The ideal male jaw angle--An Internet survey.
Mommaerts, Maurice Y
2016-04-01
The ideal male jaw angle has not been established. With the advent of additive manufacturing, precise customized shaping is a reality. This study aimed to define the ideal masculine mandibular angle as an aid for 3-dimensional (3D) design. An Internet survey was conducted using black/white photographs of celebrities and non-celebrities. Preferences regarding gonial angle (profile and frontal views), intergonial width and vertical jaw angle position (face frontal view), and angle curvature and definition in oblique views were obtained using simplified, unbalanced Likert scales. Constructs were defined for planning 3D implant designs. The preferred jaw angle had these characteristics: 130° in face profile view, intergonial width similar to facial width, vertical position in frontal view at the oral commissure or at least not below the lower lip, jawline slope in the face frontal view nearly parallel to (with a maximum 15° downward deviation from) a line extending from the lateral canthus to the alare, ascending ramus slope 65°-75° to the Frankfort horizontal, and curvature in the oblique view visible from earlobe to chin and not pointy. Photogrammetric analysis of panel preferences lead to constructs with values useful for the design of 3D printed jaw angles. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.
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.
Myint, Joy; Edgar, David F; Kotecha, Aachal; Murdoch, Ian E; Lawrenson, John G
2011-07-01
In the UK, the majority of cases of chronic open angle glaucoma are detected by community optometrists following a routine sight test. However, there is potential for variability in case finding strategies used. The aim of this study was to carry out a national web-based survey to determine current diagnostic tests used by optometrists in glaucoma case finding. Optometrists on the Association of Optometrists (AOP) electronic database were invited to participate. The survey was open for 16 weeks between April and July 2008. A total of 1875 optometrists were eligible to enter the survey, of which 1264 answered the questions relating to diagnostic equipment. Respondents were asked to indicate their usual method of examining the optic nerve head. Direct ophthalmoscopy only was used by 25% with the majority (62%) using a combination of direct and slit-lamp binocular indirect methods. The vast majority of optometrists (78%) used non-contact tonometry to measure intraocular pressure, with only 16% routinely using a Goldmann or Perkins applanation tonometer. The perimeter most frequently used was either one of the Henson range of instruments (39%) or the Humphrey Field Analyser (22%). A smaller number of optometrists (angle glaucoma, although there is a lack of standardisation with respect to equipment used. Ophthalmic & Physiological Optics © 2011 The College of Optometrists.
Orlik-Ruckemann, K. J.
1973-01-01
A survey was conducted relative to future requirements for dynamic stability information for such aerospace vehicles as the space shuttle and advanced high performance military aircraft. High-angle-of-attack and high-Reynolds number conditions were emphasized. A review was made of the wind-tunnel capabilities in North America for measuring dynamic stability derivatives, revealing an almost total lack of capabilities that could satisfy these requirements. Recommendations are made regarding equipment that should be constructed to remedy this situation. A description is given of some of the more advanced existing capabilities, which can be used to at least partly satisfy immediate demands.
Nanostructure surveys of macroscopic specimens by small-angle scattering tensor tomography
Liebi, Marianne; Georgiadis, Marios; Menzel, Andreas; Schneider, Philipp; Kohlbrecher, Joachim; Bunk, Oliver; Guizar-Sicairos, Manuel
2015-11-01
The mechanical properties of many materials are based on the macroscopic arrangement and orientation of their nanostructure. This nanostructure can be ordered over a range of length scales. In biology, the principle of hierarchical ordering is often used to maximize functionality, such as strength and robustness of the material, while minimizing weight and energy cost. Methods for nanoscale imaging provide direct visual access to the ultrastructure (nanoscale structure that is too small to be imaged using light microscopy), but the field of view is limited and does not easily allow a full correlative study of changes in the ultrastructure over a macroscopic sample. Other methods of probing ultrastructure ordering, such as small-angle scattering of X-rays or neutrons, can be applied to macroscopic samples; however, these scattering methods remain constrained to two-dimensional specimens or to isotropically oriented ultrastructures. These constraints limit the use of these methods for studying nanostructures with more complex orientation patterns, which are abundant in nature and materials science. Here, we introduce an imaging method that combines small-angle scattering with tensor tomography to probe nanoscale structures in three-dimensional macroscopic samples in a non-destructive way. We demonstrate the method by measuring the main orientation and the degree of orientation of nanoscale mineralized collagen fibrils in a human trabecula bone sample with a spatial resolution of 25 micrometres. Symmetries within the sample, such as the cylindrical symmetry commonly observed for mineralized collagen fibrils in bone, allow for tractable sampling requirements and numerical efficiency. Small-angle scattering tensor tomography is applicable to both biological and materials science specimens, and may be useful for understanding and characterizing smart or bio-inspired materials. Moreover, because the method is non-destructive, it is appropriate for in situ measurements and
Nanostructure surveys of macroscopic specimens by small-angle scattering tensor tomography.
Liebi, Marianne; Georgiadis, Marios; Menzel, Andreas; Schneider, Philipp; Kohlbrecher, Joachim; Bunk, Oliver; Guizar-Sicairos, Manuel
2015-11-19
The mechanical properties of many materials are based on the macroscopic arrangement and orientation of their nanostructure. This nanostructure can be ordered over a range of length scales. In biology, the principle of hierarchical ordering is often used to maximize functionality, such as strength and robustness of the material, while minimizing weight and energy cost. Methods for nanoscale imaging provide direct visual access to the ultrastructure (nanoscale structure that is too small to be imaged using light microscopy), but the field of view is limited and does not easily allow a full correlative study of changes in the ultrastructure over a macroscopic sample. Other methods of probing ultrastructure ordering, such as small-angle scattering of X-rays or neutrons, can be applied to macroscopic samples; however, these scattering methods remain constrained to two-dimensional specimens or to isotropically oriented ultrastructures. These constraints limit the use of these methods for studying nanostructures with more complex orientation patterns, which are abundant in nature and materials science. Here, we introduce an imaging method that combines small-angle scattering with tensor tomography to probe nanoscale structures in three-dimensional macroscopic samples in a non-destructive way. We demonstrate the method by measuring the main orientation and the degree of orientation of nanoscale mineralized collagen fibrils in a human trabecula bone sample with a spatial resolution of 25 micrometres. Symmetries within the sample, such as the cylindrical symmetry commonly observed for mineralized collagen fibrils in bone, allow for tractable sampling requirements and numerical efficiency. Small-angle scattering tensor tomography is applicable to both biological and materials science specimens, and may be useful for understanding and characterizing smart or bio-inspired materials. Moreover, because the method is non-destructive, it is appropriate for in situ measurements and
Sironi, Lorenzo
We investigate particle acceleration in relativistic magnetized collisionless pair shocks with two-dimensional particle-in-cell numerical simulations. For fixed upstream bulk Lorentz factor γ0 = 15 and magnetic to kinetic energy fraction σ = 0.1, we explore a range of inclination angles θ between the magnetic field and the shock normal. The inclination is measured in the downstream rest frame and the magnetic field lies in a plane perpendicular to the simulation plane. The downstream energy spectrum for subluminal shocks consists of a relativistic Maxwellian and a high-energy power-law tail modified by an exponential cutoff. For parallel shocks (θ = 0° ), the tail accounts for ˜ 1% of the downstream particle number and ˜ 5% of the energy, and its energy spectral index is -2.7 ± 0.1. Accelerated particles bounce between the upstream and the downstream, and the upstream scattering is provided by oblique filaments, which have both an electromagnetic and an electrostatic component. Such filaments propagate towards the shock and are generated by the accelerated particles that escape upstream. For larger inclination angles the acceleration efficiency increases, and particles are efficiently boosted by the motional upstream electric field when gyrating across the shock. Close to the superluminality threshold θ ≈ 30° , the number and energy fractions of downstream accelerated particles are ˜ 3% and ˜ 12% respectively; the spectral index of the corresponding power-law tail is -2.4 ± 0.1. When the shock becomes superluminal (θ 30° ), the acceleration efficiency abruptly drops. Our results show that the range of upstream-frame inclination angles suitable for efficient acceleration in relativistic magnetized pair shocks is indeed very small 30° /γ0 , as suggested by previous Monte-Carlo simulations. Self-generated shock turbulence is shown to be not large enough to overcome the kinematic constraints for superluminal shocks. These findings place constraints
Survey of background scattering from materials found in small-angle neutron scattering.
Barker, J G; Mildner, D F R
2015-08-01
Measurements and calculations of beam attenuation and background scattering for common materials placed in a neutron beam are presented over the temperature range of 300-700 K. Time-of-flight (TOF) measurements have also been made, to determine the fraction of the background that is either inelastic or quasi-elastic scattering as measured with a 3 He detector. Other background sources considered include double Bragg diffraction from windows or samples, scattering from gases, and phonon scattering from solids. Background from the residual air in detector vacuum vessels and scattering from the 3 He detector dome are presented. The thickness dependence of the multiple scattering correction for forward scattering from water is calculated. Inelastic phonon background scattering at small angles for crystalline solids is both modeled and compared with measurements. Methods of maximizing the signal-to-noise ratio by material selection, choice of sample thickness and wavelength, removal of inelastic background by TOF or Be filters, and removal of spin-flip scattering with polarized beam analysis are discussed.
Lee, Jin-Ah; Han, Kyungdo; Min, Jung Ah; Choi, Jin A
2016-12-01
The aim of this study is to investigate the relationship between sleep duration and glaucoma, stratified by obesity status.This study was conducted using data from the Korean National Health and Nutrition Examination Survey V 2010 to 2012. Open-angle glaucoma was diagnosed according to the International Society of Geographical and Epidemiological Ophthalmology criteria. Subjects were divided into subgroups based on those who were overweight (body mass index ≥25 kg/m or sleep duration (pattern (P for trend = 0.072). Among overweight individuals, subjects who slept exercise, education level, household income, hypertension, intraocular pressure, stress, and depression (odds ratio, 2.41; 95% confidence interval, 1.14-5.03). Unlike for overweight individuals, sleep duration in nonoverweight individuals was not statistically significantly associated with glaucoma.Our results reveal a U-shaped association between sleep duration and the prevalence of glaucoma. An effect of sleep duration on glaucoma was present in the subgroup of overweight patients.
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.)
Czech Academy of Sciences Publication Activity Database
Sabbaghi, F.; Pourayoubi, M.; Dušek, Michal; Eigner, Václav; Bayat, S.; Damodaran, K.; Nečas, M.; Kučeráková, Monika
2016-01-01
Roč. 27, č. 6 (2016), s. 1831-1844 ISSN 1040-0400 R&D Projects: GA MŠk LO1603 EU Projects: European Commission(XE) CZ.2.16/3.1.00/24510 Institutional support: RVO:68378271 Keywords : Cambridge Structural Database (CSD) * crystal structure * analysis of bond angle * hybridization Subject RIV: CC - Organic Chemistry Impact factor: 1.582, year: 2016
DEFF Research Database (Denmark)
Sparrevohn, Claus Reedtz; Nielsen, Jan; Storr-Paulsen, Marie
, as all recreational fishermen have to purchase a personal non-transferable and time limited national license before fishing. However, this list will not include those fishing illegally without a license. Therefore, two types of recall surveys with their own questionnaires and group of respondents were...
DEFF Research Database (Denmark)
SURVEY er en udbredt metode og benyttes inden for bl.a. samfundsvidenskab, humaniora, psykologi og sundhedsforskning. Også uden for forskningsverdenen er der mange organisationer som f.eks. konsulentfirmaer og offentlige institutioner samt marketingsafdelinger i private virksomheder, der arbejder...... med surveys. Denne bog gennemgår alle surveyarbejdets faser og giver en praktisk indføring i: • design af undersøgelsen og udvælgelse af stikprøver, • formulering af spørgeskemaer samt indsamling og kodning af data, • metoder til at analysere resultaterne...
Wallington, Sherrie Flynt; Blake, Kelly; Taylor-Clark, Kalahn; Viswanath, K
2010-01-01
The influence of news media on audience cognitions, attitudes, and behaviors in the realm of politics, race relations, science, and health has been extensively documented.Agenda setting and framing studies show that news media influence how people develop schema and place priorities on issues, with media stories serving as a major source of issue frames. Although news media are an important intermediary in the translation of scientific knowledge to different publics, little has been documented about the production of health news and factors that may predict media agenda setting and framing in health journalism. We used data from a 2005 national survey of U.S. health reporters and editors to examine predictors of source, resource, story angle, and frame usage among reporters and editors by variables such as organizational structure, individual characteristics of respondents (such as education and years working as a journalist),and perceptions of occupational autonomy. Multivariable logistic regression models revealed several differences among U.S. health reports and editors in the likelihood of using a variety of news sources, resources, priorities, and angles in reporting. Media agenda setting and framing theories suggest that practitioners familiar with media processes can work with journalists to frame messages, thereby increasing the probability of accurate and effective reporting. Results from this study may help to inform interactions between public health and medical practitioners and the press [corrected].
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...
Luttrell, Kevin; Beltran, Michael; Collinge, Cory A
2014-09-01
To identify the current implant and diagnostic imaging preferences among orthopaedic trauma experts for the treatment of high-energy vertical femoral neck fractures in young adult patients. Web-based survey. Not available. Active members of the OTA. A cross-sectional expert opinion survey was administered to the active members of the OTA to determine their preferences for implant use and imaging in the surgical treatment of a vertical femoral neck fracture in a young adult patient (e.g., 60-degree Pauwels angle fracture in a healthy 30-year-old patient). Questions were also asked regarding the reason why this implant was selected, whether the surgeon felt that their choice was supported by the literature, and what imaging studies are routinely obtained to guide decision making. Data were collected using simple multiple-choice questions and/or a 5-point Likert item. Two hundred seventy-two surgeons (47%) responded to the survey. The preferred constructs for a vertical femoral neck fracture in a healthy young patient were a sliding hip screw with or without an anti-rotation screw (47%), parallel cannulated screws with an off-axis screw (28%), and parallel cannulated screw constructs (15%). When asked if their designated construct "was clearly supported by the literature," 46% were either unsure or disagreed. Seventy percent of surgeons chose their preferred implant because it was "biomechanically most stable." Most surgeons required anteroposterior pelvis (70%) and standard hip (88%) radiographs; however only 29% of surgeons required a computed tomography (59% found computed tomography helpful but not required). Twenty-seven percent of surgeons have changed their implant choice intraoperatively. Femoral neck fractures in young adult patients are a challenging problem with high rates of failed treatment. Many options for treatment exist and a consensus on the best method remains elusive. Our survey demonstrates the diversity and disagreement among OTA member "expert
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...
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....
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)
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 ...
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 ...
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
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)
National Oceanic and Atmospheric Administration, Department of Commerce — The Billfish Angler Survey provides estimates of billfish angling activities in the Pacific and Indian Oceans. This collection of recreational billfish catch and...
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-.
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
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...
Schofield, W
2007-01-01
Engineering surveying involves determining the position of natural and man-made features on or beneath the Earth's surface and utilizing these features in the planning, design and construction of works. It is a critical part of any engineering project. Without an accurate understanding of the size, shape and nature of the site the project risks expensive and time-consuming errors or even catastrophic failure.Engineering Surveying 6th edition covers all the basic principles and practice of this complex subject and the authors bring expertise and clarity. Previous editions of this classic text have given readers a clear understanding of fundamentals such as vertical control, distance, angles and position right through to the most modern technologies, and this fully updated edition continues that tradition.This sixth edition includes:* An introduction to geodesy to facilitate greater understanding of satellite systems* A fully updated chapter on GPS, GLONASS and GALILEO for satellite positioning in surveying* Al...
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.
An empirical investigation of German tourist anglers’ preferences for angling in Denmark
DEFF Research Database (Denmark)
Bonnichsen, Ole; Jensen, Carsten Lynge; Olsen, Søren Bøye
at the site. To attract tourist anglers an angling site manager may use this information to target marketing efforts towards segments of tourist that prefer the type and quality of angling characteristics of the angling site in the managers possession. Additionally, he may seek to adjust and improve......The quality of angling sites is important for attracting tourists who enjoy recreational angling. In this paper, we conduct an empirical analysis investigating which attributes of angling sites are particularly important for attracting tourist anglers from abroad. We conduct an online survey of 968...... German anglers who have recently been abroad on a holiday trip in which they went angling. We focus on the particularly dedicated anglers who state that recreational angling is important for their choice of holiday destination. A stated choice experiment is employed to investigate their preferences...
Small-angle neutron scattering from colloidal dispersions
International Nuclear Information System (INIS)
Ottewill, R.H.
1991-01-01
A survey is given of recent work on the use of small-angle neutron scattering to examine colloidal dispersions. Particular attention is given to the determination of particle size and polydispersity, the determination of particle morphology and the behaviour of concentrated colloidal dispersions, both at rest and under the influence of an applied shear field. (orig.)
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...
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.
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....
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.
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...
THE BEHAVIOR OF THE PITCH ANGLE OF SPIRAL ARMS DEPENDING ON OPTICAL WAVELENGTH
Energy Technology Data Exchange (ETDEWEB)
Martínez-García, Eric E.; Puerari, Ivânio; Rosales-Ortega, F. F.; Luna, A. [Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE), Aptdo. Postal 51 y 216, 72000 Puebla, Pue. (Mexico); González-Lópezlira, Rosa A. [Centro de Radioastronomía y Astrofísica, UNAM, Campus Morelia, Michoacán, México, C.P. 58089 (Mexico); Fuentes-Carrera, Isaura, E-mail: ericmartinez@inaoep.mx [Escuela Superior de Física y Matemáticas, Instituto Politécnico Nacional, U. P. Adolfo López Mateos, Zacatenco, 07730 México, D.F. (Mexico)
2014-09-20
Based on integral field spectroscopy data from the CALIFA survey, we investigate the possible dependence of spiral arm pitch angle with optical wavelength. For three of the five studied objects, the pitch angle gradually increases at longer wavelengths. This is not the case for two objects where the pitch angle remains constant. This result is confirmed by the analysis of SDSS data. We discuss the possible physical mechanisms to explain this phenomenon, as well as the implications of the results.
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.
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...
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.
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).
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.
Clancy, John
2013-01-01
This popular and useful text has been completely revised and up-dated so that it forms and indipensible handbook for any student of surveying. An additional chapter on modern developments is included and the text has also been extended to cover ordnance survey; calculation of areas; computation of true horizontal length; measurement of vertical angles; Code of Measuring Practice; curve ranging and calculations of volumes for earthworks.
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.
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.
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
Johnson, Aylmer
2014-01-01
IntroductionAim And ScopeClassification Of SurveysThe Structure Of This BookGeneral Principles Of SurveyingErrorsRedundancyStiffnessAdjustmentPlanning And Record KeepingPrincipal Surveying ActivitiesEstablishing Control NetworksMappingSetting OutResectioningDeformation MonitoringAngle MeasurementThe Surveyor's CompassThe ClinometerThe Total StationMaking ObservationsChecks On Permanent AdjustmentsDistance MeasurementGeneralTape MeasurementsOptical Methods (Tachymetry)Electromagnetic Distance Measurement (EDM)Ultrasonic MethodsGNSSLevellingTheoryThe InstrumentTechniqueBookingPermanent Adjustmen
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....
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.
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.
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.
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...
An oilspill trajectory analysis model with a variable wind deflection angle
Samuels, W.B.; Huang, N.E.; Amstutz, D.E.
1982-01-01
The oilspill trajectory movement algorithm consists of a vector sum of the surface drift component due to wind and the surface current component. In the U.S. Geological Survey oilspill trajectory analysis model, the surface drift component is assumed to be 3.5% of the wind speed and is rotated 20 degrees clockwise to account for Coriolis effects in the Northern Hemisphere. Field and laboratory data suggest, however, that the deflection angle of the surface drift current can be highly variable. An empirical formula, based on field observations and theoretical arguments relating wind speed to deflection angle, was used to calculate a new deflection angle at each time step in the model. Comparisons of oilspill contact probabilities to coastal areas calculated for constant and variable deflection angles showed that the model is insensitive to this changing angle at low wind speeds. At high wind speeds, some statistically significant differences in contact probabilities did appear. ?? 1982.
The National Facility for Small-Angle Neutron Scattering - five years' operating experience
International Nuclear Information System (INIS)
Koehler, W.C.; Bunick, G.J.; Child, H.R.; Hayter, J.B.; Lin, J.S.; Maddox, L.; Spooner, S.; Wignall, G.D.
1986-01-01
At the time of this Conference on Neutron Scattering, the ORNL-NSF-DOE National Facility for Small-Angle Neutron Scattering will have been operating routinely in a full-time user mode for nearly five years. The Facility, located at the High Flux Isotope Reactor at ORNL, is part of the National Center for Small-Angle Scattering Research. Operating experience and scientific highlights for the past five years are surveyed. (orig.)
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.
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...
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
Introduction to nanostructural analyses by small-angle neutron scattering
International Nuclear Information System (INIS)
Shibayama, Mitsuhiro
2010-01-01
It has already passed more than 30 years since small-angle neutron scattering (SANS) technique was applied in structural analyses. SANS is now one of common tools in structure investigations and SANS instruments can be found in any neutron scattering facilities. In particular, SANS plays an important role in the field of soft matter, such as polymer, micelles, gels, vesicles, as well as biological systems and metallurgy. Here, I give a brief survey on (1) the utility of SANS in structural studies, (2) experimental aspects of SANS, and (3) some results obtained so far. (author)
Comparison of children with joint angles in spastic diplegia with those of normal children.
Kim, Chang Ju; Kim, Young Mi; Kim, Dong Dae
2014-09-01
[Purpose] The purpose of this study was to compare joint angles between normal children and those with spastic diplegia using three-dimensional gait analysis. [Subjects and Methods] The study subjects were eight patients with spastic diplegia and eight normal children. Three-dimensional gait analysis was used for the survey. The measured gait variables were the joints of the lower extremity in the sagittal plane, frontal plane, and transverse planes and the maximum and minimum angles of their stance phase and swing phases. [Results] In the sagittal plane, the maximum angles of both the right and left pelvis and hip joint in the stance phase and swing phases were significantly greater for children with spastic diplegia than for normal children. In the stance phase of the right side of the hip joint, the maximum angles of the hip in the swing phase and the knee joint's minimum angles in the stance phase differed significantly. In the transverse plane, there were a significant differences on the left side of the pelvis in the maximum angles in the swing and stance phases. There were also significant differences on the right side pelvis, in the maximum and minimum angles in the stance phase and minimum angles in the swing phase. [Conclusion] Children with spastic diplegia employ a different gait strategy and pattern from normal children.
Modified angle's classification for primary dentition
Directory of Open Access Journals (Sweden)
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.
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...
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...
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
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.)
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.
Precision surveying the principles and geomatics practice
Ogundare, John Olusegun
2016-01-01
A comprehensive overview of high precision surveying, including recent developments in geomatics and their applications This book covers advanced precision surveying techniques, their proper use in engineering and geoscience projects, and their importance in the detailed analysis and evaluation of surveying projects. The early chapters review the fundamentals of precision surveying: the types of surveys; survey observations; standards and specifications; and accuracy assessments for angle, distance and position difference measurement systems. The book also covers network design and 3-D coordinating systems before discussing specialized topics such as structural and ground deformation monitoring techniques and analysis, mining surveys, tunneling surveys, and alignment surveys. Precision Surveying: The Principles and Geomatics Practice: * Covers structural and ground deformation monitoring analysis, advanced techniques in mining and tunneling surveys, and high precision alignment of engineering structures *...
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
An evaluation of several methods of determining the local angle of attack on wind turbine blades
DEFF Research Database (Denmark)
Guntur, Srinivas; Sørensen, Niels N.
2014-01-01
Several methods of determining the angles of attack (AOAs) on wind turbine blades are discussed in this paper. A brief survey of the methods that have been used in the past are presented, and the advantages of each method are discussed relative to their application in the BEM theory. Data from...
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.
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
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.
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.
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.
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.
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 ...
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…
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 ...
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
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.
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 ...
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.
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
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.
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.
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
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.
Exclusive Backward-Angle Omega Meson Electroproduction
Energy Technology Data Exchange (ETDEWEB)
Wenliang, Li [Univ. of Regina, Regina, SK (Canada)
2017-10-01
Exclusive meson electroproduction at different squared four-momenta of the exchanged virtual photon, Q^{2} , and at different four-momentum transfers, t and u, can be used to probe QCD's transition from hadronic degrees of freedom at the long distance scale to quark-gluon degrees of freedom at the short distance scale. Backward-angle meson electroproduction was previously ignored, but is anticipated to offer complimentary information to conventional forward-angle meson electroproduction studies on nucleon structure. This work is a pioneering study of backward-angle ω cross sections through the exclusive ^{1}H(e, e'p)ω reaction using the missing mass reconstruction technique. The extracted cross sections are separated into the transverse (T), longitudinal (L), and LT, TT interference terms. The analyzed data were part of experiment E01-004 (Fπ-2), which used 2.6-5.2 GeV electron beams and HMS+SOS spectrometers in Jefferson Lab Hall C. The primary objective was to detect coincidence π in the forward-angle, where the backward-angle omega events were fortuitously detected. The experiment has central Q^{2} values of 1.60 and 2.45 GeV^{2} , at W = 2.21 GeV. There was significant coverage in phi and epsilon, which allowed separation of σ_{T,L,LT,TT} . The data set has a unique u coverage of -u ~ 0, which corresponds to -t > 4 GeV^{2} . The separated σ_{T} result suggest a flat ~ 1/Q^{1.33±1.21} dependence, whereas sigma_L seems to hold a stronger 1/Q^{9.43±6.28} dependence. The σL/σ_{T} ratio indicate σ_{T} dominance at Q^{2} = 2.45 GeV^{2} at the ~90% confidence level. After translating the results into the -t space of the published CLAS data, our data show evidence of a backward-angle omega electroproduction peak at both Q^{2} settings. Previously, this phenomenon showing both forward and backward-angle peaks was only observed in the meson
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
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
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.
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.)
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.
... to the American Academy of Dermatology's "Suntelligence" sun-smart survey. Please answer the following questions to measure ... be able to view a ranking of major cities suntelligence based on residents' responses to this survey. ...
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
[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
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.
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.
Conical pitch angle distributions of very-low energy ion fluxes observed by ISEE 1
International Nuclear Information System (INIS)
Horowitz, J.L.; Baugher, C.R.; Chappell, C.R.; Shelley, E.G.; Young, D.T.
1982-01-01
Observations of low-energy ionospheric ions by the plasma composition experiment abroad ISEE 1 often show conical pitch angle distributions, that is, peak fluxes between 0 0 and 90 0 to the directions parallel or antiparallel to the magnetic field. Frequently, all three primary ionospheric ion species (H + , He + , and O + ) simultaneously exhibit conical distributions with peak fluxes at essentially the same pitch angle. A distinction is made here between unidirectional, or streaming, distributions, in which ions are traveling essentially from only one hemisphere, and symmetrical distributions, in which significant fluxes are observed traveling from both hemispheres. The orbital coverage for this survey was largely restricted to the night sector, approximately 2100--0600 LT, and moderate geomagnetic latitudes of 20 0 --40 0 . Also, lack of complete pitch angle coverage at all times may have reduced detection for conics with small cone angles. However, we may conclude that the unidirectional conical distributions observed in the northern hemisphere are always observed to be traveling from the northern hemisphere and that they exhibit the following characteristics relative to the symmetric distributions, in that they (1) are typically observed on higher L shells (that is, higher geomagnetic latitudes or larger geocentric distances or both), (2) tend to have significantly larger cone angles, and (3), are associated with higher magnetic activity levels
Directory of Open Access Journals (Sweden)
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.
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
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
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...
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)
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.
Alderman, Amy K; Salem, Barbara
2010-10-01
Survey research is a unique methodology that can provide insight into individuals' perspectives and experiences and can be collected on a large population-based sample. Specifically, in plastic surgery, survey research can provide patients and providers with accurate and reproducible information to assist with medical decision-making. When using survey methods in research, researchers should develop a conceptual model that explains the relationships of the independent and dependent variables. The items of the survey are of primary importance. Collected data are only useful if they accurately measure the concepts of interest. In addition, administration of the survey must follow basic principles to ensure an adequate response rate and representation of the intended target sample. In this article, the authors review some general concepts important for successful survey research and discuss the many advantages this methodology has for obtaining limitless amounts of valuable information.
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.
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.
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.
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
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...
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…
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
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.
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
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.
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
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.
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.
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.
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.
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
A literature review on optimum and preferred joint angles in automotive sitting posture.
Schmidt, Susanne; Amereller, Maximilian; Franz, Matthias; Kaiser, Ralf; Schwirtz, Ansgar
2014-03-01
In this study, a survey of the scientific literature in the field of optimum and preferred human joint angles in automotive sitting posture was conducted by referring to thirty different sources published between 1940 and today. The strategy was to use only sources with numerical angle data in combination with keywords. The aim of the research was to detect commonly used joint angles in interior car design. The main analysis was on data measurement, usability and comparability of the different studies. In addition, the focus was on the reasons for the differently described results. It was found that there is still a lack of information in methodology and description of background. Due to these reasons published data is not always usable to design a modern ergonomic car environment. As a main result of our literature analysis we suggest undertaking further research in the field of biomechanics and ergonomics to work out scientific based and objectively determined "optimum" joint angles in automotive sitting position. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.
Neutron focusing optics for low-resolution small-angle scattering
International Nuclear Information System (INIS)
Mildner, D.F.R.
1994-01-01
Small-angle neutron scattering instruments use large source and sample areas with long flight paths to obtain the necessary resolution. Increased count rates may be obtained using collimators that converge to a point on the detector. Further increases may be obtained by converging guides in the form of a focusing lens. A low-resolution small-angle scattering instrument that uses converging capillary fibers as a focusing lens is proposed. Such a device requires the use of a detector that has a fine spatial resolution, perhaps less than 0.1 mm. Expressions are derived for the resolution and the intensity optimized for such an instrument. The relationship is determined between the guide dimensions, the focal length and the critical angle of the internal coating of the individual fiber channels. The critical angle of the focusing lens dominates the resolution, and such an instrument is useful only for low-resolution measurements. However, the greatly reduced length is only valuable if there is a high-resolution detector to match the dimensions of the guide. Despite its low resolution, such an instrument might eventually be useful for survey or characterization measurements. (orig.)
National Oceanic and Atmospheric Administration, Department of Commerce — Cleaned and QCd data for the Fishing Effort Survey. Questions on fishing and other out are asked on weather and outdoor activity, including fishing trips. Used for...
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.
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 ...
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
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...
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.
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.
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
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.)
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
Guillén-Ludeña, S.; Franca, M. J.; Cardoso, A. H.; Schleiss, A. J.
2016-02-01
Mountain river confluences are characterized by narrow and steep tributaries that supply abundant sediment load to a main channel that, in turn, provides the dominant flow discharge. In addition, bed sediments consist of poorly sorted mixtures that promote bed armoring. The knowledge of the hydrodynamics and morphodynamics of mountain river confluences is sparse because most of the existent studies on confluence dynamics focus on lowland confluences. This study aims at examining the influence of the junction angle (α) and discharge ratio (Qr = Qt / Qm) on flow dynamics and bed morphology of mountain river confluences. This study presents the results of six laboratory experiments in which three discharge ratios were tested (Qr = Qt / Qm = 0.11, 0.15, 0.23) with two different junction angles (α = 90° and 70°). The experiments were conducted under movable bed conditions and with continuous sediment supply to both flumes. Measurements consisted of systematic bed topography and water surface surveys performed at different instants during the experiments and at equilibrium, i.e., when the outgoing sediment rate coincided with the incoming and bed topography reached a steady state. The results show that the discharge ratio and the junction angle parameters are major controls of the dynamics of mountain river confluences. Also, the evolution of bed morphology and flow dynamics for varying junction angles and discharge ratios present some patterns that contrast with those reported for lowland confluences. Among these patterns are the different flow regimes adopted by the tributary for different junction angles and the decrease of the height of the bank-attached bar for increasing discharge ratios. Moreover, results show that the abundant sediment load of the tributary plays a major role on the dynamics of this type of confluence. This load resulted in a marked bed discordance that, in turn, influenced flow dynamics and bed morphology of the confluence.
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.
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.
Plateau iris in Japanese patients with primary angle closure and primary angle closure glaucoma
Directory of Open Access Journals (Sweden)
Mizoguchi T
2015-06-01
Full Text Available Takanori Mizoguchi,1 Mineo Ozaki,2,3 Harumi Wakiyama,1,4 Nobuchika Ogino1,51Mizoguchi Eye Clinic, Nagasaki, Japan; 2Ozaki Eye Clinic Miyazaki, Japan; 3Department of Ophthalmology, Faculty of Medicine, University of Miyazaki, Miyazaki, Japan; 4The Japanese Red Cross Nagasaki Genbaku Hospital, Nagasaki, Japan; 5Nishigaki Eye Clinic, Nagoya, JapanPurpose: 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.Methods: 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.Results: 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
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...
Physiological response to angling of Africa's premier freshwater ...
African Journals Online (AJOL)
Blood plasma was analysed for glucose, cortisol and lactate concentrations to assess the effects of angling duration, fish size and fish condition. Larger fish were angled for a longer duration. Plasma glucose concentrations decreased with greater lactate concentrations, an indication of the aerobic and anaerobic work done ...
Contact angle hysteresis: a review of fundamentals and applications
Eral, Burak; 't Mannetje, Dieter; Oh, J.M.
2013-01-01
Contact angle hysteresis is an important physical phenomenon. It is omnipresent in nature and also plays a crucial role in various industrial processes. Despite its relevance, there is a lack of consensus on how to incorporate a description of contact angle hysteresis into physical models. To
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 ...
Escape angles in bulk chi((2)) soliton interactions
DEFF Research Database (Denmark)
Johansen, Steffen Kjær; Bang, Ole; Sørensen, Mads Peter
2002-01-01
We develop a theory for nonplanar interaction between two identical type I spatial solitons propagating at opposite, but arbitrary transverse angles in quadratic nonlinear (or so-called chi((2))) bulk, media. We predict quantitatively the outwards escape angle, below which the solitons turn around...
Small angle neutron scattering from nanometer grain sized materials
Epperson, J. E.; Siegel, R. W.
1991-11-01
Small angle neutron scattering has been utilized, along with a number of complementary characterization methods suitable to the nanometer size scale, to investigate the structures of cluster-assembled nanophase materials. Results of these investigations are described and problems and opportunities in using small angle scattering for elucidating nanostructures are discussed.
Small angle polarised neutron scattering investigation of magnetic nanoparticles
International Nuclear Information System (INIS)
Bergenti, I.; Deriu, A.; Savini, L.; Bonetti, E.; Spizzo, F.; Hoell, H.
2003-01-01
Small angle scattering of polarised neutron (SANSPOL) is a powerful technique for the determination of magnetisation, density and compositional profiles of nanostructured particles. We present here some examples of the magnetic profile determination using the SANSPOL technique and we discuss in detail its advantage with respect to the conventional small angle neutron scattering approach
An assessment of recreational bank angling in the Free State ...
African Journals Online (AJOL)
Recreational angling is an important form of utilisation of inland fisheries in South Africa but there is little information on this sector. The objective of this study was to provide an assessment of recreational bank angling in the Free State Province using licence sale and tournament data. During 2013 and 2014, 8 256 and 7 ...
Determination of the Optimum Collector Angle for Composite Solar ...
African Journals Online (AJOL)
A model for predicting solar radiation available at any given time in the inhabited area in Ilorin was developed. From the equation developed, the optimum tilt angle of the collector due south was carried out. The optimum angle of tilt of the collector and the orientation are dependent on the month of the year and the location ...
Radiological assessment of the femoral bicondylar angle in a ...
African Journals Online (AJOL)
Background: Femoral bicondylar angle is the angle between the diaphysis of the femur and a line perpendicular to the infracondylar plane. It is indispensable in bipedal locomotion as it serves to place the knee and foot under the body's center of gravity during the single support phase of gait. Although the mechanism for the ...
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 ...
46 CFR 58.01-40 - Machinery, angles of inclination.
2010-10-01
... 46 Shipping 2 2010-10-01 2010-10-01 false Machinery, angles of inclination. 58.01-40 Section 58.01-40 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS General Requirements § 58.01-40 Machinery, angles of inclination. (a) Propulsion machinery and all auxiliary...
Gradient angle estimation by uniform directional simulation on a cone
DEFF Research Database (Denmark)
Ditlevsen, Ove Dalager
1997-01-01
approximation to a locally most central limit state point. Moreover, the estimated angle can be used to correct the geometric reliability index.\\bfseries Keywords: Directional simulation, effectivity factor, gradient angle estimation, maximum likelihood, model-correction-factor method, Monte Carlo simulation...
A new uncertainty relation for angular momentum and angle
International Nuclear Information System (INIS)
Kranold, H.U.
1984-01-01
An uncertainty relation of the form ΔL 2 ΔSo >=sup(h/2π)/sub(2) is derived for angular momentum and angle. The non-linear operator So measures angles and has a simple interpretation. Subject to very general conditions of rotational invariance the above relation is unique. Radial momentum is not quantized
A cephalometric assessment of the nasolabial angle of an adult ...
African Journals Online (AJOL)
Objective: One of the most important components of orthodontic diagnosis and treatment planning is an evaluation of the patient's soft tissue profile. An assessment of the nasolabial angle is a vital component of this evaluation. The purpose of this study was to establish norms for the nasolabial angle of an adult Nigerian ...
A gallery approach for off-angle iris recognition
Karakaya, Mahmut; Yoldash, Rashiduddin; Boehnen, Christopher
2015-05-01
It has been proven that hamming distance score between frontal and off-angle iris images of same eye differs in iris recognition system. The distinction of hamming distance score is caused by many factors such as image acquisition angle, occlusion, pupil dilation, and limbus effect. In this paper, we first study the effect of the angle variations between iris plane and the image acquisition systems. We present how hamming distance changes for different off-angle iris images even if they are coming from the same iris. We observe that increment in acquisition angle of compared iris images causes the increment in hamming distance. Second, we propose a new technique in off-angle iris recognition system that includes creating a gallery of different off-angle iris images (such as, 0, 10, 20, 30, 40, and 50 degrees) and comparing each probe image with these gallery images. We will show the accuracy of the gallery approach for off-angle iris recognition.
Presentation of Primary Open Angle Glaucoma (POAG) at Lions ...
African Journals Online (AJOL)
Objective Primary open angle glaucoma (POAG) is the most common type of glaucoma in Africa. We carried out a study to determine the clinical presentation pattern of patients with primary open angle glaucoma (POAG) at a tertiary hospital in Malawi. Design A cross-sectional study. Setting Lions Sight First Eye Hospital—a ...
Engineering sidewall angles of silica-on-silicon waveguides
DEFF Research Database (Denmark)
Haiyan, Ou
2004-01-01
Burned photoresist is used as etch mask when producing silica-onsilicon waveguides. The sidewall angle of the optical glass waveguides is engineered by varying photoresist thickness and etch selectivity. The principle for the formation of the angles is introduced and very promising experimental...
Angle-domain common-image gathers from anisotropic Gaussian ...
Indian Academy of Sciences (India)
An approach for extracting angle-domain common-image gathers (ADCIGs) from anisotropic Gaussian beam prestack depth migration (GB-PSDM) is presented in this paper. The propagation angle is calcu- lated in the process of migration using the real-value traveltime information of Gaussian beam. Based on the above ...
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.
A 'conveyor belt' model for the dynamic contact angle
International Nuclear Information System (INIS)
Volpe C, Della; Siboni, S
2011-01-01
The familiar Young contact angle measurement of a liquid at equilibrium on a solid is a fundamental aspect of capillary phenomena. But in the real world it is not so easy to observe it. This is due to the roughness and/or heterogeneity of real surfaces, which typically are not perfectly planar and chemically homogeneous. What can be easily detected, and in a repeatable way, are advancing and receding contact angles. In this paper, we discuss a simple model which accounts for the onset of advancing and receding contact angles measured by the Wilhelmy microbalance, one of the most powerful techniques for contact angle measurements. The model also explains the experimental observation that advancing and receding contact angles become closer to each other when the system is gently 'shaken', by supplying mechanical energy in an appropriate way. The model may be pedagogically useful in introducing students and teachers to aspects of capillary phenomena which are not usually discussed in basic physics courses.
Nonlinearity in the effect of an inhomogeneous Hall angle
Koon, Daniel W.
2007-03-01
The differential equation for the electric potential in a conducting material with an inhomogeneous Hall angle is extended to the large-field limit. This equation is solved for a square specimen, using a successive over-relaxation [SOR] technique for matrices of up to 101x101 size, and the Hall weighting function -- the effect of local pointlike perturbations on the measured Hall angle -- is calculated as both the unperturbed Hall angle, θH, and the perturbation, δθH, exceed the linear, small angle limit. Preliminary results show that the Hall angle varies by no more than 5% if both | θH |<1 and | δθH |<1. Thus, previously calculated results for the Hall weighting function can be used for most materials in all but the most extreme magnetic fields.
Does Sacrococcygeal Angle Play a Role on Pilonidal Sinus Etiology?
Directory of Open Access Journals (Sweden)
Ramazan Eryilmaz
2015-01-01
Full Text Available The predisposing factors for the development of sacrococcygeal pilonidal disease (SPD still remain undetermined. Here, we investigate the sacrococcygeal angle as a possible predisposing factor for the development of disease. Consecutive male patients admitted to our clinic with the diagnosis of SPD were included. Sex, age and BMI matched healthy controls without SPD were enrolled to the study. The predefined sacrococcygeal angles of patients and controls were measured on lateral pelvic radiographs by a single experienced radiologist. Thirty patients were included in each group. Sacrococcygeal angles of patients and control group were measured as 37.3 ± 14.5 and 36.81 ± 10.23 in patients and controls, respectively. The difference with respect to sacrococcygeal angle was not statistically significant between two groups. Sacrococcygeal angle which is the main skeletal determinant of intergluteal sulcus is not a predisposing factor for the development of sacrococcygeal pilonidal disease.
Neutron small angle scattering of irradiated aluminium-silicon alloys
International Nuclear Information System (INIS)
Kostorz, G.
1976-01-01
Technically pure aluminium and aluminium-silicon alloys (0.43, 0.83 and 1.2% Si, also containing 0.11 to 0.14 at. % Fe) were investigated by slow neutron small angle scattering after irradiation with fast neutrons at low temperatures. Different irradiation levels, ageing at room temperature and at 60/70 0 C had no measurable effect upon small angle scattering cross-sections. From the experimental precision upper limit for the amount of Si involved in clustering after irradiation can be given. The observed small angle scattering shows a strong dependence on scattering angles and is attributed to large precipitates of Al 12 Fe 3 Si. A surface layer on the as-received samples is identified as another source of low-intensity small angle scattering. (orig.) [de
Zhuo, Ye-Hong; Wang, Mei; Li, Ying; Hao, Yuan-Tao; Lin, Min-Kai; Fang, Min; Ge, Jian
2009-12-01
To investigate and compare the effects of phacoemulsification as an initial procedure to control intraocular pressure (IOP) in eyes with acute primary angle closure (APAC) and chronic primary angle-closure glaucoma (CPACG) with coexisting cataracts and peripheral anterior synechiae (PAS) of greater than 180 degrees. Prospective, cross-sectional study. Thirteen patients (13 eyes) with APAC and 10 patients (10 eyes) with CPACG were enrolled in the study. IOP control in the 2 groups was compared at final follow-up. Other outcome measures included visual acuity, anterior chamber depth, gonioscopic appearance, and complications. The postoperative IOP was reduced in both the APAC and CPACG groups. As assessed at last follow-up (median 6 mo), IOP in the APAC group was significantly lower than that in the CPACG group. The absolute success rate was 100% in the APAC group and 80% in the CPACG group. The number of hypotensive medications decreased in both APAC and CPACG group. The postoperative degree of PAS was relieved in 11 of 12 eyes with APAC and 5 of 9 eyes with CPACG. Initial phacoemulsification performed to provide short-term control of IOP is more efficacious in patients with APAC than in those with CPACG, especially when PAS is greater than 180 degrees.
Deep learning methods for protein torsion angle prediction.
Li, Haiou; Hou, Jie; Adhikari, Badri; Lyu, Qiang; Cheng, Jianlin
2017-09-18
Deep learning is one of the most powerful machine learning methods that has achieved the state-of-the-art performance in many domains. Since deep learning was introduced to the field of bioinformatics in 2012, it has achieved success in a number of areas such as protein residue-residue contact prediction, secondary structure prediction, and fold recognition. In this work, we developed deep learning methods to improve the prediction of torsion (dihedral) angles of proteins. We design four different deep learning architectures to predict protein torsion angles. The architectures including deep neural network (DNN) and deep restricted Boltzmann machine (DRBN), deep recurrent neural network (DRNN) and deep recurrent restricted Boltzmann machine (DReRBM) since the protein torsion angle prediction is a sequence related problem. In addition to existing protein features, two new features (predicted residue contact number and the error distribution of torsion angles extracted from sequence fragments) are used as input to each of the four deep learning architectures to predict phi and psi angles of protein backbone. The mean absolute error (MAE) of phi and psi angles predicted by DRNN, DReRBM, DRBM and DNN is about 20-21° and 29-30° on an independent dataset. The MAE of phi angle is comparable to the existing methods, but the MAE of psi angle is 29°, 2° lower than the existing methods. On the latest CASP12 targets, our methods also achieved the performance better than or comparable to a state-of-the art method. Our experiment demonstrates that deep learning is a valuable method for predicting protein torsion angles. The deep recurrent network architecture performs slightly better than deep feed-forward architecture, and the predicted residue contact number and the error distribution of torsion angles extracted from sequence fragments are useful features for improving prediction accuracy.
[Diagnostic value of Blumensaat angle for anterior cruciate ligament injury].
Cheng, Xiang-Yun; Feng, Jiang-Feng; Lu, Yan-Hui; Zhao, Yong-Liang; Yang, Zi-Quan
2017-08-25
The receiver operator characteristic(ROC) curve was used to determine the best Blumensaat angle for the diagnosis of anterior cruciate ligament injury, so as to objectively evaluate the diagnostic value of Blumensaat angle for anterior cruciate ligament injury. Total 167 patients who had knee arthroscopic treatment in a hospital from January 2015 to January 2016 were retrospectively studied, and the patients' age, gender, left and right limb condition were recorded. The patients were divided into two groups according to Blumensaat angle measured on the MRI: group A(Blumensaat angle0°). The ROC curve was drawn from the statistical data of the group B to get the best critical value of the anterior cruciate ligament injury when the Blumensaat angle was more than 0°. According to the best critical value obtained by ROC curve, the coincidence rate of the total sample was obtained. There were no significant differences in patients' age, gender, and affected limbs. There were 51 patients in group A, in which 49 patients were diagnosed as anterior cruciate injury under arthroscopy(gold standard for diagnosis of anterior cruciate ligament injury), and 2 patients were diagnosed as no anterior cruciate injury under arthroscopy. When the Blumensaat angle was=15°, the probability of anterior cruciate ligament injury was greater. When the Blumensaat angle was 0° to 15°, the anterior cruciate ligament was more likely to be not injured. The Blumensaat angle=15° were used to diagnose the injury of anterior cruciate ligament. Compared with the results of arthroscopy, the coincidence rate of the total sample was 92.8%. Blumensaat angle is helpful to diagnose the ACL injuries. When the Blumensaat angle was =15°, the probability of ACL injury is greater.
Preferred viewing distance and screen angle of electronic paper displays.
Shieh, Kong-King; Lee, Der-Song
2007-09-01
This study explored the viewing distance and screen angle for electronic paper (E-Paper) displays under various light sources, ambient illuminations, and character sizes. Data analysis showed that the mean viewing distance and screen angle were 495 mm and 123.7 degrees. The mean viewing distances for Kolin Chlorestic Liquid Crystal display was 500 mm, significantly longer than Sony electronic ink display, 491 mm. Screen angle for Kolin was 127.4 degrees, significantly greater than that of Sony, 120.0 degrees. Various light sources revealed no significant effect on viewing distances; nevertheless, they showed significant effect on screen angles. The screen angle for sunlight lamp (D65) was similar to that of fluorescent lamp (TL84), but greater than that of tungsten lamp (F). Ambient illumination and E-paper type had significant effects on viewing distance and screen angle. The higher the ambient illumination was, the longer the viewing distance and the lesser the screen angle. Character size had significant effect on viewing distances: the larger the character size, the longer the viewing distance. The results of this study indicated that the viewing distance for E-Paper was similar to that of visual display terminal (VDT) at around 500 mm, but greater than normal paper at about 360 mm. The mean screen angle was around 123.7 degrees, which in terms of viewing angle is 29.5 degrees below horizontal eye level. This result is similar to the general suggested viewing angle between 20 degrees and 50 degrees below the horizontal line of sight.
Tanaka, Satoshi; Ando, Kei; Kobayashi, Kazuyoshi; Hida, Tetsuro; Ito, Kenyu; Tsushima, Mikito; Morozumi, Masayoshi; Machino, Masaaki; Ota, Kyotaro; Seki, Taisuke; Ishiguro, Naoki; Hasegawa, Yukiharu; Imagama, Shiro
2018-04-05
Although the phase angle has been reported to be related to predictive factors and therapeutic effects in various diseases, its relation with osteoporosis is unclear. In our large prospective survey of community-dwelling people, a low phase angle was related with osteoporosis, and it could be a predictor of osteoporosis. The phase angle measured with bioelectrical impedance analysis (BIA) is one of the clinically important impedance parameters, and it is a predictor of prognosis and mortality for several diseases. The present cross-sectional study aimed to elucidate the association between osteoporosis and variables measured with BIA, including the phase angle. The study included 307 participants from an annual health checkup. All participants underwent measurement of bone status by quantitative ultrasound and body composition by BIA. Osteoporosis was diagnosed according to the WHO classification, and statistical comparisons were conducted between normal individuals and osteoporosis patients. Age, proteins, minerals, and the phase angle were significantly different between normal individuals and osteoporosis patients (p < 0.001). Furthermore, after controlling for age and sex, proteins, minerals, and the phase angle were significantly lower in osteoporosis patients than those in normal individuals (p < 0.001). In multivariate logistic regression analysis, older age and a low phase angle were risk factors for osteoporosis. Additionally, multiple regression analysis showed that age, sex, proteins, minerals, and the appendicular skeletal muscle index were significantly related to the phase angle. The phase angle is a predictor of osteoporosis, which is unaffected by age and sex, and a lower phase angle is associated with greater probability of osteoporosis. The phase angle can be easily measured, and osteoporosis can be confirmed even at home. This may facilitate early diagnosis and treatment, which may be useful for preventing diseases related to osteoporosis.
Brian K. Via; chi L. So; Leslie H. Groom; Todd F. Shupe; michael Stine; Jan. Wikaira
2007-01-01
A theoretical model was built predicting the relationship between microfibril angle and lignin content at the Angstrom (A) level. Both theoretical and statistical examination of experimental data supports a square root transformation of lignin to predict microfibril angle. The experimental material used came from 10 longleaf pine (Pinus palustris)...
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
Apparent and microscopic dynamic contact angles in confined flows
Omori, Takeshi; Kajishima, Takeo
2017-11-01
An abundance of empirical correlations between a dynamic contact angle and a capillary number representing a translational velocity of a contact line have been provided for the last decades. The experimentally obtained dynamic contact angles are inevitably apparent contact angles but often undistinguished from microscopic contact angles formed right on the wall. As Bonn et al. ["Wetting and spreading," Rev. Mod. Phys. 81, 739-805 (2009)] pointed out, however, most of the experimental studies simply report values of angles recorded at some length scale which is quantitatively unknown. It is therefore hard to evaluate or judge the physical validity and the generality of the empirical correlations. The present study is an attempt to clear this clutter regarding the dynamic contact angle by measuring both the apparent and the microscopic dynamic contact angles from the identical data sets in a well-controlled manner, by means of numerical simulation. The numerical method was constructed so that it reproduced the fine details of the flow with a moving contact line predicted by molecular dynamics simulations [T. Qian, X. Wang, and P. Sheng, "Molecular hydrodynamics of the moving contact line in two-phase immiscible flows," Commun. Comput. Phys. 1, 1-52 (2006)]. We show that the microscopic contact angle as a function of the capillary number has the same form as Blake's molecular-kinetic model [T. Blake and J. Haynes, "Kinetics of liquid/liquid displacement," J. Colloid Interface Sci. 30, 421-423 (1969)], regardless of the way the flow is driven, the channel width, the mechanical properties of the receding fluid, and the value of the equilibrium contact angle under the conditions where the Reynolds and capillary numbers are small. We have also found that the apparent contact angle obtained by the arc-fitting of the interface behaves surprisingly universally as claimed in experimental studies in the literature [e.g., X. Li et al., "An experimental study on dynamic pore
DEFF Research Database (Denmark)
Enemark, Stig
2009-01-01
. In surveying education there are a range of other challenges to be faced. These relate to the focus on learning to learn; the need for flexible curriculum to deal with constant change; the move towards introducing virtual academy; the demand for creating a quality culture; and the perspective of lifelong......In relation to surveying education there is one big question to be asked: Is the role of the surveyors changing? In a global perspective the answer will be "Yes". There is a big swing that could be entitled "From Measurement to Management". This does not imply that measurement is no longer...... learning perspective. This paper looks into the challenges in some details. It is stated that facing these challenges requires an innovative and adaptable approach to both curriculum design and course delivery within the framework of an overall quality culture. The success will eventually depend...
DEFF Research Database (Denmark)
Markussen, Randi; Gad, Christopher
and personhood imagined to be already there, and communication as the free-flow of information? Is it therefore considered non-problematic that people commit themselves to remembering their past and present experience of illness and share it in detail within an - to them - unknown context? Can it even...... be imagined as a positive end, as ‘making explicit’ (in a popular psychological perspective) is considered to be therapeutic and good in itself? We will discuss those questions from a Foucaultian and ANT perspective, where one does not accept that pre-existing subjects are exposed to survey procedures....... Subjectivity is rather regulated and constituted in this practice. The relevant question becomes in what particular ways subjectivity and humanness are performed here? We want to look into this question exploring the agency of surveys, their effects and the politics involved in such a scientific practice....
International Nuclear Information System (INIS)
Anon.
1984-01-01
The article reviews the last readership survey, which helped to check readers' reactions and the level and style of the journal. The majority of readers (32 per cent), not surprisingly, work in high energy physics. In fact, if the estimate of the world high energy physics population as some 5000 people is correct, CERN Courier reaches every one of them. The next large category of readers is the teaching profession (21 percent), with industrialists (12 per cent) in third place
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.
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.
Dynamic angle selection in X-ray computed tomography
Energy Technology Data Exchange (ETDEWEB)
Dabravolski, Andrei, E-mail: andrei.dabravolski@uantwerpen.be [iMinds-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Batenburg, Kees Joost, E-mail: joost.batenburg@uantwerpen.be [iMinds-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium); Centrum Wiskunde and Informatica (CWI), Science Park 123, 1098 XG Amsterdam (Netherlands); Sijbers, Jan, E-mail: jan.sijbers@uantwerpen.be [iMinds-Vision Lab, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk (Belgium)
2014-04-01
Highlights: • We propose the dynamic angle selection algorithm for CT scanning. • The approach is based on the concept of information gain over a set of solutions. • Projection angles are selected based on the already available projection data. • The approach can lead to more accurate results from fewer projections. - Abstract: In X-ray tomography, a number of radiographs (projections) are recorded from which a tomogram is then reconstructed. Conventionally, these projections are acquired equiangularly, resulting in an unbiased sampling of the Radon space. However, especially in case when only a limited number of projections can be acquired, the selection of the angles has a large impact on the quality of the reconstructed image. In this paper, a dynamic algorithm is proposed, in which new projection angles are selected by maximizing the information gain about the object, given the set of possible new angles. Experiments show that this approach can select projection angles for which the accuracy of the reconstructed image is significantly higher compared to the standard angle selections schemes.
A study of images of Projective Angles of pulmonary veins
Energy Technology Data Exchange (ETDEWEB)
Wang Jue [Beijing Anzhen Hospital, Beijing (China); Zhaoqi, Zhang [Beijing Anzhen Hospital, Beijing (China)], E-mail: zhaoqi5000@vip.sohu.com; Yu Wei; Miao Cuilian; Yan Zixu; Zhao Yike [Beijing Anzhen Hospital, Beijing (China)
2009-09-15
Aims: In images of magnetic resonance and computed tomography (CT) there are visible angles between pulmonary veins and the coronary, transversal or sagittal section of body. In this study these angles are measured and defined as Projective Angles of pulmonary veins. Several possible influential factors and characters of distribution are studied and analyzed for a better understanding of this imaging anatomic character of pulmonary veins. And it could be the anatomic base of adjusting correctly the angle of the central X-ray of the angiography of pulmonary veins undergoing the catheter ablation of atrial fibrillation (AF). Method: Images of contrast enhanced magnetic resonance angiography (CEMRA) and contrast enhanced computer tomography (CECT) of the left atrium and pulmonary veins of 137 health objects and patients with atrial fibrillation (AF) are processed with the technique of post-processing, and Projective Angles to the coronary and transversal sections are measured and analyzed statistically. Result: Project Angles of pulmonary veins are one of real and steady imaging anatomic characteristics of pulmonary veins. The statistical distribution of variables is relatively concentrated, with a fairly good representation of average value. It is possible to improve the angle of the central X-ray according to the average value in the selective angiography of pulmonary veins undergoing the catheter ablation of AF.
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.
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.
Modified dark room provocative test for primary angle closure.
Li, Dejiao; Wang, Ningli; Wang, Bingsong; Wang, Tao; Jonas, Jost B
2012-03-01
To examine the diagnostic value of a modified dark room provocative test (DRPT) in detecting primary closure of the anterior chamber angle. The cross-sectional observational prospective clinical study included suspects of primary angle closure. Using anterior segment optical coherence tomography (AS-OCT), we measured the anterior chamber angle configuration at room light and after 3 minutes of dark adaptation. Gonioscopy and Perkin's applanation tonometry were performed in room light conditions at baseline and after 1.5 hours of dark adaptation. The number of closed angle quadrants assessed on AS-OCT images and upon gonioscopy were recorded. The DRPT was positive, if intraocular pressure increased by ≥8 mm Hg after 1.5 hours of dark adaptation. The study included 76 subjects (76 eyes). Among 32 (42%) eyes with a positive DRPT, the number of eyes with an increased number of closed angle quadrants was significantly higher for the OCT examination at 3 minutes of dark adaptation than for gonioscopy at 1.5 hours of dark adaptation [29 (91%) eyes vs 21 (66%) eyes; P=0.01]. Kappa statistics showed a moderate agreement between increased closed angle quadrants obtained both after 3 minutes of dark adaptation (κ=0.44; Pdark room test (κ=0.45; Pdark room test. A modified DRPT with an anterior chamber angle assessment by OCT at 3 minutes of dark adaptation as compared with a gonioscopic angle assessment after 1.5 hours of dark adaptation had a higher diagnostic precision in predicting primary angle closure.
[Laser Iridotomy - In Cases of Acute Angle Closure Only?
Handzel, Daniel M; Meyer, Carsten H; Wegener, Alfred
2017-11-01
The narrowing of the chamber angle-as a result of anatomic predispositions like high hyperopia or increasing lens thickness-poses the greatest risk for acute angle closure. A laser iridotomy counts as a standard procedure in cases of acute angle closure, whereas there are no coherent recommendations or guidelines for a prophylactic therapy. Modern imaging techniques, such as anterior segment optical coherence tomography or Scheimpflug photography, can give valuable information for the planning of treatment. This review presents traditional and modern imaging techniques and summarises recommendations for action in relation to recent publications. Georg Thieme Verlag KG Stuttgart · New York.
Influence of Stockpile Angle in Natural Drying of Laterite Ore
Directory of Open Access Journals (Sweden)
Yoalbys Retirado-Mediaceja
2016-10-01
Full Text Available Natural drying is performed at Cuban nickel plants by depositing bulk ore in the open. The ore is currently being stockpiled without much consideration for the impact of the drying surface angle on the process power behavior. Simulations were carried out in this investigation, which prove that an increased triangular stockpile angle considerably reduces natural drying efficiency. A 45 sexagesimal degree angle to the horizontal plane results in exposure of a large volume of ore to natural drying and guarantees adequate energy performance.
Low-cost large-angle steering mirror development
Wassom, Steven R.
2009-08-01
The Space Dynamics Laboratory has combined internal funds with its background in space-rated mechanisms to develop a prototype low-cost large-angle 2-axis fine steering mirror (FSM). The FSM has a 75-mm clear aperture, 30-degree mechanical elevation angle, 120-degree mechanical azimuth angle, and a 70-Hertz small-amplitude bandwidth. Key components include a rotary voice coil, unique patent-pending feedback sensor, brushless DC motor and optical encoder. Average error is portable demonstration electronics development, and thermal-vacuum testing to pressures down to 1e-7 torr and temperatures down to 164 K.
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.
Indoor Measurement of Angle Resolved Light Absorption by Black Silicon
DEFF Research Database (Denmark)
Amdemeskel, Mekbib Wubishet; Iandolo, Beniamino; Davidsen, Rasmus Schmidt
2017-01-01
Angle resolved optical spectroscopy of photovoltaic (PV) samples gives crucial information on PV panels under realistic working conditions. Here, we introduce measurements of angle resolved light absorption by PV cells, performed indoors using a collimated high radiance broadband light source. Our...... indoor method offers a significant simplification as compared to measurements by solar trackers. As a proof-of-concept demonstration, we show characterization of black silicon solar cells. The experimental results showed stable and reliable optical responses that makes our setup suitable for indoor......, angle resolved characterization of solar cells....
The modified Cassie’s equation and contact angle hysteresis
Xu, Xianmin
2012-08-29
In this paper, we derive a modified Cassie\\'s equation for wetting on chemically patterned surfaces from a homogenization approach. The derivation reveals that effective contact angle is a local average of the static contact angle along the contact line which describes all possible equilibrium states including the local minimum of the free energy of the system. The usual Cassie\\'s state which corresponds to the global minimum is only a special case. We then discuss the contact angle hysteresis on chemically patterned surfaces. © 2012 Springer-Verlag.
Optimal fringe angle selection for digital fringe projection technique.
Wang, Yajun; Zhang, Song
2013-10-10
Existing digital fringe projection (DFP) systems mainly use either horizontal or vertical fringe patterns for three-dimensional shape measurement. This paper reveals that these two fringe directions are usually not optimal where the phase change is the largest to a given depth variation. We propose a novel and efficient method to determine the optimal fringe angle by projecting a set of horizontal and vertical fringe patterns onto a step-height object and by further analyzing two resultant phase maps. Experiments demonstrate the existence of the optimal angle and the success of the proposed optimal angle determination method.
Projection angles of mandibular condyles in panoramic and transcranial radiographs
International Nuclear Information System (INIS)
Nah, Kyung Soo
2006-01-01
To evaluate the true projection angles of film-side mandibular condyles in panoramic and transcranial radiographs. 52 panoramic and transcranial radiographs of 4 condyles from two human dry mandibles with gradual horizontal and vertical angle changes were taken. The results were compared with the standard panoramic and transcranial radiographs and the identical pairs were selected. Panoramic radiography projected 10 degree to the film-sided condyles both horizontally and vertically. Transcranial radiography projected 15 degree to the film-sided condyles vertically. The medical and lateral poles were not forming the outline of condylar images in both projections when the horizontal angles of condyles were not sufficiently big enough
Investigation of ferromagnetic domain structures by neutron small angle scattering
International Nuclear Information System (INIS)
Schild, L.
1984-01-01
The magnetic small angle scattering of thermal neutrons caused by magnetic refraction at domain walls of ferromagnetic materials without texture has been investigated. Experiments on Fe-Si alloys with a twin crystal diffractometer were carried out. It is shown that the mean extension of magnetic basic units (domains as well as parallel wall systems) can be determined. A comparison of grain sizes determined metallographically with domain sizes obtained by neutron small-angle scattering has shown that neither mean grain size nor domain size can be assessed by small-angle scattering experiments
Relationship between retinal lattice degeneration and open angle glaucoma.
Rahimi, Mansour
2005-01-01
Patients with retinal disorders may develop glaucoma of both a primary and secondary type. Pigment may contribute to trabecular obstruction in some patients with open-angle glaucoma. Lattice degeneration of the retina in its typical form is a sharply demarcated, circumferentially oriented, degenerative process with significant alterations of retinal pigmentation. The association between myopia, open angle glaucoma and pigment dispersion is striking. Therefore, it could be postulated that there is significant prevalence of open angle glaucoma in patients with retinal lattice degeneration, especially in combination with myopia.
Research advances on multifocal electroretinogram in primary open angle glaucoma
Directory of Open Access Journals (Sweden)
Feng-Fei Mo
2013-10-01
Full Text Available Primary open angle glaucoma is a chronic and progressive optic neuropathy. It can lead to serious damage of visual impairment, and it is an important eye disease of blindness. Multifocal electroretinogram is a new way to measure visual electrophysiology. It can measure electroretinogram of the whole visual field of many small parts in a relatively short period of time, and it can reflect the function of regional retina. It has an extremely important value for early diagnosis of primary open angle glaucoma. The research advances on multifocal electroretinogram in diagnosing primary open angle glaucoma were summarized in this paper.
Bair, Lucas S.; Rogowski, David L.; Neher, Christopher
2016-01-01
Glen Canyon Dam (GCD) on the Colorado River in northern Arizona provides water storage, flood control, and power system benefits to approximately 40 million people who rely on water and energy resources in the Colorado River basin. Downstream resources (e.g., angling, whitewater floating) in Glen Canyon National Recreation Area (GCNRA) and Grand Canyon National Park are impacted by the operation of GCD. The GCD Adaptive Management Program was established in 1997 to monitor and research the effects of dam operations on the downstream environment. We utilized secondary survey data and an individual observation travel cost model to estimate the net economic benefit of angling in GCNRA for each season and each type of angler. As expected, the demand for angling decreased with increasing travel cost; the annual value of angling at Lees Ferry totaled US$2.7 million at 2014 visitation levels. Demand for angling was also affected by season, with per-trip values of $210 in the summer, $237 in the spring, $261 in the fall, and $399 in the winter. This information provides insight into the ways in which anglers are potentially impacted by seasonal GCD operations and adaptive management experiments aimed at improving downstream resource conditions.
Bell, Peter M.
The United States Geological Survey (USGS) has contracted with the Institute of Oceanographic Sciences (IOS) to charter the research vessel Farnella. The project is to map the ocean floor at depths greater than 500 m along the recently established United States Exclusive Economic Zone (EEZ). The short range objectives include obtaining seafloor contours along the deep sea thermal spring zones in the Pacific Ocean basin. Should any of the zones prove economic for their sulfide mineral deposits, the charts should be of value to industry for years to come.
ILC Extraction Line for 14 mrad Crossing Angle
International Nuclear Information System (INIS)
Nosochkov, Y.; Markiewicz, T.; Maruyama, T.; Seryi, A.; Parker, B.
2005-01-01
The earlier studies of the ILC extraction line for 20 mrad and 2 mrad crossing angle options [1]-[5] showed that the 20 mrad design has an advantage of a simpler beamline and lower extraction beam loss because of the independent incoming and extraction optics. However, the large 20 mrad crossing angle requires the use of a crab cavity correction, increases synchrotron radiation emittance growth in the solenoid, and increases photon backscattering from the forward calorimeter of the detector. To reduce these effects, an attempt has been made to minimize the crossing angle while keeping the extraction and incoming lines separate. A new quadrupole scheme near the interaction point has been proposed which allows a reduction of the crossing angle to 14 mrad [6]. The optics design and results of tracking and background simulations for the 14 mrad extraction line are presented
Multi Angle Imaging With Spectral Remote Sensing for Scene Classification
National Research Council Canada - National Science Library
Prasert, Sunyaruk
2005-01-01
.... QuickBird panchromatic (0.61 meter) and multispectral (2.44 meter) imagery collected in July 2003 are examined to determine the impact of adding multi-angles and filtered texture information to the standard MSI classification approaches...
Shear wave splitting in the Isparta Angle, southwestern Turkey ...
Indian Academy of Sciences (India)
broadband station in the Isparta Angle,southwestern Turkey.We selected 21 good quality seismic events out of nearly 357 earthquakes and calculated splitting parameters (polarization direction of fast wave, and delay time between fast and ...
Small-angle neutron scattering studies of sodium butyl benzene
Indian Academy of Sciences (India)
Na-NBBS), in aqueous solutions is investigated by small-angle neutron scattering (SANS). Nearly ellipsoidal aggregates of Na-NBBS at concentrations well above its minimum hydrotrope concentration were detected by SANS. The hydrotrope ...
Setting of angles on machine tools speeded by magnetic protractor
Vale, L. B.
1964-01-01
An adjustable protractor facilitates transference of angles to remote machine tools. It has a magnetic base incorporating a beam which can be adjusted until its shadow coincides with an image on the screen of a projector.
Angle Stability Analysis for Voltage-Controlled Converters
DEFF Research Database (Denmark)
Lin, Hengwei; Jia, Chenxi; Guerrero, Josep M.
2017-01-01
a criterion to analyze the quasi-steady angle stability and the direct current (DC) side stability for VSCs. The operating limit and the angle instability mechanism are revealed, which is generally applicable to the voltage-controlled converters. During the analysis, the influence of the parameters on angle...... stability is studied. Further, the difference on instability mechanism between power electronic converters and synchronous generators are explained in detail. Finally, experiment results with corrective actions verify the analysis.......Power electronics based voltage source converters (VSCs) keep increasing in modern electrical systems. As a branch of stability problems, angle stability is significant for an electrical system. Based on small disturbance analysis and time scale decomposition perspective, this paper proposes...
Small-angle neutron scattering studies of sodium butyl benzene ...
Indian Academy of Sciences (India)
Na-NBBS), in aqueous solutions is investigated by small-angle neutron scattering (SANS). Nearly ellipsoidal aggregates of Na-NBBS at concentrations well above its minimum hydrotrope concentration were detected by SANS. The hydrotrope ...
Multi-angle Imaging SpectroRadiometer (MISR)
National Aeronautics and Space Administration — The Multi-angle Imaging SpectroRadiometer (MISR) was successfully launched into sun-synchronous polar orbit aboard Terra, NASA's first Earth Observing System (EOS)...
Ultra small angle neutron scattering from superconducting filament structures
International Nuclear Information System (INIS)
Amenitsch, H.
1999-01-01
With a perfect crystal camera, ultra small-angle scattering measurements were performed to investigate the internal diffusion process of tin inside a superconducting multi-filament wire caused by a temperature treatment. Commercially available Nb 3 Sn superconducting multi-filament wires were treated at 700 C with varying ageing times up to 144 h. A theoretical model taking into account the geometrical form, the size distribution, the interference term and the multiple scattering has been developed to understand and to describe the small angle diffraction pattern. Additionally, the diffusion of H and D into the filament wires was used to vary the scattering length density inside the wires. The results show a direct relationship between the different technological treatments and the characteristic small-angle scattering parameters, like Guinier radius and small-angle scattering probability. (orig.) [de
Quantized contact angles in the dewetting of a structured liquid.
Ilton, Mark; Stasiak, Pawel; Matsen, Mark W; Dalnoki-Veress, Kari
2014-02-14
We investigate the dewetting of a disordered melt of diblock copolymer from an ordered residual wetting layer. In contrast to simple liquids where the wetting layer has a fixed thickness and the droplets exhibit a single unique contact angle with the substrate, we find that structured liquids of diblock copolymer exhibit a discrete series of wetting layer thicknesses each producing a different contact angle. These quantized contact angles arise because the substrate and air surfaces each induce a gradient of lamellar order in the wetting layer. The interaction between the two surface profiles creates an effective interface potential that oscillates with film thickness, thus, producing a sequence of local minimums. The wetting layer thicknesses and corresponding contact angles are a direct measure of the positions and depths of these minimums. Self-consistent field theory is shown to provide qualitative agreement with the experiment.
ILC extraction line for 14 mrad crossing angle
International Nuclear Information System (INIS)
Nosochkov, Y.; Markiewicz, T.; Maruyama, T.; Seryi, A.; Parker, B.
2006-01-01
The earlier studies of the ILC extraction line for 20 mrad and 2 mrad crossing angle options showed that the 20 mrad design has an advantage of a simpler beamline and lower extraction beam loss because of the independent incoming and extraction optics. However, the large 20 mrad crossing angle requires the use of a crab cavity correction, increases synchrotron radiation emittance growth in the solenoid, and increases photon backscattering from the forward calorimeter of the detector. To reduce these effects, an attempt has been made to minimize the crossing angle while keeping the extraction and incoming lines separate. A new quadrupole scheme near the interaction point has been proposed which allows a reduction of the crossing angle to 14 mrad. The optics design and results of tracking and background simulations for the 14 mrad extraction line are presented. (author)
Parameterization of ion channeling half-angles and minimum yields
Doyle, Barney L.
2016-03-01
A MS Excel program has been written that calculates ion channeling half-angles and minimum yields in cubic bcc, fcc and diamond lattice crystals. All of the tables and graphs in the three Ion Beam Analysis Handbooks that previously had to be manually looked up and read from were programed into Excel in handy lookup tables, or parameterized, for the case of the graphs, using rather simple exponential functions with different power functions of the arguments. The program then offers an extremely convenient way to calculate axial and planar half-angles, minimum yields, effects on half-angles and minimum yields of amorphous overlayers. The program can calculate these half-angles and minimum yields for axes and [h k l] planes up to (5 5 5). The program is open source and available at
Fujiwara, Shin-Ichi
2009-09-01
Reconstruction of limb posture is a challenging task in assessing functional morphology and biomechanics of extinct tetrapods, mainly because of the wide range of motions possible at each limb joint and because of our poor knowledge of the relationship between posture and musculoskeletal structure, even in the extant taxa. This is especially true for extinct mammals such as the desmostylian taxa Desmostylus and Paleoparadoxia. This study presents a procedure that how the elbow joint angles of extinct quadruped mammals can be inferred from osteological characteristics. A survey of 67 dried skeletons and 113 step cycles of 32 extant genera, representing 25 families and 13 orders, showed that the olecranon of the ulna and the shaft of the humerus were oriented approximately perpendicular to each other during the stance phase. At this angle, the major extensor muscles maximize their torque at the elbow joint. Based on this survey, I suggest that olecranon orientation can be used for inferring the elbow joint angles of quadruped mammals with prominent olecranons, regardless of taxon, body size, and locomotor guild. By estimating the elbow joint angle, it is inferred that Desmostylus would have had more upright forelimbs than Paleoparadoxia, because their elbow joint angles during the stance phase were approximately 165 degrees and 130 degrees , respectively. Difference in elbow joint angles between these two genera suggests possible differences in stance and gait of these two mammals. Copyright 2009 Wiley-Liss, Inc.
Comparison of different passive knee extension torque-angle assessments
International Nuclear Information System (INIS)
Freitas, Sandro R; Vaz, João R; Bruno, Paula M; Valamatos, Maria J; Mil-Homens, Pedro
2013-01-01
Previous studies have used isokinetic dynamometry to assess joint torques and angles during passive extension of the knee, often without reporting upon methodological errors and reliability outcomes. In addition, the reliability of the techniques used to measure passive knee extension torque-angle and the extent to which reliability may be affected by the position of the subjects is also unclear. Therefore, we conducted an analysis of the intra- and inter-session reliability of two methods of assessing passive knee extension: (A) a 2D kinematic analysis coupled to a custom-made device that enabled the direct measurement of resistance to stretch and (B) an isokinetic dynamometer used in two testing positions (with the non-tested thigh either flexed at 45° or in the neutral position). The intra-class correlation coefficients (ICCs) of torque, the slope of the torque-angle curve, and the parameters of the mathematical model that were fit to the torque-angle data for the above conditions were measured in sixteen healthy male subjects (age: 21.4 ± 2.1 yr; BMI: 22.6 ± 3.3 kg m −2 ; tibial length: 37.4 ± 3.4 cm). The results found were: (1) methods A and B led to distinctly different torque-angle responses; (2) passive torque-angle relationship and stretch tolerance were influenced by the position of the non-tested thigh; and (3) ICCs obtained for torque were higher than for the slope and for the mathematical parameters that were fit to the torque-angle curve. In conclusion, the measurement method that is used and the positioning of subjects can influence the passive knee extension torque-angle outcome. (paper)
A study of arrival angles of natural VLF waves
Apsen, A. G.; Fedorenko, Iu. V.; Chernysheva, S. P.; Kleimenova, N. G.; Putilin, A. N.
Methods are proposed for determining the arrival angles of natural VLF waves at a ground-based observatory. A device in which the proposed method is implemented is described, and questions regarding its calibration and suppression of lightning-induced and industrial noise are addressed. Measurements of natural VLF-wave arrival angles, carried out in the auroral zone in the Murmansk region are presented.
Anthropometric study of angle of femoral torsion in Maharashtrian population
Directory of Open Access Journals (Sweden)
Anil Kumar Dwivedi
2016-01-01
Full Text Available Introduction: Angle of femoral torsion is a normal torsion or twist present in femur that plays an important role in stability and function of the hip joint. The angle of femoral torsion can be defined as the angle formed by femoral condyle′s plane (bicondylar plane and a plane passing through center of neck and femoral head. Abnormal angle of femoral torsion has been implicated in the etiology of hip osteoarthrosis and developmental dysplasia of hip joint. Materials and Methods: This study was carried out on unpaired 280, adult human femora devoid of any gross pathology, 139 male (65 right and 74 left, and 141 female (71 right and 70 left from bone banks of three medical colleges of Maharashtra. The gender of each specimen was determined by the established practice. Femora were evaluated by Kingsley Olmsted method, and data were tabulated and statistically analyzed. Results: The average angle of femoral torsion 13.39° and 11.23° on the right and left side respectively in male, 16.21° and 13.23° on the right and left side, respectively, in female. Statistical analysis using Student′s "t"-test revealed significant difference (P < 0.05, greater angle of femoral torsion in female and on the right side. Conclusion: Knowledge of angle of femoral torsion is becoming significant nowadays with an increase in demand for total hip replacement, as the angle of femoral torsion is crucial to attain a normal activity of the replaced joint.
Virtual characterization of delamination failures in pultruded GFRP angles
Girão Coelho, Ana M.; Mottram, J. Toby; Matharu, Navroop S.
2016-01-01
This paper deals with the application of cohesive zone models to study delamination failures in leg-angles of pultruded glass fibre reinforced polymer material using the general-purpose finite element software Abaqus. The objective of the study is present a finite element modelling methodology that can, for example, help to fill-in knowledge gaps in the available experimental data pertaining to the tying force resistance of angle-cleated jointing in frame construction. It may be used to optim...
Light Airplane Crash Test at Three Pitch Angles
Vaughan, Victor L., Jr.; Alfaro-Bou, Emilio
1979-01-01
Three similar twin-engine general-aviation airplane specimens were crash tested at the Langley Impact Dynamics Research Facility at 27 m/sec, a flight-path angle of -15deg, and pithch angles of -15deg, 0deg, and 15deg. Other crash parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed.
Light airplane crash tests at three pitch angles
Vaughan, V. L., Jr.; Alfaro-Bou, E.
1979-01-01
Three similar twin-engine general aviation airplane specimens were crash tested at an impact dynamics research facility at 27 m/sec, a flight path angle of -15 deg, and pitch angles of -15 deg, 0 deg, and 15 deg. Other crash parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed.
Exchange interpretation of anomalous back angle heavy ion elastic scattering
International Nuclear Information System (INIS)
Zisman, M.S.
1977-10-01
Anomalous back angle oscillations in the angular distributions obtained in the elastic scattering of 16 O + 28 Si and 12 C + 28 Si have been interpreted in terms of an elastic cluster transfer comparable to that observed in other heavy ion reactions. The calculations appear to at least qualitatively explain the data with respect to the existence and phase of the back angle oscillations. The results indicate that an exchange mechanism may play an important role in the oscillations
BIPHASIC TREATMENT OF 2ND CLASS ANGLE ANOMALIES
C. Romanec; R. Stanciu; Anca Telmecea; Valentina Dorobat
2011-01-01
Our approach aims at presenting, based on clinical observations and complementary examinations, the effects of a treatment’s setting up during the mixed dentition period. The objectives include the identification of the optimal time of treatment of II/1, II/2 Angle malocclusions, as well as the therapeutic possibilities for the treatment of 2nd class Angle malocclusion during the period of mixed and permanent dentition. The study is based on data collected from 114 cli...
Acquisition of Infrared Variable Angle Spectroscopic Ellipsometer (IR-VASE)
2016-04-22
SECURITY CLASSIFICATION OF: This award was used to acquire a J.A. Woollam Infrared Variable Angle Spectroscopic Ellipsometer ( IR -VASE). The IR -VASE...unit is capable of obtaining crucial IR information of ultrathin films whilst being complemented with ellipsometry data. This powerful and versatile...Unlimited UU UU UU UU 22-04-2016 1-Feb-2015 31-Jan-2016 Final Report: Acquisition of Infrared Variable Angle Spectroscopic Ellipsometer ( IR -VASE) The
Photovoltaic Modules: Effect of Tilt Angle on Soiling
Cano, Jose
2011-12-01
Photovoltaic (PV) systems are one of the next generation's renewable energy sources for our world energy demand. PV modules are highly reliable. However, in polluted environments, over time, they will collect grime and dust. There are also limited field data studies about soiling losses on PV modules. The study showed how important it is to investigate the effect of tilt angle on soiling. The study includes two sets of mini-modules. Each set has 9 PV modules tilted at 0, 5, 10, 15, 20, 23, 30, 33 and 40°. The first set called "Cleaned" was cleaned every other day. The second set called "Soiled" was never cleaned after the first day. The short circuit current, a measure of irradiance, and module temperature was monitored and recorded every two minutes over three months (January-March 2011). The data were analyzed to investigate the effect of tilt angle on daily and monthly soiling, and hence transmitted solar insolation and energy production by PV modules. The study shows that during the period of January through March 2011 there was an average loss due to soiling of approximately 2.02% for 0° tilt angle. Modules at tilt angles 23° and 33° also have some insolation losses but do not come close to the module at 0° tilt angle. Tilt angle 23° has approximately 1.05% monthly insolation loss, and 33° tilt angle has an insolation loss of approximately 0.96%. The soiling effect is present at any tilt angle, but the magnitude is evident: the flatter the solar module is placed the more energy it will lose.
Measurement of the angle of superficial tension by images
Yanez M., Javier; Alonso R., Sergio
2006-02-01
When a liquid is deposited on a surface, this one form a certain angle with respect to the surface, where depending on its value, it will conclude that so hard it is his adhesion with the surface. By means of the analysis of images we looked for to measure this angle of superficial tension. In order to make this measurement, we propose a technique by means of projective transformations and one method of regression to estimation parameters to conic fitting.
Determination of angle of inclination for optimum power production ...
African Journals Online (AJOL)
This study evaluates the performance of the photovoltaic modules at different tilt angle (angle of inclination) from 5º to 90º. The solar panel of 45 Watts capacity was placed on the manual tracker between the hours of 7:00am and 6:15pm on the geographical location of latitude of 40 55' 58” North and longitude of 60 59' 55” ...
NORMAL AXIAL ANGLES OF THE KNEE JOINT IN ADULT ...
African Journals Online (AJOL)
hi-tech
2003-08-01
Aug 1, 2003 ... centres of the hip, knee and ankle all lie on a straight line, forming the mechanical axis of the lower limb (Figure 1). This axis coincides with the anatomical axis of the tibia in the leg, while in the thigh it forms an angle of 6° with the anatomical axis of the femoral shaft in Caucasians (1). The mechanical angle ...
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...
Contact angle control of sessile drops on a tensioned web
Park, Janghoon; Kim, Dongguk; Lee, Changwoo
2018-04-01
In this study, the influence of the change of tension applied to flexible and thin web substrate on the contact angle of sessile drop in roll-to-roll system was investigated. Graphene oxide and deionized water solutions were used in the experiments. Tension was changed to 29, 49, and 69 N, and the casting distance of the micropipette and the material was set to 10, 20, and 40 mm, and the droplet volume was set to 10, 20, and 30 μL, respectively. Statistical analysis of three variables and analysis of the variance methodology showed that the casting distance was most significant for the contact angle change, and the most interesting tension variable was also affected. The change in tension caused the maximum contact angle to change by 5.5°. The tension was not uniform in the width direction. When the droplet was applied in the same direction in the width direction, it was confirmed that the tension unevenness had great influence on the contact angle up to 11°. Finally, the casting distance, which has a large effect on the contact angle, was calibrated in the width direction to reduce the width direction contact angle deviation to 1%. This study can be applied to fine patterning research using continuous inkjet printing and aerosol jet printing, which are roll-to-roll processes based on droplet handling.
A Universal Formula for Extracting the Euler Angles
Shuster, Malcolm D.; Markley, F. Landis
2004-01-01
Recently, the authors completed a study of the Davenport angles, which are a generalization of the Euler angles for which the initial and final Euler axes need not be either mutually parallel or mutually perpendicular or even along the coordinate axes. During the conduct of that study, those authors discovered a relationship which can be used to compute straightforwardly the Euler angles characterizing a proper-orthogonal direction-cosine matrix for an arbitrary Euler-axis set satisfying n(sub 1) x n(sub 2) = 0 and n(sub 3) x n(sub 1) = 0, which is also satisfied by the more usual Euler angles we encounter commonly in the practice of Astronautics. Rather than leave that relationship hidden in an article with very different focus from the present Engineering note, we present it and the universal algorithm derived from it for extracting the Euler angles from the direction-cosine matrix here. We also offer literal "code" for performing the operations, numerical examples, and general considerations about the extraction of Euler angles which are not universally known, particularly, the treatment of statistical error.
Hydrologic controls on junction angle of river networks
Hooshyar, Milad; Singh, Arvind; Wang, Dingbao
2017-05-01
The formation and growth of river channels and their network evolution are governed by the erosional and depositional processes operating on the landscape due to the movement of water. The branching angles, i.e., the angle between two adjoining channels, in drainage networks are important features related to the network topology and contain valuable information about the forming mechanisms of the landscape. Based on the channel networks extracted from 1 m Digital Elevation Models of 120 catchments with minimal human impacts across the United States, we show that the junction angles have two distinct modes with α1¯≈49.5° and α2¯≈75.0°. The observed angles are physically explained as the optimal angles that result in minimum energy dissipation and are linked to the exponent characterizing the slope-area curve. Our findings suggest that the flow regimes, debris-flow dominated or fluvial, have distinct characteristic angles which are functions of the scaling exponent of the slope-area curve. These findings enable us to understand the geomorphic signature of hydrologic processes on drainage networks and develop more refined landscape evolution models.
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.
Hybrid algorithm for rotor angle security assessment in power systems
Directory of Open Access Journals (Sweden)
D. Prasad Wadduwage
2015-08-01
Full Text Available Transient rotor angle stability assessment and oscillatory rotor angle stability assessment subsequent to a contingency are integral components of dynamic security assessment (DSA in power systems. This study proposes a hybrid algorithm to determine whether the post-fault power system is secure due to both transient rotor angle stability and oscillatory rotor angle stability subsequent to a set of known contingencies. The hybrid algorithm first uses a new security measure developed based on the concept of Lyapunov exponents (LEs to determine the transient security of the post-fault power system. Later, the transient secure power swing curves are analysed using an improved Prony algorithm which extracts the dominant oscillatory modes and estimates their damping ratios. The damping ratio is a security measure about the oscillatory security of the post-fault power system subsequent to the contingency. The suitability of the proposed hybrid algorithm for DSA in power systems is illustrated using different contingencies of a 16-generator 68-bus test system and a 50-generator 470-bus test system. The accuracy of the stability conclusions and the acceptable computational burden indicate that the proposed hybrid algorithm is suitable for real-time security assessment with respect to both transient rotor angle stability and oscillatory rotor angle stability under multiple contingencies of the power system.
Evaluation of the anterior chamber angle in pseudoexfoliation syndrome.
Iwanejko, Małgorzata; Turno-Kręcicka, Anna; Tomczyk-Socha, Martyna; Kaczorowski, Kamil; Grzybowski, Andrzej; Misiuk-Hojło, Marta
2017-08-01
Pseudoexfoliation syndrome (PEX) is the most frequently identifiable cause of secondary open-angle glaucoma, known as pseudoexfoliation glaucoma. The exact pathophysiology and etiology of PEX and associated glaucoma remains obscure. The purpose of this study was to determine the differences in the morphology of the anterior chamber angle in people with pseudoexfoliation syndrome and pseudoexfoliation glaucoma compared to a control group. We also evaluated the correlation between intraocular pressure (IOP) and pigmentation of the angle with the amount of exfoliated material in the anterior segment. The study group was composed of 155 eyes from 103 patients aged between 43 and 86 years. Each patient underwent a complete ophthalmological examination. Some difference was found in intraocular pressure between the PEX group and the control group and between the pseudoexfoliation glaucoma group and the control group, but no significant difference was found between the 2 study groups. There was a significant difference in the incidence of some degree of pigmentation in the anterior chamber angle and no difference in the widths of the angle between each group. A significant positive relationship was observed between intraocular pressure and the degree of pigmentation of the anterior chamber angle in both the PEX group and the pseudoexfoliation glaucoma group. The results of this study indicate that the amount of pigmentation and exfoliation material in the anterior segment significantly correlates with the level of IOP and possibly with the degree of trabecular dysfunction. It seems that for clear identification of PEX and pseudoexfoliation glaucoma factors, clinical assessment appears to be insufficient.
International Nuclear Information System (INIS)
Anon.
1993-01-01
Many, thanks to the hundreds of people who took the time to reply to the CERN Courier readership survey questionnaire published in our May issue. Bringing out a monthly journal is a lonely business. Issue after issue goes out, and the only response is when there's an occasional factual error. Send out a readership survey and a faint echo comes back. Most striking was the sheer enthusiasm of the replies. Despite the current erosion of support in the US (see page 2), subatomic physics has significant world-wide box-office appeal. Most important was to find out who our readers are. 61% of the replies came from Europe, 21% from the USA, 14% from elsewhere, (including the former Soviet Union), and 4% from inside CERN. Not surprisingly, the main audience (37%) is in the high energy physics sector. Then comes teaching (31%), followed closely by accelerators operations and design (12%) and industry (11%). Apart from detailed breakdowns of readership and feedback on the journal's content and style, the replies revealed several major features. Firstly, the CERN Courier is widely read and appreciated. There are a lot of people outside the immediate research field who want to keep broadly up to date with the latest developments in high energy physics and related fields, without getting too involved in details. It was gratifying to receive replies from far-flung places (Nepal, Indonesia,....), and learn how much distant readers appreciate getting such regular information. 'It helps us feel part of the world scene,' was a typical such reply, from Australia. Despite jet airplanes, fax and electronic mail, our planet is still big
Surveying problem solution with theory and objective type questions
Chandra, AM
2005-01-01
The book provides a lucid and step-by-step treatment of the various principles and methods for solving problems in land surveying. Each chapter starts with basic concepts and definitions, then solution of typical field problems and ends with objective type questions. The book explains errors in survey measurements and their propagation. Survey measurements are detailed next. These include horizontal and vertical distance, slope, elevation, angle, and direction. Measurement using stadia tacheometry and EDM are then highlighted, followed by various types of levelling problems. Traversing is then explained, followed by a detailed discussion on adjustment of survey observations and then triangulation and trilateration.
Gonial angle growth patterns according to age and gender.
Larrazabal-Moron, Carolina; Sanchis-Gimeno, Juan A
2018-01-01
Currently there are controversial results about gender and age differences in human gonial angle values. In this context we aimed to ascertain the gender and age differences in the gonial angle values of young Caucasian Mediterranean subjects. We tested the hypothesis of a relation between the gonial angle values and the gender and age of the subjects by means of a prospective study involving 266 subjects. Panoramic radiographs (Cranex Novus ® , XMIND Novus ® Soredex, France) were carried out in order to measure the gonial angle values. We found significant differences between females and males in the subgroups aged ≤10years old (128.6±3.4 vs 126.8±4.5, p=0.017), 16-20 years old (119.1±5.6 vs 122.3±7.7, p=0.011), 21-25 years old (117.6±5.2 vs 120.8±7.0, p=0.016) and 26-30 years old (117.5±5.4 vs 120.6±5.4, p=0.019) but not in the subgroup aged 11-15 years old (123.4±5.2 vs 123.5±5.4, p=0.927). A significant negative correlation was found between age and gonial angle values (r=-0.365, page have significantly higher values than males. The angle values decreased until the age of 11-15 years of age when there were no significant gender differences. Thus, the males aged over 16 years old presented significantly higher values than the females. The decrease in gonial angle values seems to slow or stop from 21 years onwards. Knowledge of the pattern differences will serve for age and gender determination when analyzing human remains. Copyright © 2017 Elsevier GmbH. All rights reserved.
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.
Association of iris crypts with acute primary angle closure.
Koh, Victor; Chua, Jacqueline; Shi, Yuan; Thakku, Sri Gowtham; Lee, Ryan; Nongpiur, Monisha E; Baskaran, Mani; Kumar, Rajesh S; Perera, Shamira; Aung, Tin; Cheng, Ching-Yu
2017-10-01
To determine the relationship between iris surface features and acute primary angle closure (APAC) in eyes with angle closure. Case-control study involving Asian patients diagnosed with previous APAC, primary angle closure suspect (PACS), primary angle closure (PAC) and primary angle closure glaucoma (PACG) at an eye centre in Singapore between August 2012 and January 2015. Participants underwent ophthalmic examination and digital slit-lamp iris photography. Iris surface features were graded based on crypts, furrows and colour. Fellow eyes of APAC were compared with PACS and PAC/PACG eyes with regard to their iris surface features. Occurrence of APAC. A total of 309 patients (71 APAC, 139 PACS, 47 PAC and 52 PACG) were included (mean age: 67.7±7.2 years and 36.6% male). Compared with PACS, higher crypt grade was significantly associated with lower odds of APAC (OR=0.58 for one grade higher in crypt grade; p=0.027, adjusted for age, gender, ethnicity and pupil diameter). The results remained similar when compared with PAC/PACG group (OR=0.58 for one grade higher in crypt grade; p=0.043). We did not observe any significant associations between iris furrows or colour with presence of APAC. Our study comprising Asian eyes with angle closure suggests that the presence of a higher crypt grading may be protective for APAC. As such, assessing iris surface architecture for crypts could be a new measure for risk stratification of developing APAC in eyes with angle closure. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Group of Eight (NJ1), 2012
2012-01-01
In 2011, the Group of Eight (Go8) conducted a survey on the state of its buildings and infrastructure. The survey is the third Go8 Infrastructure survey, with previous surveys being conducted in 2007 and 2009. The current survey updated some of the information collected in the previous surveys. It also collated data related to aspects of the…
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
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
Frequency of unerupted mandibular third molar in mandibular angle fractures
International Nuclear Information System (INIS)
Abbasi, M.M.; Abbas, I.; Abbas, I.; Khan, N.; Hameed, H.; Zulfiqar, K.
2012-01-01
Background: Fractures of the mandibular angle are common and comprise 31% of all mandibular fractures. Multiple recent studies report a 2-3 fold increased risk for mandibular angle fractures when un-erupted mandibular third molars are present. The objective of this study was to assess the frequency of un-erupted mandibular third molar in mandibular angle fractures. Methods: This cross sectional study was conducted at the Department of Oral and Maxillofacial Surgery, Ayub Medical College, Abbottabad from April to October 2009. One hundred and two patients were included both from the outdoor and ward on consecutive non-probability sampling base. Data were recorded on a structured Performa and analysed using SPSS-16. Results: A hemi-mandible containing un-erupted mandibular third molar was seen to have a 1.41 times the risk of mandibular angle fracture then a hemi-mandible containing an erupted mandibular third molar. Conclusion: The presence of unerupted mandibular third molar is associated with an increased risk for mandibular angle fracture. (author)
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.
Normal Foot and Ankle Radiographic Angles, Measurements, and Reference Points.
Lamm, Bradley M; Stasko, Paul A; Gesheff, Martin G; Bhave, Anil
2016-01-01
The limb deformity-based principles originate from a standard set of lower extremity radiographic angles and reference points. Objective radiographic measures are the building blocks for surgical planning. Critical preoperative planning and intraoperative and postoperative evaluation of radiographs are essential for proper deformity planning and correction of all foot and ankle cases. A total of 33 angles and reference points were measured on 24 healthy feet. The radiographic measurements were performed on standard weightbearing anteroposterior, lateral, and axial views of the right foot. A total of 4 measurements were made from the axial view, 12 from the lateral view, and 17 from the anteroposterior view. All angles were measured by both senior authors twice, independent of each other. The radiographic angles and measurements presented in the present study demonstrate a comprehensive and useful set of standard angles, measures, and reference points that can be used in clinical and perioperative evaluation of the foot and ankle. The standard radiographic measures presented in the present study provide the foundation for understanding the osseous foot and ankle position in a normal population. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.
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.
Citalopram associated with acute angle-closure glaucoma: case report
Directory of Open Access Journals (Sweden)
Hassan Sabit
2005-10-01
Full Text Available Abstract Background Acute angle-closure glaucoma is a rare complication in patients receiving anti-depressant treatment. In the following case, we report the development of acute angle closure glaucoma in a patient who overdosed on Citalopram, an antidepressant, and discuss the possible etiological mechanisms for the condition. Case presentation We report a 54 year old, Caucasian lady, with depression and alcohol dependence syndrome, who developed acute angle-closure glaucoma after an overdose of Citalopram, along with alcohol. She was treated with medications and had bilateral Yag laser iridotomies to correct the glaucoma and has made complete recovery. In this case, the underlying cause for glaucoma appears to be related to the ingestion of Citalopram. Conclusion The patho-physiological basis for acute angle closure glaucoma in relation to antidepressant medications remains unclear. The authors suggest Citalopram may have a direct action on the Iris or Ciliary body muscle through serotonergic or anti-cholinergic mechanisms or both. This case highlights the importance of the awareness of the underlying risks, which may predispose an individual to develop acute angle-closure glaucoma, and reminds the clinicians the significance of history taking and examination of the eye before and after starting anti-depressants. This area needs to be further researched.
Estimation of Upper Limb Joint Angle Using Surface EMG Signal
Directory of Open Access Journals (Sweden)
Yee Mon Aung
2013-10-01
Full Text Available In the development of robot-assisted rehabilitation systems for upper limb rehabilitation therapy, human electromyogram (EMG is widely used due to its ability to detect the user intended motion. EMG is one kind of biological signal that can be recorded to evaluate the performance of skeletal muscles by means of a sensor electrode. Based on recorded EMG signals, user intended motion could be extracted via estimation of joint torque, force or angle. Therefore, this estimation becomes one of the most important factors to achieve accurate user intended motion. In this paper, an upper limb joint angle estimation methodology is proposed. A back propagation neural network (BPNN is developed to estimate the shoulder and elbow joint angles from the recorded EMG signals. A Virtual Human Model (VHM is also developed and integrated with BPNN to perform the simulation of the estimated angle. The relationships between sEMG signals and upper limb movements are observed in this paper. The effectiveness of our developments is evaluated with four healthy subjects and a VHM simulation. The results show that the methodology can be used in the estimation of joint angles based on EMG.
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.
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.)
Development of spin echo small angle neutron scattering
International Nuclear Information System (INIS)
Bouwman, W.G.; Uca, O.; Van Oossanen, M.; Kraan, W.H.; Rekveldt, M.T.
1999-01-01
A novel kind of small angle neutron scattering (SANS) instrument is being built, based on the Larmor precession of polarised neutrons in a magnetic field. A spin echo of the polarised neutrons is used to detect the scattering. The basis of this instrument is a symmetric set-up with a spin flipper in the centre, which creates a spin echo, even with a divergent beam. The precession regions on either side of the spin flipper are shaped such to produce a very sensitive relation between the vertical angle of the neutron path and the total precession angle on one side. Any SANS of a sample placed in the instrument changes the symmetry of the neutron path and therefore decreases the echo. This amounts to measuring only the difference of the incoming and outgoing angle. This gives a huge increase in intensity of the signal with respect to conventional SANS in which both incoming and outgoing angle are defined. Magnetised foils, which rotate the neutron spin between being parallel to the magnetic field and perpendicular to the field are used to start or terminate the precession. With a preliminary set-up the first spin echo SANS signal have been measured. A full correlation function in samples over distances from 5 to 1000 nm is expected to be measured in some minutes. (author)
Contact angles of nanodrops on chemically rough surfaces.
Berim, Gersh O; Ruckenstein, Eli
2009-08-18
The experimental observations of Gao and McCarthy [Gao, L.; McCarthy, T. Langmuir, 2007, 23, 3762] that only the interfacial area near the leading edges of the drop on physically smooth but chemically rough solid surfaces affects the contact angle and that most of the contact area has no effect is checked for nanodrops on the basis of a density functional theory. The contact angle was calculated for three cases: (i) the leading edges of the drops are located on much higher or (ii) much lower hydrophobic surfaces than the remaining surface beneath the drop; (iii) the surface is composed of a periodic array of two kinds of stripelike solid plates. In the first two cases, if the distance between the leading edges and the region which has higher or lower hydrophobicity is sufficiently large, there is agreement with the experiments mentioned. However, when those distances are sufficiently small, the internal part affects the value of the angle. In the third case, we found that the internal part always affects the wetting angle. All these peculiarities, as well as the contact angle hysteresis, can be explained by accounting for the local conditions in the vicinity of the leading edges of the drop.
Contact angles of wetting and water stability of soil structure
Kholodov, V. A.; Yaroslavtseva, N. V.; Yashin, M. A.; Frid, A. S.; Lazarev, V. I.; Tyugai, Z. N.; Milanovskiy, E. Yu.
2015-06-01
From the soddy-podzolic soils and typical chernozems of different texture and land use, dry 3-1 mm aggregates were isolated and sieved in water. As a result, water-stable aggregates and water-unstable particles composing dry 3-1 mm aggregates were obtained. These preparations were ground, and contact angles of wetting were determined by the static sessile drop method. The angles varied from 11° to 85°. In most cases, the values of the angles for the water-stable aggregates significantly exceeded those for the water-unstable components. In terms of carbon content in structural units, there was no correlation between these parameters. When analyzing the soil varieties separately, the significant positive correlation between the carbon content and contact angle of aggregates was revealed only for the loamy-clayey typical chernozem. Based on the multivariate analysis of variance, the value of contact wetting angle was shown to be determined by the structural units belonging to water-stable or water-unstable components of macroaggregates and by the land use type. In addition, along with these parameters, the texture has an indirect effect.
Numerical study of hub taper angle on podded propeller performance
International Nuclear Information System (INIS)
Islam, M.F.; Veitch, B.; Bose, N.; Liu, P.
2005-01-01
Presently, the majority of podded propulsion systems are of the pulling type, because this type provides better hydrodynamic efficiency than the pushing type. There are several possible explanations for the better overall performance of a puller type podded propulsor. One is related to the difference in hub shape. Puller and pusher propellers have opposite hub taper angles, hence different hub and blade root shape. These differences cause changes in the flow condition and possibly influence the overall performance. The current study focuses on the variation in performance of pusher and puller propellers with the same blade sections, but different hub taper angles. A hyperboloidal low order source doublet steady/unsteady time domain panel method code was modified and used to evaluate effects of hub taper angle on the open water propulsive performance of some fixed pitch screw propellers used in podded propulsion systems. The modified code was first validated against measurements of two model propellers in terms of average propulsive performance and good agreement was found. Major findings include significant effects of hub taper angle on propulsive performance of tapered hub propellers and noticeable effects of hub taper angle on sectional pressure distributions of tapered hub propeller blades. (author)
Analysis of the changing Solar Radiation Angle on Hainan Island
Directory of Open Access Journals (Sweden)
Ge Zhiwu
2017-01-01
Full Text Available As the only tropical provinces in China, Hainan province has advantageous geographical location, and abundant solar energy resources. But because of Local ideas and habits, especially the lack of theoretical research on local solar resources, development and application of solar energy in Hainan is almost blank. In this paper, we studied the variation regularity of sunlight angle on Hainan tropical island, analyzed the revolution and rotation of the earth, and the change rule of sunlight angle caused by the sun’s movement between the tropic of cancer and the tropic of capricorn, deduced the change rule of sunlight angle in the spring equinox, the autumnal equinox, summer solstice and winter solstice day, and got the movement rules of solar elevation angle throughout the year. Theoretic analysis is consistent with field measurement results. These rules are of importance and can effectively guide the local People’s daily life and production, such as the reasonable layout of the buildings, floor distance between different heights of buildings, the direction of the lighting windows of tall buildings, installation angle of photovoltaic panels, and other similar solar energy absorbing and conversion equipment.
Scattering-angle based filtering of the waveform inversion gradients
Alkhalifah, Tariq Ali
2014-11-22
Full waveform inversion (FWI) requires a hierarchical approach to maneuver the complex non-linearity associated with the problem of velocity update. In anisotropic media, the non-linearity becomes far more complex with the potential trade-off between the multiparameter description of the model. A gradient filter helps us in accessing the parts of the gradient that are suitable to combat the potential non-linearity and parameter trade-off. The filter is based on representing the gradient in the time-lag normalized domain, in which the low scattering angle of the gradient update is initially muted out in the FWI implementation, in what we may refer to as a scattering angle continuation process. The result is a low wavelength update dominated by the transmission part of the update gradient. In this case, even 10 Hz data can produce vertically near-zero wavenumber updates suitable for a background correction of the model. Relaxing the filtering at a later stage in the FWI implementation allows for smaller scattering angles to contribute higher-resolution information to the model. The benefits of the extended domain based filtering of the gradient is not only it\\'s ability in providing low wavenumber gradients guided by the scattering angle, but also in its potential to provide gradients free of unphysical energy that may correspond to unrealistic scattering angles.
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.
Raccanelli, Alvise; Bertacca, Daniele; Jeong, Donghui; Neyrinck, Mark C.; Szalay, Alexander S.
2018-03-01
We study the parity-odd part (that we shall call Doppler term) of the linear galaxy two-point correlation function that arises from wide-angle, velocity, Doppler lensing and cosmic acceleration effects. As it is important at low redshift and at large angular separations, the Doppler term is usually neglected in the current generation of galaxy surveys. For future wide-angle galaxy surveys, however, we show that the Doppler term must be included. The effect of these terms is dominated by the magnification due to relativistic aberration effects and the slope of the galaxy redshift distribution and it generally mimics the effect of the local type primordial non-Gaussianity with the effective nonlinearity parameter fNLeff of a few; we show that this would affect forecasts on measurements of fNL at low-redshift. Our results show that a survey at low redshift with large number density over a wide area of the sky could detect the Doppler term with a signal-to-noise ratio of ∼ 1 - 20, depending on survey specifications.
Scanning Angle Raman spectroscopy in polymer thin film characterization
Energy Technology Data Exchange (ETDEWEB)
Nguyen, Vy H.T. [Iowa State Univ., Ames, IA (United States)
2015-12-19
The focus of this thesis is the application of Raman spectroscopy for the characterization of thin polymer films. Chapter 1 provides background information and motivation, including the fundamentals of Raman spectroscopy for chemical analysis, scanning angle Raman scattering and scanning angle Raman scattering for applications in thin polymer film characterization. Chapter 2 represents a published manuscript that focuses on the application of scanning angle Raman spectroscopy for the analysis of submicron thin films with a description of methodology for measuring the film thickness and location of an interface between two polymer layers. Chapter 3 provides an outlook and future directions for the work outlined in this thesis. Appendix A, contains a published manuscript that outlines the use of Raman spectroscopy to aid in the synthesis of heterogeneous catalytic systems. Appendix B and C contain published manuscripts that set a foundation for the work presented in Chapter 2.
Angle-of-attack estimation for analysis of CAT encounters
Bach, R. E., Jr.; Parks, E. K.
1985-01-01
Recent studies of clear-air turbulence (CAT) encounters involving wide-body airliners have been based upon flight-path wind estimates made by analyzing digital flight-data-recorder (DFDR) records and radar records. Such estimates require a time history of the aircraft angle of attack, a record that is not usually included in the DFDR measurement set. This paper describes a method for reconstructing angle of attack that utilizes available flight record and aircraft-specific information associated with an aerodynamic model of the lift coefficient. Results from two wide-body incidents in which vane measurements of angle of attack were recorded show good agreement between measured and calculated time histories. This research has been performed in cooperation with the National Transportation Safety Board to provide a better understanding of the CAT phenomenon.
Perception of angle in visual categorization by pigeons (Columba livia.
Directory of Open Access Journals (Sweden)
Walter T. Herbranson
2017-08-01
Full Text Available Pigeons are capable of learning to categorize stimuli based on visual features, and often reach levels of accuracy comparable with humans. Nevertheless, recent research has suggested that the cognitive processes behind categorization in pigeons and humans may not always be the same. Pigeons learned a categorization task in which they categorized either Shepard circles varying in size and orientation of a radial line (stimuli that are frequently used in research on human categorization, or moving dots varying in speed and direction of travel (stimuli that have been successfully used to study pigeon categorization. Even though categories were balanced so that the angles of orientation of Shepard circles matched the directions of travel for moving dots, birds failed to learn categories based on the former but not the latter. Results suggest that information about angle as a direction of travel may be more important for pigeons than information about angle of orientation.
Flow tilt angles near forest edges - Part 2: Lidar anemometry
DEFF Research Database (Denmark)
Dellwik, Ebba; Mann, Jakob; Bingöl, Ferhat
2010-01-01
A novel way of estimating near-surface mean flow tilt angles from ground based Doppler lidar measurements is presented. The results are compared with traditional mast based in-situ sonic anemometry. The tilt angle assessed with the lidar is based on 10 or 30 min mean values of the velocity field......) a fetch-limited beech forest site taken at 48–175 m a.g.l. (above ground level), (2) a reference site in flat agricultural terrain and (3) a second reference site in complex terrain are presented. The method to derive flow tilt angles and mean vertical velocities from lidar has several advantages compared...... alignment error at a multitude of heights. Disadvantages with estimating vertical velocities from a lidar compared to mast-based measurements are potentially slightly increased levels of statistical errors due to limited sampling time, because the sampling is disjunct, and a requirement for homogeneous flow...
Towards the Extraction of the CKM Angle $\\gamma$
Fleischer, Robert
1999-01-01
The determination of the angle $\\gamma$ of the unitarity triangle of the CKM matrix is regarded as a challenge for future $B$-physics experiments. In this context, the decays $B^\\pm\\to \\pi^\\pm K$ and $B_d\\to\\pi^\\mp K^\\pm$, which were observed by the CLEO collaboration last year, received a lot of interest in the literature. After a general parametrization of their decay amplitudes, strategies to constrain and determine the CKM angle $\\gamma$ with the help of the corresponding observables are reviewed. The theoretical accuracy of these methods is limited by certain rescattering and electroweak penguin effects. It is emphasized that the rescattering processes can be included in the bounds on decays, and steps towards the control of electroweak penguins are pointed out. Moreover, strategies to probe the CKM angle $\\gamma$ with the help of $B_s\\to
The National Facility for Small-Angle Neutron Scattering
International Nuclear Information System (INIS)
Koehler, W.C.
1986-01-01
On this occasion honoring Professor C.G.Shull, the 30-m small-angle neutron scattering (SANS) instrument of the National Center for Small-Angle Scattering Research (NCSASR) will have been in routine user-mode operation for five years. Professor Shull served the Center as chairman of its first Advisory Committee and in that capacity contributed his expertise to the construction phase of the 30-m machine and to the formulation of operating policy. He has had a long and varied interest in the scientific application of small-angle scattering of X-rays and of neutrons. It is a pleasure for me to dedicate this review to him on his 70th birthday. (orig.)
Small Angle Scattering in Neutron Imaging—A Review
Directory of Open Access Journals (Sweden)
Markus Strobl
2017-12-01
Full Text Available Conventional neutron imaging utilizes the beam attenuation caused by scattering and absorption through the materials constituting an object in order to investigate its macroscopic inner structure. Small angle scattering has basically no impact on such images under the geometrical conditions applied. Nevertheless, in recent years different experimental methods have been developed in neutron imaging, which enable to not only generate contrast based on neutrons scattered to very small angles, but to map and quantify small angle scattering with the spatial resolution of neutron imaging. This enables neutron imaging to access length scales which are not directly resolved in real space and to investigate bulk structures and processes spanning multiple length scales from centimeters to tens of nanometers.
Optimization of sharp and viewing-angle-independent structural color.
Hsu, Chia Wei; Miller, Owen D; Johnson, Steven G; Soljačić, Marin
2015-04-06
Structural coloration produces some of the most brilliant colors in nature and has many applications. Motivated by the recently proposed transparent displays that are based on wavelength-selective scattering, here we consider the new problem of transparent structural color, where objects are transparent under omnidirectional broad-band illumination but scatter strongly with a directional narrow-band light source. Transparent structural color requires two competing properties, narrow bandwidth and broad viewing angle, that have not been demonstrated simultaneously previously. Here, we use numerical optimization to discover geometries where a sharp 7% bandwidth in scattering is achieved, yet the peak wavelength varies less than 1%, and the peak height and peak width vary less than 6% over broad viewing angles (0-90°) under a directional illumination. Our model system consists of dipole scatterers arranged into several rings; interference among the scattered waves is optimized to yield the wavelength-selective and angle-insensitive response.
An introduction to small-angle neutron scattering
International Nuclear Information System (INIS)
Windsor, C.G.
1988-01-01
Neutron and X-ray small-angle scattering provide, along with electron microscopy and diffraction, the principal techniques for the microscopic characterization of materials. Neutron, X-ray and electron beams each have quite different properties. In fact, each has unique advantages. The penetration of neutrons through most materials is responsible for many applications. The ever-increasing intensity of available X-ray beams is opening new fields. The advantage of electron beams is their ability to work in both real and reciprocal space. The problems of transforming the results of an experiment in reciprocal space to give an interpretation in real space are central to small-angle scattering, and are discussed. Several examples will be given of the successful use of small-angle neutron scattering applied to problems where other techniques have failed to make a decisive contribution. (orig.)
Effect of inlet cone pipe angle in catalytic converter
Amira Zainal, Nurul; Farhain Azmi, Ezzatul; Arifin Samad, Mohd
2018-03-01
The catalytic converter shows significant consequence to improve the performance of the vehicle start from it launched into production. Nowadays, the geometric design of the catalytic converter has become critical to avoid the behavior of backpressure in the exhaust system. The backpressure essentially reduced the performance of vehicles and increased the fuel consumption gradually. Consequently, this study aims to design various models of catalytic converter and optimize the volume of fluid flow inside the catalytic converter by changing the inlet cone pipe angles. Three different geometry angles of the inlet cone pipe of the catalytic converter were assessed. The model is simulated in Solidworks software to determine the optimum geometric design of the catalytic converter. The result showed that by decreasing the divergence angle of inlet cone pipe will upsurge the performance of the catalytic converter.
Standing phase angle reduction for power system restoration
Energy Technology Data Exchange (ETDEWEB)
Hazarika, D. [Assam Engineering College (India). Electrical Engineering Dept.; Sinha, A.K. [IIT Khargpur (India). Electrical Engineering Dept.
1998-01-01
The paper describes a methodology for the reduction of standing phase angle (SPA) difference between two buses of a power system, which is essential before interconnecting a line between two buses. This problem is encountered normally during restoration operations of a power system. For this purpose, the standing phase angle difference between two specific buses is represented in terms of sensitivity factors associated with the change in real power injections at the buses. To arrive at the desired standing phase angle difference between two buses, the modified contribution at generation/load buses have been evaluated based on 'higher the sensitivity higher the participation' logic. This methodology acts as a direct help to reduce excessive SPA difference between two buses to an acceptable limit, which otherwise requires regulation of various generation levels on a trial and error basis. (author)
Bilateral Acute Angle-closure after Intraocular Surgery.
Hoskens, Kirsten; Pinto, Luis Abegão; Vandewalle, Evelien; Verdonk, Nancy; Stalmans, Ingeborg
2014-01-01
We report the case of a 75-year-old woman who developed an acute bilateral angle-closure associated with choroidal effusion a day after an uneventful cataract surgery. The same patient had undergone a similarly uneventful cataract surgery two weeks before, under the same protocol, with no postoperative complication in the other eye. Medical treatment, including the use of oral sulfamide-related drugs (acetazolamide), topical beta-blockers and steroids led to a gradual decrease in intraocular pressure (IOP) and choroidal effusion. Despite initial reports suggesting a link between sulfamide-exposure and these rare forms of angle-closure, our report would suggest a more complex pathophysiology behind this intriguing phenomenon. How to cite this article: Hoskens K, Pinto LA, Vandewalle E, Verdonk N, Stalmans I. Bilateral Acute Angle-closure after Intraocular Surgery. J Curr Glaucoma Pract 2014;8(3):113-114.
An optimal algorithm for computing angle-constrained spanners
Paz Carmi; Michiel Smid
2012-01-01
Let S be a set of n points in Rd and let t>1 be a real number. A graph G=(S,E) is called a t-spanner for S, if for any two points p and q in S, the shortest-path distance in G between p andq is at most t|pq|, where |pq| denotes the Euclidean distance between p and q. The graph G is called θ-angle-constrained, if any two distinct edges sharing an endpoint make an angle of at least θ. It is shown that, for any θ with 0<θ<π/3, a θ-angle-constrained t-spanner can be computed in O(nlog n)...
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.
Cancer of the colon spleen angle. Presentation of a case
International Nuclear Information System (INIS)
Martinez Sanchez, Yariana; De la Rosa Perez, Nereida; Barcelo Casanova, Renato E
2010-01-01
The colon cancer is currently an important public health problem in developed countries. It is the fourth most common cancer in the world. We report the case of a 65-years-old, black, female patient, assisting our consultation with dyspeptic disturbances as the unique symptom, without known risk factors. We indicated a colon by enema and a distal narrowing was observed at the colon spleen angle, at the same zone of the physiologic narrowing at that level. A colonoscopy was carried out diagnosing a left colon tumor near the spleen angle. It was operated with segmental resection of the spleen angle and a biopsy was made. Pathologic anatomy informed a well-differentiated colon adenocarcinoma
Wide steering angle microscanner based on curved surface
Sabry, Yasser; Khalil, Diaa; Saadany, Bassam; Bourouina, Tarik
2013-03-01
Intensive industrial and academic research is oriented towards the design and fabrication of optical beam steering systems based on MEMS technology. In most of these systems, the scanning is achieved by rotating a flat micromirror around a central axis in which the main challenge is achieving a wide mirror rotation angle. In this work, a novel method of optical beam scanning based on reflection from a curved surface is presented. The scanning occurs when the optical axis of the curved surface is displaced with respect to the optical axis of the incident beam. To overcome the possible deformation of the spot with the scanning angle, the curved surface is designed with a specific aspherical profile. Moreover, the scanning exhibits a more linearized scanning angle-displacement relation than the conventional spherical profile. The presented scanner is fabricated using DRIE technology on an SOI wafer. The curved surface (reflector) is metalized and attached to a comb-drive actuator fabricated in the same lithography step. A single-mode fiber, behaving as a Gaussian beam source, is positioned on the substrate facing the mirror. The reflected optical beam angle and spotsize in the far field is recorded versus the relative shift between the fiber and the curved mirror. The spot size is plotted versus the scanning angle and a scanning spot size uniformity of about +/-10% is obtained for optical deflection angles up to 100 degrees. As the optical beam is propagating parallel to the wafer substrate, a completely integrated laser scanner can be achieved with filters and actuators self-aligned on the same chip that allows low cost and mass production of this important product.
Contact Angles and Surface Tension of Germanium-Silicon Melts
Croell, A.; Kaiser, N.; Cobb, S.; Szofran, F. R.; Volz, M.; Rose, M. Franklin (Technical Monitor)
2001-01-01
Precise knowledge of material parameters is more and more important for improving crystal growth processes. Two important parameters are the contact (wetting) angle and the surface tension, determining meniscus shapes and surface-tension driven flows in a variety of methods (Czochralski, EFG, floating-zone, detached Bridgman growth). The sessile drop technique allows the measurement of both parameters simultaneously and has been used to measure the contact angles and the surface tension of Ge(1-x)Si(x) (0 less than or equal to x less than or equal to 1.3) alloys on various substrate materials. Fused quartz, Sapphire, glassy carbon, graphite, SiC, carbon-based aerogel, pyrolytic boron nitride (pBN), AIN, Si3N4, and polycrystalline CVD diamond were used as substrate materials. In addition, the effect of different cleaning procedures and surface treatments on the wetting behavior were investigated. Measurements were performed both under dynamic vacuum and gas atmospheres (argon or forming gas), with temperatures up to 1100 C. In some experiments, the sample was processed for longer times, up to a week, to investigate any changes of the contact angle and/or surface tension due to slow reactions with the substrate. For pure Ge, stable contact angles were found for carbon-based substrates and for pBN, for Ge(1-x)Si(x) only for pBN. The highest wetting angles were found for pBN substrates with angles around 170deg. For the surface tension of Ge, the most reliable values resulted in gamma(T) = (591- 0.077 (T-T(sub m)) 10(exp -3)N/m. The temperature dependence of the surface tension showed similar values for Ge(1-x)Si(x), around -0.08 x 10(exp -3)N/m K, and a compositional dependence of 2.2 x 10(exp -3)N/m at%Si.
Directory of Open Access Journals (Sweden)
Н. А. Колесник
2017-06-01
Full Text Available When predicting deformations and determining measures to protect underworked objects, angular parameters are used: the boundary angles, the angles of total shift, the angle of maximum crop. The values of these angular parameters are given in the normative documents, but only for sections across and along the strike of the formation. However, at present, longwall face mining is mainly being carried out along a diagonal direction to the strike of the formation. In connection with this, the determination of the values of the angular parameters for such conditions is a topical task.The method of determination and the analytical dependences of the angles of total shifts and angles of maximum crop in sections of the longitudinal and transverse axes of coal-mining faces developed along diagonal directions to the strike of the formation are proposed. These angular parameters are used for prognosis of deformations of the earth's surface and for determining the characteristic zones of influence of mine workings on the local places.
Alpha emitters activity measurement using the defined solid angle method
International Nuclear Information System (INIS)
Blanchis, P.
1983-01-01
The defined solid angle counting method can reach a very high accuracy, specially for heavy ions as alpha particles emitted by a radioactive source. The activity measurement of such sources with a relative uncertainty of the order of 0.01% is investigated. Such an accuracy is available only under suitable conditions: the radiation emitted by the source must be isotropic and all the particles emitted in the effective solid angle must be detected. The efficiency detection value must be equal to unity and phenomena such as absorption or scattering must be null. It is shown that corrections often become necessary. All parameters which can influence the measurements are studied [fr
DESIGN OF ILC EXTRACTION LINE FOR 20 MRAD CROSSING ANGLE
International Nuclear Information System (INIS)
Nosochkov, Y.; Moffeit, K.; Seryi, A.; Woods, M.; SLAC; Arnold, R.; Massachusetts U., Amherst; Oliver, W.; Tufts U.; Parker, B.; Brookhaven; Torrence, E.; Oregon U.
2005-01-01
One of the two ILC Interaction Regions will have a large horizontal crossing angle which would allow to extract the spent beams in a separate beam line. In this paper, the extraction line design for 20 mrad crossing angle is presented. This beam line transports the primary e + /e - and beamstrahlung photon beams from the IP to a common dump, and includes diagnostic section for energy and polarization measurements. The optics is designed for a large energy acceptance to minimize losses in the low energy tail of the disrupted beam. The extraction optics, diagnostic instrumentation and particle tracking simulations are described
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 elastic scattering of electrons by noble gas atoms
International Nuclear Information System (INIS)
Wagenaar, R.W.
1984-01-01
In this thesis, measurements are carried out to obtain small angle elastic differential cross sections in order to check the validity of Kramers-Kronig dispersion relations for electrons scattered by noble gas atoms. First, total cross sections are obtained for argon, krypton and xenon. Next, a parallel plate electrostatic energy analyser for the simultaneous measurement of doubly differential cross section for small angle electron scattering is described. Also absolute differential cross sections are reported. Finally the forward dispersion relation for electron-helium collisions is dealt with. (Auth.)
Vowel Formants and Angle Measurements in Diachronic Sociophonetic Studies
DEFF Research Database (Denmark)
Fabricius, Anne
2007-01-01
This paper examines vowel formant data from a corpus of recordings of male speakers of RP born during the course of the twentieth century. It compares average formant positions in the F1/F2 plane for the short vowel FOOT in juxtaposition with LOT (for this Keyword notation see Wells [12......]). The relative positions of the two vowels are represented by a single numerical value, which is the calculated angle from LOT to FOOT relative to the vertical. Changing angle values between the early and the later part of the twentieth century reflect a diachronic process of FOOT-fronting and unrounding which...
Quantum ring models and action-angle variables
Bellucci, Stefano; Nersessian, Armen; Saghatelian, Armen; Yeghikyan, Vahagn
2010-01-01
We suggest to use the action-angle variables for the study of properties of (quasi)particles in quantum rings. For this purpose we present the action-angle variables for three two-dimensional singular oscillator systems. The first one is the usual (Euclidean) singular oscillator, which plays the role of the confinement potential for the quantum ring. We also propose two singular spherical oscillator models for the role of the confinement system for the spherical ring. The first one is based o...
Oral Rehabilitation of a Patient with Cerebellopontine Angle Epidermoid Cyst
Directory of Open Access Journals (Sweden)
Amin Nourizadeh
2015-01-01
Full Text Available Epidermoid cysts are rare congenital tumors of the central nervous system (CNS, histologically benign and slow- growing lesions. Their frequency among primitive intracranial tumors is about 1% and they account for 40% of all intracranial epidermoid cysts of the cerebellopontine angle (CPA; the most common symptom which brings about difficulties in oral rehabilitation of these patients is facial weakness which diversely affects impression processes and use of prosthesis. We report the oral rehabilitation of a patient with a cerebellopontine angle epidermoid cyst using neutral zone approach. Keywords: Soft tissue thickness; Facial reconstruction; Cone Beam Computed Tomography
Measurement of the CKM angle $\\gamma$ at LHCb
Gersabeck, M
2009-01-01
The precise measurement of the CKM unitarity triangle angle $\\gamma$ is a key goal of the LHCb physics programme. The uncertainty on $\\gamma$, the currently least-well known of the three angles, will be reduced dramatically. Complementary measurements will be made in tree-level processes, and modes where loop diagrams play an important role. The tree-level measurements will cover time-integrated as well as time- dependent measurements in both the $B^0_d$ and the $B^0_s$ sectors. The ensemble of these measurements will provide a powerful test of whether new physics phases contribute to heavy-flavour transitions.
BIPHASIC TREATMENT OF 2ND CLASS ANGLE ANOMALIES
Directory of Open Access Journals (Sweden)
C. Romanec
2011-09-01
Full Text Available Our approach aims at presenting, based on clinical observations and complementary examinations, the effects of a treatment’s setting up during the mixed dentition period. The objectives include the identification of the optimal time of treatment of II/1, II/2 Angle malocclusions, as well as the therapeutic possibilities for the treatment of 2nd class Angle malocclusion during the period of mixed and permanent dentition. The study is based on data collected from 114 clinical cases (69 girls and 45 boys with an age span between 7 and 18 years.
High contact angle hysteresis of superhydrophobic surfaces: Hydrophobic defects
Chang, Feng-Ming; Hong, Siang-Jie; Sheng, Yu-Jane; Tsao, Heng-Kwong
2009-08-01
A typical superhydrophobic surface is essentially nonadhesive and exhibits very low water contact angle (CA) hysteresis, so-called Lotus effect. However, leaves of some plants such as scallion and garlic with an advancing angle exceeding 150° show very serious CA hysteresis. Although surface roughness and epicuticular wax can explain the very high advancing CA, our analysis indicates that the unusual hydrophobic defect, diallyl disulfide, is the key element responsible for contact line pinning on allium leaves. After smearing diallyl disulfide on an extended polytetrafluoroethylene (PTFE) film, which is originally absent of CA hysteresis, the surface remains superhydrophobic but becomes highly adhesive.
Research progress on related genes for primary open angle glaucoma
Directory of Open Access Journals (Sweden)
Ailijiang·Aierken
2014-04-01
Full Text Available Primary open angle glaucoma(POAGis the main cause of blindness with visual field damage and optic nerve degeneration. In recent years, a lot of researches have been done, showing that genetic factors and gene mutation play an important role in POAG. There are more than 20 related POAG genes. Now we will review the related genes of POAG, especially the well known causative genes of MYOC, OPTN, WDR36, and CAV1/CAV2, in terms of their locations, structures, research progress, et al, and provide a reference for genetic research in primary open-angle glaucoma.
X-ray diffraction at Bragg angles around π/2
International Nuclear Information System (INIS)
Mayolo, C.M.G. de.
1991-01-01
X-ray diffraction at Bragg angles around π/2 is studied from the theoretical and experimental points of view. The proposed corrections to the dynamical theory in the θ β ≅ π/2 cases, has been reviewed showing the equivalence between two formalisms leading to a corrected expression for the dependence of the angular parameter y with the angle of incidence. An expression for y valid in the conventional and θ β ≅ π/2 cases has been obtained. A general expression for Bragg law and for energy resolution after a Bragg diffraction was also deduced. (author)
Edge effects in angle-ply composite laminates
Hsu, P. W.; Herakovich, C. T.
1977-01-01
This paper presents the results of a zeroth-order solution for edge effects in angle-ply composite laminates obtained using perturbation techniques and a limiting free body approach. The general solution for edge effects in laminates of arbitrary angle ply is applied to the special case of a (+ or - 45)s graphite/epoxy laminate. Interlaminar stress distributions are obtained as a function of the laminate thickness-to-width ratio and compared to finite difference results. The solution predicts stable, continuous stress distributions, determines finite maximum tensile interlaminar normal stress and provides mathematical evidence for singular interlaminar shear stresses in (+ or - 45) graphite/epoxy laminates.
The misalignment angle in vessel-mounted ADCP
Directory of Open Access Journals (Sweden)
Robert Osinski
2000-09-01
Full Text Available A description of the misalignment angle and the consequences if it occurs is given. It is shown that because of gyrocompass errors, the misalignment angle error a has to be computed for each cruise. A simple method of calibrating the acoustic Doppler current profiler (ADCP mounted on a vessel has been devised by fitting the cosinusoidal function. This is a post-processing method, suitable for calibrating previously collected data. Nevertheless, because of ADCP's constructional peculiarities, the procedure must be repeated for each cruise.
Right-angled polyhedra and hyperbolic 3-manifolds
Vesnin, A. Yu.
2017-04-01
Hyperbolic 3-manifolds whose fundamental groups are subgroups of finite index in right-angled Coxeter groups are under consideration. The construction of such manifolds is associated with regular colourings of the faces of polyhedra and, in particular, with 4-colourings. The following questions are discussed: the structure of the set of right-angled polytopes in Lobachevskii space; examples of orientable and non-orientable manifolds, including the classical Löbell manifold constructed in 1931; connections between the Hamiltonian property of a polyhedron and the existence of hyperelliptic involutions of manifolds; the volumes and complexity of manifolds; isometry between hyperbolic manifolds constructed from 4-colourings. Bibliography: 89 titles.
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)
Automatic learning-based beam angle selection for thoracic IMRT.
Amit, Guy; Purdie, Thomas G; Levinshtein, Alex; Hope, Andrew J; Lindsay, Patricia; Marshall, Andrea; Jaffray, David A; Pekar, Vladimir
2015-04-01
The treatment of thoracic cancer using external beam radiation requires an optimal selection of the radiation beam directions to ensure effective coverage of the target volume and to avoid unnecessary treatment of normal healthy tissues. Intensity modulated radiation therapy (IMRT) planning is a lengthy process, which requires the planner to iterate between choosing beam angles, specifying dose-volume objectives and executing IMRT optimization. In thorax treatment planning, where there are no class solutions for beam placement, beam angle selection is performed manually, based on the planner's clinical experience. The purpose of this work is to propose and study a computationally efficient framework that utilizes machine learning to automatically select treatment beam angles. Such a framework may be helpful for reducing the overall planning workload. The authors introduce an automated beam selection method, based on learning the relationships between beam angles and anatomical features. Using a large set of clinically approved IMRT plans, a random forest regression algorithm is trained to map a multitude of anatomical features into an individual beam score. An optimization scheme is then built to select and adjust the beam angles, considering the learned interbeam dependencies. The validity and quality of the automatically selected beams evaluated using the manually selected beams from the corresponding clinical plans as the ground truth. The analysis included 149 clinically approved thoracic IMRT plans. For a randomly selected test subset of 27 plans, IMRT plans were generated using automatically selected beams and compared to the clinical plans. The comparison of the predicted and the clinical beam angles demonstrated a good average correspondence between the two (angular distance 16.8° ± 10°, correlation 0.75 ± 0.2). The dose distributions of the semiautomatic and clinical plans were equivalent in terms of primary target volume coverage and organ at risk
Optimal BRUVs (baited remote underwater video system) survey ...
African Journals Online (AJOL)
Marine protected areas (MPAs) play an important role in coastal conservation, but there is presently no uniformly applied methodology for monitoring the efficacy of coastal fish protection. Whereas underwater visual census and controlled angling surveys have been used, their skilled-labour requirements and environmental ...
Latifi, Golshan; Moghimi, Sasan; Eslami, Yadollah; Fakhraie, Ghasem; Zarei, Reza; Lin, Shan
2013-01-21
Purpose. To evaluate the anatomic effects of phacoemulsification on drainage angle status in primary angle closure glaucoma (PACG) using anterior segment optical coherence tomography (AS-OCT). Methods. A total of 62 eyes of 58 patients underwent cataract surgery in Farabi Rye Hospital, Tehran, Iran. Patients were examined postoperatively on day 1, week 1, and week 6. Indentation gonioscopy and AS-OCT were performed preoperatively and at 6 weeks after surgery. Main outcome measures were angle and anterior segment parameters by AS-OCT and amount of peripheral anterior synechiae (PAS) by gonioscopy. Thirty-five eyes had PAS =180 degrees (group 1) and 27 eyes had >180-degree synechial closure (group 2). Results. Mean age of the patients was 64.3±9.0 years. The mean extent of PAS was significantly reduced from 45.9 to 32.2 degrees (p180 degrees.
Ekaterinaris, J. A.; Schiff, Lewis B.
1990-01-01
In the present investigation of the vortical flowfield structure over delta wings at high angles of attack, three-dimensional Navier-Stokes numerical simulations were conducted to predict the complex leeward flowfield characteristics; these encompass leading-edge separation, secondary separation, and vortex breakdown. Attention is given to the effect on solution accuracy of circumferential grid-resolution variations in the vicinity of the wing leading edge, and well as to the effect of turbulence modeling on the solutions. When a critical angle-of-attack was reached, bubble-type vortex breakdown was found. With further angle-of-attack increase, a change from bubble-type to spiral-type vortex breakdown was predicted by the numerical solution.
Boltz, Frederick W.; Kenyon, George C.; Allen, Clyde Q.
1960-01-01
An investigation was conducted in the Ames 12-Foot Low-Turbulence Pressure Tunnel to determine the effects of sweep on the boundary-layer stability characteristics of an untapered variable-sweep wing having an NACA 64(2)A015 section normal to the leading edge. Pressure distribution and transition were measured on the wing at low speeds at sweep angles of 0, 10, 20, 30, 40, and 50 deg. and at angles of attack from -3 to 3 deg. The investigation also included flow-visualization studies on the surface at sweep angles from 0 to 50 deg. and total pressure surveys in the boundary layer at a sweep angle of 30 deg. for angles of attack from -12 to 0 deg. It was found that sweep caused premature transition on the wing under certain conditions. This effect resulted from the formation of vortices in the boundary layer when a critical combination of sweep angle, pressure gradient, and stream Reynolds number was attained. A useful parameter in indicating the combined effect of these flow variables on vortex formation and on beginning transition is the crossflow Reynolds number. The critical values of crossflow Reynolds number for vortex formation found in this investigation range from about 135 to 190 and are in good agreement with those reported in previous investigations. The values of crossflow Reynolds number for beginning transitions were found to be between 190 and 260. For each condition (i.e., development of vortices and initiation of transition at a given location) the lower values in the specified ranges were obtained with a light coating of flow-visualization material on the surface. A method is presented for the rapid computation of crossflow Reynolds number on any swept surface for which the pressure distribution is known. From calculations based on this method, it was found that the maximum values of crossflow Reynolds number are attained under conditions of a strong pressure gradient and at a sweep angle of about 50 deg. Due to the primary dependence on pressure
Masoodi, Habibeh; Jafarzadehpur, Ebrahim; Esmaeili, Alireza; Abolbashari, Fereshteh; Ahmadi Hosseini, Seyed Mahdi
2014-08-01
To evaluate changes of nasal and temporal anterior chamber angle (ACA) in subjects with angle closure glaucoma using Spectralis AS-OCT (SAS-OCT) under dark and light conditions. Based on dark-room gonioscopy, 24 subjects with open angles and 86 with narrow angles participated in this study. The nasal and temporal angle opening distance at 500 μm anterior to the scleral spur (AOD500), nasal and temporal ACA were measured using SAS-OCT in light and dark conditions. In 2 groups, ACA and AOD500 in nasal and temporal quadrants were significantly greater in light compared to dark (all with p=0.000). The AOD500 and ACA were significantly higher in nasal than temporal in measured conditions for 2 groups except the ACA and AOD500 of normal group measured in light. The difference between nasal and temporal in dark (29.07 ± 65.71 μm for AOD500 and 5.7 ± 4.07° for ACA) was greater than light (24.86 ± 79.85 μm for AOD500 and 2.09 ± 7.21° for ACA) condition. But the difference was only significant for ACA (p=0.000). The correlation analysis showed a negative correlation between AOD500 and pupil diameter in temporal and nasal quadrants (both with p=0.000). While temporal AOD500 difference correlated with spherical equivalent, temporal and asal gonioscopy, nasal AOD correlated with IOP, temporal and nasal gonioscopy. Clinically important changes in ACA structure could be detected with SAS-OCT in nasal and temporal quadrants under different illumination intensity. The results could help in improvement of examination condition for better and more accurate assessment of individuals with angle closure glaucoma. Copyright © 2014 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.
NEŞELİ, Süleyman; YALDIZ, Süleyman
2007-01-01
In this study, the effect of the chatter vibrations depend on tool geometry on surface roughness in turning has been investigated. Machining process in universal lathe is carried out on AISI 1040 steel in dry cutting condition using various approaching/entering angles (60°, 75°, 90°) and rake angles (-3°,-6°,-9°) at depth of cut of 0.5 mm. During cutting processes, tool nose radius and tool overhang (tool noise of kept point distance) and cutting speed, feed rate and spindle speed as cutting ...
small signal analysis of load angle governing and excitation control
African Journals Online (AJOL)
Dr Obe
optimal value of regulator gain for damping as far as this study is concerned will be some value above 0.25. This is similar to the findings of Aldred and Shackshaft [2] using frequency response methods. Following as above for the same machine with excitation control only, but this time around, utilizing the load angle.
Characterization of porous materials by small-angle scattering
Indian Academy of Sciences (India)
Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. E-mail: smazu@apsara.barc.ernet.in. Abstract. Characterization of porous materials by small-angle scattering has been ex- tensively pursued for several years now as the pores are often of mesoscopic size and compatible with the ...
Non-linear Flight Dynamics at High Angles of Attack
DEFF Research Database (Denmark)
Granasy, P.; Sørensen, C.B.; Mosekilde, Erik
1998-01-01
The methods of nonlinear dynamics are applied to the longitudinal motion of a vectored thrust aircraft, in particular the behavior at high angles of attack. Our model contains analytic nonlinear aerodynamical coefficients based on NASA windtunnel experiments on the F-18 high-alpha research vehicl...
High Pressure Apparatus for Angle Dispersive Neutron Diffraction
Kazuo, Kamigaki; Takejiro, Kaneko; Shunya, Abe; Masayoshi, Ohashi
1983-01-01
A piston-cylinder type high pressure apparatus was designed for the angle dispersive neutron diffraction. A Ti-53wt% Zr alloy was used for the cylinder. The performance was tested by observing the structural transformation under pressure in RbBr from an NaCl-type to a CsCl-type.
Contact angle hysteresis of liquid drops as means to measure ...
Indian Academy of Sciences (India)
A comparison of the two methods shows that the extent of contact angle hysteresis is indicative of both hydrophobicity of the surface as well as the force of adhesion. Mechanical properties and microstructure of zein films prepared by casting from solutions and using Langmuir-Blodgett film technique have been investigated.
Metrology concept design of the GAIA basic angle monitoring system
Veggel, M. van; Vink, R.; Rosielle, N.; Nijmeijer, H.; Wielders, A.A.
2004-01-01
The GAIA satellite, scheduled for launch in 2010, will make a highly accurate map of our Galaxy. It will measure the position of stars with an accuracy of 50 prad using two telescopes, which are positioned under a 'basic' angle between the the lines-of-sight of the telescopes of 106°. With a Basic
The Perspective Effect of Wide-Angle Lenses in Laparoscopes
Wentink, M.; Fischer, H.; Dankelman, J.; Stassen, L.P.S.; Wieringa, P.A.
2002-01-01
Purpose: To evaluate the effect of perspective distortion of wide-angle lenses in laparoscopes on hand-eye coordination during endoscopic manipulation. Methods: Sixteen subjects repeatedly performed a standardized positioning task in a pelvi-trainer under two conditions. The subjects had no prior
Gluon transport equations with condensate in the small angle approximation
Energy Technology Data Exchange (ETDEWEB)
Blaizot, Jean-Paul [Institut de Physique Théorique (IPhT), CNRS/URA2306, CEA Saclay, F-91191 Gif-sur-Yvette (France); Liao, Jinfeng [Physics Department and Center for Exploration of Energy and Matter, Indiana University, 2401 N Milo B. Sampson Lane, Bloomington, IN 47408 (United States); RIKEN BNL Research Center, Bldg. 510A, Brookhaven National Laboratory, Upton, NY 11973 (United States)
2016-05-15
We derive the set of kinetic equations that control the evolution of gluons in the presence of a condensate. We show that the dominant singularities remain logarithmic when the scattering involves particles in the condensate. This allows us to define a consistent small angle approximation.
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 ...
THE EFFECTS OF OFF TAKE ANGLE ON THE VELOCITY ...
African Journals Online (AJOL)
Smiegle
Sediments could either originate in the canals themselves through bank and bed erosion or they could be transported from the surroundings by flood and run off, or they could ... In fact, an idealized fluvial ... THE EFFECTS OF OFF TAKE ANGLE ON THE VELOCITY DISTRIBUTION AND RATE OF SILTATION OF CANALS.
[Morphometric analysis of nasal shapes and angles in young adults].
Uzun, Ahmet; Ozdemir, Fikri
2014-01-01
The size, angle, shape and type of nose are a signature indicating race, age and sex. Describe and compare nasal angles, nose types, nostril models, and nasal profiles in young Turkish males and females. The study group consisted of university students, 56 males and 59 females. Nasal measurements were obtained from all subjects, using anthropometric methods. The nose types of females and males were 78% and 70% narrow nose, respectively. The means of females' nasofrontal, nasal tip, nasolabial, and alar slope angles were 133.16° ± 8.88°; 77.91° ± 9.80°; 98.91° ± 10.01°, and 80.89° ± 8.33°, respectively. The means of males' nasofrontal, nasal tip, nasolabial, and alar slope angles were 123.85° ± 13.23°; 82.16° ± 9.98°; 97.91° ± 8.78° and 85.98° ± 8.72°, respectively. The average values of the nose in this population may be used as a guide to plan corrective esthetic-cosmetic surgery and for burn scars of the nose. Copyright © 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.
Optimisation of underwater visual census and controlled angling ...
African Journals Online (AJOL)
Whereas UVC provided less variable estimates of relative density, controlled angling provided greater sampling efficiency. It is thus recommended that the two methods be used in conjunction. The optimal sampling protocols identified are suitable for rapid assessments or long-term monitoring of subtidal, temperate reef fish ...
THE TREATMENT OF OPEN- AND NARROW-ANGLE GLAUCOMA
African Journals Online (AJOL)
1971-04-10
Apr 10, 1971 ... Treatment. A more realistic approach to the treatment of open-angle glaucoma is necessary. Medical therapy. The general trend of thought concern- ... sibility on the ophthalmologists because of the adequate follow-up which has become mandatory. Cupping. Although it is frequently stated that with.
Anthropometric characterisation of elbow angles and lines among Indian children
Directory of Open Access Journals (Sweden)
Bhanu Awasthi
2017-01-01
Full Text Available Background: For understanding injuries in paediatric elbow and checking the degree of reduction after manipulation, various radiological criteria using anthropometric parameters are used. Since anthropometric parameters of Caucasians are different from European and Mongoloids, their parameters cannot be applied on our population. Hence, there is a need to characterise anthropometric parameters of elbow among children in the Indian population. Materials and Methods: The study population comprised all cases of injury to the elbow joint between 3 and 13 years of age reporting to the Department of Orthopaedics during the study. The X-rays films were preserved, and the angles and lines (as anthropometric parameters were drawn on the radiographs. Results: Mean ± (standard deviation [SD] for Baumann angle in children included in this study was 75° ± 4.70°. Mean ± (SD of Baumann angle in males was 76° ± 4.44° and females was 74° ± 5.37°. Mean ± (SD for lateral capitellohumeral angle in children from 3 to 13 years of age was 49 ± 5.75. Conclusions: As the values of normal side have been found to affect the functional and cosmetic outcome of the affected extremity, slight changes in values of our population in comparison to that of the Western population can significantly affect the outcome.
Hereditary primary open angle glaucoma: case study of a Nigerian ...
African Journals Online (AJOL)
Objective: To present a case of hereditary primary open angle glaucoma in a Nigerian family. Method: Six members of an Ibo family from Delta State, Nigeria were interviewed and examined by the authors. Information on age, gender, tribe, history of blindness, eye disease and other medical conditions was recorded.
Determinants of Primary Open Angle Glaucoma: Review of records ...
African Journals Online (AJOL)
Background: Primary open angle glaucoma (POAG) has continued to cause high disease burden globally and Zambia is no exception. We investigated the prevalence and socio-demographic determinants of POAG based on records of clients attending the eye clinic at University Teaching Hospital (UTH), Lusaka. Methods: ...
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
Variability and Similarity of Gait as Evaluated by Joint Angles
DEFF Research Database (Denmark)
Yang, Sylvia X M; Larsen, Peter Kastmand; Alkjær, Tine
2014-01-01
Closed-circuit television (CCTV) footage is used in criminal investigations to compare perpetrators with suspects. Usually, incomplete gait cycles are collected, making evidential gait analysis challenging. This study aimed to analyze the discriminatory power of joint angles throughout a gait cyc...
Small angle neutron scattering study of two nonionic surfactants in ...
Indian Academy of Sciences (India)
cO Indian Academy of Sciences. Vol. 71, No. 5. — journal of. November 2008 physics pp. 1079–1083. Small angle neutron scattering study of two nonionic surfactants in water micellar solutions. RAJEWSKA ALDONA. Institute of Atomic Energy, 05-400 Swierk-Otwock, Poland. E-mail: aldonar@cyf.gov.pl. Abstract.
Nonlinear joint angle control for artificially stimulated muscle
Veltink, Petrus H.; Chizeck, Howard J.; Crago, Patrick E.; El-Bialy, Ahmed
1992-01-01
Designs of both open- and closed-loop controllers of electrically stimulated muscle that explicitly depend on a nonlinear mathematical model of muscle input-output properties are presented and evaluated. The muscle model consists of three factors: a muscle activation dynamics factor, an angle-torque
Small angle neutron scattering studies on the interaction of cationic ...
Indian Academy of Sciences (India)
in a wide variety of industrial, biological, pharmaceutical and cosmetic systems. The mechanism of unfolding of proteins on addition of the surfactant has been studied by several techniques such as circular dichroism (CD), nuclear magnetic resonance (NMR), microcalorimetry, light scattering and small angle scattering.
The effect of Q angle on ankle sprain occurrence.
Pefanis, Nikolaos; Papaharalampous, Xenofon; Tsiganos, Georgios; Papadakou, Eugenia; Baltopoulos, Panagiotis
2009-02-01
The intersegmental joint forces and the structures that must resist them (articular surfaces, ligaments, and musculature) are related through anatomical alignment of the joints and skeletal system. Ankle joint structure can affect or be affected by bony malformations of the surrounding areas, including the knee and hip. The aim of the current study is to examine the possible relationship between the quadriceps (Q) angle and other factors (anthropometric characteristics, medical history, and age) on the occurrence of ankle sprains, because its value, when assessed correctly, provides useful information for the anatomical alignment of the lower extremity. The study sample consisted of 45 high-level athletes, evenly distributed among 3 sports (basketball, soccer, and volleyball). Q angle measurements were made on radiographs. The study lasted for 2 years. A logistic regression was used to determine the importance of each factor on the probability in question. A significance level of P = .1 was used. The factors contributing more to an ankle sprain were a previous injury of the same type ( P .10). The results were valid even when the BMI variable was substituted by body inertia propensity, a derived variable. The Q angle remained statistically nonsignificant ( P > .10). The Q angle magnitude does not seem to be a decisive factor that could increase the probability of spraining an ankle. The most important factors that could affect the probability of sustaining an ankle sprain are the athlete's age, anthropometric characteristics, and prior injuries.
Clinical imaging of the cerebello-pontine angle
Energy Technology Data Exchange (ETDEWEB)
Valavanis, A.; Schubiger, O.; Naidich, T.P.
1986-01-01
This book describes the diagnostic problems encountered in cerebello-pontine angle lesions. It includes the differential diagnostic criteria for each specific lesion. The former radiological methods of examination are briefly reviewed, but the main stress is on computer tomography. A chapter is devoted to magnetic resonance imaging.
Angle-dependent bandgap engineering in gated graphene superlattices
Energy Technology Data Exchange (ETDEWEB)
García-Cervantes, H.; Sotolongo-Costa, O. [Centro de Investigación en Ciencias, IICBA, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, 62209 Cuernavaca, Morelos, México (Mexico); Gaggero-Sager, L. M. [CIICAp, IICBA, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, 62209 Cuernavaca, Morelos, México (Mexico); Naumis, G. G. [Instituto Física, Depto. de Física-Química, Universidad Nacional Autónoma de México (UNAM). Apdo. Postal 20-364, 01000, México D.F., México (Mexico); Rodríguez-Vargas, I., E-mail: isaac@fisica.uaz.edu.mx [Centro de Investigación en Ciencias, IICBA, Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, 62209 Cuernavaca, Morelos, México (Mexico); Unidad Académica de Física, Universidad Autónoma de Zacatecas, Calzada Solidaridad Esquina Con Paseo La Bufa S/N, 98060 Zacatecas, Zac., México (Mexico)
2016-03-15
Graphene Superlattices (GSs) have attracted a lot of attention due to its peculiar properties as well as its possible technological implications. Among these characteristics we can mention: the extra Dirac points in the dispersion relation and the highly anisotropic propagation of the charge carriers. However, despite the intense research that is carried out in GSs, so far there is no report about the angular dependence of the Transmission Gap (TG) in GSs. Here, we report the dependence of TG as a function of the angle of the incident Dirac electrons in a rather simple Electrostatic GS (EGS). Our results show that the angular dependence of the TG is intricate, since for moderated angles the dependence is parabolic, while for large angles an exponential dependence is registered. We also find that the TG can be modulated from meV to eV, by changing the structural parameters of the GS. These characteristics open the possibility for an angle-dependent bandgap engineering in graphene.
Small angle X-ray scattering from hydrating tricalcium silicate
International Nuclear Information System (INIS)
Vollet, D.
1983-01-01
The small-angle X-ray scattering technique was used to study the structural evolution of hydrated tricalcium silicate at room temperature. The changes in specific area of the associated porosity and the evolution of density fluctuations in the solid hydrated phase were deduced from the scattering data. A correlation of these variations with the hydration mechanism is tried. (Author) [pt
Discrete symmetries, cabibbo universality and flavor mixing angles
International Nuclear Information System (INIS)
Branco, C.G.
1977-12-01
A six quark SU(2)sub(L) (x) SU(2)sub(R) x U(1) model with additional discrete symmetries is proposed, where deviations from exact Cabibbo universality are naturally small, and the correct value for the Cabibbo angle is obtained. (orig.) [de
Small angle neutron scattering study on the aggregation behaviour ...
Indian Academy of Sciences (India)
Small angle neutron scattering (SANS) measurements on aqueous solutions of four polyethylene oxide–polypropylene oxide–polyethylene oxide block copolymers (commercially known as Pluronic®)F88, P85, F127 and P123 in the presence of hydrophobic C14Diol (also known as Surfynol® 104) reveal information on ...
Small angle neutron scattering studies of mixed micelles of sodium
Indian Academy of Sciences (India)
The aqueous solutions of sodium cumene sulphonate (NaCS) and its mixtures with each of cetyl trimethylammonium bromide (CTAB) and sodium dodecyl sulphate (SDS) are characterized by small angle neutron scattering (SANS). NaCS when added to CTAB solution leads to the formation of long rod-shaped micelles with ...
Estimation of Sideslip Angle Based on Extended Kalman Filter
Directory of Open Access Journals (Sweden)
Yupeng Huang
2017-01-01
Full Text Available The sideslip angle plays an extremely important role in vehicle stability control, but the sideslip angle in production car cannot be obtained from sensor directly in consideration of the cost of the sensor; it is essential to estimate the sideslip angle indirectly by means of other vehicle motion parameters; therefore, an estimation algorithm with real-time performance and accuracy is critical. Traditional estimation method based on Kalman filter algorithm is correct in vehicle linear control area; however, on low adhesion road, vehicles have obvious nonlinear characteristics. In this paper, extended Kalman filtering algorithm had been put forward in consideration of the nonlinear characteristic of the tire and was verified by the Carsim and Simulink joint simulation, such as the simulation on the wet cement road and the ice and snow road with double lane change. To test and verify the effect of extended Kalman filtering estimation algorithm, the real vehicle test was carried out on the limit test field. The experimental results show that the accuracy of vehicle sideslip angle acquired by extended Kalman filtering algorithm is obviously higher than that acquired by Kalman filtering in the area of the nonlinearity.
Anterior segment optical coherence tomography of acute primary angle closure.
Zhang, Hai Tao; Xu, Liang; Cao, Wei Fang; Wang, Ya Xing; Jonas, Jost B
2010-06-01
To assess anterior segment optical coherence tomographic measurements of patients after acute unilateral primary angle closure (APAC) compared with those of normal subjects. The clinical observational study included 41 hospital-based patients after unilateral APAC, their unaffected contralateral eyes, and 205 subjects. These were selected from the population-based Beijing Eye Study, and were matched with the APAC group for age, gender, and refractive error. All study participants underwent slit-lamp adapted optical coherence tomography (OCT). Compared with the unaffected contralateral eyes, eyes with APAC had a significantly shallower anterior chamber (P APAC and the unaffected contralateral eyes both showed more shallow anterior chambers (P APAC group, the anterior chamber angle was closed in three or more quadrants. Anterior segment OCT measurements show significant differences between eyes with APAC, contralateral eyes at risk for APAC, and normal eyes. This may open possibilities for a semi-automatic assessment of subjects at risk for APAC by anterior segment OCT. The anterior chamber angle was closed most often in the nasal quadrant, and, in APAC, the angle was closed in three or more quadrants.
Carbon microtubes: tuning internal diameters and conical angles.
Bhimarasetti, Gopinath; Cowley, John M; Sunkara, Mahendra K
2005-07-01
In this paper, we report a synthesis strategy for a new class of hollow, curved carbon morphologies, 'carbon microtubes' (CMTs), with absolute control over their conical angles and internal diameters. Our synthesis methodology employs nitrogen or oxygen dosing to change the wetting behaviour of gallium metal with the growing carbon walls to tune the conical angles. Increasing N(2) concentrations in the gas phase during growth increases the conical angles of CMTs from +25° to about -20°. A methodology using the timing of oxygen or nitrogen dosing during CMT growth is shown to tune the internal diameters anywhere from a few nanometres to a few microns. The walls of the carbon microtubes are characterized using transmission electron microscopy (TEM) and Raman spectroscopy and are found to consist of aligned graphite nanocrystals (2-5 nm in size). Furthermore, dark field images of CMTs showed that the graphite nanocrystals are aligned with their c-axes perpendicular to the wall surface and that the crystals themselves are oriented with respect to the wall surface depending upon the conical angle of the CMT.
Improved Angle Potentials for Coarse-Grained Molecular Dynamics Simulations
Bulacu, Monica; Goga, Nicolae; Zhao, Wei; Rossi, Giulia; Monticelli, Luca; Periole, Xavier; Tieleman, D. Peter; Marrink, Siewert J.
Potentials routinely used in atomistic molecular dynamics simulations are not always suitable for modeling systems at coarse-grained resolution. For example, in the calculation of traditional torsion angle potentials, numerical instability is often encountered in the case of very flexible molecules.
An angle-sensitive detection system for scattered heavy ions
Ganz, R E; Bär, R; Bethge, Klaus; Bokemeyer, H; Folger, H; Samek, M; Salabura, P; Schwalm, D; Stiebing, K E
1999-01-01
A compact detection system for heavy ions scattered in collisions at the Coulomb barrier is presented. This system, consisting of four identical, low-pressure Parallel Plate Avalanche Counter (PPAC) modules with two sensitive layers each, was built to operate in an ultra-high-vacuum environment inside the EPoS II solenoid spectrometer at GSI Darmstadt. The detector covers polar angles between 20 deg. and 70 deg. with respect to the beam axis, and about 80% of 2 pi in azimuthal angle. Segmented cathodes and a delay-line read-out allow for a determination of both angles with a precision of delta THETA approx 0.7 deg. in polar and delta PHI approx 1.5 deg. in azimuthal angle, respectively. The system has been proven to be capable of handling instantaneous rates of up to 5x10 sup 5 detected ions per second per module. It neither exhibits the degradation of detection efficiency nor loss in resolution over a 500 h period of a 6 MeV/u sup 2 sup 3 sup 8 U+ sup 1 sup 8 sup 1 Ta measurement at average luminosities of 8...
Small Angle Scattering in Neutron Imaging : A Review
Strobl, Markus; Harti, Ralph P.; Grünzweig, Christian; Woracek, Robin; Plomp, J.
2017-01-01
Conventional neutron imaging utilizes the beam attenuation caused by scattering and absorption through the materials constituting an object in order to investigate its macroscopic inner structure. Small angle scattering has basically no impact on such images under the geometrical conditions applied.
Small-angle neutron scattering from micellar solutions
Indian Academy of Sciences (India)
The structure (shape and size) and the interaction of these aggregates, referred to as micelles, depend on the molecular architecture of the surfactant molecule, presence of additives and the solution conditions such as temperature, concentration etc. This paper gives the usefulness of small-angle neutron scattering to the ...
Multiple small-angle neutron scattering studies of anisotropic materials
Allen, A J; Long, G G; Ilavsky, J
2002-01-01
Building on previous work that considered spherical scatterers and randomly oriented spheroidal scatterers, we describe a multiple small-angle neutron scattering (MSANS) analysis for nonrandomly oriented spheroids. We illustrate this with studies of the multi-component void morphologies found in plasma-spray thermal barrier coatings. (orig.)
Angles of Elevation of the Pyramids of Egypt.
Smith, Arthur F.
1982-01-01
The nature and history of the construction of pyramids in Egypt is detailed. It is noted that one can only theorize about why the Egyptians used particular angles of elevation. It is thought, perhaps, that new clues will provide a clear solution to this mystery as additional artifacts and hieroglyphics are discovered. (MP)
Vowel Formants and Angle Measurements in Diachronic Sociophonetic Studies
DEFF Research Database (Denmark)
Fabricius, Anne
2007-01-01
is well documented in varieties of British English, such as Torgersen and Kerswill [10], including RP, as in Hawkins and Midgley [6]. The paper also demonstrates the versatility of an angle calculation method (Fabricius [3]), used in combination with F1/F2 plots, in producing replicable quantified...
Neutrino Mass Models: Impact of non-zero reactor angle
King, Stephen F.
2011-01-01
In this talk neutrino mass models are reviewed and the impact of a non-zero reactor angle and other deviations from tri-bimaximal mixing are discussed. We propose some benchmark models, where the only way to discriminate between them is by high precision neutrino oscillation experiments.
Visual disability in Newly Diagnosed Primary open Angle Glaucoma ...
African Journals Online (AJOL)
Background: Glaucoma remains the second leading cause of blindness worldwide and the highest cause of irreversible blindness worldwide. In Nigeria, Glaucoma accounts for 16% of blindness and primary open angle glaucoma is the most prevalent clinical type. Aim: The aim of this study is to assess the visual disability ...
Temperature dependent small-angle neutron scattering of CTABr ...
Indian Academy of Sciences (India)
Atomic Research Centre, Mumbai 400 085, India. cDepartment of Physics, Bhavnagar University, Bhavnagar 364 002, India. E-mail: ruv@bhavuni.edu. Abstract. Small-angle neutron scattering studies have been carried out to check the structural integrity of ... the surface of the micelle. Micellar solution of CTABr is isotropic ...
Characterization of porous materials by small-angle scattering
Indian Academy of Sciences (India)
With the availability of ultra small-angle scattering instru- ments, one can investigate porous materials in the sub-micron length scale. Because of the increased accessible length scale vis-a-vis the multiple scattering effect, conventional data analysis procedures based on single scattering approximation quite often fail. The.
Characterization of porous materials by small-angle scattering
Indian Academy of Sciences (India)
With the availability of ultra small-angle scattering instruments, one can investigate porous materials in the sub-micron length scale. Because of the increased accessible length scale vis-a-vis the multiple scattering effect, conventional data analysis procedures based on single scattering approximation quite often fail.
Small-angle neutron scattering studies on water soluble complexes ...
Indian Academy of Sciences (India)
... by small-angle neutron scattering. SANS data showed a positive indication of the formation of RCP-SDS complexes. Even though the complete structure of the polyion complexes could not be ascertained, the results obtained give us the information on the local structure in these polymer-surfactant systems. The data were ...
Characterization of alumina using small angle neutron scattering (SANS)
International Nuclear Information System (INIS)
Megat Harun Al Rashidn Megat Ahmad; Abdul Aziz Mohamed; Azmi Ibrahim; Che Seman Mahmood; Edy Giri Rachman Putra; Muhammad Rawi Muhammad Zin; Razali Kassim; Rafhayudi Jamro
2007-01-01
Alumina powder was synthesized from an aluminium precursor and studied using small angle neutron scattering (SANS) technique and complemented with transmission electron microscope (TEM). XRD measurement confirmed that the alumina produced was high purity and highly crystalline αphase. SANS examination indicates the formation of mass fractals microstructures with fractal dimension of about 2.8 on the alumina powder. (Author)
Neutron imaging and small angle neutron scattering instruments at KUR
International Nuclear Information System (INIS)
Saito, Yasushi; Oba, Yojiro; Hino, Masahiro
2015-01-01
We review the neutron imaging (NI) and small-angle neutron scattering (SANS) instruments at KUR, Kumatori, Osaka, Japan. There are two NI and one SANS instruments. The both instruments are compact and used flexibly. Some challenging experiments taking advantage of low neutron fluence are described. The feature of KUR is also described briefly. (author)
Evaluation of the Contact Angle from Molecular Simulations.
Czech Academy of Sciences Publication Activity Database
Škvára, J.; Škvor, J.; Nezbeda, Ivo
2018-01-01
Roč. 44, č. 3 (2018), s. 190-199 ISSN 0892-7022 R&D Projects: GA ČR GA15-19542S Institutional support: RVO:67985858 Keywords : contact angle * argon droplet * surface molecules Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 1.254, year: 2016
First inter metatarsal (IM) angles in Nigerians and their relationship ...
African Journals Online (AJOL)
Background: No age is immune to the deformity known as Hallux valgus as it has been proven that 50% of adults developed it during adolescence, while 40% of juveniles developed it before the age of 10.5 years. Aim: To determine from radiographs the normal value of the first inter metatarsal (IM) angle and to establish if ...
The effect of circular bridge piers with different inclination angles ...
Indian Academy of Sciences (India)
c Indian Academy of Sciences. The effect of circular bridge piers with different inclination angles toward downstream on scour. MOHAMMAD VAGHEFI1,∗, MASOUD GHODSIAN2 and. SAEID SALIMI3. 1Department of Civil Engineering, Persian Gulf University, Shahid Mahini Street, P.O. Box: 75169-13817,. Bushehr, Iran.
Temperature dependent small-angle neutron scattering of CTABr ...
Indian Academy of Sciences (India)
Micelles are aggregates of surfactant molecules and these aggregates are usually formed in different shapes of spherical, cylindrical, ellipsoidal, disc-like etc. The size and shapes of these micelles are studied using small-angle neutron scattering (SANS) [2]. A preparation of stable emulsion of magnetic fluid with micelles ...
Small-angle neutron scattering studies of nonionic surfactant: Effect
Indian Academy of Sciences (India)
Micellar solution of nonionic surfactant -dodecyloligo ethyleneoxide surfactant, decaoxyethylene monododecyl ether [CH3(CH2)11(OCH2CH2)10OH], C12E10 in D2O solution have been analysed by small-angle neutron scattering (SANS) at different temperatures (30, 45 and 60°C) both in the presence and absence of ...
Small angle neutron scattering studies on the interaction of cationic
Indian Academy of Sciences (India)
The structure of the protein–surfactant complex of bovine serum albumin (BSA) and cationic surfactants has been studied by small angle neutron scattering. At low concentrations, the CTAB monomers are observed to bind to the protein leading to an increase in its size. On the other hand at high concentrations, surfactant ...
The inter-relationships between angle of inclination, height and ...
African Journals Online (AJOL)
Experiments were conducted to investigate the dependence of number of sprouted teak (Tectona grandis Linn. F) stumps on the height above root collar and angle of inclination of planted teak stumps. The studies were aim-ed at developing suitable methods of converting teak seedlings into stumps and planting practices to ...
Angle dependence of Andreev scattering at semiconductor-superconductor interfaces
DEFF Research Database (Denmark)
Mortensen, Asger; Flensberg, Karsten; Jauho, Antti-Pekka
1999-01-01
We study the angle dependence of the Andreev scattering at a semiconductor-superconductor interface, generalizing the one-dimensional theory of Blonder, Tinkham, and Klapwijk (BTK),An increase of the momentum parallel to the interface leads to suppression of the probability of Andreev reflection...
Combined surgical management of mandibular angle prominence and microgenia
International Nuclear Information System (INIS)
Portelles Masso, Ayelen Maria; Berger Kohn, Carlos
2010-01-01
Chin play a very important role in facial aesthetics. Different deformities of volume and of position may occur at this level and it is the microgenia one of the more frequent. Treatment options include the use of silicone, alloplasty materials and autologous bone graft. Authors report the use of the bone removed from mandibular angle to increase the chin. This is the case of a white female patient aged 18 seen by the Orthognathics Multidisciplinary Staff of 'V. I. Lenin' Hospital due to its uncommon face width. The corresponding physical examination as well as the complementary ones diagnosed a bilateral prominence of mandibular angle associated with a microgenia. Surgery carried out was of remodeling type of both mandibular angles and genioplasty of height increase and a discrete advancement using the bone removed from the gonion. There were satisfactory aesthetic results without evidence of bone reabsorption. We conclude that use of autologous graft of mandibular angle is an effective treatment alternative for correction of microgenia. (author)
Angle-domain common-image gathers from anisotropic Gaussian ...
Indian Academy of Sciences (India)
s12040-016-0783-x. Angle-domain common-image gathers from anisotropic ..... are not flat. The test results demonstrate that anisotropy has a great influence on GB-PSDM in. VTI media, and ignoring anisotropy in migration may lead to obvious ...
Selected fishery and population parameters of eight shore-angling ...
African Journals Online (AJOL)
The large inter annual variations in mean CPUE and size for all species indicated that a minimum assessment period of four years is required to obtain reliable estimates. Keywords: catch per unit effort; fisheries management; marine protected area; natural mortality; shore-angling fishery. African Journal of Marine Science ...
Angle Resolved Performance Measurements on PV Glass and Modules
DEFF Research Database (Denmark)
Juutilainen, Line Tollund; Thorsteinsson, Sune; Poulsen, Peter Behrensdorff
2016-01-01
The angular response of PV-modules has significant impact on the energy production. This is especially pronounced in BIPV where installation angles often are far from optimal. Nevertheless, a gain in energy yield may be obtained by choosing a proper glass as superstrate. In this work we present t...
Comparison of various methods for estimating wave incident angles ...
African Journals Online (AJOL)
Five different methods were examined for their suitability in estimating the inshore wave incident angles on a nearshore zone with a complex topography. Visual observation provided preliminary estimates. Two frequency independent methods and one frequency dependent method based on current meter measurements ...
Ultra-small angle X-ray diffraction from muscle
Energy Technology Data Exchange (ETDEWEB)
Nave, C.; Diakun, G.P.; Bordas, J.
1986-05-15
An ultra-small angle X-ray scattering instrument is described. It uses two channel cut crystals, one to monochromatise and collimate the beam and the other to analyse the scattered radiation. It has been used to collect diffraction data from muscle, in which the physiological unit cell, the sarcomere, has a repeat of 2000 nm or more.
Drop shape visualization and contact angle measurement on curved surfaces.
Guilizzoni, Manfredo
2011-12-01
The shape and contact angles of drops on curved surfaces is experimentally investigated. Image processing, spline fitting and numerical integration are used to extract the drop contour in a number of cross-sections. The three-dimensional surfaces which describe the surface-air and drop-air interfaces can be visualized and a simple procedure to determine the equilibrium contact angle starting from measurements on curved surfaces is proposed. Contact angles on flat surfaces serve as a reference term and a procedure to measure them is proposed. Such procedure is not as accurate as the axisymmetric drop shape analysis algorithms, but it has the advantage of requiring only a side view of the drop-surface couple and no further information. It can therefore be used also for fluids with unknown surface tension and there is no need to measure the drop volume. Examples of application of the proposed techniques for distilled water drops on gemstones confirm that they can be useful for drop shape analysis and contact angle measurement on three-dimensional sculptured surfaces. Copyright © 2011 Elsevier Inc. All rights reserved.
Comparison of Primary Open Angle Glaucoma Patients in Rural and ...
African Journals Online (AJOL)
Purpose: To compare the clinical features of glaucoma patients who present at a rural hospital in North Eastern Ghana and an urban hospital in the capital city of Accra. Methods: This is a multi-center retrospective case series involving records of newly diagnosed glaucoma patients with emphasis on primary open angle ...
Impaired Saccadic Eye Movement in Primary Open-angle Glaucoma
DEFF Research Database (Denmark)
Lamirel, Cédric; Milea, Dan; Cochereau, Isabelle
2013-01-01
PURPOSE:: Our study aimed at investigating the extent to which saccadic eye movements are disrupted in patients with primary open-angle glaucoma (POAG). This approach followed upon the discovery of differences in the eye-movement behavior of POAG patients during the exploration of complex visual...
Is angle closure glaucoma a problem in Nigeria? | Olawoye ...
African Journals Online (AJOL)
Purpose: The aim of this study was to report the characteristics of angle closure glaucoma (ACG) in eye clinic patients of University College Hospital (UCH), Ibadan, Nigeria. Materials and Methods: A total of 336 consecutive new glaucoma patients of all age groups who presented to the glaucoma clinic of UCH over a 1 year ...
Compliance to Medical Therapy of Primary Open Angle Glaucoma in ...
African Journals Online (AJOL)
Background: The aim of this study was to determinethe rate of compliance to medical therapy of primary open angle glaucoma in Enugu with a view to improving patient care and reducing visual deterioration and loss from glaucoma. Method: One hundred and five patients were reviewed from the glaucoma patients who ...
Presenting features ofprimary angle-closure glaucotna in patients ...
African Journals Online (AJOL)
underwent a full ophthalmic examination including slit- lamp examination, applanation tonometry and direct ophthalmoscopy. The best corrected visual acuity was recorded after control of the acme episode of intra-ocu- lar pressure rise. The drainage angle was assessed by means of manipulative Goldmann gonioscopy or ...
Small-angle neutron scattering in materials science - an introduction
Energy Technology Data Exchange (ETDEWEB)
Fratzl, P. [Vienna Univ., Inst. fuer Materialphysik, Vienna (Austria)
1996-12-31
The basic principles of the application of small-angle neutron scattering to materials research are summarized. The text focusses on the classical methods of data evaluation for isotropic and for anisotropic materials. Some examples of applications to the study of alloys, porous materials, composites and other complex materials are given. (author) 9 figs., 38 refs.
IMU-Based Joint Angle Measurement for Gait Analysis
Directory of Open Access Journals (Sweden)
Thomas Seel
2014-04-01
Full Text Available This contribution is concerned with joint angle calculation based on inertial measurement data in the context of human motion analysis. Unlike most robotic devices, the human body lacks even surfaces and right angles. Therefore, we focus on methods that avoid assuming certain orientations in which the sensors are mounted with respect to the body segments. After a review of available methods that may cope with this challenge, we present a set of new methods for: (1 joint axis and position identification; and (2 flexion/extension joint angle measurement. In particular, we propose methods that use only gyroscopes and accelerometers and, therefore, do not rely on a homogeneous magnetic field. We provide results from gait trials of a transfemoral amputee in which we compare the inertial measurement unit (IMU-based methods to an optical 3D motion capture system. Unlike most authors, we place the optical markers on anatomical landmarks instead of attaching them to the IMUs. Root mean square errors of the knee flexion/extension angles are found to be less than 1° on the prosthesis and about 3° on the human leg. For the plantar/dorsiflexion of the ankle, both deviations are about 1°.
Lower extremity angle measurement with accelerometers - error and sensitivity analysis
Willemsen, A.T.M.; Willemsen, Antoon Th.M.; Frigo, Carlo; Boom, H.B.K.
1991-01-01
The use of accelerometers for angle assessment of the lower extremities is investigated. This method is evaluated by an error-and-sensitivity analysis using healthy subject data. Of three potential error sources (the reference system, the accelerometers, and the model assumptions) the last is found
Molecular complexity of primary open angle glaucoma: current ...
Indian Academy of Sciences (India)
2009-12-31
Dec 31, 2009 ... [Ray K. and Mookherjee S. 2009 Molecular complexity of primary open angle glaucoma: current concepts J. Genet. 88, 451–467]. Introduction .... cellular matrix (ECM) protein but its function is still not well elucidated. Although a large ...... ergy starvation of the nerve cells is possible. Opening of. PTPC will ...
Visual angle model for car-following theory
Jin, Sheng; Wang, Dian-Hai; Huang, Zhi-Yi; Tao, Peng-Fei
2011-06-01
The vast majority of car-following models are lack of the consideration of human drivers' characteristics. Based on the fact that each driver of a following vehicle perceives closing-in or shying-away a leading vehicle in front of him/her, primarily due to changes in the apparent size of the leading vehicle, we improved the full velocity difference (FVD) model and presented a visual angle car-following model. This model is in view of the stimulus-response framework and uses the visual angle and the change rate of the visual angle as stimulus. Results from linear analysis showed that the neutral stability line is asymmetry and the width of the leading vehicle has a great impact on the stability of traffic flow. Numerical simulations obtained the same results as theoretical analysis clearly such as density wave, shrinking hysteresis, asymmetry and wide scattering. Thus, the introducing of the visual angle can explain some complex nature of traffic flow and contribute to the design of more realistic car-following models.
Control of polyaniline conductivity and contact angles by partial protonation
Czech Academy of Sciences Publication Activity Database
Blinova, Natalia V.; Stejskal, Jaroslav; Trchová, Miroslava; Prokeš, J.
2008-01-01
Roč. 57, č. 1 (2008), s. 66-69 ISSN 0959-8103 R&D Projects: GA MŠk ME 847; GA ČR GA202/06/0419 Institutional research plan: CEZ:AV0Z40500505 Keywords : conducting polymer * conductivity * contact angle Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.029, year: 2008
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.
Parameter dependence of conic angle of nanofibres during electrospinning
International Nuclear Information System (INIS)
Zhou Zhengping; Wu Xiangfa; Jiang Long; Gao Xueqin; Zhao Yong; Fong Hao
2011-01-01
This paper reports the dependence of conic angle of nanofibres on the processing and material parameters during electrospinning. Solutions of polyacrylonitrile (PAN) in dimethylformamide (DMF) with varied PAN concentrations were studied as the model systems, and they were electrospun into nanofibres at different high direct current (dc) voltages, flow rates and needle diameters. The dynamic and transient shear viscosities of the PAN/DMF solutions were characterized by a parallel-plate rheometer at varied shear rates. Rheological measurements showed that the PAN/DMF solutions behaved as Newtonian fluids at relatively low to medium shear rates, while the solutions with high PAN concentrations of 18 and 20 wt% exhibited a significant shear-thinning behaviour at high shear rates, especially in the case of transient shear mode. Experimental results indicated that at the electrostatic field of ∼80 kV m -1 and needle inner diameter of 0.48 mm (22 gauge), the conic angle of the nanofibre envelope decreased from ∼160° to ∼75° with an increase in PAN concentration from 12 to 20 wt%; at the PAN concentration of 16 wt%, the conic angle increased nonlinearly from ∼40° to ∼160° with an increase in electric field from 50 to 140 kV m -1 . In addition, experimental results showed that the needle inner diameter also noticeably influenced the conic angle. This study provided the experimental evidence useful for understanding the scaling properties of electrohydrodynamic jet motion for controllable electrospinning and process modelling.
Optical Enhancement of Exoskeleton-Based Estimation of Glenohumeral Angles
Directory of Open Access Journals (Sweden)
Camilo Cortés
2016-01-01
Full Text Available In Robot-Assisted Rehabilitation (RAR the accurate estimation of the patient limb joint angles is critical for assessing therapy efficacy. In RAR, the use of classic motion capture systems (MOCAPs (e.g., optical and electromagnetic to estimate the Glenohumeral (GH joint angles is hindered by the exoskeleton body, which causes occlusions and magnetic disturbances. Moreover, the exoskeleton posture does not accurately reflect limb posture, as their kinematic models differ. To address the said limitations in posture estimation, we propose installing the cameras of an optical marker-based MOCAP in the rehabilitation exoskeleton. Then, the GH joint angles are estimated by combining the estimated marker poses and exoskeleton Forward Kinematics. Such hybrid system prevents problems related to marker occlusions, reduced camera detection volume, and imprecise joint angle estimation due to the kinematic mismatch of the patient and exoskeleton models. This paper presents the formulation, simulation, and accuracy quantification of the proposed method with simulated human movements. In addition, a sensitivity analysis of the method accuracy to marker position estimation errors, due to system calibration errors and marker drifts, has been carried out. The results show that, even with significant errors in the marker position estimation, method accuracy is adequate for RAR.
Optical Enhancement of Exoskeleton-Based Estimation of Glenohumeral Angles.
Cortés, Camilo; Unzueta, Luis; de Los Reyes-Guzmán, Ana; Ruiz, Oscar E; Flórez, Julián
2016-01-01
In Robot-Assisted Rehabilitation (RAR) the accurate estimation of the patient limb joint angles is critical for assessing therapy efficacy. In RAR, the use of classic motion capture systems (MOCAPs) (e.g., optical and electromagnetic) to estimate the Glenohumeral (GH) joint angles is hindered by the exoskeleton body, which causes occlusions and magnetic disturbances. Moreover, the exoskeleton posture does not accurately reflect limb posture, as their kinematic models differ. To address the said limitations in posture estimation, we propose installing the cameras of an optical marker-based MOCAP in the rehabilitation exoskeleton. Then, the GH joint angles are estimated by combining the estimated marker poses and exoskeleton Forward Kinematics. Such hybrid system prevents problems related to marker occlusions, reduced camera detection volume, and imprecise joint angle estimation due to the kinematic mismatch of the patient and exoskeleton models. This paper presents the formulation, simulation, and accuracy quantification of the proposed method with simulated human movements. In addition, a sensitivity analysis of the method accuracy to marker position estimation errors, due to system calibration errors and marker drifts, has been carried out. The results show that, even with significant errors in the marker position estimation, method accuracy is adequate for RAR.
Small Angle Neutron Scattering instrument at Malaysian TRIGA reactor
Energy Technology Data Exchange (ETDEWEB)
Shukri Mohd; Razali Kassim; Zal Uyun Mahmood [Malaysian Inst. for Nuclear Technology Research (MINT), Bangi, Kajang (Malaysia); Shahidan Radiman
1998-10-01
The TRIGA MARK II Research reactor at the Malaysian Institute for Nuclear Research (MINT) was commissioned in July 1982. Since then various works have been performed to utilise the neutrons produced from this steady state reactor. One of the project involved the Small Angle Neutron Scattering (SANS). (author)
Small angle neutron scattering in surface-active agents mixtures
Bulavin, L. A.; Garamus, V. M.; Ostanevich, Yu. M.
The method of study of micelle structure by small angle neutron scattering is studied. The determination of maximum size, radius of gyration, average scattering density of micelles is presented. The way of study of distribution of scattering density in micelle is described. The problem of micelles interaction is discussed.
IMU-based joint angle measurement for gait analysis.
Seel, Thomas; Raisch, Jörg; Schauer, Thomas
2014-04-16
This contribution is concerned with joint angle calculation based on inertial measurement data in the context of human motion analysis. Unlike most robotic devices, the human body lacks even surfaces and right angles. Therefore, we focus on methods that avoid assuming certain orientations in which the sensors are mounted with respect to the body segments. After a review of available methods that may cope with this challenge, we present a set of new methods for: (1) joint axis and position identification; and (2) flexion/extension joint angle measurement. In particular, we propose methods that use only gyroscopes and accelerometers and, therefore, do not rely on a homogeneous magnetic field. We provide results from gait trials of a transfemoral amputee in which we compare the inertial measurement unit (IMU)-based methods to an optical 3D motion capture system. Unlike most authors, we place the optical markers on anatomical landmarks instead of attaching them to the IMUs. Root mean square errors of the knee flexion/extension angles are found to be less than 1° on the prosthesis and about 3° on the human leg. For the plantar/dorsiflexion of the ankle, both deviations are about 1°.
Determination Method of Bridge Rotation Angle Response Using MEMS IMU.
Sekiya, Hidehiko; Kinomoto, Takeshi; Miki, Chitoshi
2016-11-09
To implement steel bridge maintenance, especially that related to fatigue damage, it is important to monitor bridge deformations under traffic conditions. Bridges deform and rotate differently under traffic load conditions because their structures differ in terms of length and flexibility. Such monitoring enables the identification of the cause of stress concentrations that cause fatigue damage and the proposal of appropriate countermeasures. However, although bridge deformation monitoring requires observations of bridge angle response as well as the bridge displacement response, measuring the rotation angle response of a bridge subject to traffic loads is difficult. Theoretically, the rotation angle response can be calculated by integrating the angular velocity, but for field measurements of actual in-service bridges, estimating the necessary boundary conditions would be difficult due to traffic-induced vibration. To solve the problem, this paper proposes a method for determining the rotation angle response of an in-service bridge from its angular velocity, as measured by a inertial measurement unit (IMU). To verify our proposed method, field measurements were conducted using nine micro-electrical mechanical systems (MEMS) IMUs and two contact displacement gauges. The results showed that our proposed method provided high accuracy when compared to the reference responses calculated by the contact displacement gauges.
Contrast-enhanced CISS imaging of cerebellopontine angle tumors
Energy Technology Data Exchange (ETDEWEB)
Tozaki, Mitsuhiro; Toyoda, Keiko; Hata, Yuichi; Fukuda, Yasushi; Fukuda, Kunihiko [Jikei Univ., Tokyo (Japan). School of Medicine; Katano, Shuichi
1999-10-01
Our purpose of this study was to evaluate the clinical usefulness of contrast-enhanced CISS-3DFT MR imaging for the diagnosis of CP angle tumors. CISS-3DFT MR imaging is expected for screening procedure of acoustic schwannoma because of excellent spatial resolution. Recently, we discovered contrast enhancement effect on CISS sequence in spite of heavily T{sub 2}-weighted images. Fourteen patients with CP angle tumors were performed on a 1.0 T MR unit. Transaxial CISS-3DFT MRI was obtained both before and after intravenous injections of Gd-DTPA. Multiplanar reconstructions (MPRs) were performed in all cases. Contrast enhancement effect of CP angle tumors, and the relationship between tumors and the adjacent cranial nerves were evaluated. Contrast enhancement effect of the tumors was present in all cases in spite of heavily T{sub 2}-weighted images of CISS sequences. In the internal auditory canal, relationship between the tumors and the cranial nerves was demonstrated in 6 cases (6/9). In the cerebellopontine cistern, all cases were demonstrated (11/11). Contrast-enhanced CISS-3DFT MR imaging with a good contrast resolution and an excellent spatial resolution is useful for the diagnosis of CP angle tumors. (author)
Tight bounds on angle sums of nonobtuse simplices
Czech Academy of Sciences Publication Activity Database
Brandts, J.; Cihangir, A.; Křížek, Michal
2015-01-01
Roč. 267, 15 September (2015), s. 397-408 ISSN 0096-3003 R&D Projects: GA ČR GA14-02067S Institutional support: RVO:67985840 Keywords : nonobtuse simplex * angle sum s * spherical geometry * polar simplex Subject RIV: BA - General Mathematics Impact factor: 1.345, year: 2015 http://www.sciencedirect.com/science/article/pii/S0096300315002155
determination of determination of optimal tilt angle for maximum
African Journals Online (AJOL)
eobe
The analysis showed that the best tilt angle for PV energy production is 60 if the module is fixed module ... suitable solar technology at an efficiency of 1%. Also, ... it. Thus, achieving the maximum possible performance is critical in PV power generation [14]. Installing PV modules on either a single or dual-axis trackers is one.
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
Deformation effects in the heavy ion quarter-point angle
International Nuclear Information System (INIS)
Almeida, F.I.A. de; Hussein, M.S.
1984-01-01
The effects of static and dynamic deformation on the heavy-ion elastic scattering quarter-point angle are discussed and analyzed in the sudden approximation. Simple expressions are derived within the Fresnel model and applications to several heavy-ion systems are presented. (Author) [pt
Small-angle neutron scattering study of structural evolution of ...
Indian Academy of Sciences (India)
Small-angle neutron scattering; biological macromolecules; protein solution. PACS Nos 61.12.Ex; 87.14.Ee; 87.15.Nn. Biological macromolecules such as proteins possess a specific shape and charge, which regulate and ... Figure 1a shows the phase diagram of crystallization of 1 wt% lysozyme protein solution as a ...
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.
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
Calcaneal Fractures and Böhler’s Angle
Directory of Open Access Journals (Sweden)
Lindsey Spiegelman
2017-01-01
Full Text Available History of present illness: 40-year-old male presents to the emergency department after falling off a ladder. He was repairing a window when he fell, landing on the ground 12 feet below. The patient landed onto his feet bilaterally and then fell backwards onto his buttocks. On arrival, the patient had bilateral foot pain. He denied any back pain, headache, or loss of consciousness. Significant findings: The right ankle lateral radiograph shows a comminuted, non-displaced fracture of the posterior calcaneus (red arrow in addition to fracture fragments along the heel pad margin (blue arrow. The left ankle lateral radiograph shows a displaced, comminuted fracture of the mid to posterior calcaneus with extension into the subtalar joint posteriorly (purple arrow. There is subcutaneous air seen anteriorly to the tibiotalar joint space (green arrow in addition to a joint effusion. Of note, the Böhler’s angle in the left x-ray is 16 degrees which is consistent with a fracture (see red annotation showing Böhler’s angle. Discussion: Calcaneal fractures occur typically in adults who have undergone significant axial load on their feet secondary to a fall from high height.2,3 There are two broad types of calcaneal fractures: intraarticular and extraarticular.2 The intraarticular fractures are colloquially referred to as a “Lover’s Fracture” as they have been known to occur in those jumping out of a tall window to escape the wrath of a lover’s spouse.1 Calcaneal fractures are best diagnosed with a CT scan or with lateral x-ray by measuring Böhler’s angle.2,3 This is the angle formed by the intersection of two lines demonstrated on a normal lateral ankle radiograph. The first line is drawn between the superior aspect of the anterior process of the calcaneus (point A and the superior edge of the posterior articular facet (point B. The second line is drawn between the superior aspect of the posterior calcaneal tuberosity (point C and point B.2
Carbon Condensation during High Explosive Detonation with Time Resolved Small Angle X-ray Scattering
Hammons, Joshua; Bagge-Hansen, Michael; Nielsen, Michael; Lauderbach, Lisa; Hodgin, Ralph; Bastea, Sorin; Fried, Larry; May, Chadd; Sinclair, Nicholas; Jensen, Brian; Gustavsen, Rick; Dattelbaum, Dana; Watkins, Erik; Firestone, Millicent; Ilavsky, Jan; van Buuren, Tony; Willey, Trevor; Lawrence Livermore National Lab Collaboration; Los Alamos National Laboratory Collaboration; Washington State University/Advanced Photon Source Team
Carbon condensation during high-energy detonations occurs under extreme conditions and on very short time scales. Understanding and manipulating soot formation, particularly detonation nanodiamond, has attracted the attention of military, academic and industrial research. An in-situ characterization of these nanoscale phases, during detonation, is highly sought after and presents a formidable challenge even with today's instruments. Using the high flux available with synchrotron X-rays, pink beam small angle X-ray scattering is able to observe the carbon phases during detonation. This experimental approach, though powerful, requires careful consideration and support from other techniques, such as post-mortem TEM, EELS and USAXS. We present a comparative survey of carbon condensation from different CHNO high explosives. This work was performed under the auspices of the US DOE by LLNL under Contract DE-AC52-07NA27344.
Asymmetric-cut variable-incident-angle monochromator.
Smither, R K; Graber, T J; Fernandez, P B; Mills, D M
2012-03-01
A novel asymmetric-cut variable-incident-angle monochromator was constructed and tested in 1997 at the Advanced Photon Source of Argonne National Laboratory. The monochromator was originally designed as a high heat load monochromator capable of handling 5-10 kW beams from a wiggler source. This was accomplished by spreading the x-ray beam out on the surface an asymmetric-cut crystal and by using liquid metal cooling of the first crystal. The monochromator turned out to be a highly versatile monochromator that could perform many different types of experiments. The monochromator consisted of two 18° asymmetrically cut Si crystals that could be rotated about 3 independent axes. The first stage (Φ) rotates the crystal around an axis perpendicular to the diffraction plane. This rotation changes the angle of the incident beam with the surface of the crystal without changing the Bragg angle. The second rotation (Ψ) is perpendicular to the first and is used to control the shape of the beam footprint on the crystal. The third rotation (Θ) controls the Bragg angle. Besides the high heat load application, the use of asymmetrically cut crystals allows one to increase or decrease the acceptance angle for crystal diffraction of a monochromatic x-ray beam and allows one to increase or decrease the wavelength bandwidth of the diffraction of a continuum source like a bending-magnet beam or a normal x-ray-tube source. When the monochromator is used in the doubly expanding mode, it is possible to expand the vertical size of the double-diffracted beam by a factor of 10-15. When this was combined with a bending magnet source, it was possible to generate an 8 keV area beam, 16 mm wide by 26 mm high with a uniform intensity and parallel to 1.2 arc sec that could be applied in imaging experiments.
Reliability of goniometry-based Q-angle.
Weiss, Lawrence; DeForest, Bradley; Hammond, Kelley; Schilling, Brian; Ferreira, Lucas
2013-09-01
To establish the stability reliability, precision, and minimum value for detecting real differences for quadriceps angle (Q-angle) measurements based on standardized protocols and surface goniometry. An intratester reliability study. University research laboratory. Fifty-two healthy, young, relatively lean adults (25 men and 27 women) from the university community with no history of knee injury. Q-angle was assessed with surface goniometry on 2 separate occasions separated by 48 hours. Subjects assumed a supine position with: (1) extended hips and knees, (2) neutral hip rotational position, (3) neutral foot position, and (4) isometrically contracted quadriceps femoris muscles. The axis of a manual extendable-arm goniometer was placed over the center of the right patella with the proximal arm situated over the anterior-superior iliac spine and the distal arm over the center of the tibial tuberosity. Stability reliability was calculated with use of intraclass correlation (ICC, 2-way random model) and precision was calculated by standard error of measurement (SEM). The 95% limits of agreement also were calculated to estimate the minimum detectable difference in Q-angles. The lowest acceptable ICC was set at ≥0.70 for stability reliability. The following ICC (SEM) values were found: all subjects = 0.88 (1.0°), men = 0.77 (1.0°), and women = 0.85 (1.0°). The 95% limits of agreement were 3° for the same 3 groups. The surface goniometry protocol described herein appeared to be reliable for relatively lean young men and women. Although measures were precise to 1.0°, it appears a difference of 3° may be needed to detect a real difference in Q-angles when measured in this fashion. Copyright © 2013 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.