenomena. ERC Consolidator Grant No. 616918.
Ocular biometry in angle closure.
Razeghinejad, Mohammad Reza; Banifatemi, Mohammad
2013-01-01
To compare ocular biometric parameters in primary angle closure suspects (PACS), primary angle closure glaucoma (PACG) and acute primary angle closure (APAC). This cross-sectional study was performed on 113 patients including 33 cases of PACS, 45 patients with PACG and 35 subjects with APAC. Central corneal thickness (CCT), axial length (AL), anterior chamber depth (ACD) and lens thickness (LT) were measured with an ultrasonic biometer. Lens-axial length factor (LAF), relative lens position, corrected ACD (CACD) and corrected lens position were calculated. The parameters were measured bilaterally but only data from the right eyes were compared. In the APAC group, biometric parameters were also compared between affected and unaffected fellow eyes. Logistic regression analysis was performed to identify risk factors. No statistically significant difference was observed in biometric parameters between PACS and PACG eyes, or between affected and fellow eyes in the APAC group (P>0.05 for all comparisons). However, eyes with APAC had thicker cornea (P=0.001), thicker lens (PAPAC. In the APAC group, LAF (PAPAC.
Design of a self-calibration high precision micro-angle deformation optical monitoring scheme
Gu, Yingying; Wang, Li; Guo, Shaogang; Wu, Yun; Liu, Da
2018-03-01
In order to meet the requirement of high precision and micro-angle measurement on orbit, a self-calibrated optical non-contact real-time monitoring device is designed. Within three meters, the micro-angle variable of target relative to measuring basis can be measured in real-time. The range of angle measurement is +/-50'', the angle measurement accuracy is less than 2''. The equipment can realize high precision real-time monitoring the micro-angle deformation, which caused by high strength vibration and shock of rock launching, sun radiation and heat conduction on orbit and so on.
A variable angle slant-hole collimator
International Nuclear Information System (INIS)
Moore, R.H.; Alpert, N.M.; Strauss, H.W.
1983-01-01
A variable-angle slant-hole (VASH) collimator was constructed to show the feasibility of using multiple sliding plates to achieve a range of collimator channel inclinations. One hundred and sixty tungsten plates, 0.125 mm thick and 14 cm square, were photoetched to produce 3025 1.5-mm2 holes in each plate, separated by 0.8-mm septa. Along with the collimator holes, registration holes and positioning grooves were also etched. The plates were placed in a holder and stacked to form a collimator 2.0 cm high. The holder permitted the plates to be sheared to achieve viewing angles from 0 to 40 degrees from the vertical. Resolution and sensitivity were determined both across and along the shear directions. Resolution of a thin /sup 99m/Tc source, 1.24 mm diam and 7 cm long, located 5 cm from the collimator face in air, was 1.1 cm FWHM at 0 degree shear and remained unchanged with increasing slant. The resolution was similar both across and along the shear plane. Sensitivity was determined with a point source placed 7 cm from the collimator face. At 0 degree slant the sensitivity was 169 cps/MBq (6.24 csp/mu Ci). A general all purpose (GAP) collimator had a FWHM of 1 cm for the line source in air at 5 cm, and a sensitivity of 205 cps/MBq (7.58 cps/mu Ci) for the point source at 7 cm. The data suggest that a variable-angle slant-hole collimator can be constructed of laminated plates
Metasurface Enabled Wide-Angle Fourier Lens.
Liu, Wenwei; Li, Zhancheng; Cheng, Hua; Tang, Chengchun; Li, Junjie; Zhang, Shuang; Chen, Shuqi; Tian, Jianguo
2018-04-19
Fourier optics, the principle of using Fourier transformation to understand the functionalities of optical elements, lies at the heart of modern optics, and it has been widely applied to optical information processing, imaging, holography, etc. While a simple thin lens is capable of resolving Fourier components of an arbitrary optical wavefront, its operation is limited to near normal light incidence, i.e., the paraxial approximation, which puts a severe constraint on the resolvable Fourier domain. As a result, high-order Fourier components are lost, resulting in extinction of high-resolution information of an image. Other high numerical aperture Fourier lenses usually suffer from the bulky size and costly designs. Here, a dielectric metasurface consisting of high-aspect-ratio silicon waveguide array is demonstrated experimentally, which is capable of performing 1D Fourier transform for a large incident angle range and a broad operating bandwidth. Thus, the device significantly expands the operational Fourier space, benefitting from the large numerical aperture and negligible angular dispersion at large incident angles. The Fourier metasurface will not only facilitate efficient manipulation of spatial spectrum of free-space optical wavefront, but also be readily integrated into micro-optical platforms due to its compact size. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Anomalous and resonance small-angle scattering
International Nuclear Information System (INIS)
Epperson, J.E.; Thiyagarajan, P.
1988-01-01
Significant changes in the small-angle scattered intensity can be induced by making measurements with radiation close to an absorption edge of an appropriate atomic species contained in the sample. These changes can be related quantitatively to the real and imaginary anomalous-dispersion terms for the scattering factor (X-rays) or scattering length (neutrons). The physics inherent in these anomalous-dispersion terms is first discussed before consideration of how they enter the relevant scattering theory. Two major areas of anomalous-scattering research have emerged; macromolecules in solution and unmixing of metallic alloys. Research in each area is reviewed, illustrating both the feasibility and potential of these techniques. All the experimental results reported to date have been obtained with X-rays. However, it is pointed out that the formalism is the same for the analog experiment with neutrons, and a number of suitable isotopes exist which exhibit resonance in an accessible range of energy. Potential applications of resonance small-angle neutron scattering are discussed. (orig.)
Anomalous and resonance small angle scattering
International Nuclear Information System (INIS)
Epperson, J.E.; Thiyagarajan, P.
1987-11-01
Significant changes in the small angle scattered intensity can be induced by making measurements with radiation close to an absorption edge of an appropriate atomic species contained in the sample. These changes can be related quantitatively to the real and imaginary anomalous dispersion terms for the scattering factor (x-rays) or scattering length (neutrons). The physics inherent in these anomalous dispersion terms is first discussed before considering how they enter the relevant scattering theory. Two major areas of anomalous scattering research have emerged; macromolecules in solution and unmixing of metallic alloys. Research in each area is reviewed, illustrating both the feasibility and potential of these techniques. All the experimental results reported to date have been obtained with x-rays. However, it is pointed out that the formalism is the same or the analogue experiment with neutrons, and a number of suitable isotopes exist which exhibit resonance in an accessible range of energy. Potential applications of resonance small-angle neutron scatterings are discussed. 8 figs
Limbus Impact on Off-angle Iris Degradation
Energy Technology Data Exchange (ETDEWEB)
Karakaya, Mahmut [ORNL; Barstow, Del R [ORNL; Santos-Villalobos, Hector J [ORNL; Thompson, Joseph W [ORNL; Bolme, David S [ORNL; Boehnen, Chris Bensing [ORNL
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.
Small angle neutron scattering study of mixed micelles of oppositely ...
Indian Academy of Sciences (India)
- methylammonium bromide (DTAB) and sodium dodecyl sulphate (SDS) have been studied using small angle neutron scattering. The concentration of one of the components was kept fixed (0.3 M) and that of another varied in the range 0 to ...
A national facility for small angle neutron scattering
International Nuclear Information System (INIS)
Buyers, W.J.L.; Katsaras, J.; Mellors, W.; Potter, M.M.; Powell, B.M.; Rogge, R.B.; Root, J.H.; Tennant, D.C.; Tun, Z.
1995-01-01
A world-class small angle neutron scattering (SANS) facility is proposed for Canada. It will provide users from the fields of biology, chemistry, physics, materials science and engineering with a uniquely powerful tool for investigating microstructural properties whose length scales lie in the optical to atomic range. (author). 7 refs
Ultra Small-Angle Neutron Scattering Study of Porous Glass
International Nuclear Information System (INIS)
Desai, Reshma R.; Desa, J. A. Erwin; Sen, D.; Mazumder, S.
2011-01-01
Compacts of silica micro-spheres prepared for different times at sintering temperatures of 640 deg. C and 740 deg. C have been studied by Ultra Small-Angle Neutron Scattering (USANS) and Scanning Electron Microscopy (SEM). Stress versus strain measurements display several breakage points related to a range of nearest neighbour coordination around each microsphere.
Spin-Echo Small-Angle Neutron Scattering Development
Uca, O.
2003-01-01
Spin-Echo Small-Angle Neutron Scattering (SESANS) instrument is a novel SANS technique which enables one to characterize distances from a few nanometers up to the micron range. The most striking difference between normal SANS and SESANS is that in SESANS one gets information in real space, whereas
Influence of gender on quadriceps (Q) angle among adult Urhobos ...
African Journals Online (AJOL)
... adult Nigerian population of Urhobo ethnicity between the age range of 19-32 years, measurements were taken from healthy individuals with no previous history of musculoskeletal disorder to establish a standard value. The Q-angle was taken using a goniometer with the subject standing on a weight bearing position.
Ocular Biometry in Angle Closure
Directory of Open Access Journals (Sweden)
Mohammad Reza Razeghinejad
2013-01-01
Full Text Available Purpose: To compare ocular biometric parameters in primary angle closure suspects (PACS, primary angle closure glaucoma (PACG and acute primary angle closure (APAC. Methods: This cross-sectional study was performed on 113 patients including 33 cases of PACS, 45 patients with PACG and 35 subjects with APAC. Central corneal thickness (CCT, axial length (AL, anterior chamber depth (ACD and lens thickness (LT were measured with an ultrasonic biometer. Lens-axial length factor (LAF, relative lens position, corrected ACD (CACD and corrected lens position were calculated. The parameters were measured bilaterally but only data from the right eyes were compared. In the APAC group, biometric parameters were also compared between affected and unaffected fellow eyes. Logistic regression analysis was performed to identify risk factors. Results: No statistically significant difference was observed in biometric parameters between PACS and PACG eyes, or between affected and fellow eyes in the APAC group (P>0.05 for all comparisons. However, eyes with APAC had thicker cornea (P=0.001, thicker lens (P<0.0001, shallower ACD (P=0.009, shallower CACD (P=0.003 and larger LAF (P<0.0001. Based on ROC curve analysis, lower ACD, and larger LT, LAF and CCT values were associated with APAC. In the APAC group, LAF (P<0.0001 and CCT (P=0.001 were significant risk factors. Conclusion: This study revealed no significant difference in biometric characteristics in eyes with PACS and PACG. However, larger LAF and CCT were predictive of APAC.
Discriminating electromagnetic radiation based on angle of incidence
Hamam, Rafif E.; Bermel, Peter; Celanovic, Ivan; Soljacic, Marin; Yeng, Adrian Y. X.; Ghebrebrhan, Michael; Joannopoulos, John D.
2015-06-16
The present invention provides systems, articles, and methods for discriminating electromagnetic radiation based upon the angle of incidence of the electromagnetic radiation. In some cases, the materials and systems described herein can be capable of inhibiting reflection of electromagnetic radiation (e.g., the materials and systems can be capable of transmitting and/or absorbing electromagnetic radiation) within a given range of angles of incidence at a first incident surface, while substantially reflecting electromagnetic radiation outside the range of angles of incidence at a second incident surface (which can be the same as or different from the first incident surface). A photonic material comprising a plurality of periodically occurring separate domains can be used, in some cases, to selectively transmit and/or selectively absorb one portion of incoming electromagnetic radiation while reflecting another portion of incoming electromagnetic radiation, based upon the angle of incidence. In some embodiments, one domain of the photonic material can include an isotropic dielectric function, while another domain of the photonic material can include an anisotropic dielectric function. In some instances, one domain of the photonic material can include an isotropic magnetic permeability, while another domain of the photonic material can include an anisotropic magnetic permeability. In some embodiments, non-photonic materials (e.g., materials with relatively large scale features) can be used to selectively absorb incoming electromagnetic radiation based on angle of incidence.
Small angle scattering and polymers
Energy Technology Data Exchange (ETDEWEB)
Cotton, J.P. [Laboratoire Leon Brillouin (LLB) - Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France)
1996-12-31
The determination of polymer structure is a problem of interest for both statistical physics and industrial applications. The average polymer structure is defined. Then, it is shown why small angle scattering, associated with isotopic substitution, is very well suited to the measurement of the chain conformation. The corresponding example is the old, but pedagogic, measurement of the chain form factor in the polymer melt. The powerful contrast variation method is illustrated by a recent determination of the concentration profile of a polymer interface. (author) 12 figs., 48 refs.
Wide Angle Michelson Doppler Imaging Interferometer (WAMDII)
Roberts, B.
1986-01-01
The wide angle Michelson Doppler imaging interferometer (WAMDII) is a specialized type of optical Michelson interferometer working at sufficiently long path difference to measure Doppler shifts and to infer Doppler line widths of naturally occurring upper atmospheric Gaussian line emissions. The instrument is intended to measure vertical profiles of atmospheric winds and temperatures within the altitude range of 85 km to 300 km. The WAMDII consists of a Michelson interferometer followed by a camera lens and an 85 x 106 charge coupled device photodiode array. Narrow band filters in a filter wheel are used to isolate individual line emissions and the lens forms an image of the emitting region on the charge coupled device array.
Extended-range tiltable micromirror
Allen, James J [Albuquerque, NM; Wiens, Gloria J [Newberry, FL; Bronson, Jessica R [Gainesville, FL
2009-05-05
A tiltable micromirror device is disclosed in which a micromirror is suspended by a progressive linkage with an electrostatic actuator (e.g. a vertical comb actuator or a capacitive plate electrostatic actuator) being located beneath the micromirror. The progressive linkage includes a pair of torsion springs which are connected together to operate similar to a four-bar linkage with spring joints. The progressive linkage provides a non-linear spring constant which can allow the micromirror to be tilted at any angle within its range substantially free from any electrostatic instability or hysteretic behavior.
Contact Angle Measurement in Lattice Boltzmann Method
Wen, Binghai; Huang, Bingfang; Qin, Zhangrong; Wang, Chunlei; Zhang, Chaoying
2017-01-01
Contact angle is an essential characteristic in wetting, capillarity and moving contact line; however, although contact angle phenomena are effectively simulated, an accurate and real-time measurement for contact angle has not been well studied in computational fluid dynamics, especially in dynamic environments. Here, we design a geometry-based mesoscopic scheme to onthesport measure the contact angle in the lattice Boltzmann method. The computational results without gravity effect are in exc...
30 CFR 56.19037 - Fleet angles.
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 be...
30 CFR 57.19037 - Fleet angles.
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 be...
Lateral angle and cranial base sexual dimorphism
DEFF Research Database (Denmark)
Duquesnel Mana, Mathilde; Adalian, Pascal; Lynnerup, Niels
2016-01-01
, to examine sexual dimorphism in the relationship between the lateral angle and cranial base shape. The lateral angle method was tested using a forensic sample of 102 CT scans of the head with known sex. We measured the angle using two methods: measurements directly on the CT slide, the method usually applied...
Small-angle scattering, topography and radiography
International Nuclear Information System (INIS)
Schelten, J.
1978-01-01
A table is given showing scattering and imaging methods for X-rays and neutrons, followed, by a discussion of such topics as 1. Radiography 2. Topography 3. Small-angle scattering 3.1. The differential cross section 3.2. Comparison of X-ray and neutron small-angle scattering 3.3. Examples of small-angle scattering. (orig.) [de
Energy Technology Data Exchange (ETDEWEB)
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.
Small-angle neutron scattering in materials science
International Nuclear Information System (INIS)
Fratzl, P.
1999-01-01
Small-angle scattering (SAS) in an ideal tool for studying the structure of materials in the mesoscopic size range between 1 and about 100 nanometers. The basic principles of the method are reviewed, with particular emphasis on data evaluation and interpretation for isotropic as well as oriented or single-crystalline materials. Examples include metal alloys, composites and porous materials. The last section gives a comparison between the use of neutrons and (synchrotron) x-rays for small-angle scattering in materials physics. (author)
DEFF Research Database (Denmark)
Hahn, Thomas; Foldspang, Anders
1997-01-01
Quadriceps muscle contraction tends to straighten the Q angle. We expected that sports comprising a high amount of quadriceps training could be associated with low Q angles. The aim of the present study was to estimate the Q angle in athletes and to investigate its potential associations with par......Quadriceps muscle contraction tends to straighten the Q angle. We expected that sports comprising a high amount of quadriceps training could be associated with low Q angles. The aim of the present study was to estimate the Q angle in athletes and to investigate its potential associations...... with participation in sport. Three hundred and thirty-nine athletes had their Q angle measured. The mean of right-side Q angles was higher than left side, and the mean Q angle was higher in women than in men. The Q angle was positively associated with years of jogging, and negatively with years of soccer, swimming...... and sports participation at all. It is concluded that the use of Q angle measurements is questionable....
Wafer scale oblique angle plasma etching
Burckel, David Bruce; Jarecki, Jr., Robert L.; Finnegan, Patrick Sean
2017-05-23
Wafer scale oblique angle etching of a semiconductor substrate is performed in a conventional plasma etch chamber by using a fixture that supports a multiple number of separate Faraday cages. Each cage is formed to include an angled grid surface and is positioned such that it will be positioned over a separate one of the die locations on the wafer surface when the fixture is placed over the wafer. The presence of the Faraday cages influences the local electric field surrounding each wafer die, re-shaping the local field to be disposed in alignment with the angled grid surface. The re-shaped plasma causes the reactive ions to follow a linear trajectory through the plasma sheath and angled grid surface, ultimately impinging the wafer surface at an angle. The selected geometry of the Faraday cage angled grid surface thus determines the angle at with the reactive ions will impinge the wafer.
Surface tension and contact angles of molten cadmium telluride
Balasubramanian, R.; Wilcox, W. R.
1990-01-01
The surface tension and contact angle of molten cadmium telluride (CdTe) were measured as a function of temperature by the sessile drop technique. A FORTRAN code was developed to calculate the surface tension of sessile drops, with the contact angle ranging from O to 180°. The wetting of cadmium telluride melt was studied on different surfaces. The surface tension of cadmium telluride was about 160 ±5 dynes · cm-1[1.6 m-1] at the melting point of 1093°C. The contact angle of CdTe melt was about 65° on a quartz optical flat, 75° on commercial fused quartz, and 125° on boron nitride coated quartz.
Reliability of the ATD Angle in Dermatoglyphic Analysis.
Brunson, Emily K; Hohnan, Darryl J; Giovas, Christina M
2015-09-01
The "ATD" angle is a dermatoglyphic trait formed by drawing lines between the triradii below the first and last digits and the most proximal triradius on the hypothenar region of the palm. This trait has been widely used in dermatoglyphic studies, but several researchers have questioned its utility, specifically whether or not it can be measured reliably. The purpose of this research was to examine the measurement reliability of this trait. Finger and palm prints were taken using the carbon paper and tape method from the right and left hands of 100 individuals. Each "ATD" angle was read twice, at different times, by Reader A, using a goniometer and a magnifying glass, and three times by a Reader B, using Adobe Photoshop. Inter-class correlation coefficients were estimated for the intra- and inter-reader measurements of the "ATD" angles. Reader A was able to quantify ATD angles on 149 out of 200 prints (74.5%), and Reader B on 179 out of 200 prints (89.5%). Both readers agreed on whether an angle existed on a print 89.8% of the time for the right hand and 78.0% for the left. Intra-reader correlations were 0.97 or greater for both readers. Inter-reader correlations for "ATD" angles measured by both readers ranged from 0.92 to 0.96. These results suggest that the "ATD" angle can be measured reliably, and further imply that measurement using a software program may provide an advantage over other methods.
Rotating Shaft Tilt Angle Measurement Using an Inclinometer
Luo, Jun; Wang, Zhiqian; Shen, Chengwu; Wen, Zhuoman; Liu, Shaojin; Cai, Sheng; Li, Jianrong
2015-10-01
This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.
Rotating Shaft Tilt Angle Measurement Using an Inclinometer
Directory of Open Access Journals (Sweden)
Luo Jun
2015-10-01
Full Text Available This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendicular to the rotating shaft. The reversal measurement method is applied to decrease the effect of inclinometer drifts caused by temperature, to eliminate inclinometer and rotating shaft mechanical error and inclinometer systematic error to attain high measurement accuracy. The uncertainty estimation shows that the accuracy of rotating shaft tilt angle measurement depends mainly on the inclinometer uncertainty and its uncertainty is almost the same as the inclinometer uncertainty in the simulation. The experimental results indicate that measurement time is 4 seconds; the range of rotating shaft tilt angle is 0.002° and its standard deviation is 0.0006° using NS-5/P2 inclinometer, whose precision and resolution are ±0.01° and 0.0005°, respectively.
Small-angle neutron-scattering experiment, (2)
International Nuclear Information System (INIS)
Niimura, Nobuo; Kaji, Harumi.
1983-01-01
Elementary explanation is given to the experiment on the small angle scattering using neutrons having long wave-length (3-12A), continued from the previous report. Two types of the apparatus for small angle neutron scattering experiment are described. The first is angle dispersion type, which uses the neutron beam from research reactors, and the second is wavelength dispersion type, which uses pulsed cold neutron sources. The principles of these experiments are explained. Especially the wavelength dispersion is described in detail. The apparatus in the booster facility at the Institute for High Energy Physics is shown as an example for the latter type. The two-dimensional position sensitive detector, which is essential for angle dispersion type, is also used for the wavelength dispersion type, and its data processing is also described. In the small angle neutron scattering experiment for the studies on the structure of living body substances, the techniques that should be taken into account in common are discussed; the proportion of D 2 O-H 2 O in solvent, the measurable range of Q, the size of specimens, the correction of incident neutron spectra, and the analysis of measured data. (Asami, T.)
Angle-selective all-dielectric Huygens’ metasurfaces
Arslan, D.; Chong, K. E.; Miroshnichenko, A. E.; Choi, D.-Y.; Neshev, D. N.; Pertsch, T.; Kivshar, Y. S.; Staude, I.
2017-11-01
We experimentally and numerically study the angularly resolved transmission properties of dielectric metasurfaces consisting of silicon nanodisks which support electric and magnetic dipolar Mie-type resonances in the near-infrared spectral range. First, we concentrate on Huygens’ metasurfaces which are characterised by a spectral overlap of the fundamental electric and magnetic dipole resonances of the silicon nanodisks at normal incidence. Huygens’ metasurfaces exhibit a high transmitted intensity over the spectral width of the resonances due to impedance matching, while the transmitted phase shows a variation of 2π as the wavelength is swept across the width of the resonances. We observe that the transmittance of the Huygens’ metasurfaces depends on the incidence angle and is sensitive to polarisation for non-normal incidence. As the incidence angle is increased starting from normal incidence, the two dipole resonances are shifted out of the spectral overlap and the resonant features appear as pronounced transmittance minima. Next, we consider a metasurface with an increased nanodisk radius as compared to the Huygens’ metasurface, which supports spectrally separate electric and magnetic dipole resonances at normal incidence. We show that for TM polarisation, we can shift the resonances of this metasurface into spectral overlap and regain the high resonant transmittance characteristic of Huygens’ metasurfaces at a particular incidence angle. Furthermore, both metasurfaces are demonstrated to reject all TM polarised light incident under angles other than the design overlap angle at their respective operation frequency. Our experimental observations are in good qualitative agreement with numerical calculations.
Neutron elastic scattering at very small angles
2002-01-01
This experiment will measure neutron-proton elastic scattering at very small angles and hence very small four-momentum transfer, |t|. The range of |t| depends on the incident neutron momentum of the events but the geometrical acceptance will cover the angular range 0.025 < $\\Theta_{lab}$ < 1.9 mrad. The higher figure could be extended to 8.4 mrad by changing the geometry of the experiment in a later phase. \\\\ \\\\ The neutron beam will be highly collimated and will be derived from a 400 GeV external proton beam of up to $4 \\times 10^{10}$ protons per pulse in the SPS North Area Hall 1. The hydrogen target will be gaseous, operating at 40 atm. pressure and acts as a multiwire proportional chamber to detect the recoil protons. The forward neutron will be detected and located by interaction in a neutron vertex detector and its energy measured by a conventional steel plate calorimeter. \\\\ \\\\ The experiment will cover the angular region of nucleon-nucleon scattering which is dominated by Coulomb scattering ...
Note: Optimization of magnifying a polarization angle with Littrow layout blazed gratings.
Sasao, H; Arakawa, H; Imazawa, R; Kawano, Y; Itami, K; Kubo, H
2017-03-01
Magnification of a polarization angle with Littrow layout gratings has been developed. High magnification with a factor of 7.7 using two gratings in Littrow layout was experimentally proved. The magnification range was investigated by calculation at a wavelength of 10.6 μm. The method can be applied for a high magnification factor >30. Larger groove numbers and smaller blaze angles are suitable for the large magnification. Statistical fluctuation of the diffracted polarization angle is compared with that of the incident polarization angle.
Angle closure glaucoma secondary to psychotropic medications
Directory of Open Access Journals (Sweden)
John Ross Rocke
2017-07-01
Full Text Available Background Psychotropic medications are commonly associated anticholinergic side-effects. In susceptible patients, this can result in angle closure induced permanent loss of vision Aims To review the mechanism of angle closure and which psychotropics are most likely to precipitate this complication. Methods Literature review surrounding the mechanism of angle closure and pharmacology of various psychotropics Results Mydriasis, forward-displacement of the lens-iris diaphragm and ciliary body swelling are the mechanisms by which angle closure occurs. Anticholinergic side effects of psychotropic medications are most implicated in causing this. Conclusion Screening patients for risk factors of angle closure and either having them formally assessed or choosing psychotropics with minimal anticholinergic effects may avoid inducing angle closure.
Uncertainty incorporated beam angle optimization for IMPT treatment planning.
Cao, Wenhua; Lim, Gino J; Lee, Andrew; Li, Yupeng; Liu, Wei; Ronald Zhu, X; Zhang, Xiaodong
2012-08-01
Beam angle optimization (BAO) by far remains an important and challenging problem in external beam radiation therapy treatment planning. Conventional BAO algorithms discussed in previous studies all focused on photon-based therapies. Impact of BAO on proton therapy is important while proton therapy increasingly receives great interests. This study focuses on potential benefits of BAO on intensity-modulated proton therapy (IMPT) that recently began available to clinical cancer treatment. The authors have developed a novel uncertainty incorporated BAO algorithm for IMPT treatment planning in that IMPT plan quality is highly sensitive to uncertainties such as proton range and setup errors. A linear programming was used to optimize robust intensity maps to scenario-based uncertainties for an incident beam angle configuration. Unlike conventional intensity-modulated radiation therapy with photons (IMXT), the search space for IMPT treatment beam angles may be relatively small but optimizing an IMPT plan may require higher computational costs due to larger data size. Therefore, a deterministic local neighborhood search algorithm that only needs a very limited number of plan objective evaluations was used to optimize beam angles in IMPT treatment planning. Three prostate cancer cases and two skull base chordoma cases were studied to demonstrate the dosimetric advantages and robustness of optimized beam angles from the proposed BAO algorithm. Two- to four-beam plans were optimized for prostate cases, and two- and three-beam plans were optimized for skull base cases. By comparing plans with conventional two parallel-opposed angles, all plans with optimized angles consistently improved sparing at organs at risks, i.e., rectum and femoral heads for prostate, brainstem for skull base, in either nominal dose distribution or uncertainty-based dose distributions. The efficiency of the BAO algorithm was demonstrated by comparing it with alternative methods including simulated
The Ranging and Nanosatellite Guidance Experiment (RANGE)
Gunter, Brian C.; Davis, Byron; Lightsey, Glenn; Braun, Robert D.
2016-01-01
The Ranging And Nanosatellite Guidance Experiment (RANGE) cubesat mission was recently selected for a flight opportunity as part of the Skybox University Cubesat Partnership, with a tentative launch date scheduled for 2016. The RANGE mission involves two 1.5U cubesats flying in a leader-follower formation with the goal of improving the relative and absolute positioning capabilities of nanosatellites. The satellites' absolute positions will be tracked using GPS receivers synchronized with mini...
The equivalent incidence angle for porous absorbers backed by a hard surface
DEFF Research Database (Denmark)
Jeong, Cheol-Ho; Brunskog, Jonas
2013-01-01
experiment using a free-field absorption measurement technique with a source at the equivalent angle. This study investigates the equivalent angle for locally and extendedly reacting porous media mainly by a numerical approach: Numerical minimizations of a cost function that is the difference between...... coefficients by free-field techniques, a broad incidence angle range can be suggested: 20 hi65 for extended reaction and hi65 for locally reacting porous absorbers, if an average difference of 0.05 is allowed.......An equivalent incidence angle is defined as the incidence angle at which the oblique incidence absorption coefficient best approximates the random incidence absorption coefficient. Once the equivalent angle is known, the random incidence absorption coefficient can be estimated by a single...
Direct angle resolved photoemission spectroscopy and ...
Indian Academy of Sciences (India)
Keywords. Condensed matter physics; high-c superconductivity; electronic properties; photoemission spectroscopy; angle resolved photoemission spectroscopy; cuprates; films; strain; pulsed laser deposition.
The qualitative criterion of transient angle stability
DEFF Research Database (Denmark)
Lyu, R.; Xue, Y.; Xue, F.
2015-01-01
In almost all the literatures, the qualitative assessment of transient angle stability extracts the angle information of generators based on the swing curve. As the angle (or angle difference) of concern and the threshold value rely strongly on the engineering experience, the validity and robust...... of these criterions are weak. Based on the stability mechanism from the extended equal area criterion (EEAC) theory and combining with abundant simulations of real system, this paper analyzes the criterions in most literatures and finds that the results could be too conservative or too optimistic. It is concluded...
Effect of Chamfer Angle on the Calibration Curves of Five Hole Probes
Directory of Open Access Journals (Sweden)
Nekkanti Sitaram
2014-01-01
Full Text Available Five hole probes are extensively used for measurement of total and static pressures, flow angles, velocity and its components in turbomachinery, and other aerodynamic flows. Their operating range is usually limited to 30–40° depending on the type of the probe head. The chamfer angle of the probe is usually taken around 45°. Recent studies on three hole probes have shown that 30° chamfer angle is desirable for unsteady flow measurements. Hence the present investigation is undertaken to find the optimum chamfer angle of five-hole probes. A special five-hole probe of 9.6 mm head diameter and 3 mm diameter pressure take off tubes was designed and fabricated. The large size of the probe was chosen to minimize machining inaccuracies. The probe chamfer angle was varied from 30° to 60° in 5° steps. For each of the chamfer angles, the probe was calibrated in the range of −30° to +30° in 5° interval and the calibration curves are presented. In addition the sensitivities of the calibration coefficients are determined. It is concluded that five-hole probe with a chamfer angle 30° has large operating range, while five-hole probe with a chamfer angle of 50° has good sensitivity.
Large Solid Angle Spectrometer for Inelastic X-ray Scattering
International Nuclear Information System (INIS)
Gelebart, F.; Morand, M.; Dermigny, Q.; Giura, P.; Shukla, A.; Rueff, J.-P.
2007-01-01
We have designed a large solid angle spectrometer mostly devoted to inelastic x-ray scattering (IXS) studies of materials under extreme conditions (high pressure / temperature) in the hard x-ray range. The new IXS spectrometer is designed to optimize the photon throughput while preserving an excellent resolving power of ∼10000 in the considered energy range. The spectrometer consists of an array of up to 4 spherically bent 0.5 m radius analyzer crystals and a solid-state detector positioned on the Rowland circle. The four analyzers can cover a solid angle more than one order of magnitude larger than conventional spectrometers. The spectrometer is to be installed on the GALAXIES beamline at SOLEIL in the near future
Oh, Joo Han; Shin, Sang-Jin; McGarry, Michelle H; Scott, Jonathan H; Heckmann, Nathanael; Lee, Thay Q
2014-08-01
The variability in functional outcomes and the occurrence of scapular notching and instability after reverse total shoulder arthroplasty remain problems. The objectives of this study were to measure the effect of reverse humeral component neck-shaft angle on impingement-free range of motion, abduction moment, and anterior dislocation force and to evaluate the effect of subscapularis loading on dislocation force. Six cadaveric shoulders were tested with 155°, 145°, and 135° reverse shoulder humeral neck-shaft angles. The adduction angle at which bone contact occurred and the internal and external rotational impingement-free range of motion angles were measured. Glenohumeral abduction moment was measured at 0° and 30° of abduction, and anterior dislocation forces were measured at 30° of internal rotation, 0°, and 30° of external rotation with and without subscapularis loading. Adduction deficit angles for 155°, 145°, and 135° neck-shaft angle were 2° ± 5° of abduction, 7° ± 4° of adduction, and 12° ± 2° of adduction (P angles of humeral rotation and abduction moments were not statistically different between the neck-shaft angles. The anterior dislocation force was significantly higher for the 135° neck-shaft angle at 30° of external rotation and significantly higher for the 155° neck-shaft angle at 30° of internal rotation (P angle was more prone to scapular bone contact during adduction but was more stable at the internally rotated position, which was the least stable humeral rotation position. Subscapularis loading gave further anterior stability with all neck-shaft angles at all positions. Published by Mosby, Inc.
Large optical field enhancement for nanotips with large opening angles
Thomas, Sebastian; Wachter, Georg; Lemell, Christoph; Burgdörfer, Joachim; Hommelhoff, Peter
2015-01-01
We theoretically investigate the dependence of the enhancement of optical near-fields at nanometric tips on the shape, size, and material of the tip. We confirm a strong dependence of the field enhancement factor on the radius of curvature. In addition, we find a surprisingly strong increase of field enhancement with increasing opening angle of the nanotips. For gold and tungsten nanotips in the experimentally relevant parameter range (radius of curvature $\\geq 5\\,$nm at $800\\,$nm laser wavel...
KWS-3: Very small angle scattering diffractometer with focusing mirror
Directory of Open Access Journals (Sweden)
Vitaliy Pipich
2015-08-01
Full Text Available KWS-3, which is operated by JCNS, Forschungszentrum Jülich, is a very small angle neutron scattering (VSANS instrument running on the focussing mirror principle. KWS-3 is designed to bridge the gap between Bonse-Hart and pinhole cameras. Owing to its extended Q range, optimized flux, and good wavelength resolution, KWS-3 has shown good performance and has become scientifically productive to the user community.
The diagnostic accuracy of Böhler's angle in fractures of the calcaneus.
Isaacs, Joseph D; Baba, Mohammed; Huang, Phil; Symes, Michael; Guzman, Maurice; Nandapalan, Haren; Moopanar, Terence; Marchalleck, Steve; Szomor, Zoltan
2013-12-01
Böhler's historical tuber-joint angle of the calcaneus has been used since 1931. Surprisingly, there is a paucity of literature on its use. To confirm the normal range for Böhler's angle and determine the angle with the highest accuracy in the diagnosis of calcaneal fractures. A retrospective cohort study was performed. The study cohort comprised 424 patients spanning a 5-year period from April 2005 to March 2010. Böhler's angle was measured by two independent observers on lateral x-ray study using the digital angle tool from the Picture Archival and Communication System. Data were analyzed using Stata 8 statistical software package. The mean Böhler's angle in patients without calcaneal fracture was 29.4°. In this group there was no difference in Böhler's angle between male and female patients, left and right feet, or across age. In those patients with calcaneal fractures, a Böhler's angle below 25° was moderately predictive of calcaneal fracture (sensitivity = 100%, specificity = 82%), an angle below 23° was highly predictive of calcaneal fracture (sensitivity = 100%, specificity = 89%), and an angle below 21° was strongly suggestive of calcaneal fracture (sensitivity = 99%, specificity = 99%). A Böhler's angle of ≤ 20° had the highest diagnostic accuracy. A Böhler's angle of 20° or less is highly accurate in determining the presence or absence of calcaneal fracture. Böhler's angle serves as a useful screening tool in fracture diagnosis. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.
Carpal angles as measured on CT and MRI: can we simply translate radiographic measurements?
International Nuclear Information System (INIS)
Tan, Stephanie; Ghumman, Simranjit S.; Moser, Thomas P.; Ladouceur, Martin
2014-01-01
To determine the reliability of carpal angles measured on CT and MRI compared to radiography and assess if these measurements are interchangeable. Our institutional ethic research committee approved this study. For this retrospective study, two independent observers measured the scapholunate (SL), capitolunate (CL), radiolunate (RL), and radioscaphoid (RS) angles on 21 sets of exams, with each set including a radiograph, CT, and MRI of the same wrist. Inter- and intra-observer agreements were evaluated with the intraclass correlation coefficient (ICC). Linear mixed models and two-way contingency tables were used to determine if the angles measured on cross-sectional modalities were significantly different from those obtained on radiography. Inter-observer agreement was strong (ICC >0.8) for all angles, except for the RL angle measured on MRI (ICC 0.68). Intra-observer agreement was also strong for all angles, except for the CL angle measured on CT (ICC 0.66). SL angles measured on CT and MRI were not statistically different from those measured on radiographs (p = 0.37 and 0.36, respectively), unlike CL, RL, and RS angles (p < 0.05). Accuracy between modalities varied between 76 and 86 % for the SL angle and ranged between 43 and 76 % for the other angles. CL, RL, and RS angles showed large intermodality variability. Therefore, their measurements on CT or MRI could potentially lead to miscategorization. Conversely, our data showing no significant difference between modalities, SL angle could be measured on CT and MRI to assess wrist instability with a lower risk of error. (orig.)
Hadron elastic scattering at small angles
2002-01-01
This experiment is an extension of the measurements of the WA9 experiment up to the highest energies available in the North Area. It will measure the differential cross-section for hadron elastic scattering in the t-range 0.002-0.05 (GeV/c)$^{2}$ using an ionization chamber for the measurement of the energy and the angle of the recoil and a magnet-WC spectrometer to measure the momentum and direction of the forward particle. From these measurements will be obtained the ratio $\\rho$ of the real to imaginary parts of the forward elastic amplitude and the exponential slope parameter b of the hadronic amplitude at small t. The precision expected in these measurements is $\\Delta \\rho \\approx \\pm 0.01$ and $\\Delta$b $\\approx \\pm 0.2$ (GeV/c)$^{-2}$. \\\\ \\\\ The experimental programme includes: \\\\\\\\ i) measurements of $\\rho$ and b for $\\pi$p elastic scattering at incident momenta between 150 GeV/c and 300 GeV/c; \\\\ ii) measurements of $\\rho$ and b for $\\pi^{+}$p and pp elastic scattering at incident momenta between 5...
Gaugings at angles from orientifold reductions
International Nuclear Information System (INIS)
Roest, Diederik
2009-01-01
We consider orientifold reductions to N= 4 gauged supergravity in four dimensions. A special feature of this theory is that different factors of the gauge group can have relative angles with respect to the electro-magnetic SL(2) symmetry. These are crucial for moduli stabilization and de Sitter vacua. We show how such gaugings at angles generically arise in orientifold reductions.
Custom total occlusal convergence angle sticker fabrication.
Cho, Seok-Hwan; Nagy, William W
2015-09-01
This article describes a method of fabricating a custom total occlusal convergence angle sticker with photo editing software and label stickers. The custom total occlusal convergence angle sticker can help clinicians achieve an accurate degree of taper during axial wall reduction of tooth preparation. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.
Practical evaluation of action-angle variables
International Nuclear Information System (INIS)
Boozer, A.H.
1984-02-01
A practical method is described for establishing action-angle variables for a Hamiltonian system. That is, a given nearly integrable Hamiltonian is divided into an exactly integrable system plus a perturbation in action-angle form. The transformation of variables, which is carried out using a few short trajectory integrations, permits a rapid determination of trajectory properties throughout a phase space volume
Acute angle closure glaucoma following ileostomy surgery
Directory of Open Access Journals (Sweden)
Mariana Meirelles Lopes
2015-02-01
Full Text Available Angle-closure glaucoma can be induced by drugs that may cause pupillary dilatation. We report a case of a patient that developed bilateral angle closure glaucoma after an ileostomy surgery because of systemic atropine injection. This case report highlights the importance of a fast ophthalmologic evaluation in diseases with ocular involvement in order to make accurate diagnoses and appropriate treatments.
Highly efficient and broadband wide-angle holography using patch-dipole nanoantenna reflectarrays.
Yifat, Yuval; Eitan, Michal; Iluz, Zeev; Hanein, Yael; Boag, Amir; Scheuer, Jacob
2014-05-14
We demonstrate wide-angle, broadband, and efficient reflection holography by utilizing coupled dipole-patch nanoantenna cells to impose an arbitrary phase profile on the reflected light. High-fidelity images were projected at angles of 45 and 20° with respect to the impinging light with efficiencies ranging between 40-50% over an optical bandwidth exceeding 180 nm. Excellent agreement with the theoretical predictions was found at a wide spectral range. The demonstration of such reflectarrays opens new avenues toward expanding the limits of large-angle holography.
Laser peripheral iridoplasty for angle-closure.
Ng, Wai Siene; Ang, Ghee Soon; Azuara-Blanco, Augusto
2012-02-15
Angle-closure glaucoma is a leading cause of irreversible blindness in the world. Treatment is aimed at opening the anterior chamber angle and lowering the IOP with medical and/or surgical treatment (e.g. trabeculectomy, lens extraction). Laser iridotomy works by eliminating pupillary block and widens the anterior chamber angle in the majority of patients. When laser iridotomy fails to open the anterior chamber angle, laser iridoplasty may be recommended as one of the options in current standard treatment for angle-closure. Laser peripheral iridoplasty works by shrinking and pulling the peripheral iris tissue away from the trabecular meshwork. Laser peripheral iridoplasty can be used for crisis of acute angle-closure and also in non-acute situations. To assess the effectiveness of laser peripheral iridoplasty in the treatment of narrow angles (i.e. primary angle-closure suspect), primary angle-closure (PAC) or primary angle-closure glaucoma (PACG) in non-acute situations when compared with any other intervention. In this review, angle-closure will refer to patients with narrow angles (PACs), PAC and PACG. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 12), MEDLINE (January 1950 to January 2012), EMBASE (January 1980 to January 2012), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to January 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 5 January 2012. We included only randomised controlled trials (RCTs) in this review. Patients with narrow angles, PAC or PACG were eligible. We excluded studies that included only patients with acute presentations
Limited flip angle MR imaging: Hemorrhagic applications
International Nuclear Information System (INIS)
Drayer, B.P.; Rigamonti, D.; Johnson, P.C.; Spetzler, R.F.; Keller, P.J.; Flom, R.A.; Bird, C.R.; Hodak, J.A.
1987-01-01
The authors studied 64 patients with hemorrhagic brain lesions, including vascular malformations (n = 29), hemorrhagic infarctions (n = 9), chronic slit hemorrhagic residua of hypertensive hematoma (n = 10), trauma (n = 8), and gliobastoma multiforme (n = 8). With a 1.5-T MR imaging system, 5-mm sections were obtained at a repetition time of 300 msec (or 500), an echo time of 12.3 msec (or 10 and 40), and a flip angle of 60 0 (or 20 0 ). The limited flip angle study was always extremely sensitive for the detection of hemosiderin. With multiple cavernous angiomas, additional small lesions (in five of 18 patients) were detected only with the limited flip angle technique. The hemosiderin-laden macrophage residua of hemorrhagic infarction and hypertensive hematoma were better seen on limited flip angle images than on T2-weighted spin-echo images. The detection of blood on limited flip angle images permitted the grading of glioma as glioblastoma multiforme
Experimental study of crossing angle collision
International Nuclear Information System (INIS)
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 (∼12mrad) crossing angle is to excite 5Q x ±Q s =integer coupling resonance family on large amplitude particles, which results in bad lifetime. On the CESR, a small crossing angle (∼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
Experimental study of crossing angle collision
International Nuclear Information System (INIS)
Chen, T.; Rice, D.; Rubin, D.; Sagan, D.; Tigner, M.
1993-01-01
The non-linear coupling due to the beam-beam interaction with crossing angle has been studied. The major effect of a small (∼12mrad) crossing angle is to excite 5Q x ±Q s =integer coupling resonance family on large amplitude particles, which results in bad lifetime. On the CESR, a small crossing angle (∼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
Guler, Olcay; Isyar, Mehmet; Karataş, Dilek; Ormeci, Tugrul; Cerci, Halis; Mahirogulları, Mahir
2016-11-15
We aimed to search whether alpha angle, a radiological clue used in the diagnosis of femoroacetabular impingement, is correlated with the presence of hip pain, internal rotation angle, and impingement test results on hip impingement patients (CAM type). Medical records of 334 patients (156 women, 178 men) with an average age of 33.8 ± 8.4 (range 20-50) years were retrospectively studied for the alpha angle of the hip measured on magnetic resonance images (MRI). Hip pain and internal rotation angles as well as results of impingement tests were reviewed. Hip pain was reported more frequently on the right side (n = 35, 10.5%) compared to the left side (n = 22, 6.6%) (p = 0.047). No difference was observed between the right and left sides regarding alpha angles (p = 0.145), internal rotation angles (p = 0.637), or positivity of impingement test (p = 0.210). Internal rotation angles were significantly higher in cases without hip pain (p < 0.001) and in patients with negative impingement test result (p < 0.001). Internal rotation angle correlated positively with age and negatively with the alpha angle. Alpha angle was increased in cases that report pain, those with an internal rotation angle <20°, or cases with positive impingement test. The pain was more common, internal rotation angle was higher, and positivity for impingement was more frequent if the alpha angle was <55°. Patients with hip pain or positive impingement test or internal rotation angle <20° had increased alpha angles (p < 0.001). The pain, impingement test results, and internal rotation angle seem to be associated with alpha angle of the hip measured on MRI in hip impingement patients.
Nutcracker and SMA syndromes: What is the normal SMA angle in children?
International Nuclear Information System (INIS)
Arthurs, O.J.; Mehta, U.; Set, P.A.K.
2012-01-01
Objective: The nutcracker and superior mesenteric artery (SMA) syndromes are rare conditions where the left renal vein or duodenum may be compressed by an unusually acute angle between the SMA and aorta, although the normal angle in children is unknown. We measured the SMA angle to define the normal range in children. Methods: We retrospectively measured SMA angles, left renal vein (LRV) distance, and duodenal distance (DD) in 205 consecutive pediatric abdominal CT. Total and visceral intra-abdominal fat at the level of the umbilicus were also assessed. Results: Mean SMA angle was 45.6 ± 19.6° (range 10.6–112.9°), mean LRV distance was 8.6 ± 3.9 mm (range 2.0–28.6 mm) and mean DD was 11.3 ± 4.8 mm (range 3.6–35.3 mm). There was a significant but weak correlation between %visceral fat volume (%VF) and SMA angle (R = 0.30; p < 0.001), LRV distance (R = 0.37, p < 0.001) and DD (R = 0.32; p < 0.001). Conclusion: There is a wide range of SMA angle, LRV and DD in normal children, which correlated weakly with visceral fat volume. Using a definition of SMA angle <25° would diagnose 9.3% of asymptomatic children with nutcracker syndrome, and using a DD definition of <8 mm would diagnose 20% with SMA compression. Our findings suggest exercising caution when attributing these rare syndromes to an absolute SMA angle.
Nutcracker and SMA syndromes: What is the normal SMA angle in children?
Energy Technology Data Exchange (ETDEWEB)
Arthurs, O.J., E-mail: oja20@owenarthurs.co.uk [Department of Radiology, Box 219, Addenbrooke' s Hospital, Cambridge University Teaching Hospitals NHS Foundation Trust, Hills Road, Cambridge, CB2 0QQ (United Kingdom); Mehta, U. [Department of Radiology, Box 219, Addenbrooke' s Hospital, Cambridge University Teaching Hospitals NHS Foundation Trust, Hills Road, Cambridge, CB2 0QQ (United Kingdom); Set, P.A.K., E-mail: p.set@addenbrookes.nhs.uk [Department of Radiology, Box 219, Addenbrooke' s Hospital, Cambridge University Teaching Hospitals NHS Foundation Trust, Hills Road, Cambridge, CB2 0QQ (United Kingdom)
2012-08-15
Objective: The nutcracker and superior mesenteric artery (SMA) syndromes are rare conditions where the left renal vein or duodenum may be compressed by an unusually acute angle between the SMA and aorta, although the normal angle in children is unknown. We measured the SMA angle to define the normal range in children. Methods: We retrospectively measured SMA angles, left renal vein (LRV) distance, and duodenal distance (DD) in 205 consecutive pediatric abdominal CT. Total and visceral intra-abdominal fat at the level of the umbilicus were also assessed. Results: Mean SMA angle was 45.6 {+-} 19.6 Degree-Sign (range 10.6-112.9 Degree-Sign ), mean LRV distance was 8.6 {+-} 3.9 mm (range 2.0-28.6 mm) and mean DD was 11.3 {+-} 4.8 mm (range 3.6-35.3 mm). There was a significant but weak correlation between %visceral fat volume (%VF) and SMA angle (R = 0.30; p < 0.001), LRV distance (R = 0.37, p < 0.001) and DD (R = 0.32; p < 0.001). Conclusion: There is a wide range of SMA angle, LRV and DD in normal children, which correlated weakly with visceral fat volume. Using a definition of SMA angle <25 Degree-Sign would diagnose 9.3% of asymptomatic children with nutcracker syndrome, and using a DD definition of <8 mm would diagnose 20% with SMA compression. Our findings suggest exercising caution when attributing these rare syndromes to an absolute SMA angle.
Effect of interface shape on advancing and receding fluid-contact angles around spherical particles.
Şenbil, Nesrin; He, Wei; Démery, Vincent; Dinsmore, Anthony D
2015-07-07
The angle of contact between a solid surface and a fluid interface plays a key role in wetting and is therefore a focus in studies of a wide range of natural phenomena and fluidic technologies. The contact angle ranges between two values, a maximum (advancing) angle and a minimum (receding) angle. These limiting angles are thought to be properties of the fluids and of the chemistry or topography of the solid. By contrast, we find that the value of the receding angle can be significantly reduced by altering the interface shape. Using millimeter-sized spheres coated with polydimethylsiloxane and pulled through an air-water interface, we observe that the receding angle decreases from 101 ± 1° at a planar interface to as low as 80 ± 1° at saddle- or cylinder-shaped interfaces. The angle decreases smoothly with the deviatoric curvature of the interface (a measure of the shape anisotropy) and is linked to a non-circular contact line.
In situ beam angle measurement in a multi-wafer high current ion implanter
International Nuclear Information System (INIS)
Freer, B.S.; Reece, R.N.; Graf, M.A.; Parrill, T.; Polner, D.
2005-01-01
Direct, in situ measurement of the average angle and angular content of an ion beam in a multi-wafer ion implanter is reported for the first time. A new type of structure and method are described. The structures are located on the spinning disk, allowing precise angular alignment to the wafers. Current that passes through the structures is known to be within a range of angles and is detected behind the disk. By varying the angle of the disk around two axes, beam current versus angle is mapped and the average angle and angular spread are calculated. The average angle measured in this way is found to be consistent with that obtained by other techniques, including beam centroid offset and wafer channeling methods. Average angle of low energy beams, for which it is difficult to use other direct methods, is explored. A 'pencil beam' system is shown to give average angle repeatability of 0.13 deg. (1σ) or less, for two low energy beams under normal tuning variations, even though no effort was made to control the angle
Use of an amorphous silicon EPID for measuring MLC calibration at varying gantry angle
International Nuclear Information System (INIS)
Clarke, M F; Budgell, G J
2008-01-01
Amorphous silicon electronic portal imaging devices (EPIDs) are used to perform routine quality control (QC) checks on the multileaf collimators (MLCs) at this centre. Presently, these checks are performed at gantry angle 0 0 and are considered to be valid for all other angles. Since therapeutic procedures regularly require the delivery of MLC-defined fields to the patient at a wide range of gantry angles, the accuracy of the QC checks at other gantry angles has been investigated. When the gantry is rotated to angles other than 0 0 it was found that the apparent pixel size measured using the EPID varies up to a maximum value of 0.0015 mm per pixel due to a sag in the EPID of up to 9.2 mm. A correction factor was determined using two independent methods at a range of gantry angles between 0 deg. and 360 deg. The EPID was used to measure field sizes (defined by both x-jaws and MLC) at a range of gantry angles and, after this correction had been applied, any residual gravitational sag was studied. It was found that, when fields are defined by the x-jaws and y-back-up jaws, no errors of greater than 0.5 mm were measured and that these errors were no worse when the MLC was used. It was therefore concluded that, provided the correction is applied, measurements of the field size are, in practical terms, unaffected by gantry angle. Experiments were also performed to study how the reproducibility of individual leaves is affected by gantry angle. Measurements of the relative position of each individual leaf (minor offsets) were performed at a range of gantry angles and repeated three times. The position reproducibility was defined by the RMS error in the position of each leaf and this was found to be 0.24 mm and 0.21 mm for the two leaf banks at a gantry angle of 0 0 . When measurements were performed at a range of gantry angles, these reproducibility values remained within 0.09 mm and 0.11 mm. It was therefore concluded that the calibration of the Elekta MLC is stable at
Energy Technology Data Exchange (ETDEWEB)
Sampoorna, M.; Nagendra, K. N. [Indian Institute of Astrophysics, Koramangala, Bengaluru 560 034 (India); Stenflo, J. O., E-mail: sampoorna@iiap.res.in, E-mail: knn@iiap.res.in, E-mail: stenflo@astro.phys.ethz.ch [Institute of Astronomy, ETH Zurich, CH-8093 Zurich (Switzerland)
2017-08-01
Magnetic fields in the solar atmosphere leave their fingerprints in the polarized spectrum of the Sun via the Hanle and Zeeman effects. While the Hanle and Zeeman effects dominate, respectively, in the weak and strong field regimes, both these effects jointly operate in the intermediate field strength regime. Therefore, it is necessary to solve the polarized line transfer equation, including the combined influence of Hanle and Zeeman effects. Furthermore, it is required to take into account the effects of partial frequency redistribution (PRD) in scattering when dealing with strong chromospheric lines with broad damping wings. In this paper, we present a numerical method to solve the problem of polarized PRD line formation in magnetic fields of arbitrary strength and orientation. This numerical method is based on the concept of operator perturbation. For our studies, we consider a two-level atom model without hyperfine structure and lower-level polarization. We compare the PRD idealization of angle-averaged Hanle–Zeeman redistribution matrices with the full treatment of angle-dependent PRD, to indicate when the idealized treatment is inadequate and what kind of polarization effects are specific to angle-dependent PRD. Because the angle-dependent treatment is presently computationally prohibitive when applied to realistic model atmospheres, we present the computed emergent Stokes profiles for a range of magnetic fields, with the assumption of an isothermal one-dimensional medium.
Modified angle's classification for primary dentition
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Kaushik Narendra Chandranee
2017-01-01
Full Text Available Aim: This study aims to propose a modification of Angle's classification for primary dentition and to assess its applicability in children from Central India, Nagpur. Methods: Modification in Angle's classification has been proposed for application in primary dentition. Small roman numbers i/ii/iii are used for primary dentition notation to represent Angle's Class I/II/III molar relationships as in permanent dentition, respectively. To assess applicability of modified Angle's classification a cross-sectional preschool 2000 children population from central India; 3–6 years of age residing in Nagpur metropolitan city of Maharashtra state were selected randomly as per the inclusion and exclusion criteria. Results: Majority 93.35% children were found to have bilateral Class i followed by 2.5% bilateral Class ii and 0.2% bilateral half cusp Class iii molar relationships as per the modified Angle's classification for primary dentition. About 3.75% children had various combinations of Class ii relationships and 0.2% children were having Class iii subdivision relationship. Conclusions: Modification of Angle's classification for application in primary dentition has been proposed. A cross-sectional investigation using new classification revealed various 6.25% Class ii and 0.4% Class iii molar relationships cases in preschool children population in a metropolitan city of Nagpur. Application of the modified Angle's classification to other population groups is warranted to validate its routine application in clinical pediatric dentistry.
Patellar angle in Osgood-Schlatter disease.
Sen, R K; Sharma, L R; Thakur, S R; Lakhanpal, V P
1989-02-01
A new patellar angle is described in lateral radiographs of the knee joint. One line is drawn along the articular surface of the patella and another from the end of the inferior articular cartilage to the patellar apex. The angle formed by these two lines averaged 33 degrees in 68 knees joints afflicted with Osgood-Schlatter disease and 47 degrees in 71 age-matched controls and 198 adult controls. The small angle in Osgood-Schlatter disease is proposed to be an important factor in the pathogenesis of the traction apophysitis.
Small-angle scattering on soft materials
International Nuclear Information System (INIS)
Mortensen, K.
1994-01-01
Small angle x-ray and neutron scattering provides tools for investigation of structures on the length scale 10 to 1000 A. This is the length scale which is relevant for many topics within soft materials, like biological macromolecules, polymers, colloids, etc. The very large difference between the scattering amplitude of neutrons by regular hydrogen and deuterium makes neutron scattering a very important technique within soft condensed matter. The basic theory for small angle scattering is reviewed. Experimental results obtained by small angle scattering are shown, with emphasis on soft materials. (author). 33 refs, 6 figs, 1 tab
Computing angle of arrival of radio signals
Borchardt, John J.; Steele, David K.
2017-11-07
Various technologies pertaining to computing angle of arrival of radio signals are described. A system that is configured for computing the angle of arrival of a radio signal includes a cylindrical sheath wrapped around a cylindrical object, where the cylindrical sheath acts as a ground plane. The system further includes a plurality of antennas that are positioned about an exterior surface of the cylindrical sheath, and receivers respectively coupled to the antennas. The receivers output measurements pertaining to the radio signal. A processing circuit receives the measurements and computes the angle of arrival of the radio signal based upon the measurements.
Signal Waveforms and Range/Angle Coupling in Coherent Colocated MIMO Radar
2014-10-09
transmit. For instance, if the transmitted pulse is a chirp, then we can set Nc = 1 and use a chirp for elementary pulse u(t). Using the vectorial ...notation, the transmitted signal can be expressed as: s(t) = (W ◦ F(t))u(t), where ◦ represents the Hadamard product , W and F(t) are matrices of size NE
Rapid emission angle selection for rotating-shield brachytherapy
International Nuclear Information System (INIS)
Liu, Yunlong; Flynn, Ryan T.; Kim, Yusung; Bhatia, Sudershan K.; Sun, Wenqing; Yang Wenjun; Wu Xiaodong
2013-01-01
Purpose: The authors present a rapid emission angle selection (REAS) method that enables the efficient selection of the azimuthal shield angle for rotating shield brachytherapy (RSBT). The REAS method produces a Pareto curve from which a potential RSBT user can select a treatment plan that balances the tradeoff between delivery time and tumor dose conformity. Methods: Two cervical cancer patients were considered as test cases for the REAS method. The RSBT source considered was a Xoft Axxent TM electronic brachytherapy source, partially shielded with 0.5 mm of tungsten, which traveled inside a tandem intrauterine applicator. Three anchor RSBT plans were generated for each case using dose-volume optimization, with azimuthal shield emission angles of 90°, 180°, and 270°. The REAS method converts the anchor plans to treatment plans for all possible emission angles by combining neighboring beamlets to form beamlets for larger emission angles. Treatment plans based on exhaustive dose-volume optimization (ERVO) and exhaustive surface optimization (ERSO) were also generated for both cases. Uniform dwell-time scaling was applied to all plans such that that high-risk clinical target volume D 90 was maximized without violating the D 2cc tolerances of the rectum, bladder, and sigmoid colon. Results: By choosing three azimuthal emission angles out of 32 potential angles, the REAS method performs about 10 times faster than the ERVO method. By setting D 90 to 85–100 Gy 10 , the delivery times used by REAS generated plans are 21.0% and 19.5% less than exhaustive surface optimized plans used by the two clinical cases. By setting the delivery time budget to 5–25 and 10–30 min/fx, respectively, for two the cases, the D 90 contributions for REAS are improved by 5.8% and 5.1% compared to the ERSO plans. The ranges used in this comparison were selected in order to keep both D 90 and the delivery time within acceptable limits. Conclusions: The REAS method enables efficient RSBT
Dependance of sputtering yield on incident angle for ion beam
Energy Technology Data Exchange (ETDEWEB)
Tanizaki, Hironori; Ooba, Hikaru; Masuhara, Kenichi
1987-07-01
The relationship between sputtering yeild (S/sub theta/) and the incident angle (theta) of an ion beam to some metals such as Fe, Ni, Zn and SUS304, was studied by Ion Micro Analyzer (IMA). It was confirmed that S/sub theta/ varied as a function of (costheta)/sup -f/. The value of f was differed with each sample, and ranged from 1.0 to 1.5 in this study. As theta increased, the surface roughness of the sputtered samples became greater, and the depth resolution of the depth profile became worse. It is necessary to pay attention to depth resolution, when various data concerning different incident angles are compared.
Resolution of pulsed-source small-angle neutron scattering
International Nuclear Information System (INIS)
Seeger, P.A.; Pynn, R.
1986-01-01
An analytic form is found for resolution of small-angle scattering in a plane, at a pulsed source with a white neutron spectrum. The function is found to be asymmetric at low values of Q and to have broad tails if data recorded over the entire wavelength range are combined. Monte Carlo calculations in three dimensions and including realistic spectra and collimator geometry confirm these features and provide ''data'' for studying the question of what regions of scattering angle and wavelength should be retained in data reduction. Comparisons are made with a spectrometer at a reactor, based on the accuracy, statistical precision, and time required to collect data for (simulated) monodisperse hard spheres of various radii. (orig.)
Bohler′s and Gissane Angles in the Indian Population
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Vetrivel C Sengodan
2012-01-01
Full Text Available Objective: The aim of our study is to determine the normal ranges of the calcaneal parameters in the Indian population, and to compare the results with the data in the literature. Materials and Methods: The study was conducted at Coimbatore Medical College Hospital, Coimbatore on the feet (324 in number of male and female Indian adults. Lateral view of the ankle was taken using a digital X-ray machine. Two parameters namely Bohler`s and Gissane angles were measured, independently by two radiologists to prevent inter-observer variation. Results: The Bohler`s and Gissane angles for the Indian population are statistically different from those seen in the published data for other population groups, as evidenced by the P value ( P < 0.05. Conclusion: Calcaneal parameters specific to the Indian population have to be taken into consideration by the orthopedic surgeon to improve the standard of calcaneal fracture treatment in India.
Crystalline misfit-angle implications for solid sliding
International Nuclear Information System (INIS)
Manini, Nicola; Braun, O.M.
2011-01-01
For the contact of two finite portions of interacting rigid crystalline surfaces, we compute the pinning energy barrier dependency on the misfit angle and contact area. This simple model allows us to investigate a broad contact-size and angular range, thus obtaining the statistical properties of the energy barriers opposing sliding for a single asperity. These data are used to generate the distribution of static frictional thresholds for the contact of polycrystals, as in dry or even lubricated friction. This distribution is used as the input of a master equation to predict the sliding properties of macroscopic contacts. -- Highlights: → The pinning energy barrier depends on the misfit angle and contact area. → We compute this dependence for a idealized rigid model. → We obtain a distribution of static frictional thresholds. → It is used as input of a master-equation model for macroscopic surfaces in contact. → Overall we predict a transition from stick-slip to smooth sliding.
GAIA basic angle monitoring system
Gielesen, W.; de Bruijn, D.; van den Dool, T.; Kamphues, F.; Meijer, E.; Braam, B. C.
2017-11-01
GAIA1 is a global space astrometry mission, successor to the Hipparcos mission, launched in 1989. The GAIA spacecraft is being built by EADS Astrium France and is scheduled for launch in 2013. At a distance of 1.5 million km from Earth at Lagrangian point L2, slowly spinning around its axis, GAIA will monitor each target star about 100 times over a 5- year period, precisely measuring its distance, movement, and change in brightness. Through spectrophotometric classification, it will provide the detailed physical properties of each star observed: luminosity, temperature, gravity, and elemental composition. This massive stellar census will provide the basic data to tackle an enormous range of important questions related to the origin, structure, and evolutionary history of our Galaxy. The measurements performed with GAIA will be accurate to 24 microarcsec, about 100 times more accurate than Hipparcos. To achieve this extreme accuracy at an operational temperature of 100 K, the entire GAIA Payload is made out of Silicon Carbide (SiC).
Angles-Only Navigation System for Nanosatellites
National Aeronautics and Space Administration — The objective of the proposed work is to develop and implement an angles-only relative navigation system on hardware suitable for deployment on nanosatellites or...
International Nuclear Information System (INIS)
Torrianni, I.L.
1983-01-01
The theoretical and experimental problems appearing in diffraction experiments at very low angles by several kinds of materials are discussed. The importance of synchrotron radiation in such problems is shown. (L.C.) [pt
Development of a body joint angle measurement system using IMU sensors.
Bakhshi, Saba; Mahoor, Mohammad H; Davidson, Bradley S
2011-01-01
This paper presents an approach for measuring and monitoring human body joint angles using inertial measurement unit (IMU) sensors. This type of monitoring is beneficial for therapists and physicians because it facilitates remote assessment of patient activities. In our approach, two IMUs are mounted on the upper leg and the lower leg to measure the Euler angles of each segment. The Euler angles are sent via Bluetooth protocols to a pc for calculating the knee joint angle. In our experiments, we utilized a motion capture system to accurately measure the knee joint angle and used this as the ground truth to assess the accuracy of the IMU system. The range of average error of the system across a variety of motion trials was 0.08 to 3.06 degrees. In summary, the accuracy of the IMU measurement system currently outperforms existing wearable systems such as conductive fiber optic sensors and flex-sensors.
Prompt angle measurements with large aperture scintillators
International Nuclear Information System (INIS)
Schneid, E.J.
1976-01-01
A technique is described for the measurement of particle trajectory angle through a pair of scintillator tiles. Signal processing provides an analog signal proportional to the tangent of the angle between the particle trajectory and the axis normal to the pair of tiles. This signal is readily available for use in fast decision logic if required: i.e., sorting energy loss signals from the tiles according to geometrical factors or restricting the events to be analyzed on the basis of incident direction
Small-angle neutron-scattering experiments
International Nuclear Information System (INIS)
Hardy, A.D.; Thomas, M.W.; Rouse, K.D.
1981-04-01
A brief introduction to the technique of small-angle neutron scattering is given. The layout and operation of the small-angle scattering spectrometer, mounted on the AERE PLUTO reactor, is also described. Results obtained using the spectrometer are presented for three materials (doped uranium dioxide, Magnox cladding and nitrided steel) of interest to Springfields Nuclear Power Development Laboratories. The results obtained are discussed in relation to other known data for these materials. (author)
Axial vector mass spectrum and mixing angles
International Nuclear Information System (INIS)
Caffarelli, R.V.; Kang, K.
1976-01-01
Spectral sum rules of the axial-vector current and axial-vector current-pseudoscalar field are used to study the axial-vector mass spectrum and mixing angles, as well as the decay constants and mixing angles of the pseudoscalar mesons. In general, the result is quite persuasive for the existence of the Jsup(PC) = 1 ++ multiplet in which one has a canonical D-E mixing. (Auth.)
Estimation of continuous thumb angle and force using electromyogram classification
Directory of Open Access Journals (Sweden)
Abdul Rahman Siddiqi
2016-09-01
Full Text Available Human hand functions range from precise minute handling to heavy and robust movements. Remarkably, 50% of all hand functions are made possible by the thumb. Therefore, developing an artificial thumb that can mimic the actions of a real thumb precisely is a major achievement. Despite many efforts dedicated to this area of research, control of artificial thumb movements in resemblance to our natural movement still poses as a challenge. Most of the development in this area is based on discontinuous thumb position control, which makes it possible to recreate several of the most important functions of the thumb but does not result in total imitation. This work looks into the classification of electromyogram signals from thumb muscles for the prediction of thumb angle and force during flexion motion. For this purpose, an experimental setup is developed to measure the thumb angle and force throughout the range of flexion and simultaneously gather the electromyogram signals. Further, various features are extracted from these signals for classification and the most suitable feature set is determined and applied to different classifiers. A “piecewise discretization” approach is used for continuous angle prediction. Breaking away from previous research studies, the frequency-domain features performed better than the time-domain features, with the best feature combination turning out to be median frequency–mean frequency–mean power. As for the classifiers, the support vector machine proved to be the most accurate classifier giving about 70% accuracy for both angle and force classification and close to 50% for joint angle–force classification.
Howard, Richard T.; Briscoe, Jeri M.; Corder, Eric L.; Broderick, David
2006-01-01
Optoelectronic sensors of a proposed type would perform the functions of both electronic cameras and triangulation- type laser range finders. That is to say, these sensors would both (1) generate ordinary video or snapshot digital images and (2) measure the distances to selected spots in the images. These sensors would be well suited to use on robots that are required to measure distances to targets in their work spaces. In addition, these sensors could be used for all the purposes for which electronic cameras have been used heretofore. The simplest sensor of this type, illustrated schematically in the upper part of the figure, would include a laser, an electronic camera (either video or snapshot), a frame-grabber/image-capturing circuit, an image-data-storage memory circuit, and an image-data processor. There would be no moving parts. The laser would be positioned at a lateral distance d to one side of the camera and would be aimed parallel to the optical axis of the camera. When the range of a target in the field of view of the camera was required, the laser would be turned on and an image of the target would be stored and preprocessed to locate the angle (a) between the optical axis and the line of sight to the centroid of the laser spot.
Schreurs, Mervin J; Benjaminse, Anne; Lemmink, Koen A P M
2017-10-03
Cutting is an important skill in team-sports, but unfortunately is also related to non-contact ACL injuries. The purpose was to examine knee kinetics and kinematics at different cutting angles. 13 males and 16 females performed cuts at different angles (45°, 90°, 135° and 180°) at maximum speed. 3D kinematics and kinetics were collected. To determine differences across cutting angles (45°, 90°, 135° and 180°) and sex (female, male), a 4×2 repeated measures ANOVA was conducted followed by post hoc comparisons (Bonferroni) with alpha level set at α≤0.05a priori. At all cutting angles, males showed greater knee flexion angles than females (pknee flexion -42.53°±8.95°, females decreased their knee flexion angle from -40.6°±7.2° when cutting at 45° to -36.81°±9.10° when cutting at 90°, 135° and 180° (pKnee flexion moment decreased for both sexes when cutting towards sharper angles (pknee valgus moments than females. For both sexes, knee valgus moment increased towards the sharper cutting angles and then stabilized compared to the 45° cutting angle (pknee kinematics and kinetics. Sharper cutting angles place the knee more at risk. However, females and males handle this differently, which has implications for injury prevention. Copyright © 2017 Elsevier Ltd. All rights reserved.
The Böhler’s angle in population of central Serbia - a radiological study
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Živanović-Mačužić Ivana
2018-01-01
Full Text Available Background/Aim. The values of the Böhler’s angle (BA are relevant parameters for diagnosis, management and prognosis of the calcaneal fracture and the outcome. Range of normal values of Böhler’s angle (BA in adults varies depending on the examined population, age, gender or ethnicity. The aim of this study was to determine the range of normal values of the Böhler’s angle in the central part of Serbia. Methods. The lateral foot radiographs of 225 subjects (111 males and 114 females without calcaneal fractures, divided into 6 age groups were observed to determine the normal values of the Böhler’s angle by using the IMPAX 6.5.2.114 Enterprise software. Obtained values for Böhler’s angle were compared among gender and groups using appropriate statistical tests. Results. The mean of Böhler’s angle in observed population was 34.06°, ranging from 25.1° to 49.5° and was higher in males than in females included in our study. Gender difference was statistically significant. The distribution of the mean BA across the age groups showed tendency of decreasing with age and the highest BA was found in the youngest group. Conclusion. The findings presented in this paper confirmed the existence of wide range of BA values as well as its gender and age differences.
Design and simulation of betavoltaic angle sensor Based on 63Ni–Si
International Nuclear Information System (INIS)
Ghasemi Nejad, Gholam Reza; Rahmani, Faezeh
2016-01-01
A theoretical design and simulation of betavoltaic angle sensor (beta-AS) based on 63 Ni–Si using MCNP code is presented in this article. It can measure the full angle of 0–360° in the temperature range of 233–353 K. Beta-AS is composed of semicircular 63 Ni as the beta source, which rotates along the circular (four-quadrant) surface of Si as a semiconductor (in p–n structure), so that the change in the source angle in relation to Si surface can be measured based on the changes in V oc observed in each quadrant of Si. For better performance, characteristics of Si and 63 Ni have been optimized: N D and N A values of 8e19 and 4e18 cm −3 (donor and acceptor doping concentration in Si, respectively), source thickness and activity of 1.5 µm and 18 mCi, respectively. The relation between angle and V oc is also investigated. The maximum difference between measured and real values of angle (the worst case, i.e., 0.18° for the angle of 45°) occurs at 233 K. It has been shown that sensitivity of the sensor decreases with an increase of angle. The results also show that the change in activity does not affect the sensitivity. - Highlights: • The angle sensor based on 63 Ni–Si in small dimensions for operating in the wide range of temperature and full-angle measurement was proposed. • The rate of electron–hole pair generation in silicon was obtained using Monte Carlo MCNP4C code. • Effects of temperature and activity on the accuracy of the measurement of angle were investigated. • Temperature calibration was considered simultaneously in the proposed structure (self-correcting).
Solar cell angle of incidence corrections
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
Influence of visual angle on pattern reversal visual evoked potentials
Directory of Open Access Journals (Sweden)
Ruchi Kothari
2014-01-01
Full Text Available Purpose: The aim of this study was to find whether the visual evoked potential (VEP latencies and amplitude are altered with different visual angles in healthy adult volunteers or not and to determine the visual angle which is the optimum and most appropriate among a wide range of check sizes for the reliable interpretation of pattern reversal VEPs (PRVEPs. Materials and Methods: The present study was conducted on 40 healthy volunteers. The subjects were divided into two groups. One group consisted of 20 individuals (nine males and 11 females in the age range of 25-57 years and they were exposed to checks subtending a visual angle of 90, 120, and 180 minutes of arc. Another group comprised of 20 individuals (10 males and 10 females in the age range of 36-60 years and they were subjected to checks subtending a visual angle of 15, 30, and 120 minutes of arc. The stimulus configuration comprised of the transient pattern reversal method in which a black and white checker board is generated (full field on a VEP Monitor by an Evoked Potential Recorder (RMS EMG. EPMARK II. The statistical analysis was done by One Way Analysis of Variance (ANOVA using EPI INFO 6. Results: In Group I, the maximum (max. P100 latency of 98.8 ± 4.7 and the max. P100 amplitude of 10.05 ± 3.1 μV was obtained with checks of 90 minutes. In Group II, the max. P100 latency of 105.19 ± 4.75 msec as well as the max. P100 amplitude of 8.23 ± 3.30 μV was obtained with 15 minutes. The min. P100 latency in both the groups was obtained with checks of 120 minutes while the min. P100 amplitude was obtained with 180 minutes. A statistically significant difference was derived between means of P100 latency for 15 and 30 minutes with reference to its value for 120 minutes and between the mean value of P100 amplitude for 120 minutes and that of 90 and 180 minutes. Conclusion: Altering the size of stimulus (visual angle has an effect on the PRVEP parameters. Our study found that the 120
Majee, Arnab K; Foss, Cameron J; Aksamija, Zlatan
2017-11-29
We study the impact of grain boundaries (GB) and misorientation angles between grains on electronic transport in 2-dimensional materials. Here we have developed a numerical model based on the first-principles electronic bandstructure calculations in conjunction with a method which computes electron transmission coefficients from simultaneous conservation of energy and momentum at the interface to essentially evaluate GB/interface resistance in a Landauer formalism. We find that the resistance across graphene GBs vary over a wide range depending on misorientation angles and type of GBs, starting from 53 Ω μm for low-mismatch angles in twin (symmetric) GBs to about 10 20 Ω μm for 21° mismatch in tilt (asymmetric) GBs. On the other hand, misorientation angles have weak influence on the resistance across MoS 2 GBs, ranging from about 130 Ω μm for low mismatch angles to about 6000 Ω μm for 21°. The interface resistance across graphene-MoS 2 heterojunctions also exhibits a strong dependence on misorientation angles with resistance values ranging from about 100 Ω μm for low-mismatch angles in Class-I (symmetric) interfaces to 10 15 Ω μm for 14° mismatch in Class-II (asymmetric) interfaces. Overall, symmetric homo/heterojunctions exhibit a weak dependence on misorientation angles, while in MoS 2 both symmetric and asymmetric GBs show a gradual dependence on mismatch angles.
Comparison of different methods to measure contact angles of soil colloids.
Shang, Jianying; Flury, Markus; Harsh, James B; Zollars, Richard L
2008-12-15
We compared five different methods, static sessile drop, dynamic sessile drop, Wilhelmy plate, thin-layer wicking, and column wicking, to determine the contact angle of colloids typical for soils and sediments. The colloids (smectite, kaolinite, illite, goethite, hematite) were chosen to represent 1:1 and 2:1 layered aluminosilicate clays and sesquioxides, and were either obtained in pure form or synthesized in our laboratory. Colloids were deposited as thin films on glass slides, and then used for contact angle measurements using three different test liquids (water, formamide, diiodomethane). The colloidal films could be categorized into three types: (1) films without pores and with polar-liquid interactions (smectite), (2) films with pores and with polar-liquid interactions (kaolinite, illite, goethite), and (3) films without pores and no polar-liquid interactions (hematite). The static and dynamic sessile drop methods yielded the most consistent contact angles. For porous films, the contact angles decreased with time, and we consider the initial contact angle to be the most accurate. The differences in contact angles among the different methods were large and varied considerably: the most consistent contact angles were obtained for kaolinite with water, and illite with diiodomethane (contact angles were within 3 degrees); but mostly the differences ranged from 10 degrees to 40 degrees among the different methods. The thin-layer and column wicking methods were the least consistent methods.
Directory of Open Access Journals (Sweden)
Maximilian J Hartel
Full Text Available Exact knowledge of femoral neck inclination and torsion angles is important in recognizing, understanding and treating pathologic conditions in the hip joint. However, published results vary widely between different studies, which indicates that there are persistent difficulties in carrying out exact measurements.A three dimensional modeling and analytical technology was used for the analysis of 1070 CT datasets of skeletally mature femurs. Individual femoral neck angles and torsion angles were precisely computed, in order to establish whether gender, age, body mass index and ethnicity influence femoral neck angles and torsion angles.The median femoral neck angle was 122.2° (range 100.1-146.2°, IQR 117.9-125.6°. There are significant gender (female 123.0° vs. male 121.5°; p = 0.007 and ethnic (Asian 123.2° vs. Caucasian 121.9°; p = 0.0009 differences. The median femoral torsion angle was 14.2° (-23.6-48.7°, IQR 7.4-20.4°. There are significant gender differences (female 16.4° vs. male 12.1°; p = 0.0001. Femoral retroversion was found in 7.8% of the subjects.Precise femoral neck and torsion angles were obtained in over one thousand cases. Systematic deviations in measurement due to human error were eliminated by using automated high accuracy morphometric analysis. Small but significant gender and ethnic differences were found in femoral neck and torsion angles.
Quantitative angle-insensitive flow measurement using relative standard deviation OCT.
Zhu, Jiang; Zhang, Buyun; Qi, Li; Wang, Ling; Yang, Qiang; Zhu, Zhuqing; Huo, Tiancheng; Chen, Zhongping
2017-10-30
Incorporating different data processing methods, optical coherence tomography (OCT) has the ability for high-resolution angiography and quantitative flow velocity measurements. However, OCT angiography cannot provide quantitative information of flow velocities, and the velocity measurement based on Doppler OCT requires the determination of Doppler angles, which is a challenge in a complex vascular network. In this study, we report on a relative standard deviation OCT (RSD-OCT) method which provides both vascular network mapping and quantitative information for flow velocities within a wide range of Doppler angles. The RSD values are angle-insensitive within a wide range of angles, and a nearly linear relationship was found between the RSD values and the flow velocities. The RSD-OCT measurement in a rat cortex shows that it can quantify the blood flow velocities as well as map the vascular network in vivo .
Small-angle scattering of neutrons from normal and superfluid liquid helium
International Nuclear Information System (INIS)
Tsipenyuk, Yu.M.; Kirichek, O.; Petrenko, O.
2013-01-01
The results of experiments on small-angle neutron scattering in liquid helium in the range of temperatures of 1-5 K, performed on a neutron pulse source ISIS (England), are presented. The detailed measurements of angular distribution of scattered neutrons allowed one to observe an essential change in temperature dependence of the second moment of pair correlation function (the first derivative of angular distribution at small angles of scattering). At high temperatures the angular distribution of scattered neutrons follows the classical description of small-angle scattering, but at temperatures below the l-point a quantum behavior is observed neutron-scattering by quantum fluctuations. It is experimentally confirmed that in the whole temperature range the cross-section of neutron scattering at a zero angle is determined by the classical thermodynamic fluctuations of density.
Diniz Filho, Alberto; Cronemberger, Sebastião; Mérula, Rafael Vidal; Calixto, Nassim
2009-01-01
To investigate biometrically the differences between plateau iris configuration (PIC) eyes and primary open angle glaucoma with narrow angle eyes. A comparative study involving a case series with 20 eyes of 11 plateau iris configuration patients and 45 eyes of 27 primary open angle glaucoma with narrow angle eyes patients was done. The following measurements were taken: corneal curvature, central corneal thickness, anterior chamber depth, lens thickness (LT), axial length (AL), lens thickness and axial length ratio, lens position (LP) and relative lens position (RLP). The plateau iris configuration eyes presented a higher corneal cuvature value than primary open angle glaucoma with narrow angle eyes eyes but not with clinical and statistical difference (P=0.090). The plateau iris configuration eyes demonstrated a higher central corneal thickness, with statistical significance, when compared to primary open angle glaucoma with narrow angle eyes (P=0.010). Statistical significant difference between plateau iris configuration and primary open angle glaucoma with narrow angle eyes was found in axial length (21.69 +/- 0.98 vs. 22.42 +/- 0.89; P=0.003). No significant difference was found when anterior chamber depth (2.62 +/- 0.23 vs. 2.71 +/- 0.31; P=0.078), LT (4.67 +/- 0.36 vs. 4.69 +/- 0.45; P=0.975), LT/AL (2.16 +/- 0.17 vs. 2.10 +/- 0.21; P=0.569), LP (4.95 +/- 0.25 vs. 5.06 +/- 0.34; P=0.164) and RLP (0.23 +/- 0.01 vs. 0.22 +/- 0.14; P=0.348) were evaluated. The eyes with plateau iris configuration presented statistical significantly shorter axial length and higher central corneal thickness than primary open angle glaucoma with narrow angle eyes.
International Nuclear Information System (INIS)
Lo Celso, F.; Triolo, R.; Triolo, F.; Triolo, A.; Lin, J.S.; Lucido, G.
2000-01-01
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
International Nuclear Information System (INIS)
LoCelso, F.; Triolo, F.; Triolo, A.; Lin, J.S.; Lucido, G.; Triolo, R.
1999-01-01
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
Hamkins, Jon; Vilnrotter, Victor A.; Andrews, Kenneth S.; Shambayati, Shervin
2011-01-01
A telemetry-based ranging scheme was developed in which the downlink ranging signal is eliminated, and the range is computed directly from the downlink telemetry signal. This is the first Deep Space Network (DSN) ranging technology that does not require the spacecraft to transmit a separate ranging signal. By contrast, the evolutionary ranging techniques used over the years by NASA missions, including sequential ranging (transmission of a sequence of sinusoids) and PN-ranging (transmission of a pseudo-noise sequence) whether regenerative (spacecraft acquires, then regenerates and retransmits a noise-free ranging signal) or transparent (spacecraft feeds the noisy demodulated uplink ranging signal into the downlink phase modulator) relied on spacecraft power and bandwidth to transmit an explicit ranging signal. The state of the art in ranging is described in an emerging CCSDS (Consultative Committee for Space Data Systems) standard, in which a pseudo-noise (PN) sequence is transmitted from the ground to the spacecraft, acquired onboard, and the PN sequence is coherently retransmitted back to the ground, where a delay measurement is made between the uplink and downlink signals. In this work, the telemetry signal is aligned with the uplink PN code epoch. The ground station computes the delay between the uplink signal transmission and the received downlink telemetry. Such a computation is feasible because symbol synchronizability is already an integral part of the telemetry design. Under existing technology, the telemetry signal cannot be used for ranging because its arrival-time information is not coherent with any Earth reference signal. By introducing this coherence, and performing joint telemetry detection and arrival-time estimation on the ground, a high-rate telemetry signal can provide all the precision necessary for spacecraft ranging.
Effect of leaning angle of gecko-inspired slanted polymer nanohairs on dry adhesion
Jeong, Hoon Eui
2010-01-01
We present analysis of adhesion properties of angled polymer nanohairs with a wide range of leaning angles from 0° to 45° and ultraviolet (UV)-curable polyurethane acrylate (PUA) materials of two different elastic moduli (19.8 and 320 MPa). It is demonstrated that shear adhesion and adhesion hysteresis can be greatly enhanced by increasing the leaning angle of nanohairs both for soft and hard materials due to increased contact area and reduced structural stiffness. © 2010 American Institute of Physics.
Directory of Open Access Journals (Sweden)
P. Pignalosa
2011-09-01
Full Text Available Antireflection with broadband and wide angle properties is important for a wide range of applications on photovoltaic cells and display. The SiOx shell layer provides a natural antireflection from air to the Si core absorption layer. In this work, we have demonstrated the random core-shell silicon nanowires with both broadband (from 400nm to 900nm and wide angle (from normal incidence to 60º antireflection characteristics within AM1.5 solar spectrum. The graded index structure from the randomly oriented core-shell (Air/SiOx/Si nanowires may provide a potential avenue to realize a broadband and wide angle antireflection layer.
The small and wide angle neutron scattering instrument TAIKAN at J-PARC
International Nuclear Information System (INIS)
Takata, Shin-ichi; Shinohara, Takenao; Oku, Takayuki; Inamura, Yasuhiro; Nakatani, Takeshi; Suzuya, Kentaro; Aizawa, Kazuya; Arai, Masatoshi; Suzuki, Jun-ichi; Ohishi, Kazuki; Iwase, Hiroki; Tominaga, Taiki; Ito, Takayoshi; Otomo, Toshiya; Sugiyama, Masaaki
2014-01-01
The small and wide angle neutron scattering instrument (TAIKAN) is designed to cover the wide q range of 0.0005range of 0.5<λ<7.8Å and five detector banks which are small-, middle-, high-, ultra-small-angle, and backward detector banks. In this paper, the status of detector installation and data reduction method are presented. In addition, the instrument performance on the wide q-range measurement with high q-resolution is discussed with experimental results of two standard samples, a glassy carbon and a silver behenate. (author)
Near field phased array DOA and range estimation of UHF RFID tags
Huiting, J.; Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria
2015-01-01
This paper presents a near field localization system based on a phased array for UHF RFID tags. To estimate angle and range the system uses a two-dimensional MUSIC algorithm. A four channel phased array is used to experimentally verify the estimation of angle and range for an EPC gen2 tag. The
Fabrication of black-gold coatings by glancing angle deposition with sputtering
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Alan Vitrey
2017-02-01
Full Text Available The fabrication of black-gold coatings using sputtering is reported here. Glancing angle deposition with a rotating substrate is needed to obtain vertical nanostructures. Enhanced light absorption is obtained in the samples prepared in the ballistic regime with high tilt angles. Under these conditions the diameter distribution of the nanostructures is centered at about 60 nm and the standard deviation is large enough to obtain black-metal behavior in the visible range.
MULLIGAN VERSUS MAITLAND MOBILIZATION ON THORACIC KYPHOTIC ANGLE IN POSTURAL KYPHOSIS
Mohamed Ibrahim Fathallah Abdelhay; Mohamed Hussein Elgendy; Yasser Ramzy Lasheen
2017-01-01
Background: Postural hypnosis can lead to cervical pain or bad cosmetic appearance.There is a lack in the literature supporting the efficacy of spinal mobilization techniques in restoring normal thoracic curvature.Mulligan and Maitland's mobilization were used to improve range of motion and referred pain not to restore normal kyphotic angle. The purpose: this study was conducted to compare the efficacy of Mulligan and Maitland spinal mobilization on a kyphotic angle in postural kyphosis. Subj...
Small angle X-ray scattering on concentrated hemoglobin solutions
International Nuclear Information System (INIS)
Zinke, M.; Damaschun, G.; Mueller, J.J.; Ruckpaul, K.
1978-01-01
The small-angle X-ray scattering technique was used to determine the intermolecular structure and interaction potentials in oxi-and deoxi-hemoglobin solutions. The pair correlation function obtained by the ZERNICKE-PRINS equation characterizes the intermolecular structure of the hemoglobin molecules. The intermolecular structure is concentration dependent. The hemoglobin molecules have a 'short range order structure' with a range of about 4 molecule diameters at 324 g/l. The potential functions of the hemoglobin-hemoglobin interaction have been determined on the basis of fluid theories. Except for the deoxi-hemoglobin solution having the concentration 370 g/l, the pair interaction consists in a short repulsion and a weak short-range attraction against kT. The potential minimum is between 1.2 - 1.5 nm above the greatest hemoglobin diameter. (author)
Graphene spin valve: An angle sensor
Energy Technology Data Exchange (ETDEWEB)
Iqbal, Muhammad Zahir, E-mail: zahir.upc@gmail.com [Faculty of Engineering Sciences, GIK Institute of Engineering Sciences and Technology, Topi 23640, Khyber Pakhtunkhwa (Pakistan); Hussain, Ghulam [Faculty of Engineering Sciences, GIK Institute of Engineering Sciences and Technology, Topi 23640, Khyber Pakhtunkhwa (Pakistan); Siddique, Salma [Department of Bioscience & Biotechnology, Sejong University, Seoul 143-747 (Korea, Republic of); Iqbal, Muhammad Waqas [Department of Physics, Riphah Institute of Computing and Applied Sciences (RICAS), Riphah International University, Lahore (Pakistan)
2017-06-15
Graphene spin valves can be optimized for various spintronic applications by tuning the associated experimental parameters. In this work, we report the angle dependent magnetoresistance (MR) in graphene spin valve for different orientations of applied magnetic field (B). The switching points of spin valve signals show a clear shift towards higher B for each increasing angle of the applied field, thus sensing the response for respective orientation of the magnetic field. The angular variation of B shifts the switching points from ±95 G to ±925 G as the angle is varied from 0° to 90° at 300 K. The observed shifts in switching points become more pronounced (±165 G to ±1450 G) at 4.2 K for similar orientation. A monotonic increase in MR ratio is observed as the angle of magnetic field is varied in the vertical direction at 300 K and 4.2 K temperatures. This variation of B (from 0° to 90°) increases the magnitude of MR ratio from ∼0.08% to ∼0.14% at 300 K, while at 4.2 K it progresses to ∼0.39% from ∼0.14%. The sensitivity related to angular variation of such spin valve structure can be employed for angle sensing applications.
A Viewpoint on the Quantity "Plane Angle"
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.
PRIMARY OPEN ANGLE GLAUCOMA IN THYROID DISORDER
Directory of Open Access Journals (Sweden)
Pragati Garg
2016-07-01
Full Text Available PURPOSE To assess the association of thyroid profile with open angle glaucoma. DESIGN Cross-sectional observational study. MATERIAL AND METHOD 128 cases of diagnosed thyroid disorder were enrolled. 5 cases dropped out. Ocular examination included applanation tonometry, stereoscopic optic disc photography, and automated perimetry. Correlative association of thyroid disorder and open angle glaucoma was assessed. RESULTS Of 123 patients of thyroid disorder, 87.8% had hypothyroidism and remaining 12.2% had hyperthyroidism. 15.74% of hypothyroidism and 20% of hyperthyroidism patients had open angle glaucoma, which was statistically significant (Pearson chi-square: Value=6.548, df=2, p=0.040. On multivariate analysis with other risk factors like female sex, family history of glaucoma, myopia, hypertension, and diabetes; it was found that hypothyroidism is an independent risk factor for open angle glaucoma. CONCLUSION All patients having thyroid disorder should be investigated for early diagnosis of open angle glaucoma so that if need be antiglaucoma treatment is started at the earliest and the eye maybe saved from any further deterioration.
Determining Pitch-angle Diffusion Coefficients from Test Particle Simulations
Ivascenko, Alex; Lange, Sebastian; Spanier, Felix; Vainio, Rami
2016-12-01
The transport and acceleration of charged particles in turbulent media are topics of great interest in space physics and interstellar astrophysics. These processes are dominated by the scattering of particles off magnetic irregularities. The scattering process itself is usually described by small-angle scattering, with the pitch-angle coefficient {D}μ μ playing a major role. Since the diffusion coefficient {D}μ μ can be determined analytically only for the approximation of quasilinear theory, the determination of this coefficient from numerical simulations has become more important. So far these simulations have yielded particle tracks for small-scale scattering, which can then be interpreted using the running diffusion coefficients. This method has a limited range of validity. This paper presents two new methods that allow for the calculation of the pitch-angle diffusion coefficient from numerical simulations. These methods no longer analyze particle trajectories and instead examine the change of particle distribution functions. It is shown that these methods provide better resolved results and allow for the analysis of strong turbulence. The application of these methods to Monte Carlo simulations of particle scattering and hybrid MHD-particle simulations is presented. Both analysis methods are able to recover the diffusion coefficients used as input for the Monte Carlo simulations and provide better results in MHD simulations, especially for stronger turbulence.
Sparse Representation Based SAR Vehicle Recognition along with Aspect Angle
Directory of Open Access Journals (Sweden)
Xiangwei Xing
2014-01-01
Full Text Available As a method of representing the test sample with few training samples from an overcomplete dictionary, sparse representation classification (SRC has attracted much attention in synthetic aperture radar (SAR automatic target recognition (ATR recently. In this paper, we develop a novel SAR vehicle recognition method based on sparse representation classification along with aspect information (SRCA, in which the correlation between the vehicle’s aspect angle and the sparse representation vector is exploited. The detailed procedure presented in this paper can be summarized as follows. Initially, the sparse representation vector of a test sample is solved by sparse representation algorithm with a principle component analysis (PCA feature-based dictionary. Then, the coefficient vector is projected onto a sparser one within a certain range of the vehicle’s aspect angle. Finally, the vehicle is classified into a certain category that minimizes the reconstruction error with the novel sparse representation vector. Extensive experiments are conducted on the moving and stationary target acquisition and recognition (MSTAR dataset and the results demonstrate that the proposed method performs robustly under the variations of depression angle and target configurations, as well as incomplete observation.
Ultra-Wideband Angle-of-Arrival Tracking Systems
Arndt, G. Dickey; Ngo, Phong H.; Phan, Chau T.; Gross, Julia; Ni, Jianjun; Dusl, John
2010-01-01
Systems that measure the angles of arrival of ultra-wideband (UWB) radio signals and perform triangulation by use of those angles in order to locate the sources of those signals are undergoing development. These systems were originally intended for use in tracking UWB-transmitter-equipped astronauts and mobile robots on the surfaces of remote planets during early stages of exploration, before satellite-based navigation systems become operational. On Earth, these systems could be adapted to such uses as tracking UWB-transmitter-equipped firefighters inside buildings or in outdoor wildfire areas obscured by smoke. The same characteristics that have made UWB radio advantageous for fine resolution ranging, covert communication, and ground-penetrating radar applications in military and law-enforcement settings also contribute to its attractiveness for the present tracking applications. In particular, the waveform shape and the short duration of UWB pulses make it possible to attain the high temporal resolution (of the order of picoseconds) needed to measure angles of arrival with sufficient precision, and the low power spectral density of UWB pulses enables UWB radio communication systems to operate in proximity to other radio communication systems with little or no perceptible mutual interference.
Large area optical mapping of surface contact angle.
Dutra, Guilherme; Canning, John; Padden, Whayne; Martelli, Cicero; Dligatch, Svetlana
2017-09-04
Top-down contact angle measurements have been validated and confirmed to be as good if not more reliable than side-based measurements. A range of samples, including industrially relevant materials for roofing and printing, has been compared. Using the top-down approach, mapping in both 1-D and 2-D has been demonstrated. The method was applied to study the change in contact angle as a function of change in silver (Ag) nanoparticle size controlled by thermal evaporation. Large area mapping reveals good uniformity for commercial Aspen paper coated with black laser printer ink. A demonstration of the forensic and chemical analysis potential in 2-D is shown by uncovering the hidden CsF initials made with mineral oil on the coated Aspen paper. The method promises to revolutionize nanoscale characterization and industrial monitoring as well as chemical analyses by allowing rapid contact angle measurements over large areas or large numbers of samples in ways and times that have not been possible before.
Small-angle neutron scattering at pulsed spallation sources
International Nuclear Information System (INIS)
Seeger, P.A.; Hjelm, R.P. Jr.
1990-01-01
The importance of small-angle neutron scattering (SANS) in biological, chemical, physical, and engineering research mandates that all intense neutron sources be equipped with SANS instruments. Four existing instruments are described, and the general differences between pulsed-source and reactor-based instrument designs are discussed. The basic geometries are identical, but dynamic range is achieved by using a broad band of wavelengths (with time-of-flight analysis) rather than by moving the detector. This allows a more optimized collimation system. Data acquisition requirements at a pulsed source are more severe, requiring large, fast histogramming memories. Data reduction is also more complex, as all wave length-dependent and angle-dependent backgrounds and non-linearities must be accounted for before data can be transformed to intensity vs Q. A comparison is shown between the Los Alamos pulsed instrument and D-11 (Institute Laue-Langevin), and examples from the four major topics of the conference are shown. The general conclusion is that reactor-based instruments remain superior at very low Q or if only a narrow range of Q is required, but that the current generation of pulsed-source instruments is competitive at moderate Q and may be faster when a wide range of Q is required. In principle, a user should choose which facility to use on the basis of optimizing the experiment; in practice the tradeoffs are not severe and the choice is usually made on the basis of availability
Dryden Aeronautical Test Range
Federal Laboratory Consortium — Recently redesignated to honor Dr. Hugh L. Dryden, NASA's Dryden Aeronautical Test Range (DATR) supports aerospace flight research and technology integration, space...
Angle-averaged Compton cross sections
Energy Technology Data Exchange (ETDEWEB)
Nickel, G.H.
1983-01-01
The scattering of a photon by an individual free electron is characterized by six quantities: ..cap alpha.. = initial photon energy in units of m/sub 0/c/sup 2/; ..cap alpha../sub s/ = scattered photon energy in units of m/sub 0/c/sup 2/; ..beta.. = initial electron velocity in units of c; phi = angle between photon direction and electron direction in the laboratory frame (LF); theta = polar angle change due to Compton scattering, measured in the electron rest frame (ERF); and tau = azimuthal angle change in the ERF. We present an analytic expression for the average of the Compton cross section over phi, theta, and tau. The lowest order approximation to this equation is reasonably accurate for photons and electrons with energies of many keV.
On the dip angle of subducting plates
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.
Angle-averaged Compton cross sections
International Nuclear Information System (INIS)
Nickel, G.H.
1983-01-01
The scattering of a photon by an individual free electron is characterized by six quantities: α = initial photon energy in units of m 0 c 2 ; α/sub s/ = scattered photon energy in units of m 0 c 2 ; β = initial electron velocity in units of c; phi = angle between photon direction and electron direction in the laboratory frame (LF); theta = polar angle change due to Compton scattering, measured in the electron rest frame (ERF); and tau = azimuthal angle change in the ERF. We present an analytic expression for the average of the Compton cross section over phi, theta, and tau. The lowest order approximation to this equation is reasonably accurate for photons and electrons with energies of many keV
Precision measurements of the CKM angle gamma
CERN. Geneva
2016-01-01
The level of CP-violation permitted within the Standard Model cannot account for the matter dominated universe in which we live. Within the Standard Model the CKM matrix, which describes the quark couplings, is expected to be unitary. By making precise measurements of the CKM matrix parameters new physics models can be constrained, or with sufficient precision the effects of physics beyond the standard model might become apparent. The CKM angle gamma is the least well known angle of the unitarity triangle. It is the only angle easily accessible at tree-level, and furthermore has almost no theoretical uncertainties. Therefore it provides an invaluable Standard Model benchmark against which other new physics sensitive tests of the CP-violation can be made. I will discuss recent measurements of gamma using the the Run 1 LHCb dataset, which improve our knowledge of this key parameter.
Flocking and invariance of velocity angles.
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.
PHASE ANGLE EFFECTS ON 3 μm ABSORPTION BAND ON CERES: IMPLICATIONS FOR DAWN MISSION
International Nuclear Information System (INIS)
Takir, D.; Reddy, V.; Sanchez, J. A.; Corre, L. Le; Hardersen, P. S.; Nathues, A.
2015-01-01
Phase angle-induced spectral effects are important to characterize since they affect spectral band parameters such as band depth and band center, and therefore skew mineralogical interpretations of planetary bodies via reflectance spectroscopy. Dwarf planet (1) Ceres is the next target of NASA’s Dawn mission, which is expected to arrive in 2015 March. The visible and near-infrared mapping spectrometer (VIR) on board Dawn has the spatial and spectral range to characterize the surface between 0.25–5.0 μm. Ceres has an absorption feature at 3.0 μm due to hydroxyl- and/or water-bearing minerals. We analyzed phase angle-induced spectral effects on the 3 μm absorption band on Ceres using spectra measured with the long-wavelength cross-dispersed (LXD: 1.9–4.2 μm) mode of the SpeX spectrograph/imager at the NASA Infrared Telescope Facility. Ceres LXD spectra were measured at different phase angles ranging from 0.°7 to 22°. We found that the band center slightly increases from 3.06 μm at lower phase angles (0.°7 and 6°) to 3.07 μm at higher phase angles (11° and 22°), the band depth decreases by ∼20% from lower phase angles to higher phase angles, and the band area decreases by ∼25% from lower phase angles to higher phase angles. Our results will have implications for constraining the abundance of OH on the surface of Ceres from VIR spectral data, which will be acquired by Dawn starting spring 2015
Liu, Zhen; Bao, Hongda; Qiu, Yong; Qiao, Jun; Xu, Leilei; Zhu, Feng; Qian, Bangping; Zhu, Zezhang
2015-02-01
The objectives of the present study are to evaluate the correlation between pelvic tilt (PT) and the sacro-femoral-pubic (SFP) angle in Asian healthy adolescents, to provide the normal value of SFP angle as reference data in Asian adolescents, and to clarify whether the predictability of PT could be affected by gender and ontogenesis. In all, 100 girls with a mean age of 12.66 years (range 8-18 years) and 70 boys with a mean age of 13.35 years (range 8-18 years) were recruited in this retrospective study. SFP angles and PT were obtained on long-cassette standing upright radiographs. The subjects were grouped based on age. Independent-sample t-tests were performed to compare age, SFP angle, and PT between genders. In all age groups, the relationship between SFP angle and PT was analyzed by Pearson's correlation analysis and linear regression analysis, respectively. Reliability analysis showed high intra- and inter-observer agreements in PT and SFP, with an intra-class correlation coefficient (ICC) > 0.8. SFP angle averaged 71.64° ± 4.91 in all the normal subjects, of which the mean PT was 72.03°± 4.94 in the female group and 71.09°± 4.83 in the male group. SFP and PT were strongly correlated in all the age groups according to Pearson's correlation analysis. The overall coefficient was 0.679 in girls and 0.584 in boys. The present study is the first to describe the normal value of SFP angle in healthy Asian adolescents to serve as a reference data. In all age groups, SFP angles can be used to predict PT when lateral radiographs do not permit assessment of PT. The predictability of SFP angle for PT was not affected by gender or maturation status. © 2014 Anatomical Society.
DEFF Research Database (Denmark)
Hansen, Thomas Dueholm; Miltersen, Peter Bro; Sørensen, Troels Bjerre
2008-01-01
size (and doubly exponential in its depth). We also provide techniques that yield concrete bounds for unbalanced game trees and apply these to estimate the Range of Skill of Tic-Tac-Toe and Heads-Up Limit Texas Hold'em Poker. In particular, we show that the Range of Skill of Tic-Tac-Toe is more than...
Angles between Curves in Metric Measure Spaces
Directory of Open Access Journals (Sweden)
Han Bang-Xian
2017-09-01
Full Text Available The goal of the paper is to study the angle between two curves in the framework of metric (and metric measure spaces. More precisely, we give a new notion of angle between two curves in a metric space. Such a notion has a natural interplay with optimal transportation and is particularly well suited for metric measure spaces satisfying the curvature-dimension condition. Indeed one of the main results is the validity of the cosine formula on RCD*(K, N metric measure spaces. As a consequence, the new introduced notions are compatible with the corresponding classical ones for Riemannian manifolds, Ricci limit spaces and Alexandrov spaces.
Small angle neutron scattering and small angle X-ray scattering ...
Indian Academy of Sciences (India)
Abstract. The morphology of carbon nanofoam samples comprising platinum nanopar- ticles dispersed in the matrix was characterized by small angle neutron scattering (SANS) and small angle X-ray scattering (SAXS) techniques. Results show that the structure of pores of carbon matrix exhibits a mass (pore) fractal nature ...
Fea, Antonio Maria; Dallorto, Laura; Lavia, Carlo; Pignata, Giulia; Rolle, Teresa; Aung, Tin
2017-07-19
There is a lack of information about long-term results of chronic angle closure glaucoma following an acute primary angle closure attack in Caucasian patients. The aim of the study was to report morphological and functional long-term data of chronic angle closure eyes following a monolateral primary angle closure attack and to provide a comparison with their fellow eyes. Observational retrospective case series. Fifty-seven consecutive patients (114 eyes) underwent long-term follow-up analysis. Patients underwent ophthalmic assessment more than 5 years since the angle closure attack. Intraocular pressure, best-corrected visual acuity, angle assessment, vertical C/D ratio and standard automated perimetry were the main outcome measures. Comparisons were made between angle closure attack eyes and fellow eyes and between phakic and pseudophakic eyes. Mean follow-up time was 5.86 ± 1.19 years. A significant greater damage in the angle closure eyes compared with fellow eyes in both structural (mean C/D 0.61 ± 0.16; P APAC attack to prevent potential glaucoma damage in both APAC and fellow eye. © 2017 The Authors Clinical & Experimental Ophthalmology published by John Wiley & Sons Australia, Ltd on behalf of Royal Australian and New Zealand College of Ophthalmologists.
Small angle neutron scattering and small angle X-ray scattering ...
Indian Academy of Sciences (India)
Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. *Corresponding author ... ticles dispersed in the matrix was characterized by small angle neutron scattering (SANS) and small angle X-ray ... for scattering from rough pore–mass interfaces, α > 3 and the (surface) fractal dimension Ds = 6 ...
Sharper angle, higher risk? The effect of cutting angle on knee mechanics in invasion sport athletes
Schreurs, Mervin J.; Benjaminse, Anne; Lemmink, Koen A. P. M.
2017-01-01
Introduction: Cutting is an important skill in team-sports, but unfortunately is also related to non-contact ACL injuries. The purpose was to examine knee kinetics and kinematics at different cutting angles. Material and methods: 13 males and 16 females performed cuts at different angles (45°, 90°,
Small angle neutron scattering and small angle X-ray scattering ...
Indian Academy of Sciences (India)
2015-11-27
Nov 27, 2015 ... Small angle neutron scattering and small angle X-ray scattering studies of platinum-loaded carbon foams. P U Sastry V K Aswal A G Wagh ... Proceedings of the International Workshop/Conference on Computational Condensed Matter Physics and Materials Science (IWCCMP-2015). Posted on November ...
Stickel, L.F.; King, John A.
1968-01-01
The concept of home range was expressed by Seton (1909) in the term 'home region,' which Burr (1940, 1943) clarified with a definition of home range and exemplified in a definitive study of Peromyscus in the field. Burt pointed out the ever-changing characteristics of home-range area and the consequent absence of boundaries in the usual sense--a finding verified by investigators thereafter. In the studies summarized in this paper, sizes of home ranges of Peromyscus varied within two magnitudes, approximately from 0.1 acre to ten acres, in 34 studies conducted in a variety of habitats from the seaside dunes of Florida to the Alaskan forests. Variation in sizes of home ranges was correlated with both environmental and physiological factors; with habitat it was conspicuous, both in the same and different regions. Food supply also was related to size of home range, both seasonally and in relation to habitat. Home ranges generally were smallest in winter and largest in spring, at the onset of the breeding season. Activity and size also were affected by changes in weather. Activity was least when temperatures were low and nights were bright. Effects of rainfall were variable. Sizes varied according to sex and age; young mice remained in the parents' range until they approached maturity, when they began to travel more widely. Adult males commonly had larger home ranges than females, although there were a number of exceptions. An inverse relationship between population density and size of home range was shown in several studies and probably is the usual relationship. A basic need for activity and exploration also appeared to influence size of home range. Behavior within the home range was discussed in terms of travel patterns, travels in relation to home sites and refuges, territory, and stability of size of home range. Travels within the home range consisted of repeated use of well-worn trails to sites of food, shelter, and refuge, plus more random exploratory travels
Angle at the Medial Border: The Spinovertebra Angle and Its Significance
Directory of Open Access Journals (Sweden)
G. S. Oladipo
2015-01-01
Full Text Available 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
Efficacy of goniosynechialysis for advanced chronic angle-closure glaucoma
Directory of Open Access Journals (Sweden)
Qing G
2012-10-01
Full Text Available Guoping Qing,1,2 Ningli Wang,1 Dapeng Mu11Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Lab, Beijing, China; 2State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing, ChinaPurpose: To evaluate the intraocular pressure (IOP-lowering efficacy of goniosynechialysis (GSL for advanced chronic angle-closure glaucoma (CACG using a simplified slit-lamp technique.Patients and methods: Patients with CACG with one severely affected eye with best-corrected visual acuity below 20/200 and a mildly or functionally unaffected fellow eye were enrolled in this study. All patients underwent ophthalmologic examinations including measurement of visual acuity, best-corrected visual acuity, and IOP; biomicroscopy; specular microscopy; fundus examination; and gonioscopy followed by anterior chamber paracentesis and GSL for nasal peripheral anterior synechiae in the eye with severe CACG.Results: Thirty patients (18 men, 12 women were identified as having CACG with an initial mean IOP of 47.1 ± 6.7 mmHg (range 39–61 mmHg in the severely affected eye. One week after GSL, the mean IOP of the treated eyes decreased to 19.3 ± 2.8 mmHg (range 14–26 mmHg without antiglaucoma medication (average decrease 27.7 ± 6.5 mmHg; range 16–41 mmHg, which was significant (P < 0.00001 compared with baseline. After an average follow-up period of 36.6 ± 1.0 months (range 35–38 months, the mean IOP stabilized at 17.4 ± 2.2 mmHg (range 12–21 mmHg. The nasal angle recess did not close again in any one of the patients during the follow-up period. The average significant (P < 0.00001 decrease in corneal endothelial cell density in the treated eyes was 260 ± 183 cells/mm2 (range 191–328 cells/mm2.Conclusions: Anterior chamber paracentesis and GSL lowers IOP in advanced CACG, though it may lead to mild corneal endothelial cell loss
Soliton microcomb range measurement
Suh, Myoung-Gyun; Vahala, Kerry J.
2018-02-01
Light detection and ranging systems are used in many engineering and environmental sensing applications. Their relatively large size and cost, however, tend to be prohibitive for general use in autonomous vehicles and drones. Suh and Vahala and Trocha et al. show that optical frequency combs generated by microresonator devices can be used for precision ranging and the tracking of fast-moving objects. The compact size of the microresonators could broaden the scope for widespread applications, providing a platform for miniaturized laser ranging systems suitable for photonic integration.
CKM matrix exponential parametrization and Euler angles
International Nuclear Information System (INIS)
Dattoli, G.; Sabia, E.; Torre, A.
1997-01-01
They show that the exponential parametrization of the CKM matrix allows to establish exact relations between the Euler weak rotation angles and the entries of the CKM generating matrix, which has already been shown to include the hierarchy features of the Wolfenstein parametrization. The analysis includes CP-violating effects and its usefulness to treat the experimental data is also proved
Gaugings at angles from orientifold reductions
Roest, D.
2009-01-01
We consider orientifold reductions to N = 4 gauged supergravity in four dimensions. A special feature of this theory is that different factors of the gauge group can have relative angles with respect to the electro-magnetic SL(2) symmetry. These are crucial for moduli stabilization and de Sitter
Experimental technique of small angle neutron scattering
International Nuclear Information System (INIS)
Xia Qingzhong; Chen Bo
2006-03-01
The main parts of Small Angle Neutron Scattering (SANS) spectrometer, and their function and different parameters are introduced from experimental aspect. Detailed information is also introduced for SANS spectrometer 'Membrana-2'. Based on practical experiments, the fundamental requirements and working condition for SANS experiments, including sample preparation, detector calibration, standard sample selection and data preliminary process are described. (authors)
The resection angle in apical surgery
DEFF Research Database (Denmark)
von Arx, Thomas; Janner, Simone F M; Jensen, Simon S
2016-01-01
OBJECTIVES: The primary objective of the present radiographic study was to analyse the resection angle in apical surgery and its correlation with treatment outcome, type of treated tooth, surgical depth and level of root-end filling. MATERIALS AND METHODS: In the context of a prospective clinical...
A thin film magnetoresistive angle detector
Eijkel, C.J.M.; Wieberdink, Johan W.; Fluitman, J.H.J.; Popma, T.J.A.; Groot, Peter; Leeuwis, Henk
1990-01-01
An overview is given of the results of our research on a contactless angle detector based on the anisotropic magnetoresistance effect (AMR effect) in a permalloy thin film. The results of high-temperature annealing treatment of the pemalloy film are discussed. Such a treatment suppresses the effects
A small-angle neutron scattering study
Indian Academy of Sciences (India)
400Da [9]. Low-angle X-ray scattering [10] and neutron scattering [11] also in- dicated serum albumin to be a prolate ellipsoid. However, studies using 1H NMR indicated that a prolate structure was unlikely; rather a heart-shaped structure was proposed [12]. The shape of albumin reveals a heart-shaped molecule that can.
Solid angle subtended by two circular discs
International Nuclear Information System (INIS)
Gilly, Louis.
1978-09-01
Methods of calculation of solid angles, subtended by two circular discs are analysed. Calculus are methodically classified as follow: series development Legendre polynomes, defined integral, elliptic integrals, Bessel integrals, multiple integrals, Monte Carlo method, electrostatic analogy. Applications in Nuclear Physics are added as examples. List of numeric tables completes bibliography [fr
Small Angle Light Scattering by Biological Objects
International Nuclear Information System (INIS)
Berdzenishvili, L.; Melikishvili, Z.
2005-01-01
In this paper the small angle laser radiation scattering by the particles of different shape and size is analyzed. Experimental results and theoretical calculations show that after ejection from bacteriophage DNA forms the scattering medium consisted of quasi-spherical elements with radius of R⁓10λ 0 . (author)
Direct angle resolved photoemission spectroscopy and ...
Indian Academy of Sciences (India)
Since 1997 we systematically perform direct angle resolved photoemission spectroscopy (ARPES) on in-situ grown thin (< 30 nm) cuprate films. Specifically, we probe low-energy electronic structure and properties of high-c superconductors (HTSC) under different degrees of epitaxial (compressive vs. tensile) strain.
Right-Angle Mechanized Electrical Connector
Collins, Clint A.; Blackler, David T.
1996-01-01
Right-angle electrical connector embedded in mechanism accommodates some initial misalignment and aligns itself. Connection and disconnection effected with relatively small forces and torques and simple movements. Actuated by one gloved hand or by robotic manipulator. Useful in underwater, nuclear, hot, cold, or toxic environments in which connections made or broken by heavily clothed technicians or by robots.
SANS-1: Small angle neutron scattering
Directory of Open Access Journals (Sweden)
André Heinemann
2015-08-01
Full Text Available The new small angle scattering instrument SANS-1, jointly operated by the Technische Universität München and GEMS, Helmholtz-Zentrum Geesthacht, has completed commissioning and is in regular user service (Gilles et al., 2006. SANS-1 is located at the end of neutron guide NL4a in the Neutron Guide Hall West.
SANS-1: Small angle neutron scattering
Heinemann, André; Mühlbauer, Sebastian
2015-01-01
The new small angle scattering instrument SANS-1, jointly operated by the Technische Universität München and GEMS, Helmholtz-Zentrum Geesthacht, has completed commissioning and is in regular user service (Gilles et al., 2006). SANS-1 is located at the end of neutron guide NL4a in the Neutron Guide Hall West.
Camber Angle Inspection for Vehicle Wheel Alignments.
Young, Jieh-Shian; Hsu, Hong-Yi; Chuang, Chih-Yuan
2017-02-03
This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU)-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x -axis or z -axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ± 0.015 ∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi.
Camber Angle Inspection for Vehicle Wheel Alignments
Directory of Open Access Journals (Sweden)
Jieh-Shian Young
2017-02-01
Full Text Available This paper introduces an alternative approach to the camber angle measurement for vehicle wheel alignment. Instead of current commercial approaches that apply computation vision techniques, this study aims at realizing a micro-control-unit (MCU-based camber inspection system with a 3-axis accelerometer. We analyze the precision of the inspection system for the axis misalignments of the accelerometer. The results show that the axes of the accelerometer can be aligned to the axes of the camber inspection system imperfectly. The calibrations that can amend these axis misalignments between the camber inspection system and the accelerometer are also originally proposed since misalignments will usually happen in fabrications of the inspection systems. During camber angle measurements, the x-axis or z-axis of the camber inspection system and the wheel need not be perfectly aligned in the proposed approach. We accomplished two typical authentic camber angle measurements. The results show that the proposed approach is applicable with a precision of ± 0.015 ∘ and therefore facilitates the camber measurement process without downgrading the precision by employing an appropriate 3-axis accelerometer. In addition, the measured results of camber angles can be transmitted via the medium such as RS232, Bluetooth, and Wi-Fi.
A small-angle neutron scattering investigation
Indian Academy of Sciences (India)
Hence, the steel is used in aircraft, nuclear reactor, petrochemical plants and many other industries. However, presence of carbide formers such as Mo and Cr war- rants the possibility of carbide precipitates in the structure and in turn affects the mechanical properties. Small-angle neutron scattering (SANS) is an important ...
Contact angle measurement with a smartphone
Chen, H.; Muros-Cobos, Jesus L.; Amirfazli, A.
2018-03-01
In this study, a smartphone-based contact angle measurement instrument was developed. Compared with the traditional measurement instruments, this instrument has the advantage of simplicity, compact size, and portability. An automatic contact point detection algorithm was developed to allow the instrument to correctly detect the drop contact points. Two different contact angle calculation methods, Young-Laplace and polynomial fitting methods, were implemented in this instrument. The performance of this instrument was tested first with ideal synthetic drop profiles. It was shown that the accuracy of the new system with ideal synthetic drop profiles can reach 0.01% with both Young-Laplace and polynomial fitting methods. Conducting experiments to measure both static and dynamic (advancing and receding) contact angles with the developed instrument, we found that the smartphone-based instrument can provide accurate and practical measurement results as the traditional commercial instruments. The successful demonstration of use of a smartphone (mobile phone) to conduct contact angle measurement is a significant advancement in the field as it breaks the dominate mold of use of a computer and a bench bound setup for such systems since their appearance in 1980s.
Measurement of the angle alpha at BABAR
International Nuclear Information System (INIS)
Perez, A.
2009-01-01
The authors present recent measurements of the CKM angle α using data collected by the BABAR detector at the PEP-II asymmetric-energy e + e - collider at the SLAC National Accelerator Laboratory, operating at the Υ(4S) resonance. They present constraints on α from B → ππ, B → ρρ and B → ρπ decays.
Evaluation of protein dihedral angle prediction methods.
Directory of Open Access Journals (Sweden)
Harinder Singh
Full Text Available Tertiary structure prediction of a protein from its amino acid sequence is one of the major challenges in the field of bioinformatics. Hierarchical approach is one of the persuasive techniques used for predicting protein tertiary structure, especially in the absence of homologous protein structures. In hierarchical approach, intermediate states are predicted like secondary structure, dihedral angles, Cα-Cα distance bounds, etc. These intermediate states are used to restraint the protein backbone and assist its correct folding. In the recent years, several methods have been developed for predicting dihedral angles of a protein, but it is difficult to conclude which method is better than others. In this study, we benchmarked the performance of dihedral prediction methods ANGLOR and SPINE X on various datasets, including independent datasets. TANGLE dihedral prediction method was not benchmarked (due to unavailability of its standalone and was compared with SPINE X and ANGLOR on only ANGLOR dataset on which TANGLE has reported its results. It was observed that SPINE X performed better than ANGLOR and TANGLE, especially in case of prediction of dihedral angles of glycine and proline residues. The analysis suggested that angle shifting was the foremost reason of better performance of SPINE X. We further evaluated the performance of the methods on independent ccPDB30 dataset and observed that SPINE X performed better than ANGLOR.
Measurement of critical angle in SSTDs
International Nuclear Information System (INIS)
Marques, A.; Serra, D.A.B.
1984-01-01
A method of measurement of critical angles of etching is described, relying upon the distortion caused in the shape of the distribution in the number of etched tracks of ions emitted from a 'point-like' source. The method is applied to quartz and mica samples. (author)
Contact angle measurement with a smartphone.
Chen, H; Muros-Cobos, Jesus L; Amirfazli, A
2018-03-01
In this study, a smartphone-based contact angle measurement instrument was developed. Compared with the traditional measurement instruments, this instrument has the advantage of simplicity, compact size, and portability. An automatic contact point detection algorithm was developed to allow the instrument to correctly detect the drop contact points. Two different contact angle calculation methods, Young-Laplace and polynomial fitting methods, were implemented in this instrument. The performance of this instrument was tested first with ideal synthetic drop profiles. It was shown that the accuracy of the new system with ideal synthetic drop profiles can reach 0.01% with both Young-Laplace and polynomial fitting methods. Conducting experiments to measure both static and dynamic (advancing and receding) contact angles with the developed instrument, we found that the smartphone-based instrument can provide accurate and practical measurement results as the traditional commercial instruments. The successful demonstration of use of a smartphone (mobile phone) to conduct contact angle measurement is a significant advancement in the field as it breaks the dominate mold of use of a computer and a bench bound setup for such systems since their appearance in 1980s.
Biological Small Angle Scattering: Techniques, Strategies and Tips
Energy Technology Data Exchange (ETDEWEB)
Chaudhuri, Barnali [University at Buffalo (SUNY); Muñoz, Inés G. [Centro Nacional de Investigaciones Oncológicas Madrid, Madrid, Spain; Urban, Volker S. [ORNL; Qian, Shuo [ORNL
2017-12-01
This book provides a clear, comprehensible and up-to-date description of how Small Angle Scattering (SAS) can help structural biology researchers. SAS is an efficient technique that offers structural information on how biological macromolecules behave in solution. SAS provides distinct and complementary data for integrative structural biology approaches in combination with other widely used probes, such as X-ray crystallography, Nuclear magnetic resonance, Mass spectrometry and Cryo-electron Microscopy. The development of brilliant synchrotron small-angle X-ray scattering (SAXS) beam lines has increased the number of researchers interested in solution scattering. SAS is especially useful for studying conformational changes in proteins, highly flexible proteins, and intrinsically disordered proteins. Small-angle neutron scattering (SANS) with neutron contrast variation is ideally suited for studying multi-component assemblies as well as membrane proteins that are stabilized in surfactant micelles or vesicles. SAS is also used for studying dynamic processes of protein fibrillation in amyloid diseases, and pharmaceutical drug delivery. The combination with size-exclusion chromatography further increases the range of SAS applications.The book is written by leading experts in solution SAS methodologies. The principles and theoretical background of various SAS techniques are included, along with practical aspects that range from sample preparation to data presentation for publication. Topics covered include techniques for improving data quality and analysis, as well as different scientific applications of SAS. With abundant illustrations and practical tips, we hope the clear explanations of the principles and the reviews on the latest progresses will serve as a guide through all aspects of biological solution SAS.The scope of this book is particularly relevant for structural biology researchers who are new to SAS. Advanced users of the technique will find it helpful for
Federal Laboratory Consortium — TheAntenna Pattern Range (APR)features a non-metallic arch with a trolley to move the transmit antenna from the horizon to zenith. At the center of the ground plane,...
Federal Laboratory Consortium — ATR controls fully-instrumented and integrated test ranges that provide full-service support for cradle-to-grave testing. Airspace and surface target areas are used...
Ultra-small angle neutron scattering on structured materials
International Nuclear Information System (INIS)
Hainbuchner, M.
2000-12-01
In this work investigations of the inner macroscopic structure of various materials using the ultra small angle neutron scattering (USANS) technique are presented. First, the silicon double crystal and pinhole instruments used for the experiments are described. Then the basics of small angle neutron scattering theory are discussed. The treatment of the experimental scattering measurement data and the fitting of theoretical scattering models are thoroughly discussed, in particular the specific effects of the double crystal instrument geometry are considered. The used numerical procedures of the automatic data treatment and model fitting are presented. The quality and the reliability of these procedures and of the ultra small angle scattering experiments, performed on the neutron optical bench instrument S18 at the high flux reactor of the Institute Laue-Langevin, are illustrated by various measurements. The ultra small angle scattering measurements connect seamlessly or overlap with conventional pinhole measurements. For the determination the inner structure of the investigated materials a combination of ultra small and small angle scattering patterns can be used, which cover more than three orders of magnitude in momentum transfer and ten orders of magnitude in macroscopic differential scattering cross section. The specimens were carefully selected in order to represent a wide range of different materials. Artificial periodic silicon gratings were examined in order to prove high order interference effects. Measuring this kind of samples the performance of an USANS instrument can simply be determined. This allows the comparison of different instruments. For the calibration of the instrument and testing of the data treatment routines suspensions of latex spheres of various diameters were examined. In order to demonstrate that the evaluation of samples showing strong multiple scattering can produce meaningful results, measurements on sintered alumina using various
The behavior of tillage tools with acute and obtuse lift angles
Energy Technology Data Exchange (ETDEWEB)
Abbaspour-Fard, M. H.; Hoseini, S. A.; Agkhani, M. H.; Sharifi, A.
2014-06-01
An experimental investigation was conducted to study the trend of draft force against forward speed and working depth for a range of lift angles beyond acute angles for a simple plane tillage tool. The experiments were performed in an indoor soil bin facility equipped with a tool carriage and a soil preparation unit propelled by an integrated hydraulic power system. The system was also equipped with electronic instrumentation including an Extended Octagonal Ring Transducer (EORT) and a data logger. The factorial experiment (4 × 3 × 3) with three replications was used based on Randomized Complete Block Design (RCBD). The independent variables were lift angle of the blade (45, 70, 90 and 120 degree centigrade), forward speed (2, 4 and 6 km h{sup -}1) and working depth (10, 25 and 40 cm). The variance analysis for the draft force shows that all independent variables affect the draft force at 1% level of significance. The trend of the draft force against working depth and forward speed had almost a linear increase. However, the trend of the draft force against the lift angle is reversed for lift angles > 90 degree centigrade. This finding, conflicts with the results of analytical and numerical studies which extrapolate the results achieved for acute lift angles to obtuse lift angles and have not been reported experimentally. (Author)
The relationship between drained angle and flow rate of size fractions of powder excipients.
Sklubalová, Z; Zatloukal, Z
2009-12-01
The influence of powder size of chosen pharmaceutical powder excipients on drained angle as well as the correlation between drained angle and the mass flow rate of certain powder size fractions were investigated in this work. A method of the indirect estimation of the three-dimensional drained angle from the mass of the residual powder was used experimentally to study the influence of powder size fractions in range of 0.200-0.630 mm for sodium chloride, sodium citrate, potassium chloride, and potassium citrate. Failures of flow significantly increased the drained angles for powder size fraction of 0.200-0.250 mm. For the uniformly flowable powder size fraction of 0.400-0.500 mm, the faster the flow rate, the smaller drained angles were observed for excipients investigated. To estimate parameters of the flow equation, the measurement of material flow rates from the hopper of different orifice sizes is needed, while the estimation of drained angle is much easier needing only one hopper. Finally, the increase of the hopper wall angle of the standard conical hopper to 70 degrees could be recommended to achieve uniform mass flow and to reduce the adverse effect of powder gliding along the hopper walls.
Joint angles of the ankle, knee, and hip and loading conditions during split squats.
Schütz, Pascal; List, Renate; Zemp, Roland; Schellenberg, Florian; Taylor, William R; Lorenzetti, Silvio
2014-06-01
The aim of this study was to quantify how step length and the front tibia angle influence joint angles and loading conditions during the split squat exercise. Eleven subjects performed split squats with an additional load of 25% body weight applied using a barbell. Each subject's movements were recorded using a motion capture system, and the ground reaction force was measured under each foot. The joint angles and loading conditions were calculated using a cluster-based kinematic approach and inverse dynamics modeling respectively. Increases in the tibia angle resulted in a smaller range of motion (ROM) of the front knee and a larger ROM of the rear knee and hip. The external flexion moment in the front knee/hip and the external extension moment in the rear hip decreased as the tibia angle increased. The flexion moment in the rear knee increased as the tibia angle increased. The load distribution between the legs changed squat execution was varied. Our results describing the changes in joint angles and the resulting differences in the moments of the knee and hip will allow coaches and therapists to adapt the split squat exercise to the individual motion and load demands of athletes.
Erosion Behaviour of API X100 Pipeline Steel at Various Impact Angles and Particle Speeds
Directory of Open Access Journals (Sweden)
Paul C. Okonkwo
2016-09-01
Full Text Available Erosion is the gradual removal of material due to solid particle impingement and results in a failure of pipeline materials. In this study, a series of erosion tests were carried out to investigate the influence of particle speed and impact angle on the erosion mechanism of API X100 pipeline steel. A dry erosion machine was used as the test equipment, while the particle speed ranged from 20 to 80 m/s and impact angles of 30° and 90° were used as test parameters. The eroded API X100 steel surface was characterized using scanning electron microscope (SEM and X-ray photoelectron spectroscopy (XPS. The weight loss and erosion rate were also investigated. The results showed that at a 90° impact angle, a ploughing mechanism was occurring on the tested specimens, while material removal through low-angle cutting was the dominant mechanism at lower impact angles. Embedment of alumina particles on the target steel surface, micro-cutting, and low-angle cutting were observed at low impact angles. Therefore, the scratches, cuttings, and severe ploughings observed on some failed oil and gas pipelines could be attributed to the erosion mechanism.
Measure Advancing, Receding and Dynamic Contact Angles of granular materials in a close column
Callegari, Gerardo; Li, Minglu; Moghtadernejad, Sara; Drazer, German
2017-11-01
Wetting properties of granular materials are usually obtained by the Washburn column technique. One problem is that the effective contact angle measured is dynamic and variable. The open column technique also allows to measure static advancing contact angle when the interface stops because the driving capillary pressure is balanced by the hydrostatic pressure. However, when particle diameters are in the range of tens of microns the static condition cannot be achieved at practical heights. Also, the open column device cannot be used to measure receding contact angles or contact angles of non-wetting liquids. Dynamics of a close column filled with granular material of different particle sizes where the liquid mass, the enclosed air pressure and the front position are monitored as a function of time is studied. Contact angle is calculated in dynamic and advancing static conditions. Then, a Syringe pump is used to increase the pressure inside the column so that the receding contact angle can also be studied. Supplementary experiments with a reference liquid that completely wets the powder are performed. Using a second liquid decouples the properties of the bed from the result and allows to measure the contact angles without making assumptions on the pore size or geometry.
International Nuclear Information System (INIS)
Xu, X P; Zhang, G Y; Zhang, N; Wang, L Y
2006-01-01
Tilt angle of scanning mirror is one of the important qualifications of performance measurement on the earth surface for swing scanning mode infrared the earth sensor. In order to settle the problem of measuring the tilt angle of scanning mirror in dynamic, real-time and non-contact, based on laser inspecting technology and CCD probing technology, a method of laser dynamical measurement for tilt angle of scanning mirror of the infrared earth sensor is presented. The measurement system developed in this paper can accomplish the dynamic and static laser non-contact measurement for the parameters of scanning mirror such as tilt angle, swing frequency, etc. In this paper the composition and overall structure of system are introduced. Emphasis on analyzing and discussing the theory of dynamically measuring tilt angle of scanning mirror, the problems of data processing and error correction are settled by established mathematic model of system. The accuracy of measurement system is verified by experiment, the results indicated that measurement range of system for tilt angle is 0∼±12 0 , accuracy of dynamic and static measurement is less than ±0.05 0 , this method of dynamically measuring tilt angle is suitable
A new method for measuring the contact angles from digital images of liquid drops.
Mirzaei, M
2017-11-01
The drop hitting a solid surface may be symmetric or asymmetric, which depends on the surface texture and external force orientations. The accurate measurement of the contact angle is of fundamental importance for the purpose of scientific research, while having a substantial role in a wide range of practical applications. This paper presents a new image processing based method, as a computational scheme to measure the inclination angle of apparent edge curves in digital images. The main concept of the scheme is the emulation of a moving goniometer mask coupled with a Gaussian weighted function, which does not require edge fitting with analytic curves for the angle calculation. The algorithm produces as follow: allocating the exact position of the contact points by Harris corner detector function, selecting a series of points on the drop boundary near the contact points, setting goniometric mask on each given point and calculating the angles, applying the Gaussian weighted average function on the calculated angles and measure the objective contact angle. The scheme is tested on several images from recent studies in the available literature. The comparison between analytical and calculated angles shows less than 1° difference. Copyright © 2017 Elsevier Ltd. All rights reserved.
A novel method of measuring spatial rotation angle using MEMS tilt sensors
International Nuclear Information System (INIS)
Cao, Jian’an; Zhu, Xin; Zhang, Leping; Wu, Hao
2017-01-01
This paper presents a novel method of measuring spatial rotation angle with a dual-axis micro-electro-mechanical systems tilt sensor. When the sensor is randomly mounted on the surface of the rotating object, there are three unpredictable and unknown mounting position parameters: α , the sensor’s swing angle on the measuring plane; β , the angle between the rotation axis and the horizontal plane; and γ , the angle between the measuring plane and the rotation axis. Thus, the sensor’s spatial rotation model is established to describe the relationship between the measuring axis, rotation axis, and horizontal plane, and the corresponding analytical equations are derived. Furthermore, to eliminate the deviation caused by the uncertain direction of the rotation axis, an extra perpendicularly mounted, single-axis tilt sensor is combined with the dual-axis tilt sensor, forming a three-axis tilt sensor. Then, by measuring the sensors’ three tilts and solving the model’s equations, the object’s spatial rotation angle is obtained. Finally, experimental results show that the developed tilt sensor is capable of measuring spatial rotation angle in the range of ±180° with an accuracy of 0.2° if the angle between the rotation axis and the horizontal plane is less than 75°. (paper)
Directory of Open Access Journals (Sweden)
Girish Katti
2016-01-01
Full Text Available Introduction: Gonial angle is an important angle of the craniofacial complex. Lateral cephalogram and orthopantomogram (OPG can be used to determine this angle. Objectives: To investigate whether OPGs can be used as an alternative to lateral cephalogram for measuring the gonial angle. Study Design: A total of 100 radiographs were collected from patients with Angle's Class I malocclusion (50 males and 50 females with age ranging from 15 to 30 years, with a mean age of 18.24 years. Materials and Methods: The radiographs were taken with digital panoramic system (Kodak 8000C under standard exposure factors, as recommended by the manufacturer. Gonial angle was determined by the tangent of the inferior border of the mandible and the most distal aspect of the ascending ramus and condyle on both panoramic and cephalometric radiographs. Statistical Analysis: Mean values were evaluated using z test. The statistical analysis was performed by using the Statistical Package for the Social Sciences (version 11.5. Results: The mean gonial angle was 121.13° and 122.22° on panoramic and cephalometric radiographs, respectively. There was no statistical significant difference between the measured gonial angles on panoramic and cephalometric radiographs (P > 0.005. Conclusion: Panoramic radiography can be used to determine the gonial angle as accurately as lateral cephalogram. In addition, we can determine the right and left gonial angles of a patient in an OPG without interferences due to superimposed images of anatomical structures in lateral cephalogram.
Tailoring beams for small-angle neutron diffractometers
International Nuclear Information System (INIS)
Crawford, R.K.; Carpenter, J.M.
1988-01-01
Small-angle neutron scattering instruments can be built to use either steady-state or time-of-flight techniques, although only the latter are practical at pulsed neutron sources. The techniques used to provide beams of suitable quality, wavelength range and angular collimation are considered in detail for steady-state and time-of-flight instruments at reactor neutron sources, and for time-of-flight instruments at pulsed neutron sources. For both instrument types a cold neutron source provides a definite advantage. Most, but not all, steady-state instruments use long flight paths, which can be shown to provide conditions which are optimum in many ways. However, frame-overlap considerations force the use of a short flight path for time-of-flight instruments, and this in turn forces these instruments to use different collimation and beam-quality techniques from those that are usually used for steady-state instruments. Although adequate techniques now exist for building short-flight-path small-angle neutron scattering instruments, some of these short-path techniques are still developing, and can be expected to improve in the future. At present the time-of-flight instruments are more difficult to build and use, but for many experiments this difficulty is more than compensated by the large wave-vector range covered in a single measurement with such instruments. (orig.)
Energy and zenith angle dependence of atmospheric muons
Maeda, K
1973-01-01
The recently proposed new process for energetic-muon production in the atmosphere should be tested at Mt. Chacaltaya. Rigorous calculations of zenith-angle distribution of atmospheric muons have been made for the altitude of 5200 m above sea level with energy range from 100 GeV to 100 TeV and for zenith angles from 0 degrees to 92.3 degrees . Calculations are based on the extension of the Chapman function to the case of a non-isothermal atmosphere, taking into account (i) energy- dependent nuclear-interaction mean free path of cosmic-ray hadrons in air, (ii) different magnitudes of photonuclear cross-section in the energy-loss process of muons in the atmosphere, (iii) contributions of atmospheric muons arriving below the horizontal directions, and (iv) atmospheric structure and geomagnetic deflection. Results are compared with those corresponding to sea level. Range straggling, particularly its effect on horizontally incident muons, is investigated by Monte Carlo calculation, indicating that its effects and t...
Huang, Guofu; Gonzalez, Eduardo; Lee, Roland; Osmonavic, Senad; Leeungurasatien, Thidarat; He, Mingguang; Lin, Shan C
2012-07-01
To investigate anterior chamber parameters and biometric factors associated with degree of angle opening after laser peripheral iridotomy (LPI) for narrow angles. In this prospective cohort study, patients with narrow angles who were scheduled for LPI were recruited. Anterior chamber parameters by anterior segment coherence tomography (ASOCT) under dark conditions were compared before and after LPI. Only the right eye was used for analysis if both eyes were eligible. Measurements performed by customized software included anterior chamber depth, iris area, angle opening distance at 500 µm (AOD500) anterior to the scleral spur, iris thickness at 750 µm from sclera spur (IT750), trabecular-iris space area 500 (TISA500), and iris curvature (I-Curv). Univariate and multiple regression analyses were performed to determine the predictive factors of angle opening after LPI. Eighty-one patients with narrow angles were prospectively recruited in this study. The AOD500 increased significantly from 0.128 ± 0.081 mm (before) to 0.209 ± 0.087 mm (after) in the nasal quadrant, and from 0.103 ± 0.067 mm (before) to 0.197 ± 0.071 mm (after) in the temporal quadrant (p chamber angle widening after LPI were older age, smaller iris area, and steeper iris.
The relationship between knee joint angle and knee flexor and extensor muscle strength.
Ha, Misook; Han, Dongwook
2017-04-01
[Purpose] The aim of this study was to determine a relationship between joint angle and muscular strength. In particular, this research investigated the differences in maximum muscular strength and average muscular strength at the knee-joint posture. [Subjects and Methods] The study subjects comprised eight female students in their 20s attending S University in Busan. None of the subjects had functional disabilities or had experienced damage to the lower extremities in terms of measurement of muscular strength. A BIODEX system III model (Biodex medical system, USA) was used to measure joint angles and muscular strength. The axis of the dynamometer was consistent with the axis of motion, and measurements were made at 25° and 67° to examine differences in maximum muscular strength according to joint angle. [Results] The maximum muscular strength both knee-joint extension value, at 67° and flexion value, at 25° the value was larger. The average muscular strength both knee-joint extension value, at 67° and flexion value, at 25° the value was larger. [Conclusion] The results of this study reveal that muscular strength does not reach maximum at particular range angles, such as the knee-joint resting posture angle or the knee-joint middle range angle. Rather, a stretched muscle is stronger than a contracted muscle. Therefore, it is considered that it will be necessary to study the effects of the joint change ratio on muscular strength on the basis of the maximum stretched muscle.
Bezci, Semih E; Klineberg, Eric O; O'Connell, Grace D
2018-01-01
The intervertebral disc is a complex joint that acts to support and transfer large multidirectional loads, including combinations of compression, tension, bending, and torsion. Direct comparison of disc torsion mechanics across studies has been difficult, due to differences in loading protocols. In particular, the lack of information on the combined effect of multiple parameters, including axial compressive preload and rotation angle, makes it difficult to discern whether disc torsion mechanics are sensitive to the variables used in the test protocol. Thus, the objective of this study was to evaluate compression-torsion mechanical behavior of healthy discs under a wide range of rotation angles. Bovine caudal discs were tested under a range of compressive preloads (150, 300, 600, and 900N) and rotation angles (± 1, 2, 3, 4, or 5°) applied at a rate of 0.5°/s. Torque-rotation data were used to characterize shape changes in the hysteresis loop and to calculate disc torsion mechanics. Torsional mechanical properties were described using multivariate regression models. The rate of change in torsional mechanical properties with compression depended on the maximum rotation angle applied, indicating a strong interaction between compressive stress and maximum rotation angle. The regression models reported here can be used to predict disc torsion mechanics under axial compression for a given disc geometry, compressive preload, and rotation angle. Copyright © 2017 Elsevier Ltd. All rights reserved.
Carvalho, Humberto M
2015-01-01
The aim of this paper was to outline a multilevel modeling approach to fit individual angle-specific torque curves describing concentric knee extension and flexion isokinetic muscular actions in Master athletes. The potential of the analytical approach to examine between individual differences across the angle-specific torque curves was illustrated including between-individuals variation due to gender differences at a higher level. Torques in concentric muscular actions of knee extension and knee extension at 60º·s−1 were considered within a range of motion between 5º and 85º (only torques “truly” isokinetic). Multilevel time series models with autoregressive covariance structures with standard multilevel models were superior fits compared with standard multilevel models for repeated measures to fit angle-specific torque curves. Third and fourth order polynomial models were the best fits to describe angle-specific torque curves of isokinetic knee flexion and extension concentric actions, respectively. The fixed exponents allow interpretations for initial acceleration, the angle at peak torque and the decrement of torque after peak torque. Also, the multilevel models were flexible to illustrate the influence of gender differences on the shape of torque throughout the range of motion and in the shape of the curves. The presented multilevel regression models may afford a general framework to examine angle-specific moment curves by isokinetic dynamometry, and add to the understanding mechanisms of strength development, particularly the force-length relationship, both related to performance and injury prevention. PMID:26839603
Effect of EMIC Wave Normal Angle Distribution on Relativistic Electron Scattering in Outer RB
Khazanov, G. V.; Gamayunov, K. V.
2007-01-01
We present the equatorial and bounce average pitch angle diffusion coefficients for scattering of relativistic electrons by the H+ mode of EMIC waves. Both the model (prescribed) and self consistent distributions over the wave normal angle are considered. The main results of our calculation can be summarized as follows: First, in comparison with field aligned waves, the intermediate and highly oblique waves reduce the pitch angle range subject to diffusion, and strongly suppress the scattering rate for low energy electrons (E less than 2 MeV). Second, for electron energies greater than 5 MeV, the |n| = 1 resonances operate only in a narrow region at large pitch-angles, and despite their greatest contribution in case of field aligned waves, cannot cause electron diffusion into the loss cone. For those energies, oblique waves at |n| greater than 1 resonances are more effective, extending the range of pitch angle diffusion down to the loss cone boundary, and increasing diffusion at small pitch angles by orders of magnitude.
Small-angle scattering applications to materials science
International Nuclear Information System (INIS)
Gerold, V.
1978-01-01
The review describes results of the last three or four years from the application of both X-ray and neutron small-angle scattering (SAS) to problems in the general field of materials science. A wide range of topics has been covered including phase separation in binary and ternary systems (early stages as well as the determination of the metastable miscibility gap), density and concentration fluctuations in single-phase systems, and studies of various structural defects such as voids, radiation damage, dislocations, and surfaces and interfaces. The interaction between magnetic moments and neutrons has made possible SAS research on the long-range interaction of spins in complicated magnetic systems and flux-line studies in type-II superconductors, and this work is also reviewed. (Auth.)
HYDRODYNAMICS OF OSCILLATING WING ON THE PITCH ANGLE
Directory of Open Access Journals (Sweden)
Vitalii Korobov
2017-07-01
Full Text Available Purpose: research of the hydrodynamic characteristics of a wing in a nonstationary stream. Methods: The experimental studies of the hydrodynamic load acting on the wing of 1.5 elongation, wich harmonically oscillated respect to the transversal axis in the frequency range of 0.2-2.5 Hz. The flow speed in the hydrodynamic tunnel ranged of 0.2-1.5 m/s. Results: The instantaneous values of the coefficients of lift and drag / thrust on the pitch angle at unsteady flow depends on the Strouhal number.Discussion: with increasing oscillation frequency coefficients of hydrodynamic force components significantly higher than the data for the stationary blowing out of the wing.
Aerodynamic performance of wind turbine under different yaw angles
DEFF Research Database (Denmark)
Shi, Yali; Zuo, Hongmei; Yang, Hua
2015-01-01
reduced. When the yaw angle is within 30°, the relative error of axial load coefficients is in the range of ±5% and the relative error of tangential load coefficients is in the range of ±15%. CFD method is higher than BEM (blade element momentum) method in forecasting accuracy of dynamic load calculation......A typical dynamic characteristic of horizontal axis wind turbine shows up under yaw condition. Prediction accuracy is low for momentum-blade element theory and related engineering prediction model. In order to improve the prediction accuracy of dynamic load characteristics, the whole wind turbine......×10-6 m to ensure the first dimensionless size near the wall Y+load on the airfoil in the 60% section of blades, which respectively are 6 572 451 and 2 961 385. The aerodynamic performance of models under rated condition...
Dye and pigment-free structural colors and angle-insensitive spectrum filters
Energy Technology Data Exchange (ETDEWEB)
Guo, Lingjie Jay; Hollowell, Andrew E.; Wu, Yi-Kuei
2017-01-17
Optical spectrum filtering devices displaying minimal angle dependence or angle insensitivity are provided. The filter comprises a localized plasmonic nanoresonator assembly having a metal material layer defining at least one nanogroove and a dielectric material disposed adjacent to the metal material layer. The dielectric material is disposed within the nanogroove(s). The localized plasmonic nanoresonator assembly is configured to funnel and absorb a portion of an electromagnetic spectrum in the at least one nanogroove via localized plasmonic resonance to generate a filtered output having a predetermined range of wavelengths that displays angle insensitivity. Thus, flexible, high efficiency angle independent color filters having very small diffraction limits are provided that are particularly suitable for use as pixels for various display devices or for use in anti-counterfeiting and cryptography applications. The structures can also be used for colored print applications and the elements can be rendered as pigment-like particles.
Contact angles on a soft solid: from Young's law to Neumann's law.
Marchand, Antonin; Das, Siddhartha; Snoeijer, Jacco H; Andreotti, Bruno
2012-12-07
The contact angle that a liquid drop makes on a soft substrate does not obey the classical Young's relation, since the solid is deformed elastically by the action of the capillary forces. The finite elasticity of the solid also renders the contact angles differently from those predicted by Neumann's law, which applies when the drop is floating on another liquid. Here, we derive an elastocapillary model for contact angles on a soft solid by coupling a mean-field model for the molecular interactions to elasticity. We demonstrate that the limit of a vanishing elastic modulus yields Neumann's law or a variation thereof, depending on the force transmission in the solid surface layer. The change in contact angle from the rigid limit to the soft limit appears when the length scale defined by the ratio of surface tension to elastic modulus γ/E reaches the range of molecular interactions.
Mandibular Angle Fractures: A Clinical and Biomechanical Comparison-the Works of Ellis and Haug.
Haug, Richard H; Serafin, Bethany L
2008-11-01
In a series of articles spanning 8 years, Ed Ellis reviewed the clinical results of the treatment of 478 mandibular angle fractures managed by eight different techniques. During a series of benchtop investigations employing polyurethane synthetic mandible replicas, Rich Haug investigated the biomechanical behavior of approximately 15 different techniques designed to reconstruct mandibular angle fractures. This article reviews these two series of investigations in an attempt to gain insight into the biomechanical and biological factors that affect the successful reconstruction of mandibular angle fractures. It appears that the current techniques used to reconstruct mandibular angle fractures are sound from the standpoint of biomechanics within a range of forces encountered during clinical function. It also appears that an unsuccessful reconstruction is based on a biological result of a behavioral issue such as noncompliance, substance abuse, and/or nutritional or immune compromise.
Contact angle of water droplets in a high temperature, high pressure environment
International Nuclear Information System (INIS)
Hayashi, T.; Hazuku, T.; Takamasa, T.; Takamori, K.
2004-01-01
This paper presents an experimental study of surface wettability on a stainless plate in a high-temperature, high-pressure environment. Using a pressure vessel, we measured contact angles of water droplets at temperatures from 20 to 300 C. deg. and a constant pressure of 15 MPa, as an indicator of macroscopic surface wettability. Measured contact angles decreased with temperature below 250 C. deg., clustering around a straight line at temperatures below 120 C. deg. and around another line in the range from 120 to 250 C. deg.. At temperatures above 250 C. deg., on the other hand, the contact angles remained constant, independent of temperature, and contrary to the existing theoretical model, no highly hydrophilic condition or null contact angle condition was achieved. This result will enable more accurate assessment of heat transfer not only in steam pipes of a boiler but also in subchannel of a BWR-type reactor. (authors)
MR study of the intrinsic acromial angle in 74 symptomatic patients
International Nuclear Information System (INIS)
Di Mario, Mario; Fraracci, Lucio
2005-01-01
Purpose. The study was undertaken to define some measurements on sagittal MR images that could provide quantitative data on the subacromial spece in patients affected by nonspecific impingement syndrome and to correlate these measurements with the Bigliani classification of acromial morphology. Materials and methods. We retrospectively reviewed 74 shoulders in 74 patients (47 males, 27 females, age range 35-62 years) who presented with mechanical disability and pain. The patients underwent MRl using TI-weighted sagittal oblique and coronaI SE sequences (TR 500 ms,TE 12 ms) and T2-weighted FSE sequences (TR 3500, TE 25 ms) with dedicated coil. Two parameters were evaluated: the intrinsic acromial angle and the acromio-humeral distance. The measurements were made on the sagittal images at the acromion-clavicular junction and correlated to the Bigliani classification of acromial morphology. The images were evaluated by two radiologists blinded to the patients' identity, history and arthroscopic results. Results. The acromial angle was measured in 72 shoulders. The values were found to correlate with tue Bigliani classification. In our series, the intrinsic acromial angle (resulting from the intersection between the longitudinal acromial axis and the tangent to the acromial undersurface) ranged from 0 o to 17 o . In shoulders with rotator cuff tears the acromial angle varied between 8 o and 17 o . There were no tears for acromial angles below 8 o , whereas in patients with full-thickness tears the angles ranged from a minimum of 12 o to a maximum of 15 o . Acromio-humeral distance ranged from 2 mm to 10 mm; in patients with cuff tears it could not be assessed as it was close to zero in nearly all cases, whereas in cases of impingement without cuff tear it ranged from 5 mm to 10 mm. Impingement without cuff tear was detected in 31 cases, with angles ranging from 10 o to 17 o . Conclusions. Our findings demonstrate the effectiveness of the two quantitative parameters
DEFF Research Database (Denmark)
Jørgensen, Allan Grønlund; Larsen, Kasper Green
2011-01-01
and several natural special cases thereof. The rst special case is known as range median, which arises when k is xed to b(j i + 1)=2c. The second case, denoted prex selection, arises when i is xed to 0. Finally, we also consider the bounded rank prex selection problem and the xed rank range......Range selection is the problem of preprocessing an input array A of n unique integers, such that given a query (i; j; k), one can report the k'th smallest integer in the subarray A[i];A[i+1]; : : : ;A[j]. In this paper we consider static data structures in the word-RAM for range selection...... selection problem. In the former, data structures must support prex selection queries under the assumption that k for some value n given at construction time, while in the latter, data structures must support range selection queries where k is xed beforehand for all queries. We prove cell probe lower bounds...
International Nuclear Information System (INIS)
Olsson, Anders; Hellsing, Maja S; Rennie, Adrian R
2013-01-01
Sedimentation, or creaming, of samples can significantly alter the amount of material in the beam during small-angle scattering experiments. Simple rotating mounts that ameliorate this effect are described and the design criteria are carefully discussed. A modular design permits simple adaptation to various instruments and different sample cells. Temperature control in the range 10 °C below ambient to about +40 °C has been implemented using air flow and a Peltier device. Example ultra small-angle neutron scattering data are shown that exploit the simplicity of the mounts and the capability to position several samples close together on a translation stage. (paper)
DEFF Research Database (Denmark)
Bille, Philip; Gørtz, Inge Li
2011-01-01
We revisit various string indexing problems with range reporting features, namely, position-restricted substring searching, indexing substrings with gaps, and indexing substrings with intervals. We obtain the following main results. – We give efficient reductions for each of the above problems...... to a new problem, which we call substring range reporting. Hence, we unify the previous work by showing that we may restrict our attention to a single problem rather than studying each of the above problems individually. – We show how to solve substring range reporting with optimal query time and little...... space. Combined with our reductions this leads to significantly improved time-space trade-offs for the above problems. In particular, for each problem we obtain the first solutions with optimal time query and O(n logO(1) n) space, where n is the length of the indexed string. Our bounds for substring...
DEFF Research Database (Denmark)
Bille, Philip; Gørtz, Inge Li
2014-01-01
We revisit various string indexing problems with range reporting features, namely, position-restricted substring searching, indexing substrings with gaps, and indexing substrings with intervals. We obtain the following main results. We give efficient reductions for each of the above problems...... to a new problem, which we call substring range reporting. Hence, we unify the previous work by showing that we may restrict our attention to a single problem rather than studying each of the above problems individually. We show how to solve substring range reporting with optimal query time and little...... space. Combined with our reductions this leads to significantly improved time-space trade-offs for the above problems. In particular, for each problem we obtain the first solutions with optimal time query and O(nlog O(1) n) space, where n is the length of the indexed string. We show that our techniques...
Pre-Launch JPSS-2 VIIRS Response versus Scan Angle Characterization
Directory of Open Access Journals (Sweden)
Jeff McIntire
2017-12-01
Full Text Available On-orbit whisk-broom sensors have scanning mirror assemblies, whose reflectance variations with scan angle must be characterized prior to launch. One such instrument is the Visible Infrared Imaging Radiometer Suite (VIIRS onboard the Joint Polar Satellite System 2 (JPSS-2 platform. The scanning optics inside VIIRS includes a four mirror rotating telescope assembly (RTA and a half angle mirror (HAM, rotating at half the speed of the RTA, which de-rotates the light before it enters the aft-optics assembly. The angle of incidence (AOI on the HAM varies with scan angle; all of the other optical components in VIIRS have a fixed AOI with scan angle. In general, the reflectance of the HAM will vary with AOI. This parameter is difficult to quantify once in orbit and therefore must be characterized pre-launch. Ground measurements were performed in the summer of 2016 to determine the relative reflectance change of the instrument with scan angle, referred to as the response versus scan angle (RVS. This work will describe the RVS testing performed and the results obtained, including an atmospheric water vapor correction and an uncertainty analysis. Results indicate that the reflectance variation with scan angle is small for spectral bands between 0.4 μ m and 4 μ m (less than 2% over the full range of AOI; in contrast, the reflectance variation is between 3% and 10% for the spectral bands in the 8 μ m to 12 μ m range. Uncertainties are below 0.05% in the reflective solar spectral region and below 0.26% in the thermal emissive spectral region. Comparisons to previous VIIRS builds (on the SNPP and JPSS-1 satellites show comparable performance.
Rotational error in path integration: encoding and execution errors in angle reproduction.
Chrastil, Elizabeth R; Warren, William H
2017-06-01
Path integration is fundamental to human navigation. When a navigator leaves home on a complex outbound path, they are able to keep track of their approximate position and orientation and return to their starting location on a direct homebound path. However, there are several sources of error during path integration. Previous research has focused almost exclusively on encoding error-the error in registering the outbound path in memory. Here, we also consider execution error-the error in the response, such as turning and walking a homebound trajectory. In two experiments conducted in ambulatory virtual environments, we examined the contribution of execution error to the rotational component of path integration using angle reproduction tasks. In the reproduction tasks, participants rotated once and then rotated again to face the original direction, either reproducing the initial turn or turning through the supplementary angle. One outstanding difficulty in disentangling encoding and execution error during a typical angle reproduction task is that as the encoding angle increases, so does the required response angle. In Experiment 1, we dissociated these two variables by asking participants to report each encoding angle using two different responses: by turning to walk on a path parallel to the initial facing direction in the same (reproduction) or opposite (supplementary angle) direction. In Experiment 2, participants reported the encoding angle by turning both rightward and leftward onto a path parallel to the initial facing direction, over a larger range of angles. The results suggest that execution error, not encoding error, is the predominant source of error in angular path integration. These findings also imply that the path integrator uses an intrinsic (action-scaled) rather than an extrinsic (objective) metric.
Associations between alpha angle and herniation pit on MRI revisited in 185 asympomatic hip joints
Energy Technology Data Exchange (ETDEWEB)
Lee, Eun Chae; Choi, Jung Ah [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)
2015-12-15
To evaluate the association between alpha angle and herniation pit on MRI in asymptomatic hip joints and their associations with demographic variables.Hip MRI of 185 asymptomatic hip joints of 105 adults (age 18 to 80 years) from September 2011 through December 2012 were retrospectively studied. Alpha angles were measured on oblique axial MR images by 2 observers. Herniation pit was determined by 1 observer. Size measures, prevalence, and statistical analyses were conducted regarding its association with age, gender, laterality (right or left hip). Intra- and inter-observer agreements were determined by intra-class correlation coefficient. The prevalence of herniation pit in asymptomatic hips was 21.6%. The range of alpha angle was 27.6-65.0 degrees. Seventeen and 16 out of 185 (9.1% and 8.6%) hip joints showed alpha angle of ≥ 55 degrees in first and second measurement sessions, respectively. There was no association between alpha angle ≥ 55 and presence of herniation pit. There was no association between alpha angle ≥ 55 and the size of herniation pit. Inter-observer agreement of alpha angle was 0.485 between first measurements of first vs. second observer, respectively. Intra-observer agreement of alpha angle was 0.654, respectively. Forty (21.6%) of 185 hip joints (35 of 105 patients, 33.3%) had herniation pit, with no difference according to age, gender, or laterality of hip joint. There is no association between alpha angle ≥ 55 degrees and presence of herniation pit or demographic variables.
Chincisan, Andra; Tecante, Karelia; Becker, Matthias; Magnenat-Thalmann, Nadia; Hurschler, Christof; Choi, Hon Fai
2016-05-01
Muscles are the primary component responsible for the locomotion and change of posture of the human body. The physiologic basis of muscle force production and movement is determined by the muscle architecture (maximum muscle force, [Formula: see text], optimal muscle fiber length, [Formula: see text], tendon slack length, [Formula: see text], and pennation angle at optimal muscle fiber length, [Formula: see text]). The pennation angle is related to the maximum force production and to the range of motion. The aim of this study was to investigate a computational approach to calculate subject-specific pennation angle from magnetic resonance images (MRI)-based 3D anatomical model and to determine the impact of this approach on the motion analysis with personalized musculoskeletal models. A 3D method that calculates the pennation angle using MRI was developed. The fiber orientations were automatically computed, while the muscle line of action was determined using approaches based on anatomical landmarks and on centroids of image segmentation. Three healthy male volunteers were recruited for MRI scanning and motion capture acquisition. This work evaluates the effect of subject-specific pennation angle as musculoskeletal parameter in the lower limb, focusing on the quadriceps group. A comparison was made for assessing the contribution of personalized models on motion analysis. Gait and deep squat were analyzed using neuromuscular simulations (OpenSim). The results showed variation of the pennation angle between the generic and subject-specific models, demonstrating important interindividual differences, especially for the vastus intermedius and vastus medialis muscles. The pennation angle variation between personalized and generic musculoskeletal models generated significant variation in muscle moments and forces during dynamic motion analysis. A MRI-based approach to define subject-specific pennation angle was proposed and evaluated in motion analysis models. The
Associations between alpha angle and herniation pit on MRI revisited in 185 asympomatic hip joints
International Nuclear Information System (INIS)
Lee, Eun Chae; Choi, Jung Ah
2015-01-01
To evaluate the association between alpha angle and herniation pit on MRI in asymptomatic hip joints and their associations with demographic variables.Hip MRI of 185 asymptomatic hip joints of 105 adults (age 18 to 80 years) from September 2011 through December 2012 were retrospectively studied. Alpha angles were measured on oblique axial MR images by 2 observers. Herniation pit was determined by 1 observer. Size measures, prevalence, and statistical analyses were conducted regarding its association with age, gender, laterality (right or left hip). Intra- and inter-observer agreements were determined by intra-class correlation coefficient. The prevalence of herniation pit in asymptomatic hips was 21.6%. The range of alpha angle was 27.6-65.0 degrees. Seventeen and 16 out of 185 (9.1% and 8.6%) hip joints showed alpha angle of ≥ 55 degrees in first and second measurement sessions, respectively. There was no association between alpha angle ≥ 55 and presence of herniation pit. There was no association between alpha angle ≥ 55 and the size of herniation pit. Inter-observer agreement of alpha angle was 0.485 between first measurements of first vs. second observer, respectively. Intra-observer agreement of alpha angle was 0.654, respectively. Forty (21.6%) of 185 hip joints (35 of 105 patients, 33.3%) had herniation pit, with no difference according to age, gender, or laterality of hip joint. There is no association between alpha angle ≥ 55 degrees and presence of herniation pit or demographic variables
Small-angle neutron scattering measurement of silicon nanoparticle size
International Nuclear Information System (INIS)
Choi, Jonghoon; Tung, Shih-Huang; Wang, Nam Sun; Reipa, Vytas
2008-01-01
We have determined the particle size distribution profiles of octane-terminated silicon nanoparticle suspensions, produced using the sonication of electrochemically etched Si wafers. Small-angle neutron scattering data was analyzed separately in high (0.4 nm -1 -1 ) and low (q -1 ) scattering vector ranges. Data in the high q range is consistent with the log-normal distribution of isolated spherical particles with median diameter d = 3 ± 0.2 nm. Particle sizes were also indirectly assessed from photoluminescence and optical transmission spectroscopy using the size/bandgap relation: E g = 3.44d -0.5 , where E g is in eV and d in nm. Both measurements were consistent with the particle size distribution profiles, estimated from ANS data fitting and TEM image analysis. A subpopulation of larger, irregular shape structures in the size range 10-50 nm was also indicated by neutron scattering in the low q range and HRTEM images. However, further studies are warranted to explain a relationship between the slope of scattering intensity versus scattering vector dependence in the intermediate scattering vector range (0.4 nm -1 -1 ) and the role of non-geometrical Si nanoparticle characteristics (mutual interaction forces, surface termination, etc)
A wide-range magnetic spectrometer for electron scattering in medium energy range
International Nuclear Information System (INIS)
Mao Zhenlin
1988-01-01
A non-focusing magnetic spectrometer design for electron scattering in medium energy region is proposed. The positions read out from the position-sensitive detectors in the spectrometer are used for track reconstruction and momentum measurement by means of a computer program. The construction of this spectrometer is simple and there is no special technique and element for correction to aberration. It is suitable for usage of spectrometer with large solid angle and wide momentum range. The momentum resolution, momentum range and acceptance in a practical case are calculated by Monte Carlo simulation
Contact angle and contact angle hysteresis measurements using the capillary bridge technique.
Restagno, Frédéric; Poulard, Christophe; Cohen, Céline; Vagharchakian, Laurianne; Léger, Liliane
2009-09-15
A new experimental technique is proposed to easily measure both advancing and receding contact angles of a liquid on a solid surface, with unprecedented accuracy. The technique is based on the analysis of the evolution of a capillary bridge formed between a liquid bath and a solid surface (which needs to be spherical) when the distance between the surface and the liquid bath is slowly varied. The feasibility of the technique is demonstrated using a low-energy perfluorinated surface with two different test liquids (water and hexadecane). A detailed description of both experimental procedures and computational modeling are given, allowing one to determine contact angle values. It is shown that the origin of the high accuracy of this technique relies on the fact that the contact angles are automatically averaged over the whole periphery of the contact. This method appears to be particularly adapted to the characterization of surfaces with very low contact angle hysteresis.
DEFF Research Database (Denmark)
Abrahamsen, Mikkel; de Berg, Mark; Buchin, Kevin
2017-01-01
an optimal k-clustering for S P ∩ Q. We obtain the following results. • We present a general method to compute a (1 + ϵ)-approximation to a range-clustering query, where ϵ > 0 is a parameter that can be specified as part of the query. Our method applies to a large class of clustering problems, including k...
Agriculture, forestry, range resources
Macdonald, R. B.
1974-01-01
The necessary elements to perform global inventories of agriculture, forestry, and range resources are being brought together through the use of satellites, sensors, computers, mathematics, and phenomenology. Results of ERTS-1 applications in these areas, as well as soil mapping, are described.
2008-01-01
Space-Based Range (SBR), previously known as Space-Based Telemetry and Range Safety (STARS), is a multicenter NASA proof-of-concept project to determine if space-based communications using NASA's Tracking and Data Relay Satellite System (TDRSS) can support the Range Safety functions of acquiring tracking data and generating flight termination signals, while also providing broadband Range User data such as voice, video, and vehicle/payload data. There was a successful test of the Range Safety system at Wallops Flight Facility (WFF) on December 20, 2005, on a two-stage Terrier-Orion spin-stabilized sounding rocket. SBR transmitted GPS tracking data and maintained links with two TDRSS satellites simultaneously during the 10-min flight. The payload section deployed a parachute, landed in the Atlantic Ocean about 90 miles downrange from the launch site, and was successfully recovered. During the Terrier-Orion tests flights, more than 99 percent of all forward commands and more than 95 percent of all return frames were successfully received and processed. The time latency necessary for a command to travel from WFF over landlines to White Sands Complex and then to the vehicle via TDRSS, be processed onboard, and then be sent back to WFF was between 1.0 s and 1.1 s. The forward-link margins for TDRS-10 (TDRS East [TDE]) were 11 dB to 12 dB plus or minus 2 dB, and for TDRS-4 (TDRS Spare [TDS]) were 9 dB to 10 dB plus or minus 1.5 dB. The return-link margins for both TDE and TDS were 6 dB to 8 dB plus or minus 3 dB. There were 11 flights on an F-15B at Dryden Flight Research Center (DFRC) between November 2006 and February 2007. The Range User system tested a 184-element TDRSS Ku-band (15 GHz) phased-array antenna with data rates of 5 Mbps and 10 Mbps. This data was a combination of black-and-white cockpit video, Range Safety tracking and transceiver data, and aircraft and antenna controller data streams. IP data formatting was used.
Fan Stagger Angle for Dirt Rejection
Gallagher, Edward J. (Inventor); Rose, Becky E. (Inventor); Brilliant, Lisa I. (Inventor)
2015-01-01
A gas turbine engine includes a spool, a turbine coupled to drive the spool, a propulsor coupled to be rotated about an axis by the turbine through the spool, and a gear assembly coupled between the propulsor and the spool such that rotation of the turbine drives the propulsor at a different speed than the spool. The propulsor includes a hub and a row of propulsor blades that extend from the hub. Each of the propulsor blades has a span between a root at the hub and a tip, and a chord between a leading edge and a trailing edge. The chord forms a stagger angle alpha with the axis, and the stagger angle alpha is less than 15 deg. at a position along the propulsor blade that is within an inboard 20% of the span.
The small angle diffractometer SANS at PSI
Energy Technology Data Exchange (ETDEWEB)
Wagner, W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)
1996-11-01
With the start-up of SINQ an instrument for small angle neutron scattering will be operational which compares well with the world`s largest and most powerful facilities of this kind. Following the classical principle of the D11-instrument of ILL, it is equipped with state-of-the-art components as are nowadays available, including options for further upgrading. Great emphasis was laid upon providing a flexible, universal multi-user facility which guarantees a comfortable and reliable operation. In the present paper, the principle layout of the instrument is presented, and the individual components are described in detail. The paper concludes with model application of small angle scattering to a system of dilute CuCo alloys which undergo a phase separation under thermal treatment, forming spherical Co-precipitates dispersed in a Cu-rich matrix. (author) 3 figs., 1 tab., 14 refs.
Didactical Design Enrichment of Angle in Geometry
Setiadi, D. R.; Suryadi, D.; Mulyana, E.
2017-09-01
The underlying problem of this research is the lack of student’s competencies in understanding the concept of angle in geometry as the results of the teaching and learning pattern that only to receive the topic rather than to construct the topic and has not paid attention to the learning trajectory. The purpose of this research is to develop the didactical design of angle in space learning activity. The used research method is a method of qualitative research in the form of a didactical design research through three phases of analysis i.e. didactical situation analysis, metapedadidactical analysis, and retrospective analysis, which conducted in students from 10th grade at one of private schools in Bandung. Based on the results of research and discussion, the didactical design that has been made, is capable to change student’s learning habit and quite capable to develop student’s competencies although not optimal.
What's the angle: a study of the angle bisected in intraoral radiography.
Manson-Hing, L R
1980-01-01
Intraoral radiographs were made via the bisecting-the-angle technique on patients of different ages, sexes, and races. The tooth-film angles for various areas of the mouth were measured and found to be close to 30 degrees for all areas of the mouth except the mandibular posterior regions. The study was conducted to assist in quick positioning of the x-ray beam in difficult cases.
Measurement of the angle alpha at BABAR
Energy Technology Data Exchange (ETDEWEB)
Perez, A.; /Orsay, LAL
2009-06-25
The authors present recent measurements of the CKM angle {alpha} using data collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory, operating at the {Upsilon}(4S) resonance. They present constraints on {alpha} from B {yields} {pi}{pi}, B {yields} {rho}{rho} and B {yields} {rho}{pi} decays.
Small-Angle Scattering on Magnetoferritin Nanoparticles
Balejčíková Petrenko, L., VI; Avdeev, MV; Garamus, VM; Almásy, L.; Kopčanský, P.
2017-05-01
Magnetoferritin is a synthetically prepared magnetic bio-complex, consisting of apoferritin shell and iron-based nanoparticles. Superparamagnetic behaviour, nanoscale size (about 12 nm) and biological origin allow to use magnetoferritin in various applications. In this report, we present a general overview about basic physicochemical properties of magnetoferritin, as determined by small-angle X-ray and neutron scattering experiments and some interesting references on their potential bio-applications.
Neutron Reflectivity and Grazing Angle Diffraction
Ankner, J. F.; Majkrzak, C. F.; Satija, S. K.
1993-01-01
Over the last 10 years, neutron reflectivity has emerged as a powerful technique for the investigation of surface and interfacial phenomena in many different fields. In this paper, a short review of some of the work on neutron reflectivity and grazing-angle diffraction as well as a description of the current and planned neutron rcflectometers at NIST is presented. Specific examples of the characterization of magnetic, superconducting, and polymeric surfaces and interfaces are included.
Neutron Reflectivity and Grazing Angle Diffraction.
Ankner, J F; Majkrzak, C F; Satija, S K
1993-01-01
Over the last 10 years, neutron reflectivity has emerged as a powerful technique for the investigation of surface and interfacial phenomena in many different fields. In this paper, a short review of some of the work on neutron reflectivity and grazing-angle diffraction as well as a description of the current and planned neutron rcflectometers at NIST is presented. Specific examples of the characterization of magnetic, superconducting, and polymeric surfaces and interfaces are included.
Ultra small angle scattering versus diffraction
Ebrahimi, O.; Treimer, W.; Strobl, M.; Feye-Treimer, U.; Beul, N.; Jericha, E.; Seidel, S. O.
2010-11-01
In the case of ultra small angle (neutron or x-ray) scattering (USANS, USAXS) it may happen that structures under investigations are not fully coherently illuminated by the incident wave. Despite this fact interference effects are observed similar to SAS data. In this case the measured scattering patterns must be different interpreted. We propose a procedure to calculate and adapt such scattering patterns to experimental data.
Ultra small angle scattering versus diffraction
International Nuclear Information System (INIS)
Ebrahimi, O; Treimer, W; Strobl, M; Feye-Treimer, U; Beul, N; Jericha, E; Seidel, S O
2010-01-01
In the case of ultra small angle (neutron or x-ray) scattering (USANS, USAXS) it may happen that structures under investigations are not fully coherently illuminated by the incident wave. Despite this fact interference effects are observed similar to SAS data. In this case the measured scattering patterns must be different interpreted. We propose a procedure to calculate and adapt such scattering patterns to experimental data.
Resonances and backward-angle scattering
International Nuclear Information System (INIS)
Stokstad, R.G.
1978-01-01
The strong enhancement of elastic scattering at large angles observed for systems such as α + 40 Ca and recently for 12 C + 28 Si and 16 O 28 Si was interpreted in terms of entrance channel resonances having a quasi-molecular character. Alternative explanations in terms of potential scattering were also presented. An overview is given of the experimental data and their interpretations. A consistent procedure for the evaluation of the experimental data is discussed. 50 references
Aerodynamic Investigation of Incidence Angle Effects in a Large Scale Transonic Turbine Cascade
McVetta, Ashlie B.; Giel, Paul W.; Welch, Gerard E.
2013-01-01
Aerodynamic measurements showing the effects of large incidence angle variations on an HPT turbine blade set are presented. Measurements were made in NASA's Transonic Turbine Blade Cascade Facility which has been used in previous studies to acquire detailed aerodynamic and heat transfer measurements for CFD code validation. The current study supports the development of variable-speed power turbine (VSPT) speed-change technology for the NASA Large Civil Tilt Rotor (LCTR) vehicle. In order to maintain acceptable main rotor propulsive efficiency, the VSPT operates over a nearly 50 percent speed range from takeoff to altitude cruise. This results in 50deg or more variations in VSPT blade incidence angles. The cascade facility has the ability to operate over a wide range of Reynolds numbers and Mach numbers, but had to be modified in order to accommodate the negative incidence angle variation required by the LCTR VSPT operation. Using existing blade geometry with previously acquired aerodynamic data, the tunnel was re-baselined and the new incidence angle range was exercised. Midspan exit total pressure and flow angle measurements were obtained at seven inlet flow angles. For each inlet angle, data were obtained at five flow conditions with inlet Reynolds numbers varying from 6.83×10(exp 5) to 0.85×10(exp 5) and two isentropic exit Mach numbers of 0.74 and 0.34. The midspan flowfield measurements were acquired using a three-hole pneumatic probe located in a survey plane 8.6 percent axial chord downstream of the blade trailing edge plane and covering three blade passages. Blade and endwall static pressure distributions were also acquired for each flow condition.
McVetta, Ashlie B.; Giel, Paul W.; Welch, Gerard E.
2014-01-01
Aerodynamic measurements showing the effects of large incidence angle variations on an HPT turbine blade set are presented. Measurements were made in NASA's Transonic Turbine Blade Cascade Facility which has been used in previous studies to acquire detailed aerodynamic and heat transfer measurements for CFD code validation. The current study supports the development of variable-speed power turbine (VSPT) speed-change technology for the NASA Large Civil Tilt Rotor (LCTR) vehicle. In order to maintain acceptable main rotor propulsive efficiency, the VSPT operates over a nearly 50 percent speed range from takeoff to altitude cruise. This results in 50 deg or more variations in VSPT blade incidence angles. The cascade facility has the ability to operate over a wide range of Reynolds numbers and Mach numbers, but had to be modified in order to accommodate the negative incidence angle variation required by the LCTR VSPT operation. Using existing blade geometry with previously acquired aerodynamic data, the tunnel was re-baselined and the new incidence angle range was exercised. Midspan exit total pressure and flow angle measurements were obtained at seven inlet flow angles. For each inlet angle, data were obtained at five flow conditions with inlet Reynolds numbers varying from 6.83×10 (exp 5) to 0.85×10(exp 5) and two isentropic exit Mach numbers of 0.74 and 0.34. The midspan flowfield measurements were acquired using a three-hole pneumatic probe located in a survey plane 8.6 percent axial chord downstream of the blade trailing edge plane and covering three blade passages. Blade and endwall static pressure distributions were also acquired for each flow condition.
Off-Angle Iris Correction Methods
Energy Technology Data Exchange (ETDEWEB)
Santos-Villalobos, Hector J [ORNL; Thompson, Joseph T [ORNL; Karakaya, Mahmut [ORNL; Boehnen, Chris Bensing [ORNL
2016-01-01
In many real world iris recognition systems obtaining consistent frontal images is problematic do to inexperienced or uncooperative users, untrained operators, or distracting environments. As a result many collected images are unusable by modern iris matchers. In this chapter we present four methods for correcting off-angle iris images to appear frontal which makes them compatible with existing iris matchers. The methods include an affine correction, a retraced model of the human eye, measured displacements, and a genetic algorithm optimized correction. The affine correction represents a simple way to create an iris image that appears frontal but it does not account for refractive distortions of the cornea. The other method account for refraction. The retraced model simulates the optical properties of the cornea. The other two methods are data driven. The first uses optical flow to measure the displacements of the iris texture when compared to frontal images of the same subject. The second uses a genetic algorithm to learn a mapping that optimizes the Hamming Distance scores between off-angle and frontal images. In this paper we hypothesize that the biological model presented in our earlier work does not adequately account for all variations in eye anatomy and therefore the two data-driven approaches should yield better performance. Results are presented using the commercial VeriEye matcher that show that the genetic algorithm method clearly improves over prior work and makes iris recognition possible up to 50 degrees off-angle.
Studies in small angle scattering techniques
International Nuclear Information System (INIS)
Moellenbach, K.
1980-03-01
Small angle scattering of neutrons, X-rays and γ-rays are found among the spectroscopic methods developed in the recent years. Although these techniques differ from each other in many respects, e.g. radiation sources and technical equipment needed, their power to resolve physical phenomena and areas of application can be discussed in a general scheme. Selected examples are given illustrating the use of specific technical methods. Jahn-Teller driven structural phase transitions in Rare Earth zircons were studied with neutron scattering as well as small angle γ-ray diffraction. The study of neutron scattering from formations of magnetic domains in the Ising ferromagnet LiTbF 4 is a second example. Both these examples represent more than experimental test cases since the theoretical interpretations of the data obtained are discussed as well. As a last example the use of small angle scattering methods for the study of molecular biological samples is discussed. In particular the experimental procedures used in connection with scattering from aqueous solutions of proteins and protein complexes are given. (Auth.)
Research on recognition of ramp angle based on transducer
Directory of Open Access Journals (Sweden)
Wenhao GU
2015-12-01
Full Text Available Focusing on the recognition of ramp angle, the relationship between the signal of vehicle transducer and real ramp angle is studied. The force change of vehicle on the ramp, and the relationship between the body tilt angle and front and rear suspension scale is discussed. According to the suspension and tire deformation, error angle of the ramp angle is deduced. A mathematical model is established with Matlab/Simulink and used for simulation to generate error curve of ramp angle. The results show that the error angle increases with the increasing of the ramp angle, and the limit value can reach 6.5%, while the identification method can effectively eliminate this error, and enhance the accuracy of ramp angle recognition.
The effect of beam angle in abrasive-waterjet machining
International Nuclear Information System (INIS)
Hashish, M.
1989-01-01
In the machining of materials, abrasive-waterjets are typically applied at a 90-degree angle to the surface of the workpiece. This paper presents results and observations on machining with abrasive-waterjets at angles other than 90 degrees. Previous visualization studies of the cutting process in transparent materials has shown that there are optimal angles for maximum depth of cut and kerf depth uniformity. Here, observations on the effect of angle in machining applications, such as turning, milling. linear cutting, and drilling, are addressed. The effects of variations in both the impact angle and the rake angle are investigated. Results indicate that the volume removal rate is significantly affected by these angles and that surface finish can be improved by angling the jet. However, shallow angle drilling of small holes in laminated or ceramic-coated materials requires further investigation
Range Flight Safety Requirements
Loftin, Charles E.; Hudson, Sandra M.
2018-01-01
The purpose of this NASA Technical Standard is to provide the technical requirements for the NPR 8715.5, Range Flight Safety Program, in regards to protection of the public, the NASA workforce, and property as it pertains to risk analysis, Flight Safety Systems (FSS), and range flight operations. This standard is approved for use by NASA Headquarters and NASA Centers, including Component Facilities and Technical and Service Support Centers, and may be cited in contract, program, and other Agency documents as a technical requirement. This standard may also apply to the Jet Propulsion Laboratory or to other contractors, grant recipients, or parties to agreements to the extent specified or referenced in their contracts, grants, or agreements, when these organizations conduct or participate in missions that involve range flight operations as defined by NPR 8715.5.1.2.2 In this standard, all mandatory actions (i.e., requirements) are denoted by statements containing the term “shall.”1.3 TailoringTailoring of this standard for application to a specific program or project shall be formally documented as part of program or project requirements and approved by the responsible Technical Authority in accordance with NPR 8715.3, NASA General Safety Program Requirements.
[Measurement of the lumbosacral angle and its clinical significance].
Bene, E
1981-01-01
The author reports about the result of a series of investigations and tests concerning the angle of the L-S vertebral column. Different factors influencing the values of L-S angle are analyzed. The clinical importance of the respective angles is small, the statics of the L-S transition is determined by all angles together. The reduced L-S angle cannot be considered as an aetiological factor of the spondylolysthesis. The pathological angle values as well as the positions play a role in the induction of the discopathy
Effect of fence height on joint angles of agility dogs.
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. Copyright © 2013 Elsevier Ltd. All rights reserved.
Measurements of normal joint angles by goniometry in calves.
Sengöz Şirin, O; Timuçin Celik, M; Ozmen, A; Avki, S
2014-01-01
The aim of this study was to establish normal reference values of the forelimb and hindlimb joint angles in normal Holstein calves. Thirty clinically normal Holstein calves that were free of any detectable musculoskeletal abnormalities were included in the study. A standard transparent plastic goniometer was used to measure maximum flexion, maximum extension, and range-of-motion of the shoulder, elbow, carpal, hip, stifle, and tarsal joints. The goniometric measurements were done on awake calves that were positioned in lateral recumbency. The goniometric values were measured and recorded by two independent investigators. As a result of the study it was concluded that goniometric values obtained from awake calves in lateral recumbency were found to be highly consistent and accurate between investigators (p <0.05). The data of this study acquired objective and useful information on the normal forelimb and hindlimb joint angles in normal Holstein calves. Further studies can be done to predict detailed goniometric values from different diseases and compare them.
Simultaneous tracking of spin angle and amplitude beyond classical limits
Colangelo, Giorgio; Ciurana, Ferran Martin; Bianchet, Lorena C.; Sewell, Robert J.; Mitchell, Morgan W.
2017-03-01
Measurement of spin precession is central to extreme sensing in physics, geophysics, chemistry, nanotechnology and neuroscience, and underlies magnetic resonance spectroscopy. Because there is no spin-angle operator, any measurement of spin precession is necessarily indirect, for example, it may be inferred from spin projectors at different times. Such projectors do not commute, and so quantum measurement back-action—the random change in a quantum state due to measurement—necessarily enters the spin measurement record, introducing errors and limiting sensitivity. Here we show that this disturbance in the spin projector can be reduced below N1/2—the classical limit for N spins—by directing the quantum measurement back-action almost entirely into an unmeasured spin component. This generates a planar squeezed state that, because spins obey non-Heisenberg uncertainty relations, enables simultaneous precise knowledge of spin angle and spin amplitude. We use high-dynamic-range optical quantum non-demolition measurements applied to a precessing magnetic spin ensemble to demonstrate spin tracking with steady-state angular sensitivity 2.9 decibels below the standard quantum limit, simultaneously with amplitude sensitivity 7.0 decibels below the Poissonian variance. The standard quantum limit and Poissonian variance indicate the best possible sensitivity with independent particles. Our method surpasses these limits in non-commuting observables, enabling orders-of-magnitude improvements in sensitivity for state-of-the-art sensing and spectroscopy.
Accurate Angle Estimator for High-Frame-rate 2-D Vector Flow Imaging
DEFF Research Database (Denmark)
Villagómez Hoyos, Carlos Armando; Stuart, Matthias Bo; Lindskov Hansen, Kristoffer
2016-01-01
This paper presents a novel approach for estimating 2-D flow angles using a high-frame-rate ultrasound method. The angle estimator features high accuracy and low standard deviation (SD) over the full 360° range. The method is validated on Field II simulations and phantom measurements using...... the experimental ultrasound scanner SARUS and a flow rig before being tested in vivo. An 8-MHz linear array transducer is used with defocused beam emissions. In the simulations of a spinning disk phantom, a 360° uniform behavior on the angle estimation is observed with a median angle bias of 1.01° and a median...... angle SD of 1.8°. Similar results are obtained on a straight vessel for both simulations and measurements, where the obtained angle biases are below 1.5° with SDs around 1°. Estimated velocity magnitudes are also kept under 10% bias and 5% relative SD in both simulations and measurements. An in vivo...
Measurement of the convergence angle in teeth prepared for single crown
Directory of Open Access Journals (Sweden)
NokarS
2002-07-01
Full Text Available Retention, resistance and marginal integrity mostly depend on tooth preparation. An appropriate convergence angle fulfil this purpose, to high extent. In this study, a new method was used to measure the convergence angle of the teeth prepared for single crowns in Genera! practitioners" offices in Tehran. In order to do this. 325 dyes, prepared by General dentists in Tehran, were collected from 10 laboratories. All dyes wore trimmed at the area below the finishing line and then were scanned (Genius Color page- FIR 6 buccoiingualiy and mesiodistaily. Convergence angle of dyes were also measured with Adobe Photoshop (5.0 software. Data were analyzed by variance analysis test and 1- student bv the help of SPSS software. Results showed that the average convergence angle ranged from 16.18+8.34 to 35.1 8~10.38 which belonged to maxillary canine and mandibular molars, respectively, and the measured convergence angle is more than the ideal value of 10-16 degrees. Dyes of the madibular molars were ma"illar" convergent. These conclusions are helpful for professors, dentistry students and dentists, and arc an indicative of the practice quality of General practitioners in Tehran. Due to the fact that a convergence angle, more than the allowed limitation, endangers retention, resistance and marginal integrity of the restoration, paying attention to the principles of tooth preparation and proper application of instruments and dental cements, can progress fwed restorations quality.
Moment arms and lengths of human upper limb muscles as functions of joint angles.
Pigeon, P; Yahia, L; Feldman, A G
1996-10-01
Modeling of musculoskeletal structures requires accurate data on anatomical parameters such as muscle lengths (MLs), moment arms (MAs) and those describing the upper limb position. Using a geometrical model of planar arm movements with three degrees of freedom, we present, in an analytical form, the available information on the relationship between MAs and MLs and joint angles for thirteen human upper limb muscles. The degrees of freedom included are shoulder flexion/extension, elbow flexion/extension, and either wrist flexion/extension (the forearm in supination) or radial/ulnar deviation (the forearm in mid-pronation). Previously published MA/angle curves were approximated by polynomials. ML/angle curves were obtained by combining the constant values of MLs (defined by the distance between the origin and insertion points for a specific upper limb position) with a variable part obtained by multiplying the MA (joint radius) and the joint angle. The MAs of the prime wrist movers in radial/ulnar deviation were linear functions of the joint angle (R2 > or = 0.9954), while quadratic polynomials accurately described their MAs during wrist flexion/extensions. The relationship between MAs and the elbow angle was described by 2nd, 3rd or 5th-order polynomials (R2 > or = 0.9904), with a lesser quality of fit for the anconeus (R2 = 0.9349). In the full range of angular displacements, the length of wrist, elbow and shoulder muscles can change by 8.5, 55 and 200%, respectively.
Uniform tilt-angle micromirror array for multi-object spectroscopy
Waldis, Severin; Clerc, Pierre-Andre; Zamkotsian, Frederic; Zickar, Michael; Noell, Wilfried; de Rooij, Nico
2007-01-01
We report on micromirror arrays being developed for the use as reflective slit mask in Multi Object Spectrographs for astronomical applications. The micromirrors are etched in bulk single crystal silicon whereas the cantilever type suspension is realized by surface micromachining. One micromirror element is 100μm x 200μm in size. The micromirrors are actuated electrostatically by electrodes located on a second chip. The use of silicon on insulator (SOI) wafers for both mirror and electrode chip ensures thermal compatibility for cryogenic operation. A system of multiple landing beams has been developed, which passively locks the mirror at a well defined tilt angle when actuated. The mechanical tilt angle obtained is 20 ° at a pull-in voltage of 90V. Measurements with an optical profiler showed that the tilt angle of the actuated and locked mirror is stable with a precision of one arc minute over a range of 15V. This locking system makes the tilt angle merely independent from process variations across the wafer and thus provides uniform tilt angle over the whole array. The precision on tilt angle from mirror to mirror measured is one arc minute. The surface quality of the mirrors in actuated state is better than 10nm peak-to-valley and the local roughness is around 1nm RMS.
Value of the lumbar lordotic angle taken from CT scanogram as an index of back pain
Energy Technology Data Exchange (ETDEWEB)
Jeon, Hea Sang; Kim, Guk Hee; Kim, Dae Young [Kangnam General Hospital Public Corporation, Seoul (Korea, Republic of)
1986-10-15
'Normal' spinal posture is generally accepted as moderate lordosis of the cervical and the lumbar sections of spine and moderate kyphosis of the thoracic and sacrococcygeal sections. Among these normal range of the lumbar lordosis is less well defined. CT is very useful method to identified the bony structure and adjacent soft tissue of the spine, so it is very available method to detect accurate lumbar lordotic angle by using lateral Scanogram. Analysis and comparison of lumbar lordotic angles, crossing angle are drawn each parallel line to the superior end plate of body of 1st. lumbar vertebra and to the inferior end plate of the 5th. lumbar vertebra, in 174 cases with backache and 50 cases normal groups at Kangnam General Hospital Public Corporation, from Aug. 1985 to Jul 1986. Male and female were almostly same affected in backache group (1.1:1). And most lumbar lordotic angles were 10 to 40 between all backache age group. On backache group, over all mean lumbar lordotic angles were 24.7+-8.9 but no significant difference at mean value of the each diseases, such as HIVD, Degenerative Spondylosis or No Remarkable Findings group. On control group, over all mean ones were 29.2+-8.0. So, significant difference of lumbar lordotic angle between backache and control group, and most difference is at 5th. decade group (p 0.01).
MULLIGAN VERSUS MAITLAND MOBILIZATION ON THORACIC KYPHOTIC ANGLE IN POSTURAL KYPHOSIS
Directory of Open Access Journals (Sweden)
Mohamed Ibrahim Fathallah Abdelhay
2017-06-01
Full Text Available Background: Postural hypnosis can lead to cervical pain or bad cosmetic appearance.There is a lack in the literature supporting the efficacy of spinal mobilization techniques in restoring normal thoracic curvature.Mulligan and Maitland's mobilization were used to improve range of motion and referred pain not to restore normal kyphotic angle. The purpose: this study was conducted to compare the efficacy of Mulligan and Maitland spinal mobilization on a kyphotic angle in postural kyphosis. Subjects: seventy-five male subjects with postural kyphosis their age (17-21 years were included in the study by initial postural examination and were randomly assigned into three equal groups. Methods: Group I each subject in this group received mulligan mobilization in addition to back exercises as conservative treatment, Group II each subject in this group received Maitland mobilization in addition to back exercises as conservative treatment, Group III this group was considered as a control group. Subjects within this group will perform exercises only as a conservative treatment. Kyphotic angle was measured by using formetric raster-stereography pre and post treatment. Result: The result of the study showed a significant effect of Mulligan mobilization in reducing kyphotic angle in patients with postural kyphosis p-value was (0.001, and there was no significant effect on Maitland mobilization on a kyphotic angle and the p-value was (0.256. Conclusion: Mulligan mobilization is effective in restoring normal kyphotic angle in cases of postural kyphosis
Skin movement errors in measurement of sagittal lumbar and hip angles in young and elderly subjects.
Kuo, Yi-Liang; Tully, Elizabeth A; Galea, Mary P
2008-02-01
Errors in measurement of sagittal lumbar and hip angles due to skin movement on the pelvis and/or lateral thigh were measured in young (n = 21, age = 18.6 +/- 2.1 years) and older (n = 23, age = 70.9 +/- 6.4 years) age groups. Skin reference markers were attached over specific landmarks of healthy young and elderly subjects, who were videotaped in three static positions of hip flexion using the 2D PEAK Motus video analysis system. Sagittal lumbar and hip angles were calculated from skin reference markers and manually palpated landmarks. The elderly subjects demonstrated greater errors in lumbar angle due to skin movement on the pelvis only in the maximal hip flexion position. The traditional model (ASIS-PSIS-GT-LFE) underestimated sagittal hip angle and the revised model (ASIS-PSIS-2/3Th-1/4Th) provided more accurate measurement of sagittal hip angle throughout the full available range of hip flexion. Skin movement on the pelvis had a small counterbalancing effect on the larger errors from lateral thigh markers (GT-LFE), thereby decreasing hip angle error.
Theoretical study of cylindrical energy analyzers for MeV range heavy ion beam probes
International Nuclear Information System (INIS)
Fujisawa, A.; Hamada, Y.
1993-07-01
A cylindrical energy analyzer with drift spaces is shown to have a second order focusing for beam incident angle when the deflection angle is properly chosen. The analyzer has a possibility to be applied to MeV range heavy ion beam probes, and will be also available for accurate particle energy measurements in many other fields. (author)
Wren, Tishya A L; Mitiguy, Paul C
2007-08-01
Clinical gait analysis usually describes joint kinematics using Euler angles, which depend on the sequence of rotation. Studies have shown that pelvic obliquity angles from the traditional tilt-obliquity-rotation (TOR) Euler angle sequence can deviate considerably from clinical expectations and have suggested that a rotation-obliquity-tilt (ROT) Euler angle sequence be used instead. We propose a simple alternate approach in which clinical joint angles are defined and exactly calculated in terms of Euler angles from any rotation sequence. Equations were derived to calculate clinical pelvic elevation, progression, and lean angles from TOR and ROT Euler angles. For the ROT Euler angles, obliquity was exactly the same as the clinical elevation angle, rotation was similar to the clinical progression angle, and tilt was similar to the clinical lean angle. Greater differences were observed for TOR. These results support previous findings that ROT is preferable to TOR for calculating pelvic Euler angles for clinical interpretation. However, we suggest that exact clinical angles can and should be obtained through a few extra calculations as demonstrated in this technical note.
Hirose, Fumitaka; Hata, Masayuki; Ito, Shin-ichiro; Matsuki, Takaaki; Kurimoto, Yasuo
2013-10-01
The purpose of this study was to investigate and measure light-dark changes in iris thickness (IT) and anterior chamber angle width in eyes with occludable angles and open angles by using anterior segment optical coherence tomography (AS-OCT). We examined 153 eyes of 153 Japanese patients with primary angle closure suspect, primary angle closure, primary angle closure glaucoma, or primary open angle glaucoma. AS-OCT was used to determine pupil diameter, IT, angle opening distance at 500 μm (AOD₅₀₀), and trabecular-iris space area at 500 μm (TISA₅₀₀) in each quadrant of the anterior chamber angle (superior, inferior, temporal, and nasal) under light and dark conditions. In the angle closure cases, IT, AOD₅₀₀ and TISA₅₀₀ in the dark varied significantly among the four quadrants (P dark did not differ significantly among the four quadrants. In the angle closure cases and the open angle cases, significant negative associations were found between IT difference [IT(light)-IT(dark)] and AOD₅₀₀ difference [AOD₅₀₀(light)-AOD₅₀₀(dark)] (R = -0.411, P dark)] (R = -0.475, P dark conditions is related to the mechanism of primary angle closure. It is important to analyze both the angle structure and peripheral IT in each quadrant.
Effects of drift angle on model ship flow
Longo, J.; Stern, F.
The effects of drift angle on model ship flow are investigated through towing tank tests for the Series 60 CB=0.6 cargo/container model ship. Resistance, side force, drift moment, sinkage, trim, and heel data are procured for a range of drift angles β and Froude numbers (Fr) and the model free condition. Detailed free-surface and mean velocity and pressure flow maps are procured for high and low Fr=0.316 and 0.16 and β=5° and 10° (free surface) and β=10° (mean velocity and pressure) for the model fixed condition (i.e. fixed with zero sinkage, trim, and heel). Comparison of results at high and low Fr and previous data for β=0° enables identification of important free-surface and drift effects. Geometry, conditions, data, and uncertainty analysis are documented in sufficient detail so as to be useful as a benchmark for computational fluid dynamics (CFD) validation. The resistance increases linearly with β with same slope for all Fr, whereas the increases in the side force, drift moment, sinkage, trim, and heel with β are quadratic. The wave profile is only affected near the bow, i.e. the bow wave amplitude increases/decreases on the windward/leeward sides, whereas the wave elevations are affected throughout the entire wave field. However, the wave envelope angle on both sides is nearly the same as β=0°, i.e. the near-field wave pattern rotates with the hull and remains within a similar wave envelope as β=0°. The wave amplitudes are significantly increased/decreased on the windward/leeward sides. The wake region is also asymmetric with larger wedge angle on the leeward side. The boundary layer and wake are dominated by the hull vortex system consisting of fore body keel, bilge, and wave-breaking vortices and after body bilge and counter-rotating vortices. The occurrence of a wave-breaking vortex for breaking bow waves has not been previously documented in the literature. The trends for the maximum vorticity, circulation, minimum axial velocity, and
Small angle neutron scattering of micro- and nanostructured materials
International Nuclear Information System (INIS)
Trinker, M.
2006-05-01
-dimensional scattering length density profiles is shown. In the last part of this work a completely new method for the characterization of magnetic structures in solids in the μm-range is presented: The principle and experimental setup for ultra-small angle scattering of polarized neutrons (PUSANS) are described and first measurements are presented. (author)
The formation of low-angle eolian stratification through the migration of protodunes
Ewing, R. C.; Phillips, J. D.; Weymer, B. A.; Barrineaux, P.; Bowling, R.; Nittrouer, J. A.
2017-12-01
Protodunes are low-relief, slipfaceless migrating bed forms that represent the emergent form of eolian sand dunes. Protodunes develop as cm-scale topography out of a flat bed of sand and evolve spatially and temporally into dunes with angle-of-repose slipfaces. Protodunes at White Sands Dune Field in New Mexico form at the upwind, trailing margin of the field, on dune stoss slopes, and in interdune areas. Here we analyze protodunes at the upwind margin of White Sands by coupling 200 mHz ground penetrating radar (GPR) with time-series high-resolution topography to characterize the origin and evolution of protodune stratification and the stratigraphic transition into fully developed dunes. We surveyed a 780m transect in the resultant transport direction of the dune field from SW to NE from sand patches through protodunes and into the first dune. We used airborne lidar surveys and structure-from-motion photogrammetry from 2007, 2008, 2009, 2010, 2015, and 2016. We find that protodune stratification forms at angles between 0-10 degrees by protodune migration. Dip angles increase as protodune amplitude increases along the transect. Accumulation of low-angle stratification increases across the first 650m and ranges from none to subcritical. Nearly aggradational accumulation of low-angle stratification occurs over the last 100m and is a precursor to angle-of-repose slipface formation. The origins of the aggradation and slipface development appear to be linked to protodune merging, dune interactions, and possibly to the development of a dune field-scale boundary layer. Protodunes and the formation of low-angle stratification at the upwind margin of White Sands are a good analog to the initiation of dune field development from sand sheets and the formation of low-angle stratification found at the base of eolian successions in the stratigraphic record.
Surface pressure model for simple delta wings at high angles of attack
Indian Academy of Sciences (India)
A new aerodynamic modelling approach is proposed for the longitudinal static characteristics of a simple delta wing. It captures the static variation of normal force and pitching moment characteristics throughout the angle of attack range. The pressure model is based on parametrizing the surface pressure distribution on a ...
Geometrically distributed one-dimensional photonic crystals for light-reflection in all angles.
Alagappan, G; Wu, P
2009-07-06
We demonstrate that a series of one-dimensional photonic crystals made of any dielectric materials, with the periods are distributed in a geometrical progression of a common ratio, r light of any spectral range. If an omni-directional reflection is desired for all polarizations and for all incident angles smaller than thetao, then r light reflection.
V4: The Small Angle Scattering Instrument (SANS at BER II
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Uwe Keiderling
2016-11-01
Full Text Available V4 is a small-angle neutron scatting instrument with an accessible range of scattering vector 0.01 nm-1 < Q < 8.5 nm-1. Outstanding features of the instrument are the polarized neutron option and the list mode data acquisition, allowing for time-resolved measurements with µs time resolution.
Structure of Co–Zn ferrite ferrofluid: A small angle neutron scattering
Indian Academy of Sciences (India)
A hydrothermal synthesis route is used to synthesize nanomagnetic particles of Co0.3Zn0.7Fe2O4 ferrite ferrofluids with particle diameter ranging from 5.5–9 nm. XRD analysis shows the formation of a single phase spinel structure. EDX results confirm the stoichiometric composition of the cations. Small angle neutron ...
A high-temperature furnace for small-angle neutron scattering
International Nuclear Information System (INIS)
Jal, J.F.; Guiraud, G.; Chieux, P.; Dupuy, J.
1977-01-01
A high temperature furnace (T 0 C) has been developed for small-angle neutron scattering experiments in the range of momentum transfer above 0.2 nm -1 . It is especially suited for the study of highly corrosive liquids such as alkali-alkali-halide mixtures. It allows critical fluctuations near liquid-liquid miscibility gaps to be investigated. (author)
Coulomb correction to the screening angle of the Moliere multiple scattering theory
International Nuclear Information System (INIS)
Kuraev, E.A.; Voskresenskaya, O.O.; Tarasov, A.V.
2012-01-01
Coulomb correction to the screening angular parameter of the Moliere multiple scattering theory is found. Numerical calculations are presented in the range of nuclear charge 4 ≤ Z ≤ 82. Comparison with the Moliere result for the screening angle reveals up to 30% deviation from it for sufficiently heavy elements of the target material
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Shi-Wei Li
2015-08-01
Full Text Available 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.
Walton, J. M.; Marchal, C.; Culp, R. D.
1971-01-01
The impulsive transfer of minimum characteristic velocity between two given hyperbolic asymptotes associated with a real planet is considered. The constraint of remaining above the surface of the planet introduces a maximum natural turn angle. This divides the problem naively into two categories. The first is the case when the turn angle required by the given asymptotes is less than or equal to the maximum natural turn angle. This is the more reasonable situation for a swingby maneuver, and is the case considered in this paper. The resulting optimal transfers are of five basic types. In boundary conditions space, by far the largest area of transfers are either single impulse transfers or transfers through the parabolic level requiring two finite impulses. In no case has an optimal transfer been found which uses more than two finite impulses and three infinitesimal impulses. Complete results are presented for the case in which the given turn angle is less than or equal to the maximum natural turn angle.
Instrument Display Visual Angles for Conventional Aircraft and the MQ-9 Ground Control Station
Bendrick, Gregg A.; Kamine, Tovy Haber
2008-01-01
Aircraft instrument panels should be designed such that primary displays are in optimal viewing location to minimize pilot perception and response time. Human Factors engineers define three zones (i.e. "cones") of visual location: 1) "Easy Eye Movement" (foveal vision); 2) "Maximum Eye Movement" (peripheral vision with saccades), and 3) "Head Movement" (head movement required). Instrument display visual angles were measured to determine how well conventional aircraft (T-34, T-38, F- 15B, F-16XL, F/A-18A, U-2D, ER-2, King Air, G-III, B-52H, DC-10, B747-SCA) and the MQ-9 ground control station (GCS) complied with these standards, and how they compared with each other. Methods: Selected instrument parameters included: attitude, pitch, bank, power, airspeed, altitude, vertical speed, heading, turn rate, slip/skid, AOA, flight path, latitude, longitude, course, bearing, range and time. Vertical and horizontal visual angles for each component were measured from the pilot s eye position in each system. Results: The vertical visual angles of displays in conventional aircraft lay within the cone of "Easy Eye Movement" for all but three of the parameters measured, and almost all of the horizontal visual angles fell within this range. All conventional vertical and horizontal visual angles lay within the cone of "Maximum Eye Movement". However, most instrument vertical visual angles of the MQ-9 GCS lay outside the cone of "Easy Eye Movement", though all were within the cone of "Maximum Eye Movement". All the horizontal visual angles for the MQ-9 GCS were within the cone of "Easy Eye Movement". Discussion: Most instrument displays in conventional aircraft lay within the cone of "Easy Eye Movement", though mission-critical instruments sometimes displaced less important instruments outside this area. Many of the MQ-9 GCS systems lay outside this area. Specific training for MQ-9 pilots may be needed to avoid increased response time and potential error during flight.
Read, Michael L; Morgan, Philip B; Maldonado-Codina, Carole
2009-11-01
This work sought to undertake a comprehensive investigation of the measurement errors associated with contact angle assessment of curved hydrogel contact lens surfaces. The contact angle coefficient of repeatability (COR) associated with three measurement conditions (image analysis COR, intralens COR, and interlens COR) was determined by measuring the contact angles (using both sessile drop and captive bubble methods) for three silicone hydrogel lenses (senofilcon A, balafilcon A, lotrafilcon A) and one conventional hydrogel lens (etafilcon A). Image analysis COR values were about 2 degrees , whereas intralens COR values (95% confidence intervals) ranged from 4.0 degrees (3.3 degrees , 4.7 degrees ) (lotrafilcon A, captive bubble) to 10.2 degrees (8.4 degrees , 12.1 degrees ) (senofilcon A, sessile drop). Interlens COR values ranged from 4.5 degrees (3.7 degrees , 5.2 degrees ) (lotrafilcon A, captive bubble) to 16.5 degrees (13.6 degrees , 19.4 degrees ) (senofilcon A, sessile drop). Measurement error associated with image analysis was shown to be small as an absolute measure, although proportionally more significant for lenses with low contact angle. Sessile drop contact angles were typically less repeatable than captive bubble contact angles. For sessile drop measures, repeatability was poorer with the silicone hydrogel lenses when compared with the conventional hydrogel lens; this phenomenon was not observed for the captive bubble method, suggesting that methodological factors related to the sessile drop technique (such as surface dehydration and blotting) may play a role in the increased variability of contact angle measurements observed with silicone hydrogel contact lenses.
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Carvalho Humberto M.
2015-12-01
Full Text Available The aim of this paper was to outline a multilevel modeling approach to fit individual angle-specific torque curves describing concentric knee extension and flexion isokinetic muscular actions in Master athletes. The potential of the analytical approach to examine between individual differences across the angle-specific torque curves was illustrated including between-individuals variation due to gender differences at a higher level. Torques in concentric muscular actions of knee extension and knee extension at 60°·s-1 were considered within a range of motion between 5°and 85° (only torques “truly” isokinetic. Multilevel time series models with autoregressive covariance structures with standard multilevel models were superior fits compared with standard multilevel models for repeated measures to fit anglespecific torque curves. Third and fourth order polynomial models were the best fits to describe angle-specific torque curves of isokinetic knee flexion and extension concentric actions, respectively. The fixed exponents allow interpretations for initial acceleration, the angle at peak torque and the decrement of torque after peak torque. Also, the multilevel models were flexible to illustrate the influence of gender differences on the shape of torque throughout the range of motion and in the shape of the curves. The presented multilevel regression models may afford a general framework to examine angle-specific moment curves by isokinetic dynamometry, and add to the understanding mechanisms of strength development, particularly the force-length relationship, both related to performance and injury prevention.
Small-angle X-ray scattering (SAXS) studies of the structure of mesoporous silicas
Zienkiewicz-Strzałka, M.; Skibińska, M.; Pikus, S.
2017-11-01
Mesoporous ordered silica nanostructures show strong interaction with X-ray radiation in the range of small-angles. Small-angle X-ray scattering (SAXS) measurements based on the elastically scattered X-rays are important in analysis of condensed matter. In the case of mesoporous silica materials SAXS technique provides information on the distribution of electron density in the mesoporous material, in particular describing their structure and size of the unit cell as well as type of ordered structure and finally their parameters. The characterization of nanopowder materials, nanocomposites and porous materials by Small-Angle X-ray Scattering seems to be valuable and useful. In presented work, the SAXS investigation of structures from the group of mesoporous ordered silicates was performed. This work has an objective to prepare functional materials modified by noble metal ions and nanoparticles and using the small-angle X-ray scattering to illustrate their properties. We report the new procedure for describing mesoporous materials belonging to SBA-15 and MCM-41 family modified by platinum, palladium and silver nanoparticles, based on detailed analysis of characteristic peaks in the small-angle range of X-ray scattering. This procedure allows to obtained the most useful parameters for mesoporous materials characterization and their successfully compare with experimental measurements reducing the time and material consumption with good precision for particles and pores with a size below 10 nm.
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Thabet Abouzeid A.
2015-01-01
Full Text Available ANGLE software for semiconductor detector efficiency calculations - long existing and widely accepted tool in quantitative gamma spectrometry - has been recently extended to scintillation NaI detectors. The extension features in the latest edition (ANGLE 4 and it is briefly outlined. Discretization of reference efficiency curve, meaning possibility of using ANGLE 4 for particular gamma energies without constructing the complete reference efficiency curve, is particularly emphasized. This yields both in enhanced practicality and higher accuracy, while reducing the potential for systematic errors. The present work is primarily focussed on experimental verification of ANGLE 4 for NaI detectors. Two detectors (2 ´ 2 and 3 x 3 inches were employed in the experiment. Commercially calibrated gamma sources (in the forms of quasi point and cylinder and homemade solutions (diluted from calibrated ones were measured at various distances from the detector(s, ranging 0 cm to 50 cm. Energy range observed was 59 keV to 1408 keV. Versatility of counting conditions, in terms of detectors and sources used, gamma energies observed, source detector separations, etc., was aimed at creating as large experimental evidence as possible for verification purposes. Experimentally obtained efficiencies are compared with those calculated by ANGLE 4. Very good agreement is obtained - well within the experimental uncertainties - thus proving the reliability of the software.
The Sphaleron at finite mixing angle
International Nuclear Information System (INIS)
Klinkhamer, F.R.; Laterveer, R.
1990-01-01
The exact Sphaleron solution in the bosonic sector of the electro-weak standard model is only known for weak mixing angle θ W =0. To investigate the behaviour closer to the experimental value θ W exp approx 30 deg a non-contractible loop in configuration space which is sensitive to θ W is constructed. The numerical results for the energy and the magnetic dipole moment indicate that the dependence on θ W is rather weak. (author). 8 refs.; 4 figs.; 1 tab
Pair production in small angle Bhabha scattering
International Nuclear Information System (INIS)
Arbuzov, A.B.; Kuraev, Eh.A.; Merenkov, N.P.; Trentadue, L.
1995-01-01
The radiative corrections due to a pair production in the small angle high energy e + e - Bhabha scattering are considered. The corrections due to the production of virtual pairs as well as real soft and hard ones are calculated analytically. The collinear and semi-collinear kinematical regions of the hard pair production are taken into account. The results in the leading and next-to-leading logarithmic approximations provide the accuracy of Ο (0.1%). The results of numerical calculations show that the effects of pairs production are to be taken into account in the precise luminosity determination at LEP. 9 refs., 3 figs., 2 tabs
Joining by plating: optimization of occluded angle
International Nuclear Information System (INIS)
Dini, J.W.; Johnson, H.R.; Kan, Y.R.
1978-11-01
An empirical method has been developed for predicting the minimum angle required for maximum joint strength for materials joined by plating. This is done through a proposed power law failure function, whose coefficients are taken from ring shear and conical head tensile data for plating/substrate combinations and whose exponent is determined from one set of plated-joint data. Experimental results are presented for Al-Ni-Al (7075-T6) and AM363-Ni-AM363 joints, and the failure function is used to predict joint strengths for Al-Ni-Al (2024-T6), UTi-Ni-UTi, and Be-Ti-Be
Rapidly-Indexing Incremental-Angle Encoder
Christon, Philip R.; Meyer, Wallace W.
1989-01-01
Optoelectronic system measures relative angular position of shaft or other device to be turned, also measures absolute angular position after device turned through small angle. Relative angular position measured with fine resolution by optoelectronically counting finely- and uniformly-spaced light and dark areas on encoder disk as disk turns past position-sensing device. Also includes track containing coarsely- and nonuniformly-spaced light and dark areas, angular widths varying in proportion to absolute angular position. This second track provides gating and indexing signal.
Weak mixing angles and heavy flavours
International Nuclear Information System (INIS)
Jarlskog, C.
1984-05-01
The present status of the weak mixing angles, in the standard six quark model, is reviewed. The implications of the recent measurements of the beauty lifetime and branching ratios are discussed, in the framework of the Kobayashi-Maskawa and the Wolfenstein parametrizations. Expectations for B(sup)o - B(sup)-o mixing and consequences for the collider data are given. Other topics briefly reviewed are CP-violation, top quark mass and possible implications of the existence of a fourth family. (author)
Directory of Open Access Journals (Sweden)
Mohammad Jafari
2017-12-01
Full Text Available The pore-level two-phase fluids flow mechanism needs to be understood for geological CO2 sequestration as a solution to mitigate anthropogenic emission of carbon dioxide. Capillary pressure at the interface of water–CO2 influences CO2 injectability, capacity, and safety of the storage system. Wettability usually measured by contact angle is always a major uncertainty source among important parameters affecting capillary pressure. The contact angle is mostly determined on a flat surface as a representative of the rock surface. However, a simple and precise method for determining in situ contact angle at pore-scale is needed to simulate fluids flow in porous media. Recent progresses in X-ray tomography technique has provided a robust way to measure in situ contact angle of rocks. However, slow imaging and complicated image processing make it impossible to measure dynamic contact angle. In the present paper, a series of static and dynamic contact angles as well as contact angles on flat surface were measured inside a micromodel with random pattern of channels under high pressure condition. Our results showed a wide range of pore-scale contact angles, implying complexity of the pore-scale contact angle even in a highly smooth and chemically homogenous glass micromodel. Receding contact angle (RCA showed more reproducibility compared to advancing contact angle (ACA and static contact angle (SCA for repeating tests and during both drainage and imbibition. With decreasing pore size, RCA was increased. The hysteresis of the dynamic contact angle (ACA–RCA was higher at pressure of one megapascal in comparison with that at eight megapascals. The CO2 bubble had higher mobility at higher depths due to lower hysteresis which is unfavorable. CO2 bubbles resting on the flat surface of the micromodel channel showed a wide range of contact angles. They were much higher than reported contact angle values observed with sessile drop or captive bubble tests on a
Angles of entry of ultraviolet radiation into welding helmets.
Tenkate, T S; Collins, M J
1997-01-01
To investigate the angles of entry of ultraviolet (UV) radiation into welding helmets, a UV detector was placed in the eye socket of a head form that was then fitted with a range of welding helmets. The head form was exposed to a collimated beam of UV radiation from various orientations, and the amount of infiltration was measured. Radiation was found to be reflected from the filter plate and into the detector (eye) after entering through (1) an opening between the edge of the shield and the side of the face, and (2) an opening between the top edge of the shield and the top of the head. These results have significance for UV exposure when welding is performed in highly reflective and enclosed situations, and for the design of welding helmets.
Small angle neutron scattering experiment and raw data reduction
International Nuclear Information System (INIS)
Wei Guohai; Li Tianfu; Zhang Li; Wang Yu; Wang Hongli; Liu Xiangfeng
2010-01-01
Small angle neutron scattering (SANS) technique is a powerful tool for nanometer structural analysis of materials. The process of SANS measurement, and the raw data reduction, is relatively complicated. In order to obtain the absolute SANS intensity, one needs to measure intensities of the incident and scattered beams, the sample transmission, the background, the scattering and transmission of the empty cell etc. If a wide scattering vector range is needed, one has to measure the same sample under different instrument configurations. Also, a large number of data treatments are needed before one obtains the SANS data for further analysis. In this paper, after a short introduction to the SANS basic theory and the experimental system, we focus on the raw data reduction method, in which the averaging and the combination of the isotropically scattered data are discussed in detail. (authors)
Two wide-angle imaging neutral-atom spectrometers
Energy Technology Data Exchange (ETDEWEB)
McComas, D.J.
1997-12-31
The Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) mission provides a new capability for stereoscopically imaging the magnetosphere. By imaging the charge exchange neutral atoms over a broad energy range (1 < E , {approximately} 100 keV) using two identical instruments on two widely-spaced high-altitude, high-inclination spacecraft, TWINS will enable the 3-dimensional visualization and the resolution of large scale structures and dynamics within the magnetosphere for the first time. These observations will provide a leap ahead in the understanding of the global aspects of the terrestrial magnetosphere and directly address a number of critical issues in the ``Sun-Earth Connections`` science theme of the NASA Office of Space Science.
Two wide-angle imaging neutral-atom spectrometers
International Nuclear Information System (INIS)
McComas, D.J.
1997-01-01
The Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) mission provides a new capability for stereoscopically imaging the magnetosphere. By imaging the charge exchange neutral atoms over a broad energy range (1 < E , ∼ 100 keV) using two identical instruments on two widely-spaced high-altitude, high-inclination spacecraft, TWINS will enable the 3-dimensional visualization and the resolution of large scale structures and dynamics within the magnetosphere for the first time. These observations will provide a leap ahead in the understanding of the global aspects of the terrestrial magnetosphere and directly address a number of critical issues in the ''Sun-Earth Connections'' science theme of the NASA Office of Space Science
Angle-tip Fiber Probe as Humidity Sensor
Directory of Open Access Journals (Sweden)
Pabitra NATH
2010-05-01
Full Text Available In this paper, I present a simple fiber optic relative humidity sensor (FORHS using an angled-tip multimode optical fiber. The sensing region is fabricated by coating moisture sensitive Cobalt Chloride (CoCl2 doped polyvinyl alcohol (PVA film on the surface of fiber optic tip. Light signal introducing from flat-end of the fiber is back-reflected at the fiber tip-air interface by the effect of total internal refection. The change of relative humidity (RH in the outstanding medium affects of evanescent field absorption at the fiber tip-sensing film interface thus, modulates the back-reflected signal. With the present sensing investigation, RH ranging from 5 % to 95 % can be measured with high degree of repeatability and has a fast response time of about 2 seconds.
Lateral angle: a method for sexing using the petrous bone
DEFF Research Database (Denmark)
Norén, Anna; Lynnerup, Niels; Czarnetzki, Alfred
2005-01-01
We report on the results of applying the so-called lateral angle method for sex determination on skeletal remains. The lateral angle denotes the angle of the internal auditory canal in relation to the medial surface of the petrous part of the temporal bone. The method involves making a small cast...... and females (mean angle size of males, 39.3 degrees ; mean angle size of females, 48.2 degrees ; P lateral angle method against an archaeological skeletal...... sample. True sex was not known for this sample; instead, sexing had been carried out by assessing pelvic and cranial morphology in independent trials. We found a higher concordance between the lateral angle and "pelvic" sex than for lateral angle and "cranial" sex. Finally, we note that subadult sexing...
Measurement of Angle Kappa Using Ultrasound Biomicroscopy and Corneal Topography.
Yeo, Joon Hyung; Moon, Nam Ju; Lee, Jeong Kyu
2017-06-01
To introduce a new convenient and accurate method to measure the angle kappa using ultrasound biomicroscopy (UBM) and corneal topography. Data from 42 eyes (13 males and 29 females) were analyzed in this study. The angle kappa was measured using Orbscan II and calculated with UBM and corneal topography. The angle kappa of the dominant eye was compared with measurements by Orbscan II. The mean patient age was 36.4 ± 13.8 years. The average angle kappa measured by Orbscan II was 3.98° ± 1.12°, while the average angle kappa calculated with UBM and corneal topography was 3.19° ± 1.15°. The difference in angle kappa measured by the two methods was statistically significant (p topography to calculate the angle kappa. This method is convenient to use and allows for measurement of the angle kappa without an expensive device. © 2017 The Korean Ophthalmological Society
Apparatus and method for variable angle slant hole collimator
Lee, Seung Joon; Kross, Brian J.; McKisson, John E.
2017-07-18
A variable angle slant hole (VASH) collimator for providing collimation of high energy photons such as gamma rays during radiological imaging of humans. The VASH collimator includes a stack of multiple collimator leaves and a means of quickly aligning each leaf to provide various projection angles. Rather than rotate the detector around the subject, the VASH collimator enables the detector to remain stationary while the projection angle of the collimator is varied for tomographic acquisition. High collimator efficiency is achieved by maintaining the leaves in accurate alignment through the various projection angles. Individual leaves include unique angled cuts to maintain a precise target collimation angle. Matching wedge blocks driven by two actuators with twin-lead screws accurately position each leaf in the stack resulting in the precise target collimation angle. A computer interface with the actuators enables precise control of the projection angle of the collimator.
Kernel density estimation applied to bond length, bond angle, and torsion angle distributions.
McCabe, Patrick; Korb, Oliver; Cole, Jason
2014-05-27
We describe the method of kernel density estimation (KDE) and apply it to molecular structure data. KDE is a quite general nonparametric statistical method suitable even for multimodal data. The method generates smooth probability density function (PDF) representations and finds application in diverse fields such as signal processing and econometrics. KDE appears to have been under-utilized as a method in molecular geometry analysis, chemo-informatics, and molecular structure optimization. The resulting probability densities have advantages over histograms and, importantly, are also suitable for gradient-based optimization. To illustrate KDE, we describe its application to chemical bond length, bond valence angle, and torsion angle distributions and show the ability of the method to model arbitrary torsion angle distributions.
Puigdellívol-Sánchez, Anna; Reina, Miguel A; Sala-Blanch, Xavier; Pomés-Talló, Jaume; Prats-Galino, Alberto
2016-11-01
The classical recommendation for paramedian approaches is needle insertion 1-2 cm paramedian and an angle of 10°-15° medial-cephalad to the plane of the back, but contact with vertebrae is frequent. A mathematical approach to individualizing punctures is proposed on the basis of skin-dural sac distance (d): Optimal angle ∼ inverse cosine [d/ √(1+d^2) ] and the distance covered by the needle ∼ √(1+d^2) for 1 cm paramedian punctures. The inferred angles were compared to optimal angles leading to the central dorsal part of the dural sac from 1 to 2 cm paramedian, measured by Magnetic Resonance Imaging (MRI) in seven cases and in a short stature volunteer (1.58 m, Body Mass Index (BMI) 23.2), to study supine and fetal positions using both closed MR and ultrasound. The average (d) decreased rostrally [6.8 cm (L4-L5)-4.3 cm (T11-T12)] while the mean optimal incidence angles increased [8.3°-16.5° (L4-L5) to 12.7°-24.1° (T11-T12) at 1-2 cm paramedian, respectively] and coincided with the estimated angles with a correlation coefficient = 0.98. In the volunteer, the optimal lateromedial angles increased from 14.4° to 26.7° (L3-L4) to 17.1°-30.3° (T11-T12) for a (d) = 3.7 cm (L3-L4)-3.1 cm (T11-T12) and increased ≤3.7° and ≤5.1° at 1 and 2 cm paramedian, respectively, in fetal positions in MR. Ultrasound yielded comparable figures. The range of possible angles for dural punctures is wider at 1 cm paramedian in lower approaches in lateral decubitus [from 3.6° at T12L1 (12.2°-15.8°) to 9° at L3L4 (8.8°-18.7°)]. The classically recommended angles of 10°-15° differ from the optimal angles, particularly in small patients, suggesting the need for ultrasound guidance or for inferring angles prior to spinal anesthesia. Clin. Anat. 29:1046-1052, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
Radhakrishnan, Sunita; Chen, Philip P; Junk, Anna K; Nouri-Mahdavi, Kouros; Chen, Teresa C
2018-02-23
To examine the efficacy and complications of laser peripheral iridotomy (LPI) in subjects with primary angle closure (PAC). Literature searches in the PubMed and Cochrane databases were last conducted in August 2017 and yielded 300 unique citations. Of these, 36 met the inclusion criteria and were rated according to the strength of evidence; 6 articles were rated level I, 11 articles were rated level II, and 19 articles were rated level III. Reported outcomes were change in angle width, effect on intraocular pressure (IOP) control, disease progression, and complications. Most of the studies (29/36, 81%) included only Asian subjects. Angle width (measured by gonioscopy, ultrasound biomicroscopy, and anterior segment OCT) increased after LPI in all stages of angle closure. Gonioscopically defined persistent angle closure after LPI was reported in 2% to 57% of eyes across the disease spectrum. Baseline factors associated with persistent angle closure included narrower angle and parameters representing nonpupillary block mechanisms of angle closure, such as a thick iris, an anteriorly positioned ciliary body, or a greater lens vault. After LPI, further treatment to control IOP was reported in 0%-8% of PAC suspect (PACS), 42% to 67% of PAC, 21% to 47% of acute PAC (APAC), and 83%-100% of PAC glaucoma (PACG) eyes. Progression to PACG ranged from 0% to 0.3% per year in PACS and 0% to 4% per year in PAC. Complications after LPI included IOP spike (8-17 mmHg increase from baseline in 6%-10%), dysphotopsia (2%-11%), anterior chamber bleeding (30%-41%), and cataract progression (23%-39%). Laser peripheral iridotomy increases angle width in all stages of primary angle closure and has a good safety profile. Most PACS eyes do not receive further intervention, whereas many PAC and APAC eyes, and most PACG eyes, receive further treatment. Progression to PACG is uncommon in PACS and PAC. There are limited data on the comparative efficacy of LPI versus other treatments for the
Breves, E. A.; Lepore, K.; Dyar, M. D.; Bender, S. C.; Tokar, R. L.; Boucher, T.
2017-11-01
Laser-induced breakdown spectroscopy has become a popular tool for rapid elemental analysis of geological materials. However, quantitative applications of LIBS are plagued by variability in collected spectra that cannot be attributed to differences in geochemical composition. Even under ideal laboratory conditions, variability in LIBS spectra creates a host of difficulties for quantitative analysis. This is only exacerbated during field work, when both the laser-sample distance and the angle of ablation/collection are constantly changing. A primary goal of this study is to use empirical evidence to provide a more accurate assessment of uncertainty in LIBS-derived element predictions. We hope to provide practical guidance regarding the angles of ablation and collection that can be tolerated without substantially increasing prediction uncertainty beyond that which already exists under ideal laboratory conditions. Spectra were collected from ten geochemically diverse samples at angles of ablation and collection ranging from 0° to ± 60°. Ablation and collection angles were changed independently and simultaneously in order to isolate spectral changes caused by differences in ablation angle from those due to differences in collection angle. Most of the variability in atomic and continuum spectra is attributed to changes in the ablation angle, rather than the collection angle. At higher angles, the irradiance of the laser beam is lower and produces smaller, possibly less dense plasmas. Simultaneous changes in the collection angle do not appear to affect the collected spectra, possibly because smaller plasmas are still within the viewing area of the collection optics, even though this area is reduced at higher collection angles. A key observation is that changes in the magnitude of atomic and total emission are team is using lab data acquired under normal incidence and collection angles to predict the compositions of Mars targets at varying angles. Thus, the increased
Rotation Estimation for Wide-Angle Inverse Synthetic Aperture Radar Imaging
Directory of Open Access Journals (Sweden)
Wei Zhou
2016-01-01
Full Text Available To present focused ISAR imaging results in the homogenous range and cross-range domain, an integrated scheme is proposed to estimate both the targets equivalent rotational velocity (RV and rotational center (RC. The RV estimation is improved by radial projection combined with keystone processing, and then the RC is estimated through image entropy minimization. Finally, delicate imaging results may be obtained for wide-angle scenarios. Experiment results are provided to demonstrate the effectiveness of the proposed method.
Wicki Flavio; Longchamp Jean-Nicolas; Latychevskaia Tatiana; Escher Conrad; Fink Hans-Werner
2016-01-01
We report angle-resolved electron transmission measurements through freestanding graphene sheets in the energy range of 18 to 30 eV above the Fermi level. The measurements are carried out in a low-energy electron point source microscope, which allows simultaneously probing the transmission for a large angular range. The characteristics of low-energy electron transmission through graphene depend on its electronic structure above the vacuum level. The experimental technique described here allow...
International Nuclear Information System (INIS)
Shi, F X; Yang, J H; Wang, X H; Zhang, R H; Li, C E
2012-01-01
In this paper, in order to research the impact of inlet angle and outlet angle of guide vane on hydraulic turbine performance, a centrifugal pump in reversal is adopted as turbine. A numerical simulation method is adopted for researching outer performance and flow field of turbine. The results show: inlet angle has a crucial role to turbine, to the same flow, there is a noticeable decline for the efficiency and head of turbine with the inlet angle increases. At the best efficiency point(EFP),to a same inlet angle, when the inlet angle greater than inlet angle, velocity circulation in guide vane outlet decreases, which lead the efficiency of turbine to reduce, Contrarily, the efficiency rises. With the increase of inlet angle and outlet angle, the EFP moves to the big flow area and the uniformity of pressure distribution becomes worse. The paper indicates that the inlet angle and outlet angle have great impact on the turbine performance, and the best combination exists for the inlet angle and outlet angle of the guide vane.
Cluster headache or narrow angle glaucoma?
Directory of Open Access Journals (Sweden)
Prasad Palimar
1991-01-01
Full Text Available A 47 year old man with episodes of attacks of pain, redness and mild blurring of vision was investigated for narrow angle glaucoma in view of shallow anterior chambers and a cupped optic disc. The history was reviewed following a spontaneous attack in hospital, which had features other than acute glaucoma. A diagnosis of cluster headache was made on the basis of tests. Cluster headache has been defined as unilateral intense pain, involving the eye and head on one side, usually associated with flushing, nasal congestion and lacrimation; the attacks recurring one or more times daily and lasting 20 - 120 minutes. Such attacks commonly continue for weeks or months and are separated by an asymptomatic period of months to years. This episodic nature, together with unilaterality and tendency to occur at night, closely mimics narrow angle glaucoma. Further, if patients have shallow anterior chambers and disc cupping, the differentiation becomes more difficult yet critical. Resource to provocative tests is often the only answer as the following case report demonstrates.
A LEGO Mindstorms Brewster angle microscope
Fernsler, Jonathan; Nguyen, Vincent; Wallum, Alison; Benz, Nicholas; Hamlin, Matthew; Pilgram, Jessica; Vanderpoel, Hunter; Lau, Ryan
2017-09-01
A Brewster Angle Microscope (BAM) built from a LEGO Mindstorms kit, additional LEGO bricks, and several standard optics components, is described. The BAM was built as part of an undergraduate senior project and was designed, calibrated, and used to image phospholipid, cholesterol, soap, and oil films on the surface of water. A BAM uses p-polarized laser light reflected off a surface at the Brewster angle, which ideally yields zero reflectivity. When a film of different refractive index is added to the surface a small amount of light is reflected, which can be imaged in a microscope camera. Films of only one molecule (approximately 1 nm) thick, a monolayer, can be observed easily in the BAM. The BAM was used in a junior-level Physical Chemistry class to observe phase transitions of a monolayer and the collapse of a monolayer deposited on the water surface in a Langmuir trough. Using a photometric calculation, students observed a change in thickness of a monolayer during a phase transition of 7 Å, which was accurate to within 1 Å of the value determined by more advanced methods. As supplementary material, we provide a detailed manual on how to build the BAM, software to control the BAM and camera, and image processing software.
SU-E-T-446: Group-Sparsity Based Angle Generation Method for Beam Angle Optimization
International Nuclear Information System (INIS)
Gao, H
2015-01-01
Purpose: This work is to develop the effective algorithm for beam angle optimization (BAO), with the emphasis on enabling further improvement from existing treatment-dependent templates based on clinical knowledge and experience. Methods: The proposed BAO algorithm utilizes a priori beam angle templates as the initial guess, and iteratively generates angular updates for this initial set, namely angle generation method, with improved dose conformality that is quantitatively measured by the objective function. That is, during each iteration, we select “the test angle” in the initial set, and use group-sparsity based fluence map optimization to identify “the candidate angle” for updating “the test angle”, for which all the angles in the initial set except “the test angle”, namely “the fixed set”, are set free, i.e., with no group-sparsity penalty, and the rest of angles including “the test angle” during this iteration are in “the working set”. And then “the candidate angle” is selected with the smallest objective function value from the angles in “the working set” with locally maximal group sparsity, and replaces “the test angle” if “the fixed set” with “the candidate angle” has a smaller objective function value by solving the standard fluence map optimization (with no group-sparsity regularization). Similarly other angles in the initial set are in turn selected as “the test angle” for angular updates and this chain of updates is iterated until no further new angular update is identified for a full loop. Results: The tests using the MGH public prostate dataset demonstrated the effectiveness of the proposed BAO algorithm. For example, the optimized angular set from the proposed BAO algorithm was better the MGH template. Conclusion: A new BAO algorithm is proposed based on the angle generation method via group sparsity, with improved dose conformality from the given template. Hao Gao was partially supported by the
Evaluation of the normal calcaneal angles in Egyptian population
African Journals Online (AJOL)
Fahmy Anwar Shoukry
2012-02-01
Feb 1, 2012 ... ison of the angles according to the side), independent t-test was used to compare the angles according to the sex), distribution of the angles within different age groups was compared with one way analysis of variance (ANOVA) test. The level of sig- nificance was set at p < 0.05, and compared the results of.
Objectifying the Adjacent and Opposite Angles: A Cultural Historical Analysis
Daher, Wajeeh; Musallam, Nadera
2018-01-01
The angle topic is central to the development of geometric knowledge. Two of the basic concepts associated with this topic are the adjacent and opposite angles. It is the goal of the present study to analyze, based on the cultural historical semiotics framework, how high-achieving seventh grade students objectify the adjacent and opposite angles'…
Small angle neutron scattering from glassy SiO2
International Nuclear Information System (INIS)
Spooner, S.; Hastings, J.B.
1976-01-01
The present investigation of neutron scattering from glassy silica was undertaken to resolve whether the small angle scattering observed by Renninger and Uhlmann could also be seen in the bulk samples typically used in neutron-scattering experiments. Within the rather large error bars of this experiment no small angle scattering increase at small angles could be seen. (Auth.)
Goniodysgenesis in familial primary open-angle glaucoma
Verbraak, F. D.; vd Berg, W.; Delleman, J. W.; Greve, E. L.
1994-01-01
Results of a pilot study to evaluate goniodysgenesis as a cause of familial open-angle glaucoma are reported. Patients with a familial high tension open-angle glaucoma and a goniodysgenetic chamber angle (n = 11), a number of their relatives with glaucoma (n = 12), and their relatives without
Cubic Equations and the Ideal Trisection of the Arbitrary Angle
Farnsworth, Marion B.
2006-01-01
In the year 1837 mathematical proof was set forth authoritatively stating that it is impossible to trisect an arbitrary angle with a compass and an unmarked straightedge in the classical sense. The famous proof depends on an incompatible cubic equation having the cosine of an angle of 60 and the cube of the cosine of one-third of an angle of 60 as…
Fostering Students' Development of the Concept of Angles Using Technology
Richardson, Sue Ellen; Koyunkaya, Melike Yigit
2017-01-01
We have used "GeoGebra," a dynamic geometry software environment, to explore how Year 4 students understand definitions of angles. Seven students defined angle and then completed several activities adapted for the dynamic environment. Afterward, students again shared their definitions of angles. We found that even a short investigation…
47 CFR 25.205 - Minimum angle of antenna elevation.
2010-10-01
... 47 Telecommunication 2 2010-10-01 2010-10-01 false Minimum angle of antenna elevation. 25.205... SATELLITE COMMUNICATIONS Technical Standards § 25.205 Minimum angle of antenna elevation. (a) Earth station antennas shall not normally be authorized for transmission at angles less than 5° measured from the...
Ultra-small-angle neutron scattering with azimuthal asymmetry.
Gu, X; Mildner, D F R
2016-06-01
Small-angle neutron scattering (SANS) measurements from thin sections of rock samples such as shales demand as great a scattering vector range as possible because the pores cover a wide range of sizes. The limitation of the scattering vector range for pinhole SANS requires slit-smeared ultra-SANS (USANS) measurements that need to be converted to pinhole geometry. The desmearing algorithm is only successful for azimuthally symmetric data. Scattering from samples cut parallel to the plane of bedding is symmetric, exhibiting circular contours on a two-dimensional detector. Samples cut perpendicular to the bedding show elliptically dependent contours with the long axis corresponding to the normal to the bedding plane. A method is given for converting such asymmetric data collected on a double-crystal diffractometer for concatenation with the usual pinhole-geometry SANS data. The aspect ratio from the SANS data is used to modify the slit-smeared USANS data to produce quasi-symmetric contours. Rotation of the sample about the incident beam may result in symmetric data but cannot extract the same information as obtained from pinhole geometry.
Energy Technology Data Exchange (ETDEWEB)
Trinker, M. [Atominstitut, Vienna University of Technology, A-1020 Vienna (Austria)], E-mail: mtrinker@ati.ac.at; Jericha, E. [Atominstitut, Vienna University of Technology, A-1020 Vienna (Austria); Bouwman, W.G. [Faculty of Applied Sciences, Delft University of Technology, 2629 JB Delft (Netherlands); Loidl, R. [Atominstitut, Vienna University of Technology, A-1020 Vienna (Austria); Institute Laue-Langevin, F-38042 Grenoble (France); Rauch, H. [Atominstitut, Vienna University of Technology, A-1020 Vienna (Austria)
2007-09-11
Ultra-Small-Angle Neutron Scattering (USANS) is currently becoming an effective technique for the analysis of structures in the micrometer range. The new Spin-Echo SANS (SESANS) method measures a signal in real space. In both cases microfabricated silicon gratings provide unique test procedures for the related devices and interpretations of the experimental data. A series of one-dimensional gratings was fabricated using a highly anisotropic ion etching technique (RIE) and measured at the USANS instrument S18 at ILL, Grenoble. Grating parameters derived from the experimental data are in agreement with the nominal values. Scattering length density correlation functions calculated from the USANS data are compared to SESANS correlation functions measured at the Delft University of Technology, demonstrating the reciprocity of the two scattering methods. Reconstruction techniques for one-dimensional scattering length density distributions are applied to the USANS data. The results are in good agreement with SEM micrographs of the samples.
Directory of Open Access Journals (Sweden)
T Nagata
2011-01-01
Full Text Available Background : The authors have focused their attention to the radiological durability of cervical sagittal alignment after anterior cervical discectomy and fusion (ACDF using autologous bone grafting. Materials and Methods : Among the patients who underwent ACDF with trans-unco-discal (TUD approach between 1976 and 1997, 22 patients (16 males and 6 females made return visits for a clinical evaluation. Patients with trauma or previously treated by anterior cervical fusion or by posterior decompression were excluded from the present study. Clinical evaluation included adjacent segment degeneration (ASD, osseous fusion, local angle at the fused segments and C2-7 angle of cervical spine. Results : The duration after ACDF ranged from 13 to 34 years with an average of 21.3 ± 7.0 years. A single level fusion was done on 8 patients, 2 levels on 11 patients, 3 levels on 2 patients, and 4 levels on 1 patient. Imaging studies indicated that 12 of the 22 patients (54.5% were graded as having symptomatic ASD. Osseous bony fusion at ACDF was recognized in all cases. None of the patients demonstrated kyphotic malalignment of the cervical spine. Average degrees of local angle at the fused segments and the C2-7 angle were 7.06 and 17.6, respectively. Statistical analysis indicated a significant relationship between the local at the fused segments and C2-7 angles. Conclusions : Sagittal alignment of the cervical spine was durable long after ACDF when the local angle at the fused segments was well stabilized.
Manglos, Stephen H.
1989-06-06
A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are collimnated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. The computer solves the following equation in the analysis: ##EQU1## where: N(x).DELTA.x=the number of neutron interactions measured between a position x and x+.DELTA.x, A.sub.i (E.sub.i).DELTA.E.sub.i =the number of incident neutrons with energy between E.sub.i and E.sub.i +.DELTA.E.sub.i, and C=C(E.sub.i)=N .sigma.(E.sub.i) where N=the number density of absorbing atoms in the position sensitive counter means and .sigma. (E.sub.i)=the average cross section of the absorbing interaction between E.sub.i and E.sub.i +.DELTA.E.sub.i.
A new optical method for measuring surface temperature at large incident probe angles
Lee, A. S.; Norris, P. M.
1997-02-01
A novel thermoreflectance technique has been developed for noncontact temperature measurements using laser light incident at large angles on solid materials and devices. The method involves measuring the differential reflectance from a polarization modulated laser beam. The polarization differential reflectance technique is demonstrated on single-crystal Si wafers and on a polycrystalline carbon thin film over a temperature range of 20-60 °C. The method is shown to be an extremely sensitive temperature probe for near grazing angle measurements, which could be useful for monitoring the surface temperature of closely stacked silicon wafers used in batch processing in the microelectronics industry.
Evaluation of solution stability for two-component polydisperse systems by small-angle scattering
Kryukova, A. E.; Konarev, P. V.; Volkov, V. V.
2017-12-01
The article is devoted to the modelling of small-angle scattering data using the program MIXTURE designed for the study of polydisperse multicomponent mixtures. In this work we present the results of solution stability studies for theoretical small-angle scattering data sets from two-component models. It was demonstrated that the addition of the noise to the data influences the stability range of the restored structural parameters. The recommendations for the optimal minimization schemes that permit to restore the volume size distributions for polydisperse systems are suggested.
DCE-PWI 3D T1-measurement as function of time or flip angle
DEFF Research Database (Denmark)
Mikkelsen, Irene Klærke; Peters, David Alberg; Tietze, Anna
Dynamic Contrast Enhanced Perfusion Weighted Imaging (DCE-PWI) and the preceding T1 measurement is usually performed with a FLASH sequence. For the sake of speed, the 3D T1 measurement is often performed by measuring the signal for a range of flip angles instead of as a function the inversion (or...... saturation) time [1,2]. This work investigates how off-set in flip angles in the presence of B1 inhomogeneities propagates into large errors in the T1 estimates. The errors are markedly reduced when the measurement is performed as a function of time, however this requires signal preparation....
Apparent Contact Angle and Triple-Line Tension of a Soap Bubble on a Substrate.
Rodrigues, João Filipe; Saramago, Benilde; Fortes, Manuel Amaral
2001-07-15
The contact angle, θ, of a small bubble on a flat solid substrate was measured as a function of bubble radius, R. The observed deviation of the contact angle from 90 degrees can be accounted for in terms of a negative line tension, tau. The measured values of |tau|/gamma(f), where gamma(f) is the film tension, ranged between 0.15 and 0.6 mm and are proportional to the height, h, of the Plateau border, with |tau| congruent with1.7gamma(f)h. Copyright 2001 Academic Press.
Analysis of the conoscopic measurement for uniaxial liquid-crystal tilt angles.
Van Horn, B L; Winter, H H
2001-05-01
Conoscopy as an optical method for accurate measurement of crystal tilt angles from interference figures is analyzed for the special case of uniaxial crystals. The displacement of interference figures is related to the crystal tilt angle in an explicit, noniterative manner that is accurate to within ~2%. The analysis applies to uniaxial nematic liquid-crystal monodomains and homogeneous crystals when a symmetrical center of the conoscopic interference figure is visible. The equations developed are also used to derive other previously reported expressions that are approximations with a limited range of applicability.
Non-contact angle measurement based on parallel multiplex laser feedback interferometry
International Nuclear Information System (INIS)
Zhang Song; Tan Yi-Dong; Zhang Shu-Lian
2014-01-01
We present a novel precise angle measurement scheme based on parallel multiplex laser feedback interferometry (PLFI), which outputs two parallel laser beams and thus their displacement difference reflects the angle variation of the target. Due to its ultrahigh sensitivity to the feedback light, PLFI realizes the direct non-contact measurement of non-cooperative targets. Experimental results show that PLFI has an accuracy of 8″ within a range of 1400″. The yaw of a guide is also measured and the experimental results agree with those of the dual-frequency laser interferometer Agilent 5529A. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)
Direct image reconstruction with limited angle projection data for computerized tomography
International Nuclear Information System (INIS)
Inouye, T.
1980-01-01
Discussions are made on the minimum angle range for projection data necessary to reconstruct the complete CT image. As is easily shown from the image reconstruction theorem, the lack of projection angle provides no data for the Fourier transformed function of the object on the corresponding angular directions, where the projections are missing. In a normal situation, the Fourier transformed function of an object image holds an analytic characteristic with respect to two-dimensional orthogonal parameters. This characteristic enables uniquely prolonging the function outside the obtained region employing a sort of analytic continuation with respect to both parameters. In the method reported here, an object pattern, which is confined within a finite range, is shifted to a specified region to have complete orthogonal function expansions without changing the projection angle directions. These orthogonal functions are analytically extended to the missing projection angle range and the whole function is determined. This method does not include any estimation process, whose effectiveness is often seriously jeopardized by the presence of a slight fluctuation component. Computer simulations were carried out to demonstrate the effectiveness of the method
Englund, Carl-Johan; Agåker, Marcus; Fredriksson, Pierre; Olsson, Anders; Johansson, Niklas; Rubensson, Jan-Erik; Nordgren, Joseph
2015-09-01
A concept that enables in-vacuum continuous variation of the angle between two ports in one plane has been developed and implemented. The vacuum chamber allows for measuring scattering cross sections as a function of scattering angle and is intended for resonant inelastic X-ray scattering experiments. The angle between the ports can be varied in the range of 30°-150°, while the pressure change is less than 2 × 10(-10) mbars.
Scott, David J
2016-12-01
Hydrodynamic studies of the solution properties of proteins and other biological macromolecules are often hard to interpret when the sample is present at a reasonably concentrated solution. The reason for this is that solutions exhibit deviations from ideal behaviour which is manifested as thermodynamic non-ideality. The range of concentrations at which this behaviour typically is exhibited is as low as 1-2 mg/ml, well within the range of concentrations used for their analysis by techniques such as small-angle scattering. Here we discuss thermodynamic non-ideality used previously used in the context of light scattering and sedimentation equilibrium analytical ultracentrifugation and apply it to the Guinier region of small-angle scattering data. The results show that there is a complementarity between the radially averaged structure factor derived from small-angle X-ray scattering/small-angle neutron scattering studies and the second virial coefficient derived from sedimentation equilibrium analytical ultracentrifugation experiments.
Using Digital Technology to See Angles from Different Angles. Part 1: Corners
Host, Erin; Baynham, Emily; McMaster, Heather
2014-01-01
In Part 1 of their article, Erin Host, Emily Baynham and Heather McMaster use a combination of digital technology and concrete materials to explore the concept of "corners". They provide a practical, easy to follow sequence of activities that builds on students' understandings. [For "Using Digital Technology to See Angles from…
Spondylolysis and the sacro-horizontal angle in athletes
International Nuclear Information System (INIS)
Swaerd, L.; Hellstroem, M.; Jacobsson, B.; Peterson, L.; Sahlgrenska Sjukhuset, Goeteborg; King Faisal Specialist Hospital and Research Centre, Riyadh
1989-01-01
The frequency of spondylolysis and the relationship between spondylolysis and the sacro-horizontal angle in 143 athletes and 30 non-athletes is reported. Athletes had a larger sacro-horizontal angle than non-athletes. The sacro-horizontal angle was larger in athletes with spondylolysis as compared with those without. An increased incidence of spondylolysis with an increased angle was demonstrated. It is suggested that an increased sacro-horizontal angle may predispose to spondylolysis, especially in combination with the high mechanical loads sustained in certain sports. (orig.)
Spondylolysis and the sacro-horizontal angle in athletes
Energy Technology Data Exchange (ETDEWEB)
Swaerd, L.; Hellstroem, M.; Jacobsson, B.; Peterson, L. (Oestra Sjukhuset, Goeteborg (Sweden). Dept. of Orthopaedics; Sahlgrenska Sjukhuset, Goeteborg (Sweden). Dept. of Diagnostic Radiology; King Faisal Specialist Hospital and Research Centre, Riyadh (Saudi Arabia). Dept. of Radiology)
The frequency of spondylolysis and the relationship between spondylolysis and the sacro-horizontal angle in 143 athletes and 30 non-athletes is reported. Athletes had a larger sacro-horizontal angle than non-athletes. The sacro-horizontal angle was larger in athletes with spondylolysis as compared with those without. An increased incidence of spondylolysis with an increased angle was demonstrated. It is suggested that an increased sacro-horizontal angle may predispose to spondylolysis, especially in combination with the high mechanical loads sustained in certain sports. (orig.).
Sinusoidal Order Estimation Using Angles between Subspaces
Directory of Open Access Journals (Sweden)
Søren Holdt Jensen
2009-01-01
Full Text Available We consider the problem of determining the order of a parametric model from a noisy signal based on the geometry of the space. More specifically, we do this using the nontrivial angles between the candidate signal subspace model and the noise subspace. The proposed principle is closely related to the subspace orthogonality property known from the MUSIC algorithm, and we study its properties and compare it to other related measures. For the problem of estimating the number of complex sinusoids in white noise, a computationally efficient implementation exists, and this problem is therefore considered in detail. In computer simulations, we compare the proposed method to various well-known methods for order estimation. These show that the proposed method outperforms the other previously published subspace methods and that it is more robust to the noise being colored than the previously published methods.
Experimental bounds on sterile neutrino mixing angles
Ruchayskiy, Oleg
2012-01-01
We derive bounds on the mixing between the left-chiral ("active") and the right-chiral ("sterile") neutrinos, provided from the combination of neutrino oscillation data and direct experimental searches for sterile neutrinos. We demonstrate that the mixing of sterile neutrinos with any flavour can be significantly suppressed, provided that the angle theta_13 is non-zero. This means that the lower bounds on sterile neutrino lifetime, coming from the negative results of direct experimental searches can be relaxed (by as much as the order of magnitude at some masses). We also demonstrate that the results of the negative searches of sterile neutrinos with PS191 and CHARM experiments are not applicable directly to the see-saw models. The reinterpretation of these results provides up to the order of magnitude stronger bounds on sterile neutrino lifetime than previously discussed in the literature. We discuss the implications of our results for the Neutrino Minimal Standard Model (the NuMSM).
Vascular anomalies of the cerebellopontine angle
International Nuclear Information System (INIS)
Papanagiotou, P.; Grunwald, I.Q.; Politi, M.; Struffert, T.; Ahlhelm, F.; Reith, W.
2006-01-01
Vascular anomalies of the cerebellopontine angle are rare compared to tumors in this area. Irritation of the trigeminal, facial, or vestibulocochlear nerve may cause trigeminal neuralgia, hemifacial spasm and vertigo, or tinnitus accordingly. Vessel loops in the cerebellopontine cisterns may cause compression at the root entry or exit zone of the cranial nerves V, VII, and VIII, a phenomenon which is called ''vascular loop syndrome.'' Megadolichobasilar artery and aneurysms of the vertebrobasilar system can also lead to dislocation and compression of the cranial nerves and brain stem. Three-dimensional CISS MR imaging and MR angiography are useful in the detection of neurovascular compression. Microvascular decompression is an effective surgical procedure in the management of compression syndromes of the cranial nerves V, VII, and VIII. (orig.) [de
Foreign Body Embedded in Anterior Chamber Angle
Directory of Open Access Journals (Sweden)
Shmuel Graffi
2012-01-01
Full Text Available Introduction. We present a case of a metallic foreign body embedded in the anterior chamber angle. After standing in close proximity to a construction worker breaking a tile, a 26-year-old woman using soft contact lens for the correction of mild myopia presented to emergency department for evaluation of a foreign body sensation of her right eye. Methods and Results. Diagnosis was confirmed by gonioscopic examination and a noncontrast CT scan of head and orbits. The foreign body was removed by an external approach without utilizing a magnet. The patient's final outcome was favorable. Discussion. The above is a rare clinical situation, which is impossible to detect on slit-lamp examination without a gonioscopic view. Proper imaging and a specific management are mandatory in order to achieve favorable outcome.
Mirtazapine-induced acute angle closure
Directory of Open Access Journals (Sweden)
Nilay Kahraman
2015-01-01
Full Text Available Acute angle closure (AAC is an ocular emergency with symptoms including blurred vision, eye pain, headache, nausea, vomiting and reddening of the eye those results from increased intraocular pressure. This clinical condition can lead to permanent damage in vision, thus causing blindness by generating progressive and irreversible optic neuropathy if left untreated. There are several reasons of AAC, including several types of local and systemic medications; mainly sympathomimetics, cholinergics, anti-cholinergics, mydriatics, anti-histamines, antiepileptics like topiramate, tricyclic and tetracyclic antidepressants, serotonin reuptake inhibitors, antipsychotics, sulfa-based drugs and anticoagulants. Mirtazapine, a noradrenergic and specific serotonergic antidepressant, is an atypical antidepressant with a complex pharmacological profile. This case report describes a patient with major depressive disorder, who experienced AAC after the first dosage of mirtazapine treatment, and highlights the importance of close monitoring of individuals under antidepressant treatment particularly immediately after initiation of the drug.
Multifunctional patchy particles by glancing angle deposition.
Pawar, Amar B; Kretzschmar, Ilona
2009-08-18
The application of glancing angle deposition (GLAD) as a means to produce a variety of multifunctional patchy particles is reported. The GLAD technique has been previously used to produce anisotropic particles with an anisotropy dimension of "patchiness". Here, we extend the technique to produce multifunctional patchy particles with anisotropy dimensions of "patchiness", "branching", and "chemical ordering". To access the entire particle surface, a particle stamping technique is employed using a polydimethylsiloxane (PDMS) stamp. The particle stamping technique along with GLAD yields multifunctional patchy particles having patches on opposite poles. The potential of the developed techniques in producing a wide variety of surface-anisotropic particles with variable patch size, shape, and orientation is demonstrated.
Contact angle measurement of natural materials.
Zhao, Tianyi; Jiang, Lei
2018-01-01
Contact angle (CA) is the most important parameter used to quantify the wettability of solid surfaces. In order to evaluate wettability performance, numerous methods have been developed to measure the CA of solid surfaces. Recent years have seen increased focus on the special wettability performance of various biological materials. Biomimetic wettability has become one of the most popular research fields, and novel CA measurements have been invented accordingly. In this protocol, we introduce several CA measurement techniques mainly based on the image capture method, which is commonly to investigate the wettability of natural materials. According to the solid/liquid/gas context, we classify CA measurements into three types: in air, under liquid, and air bubble measurements, and describe methods for each. The precise measurement of CA together with study of surface structure can reveal the mechanisms of special wettability, thus accelerating the investigation of biomaterials. Copyright © 2017. Published by Elsevier B.V.
Dilemma of gonial angle measurement: Panoramic radiograph or lateral cephalogram
Energy Technology Data Exchange (ETDEWEB)
Radhakrishnan, Pillai Devu; Varma, Nilambur Kovilakam Sapna; Ajith, Vallikat Velath [Dept. of Orthodontics, Amrita School of Dentistry, Kochi (India)
2017-06-15
The purpose of this study was to evaluate the accuracy of panoramic imaging in measuring the right and left gonial angles by comparing the measured angles with the angles determined using a lateral cephalogram of adult patients with class I malocclusion. The gonial angles of 50 class I malocclusion patients (25 males and 25 females; mean age: 23 years) were measured using both a lateral cephalogram and a panoramic radiograph. In the lateral cephalograms, the gonial angle was measured at the point of intersection of the ramus plane and the mandibular plane. In the panoramic radiographs, the gonial angle was measured by drawing a line tangent to the lower border of the mandible and another line tangent to the distal border of the ascending ramus and the condyle on both sides. The data obtained from both radiographs were statistically compared. No statistically significant difference was observed between the gonial angle measured using the lateral cephalograms and that determined using the panoramic radiographs. Further, there was no statistically significant difference in the measured gonial angle with respect to gender. The results also showed a statistically insignificant difference in the mean of the right and the left gonial angles measured using the panoramic radiographs. As the gonial angle measurements using panoramic radiographs and lateral cephalograms showed no statistically significant difference, panoramic radiography can be considered in orthodontics for measuring the gonial angle without any interference due to superimposed images.
Effects of setting angle on performance of fish-bionic wind wheel
Li, G. S.; Yang, Z. X.; Song, L.; Chen, Q.; Li, Y. B.; Chen, W.
2016-08-01
With the energy crisis and the increasing environmental pollutionmore and more efforts have been made about wind power development. In this paper, a new type of vertical axis named the fish-bionic wind wheel was proposed, and the outline of wind wheel was constructed by curve of Fourier fitting and polynomial equations. This paper attempted to research the relationship between the setting angle and the wind turbine characteristics by computational fluid dynamics (CFD) simulation. The results showed that the setting angle of the fish-bionic wind wheel has some significant effects on the efficiency of the wind turbine, Within the range of wind speed from 13m/s to 15m/s, wind wheel achieves the maximum efficiency when the setting angle is at 37 degree. The conclusion will work as a guideline for the improvement of wind turbine design.
Effects of setting angle and chord length on performance of four blades bionic wind turbine
Yang, Z. X.; Li, G. S.; Song, L.; Bai, Y. F.
2017-11-01
With the energy crisis and the increasing environmental pollution, more and more efforts have been made about wind power development. In this paper, a four blades bionic wind turbine was proposed, and the outline of wind turbine was constructed by the fitted curve. This paper attempted to research the effects of setting angle and chord length on performance of four blades bionic wind turbine by computational fluid dynamics (CFD) simulation. The results showed that the setting angle and chord length of the bionic wind turbine has some significant effects on the efficiency of the wind turbine, and within the range of wind speed from 7 m/s to 15 m/s, the wind turbine achieved maximum efficiency when the setting angle is 31 degree and the chord length is 125 mm. The conclusion will work as a guideline for the improvement of wind turbine design
Directory of Open Access Journals (Sweden)
Diptasree Maitra Ghosh
Full Text Available This study has described and experimentally validated the differential electrodes surface electromyography (sEMG model for tibialis anterior muscles during isometric contraction. This model has investigated the effect of pennation angle on the simulated sEMG signal. The results show that there is no significant effect of pennation angle in the range 0° to 20° to the single fibre action potential shape recorded on the skin surface. However, the changes with respect to pennation angle are observed in sEMG amplitude, frequency and fractal dimension. It is also observed that at different levels of muscle contractions there is similarity in the relationships with Root Mean Square, Median Frequency, and Fractal Dimension of the recorded and simulated sEMG signals.
Hou, Zhipeng
2018-01-10
Recently, there have been increasingly debates on whether there exists a surface resonance state (SRS) in black phosphorus (BP), as suggested by recent angle-resolved photoemission spectroscopy (ARPES) results. To resolve this issue, we have performed temperature- and angle-dependent magnetoconductivity measurements on exfoliated, high-quality BP single crystals. A pronounced weak-antilocalization (WAL) effect was observed within a narrow temperature range of 8 - 16 K, with the electrical current flowing parallel to the cleaved ac-plane (along the a- or c-axis) and the magnetic field along the b-axis. The angle-dependent magnetoconductivity and the Hikami-Larkin-Nagaoka (HLN) model-fitted results have revealed that the observed WAL effect shows surface-bulk coherent features, which supports the existence of SRS in black phosphorus.
Directory of Open Access Journals (Sweden)
Abdal Karim Z. Mansoor
2013-05-01
Full Text Available This paper presents design and analysis of a single phase multilevel inverter by optimizing both switching angles and DC link voltage of a cascaded inverter. The switching angles and dc link voltage are chosen such that to minimize the total harmonic distortion of the output voltage. The main power devices are switched only once per cycle , so that to overcome the switching loss problem, as well as electromagnetic interference (EMI problem, a method is given to determine the optimum value of the switching angles and the value of the dc link voltage. Theoretical analysis and simulation of a single phase 5-level cascaded inverter are introduced with a wide range of modulation index
Investigation of porous silicon obtained under different conditions by the contact angle method
Belorus, A. O.; Bukina, Y. V.; Pastukhov, A. I.; Stebko, D. S.; Spivak, Yu M.; Moshnikov, V. A.
2017-11-01
This paper investigates a hydrophobicity/hydrophilicity of porous silicon by the contact angle method. Porous silicon series were obtained by electrochemical anodic etching of n-Si (100) and (111) under the current anodization density range of 5-120 mA/cm2. For this purpose the original laboratory installation and the software «Measurement of contact angle» were developed. It is shown that, the contact angle can vary significantly (up to 80 degrees for (100)) depending on the current anodization Discussion of the results is carried out taking in account the composition of the functional groups and of surface morphology of the porous silicon. These results are important for developing porous silicon particles as nanocontainers in the targeted drug delivery.
Kaplan, A. F. H.
2012-10-01
The modulation of the angle-dependent Fresnel absorptivity across wavy molten steel surfaces during laser materials processing, like drilling, cutting, or welding, has been calculated. The absorptivity is strongly altered by the grazing angle of incidence of the laser beam on the processing front. Owing to its specific Brewster-peak characteristics, the 10.64 μm wavelength CO2-laser shows an opposite trend with respect to roughness and angle-of-incidence compared to lasers in the wavelength range of 532-1070 nm. Plateaus or rings of Brewster-peak absorptivity can lead to hot spots on a wavy surface, often in close proximity to cold spots caused by shadow domains.
Directory of Open Access Journals (Sweden)
B Sreedhara Rao
2015-04-01
Full Text Available In the present investigation heat transfer studies are conducted in corrugated plate heat exchangers (PHEs having three different corrugation angles of 300, 400 and 500. The plate heat exchangers have a length of 30 cm and a width of 10 cm with a spacing of 5 mm. Water and 20% glycerol solution are taken as test fluids and hot fluid is considered as heating medium. The wall temperatures are measured along the length of exchanger at seven different locations by means of thermocouples. The inlet and outlet temperatures of test fluid and hot fluid are measured by means of four more thermocouples. The experiments are conducted at a flowrate ranging from 0.5 lpm to 6 lpm with the test fluid. Film heat transfer coefficient and Nusselt number are determined from the experimental data. These values are compared with different corrugation angles. The effects of corrugation angles on heat transfer rates are discussed.
Dielectric-based subwavelength metallic meanders for wide-angle band absorbers.
Shen, Su; Qiao, Wen; Ye, Yan; Zhou, Yun; Chen, Linsen
2015-01-26
We propose nano-meanders that can achieve wide-angle band absorption in visible regime. The nano-meander consists of a subwavelength dielectric grating covered by continuous ultra-thin Aluminum film (less than one tenth of the incident wavelength). The excited photonic resonant modes, such as cavity mode, surface plasmonic mode and Rayleigh-Wood anomaly, are discussed in detail. Nearly total resonant absorption due to funneling mechanism in the air nano-groove is almost invariant with large incident angle in transverse magnetic polarization. From both the structural geometry and the nanofabrication point of view, the light absorber has a very simple geometrical structure and it is easy to be integrated into complex photonic devices. The highly efficient angle-robust light absorber can be potential candidate for a range of passive and active photonic applications, including solar-energy harvesting as well as producing artificial colors on a large scale substrate.
Directory of Open Access Journals (Sweden)
Ľuboš Hládek
Full Text Available The manuscript proposes and evaluates a real-time algorithm for estimating eye gaze angle based solely on single-channel electrooculography (EOG, which can be obtained directly from the ear canal using conductive ear moulds. In contrast to conventional high-pass filtering, we used an algorithm that calculates absolute eye gaze angle via statistical analysis of detected saccades. The estimated eye positions of the new algorithm were still noisy. However, the performance in terms of Pearson product-moment correlation coefficients was significantly better than the conventional approach in some instances. The results suggest that in-ear EOG signals captured with conductive ear moulds could serve as a basis for light-weight and portable horizontal eye gaze angle estimation suitable for a broad range of applications. For instance, for hearing aids to steer the directivity of microphones in the direction of the user's eye gaze.
The influence of incidence angle on disorder production in Cl and Ar ion implanted Si
International Nuclear Information System (INIS)
Sukirno; Carter, G.
1989-01-01
Cl and Ar ions have been implanted, at 30 keV and at various incidence angles, into Si substrates maintained at room temperature during implantation. Implantation induced Si disorder was measured using Rutherford backscattering channelling. The effects upon disorder of various incidence angles were studied over a fluence range of 10 12 -6·10 15 ions·cm -2 . The results show that, at low fluences Cl and Ar ion implantations generate a bimodal disorder-depth profile, whilst at higher fluences measurements of amorphised layer thickness as a function of ion incidence angle allow values of the standard deviation of the disorder profile parallel and transverse to the ion beam direction for each ion to be obtained in good agreement with theoretical predictions. The disorder-fluence behaviour under these conditions is ion species independent. (author)
The effect of incidence angle on disorder production in ion implanted Si
International Nuclear Information System (INIS)
Sukirno; Carter, G.
1989-01-01
Ne, Ar, Sb, and Xe ions have been implanted, at 30 keV or 80 keV and at various incidence angles, into Si substrates maintained at room temperature during implantation. Implantation-induced Si disorder was measured using Rutherford backscattering channelling. The effects upon disorder of various incidence angles were studied over a fluence range of 10 12 -10 16 ions·cm -2 . The results show that, at low fluences the lighter (Ne) and slightly heavier (Ar) ion implantations generate a bimodal disorder-depth profile, whilst at higher fluences measurements of amorphised layer thickness as a function of ion incidence angle allow values of the standard deviation of the disorder profile parallel and transverse to the ion beam direction for each ion to be obtained with good agreement to theoretical predictions. (author)
Misdaq, M A; Ktata, A; Merzouki, A; Youbi, N
1999-01-01
The critical angles of the CR-39 (theta sub c) and LR-115 type II (theta sub c ') solid state nuclear track detectors (SSNTD) for detecting alpha-particles emitted by the uranium and thorium series have been evaluated by calculating the corresponding ranges of the emitted alpha-particles in different material samples and in the SSNTD studied. The influence of the emitted alpha-particles initial and residual energies on the critical angles of the SSNTD studied has been investigated. The uranium and thorium contents of different geological samples have been evaluated by exploiting data obtained for the critical angles of the CR-39 and LR-115 type II solid state nuclear track detectors and measuring the corresponding densities of tracks.
Directory of Open Access Journals (Sweden)
Lawan H. Adamu
2016-12-01
Full Text Available The aim of the study was to determine sexual dimorphism as well as to predict sex using facial linear dimensions and angles among Hausas of Kano state Nigeria. A total of 283 subjects comprising 147 males and 136 females age range 18–25 years participated. Photographs methods were used to capture the face. Independent sample t-test was used to test for sex differences in the variables. Binary logistic regression was applied to obtain a predicting equation (BLR model for sex. The predicted probabilities of BLR were analyzed using receiver operating characteristic curve. The results showed that all the facial linear dimensions showed significance sexual dimorphism except interocular distance, upper facial width, philtrum length, lower vermilion width, left and right orbital width. With regards to sex prediction, upper facial height was the single best predictor of sex with an accuracy of 76.2% and 24–33% contribution to the prediction. However, the percentage accuracy increased to 91% when six variables were pooled together in the equations. For facial angles, only nasion and aperture modified angle did not show significant gender differences. However, in the variables with significant sexual dimorphism only nasomental angle showed a significant level of sex prediction with an accuracy of 70.3%. In conclusion, sex discrimination using facial linear dimensions and angles was well established in this study. The sex of an individual of Hausa ethnic group can be determined using facial linear dimensions. Dispite sexual dimorphsm shown by facial angles, only nasomental angle was good discriminator of sex.
RE-EXAMINING SUNSPOT TILT ANGLE TO INCLUDE ANTI-HALE STATISTICS
Energy Technology Data Exchange (ETDEWEB)
McClintock, B. H. [University of Southern Queensland, Toowoomba, 4350 (Australia); Norton, A. A. [HEPL, Stanford University, Palo Alto, CA 94305 (United States); Li, J., E-mail: u1049686@umail.usq.edu.au, E-mail: aanorton@stanford.edu, E-mail: jli@igpp.ucla.edu [Department of Earth, Planetary, and Space Sciences, University of California at Los Angeles, Los Angeles, CA 90095 (United States)
2014-12-20
Sunspot groups and bipolar magnetic regions (BMRs) serve as an observational diagnostic of the solar cycle. We use Debrecen Photohelographic Data (DPD) from 1974-2014 that determined sunspot tilt angles from daily white light observations, and data provided by Li and Ulrich that determined sunspot magnetic tilt angle using Mount Wilson magnetograms from 1974-2012. The magnetograms allowed for BMR tilt angles that were anti-Hale in configuration, so tilt values ranged from 0 to 360° rather than the more common ±90°. We explore the visual representation of magnetic tilt angles on a traditional butterfly diagram by plotting the mean area-weighted latitude of umbral activity in each bipolar sunspot group, including tilt information. The large scatter of tilt angles over the course of a single cycle and hemisphere prevents Joy's law from being visually identified in the tilt-butterfly diagram without further binning. The average latitude of anti-Hale regions does not differ from the average latitude of all regions in both hemispheres. The distribution of anti-Hale sunspot tilt angles are broadly distributed between 0 and 360° with a weak preference for east-west alignment 180° from their expected Joy's law angle. The anti-Hale sunspots display a log-normal size distribution similar to that of all sunspots, indicating no preferred size for anti-Hale sunspots. We report that 8.4% ± 0.8% of all bipolar sunspot regions are misclassified as Hale in traditional catalogs. This percentage is slightly higher for groups within 5° of the equator due to the misalignment of the magnetic and heliographic equators.
RE-EXAMINING SUNSPOT TILT ANGLE TO INCLUDE ANTI-HALE STATISTICS
International Nuclear Information System (INIS)
McClintock, B. H.; Norton, A. A.; Li, J.
2014-01-01
Sunspot groups and bipolar magnetic regions (BMRs) serve as an observational diagnostic of the solar cycle. We use Debrecen Photohelographic Data (DPD) from 1974-2014 that determined sunspot tilt angles from daily white light observations, and data provided by Li and Ulrich that determined sunspot magnetic tilt angle using Mount Wilson magnetograms from 1974-2012. The magnetograms allowed for BMR tilt angles that were anti-Hale in configuration, so tilt values ranged from 0 to 360° rather than the more common ±90°. We explore the visual representation of magnetic tilt angles on a traditional butterfly diagram by plotting the mean area-weighted latitude of umbral activity in each bipolar sunspot group, including tilt information. The large scatter of tilt angles over the course of a single cycle and hemisphere prevents Joy's law from being visually identified in the tilt-butterfly diagram without further binning. The average latitude of anti-Hale regions does not differ from the average latitude of all regions in both hemispheres. The distribution of anti-Hale sunspot tilt angles are broadly distributed between 0 and 360° with a weak preference for east-west alignment 180° from their expected Joy's law angle. The anti-Hale sunspots display a log-normal size distribution similar to that of all sunspots, indicating no preferred size for anti-Hale sunspots. We report that 8.4% ± 0.8% of all bipolar sunspot regions are misclassified as Hale in traditional catalogs. This percentage is slightly higher for groups within 5° of the equator due to the misalignment of the magnetic and heliographic equators
Use of the iPhone for Cobb angle measurement in scoliosis.
Shaw, Matthew; Adam, Clayton J; Izatt, Maree T; Licina, Paul; Askin, Geoffrey N
2012-06-01
The Cobb technique is the universally accepted method for measuring the severity of spinal deformities. Traditionally, Cobb angles have been measured using protractor and pencil on hardcopy radiographic films. The new generation of mobile 'smartphones' make accurate angle measurement possible using an integrated accelerometer, providing a potentially useful clinical tool for assessing Cobb angles. The purpose of this study was to compare Cobb angle measurements performed using a smartphone and traditional protractor in a series of 20 adolescent idiopathic scoliosis patients. Seven observers measured major Cobb angles on 20 pre-operative postero-anterior radiographs of Adolescent Idiopathic Scoliosis patients with both a standard protractor and using an Apple iPhone. Five of the observers repeated the measurements at least a week after the original measurements. The mean absolute difference between pairs of smartphone/protractor measurements was 2.1°, with a small (1°) bias toward lower Cobb angles with the iPhone. 95% confidence intervals for intra-observer variability were ±3.3° for the protractor and ±3.9° for the iPhone. 95% confidence intervals for inter-observer variability were ±8.3° for the iPhone and ±7.1° for the protractor. Both of these confidence intervals were within the range of previously published Cobb measurement studies. We conclude that the iPhone is an equivalent Cobb measurement tool to the manual protractor, and measurement times are about 15% less. The widespread availability of inclinometer-equipped mobile phones and the ability to store measurements in later versions of the angle measurement software may make these new technologies attractive for clinical measurement applications.
International Nuclear Information System (INIS)
Kuklin, A I; Rogachev, A V; Soloviov, D V; Ivankov, O I; Kovalev, Yu S; Kutuzov, S A; Soloviev, A G; Rulev, M I; Gordeliy, V I; Utrobin, P K
2017-01-01
Abstract.The work is a review of neutronographic investigations of supramolecular structures on upgraded small-angle spectrometer YuMO. Here, key parameters of small-angle spectrometers are considered. It is shown that two-detector system is the basis of YuMO upgrade. It allows to widen the dynamic q-range twice. In result, the available q-range is widened and dynamic q-range and data collection rate are doubled. The detailed description of YuMO spectrometer is given.The short review of experimental researches made on the spectrometer in the polymers field, biology, material science and physical chemistry is given. The current investigations also have a methodological aspect. It is shown that upgraded spectrometer provides advanced world level of research of supramolecular structures. (paper)
Effect of image resolution manipulation in rearfoot angle measurements obtained with photogrammetry.
Sacco, I C N; Picon, A P; Ribeiro, A P; Sartor, C D; Camargo-Junior, F; Macedo, D O; Mori, E T T; Monte, F; Yamate, G Y; Neves, J G; Kondo, V E; Aliberti, S
2012-09-01
The aim of this study was to investigate the influence of image resolution manipulation on the photogrammetric measurement of the rearfoot static angle. The study design was that of a reliability study. We evaluated 19 healthy young adults (11 females and 8 males). The photographs were taken at 1536 pixels in the greatest dimension, resized into four different resolutions (1200, 768, 600, 384 pixels) and analyzed by three equally trained examiners on a 96-pixels per inch (ppi) screen. An experienced physiotherapist marked the anatomic landmarks of rearfoot static angles on two occasions within a 1-week interval. Three different examiners had marked angles on digital pictures. The systematic error and the smallest detectable difference were calculated from the angle values between the image resolutions and times of evaluation. Different resolutions were compared by analysis of variance. Inter- and intra-examiner reliability was calculated by intra-class correlation coefficients (ICC). The rearfoot static angles obtained by the examiners in each resolution were not different (P > 0.05); however, the higher the image resolution the better the inter-examiner reliability. The intra-examiner reliability (within a 1-week interval) was considered to be unacceptable for all image resolutions (ICC range: 0.08-0.52). The whole body image of an adult with a minimum size of 768 pixels analyzed on a 96-ppi screen can provide very good inter-examiner reliability for photogrammetric measurements of rearfoot static angles (ICC range: 0.85-0.92), although the intra-examiner reliability within each resolution was not acceptable. Therefore, this method is not a proper tool for follow-up evaluations of patients within a therapeutic protocol.
Comparison of two- and three-dimensional measurement of the Cobb angle in scoliosis.
Lechner, Ricarda; Putzer, David; Dammerer, Dietmar; Liebensteiner, Michael; Bach, Christian; Thaler, Martin
2017-05-01
The Cobb angle as an objective measure is used to determine the progression of deformity, and is the basis in the planning of conservative and surgical treatment. However, studies have shown that the Cobb angle has two limitations: an inter- and intraobserver variability of the measurement is approximately 3-5 degrees, and high variability regarding the definition of the end vertebra. Scoliosis is a three-dimensional (3D) pathology, and 3D pathologies cannot be completely assessed by two-dimensional (2D) methods, like 2D radiography. The objective of this study was to determine the intraobserver and interobserver reliability of end vertebra definition and Cobb angle measurement using X-rays and 3D computer tomography (CT) reconstructions in scoliotic spines. To assess interoberver variation the Cobb angle and the end vertebra were assessed by five observers in 55 patients using X-rays and 3D CT reconstructions. Definition of end vertebra and measurement of the Cobb angle was repeated two times with a three-week interval. Intraclass correlation coefficients (ICC) were used to determine the interobserver and intraobserver reliabilities. 95% prediction limits were provided for measurement errors. Intraclass correlation coefficient (ICC) showed excellent reliability for both methods. The measured Cobb angle was on average 9.2 degrees larger in the 3D CT group (72.8°, range 30-144) than on 2D radiography (63.6°, range 24-152). In scoliosis treatment it is very essential to determine the curve magnitude, which is larger in a 3D measurement compared to 2D radiography.
Research on the laser angle deception jamming technology of laser countermeasure
Ma, Shi-wei; Chen, Wen-jian; Gao, Wei; Duan, Yuan-yuan
2015-10-01
In recent years , laser guided weapons behave very well at destroying the military goals in the local wars, the single-shot probability, effective range and hitting precision getting better. And the semi-active laser guided weapons are the most widely used laser guided weapons. In order to improve the viability and protect important military goals, it's necessary to study the technology to against the semi-active guided weapons. This paper studies the working principle, the advantages and disadvantages of the semi-active guided weapons at first, and analyze the possibility of laser angle deception jamming system working. Then it analyzes the working principle and process of laser angle deception jamming technology. Finally it designs a half-real simulation system of laser angle deception jamming, which consists of semi-active laser guided weapons simulation system and laser angle deception jamming system. The simulation system demonstrates the working process of the laser angle deception jamming system. This paper provides fundamental base for the research on the countermeasure technology of semi-active laser guided weapons.
Zheng, Haijing; Bai, Tingzhu; Wang, Quanxi; Cao, Fengmei; Shao, Long; Sun, Zhaotian
2018-02-01
This study investigates multispectral characteristics of an unmanned aerial vehicle (UAV) at different observation angles by experiment. The UAV and its engine are tested on the ground in the cruise state. Spectral radiation intensities at different observation angles are obtained in the infrared band of 0.9-15 μm by a spectral radiometer. Meanwhile, infrared images are captured separately by long-wavelength infrared (LWIR), mid-wavelength infrared (MWIR), and short-wavelength infrared (SWIR) cameras. Additionally, orientation maps of the radiation area and radiance are obtained. The results suggest that the spectral radiation intensity of the UAV is determined by its exhaust plume and that the main infrared emission bands occur at 2.7 μm and 4.3 μm. At observation angles in the range of 0°-90°, the radiation area of the UAV in MWIR band is greatest; however, at angles greater than 90°, the radiation area in the SWIR band is greatest. In addition, the radiance of the UAV at an angle of 0° is strongest. These conclusions can guide IR stealth technique development for UAVs.
An angled nano-tunnel fabricated on poly(methyl methacrylate) by a focused ion beam
International Nuclear Information System (INIS)
Her, Eun Kyu; Chung, Hee-Suk; Oh, Kyu Hwan; Moon, Myoung-Woon
2009-01-01
Angled nano-scale tunnels with high aspect ratio were fabricated on poly(methyl methacrylate) (PMMA) using a focused ion beam (FIB). The fabrication parameters such as ion fluence, incidence angle, and acceleration voltage of the Ga + ion beam were first studied on the PMMA surface to explore the formation of the nano-scale configurations such as nano-holes and cones with diameter in the range of 50-150 nm at an ion beam acceleration voltage of 5-20 kV. It was also found that the PMMA surface exposed to FIB was changed into an amorphous graphitic structure. Angled nano-scale tunnels were fabricated with high aspect ratio of 700-1500 nm in depth and 60 nm in mean diameter at an ion beam acceleration voltage of 5 kV and under a specific ion beam current. The angle of the nano-tunnels was found to follow the incident angle of the ion beam tilted from 0 0 to 85 0 , which has the potential for creating a mold for anisotropic adhesives by mimicking the hairs on a gecko's feet.
Contact angle of 63Sn-37Pb and Pb-free solder on Cu plating
International Nuclear Information System (INIS)
Lin, C.-T.; Lin, K.-L.
2003-01-01
This study investigated the wetting behavior of 63Sn-37Pb and Pb-free solder on different surface roughness Cu plating. The Cu plating roughness was controlled by current density and deposition time. The contact angles were measured to investigate the wetting behavior. The contact angles of DI (de-ionized) water obey Wenzel's equation and decrease with the increase of surface roughness. Daubing the flux on solder balls as well as on the Cu plating lowers the magnitude of contact angle by 2-23 deg. and the deviation of measured values by 4-6 deg. . The contact angles decrease with the increase of Cu substrate surface roughness in the temperature range of 250-280 deg. C. The cleaning effect of flux was analyzed by Auger electron spectroscopy. The oxide on the Cu substrate surface was well removed by flux. The carbon residue left behind on the substrate surface after reflow raises both the magnitude and the scattering of contact angle
Distribution of angle kappa measurements with Orbscan II in a population-based survey.
Hashemi, Hassan; KhabazKhoob, Mehdi; Yazdani, Kamran; Mehravaran, Shiva; Jafarzadehpur, Ebrahim; Fotouhi, Akbar
2010-12-01
To determine the mean angle kappa and its determinants in the population of Tehran, Iran. In a cross-sectional survey with random cluster sampling, a total of 442 participants aged >14 years were selected from 4 municipality districts of Tehran for Orbscan acquisitions. Exclusion criteria were history of eye surgery for refractive errors, cataract or glaucoma, and use of topical medication or any type of contact lens at the time of the study. Mean angle kappa in different age and gender groups and its association with other factors was assessed. Considering the high correlation between the right and left eyes, only results of the right eyes are presented. After applying exclusion criteria, 800 eyes (399 right eyes and 401 left eyes) were examined. Mean participant age was 40.6±16.8 years (range: 14 to 81 years), and 38.8% of eyes were from men. Mean angle kappa was 5.46±1.33° in total; 5.41±1.32° in men and 5.49±1.34° in women (P=.558). It decreased significantly with age; 0.015°/year (Pangle kappa reduces with age, and the inter-gender difference is not significant. Largest angle kappas were seen among individuals with emmetropia. Angle kappas were larger in the hypermetropic population compared to the myopic population. Copyright 2010, SLACK Incorporated.
Comparing the techniques of defining the synchronous machine load angle
Kovalenko, P. Y.; Moiseichenkov, A. N.
2017-07-01
The low-frequency oscillations are natural for power systems and may arise due to both small variations of load and large disturbance. The effect of slight load changes may significantly differ for cases of low-magnitude permanent oscillations, which may be considered acceptable, and unstable oscillations, which may lead to a major system emergency. The existing trend of increasing the capacity of long-range power transmission has led to the situation where inter-area oscillations may appear underdamped or even rising in terms of magnitude. Effective oscillations detection with the corresponding countermeasures along with eliminating the prerequisites leading to the oscillations is a guarantee of minimizing their negative consequences. Therefore, it is of crucial importance to perform continuous monitoring which is to provide the information on the “source” of oscillations - a generator or a group of generators, which do not contribute to the oscillations damping or even support their development. The algorithm of quantitative estimation of synchronous generators participation in low-frequency oscillations damping based on synchronized phasor measurements has been proposed previously. It implies utilizing the concept of synchronizing power as a measure of the capability of the machine to maintain synchronous operation. The load angle of the generator is necessary to define the value of the synchronizing power and since the direct measurement of the load angle is generally not available the techniques of its derivation have been developed. The comparison of these techniques is presented with the estimation of the adopted assumptions effect on the synchronizing power evaluation results.
Matsuki, Takaaki; Hirose, Fumitaka; Ito, Shin-Ichiro; Hata, Masayuki; Hirami, Yasuhiko; Kurimoto, Yasuo
2015-02-01
To predict angle narrowing in eyes with angle closure in a Japanese population using anterior segment optical coherence tomography (AS-OCT) quantitative parameters. AS-OCT was used to examine 118 eyes of 118 patients with angle closure and 40 eyes of 40 patients with open angle under dark conditions. After measuring the angle opening distance 500 (AOD500), anterior chamber depth, iris thickness (IT), iris convexity (IC), pupil diameter, anterior chamber width, and crystalline lens rise, multivariate regression analyses were performed for the AOD500 in each group. With the exception of IT, significant differences were observed between the AS-OCT parameters for the angle closure and open-angle groups. Anterior chamber depth, IT, and IC were the explanatory variables associated with AOD500 for each group (P≤0.001). A significant negative association was found between IT and IC only in the angle-closure group (Pchamber depth was a major mechanism of angle narrowing, and that both IT and IC had a strong impact on angle narrowing. Moreover, the negative association found between IT and IC in only the angle closure group indicated the existence of the stretch force placed on the iris by relative pupillary block.
New Very Small Angle Neutron Scattering (VSANS) Instrument
International Nuclear Information System (INIS)
Van Every, E; Kulesza, J; Deyhim, A
2016-01-01
The design of a new Very Small Angle Neutron Scattering (VSANS) Instrument for use in National Institute of Standards And Technology (NIST) will be discussed. This instrument is similar to a shorter instrument we designed and delivered to ANSTO in Australia called the Bilby SANS instrument. The NIST VSANS and the ANSTO Bilby SANS instruments have very similar dimensions for length and diameter and have similar requirements for internal detector motion, top access port, walkway supports, and ports; however, the Bilby SANS instrument vacuum requirement was lower (7.5×10-5 Torr) and the entire (60,000 pound) vessel was required to move 1.5 meters on external rails with a repeatability of 100 um, which ADC achieved. The NIST VSANS length is 24 meter, internal diameter 2.3 meter with three internal carriages. The NIST VSANS instrument, which covers the usual SANS range will also allow configuration to cover the range between q ∼| 10 -4 A -1 to 10 -3 A -1 with a sample beam current of (10 4 neutrons/s). The key requirements are a second position-sensitive detector system having a 1 mm pixel size and a longer sample-detector flight path of 20 m (i.e., a 40 m instrument). (paper)
Heparin's solution structure determined by small-angle neutron scattering.
Rubinson, Kenneth A; Chen, Yin; Cress, Brady F; Zhang, Fuming; Linhardt, Robert J
2016-12-01
Heparin is a linear, anionic polysaccharide that is widely used as a clinical anticoagulant. Despite its discovery 100 years ago in 1916, the solution structure of heparin remains unknown. The solution shape of heparin has not previously been examined in water under a range of concentrations, and here is done so in D2 O solution using small-angle neutron scattering (SANS). Solutions of 10 kDa heparin-in the millimolar concentration range-were probed with SANS. Our results show that when sodium concentrations are equivalent to the polyelectrolyte's charge or up to a few hundred millimoles higher, the molecular structure of heparin is compact and the shape could be well modeled by a cylinder with a length three to four times its diameter. In the presence of molar concentrations of sodium, the molecule becomes extended to nearly its full length estimated from reported X-ray measurements on stretched fibers. This stretched form is not found in the presence of molar concentrations of potassium ions. In this high-potassium environment, the heparin molecules have the same shape as when its charges were mostly protonated at pD ≈ 0.5, that is, they are compact and approximately half the length of the extended molecules. © 2016 Wiley Periodicals, Inc.
Lei, Da; Lin, Mian; Li, Yun; Jiang, Wenbin
2018-03-01
An accurate model of the dynamic contact angle θ d is critical for the calculation of capillary force in applications like enhanced oil recovery, where the capillary number Ca ranges from 10 -10 to 10 -5 and the Bond number Bo is less than 10 -4 . The rate-dependence of the dynamic contact angle under such conditions remains blurred, and is the main target of this study. Featuring with pressure control and interface tracking, the innovative experimental system presented in this work achieves the desired ranges of Ca and Bo, and enables the direct optical measurement of dynamic contact angles in capillaries as tiny as 40 × 20 (width × height) μm and 80 × 20 μm. The advancing and receding processes of wetting and nonwetting liquids were tested. The dynamic contact angle was confirmed velocity-independent with 10 -9 < Ca < 10 -5 (contact line velocity V = 0.135-490 μm/s) and it can be described by a two-angle model with desirable accuracy. A modified two-angle model was developed and an empirical form was obtained from experiments. For different liquids contacting the same surface, the advancing angle θ adv approximately equals the static contact angle θ o . The receding angle θ rec was found to be a linear function of θ adv , in good agreement with our and other experiments from the literature. Copyright © 2018 Elsevier Inc. All rights reserved.
In Situ Local Contact Angle Measurement in a CO2-Brine-Sand System Using Microfocused X-ray CT.
Lv, Pengfei; Liu, Yu; Wang, Zhe; Liu, Shuyang; Jiang, Lanlan; Chen, Junlin; Song, Yongchen
2017-04-11
The wettability of porous media is of major interest in a broad range of natural and engineering applications. The wettability of a fluid on a solid surface is usually evaluated by the contact angle between them. While in situ local contact angle measurements are complicated by the topology of porous media, which can make it difficult to use traditional methods, recent advances in microfocused X-ray computed tomography (micro-CT) and image processing techniques have made it possible to measure contact angles on the scale of the pore sizes in such media. However, the effects of ionic strength, CO 2 phase, and flow pattern (drainage or imbibition) on pore-scale contact angle distribution are still not clear and have not been reported in detail in previous studies. In this study, we employed a micro-CT scanner for in situ investigation of local contact angles in a CO 2 -brine-sand system under various conditions. The effects of ionic strength, CO 2 phase, and flow pattern on the local contact-angle distribution were examined in detail. The results showed that the local contact angles vary over a wide range as a result of the interaction of surface contaminants, roughness, pore topology, and capillarity. The wettability of a porous surface could thus slowly weaken with increasing ionic strength, and the average contact angle could significantly increase when gaseous CO 2 (gCO 2 ) turns into supercritical CO 2 (scCO 2 ). Contact angle hysteresis also occurred between drainage and imbibition procedures, and the hysteresis was more significant under gCO 2 condition.
Chen, Xiping; Li, Qianqian; Liu, Xiaoqin; Yang, Li; Xia, Wentao; Tao, Luyang
2012-12-01
To systemically explore the range of visual angles that affect visual acuity, and to establish the relationship between the P1 component (peak latency ~100 ms) of the pattern-reversal visual-evoked potential (PRVEP) and the visual acuity at particular visual angles. Two hundred and ten volunteers were divided into seven groups, according to visual acuity as assessed by the standard logarithmic visual acuity chart (SLD-ii). For each group, the PRVEP components were elicited in response to visual angle presentations at 8°, 4°, 2°, 1°/60', 30', 15', and 7.5', in the whiteblack chess-board reversal mode with a contrast level of 100% at a frequency of 2 Hz. Visual stimuli were presented monocularly, and 200 presentations were averaged for each block of trials. The early and stable component P1 was recorded at the mid-line of the occipital region (oz) and analyzed with SPSS 13.00. (1) oz had the maximum P1 amplitude; there was no significant difference between genders or for interocular comparison in normal controls and subjects with optic myopia. (2) The P1 latency decreased slowly below 30', then increased rapidly. The P1 amplitude initially increased with check size, and was maximal at ~1° and ~30'. (3) The P1 latency in the group with visual acuity ≤0.2 was significantly different at 8°, 15' and 7.5', while the amplitude differed at all visual angles, compared with the group with normal vision. Differences in P1 for the groups with 0.5 and 0.6 acuity were only present at visual angles <1°. (4) Regression analysis showed that the P1 latency and amplitude were associated with visual acuity over the full range of visual angles. There was a moderate correlation at visual angles <30'. Regression equations were calculated for the P1 components and visual acuity, based on visual angle. (1) Visual angle should be taken into consideration when exploring the function of the visual pathway, especially visual acuity. A visual angle ~60' might be appropriate when using
Multi-angle Imaging SpectroRadiometer
Diner, David J. (Principal Investigator)
MISR views the sunlit Earth simultaneously at nine widely spaced angles and provides ongoing global coverage with high spatial detail. Its imagery is carefully calibrated to provide accurate measures of the brightness, contrast, and color of reflected sunlight. MISR provides new types of information for scientists studying Earth's climate, such as the regional and global distribution of different types of atmospheric particles and aerosols. The change in reflection at different view angles provides the means to distinguish aerosol types, cloud forms, and land surface cover. Combined with stereoscopic techniques, this enables construction of 3-D cloud models and estimation of the total amount of sunlight reflected by Earth's diverse environments. MISR was built for NASA by the Jet Propulsion Laboratory (JPL) in Pasadena, California. It is part of NASA's first Earth Observing System (EOS) spacecraft, the Terra spacecraft, which was launched into polar orbit from Vandenberg Air Force Base on December 18, 1999. MISR has been continuously providing data since February 24, 2000. [Mission Objectives] The MISR instrument acquires systematic multi-angle measurements for global monitoring of top-of-atmosphere and surface albedos and for measuring the shortwave radiative properties of aerosols, clouds, and surface scenes in order to characterize their impact on the Earth's climate. The Earth's climate is constantly changing -- as a consequence of both natural processes and human activities. Scientists care a great deal about even small changes in Earth's climate, since they can affect our comfort and well-being, and possibly our survival. A few years of below-average rainfall, an unusually cold winter, or a change in emissions from a coal-burning power plant, can influence the quality of life of people, plants, and animals in the region involved. The goal of NASA's Earth Observing System (EOS) is to increase our understanding of the climate changes that are occurring on our
Angle-resolved catholdoluminescence imaging polarimetry
Osorio, C.I.; Coenen, T.; Brenny, B.J.M.; Polman, A.; Koenderink, A.F.
2015-01-01
Cathodoluminescence spectroscopy (CL) allows characterizing light emission in bulk and nanostructured materials and is a key tool in fields ranging from materials science to nanophotonics. Previously, CL measurements focused on the spectral content and angular distribution of emission, while the
Atmospheric Error Correction of the Laser Beam Ranging
Directory of Open Access Journals (Sweden)
J. Saydi
2014-01-01
Full Text Available Atmospheric models based on surface measurements of pressure, temperature, and relative humidity have been used to increase the laser ranging accuracy by ray tracing. Atmospheric refraction can cause significant errors in laser ranging systems. Through the present research, the atmospheric effects on the laser beam were investigated by using the principles of laser ranging. Atmospheric correction was calculated for 0.532, 1.3, and 10.6 micron wavelengths through the weather conditions of Tehran, Isfahan, and Bushehr in Iran since March 2012 to March 2013. Through the present research the atmospheric correction was computed for meteorological data in base of monthly mean. Of course, the meteorological data were received from meteorological stations in Tehran, Isfahan, and Bushehr. Atmospheric correction was calculated for 11, 100, and 200 kilometers laser beam propagations under 30°, 60°, and 90° rising angles for each propagation. The results of the study showed that in the same months and beam emission angles, the atmospheric correction was most accurate for 10.6 micron wavelength. The laser ranging error was decreased by increasing the laser emission angle. The atmospheric correction with two Marini-Murray and Mendes-Pavlis models for 0.532 nm was compared.
The Evaluation of Usefulness of the Manufactured DTAB (Double Tilt Angle Board) System
International Nuclear Information System (INIS)
Lee, Joung Jin; Jang, In Gi; Kim, Wan Sun
2006-01-01
To resolution of A hospital-handmade modification double tilt angle immobilization system (DTAB immobilization system) and to report the clinical results of it. It was developed in conjunction with the breast board for patients unable to achieve and maintain the desired uncomfortable respiration and position of set-up needed in the treatment of RT (This custom design provides an alternative to accomplishing this desired head angle needed to relax position treatment area, realizing that the lenses totally protected eye-ball out) By using the angled breast board and SBDD(small bowel device), reproducibility of set-up and patient comfort were addressed throughout the simulation, computed tomography planning and treatment process. Usually patients the error range-within 5 mm. When use of Aqua patients error range-within 3 mm. It was constructed in tandem with a unique custom-built double tilt angle board (DTAB). It was designed to eliminate clinical set-up problems with head immobilization and instability during treatment, thus providing for a more comfortable head rest for the patient.
Effects of Strand Lay Direction and Crossing Angle on Tribological Behavior of Winding Hoist Rope
Directory of Open Access Journals (Sweden)
Xiang-dong Chang
2017-06-01
Full Text Available Friction and wear behavior exists between hoisting ropes that are wound around the drums of a multi-layer winding hoist. It decreases the service life of ropes and threatens mine safety. In this research, a series of experiments were conducted using a self-made test rig to study the effects of the strand lay direction and crossing angle on the winding rope’s tribological behavior. Results show that the friction coefficient in the steady-state period shows a decreasing tendency with an increase of the crossing angle in both cross directions, but the variation range is different under different cross directions. Using thermal imaging, the high temperature regions always distribute along the strand lay direction in the gap between adjacent strands, as the cross direction is the same with the strand lay direction (right cross contact. Additionally, the temperature rise in the steady-state increases with the increase of the crossing angle in both cross directions. The differences of the wear scar morphology are obvious under different cross directions, especially for the large crossing angle tests. In the case of right cross, the variation range of wear mass loss is larger than that in left cross. The damage that forms on the wear surface is mainly ploughing, pits, plastic deformation, and fatigue fracture. The major wear mechanisms are adhesive wear, and abrasive and fatigue wear.
Effects of Strand Lay Direction and Crossing Angle on Tribological Behavior of Winding Hoist Rope.
Chang, Xiang-Dong; Peng, Yu-Xing; Zhu, Zhen-Cai; Gong, Xian-Sheng; Yu, Zhang-Fa; Mi, Zhen-Tao; Xu, Chun-Ming
2017-06-09
Friction and wear behavior exists between hoisting ropes that are wound around the drums of a multi-layer winding hoist. It decreases the service life of ropes and threatens mine safety. In this research, a series of experiments were conducted using a self-made test rig to study the effects of the strand lay direction and crossing angle on the winding rope's tribological behavior. Results show that the friction coefficient in the steady-state period shows a decreasing tendency with an increase of the crossing angle in both cross directions, but the variation range is different under different cross directions. Using thermal imaging, the high temperature regions always distribute along the strand lay direction in the gap between adjacent strands, as the cross direction is the same with the strand lay direction (right cross contact). Additionally, the temperature rise in the steady-state increases with the increase of the crossing angle in both cross directions. The differences of the wear scar morphology are obvious under different cross directions, especially for the large crossing angle tests. In the case of right cross, the variation range of wear mass loss is larger than that in left cross. The damage that forms on the wear surface is mainly ploughing, pits, plastic deformation, and fatigue fracture. The major wear mechanisms are adhesive wear, and abrasive and fatigue wear.
SCATTTERING OF HIGH-ENERGY PARTICLES AT A COLLISIONLESS SHOCK FRONT: DEPENDENCE ON THE SHOCK ANGLE
Energy Technology Data Exchange (ETDEWEB)
Gedalin, M. [Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva (Israel); Dröge, W.; Kartavykh, Y. Y., E-mail: gedalin@bgu.ac.il [Institute for Theoretical Physics and Astrophysics, University of Würzburg, Würzburg (Germany)
2015-07-10
Many shock acceleration theories deal with gyrophase-averaged particle distributions that depend only on the energy and pitch angle of the particles. Diffusive shock acceleration includes shock crossing as a necessary component. As long as the shock width is much smaller than the mean free path of a particle, the crossing is governed by the macroscopic fields inside the transition layer. The dynamics of high-energy particles in these fields is non-adiabatic and gyrophase dependent. The magnetic moment is not conserved in a wide range of shock angles, nor is the condition of reflection determined by the magnetic bottle relation. Instead, for a pitch angle and unknown gyrophase of an incident particle there is a finite probability of reflection. This probability varies between zero and unity in a wide range of pitch angles. In this work we investigate how the matching conditions at the shock front could be modified with the gyrophase dependence taken into account, e.g., in the form of the scattering probabilities.
SCATTTERING OF HIGH-ENERGY PARTICLES AT A COLLISIONLESS SHOCK FRONT: DEPENDENCE ON THE SHOCK ANGLE
International Nuclear Information System (INIS)
Gedalin, M.; Dröge, W.; Kartavykh, Y. Y.
2015-01-01
Many shock acceleration theories deal with gyrophase-averaged particle distributions that depend only on the energy and pitch angle of the particles. Diffusive shock acceleration includes shock crossing as a necessary component. As long as the shock width is much smaller than the mean free path of a particle, the crossing is governed by the macroscopic fields inside the transition layer. The dynamics of high-energy particles in these fields is non-adiabatic and gyrophase dependent. The magnetic moment is not conserved in a wide range of shock angles, nor is the condition of reflection determined by the magnetic bottle relation. Instead, for a pitch angle and unknown gyrophase of an incident particle there is a finite probability of reflection. This probability varies between zero and unity in a wide range of pitch angles. In this work we investigate how the matching conditions at the shock front could be modified with the gyrophase dependence taken into account, e.g., in the form of the scattering probabilities
Characterization of actinide targets by low solid-angle alpha particle counting
Denecke, B; Pauwels, J; Robouch, P; Gilliam, D M; Hodge, P; Hutchinson, J M R; Nico, J S
1999-01-01
Actinide samples were characterized in an interlaboratory comparison between IRMM and NIST, including alpha-particle counting at defined low solid angle and counting in a 2 pi proportional gas counter. For this comparison, nine sup 2 sup 3 sup 3 UF sub 4 samples with high uniformity in the layer thickness were prepared at IRMM by deposition under vacuum. Polished silicon wafers were used as source substrates, and these were rotated during the deposition using a planetary rotation system. The estimated uncertainties for the defined low solid-angle methods were about 0.1% at both NIST and IRMM. The agreement of reported alpha-particle emission rates in the energy range 2.5-5.09 MeV was better than or equal to 0.02% for the defined solid-angle methods. When comparing total alpha-particle emission rates over the larger energy range 0-9 MeV (which includes all emissions from the daughter nuclides and the impurities), the agreement of the defined solid-angle methods was better than or equal to 0.05%. The 2 pi propo...
The EUVE Right Angle Program (RAP)
Sommers, J.; Christian, D.; Craig, N.; Jessop, H.; Stroozas, B.
1996-05-01
The Extreme Ultraviolet Explorer (EUVE ) has three scanning telescopes that observe in a direction perpendicular to that of the primary guest observer (GO) telescope---the Deep Survey/Spectrometer (DS/S). During the first 6 months of the EUVE mission, the scanning telescopes were used to conduct an all-sky survey consisting of short exposures ( ~ 500 s) of the entire sky between 58--740 Angstroms . These telescopes are now being used during GO observations to conduct simultaneous long exposure (typically 40+ ks) observations as part of the very successful---and publicly accessible---EUVE Right Angle Program (RAP). To date, the EUVE RAP has provided photometric and timing data on late-type stars and CVs and has been responsible for detecting dozens of previously unknown extreme ultraviolet sources, including many stars without optical counterparts. This poster presents some of the exciting results found with EUVE RAP data, along with general information about the program and instructions for submitting RAP proposals. This work is supported by NASA contract NAS5-29298.
Rubber hand illusion affects joint angle perception.
Directory of Open Access Journals (Sweden)
Martin V Butz
Full Text Available The Rubber Hand Illusion (RHI is a well-established experimental paradigm. It has been shown that the RHI can affect hand location estimates, arm and hand motion towards goals, the subjective visual appearance of the own hand, and the feeling of body ownership. Several studies also indicate that the peri-hand space is partially remapped around the rubber hand. Nonetheless, the question remains if and to what extent the RHI can affect the perception of other body parts. In this study we ask if the RHI can alter the perception of the elbow joint. Participants had to adjust an angular representation on a screen according to their proprioceptive perception of their own elbow joint angle. The results show that the RHI does indeed alter the elbow joint estimation, increasing the agreement with the position and orientation of the artificial hand. Thus, the results show that the brain does not only adjust the perception of the hand in body-relative space, but it also modifies the perception of other body parts. In conclusion, we propose that the brain continuously strives to maintain a consistent internal body image and that this image can be influenced by the available sensory information sources, which are mediated and mapped onto each other by means of a postural, kinematic body model.
Phase sensitive small angle neutron scattering
Brok, Erik; Majkrzak, Charles F.; Krycka, Kathryn
It is a well-known problem that information about the scattered wave is lost in scattering experiments because the measured quantity is the modulus squared of the complex wave function. This ''phase problem'' leads to ambiguity in determining the physical properties of the scattering sample. Small angle neutron scattering (SANS) is a useful technique for determining the structure of biomolecules, in particular proteins that cannot be crystallized and studied with x-ray crystallography. However, because the biomolecules are usually suspended in a liquid the observed scattering is an average of all possible orientations, making it difficult to obtain three dimensional structural information. In a proposed method polarized SANS and magnetic nanoparticle references attached to the sample molecules is used to obtain phase sensitive structural information and simultaneously circumvent the problem of orientational averaging (Majkrzak et al. J. Appl. Cryst. 47, 2014) If realized and perfected the technique is very promising for unambiguous determination of the three dimensional structure of biomolecules. We demonstrate the principles of our method and show the first experimental data obtained on a simple test system consisting of core shell magnetic nanoparticles.
Iris melanoma invading the camerular angle
International Nuclear Information System (INIS)
Verona Ugando, Leticia; Landrian Iglesias, Beatriz; Padierne Gonzalez, Naysa
2011-01-01
Uveal melanomas are the most frequent primary uveal tumors, having an incidence of 8/1 000 000 a year in Caucasian people. Specifically, iris Melanoma represents 5 to 7 % of the uveal malignant melanomas and they may be amelanic or pigmented, generally very vascularized. An eighteen years old male patient with a history of health problems was presented, who had been seen at the Ophthalmological Emergency Service because of eye pain and sudden visual reduction in his right eye. In the physical exam, a marked ocular hypertension was confirmed as well as a 2 mm hyphema and corneal edema. These conditions were overcome with treatment and afterwards, there was observed iris tumoration invading the iridocorneal angle. Some complementary studies were carried out to search further tumors at other levels and finally a fine needle aspiration biopsy was performed. The diagnosis was amelanic Iris Melanoma invading the ciliary body. The patient was referred for surgical treatment at the National Institute of Oncology and Radiology
Small angle x-ray and neutron scattering for materials characterisation
Energy Technology Data Exchange (ETDEWEB)
Buckley, C.E. [Curtin University of Technology, Perth, WA (Australia). Department of Applied Physics
1999-12-01
Full text: Small angle X-ray and neutron scattering (SAXS and SANS) are excellent techniques to characterise inhomogeneities in materials in the size range from 10 Angstroms to several thousand Angstroms. Ultra small angle neutron and X-ray scattering (USANS and USAXS) have extended this size range out to 20 {mu}m. SAXS is due to the electron density difference between the matrix and the inhomogeneity, whereas SANS is due to the scattering length density difference. SANS and SAXS have been used successfully to characterise colloidal particles in solution, colloidal powders, glasses and a wide range of solids such as metals, alloys, and natural and synthetic high polymers. Small angle scattering and complementary techniques, such transmission and scanning electron microscopy (TEM and SEM) are a powerful combination for the investigation of submicron particles. This paper will introduce the reader to the small angle scattering techniques and will use the aluminium hydrogen (Al-H) system as an example to demonstrate the applicability of each method. Aluminium foils (99.99% purity) and single crystals (99.999% purity) were charged with hydrogen using a gas plasma method (voltage range of 1.0 - 1.2 keV). The results from the SANS, USANS, TEM, SEM, X-ray diffraction and inelastic neutron scattering experiments showed a wide range of H{sub 2} bubbles on the surface and in the bulk of the Al-H sample (< 10 Angstroms up to several microns in size). The volume of the H{sub 2} bubbles was formed by the diffusion of H-vacancy complexes into the bulk. The volume concentration of vacant sites determined from precision density measurements was within experimental error to that calculated from the SANS and USANS experiments. Copyright (1999) Australian X-ray Analytical Association Inc. 5 refs.
Small angle x-ray and neutron scattering for materials characterisation
International Nuclear Information System (INIS)
Buckley, C.E.
1999-01-01
Full text: Small angle X-ray and neutron scattering (SAXS and SANS) are excellent techniques to characterise inhomogeneities in materials in the size range from 10 Angstroms to several thousand Angstroms. Ultra small angle neutron and X-ray scattering (USANS and USAXS) have extended this size range out to 20 μm. SAXS is due to the electron density difference between the matrix and the inhomogeneity, whereas SANS is due to the scattering length density difference. SANS and SAXS have been used successfully to characterise colloidal particles in solution, colloidal powders, glasses and a wide range of solids such as metals, alloys, and natural and synthetic high polymers. Small angle scattering and complementary techniques, such transmission and scanning electron microscopy (TEM and SEM) are a powerful combination for the investigation of submicron particles. This paper will introduce the reader to the small angle scattering techniques and will use the aluminium hydrogen (Al-H) system as an example to demonstrate the applicability of each method. Aluminium foils (99.99% purity) and single crystals (99.999% purity) were charged with hydrogen using a gas plasma method (voltage range of 1.0 - 1.2 keV). The results from the SANS, USANS, TEM, SEM, X-ray diffraction and inelastic neutron scattering experiments showed a wide range of H 2 bubbles on the surface and in the bulk of the Al-H sample ( 2 bubbles was formed by the diffusion of H-vacancy complexes into the bulk. The volume concentration of vacant sites determined from precision density measurements was within experimental error to that calculated from the SANS and USANS experiments. Copyright (1999) Australian X-ray Analytical Association Inc
Steering Angle Function Algorithm of Morphing of Residential Area
Directory of Open Access Journals (Sweden)
XIE Tian
2015-07-01
Full Text Available A residential area feature morphing method based on steering angle function is presented. To residential area with the same representation under two different scales,transforming the representation of the residential area polygon from vector coordinates to steering angle function,then using the steering angle function to match,and finding out the similarity and the differences between the residential areas under different scale to get the steering angle function of the the residential areas under any middle scale,the final,transforming the middle scale steering angle function to vector coordinates form,and get the middle shape interpolation of the the residential area polygon.Experimental results show:the residential area morphing method by using steering angle function presented can realize the continuous multi-scale representation under the premise of keeping in shape for the residential area with the rectangular boundary features.
Non-contact measurement of rotation angle with solo camera
Gan, Xiaochuan; Sun, Anbin; Ye, Xin; Ma, Liqun
2015-02-01
For the purpose to measure a rotation angle around the axis of an object, a non-contact rotation angle measurement method based on solo camera was promoted. The intrinsic parameters of camera were calibrated using chessboard on principle of plane calibration theory. The translation matrix and rotation matrix between the object coordinate and the camera coordinate were calculated according to the relationship between the corners' position on object and their coordinates on image. Then the rotation angle between the measured object and the camera could be resolved from the rotation matrix. A precise angle dividing table (PADT) was chosen as the reference to verify the angle measurement error of this method. Test results indicated that the rotation angle measurement error of this method did not exceed +/- 0.01 degree.
Vehicle Sideslip Angle Estimation Based on General Regression Neural Network
Directory of Open Access Journals (Sweden)
Wang Wei
2016-01-01
Full Text Available Aiming at the accuracy of estimation of vehicle’s mass center sideslip angle, an estimation method of slip angle based on general regression neural network (GRNN and driver-vehicle closed-loop system has been proposed: regarding vehicle’s sideslip angle as time series mapping of yaw speed and lateral acceleration; using homogeneous design project to optimize the training samples; building the mapping relationship among sideslip angle, yaw speed, and lateral acceleration; at the same time, using experimental method to measure vehicle’s sideslip angle to verify validity of this method. Estimation results of neural network and real vehicle experiment show the same changing tendency. The mean of error is within 10% of test result’s amplitude. Results show GRNN can estimate vehicle’s sideslip angle correctly. It can offer a reference to the application of vehicle’s stability control system on vehicle’s state estimation.
Moghimi, Sasan; Ramezani, Farshid; He, Mingguang; Coleman, Anne L; Lin, Shan C
2015-12-01
The purpose of this study is to compare anterior segment-optical coherence tomography (AS-OCT) parameters in phacomorphic angle closure and acute primary angle closure (APAC) eyes. In this cross-sectional case series, a total of 134 patients with phacomorphic angle closure (28 eyes) or APAC (54 eyes), as well as normal control subjects (52 eyes), were enrolled. Patients underwent AS-OCT imaging and A-scan biometry of both eyes. Anterior chamber depth (ACD), anterior chamber area (ACA), iris thickness (IT), iris curvature, lens vault (LV), anterior vault (AV), and angle parameters including angle opening distance (AOD 500 and AOD750) and trabecular iris space area (TISA500 and TISA750) were measured in qualified images using the Zhongshan Angle Assessment Program and compared among eyes with phacomorphic angle closure, APAC, and normal control subjects. Phacomorphic angle closure and APAC eyes had smaller AOD, ACD, ACA, ACW, AV, and posterior corneal arc length and greater LV than normal controls (P APAC eyes: ACD 1042 μm (OR,12.12; P APAC eyes. In multivariate analysis, ACD, LV, AOD500, and axial length could significantly distinguish the two entities. Ocular biometric parameters can differentiate phacomorphic angle closure from APAC eyes. Shallower ACD and greater LV, axial length, and ACA are the main parameters that distinguish phacomorphic angle closure from APAC.
Correlated insulator behaviour at half-filling in magic-angle graphene superlattices
Cao, Yuan; Fatemi, Valla; Demir, Ahmet; Fang, Shiang; Tomarken, Spencer L.; Luo, Jason Y.; Sanchez-Yamagishi, Javier D.; Watanabe, Kenji; Taniguchi, Takashi; Kaxiras, Efthimios; Ashoori, Ray C.; Jarillo-Herrero, Pablo
2018-04-01
A van der Waals heterostructure is a type of metamaterial that consists of vertically stacked two-dimensional building blocks held together by the van der Waals forces between the layers. This design means that the properties of van der Waals heterostructures can be engineered precisely, even more so than those of two-dimensional materials. One such property is the ‘twist’ angle between different layers in the heterostructure. This angle has a crucial role in the electronic properties of van der Waals heterostructures, but does not have a direct analogue in other types of heterostructure, such as semiconductors grown using molecular beam epitaxy. For small twist angles, the moiré pattern that is produced by the lattice misorientation between the two-dimensional layers creates long-range modulation of the stacking order. So far, studies of the effects of the twist angle in van der Waals heterostructures have concentrated mostly on heterostructures consisting of monolayer graphene on top of hexagonal boron nitride, which exhibit relatively weak interlayer interaction owing to the large bandgap in hexagonal boron nitride. Here we study a heterostructure consisting of bilayer graphene, in which the two graphene layers are twisted relative to each other by a certain angle. We show experimentally that, as predicted theoretically, when this angle is close to the ‘magic’ angle the electronic band structure near zero Fermi energy becomes flat, owing to strong interlayer coupling. These flat bands exhibit insulating states at half-filling, which are not expected in the absence of correlations between electrons. We show that these correlated states at half-filling are consistent with Mott-like insulator states, which can arise from electrons being localized in the superlattice that is induced by the moiré pattern. These properties of magic-angle-twisted bilayer graphene heterostructures suggest that these materials could be used to study other exotic many
Rotating Shaft Tilt Angle Measurement Using an Inclinometer
Luo Jun; Wang Zhiqian; Shen Chengwu; Wen Zhuoman; Liu Shaojin; Cai Sheng; Li Jianrong
2015-01-01
This paper describes a novel measurement method to accurately measure the rotating shaft tilt angle of rotating machine for alignment or compensation using a dual-axis inclinometer. A model of the rotating shaft tilt angle measurement is established using a dual-axis inclinometer based on the designed mechanical structure, and the calculation equation between the rotating shaft tilt angle and the inclinometer axes outputs is derived under the condition that the inclinometer axes are perpendic...
Angle Dependent Optics of Plasmonic Core-Shell Nanoparticles
2018-02-21
function of spherical co-ordinates: azimuthal and polar angles. Absorption, scattering and emission of light from nanoparticles, especially when they are...placed on a substrate, can drastically depend on angle of excitation and angle of scattering/ emission . Such particle-substrate coupling can...V’ antenna with the Raman marker molecule nile blue chloride. Typical SERS spectra of nile blue from a ‘V’ antenna under different polarizations (0
Glancing angle x-ray studies of oxide films
International Nuclear Information System (INIS)
Davenport, A.J.; Isaacs, H.S.
1989-01-01
High brightness synchrotron radiation incident at glancing angles has been used to study inhibiting species present in low concentrations in oxide films on aluminum. Glancing incident angle fluorescence measurements give surface-sensitive information on the valence state of elements from the shape of the x-ray absorption edge. Angle-resolved measurements show the depth distribution of the species present. 15 refs., 4 figs
Relation between Angle Class II malocclusion and deleterious oral habits
Directory of Open Access Journals (Sweden)
José Tarcísio Lima Ferreira
2012-12-01
Full Text Available INTRODUCTION: Oral habits may interfere on the growth and development of the stomatognathic system and orofacial myofunctional conditions, producing changes in the position of teeth in their dental arches. OBJECTIVE: The purpose of this study was to verify the presence of deleterious oral habits in individuals with malocclusion and see if there is a predominance of Class II malocclusion in these individuals. METHODS: The records of 140 patients treated at the Clinic of Preventive Orthodontics FORP-USP who had already completed treatment were randomly selected and analyzed. Their ages ranged from 6 to 10 years and 11 months. Associations were made between the presence or absence of deleterious oral habits, type and number of habits found in each individual and the type of malocclusion according to Angle classification. The statistical analysis used was the Chi-square test with a significance level of 5%. History of deleterious oral habits was found in 67.1% of individuals. RESULTS: The Class I malocclusion was most frequent (82.9%, followed by Class II malocclusion (12.1% and Class III (5%. CONCLUSION: There was a predominance of Class II malocclusion in individuals with a history of deleterious oral habits.INTRODUÇÃO: hábitos bucais podem interferir no crescimento e desenvolvimento do sistema estomatognático e nas condições miofuncionais bucofaciais, acarretando alterações no posicionamento dos dentes nas respectivas arcadas dentárias. OBJETIVO: o objetivo dessa pesquisa foi verificar a presença de hábitos bucais deletérios em indivíduos portadores de má oclusão e observar se existe predominância de má oclusão Classe II de Angle nesses indivíduos. MÉTODOS: foram selecionadas, aleatoriamente, e analisadas 140 fichas de pacientes atendidos na Clínica de Ortodontia Preventiva da FORP-USP, que já haviam recebido alta no tratamento. A faixa etária variou dos 6 anos a 10 anos e 11 meses. Foram realizadas associações entre
Small-angle neutron scattering technique in liquid crystal studies
International Nuclear Information System (INIS)
Shahidan Radiman
2005-01-01
The following topics discussed: general principles of SAS (Small-angle Neutron Scattering), liquid crystals, nanoparticle templating on liquid crystals, examples of SAS results, prospects of this studies
Changes in the foot angle after calcaneal fractures
International Nuclear Information System (INIS)
Frahm, R.; Fritz, H.; Drescher, E.
1989-01-01
Forty fractured calcanei (13 without and 27 with involvement of the joint) were examined by CT and the angle of the hind foot measured. Following a typical compression fracture there is a negative calcaneusvalgus angle, i.e. varus deformity of the tuberosity fragment. The sustentaculum angle is increased. There are changes in the talo-calcaneal and calcaneo-cuboidal angles. The length ratio of calcaneus to talus is reduced. Reproducible measurements make it possible to compare the results of operative correction and of changes in shape following conservative treatment, e.g. during weight-bearing. (orig.) [de
Flow tilt angles near forest edges - Part 1: Sonic anemometry
DEFF Research Database (Denmark)
Dellwik, Ebba; Mann, Jakob; Larsen, Klaus Steenberg
2010-01-01
An analysis of flow tilt angles from a fetch-limited beech forest site with clearings is presented in the context of vertical advection of carbon dioxide. Flow angles and vertical velocities from two sonic anemometers by different manufacturers were analyzed. Instead of using rotations, where zero...... distortion and vertical alignment, it was only possible to a limited extent to relate sonic anemometer flow tilt angles to upwind forest edges, but the results by the lidar indicated that an internal boundary layer affect flow tilt angles at 21m above the forest. This is in accordance with earlier studies...
Beam-beam collisions and crossing angles in RHIC
International Nuclear Information System (INIS)
Peggs, S.
1999-01-01
This paper evaluates the strength of head on and parasitic beam-beam collisions in RHIC when the crossing angle is zero. A non-zero crossing angle is not required in normal operation with 120 bunches, thanks to the early separation of the two beams. The RHIC lattice is shown to easily accommodate even conservatively large crossing angles, for example in beam dynamics studies, or in future operational upgrades to as many as 360 bunches per ring. A modest loss in luminosity is incurred when gold ions collide at an angle after 10 hours of storage
The wave vane - A device to measure the breaker angle
Digital Repository Service at National Institute of Oceanography (India)
Chandramohan, P.; Nayak, B.U.; Anand, N.M.
with the shoreline at the wave vane is equal to the breaker angle as the wave vane is installed very close to breaker zone. Repeating the procedure, the breaker angles for a required duration can be estimated. FIELD TEST A 4 km long beach near Karwar on the west... in Table 1. Ob- servations on breaker angles were made for 20 minutes duration every day. The average breaker angle computed based on the 20 minute observation is presented in Table 1. A directional wave rider buoy was deployed at 16 m water depth...
Contact angle distribution of particles at fluid interfaces.
Snoeyink, Craig; Barman, Sourav; Christopher, Gordon F
2015-01-27
Recent measurements have implied a distribution of interfacially adsorbed particles' contact angles; however, it has been impossible to measure statistically significant numbers for these contact angles noninvasively in situ. Using a new microscopy method that allows nanometer-scale resolution of particle's 3D positions on an interface, we have measured the contact angles for thousands of latex particles at an oil/water interface. Furthermore, these measurements are dynamic, allowing the observation of the particle contact angle with high temporal resolution, resulting in hundreds of thousands of individual contact angle measurements. The contact angle has been found to fit a normal distribution with a standard deviation of 19.3°, which is much larger than previously recorded. Furthermore, the technique used allows the effect of measurement error, constrained interfacial diffusion, and particle property variation on the contact angle distribution to be individually evaluated. Because of the ability to measure the contact angle noninvasively, the results provide previously unobtainable, unique data on the dynamics and distribution of the adsorbed particles' contact angle.
Tibial and fibular angles in homozygous sickle cell disease
International Nuclear Information System (INIS)
Akamaguna, A.I.; Odita, J.C.; Ugbodaga, C.I.; Okafor, L.A.
1986-01-01
Measurements of the tibial and fibular angles made on ankle radiographs of 34 patients with sickle cell disease were compared with those of 36 normal Nigerians. Widening of the fibular angle, which is an indication of tibiotalar slant, was demonstrated in about 79% of sickle cell disease patients. By using fibular angle measurements as an objective method of assessing subtle tibiotalar slant, it is concluded that the incidence of this deformity is much higher among sickle cell disease patients than previously reported. The mean values of tibial and fibular angles in normal Nigerians are higher than has been reported amongst Caucasians. (orig.)
Super-ranging. A new ranging strategy in European badgers.
Directory of Open Access Journals (Sweden)
Aoibheann Gaughran
Full Text Available We monitored the ranging of a wild European badger (Meles meles population over 7 years using GPS tracking collars. Badger range sizes varied seasonally and reached their maximum in June, July and August. We analysed the summer ranging behaviour, using 83 home range estimates from 48 individuals over 6974 collar-nights. We found that while most adult badgers (males and females remained within their own traditional social group boundaries, several male badgers (on average 22% regularly ranged beyond these traditional boundaries. These adult males frequently ranged throughout two (or more social group's traditional territories and had extremely large home ranges. We therefore refer to them as super-rangers. While ranging across traditional boundaries has been recorded over short periods of time for extraterritorial mating and foraging forays, or for pre-dispersal exploration, the animals in this study maintained their super-ranges from 2 to 36 months. This study represents the first time such long-term extra-territorial ranging has been described for European badgers. Holding a super-range may confer an advantage in access to breeding females, but could also affect local interaction networks. In Ireland & the UK, badgers act as a wildlife reservoir for bovine tuberculosis (TB. Super-ranging may facilitate the spread of disease by increasing both direct interactions between conspecifics, particularly across social groups, and indirect interactions with cattle in their shared environment. Understanding super-ranging behaviour may both improve our understanding of tuberculosis epidemiology and inform future control strategies.
Yosmaoğlu, Hayri Baran; Baltacı, Gül; Sönmezer, Emel; Özer, Hamza; Doğan, Deha
2017-12-01
This study aims to compare the effects of anterior cruciate ligament (ACL) reconstruction using autogenous hamstring or patellar tendon graft on the peak torque angle. The study included 132 patients (103 males, 29 females; mean age 29±9 year) who were performed ACL reconstruction with autogenous hamstring or patellar tendon graft. The peak torque angles in the quadriceps and hamstring muscles were recorded using an isokinetic dynamometer. Angle of peak knee flexion torque occurred significantly earlier within the range of motion on the operated side than nonoperated side at 180°/second in the hamstring tendon group. Angle of peak knee extension torque occurred significantly earlier within the range of motion on the operated side than nonoperated side at 180°/second in the patellar tendon group. There were no statistically significant differences in the flexion and extension peak torque angles between the operated and nonoperated knees at 60°/second in both groups. The angle of peak torque at relatively high angular velocities is affected after ACL reconstruction in patients with hamstring or patellar tendon grafts. The graft donor site directly influences this parameter. This finding may be important for clinicians in terms of preventing re-injury.
Characterizing the combinatorial beam angle selection problem
International Nuclear Information System (INIS)
Bangert, Mark; Ziegenhein, Peter; Oelfke, Uwe
2012-01-01
The beam angle selection (BAS) problem in intensity-modulated radiation therapy is often interpreted as a combinatorial optimization problem, i.e. finding the best combination of η beams in a discrete set of candidate beams. It is well established that the combinatorial BAS problem may be solved efficiently with metaheuristics such as simulated annealing or genetic algorithms. However, the underlying parameters of the optimization process, such as the inclusion of non-coplanar candidate beams, the angular resolution in the space of candidate beams, and the number of evaluated beam ensembles as well as the relative performance of different metaheuristics have not yet been systematically investigated. We study these open questions in a meta-analysis of four strategies for combinatorial optimization in order to provide a reference for future research related to the BAS problem in intensity-modulated radiation therapy treatment planning. We introduce a high-performance inverse planning engine for BAS. It performs a full fluence optimization for ≈3600 treatment plans per hour while handling up to 50 GB of dose influence data (≈1400 candidate beams). For three head and neck patients, we compare the relative performance of a genetic, a cross-entropy, a simulated annealing and a naive iterative algorithm. The selection of ensembles with 5, 7, 9 and 11 beams considering either only coplanar or all feasible candidate beams is studied for an angular resolution of 5°, 10°, 15° and 20° in the space of candidate beams. The impact of different convergence criteria is investigated in comparison to a fixed termination after the evaluation of 10 000 beam ensembles. In total, our simulations comprise a full fluence optimization for about 3000 000 treatment plans. All four combinatorial BAS strategies yield significant improvements of the objective function value and of the corresponding dose distributions compared to standard beam configurations with equi
Angle Class II correction with MARA appliance
Directory of Open Access Journals (Sweden)
Kelly Chiqueto
2013-02-01
Full Text Available OBJECTIVE: To assess the effects produced by the MARA appliance in the treatment of Angle's Class II, division 1 malocclusion. METHODS: The sample consisted of 44 young patients divided into two groups: The MARA Group, with initial mean age of 11.99 years, treated with the MARA appliance for an average period of 1.11 years, and the Control Group, with initial mean age of 11.63 years, monitored for a mean period of 1.18 years with no treatment. Lateral cephalograms were used to compare the groups using cephalometric variables in the initial and final phases. For these comparisons, Student's t test was employed. RESULTS: MARA appliance produced the following effects: Maxillary growth restriction, no change in mandibular development, improvement in maxillomandibular relationship, increased lower anterior facial height and counterclockwise rotation of the functional occlusal plane. In the upper arch, the incisors moved lingually and retruded, while the molars moved distally and tipped distally. In the lower arch, the incisors proclined and protruded, whereas the molars mesialized and tipped mesially. Finally, there was a significant reduction in overbite and overjet, with an obvious improvement in molar relationship. CONCLUSIONS: It was concluded that the MARA appliance proved effective in correcting Angle's Class II, division 1 malocclusion while inducing skeletal changes and particularly dental changes.OBJETIVO: avaliar os efeitos proporcionados pelo aparelho MARA no tratamento da má oclusão de Classe II, 1ª divisão. MÉTODOS: utilizou-se uma amostra de 44 jovens, divididos em dois grupos - Grupo MARA, com idade inicial média de 11,99 anos e tratado com o aparelho MARA por um período médio de 1,11 ano; e Grupo Controle, com idade inicial média de 11,63 ano e observado por um período médio de 1,18 ano, sem nenhum tratamento. Utilizou-se as telerradiografias em norma lateral para comparar os grupos quanto às variáveis cefalométricas das
Characterizing the combinatorial beam angle selection problem
Bangert, Mark; Ziegenhein, Peter; Oelfke, Uwe
2012-10-01
The beam angle selection (BAS) problem in intensity-modulated radiation therapy is often interpreted as a combinatorial optimization problem, i.e. finding the best combination of η beams in a discrete set of candidate beams. It is well established that the combinatorial BAS problem may be solved efficiently with metaheuristics such as simulated annealing or genetic algorithms. However, the underlying parameters of the optimization process, such as the inclusion of non-coplanar candidate beams, the angular resolution in the space of candidate beams, and the number of evaluated beam ensembles as well as the relative performance of different metaheuristics have not yet been systematically investigated. We study these open questions in a meta-analysis of four strategies for combinatorial optimization in order to provide a reference for future research related to the BAS problem in intensity-modulated radiation therapy treatment planning. We introduce a high-performance inverse planning engine for BAS. It performs a full fluence optimization for ≈3600 treatment plans per hour while handling up to 50 GB of dose influence data (≈1400 candidate beams). For three head and neck patients, we compare the relative performance of a genetic, a cross-entropy, a simulated annealing and a naive iterative algorithm. The selection of ensembles with 5, 7, 9 and 11 beams considering either only coplanar or all feasible candidate beams is studied for an angular resolution of 5°, 10°, 15° and 20° in the space of candidate beams. The impact of different convergence criteria is investigated in comparison to a fixed termination after the evaluation of 10 000 beam ensembles. In total, our simulations comprise a full fluence optimization for about 3000 000 treatment plans. All four combinatorial BAS strategies yield significant improvements of the objective function value and of the corresponding dose distributions compared to standard beam configurations with equi
Rock glaciers, Zailiysiky Range, Kungei Ranges, Tienshan, Kazakhstan, Version 1
National Aeronautics and Space Administration — The Zailiyskiy Alatau is the northernmost parallel latitudinal ranges of the Northern Tien Shan. The highest point of this range is the Talgar peak (4973 m a.s.l.)....
Ultra-broadband and wide-angle perfect absorber based on composite metal-semiconductor grating
Li, Xu; Wang, Zongpeng; Hou, Yumin
2018-01-01
In this letter, we present an ultra-broadband and wide-angle perfect absorber based on composite Ge-Ni grating. Near perfect absorption above 90% is achieved in a wide frequency range from 150 nm to 4200 nm, which covers almost the full spectrum of solar radiation. The absorption keeps robust in a wide range of incident angle from 0º to 60º. The upper triangle Ge grating works as an antireflection coating. The lower Ni grating works as a reflector and an effective energy trapper. The guided modes inside Ge grating are excited due to reflection of the lower Ni grating surface. In longer wavelength band, gap surface plasmons (GSPs) in the Ni grating are excited and couple with the guided modes inside the Ge grating. The coupled modes extend the perfect absorption band to the near-infrared region (150 nm-4200 nm). This design has potential application in photovoltaic devices and thermal emitters.
Vibrating phase echo concept for small-angle inelastic neutron scattering
International Nuclear Information System (INIS)
Michalec, R.
1989-01-01
Small-angle inelastic neutron scattering measurements are based on the vibrating phase echo concept. The double neutron diffraction is carried out by two thin vibrating single crystals, for example Si or Ge. The neutron beam diffracted at the monochromator crystal M is modulated with a frequency 2 Ω, where Ω is the circular frequency of the ultrasonic transducer. The second crystal A (analyser) vibrates at a frequency Ω with a phase shift φ. A neutron spectrometer on the basis of two vibrating single crystals is suitable within the scattering angle range 0.5' ≤ θ ≤ 50' and within the range of magnitude of the scattering vector Q = (2 to 500) x 10 -3 nm -1 . The described equipment covers the Q values of major part of the classical optical spectroscopy as well as Q values of part of the spin echo spectroscopy
Multi-pinhole camera for beam position and vertical angle stabilization
Meshkov, O. I.; Zhuravlev, A. N.; Smaluk, V. V.
2010-03-01
The VEPP-4M electron-positron collider is now operating with the KEDR detector for the high-energy physics experiments in the energy range from 1100 to 4000 MeV. For these experiments, monitoring of beam transverse position and angles at the interaction point is important for energy stabilization. BPM system of VEPP-4M doesn't provide the reliable information about beam orbit when the machine operates in colliding mode. The beam diagnostic instrument, described in this paper, is a good supplement for the BPM system. The vertical coordinate and angle of the beam can be measured and stabilized at two points, which are symmetrical with respect to the beam interaction point. The precision of the measurements and the collider energy range accessible for the diagnostics are discussed.
International Nuclear Information System (INIS)
Zhan, Shuyue; Wang, Xiaoping; Liu, Yuling
2011-01-01
To simplify the algorithm for determining the surface plasmon resonance (SPR) angle for special applications and development trends, a fast method for determining an SPR angle, called the fixed-boundary centroid algorithm, has been proposed. Two experiments were conducted to compare three centroid algorithms from the aspects of the operation time, sensitivity to shot noise, signal-to-noise ratio (SNR), resolution, and measurement range. Although the measurement range of this method was narrower, the other performance indices were all better than the other two centroid methods. This method has outstanding performance, high speed, good conformity, low error and a high SNR and resolution. It thus has the potential to be widely adopted
Directory of Open Access Journals (Sweden)
Verhey Janko F
2008-02-01
Full Text Available Abstract Background Because of higher life expectancy, the number of elderly patients today with degenerative aortic diseases is on the increase. Often artificial aortic roots are needed to replace the native tissue. This surgical procedure requires re-implantation of the previous separated coronary arteries into the wall of the prosthesis. Regardless of the prosthesis type, changes in the reinsertion technique, e.g., the variation of the outlet angle of the coronary arteries, could influence the coronary blood flow. Whether the prosthesis type or the outlet angle variation significantly improves the blood circulation and lowers the risk of coronary insufficiency is still an open question. The numerical calculations presented can help to clear up these disputable questions. Methods Two simplified base geometries are used for simulating the blood flow in order to determine velocity and pressure distributions. One model uses a straight cylindrical tube to approximate the aortic root geometry; the other uses a sinus design with pseudosinuses of Valsalva. The coronary outlet angle of the right coronary artery was discretely modified in both models in the range from 60° to 120°. The pressure and velocity distributions of both models are compared in the ascending aorta as well as in the right and the left coronary artery. Results The potentially allowed and anatomic limited variation of the outlet angle influences the pressure only a little bit and shows a very slight relative maximum between 70° and 90°. The sinus design and variations of the outlet angle of the coronary arteries were able to minimally optimize the perfusion pressure and the velocities in the coronary circulation, although the degree of such changes is rather low and would probably not achieve any clinical influence. Conclusion Our results show that surgeons should feel relatively free to vary the outlet angle within the anatomic structural conditions when employing the technique
Planar microlens with front-face angle: design, fabrication, and characterization
Hafiz, Md Abdullah Al
2016-07-08
This paper studies the effect of microlens front-face angle on the performance of an optical system consisting of a planar-graded refractive index (GRIN) lens pair facing each other separated by a free-space region. The planar silica microlens pairs are designed to facilitate low-loss optical signal propagation in the free-space region between the opposing optical waveguides. The planar lens is fabricated from a 38-μm-thick fluorine-doped silica layer on a silicon substrate. It has a parabolic refractive index profile in the vertical direction, which is achieved by controlled fluorine incorporation in the silica film to collimate the optical beam in the vertical direction. Horizontal beam collimation is achieved by incorporating a horizontal curvature at the front face of the lens defined by deep oxide etch. A generalized 3×3ABCDGH transformation matrix method has been derived to compute the coupling efficiency of such microlens pairs to take front-face angles that may be present due to fabrication variations or limitations and possible input/output optical fiber offset/tilt into considerations. Pairs of such planar GRIN lens with various free-space propagation distances between them ranging from 75 to 2500 μm and with front-face angles of 1.5 deg, 2 deg, and 4 deg have been fabricated and characterized. Beam propagation method simulations have been carried out to substantiate the theoretical and experimental results. The results indicate that the optical loss is reasonably low up to 1.5 deg of front-face angles and increases significantly with further increase in the front-face angle. Analysis shows that for a given system with specific microlens front-face angle, the optical loss can be significantly reduced by properly compensating the vertical position of the input and output fibers.
Correlation of resting elbow angle with spasticity in chronic stroke survivors
Directory of Open Access Journals (Sweden)
Minal Y Bhadane
2015-08-01
Full Text Available Objective: To evaluate whether resting joint angle is indicative of severity of spasticity of the elbow flexors in chronic stroke survivors. Methods: Seventeen hemiparetic stroke subjects (male: n=13; female: n=4; age: 37-89 years; 11 right and 6 left hemiplegia; averaged 54.8 months after stroke, ranging 12-107 months participated in the study. The number of subjects with modified Ashworth scale score (MAS = 0, 1, 1+, 2, 3 was 3, 3, 5, 3, 3, respectively. In a single experimental session, resting elbow joint angle, MAS, and Tardieu scale score (Tardieu R1 were measured. A customized motorized stretching device was used to stretch elbow flexors at 5°/s, 50°/s, and 100°/s, respectively. Biomechanical responses (peak reflex torque and reflex stiffness of elbow flexors were quantified. Correlation analyses between clinical and biomechanical assessments were performed. Results: Resting elbow joint angle showed a strong positive correlation with Tardieu R1 (r = 0.77, p<0.01 and a very strong negative correlation with MAS (r = −0.89, p<0.01. The resting angle also had strong correlations with biomechanical measures (r= −0.63 to −0.76, p<0.01. Conclusion: Our study provides experimental evidence for anecdotal observation that the resting elbow joint angle correlates with severity of spasticity in chronic stroke. Resting angle observation for spasticity assessment can and will be an easy, yet a valid way of spasticity estimation in clinical settings, particularly for small muscles or muscles which are not easily measurable by common clinical methods.
Relationship between intraocular pressure and angle configuration: an anterior segment OCT study.
Chong, Rachel S; Sakata, Lisandro M; Narayanaswamy, Arun K; Ho, Sue-Wei; He, Mingguang; Baskaran, Mani; Wong, Tien Yin; Perera, Shamira A; Aung, Tin
2013-03-05
To assess the relationship between intraocular pressure (IOP) and anterior chamber angle (ACA) configuration as assessed by gonioscopy and anterior segment optical coherence tomography (AS-OCT). A total of 2045 subjects aged 50 years and older, were recruited from a community clinic and underwent AS-OCT, Goldmann applanation tonometry, and gonioscopy. A quadrant was classified as closed on gonioscopy if the posterior trabecular meshwork could not be seen. A closed quadrant on AS-OCT was defined by the presence of any contact between the iris and angle wall anterior to the scleral spur. Customized software (Zhongshan Angle Assessment Program, Guangzhou, China) was used to measure AS-OCT parameters on AS-OCT scans, including anterior chamber depth, area, and volume; iris thickness (IT) and curvature; lens vault; angle opening distance; and trabecular-iris space area. IOP values were adjusted for age, sex, diabetes and hypertension status, body mass index, central corneal thickness, and presence of peripheral anterior synechiae. Mean age of study subjects was 63.2 ± 8.0 years, 52.6% were female, and 89.4% were Chinese. Mean IOP was 14.8 ± 2.4 mm Hg (range 826). IOP (mean ± SE) increased with number of quadrants with gonioscopic angle closure (none: 14.6 ± 0.2; one: 14.7 ± 0.3; two: 15.0 ± 0.3; three: 15.0 ± 0.3; four: 15.6 ± 0.3 mm Hg; P measured on AS-OCT images, except for IT and lens vault. There was an association between the extent of angle closure, as assessed on AS-OCT and gonioscopy, with increasing IOP.
International Nuclear Information System (INIS)
Koizumi, Satoshi; Motokawa, Ryuhei; Iwase, Hiroki; Miyamoto, Nobuyoshi; Tanaka, Kazuhiro; Masui, Tomomi; Iida, You; Yue, Zhao; Chiba, Kaori; Kumada, Takayuki; Yamaguchi, Daisuke; Hashimoto, Takeji
2007-01-01
To address the question as to how small-angle scattering is effectively applied to the cell, i.e., a hierarchically ordered system comprising multi-components of macro and small molecules, the size of which ranges from 100 μm to several μm, we reconstructed SANS-J (pinhole small-angle neutron scattering spectrometer at research reactor JRR3, Tokai) to focusing and polarized neutron small-angle spectrometer (SANS-J-II), by employing focusing neutron lenses and high resolution photomultiplier. Consequently, an accessible minimum wave number q min was improved from 3x10 -3 A -1 to medium ultra-small angle scattering of 3x10 -4 A -1 . The focusing USANS method, thus developed, is crucial to fill the gap in wave number q between those covered by a double crystal method and by a conventional pin-hole method. (author)
KWS-2: Small angle scattering diffractometer
Directory of Open Access Journals (Sweden)
Aurel Radulescu
2015-08-01
Full Text Available KWS-2, operated by JCNS, Forschungszentrum Jülich, represents a classical pinhole SANS instrument where, combining the pinhole mode using different neutron wavelengths and detection distances with the focusing mode using MgF2 lenses, a wide Q-range between 1 x 10-4 and 0.5 Å-1 can be explored.
Small angle neutron scattering study of isolated single wall carbon nano tubes in water
International Nuclear Information System (INIS)
Doe, Chang-Woo; Kim, Tae-Hwan; Choi, Sung-Min; Kline, Steven R.
2007-01-01
As an effort to provide more practical approaches to a wide range of potential applications of carbon nano tubes, we report a new type of noncovalently functionalized isolated single-walled carbon nano tube(SWNT) which is easily dispersible in water by only ten minutes of mild vortex mixing. The structure and quality of dispersion have been investigated using small angle neutron scattering (SANS) technique
International Nuclear Information System (INIS)
Vorobyov, A.A.; Korolev, G.A.; Dobrovolsky, A.V.; Khanzadeev, A.V.; Petrov, G.E.; Spiridenkov, E.M.; Terrien, Y.; Lugol, J.C.; Saudinos, J.; Silverman, B.H.; Wellers, F.
1988-01-01
An experimental setup for measurements of absolute differential cross sections and analyzing powers in small angle elastic np scattering is described. The main part of the apparatus consists of a multielectrode ionization chamber IKAR filled with methane, serving as both a gas target and a recoil detector. The apparatus was used in measurements with a polarized neutron beam from the Saturne synchrotron (Saclay, France) in the energy range from 378 to 1135 MeV. (orig.)
Plateau iris in Japanese patients with primary angle closure and primary angle closure glaucoma.
Mizoguchi, Takanori; Ozaki, Mineo; Wakiyama, Harumi; Ogino, Nobuchika
2015-01-01
To determine the prevalence of plateau iris in Japanese patients with primary angle closure (PAC) and primary angle closure glaucoma (PACG) and analyze the biometric parameters in patients with plateau iris using ultrasound biomicroscopy (UBM). In this cross-sectional observational study, subjects aged >50 years with PAC and PACG who had previously undergone a patent laser peripheral iridotomy underwent UBM in one eye. UBM images were qualitatively analyzed using standardized criteria. Plateau iris in a quadrant was defined by anteriorly directed ciliary body, absent ciliary sulcus, steep iris root from its point of insertion followed by a downward angulation, flat iris plane, and irido-angle contact. At least two quadrants had to fulfill these UBM criteria for an eye to be classified as having plateau iris. A-scan biometry was used to measure anterior segment parameters. Ninety-one subjects with PAC (58 subjects) or PACG (33 subjects) and 68 normal controls were recruited. The mean (standard deviation) ages of PAC and PACG patients and normal controls were 73.5 (6.2) and 72.6 (7.3), respectively. Based on UBM criteria, plateau iris was found in 16 eyes (17.6%) of 91 eyes. In these 16 eyes, quadrant-wise analysis showed ten eyes (62.5%) had plateau iris in two quadrants; four eyes (25%) had plateau iris in three quadrants; and two eyes (12.5%) had plateau iris in four quadrants. Anterior chamber depth, lens thickness, axial length, lens position, and relative lens position were not statistically significant between the group having plateau iris and that not having plateau iris, respectively. Approximately 20% of Japanese subjects with PAC and PACG with a patent laser peripheral iridotomy were found to have plateau iris on UBM. No morphological difference was noted in the anterior segment of the eye between those with or without plateau iris.