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Sample records for surface features intensity

  1. Thin plate spline feature point matching for organ surfaces in minimally invasive surgery imaging

    Science.gov (United States)

    Lin, Bingxiong; Sun, Yu; Qian, Xiaoning

    2013-03-01

    Robust feature point matching for images with large view angle changes in Minimally Invasive Surgery (MIS) is a challenging task due to low texture and specular reflections in these images. This paper presents a new approach that can improve feature matching performance by exploiting the inherent geometric property of the organ surfaces. Recently, intensity based template image tracking using a Thin Plate Spline (TPS) model has been extended for 3D surface tracking with stereo cameras. The intensity based tracking is also used here for 3D reconstruction of internal organ surfaces. To overcome the small displacement requirement of intensity based tracking, feature point correspondences are used for proper initialization of the nonlinear optimization in the intensity based method. Second, we generate simulated images from the reconstructed 3D surfaces under all potential view positions and orientations, and then extract feature points from these simulated images. The obtained feature points are then filtered and re-projected to the common reference image. The descriptors of the feature points under different view angles are stored to ensure that the proposed method can tolerate a large range of view angles. We evaluate the proposed method with silicon phantoms and in vivo images. The experimental results show that our method is much more robust with respect to the view angle changes than other state-of-the-art methods.

  2. Facial feature tracking: a psychophysiological measure to assess exercise intensity?

    Science.gov (United States)

    Miles, Kathleen H; Clark, Bradley; Périard, Julien D; Goecke, Roland; Thompson, Kevin G

    2018-04-01

    The primary aim of this study was to determine whether facial feature tracking reliably measures changes in facial movement across varying exercise intensities. Fifteen cyclists completed three, incremental intensity, cycling trials to exhaustion while their faces were recorded with video cameras. Facial feature tracking was found to be a moderately reliable measure of facial movement during incremental intensity cycling (intra-class correlation coefficient = 0.65-0.68). Facial movement (whole face (WF), upper face (UF), lower face (LF) and head movement (HM)) increased with exercise intensity, from lactate threshold one (LT1) until attainment of maximal aerobic power (MAP) (WF 3464 ± 3364mm, P exercise intensities (UF minus LF at: LT1, 1048 ± 383mm; LT2, 1208 ± 611mm; MAP, 1401 ± 712mm; P exercise intensity.

  3. Archeomagnetic Intensity Spikes: Global or Regional Geomagnetic Field Features?

    Directory of Open Access Journals (Sweden)

    Monika Korte

    2018-03-01

    Full Text Available Variations of the geomagnetic field prior to direct observations are inferred from archeo- and paleomagnetic experiments. Seemingly unusual variations not seen in the present-day and historical field are of particular interest to constrain the full range of core dynamics. Recently, archeomagnetic intensity spikes, characterized by very high field values that appear to be associated with rapid secular variation rates, have been reported from several parts of the world. They were first noted in data from the Levant at around 900 BCE. A recent re-assessment of previous and new Levantine data, involving a rigorous quality assessment, interprets the observations as an extreme local geomagnetic high with at least two intensity spikes between the 11th and 8th centuries BCE. Subsequent reports of similar features from Asia, the Canary Islands and Texas raise the question of whether such features might be common occurrences, or whether they might even be part of a global magnetic field feature. Here we use spherical harmonic modeling to test two hypotheses: firstly, whether the Levantine and other potential spikes might be associated with higher dipole field intensity than shown by existing global field models around 1,000 BCE, and secondly, whether the observations from different parts of the world are compatible with a westward drifting intense flux patch. Our results suggest that the spikes originate from intense flux patches growing and decaying mostly in situ, combined with stronger and more variable dipole moment than shown by previous global field models. Axial dipole variations no more than 60% higher than observed in the present field, probably within the range of normal geodynamo behavior, seem sufficient to explain the observations.

  4. An ontology design pattern for surface water features

    Science.gov (United States)

    Sinha, Gaurav; Mark, David; Kolas, Dave; Varanka, Dalia; Romero, Boleslo E.; Feng, Chen-Chieh; Usery, E. Lynn; Liebermann, Joshua; Sorokine, Alexandre

    2014-01-01

    Surface water is a primary concept of human experience but concepts are captured in cultures and languages in many different ways. Still, many commonalities exist due to the physical basis of many of the properties and categories. An abstract ontology of surface water features based only on those physical properties of landscape features has the best potential for serving as a foundational domain ontology for other more context-dependent ontologies. The Surface Water ontology design pattern was developed both for domain knowledge distillation and to serve as a conceptual building-block for more complex or specialized surface water ontologies. A fundamental distinction is made in this ontology between landscape features that act as containers (e.g., stream channels, basins) and the bodies of water (e.g., rivers, lakes) that occupy those containers. Concave (container) landforms semantics are specified in a Dry module and the semantics of contained bodies of water in a Wet module. The pattern is implemented in OWL, but Description Logic axioms and a detailed explanation is provided in this paper. The OWL ontology will be an important contribution to Semantic Web vocabulary for annotating surface water feature datasets. Also provided is a discussion of why there is a need to complement the pattern with other ontologies, especially the previously developed Surface Network pattern. Finally, the practical value of the pattern in semantic querying of surface water datasets is illustrated through an annotated geospatial dataset and sample queries using the classes of the Surface Water pattern.

  5. Feature-based handling of surface faults in compact disc players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Andersen, Palle

    2006-01-01

    In this paper a novel method called feature-based control is presented. The method is designed to improve compact disc players’ handling of surface faults on the discs. The method is based on a fault-tolerant control scheme, which uses extracted features of the surface faults to remove those from...... the detector signals used for control during the occurrence of surface faults. The extracted features are coefficients of Karhunen–Loève approximations of the surface faults. The performance of the feature-based control scheme controlling compact disc players playing discs with surface faults has been...... validated experimentally. The proposed scheme reduces the control errors due to the surface faults, and in some cases where the standard fault handling scheme fails, our scheme keeps the CD-player playing....

  6. An Ontology Design Pattern for Surface Water Features

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Gaurav [Ohio University; Mark, David [University at Buffalo (SUNY); Kolas, Dave [Raytheon BBN Technologies; Varanka, Dalia [U.S. Geological Survey, Rolla, MO; Romero, Boleslo E [University of California, Santa Barbara; Feng, Chen-Chieh [National University of Singapore; Usery, Lynn [U.S. Geological Survey, Rolla, MO; Liebermann, Joshua [Tumbling Walls, LLC; Sorokine, Alexandre [ORNL

    2014-01-01

    Surface water is a primary concept of human experience but concepts are captured in cultures and languages in many different ways. Still, many commonalities can be found due to the physical basis of many of the properties and categories. An abstract ontology of surface water features based only on those physical properties of landscape features has the best potential for serving as a foundational domain ontology. It can then be used to systematically incor-porate concepts that are specific to a culture, language, or scientific domain. The Surface Water ontology design pattern was developed both for domain knowledge distillation and to serve as a conceptual building-block for more complex surface water ontologies. A fundamental distinction is made in this on-tology between landscape features that act as containers (e.g., stream channels, basins) and the bodies of water (e.g., rivers, lakes) that occupy those containers. Concave (container) landforms semantics are specified in a Dry module and the semantics of contained bodies of water in a Wet module. The pattern is imple-mented in OWL, but Description Logic axioms and a detailed explanation is provided. The OWL ontology will be an important contribution to Semantic Web vocabulary for annotating surface water feature datasets. A discussion about why there is a need to complement the pattern with other ontologies, es-pecially the previously developed Surface Network pattern is also provided. Fi-nally, the practical value of the pattern in semantic querying of surface water datasets is illustrated through a few queries and annotated geospatial datasets.

  7. Probability mapping of scarred myocardium using texture and intensity features in CMR images

    Science.gov (United States)

    2013-01-01

    Background The myocardium exhibits heterogeneous nature due to scarring after Myocardial Infarction (MI). In Cardiac Magnetic Resonance (CMR) imaging, Late Gadolinium (LG) contrast agent enhances the intensity of scarred area in the myocardium. Methods In this paper, we propose a probability mapping technique using Texture and Intensity features to describe heterogeneous nature of the scarred myocardium in Cardiac Magnetic Resonance (CMR) images after Myocardial Infarction (MI). Scarred tissue and non-scarred tissue are represented with high and low probabilities, respectively. Intermediate values possibly indicate areas where the scarred and healthy tissues are interwoven. The probability map of scarred myocardium is calculated by using a probability function based on Bayes rule. Any set of features can be used in the probability function. Results In the present study, we demonstrate the use of two different types of features. One is based on the mean intensity of pixel and the other on underlying texture information of the scarred and non-scarred myocardium. Examples of probability maps computed using the mean intensity of pixel and the underlying texture information are presented. We hypothesize that the probability mapping of myocardium offers alternate visualization, possibly showing the details with physiological significance difficult to detect visually in the original CMR image. Conclusion The probability mapping obtained from the two features provides a way to define different cardiac segments which offer a way to identify areas in the myocardium of diagnostic importance (like core and border areas in scarred myocardium). PMID:24053280

  8. Improved Feature Detection in Fused Intensity-Range Images with Complex SIFT (ℂSIFT

    Directory of Open Access Journals (Sweden)

    Boris Jutzi

    2011-09-01

    Full Text Available The real and imaginary parts are proposed as an alternative to the usual Polar representation of complex-valued images. It is proven that the transformation from Polar to Cartesian representation contributes to decreased mutual information, and hence to greater distinctiveness. The Complex Scale-Invariant Feature Transform (ℂSIFT detects distinctive features in complex-valued images. An evaluation method for estimating the uniformity of feature distributions in complex-valued images derived from intensity-range images is proposed. In order to experimentally evaluate the proposed methodology on intensity-range images, three different kinds of active sensing systems were used: Range Imaging, Laser Scanning, and Structured Light Projection devices (PMD CamCube 2.0, Z+F IMAGER 5003, Microsoft Kinect.

  9. Estimating nonrigid motion from inconsistent intensity with robust shape features

    International Nuclear Information System (INIS)

    Liu, Wenyang; Ruan, Dan

    2013-01-01

    Purpose: To develop a nonrigid motion estimation method that is robust to heterogeneous intensity inconsistencies amongst the image pairs or image sequence. Methods: Intensity and contrast variations, as in dynamic contrast enhanced magnetic resonance imaging, present a considerable challenge to registration methods based on general discrepancy metrics. In this study, the authors propose and validate a novel method that is robust to such variations by utilizing shape features. The geometry of interest (GOI) is represented with a flexible zero level set, segmented via well-behaved regularized optimization. The optimization energy drives the zero level set to high image gradient regions, and regularizes it with area and curvature priors. The resulting shape exhibits high consistency even in the presence of intensity or contrast variations. Subsequently, a multiscale nonrigid registration is performed to seek a regular deformation field that minimizes shape discrepancy in the vicinity of GOIs. Results: To establish the working principle, realistic 2D and 3D images were subject to simulated nonrigid motion and synthetic intensity variations, so as to enable quantitative evaluation of registration performance. The proposed method was benchmarked against three alternative registration approaches, specifically, optical flow, B-spline based mutual information, and multimodality demons. When intensity consistency was satisfied, all methods had comparable registration accuracy for the GOIs. When intensities among registration pairs were inconsistent, however, the proposed method yielded pronounced improvement in registration accuracy, with an approximate fivefold reduction in mean absolute error (MAE = 2.25 mm, SD = 0.98 mm), compared to optical flow (MAE = 9.23 mm, SD = 5.36 mm), B-spline based mutual information (MAE = 9.57 mm, SD = 8.74 mm) and mutimodality demons (MAE = 10.07 mm, SD = 4.03 mm). Applying the proposed method on a real MR image sequence also provided

  10. High intensity surface plasma waves, theory and PIC simulations

    Science.gov (United States)

    Raynaud, M.; Héron, A.; Adam, J.-C.

    2018-01-01

    With the development of intense (>1019 W cm-2) short pulses (≤25 fs) laser with very high contrast, surface plasma wave (SPW) can be explored in the relativistic regime. As the SPW propagates with a phase velocity close to the speed of light it may results in a strong acceleration of electron bunches along the surface permitting them to reach relativistic energies. This may be important e.g. for applications in the field of plasma-based accelerators. We investigate in this work the excitation of SPWs on grating preformed over-dense plasmas for laser intensities ranging from 1019 up to 1021 W cm-2. We discuss the nature of the interaction with respect to the solid case in which surface plasmon can be resonantly excited with weak laser intensity. In particular, we show the importance of the pulse duration and focalization of the laser beam on the amplitude of the SPW.

  11. Local-Scale Simulations of Nucleate Boiling on Micrometer-Featured Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Sitaraman, Hariswaran [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Moreno, Gilberto [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Narumanchi, Sreekant V [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dede, Ercan M. [Toyota Research Institute of North America; Joshi, Shailesh N. [Toyota Research Institute of North America; Zhou, Feng [Toyota Research Institute of North America

    2017-07-12

    A high-fidelity computational fluid dynamics (CFD)-based model for bubble nucleation of the refrigerant HFE7100 on micrometer-featured surfaces is presented in this work. The single-fluid incompressible Navier-Stokes equations, along with energy transport and natural convection effects are solved on a featured surface resolved grid. An a priori cavity detection method is employed to convert raw profilometer data of a surface into well-defined cavities. The cavity information and surface morphology are represented in the CFD model by geometric mesh deformations. Surface morphology is observed to initiate buoyancy-driven convection in the liquid phase, which in turn results in faster nucleation of cavities. Simulations pertaining to a generic rough surface show a trend where smaller size cavities nucleate with higher wall superheat. This local-scale model will serve as a self-consistent connection to larger device scale continuum models where local feature representation is not possible.

  12. Replication of surface features from a master model to an amorphous metallic article

    Science.gov (United States)

    Johnson, William L.; Bakke, Eric; Peker, Atakan

    1999-01-01

    The surface features of an article are replicated by preparing a master model having a preselected surface feature thereon which is to be replicated, and replicating the preselected surface feature of the master model. The replication is accomplished by providing a piece of a bulk-solidifying amorphous metallic alloy, contacting the piece of the bulk-solidifying amorphous metallic alloy to the surface of the master model at an elevated replication temperature to transfer a negative copy of the preselected surface feature of the master model to the piece, and separating the piece having the negative copy of the preselected surface feature from the master model.

  13. Analysis of progression of fatigue conditions in biceps brachii muscles using surface electromyography signals and complexity based features.

    Science.gov (United States)

    Karthick, P A; Makaram, Navaneethakrishna; Ramakrishnan, S

    2014-01-01

    Muscle fatigue is a neuromuscular condition where muscle performance decreases due to sustained or intense contraction. It is experienced by both normal and abnormal subjects. In this work, an attempt has been made to analyze the progression of muscle fatigue in biceps brachii muscles using surface electromyography (sEMG) signals. The sEMG signals are recorded from fifty healthy volunteers during dynamic contractions under well defined protocol. The acquired signals are preprocessed and segmented in to six equal parts for further analysis. The features, such as activity, mobility, complexity, sample entropy and spectral entropy are extracted from all six zones. The results are found showing that the extracted features except complexity feature have significant variations in differentiating non-fatigue and fatigue zone respectively. Thus, it appears that, these features are useful in automated analysis of various neuromuscular activities in normal and pathological conditions.

  14. Local-Scale Simulations of Nucleate Boiling on Micrometer Featured Surfaces: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Sitaraman, Hariswaran [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Moreno, Gilberto [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Narumanchi, Sreekant V [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Dede, Ercan M. [Toyota Research Institute of North America; Joshi, Shailesh N. [Toyota Research Institute of North America; Zhou, Feng [Toyota Research Institute of North America

    2017-08-03

    A high-fidelity computational fluid dynamics (CFD)-based model for bubble nucleation of the refrigerant HFE7100 on micrometer-featured surfaces is presented in this work. The single-fluid incompressible Navier-Stokes equations, along with energy transport and natural convection effects are solved on a featured surface resolved grid. An a priori cavity detection method is employed to convert raw profilometer data of a surface into well-defined cavities. The cavity information and surface morphology are represented in the CFD model by geometric mesh deformations. Surface morphology is observed to initiate buoyancy-driven convection in the liquid phase, which in turn results in faster nucleation of cavities. Simulations pertaining to a generic rough surface show a trend where smaller size cavities nucleate with higher wall superheat. This local-scale model will serve as a self-consistent connection to larger device scale continuum models where local feature representation is not possible.

  15. Staphylococcus cohnii--resident of hospital environment: cell-surface features and resistance to antibiotics.

    Science.gov (United States)

    Szewczyk, E M; Rózalska, M

    2000-01-01

    Staphylococcus cohnii strains dominated in the environment of investigated hospitals. We isolated 420 strains of the species mainly from hospitals environments, but also from infants--Intensive Care Units patients, its medical staff and non-hospital environments. S. cohnii subspecies cohnii was seen to dominate (361 strains). Seventy seven percent of these strains expressed cell-surface hydrofobicity, most of them were slime producers (61%) and this feature was correlated with their methicillin resistance. Among S. cohnii ssp. cohnii strains isolated from ICU environment 90% were resistant to methicillin, 43% expressed high-level resistance to mupirocin and high percentages were resistant to many other antibiotics. These strains may constitute a dangerous reservoir of resistance genes in a hospital.

  16. Design features and performance of the LAMPF high-intensity beam area

    International Nuclear Information System (INIS)

    Agnew, L.; Grisham, D.; Macek, R.J.; Sommer, W.F.; Werbeck, R.D.

    1983-01-01

    LAMPF is a multi-purpose high-intensity meson factory capable of producing a 1 mA beam of 800-MeV protons. The three target cells and the beam stop facilities in the high intensity area have many special design features that are required for operation in the presence of high heat loads and intense radiation fields where accessibility is extremely limited. Reliable targets, beam windows, beam stops, beam transport and diagnostic components, vacuum enclosures, and auxiliary systems have been developed. Sophisticated remote-handling systems are employed for maintenance. Complex protection systems have been developed to guard against damage caused by errant beam. Beam availability approaching 90% has been achieved at currents of 600 to 700 μA. A new facility for direct proton and neutron radiation effects studies will be installed in 1985. The new facility will provide an integrated spallation neutron flux of up to 5 x 10 17 m -2 s -1 and will anable proton irradiation studies in the primary beam

  17. Effects of surface irregularities on intensity data from laser scanning: an experimental approach.

    Directory of Open Access Journals (Sweden)

    G. Teza

    2008-06-01

    Full Text Available The results of an experiment carried out with the aim to investigate the role of surface irregularities on the intensity data provided by a terrestrial laser scanner (TLS survey are reported here. Depending on surface roughness, the interaction between an electromagnetic wave and microscopic irregularities leads to a Lambertian-like diffusive light reflection, allowing the TLS to receive the backscattered component of the signal. The described experiment consists in a series of TLS-based acquisitions of a rotating artificial target specifically conceived in order to highlight the effects on the intensity data due to surface irregularity. This target is articulated in a flat plate and in an irregular surface, whose macro-roughness has a characteristic length with the same order of the spot size. Results point out the different behavior of the plates. The intensity of the signal backscattered by the planar element decreases if the incidence angle increases, whereas the intensity of the signal backscattered by the irregular surface is almost constant if the incidence angle varies. Since the typical surfaces acquired in a geological/geophysical survey are generally irregular, these results imply that the intensity data can be easily used in order to evaluate the reflectance of the material at the considered wavelength, e.g. for pattern recognition purposes.

  18. Dome shaped features on Europa's surface

    Science.gov (United States)

    1997-01-01

    The Solid State Imaging system aboard the spacecraft Galileo took this image of the surface of Europa on February 20, 1997 during its sixth orbit around Jupiter. The image is located near 16 North, 268 West; illumination is from the lower-right. The area covered is approximately 48 miles (80 kilometers) by 56 miles (95 kilometers) across. North is toward the top of the image.This image reveals that the icy surface of Europa has been disrupted by ridges and faults numerous times during its past. These ridges have themselves been disrupted by the localized formation of domes and other features that may be indicative of thermal upwelling of water from beneath the crust. These features provide strong evidence for the presence of subsurface liquid during Europa's recent past.The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  19. Muscle fatigue and contraction intensity modulates the complexity of surface electromyography.

    Science.gov (United States)

    Cashaback, Joshua G A; Cluff, Tyler; Potvin, Jim R

    2013-02-01

    Nonlinear dynamical techniques offer a powerful approach for the investigation of physiological time series. Multiscale entropy analyses have shown that pathological and aging systems are less complex than healthy systems and this finding has been attributed to degraded physiological control processes. A similar phenomenon may arise during fatiguing muscle contractions where surface electromyography signals undergo temporal and spectral changes that arise from the impaired regulation of muscle force production. Here we examine the affect of fatigue and contraction intensity on the short and long-term complexity of biceps brachii surface electromyography. To investigate, we used an isometric muscle fatigue protocol (parsed into three windows) and three contraction intensities (% of maximal elbow joint moment: 40%, 70% and 100%). We found that fatigue reduced the short-term complexity of biceps brachii activity during the last third of the fatiguing contraction. We also found that the complexity of surface electromyography is dependent on contraction intensity. Our results show that multiscale entropy is sensitive to muscle fatigue and contraction intensity and we argue it is imperative that both factors be considered when evaluating the complexity of surface electromyography signals. Our data contribute to a converging body of evidence showing that multiscale entropy can quantify subtle information content in physiological time series. Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. The relation between rumination and temporal features of emotion intensity.

    Science.gov (United States)

    Résibois, Maxime; Kalokerinos, Elise K; Verleysen, Gregory; Kuppens, Peter; Van Mechelen, Iven; Fossati, Philippe; Verduyn, Philippe

    2018-03-01

    Intensity profiles of emotional experience over time have been found to differ primarily in explosiveness (i.e. whether the profile has a steep vs. a gentle start) and accumulation (i.e. whether intensity increases over time vs. goes back to baseline). However, the determinants of these temporal features remain poorly understood. In two studies, we examined whether emotion regulation strategies are predictive of the degree of explosiveness and accumulation of negative emotional episodes. Participants were asked to draw profiles reflecting changes in the intensity of emotions elicited either by negative social feedback in the lab (Study 1) or by negative events in daily life (Study 2). In addition, trait (Study 1 & 2), and state (Study 2) usage of a set of emotion regulation strategies was assessed. Multilevel analyses revealed that trait rumination (especially the brooding component) was positively associated with emotion accumulation (Study 1 & 2). State rumination was also positively associated with emotion accumulation and, to a lesser extent, with emotion explosiveness (Study 2). These results provide support for emotion regulation theories, which hypothesise that rumination is a central mechanism underlying the maintenance of negative emotions.

  1. Stress intensity factor analyses of surface cracks in three-dimensional structures

    International Nuclear Information System (INIS)

    Miyazaki, Noriyuki; Shibata, Katsuyuki; Watanabe, Takayuki; Tagata, Kazunori.

    1983-11-01

    The stress intensity factor analyses of surface cracks in various three-dimensional structures were performed using the finite element computer program EPAS-J1. The results obtained by EPAS-J1 were compared with other finite element solutions or results obtained by the simplified estimation methods. Among the simplified estimation methods, the equations proposed by Newman and Raju give the distributions of the stress intensity factor along a crack front, which were compared with the result obtained by EPAS-J1. It was confirmed by comparing the results that EPAS-J1 gives reasonable stress intensity factors of surface cracks in three-dimensional structures. (author)

  2. Analysis of root surface properties by fluorescence/Raman intensity ratio.

    Science.gov (United States)

    Nakamura, Shino; Ando, Masahiro; Hamaguchi, Hiro-O; Yamamoto, Matsuo

    2017-11-01

    The aim of this study is to evaluate the existence of residual calculus on root surfaces by determining the fluorescence/Raman intensity ratio. Thirty-two extracted human teeth, partially covered with calculus on the root surface, were evaluated by using a portable Raman spectrophotometer, and a 785-nm, 100-mW laser was applied for fluorescence/Raman excitation. The collected spectra were normalized to the hydroxyapatite Raman band intensity at 960 cm -1 . Raman spectra were recorded from the same point after changing the focal distance of the laser and the target radiating angle. In seven teeth, the condition of calculus, cementum, and dentin were evaluated. In 25 teeth, we determined the fluorescence/Raman intensity ratio following three strokes of debridement. Raman spectra collected from the dentin, cementum, and calculus were different. After normalization, spectra values were constant. The fluorescence/Raman intensity ratio of calculus region showed significant differences compared to the cementum and dentin (p Raman intensity ratio decreased with calculus debridement. For this analysis, the delta value was defined as the difference between the values before and after three strokes, with the final 2 delta values close to zero, indicating a gradual asymptotic curve and the change in intensity ratio approximating that of individual constants. Fluorescence/Raman intensity ratio was effectively used to cancel the angle- and distance-dependent fluctuations of fluorescence collection efficiency during measurement. Changes in the fluorescence/Raman intensity ratio near zero suggested that cementum or dentin was exposed, and calculus removed.

  3. Light induced modulation instability of surfaces under intense illumination

    KAUST Repository

    Burlakov, V. M.

    2013-12-17

    We show that a flat surface of a polymer in rubber state illuminated with intense electromagnetic radiation is unstable with respect to periodic modulation. Initial periodic perturbation is amplified due to periodic thermal expansion of the material heated by radiation. Periodic heating is due to focusing-defocusing effects caused by the initial surface modulation. The surface modulation has a period longer than the excitation wavelength and does not require coherent light source. Therefore, it is not related to the well-known laser induced periodic structures on polymer surfaces but may contribute to their formation and to other phenomena of light-matter interaction.

  4. Improvement in surface fatigue life of hardened gears by high-intensity shot peening

    Science.gov (United States)

    Townsend, Dennis P.

    1992-04-01

    Two groups of carburized, hardened, and ground spur gears that were manufactured from the same heat vacuum induction melted vacuum arc melted (VIM VAR) AISI 9310 steel were endurance tested for surface fatigue. Both groups were manufactured with a standard ground 16 rms surface finish. One group was subjected to a shot peening (SP) intensity of 7 to 9A, and the second group was subjected to a SP intensity of 15 to 17A. All gears were honed after SP to a surface finish of 16 rms. The gear pitch diameter was 8.89 cm. Test conditions were a maximum Hertz stress of 1.71 GPa, a gear temperature of 350 K, and a speed of 10000 rpm. The lubricant used for the tests was a synthetic paraffinic oil with an additive package. The following results were obtained: The 10 pct. surface fatigue (pitting) life of the high intensity (15 to 17A) SPed gears was 2.15 times that of the medium intensity (7 to 9A) SPed gears, the same as that calculated from measured residual stress at a depth of 127 microns. The measured residual stress for the high intensity SPed gears was 57 pct. higher than that for the medium intensity SPed gears at a depth of 127 microns and 540 pct. higher at a depth of 51 microns.

  5. Analysis of iris surface features in populations of diverse ancestry

    Science.gov (United States)

    Edwards, Melissa; Cha, David; Krithika, S.; Johnson, Monique; Parra, Esteban J.

    2016-01-01

    There are many textural elements that can be found in the human eye, including Fuchs’ crypts, Wolfflin nodules, pigment spots, contraction furrows and conjunctival melanosis. Although iris surface features have been well-studied in populations of European ancestry, the worldwide distribution of these traits is poorly understood. In this paper, we develop a new method of characterizing iris features from photographs of the iris. We then apply this method to a diverse sample of East Asian, European and South Asian ancestry. All five iris features showed significant differences in frequency between the three populations, indicating that iris features are largely population dependent. Although none of the features were correlated with each other in the East and South Asian groups, Fuchs’ crypts were significantly correlated with contraction furrows and pigment spots and contraction furrows were significantly associated with pigment spots in the European group. The genetic marker SEMA3A rs10235789 was significantly associated with Fuchs’ crypt grade in the European, East Asian and South Asian samples and a borderline association between TRAF3IP1 rs3739070 and contraction furrow grade was found in the European sample. The study of iris surface features in diverse populations may provide valuable information of forensic, biomedical and ophthalmological interest. PMID:26909168

  6. Beyond intensity: Spectral features effectively predict music-induced subjective arousal.

    Science.gov (United States)

    Gingras, Bruno; Marin, Manuela M; Fitch, W Tecumseh

    2014-01-01

    Emotions in music are conveyed by a variety of acoustic cues. Notably, the positive association between sound intensity and arousal has particular biological relevance. However, although amplitude normalization is a common procedure used to control for intensity in music psychology research, direct comparisons between emotional ratings of original and amplitude-normalized musical excerpts are lacking. In this study, 30 nonmusicians retrospectively rated the subjective arousal and pleasantness induced by 84 six-second classical music excerpts, and an additional 30 nonmusicians rated the same excerpts normalized for amplitude. Following the cue-redundancy and Brunswik lens models of acoustic communication, we hypothesized that arousal and pleasantness ratings would be similar for both versions of the excerpts, and that arousal could be predicted effectively by other acoustic cues besides intensity. Although the difference in mean arousal and pleasantness ratings between original and amplitude-normalized excerpts correlated significantly with the amplitude adjustment, ratings for both sets of excerpts were highly correlated and shared a similar range of values, thus validating the use of amplitude normalization in music emotion research. Two acoustic parameters, spectral flux and spectral entropy, accounted for 65% of the variance in arousal ratings for both sets, indicating that spectral features can effectively predict arousal. Additionally, we confirmed that amplitude-normalized excerpts were adequately matched for loudness. Overall, the results corroborate our hypotheses and support the cue-redundancy and Brunswik lens models.

  7. Superhydrophobic Polyimide via Ultraviolet Photooxidation: The Evolution of Surface Morphology and Hydrophobicity under Different Ultraviolet Intensities

    Directory of Open Access Journals (Sweden)

    Hongyu Gu

    2015-01-01

    Full Text Available Ultraviolet (UV photooxidation has recently been developed to fabricate superhydrophobic polyimide (PI films in combination with fluoroalkylsilane modification. However, it remains unclear whether the surface morphology and hydrophobicity are sensitive to technical parameters such as UV intensity and radiation environment. Herein, we focus on the effects of UV intensity on PI surface structure and wettability to gain comprehensive understanding and more effective control of this technology. Scanning electron microscopy (SEM and atomic force microscopy (AFM results showed that UV intensity governed the evolutionary pattern of surface morphology: lower UV intensity (5 mW/cm2 facilitated in-plane expansion of dendritic protrusions while stronger UV (10 and 15 mW/cm2 encouraged localized growth of protrusions in a piling-up manner. Surface roughness and hydrophobicity maximized at the intensity of 10 mW/cm2, as a consequence of the slowed horizontal expansion and preferred vertical growth of the protrusions when UV intensity increased. Based on these results, the mechanism that surface micro/nanostructures developed in distinct ways when exposed to different UV intensities was proposed. Though superhydrophobicity (water contact angle larger than 150° can be achieved at UV intensity not less than 10 mW/cm2, higher intensity decreased the effectiveness. Therefore, the UV photooxidation under 10 mW/cm2 for 72 h is recommended to fabricate superhydrophobic PI films.

  8. Analysis of stress intensity factors for surface cracks in pre/post penetration

    International Nuclear Information System (INIS)

    Miyoshi, Toshiro; Yoshida, Yuichiro

    1988-01-01

    It is important to evaluate the penetration of surface cracks in a Leak-Before-Break analysis. Because the stress intensity factors for surface cracks in pre/post penetration had not yet been analyzed, the authors carried three-dimensional boundary element analyses in order to obtain them. First, the authors developed the technique of nodal breakdown appropriate for cracks with short ligament length in a two-dimensional boundary element analysis. Next, analyses of stress intensity factor for surface cracks in pre/post penetration were carried out using the technique of nodal breakdown for cracks with short ligament length and the three-dimensional boundary element code BEM 3 D which was designed for a supercomputer. (author)

  9. Phase shift errors in the theory and practice of surface intensity measurements

    Science.gov (United States)

    Mcgary, M. C.; Crocker, M. J.

    1982-01-01

    The surface acoustical intensity method (sometimes known as the microphone-accelerometer cross-spectral method) is a relatively new noise source/path identification tool. Several researchers have had difficulties implementing this method because of instrumentation phase mis-match. A simple technique for measuring and correcting instrumentation phase mis-match has been developed. This new technique has been tested recently on a noise source identification problem of practical interest. The results of the experiments indicate that the surface acoustic intensity method produces reliable data and can be applied to a variety of noise source/path problems.

  10. Polarization controlled deep sub-wavelength periodic features written by femtosecond laser on nanodiamond thin film surface

    Energy Technology Data Exchange (ETDEWEB)

    Kumar Kuntumalla, Mohan; Srikanth, Vadali V. S. S., E-mail: vvsssse@uohyd.ernet.in [School of Engineering Sciences and Technology, University of Hyderabad, Hyderabad 500046 (India); Rajamudili, Kuladeep; Rao Desai, Narayana [School of Physics, University of Hyderabad, Hyderabad 500046 (India)

    2014-04-21

    Deep sub-wavelength (Λ/λ = ∼0.22) periodic features are induced uniformly on a nanodiamond (ND) thin film surface using femtosecond (fs) laser irradiation (pulse duration = ∼110 fs and central wavelength of ∼800 nm). The topography of the surface features is controlled by the laser polarization. Orientation of features is perpendicular to laser polarization. Periodicity (spatial periodicity of < λ/4) of the surface features is less than the laser wavelength. This work gives an experimental proof of polarization controlled surface plasmon-fs laser coupling mechanism prompting the interaction between fs laser and solid matter (here ND thin film) which in turn is resulting in the periodic surface features. Scanning electron microscopy in conjunction with micro Raman scattering, X-ray diffraction, and atomic force microscopy are carried out to extract surface morphology and phase information of the laser irradiated regions. This work demonstrates an easy and efficient surface fabrication technique.

  11. Grain surface features and clay mineralogy of the quaternary sediments from Western Deccan Trap Region, India, and their palaeoclimatic significance

    Directory of Open Access Journals (Sweden)

    Veena U. Joshi

    2011-06-01

    Full Text Available Quartz sand grains obtained from a deeply gullied topography along the banks of two tributaries of River Pravara in Maharashtra (India have been examined with a scanning electron microscope (SEM. Quartz grains have been selected after a heavy mineral separation and micro-photographs of each grain were taken at various angles and magnifications. The sediments reveal features resulting from mechanical grinding as well as from chemical alteration. Conchoidal fractures, cleavage planes, grooves, v-shaped indentations etc. are the mechanical features documented on the grains whereas solution pits of varying sizes and intensity, precipitation surfaces, oriented v-pits, solution crevasses and etching are the features of chemical origin. Several evidences indicate that the samples have undergone digenetic changes. Few grains show the features of intense chemical breakdown. The overall assemblages of the grain surface features suggest that the samples have been subjected to subaqueous transport for a considerable period of time. The minor chemical features such as solution pits or semi circular arcuate steps found in abundance on these grains are due to the dissolution of the sediments in a low energy fluviatile environment. For clay mineralogy, fractions between <2 and <0.2 mm were separated out from the sediments. The clay fractions were then subjected to examination by X-ray diffraction (XRD of oriented K/Ca saturated samples using a Philips Diffractometer and Ni-filtered Cu Ka radiation with the scanning speed of 10 2Ө min -1. The main clay minerals for all the samples are identical and show the presence of hydroxy-interlayered smectites with minor quantities of mica, kaolinite, smectites, quartz and feldspar. The first weathering product of the Deccan Basalt (DB is the dioctahedral smectite. Since the present semi aridic climatic condition of the study area can not transform a smectite to HIS and either smectite to kaolin, it is quite likely that

  12. Modification of solid surface by intense pulsed light-ion and metal-ion beams

    Science.gov (United States)

    Nakagawa, Y.; Ariyoshi, T.; Hanjo, H.; Tsutsumi, S.; Fujii, Y.; Itami, M.; Okamoto, A.; Ogawa, S.; Hamada, T.; Fukumaru, F.

    1989-03-01

    Metal surfaces of Al, stainless-steel and Ti were bombarded with focused intense pulsed proton and carbon ion beams (energy ˜ 80 keV, current density ≲ 1000 A/cm 2, pulse width ˜ 300 ns). Thin titanium carbide layers were produced by carbon-ion irradiation on the titanium surface. The observed molten surface structures and recrystallized layer (20 μm depth) indicated that the surfaces reached high temperatures as a result of the irradiation. The implantation of intense pulsed metal ion beams (Al +, ˜ 20 A/cm 2) with simultaneous deposition of anode metal vapor on Ti and Fe made a mixed layer of AlTi and AlFe of about 0.5 μm depth. Ti and B multilayered films evaporated on glass substrates were irradiated by intense pulsed proton beams of relatively lower current density (10-200 A/cm 2). Ti films containing B atoms above 10 at.% were obtained. When the current density was about 200 A/cm 2 diffraction peaks of TiB 2 appeared.

  13. Touching Textured Surfaces: Cells in Somatosensory Cortex Respond Both to Finger Movement and to Surface Features

    Science.gov (United States)

    Darian-Smith, Ian; Sugitani, Michio; Heywood, John; Karita, Keishiro; Goodwin, Antony

    1982-11-01

    Single neurons in Brodmann's areas 3b and 1 of the macaque postcentral gyrus discharge when the monkey rubs the contralateral finger pads across a textured surface. Both the finger movement and the spatial pattern of the surface determine this discharge in each cell. The spatial features of the surface are represented unambiguously only in the responses of populations of these neurons, and not in the responses of the constituent cells.

  14. An image-processing method to detect sub-optical features based on understanding noise in intensity measurements.

    Science.gov (United States)

    Bhatia, Tripta

    2018-02-01

    Accurate quantitative analysis of image data requires that we distinguish between fluorescence intensity (true signal) and the noise inherent to its measurements to the extent possible. We image multilamellar membrane tubes and beads that grow from defects in the fluid lamellar phase of the lipid 1,2-dioleoyl-sn-glycero-3-phosphocholine dissolved in water and water-glycerol mixtures by using fluorescence confocal polarizing microscope. We quantify image noise and determine the noise statistics. Understanding the nature of image noise also helps in optimizing image processing to detect sub-optical features, which would otherwise remain hidden. We use an image-processing technique "optimum smoothening" to improve the signal-to-noise ratio of features of interest without smearing their structural details. A high SNR renders desired positional accuracy with which it is possible to resolve features of interest with width below optical resolution. Using optimum smoothening, the smallest and the largest core diameter detected is of width [Formula: see text] and [Formula: see text] nm, respectively, discussed in this paper. The image-processing and analysis techniques and the noise modeling discussed in this paper can be used for detailed morphological analysis of features down to sub-optical length scales that are obtained by any kind of fluorescence intensity imaging in the raster mode.

  15. Intense positron beam and its application to surface science

    International Nuclear Information System (INIS)

    Ito, Y.; Hirose, M.; Kanazawa, I.; Sueoka, O.; Takamura, S.; Okada, S.

    1992-01-01

    Intense pulsed slow positron beam has been produced using the 100 MeV electron LINAC of JAERI · Tokai. In order to use the beam for surface studies such as positron diffraction and positron microscopy, it was transferred from the solenoid magnetic field to field free region and then was brightness-enhanced. The beam size was reduced from 10 mmφ (in the magnetic field) to 0.5 mmφ after two stages of re-moderation. Using the intense brightness-enhanced positron beam we have observed for the first time RHEPD (Reflection High-Energy Positron Diffraction) patterns. A design of re-emission positron microscopy is also described. (author)

  16. Enhancing Plasma Surface Modification using high Intensity and high Power Ultrasonic Acoustic Waves

    DEFF Research Database (Denmark)

    2010-01-01

    high intensity and high power acoustic waves (102) by at least one ultrasonic high intensity and high power acoustic wave generator (101 ), wherein the ultrasonic acoustic waves are directed to propagate towards said surface (314) of the object (100) so that a laminar boundary layer (313) of a gas...... or a mixture of gases (500) flow in contact with said solid object (100) is thinned or destructed for at least a part of said surface (314). In this way, the plasma can more efficiently access and influence the surface of the solid object to be treated by the plasma, which speeds the process time up...

  17. Robust Features Of Surface Electromyography Signal

    Science.gov (United States)

    Sabri, M. I.; Miskon, M. F.; Yaacob, M. R.

    2013-12-01

    Nowadays, application of robotics in human life has been explored widely. Robotics exoskeleton system are one of drastically areas in recent robotic research that shows mimic impact in human life. These system have been developed significantly to be used for human power augmentation, robotics rehabilitation, human power assist, and haptic interaction in virtual reality. This paper focus on solving challenges in problem using neural signals and extracting human intent. Commonly, surface electromyography signal (sEMG) are used in order to control human intent for application exoskeleton robot. But the problem lies on difficulty of pattern recognition of the sEMG features due to high noises which are electrode and cable motion artifact, electrode noise, dermic noise, alternating current power line interface, and other noise came from electronic instrument. The main objective in this paper is to study the best features of electromyography in term of time domain (statistical analysis) and frequency domain (Fast Fourier Transform).The secondary objectives is to map the relationship between torque and best features of muscle unit activation potential (MaxPS and RMS) of biceps brachii. This project scope use primary data of 2 male sample subject which using same dominant hand (right handed), age between 20-27 years old, muscle diameter 32cm to 35cm and using single channel muscle (biceps brachii muscle). The experiment conduct 2 times repeated task of contraction and relaxation of biceps brachii when lifting different load from no load to 3kg with ascending 1kg The result shows that Fast Fourier Transform maximum power spectrum (MaxPS) has less error than mean value of reading compare to root mean square (RMS) value. Thus, Fast Fourier Transform maximum power spectrum (MaxPS) show the linear relationship against torque experience by elbow joint to lift different load. As the conclusion, the best features is MaxPS because it has the lowest error than other features and show

  18. Robust Features Of Surface Electromyography Signal

    International Nuclear Information System (INIS)

    Sabri, M I; Miskon, M F; Yaacob, M R

    2013-01-01

    Nowadays, application of robotics in human life has been explored widely. Robotics exoskeleton system are one of drastically areas in recent robotic research that shows mimic impact in human life. These system have been developed significantly to be used for human power augmentation, robotics rehabilitation, human power assist, and haptic interaction in virtual reality. This paper focus on solving challenges in problem using neural signals and extracting human intent. Commonly, surface electromyography signal (sEMG) are used in order to control human intent for application exoskeleton robot. But the problem lies on difficulty of pattern recognition of the sEMG features due to high noises which are electrode and cable motion artifact, electrode noise, dermic noise, alternating current power line interface, and other noise came from electronic instrument. The main objective in this paper is to study the best features of electromyography in term of time domain (statistical analysis) and frequency domain (Fast Fourier Transform).The secondary objectives is to map the relationship between torque and best features of muscle unit activation potential (MaxPS and RMS) of biceps brachii. This project scope use primary data of 2 male sample subject which using same dominant hand (right handed), age between 20–27 years old, muscle diameter 32cm to 35cm and using single channel muscle (biceps brachii muscle). The experiment conduct 2 times repeated task of contraction and relaxation of biceps brachii when lifting different load from no load to 3kg with ascending 1kg The result shows that Fast Fourier Transform maximum power spectrum (MaxPS) has less error than mean value of reading compare to root mean square (RMS) value. Thus, Fast Fourier Transform maximum power spectrum (MaxPS) show the linear relationship against torque experience by elbow joint to lift different load. As the conclusion, the best features is MaxPS because it has the lowest error than other features and

  19. Surfaces in the interaction of intense long wavelength laser light with plasmas

    International Nuclear Information System (INIS)

    Jones, R.D.

    1985-01-01

    The role of surface in the interaction of intense CO 2 laser light with plasmas is reviewed. The collisionless absorption of long wavelength light is discussed. Specific comments on the role of ponderomotive forces and profile steepening on resonant absorption are made. It is shown that at intensities above 10 15 W/cm 2 the absorption is determined by ion acoustic-like surface modes. It is demonstrated experimentally that harmonics up to the forty-sixth can be generated in steep density profiles. Computer simulations and theoretical mechanisms for this phenomena are presented. The self generation of magnetic fields on surfaces is discussed. The role these fields play in the lateral transport of energy, the insulation of the target from hot electrons, and the acceleration of fast ions is discussed

  20. Airborne laser: a tool to study landscape surface features

    International Nuclear Information System (INIS)

    Ritchie, J.C.; Jackson, T.J.; Everitt, J.H.; Escobar, D.E.; Murphey, J.B.; Grissinger, E.H.

    1992-01-01

    Landscape surface features related to erosion and hydrology were measured using an airborne laser profiler. The airborne laser profiler made 4,000 measurements per second with a recording accuracy of 5 cm (1.9 inches) on a single measurement. Digital data from the laser are recorded and analyzed with a personal computer. These airborne laser profiles provide information on surface landscape features. Topography and canopy heights, cover, and distribution of natural vegetation were determined in studies in South Texas. Laser measurements of shrub cover along flightlines were highly correlated (R 2 = 0.98) with ground measurements made with line-intercept methods. Stream channel cross sections on Goodwin Creek in Mississippi were measured quickly and accurately with airborne laser data. Airborne laser profile data were used to measure small gullies in a level fallow field and in field with mature soybeans. While conventional ground-based techniques can be used to make these measurements, airborne laser profiler techniques allow data to be collected quickly, at a high density, and in areas that are essentially inaccessible for ground surveys. Airborne laser profiler data can quantify landscape features related to erosion and runoff, and the laser proler has the potential to be a useful tool for providing other data for studying and managing natural resources

  1. Comparing experts and novices in Martian surface feature change detection and identification

    Science.gov (United States)

    Wardlaw, Jessica; Sprinks, James; Houghton, Robert; Muller, Jan-Peter; Sidiropoulos, Panagiotis; Bamford, Steven; Marsh, Stuart

    2018-02-01

    Change detection in satellite images is a key concern of the Earth Observation field for environmental and climate change monitoring. Satellite images also provide important clues to both the past and present surface conditions of other planets, which cannot be validated on the ground. With the volume of satellite imagery continuing to grow, the inadequacy of computerised solutions to manage and process imagery to the required professional standard is of critical concern. Whilst studies find the crowd sourcing approach suitable for the counting of impact craters in single images, images of higher resolution contain a much wider range of features, and the performance of novices in identifying more complex features and detecting change, remains unknown. This paper presents a first step towards understanding whether novices can identify and annotate changes in different geomorphological features. A website was developed to enable visitors to flick between two images of the same location on Mars taken at different times and classify 1) if a surface feature changed and if so, 2) what feature had changed from a pre-defined list of six. Planetary scientists provided ;expert; data against which classifications made by novices could be compared when the project subsequently went public. Whilst no significant difference was found in images identified with surface changes by expert and novices, results exhibited differences in consensus within and between experts and novices when asked to classify the type of change. Experts demonstrated higher levels of agreement in classification of changes as dust devil tracks, slope streaks and impact craters than other features, whilst the consensus of novices was consistent across feature types; furthermore, the level of consensus amongst regardless of feature type. These trends are secondary to the low levels of consensus found, regardless of feature type or classifier expertise. These findings demand the attention of researchers who

  2. Texture-based segmentation with Gabor filters, wavelet and pyramid decompositions for extracting individual surface features from areal surface topography maps

    International Nuclear Information System (INIS)

    Senin, Nicola; Leach, Richard K; Pini, Stefano; Blunt, Liam A

    2015-01-01

    Areal topography segmentation plays a fundamental role in those surface metrology applications concerned with the characterisation of individual topography features. Typical scenarios include the dimensional inspection and verification of micro-structured surface features, and the identification and characterisation of localised defects and other random singularities. While morphological segmentation into hills or dales is the only partitioning operation currently endorsed by the ISO specification standards on surface texture metrology, many other approaches are possible, in particular adapted from the literature on digital image segmentation. In this work an original segmentation approach is introduced and discussed, where topography partitioning is driven by information collected through the application of texture characterisation transforms popular in digital image processing. Gabor filters, wavelets and pyramid decompositions are investigated and applied to a selected set of test cases. The behaviour, performance and limitations of the proposed approach are discussed from the viewpoint of the identification and extraction of individual surface topography features. (paper)

  3. Untreated runoff quality from roof and road surfaces in a low intensity rainfall climate.

    Science.gov (United States)

    Charters, Frances J; Cochrane, Thomas A; O'Sullivan, Aisling D

    2016-04-15

    Sediment and heavy metals in stormwater runoff are key pollutants of urban waterways, and their presence in stormwater is driven by climatic factors such as rainfall intensity. This study describes the total suspended solids (TSS) and heavy metal concentrations found in runoff from four different urban surfaces within a residential/institutional catchment, in a climate where rainfall is typically of low intensity (runoff quality from a compilation of international studies. The road runoff had the highest TSS concentrations, while copper and galvanized roof runoff had the highest copper and zinc concentrations, respectively. Pollutant concentrations were found to be significantly different between surfaces; quantification and prediction of pollutant contributions from urban surfaces should thus take account of the different surface materials, instead of being aggregated into more generalized categories such as land use. The TSS and heavy metal concentrations were found to be at the low to medium end of ranges observed internationally, except for total copper and zinc concentrations generated by dissolution of copper and galvanized roofing material respectively; these concentrations were at least as high as those reported internationally. TSS wash-off from the roofs was seen to be a source-limited process, where all available TSS is washed off during the rain event despite the low intensity rainfall, whereas both road TSS and heavy metals wash-off from roof and road surfaces appeared to all be transport-limited and therefore some carryover of pollutants occurs between rain events. A first flush effect was seen from most surfaces for TSS, but not for heavy metals. This study demonstrates that in low intensity rainfall climates, quantification of untreated runoff quality from key individual surface types in a catchment are needed to enable development of targeted and appropriately sized stormwater treatment systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Remote sensing of coastal sea-surface features off northern British Columbia

    International Nuclear Information System (INIS)

    Jardine, I.D.; Thomson, K.A.; LeBlond, P.H.; Foreman, M.G.

    1993-01-01

    This article presents an overview of surface oceanographic features identified by AVHRR imagery in Hecate Strait and adjacent waters surrounding the Queen Charlotte Islands, Canada, an area still poor in in situ observations. The observed features and their temporal variability are interpreted in terms of meteorological and hydrological forcing. The effects of tidal mixing are discussed through the application of a finite element numerical model

  5. Automatic selective feature retention in patient specific elastic surface registration

    CSIR Research Space (South Africa)

    Jansen van Rensburg, GJ

    2011-01-01

    Full Text Available The accuracy with which a recent elastic surface registration algorithm deforms the complex geometry of a skull is examined. This algorithm is then coupled to a line based algorithm as is frequently used in patient specific feature registration...

  6. Fabrication of narrow surface relief features in a side-chain azobenzene polyester with a scanning near-field microscope

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Holme, N. C. R.; Pedersen, M.

    2001-01-01

    We show that it is possible to fabricate topographic submicron features in a side-chain azobenzene polyester with a scanning near-field optical microscope, Through irradiation at a wavelength of 488 run at intensity levels of 12 W/cm(2), topographic features as narrow as 240 nm and as high as 6 nm...... have been reproducibly recorded in a thin film of the polyester. These observations are consistent with the fact that at low intensities peaks are produced evolving into formation of trenches at high intensities in the case of amorphous side-chain azobenzene polyesters. This may find applications...

  7. Simulation of infiltration and redistribution of intense rainfall using Land Surface Models

    Science.gov (United States)

    Mueller, Anna; Verhoef, Anne; Cloke, Hannah

    2016-04-01

    Flooding from intense rainfall (FFIR) can cause widespread damage and disruption. Numerical Weather Prediction (NWP) models provide distributed information about atmospheric conditions, such as precipitation, that can lead to a flooding event. Short duration, high intensity rainfall events are generally poorly predicted by NWP models, because of the high spatiotemporal resolution required and because of the way the convective rainfall is described in the model. The resolution of NWP models is ever increasing. Better understanding of complex hydrological processes and the effect of scale is important in order to improve the prediction of magnitude and duration of such events, in the context of disaster management. Working as part of the NERC SINATRA project, we evaluated how the Land Surface Model (LSM) components of NWP models cope with high intensity rainfall input and subsequent infiltration problems. Both in terms of the amount of water infiltrated in the soil store, as well as the timing and the amount of surface and subsurface runoff generated. The models investigated are SWAP (Soil Water Air Plant, Alterra, the Netherlands, van Dam 1997), JULES (Joint UK Land Environment Simulator a component of Unified Model in UK Met Office, Best et al. 2011) and CHTESSEL (Carbon and Hydrology- Tiled ECMWF Scheme for Surface Exchanges over Land, Balsamo et al. 2009) We analysed the numerical aspects arising from discontinuities (or sharp gradients) in forcing and/or the model solution. These types of infiltration configurations were tested in the laboratory (Vachaud 1971), for some there are semi-analytical solutions (Philip 1957, Parlange 1972, Vanderborght 2005) or reference numerical solutions (Haverkamp 1977, van Dam 2000, Vanderborght 2005). The maximum infiltration by the surface, Imax, is in general dependent on atmospheric conditions, surface type, soil type, soil moisture content θ, and surface orographic factor σ. The models used differ in their approach to

  8. Surface feature congruency effects in the object-reviewing paradigm are dependent on task memory demands.

    Science.gov (United States)

    Kimchi, Ruth; Pirkner, Yossef

    2014-08-01

    Perception of object continuity depends on establishing correspondence between objects viewed across disruptions in visual information. The role of spatiotemporal information in guiding object continuity is well documented; the role of surface features, however, is controversial. Some researchers have shown an object-specific preview benefit (OSPB)-a standard index of object continuity-only when correspondence could be based on an object's spatiotemporal information, whereas others have found color-based OSPB, suggesting that surface features can also guide object continuity. This study shows that surface feature-based OSPB is dependent on the task memory demands. When the task involved letters and matching just one target letter to the preview ones, no color congruency effect was found under spatiotemporal discontinuity and spatiotemporal ambiguity (Experiments 1-3), indicating that the absence of feature-based OSPB cannot be accounted for by salient spatiotemporal discontinuity. When the task involved complex shapes and matching two target shapes to the preview ones, color-based OSPB was obtained. Critically, however, when a visual working memory task was performed concurrently with the matching task, the presence of a nonspatial (but not a spatial) working memory load eliminated the color-based OSPB (Experiments 4 and 5). These results suggest that the surface feature congruency effects that are observed in the object-reviewing paradigm (with the matching task) reflect memory-based strategies that participants use to solve a memory-demanding task; therefore, they are not reliable measures of online object continuity and cannot be taken as evidence for the role of surface features in establishing object correspondence.

  9. From Intensity Profile to Surface Normal: Photometric Stereo for Unknown Light Sources and Isotropic Reflectances.

    Science.gov (United States)

    Lu, Feng; Matsushita, Yasuyuki; Sato, Imari; Okabe, Takahiro; Sato, Yoichi

    2015-10-01

    We propose an uncalibrated photometric stereo method that works with general and unknown isotropic reflectances. Our method uses a pixel intensity profile, which is a sequence of radiance intensities recorded at a pixel under unknown varying directional illumination. We show that for general isotropic materials and uniformly distributed light directions, the geodesic distance between intensity profiles is linearly related to the angular difference of their corresponding surface normals, and that the intensity distribution of the intensity profile reveals reflectance properties. Based on these observations, we develop two methods for surface normal estimation; one for a general setting that uses only the recorded intensity profiles, the other for the case where a BRDF database is available while the exact BRDF of the target scene is still unknown. Quantitative and qualitative evaluations are conducted using both synthetic and real-world scenes, which show the state-of-the-art accuracy of smaller than 10 degree without using reference data and 5 degree with reference data for all 100 materials in MERL database.

  10. On Feature Extraction from Large Scale Linear LiDAR Data

    Science.gov (United States)

    Acharjee, Partha Pratim

    Airborne light detection and ranging (LiDAR) can generate co-registered elevation and intensity map over large terrain. The co-registered 3D map and intensity information can be used efficiently for different feature extraction application. In this dissertation, we developed two algorithms for feature extraction, and usages of features for practical applications. One of the developed algorithms can map still and flowing waterbody features, and another one can extract building feature and estimate solar potential on rooftops and facades. Remote sensing capabilities, distinguishing characteristics of laser returns from water surface and specific data collection procedures provide LiDAR data an edge in this application domain. Furthermore, water surface mapping solutions must work on extremely large datasets, from a thousand square miles, to hundreds of thousands of square miles. National and state-wide map generation/upgradation and hydro-flattening of LiDAR data for many other applications are two leading needs of water surface mapping. These call for as much automation as possible. Researchers have developed many semi-automated algorithms using multiple semi-automated tools and human interventions. This reported work describes a consolidated algorithm and toolbox developed for large scale, automated water surface mapping. Geometric features such as flatness of water surface, higher elevation change in water-land interface and, optical properties such as dropouts caused by specular reflection, bimodal intensity distributions were some of the linear LiDAR features exploited for water surface mapping. Large-scale data handling capabilities are incorporated by automated and intelligent windowing, by resolving boundary issues and integrating all results to a single output. This whole algorithm is developed as an ArcGIS toolbox using Python libraries. Testing and validation are performed on a large datasets to determine the effectiveness of the toolbox and results are

  11. Contributions of feature shapes and surface cues to the recognition of facial expressions.

    Science.gov (United States)

    Sormaz, Mladen; Young, Andrew W; Andrews, Timothy J

    2016-10-01

    Theoretical accounts of face processing often emphasise feature shapes as the primary visual cue to the recognition of facial expressions. However, changes in facial expression also affect the surface properties of the face. In this study, we investigated whether this surface information can also be used in the recognition of facial expression. First, participants identified facial expressions (fear, anger, disgust, sadness, happiness) from images that were manipulated such that they varied mainly in shape or mainly in surface properties. We found that the categorization of facial expression is possible in either type of image, but that different expressions are relatively dependent on surface or shape properties. Next, we investigated the relative contributions of shape and surface information to the categorization of facial expressions. This employed a complementary method that involved combining the surface properties of one expression with the shape properties from a different expression. Our results showed that the categorization of facial expressions in these hybrid images was equally dependent on the surface and shape properties of the image. Together, these findings provide a direct demonstration that both feature shape and surface information make significant contributions to the recognition of facial expressions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Examining the Impact of Question Surface Features on Students' Answers to Constructed-Response Questions on Photosynthesis

    Science.gov (United States)

    Weston, Michele; Haudek, Kevin C.; Prevost, Luanna; Urban-Lurain, Mark; Merrill, John

    2015-01-01

    One challenge in science education assessment is that students often focus on surface features of questions rather than the underlying scientific principles. We investigated how student written responses to constructed-response questions about photosynthesis vary based on two surface features of the question: the species of plant and the order of…

  13. Stereoscopic Feature Tracking System for Retrieving Velocity of Surface Waters

    Science.gov (United States)

    Zuniga Zamalloa, C. C.; Landry, B. J.

    2017-12-01

    The present work is concerned with the surface velocity retrieval of flows using a stereoscopic setup and finding the correspondence in the images via feature tracking (FT). The feature tracking provides a key benefit of substantially reducing the level of user input. In contrast to other commonly used methods (e.g., normalized cross-correlation), FT does not require the user to prescribe interrogation window sizes and removes the need for masking when specularities are present. The results of the current FT methodology are comparable to those obtained via Large Scale Particle Image Velocimetry while requiring little to no user input which allowed for rapid, automated processing of imagery.

  14. Fusion of geometric and texture features for finger knuckle surface recognition

    Directory of Open Access Journals (Sweden)

    K. Usha

    2016-03-01

    Full Text Available Hand-based biometrics plays a significant role in establishing security for real-time environments involving human interaction and is found to be more successful in terms of high speed and accuracy. This paper investigates on an integrated approach for personal authentication using Finger Back Knuckle Surface (FBKS based on two methodologies viz., Angular Geometric Analysis based Feature Extraction Method (AGFEM and Contourlet Transform based Feature Extraction Method (CTFEM. Based on these methods, this personal authentication system simultaneously extracts shape oriented feature information and textural pattern information of FBKS for authenticating an individual. Furthermore, the proposed geometric and textural analysis methods extract feature information from both proximal phalanx and distal phalanx knuckle regions (FBKS, while the existing works of the literature concentrate only on the features of proximal phalanx knuckle region. The finger joint region found nearer to the tip of the finger is called distal phalanx region of FBKS, which is a unique feature and has greater potentiality toward identification. Extensive experiments conducted using newly created database with 5400 FBKS images and the obtained results infer that the integration of shape oriented features with texture feature information yields excellent accuracy rate of 99.12% with lowest equal error rate of 1.04%.

  15. MRI intensity inhomogeneity correction by combining intensity and spatial information

    International Nuclear Information System (INIS)

    Vovk, Uros; Pernus, Franjo; Likar, Bostjan

    2004-01-01

    We propose a novel fully automated method for retrospective correction of intensity inhomogeneity, which is an undesired phenomenon in many automatic image analysis tasks, especially if quantitative analysis is the final goal. Besides most commonly used intensity features, additional spatial image features are incorporated to improve inhomogeneity correction and to make it more dynamic, so that local intensity variations can be corrected more efficiently. The proposed method is a four-step iterative procedure in which a non-parametric inhomogeneity correction is conducted. First, the probability distribution of image intensities and corresponding second derivatives is obtained. Second, intensity correction forces, condensing the probability distribution along the intensity feature, are computed for each voxel. Third, the inhomogeneity correction field is estimated by regularization of all voxel forces, and fourth, the corresponding partial inhomogeneity correction is performed. The degree of inhomogeneity correction dynamics is determined by the size of regularization kernel. The method was qualitatively and quantitatively evaluated on simulated and real MR brain images. The obtained results show that the proposed method does not corrupt inhomogeneity-free images and successfully corrects intensity inhomogeneity artefacts even if these are more dynamic

  16. Analyzing surface features on icy satellites using a new two-layer analogue model

    Science.gov (United States)

    Morales, K. M.; Leonard, E. J.; Pappalardo, R. T.; Yin, A.

    2017-12-01

    The appearance of similar surface morphologies across many icy satellites suggests potentially unified formation mechanisms. Constraining the processes that shape the surfaces of these icy worlds is fundamental to understanding their rheology and thermal evolution—factors that have implications for potential habitability. Analogue models have proven useful for investigating and quantifying surface structure formation on Earth, but have only been sparsely applied to icy bodies. In this study, we employ an innovative two-layer analogue model that simulates a warm, ductile ice layer overlain by brittle surface ice on satellites such as Europa and Enceladus. The top, brittle layer is composed of fine-grained sand while the ductile, lower viscosity layer is made of putty. These materials were chosen because they scale up reasonably to the conditions on Europa and Enceladus. Using this analogue model, we investigate the role of the ductile layer in forming contractional structures (e.g. folds) that would compensate for the over-abundance of extensional features observed on icy satellites. We do this by simulating different compressional scenarios in the analogue model and analyzing whether the resulting features resemble those on icy bodies. If the resulting structures are similar, then the model can be used to quantify the deformation by calculating strain. These values can then be scaled up to Europa or Enceladus and used to quantity the observed surface morphologies and the amount of extensional strain accommodated by certain features. This presentation will focus on the resulting surface morphologies and the calculated strain values from several analogue experiments. The methods and findings from this work can then be expanded and used to study other icy bodies, such as Triton, Miranda, Ariel, and Pluto.

  17. Orienting in virtual environments: How are surface features and environmental geometry weighted in an orientation task?

    Science.gov (United States)

    Kelly, Debbie M; Bischof, Walter F

    2008-10-01

    We investigated how human adults orient in enclosed virtual environments, when discrete landmark information is not available and participants have to rely on geometric and featural information on the environmental surfaces. In contrast to earlier studies, where, for women, the featural information from discrete landmarks overshadowed the encoding of the geometric information, Experiment 1 showed that when featural information is conjoined with the environmental surfaces, men and women encoded both types of information. Experiment 2 showed that, although both types of information are encoded, performance in locating a goal position is better if it is close to a geometrically or featurally distinct location. Furthermore, although features are relied upon more strongly than geometry, initial experience with an environment influences the relative weighting of featural and geometric cues. Taken together, these results show that human adults use a flexible strategy for encoding spatial information.

  18. Associations between motor unit action potential parameters and surface EMG features.

    Science.gov (United States)

    Del Vecchio, Alessandro; Negro, Francesco; Felici, Francesco; Farina, Dario

    2017-10-01

    The surface interference EMG signal provides some information on the neural drive to muscles. However, the association between neural drive to muscle and muscle activation has long been debated with controversial indications due to the unavailability of motor unit population data. In this study, we clarify the potential and limitations of interference EMG analysis to infer motor unit recruitment strategies with an experimental investigation of several concurrently active motor units and of the associated features of the surface EMG. For this purpose, we recorded high-density surface EMG signals during linearly increasing force contractions of the tibialis anterior muscle, up to 70% of maximal force. The recruitment threshold (RT), conduction velocity (MUCV), median frequency (MDF MU ), and amplitude (RMS MU ) of action potentials of 587 motor units from 13 individuals were assessed and associated with features of the interference EMG. MUCV was positively associated with RT ( R 2 = 0.64 ± 0.14), whereas MDF MU and RMS MU showed a weaker relation with RT ( R 2 = 0.11 ± 0.11 and 0.39 ± 0.24, respectively). Moreover, the changes in average conduction velocity estimated from the interference EMG predicted well the changes in MUCV ( R 2 = 0.71), with a strong association to ankle dorsiflexion force ( R 2 = 0.81 ± 0.12). Conversely, both the average EMG MDF and RMS were poorly associated with motor unit recruitment. These results clarify the limitations of EMG spectral and amplitude analysis in inferring the neural strategies of muscle control and indicate that, conversely, the average conduction velocity could provide relevant information on these strategies. NEW & NOTEWORTHY The surface EMG provides information on the neural drive to muscles. However, the associations between EMG features and neural drive have been long debated due to unavailability of motor unit population data. Here, by using novel highly accurate decomposition of the EMG, we related motor unit

  19. Feature Surfaces in Symmetric Tensor Fields Based on Eigenvalue Manifold.

    Science.gov (United States)

    Palacios, Jonathan; Yeh, Harry; Wang, Wenping; Zhang, Yue; Laramee, Robert S; Sharma, Ritesh; Schultz, Thomas; Zhang, Eugene

    2016-03-01

    Three-dimensional symmetric tensor fields have a wide range of applications in solid and fluid mechanics. Recent advances in the (topological) analysis of 3D symmetric tensor fields focus on degenerate tensors which form curves. In this paper, we introduce a number of feature surfaces, such as neutral surfaces and traceless surfaces, into tensor field analysis, based on the notion of eigenvalue manifold. Neutral surfaces are the boundary between linear tensors and planar tensors, and the traceless surfaces are the boundary between tensors of positive traces and those of negative traces. Degenerate curves, neutral surfaces, and traceless surfaces together form a partition of the eigenvalue manifold, which provides a more complete tensor field analysis than degenerate curves alone. We also extract and visualize the isosurfaces of tensor modes, tensor isotropy, and tensor magnitude, which we have found useful for domain applications in fluid and solid mechanics. Extracting neutral and traceless surfaces using the Marching Tetrahedra method can cause the loss of geometric and topological details, which can lead to false physical interpretation. To robustly extract neutral surfaces and traceless surfaces, we develop a polynomial description of them which enables us to borrow techniques from algebraic surface extraction, a topic well-researched by the computer-aided design (CAD) community as well as the algebraic geometry community. In addition, we adapt the surface extraction technique, called A-patches, to improve the speed of finding degenerate curves. Finally, we apply our analysis to data from solid and fluid mechanics as well as scalar field analysis.

  20. Nanostructured surface processing by an intense pulsed ion beam irradiation

    International Nuclear Information System (INIS)

    Yatsuzuka, M.; Masuda, T.; Yamasaki, T.; Uchida, H.; Nobuhara, S.; Hashimoto, Y.; Yoshihara, Y.

    1997-01-01

    Metal surface modification by irradiating an intense pulsed ion beam (IPIB) with short pulse width has been studied experimentally. An IPIB irradiation to a target leads to rapid heating above its melting point. After the beam is turned off, the heated region is immediately cooled by thermal conduction at a cooling rate of typically 10 10 K/s. This rapid cooling and resolidification results in generation of nanostructured phase in the top of surface. The typical hydrogen IPIB parameters are 200 kV of energy, 500 A/cm 2 of current density and 70 ns of pulsewidth. The IPIB was irradiated on a pure titanium to generate nanocrystalline phase. The IPIB-irradiated surface was examined with X-ray diffraction, SEM, and HR-TEM. The randomly oriented lattice fringes as well as a halo diffraction pattern are observed in the HR-TEM micrograph of IPIB-irradiated titanium. The average grain size is found to be 32 nanometers

  1. Stream/Bounce Event Perception Reveals a Temporal Limit of Motion Correspondence Based on Surface Feature over Space and Time

    Directory of Open Access Journals (Sweden)

    Yousuke Kawachi

    2011-06-01

    Full Text Available We examined how stream/bounce event perception is affected by motion correspondence based on the surface features of moving objects passing behind an occlusion. In the stream/bounce display two identical objects moving across each other in a two-dimensional display can be perceived as either streaming through or bouncing off each other at coincidence. Here, surface features such as colour (Experiments 1 and 2 or luminance (Experiment 3 were switched between the two objects at coincidence. The moment of coincidence was invisible to observers due to an occluder. Additionally, the presentation of the moving objects was manipulated in duration after the feature switch at coincidence. The results revealed that a postcoincidence duration of approximately 200 ms was required for the visual system to stabilize judgments of stream/bounce events by determining motion correspondence between the objects across the occlusion on the basis of the surface feature. The critical duration was similar across motion speeds of objects and types of surface features. Moreover, controls (Experiments 4a–4c showed that cognitive bias based on feature (colour/luminance congruency across the occlusion could not fully account for the effects of surface features on the stream/bounce judgments. We discuss the roles of motion correspondence, visual feature processing, and attentive tracking in the stream/bounce judgments.

  2. Correlation between the histological features of corneal surface pannus following ocular surface burns and the final outcome of cultivated limbal epithelial transplantation.

    Science.gov (United States)

    Sati, Alok; Basu, Sayan; Sangwan, Virender S; Vemuganti, Geeta K

    2015-04-01

    To report the influence of histological features of corneal surface pannus following ocular surface burn on the outcome of cultivated limbal epithelial transplantation (CLET). On retrospectively reviewing the medical records of the patients who underwent autologous CLET from April 2002 to June 2012 at L V Prasad Eye Institute, Hyderabad, India, we could trace the histological reports in only 90 records. These 90 records, besides clinical parameters, were reviewed for the influence of various histological features on the final outcome of CLET. The histological features include epithelial hyperplasia (21.1%), surface ulceration (2.2%), goblet cells (62.2%), squamous metaplasia (11.1%), active fibrosis (31.1%), severe inflammation (8.9%), multinucleated giant cells (3.3%), stromal calcification (8.9%) and active proliferating vessels (5.6%). Among these histological features, patients with either hyperplasia or calcification in their excised corneal pannus show an unfavourable outcome compared with patients without hyperplasia (p=0.003) or calcification (p=0.018). A similar unfavourable outcome was not seen with other histological features and various clinical parameters. Presence of either calcific deposits or hyperplasia in the excised corneal pannus provides poor prognostication; hence, a proper counselling of such patients is mandatory along with a close follow-up. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. Reduced adhesion of macrophages on anodized titanium with select nanotube surface features

    Directory of Open Access Journals (Sweden)

    Balasubramanian K

    2011-08-01

    Full Text Available Amancherla Rajyalakshmi1, Batur Ercan2,3, K Balasubramanian1, Thomas J Webster2,31Non-Ferrous Materials Technology Development Centre, Hyderabad, India; 2School of Engineering, 3Department of Orthopedics, Brown University, Providence, RI, USAAbstract: One of the important prerequisites for a successful orthopedic implant apart from being osteoconductive is the elicitation of a favorable immune response that does not lead to the rejection of the implant by the host tissue. Anodization is one of the simplest surface modification processes used to create nanotextured and nanotubular features on metal oxides which has been shown to improve bone formation. Anodization of titanium (Ti leads to the formation of TiO2 nanotubes on the surface, and the presence of these nanotubes mimics the natural nanoscale features of bone, which in turn contributes to improved bone cell attachment, migration, and proliferation. However, inflammatory cell responses on anodized Ti remains to be tested. It is hypothesized that surface roughness and surface feature size on anodized Ti can be carefully manipulated to control immune cell (specifically, macrophages responses. Here, when Ti samples were anodized at 10 V in the presence of 1% hydrofluoric acid (HF for 1 minute, nanotextured (nonnanotube surfaces were created. When anodization of Ti samples was carried out with 1% HF for 10 minutes at 15 V, nanotubes with 40–50 nm diameters were formed, whereas at 20 V with 1% HF for 10 minutes, nanotubes with 60–70 nm diameters were formed. In this study, a reduced density of macrophages was observed after 24 hours of culture on nanotextured and nanotubular Ti samples which were anodized at 10, 15, and 20 V, compared with conventional unmodified Ti samples. This in vitro study thus demonstrated a reduced density of macrophages on anodized Ti, thereby providing further evidence of the greater efficacy of anodized Ti for orthopedic applications.Keywords: anodization, titanium

  4. Surface features on Sahara soil dust particles made visible by atomic force microscope (AFM phase images

    Directory of Open Access Journals (Sweden)

    M. O. Andreae

    2008-10-01

    Full Text Available We show that atomic force microscopy (AFM phase images can reveal surface features of soil dust particles, which are not evident using other microscopic methods. The non-contact AFM method is able to resolve topographical structures in the nanometer range as well as to uncover repulsive atomic forces and attractive van der Waals' forces, and thus gives insight to surface properties. Though the method does not allow quantitative assignment in terms of chemical compound description, it clearly shows deposits of distinguishable material on the surface. We apply this technique to dust aerosol particles from the Sahara collected over the Atlantic Ocean and describe micro-features on the surfaces of such particles.

  5. C2H6 scattering from LiF(0 0 1): Influence of the molecular anisotropy on rainbow scattering in both intensity and speed distributions

    International Nuclear Information System (INIS)

    Kondo, Takahiro; Tomii, Takashi; Yamamoto, Shigehiko

    2006-01-01

    We have measured the angle-resolved intensity and speed distributions of C 2 H 6 scattered from LiF(0 0 1) along the [1 0 0] azimuthal direction, the largest structural corrugation direction, to investigate the effect of the molecular anisotropy on the gas-surface interaction at the corrugated surface. While clear rainbow feature is observed in the mean energy angular distribution, no rainbow feature is detected in the intensity angular distribution. From the comparisons of the obtained results to the calculated predictions based on the simple classical theory of the ellipsoid-washboard model, the effect of the molecular anisotropy is found to play a crucial role in the rainbow feature. With an increase in the extent of the molecular anisotropy such as that of C 2 H 6 as compared with rare gas atoms, the integration of the intensity angular distributions for various molecular orientations results in the smearing of the rainbow feature on the corrugated surface. The rainbow scattering in the mean energy angular distribution, however, is not completely smeared out

  6. A statistical-textural-features based approach for classification of solid drugs using surface microscopic images.

    Science.gov (United States)

    Tahir, Fahima; Fahiem, Muhammad Abuzar

    2014-01-01

    The quality of pharmaceutical products plays an important role in pharmaceutical industry as well as in our lives. Usage of defective tablets can be harmful for patients. In this research we proposed a nondestructive method to identify defective and nondefective tablets using their surface morphology. Three different environmental factors temperature, humidity and moisture are analyzed to evaluate the performance of the proposed method. Multiple textural features are extracted from the surface of the defective and nondefective tablets. These textural features are gray level cooccurrence matrix, run length matrix, histogram, autoregressive model and HAAR wavelet. Total textural features extracted from images are 281. We performed an analysis on all those 281, top 15, and top 2 features. Top 15 features are extracted using three different feature reduction techniques: chi-square, gain ratio and relief-F. In this research we have used three different classifiers: support vector machine, K-nearest neighbors and naïve Bayes to calculate the accuracies against proposed method using two experiments, that is, leave-one-out cross-validation technique and train test models. We tested each classifier against all selected features and then performed the comparison of their results. The experimental work resulted in that in most of the cases SVM performed better than the other two classifiers.

  7. Efficient computer program EPAS-J1 for calculating stress intensity factors of three-dimensional surface cracks

    International Nuclear Information System (INIS)

    Miyazaki, Noriyuki; Watanabe, Takayuki; Yagawa, Genki.

    1982-03-01

    A finite element computer program EPAS-J1 was developed to calculate the stress intensity factors of three-dimensional cracks. In the program, the stress intensity factor is determined by the virtual crack extension method together with the distorted elements allocated along the crack front. This program also includes the connection elements based on the Lagrange multiplier concept to connect such different kinds of elements as the solid and shell elements, or the shell and beam elements. For the structure including three-dimensional surface cracks, the solid elements are employed only at the neighborhood of a surface crack, while the remainder of the structure is modeled by the shell or beam elements due to the reason that the crack singularity is very local. Computer storage and computational time can be highly reduced with the application of the above modeling technique for the calculation of the stress intensity factors of the three-dimensional surface cracks, because the three-dimensional solid elements are required only around the crack front. Several numerical analyses were performed by the EPAS-J1 program. At first, the accuracies of the connection element and the virtual crack extension method were confirmed using the simple structures. Compared with other techniques of connecting different kinds of elements such as the tying method or the method using anisotropic plate element, the present connection element is found to provide better results than the others. It is also found that the virtual crack extension method provides the accurate stress intensity factor. Furthermore, the results are also presented for the stress intensity factor analyses of cylinders with longitudinal or circumferential surface cracks using the combination of the various kinds of elements together with the connection elements. (author)

  8. Copper surfaces are associated with significantly lower concentrations of bacteria on selected surfaces within a pediatric intensive care unit.

    Science.gov (United States)

    Schmidt, Michael G; von Dessauer, Bettina; Benavente, Carmen; Benadof, Dona; Cifuentes, Paulina; Elgueta, Alicia; Duran, Claudia; Navarrete, Maria S

    2016-02-01

    Health care-associated infections result in significant patient morbidity and mortality. Although cleaning can remove pathogens present on hospital surfaces, those surfaces may be inadequately cleaned or recontaminated within minutes. Because of copper's inherent and continuous antimicrobial properties, copper surfaces offer a solution to complement cleaning. The objective of this study was to quantitatively assess the bacterial microbial burden coincident with an assessment of the ability of antimicrobial copper to limit the microbial burden associated with 3 surfaces in a pediatric intensive care unit. A pragmatic trial was conducted enrolling 1,012 patients from 2 high acuity care units within a 249-bed tertiary care pediatric hospital over 12 months. The microbial burden was determined from 3 frequently encountered surfaces, regardless of room occupancy, twice monthly, from 16 rooms, 8 outfitted normally and 8 outfitted with antimicrobial copper. Copper surfaces were found to be equivalently antimicrobial in pediatric settings to activities reported for adult medical intensive care units. The log10 reduction to the microbial burden from antimicrobial copper surfaced bed rails was 1.996 (99%). Surprisingly, introduction of copper objects to 8 study rooms was found to suppress the microbial burden recovered from objects assessed in control rooms by log10 of 1.863 (73%). Copper surfaces warrant serious consideration when contemplating the introduction of no-touch disinfection technologies for reducing burden to limit acquisition of HAIs. Copyright © 2016 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  9. Intense Adrenal Enhancement: A CT Feature of Cardiogenic Shock

    International Nuclear Information System (INIS)

    Hrabak-Paar, Maja

    2016-01-01

    In this report, images of intense adrenal enhancement in a 79-year-old female patient with right-sided heart failure and severe tricuspid insufficiency are presented. Only two cases of intense adrenal enhancement as a sign of cardiogenic shock were previously reported in the literature. Intense adrenal enhancement could be one of the earliest CT signs of cardiogenic shock. Its presence should be immediately reported to the referring physician as a sign of significant hemodynamic instability warranting early critical-care management

  10. Intense Adrenal Enhancement: A CT Feature of Cardiogenic Shock

    Energy Technology Data Exchange (ETDEWEB)

    Hrabak-Paar, Maja, E-mail: maja.hrabak.paar@mef.hr [University of Zagreb School of Medicine, Department of Diagnostic and Interventional Radiology, University Hospital Center Zagreb (Croatia)

    2016-02-15

    In this report, images of intense adrenal enhancement in a 79-year-old female patient with right-sided heart failure and severe tricuspid insufficiency are presented. Only two cases of intense adrenal enhancement as a sign of cardiogenic shock were previously reported in the literature. Intense adrenal enhancement could be one of the earliest CT signs of cardiogenic shock. Its presence should be immediately reported to the referring physician as a sign of significant hemodynamic instability warranting early critical-care management.

  11. Surface Features and Cathodoluminescence (CL) Characteristics of Corundum Gems from Eastern of Thailand

    Science.gov (United States)

    Boonsoong, A.

    2017-12-01

    Thailand has long been well known as a supplier of gemstones and also one of the world's color stone centers for decades. The principal gemstones are corundum, garnet and zircon. The corundum deposits of Chanthaburi-Trat Provinces form the most significant ruby-sapphire concentration in Thailand. Corundums are commonly found in secondary deposits (alluvium, elluvial, residual-soil and colluvium deposits as well as stream sediments) with the thickness of the gem-bearing layer varying from 10-100cm and the thickness of the overburden ranging up to 15m. A number of corundum samples were collected from each of the twenty-nine corundum deposits in the Chanthaburi-Trat gem fields, eastern of Thailand. Corundum varies in colour across the region with colours associated with three geographic zones; a western zone, characterized by blue, green and yellow sapphires; a middle zone with blue, green sapphires plus rubies; and an eastern zone yielding mainly rubies. This project has aim to study surface features and characterize the Cathodoluminescence (CL) of corundum gems in the Chanthaburi-Trat gem fields, Thailand. Surfaces of the corundums under a scanning electron microscope show triangular etch features and randomly oriented needle-like patterns. These reveal that the corundums have interacted with the magma during their ascent to the Earth's surface. Surface features attributable to transport and weathering processes are scratches, conchoidal fractures and a spongy surface appearance. Clay minerals and Fe-Ti oxide minerals deposited on the spongy surfaces of some corundums also indicate that these grains experienced chemical weathering or reacted with the soil solution while they were in the alluvium. Cathodoluminescence shows some blue sapphires to exhibit dull blue luminescence. The main cause of the CL appearance of sapphires is likely to be a quench centre, Fe2+ in their structure. The bright red luminescence in corundum reflects a high Cr3+ content and is always

  12. Game Theoretic Approach for Systematic Feature Selection; Application in False Alarm Detection in Intensive Care Units

    Directory of Open Access Journals (Sweden)

    Fatemeh Afghah

    2018-03-01

    Full Text Available Intensive Care Units (ICUs are equipped with many sophisticated sensors and monitoring devices to provide the highest quality of care for critically ill patients. However, these devices might generate false alarms that reduce standard of care and result in desensitization of caregivers to alarms. Therefore, reducing the number of false alarms is of great importance. Many approaches such as signal processing and machine learning, and designing more accurate sensors have been developed for this purpose. However, the significant intrinsic correlation among the extracted features from different sensors has been mostly overlooked. A majority of current data mining techniques fail to capture such correlation among the collected signals from different sensors that limits their alarm recognition capabilities. Here, we propose a novel information-theoretic predictive modeling technique based on the idea of coalition game theory to enhance the accuracy of false alarm detection in ICUs by accounting for the synergistic power of signal attributes in the feature selection stage. This approach brings together techniques from information theory and game theory to account for inter-features mutual information in determining the most correlated predictors with respect to false alarm by calculating Banzhaf power of each feature. The numerical results show that the proposed method can enhance classification accuracy and improve the area under the ROC (receiver operating characteristic curve compared to other feature selection techniques, when integrated in classifiers such as Bayes-Net that consider inter-features dependencies.

  13. Surface and morphological features of laser-irradiated silicon under vacuum, nitrogen and ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Hayat, Asma, E-mail: asmahayat@gcu.edu.pk; Bashir, Shazia; Akram, Mahreen; Mahmood, Khaliq; Iqbal, Muhammad Hassan

    2015-12-01

    Highlights: • Laser irradiation effects on Si surface have been explored. • An Excimer Laser was used as a source. • SEM analysis was performed to explore surface morphology. • Raman spectroscopy analysis was carried out to find crystallographical alterations. - Abstract: Laser-induced surface and structural modification of silicon (Si) has been investigated under three different environments of vacuum, nitrogen (100 Torr) and ethanol. The interaction of 1000 pulses of KrF (λ ≈ 248 nm, τ ≈ 18 ns, repetition rate ≈ 30 Hz) Excimer laser at two different fluences of 2.8 J/cm{sup 2} and 4 J/cm{sup 2} resulted in formation of various kinds of features such as laser induced periodic surface structures (LIPSS), spikes, columns, cones and cracks. Surface morphology has been observed by Scanning Electron Microscope (SEM). Whereas, structural modification of irradiated targets is explored by Raman spectroscopy. SEM analysis exhibits a non-uniform distribution of micro-scale pillars and spikes at the central ablated regime of silicon irradiated at low laser fluence of 2.8 J/cm{sup 2} under vacuum. Whereas cones, pits, cavities and ripples like features are seen at the boundaries. At higher fluence of 4 J/cm{sup 2}, laser induced periodic structures as well as micro-columns are observed. In the case of ablation in nitrogen environment, melting, splashing, self-organized granular structures and cracks along with redeposition are observed at lower fluence. Such types of small scaled structures in nitrogen are attributed to confinement and shielding effects of nitrogen plasma. Whereas, a crater with multiple ablative layers is formed in the case of ablation at higher fluence. Significantly different surface morphology of Si is observed in the case of ablation in ethanol. It reveals the formation of cavities along with small scale pores and less redeposition. These results reveal that the growth of surface and morphological features of irradiated Si are strongly

  14. Surface and morphological features of laser-irradiated silicon under vacuum, nitrogen and ethanol

    International Nuclear Information System (INIS)

    Hayat, Asma; Bashir, Shazia; Akram, Mahreen; Mahmood, Khaliq; Iqbal, Muhammad Hassan

    2015-01-01

    Highlights: • Laser irradiation effects on Si surface have been explored. • An Excimer Laser was used as a source. • SEM analysis was performed to explore surface morphology. • Raman spectroscopy analysis was carried out to find crystallographical alterations. - Abstract: Laser-induced surface and structural modification of silicon (Si) has been investigated under three different environments of vacuum, nitrogen (100 Torr) and ethanol. The interaction of 1000 pulses of KrF (λ ≈ 248 nm, τ ≈ 18 ns, repetition rate ≈ 30 Hz) Excimer laser at two different fluences of 2.8 J/cm 2 and 4 J/cm 2 resulted in formation of various kinds of features such as laser induced periodic surface structures (LIPSS), spikes, columns, cones and cracks. Surface morphology has been observed by Scanning Electron Microscope (SEM). Whereas, structural modification of irradiated targets is explored by Raman spectroscopy. SEM analysis exhibits a non-uniform distribution of micro-scale pillars and spikes at the central ablated regime of silicon irradiated at low laser fluence of 2.8 J/cm 2 under vacuum. Whereas cones, pits, cavities and ripples like features are seen at the boundaries. At higher fluence of 4 J/cm 2 , laser induced periodic structures as well as micro-columns are observed. In the case of ablation in nitrogen environment, melting, splashing, self-organized granular structures and cracks along with redeposition are observed at lower fluence. Such types of small scaled structures in nitrogen are attributed to confinement and shielding effects of nitrogen plasma. Whereas, a crater with multiple ablative layers is formed in the case of ablation at higher fluence. Significantly different surface morphology of Si is observed in the case of ablation in ethanol. It reveals the formation of cavities along with small scale pores and less redeposition. These results reveal that the growth of surface and morphological features of irradiated Si are strongly dependent upon the

  15. Potential energy surface, dipole moment surface and the intensity calculations for the 10 μm, 5 μm and 3 μm bands of ozone

    Science.gov (United States)

    Polyansky, Oleg L.; Zobov, Nikolai F.; Mizus, Irina I.; Kyuberis, Aleksandra A.; Lodi, Lorenzo; Tennyson, Jonathan

    2018-05-01

    Monitoring ozone concentrations in the Earth's atmosphere using spectroscopic methods is a major activity which undertaken both from the ground and from space. However there are long-running issues of consistency between measurements made at infrared (IR) and ultraviolet (UV) wavelengths. In addition, key O3 IR bands at 10 μm, 5 μm and 3 μm also yield results which differ by a few percent when used for retrievals. These problems stem from the underlying laboratory measurements of the line intensities. Here we use quantum chemical techniques, first principles electronic structure and variational nuclear-motion calculations, to address this problem. A new high-accuracy ab initio dipole moment surface (DMS) is computed. Several spectroscopically-determined potential energy surfaces (PESs) are constructed by fitting to empirical energy levels in the region below 7000 cm-1 starting from an ab initio PES. Nuclear motion calculations using these new surfaces allow the unambiguous determination of the intensities of 10 μm band transitions, and the computation of the intensities of 10 μm and 5 μm bands within their experimental error. A decrease in intensities within the 3 μm is predicted which appears consistent with atmospheric retrievals. The PES and DMS form a suitable starting point both for the computation of comprehensive ozone line lists and for future calculations of electronic transition intensities.

  16. Predicting the Occurrence of Cave-Inhabiting Fauna Based on Features of the Earth Surface Environment.

    Science.gov (United States)

    Christman, Mary C; Doctor, Daniel H; Niemiller, Matthew L; Weary, David J; Young, John A; Zigler, Kirk S; Culver, David C

    2016-01-01

    One of the most challenging fauna to study in situ is the obligate cave fauna because of the difficulty of sampling. Cave-limited species display patchy and restricted distributions, but it is often unclear whether the observed distribution is a sampling artifact or a true restriction in range. Further, the drivers of the distribution could be local environmental conditions, such as cave humidity, or they could be associated with surface features that are surrogates for cave conditions. If surface features can be used to predict the distribution of important cave taxa, then conservation management is more easily obtained. We examined the hypothesis that the presence of major faunal groups of cave obligate species could be predicted based on features of the earth surface. Georeferenced records of cave obligate amphipods, crayfish, fish, isopods, beetles, millipedes, pseudoscorpions, spiders, and springtails within the area of Appalachian Landscape Conservation Cooperative in the eastern United States (Illinois to Virginia and New York to Alabama) were assigned to 20 x 20 km grid cells. Habitat suitability for these faunal groups was modeled using logistic regression with twenty predictor variables within each grid cell, such as percent karst, soil features, temperature, precipitation, and elevation. Models successfully predicted the presence of a group greater than 65% of the time (mean = 88%) for the presence of single grid cell endemics, and for all faunal groups except pseudoscorpions. The most common predictor variables were latitude, percent karst, and the standard deviation of the Topographic Position Index (TPI), a measure of landscape rugosity within each grid cell. The overall success of these models points to a number of important connections between the surface and cave environments, and some of these, especially soil features and topographic variability, suggest new research directions. These models should prove to be useful tools in predicting the

  17. Fractal structure formation on the surfaces of solids subjected to high intensity electron and ion treatment

    International Nuclear Information System (INIS)

    Altajskij, M.V.; Ivanov, V.V.; Korenev, S.A.; Orelovich, O.L.; Puzynin, I.V.; Chernik, V.V.

    1997-01-01

    We discuss the results of scanning electron microscopy of surfaces of the solids subjected to high intensity electron and ion beam treatment. The appearance of fractal structures on the modified surfaces is shown. The fractal dimensions of these structures were estimated by box-counting algorithm

  18. Investigation of selected surface integrity features of duplex stainless steel (DSS after turning

    Directory of Open Access Journals (Sweden)

    G. Krolczyk

    2015-01-01

    Full Text Available The article presents surface roughness profiles and Abbott - Firestone curves with vertical and amplitude parameters of surface roughness after turning by means of a coated sintered carbide wedge with a coating with ceramic intermediate layer. The investigation comprised the influence of cutting speed on the selected features of surface integrity in dry machining. The material under investigation was duplex stainless steel with two-phase ferritic-austenitic structure. The tests have been performed under production conditions during machining of parts for electric motors and deep-well pumps. The obtained results allow to draw conclusions about the characteristics of surface properties of the machined parts.

  19. The effects of droplet characteristics on the surface features in a rain field

    Science.gov (United States)

    Liu, R.; Brown, H.; Liu, X.; Duncan, J. H.

    2013-11-01

    The characteristics of the shape of a water surface in response to the impact of simulated raindrops are studied experimentally in a 1.22-m-by-1.22-m water pool with a water depth of 0.3 m. A rain generator consisting of an open-surface water tank with an array of 22-gauge hypodermic needles (typical needle-to-needle spacing of about L0 = 3 . 5 cm) attached to holes in the tank bottom is mounted 2 m above the water pool. The tank is connected to a 2D translation stage to provide a small-radius (volumetric flow rate (nπd3 / 6) through control of the water depth in the generator tank. The water surface features, including the crown, stalk and ring waves, due to the impacts of the drops are measured with a cinematic laser-induced- fluorescence (LIF) technique. The dependence of these features on the rain characteristics are discussed. The support of the National Science Foundation, Division of Ocean Sciences, and the assistance of Mr. Larry Gong are gratefully acknowledged.

  20. Induction of subterahertz surface waves on a metal wire by intense laser interaction with a foil

    Science.gov (United States)

    Teramoto, Kensuke; Inoue, Shunsuke; Tokita, Shigeki; Yasuhara, Ryo; Nakamiya, Yoshihide; Nagashima, Takeshi; Mori, Kazuaki; Hashida, Masaki; Sakabe, Shuji

    2018-02-01

    We have demonstrated that a pulsed electromagnetic wave (Sommerfeld wave) of subterahertz frequency and 11-MV/m field strength can be induced on a metal wire by the interaction of an intense femtosecond laser pule with an adjacent metal foil at a laser intensity of 8.5 × 1018W /c m2 . The polarity of the electric field of this surface wave is opposite to that obtained by the direct interaction of the laser with the wire. Numerical simulations suggest that an electromagnetic wave associated with electron emission from the foil induces the surface wave. A tungsten wire is placed normal to an aluminum foil with a gap so that the wire is not irradiated and damaged by the laser pulse, thus making it possible to generate surface waves on the wire repeatedly.

  1. Adaptive pixel-to-pixel projection intensity adjustment for measuring a shiny surface using orthogonal color fringe pattern projection

    Science.gov (United States)

    Chen, Chao; Gao, Nan; Wang, Xiangjun; Zhang, Zonghua

    2018-05-01

    Three-dimensional (3D) shape measurement based on fringe pattern projection techniques has been commonly used in various fields. One of the remaining challenges in fringe pattern projection is that camera sensor saturation may occur if there is a large range of reflectivity variation across the surface that causes measurement errors. To overcome this problem, a novel fringe pattern projection method is proposed to avoid image saturation and maintain high-intensity modulation for measuring shiny surfaces by adaptively adjusting the pixel-to-pixel projection intensity according to the surface reflectivity. First, three sets of orthogonal color fringe patterns and a sequence of uniform gray-level patterns with different gray levels are projected onto a measured surface by a projector. The patterns are deformed with respect to the object surface and captured by a camera from a different viewpoint. Subsequently, the optimal projection intensity at each pixel is determined by fusing different gray levels and transforming the camera pixel coordinate system into the projector pixel coordinate system. Finally, the adapted fringe patterns are created and used for 3D shape measurement. Experimental results on a flat checkerboard and shiny objects demonstrate that the proposed method can measure shiny surfaces with high accuracy.

  2. Structural features of the adsorption layer of pentacene on the graphite surface and the PMMA/graphite hybrid surface

    Science.gov (United States)

    Fadeeva, A. I.; Gorbunov, V. A.; Litunenko, T. A.

    2017-08-01

    Using the molecular dynamics and the Monte Carlo methods, we have studied the structural features and growth mechanism of the pentacene film on graphite and polymethylmethacrylate /graphite surfaces. Monolayer capacity and molecular area, optimal angles between the pentacene molecules and graphite and PMMA/graphite surfaces as well as the characteristic angles between the neighboring pentacene molecules in the adsorption layer were estimated. It is shown that the orientation of the pentacene molecules in the film is determined by a number of factors, including the surface concentration of the molecules, relief of the surface, presence or absence of the polymer layer and its thickness. The pentacene molecules adsorbed on the graphite surface keep a horizontal position relative to the long axis at any surface coverage/thickness of the film. In the presence of the PMMA layer on the graphite, the increase of the number of pentacene molecules as well as the thickness of the PMMA layer induce the change of molecular orientation from predominantly horizontal to vertical one. The reason for such behavior is supposed to be the roughness of the PMMA surface.

  3. Observation of surface features on an active landslide, and implications for understanding its history of movement

    Directory of Open Access Journals (Sweden)

    M. Parise

    2003-01-01

    Full Text Available Surface features are produced as a result of internal deformation of active landslides, and are continuously created and destroyed by the movement. Observation of their presence and distribution, and surveying of their evolution may provide insights for the zonation of the mass movement in sectors characterized by different behaviour. The present study analyses and describes some example of surface features observed on an active mass movement, the Slumgullion earthflow, in the San Juan Mountains of southwestern Colorado. The Slumgullion earthflow is one of the most famous and spectacular landslides in the world; it consists of a younger, active part which moves on and over an older, much larger, inactive part. Total length of the earthflow is 6.8 km, with an estimated volume of 170 × 10 6 m 3 . Its nearly constant rate of movement (ranging from about 2 m per year at the head, to a maximum of 6–7 m per year at its narrow and central part, to values between 1.3 and 2 m per year at the active toe, and the geological properties of moving material, are well suited for the observation of the development and evolution of surface features. In the last 11 years, repeated surveying at the Slumgullion site has been performed through recognition of surface features, measurements of their main characteristics, and detailed mapping. In this study, two sectors of the Slumgullion earthflow are analysed through comparison of the features observed in this time span, and evaluation of the changes occurred: they are the active toe and an area located at the left flank of the landslide. Choice of the sectors was dictated in the first case, by particular activity of movement and the nearby presence of elements at risk (highway located only 250 m downhill from the toe; and in the second case, by the presence of many surface features, mostly consisting of several generations of flank ridges. The active toe of the landslide is characterized by continuous movement

  4. Cross-cutting Relationships of Surface Features on Europa

    Science.gov (United States)

    1997-01-01

    This image of Jupiter's moon Europa shows a very complex terrain of ridges and fractures. The absence of large craters and the low number of small craters indicates that this surface is geologically young. The relative ages of the ridges can be determined by using the principle of cross-cutting relationships; i.e. older features are cross-cut by younger features. Using this principle, planetary geologists are able to unravel the sequence of events in this seemingly chaotic terrain to unfold Europa's unique geologic history.The spacecraft Galileo obtained this image on February 20, 1997. The area covered in this image is approximately 11 miles (18 kilometers) by 8.5 miles (14 kilometers) across, near 15 North, 273 West. North is toward the top of the image, with the sun illuminating from the right.The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  5. Study of Dynamic Features of Surface Plasma in High-Power Disk Laser Welding

    International Nuclear Information System (INIS)

    Wang Teng; Gao Xiangdong; Seiji, Katayama; Jin, Xiaoli

    2012-01-01

    High-speed photography was used to obtain the dynamic changes in the surface plasma during a high-power disk laser welding process. A color space clustering algorithm to extract the edge information of the surface plasma region was developed in order to improve the accuracy of image processing. With a comparative analysis of the plasma features, i.e., area and height, and the characteristics of the welded seam, the relationship between the surface plasma and the stability of the laser welding process was characterized, which provides a basic understanding for the real-time monitoring of laser welding.

  6. Surface characteristics modeling and performance evaluation of urban building materials using LiDAR data.

    Science.gov (United States)

    Li, Xiaolu; Liang, Yu

    2015-05-20

    Analysis of light detection and ranging (LiDAR) intensity data to extract surface features is of great interest in remote sensing research. One potential application of LiDAR intensity data is target classification. A new bidirectional reflectance distribution function (BRDF) model is derived for target characterization of rough and smooth surfaces. Based on the geometry of our coaxial full-waveform LiDAR system, the integration method is improved through coordinate transformation to establish the relationship between the BRDF model and intensity data of LiDAR. A series of experiments using typical urban building materials are implemented to validate the proposed BRDF model and integration method. The fitting results show that three parameters extracted from the proposed BRDF model can distinguish the urban building materials from perspectives of roughness, specular reflectance, and diffuse reflectance. A comprehensive analysis of these parameters will help characterize surface features in a physically rigorous manner.

  7. FIRST SIMULTANEOUS DETECTION OF MOVING MAGNETIC FEATURES IN PHOTOSPHERIC INTENSITY AND MAGNETIC FIELD DATA

    International Nuclear Information System (INIS)

    Lim, Eun-Kyung; Yurchyshyn, Vasyl; Goode, Philip

    2012-01-01

    The formation and the temporal evolution of a bipolar moving magnetic feature (MMF) was studied with high-spatial and temporal resolution. The photometric properties were observed with the New Solar Telescope at Big Bear Solar Observatory using a broadband TiO filter (705.7 nm), while the magnetic field was analyzed using the spectropolarimetric data obtained by Hinode. For the first time, we observed a bipolar MMF simultaneously in intensity images and magnetic field data, and studied the details of its structure. The vector magnetic field and the Doppler velocity of the MMF were also studied. A bipolar MMF with its positive polarity closer to the negative penumbra formed, accompanied by a bright, filamentary structure in the TiO data connecting the MMF and a dark penumbral filament. A fast downflow (≤2 km s –1 ) was detected at the positive polarity. The vector magnetic field obtained from the full Stokes inversion revealed that a bipolar MMF has a U-shaped magnetic field configuration. Our observations provide a clear intensity counterpart of the observed MMF in the photosphere, and strong evidence of the connection between the MMF and the penumbral filament as a serpentine field.

  8. Computer vision approach to morphometric feature analysis of basal cell nuclei for evaluating malignant potentiality of oral submucous fibrosis.

    Science.gov (United States)

    Muthu Rama Krishnan, M; Pal, Mousumi; Paul, Ranjan Rashmi; Chakraborty, Chandan; Chatterjee, Jyotirmoy; Ray, Ajoy K

    2012-06-01

    This research work presents a quantitative approach for analysis of histomorphometric features of the basal cell nuclei in respect to their size, shape and intensity of staining, from surface epithelium of Oral Submucous Fibrosis showing dysplasia (OSFD) to that of the Normal Oral Mucosa (NOM). For all biological activity, the basal cells of the surface epithelium form the proliferative compartment and therefore their morphometric changes will spell the intricate biological behavior pertaining to normal cellular functions as well as in premalignant and malignant status. In view of this, the changes in shape, size and intensity of staining of the nuclei in the basal cell layer of the NOM and OSFD have been studied. Geometric, Zernike moments and Fourier descriptor (FD) based as well as intensity based features are extracted for histomorphometric pattern analysis of the nuclei. All these features are statistically analyzed along with 3D visualization in order to discriminate the groups. Results showed increase in the dimensions (area and perimeter), shape parameters and decreasing mean nuclei intensity of the nuclei in OSFD in respect to NOM. Further, the selected features are fed to the Bayesian classifier to discriminate normal and OSFD. The morphometric and intensity features provide a good sensitivity of 100%, specificity of 98.53% and positive predicative accuracy of 97.35%. This comparative quantitative characterization of basal cell nuclei will be of immense help for oral onco-pathologists, researchers and clinicians to assess the biological behavior of OSFD, specially relating to their premalignant and malignant potentiality. As a future direction more extensive study involving more number of disease subjects is observed.

  9. Morphological features of the copper surface layer under sliding with high density electric current

    Energy Technology Data Exchange (ETDEWEB)

    Fadin, V. V., E-mail: fvv@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Aleutdinova, M. I., E-mail: aleut@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Seversk Technological Institute, Branch of State Autonomous Educational Institution of Higher Professional Education “National Research Nuclear University “MEPhI”, Seversk, 636036 (Russian Federation); Rubtsov, V. Ye., E-mail: rvy@ispms.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Aleutdinova, V. A., E-mail: valery-aleut@yandex.ru [National Research St. Petersburg State Polytechnical University, St. Petersburg, 195251 (Russian Federation)

    2015-10-27

    Conductivity and wear intensity of copper under the influence of dry friction and electric current with contact density higher 100 A/cm{sup 2} are presented. It is shown that an increase in hardness and heat outflow from a friction zone leads to the reduction of wear intensity and current contact density increase corresponding to the beginning of catastrophic wear. Structural changes, such as the formation of FeO oxide and α-Fe particles in the copper surface layer, have also been found. It is observed that a worn surface is deformed according to a viscous liquid mechanism. Such singularity is explained in terms of appearance of high-excited atomic states in deforming micro-volumes near contact spots that lead to easy stress relaxation by local plastic shears in the vicinity of stress concentrators. In common this effect allows to achieve high wear resistance.

  10. Use of Intense Ion Beams for Surface Modification and Creation of New Materials

    CERN Document Server

    Renk, T; Prasad, S V; Provencio, P P; Thompson, M

    2002-01-01

    We have conducted surface treatment and alloying experiments with Al, Fe, and Ti-based metals on the RHEPP-1 accelerator (0.8 MV, 20 W, 80 ns FHWM, up to 1 Hz repetition rate) at Sandia National Laboratories. Ions are generated by the MAP gas-breakdown active anode, which can yield a number of different beam species including H, N, and C, depending upon the injected gas. Beams of intense pulsed high-power ion beams have been used to produce surface modification by changes in microstructure caused by rapid heating and cooling of the surface. Increase of beam power leads to ablation of a target surface, and redeposition of ablated material onto a separate substrate. Experiments are described in which ion beams are used in an attempt to increase high-voltage breakdown of a treated surface. Surface alloying of coated Pt and Hf layers is also described. This mixing of a previously deposited thin-film layer into a Ti-alloy substrate leads to significantly enhanced surface wear durability, compared to either untreat...

  11. Multimodal Discrimination of Schizophrenia Using Hybrid Weighted Feature Concatenation of Brain Functional Connectivity and Anatomical Features with an Extreme Learning Machine

    Directory of Open Access Journals (Sweden)

    Muhammad Naveed Iqbal Qureshi

    2017-09-01

    Full Text Available Multimodal features of structural and functional magnetic resonance imaging (MRI of the human brain can assist in the diagnosis of schizophrenia. We performed a classification study on age, sex, and handedness-matched subjects. The dataset we used is publicly available from the Center for Biomedical Research Excellence (COBRE and it consists of two groups: patients with schizophrenia and healthy controls. We performed an independent component analysis and calculated global averaged functional connectivity-based features from the resting-state functional MRI data for all the cortical and subcortical anatomical parcellation. Cortical thickness along with standard deviation, surface area, volume, curvature, white matter volume, and intensity measures from the cortical parcellation, as well as volume and intensity from sub-cortical parcellation and overall volume of cortex features were extracted from the structural MRI data. A novel hybrid weighted feature concatenation method was used to acquire maximal 99.29% (P < 0.0001 accuracy which preserves high discriminatory power through the weight of the individual feature type. The classification was performed by an extreme learning machine, and its efficiency was compared to linear and non-linear (radial basis function support vector machines, linear discriminant analysis, and random forest bagged tree ensemble algorithms. This article reports the predictive accuracy of both unimodal and multimodal features after 10-by-10-fold nested cross-validation. A permutation test followed the classification experiment to assess the statistical significance of the classification results. It was concluded that, from a clinical perspective, this feature concatenation approach may assist the clinicians in schizophrenia diagnosis.

  12. Stress intensity evaluation for surface crack with use of boundary element method and influence function method and the surface crack extension analysis

    International Nuclear Information System (INIS)

    Yuuki, R.; Ejima, K.

    1991-01-01

    In this study, three-dimensional boundary element elastostatic analysis is carried out on various surface crack problems. The present BEM uses a Mindlin's solution as well as a Kelvin's solution as a fundamental solution. So we can obtain accurate solutions for a surface crack just before or after a penetration. The obtained solutions for various shapes of surface cracks are stored as the data base, based on the influence function method. We develop the surface crack extension analysis system using the stress intensity factor data base and also the fatigue crack growth law. Our system seems to be useful especially for the analysis of the surface crack just before or after the penetration and also under the residual stresses

  13. Durable superhydrophobic surfaces made by intensely connecting a bipolar top layer to the substrate with a middle connecting layer.

    Science.gov (United States)

    Zhi, Jinghui; Zhang, Li-Zhi

    2017-08-30

    This study reported a simple fabrication method for a durable superhydrophobic surface. The superhydrophobic top layer of the durable superhydrophobic surface was connected intensely to the substrate through a middle connecting layer. Glycidoxypropyltrimethoxysilane (KH-560) after hydrolysis was used to obtain a hydrophilic middle connecting layer. It could be adhered to the hydrophilic substrate by covalent bonds. Ring-open reaction with octadecylamine let the KH-560 middle layer form a net-like structure. The net-like sturcture would then encompass and station the silica particles that were used to form the coarse micro structures, intensely to increase the durability. The top hydrophobic layer with nano-structures was formed on the KH-560 middle layer. It was obtained by a bipolar nano-silica solution modified by hexamethyldisilazane (HMDS). This layer was connected to the middle layer intensely by the polar Si hydroxy groups, while the non-polar methyl groups on the surface, accompanied by the micro and nano structures, made the surface rather hydrophobic. The covalently interfacial interactions between the substrate and the middle layer, and between the middle layer and the top layer, strengthened the durability of the superhydrophobic surface. The abrasion test results showed that the superhydrophobic surface could bear 180 abrasion cycles on 1200 CW sandpaper under 2 kPa applied pressure.

  14. Understanding the Impact of Intensive Horticulture Land-Use Practices on Surface Water Quality in Central Kenya

    Directory of Open Access Journals (Sweden)

    Faith K. Muriithi

    2015-11-01

    Full Text Available Rapid expansion of commercial horticulture production and related activities contribute to declining surface water quality. The study sought to understand the impacts on select rivers in Laikipia and Meru, production hotspots. The specific aims were (1 to identify prevailing surface water quality by examining variations of 14 physico-chemical parameters, and (2 to categorize measured surface water quality parameters into land use types highlighting potential pollutant source processes. Water samples were collected in July and August 2013 along 14 rivers in the study area. The data were analyzed using principal component analysis (PCA and discriminant analysis (DA. Principal components (PCs explained 70% of the observed total variability of water quality, indicating a prevalence of heavy metal traces (cadmium, phosphate, and zinc. These were linked to the rigorous use of phosphate fertilizers and copper-based agrochemicals in intensive farming. DA provided four significant (p < 0.05 discriminant functions, with 89.5% correct assignment enabling the association of land use with observed water quality. Concentrations of dissolved solids, electro-conductivity, and salinity spiked at locations with intensive small-scale and large-scale horticulture. Understanding the impacts of intensive commercial horticulture and land use practices on water quality is critical to formulating ecologically sound watershed management and pollution abatement plans.

  15. Shape based automated detection of pulmonary nodules with surface feature based false positive reduction

    International Nuclear Information System (INIS)

    Nomura, Y.; Itoh, H.; Masutani, Y.; Ohtomo, K.; Maeda, E.; Yoshikawa, T.; Hayashi, N.

    2007-01-01

    We proposed a shape based automated detection of pulmonary nodules with surface feature based false positive (FP) reduction. In the proposed system, the FP existing in internal of vessel bifurcation is removed using extracted surface of vessels and nodules. From the validation with 16 chest CT scans, we find that the proposed CAD system achieves 18.7 FPs/scan at 90% sensitivity, and 7.8 FPs/scan at 80% sensitivity. (orig.)

  16. Effect of instruction, surface stability, and load intensity on trunk muscle activity.

    Science.gov (United States)

    Bressel, Eadric; Willardson, Jeffrey M; Thompson, Brennan; Fontana, Fabio E

    2009-12-01

    The aim of this study was to assess the effect of verbal instruction, surface stability, and load intensity on trunk muscle activity levels during the free weight squat exercise. Twelve trained males performed a free weight squat under four conditions: (1) standing on stable ground lifting 50% of their 1-repetition maximum (RM), (2) standing on a BOSU balance trainer lifting 50% of their 1-RM, (3) standing on stable ground lifting 75% of their 1-RM, and (4) receiving verbal instructions to activate the trunk muscles followed by lifting 50% of their 1-RM. Surface EMG activity from muscles rectus abdominis (RA), external oblique (EO), transversus abdominis/internal oblique (TA/IO), and erector spinae (ES) were recorded for each condition and normalized for comparisons. Muscles RA, EO, and TA/IO displayed greater peak activity (39-167%) during squats with instructions compared to the other squat conditions (P=0.04-0.007). Peak EMG activity of muscle ES was greater for the 75% 1-RM condition than squats with instructions or lifting 50% of 1-RM (P=0.04-0.02). The results indicate that if the goal is to enhance EMG activity of the abdominal muscles during a multi-joint squat exercise then verbal instructions may be more effective than increasing load intensity or lifting on an unstable surface. However, in light of other research, conscious co-activation of the trunk muscles during the squat exercise may lead to spinal instability and hazardous compression forces in the lumbar spine.

  17. Evidence on a link between the intensity of Schumann resonance and global surface temperature

    Directory of Open Access Journals (Sweden)

    M. Sekiguchi

    2006-08-01

    Full Text Available A correlation is investigated between the intensity of the global electromagnetic oscillations (Schumann resonance with the planetary surface temperature. The electromagnetic signal was monitored at Moshiri (Japan, and temperature data were taken from surface meteorological observations. The series covers the period from November 1998 to May 2002. The Schumann resonance intensity is found to vary coherently with the global ground temperature in the latitude interval from 45° S to 45° N: the relevant cross-correlation coefficient reaches the value of 0.9. It slightly increases when the high-latitude temperature is incorporated. Correspondence among the data decreases when we reduce the latitude interval, which indicates the important role of the middle-latitude lightning in the Schumann resonance oscillations. We apply the principal component (or singular spectral analysis to the electromagnetic and temperature records to extract annual, semiannual, and interannual variations. The principal component analysis (PCA clarifies the links between electromagnetic records and meteorological data.

  18. Removing roughness on metal surface by irradiation of intense short-pulsed ion beams

    International Nuclear Information System (INIS)

    Hashimoto, Y.

    1995-01-01

    Surface modification of metals with an intense pulsed ion beam (IPIB) was studied experimentally. When the temperature rise of metal surfaces by IPIB irradiation exceeds their boiling point, it is found that machining roughness on surfaces is removed. The experiments were performed with the pulsed power generator HARIMA-II at Himeji Institute of Technology. The main components of the ion beam were carbon and fluorine ions. The IPIB was irradiated to metal plates (Al, Cu and Ti) which were placed at the focal point. Machining roughness on Ti surface was removed after IPIB irradiation, while roughness on Al and Cu plates was not removed. Using the present experimental parameters (beam power density: 32 W/cm 2 , pulse width: 25 ns), the temperature rise of the Ti surface was estimated to be 8,100 K which exceed its boiling point (3,000 K). However, the estimated temperatures of Al and Cu surfaces was 2,500 and 1,500 K, respectively, that are less than their boiling points. These studies above suggests that temperature rise over the boiling point of metals is necessary for removing machining roughness on metal surfaces

  19. Memory for surface features of unfamiliar melodies: independent effects of changes in pitch and tempo.

    Science.gov (United States)

    Schellenberg, E Glenn; Stalinski, Stephanie M; Marks, Bradley M

    2014-01-01

    A melody's identity is determined by relations between consecutive tones in terms of pitch and duration, whereas surface features (i.e., pitch level or key, tempo, and timbre) are irrelevant. Although surface features of highly familiar recordings are encoded into memory, little is known about listeners' mental representations of melodies heard once or twice. It is also unknown whether musical pitch is represented additively or interactively with temporal information. In two experiments, listeners heard unfamiliar melodies twice in an initial exposure phase. In a subsequent test phase, they heard the same (old) melodies interspersed with new melodies. Some of the old melodies were shifted in key, tempo, or key and tempo. Listeners' task was to rate how well they recognized each melody from the exposure phase while ignoring changes in key and tempo. Recognition ratings were higher for old melodies that stayed the same compared to those that were shifted in key or tempo, and detrimental effects of key and tempo changes were additive in between-subjects (Experiment 1) and within-subjects (Experiment 2) designs. The results confirm that surface features are remembered for melodies heard only twice. They also imply that key and tempo are processed and stored independently.

  20. Simulation study and guidelines to generate Laser-induced Surface Acoustic Waves for human skin feature detection

    Science.gov (United States)

    Li, Tingting; Fu, Xing; Chen, Kun; Dorantes-Gonzalez, Dante J.; Li, Yanning; Wu, Sen; Hu, Xiaotang

    2015-12-01

    Despite the seriously increasing number of people contracting skin cancer every year, limited attention has been given to the investigation of human skin tissues. To this regard, Laser-induced Surface Acoustic Wave (LSAW) technology, with its accurate, non-invasive and rapid testing characteristics, has recently shown promising results in biological and biomedical tissues. In order to improve the measurement accuracy and efficiency of detecting important features in highly opaque and soft surfaces such as human skin, this paper identifies the most important parameters of a pulse laser source, as well as provides practical guidelines to recommended proper ranges to generate Surface Acoustic Waves (SAWs) for characterization purposes. Considering that melanoma is a serious type of skin cancer, we conducted a finite element simulation-based research on the generation and propagation of surface waves in human skin containing a melanoma-like feature, determine best pulse laser parameter ranges of variation, simulation mesh size and time step, working bandwidth, and minimal size of detectable melanoma.

  1. Land surface and climate parameters and malaria features in Vietnam

    Science.gov (United States)

    Liou, Y. A.; Anh, N. K.

    2017-12-01

    Land surface parameters may affect local microclimate, which in turn alters the development of mosquito habitats and transmission risks (soil-vegetation-atmosphere-vector borne diseases). Forest malaria is a chromic issue in Southeast Asian countries, in particular, such as Vietnam (in 1991, approximate 2 million cases and 4,646 deaths were reported (https://sites.path.org)). Vietnam has lowlands, sub-tropical high humidity, and dense forests, resulting in wide-scale distribution and high biting rate of mosquitos in Vietnam, becoming a challenging and out of control scenario, especially in Vietnamese Central Highland region. It is known that Vietnam's economy mainly relies on agriculture and malaria is commonly associated with poverty. There is a strong demand to investigate the relationship between land surface parameters (land cover, soil moisture, land surface temperature, etc.) and climatic variables (precipitation, humidity, evapotranspiration, etc.) in association with malaria distribution. GIS and remote sensing have been proven their powerful potentials in supporting environmental and health studies. The objective of this study aims to analyze physical attributes of land surface and climate parameters and their links with malaria features. The outcomes are expected to illustrate how remotely sensed data has been utilized in geohealth applications, surveillance, and health risk mapping. In addition, a platform with promising possibilities of allowing disease early-warning systems with citizen participation will be proposed.

  2. Image mosaicking based on feature points using color-invariant values

    Science.gov (United States)

    Lee, Dong-Chang; Kwon, Oh-Seol; Ko, Kyung-Woo; Lee, Ho-Young; Ha, Yeong-Ho

    2008-02-01

    In the field of computer vision, image mosaicking is achieved using image features, such as textures, colors, and shapes between corresponding images, or local descriptors representing neighborhoods of feature points extracted from corresponding images. However, image mosaicking based on feature points has attracted more recent attention due to the simplicity of the geometric transformation, regardless of distortion and differences in intensity generated by camera motion in consecutive images. Yet, since most feature-point matching algorithms extract feature points using gray values, identifying corresponding points becomes difficult in the case of changing illumination and images with a similar intensity. Accordingly, to solve these problems, this paper proposes a method of image mosaicking based on feature points using color information of images. Essentially, the digital values acquired from a real digital color camera are converted to values of a virtual camera with distinct narrow bands. Values based on the surface reflectance and invariant to the chromaticity of various illuminations are then derived from the virtual camera values and defined as color-invariant values invariant to changing illuminations. The validity of these color-invariant values is verified in a test using a Macbeth Color-Checker under simulated illuminations. The test also compares the proposed method using the color-invariant values with the conventional SIFT algorithm. The accuracy of the matching between the feature points extracted using the proposed method is increased, while image mosaicking using color information is also achieved.

  3. Automatic Feature Selection and Weighting for the Formation of Homogeneous Groups for Regional Intensity-Duration-Frequency (IDF) Curve Estimation

    Science.gov (United States)

    Yang, Z.; Burn, D. H.

    2017-12-01

    Extreme rainfall events can have devastating impacts on society. To quantify the associated risk, the IDF curve has been used to provide the essential rainfall-related information for urban planning. However, the recent changes in the rainfall climatology caused by climate change and urbanization have made the estimates provided by the traditional regional IDF approach increasingly inaccurate. This inaccuracy is mainly caused by two problems: 1) The ineffective choice of similarity indicators for the formation of a homogeneous group at different regions; and 2) An inadequate number of stations in the pooling group that does not adequately reflect the optimal balance between group size and group homogeneity or achieve the lowest uncertainty in the rainfall quantiles estimates. For the first issue, to consider the temporal difference among different meteorological and topographic indicators, a three-layer design is proposed based on three stages in the extreme rainfall formation: cloud formation, rainfall generation and change of rainfall intensity above urban surface. During the process, the impacts from climate change and urbanization are considered through the inclusion of potential relevant features at each layer. Then to consider spatial difference of similarity indicators for the homogeneous group formation at various regions, an automatic feature selection and weighting algorithm, specifically the hybrid searching algorithm of Tabu search, Lagrange Multiplier and Fuzzy C-means Clustering, is used to select the optimal combination of features for the potential optimal homogenous groups formation at a specific region. For the second issue, to compare the uncertainty of rainfall quantile estimates among potential groups, the two sample Kolmogorov-Smirnov test-based sample ranking process is used. During the process, linear programming is used to rank these groups based on the confidence intervals of the quantile estimates. The proposed methodology fills the gap

  4. [Surface disinfection in the context of infection prevention in intensive care units].

    Science.gov (United States)

    Kossow, A; Schaber, S; Kipp, F

    2013-03-01

    The highest proportion of nosocomial infections occurs on intensive care units (ICU) and infections with multiresistant pathogens are an ever increasing problem. Preventative measures should consist of a bundle of different measures including measures that address a specific problem and standard hygiene measures that are relevant in all areas. Specific measures in ICUs primarily aim at the prevention of ventilator associated pneumonia, blood vessel catheter associated infections and nosocomial urinary tract infections. Surface disinfection belongs to the standard hygiene measures and plays an inferior role compared to hand hygiene; however, surfaces come into focus in outbreak situations. The Commission on Hospital Hygiene (KRINKO) at the Robert Koch Institute (the German health protection agency) published recommendations regarding the cleaning and disinfection of surfaces. The frequency with which cleaning and/or disinfection is required varies according to defined areas of risk. The frequency and the disinfection agents used are documented in the disinfection plan.

  5. Effects of surface shape on the geometry and surface topography of the melt pool in low-power density laser melting

    KAUST Repository

    Kim, Youngdeuk

    2011-04-15

    The quantitative correlations between workpiece volume and melt pool geometry, as well as the flow and thermal features of the melt pool are established. Thermocapillary convections in melt pool with a deformable free surface are investigated with respect to surface shape and laser intensity. When the contact angle between the tangent to the top surface and the vertical wall at the hot center is acute, the free surface flattens, compared with that of the initial free surface. Otherwise, the free surface forms a bowl-like shape with a deep crater and a low peripheral rim when the contact angle at the hot center is obtuse. Increasing the workpiece volume at a fixed laser intensity and a negative radial height gradient cause linear decreases in the geometric size and magnitude of flow and temperature of the melt pool. Conversely, linear increases are observed with a positive radial height gradient. © 2011 American Institute of Chemical Engineers (AIChE).

  6. As-grown graphene/copper nanoparticles hybrid nanostructures for enhanced intensity and stability of surface plasmon resonance

    Science.gov (United States)

    Li, Yun-Fei; Dong, Feng-Xi; Chen, Yang; Zhang, Xu-Lin; Wang, Lei; Bi, Yan-Gang; Tian, Zhen-Nan; Liu, Yue-Feng; Feng, Jing; Sun, Hong-Bo

    2016-11-01

    The transfer-free fabrication of the high quality graphene on the metallic nanostructures, which is highly desirable for device applications, remains a challenge. Here, we develop the transfer-free method by direct chemical vapor deposition of the graphene layers on copper (Cu) nanoparticles (NPs) to realize the hybrid nanostructures. The graphene as-grown on the Cu NPs permits full electric contact and strong interactions, which results in a strong localization of the field at the graphene/copper interface. An enhanced intensity of the localized surface plasmon resonances (LSPRs) supported by the hybrid nanostructures can be obtained, which induces a much enhanced fluorescent intensity from the dye coated hybrid nanostructures. Moreover, the graphene sheets covering completely and uniformly on the Cu NPs act as a passivation layer to protect the underlying metal surface from air oxidation. As a result, the stability of the LSPRs for the hybrid nanostructures is much enhanced compared to that of the bare Cu NPs. The transfer-free hybrid nanostructures with enhanced intensity and stability of the LSPRs will enable their much broader applications in photonics and optoelectronics.

  7. Negative secondary ion emission from oxidized surfaces

    International Nuclear Information System (INIS)

    Gnaser, H.; Kernforschungsanlage Juelich G.m.b.H.

    1984-01-01

    The emission of negative secondary ions from 23 elements was studied for 10 keV O 2 + and 10 keV In + impact at an angle of incidence of 45 0 . Partial oxidation of the sample surfaces was achieved by oxygen bombardment and/or by working at a high oxygen partial pressure. It was found that the emission of oxide ions shows an element-characteristic pattern. For the majority of the elements investigated these features are largely invariant against changes of the surface concentration of oxygen. For the others admission of oxygen strongly changes the relative intensities of oxide ions: a strong increase of MO 3 - signals (M stands for the respective element) is accompanied by a decrease of MO - and M - intensities. Different primary species frequently induce changes of both the relative and the absolute negative ion intensities. Carbon - in contrast to all other elements - does not show any detectable oxide ion emission but rather intense cluster ions Csub(n) - (detected up to n=12) whose intensities oscillate in dependence on n. (orig./RK)

  8. Evaluation of stress intensity factor for craks in surface of tubes with internal pressure

    International Nuclear Information System (INIS)

    Cesari, F.; Hellen, T.K.

    1977-01-01

    In this report the authors have examined the different methods for calculation of the stress intensity factor in tubes subject at internal pressure with surface cracks. The analysis includes cracks in 2-D axialsymmetric and 3-D. Moreover the authors have clarified the difference between the ASME Sec.11 and the procedure more rigorous

  9. HYDROLOGIC AND FEATURE-BASED SURFACE ANALYSIS FOR TOOL MARK INVESTIGATION ON ARCHAEOLOGICAL FINDS

    Directory of Open Access Journals (Sweden)

    K. Kovács

    2012-07-01

    Full Text Available The improvement of detailed surface documentation methods provides unique tool mark-study opportunities in the field of archaeological researches. One of these data collection techniques is short-range laser scanning, which creates a digital copy of the object’s morphological characteristics from high-resolution datasets. The aim of our work was the accurate documentation of a Bronze Age sluice box from Mitterberg, Austria with a spatial resolution of 0.2 mm. Furthermore, the investigation of the entirely preserved tool marks on the surface of this archaeological find was also accomplished by these datasets. The methodology of this tool mark-study can be summarized in the following way: At first, a local hydrologic analysis has been applied to separate the various patterns of tools on the finds’ surface. As a result, the XYZ coordinates of the special points, which represent the edge lines of the sliding tool marks, were calculated by buffer operations in a GIS environment. During the second part of the workflow, these edge points were utilized to manually clip the triangle meshes of these patterns in reverse engineering software. Finally, circle features were generated and analysed to determine the different sections along these sliding tool marks. In conclusion, the movement of the hand tool could be reproduced by the spatial analysis of the created features, since the horizontal and vertical position of the defined circle centre points indicated the various phases of the movements. This research shows an exact workflow to determine the fine morphological structures on the surface of the archaeological find.

  10. A multicolor photometric study of the tidal features in interacting galaxies

    International Nuclear Information System (INIS)

    Schombert, J.M.; Wallin, J.F.; Struck-Marcell, C.

    1990-01-01

    Four-color surface photometry (BVri) is presented for low-surface-brightness tidal features in interacting galaxies. Objects were selected on the basis of visual morphology including a cross section of tails, bridges, plumes, shells, and extended envelopes. Intensity cross sections and surface brightness suggests that plumes are face-on or near face-on sheets; tails and bridges are more nearly one-dimensional, linear figures. In many cases the colors of tidal features are similar to the outer regions of the primary galaxies, confirming the stripping origin hypothesis. However, large color variations are found among the morphological components within most systems, and within individual components. Blue colors in primaries and tidal features are most dramatic in B-V, not V-1, indicating that star formation, not metallicity or age, is the dominant component. There is clear evidence in the sample of a correlation between the magnitude of the color variation and the time. The color variations are largest a short time after the beginning of the interaction, and they diminish to a very low level in merged systems. This correlation provides an alternate estimator of interaction age in systems with ambiguous morphologies. 49 refs

  11. The Impact of Solid Surface Features on Fluid-Fluid Interface Configuration

    Science.gov (United States)

    Araujo, J. B.; Brusseau, M. L. L.

    2017-12-01

    Pore-scale fluid processes in geological media are critical for a broad range of applications such as radioactive waste disposal, carbon sequestration, soil moisture distribution, subsurface pollution, land stability, and oil and gas recovery. The continued improvement of high-resolution image acquisition and processing have provided a means to test the usefulness of theoretical models developed to simulate pore-scale fluid processes, through the direct quantification of interfaces. High-resolution synchrotron X-ray microtomography is used in combination with advanced visualization tools to characterize fluid distributions in natural geologic media. The studies revealed the presence of fluid-fluid interface associated with macroscopic features on the surfaces of the solids such as pits and crevices. These features and respective fluid interfaces, which are not included in current theoretical or computational models, may have a significant impact on accurate simulation and understanding of multi-phase flow, energy, heat and mass transfer processes.

  12. Mapping stellar surface features

    International Nuclear Information System (INIS)

    Noah, P.V.

    1987-01-01

    New photometric and spectroscopic observations of the RS Canum Venaticorum binaries Sigma Geminorum and UX Arietis are reported along with details of the Doppler-imaging program SPOTPROF. The observations suggest that the starspot activity on Sigma Gem has decreased to 0.05 magnitude in two years. A photometric spot model for September 1984 to January 1985 found that a single spot covering 2% of the surface and 1000 K cooler than the surrounding photosphere could model the light variations. Equivalent-width observations contemporaneous with the photometric observations did not show any significant variations. Line-profile models from SPOTPROF predict that the variation of the equivalent width of the 6393 A Fe I line should be ∼ 1mA. Photometric observations of UX Ari from January 1984 to March 1985 show an 0.3 magnitude variation indicating a large spot group must cover the surface. Contemporaneous spectroscopic observations show asymmetric line profiles. The Doppler imaging and the photometric light-curve models were used in an iterative method to describe the stellar surface-spot distribution and successfully model both the photometric and the spectroscopic variations

  13. ALBOREX: an intensive multi-platform and multidisciplinary experiment in the Alboran Sea

    Science.gov (United States)

    Ruiz, Simón; Pascual, Ananda; Allen, John; Olita, Antonio; Tovar, Antonio; Oguz, Temel; Mahadevan, Amala; Poulain, Pierre; Tintoré, Joaquín

    2015-04-01

    An intensive multi-platform and multidisciplinary experiment was completed in May 2014 as part of PERSEUS EU Project. 25 drifters, 2 gliders, 3 Argo floats and one ship were dedicated to sample an area of about 50x50 km in the eastern Alboran Sea during one week. The experiment, which also includes 66 CTD stations and 500 water samples (salinity, chlorophyll and nutrients), was designed to capture the intense but transient vertical exchanges associated with mesoscale and submesoscale features. The vertical motion associated with mesoscale and submesoscale features such as ocean eddies, filaments and fronts plays a major role in determining ocean productivity, due to the exchange of properties between the surface and the ocean interior. Understanding the relationship between these physical and biological processes is crucial for predicting the marine ecosystems response to changes in the climate system and to sustainable marine resource management. However, to understand the links between mesoscale and submesoscale features and ecosystem responses, it is necessary to collect data at a range of temporal and spatial scales, and then combine these data with coupled physical and biochemical models. Data from thermosalinograph revealed a sharp surface salinity front with values ranging from 36.6 (Atlantic Waters) to 38.2 (Mediterranean Waters) in conjunction with a filament in temperature. Drifters followed a massive anticyclonic gyre. Near real time data from ADCP showed coherent patterns with currents up to 1m/s. Gliders detected a subduction of chlorophyll located in areas adjacent to the front. We also present results on the horizontal strain rate, relative vorticity and quasi-geostrophic vertical motion to understand the dynamics of this intense ocean front.

  14. LSAH: a fast and efficient local surface feature for point cloud registration

    Science.gov (United States)

    Lu, Rongrong; Zhu, Feng; Wu, Qingxiao; Kong, Yanzi

    2018-04-01

    Point cloud registration is a fundamental task in high level three dimensional applications. Noise, uneven point density and varying point cloud resolutions are the three main challenges for point cloud registration. In this paper, we design a robust and compact local surface descriptor called Local Surface Angles Histogram (LSAH) and propose an effectively coarse to fine algorithm for point cloud registration. The LSAH descriptor is formed by concatenating five normalized sub-histograms into one histogram. The five sub-histograms are created by accumulating a different type of angle from a local surface patch respectively. The experimental results show that our LSAH is more robust to uneven point density and point cloud resolutions than four state-of-the-art local descriptors in terms of feature matching. Moreover, we tested our LSAH based coarse to fine algorithm for point cloud registration. The experimental results demonstrate that our algorithm is robust and efficient as well.

  15. Experimental study of intense radiation in terahertz region based on cylindrical surface wave resonator

    International Nuclear Information System (INIS)

    Gong, Shaoyan; Ogura, Kazuo; Yambe, Kiyoyuki; Nomizu, Shintaro; Shirai, Akihiro; Yamazaki, Kosuke; Kawamura, Jun; Miura, Takuro; Takanashi, Sho; San, Min Thu

    2015-01-01

    Periodical corrugations structured on a cylindrical conductor have cylindrical surface waves (CSWs), which are reflected at the corrugation ends and form a CSW-resonator. In this paper, intense radiations in terahertz region based on the CSW-resonator are reported. The CSW-resonators with upper cut off frequencies in the modern IEEE G-band (110–300 GHz) are excited by a coaxially injected annular beam in a weakly relativistic region less than 100 kV. It is shown that there exists an oscillation starting energy for the CSW-resonator. Above the starting energy, very intense terahertz radiations on the order of kW are obtained. The operation frequencies in the range of 166–173 GHz and 182–200 GHz are obtained using two types of CSW-resonator with the different corrugation amplitude. Electromagnetic properties of the CSW-resonator can be controlled by the artificial structure and may play an important role in high-intensity terahertz generations and applications

  16. Trichodesmium blooms and warm-core ocean surface features in the Arabian Sea and the Bay of Bengal.

    Science.gov (United States)

    Jyothibabu, R; Karnan, C; Jagadeesan, L; Arunpandi, N; Pandiarajan, R S; Muraleedharan, K R; Balachandran, K K

    2017-08-15

    Trichodesmium is a bloom-forming, diazotrophic, non-heterocystous cyanobacteria widely distributed in the warmer oceans, and their bloom is considered a 'biological indication' of stratification and nitrogen limitation in the ocean surface layer. In the first part of this paper, based on the retrospective analyses of the ocean surface mesoscale features associated with 59 Trichodesmium bloom incidences recorded in the past, 32 from the Arabian Sea and the Bay of Bengal, and 27 from the rest of the world, we have showed that warm-core features have an inducing effect on bloom formation. In the second part, we have considered the environmental preferences of Trichodesmium bloom based on laboratory and field studies across the globe, and proposed a view about how warm-core features could provide an inducing pre-requisite condition for the bloom formation in the Arabian Sea and the Bay of Bengal. Proposed that the subsurface waters of warm-core features maintain more likely chances for the conducive nutrient and light conditions required for the triggering of the blooms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Features of time–intensity curve parameters of colorectal adenocarcinomas evaluated by double-contrast enhanced ultrasonography: Initial observation

    International Nuclear Information System (INIS)

    Zhuang Hua; Yang Zhigang; Wang Ziqiang; Wang Xiaodong; Chen Huijiao; Zhang Yuanchuan; Luo Yan

    2012-01-01

    Purpose: This study is to investigate the value of double contrast-enhanced ultrasonography (DCEU) in assessing microcirculation of colorectal adenocarcinomas and to describe the perfusion features of the tumours. Material and methods: DCEUS was performed in 42 patients with adenocarcinoma. The time–intensity curve parameters (arrival time (AT), time-to-peak (TTP), peak intensity (PI) and area under the curve (AUC)) within the tumours were extracted. The parameters were compared among the tumours with different CEUS features and stages. Results: The mean values of AT, TTP, PI and AUC of the colorectal adenocarcinomas were 13.68 ± 13.36 s, 32.61 ± 19.56 s, 19.82 ± 16.54 dB and 271.10 ± 159.19 dB s, respectively. In the adenocarcinomas with necrosis, the mean values of AUC was significantly lower than that of the adenocarcinomas without (231.10 ± 219.27 dB s, 278.10 ± 123.20 dB s, p = 0.004). In the adenocarcinomas with necrosis, the AUC and PI of the non-necrotic part were significantly higher than that of the necrotic part (p = 0.007, 0.0025, respectively). AUC increased progressively in the subgroups of T2, T3 and T4 and the difference of AUC between T2 and T4 subgroup was significant (p = 0.008). Conclusions: Double contrast-enhanced ultrasonography is a valuable technique for quantifying tumour vascularity of colorectal adenocarcinomas. AUC was significantly different in the subgroups of different T stage. AUC and PI could reflect the different perfusion status of tumours with or without necrosis.

  18. Supplementary Microstructural Features Induced During Laser Surface Melting of Thermally Sprayed Inconel 625 Coatings

    Science.gov (United States)

    Ahmed, Nauman; Voisey, K. T.; McCartney, D. G.

    2014-02-01

    Laser surface melting of thermally sprayed coatings has the potential to enhance their corrosion properties by incorporating favorable microstructural changes. Besides homogenizing the as-sprayed structure, laser melting may induce certain microstructural modifications (i.e., supplementary features) in addition to those that directly improve the corrosion performance. Such features, being a direct result of the laser treatment process, are described in this paper which is part of a broader study in which high velocity oxy-fuel sprayed Inconel 625 coatings on mild-steel substrates were treated with a diode laser and the modified microstructure characterized using optical and scanning electron microscopy and x-ray diffraction. The laser treated coating features several different zones, including a region with a microstructure in which there is a continuous columnar dendritic structure through a network of retained oxide stringers.

  19. Specific Features of Chip Making and Work-piece Surface Layer Formation in Machining Thermal Coatings

    Directory of Open Access Journals (Sweden)

    V. M. Yaroslavtsev

    2016-01-01

    Full Text Available A wide range of unique engineering structural and performance properties inherent in metallic composites characterizes wear- and erosion-resistant high-temperature coatings made by thermal spraying methods. This allows their use both in manufacturing processes to enhance the wear strength of products, which have to operate under the cyclic loading, high contact pressures, corrosion and high temperatures and in product renewal.Thermal coatings contribute to the qualitative improvement of the technical level of production and product restoration using the ceramic composite materials. However, the possibility to have a significantly increased product performance, reduce their factory labour hours and materials/output ratio in manufacturing and restoration is largely dependent on the degree of the surface layer quality of products at their finishing stage, which is usually provided by different kinds of machining.When machining the plasma-sprayed thermal coatings, a removing process of the cut-off layer material is determined by its distinctive features such as a layered structure, high internal stresses, low ductility material, high tendency to the surface layer strengthening and rehardening, porosity, high abrasive properties, etc. When coatings are machined these coating properties result in specific characteristics of chip formation and conditions for formation of the billet surface layer.The chip formation of plasma-sprayed coatings was studied at micro-velocities using an experimental tool-setting microscope-based setup, created in BMSTU. The setup allowed simultaneous recording both the individual stages (phases of the chip formation process and the operating force factors.It is found that formation of individual chip elements comes with the multiple micro-cracks that cause chipping-off the small particles of material. The emerging main crack in the cut-off layer of material leads to separation of the largest chip element. Then all the stages

  20. Study of 2ω and 3/2ω harmonics in ultrashort high-intensity laser ...

    Indian Academy of Sciences (India)

    An experimental study is presented on measurements of optical spectrum of the laser light scattered from solid surface irradiated by Ti:sapphire laser pulses up to an intensity of 1.2 × 1018 W cm-2. The spectrum has well-defined peaks at wavelengths corresponding to 2 and 3/2 radiations. The spectral features vary with ...

  1. Surface features of central North America: a synoptic view from computer graphics

    Science.gov (United States)

    Pike, R.J.

    1991-01-01

    A digital shaded-relief image of the 48 contiguous United States shows the details of large- and small-scale landforms, including several linear trends. The features faithfully reflect tectonism, continental glaciation, fluvial activity, volcanism, and other surface-shaping events and processes. The new map not only depicts topography accurately and in its true complexity, but does so in one synoptic view that provides a regional context for geologic analysis unobscured by clouds, culture, vegetation, or artistic constraints. -Author

  2. Identification of individual features in areal surface topography data by means of template matching and the ring projection transform

    International Nuclear Information System (INIS)

    Senin, Nicola; Moretti, Michele; Blunt, Liam A

    2014-01-01

    Starting from areal surface topography data as provided by current commercial three-dimensional (3D) profilometers and 3D digital microscopes, this work investigates the problem of automatically identifying and extracting functionally relevant, individual features within the acquisition area. Feature identification is achieved by adopting an original template-matching algorithmic procedure, based on applying the ring projection transform in combination with a parametric template. The proposed algorithmic procedure addresses in particular template-matching scenarios where significant variability may be associated with the features to be compared to the reference template. The algorithm is applied to a test case involving the characterization of the surface texture of a superabrasive polishing tool used in hard-disk manufacturing. (paper)

  3. Target Surface Area Effects on Hot Electron Dynamics from High Intensity Laser-Plasma Interactions

    Science.gov (United States)

    2016-08-19

    Science, University ofMichigan, AnnArbor,MI 48109-2099, USA E-mail: czulick@umich.edu Keywords: laser- plasma ,mass-limited, fast electrons , sheath...New J. Phys. 18 (2016) 063020 doi:10.1088/1367-2630/18/6/063020 PAPER Target surface area effects on hot electron dynamics from high intensity laser... plasma interactions CZulick, ARaymond,AMcKelvey, VChvykov, AMaksimchuk, AGRThomas, LWillingale, VYanovsky andKKrushelnick Center forUltrafast Optical

  4. MRI features of placenta accreta

    International Nuclear Information System (INIS)

    Cao Manrui; Du Mu; Huang Yi; Liu Bingguang; Zhang Fangjing; Guo Jimin; Zhu Zhijun

    2012-01-01

    Objective: To investigate the MRI features of placenta accreta. Methods: From Apr 2009 to Jun 2011, 15 patients with placenta accrete received MRI examination. In them, placenta accreta was diagnosed based on clinical manifestations or postoperative histopathology. The MR features of placenta accreta in them (study group) were retrospectively analyzed and compared with those in 15 pregnant women without placenta accreta (control group) with Fisher exact test. Results: In the 15 patients with placenta accreta,uterine bulging and (or) a focal outward contour bulge was detected in 14 patients; heterogeneous signal intensity in the placenta was detected in 15 patients; dark intraplacental bands on T 2 -weighted images was detected in 15 patients; and increased subplacental vascularity was detected in 11 patients on T 1 - weighted images. In the study group, 14 patients showed at least three of the above four features, and in all of them uterine bulging and (or) a focal outward contour bulge, heterogeneous signal intensity in the placenta and dark intraplacental bands on T 2 -weighted images were detected; one patient showed heterogeneous signal intensity in the placenta, dark intraplacental bands on T 2 -weighted images and increased subplacental vascularity. In the control group,none patient had three of the above features.Uterine bulging and (or) a focal outward contour bulge, heterogeneous signal intensity in the placenta, dark intraplacental bands on T 2 -weighted images and increased subplacental vascularity were detected in 3, 6, 3 and 4 patients (P=0.000, 0.001, 0.000 and 0.027), respectively. Conclusions: The main MRI features of placenta accreta are uterine bulging and (or) a focal outward contour bulge, heterogeneous signal intensity in the placenta and dark intraplacental bands on T 2 -weighted images Besides, increased subplacental vascularity also could provide useful information for the diagnosis of placenta accreta. (authors)

  5. A hybrid 3D SEM reconstruction method optimized for complex geologic material surfaces.

    Science.gov (United States)

    Yan, Shang; Adegbule, Aderonke; Kibbey, Tohren C G

    2017-08-01

    Reconstruction methods are widely used to extract three-dimensional information from scanning electron microscope (SEM) images. This paper presents a new hybrid reconstruction method that combines stereoscopic reconstruction with shape-from-shading calculations to generate highly-detailed elevation maps from SEM image pairs. The method makes use of an imaged glass sphere to determine the quantitative relationship between observed intensity and angles between the beam and surface normal, and the detector and surface normal. Two specific equations are derived to make use of image intensity information in creating the final elevation map. The equations are used together, one making use of intensities in the two images, the other making use of intensities within a single image. The method is specifically designed for SEM images captured with a single secondary electron detector, and is optimized to capture maximum detail from complex natural surfaces. The method is illustrated with a complex structured abrasive material, and a rough natural sand grain. Results show that the method is capable of capturing details such as angular surface features, varying surface roughness, and surface striations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Measurements of land surface features using an airborne laser altimeter: the HAPEX-Sahel experiment

    International Nuclear Information System (INIS)

    Ritchie, J.C.; Menenti, M.; Weltz, M.A.

    1997-01-01

    An airborne laser profiling altimeter was used to measure surface features and properties of the landscape during the HAPEX-Sahel Experiment in Niger, Africa in September 1992. The laser altimeter makes 4000 measurements per second with a vertical resolution of 5 cm. Airborne laser and detailed field measurements of vegetation heights had similar average heights and frequency distribution. Laser transects were used to estimate land surface topography, gully and channel morphology, and vegetation properties ( height, cover and distribution). Land surface changes related to soil erosion and channel development were measured. For 1 km laser transects over tiger bush communities, the maximum vegetation height was between 4-5 and 6-5 m, with an average height of 21 m. Distances between the centre of rows of tiger bush vegetation averaged 100 m. For two laser transects, ground cover for tiger bush was estimated to be 225 and 301 per cent for vegetation greater than 0-5m tall and 190 and 25-8 per cent for vegetation greater than 10m tall. These values are similar to published values for tiger bush. Vegetation cover for 14 and 18 km transects was estimated to be 4 per cent for vegetation greater than 0-5 m tall. These cover values agree within 1-2 per cent with published data for short transects (⩾ 100 m) for the area. The laser altimeter provided quick and accurate measurements for evaluating changes in land surface features. Such information provides a basis for understanding land degradation and a basis for management plans to rehabilitate the landscape. (author)

  7. Inhibition of enteric pathogens using integrated high intensity 405 nm LED on the surface of almonds

    Science.gov (United States)

    The disinfecting properties of 405 nm light were investigated against Escherichia coli O157:H7, Salmonella, and their non-pathogenic surrogates inoculated onto the surface of almonds. High intensity monochromatic light was generated from an array of narrow-band 405 nm light emitting diodes (LED). Al...

  8. Cardiac MRI in mice at 9.4 Tesla with a transmit-receive surface coil and a cardiac-tailored intensity-correction algorithm.

    Science.gov (United States)

    Sosnovik, David E; Dai, Guangping; Nahrendorf, Matthias; Rosen, Bruce R; Seethamraju, Ravi

    2007-08-01

    To evaluate the use of a transmit-receive surface (TRS) coil and a cardiac-tailored intensity-correction algorithm for cardiac MRI in mice at 9.4 Tesla (9.4T). Fast low-angle shot (FLASH) cines, with and without delays alternating with nutations for tailored excitation (DANTE) tagging, were acquired in 13 mice. An intensity-correction algorithm was developed to compensate for the sensitivity profile of the surface coil, and was tailored to account for the unique distribution of noise and flow artifacts in cardiac MR images. Image quality was extremely high and allowed fine structures such as trabeculations, valve cusps, and coronary arteries to be clearly visualized. The tag lines created with the surface coil were also sharp and clearly visible. Application of the intensity-correction algorithm improved signal intensity, tissue contrast, and image quality even further. Importantly, the cardiac-tailored properties of the correction algorithm prevented noise and flow artifacts from being significantly amplified. The feasibility and value of cardiac MRI in mice with a TRS coil has been demonstrated. In addition, a cardiac-tailored intensity-correction algorithm has been developed and shown to improve image quality even further. The use of these techniques could produce significant potential benefits over a broad range of scanners, coil configurations, and field strengths. (c) 2007 Wiley-Liss, Inc.

  9. Seasonal and Spatial Variation of Surface Urban Heat Island Intensity in a Small Urban Agglomerate in Brazil

    Directory of Open Access Journals (Sweden)

    Elis Dener Lima Alves

    2016-12-01

    Full Text Available In recent years, SUHIs (surface urban heat islands have been greatly emphasized in urban climate studies, since it is one of the climate phenomena most influenced by human action. In this study, temporal and spatial variations of SUHIs in the cities of Ceres and Rialma (Brazil were investigated; satellite Landsat 8 TIRS/OLI images from 2013 to 2016 were used for this purpose. The results showed that in all seasons, two relationships were observed, one positive and one negative. An N D V I (Normalized Difference Vegetation Index of 0.2 is the divider of this relationship: up to this value, the relationship is positive, that is, the higher the N D V I value, the higher the surface temperature, while the relationship is negative at an N D V I greater than 0.2. There was high seasonal variation in the SUHIs, with the highest intensities recorded in the spring and summer (±12 °C, and the lowest in the winter. These temporal variations were attributed to the annual cycle of precipitation, which directly involves the robustness of the Cerrado vegetation. SUHIs occupied, on average, an area three times larger than the area of SUCIs (surface urban cool islands. The highest values of SUCIs were observed in water bodies and in valley bottoms. Overall, SUHIs showed high intensities; however, a more intense core area, such as in large cities, was not observed.

  10. Physical principles of the surface plasma method for producing beams of negative ions

    International Nuclear Information System (INIS)

    Bel'chenko, Yu.I.; Dimov, G.I.; Dudnikov, V.G.

    1977-01-01

    The processes which are important for the production of intense beams of negative ions from surface plasma sources (SPS) are examined. The formation of negative ions when atomic particles interact with a surface is analyzed on the basis of both experimental results obtained when a surface was bombarded with beams and recently developed theoretical considerations of reflection, scattering, and electron exchange. The characteristic features of these processes in SPS, when a surface is bombarded with intense fluxes of plasma particles, are revealed in special experiments. The characteristics of generation and acceleration of the bombarding particles in a gas discharge SPS plasma, the characteristics of transportation of negative ions through the plasma toward the beam forming system, the role of cesium in SPS, and the characteristics of formation of the intense negative ion beams as well as the removal of parasite electrons from the beam

  11. Multisite evaluation of environmental cleanliness of high-touch surfaces in intensive care unit patient rooms.

    Science.gov (United States)

    Hopman, Joost; Donskey, Curtis J; Boszczowski, Icaro; Alfa, Michelle J

    2018-05-23

    The efficacy of discharge cleaning and disinfection of high-touch surfaces of intensive care unit patient rooms in Brazil, Canada, the Netherlands, and the United States was evaluated and the effect of an educational intervention was determined. Significant site-to-site differences in cleaning regimens and baseline cleanliness levels were observed using ATP levels, colony-forming units, and reflective surface marker removal percent pass rates. An educational intervention that includes rapid feedback of the ATP measurements could significantly improve the quality of the cleaning and disinfection regimens. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. All rights reserved.

  12. Thermal Infrared Spectra of Microcrystalline Sedimentary Phases: Effects of Natural Surface Roughness on Spectral Feature Shape

    Science.gov (United States)

    Hardgrove, C.; Rogers, A. D.

    2012-03-01

    Thermal infrared spectral features of common microcrystalline phases (chert, alabaster, micrite) are presented. Spectra are sensitive to mineralogy and micron-scale (~1-25 µm) surface roughness. Roughness is on the scale of the average crystal size.

  13. ATP bioluminescence: Surface hygiene monitoring in milk preparation room of neonatal intensive care unit

    Science.gov (United States)

    Mohamad, Mahirah; Ishak, Shareena; Jaafar, Rohana; Sani, Norrakiah Abdullah

    2018-04-01

    ATP Bioluminescence application and standard microbiological analyses were used to evaluate the cleanliness of milk contact surfaces and non-milk contact surfaces in milk preparation room of neonatal intensive care unit (NICU) of Universiti Kebangsaan Malaysia Medical Centre (UKMMC). A total of 44 samples including the breast pump, milk bottle, milk bottle screw top and screw ring, teats, measuring cups, waterless warmer, refrigerator, dishwasher and pasteurizer inner wall were tested on May 2017. 3M Clean and Trace Hygiene Monitoring (UXL100 ATP Test swabs) and the bioluminescence reader Clean-Trace NG Luminometer (3M) were used to measure the Relative Light Unit (RLU) and microbiological analysis using 3M Quick Swab and 3MTM PetrifilmTM for enumeration of aerobic count, Staphylococcus aureus, Enterobacteriaceae, coliform and detection of Escherichia coli (CFU /100cm2 or utensil/item). The RLU values were from 11 to 194 and passed the ATP benchmark for intensive care unit (ICU), < 250 RLU as recommended. Aerobic colony count was only found in waterless warmer (0.05±0.01 mean log CFU/warmer). None of S. aureus, Enterobacteriaceae, E. coli and coliform was detected in all samples. A weak correlation was found between bioluminescence measurements RLU and the microbiological analysis (CFU). However, the use of ATP bioluminescence in monitoring milk preparation room cleanliness can be a useful method for assessing rapidly the surface hygiene as well as to verify the Sanitation Standard Operating Procedure (SSOP) prior to implementation of Hazard Analysis and Critical Control Points (HACCP) in milk preparation room.

  14. Behavioral and Neurological Responses to Musical Features in Adolescent Cochlear Implant Users Before and After an Intensive Musical Training Program

    DEFF Research Database (Denmark)

    Petersen, Bjørn

    a session of behavioral tests and EEG recordings. CI users significantly improved their overall behavioral perception of music and, in particular, their discrimination of melodic contour and rhythm. Though smaller and later compared to normal-hearing controls, CI-users showed significant mismatch negativity......This study aimed to investigate perception and processing of musical features in prelingually deaf adolescent CI-users and examine whether this is influenced by music training. Eleven adolescent CI-users received intensive music training for two weeks. Before and after training they completed...... responses for timbre, intensity and rhythm but not for pitch. No effect of training was found in the MMN responses. The findings indicate that despite congenital deafness and late implantation, young CI users are able to discriminate details in music. Furthermore, the behavioral advances suggest that...

  15. Linear surface photoelectric effect of gold in intense laser field as a possible high-current electron source

    International Nuclear Information System (INIS)

    Farkas, G.; Horvath, Z.G.; Toth, C.; Fotakis, C.; Hontzopoulos, E.

    1987-01-01

    Investigations were conducted on radiation-induced electron emission processes on a gold target surface with a high-intensity (2 MW/cm 2 ) KrF laser (λ = 248 nm). The single photon surface photoelectric emission obtained can be used for high-current density electron sources. The measured polarization dependence of electron current shows the dominance of the surface-type effect over that of the volume type, thereby making it possible to optimize the short, high-density electron current creation conditions. The advantage of the grazing light incidence and the multiphoton photoeffect giving rise to a 500 A/cm 2 electron current has been demonstrated

  16. Tactile detection of slip: surface microgeometry and peripheral neural codes.

    Science.gov (United States)

    Srinivasan, M A; Whitehouse, J M; LaMotte, R H

    1990-06-01

    1. The role of the microgeometry of planar surfaces in the detection of sliding of the surfaces on human and monkey fingerpads was investigated. By the use of a servo-controlled tactile stimulator to press and stroke glass plates on passive fingerpads of human subjects, the ability of humans to discriminate the direction of skin stretch caused by friction and to detect the sliding motion (slip) of the plates with or without micrometer-sized surface features was determined. To identify the associated peripheral neural codes, evoked responses to the same stimuli were recorded from single, low-threshold mechanoreceptive afferent fibers innervating the fingerpads of anesthetized macaque monkeys. 2. Humans could not detect the slip of a smooth glass plate on the fingerpad. However, the direction of skin stretch was perceived based on the information conveyed by the slowly adapting afferents that respond differentially to the stretch directions. Whereas the direction of skin stretch signaled the direction of impending slip, the perception of relative motion between the plate and the finger required the existence of detectable surface features. 3. Barely detectable micrometer-sized protrusions on smooth surfaces led to the detection of slip of these surfaces, because of the exclusive activation of rapidly adapting fibers of either the Meissner (RA) or the Pacinian (PC) type to specific geometries of the microfeatures. The motion of a smooth plate with a very small single raised dot (4 microns high, 550 microns diam) caused the sequential activation of neighboring RAs along the dot path, thus providing a reliable spatiotemporal code. The stroking of the plate with a fine homogeneous texture composed of a matrix of dots (1 microns high, 50 microns diam, and spaced at 100 microns center-to-center) induced vibrations in the fingerpad that activated only the PCs and resulted in an intensive code. 4. The results show that surprisingly small features on smooth surfaces are

  17. On the surface topography of ultrashort laser pulse treated steel surfaces

    International Nuclear Information System (INIS)

    Vincenc Obona, J.; Ocelík, V.; Skolski, J.Z.P.; Mitko, V.S.; Römer, G.R.B.E.; Huis in’t Veld, A.J.; De Hosson, J.Th.M.

    2011-01-01

    This paper concentrates on observations of the surface topography by scanning electron microscopy (SEM) on alloyed and stainless steels samples treated by ultrashort laser pulses with duration of 210 fs and 6.7 ps. Globular-like and jet-like objects were found depending on the various levels of the fluence applied. It is shown that these features appear due to solid-liquid and liquid-gas transitions within surface layer irradiated by intense laser light. The observations are confronted to the theory of short-pulsed laser light-matter interactions, including interference, excitation of electrons, electron-phonon coupling as well as subsequent ablation. It is shown that the orientation of small ripples does not always depend on the direction of the polarization of laser light.

  18. Surface features on Sahara soil dust particles made visible by atomic force microscope (AFM) phase images

    OpenAIRE

    G. Helas; M. O. Andreae

    2008-01-01

    We show that atomic force microscopy (AFM) phase images can reveal surface features of soil dust particles, which are not evident using other microscopic methods. The non-contact AFM method is able to resolve topographical structures in the nanometer range as well as to uncover repulsive atomic forces and attractive van der Waals' forces, and thus gives insight to surface properties. Though the method does not allow quantitative assignment in terms of chemical compound description, it clearly...

  19. Terrestrial Analogs for Surface Properties Associated with Impact Cratering on the Moon - Self-secondary Impact Features at Kings Bowl, Idaho

    Science.gov (United States)

    Matiella Novak, M. A.; Zanetti, M.; Neish, C.; Kukko, A.; Fan, K.; Heldmann, J.; Hughes, S. S.

    2017-12-01

    The Kings Bowl (KB) eruptive fissure and lava field, located in the southern end of Craters of the Moon National Monument, Idaho, is an ideal location for planetary analogue field studies of surface properties related to volcanic and impact processes. Here we look at possible impact features present in the KB lava field near the main vent that resulted in squeeze-ups of molten lava from beneath a semi-solid lava lake crust. These may have been caused by the ejection of blocks during the phreatic eruption that formed the Kings Bowl pit, and their subsequent impact into a partially solidified lava pond. We compare and contrast these features with analogous self-secondary impact features, such as irregular, rimless secondary craters ("splash craters") observed in lunar impact melt deposits, to better understand how self-secondary impacts determine the surface properties of volcanic and impact crater terrains. We do this by analyzing field measurements of these features, as well as high-resolution DEM data collected through the Kinematic LiDAR System (KLS), both of which give us feature dimensions and distributions. We then compare these data with self-secondary impact features on the Moon and related surface roughness constrained through Lunar Reconnaissance Orbiter observations (Mini-RF and LROC NACs). Possible self-secondary impact features can be found in association with many lunar impact craters. These are formed when ballistic ejecta from the crater falls onto the ejecta blanket and melt surrounding the newly formed crater. Self-secondary impact features involving impact melt deposits are particularly useful to study because the visibly smooth melt texture serves to highlight the impact points in spacecraft imagery. The unusual morphology of some of these features imply that they formed when the melt had not yet completely solidified, strongly suggesting a source of impactors from the primary crater itself. We will also discuss ongoing efforts to integrate field

  20. Use of the discriminant Fourier-derived cepstrum with feature-level post-processing for surface electromyographic signal classification

    International Nuclear Information System (INIS)

    Chen, Xinpu; Zhu, Xiangyang; Zhang, Dingguo

    2009-01-01

    Myoelectrical pattern classification is a crucial part in multi-functional prosthesis control. This paper investigates a discriminant Fourier-derived cepstrum (DFC) and feature-level post-processing (FLPP) to discriminate hand and wrist motions using the surface electromyographic signal. The Fourier-derived cepstrum takes advantage of the Fourier magnitude or sub-band power energy of signals directly and provides flexible use of spectral information changing with different motions. Appropriate cepstral coefficients are selected by a proposed separability criterion to construct DFC features. For the post-processing, FLPP which combines features from several analysis windows is used to improve the feature performance further. In this work, two classifiers (a linear discriminant classifier and quadratic discriminant classifier) without hyper-parameter optimization are employed to simplify the training procedure and avoid the possible bias of feature evaluation. Experimental results of the 11-motion problem show that the proposed DFC feature outperforms traditional features such as time-domain statistics and autoregressive-derived cepstrum in terms of the classification accuracy, and it is a promising method for the multi-functionality and high-accuracy control of myoelectric prostheses

  1. Stress intensity factors for complete internal and external cracks in spherical shells

    International Nuclear Information System (INIS)

    Chao, Y.J.; Chen, H.

    1989-01-01

    Cracks or flows found in the nuclear structure must be fully evaluated to assure the safety of the plant. The weight function method has been widely used in the determination of stress intensity factors for cracks under stress gradient e.g. for thermal shock loading. The unique features of the weight function method is that once the weight function for a particular cracked geometry is determined the stress intensity factors at the crack tip for any loading applied to the flawed structure can be calculated by a simple integration. In this paper the stress intensity factors of the complete, part-through internal and external cracks in a spherical shell are determined. The finite element method was used to develop the weight functions for the flawed geometry. The approximate crack surface profile was used to derive the weight functions. The stress intensity factors associated with the cracks in spherical shells under internal pressure are determined by both the weight functions and the direct finite element method

  2. EVIDENCE OF FILAMENT UPFLOWS ORIGINATING FROM INTENSITY OSCILLATIONS ON THE SOLAR SURFACE

    International Nuclear Information System (INIS)

    Cao, Wenda; Goode, Philip R.; Ning, Zongjun; Yurchyshyn, Vasyl; Ji Haisheng

    2010-01-01

    A filament footpoint rooted in an active region (NOAA 11032) was well observed for about 78 minutes with the 1.6 m New Solar Telescope at the Big Bear Solar Observatory on 2009 November 18 in Hα ±0.75 A. This data set had high cadence (∼15 s) and high spatial resolution (∼0.''1) and offered a unique opportunity to study filament dynamics. As in previous findings from space observations, several dark intermittent upflows were identified, and they behave in groups at isolated locations along the filament. However, we have two new findings. First, we find that the dark upflows propagating along the filament channel are strongly associated with the intensity oscillations on the solar surface around the filament footpoints. The upflows start at the same time as the peak in the oscillations, illustrating that the upflow velocities are well correlated with the oscillations. Second, the intensity of one of the seven upflows detected in our data set exhibits a clear periodicity when the upflow propagates along the filament. The periods gradually vary from ∼10 to ∼5 minutes. Our results give observational clues on the driving mechanism of the upflows in the filament.

  3. Study of the deposition features of the organic dye Rhodamine B on the porous surface of silicon with different pore sizes

    Energy Technology Data Exchange (ETDEWEB)

    Lenshin, A. S., E-mail: lenshinas@phys.vsu.ru; Seredin, P. V.; Kavetskaya, I. V.; Minakov, D. A.; Kashkarov, V. M. [Voronezh State University (Russian Federation)

    2017-02-15

    The deposition features of the organic dye Rhodamine B on the porous surface of silicon with average pore sizes of 50–100 and 100–250 nm are studied. Features of the composition and optical properties of the obtained systems are studied using infrared and photoluminescence spectroscopy. It is found that Rhodamine-B adsorption on the surface of por-Si with various porosities is preferentially physical. The optimal technological parameters of its deposition are determined.

  4. Small-Scale Morphological Features on a Solid Surface Processed by High-Pressure Abrasive Water Jet

    Directory of Open Access Journals (Sweden)

    Can Kang

    2013-08-01

    Full Text Available Being subjected to a high-pressure abrasive water jet, solid samples will experience an essential variation of both internal stress and physical characteristics, which is closely associated with the kinetic energy attached to the abrasive particles involved in the jet stream. Here, experiments were performed, with particular emphasis being placed on the kinetic energy attenuation and turbulent features in the jet stream. At jet pressure of 260 MPa, mean velocity and root-mean-square (RMS velocity on two jet-stream sections were acquired by utilizing the phase Doppler anemometry (PDA technique. A jet-cutting experiment was then carried out with Al-Mg alloy samples being cut by an abrasive water jet. Morphological features and roughness on the cut surface were quantitatively examined through scanning electron microscopy (SEM and optical profiling techniques. The results indicate that the high-pressure water jet is characterized by remarkably high mean flow velocities and distinct velocity fluctuations. Those irregular pits and grooves on the cut surfaces indicate both the energy attenuation and the development of radial velocity components in the jet stream. When the sample is positioned with different distances from the nozzle outlet, the obtained quantitative surface roughness varies accordingly. A descriptive model highlighting the behaviors of abrasive particles in jet-cutting process is established in light of the experimental results and correlation analysis.

  5. Small-Scale Morphological Features on a Solid Surface Processed by High-Pressure Abrasive Water Jet.

    Science.gov (United States)

    Kang, Can; Liu, Haixia

    2013-08-14

    Being subjected to a high-pressure abrasive water jet, solid samples will experience an essential variation of both internal stress and physical characteristics, which is closely associated with the kinetic energy attached to the abrasive particles involved in the jet stream. Here, experiments were performed, with particular emphasis being placed on the kinetic energy attenuation and turbulent features in the jet stream. At jet pressure of 260 MPa, mean velocity and root-mean-square (RMS) velocity on two jet-stream sections were acquired by utilizing the phase Doppler anemometry (PDA) technique. A jet-cutting experiment was then carried out with Al-Mg alloy samples being cut by an abrasive water jet. Morphological features and roughness on the cut surface were quantitatively examined through scanning electron microscopy (SEM) and optical profiling techniques. The results indicate that the high-pressure water jet is characterized by remarkably high mean flow velocities and distinct velocity fluctuations. Those irregular pits and grooves on the cut surfaces indicate both the energy attenuation and the development of radial velocity components in the jet stream. When the sample is positioned with different distances from the nozzle outlet, the obtained quantitative surface roughness varies accordingly. A descriptive model highlighting the behaviors of abrasive particles in jet-cutting process is established in light of the experimental results and correlation analysis.

  6. Divalent cations and the protein surface co-ordinate the intensity of human platelet adhesion and P-selectin surface expression.

    Science.gov (United States)

    Whiss, P A; Andersson, R G G

    2002-07-01

    At sites of blood vessel injury, platelets adhere to exposed vessel components, such as collagen, or immobilized fibrinogen derived from plasma or activated platelets. The divalent cations Mg(2+) and Ca(2+) are essential for platelet adhesion and activation, but Mg(2+) can also inhibit platelet activation. The present study evaluates, by an enzymatic method, the effects of various divalent cations on the adhesion of isolated human platelets to collagen, fibrinogen, albumin or plastic in vitro. By enzyme-linked immunosorbent assay, platelet surface expression of P-selectin was measured to estimate the state of activation on adherence. Mg(2+) increased platelet adhesion exclusively to collagen and fibrinogen at physiologically relevant concentrations. At higher concentrations, the adhesion declined. Ca(2+) induced a weak adhesion only to fibrinogen at physiological doses and a peak of increased adhesion to all protein-coated surfaces at 10 mmol/l. Mn(2+) elicited dose-dependent adhesion only to collagen and fibrinogen. Zn(2+), Ni(2+) and Cu(2+) increased the adhesion of platelets independently of the surface. Ca(2+) dose-dependently inhibited adhesion elicited by Mg(2+) to collagen and fibrinogen. No other combination of divalent cations elicited such an effect. Mg(2+)-dependent platelet adhesion to collagen and Ca(2+)-dependent adhesion to fibrinogen increased P-selectin expression. Thus, the present study shows that the outcome of the platelet adhesion depends on the surface and the access of divalent cations, which co-ordinate the intensity of platelet adhesion and P-selectin surface expression.

  7. A Novel Feature Optimization for Wearable Human-Computer Interfaces Using Surface Electromyography Sensors

    Directory of Open Access Journals (Sweden)

    Han Sun

    2018-03-01

    Full Text Available The novel human-computer interface (HCI using bioelectrical signals as input is a valuable tool to improve the lives of people with disabilities. In this paper, surface electromyography (sEMG signals induced by four classes of wrist movements were acquired from four sites on the lower arm with our designed system. Forty-two features were extracted from the time, frequency and time-frequency domains. Optimal channels were determined from single-channel classification performance rank. The optimal-feature selection was according to a modified entropy criteria (EC and Fisher discrimination (FD criteria. The feature selection results were evaluated by four different classifiers, and compared with other conventional feature subsets. In online tests, the wearable system acquired real-time sEMG signals. The selected features and trained classifier model were used to control a telecar through four different paradigms in a designed environment with simple obstacles. Performance was evaluated based on travel time (TT and recognition rate (RR. The results of hardware evaluation verified the feasibility of our acquisition systems, and ensured signal quality. Single-channel analysis results indicated that the channel located on the extensor carpi ulnaris (ECU performed best with mean classification accuracy of 97.45% for all movement’s pairs. Channels placed on ECU and the extensor carpi radialis (ECR were selected according to the accuracy rank. Experimental results showed that the proposed FD method was better than other feature selection methods and single-type features. The combination of FD and random forest (RF performed best in offline analysis, with 96.77% multi-class RR. Online results illustrated that the state-machine paradigm with a 125 ms window had the highest maneuverability and was closest to real-life control. Subjects could accomplish online sessions by three sEMG-based paradigms, with average times of 46.02, 49.06 and 48.08 s

  8. On the formation and nature of quasi-cleavage fracture surfaces in hydrogen embrittled steels

    Energy Technology Data Exchange (ETDEWEB)

    Martin, May L.; Fenske, Jamey A.; Liu, Grace S.; Sofronis, Petros [University of Illinois, Dept. of Materials Science and Engineering, 1304 W. Green St., Urbana, IL 61801 (United States); Robertson, Ian M., E-mail: ianr@illinois.edu [University of Illinois, Dept. of Materials Science and Engineering, 1304 W. Green St., Urbana, IL 61801 (United States)

    2011-02-15

    Quasi-cleavage, a common feature of hydrogen-induced fracture surfaces, is generally taken as being cleavage-like but not along a known cleavage plane. Despite the frequency with which this surface is observed, the relationship to the underlying microstructure remains unknown. Through a combination of topographical reconstruction of secondary electron microscope fractographs and a transmission electron microscopy study of the microstructure from site-specific locations, it will be shown that the features on quasi-cleavage surfaces are ridges that can be correlated with sub-surface intense and highly localized deformation bands. It will be demonstrated that the fracture surface arises from the growth and coalescence of voids that initiate at and extend along slip band intersections. This mechanism and process is fully consistent with hydrogen enhancing and localizing plastic processes.

  9. Surface modification of LiNbO3 and KTa1-xNbxO3 crystals irradiated by intense pulsed ion beam

    Science.gov (United States)

    Cui, Xiaojun; Shen, Jie; Zhong, Haowen; Zhang, Jie; Yu, Xiao; Liang, Guoying; Qu, Miao; Yan, Sha; Zhang, Xiaofu; Le, Xiaoyun

    2017-10-01

    In this work, we studied the surface modification of LiNbO3 and KTa1-xNbxO3 irradiated by intense pulsed ion beam, which was mainly composed of H+ (70%) and Cn+ (30%) at an acceleration voltage of about 450 kV. The surface morphologies, microstructural evolution and elemental analysis of the sample surfaces after IPIB irradiation have been analyzed by scanning electron microscope, atomic force microscope, X-ray diffraction and energy dispersive spectrometer techniques, respectively. The results show that the surface morphologies have significant difference impacted by the irradiation effect. Regular gully damages range from 200 to 400 nm in depth appeared in LiNbO3 under 2 J/cm2 energy density for 1 pulse, block cracking appeared in KTa1-xNbxO3 at the same condition. Surface of the crystals have melted and were darkened with the increasing number up to 5 pulses. Crystal lattice arrangement is believed to be the dominant reason for the different experimental results irradiated by intense pulsed ion beam.

  10. MRI features of chondroblastoma

    International Nuclear Information System (INIS)

    Cheng Xiaoguang; Liu Xia; Cheng Kebin; Liu Wei

    2009-01-01

    Objective: To evaluate the MR imaging features of chondroblastoma. Methods: MRI examinations of 20 patients with histological proven chondmblastoma were reviewed retrospectively. The MRI findings of chondroblastoma including the signal intensity, the shape, the growth patterns, and the surrounding bone marrow edema and the adjacent soft tissue edema, the periosteal reaction, the adjacent joint effusion were analyzed. Results: All 20 cases demonstrated heterogeneous MR signal intensity on T 1 WI and T 2 WI images and showed lobular margins. Sixteen cases demonstrated expansive growth patterns. Surrounding bone marrow edema was found in 18 cases and adjacent soft tissue edema in 14 cases. Periosteal reaction was identified in 6 cases. In 7 cases the tumor extended to adjacent soft tissue. Adjacent joint effusion was visible on MRI in 6 cases. Conclusion: Heterogeneous signal intensity, lobular margins and expansive growth pattern, adjacent bone marrow and soft tissue edema were the common features of chondroblastoma on MRI. (authors)

  11. Luminescence Properties of Surface Radiation-Induced Defects in Lithium Fluoride

    Science.gov (United States)

    Voitovich, A. P.; Kalinov, V. S.; Martynovich, E. F.; Novikov, A. N.; Runets, L. P.; Stupak, A. P.

    2013-11-01

    Luminescence and luminescence excitation spectra are recorded for surface radiation-induced defects in lithium fluoride at temperatures of 77 and 293 K. The presence of three bands with relatively small intensity differences is a distinctive feature of the excitation spectrum. These bands are found to belong to the same type of defects. The positions of the peaks and the widths of the absorption and luminescence bands for these defects are determined. The luminescence decay time is measured. All the measured characteristics of these surface defects differ from those of previously known defects induced by radiation in the bulk of the crystals. It is found that the luminescence of surface defects in an ensemble of nanocrystals with different orientations is not polarized. The number of anion vacancies in the surface defects is estimated using the polarization measurements. It is shown that radiative scattering distorts the intensity ratios of the luminescence excitation bands located in different spectral regions.

  12. Brain responses to language-relevant musical features in adolescent cochlear implant users before and after an intensive music training program

    DEFF Research Database (Denmark)

    Petersen, Bjørn; Weed, Ethan; Hansen, Mads

    Brain responses to language-relevant musical features in adolescent cochlear implant users before and after an intensive music training program Petersen B.1,2, Weed E.1,3, Hansen M.1,4, Sørensen S.D.3 , Sandmann P.5 , Vuust P.1,2 1Center of Functionally Integrative Neuroscience, Aarhus University......, rhythm and intensity). Difference waves for the rhythm deviant were analyzed in the time window between 300 and 320 ms. Separate mixed-model ANOVAs were performed for left and right fronto-central electrodes. Paired t-tests were used to analyze the behavioral data. Here we present preliminary analyses...... of ERP responses to the rhythm deviant stimuli and results from a behavioral rhythm discrimination test. For both left and right electrode sites we found a main effect of group, driven by higher mean amplitude in the NH group. There was no main effect of training. Left hemisphere sites showed...

  13. Dynamics of Soil Deflation Features in Kangerlussuaq, Greenland Revealed by Variations in Lichen Diameters on Exposed Surfaces

    Science.gov (United States)

    Heindel, R. C.; Kelly, M. A.; Virginia, R. A.

    2013-12-01

    Little is known about the pervasive soil deflation features in the Kangerlussuaq region, West Greenland, an area deglaciated between ~6,800 and 150 years ago. While the majority of the landscape is vegetated with low-lying shrubs and graminoids, wind erosion has removed loess and vegetation from distinct patches ranging in size from a few to tens of meters across, leaving the underlying glacial till or bedrock exposed. Although previous work has considered aeolian landforms and regional loess deposition along the Watson River Valley, these deflation features have not been investigated in detail. We aim to determine both the timing and mechanisms of formation of the deflation features and will examine whether these mechanisms were related to regional climatic conditions, such as increased aridity, to fluctuations in the Greenland Ice Sheet, or to other factors. Our ongoing research investigating these features includes geomorphic mapping using field observations and satellite imagery, lichenometry of the exposed surfaces, and cosmogenic nuclide dating of boulders and bedrock within and near the deflation features. Here we present initial results from our lichenometry studies. During the summer of 2013, we measured maximum lichen (Rhizocarpon sp.) diameters on boulder and bedrock surfaces in 15 soil deflation features located between Kangerlussuaq and the ice sheet margin. Lichen diameters vary from only a few millimeters at the outer margins of deflation features to multiple centimeters (maximum ~50 mm) in the centers of the unvegetated patches. This distinct pattern suggests that the outer margins of the soil deflation features are currently active. Based on a previously established lichen growth curve for Rhizocarpon sp. in West Greenland, our results indicate that the features are expanding at a rate of ~1.5 m per 100 yrs. In addition, the large lichen diameters (~40-50 mm) that occur in the centers of deflation features suggest that the formation mechanism has

  14. Linear and Nonlinear Gait Features in Older Adults Walking on Inclined Surfaces at Different Speeds.

    Science.gov (United States)

    Vieira, Marcus Fraga; Rodrigues, Fábio Barbosa; de Sá E Souza, Gustavo Souto; Magnani, Rina Márcia; Lehnen, Georgia Cristina; Andrade, Adriano O

    2017-06-01

    This study evaluated linear and nonlinear gait features in healthy older adults walking on inclined surfaces at different speeds. Thirty-seven active older adults (experimental group) and fifty young adults (control group) walked on a treadmill at 100% and ±20% of their preferred walking speed for 4 min under horizontal (0%), upward (UP) (+8%), and downward (DOWN) (-8%) conditions. Linear gait variability was assessed using the average standard deviation of trunk acceleration between strides (VAR). Gait stability was assessed using the margin of stability (MoS). Nonlinear gait features were assessed by using the maximum Lyapunov exponent, as a measure of local dynamic stability (LDS), and sample entropy (SEn), as a measure of regularity. VAR increased for all conditions, but the interaction effects between treadmill inclination and age, and speed and age were higher for young adults. DOWN conditions showed the lowest stability in the medial-lateral MoS, but not in LDS. LDS was smaller in UP conditions. However, there were no effects of age for either MoS or LDS. The values of SEn decreased almost linearly from the DOWN to the UP conditions, with significant interaction effects of age for anterior-posterior SEn. The overall results supported the hypothesis that inclined surfaces modulate nonlinear gait features and alter linear gait variability, particularly in UP conditions, but there were no significant effects of age for active older adults.

  15. Comparison of Surface Flow Features from Lidar-Derived Digital Elevation Models with Historical Elevation and Hydrography Data for Minnehaha County, South Dakota

    Science.gov (United States)

    Poppenga, Sandra K.; Worstell, Bruce B.; Stoker, Jason M.; Greenlee, Susan K.

    2009-01-01

    The U.S. Geological Survey (USGS) has taken the lead in the creation of a valuable remote sensing product by incorporating digital elevation models (DEMs) derived from Light Detection and Ranging (lidar) into the National Elevation Dataset (NED), the elevation layer of 'The National Map'. High-resolution lidar-derived DEMs provide the accuracy needed to systematically quantify and fully integrate surface flow including flow direction, flow accumulation, sinks, slope, and a dense drainage network. In 2008, 1-meter resolution lidar data were acquired in Minnehaha County, South Dakota. The acquisition was a collaborative effort between Minnehaha County, the city of Sioux Falls, and the USGS Earth Resources Observation and Science (EROS) Center. With the newly acquired lidar data, USGS scientists generated high-resolution DEMs and surface flow features. This report compares lidar-derived surface flow features in Minnehaha County to 30- and 10-meter elevation data previously incorporated in the NED and ancillary hydrography datasets. Surface flow features generated from lidar-derived DEMs are consistently integrated with elevation and are important in understanding surface-water movement to better detect surface-water runoff, flood inundation, and erosion. Many topographic and hydrologic applications will benefit from the increased availability of accurate, high-quality, and high-resolution surface-water data. The remotely sensed data provide topographic information and data integration capabilities needed for meeting current and future human and environmental needs.

  16. Virtual laparoscopy: Initial experience with three-dimensional ultrasonography to characterize hepatic surface features

    International Nuclear Information System (INIS)

    Sekimoto, Tadashi; Maruyama, Hitoshi; Kondo, Takayuki; Shimada, Taro; Takahashi, Masanori; Yokosuka, Osamu; Otsuka, Masayuki; Miyazaki, Masaru; Mine, Yoshitaka

    2013-01-01

    Objective: To examine the potential utility of 3D-reconstructed sonograms to distinguish cirrhotic from non-cirrhotic livers by demonstrating hepatic surface characteristics. Materials and methods: A preliminary phantom study was performed to examine the potential resolution of 3D images, recognizing surface irregularities as a difference in height. In a prospective clinical study of 31 consecutive patients with ascites (21 cirrhosis, 10 non-cirrhosis), liver volume data were acquired by transabdominal mechanical scanning. The hepatic surface features of cirrhotic and non-cirrhotic patients were compared by 2 independent reviewers. Intra- and inter-operator/reviewer agreements were also examined. Results: The phantom study revealed that 0.4 mm was the minimum recognizable difference in height on the 3D sonograms. The hepatic surface image was successfully visualized in 74% patients (23/31). Success depended on the amount of ascites; visualization was 100% with ascites of 10 mm or more between the hepatic surface and abdominal wall. The images showed irregularity of the hepatic surface in all cirrhotic patients. The surface appearance was confirmed as being very similar in 3 patients who had both 3D sonogram and liver resection for transplantation. The ability to distinguish cirrhotic liver from non-cirrhotic liver improved with the use of combination of 2D- and 3D-imaging versus 2D-imaging alone (sensitivity, p = 0.02; accuracy, p = 0.02) or 3D-imaging alone (sensitivity, p = 0.03). Intra-/inter-operator and inter-reviewer agreement were excellent (κ = 1.0). Conclusion: 3D-based sonographic visualization of the hepatic surface showed high reliability and reproducibility, acting as a virtual laparoscopy method, and the technique has the potential to improve the diagnosis of cirrhosis

  17. Surface Replication of Molded Products with Microneedle Features in Injection Molding

    Science.gov (United States)

    Uchiumi, Kazuyasu; Takayama, Tetsuo; Ito, Hiroshi; Inou, Akinori

    Micro-molding of microneedle features was conducted using several injection-molding techniques. Injection compression molding and injection molding were performed with supercritical carbon dioxide fluid and with or without vacuum processing inside the mold cavity. Effects of process parameters on processability and surface replication of the molded parts were evaluated. The height replication ratio for microneedles was improved using injection compression molding. At a shorter compression stroke, the needle height was improved, and the influence of compression delay time was also small. Moreover, the effects of vacuum processing inside the mold cavity under the filling process were slight. The height replication ratio for microneedles showed the highest values using injection molding using supercritical carbon dioxide fluid with vacuum inside the mold cavity.

  18. Proposal for an intense slow positron beam facility at PSI

    International Nuclear Information System (INIS)

    Waeber, W.B.; Taqqu, D.; Zimmermann, U.; Solt, G.

    1990-05-01

    In the domain of condensed matter physics and materials sciences monoenergetic slow positrons in the form of highest intensity beams are demonstrated to be extreamly useful and considered to be highly needed. This conclusion has been reached and the scientific relevance of the positron probe has been highlighted at an international workshop in November 1989 at PSI, where the state of the art and the international situation on slow positron beams, the fields of application of intense beams and the technical possibilities at PSI for installing intense positron sources have been evaluated. The participants agreed that a high intensity beam as a large-scale user facility at PSI would serve fundamental and applied research. The analysis of responses given by numerous members of a widespread positron community has revealed a large research potential in the domain of solid-state physics, atomic physics and surface, thin-film and defect physics, for example. The excellent feature of slow positron beams to be a suitable probe also for lattice defects near surfaces or interfaces has attracted the interest not only of science but also of industry.In this report we propose the installation of an intense slow positron beam facility at PSI including various beam lines of different qualities and based on the Cyclotron production of β + emitting source material and on a highest efficiency moderation scheme which exceeds standard moderation efficiencies by two orders of magnitude. In its proposed form, the project is estimated to be realizable in the nineties and costs will amount to between 15 and 20 MSFr. (author) 10 figs., 6 tabs., 78 refs

  19. Meteorological data for four sites at surface-disruption features in Yucca Flat, Nevada Test Site, Nye County, Nevada, 1985--1986

    International Nuclear Information System (INIS)

    Carman, R.L.

    1994-01-01

    Surface-disruption features, or craters, resulting from underground nuclear testing at the Nevada Test Site may increase the potential for ground-water recharge in an area that would normally produce little, if any, recharge. This report presents selected meteorological data resulting from a study of two surface-disruption features during May 1985 through June 1986. The data were collected at four adjacent sites in Yucca Flat, about 56 kilometers north of Mercury, Nevada. Three sites (one in each of two craters and one at an undisturbed site at the original land surface) were instrumented to collect meteorological data for calculating bare-soil evaporation. These data include (1) long-wave radiation, (2) short-wave radiation, (3) net radiation, (4) air temperature, and (5) soil surface temperature. Meteorological data also were collected at a weather station at an undisturbed site near the study craters. Data collected at this site include (1) air temperature, (2) relative humidity, (3) wind velocity, and (4) wind direction

  20. FEATURES OF A LABOUR MARKET ANALYSIS IN KNOWLEDGE-INTENSIVE INDUSTRIES

    Directory of Open Access Journals (Sweden)

    Mohamed Al Hassan

    2013-01-01

    Full Text Available Peculiarities of a formation of demand for labour and labour supply in the science-intensive economy are presented in the article. Problems of a labour mobility of Persian Gulf countries are investigated.

  1. Crystal structure and nanotopographical features on the surface of heat-treated and anodized porous titanium biomaterials produced using selective laser melting

    Energy Technology Data Exchange (ETDEWEB)

    Amin Yavari, S., E-mail: s.aminyavari@tudelft.nl [Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands); FT Innovations BV, Braamsluiper 1, 5831 PW Boxmeer (Netherlands); Wauthle, R. [KU Leuven, Department of Mechanical Engineering, Section Production Engineering, Machine Design and Automation (PMA), Celestijnenlaan 300B, 3001 Leuven (Belgium); LayerWise NV, Kapeldreef 60, Leuven (Belgium); Böttger, A.J. [Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands); Schrooten, J. [Department of Metallurgy and Materials Engineering, KU Leuven, Kasteelpark Arenberg 44 PB 2450, 3001 Heverlee (Belgium); Weinans, H. [Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands); Department of Orthopedics and Department of Rheumatology, UMC Utrecht, Heidelberglaan 100, 3584 CX Utrecht (Netherlands); Zadpoor, A.A. [Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands)

    2014-01-30

    Porous titanium biomaterials manufactured using additive manufacturing techniques such as selective laser melting are considered promising materials for orthopedic applications where the biomaterial needs to mimic the properties of bone. Despite their appropriate mechanical properties and the ample pore space they provide for bone ingrowth and osseointegration, porous titanium structures have an intrinsically bioinert surface and need to be subjected to surface bio-functionalizing procedures to enhance their in vivo performance. In this study, we used a specific anodizing process to build a hierarchical oxide layer on the surface of porous titanium structures made by selective laser melting of Ti6Al4V ELI powder. The hierarchical structure included both nanotopographical features (nanotubes) and micro-features (micropits). After anodizing, the biomaterial was heat treated in Argon at different temperatures ranging between 400 and 600 °C for either 1 or 2 h to improve its bioactivity. The effects of applied heat treatment on the crystal structure of TiO{sub 2} nanotubes and the nanotopographical features of the surface were studied using scanning electron microscopy and X-ray diffraction. It was shown that the transition from the initial crystal structure, i.e. anatase, to rutile occurs between 500 and 600 °C and that after 2 h of heat treatment at 600 °C the crystal structure is predominantly rutile. The nanotopographical features of the surface were found to be largely unchanged for heat treatments carried out at 500 °C or below, whereas they were partially or largely disrupted after heat treatment at 600 °C. The possible implications of these findings for the bioactivity of porous titanium structures are discussed.

  2. Replication of micro and nano-features on iPP by injection molding with fast cavity surface temperature evolution

    DEFF Research Database (Denmark)

    Speranzaa, Vito; Liparotia, Sara; Calaon, Matteo

    2017-01-01

    The production of polymeric components with functional structures in the micrometer and sub-micrometer range is a complex challenge for the injection molding process, since it suffers the use of low cavity surface temperatures that induce the fast formation of a frozen layer, thus preventing...... was sufficient to obtain accurate replication, with adequate surface temperatures. In the case of nano-features, the replication accuracy was affected by the morphology developed on the molding surface, that is aligned along the flow direction with dimensions comparable with the dimension of the nano...

  3. Surface emission of InxGa1-xN epilayers under strong optical excitation

    International Nuclear Information System (INIS)

    Jiang, H.X.; Lin, J.Y.; Khan, M.A.; Chen, Q.; Yang, J.W.

    1997-01-01

    Effects of strong optical excitation on the properties of surface emission from an InGaN/GaN heterostructure grown by metal-organic chemical-vapor deposition have been investigated. An intriguing feature observed was that as the excitation intensity increased the surface emission spectrum evolved abruptly from a single dominating band to two dominating bands at a critical intensity. This phenomenon has a sharp phase transition or a switching character and can be accounted for by (i) the formation of an electron endash hole plasma state in the InGaN vertical cavity under strong optical excitation, (ii) the photoreflectance effect (variation of index of refraction with excitation intensity), and (c) the Fabry endash Pacute erot interference effect in the InGaN vertical cavity. These findings are expected to have impact on the design of the laser structures, in particular on the design of the vertical-cavity surface-emitting laser diodes based on III-nitride wide-band-gap semiconductors. copyright 1997 American Institute of Physics

  4. Comprehensive surface treatment of high-speed steel tool

    Science.gov (United States)

    Fedorov, Sergey V.; Aleshin, Sergey V.; Swe, Min Htet; Abdirova, Raushan D.; Kapitanov, Alexey V.; Egorov, Sergey B.

    2018-03-01

    One of the promising directions of hardening of high-speed steel tool is the creation on their surface of the layered structures with the gradient of physic-chemical properties between the wear-resistant coatings to the base material. Among the methods of such surface modification, a special process takes place based on the use of pulsed high-intensity charged particle beams. The high speed of heating and cooling allows structural-phase transformations in the surface layer, which cannot be realized in a stationary mode. The treatment was conducted in a RITM-SP unit, which constitutes a combination of a source of low-energy high-current electron beams "RITM" and two magnetron spraying systems on a single vacuum chamber. The unit enables deposition of films on the surface of the desired product and subsequent liquid-phase mixing of materials of the film and the substrate by an intense pulse electron beam. The article discusses features of the structure of the subsurface layer of high-speed steel M2, modified by surface alloying of a low-energy high-current electron beam, and its effect on the wear resistance of the tool when dry cutting hard to machine Nickel alloy. A significant decrease of intensity of wear of high-speed steel with combined treatment happens due to the displacement of the zone of wear and decrease the radius of rounding of the cutting edge because of changes in conditions of interaction with the material being treated.

  5. Success/Failure Prediction of Noninvasive Mechanical Ventilation in Intensive Care Units. Using Multiclassifiers and Feature Selection Methods.

    Science.gov (United States)

    Martín-González, Félix; González-Robledo, Javier; Sánchez-Hernández, Fernando; Moreno-García, María N

    2016-05-17

    This paper addresses the problem of decision-making in relation to the administration of noninvasive mechanical ventilation (NIMV) in intensive care units. Data mining methods were employed to find out the factors influencing the success/failure of NIMV and to predict its results in future patients. These artificial intelligence-based methods have not been applied in this field in spite of the good results obtained in other medical areas. Feature selection methods provided the most influential variables in the success/failure of NIMV, such as NIMV hours, PaCO2 at the start, PaO2 / FiO2 ratio at the start, hematocrit at the start or PaO2 / FiO2 ratio after two hours. These methods were also used in the preprocessing step with the aim of improving the results of the classifiers. The algorithms provided the best results when the dataset used as input was the one containing the attributes selected with the CFS method. Data mining methods can be successfully applied to determine the most influential factors in the success/failure of NIMV and also to predict NIMV results in future patients. The results provided by classifiers can be improved by preprocessing the data with feature selection techniques.

  6. Off-Center Rotation of CuPc Molecular Rotor on a Bi(111) Surface and the Chiral Feature.

    Science.gov (United States)

    Sun, Kai; Tao, Min-Long; Tu, Yu-Bing; Wang, Jun-Zhong

    2017-05-04

    Molecular rotors with an off-center axis and the chiral feature of achiral CuPc molecules on a semi-metallic Bi(111) surface have been investigated by means of a scanning tunneling microscopy (STM) at liquid nitrogen (LN₂) temperature. The rotation axis of each CuPc molecular rotor is located at the end of a phthalocyanine group. As molecular coverage increases, the CuPc molecules are self-assembled into various nanoclusters and finally into two-dimensional (2D) domains, in which each CuPc molecule exhibits an apparent chiral feature. Such chiral features of the CuPc molecules can be attributed to the combined effect of asymmetric charge transfer between the CuPc and Bi(111) substrate, and the intermolecular van der Waals interactions.

  7. Examining the Impact of Question Surface Features on Students’ Answers to Constructed-Response Questions on Photosynthesis

    Science.gov (United States)

    Weston, Michele; Haudek, Kevin C.; Prevost, Luanna; Urban-Lurain, Mark; Merrill, John

    2015-01-01

    One challenge in science education assessment is that students often focus on surface features of questions rather than the underlying scientific principles. We investigated how student written responses to constructed-response questions about photosynthesis vary based on two surface features of the question: the species of plant and the order of two question prompts. We asked four versions of the question with different combinations of the two plant species and order of prompts in an introductory cell biology course. We found that there was not a significant difference in the content of student responses to versions of the question stem with different species or order of prompts, using both computerized lexical analysis and expert scoring. We conducted 20 face-to-face interviews with students to further probe the effects of question wording on student responses. During the interviews, we found that students thought that the plant species was neither relevant nor confusing when answering the question. Students identified the prompts as both relevant and confusing. However, this confusion was not specific to a single version. PMID:25999312

  8. Surface excitation parameter for rough surfaces

    International Nuclear Information System (INIS)

    Da, Bo; Salma, Khanam; Ji, Hui; Mao, Shifeng; Zhang, Guanghui; Wang, Xiaoping; Ding, Zejun

    2015-01-01

    Graphical abstract: - Highlights: • Instead of providing a general mathematical model of roughness, we directly use a finite element triangle mesh method to build a fully 3D rough surface from the practical sample. • The surface plasmon excitation can be introduced to the realistic sample surface by dielectric response theory and finite element method. • We found that SEP calculated based on ideal plane surface model are still reliable for real sample surface with common roughness. - Abstract: In order to assess quantitatively the importance of surface excitation effect in surface electron spectroscopy measurement, surface excitation parameter (SEP) has been introduced to describe the surface excitation probability as an average number of surface excitations that electrons can undergo when they move through solid surface either in incoming or outgoing directions. Meanwhile, surface roughness is an inevitable issue in experiments particularly when the sample surface is cleaned with ion beam bombardment. Surface roughness alters not only the electron elastic peak intensity but also the surface excitation intensity. However, almost all of the popular theoretical models for determining SEP are based on ideal plane surface approximation. In order to figure out whether this approximation is efficient or not for SEP calculation and the scope of this assumption, we proposed a new way to determine the SEP for a rough surface by a Monte Carlo simulation of electron scattering process near to a realistic rough surface, which is modeled by a finite element analysis method according to AFM image. The elastic peak intensity is calculated for different electron incident and emission angles. Assuming surface excitations obey the Poisson distribution the SEPs corrected for surface roughness are then obtained by analyzing the elastic peak intensity for several materials and for different incident and emission angles. It is found that the surface roughness only plays an

  9. Face recognition based on depth maps and surface curvature

    Science.gov (United States)

    Gordon, Gaile G.

    1991-09-01

    This paper explores the representation of the human face by features based on the curvature of the face surface. Curature captures many features necessary to accurately describe the face, such as the shape of the forehead, jawline, and cheeks, which are not easily detected from standard intensity images. Moreover, the value of curvature at a point on the surface is also viewpoint invariant. Until recently range data of high enough resolution and accuracy to perform useful curvature calculations on the scale of the human face had been unavailable. Although several researchers have worked on the problem of interpreting range data from curved (although usually highly geometrically structured) surfaces, the main approaches have centered on segmentation by signs of mean and Gaussian curvature which have not proved sufficient in themselves for the case of the human face. This paper details the calculation of principal curvature for a particular data set, the calculation of general surface descriptors based on curvature, and the calculation of face specific descriptors based both on curvature features and a priori knowledge about the structure of the face. These face specific descriptors can be incorporated into many different recognition strategies. A system that implements one such strategy, depth template comparison, giving recognition rates between 80% and 90% is described.

  10. Calculation of the geometrical intensity on an image surface

    International Nuclear Information System (INIS)

    Seppala, L.G.

    1975-01-01

    Laser fusion experiments involve the focusing of high power laser beams onto fuel pellets. The geometrical intensity is of interest in the cases where the laser is focused to the center of the pellet. Analytic expressions and ray trace methods for evaluating the geometrical intensity are presented

  11. Alveolar bone-loss area localization in periodontitis radiographs based on threshold segmentation with a hybrid feature fused of intensity and the H-value of fractional Brownian motion model.

    Science.gov (United States)

    Lin, P L; Huang, P W; Huang, P Y; Hsu, H C

    2015-10-01

    Periodontitis involves progressive loss of alveolar bone around the teeth. Hence, automatic alveolar bone-loss (ABL) measurement in periapical radiographs can assist dentists in diagnosing such disease. In this paper, we propose an effective method for ABL area localization and denote it as ABLIfBm. ABLIfBm is a threshold segmentation method that uses a hybrid feature fused of both intensity and texture measured by the H-value of fractional Brownian motion (fBm) model, where the H-value is the Hurst coefficient in the expectation function of a fBm curve (intensity change) and is directly related to the value of fractal dimension. Adopting leave-one-out cross validation training and testing mechanism, ABLIfBm trains weights for both features using Bayesian classifier and transforms the radiograph image into a feature image obtained from a weighted average of both features. Finally, by Otsu's thresholding, it segments the feature image into normal and bone-loss regions. Experimental results on 31 periodontitis radiograph images in terms of mean true positive fraction and false positive fraction are about 92.5% and 14.0%, respectively, where the ground truth is provided by a dentist. The results also demonstrate that ABLIfBm outperforms (a) the threshold segmentation method using either feature alone or a weighted average of the same two features but with weights trained differently; (b) a level set segmentation method presented earlier in literature; and (c) segmentation methods based on Bayesian, K-NN, or SVM classifier using the same two features. Our results suggest that the proposed method can effectively localize alveolar bone-loss areas in periodontitis radiograph images and hence would be useful for dentists in evaluating degree of bone-loss for periodontitis patients. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. In vitro bioactivity of micro metal injection moulded stainless steel with defined surface features

    Directory of Open Access Journals (Sweden)

    C Brose

    2012-05-01

    Full Text Available Micrometre- and nanometre-scale surface structuring with ordered topography features may dramatically enhance orthopaedic implant integration. In this study we utilised a previously optimised micron metal injection moulding (µ-MIM process to produce medical grade stainless steel surfaces bearing micrometre scale, protruding, hemispheres of controlled dimensions and spatial distribution. Additionally, the structured surfaces were characterised by the presence of submicrometre surface roughness resulting from metal grain boundary formation. Following cytocompatibility (cytotoxicity evaluation using 3T3 mouse fibroblast cell line, the effect on primary human cell functionality was assessed focusing on cell attachment, shape and cytoskeleton conformation. In this respect, and by day 7 in culture, significant increase in focal adhesion size was associated with the microstructured surfaces compared to the planar control. The morphological conformation of the seeded cells, as revealed by fluorescence cytoskeleton labelling, also appeared to be guided in the vertical dimension between the hemisphere bodies. Quantitative evaluation of this guidance took place using live cytoplasm fluorescence labelling and image morphometry analysis utilising both, compactness and elongation shape descriptors. Significant increase in cell compactness was associated with the hemisphere arrays indicating collective increase in focused cell attachment to the hemisphere bodies across the entire cell population. Micrometre-scale hemisphere array patterns have therefore influenced cell attachment and conformation. Such influence may potentially aid in enhancing key cellular events such as, for example, neo-osteogenesis on implanted orthopaedic surfaces.

  13. He atom scattering from ZnO surfaces: calculation of diffraction peak intensities using the close-coupling approach

    Energy Technology Data Exchange (ETDEWEB)

    MartInez-Casado, R [Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ (United Kingdom); Miret-Artes, S [Instituto de Fisica Fundamental, Consejo Superior de Investigaciones CientIficas, Serrano 123, 28006 Madrid (Spain); Meyer, B [Interdisziplinaeres Zentrum fuer Molekulare Materialien ICMM and Computer-Chemie-Centrum CCC, Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Naegelsbachstrasse 25, 91052 Erlangen (Germany); Traeger, F [Lehrstuhl fuer Physikalische Chemie I, Ruhr-Universitaet Bochum, 44801 Bochum (Germany); Woell, Ch, E-mail: r.martinezcasado@imperial.ac.u [Institut fuer Funktionelle Grenzflaechen, Karlsruher Institut fuer Technologie KIT, Kaiserstrasse 12, 76131 Karlsruhe (Germany)

    2010-08-04

    Diffraction intensities of a molecular He beam scattered off the clean and water-covered ZnO(101-bar0) surface have been simulated using a new potential model in conjunction with the close-coupling formalism. The effective corrugation functions for the systems He-ZnO(101-bar0) and He-H{sub 2}O/ZnO(101-bar0) have been obtained from density functional theory calculations within the Esbjerg-Noerskov approximation. Using these data a potential model is constructed consisting of a corrugated Morse potential at small He-surface distances and a semiempiric attractive part at larger distances. The diffraction patterns obtained from close-coupling calculations agree with the experimental data within about 10%, which opens the possibility to simulate He diffraction from surfaces of any structural complexity and to verify surface and adsorbate structures proposed theoretically by employing this kind of analysis.

  14. Validated measurements of microbial loads on environmental surfaces in intensive care units before and after disinfecting cleaning.

    Science.gov (United States)

    Frickmann, H; Bachert, S; Warnke, P; Podbielski, A

    2018-03-01

    Preanalytic aspects can make results of hygiene studies difficult to compare. Efficacy of surface disinfection was assessed with an evaluated swabbing procedure. A validated microbial screening of surfaces was performed in the patients' environment and from hands of healthcare workers on two intensive care units (ICUs) prior to and after a standardized disinfection procedure. From a pure culture, the recovery rate of the swabs for Staphylococcus aureus was 35%-64% and dropped to 0%-22% from a mixed culture with 10-times more Staphylococcus epidermidis than S. aureus. Microbial surface loads 30 min before and after the cleaning procedures were indistinguishable. The quality-ensured screening procedure proved that adequate hygiene procedures are associated with a low overall colonization of surfaces and skin of healthcare workers. Unchanged microbial loads before and after surface disinfection demonstrated the low additional impact of this procedure in the endemic situation when the pathogen load prior to surface disinfection is already low. Based on a validated screening system ensuring the interpretability and reliability of the results, the study confirms the efficiency of combined hand and surface hygiene procedures to guarantee low rates of bacterial colonization. © 2017 The Society for Applied Microbiology.

  15. The dispersion surface of X-rays very near the absorption edge

    International Nuclear Information System (INIS)

    Fukamachi, T.; Negishi, R.; Kawamura, T.

    1995-01-01

    To discuss the X-ray dynamical diffraction when the imaginary part of the X-ray polarizability is larger than the real part, the dispersion surface is studied as a function of the ratio between the real and the imaginary parts of the polarizability. The dispersion surface in the Laue case when the real part is zero has a similar form to that in the Bragg case when the imaginary part is zero. The relations between the dispersion surface and the diffracted intensity are studied in some special cases. The abnormal absorption and the abnormal transmission effect are related to the features of the dispersion surface. (orig.)

  16. Trends in Northern Hemisphere surface cyclone frequency and intensity

    Science.gov (United States)

    McCabe, G.J.; Clark, M.P.; Serreze, Mark C.

    2001-01-01

    One of the hypothesized effects of global warming from increasing concentrations of greenhouse gases is a change in the frequency and/or intensity of extratropical cyclones. In this study, winter frequencies and intensities of extratropical cyclones in the Northern Hemisphere for the period 1959-97 are examined to determine if identifiable trends are occurring. Results indicate a statistically significant decrease in midlatitude cyclone frequency and a significant increase in high-latitude cyclone frequency. In addition, storm intensity has increased in both the high and midlatitudes. The changes in storm frequency correlate with changes in winter Northern Hemisphere temperature and support hypotheses that global warming may result in a northward shift of storm tracks in the Northern Hemisphere.

  17. Modification of the large-scale features of high Reynolds number wall turbulence by passive surface obtrusions

    Energy Technology Data Exchange (ETDEWEB)

    Monty, J.P.; Lien, K.; Chong, M.S. [University of Melbourne, Department of Mechanical Engineering, Parkville, VIC (Australia); Allen, J.J. [New Mexico State University, Department of Mechanical Engineering, Las Cruces, NM (United States)

    2011-12-15

    A high Reynolds number boundary-layer wind-tunnel facility at New Mexico State University was fitted with a regularly distributed braille surface. The surface was such that braille dots were closely packed in the streamwise direction and sparsely spaced in the spanwise direction. This novel surface had an unexpected influence on the flow: the energy of the very large-scale features of wall turbulence (approximately six-times the boundary-layer thickness in length) became significantly attenuated, even into the logarithmic region. To the author's knowledge, this is the first experimental study to report a modification of 'superstructures' in a rough-wall turbulent boundary layer. The result gives rise to the possibility that flow control through very small, passive surface roughness may be possible at high Reynolds numbers, without the prohibitive drag penalty anticipated heretofore. Evidence was also found for the uninhibited existence of the near-wall cycle, well known to smooth-wall-turbulence researchers, in the spanwise space between roughness elements. (orig.)

  18. Fast and efficient search for MPEG-4 video using adjacent pixel intensity difference quantization histogram feature

    Science.gov (United States)

    Lee, Feifei; Kotani, Koji; Chen, Qiu; Ohmi, Tadahiro

    2010-02-01

    In this paper, a fast search algorithm for MPEG-4 video clips from video database is proposed. An adjacent pixel intensity difference quantization (APIDQ) histogram is utilized as the feature vector of VOP (video object plane), which had been reliably applied to human face recognition previously. Instead of fully decompressed video sequence, partially decoded data, namely DC sequence of the video object are extracted from the video sequence. Combined with active search, a temporal pruning algorithm, fast and robust video search can be realized. The proposed search algorithm has been evaluated by total 15 hours of video contained of TV programs such as drama, talk, news, etc. to search for given 200 MPEG-4 video clips which each length is 15 seconds. Experimental results show the proposed algorithm can detect the similar video clip in merely 80ms, and Equal Error Rate (ERR) of 2 % in drama and news categories are achieved, which are more accurately and robust than conventional fast video search algorithm.

  19. Sting jets in intense winter North-Atlantic windstorms

    International Nuclear Information System (INIS)

    Martínez-Alvarado, Oscar; Gray, Suzanne L; Clark, Peter A; Catto, Jennifer L

    2012-01-01

    Extratropical cyclones dominate autumn and winter weather over western Europe. The strongest cyclones, often termed windstorms, have a large socio-economic impact due to the strong surface winds and associated storm surges in coastal areas. Here we show that sting jets are a common feature of windstorms; up to a third of the 100 most intense North-Atlantic winter windstorms over the last two decades satisfy conditions for sting jets. The sting jet is a mesoscale descending airstream that can cause strong near-surface winds in the dry slot of the cyclone, a region not usually associated with strong winds. Despite their localized transient nature, these sting jets can cause significant damage, a prominent example being the storm that devastated southeast England on 16 October 1987. We present the first regional climatology of windstorms with sting jets. Previously analysed sting-jet cases appear to have been exceptional in their track over northwest Europe rather than in their strength. (letter)

  20. Differences in staining intensities affect reported occurrences and concentrations of Giardia spp. in surface drinking water sources.

    Science.gov (United States)

    Alderisio, K A; Villegas, L F; Ware, M W; McDonald, L A; Xiao, L; Villegas, E N

    2017-12-01

    USEPA Method 1623, or its equivalent, is currently used to monitor for protozoan contamination of surface drinking water sources worldwide. At least three approved staining kits used for detecting Cryptosporidium and Giardia are commercially available. This study focuses on understanding the differences among staining kits used for Method 1623. Merifluor and EasyStain labelling kits were used to monitor Cryptosporidium oocyst and Giardia cyst densities in New York City's raw surface water sources. In the year following a change to the approved staining kits for use with Method 1623, an anomaly was noted in the occurrence of Giardia cysts in New York City's raw surface water. Specifically, Merifluor-stained samples had higher Giardia cyst densities as compared with those stained with EasyStain. Side by side comparison revealed significantly lower fluorescence intensities of Giardia muris as compared with Giardia duodenalis cysts when labelled with EasyStain. This study showed very poor fluorescence intensity signals by EasyStain on G. muris cysts resulting in lower cyst counts, while Merifluor, with its broader Giardia cyst staining specificity, resulted in higher cyst counts, when using Methods 1623. These results suggest that detected Giardia cyst concentrations are dependent on the staining kits used, which can result in a more or less conservative estimation of occurrences and densities of zoonotic Giardia cysts by detecting a broader range of Giardia species/Assemblages. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  1. Hot-electron surface retention in intense short-pulse laser-matter interactions.

    Science.gov (United States)

    Mason, R J; Dodd, E S; Albright, B J

    2005-07-01

    Implicit hybrid plasma simulations predict that a significant fraction of the energy deposited into hot electrons can be retained near the surface of targets with steep density gradients illuminated by intense short-pulse lasers. This retention derives from the lateral transport of heated electrons randomly emitted in the presence of spontaneous magnetic fields arising near the laser spot, from geometric effects associated with a small hot-electron source, and from E fields arising in reaction to the ponderomotive force. Below the laser spot hot electrons are axially focused into a target by the B fields, and can filament in moderate Z targets by resistive Weibel-like instability, if the effective background electron temperature remains sufficiently low. Carefully engineered use of such retention in conjunction with ponderomotive density profile steepening could result in a reduced hot-electron range that aids fast ignition. Alternatively, such retention may disturb a deeper deposition needed for efficient radiography and backside fast ion generation.

  2. Dynamical calculations for RHEED intensity oscillations

    Science.gov (United States)

    Daniluk, Andrzej

    2005-03-01

    quantitative analysis of RHEED experimental data. Method of solution: RHEED intensities are calculated within the framework of the general matrix formulation of Peng and Whelan [Surf. Sci. Lett. 238 (1990) L446] under the one-beam condition. The dynamical diffraction calculations presented in this paper utilize the systematic reflection case in RHEED, in which the atomic potential in the planes parallel to the surface are projected on the surface normal, so that the results are insensitive to the atomic arrangement in the layers parallel to the surface. This model shows a systematic approximation in calculating dynamical RHEED intensities, and only a layer coverage factor for the nth layer was taken into account in calculating the interaction potential between the fast electron and that layer. Typical running time: The typical running time is machine and user-parameters dependent. Unusual features of the program: The program is presented in the form of a basic unit RHEED.cpp and should be compiled using C++ compilers, including C++ Builder and g++.

  3. Light intensity fluctuations on a layered microsphere irradiated by a monochromatic light wave: Modeling of an inhomogeneous cellular surface with numerical elements

    International Nuclear Information System (INIS)

    Choi, Moon Kyu

    2007-01-01

    The inhomogeneity of crystalline or amorphous unit cells of material is treated by the numerical boundary element method. This paper is especially about the effect of perturbed refractive index (or potential energy) of a material on the light intensity inside a layered microsphere when it is irradiated by monochromatic unpolarized plane light wave. The resultant light intensities on the particle surface show noise-like fluctuations depending on various parameters such as the material refractive indices, the light wavelength, the particle and core size, the numerical surface element size, etc. Both the numerical results and the experiments from a few other groups agree that large light absorption occurs just in a small wavelength range

  4. Efficient energy absorption of intense ps-laser pulse into nanowire target

    Energy Technology Data Exchange (ETDEWEB)

    Habara, H.; Honda, S.; Katayama, M.; Tanaka, K. A. [Graduate School of Engineering, Osaka University, 2-1 Suita, Osaka 565-0871 (Japan); Sakagami, H. [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Nagai, K. [Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Nagatsuda 4259, Midori-ku, Yokohama 226-8503, Kanagawa (Japan)

    2016-06-15

    The interaction between ultra-intense laser light and vertically aligned carbon nanotubes is investigated to demonstrate efficient laser-energy absorption in the ps laser-pulse regime. Results indicate a clear enhancement of the energy conversion from laser to energetic electrons and a simultaneously small plasma expansion on the surface of the target. A two-dimensional plasma particle calculation exhibits a high absorption through laser propagation deep into the nanotube array, even for a dense array whose structure is much smaller than the laser wavelength. The propagation leads to the radial expansion of plasma perpendicular to the nanotubes rather than to the front side. These features may contribute to fast ignition in inertial confinement fusion and laser particle acceleration, both of which require high current and small surface plasma simultaneously.

  5. Analysis of the Effect of Cooling Intensity Under Volume-Surface Hardening on Formation of Hardened Structures in Steel 20GL

    Science.gov (United States)

    Evseev, D. G.; Savrukhin, A. V.; Neklyudov, A. N.

    2018-01-01

    Computer simulation of the kinetics of thermal processes and structural and phase transformations in the wall of a bogie side frame produced from steel 20GL is performed with allowance for the differences in the cooling intensity under volume-surface hardening. The simulation is based on the developed method employing the diagram of decomposition of austenite at different cooling rates. The data obtained are used to make conclusion on the effect of the cooling intensity on propagation of martensite structure over the wall section.

  6. Inhibition of enteric pathogens and surrogates using integrated, high intensity 405nm led light on the surface of almonds

    Science.gov (United States)

    The disinfecting properties of 405 nm light were investigated against Escherichia coli O157:H7, Salmonella, and their non-pathogenic surrogate bacteria on the surface of almonds. High intensity monochromatic blue light (MBL) was generated from an array of narrow-band 405 nm light-emitting diodes (LE...

  7. Features of destruction of solids by laser radiation in process of formation of multiply charged ions

    International Nuclear Information System (INIS)

    Bedilov, R.M.; Bedilov, M.R.; Sabitov, M.M.; Matnazarov, A.; Niyozov, B.

    2004-01-01

    Full text: It is known, under interaction of laser radiation with solid surface a power density q > 0.01 W/cm 2 are observed destruction of a solid and issue of electrons, ions, neutrals, neutrons, plasmas, and also radiation in a wide ranges of a spectra. Despite of a plenty of works, devoted to study of processes of interaction, the studies of feature of destruction of solids by laser beam in process of formation multiply charged ions are insufficiently investigated. The results of study feature of destruction of solids by laser radiation in process of formation multiply charged ions are given in this work. In our experiments, we used the mass spectrometer with single-channel laser radiation. The laser installation had the following parameters: a power density of laser radiation q=(0.1-50) GW/cm 2 ; the angle of incidence a=18 deg. to the target surface Al, (W). It was obtained experimentally dynamics of morphology of destruction and also mass - charge and energy spectra of multiply charged ions formed under interaction of laser radiation with Al (W) in the intensity range q=(0.1-50) GW/cm 2 . These studies showed features of destruction Al(W) by laser radiation, i.e. invariable of value evaporation mass from a surface of a solid increase as the laser intensity q. But thus temperature a pair increases in accordance with increase of flow density of a laser radiation. Increase of temperature the pair gives in formation of multiply charged plasma. It is typical that, as q of the laser increases the maximum charge number of ions in laser plasma considerably increase and their energy spectra extend toward higher energies. For example, under q=0.1 GW/cm 2 and 50 GW/cm 2 the maximum charge number of ions Al (W) are equal to Z max = 1 and 7, respectively. From the experimental data obtained, we can conclude that, the formed multiply charged plasma practically completely absorption laser radiation and 'shielding' a target surface for various metals at power densities

  8. Adsorption of atomic oxygen on PdAg/Pd(111) surface alloys and coadsorption of CO

    Energy Technology Data Exchange (ETDEWEB)

    Farkas, Arnold P. [Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm (Germany); Reaction Kinetics Research Group, University of Szeged, Chemical Research Center of the Hungarian Academy of Sciences, H-6720 Szeged (Hungary); Bansmann, Joachim; Diemant, Thomas; Behm, R. Juergen [Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm (Germany)

    2011-07-01

    The interaction of dissociated oxygen with structurally well-defined PdAg/Pd(111) surface alloys and the coadsorption of CO was studied by high resolution electron energy loss spectroscopy (HREELS) and temperature-programmed desorption (TPD). After oxygen saturation of the non-modified Pd(111) surface at RT, we observed the formation of a prominent peak in the HREEL spectra at 60 meV corresponding to the perpendicular vibration of oxygen atoms adsorbed in threefold hollow sites. Deposition of small Ag amounts does not change the signal intensity of this peak; it decreases only above 20% Ag. Beyond this Ag content, the peak intensity steeply declines and disappears at around 55-60% Ag. CO coadsorption on the oxygen pre-covered surfaces at 120 K leads to the formation of additional features in HREELS. For a surface alloy with 29% Ag, three loss features due to CO adsorption in on-top, bridge, and threefold-hollow sites can be discriminated already after the lowest CO exposure. Annealing of the co-adsorbed layer to 200 K triggers a decrease of the oxygen concentration due to CO{sub 2} formation. These findings are corroborated by TPD spectra of the CO desorption and CO{sub 2} production.

  9. Generalized method for computation of true thickness and x-ray intensity information in highly blurred sub-millimeter bone features in clinical CT images.

    Science.gov (United States)

    Pakdel, Amirreza; Robert, Normand; Fialkov, Jeffrey; Maloul, Asmaa; Whyne, Cari

    2012-12-07

    In clinical computed tomography (CT) images, cortical bone features with sub-millimeter (sub-mm) thickness are substantially blurred, such that their thickness is overestimated and their intensity appears underestimated. Therefore, any inquiry of the geometry or the density of such bones based on these images is severely error prone. We present a model-based method for estimating the true thickness and intensity magnitude of cortical and trabecular bone layers at localized regions of complex shell bones down to 0.25 mm. The method also computes the width of the corresponding point spread function. This approach is applicable on any CT image data, and does not rely on any scanner-specific parameter inputs beyond what is inherently available in the images themselves. The method applied on CT intensity profiles of custom phantoms mimicking shell-bones produced average cortical thickness errors of 0.07 ± 0.04 mm versus an average error of 0.47 ± 0.29 mm in the untreated cases (t(55) = 10.92, p ≪ 0.001)). Similarly, the average error of intensity magnitude estimates of the method were 22 ± 2.2 HU versus an error of 445 ± 137 HU in the untreated cases (t(55) = 26.48, p ≪ 0.001)). The method was also used to correct the CT intensity profiles from a cadaveric specimen of the craniofacial skeleton (CFS) in 15 different regions. There was excellent agreement between the corrections and µCT intensity profiles of the same regions used as a 'gold standard' measure. These results set the groundwork towards restoring cortical bone geometry and intensity information in entire image data sets. This information is essential for the generation of finite element models of the CFS that can accurately describe the biomechanical behavior of its complex thin bone structures.

  10. COMPUTER GRAPHICS MEETS IMAGE FUSION: THE POWER OF TEXTURE BAKING TO SIMULTANEOUSLY VISUALISE 3D SURFACE FEATURES AND COLOUR

    Directory of Open Access Journals (Sweden)

    G. J. Verhoeven

    2017-08-01

    Full Text Available Since a few years, structure-from-motion and multi-view stereo pipelines have become omnipresent in the cultural heritage domain. The fact that such Image-Based Modelling (IBM approaches are capable of providing a photo-realistic texture along the threedimensional (3D digital surface geometry is often considered a unique selling point, certainly for those cases that aim for a visually pleasing result. However, this texture can very often also obscure the underlying geometrical details of the surface, making it very hard to assess the morphological features of the digitised artefact or scene. Instead of constantly switching between the textured and untextured version of the 3D surface model, this paper presents a new method to generate a morphology-enhanced colour texture for the 3D polymesh. The presented approach tries to overcome this switching between objects visualisations by fusing the original colour texture data with a specific depiction of the surface normals. Whether applied to the original 3D surface model or a lowresolution derivative, this newly generated texture does not solely convey the colours in a proper way but also enhances the smalland large-scale spatial and morphological features that are hard or impossible to perceive in the original textured model. In addition, the technique is very useful for low-end 3D viewers, since no additional memory and computing capacity are needed to convey relief details properly. Apart from simple visualisation purposes, the textured 3D models are now also better suited for on-surface interpretative mapping and the generation of line drawings.

  11. Computer Graphics Meets Image Fusion: the Power of Texture Baking to Simultaneously Visualise 3d Surface Features and Colour

    Science.gov (United States)

    Verhoeven, G. J.

    2017-08-01

    Since a few years, structure-from-motion and multi-view stereo pipelines have become omnipresent in the cultural heritage domain. The fact that such Image-Based Modelling (IBM) approaches are capable of providing a photo-realistic texture along the threedimensional (3D) digital surface geometry is often considered a unique selling point, certainly for those cases that aim for a visually pleasing result. However, this texture can very often also obscure the underlying geometrical details of the surface, making it very hard to assess the morphological features of the digitised artefact or scene. Instead of constantly switching between the textured and untextured version of the 3D surface model, this paper presents a new method to generate a morphology-enhanced colour texture for the 3D polymesh. The presented approach tries to overcome this switching between objects visualisations by fusing the original colour texture data with a specific depiction of the surface normals. Whether applied to the original 3D surface model or a lowresolution derivative, this newly generated texture does not solely convey the colours in a proper way but also enhances the smalland large-scale spatial and morphological features that are hard or impossible to perceive in the original textured model. In addition, the technique is very useful for low-end 3D viewers, since no additional memory and computing capacity are needed to convey relief details properly. Apart from simple visualisation purposes, the textured 3D models are now also better suited for on-surface interpretative mapping and the generation of line drawings.

  12. Surface morphology, microstructure and properties of as-cast AZ31 magnesium alloy irradiated by high intensity pulsed ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Xuesong [State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150080 (China); The Fourth Hospital of Harbin Medical University, Harbin 150001 (China); Zhang, Gang [Sino-Russia Joint Lab for High Energy Beam, Shenyang Ligong University, Shenyang 110159 (China); Wang, Guotian [School of Automobile and Traffic Engineering, Heilongjiang Institute of Technology, Harbin 150050 (China); Zhu, Guoliang, E-mail: glzhu1983@hotmail.com [Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming, Shanghai Jiao Tong University, Dongchuan Road 800, 200240 Shanghai (China); Zhou, Wei, E-mail: wzhou@sjtu.edu.cn [Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming, Shanghai Jiao Tong University, Dongchuan Road 800, 200240 Shanghai (China); Wang, Jun; Sun, Baode [Shanghai Key Laboratory of Advanced High-temperature Materials and Precision Forming, Shanghai Jiao Tong University, Dongchuan Road 800, 200240 Shanghai (China); The State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Dongchuan Road 800, 200240 Shanghai (China)

    2014-08-30

    Highlights: • High intensity pulsed ion beam (HIPIB) irradiation were performed to improve the properties of as-cast AZ31 magnesium alloy. • After 10 shots HIPIB irradiation, the average microhardness was increased by 27.1% and wear rate was reduced by 38.5%. • After 10 shots HIPIB irradiation, the corrosion rate was reduced by 24.8%, and the corrosion rate was decreased from 23.15 g m{sup −2} h{sup −1} to 17.4 g m{sup −2} h{sup −1}. - Abstract: High intensity pulsed ion beam (HIPIB) irradiation was performed as surface modification to improve the properties of as-cast AZ31 magnesium (Mg) alloys. The surface morphology and microstructure of the irradiated Mg alloys were characterized and their microhardness, wear resistance and corrosion resistance before and after HIPIB irradiation were measured. The results show that the formation of crater on the surface was attributed to the particles impacted from the irradiated cathode material. HIPIB irradiation resulted in more vacancy defects on the surface of the material. Moreover, new dislocations were generated by the reaction between vacancies, and the dislocation configuration was also changed. These variations caused by the HIPIB are beneficial for improving the material properties. After 10 shots of irradiation, the average microhardness increased by 27.1% but the wear rate decreased by 38.5%. The corrosion rate was reduced by 24.8% according to the salt spray corrosion experiment.

  13. Cloud and surface textural features in polar regions

    Science.gov (United States)

    Welch, Ronald M.; Kuo, Kwo-Sen; Sengupta, Sailes K.

    1990-01-01

    The study examines the textural signatures of clouds, ice-covered mountains, solid and broken sea ice and floes, and open water. The textural features are computed from sum and difference histogram and gray-level difference vector statistics defined at various pixel displacement distances derived from Landsat multispectral scanner data. Polar cloudiness, snow-covered mountainous regions, solid sea ice, glaciers, and open water have distinguishable texture features. This suggests that textural measures can be successfully applied to the detection of clouds over snow-covered mountains, an ability of considerable importance for the modeling of snow-melt runoff. However, broken stratocumulus cloud decks and thin cirrus over broken sea ice remain difficult to distinguish texturally. It is concluded that even with high spatial resolution imagery, it may not be possible to distinguish broken stratocumulus and thin clouds from sea ice in the marginal ice zone using the visible channel textural features alone.

  14. The influence of the playing surface on the exercise intensity of small-sided recreational soccer games.

    Science.gov (United States)

    Brito, João; Krustrup, Peter; Rebelo, António

    2012-08-01

    This study aimed to analyze the influence of the playing surface on movement pattern, physical loading, perceived exertion, and fatigue development during small-sided recreational soccer games. Time-motion, heart rate, blood lactate, and perceived exertion were measured for 16 recreational players aged 22 (range: 19-35) yrs. During 5-a-side soccer games on 3 different field surfaces: sand, artificial turf, and asphalt. Jump and sprint tests were performed prior to and after each game. Total distance covered was higher on asphalt and turf than on sand (3.89±0.04 and 3.73±0.12 vs. 2.59±0.21 km; p90% HR(max) (20.8±5.1% vs. 44.1±5.0%) were lower (precreational soccer games elicit high heart rates, multiple intense actions, and decreased jump performance for all the investigated playing surfaces, suggesting that multiple fitness and health benefits can be achieved through soccer on sand, artificial turf and asphalt. Nonetheless, locomotor activities, heart rate, blood lactate levels, and perceived exertion differ between surfaces. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Glazed ceramic roof tiles: influence of surface features in the solar reflectance index

    International Nuclear Information System (INIS)

    Bortoli, Leitcia Silva de; Stapait, Camila Cristina; Marinoski, Deivis Luis; Fredel, Marcio Celso; Schabbach, Luciana M.

    2016-01-01

    In this study the influence of surface features of ceramic roof tiles in the solar reflectance index were evaluated. Two glazed ceramic roof tiles (type stoneware) with the same color (ivory) but with different appearance (matte and brilliant) were the focus of the analysis. The Solar Reflectance Index (SRI) of the roofs tiles were determined by the solar reflectance values (UV-VIS-NIR) and emittance, measured in laboratory. The samples showed SRI> 39 in accordance with LEED certification criteria (Leadership in Energy and Environmental Design), contributing to minimizing the Heat Island Effects. Although the matte roof tile shows a slightly higher SRI value (82) than the brilliant one (78), the results for the variables that composes the SRI value (reflectance and emittance) were very similar. Analysis of XRD, SEM and EDS performed on the surfaces of the two roofs indicated for the matte glaze the presence of microcrystals (with barium and zinc) that can contribute to the slightly highest value of SRI. The roughness (optical interferometer white light) and the brightness (brightness meter) of the samples were also measured. (author)

  16. Surface-Enhanced Raman Spectroscopy as a Probe of the Surface Chemistry of Nanostructured Materials.

    Science.gov (United States)

    Dick, Susan; Konrad, Magdalena P; Lee, Wendy W Y; McCabe, Hannah; McCracken, John N; Rahman, Taifur M D; Stewart, Alan; Xu, Yikai; Bell, Steven E J

    2016-07-01

    Surface-enhanced Raman spectroscopy (SERS) is now widely used as a rapid and inexpensive tool for chemical/biochemical analysis. The method can give enormous increases in the intensities of the Raman signals of low-concentration molecular targets if they are adsorbed on suitable enhancing substrates, which are typically composed of nanostructured Ag or Au. However, the features of SERS that allow it to be used as a chemical sensor also mean that it can be used as a powerful probe of the surface chemistry of any nanostructured material that can provide SERS enhancement. This is important because it is the surface chemistry that controls how these materials interact with their local environment and, in real applications, this interaction can be more important than more commonly measured properties such as morphology or plasmonic absorption. Here, the opportunity that this approach to SERS provides is illustrated with examples where the surface chemistry is both characterized and controlled in order to create functional nanomaterials. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. [Rainfall intensity effects on nutrients transport in surface runoff from farmlands in gentle slope hilly area of Taihu Lake Basin].

    Science.gov (United States)

    Li, Rui-ling; Zhang, Yong-chun; Liu, Zhuang; Zeng, Yuan; Li, Wei-xin; Zhang, Hong-ling

    2010-05-01

    To investigate the effect of rainfall on agricultural nonpoint source pollution, watershed scale experiments were conducted to study the characteristics of nutrients in surface runoff under different rainfall intensities from farmlands in gentle slope hilly areas around Taihu Lake. Rainfall intensity significantly affected N and P concentrations in runoff. Rainfall intensity was positively related to TP, PO4(3-) -P and NH4+ -N event mean concentrations(EMC). However, this study have found the EMC of TN and NO3- -N to be positively related to rainfall intensity under light rain and negatively related to rainfall intensity under heavy rain. TN and TP site mean amounts (SMA) in runoff were positively related to rainfall intensity and were 1.91, 311.83, 127.65, 731.69 g/hm2 and 0.04, 7.77, 2.99, 32.02 g/hm2 with rainfall applied under light rain, moderate rain, heavy rain and rainstorm respectively. N in runoff was mainly NO3- -N and NH4+ -N and was primarily in dissolved form from Meilin soils. Dissolved P (DP) was the dominant form of TP under light rain, but particulate P (PP) mass loss increased with the increase of rainfall intensity and to be the dominant form when the rainfall intensity reaches rainstorm. Single relationships were used to describe the dependence of TN and TP mass losses in runoff on rainfall, maximum rainfall intensity, average rainfall intensity and rainfall duration respectively. The results showed a significant positive correlation between TN mass loss and rainfall, maximum rainfall intensity respectively (p < 0.01) and also TP mass loss and rainfall, maximum rainfall intensity respectively (p < 0.01).

  18. Patch layout generation by detecting feature networks

    KAUST Repository

    Cao, Yuanhao

    2015-02-01

    The patch layout of 3D surfaces reveals the high-level geometric and topological structures. In this paper, we study the patch layout computation by detecting and enclosing feature loops on surfaces. We present a hybrid framework which combines several key ingredients, including feature detection, feature filtering, feature curve extension, patch subdivision and boundary smoothing. Our framework is able to compute patch layouts through concave features as previous approaches, but also able to generate nice layouts through smoothing regions. We demonstrate the effectiveness of our framework by comparing with the state-of-the-art methods.

  19. Computation and Evaluation of Features of Surface Electromyogram to Identify the Force of Muscle Contraction and Muscle Fatigue

    Directory of Open Access Journals (Sweden)

    Sridhar P. Arjunan

    2014-01-01

    Full Text Available The relationship between force of muscle contraction and muscle fatigue with six different features of surface electromyogram (sEMG was determined by conducting experiments on thirty-five volunteers. The participants performed isometric contractions at 50%, 75%, and 100% of their maximum voluntary contraction (MVC. Six features were considered in this study: normalised spectral index (NSM5, median frequency, root mean square, waveform length, normalised root mean square (NRMS, and increase in synchronization (IIS index. Analysis of variance (ANOVA and linear regression analysis were performed to determine the significance of the feature with respect to the three factors: muscle force, muscle fatigue, and subject. The results show that IIS index of sEMG had the highest correlation with muscle fatigue and the relationship was statistically significant (P0.05.

  20. Computation and evaluation of features of surface electromyogram to identify the force of muscle contraction and muscle fatigue.

    Science.gov (United States)

    Arjunan, Sridhar P; Kumar, Dinesh K; Naik, Ganesh

    2014-01-01

    The relationship between force of muscle contraction and muscle fatigue with six different features of surface electromyogram (sEMG) was determined by conducting experiments on thirty-five volunteers. The participants performed isometric contractions at 50%, 75%, and 100% of their maximum voluntary contraction (MVC). Six features were considered in this study: normalised spectral index (NSM5), median frequency, root mean square, waveform length, normalised root mean square (NRMS), and increase in synchronization (IIS) index. Analysis of variance (ANOVA) and linear regression analysis were performed to determine the significance of the feature with respect to the three factors: muscle force, muscle fatigue, and subject. The results show that IIS index of sEMG had the highest correlation with muscle fatigue and the relationship was statistically significant (P 0.05).

  1. Local changes of work function near rough features on Cu surfaces operated under high external electric field

    Energy Technology Data Exchange (ETDEWEB)

    Djurabekova, Flyura, E-mail: flyura.djurabekova@helsinki.fi; Ruzibaev, Avaz; Parviainen, Stefan [Helsinki Institute of Physics and Department of Physics, University of Helsinki, P.O. Box 43, FI-00014 Helsinki (Finland); Holmström, Eero [Department of Physics, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki (Finland); Department of Earth Sciences, Faculty of Maths and Physical Sciences, UCL Earth Sciences, Gower Street, London WC1E 6BT (United Kingdom); Hakala, Mikko [Department of Physics, University of Helsinki, P.O. Box 64, FIN-00014 Helsinki (Finland)

    2013-12-28

    Metal surfaces operated under high electric fields produce sparks even if they are held in ultra high vacuum. In spite of extensive research on the topic of vacuum arcs, the mystery of vacuum arc origin still remains unresolved. The indications that the sparking rates depend on the material motivate the research on surface response to extremely high external electric fields. In this work by means of density-functional theory calculations we analyze the redistribution of electron density on (100) Cu surfaces due to self-adatoms and in presence of high electric fields from −1 V/nm up to −2 V/nm (−1 to −2 GV/m, respectively). We also calculate the partial charge induced by the external field on a single adatom and a cluster of two adatoms in order to obtain reliable information on charge redistribution on surface atoms, which can serve as a benchmarking quantity for the assessment of the electric field effects on metal surfaces by means of molecular dynamics simulations. Furthermore, we investigate the modifications of work function around rough surface features, such as step edges and self-adatoms.

  2. Surface Enhanced Raman Scattering Substrates Made by Oblique Angle Deposition: Methods and Applications

    Directory of Open Access Journals (Sweden)

    Hin On Chu

    2017-02-01

    Full Text Available Surface Enhanced Raman Spectroscopy presents a rapid, non-destructive method to identify chemical and biological samples with up to single molecule sensitivity. Since its discovery in 1974, the technique has become an intense field of interdisciplinary research, typically generating >2000 publications per year since 2011. The technique relies on the localised surface plasmon resonance phenomenon, where incident light can couple with plasmons at the interface that result in the generation of an intense electric field. This field can propagate from the surface from the metal-dielectric interface, so molecules within proximity will experience more intense Raman scattering. Localised surface plasmon resonance wavelength is determined by a number of factors, such as size, geometry and material. Due to the requirements of the surface optical response, Ag and Au are typical metals used for surface enhanced Raman applications. These metals then need to have nano features that improve the localised surface plasmon resonance, several variants of these substrates exist; surfaces can range from nanoparticles in a suspension, electrochemically roughened electrodes to metal nanostructures on a substrate. The latter will be the focus of this review, particularly reviewing substrates made by oblique angle deposition. Oblique angle deposition is the technique of growing thin films so that the material flux is not normal to the surface. Films grown in this fashion will possess nanostructures, due to the atomic self-shadowing effect, that are dependent mainly on the deposition angle. Recent developments, applications and highlights of surface enhanced Raman scattering substrates made by oblique angle deposition will be reviewed.

  3. Compact illumination optic with three freeform surfaces for improved beam control.

    Science.gov (United States)

    Sorgato, Simone; Mohedano, Rubén; Chaves, Julio; Hernández, Maikel; Blen, José; Grabovičkić, Dejan; Benítez, Pablo; Miñano, Juan Carlos; Thienpont, Hugo; Duerr, Fabian

    2017-11-27

    Multi-chip and large size LEDs dominate the lighting market in developed countries these days. Nevertheless, a general optical design method to create prescribed intensity patterns for this type of extended sources does not exist. We present a design strategy in which the source and the target pattern are described by means of "edge wavefronts" of the system. The goal is then finding an optic coupling these wavefronts, which in the current work is a monolithic part comprising up to three freeform surfaces calculated with the simultaneous multiple surface (SMS) method. The resulting optic fully controls, for the first time, three freeform wavefronts, one more than previous SMS designs. Simulations with extended LEDs demonstrate improved intensity tailoring capabilities, confirming the effectiveness of our method and suggesting that enhanced performance features can be achieved by controlling additional wavefronts.

  4. EFFECTIVE DETECTION OF SUB-SURFACE ARCHEOLOGICAL FEATURES FROM LASER SCANNING POINT CLOUDS AND IMAGERY DATA

    Directory of Open Access Journals (Sweden)

    A. Fryskowska

    2017-08-01

    Full Text Available The archaeological heritage is non-renewable, and any invasive research or other actions leading to the intervention of mechanical or chemical into the ground lead to the destruction of the archaeological site in whole or in part. For this reason, modern archeology is looking for alternative methods of non-destructive and non-invasive methods of new objects identification. The concept of aerial archeology is relation between the presence of the archaeological site in the particular localization, and the phenomena that in the same place can be observed on the terrain surface form airborne platform. One of the most appreciated, moreover, extremely precise, methods of such measurements is airborne laser scanning. In research airborne laser scanning point cloud with a density of 5 points/sq. m was used. Additionally unmanned aerial vehicle imagery data was acquired. Test area is located in central Europe. The preliminary verification of potentially microstructures localization was the creation of digital terrain and surface models. These models gave an information about the differences in elevation, as well as regular shapes and sizes that can be related to the former settlement/sub-surface feature. The paper presents the results of the detection of potentially sub-surface microstructure fields in the forestry area.

  5. Effective Detection of Sub-Surface Archeological Features from Laser Scanning Point Clouds and Imagery Data

    Science.gov (United States)

    Fryskowska, A.; Kedzierski, M.; Walczykowski, P.; Wierzbicki, D.; Delis, P.; Lada, A.

    2017-08-01

    The archaeological heritage is non-renewable, and any invasive research or other actions leading to the intervention of mechanical or chemical into the ground lead to the destruction of the archaeological site in whole or in part. For this reason, modern archeology is looking for alternative methods of non-destructive and non-invasive methods of new objects identification. The concept of aerial archeology is relation between the presence of the archaeological site in the particular localization, and the phenomena that in the same place can be observed on the terrain surface form airborne platform. One of the most appreciated, moreover, extremely precise, methods of such measurements is airborne laser scanning. In research airborne laser scanning point cloud with a density of 5 points/sq. m was used. Additionally unmanned aerial vehicle imagery data was acquired. Test area is located in central Europe. The preliminary verification of potentially microstructures localization was the creation of digital terrain and surface models. These models gave an information about the differences in elevation, as well as regular shapes and sizes that can be related to the former settlement/sub-surface feature. The paper presents the results of the detection of potentially sub-surface microstructure fields in the forestry area.

  6. Flocked nylon swabs versus RODAC plates for detection of multidrug-resistant organisms on environmental surfaces in intensive care units.

    Science.gov (United States)

    Okamoto, K; Rhee, Y; Schoeny, M; Lolans, K; Cheng, J; Reddy, S; Weinstein, R A; Hayden, M K; Popovich, K J

    2018-01-01

    To compare two culture methods [nylon fiber flocked swabs with broth enrichment versus RODAC ('replicate organism detection and counting') plates] for recovery of multidrug-resistant organisms, 780 environmental surfaces in 63 rooms of patients on contact precautions in four intensive care units at one hospital were examined. Among sites that had at least one positive culture, swab culture with broth enrichment detected the target organisms more frequently than RODAC plates (37.5% vs 26.0%, P = 0.06). There was moderate agreement between the two methods (κ = 0.44) with agreement better for small or flat surfaces compared to large or irregular surfaces. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  7. Combining Landform Thematic Layer and Object-Oriented Image Analysis to Map the Surface Features of Mountainous Flood Plain Areas

    Science.gov (United States)

    Chuang, H.-K.; Lin, M.-L.; Huang, W.-C.

    2012-04-01

    The Typhoon Morakot on August 2009 brought more than 2,000 mm of cumulative rainfall in southern Taiwan, the extreme rainfall event caused serious damage to the Kaoping River basin. The losses were mostly blamed on the landslides along sides of the river, and shifting of the watercourse even led to the failure of roads and bridges, as well as flooding and levees damage happened around the villages on flood bank and terraces. Alluvial fans resulted from debris flow of stream feeders blocked the main watercourse and debris dam was even formed and collapsed. These disasters have highlighted the importance of identification and map the watercourse alteration, surface features of flood plain area and artificial structures soon after the catastrophic typhoon event for natural hazard mitigation. Interpretation of remote sensing images is an efficient approach to acquire spatial information for vast areas, therefore making it suitable for the differentiation of terrain and objects near the vast flood plain areas in a short term. The object-oriented image analysis program (Definiens Developer 7.0) and multi-band high resolution satellite images (QuickBird, DigitalGlobe) was utilized to interpret the flood plain features from Liouguei to Baolai of the the Kaoping River basin after Typhoon Morakot. Object-oriented image interpretation is the process of using homogenized image blocks as elements instead of pixels for different shapes, textures and the mutual relationships of adjacent elements, as well as categorized conditions and rules for semi-artificial interpretation of surface features. Digital terrain models (DTM) are also employed along with the above process to produce layers with specific "landform thematic layers". These layers are especially helpful in differentiating some confusing categories in the spectrum analysis with improved accuracy, such as landslides and riverbeds, as well as terraces, riverbanks, which are of significant engineering importance in disaster

  8. Water content determination of soil surface in an intensive apple orchard

    Science.gov (United States)

    Riczu, Péter; Nagy, Gábor; Tamás, János

    2015-04-01

    Currently in Hungary, less than 100,000 hectares of orchards can be found, from which cultivation of apple is one of the most dominant ones. Production of marketable horticulture products can be difficult without employing advanced and high quality horticulture practices, which, in turn, depends on appropriate management and irrigation systems, basically. The got out water amount depend on climatic, edafic factors and the water demand of plants as well. The soil water content can be determined by traditional and modern methods. In order to define soil moisture content, gravimetry measurement is one of the most accurate methods, but it is time consuming and sometimes soil sampling and given results are in different times. Today, IT provides the farmers such tools, like global positioning system (GPS), geographic information system (GIS) and remote sensing (RS). These tools develop in a great integration rapidly. RS methods are ideal to survey larger area quick and accurate. Laser scanning is a novel technique which analyses a real-world or object environment to collect structural and spectral data. In order to obtain soil moisture information, the Leica ScanStation C10 terrestrial 3D laser scanner was used on an intensive apple orchard on the Study and Regional Research Farm of the University of Debrecen, near Pallag. Previously, soil samples from the study area with different moisture content were used as reference points. Based on the return intensity values of the laser scanner can be distinguished the different moisture content areas of soil surface. Nevertheless, the error of laser distance echo were examined and statistically evaluated. This research was realized in the frames of TÁMOP 4.2.4. A/2-11-1-2012-0001 "National Excellence Program - Elaborating and operating an inland student and researcher personal support system". The project was subsidized by the European Union and co-financed by the European Social Fund.

  9. Excimer laser irradiation of metal surfaces

    Science.gov (United States)

    Kinsman, Grant

    In this work a new method of enhancing CO2 laser processing by modifying the radiative properties of a metal surface is studied. In this procedure, an excimer laser (XeCl) or KrF) exposes the metal surface to overlapping pulses of high intensity, 10(exp 8) - 10(exp 9) W cm(exp -2), and short pulse duration, 30 nsec FWHM (Full Width Half Maximum), to promote structural and chemical change. The major processing effect at these intensities is the production of a surface plasma which can lead to the formation of a laser supported detonation wave (LSD wave). This shock wave can interact with the thin molten layer on the metal surface influencing to a varying degree surface oxidation and roughness features. The possibility of the expulsion, oxidation and redeposition of molten droplets, leading to the formation of micron thick oxide layers, is related to bulk metal properties and the incident laser intensity. A correlation is found between the expulsion of molten droplets and a Reynolds number, showing the interaction is turbulent. The permanent effects of these interactions on metal surfaces are observed through scanning electron microscopy (SEM), transient calorimetric measurements and Fourier transform infrared (FTIR) spectroscopy. Observed surface textures are related to the scanning procedures used to irradiate the metal surface. Fundamental radiative properties of a metal surface, the total hemispherical emissivity, the near-normal spectral absorptivity, and others are examined in this study as they are affected by excimer laser radiation. It is determined that for heavily exposed Al surface, alpha' (10.6 microns) can be increased to values close to unity. Data relating to material removal rates and chemical surface modification for excimer laser radiation is also discussed. The resultant reduction in the near-normal reflectivity solves the fundamental problem of coupling laser radiation into highly reflective and conductive metals such as copper and aluminum. The

  10. Investigating the sensitivity of hurricane intensity and trajectory to sea surface temperatures using the regional model WRF

    Directory of Open Access Journals (Sweden)

    Cevahir Kilic

    2013-12-01

    Full Text Available The influence of sea surface temperature (SST anomalies on the hurricane characteristics are investigated in a set of sensitivity experiments employing the Weather Research and Forecasting (WRF model. The idealised experiments are performed for the case of Hurricane Katrina in 2005. The first set of sensitivity experiments with basin-wide changes of the SST magnitude shows that the intensity goes along with changes in the SST, i.e., an increase in SST leads to an intensification of Katrina. Additionally, the trajectory is shifted to the west (east, with increasing (decreasing SSTs. The main reason is a strengthening of the background flow. The second set of experiments investigates the influence of Loop Current eddies idealised by localised SST anomalies. The intensity of Hurricane Katrina is enhanced with increasing SSTs close to the core of a tropical cyclone. Negative nearby SST anomalies reduce the intensity. The trajectory only changes if positive SST anomalies are located west or north of the hurricane centre. In this case the hurricane is attracted by the SST anomaly which causes an additional moisture source and increased vertical winds.

  11. Numerical Representation of Wintertime Near-Surface Inversions in the Arctic with a 2.5-km Version of the Global Environmental Multiscale (GEM) Model

    Science.gov (United States)

    Dehghan, A.; Mariani, Z.; Gascon, G.; Bélair, S.; Milbrandt, J.; Joe, P. I.; Crawford, R.; Melo, S.

    2017-12-01

    Environment and Climate Change Canada (ECCC) is implementing a 2.5-km resolution version of the Global Environmental Multiscale (GEM) model over the Canadian Arctic. Radiosonde observations were used to evaluate the numerical representation of surface-based temperature inversion which is a major feature in the Arctic region. Arctic surface-based inversions are often created by imbalance between radiative cooling processes at surface and warm air advection above. This can have a significant effect on vertical mixing of pollutants and moisture, and ultimately, on cloud formation. It is therefore important to correctly predict the existence of surface inversions along with their characteristics (i.e., intensity and depth). Previous climatological studies showed that the frequency and intensity of surface-based inversions are larger during colder months in the Arctic. Therefore, surface-based inversions were estimated using radiosonde measurements during winter (December 2015 to February 2016) at Iqaluit (Nunavut, Canada). Results show that the inversion intensity can exceed 10 K with depths as large as 1 km. Preliminary evaluation of GEM outputs reveals that the model tends to underestimate the intensity of near-surface inversions, and in some cases, the model failed to predict an inversion. This study presents the factors contributing to this bias including surface temperature and snow cover.

  12. Specific features of peroxide stress in children permanently exposed to low-intensity radiation

    International Nuclear Information System (INIS)

    Durnov, L.A.; Bajkova, V.N.; Mayakova, S.A.; Polyakov, V.G.; Kolosov, E.A.; Dumbrajs, K.O.; Gracheva, I.V.; Zakharova, N.V.; Leonidova, Yu.A.; Romanova, L.F.

    2000-01-01

    To study the peculiarities of peroxide stress in children residing at the territories with chronic low-intensity radiation effects, the investigation was performed of tyrosine level, indices of the intensity of free radical lipid peroxidation and antioxidant system status in children and teenagers living in Sverdlovsk and Kolpnyansk districts of the Orel region contaminated due to the Chernobyl accident. Regions mentioned are characterized by low-intensity contamination with radionuclides (mainly 90 Sr, 131 I, 137 Cs), 25% an increase in tyrosine content, 1.8 times in malonic dial, 25-40 % in catalase and superoxide dismutase activity was revealed in blood plasma. Contents of A and E vitamins, glutathione and glutathione-depending enzymes are decreased. It is recommended to observe children health in regions contaminated as a result of the Chernobyl accident and correct failed redox processes using antioxidative vitamins [ru

  13. Mining Videos for Features that Drive Attention

    Science.gov (United States)

    2015-04-01

    that can be added or removed from the final saliency computation. Examples of these features include intensity contrast, motion energy , color opponent...corresponding to the image. Each pixel in the feature map indicates the energy that the feature in question contributes at that location. In the standard...eye and head animation using a neurobio - logical model of visual attention. In: Bosacchi B, Fogel DB, Bezdek JC (eds) Proceedings of SPIE 48th annual

  14. An algorithm for analytical solution of basic problems featuring elastostatic bodies with cavities and surface flaws

    Science.gov (United States)

    Penkov, V. B.; Levina, L. V.; Novikova, O. S.; Shulmin, A. S.

    2018-03-01

    Herein we propose a methodology for structuring a full parametric analytical solution to problems featuring elastostatic media based on state-of-the-art computing facilities that support computerized algebra. The methodology includes: direct and reverse application of P-Theorem; methods of accounting for physical properties of media; accounting for variable geometrical parameters of bodies, parameters of boundary states, independent parameters of volume forces, and remote stress factors. An efficient tool to address the task is the sustainable method of boundary states originally designed for the purposes of computerized algebra and based on the isomorphism of Hilbertian spaces of internal states and boundary states of bodies. We performed full parametric solutions of basic problems featuring a ball with a nonconcentric spherical cavity, a ball with a near-surface flaw, and an unlimited medium with two spherical cavities.

  15. Contributions of feature shapes and surface cues to the recognition and neural representation of facial identity.

    Science.gov (United States)

    Andrews, Timothy J; Baseler, Heidi; Jenkins, Rob; Burton, A Mike; Young, Andrew W

    2016-10-01

    A full understanding of face recognition will involve identifying the visual information that is used to discriminate different identities and how this is represented in the brain. The aim of this study was to explore the importance of shape and surface properties in the recognition and neural representation of familiar faces. We used image morphing techniques to generate hybrid faces that mixed shape properties (more specifically, second order spatial configural information as defined by feature positions in the 2D-image) from one identity and surface properties from a different identity. Behavioural responses showed that recognition and matching of these hybrid faces was primarily based on their surface properties. These behavioural findings contrasted with neural responses recorded using a block design fMRI adaptation paradigm to test the sensitivity of Haxby et al.'s (2000) core face-selective regions in the human brain to the shape or surface properties of the face. The fusiform face area (FFA) and occipital face area (OFA) showed a lower response (adaptation) to repeated images of the same face (same shape, same surface) compared to different faces (different shapes, different surfaces). From the behavioural data indicating the critical contribution of surface properties to the recognition of identity, we predicted that brain regions responsible for familiar face recognition should continue to adapt to faces that vary in shape but not surface properties, but show a release from adaptation to faces that vary in surface properties but not shape. However, we found that the FFA and OFA showed an equivalent release from adaptation to changes in both shape and surface properties. The dissociation between the neural and perceptual responses suggests that, although they may play a role in the process, these core face regions are not solely responsible for the recognition of facial identity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Influence of surface roughness on the elastic-light scattering patterns of micron-sized aerosol particles

    Science.gov (United States)

    Auger, J.-C.; Fernandes, G. E.; Aptowicz, K. B.; Pan, Y.-L.; Chang, R. K.

    2010-04-01

    The relation between the surface roughness of aerosol particles and the appearance of island-like features in their angle-resolved elastic-light scattering patterns is investigated both experimentally and with numerical simulation. Elastic scattering patterns of polystyrene spheres, Bacillus subtilis spores and cells, and NaCl crystals are measured and statistical properties of the island-like intensity features in their patterns are presented. The island-like features for each class of particle are found to be similar; however, principal-component analysis applied to extracted features is able to differentiate between some of the particle classes. Numerically calculated scattering patterns of Chebyshev particles and aggregates of spheres are analyzed and show qualitative agreement with experimental results.

  17. Spatiotemporal Variation in Surface Urban Heat Island Intensity and Associated Determinants across Major Chinese Cities

    Directory of Open Access Journals (Sweden)

    Juan Wang

    2015-03-01

    Full Text Available Urban heat islands (UHIs created through urbanization can have negative impacts on the lives of people living in cities. They may also vary spatially and temporally over a city. There is, thus, a need for greater understanding of these patterns and their causes. While previous UHI studies focused on only a few cities and/or several explanatory variables, this research provides a comprehensive and comparative characterization of the diurnal and seasonal variation in surface UHI intensities (SUHIIs across 67 major Chinese cities. The factors associated with the SUHII were assessed by considering a variety of related social, economic and natural factors using a regression tree model. Obvious seasonal variation was observed for the daytime SUHII, and the diurnal variation in SUHII varied seasonally across China. Interestingly, the SUHII varied significantly in character between northern and southern China. Southern China experienced more intense daytime SUHIIs, while the opposite was true for nighttime SUHIIs. Vegetation had the greatest effect in the day time in northern China. In southern China, annual electricity consumption and the number of public buses were found to be important. These results have important theoretical significance and may be of use to mitigate UHI effects.

  18. Intense and stable surface-enhanced Raman scattering from Ag@mesoporous SiO{sub 2} film

    Energy Technology Data Exchange (ETDEWEB)

    Long, Yongjin; Wang, Xiaolong; Chen, Dong; Jiang, Tao, E-mail: jiangtao@nbu.edu.cn; Zhao, Ziqi; Zhou, Jun, E-mail: zhoujun@nbu.edu.cn

    2016-09-15

    A surface-enhanced Raman scattering (SERS) film consisting of mesoporous silica (MSiO{sub 2}) coated Ag nanoparticles (NPs) was achieved. The as-prepared hybrid NPs were uniform in size and formed large amount of aggregates in the film. “Hot spots” were supposed to appear in the MSiO{sub 2} shells with an average size as small as 15 nm. Such a novel core–shell structure therefore induced the enhancement of SERS intensity compared to the film of bare Ag NPs and polymer film of Ag-CMC. The homogeneity and stability of SERS signals from the Ag@MSiO{sub 2} film were also tested. A relative standard deviation of SERS intensity lower than 20% from Raman mapping and a stable SERS signal with excitation power of 100 mW were observed, which were both better than the other two films. Moreover, the obtained Ag@MSiO{sub 2} film was applied to detect thiram pesticides and a detection limit as low as 1×10{sup −8} M was reached, which indicates the advantages of the Ag@MSiO{sub 2} film in biosensor.

  19. Mining for diagnostic information in body surface potential maps: A comparison of feature selection techniques

    Directory of Open Access Journals (Sweden)

    McCullagh Paul J

    2005-09-01

    Full Text Available Abstract Background In body surface potential mapping, increased spatial sampling is used to allow more accurate detection of a cardiac abnormality. Although diagnostically superior to more conventional electrocardiographic techniques, the perceived complexity of the Body Surface Potential Map (BSPM acquisition process has prohibited its acceptance in clinical practice. For this reason there is an interest in striking a compromise between the minimum number of electrocardiographic recording sites required to sample the maximum electrocardiographic information. Methods In the current study, several techniques widely used in the domains of data mining and knowledge discovery have been employed to mine for diagnostic information in 192 lead BSPMs. In particular, the Single Variable Classifier (SVC based filter and Sequential Forward Selection (SFS based wrapper approaches to feature selection have been implemented and evaluated. Using a set of recordings from 116 subjects, the diagnostic ability of subsets of 3, 6, 9, 12, 24 and 32 electrocardiographic recording sites have been evaluated based on their ability to correctly asses the presence or absence of Myocardial Infarction (MI. Results It was observed that the wrapper approach, using sequential forward selection and a 5 nearest neighbour classifier, was capable of choosing a set of 24 recording sites that could correctly classify 82.8% of BSPMs. Although the filter method performed slightly less favourably, the performance was comparable with a classification accuracy of 79.3%. In addition, experiments were conducted to show how (a features chosen using the wrapper approach were specific to the classifier used in the selection model, and (b lead subsets chosen were not necessarily unique. Conclusion It was concluded that both the filter and wrapper approaches adopted were suitable for guiding the choice of recording sites useful for determining the presence of MI. It should be noted however

  20. Thermal measurements of dark and bright surface features on Vesta as derived from Dawn/VIR

    Science.gov (United States)

    Tosi, Federico; Capria, Maria Teresa; De Sanctis, M.C.; Combe, J.-Ph.; Zambon, F.; Nathues, A.; Schröder, S.E.; Li, J.-Y.; Palomba, E.; Longobardo, A.; Blewett, D.T.; Denevi, B.W.; Palmer, E.; Capaccioni, F.; Ammannito, E.; Titus, Timothy N.; Mittlefehldt, D.W.; Sunshine, J.M.; Russell, C.T.; Raymond, C.A.; Dawn/VIR Team,

    2014-01-01

    Remote sensing data acquired during Dawn’s orbital mission at Vesta showed several local concentrations of high-albedo (bright) and low-albedo (dark) material units, in addition to spectrally distinct meteorite impact ejecta. The thermal behavior of such areas seen at local scale (1-10 km) is related to physical properties that can provide information about the origin of those materials. We use Dawn’s Visible and InfraRed (VIR) mapping spectrometer hyperspectral data to retrieve surface temperatures and emissivities, with high accuracy as long as temperatures are greater than 220 K. Some of the dark and bright features were observed multiple times by VIR in the various mission phases at variable spatial resolution, illumination and observation angles, local solar time, and heliocentric distance. This work presents the first temperature maps and spectral emissivities of several kilometer-scale dark and bright material units on Vesta. Results retrieved from the infrared data acquired by VIR show that bright regions generally correspond to regions with lower temperature, while dark regions correspond to areas with higher temperature. During maximum daily insolation and in the range of heliocentric distances explored by Dawn, i.e. 2.23-2.54 AU, the warmest dark unit found on Vesta rises to a temperature of 273 K, while bright units observed under comparable conditions do not exceed 266 K. Similarly, dark units appear to have higher emissivity on average compared to bright units. Dark-material units show a weak anticorrelation between temperature and albedo, whereas the relation is stronger for bright material units observed under the same conditions. Individual features may show either evanescent or distinct margins in the thermal images, as a consequence of the cohesion of the surface material. Finally, for the two categories of dark and bright materials, we were able to highlight the influence of heliocentric distance on surface temperatures, and estimate an

  1. A possible constraint on regional precipitation intensity changes under global warming

    DEFF Research Database (Denmark)

    Gutowski, William J.; Kozak, K. A.; Arritt, R. W.

    2007-01-01

    Changes in daily precipitation versus intensity under a global warming scenario in two regional climate simulations of the United States show a well-recognized feature of more intense precipitation. More important, by resolving the precipitation intensity spectrum, the changes show a relatively...

  2. Computation of Mach reflection from rigid and yielding surfaces

    International Nuclear Information System (INIS)

    Buckingham, A.C.; Wilson, S.S.

    1976-01-01

    The present discussion centers on a theoretical description of one aspect of the irregular or Mach reflection from solid surfaces. The discussion is restricted to analytical considerations and some preliminary results using model approximations to the surface interaction phenomena. Currently, full numerical simulations of the irregular reflection surface interaction dynamics have not been obtained since the method is still under development. Discussion of the numerical method is, therefore, restricted to some special procedures for the gas-solid surface boundary dynamics. The discussion is divided into an introductory section briefly describing a particular Mach reflection process. Subsequently, some of the considerations on boundary conditions are submitted for numerical treatment of the gas-solid interface. Analysis and discussion of a yielding solid surface subjected to impulsive loading from an intense gas shock wave follows. This is used as a guide for the development of the numerical procedure. Mach reflection processes are then briefly reviewed with special attention for similitude and singular perturbation features

  3. Anisotropy effect of crater formation on single crystal silicon surface under intense pulsed ion beam irradiation

    Science.gov (United States)

    Shen, Jie; Yu, Xiao; Zhang, Jie; Zhong, Haowen; Cui, Xiaojun; Liang, Guoying; Yu, Xiang; Huang, Wanying; Shahid, Ijaz; Zhang, Xiaofu; Yan, Sha; Le, Xiaoyun

    2018-04-01

    Due to the induced extremely fast thermal and dynamic process, Intense Pulsed Ion Beam (IPIB) is widely applied in material processing, which can bring enhanced material performance and surface craters as well. To investigate the craters' formation mechanism, a specific model was built with Finite Element Methods (FEM) to simulate the thermal field on irradiated single crystal silicon. The direct evidence for the existence of the simulated 6-fold rotational symmetric thermal distribution was provided by electron microscope images obtained on single crystal silicon. The correlation of the experiment and simulation is of great importance to understand the interaction between IPIB and materials.

  4. Cortical surface registration using spherical thin-plate spline with sulcal lines and mean curvature as features.

    Science.gov (United States)

    Park, Hyunjin; Park, Jun-Sung; Seong, Joon-Kyung; Na, Duk L; Lee, Jong-Min

    2012-04-30

    Analysis of cortical patterns requires accurate cortical surface registration. Many researchers map the cortical surface onto a unit sphere and perform registration of two images defined on the unit sphere. Here we have developed a novel registration framework for the cortical surface based on spherical thin-plate splines. Small-scale composition of spherical thin-plate splines was used as the geometric interpolant to avoid folding in the geometric transform. Using an automatic algorithm based on anisotropic skeletons, we extracted seven sulcal lines, which we then incorporated as landmark information. Mean curvature was chosen as an additional feature for matching between spherical maps. We employed a two-term cost function to encourage matching of both sulcal lines and the mean curvature between the spherical maps. Application of our registration framework to fifty pairwise registrations of T1-weighted MRI scans resulted in improved registration accuracy, which was computed from sulcal lines. Our registration approach was tested as an additional procedure to improve an existing surface registration algorithm. Our registration framework maintained an accurate registration over the sulcal lines while significantly increasing the cross-correlation of mean curvature between the spherical maps being registered. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Feature-Based Retinal Image Registration Using D-Saddle Feature

    Directory of Open Access Journals (Sweden)

    Roziana Ramli

    2017-01-01

    Full Text Available Retinal image registration is important to assist diagnosis and monitor retinal diseases, such as diabetic retinopathy and glaucoma. However, registering retinal images for various registration applications requires the detection and distribution of feature points on the low-quality region that consists of vessels of varying contrast and sizes. A recent feature detector known as Saddle detects feature points on vessels that are poorly distributed and densely positioned on strong contrast vessels. Therefore, we propose a multiresolution difference of Gaussian pyramid with Saddle detector (D-Saddle to detect feature points on the low-quality region that consists of vessels with varying contrast and sizes. D-Saddle is tested on Fundus Image Registration (FIRE Dataset that consists of 134 retinal image pairs. Experimental results show that D-Saddle successfully registered 43% of retinal image pairs with average registration accuracy of 2.329 pixels while a lower success rate is observed in other four state-of-the-art retinal image registration methods GDB-ICP (28%, Harris-PIIFD (4%, H-M (16%, and Saddle (16%. Furthermore, the registration accuracy of D-Saddle has the weakest correlation (Spearman with the intensity uniformity metric among all methods. Finally, the paired t-test shows that D-Saddle significantly improved the overall registration accuracy of the original Saddle.

  6. MRI features of tuberculosis of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Sanghvi, Darshana A.; Iyer, Veena R.; Deshmukh, Tejaswini; Hoskote, Sumedh S. [Seth GS Medical College and KEM Hospital, Department of Radiology, Mumbai (India)

    2009-03-15

    The objective of this study was to describe the magnetic resonance imaging (MRI) features of tuberculosis (TB) of the knee joint. The MRI features in 15 patients with TB of the knee, as confirmed by histology of the biopsied joint synovium, were reviewed retrospectively. The images were assessed for intra-articular and peri-articular abnormalities. All patients had florid synovial proliferation. The proliferating synovium showed intermediate to low T2 signal intensity. In the patients who were administered intravenous contrast, the hypertrophic synovium was intensely enhancing. Marrow edema (n = 9), osteomyelitis (n = 4), cortical erosions (n = 5), myositis (n = 6), cellulitis (n = 2), abscesses (n = 3), and skin ulceration/sinus formation (n = 2) were seen in the adjacent bone and soft tissue. Synovial proliferation associated with tuberculous arthritis is typically hypointense on T2-weighted images. This appearance, in conjunction with other peri-articular MRI features described, can help in distinguishing TB arthritis from other proliferating synovial arthropathies. (orig.)

  7. Magnitude of Neck-Surface Vibration as an Estimate of Subglottal Pressure during Modulations of Vocal Effort and Intensity in Healthy Speakers

    Science.gov (United States)

    McKenna, Victoria S.; Llico, Andres F.; Mehta, Daryush D.; Perkell, Joseph S.; Stepp, Cara E.

    2017-01-01

    Purpose: This study examined the relationship between the magnitude of neck-surface vibration (NSV[subscript Mag]; transduced with an accelerometer) and intraoral estimates of subglottal pressure (P'[subscript sg]) during variations in vocal effort at 3 intensity levels. Method: Twelve vocally healthy adults produced strings of /p?/ syllables in 3…

  8. Cosmogenic nuclides in the Martian surface: constraints for sample recovery and transport

    International Nuclear Information System (INIS)

    Englert, P.A.J.

    1988-01-01

    Stable and radioactive cosmogenic nuclides and radiation damage effects such as cosmic ray tracks can provide information on the surface history of Mars. A recent overview on developments in cosmogenic nuclide research for historical studies of predominantly extraterrestrial materials was published previously. The information content of cosmogenic nuclides and radiation damage effects produced in the Martian surface is based on the different ways of interaction of the primary galactic and solar cosmic radiation (GCR, SCR) and the secondary particle cascade. Generally the kind and extent of interactions as seen in the products depend on the following factors: (1) composition, energy and intensity of the primary SCR and GCR; (2) composition, energy and intensity of the GCR-induced cascade of secondary particles; (3) the target geometry, i.e., the spatial parameters of Martian surface features with respect to the primary radiation source; (4) the target chemistry, i.e., the chemical composition of the Martian surface at the sampling location down to the minor element level or lower; and (5) duration of the exposure. These factors are not independent of each other and have a major influence on sample taking strategies and techniques

  9. Decoding subtle forearm flexions using fractal features of surface electromyogram from single and multiple sensors.

    Science.gov (United States)

    Arjunan, Sridhar Poosapadi; Kumar, Dinesh Kant

    2010-10-21

    Identifying finger and wrist flexion based actions using a single channel surface electromyogram (sEMG) can lead to a number of applications such as sEMG based controllers for near elbow amputees, human computer interface (HCI) devices for elderly and for defence personnel. These are currently infeasible because classification of sEMG is unreliable when the level of muscle contraction is low and there are multiple active muscles. The presence of noise and cross-talk from closely located and simultaneously active muscles is exaggerated when muscles are weakly active such as during sustained wrist and finger flexion. This paper reports the use of fractal properties of sEMG to reliably identify individual wrist and finger flexion, overcoming the earlier shortcomings. SEMG signal was recorded when the participant maintained pre-specified wrist and finger flexion movements for a period of time. Various established sEMG signal parameters such as root mean square (RMS), Mean absolute value (MAV), Variance (VAR) and Waveform length (WL) and the proposed fractal features: fractal dimension (FD) and maximum fractal length (MFL) were computed. Multi-variant analysis of variance (MANOVA) was conducted to determine the p value, indicative of the significance of the relationships between each of these parameters with the wrist and finger flexions. Classification accuracy was also computed using the trained artificial neural network (ANN) classifier to decode the desired subtle movements. The results indicate that the p value for the proposed feature set consisting of FD and MFL of single channel sEMG was 0.0001 while that of various combinations of the five established features ranged between 0.009 - 0.0172. From the accuracy of classification by the ANN, the average accuracy in identifying the wrist and finger flexions using the proposed feature set of single channel sEMG was 90%, while the average accuracy when using a combination of other features ranged between 58% and 73

  10. Decoding subtle forearm flexions using fractal features of surface electromyogram from single and multiple sensors

    Directory of Open Access Journals (Sweden)

    Kumar Dinesh

    2010-10-01

    Full Text Available Abstract Background Identifying finger and wrist flexion based actions using a single channel surface electromyogram (sEMG can lead to a number of applications such as sEMG based controllers for near elbow amputees, human computer interface (HCI devices for elderly and for defence personnel. These are currently infeasible because classification of sEMG is unreliable when the level of muscle contraction is low and there are multiple active muscles. The presence of noise and cross-talk from closely located and simultaneously active muscles is exaggerated when muscles are weakly active such as during sustained wrist and finger flexion. This paper reports the use of fractal properties of sEMG to reliably identify individual wrist and finger flexion, overcoming the earlier shortcomings. Methods SEMG signal was recorded when the participant maintained pre-specified wrist and finger flexion movements for a period of time. Various established sEMG signal parameters such as root mean square (RMS, Mean absolute value (MAV, Variance (VAR and Waveform length (WL and the proposed fractal features: fractal dimension (FD and maximum fractal length (MFL were computed. Multi-variant analysis of variance (MANOVA was conducted to determine the p value, indicative of the significance of the relationships between each of these parameters with the wrist and finger flexions. Classification accuracy was also computed using the trained artificial neural network (ANN classifier to decode the desired subtle movements. Results The results indicate that the p value for the proposed feature set consisting of FD and MFL of single channel sEMG was 0.0001 while that of various combinations of the five established features ranged between 0.009 - 0.0172. From the accuracy of classification by the ANN, the average accuracy in identifying the wrist and finger flexions using the proposed feature set of single channel sEMG was 90%, while the average accuracy when using a combination

  11. High intensity hadron accelerators

    International Nuclear Information System (INIS)

    Teng, L.C.

    1989-05-01

    This rapporteur report consists mainly of two parts. Part I is an abridged review of the status of all High Intensity Hadron Accelerator projects in the world in semi-tabulated form for quick reference and comparison. Part II is a brief discussion of the salient features of the different technologies involved. The discussion is based mainly on my personal experiences and opinions, tempered, I hope, by the discussions I participated in in the various parallel sessions of the workshop. In addition, appended at the end is my evaluation and expression of the merits of high intensity hadron accelerators as research facilities for nuclear and particle physics

  12. Reconstructing disturbance history for an intensively mined region by time-series analysis of Landsat imagery.

    Science.gov (United States)

    Li, Jing; Zipper, Carl E; Donovan, Patricia F; Wynne, Randolph H; Oliphant, Adam J

    2015-09-01

    Surface mining disturbances have attracted attention globally due to extensive influence on topography, land use, ecosystems, and human populations in mineral-rich regions. We analyzed a time series of Landsat satellite imagery to produce a 28-year disturbance history for surface coal mining in a segment of eastern USA's central Appalachian coalfield, southwestern Virginia. The method was developed and applied as a three-step sequence: vegetation index selection, persistent vegetation identification, and mined-land delineation by year of disturbance. The overall classification accuracy and kappa coefficient were 0.9350 and 0.9252, respectively. Most surface coal mines were identified correctly by location and by time of initial disturbance. More than 8 % of southwestern Virginia's >4000-km(2) coalfield area was disturbed by surface coal mining over the 28-year period. Approximately 19.5 % of the Appalachian coalfield surface within the most intensively mined county (Wise County) has been disturbed by mining. Mining disturbances expanded steadily and progressively over the study period. Information generated can be applied to gain further insight concerning mining influences on ecosystems and other essential environmental features.

  13. Features Related to Faunal Activity

    NARCIS (Netherlands)

    Kooistra, M.J.; Pulleman, M.M.

    2010-01-01

    Soil fauna plays an important role in transporting and altering various soil components, in particular the decomposition of organic matter and the development of soil structure. Fauna-induced features are found in all types of soils and can be so abundant that they determine the nature and intensity

  14. Optimal Threshold Determination for Discriminating Driving Anger Intensity Based on EEG Wavelet Features and ROC Curve Analysis

    Directory of Open Access Journals (Sweden)

    Ping Wan

    2016-08-01

    Full Text Available Driving anger, called “road rage”, has become increasingly common nowadays, affecting road safety. A few researches focused on how to identify driving anger, however, there is still a gap in driving anger grading, especially in real traffic environment, which is beneficial to take corresponding intervening measures according to different anger intensity. This study proposes a method for discriminating driving anger states with different intensity based on Electroencephalogram (EEG spectral features. First, thirty drivers were recruited to conduct on-road experiments on a busy route in Wuhan, China where anger could be inducted by various road events, e.g., vehicles weaving/cutting in line, jaywalking/cyclist crossing, traffic congestion and waiting red light if they want to complete the experiments ahead of basic time for extra paid. Subsequently, significance analysis was used to select relative energy spectrum of β band (β% and relative energy spectrum of θ band (θ% for discriminating the different driving anger states. Finally, according to receiver operating characteristic (ROC curve analysis, the optimal thresholds (best cut-off points of β% and θ% for identifying none anger state (i.e., neutral were determined to be 0.2183 ≤ θ% < 1, 0 < β% < 0.2586; low anger state is 0.1539 ≤ θ% < 0.2183, 0.2586 ≤ β% < 0.3269; moderate anger state is 0.1216 ≤ θ% < 0.1539, 0.3269 ≤ β% < 0.3674; high anger state is 0 < θ% < 0.1216, 0.3674 ≤ β% < 1. Moreover, the discrimination performances of verification indicate that, the overall accuracy (Acc of the optimal thresholds of β% for discriminating the four driving anger states is 80.21%, while 75.20% for that of θ%. The results can provide theoretical foundation for developing driving anger detection or warning devices based on the relevant optimal thresholds.

  15. Hyperspatial Thermal Imaging of Surface Hydrothermal Features at Pilgrim Hot Springs, Alaska using a small Unmanned Aerial System (sUAS)

    Science.gov (United States)

    Haselwimmer, C. E.; Wilson, R.; Upton, C.; Prakash, A.; Holdmann, G.; Walker, G.

    2013-12-01

    Thermal remote sensing provides a valuable tool for mapping and monitoring surface hydrothermal features associated with geothermal activity. The increasing availability of low-cost, small Unmanned Aerial Systems (sUAS) with integrated thermal imaging sensors offers a means to undertake very high spatial resolution (hyperspatial), quantitative thermal remote sensing of surface geothermal features in support of exploration and long-term monitoring efforts. Results from the deployment of a quadcopter sUAS equipped with a thermal camera over Pilgrim Hot Springs, Alaska for detailed mapping and heat flux estimation for hot springs, seeps, and thermal pools are presented. Hyperspatial thermal infrared imagery (4 cm pixels) was acquired over Pilgrim Hot Springs in July 2013 using a FLIR TAU 640 camera operating from an Aeryon Scout sUAS flying at an altitude of 40m. The registered and mosaicked thermal imagery is calibrated to surface temperature values using in-situ measurements of uniform blackbody tarps and the temperatures of geothermal and other surface pools acquired with a series of water temperature loggers. Interpretation of the pre-processed thermal imagery enables the delineation of hot springs, the extents of thermal pools, and the flow and mixing of individual geothermal outflow plumes with an unprecedented level of detail. Using the surface temperatures of thermal waters derived from the FLIR data and measured in-situ meteorological parameters the hot spring heat flux and outflow rate is calculated using a heat budget model for a subset of the thermal drainage. The heat flux/outflow rate estimates derived from the FLIR data are compared against in-situ measurements of the hot spring outflow rate recorded at the time of the thermal survey.

  16. Insights into Ground-Motion Processes from Intensity Data (Invited)

    Science.gov (United States)

    Atkinson, G. M.

    2009-12-01

    Analysis of intensity data gathered from the on-line “Did You Feel It?” (DYFI) questionnaire program (Wald et al., 1999, Seism. Res. L.) provides new insights into both contemporary and historical ground-motion processes; this is particularly important for sparsely-instrumented regions. The value of the DYFI data lies in their vast quantities and large spatial coverage. With thousands to tens of thousands of respondents providing information on the felt and damage characteristics of widely-felt earthquakes, DYFI intensity data provide surprisingly high resolution of ground-motion features. The large data quantities allow techniques such as binning to be used to bring out these features in a statistically-stable way (Atkinson and Wald, 2007, Seism. Res. L.), while correlations of the statistics of DYFI intensities with instrumental ground motions provide the link between intensity and engineering ground-motion parameters (Wald et al., 1999, Earthquake Spectra). This link is largely independent of region if its dependence on earthquake magnitude and distance is taken into account (Kaka and Atkinson, 2007, BSSA). Thus DYFI data provide a valuable tool with which ground motions can be estimated, if their felt and damage effects have been reported. This is useful both for understanding contemporary events in sparsely-instrumented regions, and for re-evaluating historical events, for which only intensity data are available. By using calibrated intensity observations, a number of ground-motion processes can be investigated based on DYFI and/or historical intensity data. For example, intensity data shed light on source scaling issues, and whether source parameters vary regionally. They can also be used to document regional attenuation features, such as the attenuation rate and its variation with distance (Atkinson and Wald, 2007). A key uncertainty in these investigations concerns the effect of spectral shape on intensity; the spectral shape is influenced by site

  17. The Word Composite Effect Depends on Abstract Lexical Representations But Not Surface Features Like Case and Font

    Directory of Open Access Journals (Sweden)

    Paulo Ventura

    2017-06-01

    Full Text Available Prior studies have shown that words show a composite effect: When readers perform a same-different matching task on a target-part of a word, performance is affected by the irrelevant part, whose influence is severely reduced when the two parts are misaligned. However, the locus of this word composite effect is largely unknown. To enlighten it, in two experiments, Portuguese readers performed the composite task on letter strings: in Experiment 1, in written words varying in surface features (between-participants: courier, notera, alternating-cAsE, and in Experiment 2 in pseudowords. The word composite effect, signaled by a significant interaction between alignment of the two word parts and congruence between parts was found in the three conditions of Experiment 1, being unaffected by NoVeLtY of the configuration or by handwritten form. This effect seems to have a lexical locus, given that in Experiment 2 only the main effect of congruence between parts was significant and was not modulated by alignment. Indeed, the cross-experiment analysis showed that words presented stronger congruence effects than pseudowords only in the aligned condition, because when misaligned the whole lexical item configuration was disrupted. Therefore, the word composite effect strongly depends on abstract lexical representations, as it is unaffected by surface features and is specific to lexical items.

  18. The Word Composite Effect Depends on Abstract Lexical Representations But Not Surface Features Like Case and Font.

    Science.gov (United States)

    Ventura, Paulo; Fernandes, Tânia; Leite, Isabel; Almeida, Vítor B; Casqueiro, Inês; Wong, Alan C-N

    2017-01-01

    Prior studies have shown that words show a composite effect: When readers perform a same-different matching task on a target-part of a word, performance is affected by the irrelevant part, whose influence is severely reduced when the two parts are misaligned. However, the locus of this word composite effect is largely unknown. To enlighten it, in two experiments, Portuguese readers performed the composite task on letter strings: in Experiment 1, in written words varying in surface features (between-participants: courier, notera, alternating-cAsE), and in Experiment 2 in pseudowords. The word composite effect, signaled by a significant interaction between alignment of the two word parts and congruence between parts was found in the three conditions of Experiment 1, being unaffected by NoVeLtY of the configuration or by handwritten form. This effect seems to have a lexical locus, given that in Experiment 2 only the main effect of congruence between parts was significant and was not modulated by alignment. Indeed, the cross-experiment analysis showed that words presented stronger congruence effects than pseudowords only in the aligned condition, because when misaligned the whole lexical item configuration was disrupted. Therefore, the word composite effect strongly depends on abstract lexical representations, as it is unaffected by surface features and is specific to lexical items.

  19. Automatic visual inspection of metallic surfaces

    International Nuclear Information System (INIS)

    Pernkopf, F.

    2002-02-01

    This thesis is concerned with the objectives of automatic visual inspection of metallic surfaces and involves two major parts. The first part covers three different imaging techniques, gray-level intensity imaging, light sectioning, and photometric stereo. These imaging principles more or less strongly rely on the reflection property of the surface. Therefore, a reflection model for machine vision is introduced. The second part concentrates on the analysis of the gathered data in regard to the detection and classification of surface defects. Additionally, the evaluation of genetic algorithms with a novel encoding scheme and a large number of published sequential feature selection algorithms for selection of the subset of features achieving the best classification rate is included. The genetic algorithms and the adaptive sequential forward floating selection method achieve similar results in performance and computational efficiency. Finally, the results of feature selection and classification of 540 flaw images are presented, whereby different classification approaches such as parametric classifiers, the k-nearest-neighbor decision rule, the naive Bayes classifier, and the tree augmented naive Bayes classifier were compared. For learning the structure of the augmented naive Bayes network a new approach similar to the sequential floating algorithm is presented which achieves a higher classification accuracy than hill climbing search. Basically, the introduced techniques are applied to two fundamentally different applications, whereby the experimental results of both, inspection of high-precision surfaces such as bearing rolls and flaw detection on partially scale-covered steel blocks, are presented. For the inspection of bearing rolls, the surface reflectance properties are modeled and verified with optical experiments. The aim is to determine the optical arrangement for illumination and observation, where the contrast between errors and intact surface is maximized

  20. Surface coil imaging of the spine using fast sequences: Improvement of intensity profile and contrast behavior

    International Nuclear Information System (INIS)

    Requardt, H.; Deimling, M.; Weber, H.

    1986-01-01

    Sagittal and axial images obtained using a surface coil suffer from the extreme intensity profile caused by physical properties of the coil and the anatomic entity of subcutaneous fat. The authors present a measuring device that reduces these disadvantages by means of Helmholtz-type coils, and sequences that reduce the fat signal by dephasing its signal part. The extremely short repetition time (<30 msec) allows acquisition times shorter than 10 sec. Breath-holding for this short period to avoid movement artifacts is possible. Images are presented that illustrate the enhanced contrast of spinal tissue and surrounding structures. Comparisons are made with spin-echo and CHESS images

  1. Size-effect features on the magnetothermopower of bismuth nanowires

    International Nuclear Information System (INIS)

    Condrea, E.; Nicorici, A.

    2011-01-01

    Full text: In this work we have studied the magnetic field dependence of the thermopower (TEP) and resistance of glass-coated Bi wires with diameter (d) from 100 nm to at 1.5 μm below 80 K. Nanowires have anomalously large values of the thermopower (+100 μV K.1) and relatively high effective resistivities, but their frequencies of SdH oscillations remain those of bulk Bi. The TEP stays positive in longitudinal magnetic fields up to 15 T, where the surface scattering of charge carriers is negligible. Our analysis shows that the anomalous thermopower has a diffusion origin and is a consequence of the microstructure rather than the result of the strong scattering of electrons by the wire walls. The intensities of field at which the size-effect features appear on the magnetothermopower curves correspond to a value at which the diameter of the hole cyclotron orbit equals d. Size-effect features were observed only for set of nanowires with d = 100-350 nm, where diffusion TEP is dominant. The contribution of the phonon-drag effect was observed in a wire with diameter larger than 400 nm and becomes dominant at diameter of 1 μm. (authors)

  2. Construction of Individual Morphological Brain Networks with Multiple Morphometric Features

    Directory of Open Access Journals (Sweden)

    Chunlan Yang

    2017-04-01

    Full Text Available In recent years, researchers have increased attentions to the morphological brain network, which is generally constructed by measuring the mathematical correlation across regions using a certain morphometric feature, such as regional cortical thickness and voxel intensity. However, cerebral structure can be characterized by various factors, such as regional volume, surface area, and curvature. Moreover, most of the morphological brain networks are population-based, which has limitations in the investigations of individual difference and clinical applications. Hence, we have extended previous studies by proposing a novel method for realizing the construction of an individual-based morphological brain network through a combination of multiple morphometric features. In particular, interregional connections are estimated using our newly introduced feature vectors, namely, the Pearson correlation coefficient of the concatenation of seven morphometric features. Experiments were performed on a healthy cohort of 55 subjects (24 males aged from 20 to 29 and 31 females aged from 20 to 28 each scanned twice, and reproducibility was evaluated through test–retest reliability. The robustness of morphometric features was measured firstly to select the more reproducible features to form the connectomes. Then the topological properties were analyzed and compared with previous reports of different modalities. Small-worldness was observed in all the subjects at the range of the entire network sparsity (20–40%, and configurations were comparable with previous findings at the sparsity of 23%. The spatial distributions of the hub were found to be significantly influenced by the individual variances, and the hubs obtained by averaging across subjects and sparsities showed correspondence with previous reports. The intraclass coefficient of graphic properties (clustering coefficient = 0.83, characteristic path length = 0.81, betweenness centrality = 0.78 indicates

  3. Simplified models for surface hyperchannelling

    International Nuclear Information System (INIS)

    Evdokimov, I.N.; Webb, R.; Armour, D.G.; Karpuzov, D.S.

    1979-01-01

    Experimental and detailed, three-dimensional computer simulation studies of the scattering of low energy argon ions incident at grazing angles onto a nickel single crystal have shown that under certain, well defined conditions, surface hyperchannelling dominates the reflection process. The applicability of simple computer simulation models to the study of this type of scattering has been investigated by comparing the results obtained using a 'summation of binary collisions' model and a continuous string model with both the experimental observations and the three dimensional model calculations. It has been shown that all the major features of the phenomenon can be reproduced in a qualitative way using the simple models and that the continuous string represents a good approximation to the 'real' crystal over a wide range of angles. The saving in computer time compared with the more complex model makes it practicable to use the simple models to calculate cross-sections and overall scattering intensities for a wide range of geometries. The results of these calculations suggest that the critical angle for the onset of surface hyperchannelling, which is associated with a reduction in scattering intensity and which is thus not too sensitive to the parameters of experimental apparatus is a useful quantity from the point of view of comparison of theoretical calculations with experimental measurements. (author)

  4. Feature displacement interpolation

    DEFF Research Database (Denmark)

    Nielsen, Mads; Andresen, Per Rønsholt

    1998-01-01

    Given a sparse set of feature matches, we want to compute an interpolated dense displacement map. The application may be stereo disparity computation, flow computation, or non-rigid medical registration. Also estimation of missing image data, may be phrased in this framework. Since the features...... often are very sparse, the interpolation model becomes crucial. We show that a maximum likelihood estimation based on the covariance properties (Kriging) show properties more expedient than methods such as Gaussian interpolation or Tikhonov regularizations, also including scale......-selection. The computational complexities are identical. We apply the maximum likelihood interpolation to growth analysis of the mandibular bone. Here, the features used are the crest-lines of the object surface....

  5. Texture Feature Analysis for Different Resolution Level of Kidney Ultrasound Images

    Science.gov (United States)

    Kairuddin, Wan Nur Hafsha Wan; Mahmud, Wan Mahani Hafizah Wan

    2017-08-01

    Image feature extraction is a technique to identify the characteristic of the image. The objective of this work is to discover the texture features that best describe a tissue characteristic of a healthy kidney from ultrasound (US) image. Three ultrasound machines that have different specifications are used in order to get a different quality (different resolution) of the image. Initially, the acquired images are pre-processed to de-noise the speckle to ensure the image preserve the pixels in a region of interest (ROI) for further extraction. Gaussian Low- pass Filter is chosen as the filtering method in this work. 150 of enhanced images then are segmented by creating a foreground and background of image where the mask is created to eliminate some unwanted intensity values. Statistical based texture features method is used namely Intensity Histogram (IH), Gray-Level Co-Occurance Matrix (GLCM) and Gray-level run-length matrix (GLRLM).This method is depends on the spatial distribution of intensity values or gray levels in the kidney region. By using One-Way ANOVA in SPSS, the result indicated that three features (Contrast, Difference Variance and Inverse Difference Moment Normalized) from GLCM are not statistically significant; this concludes that these three features describe a healthy kidney characteristics regardless of the ultrasound image quality.

  6. Surface composition, microstructure and corrosion resistance of AZ31 magnesium alloy irradiated by high-intensity pulsed ion beam

    International Nuclear Information System (INIS)

    Li, P.; Lei, M.K.; Zhu, X.P.

    2011-01-01

    High-intensity pulsed ion beam (HIPIB) irradiation of AZ31 magnesium alloy is performed and electrochemical corrosion experiment of irradiated samples is carried out by using potentiodynamic polarization technology in order to explore the effect of HIPIB irradiation on corrosion resistance of magnesium alloy. The surface composition, cross-sectional morphology and microstructure are characterized by using electron probe microanalyzer, optical microscope and transmission electron microscope, respectively. The results indicated that HIPIB irradiation leads to a significant improvement in corrosion resistance of magnesium alloy, in terms of the considerable increase in both corrosion potential and pitting breakdown potential. The microstructural refinement and surface purification induced by HIPIB irradiation are responsible for the improved corrosion resistance. - Research Highlights: → A modified layer about 30 μm thick is obtained by HIPIB irradiation. → Selective ablation of element/impurity phase having lower melting point is observed. → More importantly, microstructural refinement occurred on the irradiated surface. → The modified layer exhibited a significantly improved corrosion resistance. → Improved corrosion resistance is ascribed to the combined effect induced by HIPIB.

  7. River flooding due to intense precipitation

    International Nuclear Information System (INIS)

    Lin, James C.

    2014-01-01

    River stage can rise and cause site flooding due to local intense precipitation (LIP), dam failures, snow melt in conjunction with precipitation or dam failures, etc. As part of the re-evaluation of the design basis as well as the PRA analysis of other external events, the likelihood and consequence of river flooding leading to the site flooding need to be examined more rigorously. To evaluate the effects of intense precipitation on site structures, the site watershed hydrology and pond storage are calculated. To determine if river flooding can cause damage to risk-significant systems, structures, and components (SSC), water surface elevations are analyzed. Typically, the amount and rate of the input water is determined first. For intense precipitation, the fraction of the rainfall in the watershed drainage area not infiltrated into the ground is collected in the river and contributes to the rise of river water elevation. For design basis analysis, the Probable Maximum Flood (PMF) is evaluated using the Probable Maximum Precipitation (PMP) based on the site topography/configuration. The peak runoff flow rate and water surface elevations resulting from the precipitation induced flooding can then be estimated. The runoff flow hydrograph and peak discharge flows can be developed using the synthetic hydrograph method. The standard step method can then be used to determine the water surface elevations along the river channel. Thus, the flood water from the local intense precipitation storm and excess runoff from the nearby river can be evaluated to calculate the water surface elevations, which can be compared with the station grade floor elevation to determine the effects of site flooding on risk-significant SSCs. The analysis needs to consider any possible diversion flow and the effects of changes to the site configurations. Typically, the analysis is performed based on conservative peak rainfall intensity and the assumptions of failure of the site drainage facilities

  8. Protofit: A program for determining surface protonation constants from titration data

    Science.gov (United States)

    Turner, Benjamin F.; Fein, Jeremy B.

    2006-11-01

    Determining the surface protonation behavior of natural adsorbents is essential to understand how they interact with their environments. ProtoFit is a tool for analysis of acid-base titration data and optimization of surface protonation models. The program offers a number of useful features including: (1) enables visualization of adsorbent buffering behavior; (2) uses an optimization approach independent of starting titration conditions or initial surface charge; (3) does not require an initial surface charge to be defined or to be treated as an optimizable parameter; (4) includes an error analysis intrinsically as part of the computational methods; and (5) generates simulated titration curves for comparison with observation. ProtoFit will typically be run through ProtoFit-GUI, a graphical user interface providing user-friendly control of model optimization, simulation, and data visualization. ProtoFit calculates an adsorbent proton buffering value as a function of pH from raw titration data (including pH and volume of acid or base added). The data is reduced to a form where the protons required to change the pH of the solution are subtracted out, leaving protons exchanged between solution and surface per unit mass of adsorbent as a function of pH. The buffering intensity function Qads* is calculated as the instantaneous slope of this reduced titration curve. Parameters for a surface complexation model are obtained by minimizing the sum of squares between the modeled (i.e. simulated) buffering intensity curve and the experimental data. The variance in the slope estimate, intrinsically produced as part of the Qads* calculation, can be used to weight the sum of squares calculation between the measured buffering intensity and a simulated curve. Effects of analytical error on data visualization and model optimization are discussed. Examples are provided of using ProtoFit for data visualization, model optimization, and model evaluation.

  9. The development of cones and associated features on ion bombarded copper

    International Nuclear Information System (INIS)

    Whitton, J.L.; Williams, J.S.

    1977-01-01

    Observations of ion-bombardment-induced surface modifications on crystalline copper substrates have been made using scanning electron microscopy. The delineation and development of grain boundary edges, faceted and terraced etch pits and small-scale ripple structure, together with the formation of faceted conical features have all been observed on low and high purity polycrystalline substrates. In general, the density of such surface morphological features, although variable from grain to grain, is higher in the proximity of grain boundaries. In particular, cones are only found within regions where other surface erosional features are present and it would appear that the development of these other surface features is a pre-requisite to cone generation in high-purity crystalline substrates. The authors suggest the operation of a defect-induced mechanism of cone formation whereby sputter elaboration of bulk defects (either preexisting or bombardment-induced) leads to the formation and development of surface features which, in turn, may intersect and result in the generation of cones. (Auth.)

  10. The features of chlorophyll concentration long-standing dynamics in the ocean surface layer (comparison of czcs and seawifs data)

    Science.gov (United States)

    Shevyrnogov, A.; Vysotskaya, G.

    To preserve biosphere and make its utilization expedient makes imperative to comprehend in depth long-standing dynamics of the primary production process on our planet. Variability of chlorophyll concentration in the ocean is one of the most important components of this process. However, hard access and large size of the water surface make its investigation labor-consuming. Besides, the dependence of primary production on high variability of hydrophysical phenomena in the ocean (fluctuations of currents, frontal zones, etc.) makes the location of points for measuring the chlorophyll concentration dynamics significant. In this work the long-standing changes in chlorophyll concentration in the surface layer of the ocean have been analyzed on the basis of the CZCS data for 7.5 years and the SeaWiFS data from 1997 to 2003. It was shown that the average chlorophyll concentration calculated at all investigated area is varied moderately. However when analyzing spatially local trends, it was detected that areas exist with stable rise and fall of chlorophyll concentration. Some interesting features of the long-standing dynamics of chlorophyll concentration several interesting features were found. There are the various directions of long-term trends (constant increase or decrease) that cannot be explained only by large-scale hydrological phenomena in the ocean (currents, upwellings etc.). The next feature is a difference between the trends revealed by using the CZCS data and the trends based on the SeaWiFS data. Thus, the obtained results allow the possibility of identification of the ocean biota role in the global biospheric gas exchange.

  11. Climate, water use, and land surface transformation in an irrigation intensive watershed - streamflow responses from 1950 through 2010

    Science.gov (United States)

    Dale, Joseph; Zou, Chris B.; Andrews, William J.; Long, James M.; Liang, Ye; Qiao, Lei

    2015-01-01

    Climatic variability and land surface change have a wide range of effects on streamflow and are often difficult to separate. We analyzed long-term records of climate, land use and land cover, and re-constructed the water budget based on precipitation, groundwater levels, and water use from 1950 through 2010 in the Cimarron–Skeleton watershed and a portion of the Cimarron–Eagle Chief watershed in Oklahoma, an irrigation-intensive agricultural watershed in the Southern Great Plains, USA. Our results show that intensive irrigation through alluvial aquifer withdrawal modifies climatic feedback and alters streamflow response to precipitation. Increase in consumptive water use was associated with decreases in annual streamflow, while returning croplands to non-irrigated grasslands was associated with increases in streamflow. Along with groundwater withdrawal, anthropogenic-induced factors and activities contributed nearly half to the observed variability of annual streamflow. Streamflow was more responsive to precipitation during the period of intensive irrigation between 1965 and 1984 than the period of relatively lower water use between 1985 and 2010. The Cimarron River is transitioning from a historically flashy river to one that is more stable with a lower frequency of both high and low flow pulses, a higher baseflow, and an increased median flow due in part to the return of cropland to grassland. These results demonstrated the interrelationship among climate, land use, groundwater withdrawal and streamflow regime and the potential to design agricultural production systems and adjust irrigation to mitigate impact of increasing climate variability on streamflow in irrigation intensive agricultural watershed.

  12. Airborne LIDAR and high resolution satellite data for rapid 3D feature extraction

    Science.gov (United States)

    Jawak, S. D.; Panditrao, S. N.; Luis, A. J.

    2014-11-01

    This work uses the canopy height model (CHM) based workflow for individual tree crown delineation and 3D feature extraction approach (Overwatch Geospatial's proprietary algorithm) for building feature delineation from high-density light detection and ranging (LiDAR) point cloud data in an urban environment and evaluates its accuracy by using very high-resolution panchromatic (PAN) (spatial) and 8-band (multispectral) WorldView-2 (WV-2) imagery. LiDAR point cloud data over San Francisco, California, USA, recorded in June 2010, was used to detect tree and building features by classifying point elevation values. The workflow employed includes resampling of LiDAR point cloud to generate a raster surface or digital terrain model (DTM), generation of a hill-shade image and an intensity image, extraction of digital surface model, generation of bare earth digital elevation model (DEM) and extraction of tree and building features. First, the optical WV-2 data and the LiDAR intensity image were co-registered using ground control points (GCPs). The WV-2 rational polynomial coefficients model (RPC) was executed in ERDAS Leica Photogrammetry Suite (LPS) using supplementary *.RPB file. In the second stage, ortho-rectification was carried out using ERDAS LPS by incorporating well-distributed GCPs. The root mean square error (RMSE) for the WV-2 was estimated to be 0.25 m by using more than 10 well-distributed GCPs. In the second stage, we generated the bare earth DEM from LiDAR point cloud data. In most of the cases, bare earth DEM does not represent true ground elevation. Hence, the model was edited to get the most accurate DEM/ DTM possible and normalized the LiDAR point cloud data based on DTM in order to reduce the effect of undulating terrain. We normalized the vegetation point cloud values by subtracting the ground points (DEM) from the LiDAR point cloud. A normalized digital surface model (nDSM) or CHM was calculated from the LiDAR data by subtracting the DEM from the DSM

  13. Does quality control matter? Surface urban heat island intensity variations estimated by satellite-derived land surface temperature products

    Science.gov (United States)

    Lai, Jiameng; Zhan, Wenfeng; Huang, Fan; Quan, Jinling; Hu, Leiqiu; Gao, Lun; Ju, Weimin

    2018-05-01

    The temporally regular and spatially comprehensive monitoring of surface urban heat islands (SUHIs) have been extremely difficult, until the advent of satellite-based land surface temperature (LST) products. However, these LST products have relatively higher errors compared to in situ measurements. This has resulted in comparatively inaccurate estimations of SUHI indicators and, consequently, may have distorted interpretations of SUHIs. Although reports have shown that LST qualities are important for SUHI interpretations, systematic investigations of the response of SUHI indicators to LST qualities across cities with dissimilar bioclimates are rare. To address this issue, we chose eighty-six major cities across mainland China and analyzed SUHI intensity (SUHII) derived from Moderate Resolution Imaging Spectroradiometer (MODIS) LST data. The LST-based SUHII differences due to inclusion or exclusion of MODIS quality control (QC) flags (i.e., ΔSUHII) were evaluated. Our major findings included, but are not limited to, the following four aspects: (1) SUHIIs can be significantly impacted by MODIS QC flags, and the associated QC-induced ΔSUHIIs generally accounted for 24.3% (29.9%) of the total SUHII value during the day (night); (2) the ΔSUHIIs differed between seasons, with considerable differences between transitional (spring and autumn) and extreme (summer and winter) seasons; (3) significant discrepancies also appeared among cities located in northern and southern regions, with northern cities often possessing higher annual mean ΔSUHIIs. The internal variations of ΔSUHIIs within individual cities also showed high heterogeneity, with ΔSUHII variations that generally exceeded 5.0 K (3.0 K) in northern (southern) cities; (4) ΔSUHIIs were negatively related to SUHIIs and cloud cover percentages (mostly in transitional seasons). No significant relationship was found in the extreme seasons. Our findings highlight the need to be extremely cautious when using LST

  14. Adaptive Feature Based Control of Compact Disk Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Vidal, Enrique Sanchez

    2005-01-01

    Many have experienced the problem that their Compact Disc players have difficulties playing Compact Discs with surface faults like scratches and fingerprints. The cause of this is due to the two servo control loops used to keep the Optical Pick-up Unit focused and radially on the information track...... of the Compact Disc. The problem is to design servo controllers which are well suited for handling surface faults which disturb the position measurement and still react sufficiently against normal disturbances like mechanical shocks. In previous work of the same authors a feature based control scheme for CD......-players playing CDs with surface fault is derived and described. This feature based control scheme uses precomputed base to remove the surface fault influence from the position measurements. In this paper an adaptive version of the feature based control scheme is proposed and described. This adaptive scheme can...

  15. Adaptive projection intensity adjustment for avoiding saturation in three-dimensional shape measurement

    Science.gov (United States)

    Chen, Chao; Gao, Nan; Wang, Xiangjun; Zhang, Zonghua

    2018-03-01

    Phase-based fringe projection methods have been commonly used for three-dimensional (3D) measurements. However, image saturation results in incorrect intensities in captured fringe pattern images, leading to phase and measurement errors. Existing solutions are complex. This paper proposes an adaptive projection intensity adjustment method to avoid image saturation and maintain good fringe modulation in measuring objects with a high range of surface reflectivities. The adapted fringe patterns are created using only one prior step of fringe-pattern projection and image capture. First, a set of phase-shifted fringe patterns with maximum projection intensity value of 255 and a uniform gray level pattern are projected onto the surface of an object. The patterns are reflected from and deformed by the object surface and captured by a digital camera. The best projection intensities corresponding to each saturated-pixel clusters are determined by fitting a polynomial function to transform captured intensities to projected intensities. Subsequently, the adapted fringe patterns are constructed using the best projection intensities at projector pixel coordinate. Finally, the adapted fringe patterns are projected for phase recovery and 3D shape calculation. The experimental results demonstrate that the proposed method achieves high measurement accuracy even for objects with a high range of surface reflectivities.

  16. Wide-field surface plasmon microscopy of nano- and microparticles: features, benchmarking, limitations, and bioanalytical applications

    Science.gov (United States)

    Nizamov, Shavkat; Scherbahn, Vitali; Mirsky, Vladimir M.

    2017-05-01

    Detection of nano- and micro-particles is an important task for chemical analytics, food industry, biotechnology, environmental monitoring and many other fields of science and industry. For this purpose, a method based on the detection and analysis of minute signals in surface plasmon resonance images due to adsorption of single nanopartciles was developed. This new technology allows one a real-time detection of interaction of single nano- and micro-particles with sensor surface. Adsorption of each nanoparticle leads to characteristic diffraction image whose intensity depends on the size and chemical composition of the particle. The adsorption rate characterizes volume concentration of nano- and micro-particles. Large monitored surface area of sensor enables a high dynamic range of counting and to a correspondingly high dynamic range in concentration scale. Depending on the type of particles and experimental conditions, the detection limit for aqueous samples can be below 1000 particles per microliter. For application of method in complex media, nanoparticle images are discriminated from image perturbations due to matrix components. First, the characteristic SPRM images of nanoparticles (templates) are collected in aqueous suspensions or spiked real samples. Then, the detection of nanoparticles in complex media using template matching is performed. The detection of various NPs in consumer products like cosmetics, mineral water, juices, and wines was shown at sub-ppb level. The method can be applied for ultrasensitive detection and analysis of nano- and micro-particles of biological (bacteria, viruses, endosomes), biotechnological (liposomes, protein nanoparticles for drug delivery) or technical origin.

  17. Implementation of the CCGM approximation for surface diffraction using Wigner R-matrix theory

    International Nuclear Information System (INIS)

    Lauderdale, J.G.; McCurdy, C.W.

    1983-01-01

    The CCGM approximation for surface scattering proposed by Cabrera, Celli, Goodman, and Manson [Surf. Sci. 19, 67 (1970)] is implemented for realistic surface interaction potentials using Wigner R-matrix theory. The resulting procedure is highly efficient computationally and is in no way limited to hard wall or purely repulsive potentials. Comparison is made with the results of close-coupling calculations of other workers which include the same diffraction channels in order to fairly evaluate the CCGM approximation which is an approximation to the coupled channels Lippman--Schwinger equation for the T matrix. The shapes of selective adsorption features, whether maxima or minima, in the scattered intensity are well represented in this approach for cases in which the surface corrugation is not too strong

  18. Various Landscapes and Features on Europa

    Science.gov (United States)

    1997-01-01

    These 15 frames show the great variety of surface features on Jupiter's icy moon, Europa, which have been revealed by the Galileo spacecraft Solid State Imaging (CCD) system during its first six orbits around Jupiter from June 1996 to February 1997. North is to the top of each of the images. The features seen on Europa's surface document both internal and external processes shaping the icy crust. Internal processes and the possible presence of liquid water beneath the ice are indicated by features such as 'dark spots', lobe-shaped flow features, 'puddles','mottled terrain', knobs, pits, and the darker areas along ridges and triple bands.Europa is subjected to constant tugging from the giant planet, Jupiter, as well as from its neighboring moons, Io and Ganymede. This causes 'tidal' forces that affect Europa's interior and surface. Evidence for such forces includes ridges, fractures, wedge-shaped bands, and areas of 'chaos'. Some of these features result from alternate extension and compression buckling and pulling apart Europa's icy shell.Impact craters document external effects on a planet's surface. Although present on Europa, impact craters are relatively scarce compared to the number seen on Ganymede, Callisto, and on the surfaces of most other 'rocky' planets and moons in our solar system. This scarcity of craters suggests that the surface of Europa is very young. 'Maculae' on Europa may be the scars from large impact events.These images have resolutions from 27 meters (89 feet) to 7 kilometers (4.3 miles) per picture element (pixel) and were taken by Galileo at ranges of 2,500 kilometers (1,525 miles) to 677,000 kilometers (413,000 miles) from Europa.The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo

  19. Chemometric evaluation of temperature-dependent surface-enhanced Raman spectra of riboflavin: What is the best multivariate approach to describe the effect of temperature?

    Science.gov (United States)

    Kokaislová, Alžběta; Kalhousová, Milena; Gráfová, Michaela; Matějka, Pavel

    2014-10-01

    Riboflavin is an essential nutrient involved in energetic metabolism. It is used as a pharmacologically active substance in treatment of several diseases. From analytical point of view, riboflavin can be used as an active part of sensors for substances with affinity to riboflavin molecules. In biological environment, metal substrates coated with riboflavin are exposed to temperatures that are different from room temperature. Hence, it is important to describe the influence of temperature on adsorbed molecules of riboflavin, especially on orientation of molecules towards the metal surface and on stability of adsorbed molecular layer. Surface-enhanced Raman scattering (SERS) spectroscopy is a useful tool for investigation of architecture of molecular layers adsorbed on metal surfaces because the spectral features in SERS spectra change with varying orientation of molecules towards the metal surface, as well as with changes in mutual interactions among adsorbed molecules. In this study, riboflavin was adsorbed on electrochemically prepared massive silver substrates that were exposed to temperature changes according to four different temperature programs. Raman spectra measured at different temperatures were compared considering positions of spectral bands, their intensities, bandwidths and variability of all these parameters. It was found out that increase of substrate temperature up to 50 °C does not lead to any observable decomposition of riboflavin molecules, but the changes of band intensity ratios within individual spectra are apparent. To distinguish sources of variability beside changes in band intensities and widths, Principal Component Analysis (PCA) was applied. Discriminant Analysis (DA) was used to explore if the SERS spectra can be separated according to temperature. The results of Partial Least Squares (PLS) regression demonstrate the possibility to predict the sample temperature using SERS spectral features. Results of all performed experiments and

  20. Crystal surface analysis using matrix textural features classified by a Probabilistic Neural Network

    International Nuclear Information System (INIS)

    Sawyer, C.R.; Quach, V.T.; Nason, D.; van den Berg, L.

    1991-01-01

    A system is under development in which surface quality of a growing bulk mercuric iodide crystal is monitored by video camera at regular intervals for early detection of growth irregularities. Mercuric iodide single crystals are employed in radiation detectors. A microcomputer system is used for image capture and processing. The digitized image is divided into multiple overlappings subimage and features are extracted from each subimage based on statistical measures of the gray tone distribution, according to the method of Haralick [1]. Twenty parameters are derived from each subimage and presented to a Probabilistic Neural Network (PNN) [2] for classification. This number of parameters was found to be optimal for the system. The PNN is a hierarchical, feed-forward network that can be rapidly reconfigured as additional training data become available. Training data is gathered by reviewing digital images of many crystals during their growth cycle and compiling two sets of images, those with and without irregularities. 6 refs., 4 figs

  1. Grazing angle X-ray fluorescence from periodic structures on silicon and silica surfaces

    International Nuclear Information System (INIS)

    Nowak, S.H.; Banaś, D.; Błchucki, W.; Cao, W.; Dousse, J.-Cl.; Hönicke, P.; Hoszowska, J.; Jabłoński, Ł.; Kayser, Y.; Kubala-Kukuś, A.; Pajek, M.; Reinhardt, F.; Savu, A.V.; Szlachetko, J.

    2014-01-01

    Various 3-dimensional nano-scaled periodic structures with different configurations and periods deposited on the surface of silicon and silica substrates were investigated by means of the grazing incidence and grazing emission X-ray fluorescence techniques. Apart from the characteristics which are typical for particle- and layer-like samples, the measured angular intensity profiles show additional periodicity-related features. The latter could be explained by a novel theoretical approach based on simple geometrical optics (GO) considerations. The new GO-based calculations were found to yield results in good agreement with experiment, also in cases where other theoretical approaches are not valid, e.g., periodic particle distributions with an increased surface coverage

  2. Thermal features of spallation window targets

    International Nuclear Information System (INIS)

    Martinez-Val, J. M.; Sordo, F.; Leon, P. T.

    2007-01-01

    Subcritical nuclear reactors have been proposed for a number of applications, from energy production to fertile-to-fissile conversion, and to transmutation of long-lived radio nuclei into stable or much shorter-lived nuclei. The main advantage of subcritical reactors is their large reactivity margin for not to attain prompt-supercritical power surges. On the contrary, subcritical reactors present some economic drawbacks and technical complexities that deserve suitable attention in the Research and Development phase. Namely, they need a very intense neutron source in order to keep the neutron flux and the reactor power at the required level. The most intense neutron source seems to be based on the proton-induced (or deuteron-induced) spallation reaction in heavy nuclei targets, which present very demanding thermal features that must be properly limited. Those limits pose upper bounds to the neutron yield of the target. In turn, the limits depend on the features of the impinging particle beam and the material composition and geometry of the target. Although the potential design window for spallation targets is rather wide, the analysis presented in this paper identifies specific topics that must properly be covered in the detailed project of a spallation source, in order to avoid unacceptable temperatures and mechanical stresses in the most critical parts of the source. In this paper, some calculations are reported on solid targets (water cooled or helium cooled) and molten metals targets. It is seen that thermal-hydraulic and mechanical calculations of spallation targets are fundamental elements in the coherent design of this type of very intense neutron sources. This coherence implies the need of a suitable trade-off among the relevant beam parameters (proton energy, total intensity and cross-section shape) and the features of the target (structural materials, coolant characteristics and target geometry). The goal of maximizing the neutron yield has to be checked

  3. Decreasing Asian summer monsoon intensity after 1860 AD in the global warming epoch

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Hai [Institute of Earth Environment, Chinese Academy of Sciences, State Key Laboratory of Loess and Quaternary Geology, Xi' an, Shaanxi Province (China); Hong, Yetang; Hong, Bin [Institute of Geochemistry, Chinese Academy of Sciences, State Key Laboratory of Environmental Geochemistry, Guiyang (China)

    2012-10-15

    The trend of the Indian summer monsoon (ISM) intensity and its nature during the past 100 and 200 years still remain unclear. In this study we reconstructed the ISM intensity during the past 270 years from tree ring {delta}{sup 18}O at Hongyuan, eastern edge of the Tibet Plateau. The monsoon failures inferred from {delta}{sup 18}O{sub tree} {sub ring} correlate well with those recorded in ice cores, speleothem, and historical literature sources. 22.6, 59.0, and 110.9-years frequency components in the Hongyuan {delta}{sup 18}O{sub tree} {sub ring} series, which may be the responses to solar activities, synchronize well with those recorded in other ISM indices. A notable feature of the reconstructed ISM intensity is the gradually decreasing trend from about 1860 to the present, which is inversely related to the increasing temperature trend contemporaneously. Such ''decreasing ISM intensity-increasing temperature'' tendency can also be supported by ice core records and meteorological records over a wide geographic extension. The decrease in sea surface temperature gradient between tropical and north Indian Ocean, and the decrease in land-sea thermal contrast between tropical Indian Ocean and ''Indian sub-continent-western Himalaya'' are possibly responsible for the observed decreasing ISM trend. (orig.)

  4. Upwelling filaments are cold, typically narrow features in surface ...

    African Journals Online (AJOL)

    spamer

    They are defined by strong ... transporting coastally upwelled water to the deep ... surface temperature anomaly up to 2°C. The cool temperature signal was restricted to a shallow surface ... towards the important process of exchanges between.

  5. Automatic grading of appearance retention of carpets using intensity and range images

    Science.gov (United States)

    Orjuela Vargas, Sergio Alejandro; Ortiz-Jaramillo, Benhur; Vansteenkiste, Ewout; Rooms, Filip; De Meulemeester, Simon; de Keyser, Robain; Van Langenhove, Lieva; Philips, Wilfried

    2012-04-01

    Textiles are mainly used for decoration and protection. In both cases, their original appearance and its retention are important factors for customers. Therefore, evaluation of appearance parameters are critical for quality assurance purposes, during and after manufacturing, to determine the lifetime and/or beauty of textile products. In particular, appearance retention of textile products is commonly certified with grades, which are currently assigned by human experts. However, manufacturers would prefer a more objective system. We present an objective system for grading appearance retention, particularly, for textile floor coverings. Changes in appearance are quantified by using linear regression models on texture features extracted from intensity and range images. Range images are obtained by our own laser scanner, reconstructing the carpet surface using two methods that have been previously presented. We extract texture features using a variant of the local binary pattern technique based on detecting those patterns whose frequencies are related to the appearance retention grades. We test models for eight types of carpets. Results show that the proposed approach describes the degree of wear with a precision within the range allowed to human inspectors by international standards. The methodology followed in this experiment has been designed to be general for evaluating global deviation of texture in other types of textiles, as well as other surface materials.

  6. Light induced modulation instability of surfaces under intense illumination

    KAUST Repository

    Burlakov, V. M.; Foulds, Ian G.; Goriely, A.

    2013-01-01

    heated by radiation. Periodic heating is due to focusing-defocusing effects caused by the initial surface modulation. The surface modulation has a period longer than the excitation wavelength and does not require coherent light source. Therefore

  7. Stress intensity factors for deep cracks emanating from the corner formed by a hole intersecting a plate surface

    Science.gov (United States)

    Mcgowan, J. J.; Smith, C. W.

    1976-01-01

    The stress intensity factors (SIFs) at the end points of flaws emanating from the corner formed by the intersection of a plate with a hole were determined using stress freezing photoelasticity and a numerical technique known as the Taylor series correction method to extract the SIF values from the photoelastic data. The geometries studied were crack depth to thickness ratios of about 0.2, 0.5, and 0.75; crack depth to crack length ratios of about 1.0 to 2.0; and crack length to hole radius ratios of about 0.5 to 2.0. The SIFs were determined at the intersection of the flaw border with the plate surface (KS) and with the edge of the hole (KH). It is shown that extension of a crack emanating from a corner of intersection of a hole with a plate under monotonically increasing load is not self-similar and that as the flaw depth increases, KH decreases and KS increases. Existing theories and design criteria significantly overestimate the SIF at both the hole and the surface except for shallow flaws at the hole and deep flaws at the surface.

  8. Muscle conduction velocity, surface electromyography variables, and echo intensity during concentric and eccentric fatigue.

    Science.gov (United States)

    Gonzalez-Izal, Miriam; Lusa Cadore, Eduardo; Izquierdo, Mikel

    2014-03-01

    Concentric (CON) and eccentric (ECC) contractions may involve different mechanisms related to changes in sarcolemma status and the consequent alteration of action potential transmission along muscle fibers. Muscle conduction velocity (CV), surface electromyography signal (sEMG), muscle quality, and blood lactate concentrations were analyzed during CON and ECC actions. Compared with ECC, the CON protocol resulted in greater muscle force losses, blood lactate concentrations, and changes in sEMG parameters. Similar reductions in CV were detected in both protocols. Higher echo intensity values were observed 2 days after ECC due to greater muscle damage. The effects of the muscle damage produced by ECC exercise on the transmission of action potentials along muscle fibers (measured as the CV) may be comparable with the effects of hydrogen accumulation produced by CON exercise (related to greater lactate concentrations), which causes greater force loss and change in other sEMG variables during CON than during ECC actions.

  9. Combustion of methane-oxygen and methane-oxygen-CFC mixtures initiated by a high-current slipping surface discharge

    International Nuclear Information System (INIS)

    Kossyi, I.A.; Silakov, V.P.; Tarasova, N.M.

    2001-01-01

    Results are presented from experimental studies of the destruction of chlorofluorocarbon (CF 2 Cl 2 ) molecules in a methane-oxygen (air) gas mixture whose combustion is initiated by a high-current slipping surface discharge. It is found that a three-component CH 4 + O 2 (air)+ CF 2 Cl 2 gas mixture (even with a considerable amount of the third component) demonstrates properties of explosive combustion involving chain reactions that are typical of two-component CH 4 + O 2 mixtures. Experiments show the high degree of destruction (almost complete decomposition) of chlorofluorocarbons contained in the mixture during one combustion event. The combustion dynamics is studied. It is shown that the combustion initiated by a slipping surface discharge has a number of characteristic features that make it impossible to identify the combustion dynamics with the formation of a combustion or detonation wave. The features of the effects observed can be related to intense UV radiation produced by a pulsed high-current surface discharge

  10. Pathological features of olfactory neuroblastoma in an axolotl (Ambystoma mexicanum).

    Science.gov (United States)

    Shioda, Chieko; Uchida, Kazuyuki; Nakayama, Hiroyuki

    2011-08-01

    A one-year-old, female Mexican axolotl (Ambystoma mexicanum) had a rough-surfaced, polypoid, pink tumor mass of approximately 10 mm in diameter in the oral cavity. Histologically, the tumor extended from the ethmoturbinate region and into the oral cavity and had replaced some of the maxillary bone tissue. The tumor mass was composed of a lobular architecture of small round-shaped tumor cells with occasional Flexner-Wintersteiner-like rosette formation. There were no metastatic lesions in the other organs. Immunohistochemically, the tumor cells were partly positive for several neural markers (class III beta-tubulin, S-100 protein, and doublecortin) and intensely positive for an epithelial marker (cytokeratin AE1/AE3). These results suggest that the present tumor originated from neuroectodermal tissue. Considering the location and histological and immunohistochemical features of the tumor, a diagnosis of olfactory neuroblastoma was made.

  11. Human perception of electrical stimulation on the surface of somatosensory cortex.

    Directory of Open Access Journals (Sweden)

    Shivayogi V Hiremath

    Full Text Available Recent advancement in electrocorticography (ECoG-based brain-computer interface technology has sparked a new interest in providing somatosensory feedback using ECoG electrodes, i.e., cortical surface electrodes. We conducted a 28-day study of cortical surface stimulation in an individual with arm paralysis due to brachial plexus injury to examine the sensation produced by electrical stimulation of the somatosensory cortex. A high-density ECoG grid was implanted over the somatosensory and motor cortices. Stimulation through cortical surface electrodes over the somatosensory cortex successfully elicited arm and hand sensations in our participant with chronic paralysis. There were three key findings. First, the intensity of perceived sensation increased monotonically with both pulse amplitude and pulse frequency. Second, changing pulse width changed the type of sensation based on qualitative description provided by the human participant. Third, the participant could distinguish between stimulation applied to two neighboring cortical surface electrodes, 4.5 mm center-to-center distance, for three out of seven electrode pairs tested. Taken together, we found that it was possible to modulate sensation intensity, sensation type, and evoke sensations across a range of locations from the fingers to the upper arm using different stimulation electrodes even in an individual with chronic impairment of somatosensory function. These three features are essential to provide effective somatosensory feedback for neuroprosthetic applications.

  12. Surface for dummies

    CERN Document Server

    Rathbone, Andy

    2014-01-01

    Make Microsoft's Surface work-and play-just the way you want it to Microsoft's Surface tablet has the features and personality you're looking for, with a robust environment for business computing that doesn't skimp on fun. Surface for Dummies, 2nd Edition explains how Windows 8.1 Pro and Windows RT differ, and helps you decide which Surface model is best for you. Step by step, this book walks you through both the hardware and software features of the Surface, including the touch cover and type cover, Windows RT and Windows 8.1 Pro operating systems, and the coveted Office Home & Student 2013 s

  13. Results of evaluation of tailing dumps dust intensity

    Directory of Open Access Journals (Sweden)

    Masloboev V. A.

    2016-03-01

    Full Text Available A set of most acceptable and well-known methods of dust intensity evaluation has been defined and tested (dependence of Westphal D. L. et al. and DEAD scheme based on the analysis of exiting approaches (deserts, tailing dumps, etc.. The description of the chosen methods has been given. The determination of dynamic velocity u* and velocity at the height of +10 m above the dusting surface u10 which are necessary to evaluate the dust intensity has been demonstrated. The method is based on two-dimensional numerical model of atmosphere aerodynamics in the area of "tailing dumps of ANOF-2 ‒ the town of Apatity". The study provides calculations of horizontal velocity at the height of +10 m above the dusting surface at the wind speed varying from 5 to 23 m/sec. The work also suggests the results of graphical data processing related to tailing grain size distribution from the surface of the firmly established surface of the tailing dumps of ANOF-2. Comparative analysis has been given and the peculiarities of interval (based on grains sizes dust intensity of the tailing dumps of ANOF-2 have been shown using the dependence of Westphal D. L. et al. and DEAD scheme within the wind speed range. The received values of dust intensity at the lower range limit are close to the "maximum specific dust off" value which is used by project specialists for documentation development

  14. Impact of the surface wind flow on precipitation characteristics over the southern Himalayas: GPM observations

    Science.gov (United States)

    Zhang, Aoqi; Fu, Yunfei; Chen, Yilun; Liu, Guosheng; Zhang, Xiangdong

    2018-04-01

    The distribution and influence of precipitation over the southern Himalayas have been investigated on regional and global scales. However, previous studies have been limited by the insufficient emphasis on the precipitation triggers or the lack of droplet size distribution (DSD) data. Here, precipitating systems were identified using Global Precipitation Mission dual-frequency radar data, and then categorized into five classes according to surface flow from the European Centre for Medium-Range Weather Forecast Interim data. The surface flow is introduced to indicate the precipitation triggers, which is validated in this study. Using case and statistical analysis, we show that the precipitating systems with different surface flow had different precipitation characteristics, including spatio-temporal features, reflectivity profile, DSD, and rainfall intensity. Furthermore, the results show that the source of the surface flow influences the intensity and DSD of precipitation. The terrain exerts different impacts on the precipitating systems of five categories, leading to various distributions of precipitation characteristics over the southern Himalayas. Our results suggest that the introduction of surface flow and DSD for precipitating systems provides insight into the complex precipitation of the southern Himalayas. The different characteristics of precipitating systems may be caused by the surface flow. Therefore, future study on the orographic precipitations should take account the impact of the surface flow and its relevant dynamic mechanism.

  15. Meteorological Modeling Using the WRF-ARW Model for Grand Bay Intensive Studies of Atmospheric Mercury

    Directory of Open Access Journals (Sweden)

    Fong Ngan

    2015-02-01

    Full Text Available Measurements at the Grand Bay National Estuarine Research Reserve support a range of research activities aimed at improving the understanding of the atmospheric fate and transport of mercury. Routine monitoring was enhanced by two intensive measurement periods conducted at the site in summer 2010 and spring 2011. Detailed meteorological data are required to properly represent the weather conditions, to determine the transport and dispersion of plumes and to understand the wet and dry deposition of mercury. To describe the mesoscale features that might influence future plume calculations for mercury episodes during the Grand Bay Intensive campaigns, fine-resolution meteorological simulations using the Weather Research and Forecasting (WRF model were conducted with various initialization and nudging configurations. The WRF simulations with nudging generated reasonable results in comparison with conventional observations in the region and measurements obtained at the Grand Bay site, including surface and sounding data. The grid nudging, together with observational nudging, had a positive effect on wind prediction. However, the nudging of mass fields (temperature and moisture led to overestimates of precipitation, which may introduce significant inaccuracies if the data were to be used for subsequent atmospheric mercury modeling. The regional flow prediction was also influenced by the reanalysis data used to initialize the WRF simulations. Even with observational nudging, the summer case simulation results in the fine resolution domain inherited features of the reanalysis data, resulting in different regional wind patterns. By contrast, the spring intensive period showed less influence from the reanalysis data.

  16. Feature and Intensity Based Medical Image Registration Using Particle Swarm Optimization.

    Science.gov (United States)

    Abdel-Basset, Mohamed; Fakhry, Ahmed E; El-Henawy, Ibrahim; Qiu, Tie; Sangaiah, Arun Kumar

    2017-11-03

    Image registration is an important aspect in medical image analysis, and kinds use in a variety of medical applications. Examples include diagnosis, pre/post surgery guidance, comparing/merging/integrating images from multi-modal like Magnetic Resonance Imaging (MRI), and Computed Tomography (CT). Whether registering images across modalities for a single patient or registering across patients for a single modality, registration is an effective way to combine information from different images into a normalized frame for reference. Registered datasets can be used for providing information relating to the structure, function, and pathology of the organ or individual being imaged. In this paper a hybrid approach for medical images registration has been developed. It employs a modified Mutual Information (MI) as a similarity metric and Particle Swarm Optimization (PSO) method. Computation of mutual information is modified using a weighted linear combination of image intensity and image gradient vector flow (GVF) intensity. In this manner, statistical as well as spatial image information is included into the image registration process. Maximization of the modified mutual information is effected using the versatile Particle Swarm Optimization which is developed easily with adjusted less parameter. The developed approach has been tested and verified successfully on a number of medical image data sets that include images with missing parts, noise contamination, and/or of different modalities (CT, MRI). The registration results indicate the proposed model as accurate and effective, and show the posture contribution in inclusion of both statistical and spatial image data to the developed approach.

  17. The development of cones and associated features on ion bombarded copper

    International Nuclear Information System (INIS)

    Whitton, J.L.; Carter, G.; Nobes, M.J.; Williams, J.S.

    1977-01-01

    Observations of ion-bombardment-induced surface modifications on crystalline copper substrates have been made using scanning electron microscopy. The delineation and development of grain boundary edges, faceted and terraced etch pits and small-scale ripple structure, together with the formation of faceted conical features, have all been observed on low and high purity polycrystalline substrates. In general, the density of such surface morphological features, although variable from grain to grain, is higher in the proximity of grain boundaries. In particular, cones are only found within regions where other surface erosional features are present and it would appear that the development of these other features is a pre-requisite to cone generation in high-purity crystalline substrates. We suggest the operation of a defect-induced mechanism of cone formation whereby sputter elaboration of bulk defects (either pre-existing or bombardment-induced) leads to the formation and development of surface features which, in turn, may intersect and result in the generation of cones. (author)

  18. Spent coffee-based activated carbon: specific surface features and their importance for H2S separation process.

    Science.gov (United States)

    Kante, Karifala; Nieto-Delgado, Cesar; Rangel-Mendez, J Rene; Bandosz, Teresa J

    2012-01-30

    Activated carbons were prepared from spent ground coffee. Zinc chloride was used as an activation agent. The obtained materials were used as a media for separation of hydrogen sulfide from air at ambient conditions. The materials were characterized using adsorption of nitrogen, elemental analysis, SEM, FTIR, and thermal analysis. Surface features of the carbons depend on the amount of an activation agent used. Even though the residual inorganic matter takes part in the H(2)S retention via salt formation, the porous surface of carbons governs the separation process. The chemical activation method chosen resulted in formation of large volume of pores with sizes between 10 and 30Å, optimal for water and hydrogen sulfide adsorption. Even though the activation process can be optimized/changed, the presence of nitrogen in the precursor (caffeine) is a significant asset of that specific organic waste. Nitrogen functional groups play a catalytic role in hydrogen sulfide oxidation. Copyright © 2011 Elsevier B.V. All rights reserved.

  19. Effect of geometrical features various objects on the data quality obtained with measured by TLS

    Science.gov (United States)

    Pawłowicz, J. A.

    2017-08-01

    Collecting data on different building structures using Terrestrial Laser Scanning (TLS) has become in recent years a very popular due to minimize the time required to complete the task as compared to traditional methods. Technical parameters of 3D scanning devices (digitizers) are increasingly being improved, and the accuracy of the data collected allows you to play not only the geometry of an existing object in a digital image, but also enables the assessment of his condition. This is possible thanks to the digitalization of existing objects e.g., a 3D laser scanner, with which is obtained a digital data base is presented in the form of a cloud of points and by using reverse engineering. Measurements using laser scanners depends to a large extent, on the quality of the returning beam reflected from the target surface, towards the receiver. High impact on the strength and quality of the beam returning to the geometric features of the object. These properties may contribute to the emergence of some, sometimes even serious errors during scanning of various shapes. The study defined the effect of the laser beam distortion during the measurement objects with the same material but with different geometrical features on their three-dimensional imaging obtained from measurements made using TLS. We present the problem of data quality, dependent on the deflection of the beam intensity and shape of the object selected examples. The knowledge of these problems allows to obtain valuable data necessary for the implementation of digitization and the visualization of virtually any building structure made of any materials. The studies has been proven that the increase in the density of scanning does not affect the values of mean square error. The increase in the angle of incidence of the beam onto a flat surface, however, causes a decrease in the intensity of scattered radiation that reaches the receiver. The article presents an analysis of the laser beam reflected from broken at

  20. Photoemission intensity oscillations in the valence bands of C70 film

    International Nuclear Information System (INIS)

    Li Yanjun; Wang Peng; Ni Jingfu; Meng Liang; Wang Xiaobo; Sheng Chunqi; Li Hongnian; Zhang Wenhua; Xu Yang; Xu Faqiang; Zhu Junfa

    2011-01-01

    Highlights: → The article develops a procedure for obtaining the accurate spectral intensities in the studies of the photoionization cross-section oscillation of C 70 . → The article fulfills the observation of all oscillating periods of the cross-section oscillation of C 70 . → The article reports the oscillating data for more molecular orbitals (feature C in the article) as compared with the published works. → The article reveals that some simple theoretical models based on the spherical symmetric approximation survive for the ellipsoidally shaped C 70 . - Abstract: We have measured and analyzed the photoemission spectra (PES) of a C 70 film in the photon energy region from 13.4 eV to 98.4 eV. The photoelectron intensities of two C 2p π-derived features (denoted by A and B) oscillate regularly in the whole energy region with some fine structures below ∼30 eV. To obtain the detailed information of the oscillations, we have developed a sophisticated but practical procedure for intensity calculation. The procedure consists of two core concepts. The first is ascribing the PES features to their corresponding molecular orbitals with the help of density functional calculations. The second is a background subtraction algorithm. With this procedure, we obtained the oscillating behavior for individual features (A and B), which is by and large consistent with the predictions based on the spherical symmetric approximation although C 70 has the ellipsoidal shape. Owing to the solid state effect, the oscillating amplitudes of the A/B intensity ratios are smaller than those of gas phase C 70 , but an orbital shift reported recently was not observed on our sample. The oscillating curve of a deeper feature, which consists of both σ and π states, are also reported.

  1. Short term memory for single surface features and bindings in ageing: A replication study.

    Science.gov (United States)

    Isella, Valeria; Molteni, Federica; Mapelli, Cristina; Ferrarese, Carlo

    2015-06-01

    In the present study we replicated a previous experiment investigating visuo-spatial short term memory binding in young and older healthy individuals, in the attempt to verify the pattern of impairment that can be observed in normal elderly for short term memory for single items vs short term memory for bindings. Assessing a larger sample size (25 young and 25 older subjects), using a more appropriate measure of accuracy for a change detection task (A'), and adding the evaluation of speed of performance, we confirmed that old normals show a decline in short term memory for bindings of shape and colour that is of comparable extent, and not major, to the decline in memory for single shapes and single colours. The absence of a specific deficit of short term memory for conjunctions of surface features seems to distinguish cognitive ageing from Alzheimer's Disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. A Low-Cost Energy-Efficient Cableless Geophone Unit for Passive Surface Wave Surveys.

    Science.gov (United States)

    Dai, Kaoshan; Li, Xiaofeng; Lu, Chuan; You, Qingyu; Huang, Zhenhua; Wu, H Felix

    2015-09-25

    The passive surface wave survey is a practical, non-invasive seismic exploration method that has increasingly been used in geotechnical engineering. However, in situ deployment of traditional wired geophones is labor intensive for a dense sensor array. Alternatively, stand-alone seismometers can be used, but they are bulky, heavy, and expensive because they are usually designed for long-term monitoring. To better facilitate field applications of the passive surface wave survey, a low-cost energy-efficient geophone system was developed in this study. The hardware design is presented in this paper. To validate the system's functionality, both laboratory and field experiments were conducted. The unique feature of this newly-developed cableless geophone system allows for rapid field applications of the passive surface wave survey with dense array measurements.

  3. Automatic Extraction of Road Markings from Mobile Laser-Point Cloud Using Intensity Data

    Science.gov (United States)

    Yao, L.; Chen, Q.; Qin, C.; Wu, H.; Zhang, S.

    2018-04-01

    With the development of intelligent transportation, road's high precision information data has been widely applied in many fields. This paper proposes a concise and practical way to extract road marking information from point cloud data collected by mobile mapping system (MMS). The method contains three steps. Firstly, road surface is segmented through edge detection from scan lines. Then the intensity image is generated by inverse distance weighted (IDW) interpolation and the road marking is extracted by using adaptive threshold segmentation based on integral image without intensity calibration. Moreover, the noise is reduced by removing a small number of plaque pixels from binary image. Finally, point cloud mapped from binary image is clustered into marking objects according to Euclidean distance, and using a series of algorithms including template matching and feature attribute filtering for the classification of linear markings, arrow markings and guidelines. Through processing the point cloud data collected by RIEGL VUX-1 in case area, the results show that the F-score of marking extraction is 0.83, and the average classification rate is 0.9.

  4. Invariant Feature Matching for Image Registration Application Based on New Dissimilarity of Spatial Features

    Science.gov (United States)

    Mousavi Kahaki, Seyed Mostafa; Nordin, Md Jan; Ashtari, Amir H.; J. Zahra, Sophia

    2016-01-01

    An invariant feature matching method is proposed as a spatially invariant feature matching approach. Deformation effects, such as affine and homography, change the local information within the image and can result in ambiguous local information pertaining to image points. New method based on dissimilarity values, which measures the dissimilarity of the features through the path based on Eigenvector properties, is proposed. Evidence shows that existing matching techniques using similarity metrics—such as normalized cross-correlation, squared sum of intensity differences and correlation coefficient—are insufficient for achieving adequate results under different image deformations. Thus, new descriptor’s similarity metrics based on normalized Eigenvector correlation and signal directional differences, which are robust under local variation of the image information, are proposed to establish an efficient feature matching technique. The method proposed in this study measures the dissimilarity in the signal frequency along the path between two features. Moreover, these dissimilarity values are accumulated in a 2D dissimilarity space, allowing accurate corresponding features to be extracted based on the cumulative space using a voting strategy. This method can be used in image registration applications, as it overcomes the limitations of the existing approaches. The output results demonstrate that the proposed technique outperforms the other methods when evaluated using a standard dataset, in terms of precision-recall and corner correspondence. PMID:26985996

  5. Invariant Feature Matching for Image Registration Application Based on New Dissimilarity of Spatial Features.

    Directory of Open Access Journals (Sweden)

    Seyed Mostafa Mousavi Kahaki

    Full Text Available An invariant feature matching method is proposed as a spatially invariant feature matching approach. Deformation effects, such as affine and homography, change the local information within the image and can result in ambiguous local information pertaining to image points. New method based on dissimilarity values, which measures the dissimilarity of the features through the path based on Eigenvector properties, is proposed. Evidence shows that existing matching techniques using similarity metrics--such as normalized cross-correlation, squared sum of intensity differences and correlation coefficient--are insufficient for achieving adequate results under different image deformations. Thus, new descriptor's similarity metrics based on normalized Eigenvector correlation and signal directional differences, which are robust under local variation of the image information, are proposed to establish an efficient feature matching technique. The method proposed in this study measures the dissimilarity in the signal frequency along the path between two features. Moreover, these dissimilarity values are accumulated in a 2D dissimilarity space, allowing accurate corresponding features to be extracted based on the cumulative space using a voting strategy. This method can be used in image registration applications, as it overcomes the limitations of the existing approaches. The output results demonstrate that the proposed technique outperforms the other methods when evaluated using a standard dataset, in terms of precision-recall and corner correspondence.

  6. THE APPLICATION OF SUPPORT VECTOR MACHINE (SVM USING CIELAB COLOR MODEL, COLOR INTENSITY AND COLOR CONSTANCY AS FEATURES FOR ORTHO IMAGE CLASSIFICATION OF BENTHIC HABITATS IN HINATUAN, SURIGAO DEL SUR, PHILIPPINES

    Directory of Open Access Journals (Sweden)

    J. E. Cubillas

    2016-06-01

    Full Text Available This study demonstrates the application of CIELAB, Color intensity, and One Dimensional Scalar Constancy as features for image recognition and classifying benthic habitats in an image with the coastal areas of Hinatuan, Surigao Del Sur, Philippines as the study area. The study area is composed of four datasets, namely: (a Blk66L005, (b Blk66L021, (c Blk66L024, and (d Blk66L0114. SVM optimization was performed in Matlab® software with the help of Parallel Computing Toolbox to hasten the SVM computing speed. The image used for collecting samples for SVM procedure was Blk66L0114 in which a total of 134,516 sample objects of mangrove, possible coral existence with rocks, sand, sea, fish pens and sea grasses were collected and processed. The collected samples were then used as training sets for the supervised learning algorithm and for the creation of class definitions. The learned hyper-planes separating one class from another in the multi-dimensional feature space can be thought of as a super feature which will then be used in developing the C (classifier rule set in eCognition® software. The classification results of the sampling site yielded an accuracy of 98.85% which confirms the reliability of remote sensing techniques and analysis employed to orthophotos like the CIELAB, Color Intensity and One dimensional scalar constancy and the use of SVM classification algorithm in classifying benthic habitats.

  7. Locating irregularly shaped clusters of infection intensity

    Directory of Open Access Journals (Sweden)

    Niko Yiannakoulias

    2010-05-01

    Full Text Available Patterns of disease may take on irregular geographic shapes, especially when features of the physical environment influence risk. Identifying these patterns can be important for planning, and also identifying new environmental or social factors associated with high or low risk of illness. Until recently, cluster detection methods were limited in their ability to detect irregular spatial patterns, and limited to finding clusters that were roughly circular in shape. This approach has less power to detect irregularly-shaped, yet important spatial anomalies, particularly at high spatial resolutions. We employ a new method of finding irregularly-shaped spatial clusters at micro-geographical scales using both simulated and real data on Schistosoma mansoni and hookworm infection intensities. This method, which we refer to as the “greedy growth scan”, is a modification of the spatial scan method for cluster detection. Real data are based on samples of hookworm and S. mansoni from Kitengei, Makueni district, Kenya. Our analysis of simulated data shows how methods able to find irregular shapes are more likely to identify clusters along rivers than methods constrained to fixed geometries. Our analysis of infection intensity identifies two small areas within the study region in which infection intensity is elevated, possibly due to local features of the physical or social environment. Collectively, our results show that the “greedy growth scan” is a suitable method for exploratory geographical analysis of infection intensity data when irregular shapes are suspected, especially at micro-geographical scales.

  8. Surface-enhanced Raman spectroscopy on laser-engineered ruthenium dye-functionalized nanoporous gold

    Science.gov (United States)

    Schade, Lina; Franzka, Steffen; Biener, Monika; Biener, Jürgen; Hartmann, Nils

    2016-06-01

    Photothermal processing of nanoporous gold with a microfocused continuous-wave laser at λ = 532 nm provides a facile means in order engineer the pore and ligament size of nanoporous gold. In this report we take advantage of this approach in order to investigate the size-dependence of enhancement effects in surface-enhanced Raman spectroscopy (SERS). Surface structures with laterally varying pore sizes from 25 nm to ≥200 nm are characterized using scanning electron microscopy and then functionalized with N719, a commercial ruthenium complex, which is widely used in dye-sensitized solar cells. Raman spectroscopy reveals the characteristic spectral features of N719. Peak intensities strongly depend on the pore size. Highest intensities are observed on the native support, i.e. on nanoporous gold with pore sizes around 25 nm. These results demonstrate the particular perspectives of laser-fabricated nanoporous gold structures in fundamental SERS studies. In particular, it is emphasized that laser-engineered porous gold substrates represent a very well defined platform in order to study size-dependent effects with high reproducibility and precision and resolve conflicting results in previous studies.

  9. High intensity focused ultrasound treatment of adenomyosis: The relationship between the features of magnetic resonance imaging on T2 weighted images and the therapeutic efficacy

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Chunmei [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, Chongqing Haifu Hospital, College of Biomedical Engineering, Chongqing Medical University, Chongqing (China); Setzen, Raymond [Department of Obstetrics and Gynecology, Chris Hani Baragwanath Academic Hospital, Johannesburg (South Africa); Liu, Zhongqiong; Liu, Yunchang [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, Chongqing Haifu Hospital, College of Biomedical Engineering, Chongqing Medical University, Chongqing (China); Xie, Bin [Department of Ultrasound, Huanggang Central Hospital, Huanggang City, Hubei 438000 (China); Aili, Aixingzi, E-mail: 1819483078@qq.com [Shanghai First Maternity and Infant Health Hospital, Shanghai (China); Zhang, Lian, E-mail: lianwzhang@yahoo.com [State Key Laboratory of Ultrasound Engineering in Medicine Co-founded by Chongqing and the Ministry of Science and Technology, Chongqing Key Laboratory of Ultrasound in Medicine and Engineering, Chongqing Haifu Hospital, College of Biomedical Engineering, Chongqing Medical University, Chongqing (China)

    2017-04-15

    Objectives: To investigate the relationship between the features of magnetic resonance imaging (MRI) on T2 weighted images (T2WI) and the therapeutic efficacy of high intensity focused ultrasound (HIFU) on adenomyosis. Materials and methods: From January 2011 to November 2015, four hundred and twenty-eight patients with symptomatic adenomyosis were treated with HIFU. Based on the signal intensity and the number of hyperintense foci in the adenomyotic lesions on T2WI, the patients were classified into groups. The day after HIFU ablation patients underwent contrast-enhanced MRI and a comparison was made of non-perfused volume (NPV) ratio, energy efficiency factor (EEF), treatment time, sonication time, and adverse effects. Results: No significant difference in terms of HIFU treatment settings and results was observed between the group of patients with hypointense adenomyotic lesions and the group with isointense adenomyotic lesions (P > 0.05). However, the sonication time and EEF were significantly higher in the group with multiple hyperintense foci compared to the group with few hyperintense foci. The NPV ratio achieved in the lesions with multiple hyperintenese foci was significantly lower than that in the lesions with few hyperintense foci (P < 0.05). No significant difference was observed in the rate of adverse effects between the two groups. Conclusions: Based on our results, the response of the adenomyotic lesions to HIFU treatment is not related to the signal intensity of adenomyotic lesions on T2WI. However, the number of the high signal intensity foci in the adenomyotic lesions on T2WI can be considered as a predictive factor to help select patients for HIFU treatment.

  10. High intensity focused ultrasound treatment of adenomyosis: The relationship between the features of magnetic resonance imaging on T2 weighted images and the therapeutic efficacy

    International Nuclear Information System (INIS)

    Gong, Chunmei; Setzen, Raymond; Liu, Zhongqiong; Liu, Yunchang; Xie, Bin; Aili, Aixingzi; Zhang, Lian

    2017-01-01

    Objectives: To investigate the relationship between the features of magnetic resonance imaging (MRI) on T2 weighted images (T2WI) and the therapeutic efficacy of high intensity focused ultrasound (HIFU) on adenomyosis. Materials and methods: From January 2011 to November 2015, four hundred and twenty-eight patients with symptomatic adenomyosis were treated with HIFU. Based on the signal intensity and the number of hyperintense foci in the adenomyotic lesions on T2WI, the patients were classified into groups. The day after HIFU ablation patients underwent contrast-enhanced MRI and a comparison was made of non-perfused volume (NPV) ratio, energy efficiency factor (EEF), treatment time, sonication time, and adverse effects. Results: No significant difference in terms of HIFU treatment settings and results was observed between the group of patients with hypointense adenomyotic lesions and the group with isointense adenomyotic lesions (P > 0.05). However, the sonication time and EEF were significantly higher in the group with multiple hyperintense foci compared to the group with few hyperintense foci. The NPV ratio achieved in the lesions with multiple hyperintenese foci was significantly lower than that in the lesions with few hyperintense foci (P < 0.05). No significant difference was observed in the rate of adverse effects between the two groups. Conclusions: Based on our results, the response of the adenomyotic lesions to HIFU treatment is not related to the signal intensity of adenomyotic lesions on T2WI. However, the number of the high signal intensity foci in the adenomyotic lesions on T2WI can be considered as a predictive factor to help select patients for HIFU treatment.

  11. Patch layout generation by detecting feature networks

    KAUST Repository

    Cao, Yuanhao; Yan, Dongming; Wonka, Peter

    2015-01-01

    The patch layout of 3D surfaces reveals the high-level geometric and topological structures. In this paper, we study the patch layout computation by detecting and enclosing feature loops on surfaces. We present a hybrid framework which combines

  12. Three-dimensional measurement of small inner surface profiles using feature-based 3-D panoramic registration

    Science.gov (United States)

    Gong, Yuanzheng; Seibel, Eric J.

    2017-01-01

    Rapid development in the performance of sophisticated optical components, digital image sensors, and computer abilities along with decreasing costs has enabled three-dimensional (3-D) optical measurement to replace more traditional methods in manufacturing and quality control. The advantages of 3-D optical measurement, such as noncontact, high accuracy, rapid operation, and the ability for automation, are extremely valuable for inline manufacturing. However, most of the current optical approaches are eligible for exterior instead of internal surfaces of machined parts. A 3-D optical measurement approach is proposed based on machine vision for the 3-D profile measurement of tiny complex internal surfaces, such as internally threaded holes. To capture the full topographic extent (peak to valley) of threads, a side-view commercial rigid scope is used to collect images at known camera positions and orientations. A 3-D point cloud is generated with multiview stereo vision using linear motion of the test piece, which is repeated by a rotation to form additional point clouds. Registration of these point clouds into a complete reconstruction uses a proposed automated feature-based 3-D registration algorithm. The resulting 3-D reconstruction is compared with x-ray computed tomography to validate the feasibility of our proposed method for future robotically driven industrial 3-D inspection.

  13. SU-D-BRA-04: Computerized Framework for Marker-Less Localization of Anatomical Feature Points in Range Images Based On Differential Geometry Features for Image-Guided Radiation Therapy

    International Nuclear Information System (INIS)

    Soufi, M; Arimura, H; Toyofuku, F; Nakamura, K; Hirose, T; Umezu, Y; Shioyama, Y

    2016-01-01

    Purpose: To propose a computerized framework for localization of anatomical feature points on the patient surface in infrared-ray based range images by using differential geometry (curvature) features. Methods: The general concept was to reconstruct the patient surface by using a mathematical modeling technique for the computation of differential geometry features that characterize the local shapes of the patient surfaces. A region of interest (ROI) was firstly extracted based on a template matching technique applied on amplitude (grayscale) images. The extracted ROI was preprocessed for reducing temporal and spatial noises by using Kalman and bilateral filters, respectively. Next, a smooth patient surface was reconstructed by using a non-uniform rational basis spline (NURBS) model. Finally, differential geometry features, i.e. the shape index and curvedness features were computed for localizing the anatomical feature points. The proposed framework was trained for optimizing shape index and curvedness thresholds and tested on range images of an anthropomorphic head phantom. The range images were acquired by an infrared ray-based time-of-flight (TOF) camera. The localization accuracy was evaluated by measuring the mean of minimum Euclidean distances (MMED) between reference (ground truth) points and the feature points localized by the proposed framework. The evaluation was performed for points localized on convex regions (e.g. apex of nose) and concave regions (e.g. nasofacial sulcus). Results: The proposed framework has localized anatomical feature points on convex and concave anatomical landmarks with MMEDs of 1.91±0.50 mm and 3.70±0.92 mm, respectively. A statistically significant difference was obtained between the feature points on the convex and concave regions (P<0.001). Conclusion: Our study has shown the feasibility of differential geometry features for localization of anatomical feature points on the patient surface in range images. The proposed

  14. SU-D-BRA-04: Computerized Framework for Marker-Less Localization of Anatomical Feature Points in Range Images Based On Differential Geometry Features for Image-Guided Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Soufi, M; Arimura, H; Toyofuku, F [Kyushu University, Fukuoka, Fukuoka (Japan); Nakamura, K [Hamamatsu University School of Medicine, Hamamatsu, Shizuoka (Japan); Hirose, T; Umezu, Y [Kyushu University Hospital, Fukuoka, Fukuoka (Japan); Shioyama, Y [Saga Heavy Ion Medical Accelerator in Tosu, Tosu, Saga (Japan)

    2016-06-15

    Purpose: To propose a computerized framework for localization of anatomical feature points on the patient surface in infrared-ray based range images by using differential geometry (curvature) features. Methods: The general concept was to reconstruct the patient surface by using a mathematical modeling technique for the computation of differential geometry features that characterize the local shapes of the patient surfaces. A region of interest (ROI) was firstly extracted based on a template matching technique applied on amplitude (grayscale) images. The extracted ROI was preprocessed for reducing temporal and spatial noises by using Kalman and bilateral filters, respectively. Next, a smooth patient surface was reconstructed by using a non-uniform rational basis spline (NURBS) model. Finally, differential geometry features, i.e. the shape index and curvedness features were computed for localizing the anatomical feature points. The proposed framework was trained for optimizing shape index and curvedness thresholds and tested on range images of an anthropomorphic head phantom. The range images were acquired by an infrared ray-based time-of-flight (TOF) camera. The localization accuracy was evaluated by measuring the mean of minimum Euclidean distances (MMED) between reference (ground truth) points and the feature points localized by the proposed framework. The evaluation was performed for points localized on convex regions (e.g. apex of nose) and concave regions (e.g. nasofacial sulcus). Results: The proposed framework has localized anatomical feature points on convex and concave anatomical landmarks with MMEDs of 1.91±0.50 mm and 3.70±0.92 mm, respectively. A statistically significant difference was obtained between the feature points on the convex and concave regions (P<0.001). Conclusion: Our study has shown the feasibility of differential geometry features for localization of anatomical feature points on the patient surface in range images. The proposed

  15. MRI features of tuberculosis of peripheral joints

    Energy Technology Data Exchange (ETDEWEB)

    Sawlani, V.; Chandra, T.; Mishra, R.N.; Aggarwal, A.; Jain, U.K.; Gujral, R.B. E-mail: gujralrb@sgpgi.ac.in

    2003-10-01

    The aim of this article is to present the magnetic resonance imaging (MRI) features of peripheral tubercular arthritis. The clinical presentation of peripheral tubercular arthritis is variable and simulates other chronic inflammatory arthritic disorders. MRI is a highly sensitive technique which demonstrates fine anatomical details and identifies the early changes of arthritis, which are not visible on radiographs. The MRI features of tubercular arthritis include synovitis, effusion, central and peripheral erosions, active and chronic pannus, abscess, bone chips and hypo-intense synovium. These imaging features in an appropriate clinical setting may help in the diagnosis of tubercular arthritis. Early diagnosis and treatment can effectively eliminate the long-term morbidity of joints affected by tuberculosis.

  16. MRI features of tuberculosis of peripheral joints

    International Nuclear Information System (INIS)

    Sawlani, V.; Chandra, T.; Mishra, R.N.; Aggarwal, A.; Jain, U.K.; Gujral, R.B.

    2003-01-01

    The aim of this article is to present the magnetic resonance imaging (MRI) features of peripheral tubercular arthritis. The clinical presentation of peripheral tubercular arthritis is variable and simulates other chronic inflammatory arthritic disorders. MRI is a highly sensitive technique which demonstrates fine anatomical details and identifies the early changes of arthritis, which are not visible on radiographs. The MRI features of tubercular arthritis include synovitis, effusion, central and peripheral erosions, active and chronic pannus, abscess, bone chips and hypo-intense synovium. These imaging features in an appropriate clinical setting may help in the diagnosis of tubercular arthritis. Early diagnosis and treatment can effectively eliminate the long-term morbidity of joints affected by tuberculosis

  17. Stress-intensity factor equations for cracks in three-dimensional finite bodies

    Science.gov (United States)

    Newman, J. C., Jr.; Raju, I. S.

    1981-01-01

    Empirical stress intensity factor equations are presented for embedded elliptical cracks, semi-elliptical surface cracks, quarter-elliptical corner cracks, semi-elliptical surface cracks at a hole, and quarter-elliptical corner cracks at a hole in finite plates. The plates were subjected to remote tensile loading. Equations give stress intensity factors as a function of parametric angle, crack depth, crack length, plate thickness, and where applicable, hole radius. The stress intensity factors used to develop the equations were obtained from three dimensional finite element analyses of these crack configurations.

  18. Locating irregularly shaped clusters of infection intensity

    DEFF Research Database (Denmark)

    Yiannakoulias, Niko; Wilson, Shona; Kariuki, H. Curtis

    2010-01-01

    of infection intensity identifies two small areas within the study region in which infection intensity is elevated, possibly due to local features of the physical or social environment. Collectively, our results show that the "greedy growth scan" is a suitable method for exploratory geographical analysis...... for cluster detection. Real data are based on samples of hookworm and S. mansoni from Kitengei, Makueni district, Kenya. Our analysis of simulated data shows how methods able to find irregular shapes are more likely to identify clusters along rivers than methods constrained to fixed geometries. Our analysis...

  19. Absolute intensities of supersonic beams

    International Nuclear Information System (INIS)

    Beijerinck, H.C.W.; Habets, A.H.M.; Verster, N.F.

    1977-01-01

    In a molecular beam experiment the center-line intensity I(0) (particles s -1 sterad -1 ) and the flow rate dN/dt (particles s -1 ) of a beam source are important features. To compare the performance of different types of beam sources the peaking factor, kappa, is defined as the ratio kappa=π(I(0)/dN/dt). The factor π is added to normalize to kappa=1 for an effusive source. The ideal peaking factor for the supersonic flow from a nozzle follows from continuum theory. Numerical values of kappa are available. Experimental values of kappa for an argon expansion are presented in this paper, confirming these calculations. The actual center-line intensity of a supersonic beam source with a skimmer is reduced in comparison to this ideal intensity if the skimmer shields part of the virtual source from the detector. Experimental data on the virtual source radius are given enabling one to predict this shielding quantitatively. (Auth.)

  20. Pattern of side feeding intensity in mass 40 region

    International Nuclear Information System (INIS)

    Kshetri, Ritesh; Ray, Indrani; Mukherjee, A.

    2005-01-01

    Mass 40 region has many interesting features to offer to the fields of nuclear structure. In this paper, intention was made to study the effect of forward and inverse type of reaction and excitation energy on the side feeding intensity pattern in the mass region 40. The effect of coexistence of different types of structural features in this mass region will also be investigated

  1. Half-integer resonance crossing in high-intensity rings

    Directory of Open Access Journals (Sweden)

    A. V. Fedotov

    2002-02-01

    Full Text Available A detailed study of the influence of space charge on the crossing of second-order resonances is presented and associated with the space-charge limit of high-intensity rings. Two-dimensional simulation studies are compared with envelope models, which agree in the finding of an increased intensity limit due to the coherent frequency shift. This result is also found for realistic bunched beams with multiturn injection painting. Characteristic features such as the influence of tune splitting, structure resonances, and the role of envelope instabilities are discussed in detail. The theoretical limits are found to be in good agreement with the performance of high-intensity proton machines.

  2. Onset of Intense Surface Enhanced Raman Scattering and Aggregation in the Au@Ag System

    Directory of Open Access Journals (Sweden)

    Priya Bhatia

    2015-01-01

    Full Text Available Gold core/silver shell (Au@Ag nanoparticles of ~37 ± 5 nm diameter generate intense SERS (λEX=785 nm responses in solution when they interact with the SERS labels rhodamine 6G (R6G, 4-mercaptopyridine (MPY, and 4-mercaptobenzoic acid (MBA. Herein the relationship between SERS intensity, aggregation, and adsorption phenomenon isobserved by titrating Au@Ag with the above labels. As the labels adsorb to the Au@Ag, they drive aggregation as evidenced by the creation of NIR extinction peaks, and the magnitude of this NIR extinction (measured at 830 nm correlates very closely to magnitude of the intense SERS signals. The label MBA is an exception since it does not trigger aggregation nor does it result in intense SERS; rather intense SERS is recovered only after MBA coated Au@Ag is aggregated with KCl. An “inner filter” model is introduced and applied to compensate for solution extinction when the exciting laser radiation is significantly attenuated. This model permits a summary of the SERS responses in the form of plots of SERS intensity versus the aggregate absorption at 830 nm, which shows the excellent correlation between intense SERS and LSPR bands extinction.

  3. Dimensional scale effects on surface enhanced Raman scattering efficiency of self-assembled silver nanoparticle clusters

    International Nuclear Information System (INIS)

    Fasolato, C.; Domenici, F.; De Angelis, L.; Luongo, F.; Postorino, P.; Sennato, S.; Mura, F.; Costantini, F.; Bordi, F.

    2014-01-01

    A study of the Surface Enhanced Raman Scattering (SERS) from micrometric metallic nanoparticle aggregates is presented. The sample is obtained from the self-assembly on glass slides of micro-clusters of silver nanoparticles (60 and 100 nm diameter), functionalized with the organic molecule 4-aminothiophenol in water solution. For nanoparticle clusters at the micron scale, a maximum enhancement factor of 10 9 is estimated from the SERS over the Raman intensity ratio normalized to the single molecule contribution. Atomic force microscopy, correlated to spatially resolved Raman measurements, allows highlighting the connection between morphology and efficiency of the plasmonic system. The correlation between geometric features and SERS response of the metallic structures reveals a linear trend of the cluster maximum scattered intensity as a function of the surface area of the aggregate. On given clusters, the intensity turns out to be also influenced by the number of stacking planes of the aggregate, thus suggesting a plasmonic waveguide effect. The linear dependence results weakened for the largest area clusters, suggesting 30 μm 2 as the upper limit for exploiting the coherence over large scale of the plasmonic response.

  4. SPREADING OF A FLUID JET ON THE CORRUGATED SURFACE OF THE STRUCTURED PACKING OF WET SCRUBBERS

    Directory of Open Access Journals (Sweden)

    Gorodilov A.A.

    2014-08-01

    Full Text Available The new packing for wet scrubbers for cooling exhaust gases of furnaces is presented. Spreading features of the fluid jet on the corrugated surface of the proposed packing have been studied. Flow rate of the liquid flowing through slits to the opposite side of the packing element was determined. Several regimes of a fluid flow on the surface of the proposed structured packing were determined. An optimal range of rational flow rates for more intense cooling of exhaust gases is proposed. It was discovered that the range of optimum flow rates may be extended if the surface of the packing element is pre-wetted. The way of increasing the rate of effective interfacial surface area for gas-liquid contact per unit volume of the packing of the scrubber is presented.

  5. East Chestnut Ridge hydrogeologic characterization: A geophysical study of two karst features

    International Nuclear Information System (INIS)

    1991-01-01

    Permitting and site selection activities for the proposed East Chestnut Ridge landfill, located on the Oak Ridge Reservation, have required additional hydrogeologic studies of two karst features. Geophysical testing methods were utilized for investigating these karst features. The objectives of the geophysical testing was to determine the feasibility of geophysical techniques for locating subsurface karst features and to determine if subsurface anomalies exist at the proposed landfill site. Two karst features, one lacking surface expression (sinkhole) but with a known solution cavity at depth (from previous hydrologic studies), and the other with surface expression were tested with surface geophysical methods. Four geophysical profiles, two crossing and centered over each karst feature were collected using both gravimetric and electrical resistivity techniques

  6. Carabelli's trait revisited: an examination of mesiolingual features at the enamel-dentine junction and enamel surface of Pan and Homo sapiens upper molars.

    Science.gov (United States)

    Ortiz, Alejandra; Skinner, Matthew M; Bailey, Shara E; Hublin, Jean-Jacques

    2012-10-01

    Carabelli's trait is a morphological feature that frequently occurs on the mesiolingual aspect of Homo sapiens upper molars. Similar structures also referred to as Carabelli's trait have been reported in apes and fossil hominins. However, the morphological development and homology of these mesiolingual structures among hominoids are poorly understood. In this study, we employ micro-computed tomography to image the enamel-dentine junction (EDJ) and outer enamel surface (OES) of Pan (n = 48) and H. sapiens (n = 52) upper molars. We investigate the developmental origin of mesiolingual features in these taxa and establish the relative contribution of the EDJ and enamel cap to feature expression. Results demonstrate that mesiolingual features of H. sapiens molars develop at the EDJ and are similarly expressed at the OES. Morphological variation at both surfaces in this taxon can satisfactorily be assessed using standards for Carabelli's trait developed by the Arizona State University Dental Anthropology System (ASUDAS). Relative to H. sapiens, Pan has an even greater degree of correspondence in feature expression between the EDJ and OES. Morphological manifestations in Pan molars are not necessarily limited to the protocone and are best characterized by a lingual cingulum that cannot be captured by the ASUDAS. Cusp-like structures, similar to those seen in marked Carabelli's trait expressions in H. sapiens, were not found in Pan. This study provides a foundation for further analyses on the evolutionary history of mesiolingual dental traits within the hominoid lineage. It also highlights the wealth of morphological data that can be obtained at the EDJ for understanding tooth development and for characterizing tooth crown variation in worn fossil teeth. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Glacier Snowline Determination from Terrestrial Laser Scanning Intensity Data

    Directory of Open Access Journals (Sweden)

    Hannah Prantl

    2017-07-01

    Full Text Available Accurately identifying the extent of surface snow cover on glaciers is important for extrapolating end of year mass balance measurements, constraining the glacier surface radiative energy balance and evaluating model simulations of snow cover. Here, we use auxiliary information from Riegl VZ-6000 Terrestrial Laser Scanner (TLS return signals to accurately map the snow cover over a glacier throughout an ablation season. Three classification systems were compared, and we find that supervised classification based on TLS signal intensity alone is outperformed by a rule-based classification employing intensity, surface roughness and an associated optical image, which achieves classification accuracy of 68–100%. The TLS intensity signal shows no meaningful relationship with surface or bulk snow density. Finally, we have also compared our Snow Line Altitude (SLA derived from TLS with SLA derived from the model output, as well as one Landsat image. The results of the model output track the SLA from TLS well, however with a positive bias. In contrast, automatic Landsat-derived SLA slightly underestimates the SLA from TLS. To conclude, we demonstrate that the snow cover extent can be mapped successfully using TLS, although the snow mass remains elusive.

  8. Red-Shift Effects in Surface Enhanced Raman Spectroscopy: Spectral or Intensity Dependence of the Near-Field?

    KAUST Repository

    Colas, Florent; Cottat, Maximilien; Gillibert, Raymond; Guillot, Nicolas; Djaker, Nadia; Lidgi-Guigui, Nathalie; Toury, Timothé e; Barchiesi, Dominique; Toma, Andrea; Di Fabrizio, Enzo M.; Gucciardi, Pietro Giuseppe; de la Chapelle, Marc Lamy

    2016-01-01

    Optimum amplification in Surface Enhanced Raman Scattering (SERS) from individual nanoantennas is expected when the excitation is slightly blue-shifted with respect to the Localized Surface Plasmon Resonance (LSPR), so that the LSPR peak falls in the middle between the laser and the Stokes Raman emission. Recent experiments have shown when moving the excitation from the visible to the near-infrared that this rule of thumb is no more valid. The excitation has to be red-shifted with respect to the LSPR peak, up to 80nm, to obtain highest SERS. Such discrepancy is usually attributed to a Near-Field (NF) to Far-Field (FF) spectral shift. Here we critically discuss this hypothesis for the case of gold nanocylinders. By combining multi-wavelength excitation SERS experiments with numerical calculations, we show that the red-shift of the excitation energy does not originate from a spectral shift between the extinction (FF) and the near-field distribution (NF), which is found to be not larger than 10nm. Rather, it can be accounted for by looking at the peculiar spectral dependence of the near-field intensity on the cylinders diameter, characterized by an initial increase, up to 180nm diameter, followed by a decrease and a pronounced skewness.

  9. Red-Shift Effects in Surface Enhanced Raman Spectroscopy: Spectral or Intensity Dependence of the Near-Field?

    KAUST Repository

    Colas, Florent

    2016-06-06

    Optimum amplification in Surface Enhanced Raman Scattering (SERS) from individual nanoantennas is expected when the excitation is slightly blue-shifted with respect to the Localized Surface Plasmon Resonance (LSPR), so that the LSPR peak falls in the middle between the laser and the Stokes Raman emission. Recent experiments have shown when moving the excitation from the visible to the near-infrared that this rule of thumb is no more valid. The excitation has to be red-shifted with respect to the LSPR peak, up to 80nm, to obtain highest SERS. Such discrepancy is usually attributed to a Near-Field (NF) to Far-Field (FF) spectral shift. Here we critically discuss this hypothesis for the case of gold nanocylinders. By combining multi-wavelength excitation SERS experiments with numerical calculations, we show that the red-shift of the excitation energy does not originate from a spectral shift between the extinction (FF) and the near-field distribution (NF), which is found to be not larger than 10nm. Rather, it can be accounted for by looking at the peculiar spectral dependence of the near-field intensity on the cylinders diameter, characterized by an initial increase, up to 180nm diameter, followed by a decrease and a pronounced skewness.

  10. CT and MR features of xanthogranulomatous cholecystitis: An analysis of consecutive 49 cases

    International Nuclear Information System (INIS)

    Zhao, Feng; Lu, Pu-Xuan; Yan, Sen-Xiang; Wang, Gao-Feng; Yuan, Jing; Zhang, Shi-Zheng; Wang, Yi-Xiang J.

    2013-01-01

    Objective: To study the CT and MR features of xanthogranulomatous cholecystitis (XGC). Materials and methods: 49 patients had pathologically confirmed XGC. All patients underwent contrast enhanced CT, and 10 patients had additional plain MRI. The CT and MRI results were retrospectively analyzed. Results: On CT, all patients had thickening of gallbladder wall, with 87.8% cases showed diffuse thickening. 85.7% cases had intramural hypo-attenuated nodules in the thickened wall. Continuous mucosal line and luminal surface enhancement were noted in 79.6% and 85.7% cases, respectively. Gallbladder stones were seen in 69.4% patients. The coexistence of the above 5 CT features was seen in 40% cases, and 80% cases had the coexistence of ≥4 features. Diffused gallbladder wall thickening in XGC is more likely to have disrupted mucosal line, and XGC with disrupted mucosal line is more likely to be associated with liver infiltration. In 60% patients the inflammatory process extended beyond gallbladder, with the interface between gallbladder and liver and/or the surrounding fat blurred. 40% cases had an early enhancement of liver parenchyma. Infiltration to other surrounding tissues included bowel (n = 3), stomach (n = 2), and abdominal wall (n = 1). On MR images, 7 of 9 intramural nodules in 7 subjects with T1-weighted dual echo MR images showed higher signal intensity on in-phase images than out-of-phase images. Conclusion: Coexisting of diffuse gallbladder wall thickening, hypo-attenuated intramural nodules, continuous mucosal line, luminal surface enhancement, and gallbladder stone highly suggest XGC. XGC frequently infiltrate liver and surrounding fat. Chemical-shift MRI helps classifying intramural nodules in the gallbladder wall

  11. CT and MR features of xanthogranulomatous cholecystitis: An analysis of consecutive 49 cases

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Feng [Department of Radiology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016 (China); Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong (China); Lu, Pu-Xuan [Department of Radiology, Shenzhen Third People' s Hospital, Guangdong Medical College, Shenzhen 518020 (China); Yan, Sen-Xiang [Department of Radiation Oncology, First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003 (China); Wang, Gao-Feng [Department of Radiology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016 (China); Yuan, Jing [Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong (China); Zhang, Shi-Zheng, E-mail: shizhengzhang@hotmail.com [Department of Radiology, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016 (China); Wang, Yi-Xiang J., E-mail: yixiang_wang@cuhk.edu.hk [Department of Imaging and Interventional Radiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong (China); Department of Radiology, Shenzhen Third People' s Hospital, Guangdong Medical College, Shenzhen 518020 (China)

    2013-09-15

    Objective: To study the CT and MR features of xanthogranulomatous cholecystitis (XGC). Materials and methods: 49 patients had pathologically confirmed XGC. All patients underwent contrast enhanced CT, and 10 patients had additional plain MRI. The CT and MRI results were retrospectively analyzed. Results: On CT, all patients had thickening of gallbladder wall, with 87.8% cases showed diffuse thickening. 85.7% cases had intramural hypo-attenuated nodules in the thickened wall. Continuous mucosal line and luminal surface enhancement were noted in 79.6% and 85.7% cases, respectively. Gallbladder stones were seen in 69.4% patients. The coexistence of the above 5 CT features was seen in 40% cases, and 80% cases had the coexistence of ≥4 features. Diffused gallbladder wall thickening in XGC is more likely to have disrupted mucosal line, and XGC with disrupted mucosal line is more likely to be associated with liver infiltration. In 60% patients the inflammatory process extended beyond gallbladder, with the interface between gallbladder and liver and/or the surrounding fat blurred. 40% cases had an early enhancement of liver parenchyma. Infiltration to other surrounding tissues included bowel (n = 3), stomach (n = 2), and abdominal wall (n = 1). On MR images, 7 of 9 intramural nodules in 7 subjects with T1-weighted dual echo MR images showed higher signal intensity on in-phase images than out-of-phase images. Conclusion: Coexisting of diffuse gallbladder wall thickening, hypo-attenuated intramural nodules, continuous mucosal line, luminal surface enhancement, and gallbladder stone highly suggest XGC. XGC frequently infiltrate liver and surrounding fat. Chemical-shift MRI helps classifying intramural nodules in the gallbladder wall.

  12. Highly doped semiconductor plasmonic nanoantenna arrays for polarization selective broadband surface-enhanced infrared absorption spectroscopy of vanillin

    Science.gov (United States)

    Barho, Franziska B.; Gonzalez-Posada, Fernando; Milla, Maria-Jose; Bomers, Mario; Cerutti, Laurent; Tournié, Eric; Taliercio, Thierry

    2017-11-01

    Tailored plasmonic nanoantennas are needed for diverse applications, among those sensing. Surface-enhanced infrared absorption (SEIRA) spectroscopy using adapted nanoantenna substrates is an efficient technique for the selective detection of molecules by their vibrational spectra, even in small quantity. Highly doped semiconductors have been proposed as innovative materials for plasmonics, especially for more flexibility concerning the targeted spectral range. Here, we report on rectangular-shaped, highly Si-doped InAsSb nanoantennas sustaining polarization switchable longitudinal and transverse plasmonic resonances in the mid-infrared. For small array periodicities, the highest reflectance intensity is obtained. Large periodicities can be used to combine localized surface plasmon resonances (SPR) with array resonances, as shown in electromagnetic calculations. The nanoantenna arrays can be efficiently used for broadband SEIRA spectroscopy, exploiting the spectral overlap between the large longitudinal or transverse plasmonic resonances and narrow infrared active absorption features of an analyte molecule. We demonstrate an increase of the vibrational line intensity up to a factor of 5.7 of infrared-active absorption features of vanillin in the fingerprint spectral region, yielding enhancement factors of three to four orders of magnitude. Moreover, an optimized readout for SPR sensing is proposed based on slightly overlapping longitudinal and transverse localized SPR.

  13. Highly doped semiconductor plasmonic nanoantenna arrays for polarization selective broadband surface-enhanced infrared absorption spectroscopy of vanillin

    Directory of Open Access Journals (Sweden)

    Barho Franziska B.

    2017-11-01

    Full Text Available Tailored plasmonic nanoantennas are needed for diverse applications, among those sensing. Surface-enhanced infrared absorption (SEIRA spectroscopy using adapted nanoantenna substrates is an efficient technique for the selective detection of molecules by their vibrational spectra, even in small quantity. Highly doped semiconductors have been proposed as innovative materials for plasmonics, especially for more flexibility concerning the targeted spectral range. Here, we report on rectangular-shaped, highly Si-doped InAsSb nanoantennas sustaining polarization switchable longitudinal and transverse plasmonic resonances in the mid-infrared. For small array periodicities, the highest reflectance intensity is obtained. Large periodicities can be used to combine localized surface plasmon resonances (SPR with array resonances, as shown in electromagnetic calculations. The nanoantenna arrays can be efficiently used for broadband SEIRA spectroscopy, exploiting the spectral overlap between the large longitudinal or transverse plasmonic resonances and narrow infrared active absorption features of an analyte molecule. We demonstrate an increase of the vibrational line intensity up to a factor of 5.7 of infrared-active absorption features of vanillin in the fingerprint spectral region, yielding enhancement factors of three to four orders of magnitude. Moreover, an optimized readout for SPR sensing is proposed based on slightly overlapping longitudinal and transverse localized SPR.

  14. Frequency-chirped readout of spatial-spectral absorption features

    International Nuclear Information System (INIS)

    Chang, Tiejun; Mohan, R. Krishna; Harris, Todd L.; Merkel, Kristian D.; Tian Mingzhen; Babbitt, Wm. Randall

    2004-01-01

    This paper examines the physical mechanisms of reading out spatial-spectral absorption features in an inhomogeneously broadened medium using linear frequency-chirped electric fields. A Maxwell-Bloch model using numerical calculation for angled beams with arbitrary phase modulation is used to simulate the chirped field readout process. The simulation results indicate that any spatial-spectral absorption feature can be read out with a chirped field with the appropriate bandwidth, duration, and intensity. Mapping spectral absorption features into temporal intensity modulations depends on the chirp rate of the field. However, when probing a spatial-spectral grating with a chirped field, a beat signal representing the grating period can be created by interfering the emitted photon echo chirped field with a reference chirped field, regardless of the chirp rate. Comparisons are made between collinear and angled readout configurations. Readout signal strength and spurious signal distortions are investigated as functions of the grating strength and the Rabi frequency of the readout pulse. Using a collinear readout geometry, distortions from optical nutation on the transmitted field and higher-order harmonics are observed, both of which are avoided in an angled beam geometry

  15. Feature-based Alignment of Volumetric Multi-modal Images

    Science.gov (United States)

    Toews, Matthew; Zöllei, Lilla; Wells, William M.

    2014-01-01

    This paper proposes a method for aligning image volumes acquired from different imaging modalities (e.g. MR, CT) based on 3D scale-invariant image features. A novel method for encoding invariant feature geometry and appearance is developed, based on the assumption of locally linear intensity relationships, providing a solution to poor repeatability of feature detection in different image modalities. The encoding method is incorporated into a probabilistic feature-based model for multi-modal image alignment. The model parameters are estimated via a group-wise alignment algorithm, that iteratively alternates between estimating a feature-based model from feature data, then realigning feature data to the model, converging to a stable alignment solution with few pre-processing or pre-alignment requirements. The resulting model can be used to align multi-modal image data with the benefits of invariant feature correspondence: globally optimal solutions, high efficiency and low memory usage. The method is tested on the difficult RIRE data set of CT, T1, T2, PD and MP-RAGE brain images of subjects exhibiting significant inter-subject variability due to pathology. PMID:24683955

  16. Evaluation of skin surface dose for head and neck cancer patients treated with intensity-modulated radiation therapy using in vivo dosimetry

    International Nuclear Information System (INIS)

    Kim, Yeon Sil; Lee, Dong Soo; Yoo, Mi Na; Hong, Joo Young; Yoon, Se Chul; Jang, Hong Suk

    2011-01-01

    Use of intensity-modulated radiation therapy (IMRT) for head and neck cancer is gradually increasing, because it could facilitate more sophsticated treatment of target volumes and reduction of acute and late sequelae. However, theoretically, there is a potential risk of increased skin surface dose resulting from multiple obliquity effects caused by multiple tangential beams. Moreover, we sometimes confronted with more skin reactions in the patients treated with IMRT than conventional techniques. In this study, we evaluated skin surface dose adjacent to the target volumes to verify whether the use of IMRT would increase the skin dose more than we predicted. This study had shown that the use of IMRT did not increase the skin surface hot point dose. The measured skin surface dose was 20 to 40 percent of the adjacent target prescription dose, and was within acceptable dose range. Our study had some limitations with small number of experimental patients and methodological problems. Potential risk of increasing skin dose with bolus effect of aquaplaster should be examined in the future trials. In addition, the accurate set-up verification should be maintained because of steep dose gradient between skin surface and target volumes within a short distance in the head and neck cancer patients.

  17. Nanopatterned surface with adjustable area coverage and feature size fabricated by photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Bai Yang; Zhang Yan; Li Wei; Zhou Xuefeng; Wang Changsong; Feng Xin [State Key Laboratory of Materials-oriented Chemical Engineering, Nanjing University of Technology, Nanjing, Jiangsu 210009 (China); Zhang Luzheng [Petroleum Research Recovery Center, New Mexico Institute of Mining and Technology, Socorro, NM 87801 (United States); Lu Xiaohua, E-mail: xhlu@njut.edu.cn [State Key Laboratory of Materials-oriented Chemical Engineering, Nanjing University of Technology, Nanjing, Jiangsu 210009 (China)

    2009-08-30

    We report an effective approach to fabricate nanopatterns of alkylsilane self-assembly monolayers (SAMs) with desirable coverage and feature size by gradient photocatalysis in TiO{sub 2} aqueous suspension. Growth and photocatalytic degradation of octadecyltrichlorosilane (OTS) were combined to fabricate adjustable monolayered nanopatterns on mica sheet in this work. Systematic atomic force microscopy (AFM) analysis showed that OTS-SAMs that have similar area coverage with different feature sizes and similar feature size with different area coverages can be fabricated by this approach. Contact angle measurement was applied to confirm the gradually varied nanopatterns contributed to the gradient of UV light illumination. Since this approach is feasible for various organic SAMs and substrates, a versatile method was presented to prepare tunable nanopatterns with desirable area coverage and feature size in many applications, such as molecular and biomolecular recognition, sensor and electrode modification.

  18. Nanopatterned surface with adjustable area coverage and feature size fabricated by photocatalysis

    International Nuclear Information System (INIS)

    Bai Yang; Zhang Yan; Li Wei; Zhou Xuefeng; Wang Changsong; Feng Xin; Zhang Luzheng; Lu Xiaohua

    2009-01-01

    We report an effective approach to fabricate nanopatterns of alkylsilane self-assembly monolayers (SAMs) with desirable coverage and feature size by gradient photocatalysis in TiO 2 aqueous suspension. Growth and photocatalytic degradation of octadecyltrichlorosilane (OTS) were combined to fabricate adjustable monolayered nanopatterns on mica sheet in this work. Systematic atomic force microscopy (AFM) analysis showed that OTS-SAMs that have similar area coverage with different feature sizes and similar feature size with different area coverages can be fabricated by this approach. Contact angle measurement was applied to confirm the gradually varied nanopatterns contributed to the gradient of UV light illumination. Since this approach is feasible for various organic SAMs and substrates, a versatile method was presented to prepare tunable nanopatterns with desirable area coverage and feature size in many applications, such as molecular and biomolecular recognition, sensor and electrode modification.

  19. Unoccupied surface electronic structure of Gd(0001)

    International Nuclear Information System (INIS)

    Li, D.; Dowben, P.A.; Ortega, J.E.; Himpsel, F.J.

    1994-01-01

    The unoccupied surface electronic structure of Gd(0001) was investigated with high-resolution inverse-photoemission spectroscopy. An empty surface state near E F is observed at bar Γ. Two other surface-sensitive features are also revealed at 1.2 and 3.1 eV above the Fermi level. Hydrogen adsorption on Gd surfaces was used to distinguish the surface-sensitive features from the bulk features. The unoccupied bulk-band critical points are determined to be Γ 3 + at 1.9 eV and A 1 at 0.8 eV

  20. Influence of surface topography on elastically backscattered electrons

    International Nuclear Information System (INIS)

    Ding, X; Da, B; Gong, J B; Ding, Z J; Mao, S F

    2014-01-01

    A Monte Carlo simulation, taking into account of the detailed surface roughness of a realistic solid sample, has been performed to study the surface topography influence on elastic peak intensity. To describe quantitatively the surface topography effect, here we introduce surface roughness parameter (SRP) according to the ratio of elastic peak intensities between a rough surface and an ideal planar surface. Simulation results for Al sample have shown that SRP varies with surface roughness particularly at large incidence/emission angles

  1. Feature curve extraction from point clouds via developable strip intersection

    Directory of Open Access Journals (Sweden)

    Kai Wah Lee

    2016-04-01

    Full Text Available In this paper, we study the problem of computing smooth feature curves from CAD type point clouds models. The proposed method reconstructs feature curves from the intersections of developable strip pairs which approximate the regions along both sides of the features. The generation of developable surfaces is based on a linear approximation of the given point cloud through a variational shape approximation approach. A line segment sequencing algorithm is proposed for collecting feature line segments into different feature sequences as well as sequential groups of data points. A developable surface approximation procedure is employed to refine incident approximation planes of data points into developable strips. Some experimental results are included to demonstrate the performance of the proposed method.

  2. Discrimination of rectal cancer through human serum using surface-enhanced Raman spectroscopy

    Science.gov (United States)

    Li, Xiaozhou; Yang, Tianyue; Li, Siqi; Zhang, Su; Jin, Lili

    2015-05-01

    In this paper, surface-enhanced Raman spectroscopy (SERS) was used to detect the changes in blood serum components that accompany rectal cancer. The differences in serum SERS data between rectal cancer patients and healthy controls were examined. Postoperative rectal cancer patients also participated in the comparison to monitor the effects of cancer treatments. The results show that there are significant variations at certain wavenumbers which indicates alteration of corresponding biological substances. Principal component analysis (PCA) and parameters of intensity ratios were used on the original SERS spectra for the extraction of featured variables. These featured variables then underwent linear discriminant analysis (LDA) and classification and regression tree (CART) for the discrimination analysis. Accuracies of 93.5 and 92.4 % were obtained for PCA-LDA and parameter-CART, respectively.

  3. Surface phase separation, dewetting feature size, and crystal morphology in thin films of polystyrene/poly(ε-caprolactone) blend.

    Science.gov (United States)

    Ma, Meng; He, Zhoukun; Li, Yuhan; Chen, Feng; Wang, Ke; Zhang, Qing; Deng, Hua; Fu, Qiang

    2012-12-01

    Thin films of polystyrene (PS)/poly(ε-caprolactone) (PCL) blends were prepared by spin-coating and characterized by tapping mode force microscopy (AFM). Effects of the relative concentration of PS in polymer solution on the surface phase separation and dewetting feature size of the blend films were systematically studied. Due to the coupling of phase separation, dewetting, and crystallization of the blend films with the evaporation of solvent during spin-coating, different size of PS islands decorated with various PCL crystal structures including spherulite-like, flat-on individual lamellae, and flat-on dendritic crystal were obtained in the blend films by changing the film composition. The average distance of PS islands was shown to increase with the relative concentration of PS in casting solution. For a given ratio of PS/PCL, the feature size of PS appeared to increase linearly with the square of PS concentration while the PCL concentration only determined the crystal morphology of the blend films with no influence on the upper PS domain features. This is explained in terms of vertical phase separation and spinodal dewetting of the PS rich layer from the underlying PCL rich layer, leading to the upper PS dewetting process and the underlying PCL crystalline process to be mutually independent. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Parabolic features and the erosion rate on Venus

    Science.gov (United States)

    Strom, Robert G.

    1993-01-01

    The impact cratering record on Venus consists of 919 craters covering 98 percent of the surface. These craters are remarkably well preserved, and most show pristine structures including fresh ejecta blankets. Only 35 craters (3.8 percent) have had their ejecta blankets embayed by lava and most of these occur in the Atla-Beta Regio region; an area thought to be recently active. parabolic features are associated with 66 of the 919 craters. These craters range in size from 6 to 105 km diameter. The parabolic features are thought to be the result of the deposition of fine-grained ejecta by winds in the dense venusian atmosphere. The deposits cover about 9 percent of the surface and none appear to be embayed by younger volcanic materials. However, there appears to be a paucity of these deposits in the Atla-Beta Regio region, and this may be due to the more recent volcanism in this area of Venus. Since parabolic features are probably fine-grain, wind-deposited ejecta, then all impact craters on Venus probably had these deposits at some time in the past. The older deposits have probably been either eroded or buried by eolian processes. Therefore, the present population of these features is probably associated with the most recent impact craters on the planet. Furthermore, the size/frequency distribution of craters with parabolic features is virtually identical to that of the total crater population. This suggests that there has been little loss of small parabolic features compared to large ones, otherwise there should be a significant and systematic paucity of craters with parabolic features with decreasing size compared to the total crater population. Whatever is erasing the parabolic features apparently does so uniformly regardless of the areal extent of the deposit. The lifetime of parabolic features and the eolian erosion rate on Venus can be estimated from the average age of the surface and the present population of parabolic features.

  5. Piecewise Potential Vorticity Inversion for Intense Extratropical Cyclones

    Science.gov (United States)

    Seiler, C.; Zwiers, F. W.

    2017-12-01

    Global climate models (GCMs) tend to simulate too few intense extratropical cyclones (ETCs) in the Northern Hemisphere (NH) under historic climate conditions. This bias may arise from the interactions of multiple drivers, including surface temperature gradients, latent heating in the lower troposphere, and the upper-level jet stream. Previous attempts to quantify the importance of these drivers include idealized model experiments or statistical approaches. The first method however cannot easily be implemented for a multi-GCM ensemble, and the second approach does not disentangle the interactions among drivers, nor does it prove causality. An alternative method that overcomes these limitations is piecewise potential vorticity inversion (PPVI). PPVI derives the wind and geopotential height fields by inverting potential vorticity (PV) for discrete atmospheric levels. Despite being a powerful diagnostic tool, PPVI has primarily been used to study the dynamics of individual events only. This study presents the first PPVI climatology for the 5% most intense NH ETCs that occurred from 1980 to 2016. Conducting PPVI to 3273 ETC tracks identified in ERA-Interim reanalysis, we quantified the contributions from 3 atmospheric layers to ETC intensity. The respective layers are the surface (1000 hPa), a lower atmospheric level (700-850 hPa) and an upper atmospheric level (100-500 hPa) that are associated with the contributions from surface temperature gradients, latent heating, and the jet stream, respectively. Results show that contributions are dominated by the lower level (40%), followed by the upper level (20%) and the surface (17%), while the remaining 23% are associated with the background flow. Contributions from the surface and the lower level are stronger in the western ocean basins owed to the presence of the warm ocean currents, while contributions from the upper level are stronger in the eastern basins. Vertical cross sections of ETC-centered composites show an

  6. Classification and clinical features of primary headache in Akaki ...

    African Journals Online (AJOL)

    Classification and clinical features of primary headache in Akaki Textile Mill workers, ... study wherein data collection and examination of cases using a structured and ... like pressure or tightness with a mild to moderate intensity and anorexia.

  7. Fabrication of Poly(styrene-co-maleic anhydride)@Ag Spheres with High Surface Charge Intensity and their Self-Assembly into Photonic Crystal Films.

    Science.gov (United States)

    Bi, Jiajie; Fan, Genrui; Wu, Suli; Su, Xin; Xia, Hongbo; Zhang, Shu-Fen

    2017-10-01

    Herein, we developed a method to prepare monodisperse poly(styrene-co-maleic anhydride)@Ag (PSMA@Ag) core-shell microspheres with high surface charge intensity by using an in situ reduction method. In this method, ethylenediamine tetraacetic acid tetrasodium salt (Na 4 EDTA) was used as a reducing agent to promote the growth of Ag, and at the same time endowed the PSMA@Ag spheres with a surface charge. The monodispersity of PSMA and PSMA@Ag and the ordered array of the photonic crystal films were characterized by using SEM. The formation of Ag nanoparticles was confirmed by using TEM, HR-TEM, and XRD characterizations. Due to the existence of surface charges, the obtained PSMA@Ag microspheres easily self-assembled to form photonic crystal structures. In addition, the surface-enhanced Raman scattering (SERS) activity of the PSMA@Ag photonic crystal films was evaluated by detecting the signal from Raman probe molecules, 4-aminothiophenol (4-ATP). The PSMA@Ag photonic crystal films exhibited a high SERS effect, a low detection limit of up to 10 -8 for 4-ATP, good uniformity, and reproducibility.

  8. Effect of surface free energies on the heterogeneous nucleation of water droplet: A molecular dynamics simulation approach

    Energy Technology Data Exchange (ETDEWEB)

    Xu, W.; Lan, Z.; Peng, B. L.; Wen, R. F.; Ma, X. H., E-mail: xuehuma@dlut.edu.cn [Liaoning Provincial Key Laboratory of Clean Utilization of Chemical Resources, Institute of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China)

    2015-02-07

    Heterogeneous nucleation of water droplet on surfaces with different solid-liquid interaction intensities is investigated by molecular dynamics simulation. The interaction potentials between surface atoms and vapor molecules are adjusted to obtain various surface free energies, and the nucleation process and wetting state of nuclei on surfaces are investigated. The results indicate that near-constant contact angles are already established for nano-scale nuclei on various surfaces, with the contact angle decreasing with solid-liquid interaction intensities linearly. Meanwhile, noticeable fluctuation of vapor-liquid interfaces can be observed for the nuclei that deposited on surfaces, which is caused by the asymmetric forces from vapor molecules. The formation and growth rate of nuclei are increasing with the solid-liquid interaction intensities. For low energy surface, the attraction of surface atoms to water molecules is comparably weak, and the pre-existing clusters can depart from the surface and enter into the bulk vapor phase. The distribution of clusters within the bulk vapor phase becomes competitive as compared with that absorbed on surface. For moderate energy surfaces, heterogeneous nucleation predominates and the formation of clusters within bulk vapor phase is suppressed. The effect of high energy particles that embedded in low energy surface is also discussed under the same simulation system. The nucleation preferably initiates on the high energy particles, and the clusters that formed on the heterogeneous particles are trapped around their original positions instead of migrating around as that observed on smooth surfaces. This feature makes it possible for the heterogeneous particles to act as fixed nucleation sites, and simulation results also suggest that the number of nuclei increases monotonously with the number of high energy particles. The growth of nuclei on high energy particles can be divided into three sub-stages, beginning with the formation

  9. [Characteristics of nutrient loss by runoff in sloping arable land of yellow-brown under different rainfall intensities].

    Science.gov (United States)

    Chen, Ling; Liu, De-Fu; Song, Lin-Xu; Cui, Yu-Jie; Zhang, Gei

    2013-06-01

    In order to investigate the loss characteristics of N and P through surface flow and interflow under different rainfall intensities, a field experiment was conducted on the sloping arable land covered by typical yellow-brown soils inXiangxi River watershed by artificial rainfall. The results showed that the discharge of surface flow, total runoff and sediment increased with the increase of rain intensity, while the interflow was negatively correlated with rain intensity under the same total rainfall. TN, DN and DP were all flushed at the very beginning in surface flow underdifferent rainfall intensities; TP fluctuated and kept consistent in surface flow without obvious downtrend. While TN, DN and DP in interflow kept relatively stable in the whole runoff process, TP was high at the early stage, then rapidly decreased with time and kept steady finally. P was directly influenced by rainfall intensity, its concentration in the runoff increased with the increase of the rainfall intensity, the average concentration of N and P both exceeded the threshold of eutrophication of freshwater. The higher the amount of P loss was, the higher the rain intensity. The change of N loss was the opposite. The contribution rate of TN loss carried by surface flow increased from 36.5% to 57.6% with the increase of rainfall intensity, but surface flow was the primary form of P loss which contributed above 90.0%. Thus, it is crucial to control interflow in order to reduce N loss. In addition, measures should be taken to effectively manage soil erosion to mitigate P loss. The proportion of dissolved nitrogen in surface flow elevated with the decrease of rainfall intensity, but in interflow, dissolved form was predominant. P was exported mainly in the form of particulate under different rainfall intensities and runoff conditions.

  10. Long Range Dependence Prognostics for Bearing Vibration Intensity Chaotic Time Series

    Directory of Open Access Journals (Sweden)

    Qing Li

    2016-01-01

    Full Text Available According to the chaotic features and typical fractional order characteristics of the bearing vibration intensity time series, a forecasting approach based on long range dependence (LRD is proposed. In order to reveal the internal chaotic properties, vibration intensity time series are reconstructed based on chaos theory in phase-space, the delay time is computed with C-C method and the optimal embedding dimension and saturated correlation dimension are calculated via the Grassberger–Procaccia (G-P method, respectively, so that the chaotic characteristics of vibration intensity time series can be jointly determined by the largest Lyapunov exponent and phase plane trajectory of vibration intensity time series, meanwhile, the largest Lyapunov exponent is calculated by the Wolf method and phase plane trajectory is illustrated using Duffing-Holmes Oscillator (DHO. The Hurst exponent and long range dependence prediction method are proposed to verify the typical fractional order features and improve the prediction accuracy of bearing vibration intensity time series, respectively. Experience shows that the vibration intensity time series have chaotic properties and the LRD prediction method is better than the other prediction methods (largest Lyapunov, auto regressive moving average (ARMA and BP neural network (BPNN model in prediction accuracy and prediction performance, which provides a new approach for running tendency predictions for rotating machinery and provide some guidance value to the engineering practice.

  11. Comparison of specular H-atomic-beam intensity and C+ secondary-ion yield at thermally activated decrease of a carbon layer on a Ni(110) surface

    International Nuclear Information System (INIS)

    Kaarmann, H.; Hoinkes, H.; Wilsch, H.

    1983-01-01

    The thermally activated disappearance of a carbon layer on a Ni(110) surface was investigated by the scattering of atomic hydrogen and by secondary-ion mass spectrometry. Decreasing C coverage at surface temperatures kept constant in each case at values between 650 and 750 K resulted in an exponential decrease of specular H-beam intensity as well as C + secondary-ion yield. This decrease in both cases fits first-order kinetics (presumable diffusion into the bulk) with an identical rate constant as a function of surface temperature and results finally in a preexponential frequency ν = 10/sup() 10plus-or-minus1/ s -1 and an activation energy E/sub A/ = 1.8 +- 0.2 eV

  12. On Surface Order and Disorder of α-Pinene-Derived Secondary Organic Material

    Energy Technology Data Exchange (ETDEWEB)

    Shrestha, Mona; Zhang, Yue; Upshur, Mary Alice; Liu, Pengfei; Blair, Sandra L.; Wang, Hongfei; Nizkorodov, Sergey; Thomson, Regan; Martin, Scot T.; Geiger, Franz M.

    2015-05-14

    The surfaces of secondary organic aerosol particles are notoriously difficult to access experimentally, even though they are the key location where exchange between the aerosol particle phase and its gas phase occurs. Here, we overcome this difficulty by applying standard and sub 1-cm-1 resolution vibrational sum frequency generation (SFG) spectroscopy to detect C–H oscillators at the surfaces of secondary organic material (SOM) prepared from the ozonolysis of α-pinene at Harvard University and at the University of California, Irvine that were subsequently collected on Teflon filters as well as CaF2 windows using electrostatic deposition. We find both samples yield comparable SFG spectra featuring an intense peak at 2940 cm-1 that are independent of spectral resolution and location or method of preparation. We hypothesize that the SFG spectra are due to surface-active C–H oscillators associated with the four-membered ring motif of α-pinene, which produces an unresolvable spectral continuum of approximately 50 cm-1 width reminiscent of the similar, albeit much broader, O–H stretching continuum observed in the SFG spectra of aqueous surfaces. Upon subjecting the SOM samples to cycles in relative humidity (RH) between <2% RH and 95% RH, we observe reversible changes in the SFG signal intensity across the entire spectral range surveyed for a polarization combination probing components of the vibrational transition dipole moments that are oriented parallel to the plane of incidence, but no signal intensity changes for any other polarization combination investigated. These results support the notion that the C–H oscillators at the surfaces of α-pinene-derived SOM deposited on CaF2 windows shift back and forth between two different molecular orientation distributions as the RH is lowered (more ordered) or raised (less ordered). The findings thus point towards the presence of a reversible surface switch for hindering (more ordered, <2%RH) and promoting (less

  13. Evaluation of surface and build-up region dose for intensity-modulated radiation therapy in head and neck cancer

    International Nuclear Information System (INIS)

    Chung, Heeteak; Jin, Hosang; Dempsey, James F.; Liu, Chihray; Palta, Jatinder; Suh, Tae-Suk; Kim, Siyong

    2005-01-01

    Despite much development, there remains dosimetric uncertainty in the surface and build-up regions in intensity-modulated radiation therapy treatment plans for head and neck cancers. Experiments were performed to determine the dosimetric discrepancies in the surface and build-up region between the treatment planning system (TPS) prediction and experimental measurement using radiochromic film. A head and neck compression film phantom was constructed from two semicylindrical solid water slabs. Treatment plans were generated using two commercial TPSs (PINNACLE3 and CORVUS) for two cases, one with a shallow (∼0.5 cm depth) target and another with a deep (∼6 cm depth) target. The plans were evaluated for a 54 Gy prescribed dose. For each case, two pieces of radiochromic film were used for dose measurement. A small piece of film strip was placed on the surface and another was inserted within the phantom. Overall, both TPSs showed good agreement with the measurement. For the shallow target case, the dose differences were within ±300 cGy (5.6% with respect to the prescribed dose) for PINNACLE3 and ±240 cGy (4.4%) for CORVUS in 90% of the region of interest. For the deep target case, the dose differences were ±350 (6.5%) for PINNACLE3 and ±260 cGy (4.8%) for CORVUS in 90% of the region of interest. However, it was found that there were significant discrepancies from the surface to about 0.2 cm in depth for both the shallow and deep target cases. It was concluded that both TPSs overestimated the surface dose for both shallow and deep target cases. The amount of overestimation ranges from 400 to 1000 cGy (∼7.4% to 18.5% with respect to the prescribed dose, 5400 cGy)

  14. Effect of microstructure and surface features on wetting angle of a Fe-3.2 wt%C.E. cast iron with water

    Science.gov (United States)

    Riahi, Samira; Niroumand, Behzad; Dorri Moghadam, Afsaneh; Rohatgi, Pradeep K.

    2018-05-01

    In the present study, variation in surface wetting behavior of a hypoeutectic cast iron with its microstructural features and surface roughness was investigated. Samples with an identical composition, i.e. Fe-3.2 wt%C.E., and different microstructures (a gray cast iron with A-type flake graphite and a white cast iron) were fabricated by gravity casting of molten cast iron in a chill mold at different cooling rates. A variation of surface roughness was also developed by polishing, a four-stage electroetching and a four-stage mechanical abrading on the samples. Roughness and water contact angles of all surfaces were then measured. The surface roughness factor and the solid fraction in contact with water by the Wenzel and Cassie-Baxter contact models were also calculated and compared with the corresponding measured contact angles to find out which regime was active. Results indicated that the surface microstructure and the type of constituents present at the surface influenced the cast iron surface wettability and that it was possible to change the surface contact angle by modification of the surface microstructure. The mechanically abraded gray cast iron followed the Wenzel-type regime while the electroetched surfaces of gray cast iron exhibited a transition from Wenzel to Cassie-Baxter type regime. In white cast iron, the results indicated Wenzel type behavior in the electroetched samples while for the mechanically abraded samples, none of these two models could predict the wetting behavior. Furthermore, the wetting angles of both gray and white cast irons were measured after 1, 2, 3 and 4 weeks of air exposure. The results showed that the wetting angles of both samples increased to above 90° after one week of air exposure which was likely due to adsorption of low surface energy hydrocarbons on the surfaces.

  15. In situ spectroscopy of ligand exchange reactions at the surface of colloidal gold and silver nanoparticles

    International Nuclear Information System (INIS)

    Dinkel, Rebecca; Peukert, Wolfgang; Braunschweig, Björn

    2017-01-01

    Gold and silver nanoparticles with their tunable optical and electronic properties are of great interest for a wide range of applications. Often the ligands at the surface of the nanoparticles have to be exchanged in a second step after particle formation in order to obtain a desired surface functionalization. For many techniques, this process is not accessible in situ . In this review, we present second-harmonic scattering (SHS) as an inherently surface sensitive and label-free optical technique to probe the ligand exchange at the surface of colloidal gold and silver nanoparticles in situ and in real time. First, a brief introduction to SHS and basic features of the SHS of nanoparticles are given. After that, we demonstrate how the SHS intensity decrease can be correlated to the thiol coverage which allows for the determination of the Gibbs free energy of adsorption and the surface coverage. (topical review)

  16. Intense particle beam and multiple applications

    International Nuclear Information System (INIS)

    Ueda, M.; Machida, M.

    1988-01-01

    The Multiple Application Intense Particle Beam project is an experiment in which an injector of high energy neutral or ionized particles will be used to diagnose high density and high temperature plasmas. The acceleration of the particles will be carried out feeding a diode with a high voltage pulse produced by a Marx generator. Other apllications of intense particle beam generated by this injector that could be explored in the future include: heating and stabilization of compact toroids, treatment of metallic surfaces and ion implantation. (author) [pt

  17. Biomedical Imaging Modality Classification Using Combined Visual Features and Textual Terms

    Directory of Open Access Journals (Sweden)

    Xian-Hua Han

    2011-01-01

    extraction from medical images and fuses the different extracted visual features and textual feature for modality classification. To extract visual features from the images, we used histogram descriptor of edge, gray, or color intensity and block-based variation as global features and SIFT histogram as local feature. For textual feature of image representation, the binary histogram of some predefined vocabulary words from image captions is used. Then, we combine the different features using normalized kernel functions for SVM classification. Furthermore, for some easy misclassified modality pairs such as CT and MR or PET and NM modalities, a local classifier is used for distinguishing samples in the pair modality to improve performance. The proposed strategy is evaluated with the provided modality dataset by ImageCLEF 2010.

  18. Modeling of ion beam surface treatment

    Energy Technology Data Exchange (ETDEWEB)

    Stinnett, R W [Quantum Manufacturing Technologies, Inc., Albuquerque, NM (United States); Maenchen, J E; Renk, T J [Sandia National Laboratories, Albuquerque, NM (United States); Struve, K W [Mission Research Corporation, Albuquerque, NM (United States); Campbell, M M [PASTDCO, Albuquerque, NM (United States)

    1997-12-31

    The use of intense pulsed ion beams is providing a new capability for surface engineering based on rapid thermal processing of the top few microns of metal, ceramic, and glass surfaces. The Ion Beam Surface Treatment (IBEST) process has been shown to produce enhancements in the hardness, corrosion, wear, and fatigue properties of surfaces by rapid melt and re-solidification. A new code called IBMOD was created, enabling the modeling of intense ion beam deposition and the resulting rapid thermal cycling of surfaces. This code was used to model the effect of treatment of aluminum, iron, and titanium using different ion species and pulse durations. (author). 3 figs., 4 refs.

  19. Decadal features of heavy rainfall events in eastern China

    Science.gov (United States)

    Chen, Huopo; Sun, Jianqi; Fan, Ke

    2012-06-01

    Based on daily precipitation data, the spatial-temporal features of heavy rainfall events (HREs) during 1960-2009 are investigated. The results indicate that the HREs experienced strong decadal variability in the past 50 years, and the decadal features varied across regions. More HRE days are observed in the 1960s, 1980s, and 1990s over Northeast China (NEC); in the 1960s, 1970s, and 1990s over North China (NC); in the early 1960s, 1980s, and 2000s over the Huaihe River basin (HR); in the 1970s-1990s over the mid-lower reaches of the Yangtze River valley (YR); and in the 1970s and 1990s over South China (SC). These decadal changes of HRE days in eastern China are closely associated with the decadal variations of water content and stratification stability of the local atmosphere. The intensity of HREs in each sub-region is also characterized by strong decadal variability. The HRE intensity and frequency co-vary on the long-term trend, and show consistent variability over NEC, NC, and YR, but inconsistent variability over SC and HR. Further analysis of the relationships between the annual rainfall and HRE frequency as well as intensity indicates that the HRE frequency is the major contributor to the total rainfall variability in eastern China, while the HRE intensity shows only relative weak contribution.

  20. Coastal zone color scanner pigment concentrations in the southern ocean and relationships to geophysical surface features

    Science.gov (United States)

    Comiso, J. C.; Mcclain, C. R.; Sullivan, C. W.; Ryan, J. P.; Leonard, C. L.

    1993-01-01

    Climatological data on the distribution of surface pigment fields in the entire southern ocean over a seasonal cycle are examined. The occurrence of intense phytoplankton blooms during austral summer months and during other seasons in different regions is identified and analyzed. The highest pigment concentrations are observed at high latitudes and over regions with water depths usually less than 600 m. Basin-scale pigment distribution shows a slightly asymmetric pattern of enhanced pigment concentrations about Antarctica, with enhanced concentrations extending to lower latitudes in the Atlantic and Indian sectors than in the Pacific sector. A general increase in pigment concentrations is evident from the low latitudes toward the Antarctic circumpolar region. Spatial relationships between pigment and archived geophysical data reveal significant correlation between pigment distributions and both bathymetry and wind stress, while general hemispheric scale patterns of pigment distributions are most coherent with the geostrophic flow of the Antarctic Circumpolar Current.

  1. Imaging features of foot osteoid osteoma

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, Satyen; Clarke, Andrew W.; Saifuddin, Asif [Royal National Orthopaedic Hospital NHS Trust, Department of Radiology, Stanmore, Middlesex (United Kingdom)

    2010-07-15

    We performed a retrospective review of the imaging of nine patients with a diagnosis of foot osteoid osteoma (OO). Radiographs, computed tomography (CT) and magnetic resonance imaging (MRI) had been performed in all patients. Radiographic features evaluated were the identification of a nidus and cortical thickening. CT features noted were nidus location (affected bone - intramedullary, intracortical, subarticular) and nidus calcification. MRI features noted were the presence of an identifiable nidus, presence and grade of bone oedema and whether a joint effusion was identified. Of the nine patients, three were female and six male, with a mean age of 21 years (range 11-39 years). Classical symptoms of OO (night pain, relief with aspirin) were identified in five of eight (62.5%) cases (in one case, the medical records could not be retrieved). In five patients the lesion was located in the hindfoot (four calcaneus, one talus), while four were in the mid- or forefoot (two metatarsal and two phalangeal). Radiographs were normal in all patients with hindfoot OO. CT identified the nidus in all cases (89%) except one terminal phalanx lesion, while MRI demonstrated a nidus in six of nine cases (67%). The nidus was of predominantly intermediate signal intensity on T1-weighted (T1W) sequences, with intermediate to high signal intensity on T2-weighted (T2W) sequences. High-grade bone marrow oedema, limited to the affected bone and adjacent soft tissue oedema was identified in all cases. In a young patient with chronic hindfoot pain and a normal radiograph, MRI features suggestive of possible OO include extensive bone marrow oedema limited to one bone, with a possible nidus demonstrated in two-thirds of cases. The presence or absence of a nidus should be confirmed with high-resolution CT. (orig.)

  2. Preattentive extraction of abstract feature conjunctions from auditory stimulation as reflected by the mismatch negativity (MMN).

    Science.gov (United States)

    Paavilainen, P; Simola, J; Jaramillo, M; Näätänen, R; Winkler, I

    2001-03-01

    Brain mechanisms extracting invariant information from varying auditory inputs were studied using the mismatch-negativity (MMN) brain response. We wished to determine whether the preattentive sound-analysis mechanisms, reflected by MMN, are capable of extracting invariant relationships based on abstract conjunctions between two sound features. The standard stimuli varied over a large range in frequency and intensity dimensions following the rule that the higher the frequency, the louder the intensity. The occasional deviant stimuli violated this frequency-intensity relationship and elicited an MMN. The results demonstrate that preattentive processing of auditory stimuli extends to unexpectedly complex relationships between the stimulus features.

  3. Using SWAT-MODFLOW to simulate groundwater flow and groundwater-surface water interactions in an intensively irrigated stream-aquifer system

    Science.gov (United States)

    Wei, X.; Bailey, R. T.

    2017-12-01

    Agricultural irrigated watersheds in semi-arid regions face challenges such as waterlogging, high soil salinity, reduced crop yield, and leaching of chemical species due to extreme shallow water tables resulting from long-term intensive irrigation. Hydrologic models can be used to evaluate the impact of land management practices on water yields and groundwater-surface water interactions in such regions. In this study, the newly developed SWAT-MODFLOW, a coupled surface/subsurface hydrologic model, is applied to a 950 km2 watershed in the Lower Arkansas River Valley (southeastern Colorado). The model accounts for the influence of canal diversions, irrigation applications, groundwater pumping, and earth canal seepage losses. The model provides a detailed description of surface and subsurface flow processes, thereby enabling detailed description of watershed processes such as runoff, infiltration, in-streamflow, three-dimensional groundwater flow in a heterogeneous aquifer system with sources and sinks (e.g. pumping, seepage to subsurface drains), and spatially-variable surface and groundwater exchange. The model was calibrated and tested against stream discharge from 5 stream gauges in the Arkansas River and its tributaries, groundwater levels from 70 observation wells, and evapotranspiration (ET) data estimated from satellite (ReSET) data during the 1999 to 2007 period. Since the water-use patterns within the study area are typical of many other irrigated river valleys in the United States and elsewhere, this modeling approach is transferable to other regions.

  4. Superhydrophobic surfaces

    Science.gov (United States)

    Wang, Evelyn N; McCarthy, Matthew; Enright, Ryan; Culver, James N; Gerasopoulos, Konstantinos; Ghodssi, Reza

    2015-03-24

    Surfaces having a hierarchical structure--having features of both microscale and nanoscale dimensions--can exhibit superhydrophobic properties and advantageous condensation and heat transfer properties. The hierarchical surfaces can be fabricated using biological nanostructures, such as viruses as a self-assembled nanoscale template.

  5. Electron spin polarization effects in low-energy electron diffraction, ion neutralization, and metastable-atom deexcitation at solid surfaces. Progress report No. 3, January 1-December 31, 1983

    International Nuclear Information System (INIS)

    Walters, G.K.; Dunning, F.B.

    1983-01-01

    The importance of electron spin polarization (ESP) effects in the various spectroscopies used to study solid surfaces has become increasingly apparent in recent years. Recent low energy electron diffraction (LEED) investigations in this laboratory and elsewhere have shown that a great deal of new information contributing to the understanding of the geometrical arrangements of atoms at a surface can be obtained if the polarization of the various LEED beams is measured, or if the incident electron beam is polarized. Polarized LEED studies have shown large polarization features that are very sensitive to the presence of adsorbed layers, surface reconstruction, etc. In addition, theory suggests that polarization measurements can provide a more sensitive test of many of the parameters used in a surface model than can conventional LEED intensity measurements alone. Polarized LEED has also been applied to the study of surface magnetism. In the present contract year, polarized LEED has been used, together with Auger analysis and LEED intensity measurements, as a diagnostic to characterize Ni(001) surfaces produced by laser annealing

  6. Theory of inelastic effects in resonant atom-surface scattering

    International Nuclear Information System (INIS)

    Evans, D.K.

    1983-01-01

    The progress of theoretical and experimental developments in atom-surface scattering is briefly reviewed. The formal theory of atom-surface resonant scattering is reviewed and expanded, with both S and T matrix approaches being explained. The two-potential formalism is shown to be useful for dealing with the problem in question. A detailed theory based on the S-matrix and the two-potential formalism is presented. This theory takes account of interactions between the incident atoms and the surface phonons, with resonant effects being displayed explicitly. The Debye-Waller attenuation is also studied. The case in which the atom-surface potential is divided into an attractive part V/sub a/ and a repulsive part V/sub r/ is considered at length. Several techniques are presented for handling the scattering due to V/sub r/, for the case in which V/sub r/ is taken to be the hard corrugated surface potential. The theory is used to calculate the scattered intensities for the system 4 He/LiF(001). A detailed comparison with experiment is made, with polar scans, azimuthal scans, and time-of-flight measurements being considered. The theory is seen to explain the location and signature of resonant features, and to provide reasonable overall agreement with the experimental results

  7. Intensive physical activity and alexithymia: results from swimmers' discourse analysis.

    Science.gov (United States)

    Allegre, Benjamin; Noel-Jorand, Marie-Christine; Souville, Marc; Pellegrin, Liliane; Therme, Pierre

    2007-06-01

    The aim of this study was to describe and understand the relationship of swimmers' practice intensity and alexithymia features in discourse. This study investigated psychological processes in two groups of male swimmers training at different intensities. The first group was composed of 10 Expert amateurs (M age = 19.5 yr., SD = 1.9), who were competing at the national or international level and trained 22 hours per week. The second group was composed of 10 Amateur swimmers (M age = 20.5 yr., SD = 1.4), who competed at the regional level and trained 6 hours per week. The discourse of swimmers was analysed using the ALCESTE (Analyse de Lexèmes Coocurents dans les Enoncés Simples d'un Texte) method of discourse analysis. Discourse analysis was performed on speech samples produced by swimmers. All the swimmers showed alexithymic verbal behaviour as regards both the means of expression used and the feelings and emotions expressed. This lack of articulateness was more pronounced in the Expert than in the Amateur group. The difference of alexithymic features in correlation with the intensity of sport practice raises the question of the health benefits of intense sports practice and the need for psychological assessment of athletes.

  8. Comparison of grey matter volume and thickness for analysing cortical changes in chronic schizophrenia: a matter of surface area, grey/white matter intensity contrast, and curvature.

    Science.gov (United States)

    Kong, Li; Herold, Christina J; Zöllner, Frank; Salat, David H; Lässer, Marc M; Schmid, Lena A; Fellhauer, Iven; Thomann, Philipp A; Essig, Marco; Schad, Lothar R; Erickson, Kirk I; Schröder, Johannes

    2015-02-28

    Grey matter volume and cortical thickness are the two most widely used measures for detecting grey matter morphometric changes in various diseases such as schizophrenia. However, these two measures only share partial overlapping regions in identifying morphometric changes. Few studies have investigated the contributions of the potential factors to the differences of grey matter volume and cortical thickness. To investigate this question, 3T magnetic resonance images from 22 patients with schizophrenia and 20 well-matched healthy controls were chosen for analyses. Grey matter volume and cortical thickness were measured by VBM and Freesurfer. Grey matter volume results were then rendered onto the surface template of Freesurfer to compare the differences from cortical thickness in anatomical locations. Discrepancy regions of the grey matter volume and thickness where grey matter volume significantly decreased but without corresponding evidence of cortical thinning involved the rostral middle frontal, precentral, lateral occipital and superior frontal gyri. Subsequent region-of-interest analysis demonstrated that changes in surface area, grey/white matter intensity contrast and curvature accounted for the discrepancies. Our results suggest that the differences between grey matter volume and thickness could be jointly driven by surface area, grey/white matter intensity contrast and curvature. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Assessing a Tornado Climatology from Global Tornado Intensity Distributions

    OpenAIRE

    Feuerstein, B.; Dotzek, N.; Grieser, J.

    2005-01-01

    Recent work demonstrated that the shape of tornado intensity distributions from various regions worldwide is well described by Weibull functions. This statistical modeling revealed a strong correlation between the fit parameters c for shape and b for scale regardless of the data source. In the present work it is shown that the quality of the Weibull fits is optimized if only tornado reports of F1 and higher intensity are used and that the c–b correlation does indeed reflect a universal featur...

  10. Wave propagation through disordered media without backscattering and intensity variations

    Institute of Scientific and Technical Information of China (English)

    Konstantinos G Makris; Andre Brandst(o)tter; Philipp Ambichl; Ziad H Musslimani; Stefan Rotter

    2017-01-01

    A fundamental manifestation of wave scattering in a disordered medium is the highly complex intensity pattern the waves acquire due to multi-path interference.Here we show that these intensity variations can be entirely suppressed by adding disorder-specific gain and loss components to the medium.The resulting constant-intensity waves in such non-Hermitian scattering landscapes are free of any backscattering and feature perfect transmission through the disorder.An experimental demonstration of these unique wave states is envisioned based on spatially modulated pump beams that can flexibly control the gain and loss components in an active medium.

  11. Influence of Structural Features and Fracture Processes on Surface Roughness: A Case Study from the Krosno Sandstones of the Górka–Mucharz Quarry (Little Beskids, Southern Poland

    Directory of Open Access Journals (Sweden)

    Pieczara Łukasz

    2015-09-01

    Full Text Available The paper presents the results of analysis of surface roughness parameters in the Krosno Sandstones of Mucharz, southern Poland. It was aimed at determining whether these parameters are influenced by structural features (mainly the laminar distribution of mineral components and directional distribution of non-isometric grains and fracture processes. The tests applied in the analysis enabled us to determine and describe the primary statistical parameters used in the quantitative description of surface roughness, as well as specify the usefulness of contact profilometry as a method of visualizing spatial differentiation of fracture processes in rocks. These aims were achieved by selecting a model material (Krosno Sandstones from the Górka-Mucharz Quarry and an appropriate research methodology. The schedule of laboratory analyses included: identification analyses connected with non-destructive ultrasonic tests, aimed at the preliminary determination of rock anisotropy, strength point load tests (cleaved surfaces were obtained due to destruction of rock samples, microscopic analysis (observation of thin sections in order to determine the mechanism of inducing fracture processes and a test method of measuring surface roughness (two- and three-dimensional diagrams, topographic and contour maps, and statistical parameters of surface roughness. The highest values of roughness indicators were achieved for surfaces formed under the influence of intragranular fracture processes (cracks propagating directly through grains. This is related to the structural features of the Krosno Sandstones (distribution of lamination and bedding.

  12. Study on the construction of multi-dimensional Remote Sensing feature space for hydrological drought

    International Nuclear Information System (INIS)

    Xiang, Daxiang; Tan, Debao; Wen, Xiongfei; Shen, Shaohong; Li, Zhe; Cui, Yuanlai

    2014-01-01

    Hydrological drought refers to an abnormal water shortage caused by precipitation and surface water shortages or a groundwater imbalance. Hydrological drought is reflected in a drop of surface water, decrease of vegetation productivity, increase of temperature difference between day and night and so on. Remote sensing permits the observation of surface water, vegetation, temperature and other information from a macro perspective. This paper analyzes the correlation relationship and differentiation of both remote sensing and surface measured indicators, after the selection and extraction a series of representative remote sensing characteristic parameters according to the spectral characterization of surface features in remote sensing imagery, such as vegetation index, surface temperature and surface water from HJ-1A/B CCD/IRS data. Finally, multi-dimensional remote sensing features such as hydrological drought are built on a intelligent collaborative model. Further, for the Dong-ting lake area, two drought events are analyzed for verification of multi-dimensional features using remote sensing data with different phases and field observation data. The experiments results proved that multi-dimensional features are a good method for hydrological drought

  13. Challenges related to flotation cleaning of oil shales. Issues due to compositional and surface features and post-grinding surface behavior

    Directory of Open Access Journals (Sweden)

    Altun N. Emre

    2016-01-01

    Full Text Available Oil shale is an important energy resource alternative. Despite its recognition as an unconventional oil source, oil shale is also considered as an important solid fossil fuel alternative to coal and lignites due to the solid form and remarkable extent of organic content. Utilization possibilites, similar to coal and lignites, have been considered in the past decades and direct use of oil shales in thermal power production has been possible in countries like Estonia and China. In the perspective of utilization of oil shales in a similar manner to coal and lignites, problems and restrictions related to the inorganic ash-making and potentially pollutant constituents are applied. In this respect, cleaning of this important energy source through mineral processing methods, particularly by flotation, is an outstanding option. However, on the basis of unique features and distinctive characteristics, treatment of oil shales like a type of coal is a big perception and may be highly misleading. This paper discusses specific challenges regarding flotation behavior of oil shales with reference to the surface characteristics and behavior of oil shale entities – probably the most important aspect that determines the efficiency and success of the flotation based cleaning process.

  14. Derivation of Ground Surface and Vegetation in a Coastal Florida Wetland with Airborne Laser Technology

    Science.gov (United States)

    Raabe, Ellen A.; Harris, Melanie S.; Shrestha, Ramesh L.; Carter, William E.

    2008-01-01

    The geomorphology and vegetation of marsh-dominated coastal lowlands were mapped from airborne laser data points collected on the Gulf Coast of Florida near Cedar Key. Surface models were developed using low- and high-point filters to separate ground-surface and vegetation-canopy intercepts. In a non-automated process, the landscape was partitioned into functional landscape units to manage the modeling of key landscape features in discrete processing steps. The final digital ground surface-elevation model offers a faithful representation of topographic relief beneath canopies of tidal marsh and coastal forest. Bare-earth models approximate field-surveyed heights by + 0.17 m in the open marsh and + 0.22 m under thick marsh or forest canopy. The laser-derived digital surface models effectively delineate surface features of relatively inaccessible coastal habitats with a geographic coverage and vertical detail previously unavailable. Coastal topographic details include tidal-creek tributaries, levees, modest topographic undulations in the intertidal zone, karst features, silviculture, and relict sand dunes under coastal-forest canopy. A combination of laser-derived ground-surface and canopy-height models and intensity values provided additional mapping capabilities to differentiate between tidal-marsh zones and forest types such as mesic flatwood, hydric hammock, and oak scrub. Additional derived products include fine-scale shoreline and topographic profiles. The derived products demonstrate the capability to identify areas of concern to resource managers and unique components of the coastal system from laser altimetry. Because the very nature of a wetland system presents difficulties for access and data collection, airborne coverage from remote sensors has become an accepted alternative for monitoring wetland regions. Data acquisition with airborne laser represents a viable option for mapping coastal topography and for evaluating habitats and coastal change on marsh

  15. A new karren feature: hummocky karren

    Directory of Open Access Journals (Sweden)

    Plan Lukas

    2012-01-01

    Full Text Available Karren are small-scale landforms on karst surfaces and many types have been described so far. Here we present an apparently new feature which was found on the Hochschwab karst massive in the Northern Calcareous Alps of Austria. So far only few outcrops each having less than 1 m² within a very restricted area have been found. Morphometric analysis reveals that the karren consist of a randomly distributed, dispersed assemblage of small hummocks and depressions in between. The mean distance between neighbouring hummocks is 4 to 5 cm and the mean height is 0.85 cm. Longitudinal sections are gently sinuous. The occurrences are delimited by thin soil cover with grassy vegetation and the karren continue below that vegetation cover. Therefore, it is clear that the features have formed subcutaneously. Corroded fissures where water could infiltrate into the epikarst are absent. The bedrock lithology is Middle Triassic limestone of the Wetterstein Formation in lagoonal facies. Geological structures do not govern the feature. The surface is not a bedding plane and small joints and fractures do not govern the arrangement of the hummocks. Thin section analysis regarding rock texture and dolomite components show that there is no compositional difference between hummocks and depressions. Geochemical analyses show that the limestone is very pure with a very low content of Magnesia. Slightly higher Magnesia contents at the hummock surfaces are significant. The data obtained so far only indicate that some dissolution mechanism but not any rock property governs the irregular array. As there exist no descriptions of comparable features in literature, the name “hummocky karren” is suggested for that type of karren landform.

  16. [Intensive medicine in Spain].

    Science.gov (United States)

    2011-03-01

    Intensive care medicine is a medical specialty that was officially established in our country in 1978, with a 5-year training program including two years of common core training followed by three years of specific training in an intensive care unit accredited for training. During this 32-year period, intensive care medicine has carried out an intense and varied activity, which has allowed its positioning as an attractive and with future specialty in the hospital setting. This document summarizes the history of the specialty, its current situation, the key role played in the programs of organ donation and transplantation of the National Transplant Organization (after more than 20 years of mutual collaboration), its training activities with the development of the National Plan of Cardiopulmonary Resuscitation, with a trajectory of more than 25 years, its interest in providing care based on quality and safety programs for the severely ill patient. It also describes the development of reference registries due to the need for reliable data on the care process for the most prevalent diseases, such as ischemic heart disease or ICU-acquired infections, based on long-term experience (more than 15 years), which results in the availability of epidemiological information and characteristics of care that may affect the practical patient's care. Moreover, features of its scientific society (SEMICYUC) are reported, an organization that agglutinates the interests of more than 280 ICUs and more than 2700 intensivists, with reference to the journal Medicina Intensiva, the official journal of the society and the Panamerican and Iberian Federation of Critical Medicine and Intensive Care Societies. Medicina Intensiva is indexed in the Thompson Reuters products of Science Citation Index Expanded (Scisearch(®)) and Journal Citation Reports, Science Edition. The important contribution of the Spanish intensive care medicine to the scientific community is also analyzed, and in relation to

  17. OCA-II, a code for calculating the behavior of 2-D and 3-D surface flaws in a pressure vessel subjected to temperature and pressure transients

    International Nuclear Information System (INIS)

    Ball, D.G.; Drake, J.B.; Cheverton, R.D.; Iskander, S.K.

    1984-02-01

    The OCA-II computer code, like its predecessor OCA-I, performs the thermal, stress, and linear elastic fracture-mechanics analysis for long flaws on the surface of a cylinder that is subjected to thermal and pressure transients. OCA-II represents a revised and expanded version of OCA-I and includes as new features (1) cladding as a discrete region, (2) a finite-element subroutine for calculating the stresses, and (3) the ability to calculate stress intensity factors for certain three-dimensional flaws, for two-dimensional circumferential flaws on the inner surface, and for both axial and circumferential flaws on the outer surface. OCA-I considered only inner-surface flaws. An option is included in OCA-II that permits a search for critical values of fluence or nil-ductility reference temperature corresponding to a specified failure criterion. These and other features of OCA-II are described in the report, which also includes user instructions for the code

  18. Reconstruction de la surface de Fermi dans l'etat normal d'un supraconducteur a haute Tc: Une etude du transport electrique en champ magnetique intense

    Science.gov (United States)

    Le Boeuf, David

    Des mesures de resistance longitudinale et de resistance de Hall en champ magnetique intense transverse (perpendiculaire aux plans CuO2) ont ete effectuees au sein de monocristaux de YBa2Cu3Oy (YBCO) demacles, ordonnes et de grande purete, afin d'etudier l'etat fondamental des supraconducteurs a haute Tc dans le regime sous-dope. Cette etude a ete realisee en fonction du dopage et de l'orientation du courant d'excitation J par rapport a l'axe orthorhombique b de la structure cristalline. Les mesures en champ magnetique intense revelent par suppression de la supraconductivite des oscillations magnetiques des resistances longitudinale et de Hall dans YBa2Cu 3O6.51 et YBa2Cu4O8. La conformite du comportement de ces oscillations quantiques au formalisme de Lifshitz-Kosevich, apporte la preuve de l'existence d'une surface de Fermi fermee a caractere quasi-2D, abritant des quasiparticules coherentes respectant la statistique de Fermi-Dirac, dans la phase pseudogap d'YBCO. La faible frequence des oscillations quantiques, combinee avec l'etude de la partie monotone de la resistance de Hall en fonction de la temperature indique que la surface de Fermi d'YBCO sous-dope comprend une petite poche de Fermi occupee par des porteurs de charge negative. Cette particularite de la surface de Fermi dans le regime sous-dope incompatible avec les calculs de structure de bande est en fort contraste avec la structure electronique presente dans le regime surdope. Cette observation implique ainsi l'existence d'un point critique quantique dans le diagramme de phase d'YBCO, au voisinage duquel la surface de Fermi doit subir une reconstruction induite par l'etablissement d'une brisure de la symetrie de translation du reseau cristallin sous-jacent. Enfin, l'etude en fonction du dopage de la resistance de Hall et de la resistance longitudinale en champ magnetique intense suggere qu'un ordre du type onde de densite (DW) est responsable de la reconstruction de la surface de Fermi. L'analogie de

  19. Cosmic-muon intensity measurement and overburden estimation in a building at surface level and in an underground facility using two BC408 scintillation detectors coincidence counting system.

    Science.gov (United States)

    Zhang, Weihua; Ungar, Kurt; Liu, Chuanlei; Mailhot, Maverick

    2016-10-01

    A series of measurements have been recently conducted to determine the cosmic-muon intensities and attenuation factors at various indoor and underground locations for a gamma spectrometer. For this purpose, a digital coincidence spectrometer was developed by using two BC408 plastic scintillation detectors and an XIA LLC Digital Gamma Finder (DGF)/Pixie-4 software and card package. The results indicate that the overburden in the building at surface level absorbs a large part of cosmic ray protons while attenuating the cosmic-muon intensity by 20-50%. The underground facility has the largest overburden of 39 m water equivalent, where the cosmic-muon intensity is reduced by a factor of 6. The study provides a cosmic-muon intensity measurement and overburden assessment, which are important parameters for analysing the background of an HPGe counting system, or for comparing the background of similar systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Wet meadow ecosystems and the longevity of biologically-mediated geomorphic features

    Science.gov (United States)

    Nash, C.; Grant, G.; O'Connor, J. E.

    2016-12-01

    Upland meadows represent a ubiquitous feature of montane landscapes in the U.S. West and beyond. Characterized by flat valley floors flanked by higher-gradient hillslopes, these meadows are important features, both for the diverse ecosystems they support but also because they represent depositional features in what is primarily an erosional environment. As such, they serve as long-term chronometers of both geological and ecological processes in a portion of the landscape where such records are rare, and provide a useful microcosm for exploring many of the questions motivating critical zone science. Specifically, meadows can offer insights into questions regarding the longevity of theses biologically-mediated landscapes, and the geomorphic thresholds associated with transitions between metastable landscape states. Though categorically depositional, wet meadows have been shown to rapidly shift into erosional landscapes characterized by deep arroyos, declining water tables, and sparse, semi-arid ecosystems. Numerous hypotheses have been proposed explaining this shift: intensive ungulate usage, removal of beaver, climatic shifts, and intrinsic geomorphic evolution. Even less is known about the mechanisms controlling the construction of these meadow features. Evidence seems to suggest these channels oscillate between two metastable conditions: deeply incised, single-threaded channels and sheet-flow dominated valley-spanning wetlands. We present new evidence exploring the subsurface architecture of wet meadows and the bidirectional process cascades potentially responsible for their temporal evolution. Using a combination of near surface geophysical techniques and detailed stratigraphic descriptions of incised and un-incised meadows throughout the Silvies River Basin, OR, we examine mechanisms responsible both for the construction of these features and their apparently rapid transition from depositional to erosional. Our investigation focuses specifically on potential

  1. Pupil size reflects the focus of feature-based attention.

    Science.gov (United States)

    Binda, Paola; Pereverzeva, Maria; Murray, Scott O

    2014-12-15

    We measured pupil size in adult human subjects while they selectively attended to one of two surfaces, bright and dark, defined by coherently moving dots. The two surfaces were presented at the same location; therefore, subjects could select the cued surface only on the basis of its features. With no luminance change in the stimulus, we find that pupil size was smaller when the bright surface was attended and larger when the dark surface was attended: an effect of feature-based (or surface-based) attention. With the same surfaces at nonoverlapping locations, we find a similar effect of spatial attention. The pupil size modulation cannot be accounted for by differences in eye position and by other variables known to affect pupil size such as task difficulty, accommodation, or the mere anticipation (imagery) of bright/dark stimuli. We conclude that pupil size reflects not just luminance or cognitive state, but the interaction between the two: it reflects which luminance level in the visual scene is relevant for the task at hand. Copyright © 2014 the American Physiological Society.

  2. The third generation multi-purpose plasma immersion ion implanter for surface modification of materials

    CERN Document Server

    Tang Bao Yin; Wang Xiao Feng; Gan Kong Yin; Wang Song Yan; Chu, P K; Huang Nian Ning; Sun Hong

    2002-01-01

    The third generation multi-purpose plasma immersion ion implantation (PIII) equipment has been successfully used for research and development of surface modification of biomedical materials, metals and their alloys in the Southwest Jiaotong University. The implanter equipped with intense current, pulsed cathodic arc metal plasma sources which have both strong coating function and gas and metal ion implantation function. Its pulse high voltage power supply can provide big output current. It can acquire very good implantation dose uniformity. The equipment can both perform ion implantation and combine ion implantation with sputtering deposition and coating to form many kinds of synthetic surface modification techniques. The main design principles, features of important components and achievement of research works in recent time have been described

  3. Study on the Light Scattering from Random Rough Surfaces by Kirrhoff Approximation

    Directory of Open Access Journals (Sweden)

    Keding Yan

    2014-07-01

    Full Text Available In order to study the space distribution characteristics of light scattering from random rough surfaces, the linear filtering method is used to generate a series of Gaussian randomly rough surfaces, and the Kirchhoff Approximation is used to calculate the scattered light intensity distribution from random metal and dielectric rough surfaces. The three characteristics of the scattered light intensity distribution peak, the intensity distribution width and the position of peak are reviewed. Numerical calculation results show that significant differences between scattering characteristics of metal surfaces and the dielectric surfaces exist. The light scattering characteristics are jointly influenced by the slope distribution and reflectance of surface element. The scattered light intensity distribution is affected by common influence of surface local slope distribution and surface local reflectivity. The results can provide a basis theory for the research to lidar target surface scattering characteristics.

  4. Salient features in 3-D haptic shape perception

    NARCIS (Netherlands)

    Plaisier, Myrthe A; Bergmann Tiest, Wouter M.; Kappers, Astrid M L

    2009-01-01

    Shape is an important cue for recognizing an object by touch. Several features, such as edges, curvature, surface area, and aspect ratio, are associated with 3-D shape. To investigate the saliency of 3-D shape features, we developed a haptic search task. The target and distractor items consisted of

  5. Wavelength dependence of momentum-space images of low-energy electrons generated by short intense laser pulses at high intensities

    International Nuclear Information System (INIS)

    Maharjan, C M; Alnaser, A S; Litvinyuk, I; Ranitovic, P; Cocke, C L

    2006-01-01

    We have measured momentum-space images of low-energy electrons generated by the interaction of short intense laser pulses with argon atoms at high intensities. We have done this over a wavelength range from 400 to 800 nm. The spectra show considerable structure in both the energy and angular distributions of the electrons. Some, but not all, energy features can be identified as multi-photon resonances. The angular structure shows a regularity which transcends the resonant structure and may be due instead to diffraction. The complexity of the results defies easy model-dependent interpretations and invites full solutions to Schroedinger's equation for these systems

  6. Second order classical perturbation theory for atom surface scattering: Analysis of asymmetry in the angular distribution

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yun, E-mail: zhou.yun.x@gmail.com; Pollak, Eli, E-mail: eli.pollak@weizmann.ac.il [Chemical Physics Department, Weizmann Institute of Science, 76100 Rehovot (Israel); Miret-Artés, Salvador, E-mail: s.miret@iff.csic.es [Instituto de Fisica Fundamental, Consejo Superior de Investigaciones Cientificas, Serrano 123, 28006 Madrid (Spain)

    2014-01-14

    A second order classical perturbation theory is developed and applied to elastic atom corrugated surface scattering. The resulting theory accounts for experimentally observed asymmetry in the final angular distributions. These include qualitative features, such as reduction of the asymmetry in the intensity of the rainbow peaks with increased incidence energy as well as the asymmetry in the location of the rainbow peaks with respect to the specular scattering angle. The theory is especially applicable to “soft” corrugated potentials. Expressions for the angular distribution are derived for the exponential repulsive and Morse potential models. The theory is implemented numerically to a simplified model of the scattering of an Ar atom from a LiF(100) surface.

  7. Second order classical perturbation theory for atom surface scattering: analysis of asymmetry in the angular distribution.

    Science.gov (United States)

    Zhou, Yun; Pollak, Eli; Miret-Artés, Salvador

    2014-01-14

    A second order classical perturbation theory is developed and applied to elastic atom corrugated surface scattering. The resulting theory accounts for experimentally observed asymmetry in the final angular distributions. These include qualitative features, such as reduction of the asymmetry in the intensity of the rainbow peaks with increased incidence energy as well as the asymmetry in the location of the rainbow peaks with respect to the specular scattering angle. The theory is especially applicable to "soft" corrugated potentials. Expressions for the angular distribution are derived for the exponential repulsive and Morse potential models. The theory is implemented numerically to a simplified model of the scattering of an Ar atom from a LiF(100) surface.

  8. Modeling Coupled Landscape Evolution and Soil Organic Carbon Dynamics in Intensively Management Landscapes

    Science.gov (United States)

    Yan, Q.; Kumar, P.

    2017-12-01

    Soil is the largest reservoir of carbon in the biosphere but in agricultural areas it is going through rapid erosion due disturbance arising from crop harvest, tillage, and tile drainage. Identifying whether the production of soil organic carbon (SOC) from the crops can compensate for the loss due to erosion is critical to ensure our food security and adapt to climate change. In the U.S. Midwest where large areas of land are intensively managed for agriculture practices, predicting soil quantity and quality are critical for maintaining crop yield and other Critical Zone services. This work focuses on modeling the coupled landscape evolutions soil organic carbon dynamics in agricultural fields. It couples landscape evolution, surface water runoff, organic matter transformation, and soil moisture dynamics to understand organic carbon gain and loss due to natural forcing and farming practices, such as fertilizer application and tillage. A distinctive feature of the model is the coupling of surface ad subsurface processes that predicts both surficial changes and transport along with the vertical transport and dynamics. Our results show that landscape evolution and farming practices play dominant roles in soil organic carbon (SOC) dynamics both above- and below-ground. Contrary to the common assumption that a vertical profile of SOC concentration decreases exponentially with depth, we find that in many situations SOC concentration below-ground could be higher than that at the surface. Tillage plays a complex role in organic matter dynamics. On one hand, tillage would accelerate the erosion rate, on the other hand, it would improve carbon storage by burying surface SOC into below ground. Our model consistently reproduces the observed above- and below-ground patterns of SOC in the field sites of Intensively Managed Landscapes Critical Zone Observatory (IMLCZO). This model bridges the gaps between the landscape evolution, below- and above-ground hydrologic cycle, and

  9. Anisotropic surface chemistry properties and adsorption behavior of silicate mineral crystals.

    Science.gov (United States)

    Xu, Longhua; Tian, Jia; Wu, Houqin; Fang, Shuai; Lu, Zhongyuan; Ma, Caifeng; Sun, Wei; Hu, Yuehua

    2018-03-07

    Anisotropic surface properties of minerals play an important role in a variety of fields. With a focus on the two most intensively investigated silicate minerals (i.e., phyllosilicate minerals and pegmatite aluminosilicate minerals), this review highlights the research on their anisotropic surface properties based on their crystal structures. Four surface features comprise the anisotropic surface chemistry of minerals: broken bonds, energy, wettability, and charge. Analysis of surface broken bond and energy anisotropy helps to explain the cleavage and growth properties of mineral crystals, and understanding surface wettability and charge anisotropy is critical to the analysis of minerals' solution behavior, such as their flotation performance and rheological properties. In a specific reaction, the anisotropic surface properties of minerals are reflected in the adsorption strengths of reagents on different mineral surfaces. Combined with the knowledge of mineral crushing and grinding, a thorough understanding of the anisotropic surface chemistry properties and the anisotropic adsorption behavior of minerals will lead to the development of effective relational models comprising their crystal structure, surface chemistry properties, and targeted reagent adsorption. Overall, such a comprehensive approach is expected to firmly establish the connection between selective cleavage of mineral crystals for desired surfaces and designing novel reagents selectively adsorbed on the mineral surfaces. As tools to characterize the anisotropic surface chemistry properties of minerals, DLVO theory, atomic force microscopy (AFM), and molecular dynamics (MD) simulations are also reviewed. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Controllable edge feature sharpening for dental applications.

    Science.gov (United States)

    Fan, Ran; Jin, Xiaogang

    2014-01-01

    This paper presents a new approach to sharpen blurred edge features in scanned tooth preparation surfaces generated by structured-light scanners. It aims to efficiently enhance the edge features so that the embedded feature lines can be easily identified in dental CAD systems, and to avoid unnatural oversharpening geometry. We first separate the feature regions using graph-cut segmentation, which does not require a user-defined threshold. Then, we filter the face normal vectors to propagate the geometry from the smooth region to the feature region. In order to control the degree of the sharpness, we propose a feature distance measure which is based on normal tensor voting. Finally, the vertex positions are updated according to the modified face normal vectors. We have applied the approach to scanned tooth preparation models. The results show that the blurred edge features are enhanced without unnatural oversharpening geometry.

  11. Controllable Edge Feature Sharpening for Dental Applications

    Directory of Open Access Journals (Sweden)

    Ran Fan

    2014-01-01

    Full Text Available This paper presents a new approach to sharpen blurred edge features in scanned tooth preparation surfaces generated by structured-light scanners. It aims to efficiently enhance the edge features so that the embedded feature lines can be easily identified in dental CAD systems, and to avoid unnatural oversharpening geometry. We first separate the feature regions using graph-cut segmentation, which does not require a user-defined threshold. Then, we filter the face normal vectors to propagate the geometry from the smooth region to the feature region. In order to control the degree of the sharpness, we propose a feature distance measure which is based on normal tensor voting. Finally, the vertex positions are updated according to the modified face normal vectors. We have applied the approach to scanned tooth preparation models. The results show that the blurred edge features are enhanced without unnatural oversharpening geometry.

  12. Meteorite Impact "Earthquake" Features (Rock Liquefaction, Surface Wave Deformations, Seismites) from Ground Penetrating Radar (GPR) and Geoelectric Complex Resistivity/Induced Polarization (IP) Measurements, Chiemgau (Alpine Foreland, Southeast Germany)

    Science.gov (United States)

    Ernstson, K.; Poßekel, J.

    2017-12-01

    Densely spaced GPR and complex resistivity measurements on a 30,000 square meters site in a region of enigmatic sinkhole occurrences in unconsolidated Quaternary sediments have featured unexpected and highlighting results from both a meteorite impact research and an engineering geology point of view. The GPR measurements and a complex resistivity/IP electrical imaging revealed extended subrosion depressions related with a uniformly but in various degrees of intensity deformed loamy and gravelly ground down to at least 10 m depth. Two principle observations could be made from both the GPR high-resolution measurements and the more integrating resistivity and IP soundings with both petrophysical evidences in good complement. Subrosion can be shown to be the result of prominent sandy-gravelly intrusions and extrusions typical of rock liquefaction processes well known to occur during strong earthquakes. Funnel-shaped structures with diameters up to 25 m near the surface and reaching down to the floating ground water level at 10 m depth were measured. GPR radargrams could trace prominent gravelly-material transport bottom-up within the funnels. Seen in both GPR tomography and resistivity/IP sections more or less the whole investigated area is overprinted by wavy deformations of the unconsolidated sediments with wavelengths of the order of 5 - 10 m and amplitudes up to half a meter, likewise down to 10 m depth. Substantial earthquakes are not known in this region. Hence, the observed heavy underground disorder is considered the result of the prominent earthquake shattering that must have occurred during the Holocene (Bronze Age/Celtic era) Chiemgau meteorite impact event that produced a 60 km x 30 km sized crater strewn field directly hosting the investigated site. Depending on depth and size of floating aquifers local concentrations of rock liquefaction and seismic surface waves (probably LOVE waves) to produce the wavy deformations could develop, when the big

  13. Identifying anthropogenic anomalies in air, surface and groundwater temperatures in Germany.

    Science.gov (United States)

    Benz, Susanne A; Bayer, Peter; Blum, Philipp

    2017-04-15

    Human activity directly influences ambient air, surface and groundwater temperatures. The most prominent phenomenon is the urban heat island effect, which has been investigated particularly in large and densely populated cities. This study explores the anthropogenic impact on the thermal regime not only in selected urban areas, but on a countrywide scale for mean annual temperature datasets in Germany in three different compartments: measured surface air temperature, measured groundwater temperature, and satellite-derived land surface temperature. Taking nighttime lights as an indicator of rural areas, the anthropogenic heat intensity is introduced. It is applicable to each data set and provides the difference between measured local temperature and median rural background temperature. This concept is analogous to the well-established urban heat island intensity, but applicable to each measurement point or pixel of a large, even global, study area. For all three analyzed temperature datasets, anthropogenic heat intensity grows with increasing nighttime lights and declines with increasing vegetation, whereas population density has only minor effects. While surface anthropogenic heat intensity cannot be linked to specific land cover types in the studied resolution (1km×1km) and classification system, both air and groundwater show increased heat intensities for artificial surfaces. Overall, groundwater temperature appears most vulnerable to human activity, albeit the different compartments are partially influenced through unrelated processes; unlike land surface temperature and surface air temperature, groundwater temperatures are elevated in cultivated areas as well. At the surface of Germany, the highest anthropogenic heat intensity with 4.5K is found at an open-pit lignite mine near Jülich, followed by three large cities (Munich, Düsseldorf and Nuremberg) with annual mean anthropogenic heat intensities >4K. Overall, surface anthropogenic heat intensities >0K and

  14. Progress toward a microsecond duration, repetitively pulsed, intense- ion beam

    International Nuclear Information System (INIS)

    Davis, H.A.; Olson, J.C.; Reass, W.A.; Coates, D.M.; Hunt, J.W.; Schleinitz, H.M.; Greenly, J.B.

    1996-01-01

    A number of intense ion beams applications are emerging requiring repetitive high-average-power beams. These applications include ablative deposition of thin films, rapid melt and resolidification for surface property enhancement, advanced diagnostic neutral beams for the next generation of Tokamaks, and intense pulsed-neutron sources. We are developing a 200-250 keV, 15 kA, 1 μs duration, 1-30 Hz intense ion beam accelerator to address these applications

  15. Volume Decomposition and Feature Recognition for Hexahedral Mesh Generation

    Energy Technology Data Exchange (ETDEWEB)

    GADH,RAJIT; LU,YONG; TAUTGES,TIMOTHY J.

    1999-09-27

    Considerable progress has been made on automatic hexahedral mesh generation in recent years. Several automatic meshing algorithms have proven to be very reliable on certain classes of geometry. While it is always worth pursuing general algorithms viable on more general geometry, a combination of the well-established algorithms is ready to take on classes of complicated geometry. By partitioning the entire geometry into meshable pieces matched with appropriate meshing algorithm the original geometry becomes meshable and may achieve better mesh quality. Each meshable portion is recognized as a meshing feature. This paper, which is a part of the feature based meshing methodology, presents the work on shape recognition and volume decomposition to automatically decompose a CAD model into meshable volumes. There are four phases in this approach: (1) Feature Determination to extinct decomposition features, (2) Cutting Surfaces Generation to form the ''tailored'' cutting surfaces, (3) Body Decomposition to get the imprinted volumes; and (4) Meshing Algorithm Assignment to match volumes decomposed with appropriate meshing algorithms. The feature determination procedure is based on the CLoop feature recognition algorithm that is extended to be more general. Results are demonstrated over several parts with complicated topology and geometry.

  16. An estimate of intensity of windy resuspension during imitation of agricultural work

    International Nuclear Information System (INIS)

    Drugachenok, M.A.; Kudryashov, V.P.; Mironov, V.P.

    1996-01-01

    Estimation of intensity of wind rising at imitation of agricultural works. During special experiment for imitation of the agricultural activity which has been carried out in the summer of 1993, the characteristics of radioactive contamination of a surface of ground, density of radioactive fallout, concentration of radionuclides and their distribution on height of surface layer of atmosphere are measured. The value of intensity of secondary wind rising in conditions of dry weather are received. At mechanical influence on ground the intensity of wind rising exceeds on 3-4 order a background value of this parameter which are (4-6)*10 -11 1/c. The received numerical value of intensity of wind rising can be used for forecasting of inhalation intake of radionuclides in organism of the person during agricultural works. 3 tabs., 10 refs

  17. Intense air-sea exchanges and heavy orographic precipitation over Italy: The role of Adriatic sea surface temperature uncertainty

    Science.gov (United States)

    Stocchi, Paolo; Davolio, Silvio

    2017-11-01

    Strong and persistent low-level winds blowing over the Adriatic basin are often associated with intense precipitation events over Italy. Typically, in case of moist southeasterly wind (Sirocco), rainfall affects northeastern Italy and the Alpine chain, while with cold northeasterly currents (Bora) precipitations are localized along the eastern slopes of the Apennines and central Italy coastal areas. These events are favoured by intense air-sea interactions and it is reasonable to hypothesize that the Adriatic sea surface temperature (SST) can affect the amount and location of precipitation. High-resolution simulations of different Bora and Sirocco events leading to severe precipitation are performed using a convection-permitting model (MOLOCH). Sensitivity experiments varying the SST initialization field are performed with the aim of evaluating the impact of SST uncertainty on precipitation forecasts, which is a relevant topic for operational weather predictions, especially at local scales. Moreover, diagnostic tools to compute water vapour fluxes across the Italian coast and atmospheric water budget over the Adriatic Sea have been developed and applied in order to characterize the air mass that feeds the precipitating systems. Finally, the investigation of the processes through which the SST influences location and intensity of heavy precipitation allows to gain a better understanding on mechanisms conducive to severe weather in the Mediterranean area and in the Adriatic basin in particular. Results show that the effect of the Adriatic SST (uncertainty) on precipitation is complex and can vary considerably among different events. For both Bora and Sirocco events, SST does not influence markedly the atmospheric water budget or the degree of moistening of air that flows over the Adriatic Sea. SST mainly affects the stability of the atmospheric boundary layer, thus influencing the flow dynamics and the orographic flow regime, and in turn, the precipitation pattern.

  18. Image simulation and surface reconstruction of undercut features in atomic force microscopy

    Science.gov (United States)

    Qian, Xiaoping; Villarrubia, John; Tian, Fenglei; Dixson, Ronald

    2007-03-01

    CD-AFMs (critical dimension atomic force microscopes) are instruments with servo-control of the tip in more than one direction. With appropriately "boot-shaped" or flared tips, such instruments can image vertical or even undercut features. As with any AFM, the image is a dilation of the sample shape with the tip shape. Accurate extraction of the CD requires a correction for the tip effect. Analytical methods to correct images for the tip shape have been available for some time for the traditional (vertical feedback only) AFMs, but were until recently unavailable for instruments with multi-dimensional feedback. Dahlen et al. [J. Vac. Sci. Technol. B23, pp. 2297-2303, (2005)] recently introduced a swept-volume approach, implemented for 2-dimensional (2D) feedback. It permits image simulation and sample reconstruction, techniques previously developed for the traditional instruments, to be extended for the newer tools. We have introduced [X. Qian and J. S. Villarrubia, Ultramicroscopy, in press] an alternative dexel-based method, that does the same in either 2D or 3D. This paper describes the application of this method to sample shapes of interest in semiconductor manufacturing. When the tip shape is known (e.g., by prior measurement using a tip characterizer) a 3D sample surface may be reconstructed from its 3D image. Basing the CD measurement upon such a reconstruction is shown here to remove some measurement artifacts that are not removed (or are incompletely removed) by the existing measurement procedures.

  19. Pattern Analysis of El Nino and La Nina Phenomenon Based on Sea Surface Temperature (SST) and Rainfall Intensity using Oceanic Nino Index (ONI) in West Java Area

    Science.gov (United States)

    Prasetyo, Yudo; Nabilah, Farras

    2017-12-01

    Climate change occurs in 1998-2016 brings significant alteration in the earth surface. It is affects an extremely anomaly temperature such as El Nino and La Nina or mostly known as ENSO (El Nino Southern Oscillation). West Java is one of the regions in Indonesia that encounters the impact of this phenomenon. Climate change due to ENSO also affects food production and other commodities. In this research, processing data method is conducted using programming language to process SST data and rainfall data from 1998 to 2016. The data are sea surface temperature from NOAA satellite, SST Reynolds (Sea Surface Temperature) and daily rainfall temperature from TRMM satellite. Data examination is done using analysis of rainfall spatial pattern and sea surface temperature (SST) where is affected by El Nino and La Nina phenomenon. This research results distribution map of SST and rainfall for each season to find out the impacts of El Nino and La Nina around West Java. El Nino and La Nina in Java Sea are occurring every August to February. During El Nino, sea surface temperature is between 27°C - 28°C with average temperature on 27.71°C. Rainfall intensity is 1.0 mm/day - 2.0 mm/day and the average are 1.63 mm/day. During La Nina, sea surface temperature is between 29°C - 30°C with average temperature on 29.06°C. Rainfall intensity is 9.0 mm/day - 10 mm/day, and the average is 9.74 mm/day. The correlation between rainfall and SST is 0,413 which is expresses a fairly strong correlation between parameters. The conclusion is, during La Nina SST and rainfall increase. While during El Nino SST and rainfall decrease. Hopefully this research could be a guideline to plan disaster mitigation in West Java region that is related extreme climate change.

  20. Raman spectroscopy an intensity approach

    CERN Document Server

    Guozhen, Wu

    2017-01-01

    This book summarizes the highlights of our work on the bond polarizability approach to the intensity analysis. The topics covered include surface enhanced Raman scattering, Raman excited virtual states and Raman optical activity (ROA). The first chapter briefly introduces the Raman effect in a succinct but clear way. Chapter 2 deals with the normal mode analysis. This is a basic tool for our work. Chapter 3 introduces our proposed algorithm for the Raman intensity analysis. Chapter 4 heavily introduces the physical picture of Raman virtual states. Chapter 5 offers details so that the readers can have a comprehensive idea of Raman virtual states. Chapter 6 demonstrates how this bond polarizability algorithm is extended to ROA intensity analysis. Chapters 7 and 8 offer details on ROA, showing many findings on ROA mechanism that were not known or neglected before. Chapter 9 introduces our proposed classical treatment on ROA which, as combined with the results from the bond polarizability analysis, leads to a com...

  1. Imaging features of skeletal changes in children with Gaucher disease

    International Nuclear Information System (INIS)

    Zhang Ningning; Duan Xiaomin; Duan Yanlong

    2011-01-01

    Objective: To discuss the imaging features of skeletal changes in children with Gaucher disease on X-ray and MRI images. Methods: One hundred and nine children with Gaucher disease were enrolled in this study. They all received routine X-ray for spine with anterior-posterior (A-P) and lateral view and bilateral femurs with A-P view. Among them, 18 patients received X-ray for pelvic with A-P view, 14 patients received X-ray for left wrist with A-P view, and 14 patients received MRI scan for femur. The MRI scan included T 1 -weighted imaging, T 2 -weighted imaging and fat-suppressed T 2 -weighted imaging with short tau inversion recovery (STIR) sequence. The imaging features of the X-ray and MRI images were analyzed retrospectively. Results: The most common feature is osteoporosis, which presented in 91 cases (83.5%). Besides this, decreased density of metaphysis occurred in 86 cases (78.9%), erlenmeyer flask deformity of metaphysis occurred in 89 patients (81.7%), thinner cortex occurred in 69 cases (63.3%), osteolytic destruction occurred in. 31 cases (28.4%), pathological fractures occurred in 26 cases (23.9%), osteosclerosis occurred in 12 cases (11.0%). cystic degeneration of bone occurred in 16 cases (14.7%), and dislocation of the hip occurred in 4 cases. All 14 patients received MRI presented abnormal signals. Among them, 4 patients presented low signal intensity both on T 1 -weighted and T 2 -weighted images in bone marrow, the other ten presented high signal intensity mixed in low signal intensity areas on T 2 - weighted and fat-suppressed T 2 -weighted images. Conclusions: The imaging features of skeletal changes in children with Gaucher disease are of some characteristics, which could provide useful information for the clinical treatment. (authors)

  2. Progress toward a microsecond duration, repetitively pulsed, intense-ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Davis, H A; Olson, J C; Reass, W A [Los Alamos National Lab., NM (United States); Coates, D M; Hunt, J W; Schleinitz, H M [DuPont Central Research and Development, Wilmington, DE (United States); Lovberg, R H [Univ. of California, San Diego, CA (United States); Greenly, J B [Cornell Univ., Ithaca, NY (United States). Lab. of Plasma Studies

    1997-12-31

    A number of intense ion beams applications are emerging requiring repetitive high-average-power beams. These applications include ablative deposition of thin films, rapid melt and resolidification for surface property enhancement, advanced diagnostic neutral beams for the next generation of Tokamaks, and intense pulsed-neutron sources. A 200-250 keV, 15 kA, 1 {mu}s duration, 1-30 Hz intense ion beam accelerator is being developed to address these applications. (author). 4 figs., 7 refs.

  3. The Sliced Pineapple Grid Feature for Predicting Grasping Affordances

    DEFF Research Database (Denmark)

    Thomsen, Mikkel Tang; Kraft, Dirk; Krüger, Norbert

    2017-01-01

    The problem of grasping unknown objects utilising vision is addressed in this work by introducing a novel feature, the Sliced Pineapple Grid Feature (SPGF). The SPGF encode semi-local surfaces and allows for distinguishing structures such as “walls”,“edges” and “rims”. These structures are shown...

  4. Unsupervised feature learning for autonomous rock image classification

    Science.gov (United States)

    Shu, Lei; McIsaac, Kenneth; Osinski, Gordon R.; Francis, Raymond

    2017-09-01

    Autonomous rock image classification can enhance the capability of robots for geological detection and enlarge the scientific returns, both in investigation on Earth and planetary surface exploration on Mars. Since rock textural images are usually inhomogeneous and manually hand-crafting features is not always reliable, we propose an unsupervised feature learning method to autonomously learn the feature representation for rock images. In our tests, rock image classification using the learned features shows that the learned features can outperform manually selected features. Self-taught learning is also proposed to learn the feature representation from a large database of unlabelled rock images of mixed class. The learned features can then be used repeatedly for classification of any subclass. This takes advantage of the large dataset of unlabelled rock images and learns a general feature representation for many kinds of rocks. We show experimental results supporting the feasibility of self-taught learning on rock images.

  5. Giant boulders and Last Interglacial storm intensity in the North Atlantic

    Science.gov (United States)

    Rovere, Alessio; Casella, Elisa; Harris, Daniel L.; Lorscheid, Thomas; Nandasena, Napayalage A. K.; Dyer, Blake; Sandstrom, Michael R.; Stocchi, Paolo; D'Andrea, William J.; Raymo, Maureen E.

    2017-11-01

    As global climate warms and sea level rises, coastal areas will be subject to more frequent extreme flooding and hurricanes. Geologic evidence for extreme coastal storms during past warm periods has the potential to provide fundamental insights into their future intensity. Recent studies argue that during the Last Interglacial (MIS 5e, ˜128–116 ka) tropical and extratropical North Atlantic cyclones may have been more intense than at present, and may have produced waves larger than those observed historically. Such strong swells are inferred to have created a number of geologic features that can be observed today along the coastlines of Bermuda and the Bahamas. In this paper, we investigate the most iconic among these features: massive boulders atop a cliff in North Eleuthera, Bahamas. We combine geologic field surveys, wave models, and boulder transport equations to test the hypothesis that such boulders must have been emplaced by storms of greater-than-historical intensity. By contrast, our results suggest that with the higher relative sea level (RSL) estimated for the Bahamas during MIS 5e, boulders of this size could have been transported by waves generated by storms of historical intensity. Thus, while the megaboulders of Eleuthera cannot be used as geologic proof for past “superstorms,” they do show that with rising sea levels, cliffs and coastal barriers will be subject to significantly greater erosional energy, even without changes in storm intensity.

  6. Giant boulders and Last Interglacial storm intensity in the North Atlantic.

    Science.gov (United States)

    Rovere, Alessio; Casella, Elisa; Harris, Daniel L; Lorscheid, Thomas; Nandasena, Napayalage A K; Dyer, Blake; Sandstrom, Michael R; Stocchi, Paolo; D'Andrea, William J; Raymo, Maureen E

    2017-11-14

    As global climate warms and sea level rises, coastal areas will be subject to more frequent extreme flooding and hurricanes. Geologic evidence for extreme coastal storms during past warm periods has the potential to provide fundamental insights into their future intensity. Recent studies argue that during the Last Interglacial (MIS 5e, ∼128-116 ka) tropical and extratropical North Atlantic cyclones may have been more intense than at present, and may have produced waves larger than those observed historically. Such strong swells are inferred to have created a number of geologic features that can be observed today along the coastlines of Bermuda and the Bahamas. In this paper, we investigate the most iconic among these features: massive boulders atop a cliff in North Eleuthera, Bahamas. We combine geologic field surveys, wave models, and boulder transport equations to test the hypothesis that such boulders must have been emplaced by storms of greater-than-historical intensity. By contrast, our results suggest that with the higher relative sea level (RSL) estimated for the Bahamas during MIS 5e, boulders of this size could have been transported by waves generated by storms of historical intensity. Thus, while the megaboulders of Eleuthera cannot be used as geologic proof for past "superstorms," they do show that with rising sea levels, cliffs and coastal barriers will be subject to significantly greater erosional energy, even without changes in storm intensity.

  7. Biomedical imaging modality classification using combined visual features and textual terms.

    Science.gov (United States)

    Han, Xian-Hua; Chen, Yen-Wei

    2011-01-01

    We describe an approach for the automatic modality classification in medical image retrieval task of the 2010 CLEF cross-language image retrieval campaign (ImageCLEF). This paper is focused on the process of feature extraction from medical images and fuses the different extracted visual features and textual feature for modality classification. To extract visual features from the images, we used histogram descriptor of edge, gray, or color intensity and block-based variation as global features and SIFT histogram as local feature. For textual feature of image representation, the binary histogram of some predefined vocabulary words from image captions is used. Then, we combine the different features using normalized kernel functions for SVM classification. Furthermore, for some easy misclassified modality pairs such as CT and MR or PET and NM modalities, a local classifier is used for distinguishing samples in the pair modality to improve performance. The proposed strategy is evaluated with the provided modality dataset by ImageCLEF 2010.

  8. Classification of reflected signals from cavitated tooth surfaces using an artificial intelligence technique incorporating a fiber optic displacement sensor

    Science.gov (United States)

    Rahman, Husna Abdul; Harun, Sulaiman Wadi; Arof, Hamzah; Irawati, Ninik; Musirin, Ismail; Ibrahim, Fatimah; Ahmad, Harith

    2014-05-01

    An enhanced dental cavity diameter measurement mechanism using an intensity-modulated fiber optic displacement sensor (FODS) scanning and imaging system, fuzzy logic as well as a single-layer perceptron (SLP) neural network, is presented. The SLP network was employed for the classification of the reflected signals, which were obtained from the surfaces of teeth samples and captured using FODS. Two features were used for the classification of the reflected signals with one of them being the output of a fuzzy logic. The test results showed that the combined fuzzy logic and SLP network methodology contributed to a 100% classification accuracy of the network. The high-classification accuracy significantly demonstrates the suitability of the proposed features and classification using SLP networks for classifying the reflected signals from teeth surfaces, enabling the sensor to accurately measure small diameters of tooth cavity of up to 0.6 mm. The method remains simple enough to allow its easy integration in existing dental restoration support systems.

  9. Physics of high intensity nanosecond electron source

    International Nuclear Information System (INIS)

    Herrera-Gomez, A.; Spicer, W.E.

    1993-08-01

    A new high-intensity, short-time electron source is now being used at the Stanford Linear Accelerator Center (SLAC). Using a GaAs negative affinity semiconductor in the construction of the cathode, it is possible to fulfill operation requirements such as peak currents of tens of amperes, peak widths of the order of nanoseconds, hundreds of hours of operation stability, and electron spin polarization. The cathode is illuminated with high intensity laser pulses, and photoemitted electrons constitute the yield. Because of the high currents, some nonlinear effects are present. Very noticeable is the so-called Charge Limit (CL) effect, which consists of a limit on the total charge in each pulse-that is, the total bunch charge stops increasing as the light pulse total energy increases. In this paper, we explain the mechanism of the CL and how it is caused by the photovoltaic effect. Our treatment is based on the Three-Step model of photoemission. We relate the CL to the characteristics of the surface and bulk of the semiconductor, such as doping, band bending, surface vacuum level, and density of surface states. We also discuss possible ways to prevent the Char's Level effect

  10. On the intrinsic timescales of temporal variability in measurements of the surface solar radiation

    Science.gov (United States)

    Bengulescu, Marc; Blanc, Philippe; Wald, Lucien

    2018-01-01

    This study is concerned with the intrinsic temporal scales of the variability in the surface solar irradiance (SSI). The data consist of decennial time series of daily means of the SSI obtained from high-quality measurements of the broadband solar radiation impinging on a horizontal plane at ground level, issued from different Baseline Surface Radiation Network (BSRN) ground stations around the world. First, embedded oscillations sorted in terms of increasing timescales of the data are extracted by empirical mode decomposition (EMD). Next, Hilbert spectral analysis is applied to obtain an amplitude-modulation-frequency-modulation (AM-FM) representation of the data. The time-varying nature of the characteristic timescales of variability, along with the variations in the signal intensity, are thus revealed. A novel, adaptive null hypothesis based on the general statistical characteristics of noise is employed in order to discriminate between the different features of the data, those that have a deterministic origin and those being realizations of various stochastic processes. The data have a significant spectral peak corresponding to the yearly variability cycle and feature quasi-stochastic high-frequency variability components, irrespective of the geographical location or of the local climate. Moreover, the amplitude of this latter feature is shown to be modulated by variations in the yearly cycle, which is indicative of nonlinear multiplicative cross-scale couplings. The study has possible implications on the modeling and the forecast of the surface solar radiation, by clearly discriminating the deterministic from the quasi-stochastic character of the data, at different local timescales.

  11. Accessible surface area of proteins from purely sequence information and the importance of global features

    Science.gov (United States)

    Faraggi, Eshel; Zhou, Yaoqi; Kloczkowski, Andrzej

    2014-03-01

    We present a new approach for predicting the accessible surface area of proteins. The novelty of this approach lies in not using residue mutation profiles generated by multiple sequence alignments as descriptive inputs. Rather, sequential window information and the global monomer and dimer compositions of the chain are used. We find that much of the lost accuracy due to the elimination of evolutionary information is recouped by the use of global features. Furthermore, this new predictor produces similar results for proteins with or without sequence homologs deposited in the Protein Data Bank, and hence shows generalizability. Finally, these predictions are obtained in a small fraction (1/1000) of the time required to run mutation profile based prediction. All these factors indicate the possible usability of this work in de-novo protein structure prediction and in de-novo protein design using iterative searches. Funded in part by the financial support of the National Institutes of Health through Grants R01GM072014 and R01GM073095, and the National Science Foundation through Grant NSF MCB 1071785.

  12. A Multiplan Treatment-Planning Framework: A Paradigm Shift for Intensity-Modulated Radiotherapy

    International Nuclear Information System (INIS)

    Meyer, Robert R.; Zhang, Hao H.; Goadrich, Laura; Nazareth, Daryl P.; Shi Leyuan; D'Souza, Warren D.

    2007-01-01

    Purpose: To describe a multiplan intensity-modulated radiotherapy (IMRT) planning framework, and to describe a decision support system (DSS) for ranking multiple plans and modeling the planning surface. Methods and Materials: One hundred twenty-five plans were generated sequentially for a head-and-neck case and a pelvic case by varying the dose-volume constraints on each of the organs at risk (OARs). A DSS was used to rank plans according to dose-volume histogram (DVH) values, as well as equivalent uniform dose (EUD) values. Two methods for ranking treatment plans were evaluated: composite criteria and pre-emptive selection. The planning surface determined by the results was modeled using quadratic functions. Results: The DSS provided an easy-to-use interface for the comparison of multiple plan features. Plan ranking resulted in the identification of one to three 'optimal' plans. The planning surface models had good predictive capability with respect to both DVH values and EUD values and generally, errors of <6%. Models generated by minimizing the maximum relative error had significantly lower relative errors than models obtained by minimizing the sum of squared errors. Using the quadratic model, plan properties for one OAR were determined as a function of the other OAR constraint settings. The modeled plan surface can then be used to understand the interdependence of competing planning objectives. Conclusion: The DSS can be used to aid the planner in the selection of the most desirable plan. The collection of quadratic models constructed from the plan data to predict DVH and EUD values generally showed excellent agreement with the actual plan values

  13. High-level fusion of depth and intensity for pedestrian classification

    NARCIS (Netherlands)

    Rohrbach, M.; Enzweiler, M.; Gavrila, D.M.

    2009-01-01

    This paper presents a novel approach to pedestrian classification which involves a high-level fusion of depth and intensity cues. Instead of utilizing depth information only in a pre-processing step, we propose to extract discriminative spatial features (gradient orientation histograms and local

  14. Oceanic whitecaps: Sea surface features detectable via satellite that ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    experiments that the air-sea gas transfer coefficient for each of a wide range of gases, including carbon dioxide and .... generators with which the basin was equipped, the .... whitecaps in air-sea gas exchange; Gas Transfer at Water. Surfaces ...

  15. Validation of surface crack stress intensity factors of a tubular K-joint

    International Nuclear Information System (INIS)

    Lie, S.T.; Lee, C.K.; Chiew, S.P.; Shao, Y.B.

    2005-01-01

    Tubular K-joints are encountered widely in offshore structures, and the prediction of damaged joints depends very much on the accuracy of stress intensity factor solutions (SIFs). No parametric equations and very few results have been proposed and published in the literature for estimating the SIFs of any K-joints subjected to complex loading conditions. In this paper, a mesh generation method proposed previously for the Y-joint and T-joint has been extended to the K-joint. This method is realized by dividing the K-joint into several sub-zones with each zone consisting of different types of elements and mesh densities. This method has a distinct advantage of controlling the mesh quality, and most importantly the aspect ratio of the elements along the crack front. When the mesh of all the sub-zones has been generated automatically and completely, they are merged to form the complete model. The two most commonly used methods, namely the J-integral and displacement extrapolation, are used to evaluate the SIF values along the crack front of a typical K-joint. To validate the accuracy of these computed SIFs, a full-scale K-joint specimen was tested to failure under fatigue loading conditions. The standard alternating current potential drop (ACPD) technique was used to monitor the rate of crack propagation of the surface crack located at the hot spot stress region. Using the given material parameters C and m, the experimental SIFs were deduced, and they are found to be in good agreement with the computed SIFs obtained from the generated models. Hence, the proposed finite element models are both efficient and reliable

  16. Simulation of the Impact of New Aircraft- and Satellite-based Ocean Surface Wind Measurements on Estimates of Hurricane Intensity

    Science.gov (United States)

    Uhlhorn, Eric; Atlas, Robert; Black, Peter; Buckley, Courtney; Chen, Shuyi; El-Nimri, Salem; Hood, Robbie; Johnson, James; Jones, Linwood; Miller, Timothy; hide

    2009-01-01

    The Hurricane Imaging Radiometer (HIRAD) is a new airborne microwave remote sensor currently under development to enhance real-time hurricane ocean surface wind observations. HIRAD builds on the capabilities of the Stepped Frequency Microwave Radiometer (SFMR), which now operates on NOAA P-3, G-4, and AFRC C-130 aircraft. Unlike the SFMR, which measures wind speed and rain rate along the ground track directly beneath the aircraft, HIRAD will provide images of the surface wind and rain field over a wide swath (approximately 3 times the aircraft altitude). To demonstrate potential improvement in the measurement of peak hurricane winds, we present a set of Observing System Simulation Experiments (OSSEs) in which measurements from the new instrument as well as those from existing platforms (air, surface, and space-based) are simulated from the output of a high-resolution (approximately 1.7 km) numerical model. Simulated retrieval errors due to both instrument noise as well as model function accuracy are considered over the expected range of incidence angles, wind speeds and rain rates. Based on numerous simulated flight patterns and data source combinations, statistics are developed to describe relationships between the observed and true (from the model s perspective) peak wind speed. These results have implications for improving the estimation of hurricane intensity (as defined by the peak sustained wind anywhere in the storm), which may often go un-observed due to sampling limitations.

  17. Characterisation and Testing of Multifunctional Surfaces

    DEFF Research Database (Denmark)

    Godi, Alessandro

    the acronym stands for multifunctional. Produced by hard-turning followed by a highly controllable Robot Assisted Polishing process, MUFU surfaces feature reservoirs for providing extra-lubrication between the contacting parts as well as uppermost flat regions for ensuring the bearing capability...... filtered and aligned roughness profile that would be unrealistically distorted if current practice methods were used. Once an aligned profile is obtained, a further operation is introduced: feature separation. The surface features are separated with a newly developed algorithm and analysed independently...

  18. Automotive System for Remote Surface Classification.

    Science.gov (United States)

    Bystrov, Aleksandr; Hoare, Edward; Tran, Thuy-Yung; Clarke, Nigel; Gashinova, Marina; Cherniakov, Mikhail

    2017-04-01

    In this paper we shall discuss a novel approach to road surface recognition, based on the analysis of backscattered microwave and ultrasonic signals. The novelty of our method is sonar and polarimetric radar data fusion, extraction of features for separate swathes of illuminated surface (segmentation), and using of multi-stage artificial neural network for surface classification. The developed system consists of 24 GHz radar and 40 kHz ultrasonic sensor. The features are extracted from backscattered signals and then the procedures of principal component analysis and supervised classification are applied to feature data. The special attention is paid to multi-stage artificial neural network which allows an overall increase in classification accuracy. The proposed technique was tested for recognition of a large number of real surfaces in different weather conditions with the average accuracy of correct classification of 95%. The obtained results thereby demonstrate that the use of proposed system architecture and statistical methods allow for reliable discrimination of various road surfaces in real conditions.

  19. Imaging features of intracranial solitary fibrous tumors

    International Nuclear Information System (INIS)

    Yu Shuilian; Man Yuping; Ma Longbai; Liu Ying; Wei Qiang; Zhu Youkai

    2012-01-01

    Objective: To summarize the imaging features of intracranial solitary fibrous tumors (ISFT). Methods: Ten patients with ISFT proven histopathologically were collected. Four cases had CT data and all cases had MR data. The imaging features and pathological results were retrospectively analyzed. Results: All cases were misdiagnosed as meningioma at pre-operation. All lesions arose from intracranial meninges including 5 lesions above the tentorium, 4 lesions beneath the tentorium and 1 lesion growing around the tentorium. The margins of all the masses were well defined, and 8 lesions presented multilobular shape. CT demonstrated hyerattenuated masses in all 4 lesions, smooth erosion of the basicranial skull in 1 lesion, and punctiform calcification of the capsule in 1 lesion. T 1 WI showed most lesions with isointense or slight hyperintense signals including homogeneous in 4 lesions and heterogeneous in 6 lesions. T 2 WI demonstrated isointense or slight hyperintense in 2 lesions, mixed hypointense and hyperintense signals in 4, cystic portion in 2, and two distinct portion of hyperintense and hypointense signal, so called 'yin-yang' pattern, in 2. Strong enhanced was found in all lesions, especially in 8 lesion with heterogeneous with the low T 2 signal. 'Dural tail' was found in 4 lesions. Conclusions: ISFI has some specific CT and MR features including heterogeneous signal intensity on T 2 WI, strong enhancement of areas with low T 2 signal intensity, slight or no 'dural tail', without skull thickening, and the typical 'yin-yang' pattern. (authors)

  20. Processing of word stress related acoustic information: A multi-feature MMN study.

    Science.gov (United States)

    Honbolygó, Ferenc; Kolozsvári, Orsolya; Csépe, Valéria

    2017-08-01

    In the present study, we investigated the processing of word stress related acoustic features in a word context. In a passive oddball multi-feature MMN experiment, we presented a disyllabic pseudo-word with two acoustically similar syllables as standard stimulus, and five contrasting deviants that differed from the standard in that they were either stressed on the first syllable or contained a vowel change. Stress was realized by an increase of f0, intensity, vowel duration or consonant duration. The vowel change was used to investigate if phonemic and prosodic changes elicit different MMN components. As a control condition, we presented non-speech counterparts of the speech stimuli. Results showed all but one feature (non-speech intensity deviant) eliciting the MMN component, which was larger for speech compared to non-speech stimuli. Two other components showed stimulus related effects: the N350 and the LDN (Late Discriminative Negativity). The N350 appeared to the vowel duration and consonant duration deviants, specifically to features related to the temporal characteristics of stimuli, while the LDN was present for all features, and it was larger for speech than for non-speech stimuli. We also found that the f0 and consonant duration features elicited a larger MMN than other features. These results suggest that stress as a phonological feature is processed based on long-term representations, and listeners show a specific sensitivity to segmental and suprasegmental cues signaling the prosodic boundaries of words. These findings support a two-stage model in the perception of stress and phoneme related acoustical information. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. A comparative analysis of DNA barcode microarray feature size

    Directory of Open Access Journals (Sweden)

    Smith Andrew M

    2009-10-01

    Full Text Available Abstract Background Microarrays are an invaluable tool in many modern genomic studies. It is generally perceived that decreasing the size of microarray features leads to arrays with higher resolution (due to greater feature density, but this increase in resolution can compromise sensitivity. Results We demonstrate that barcode microarrays with smaller features are equally capable of detecting variation in DNA barcode intensity when compared to larger feature sizes within a specific microarray platform. The barcodes used in this study are the well-characterized set derived from the Yeast KnockOut (YKO collection used for screens of pooled yeast (Saccharomyces cerevisiae deletion mutants. We treated these pools with the glycosylation inhibitor tunicamycin as a test compound. Three generations of barcode microarrays at 30, 8 and 5 μm features sizes independently identified the primary target of tunicamycin to be ALG7. Conclusion We show that the data obtained with 5 μm feature size is of comparable quality to the 30 μm size and propose that further shrinking of features could yield barcode microarrays with equal or greater resolving power and, more importantly, higher density.

  2. Features Analysis of Dry Stone Walls of Tuscany (Italy

    Directory of Open Access Journals (Sweden)

    Mauro Agnoletti

    2015-10-01

    Full Text Available Terraced systems currently represent an indubitable added value for Tuscany, as well as for other Italian regions and for several Mediterranean countries. This value goes beyond their original function of hosting new areas for cultivation. The hydrological functions performed by these systems, including control of erosion, stabilisation of the slopes, prolongation of runoff times and the possible reduction of the volumes of surface runoff, are well-known. In addition, they also play a strategic role in the conservation of biodiversity and in maintaining local identity. At a national level, the terraced agricultural systems fall within the scope of actions scheduled in the National Strategic Plan for Rural Development 2007–2013, and the standards of Good Agricultural and Environmental Conditions (GAECs envisages that they be maintained through the granting of economic aid as laid down in the Rural Development Plans 2007–2013 and 2014–2020. Eighteen sample areas, previously selected on the basis of the terracing intensity index (defined as the ratio between the lines representing the walls and the surface of 1 ha, were subjected for on-site surveys to determine the geo-typological features through the identification and measurement of the main technical-construction parameters of the dry stone walls. This analysis also enabled assessments of the overall state of conservation of the dry stone walls in order to suggest operations for safeguarding and protection.

  3. The correlation study of parallel feature extractor and noise reduction approaches

    Energy Technology Data Exchange (ETDEWEB)

    Dewi, Deshinta Arrova; Sundararajan, Elankovan; Prabuwono, Anton Satria [Industrial Computing Research Group, Centre for Artificial Intelligence Technology, Universiti Kebangsaan Malaysia, 43600 Bangi (Malaysia)

    2015-05-15

    This paper presents literature reviews that show variety of techniques to develop parallel feature extractor and finding its correlation with noise reduction approaches for low light intensity images. Low light intensity images are normally displayed as darker images and low contrast. Without proper handling techniques, those images regularly become evidences of misperception of objects and textures, the incapability to section them. The visual illusions regularly clues to disorientation, user fatigue, poor detection and classification performance of humans and computer algorithms. Noise reduction approaches (NR) therefore is an essential step for other image processing steps such as edge detection, image segmentation, image compression, etc. Parallel Feature Extractor (PFE) meant to capture visual contents of images involves partitioning images into segments, detecting image overlaps if any, and controlling distributed and redistributed segments to extract the features. Working on low light intensity images make the PFE face challenges and closely depend on the quality of its pre-processing steps. Some papers have suggested many well established NR as well as PFE strategies however only few resources have suggested or mentioned the correlation between them. This paper reviews best approaches of the NR and the PFE with detailed explanation on the suggested correlation. This finding may suggest relevant strategies of the PFE development. With the help of knowledge based reasoning, computational approaches and algorithms, we present the correlation study between the NR and the PFE that can be useful for the development and enhancement of other existing PFE.

  4. The correlation study of parallel feature extractor and noise reduction approaches

    International Nuclear Information System (INIS)

    Dewi, Deshinta Arrova; Sundararajan, Elankovan; Prabuwono, Anton Satria

    2015-01-01

    This paper presents literature reviews that show variety of techniques to develop parallel feature extractor and finding its correlation with noise reduction approaches for low light intensity images. Low light intensity images are normally displayed as darker images and low contrast. Without proper handling techniques, those images regularly become evidences of misperception of objects and textures, the incapability to section them. The visual illusions regularly clues to disorientation, user fatigue, poor detection and classification performance of humans and computer algorithms. Noise reduction approaches (NR) therefore is an essential step for other image processing steps such as edge detection, image segmentation, image compression, etc. Parallel Feature Extractor (PFE) meant to capture visual contents of images involves partitioning images into segments, detecting image overlaps if any, and controlling distributed and redistributed segments to extract the features. Working on low light intensity images make the PFE face challenges and closely depend on the quality of its pre-processing steps. Some papers have suggested many well established NR as well as PFE strategies however only few resources have suggested or mentioned the correlation between them. This paper reviews best approaches of the NR and the PFE with detailed explanation on the suggested correlation. This finding may suggest relevant strategies of the PFE development. With the help of knowledge based reasoning, computational approaches and algorithms, we present the correlation study between the NR and the PFE that can be useful for the development and enhancement of other existing PFE

  5. Clinical and Immunological Features of Opsoclonus-Myoclonus Syndrome in the Era of Neuronal Cell Surface Antibodies.

    Science.gov (United States)

    Armangué, Thaís; Sabater, Lidia; Torres-Vega, Estefanía; Martínez-Hernández, Eugenia; Ariño, Helena; Petit-Pedrol, Mar; Planagumà, Jesús; Bataller, Luis; Dalmau, Josep; Graus, Francesc

    2016-04-01

    Most studies on opsoclonus-myoclonus syndrome (OMS) in adults are based on small case series before the era of neuronal cell surface antibody discovery. To report the clinical and immunological features of idiopathic OMS (I-OMS) and paraneoplastic OMS (P-OMS), the occurrence of antibodies to cell surface antigens, and the discovery of a novel cell surface epitope. Retrospective cohort study and laboratory investigations of 114 adult patients with OMS at a center for autoimmune neurological disorders done between January 2013 and September 2015. Review of clinical records. Immunohistochemistry on rat brain and cultured neurons as well as cell-based assays were used to identify known autoantibodies. Immunoprecipitation and mass spectrometry were used to characterize novel antigens. Of the 114 patients (62 [54%] female; median age, 45 years; interquartile range, 32-60 years), 45 (39%) had P-OMS and 69 (61%) had I-OMS. In patients with P-OMS, the associated tumors included lung cancer (n = 19), breast cancer (n = 10), other cancers (n = 5), and ovarian teratoma (n = 8); 3 additional patients without detectable cancer were considered to have P-OMS because they had positive results for onconeuronal antibodies. Patients with I-OMS, compared with those who had P-OMS, were younger (median age, 38 [interquartile range, 31-50] vs 54 [interquartile range, 45-65] years; P OMS with lung cancer (21% vs 5% in patients with OMS without lung cancer; P = .02); however, a similar frequency of glycine receptor antibodies was found in patients with lung cancer without OMS (13 of 65 patients [20%]). A novel cell surface epitope, human natural killer 1 (HNK-1), was the target of the antibodies in 3 patients with lung cancer and P-OMS. Patients with I-OMS responded better to treatment and had fewer relapses than those with P-OMS. Older age and encephalopathy, significantly associated with P-OMS, are clinical clues suggesting an underlying tumor. Glycine receptor antibodies occur

  6. Average features of cosmic ray variation associated with sudden commencement of magnetic storm

    International Nuclear Information System (INIS)

    Wada, Masami; Suda, Tomoshige.

    1980-01-01

    In order to obtain average features of cosmic ray variation associated with a passage of shock front in space, superposed epoch analysis of cosmic ray intensity with respect to the time of occurrence of sudden commencement (SC) of magnetic storm during solar cycle 20, 1964 - 1975, is carried out for hundreds of SC. When SC's are distributed evenly over the day, the onset in cosmic ray decrease is seen clearly within one hour of SC, followed by a sharp decrease in the intensity, but without any precursory fluctuation. The magnitude distribution and the rigidity spectrum for maximum depression show the features of Forbush decrease (FD). Superposed epoch analysis is also applied to solar wind and the interplanetary magnetic field data, and their relation to cosmic ray variation is studied. Effects of the superposition of the isotropic and anisotropic variations on the time profile of cosmic ray intensity observed at a station are discussed. (author)

  7. Rapid surface-water volume estimations in beaver ponds

    Science.gov (United States)

    Karran, Daniel J.; Westbrook, Cherie J.; Wheaton, Joseph M.; Johnston, Carol A.; Bedard-Haughn, Angela

    2017-02-01

    Beaver ponds are surface-water features that are transient through space and time. Such qualities complicate the inclusion of beaver ponds in local and regional water balances, and in hydrological models, as reliable estimates of surface-water storage are difficult to acquire without time- and labour-intensive topographic surveys. A simpler approach to overcome this challenge is needed, given the abundance of the beaver ponds in North America, Eurasia, and southern South America. We investigated whether simple morphometric characteristics derived from readily available aerial imagery or quickly measured field attributes of beaver ponds can be used to approximate surface-water storage among the range of environmental settings in which beaver ponds are found. Studied were a total of 40 beaver ponds from four different sites in North and South America. The simplified volume-area-depth (V-A-h) approach, originally developed for prairie potholes, was tested. With only two measurements of pond depth and corresponding surface area, this method estimated surface-water storage in beaver ponds within 5 % on average. Beaver pond morphometry was characterized by a median basin coefficient of 0.91, and dam length and pond surface area were strongly correlated with beaver pond storage capacity, regardless of geographic setting. These attributes provide a means for coarsely estimating surface-water storage capacity in beaver ponds. Overall, this research demonstrates that reliable estimates of surface-water storage in beaver ponds only requires simple measurements derived from aerial imagery and/or brief visits to the field. Future research efforts should be directed at incorporating these simple methods into both broader beaver-related tools and catchment-scale hydrological models.

  8. A novel vision-based mold monitoring system in an environment of intense vibration

    International Nuclear Information System (INIS)

    Hu, Fen; He, Zaixing; Zhao, Xinyue; Zhang, Shuyou

    2017-01-01

    Mold monitoring has been more and more widely used in the modern manufacturing industry, especially when based on machine vision, but these systems cannot meet the detection speed and accuracy requirements for mold monitoring because they must operate in environments that exhibit intense vibration during production. To ensure that the system runs accurately and efficiently, we propose a new descriptor that combines the geometric relationship-based global context feature and the local scale-invariant feature transform for the image registration step of the mold monitoring system. The experimental results of four types of molds showed that the detection accuracy of the mold monitoring system is improved in the environment with intense vibration. (paper)

  9. A novel vision-based mold monitoring system in an environment of intense vibration

    Science.gov (United States)

    Hu, Fen; He, Zaixing; Zhao, Xinyue; Zhang, Shuyou

    2017-10-01

    Mold monitoring has been more and more widely used in the modern manufacturing industry, especially when based on machine vision, but these systems cannot meet the detection speed and accuracy requirements for mold monitoring because they must operate in environments that exhibit intense vibration during production. To ensure that the system runs accurately and efficiently, we propose a new descriptor that combines the geometric relationship-based global context feature and the local scale-invariant feature transform for the image registration step of the mold monitoring system. The experimental results of four types of molds showed that the detection accuracy of the mold monitoring system is improved in the environment with intense vibration.

  10. The intense proton accelerator program

    International Nuclear Information System (INIS)

    Kaneko, Yoshihiko

    1990-01-01

    The Science and Technology Agency of Japan has formulated the OMEGA project, in which incineration of nuclear wastes by use of accelerators is defined as one of the important tasks. Japan Atomic Energy Research Institute (JAERI) has been engaged for several years in basic studies in incineration technology with use of an intense proton linear accelerator. The intense proton accelerator program intends to provide a large scale proton linear accelerator called Engineering Test Accelerator. The principal purpose of the accelerator is to develop nuclear waste incineration technology. The accelerator will also be used for other industrial applications and applied science studies. The present report further outlines the concept of incineration of radio-activities of nuclear wastes, focusing on nuclear reactions and a concept of incineration plant. Features of Engineering Test Accelerator are described focusing on the development of the accelerator, and research and development of incineration technology. Applications of science and technology other than nuclear waste incineration are also discussed. (N.K.)

  11. Emotional processing in patients with mild cognitive impairment: the influence of the valence and intensity of emotional stimuli: the valence and intensity of emotional stimuli influence emotional processing in patients with mild cognitive impairment.

    Science.gov (United States)

    Sarabia-Cobo, Carmen M; García-Rodríguez, Beatriz; Navas, M José; Ellgring, Heiner

    2015-10-15

    We studied the ability of individuals with mild cognitive impairment (MCI) to process emotional facial expressions (EFEs). To date, no systematic study has addressed how variation in intensity affects recognition of the different type of EFEs in such subjects. Two groups of 50 elderly subjects, 50 healthy individuals and 50 with MCI, completed a task that involved identifying 180 EFEs prepared using virtual models. Two features of the EFEs were contemplated, their valence (operationalized in six basic emotions) and five levels of intensity. At all levels of intensity, elderly individuals with MCI were significantly worse at identifying each EFE than healthy subjects. Some emotions were easier to identify than others, with happiness proving to be the easiest to identify and disgust the hardest, and intensity influenced the identification of the EFEs (the stronger the intensity, the greater the number of correct identifications). Overall, elderly individuals with MCI had a poorer capacity to process EFEs, suggesting that cognitive ability modulates the processing of emotions, where features of such stimuli also seem to play a prominent role (e.g., valence and intensity). Thus, the neurological substrates involved in emotional processing appear to be affected by MCI. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Hyperspectral image classifier based on beach spectral feature

    International Nuclear Information System (INIS)

    Liang, Zhang; Lianru, Gao; Bing, Zhang

    2014-01-01

    The seashore, especially coral bank, is sensitive to human activities and environmental changes. A multispectral image, with coarse spectral resolution, is inadaptable for identify subtle spectral distinctions between various beaches. To the contrary, hyperspectral image with narrow and consecutive channels increases our capability to retrieve minor spectral features which is suit for identification and classification of surface materials on the shore. Herein, this paper used airborne hyperspectral data, in addition to ground spectral data to study the beaches in Qingdao. The image data first went through image pretreatment to deal with the disturbance of noise, radiation inconsistence and distortion. In succession, the reflection spectrum, the derivative spectrum and the spectral absorption features of the beach surface were inspected in search of diagnostic features. Hence, spectra indices specific for the unique environment of seashore were developed. According to expert decisions based on image spectrums, the beaches are ultimately classified into sand beach, rock beach, vegetation beach, mud beach, bare land and water. In situ surveying reflection spectrum from GER1500 field spectrometer validated the classification production. In conclusion, the classification approach under expert decision based on feature spectrum is proved to be feasible for beaches

  13. Quadrilateral mesh fitting that preserves sharp features based on multi-normals for Laplacian energy

    Directory of Open Access Journals (Sweden)

    Yusuke Imai

    2014-04-01

    Full Text Available Because the cost of performance testing using actual products is expensive, manufacturers use lower-cost computer-aided design simulations for this function. In this paper, we propose using hexahedral meshes, which are more accurate than tetrahedral meshes, for finite element analysis. We propose automatic hexahedral mesh generation with sharp features to precisely represent the corresponding features of a target shape. Our hexahedral mesh is generated using a voxel-based algorithm. In our previous works, we fit the surface of the voxels to the target surface using Laplacian energy minimization. We used normal vectors in the fitting to preserve sharp features. However, this method could not represent concave sharp features precisely. In this proposal, we improve our previous Laplacian energy minimization by adding a term that depends on multi-normal vectors instead of using normal vectors. Furthermore, we accentuate a convex/concave surface subset to represent concave sharp features.

  14. Empirical Retrieval of Surface Melt Magnitude from Coupled MODIS Optical and Thermal Measurements over the Greenland Ice Sheet during the 2001 Ablation Season.

    Science.gov (United States)

    Lampkin, Derrick; Peng, Rui

    2008-08-22

    Accelerated ice flow near the equilibrium line of west-central Greenland Ice Sheet (GIS) has been attributed to an increase in infiltrated surface melt water as a response to climate warming. The assessment of surface melting events must be more than the detection of melt onset or extent. Retrieval of surface melt magnitude is necessary to improve understanding of ice sheet flow and surface melt coupling. In this paper, we report on a new technique to quantify the magnitude of surface melt. Cloud-free dates of June 10, July 5, 7, 9, and 11, 2001 Moderate Resolution Imaging Spectroradiometer (MODIS) daily reflectance Band 5 (1.230-1.250μm) and surface temperature images rescaled to 1km over western Greenland were used in the retrieval algorithm. An optical-thermal feature space partitioned as a function of melt magnitude was derived using a one-dimensional thermal snowmelt model (SNTHERM89). SNTHERM89 was forced by hourly meteorological data from the Greenland Climate Network (GC-Net) at reference sites spanning dry snow, percolation, and wet snow zones in the Jakobshavn drainage basin in western GIS. Melt magnitude or effective melt (E-melt) was derived for satellite composite periods covering May, June, and July displaying low fractions (0-1%) at elevations greater than 2500m and fractions at or greater than 15% at elevations lower than 1000m assessed for only the upper 5 cm of the snow surface. Validation of E-melt involved comparison of intensity to dry and wet zones determined from QSCAT backscatter. Higher intensities (> 8%) were distributed in wet snow zones, while lower intensities were grouped in dry zones at a first order accuracy of ~ ±2%.

  15. Contact area measurements on structured surfaces

    DEFF Research Database (Denmark)

    Kücükyildiz, Ömer Can; Jensen, Sebastian Hoppe Nesgaard; De Chiffre, Leonardo

    In connection with the use of brass specimens featuring structured surfaces in a tribology test, an algorithm was developed for automatic measurement of the contact area by optical means.......In connection with the use of brass specimens featuring structured surfaces in a tribology test, an algorithm was developed for automatic measurement of the contact area by optical means....

  16. Internal Physical Features of a Land Surface Model Employing a Tangent Linear Model

    Science.gov (United States)

    Yang, Runhua; Cohn, Stephen E.; daSilva, Arlindo; Joiner, Joanna; Houser, Paul R.

    1997-01-01

    The Earth's land surface, including its biomass, is an integral part of the Earth's weather and climate system. Land surface heterogeneity, such as the type and amount of vegetative covering., has a profound effect on local weather variability and therefore on regional variations of the global climate. Surface conditions affect local weather and climate through a number of mechanisms. First, they determine the re-distribution of the net radiative energy received at the surface, through the atmosphere, from the sun. A certain fraction of this energy increases the surface ground temperature, another warms the near-surface atmosphere, and the rest evaporates surface water, which in turn creates clouds and causes precipitation. Second, they determine how much rainfall and snowmelt can be stored in the soil and how much instead runs off into waterways. Finally, surface conditions influence the near-surface concentration and distribution of greenhouse gases such as carbon dioxide. The processes through which these mechanisms interact with the atmosphere can be modeled mathematically, to within some degree of uncertainty, on the basis of underlying physical principles. Such a land surface model provides predictive capability for surface variables including ground temperature, surface humidity, and soil moisture and temperature. This information is important for agriculture and industry, as well as for addressing fundamental scientific questions concerning global and local climate change. In this study we apply a methodology known as tangent linear modeling to help us understand more deeply, the behavior of the Mosaic land surface model, a model that has been developed over the past several years at NASA/GSFC. This methodology allows us to examine, directly and quantitatively, the dependence of prediction errors in land surface variables upon different vegetation conditions. The work also highlights the importance of accurate soil moisture information. Although surface

  17. Feature-Sensitive Tetrahedral Mesh Generation with Guaranteed Quality

    OpenAIRE

    Wang, Jun; Yu, Zeyun

    2012-01-01

    Tetrahedral meshes are being extensively used in finite element methods (FEM). This paper proposes an algorithm to generate feature-sensitive and high-quality tetrahedral meshes from an arbitrary surface mesh model. A top-down octree subdivision is conducted on the surface mesh and a set of tetrahedra are constructed using adaptive body-centered cubic (BCC) lattices. Special treatments are given to the tetrahedra near the surface such that the quality of the resulting tetrahedral mesh is prov...

  18. Middle latency response correlates of single and double deviant stimuli in a multi-feature paradigm.

    Science.gov (United States)

    Althen, H; Huotilainen, M; Grimm, S; Escera, C

    2016-01-01

    This study aimed to test single and double deviance-related modulations of the middle latency response (MLR) and the applicability of the optimum-2 multi-feature paradigm. The MLR and the MMN to frequency, intensity and double-feature deviants of an optimum-2 multi-feature paradigm and the MMN to double-feature deviants of an oddball paradigm were recorded in young adults. Double deviants elicited significant enhancements of the Nb and Pb MLR waves compared with the waves elicited by standard stimuli. These enhancements equalled approximately the sum of the numerical amplitude differences elicited by the single deviants. In contrast, the MMN to double deviants did not show such additivity. MMNs elicited by double deviants of the multi-feature and the oddball paradigm showed no significant difference in amplitude or latency. The optimum-2 multi-feature paradigm is suitable for recording double deviance-related modulations of the MLR. Interspersed intensity and frequency deviants in the standard trace of the optimum-2 condition multi-feature paradigm did not weaken the double MMN. The optimum-2 multi-feature paradigm could be especially beneficial for clinical studies on early deviance-related modulations in the MLR, due to its optimized utilization of the recording time. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  19. Tropical Cyclone Intensity Estimation Using Deep Convolutional Neural Networks

    Science.gov (United States)

    Maskey, Manil; Cecil, Dan; Ramachandran, Rahul; Miller, Jeffrey J.

    2018-01-01

    Estimating tropical cyclone intensity by just using satellite image is a challenging problem. With successful application of the Dvorak technique for more than 30 years along with some modifications and improvements, it is still used worldwide for tropical cyclone intensity estimation. A number of semi-automated techniques have been derived using the original Dvorak technique. However, these techniques suffer from subjective bias as evident from the most recent estimations on October 10, 2017 at 1500 UTC for Tropical Storm Ophelia: The Dvorak intensity estimates ranged from T2.3/33 kt (Tropical Cyclone Number 2.3/33 knots) from UW-CIMSS (University of Wisconsin-Madison - Cooperative Institute for Meteorological Satellite Studies) to T3.0/45 kt from TAFB (the National Hurricane Center's Tropical Analysis and Forecast Branch) to T4.0/65 kt from SAB (NOAA/NESDIS Satellite Analysis Branch). In this particular case, two human experts at TAFB and SAB differed by 20 knots in their Dvorak analyses, and the automated version at the University of Wisconsin was 12 knots lower than either of them. The National Hurricane Center (NHC) estimates about 10-20 percent uncertainty in its post analysis when only satellite based estimates are available. The success of the Dvorak technique proves that spatial patterns in infrared (IR) imagery strongly relate to tropical cyclone intensity. This study aims to utilize deep learning, the current state of the art in pattern recognition and image recognition, to address the need for an automated and objective tropical cyclone intensity estimation. Deep learning is a multi-layer neural network consisting of several layers of simple computational units. It learns discriminative features without relying on a human expert to identify which features are important. Our study mainly focuses on convolutional neural network (CNN), a deep learning algorithm, to develop an objective tropical cyclone intensity estimation. CNN is a supervised learning

  20. Design of the environment of care for safety of patients and personnel: does form follow function or vice versa in the intensive care unit?

    Science.gov (United States)

    Bartley, Judene; Streifel, Andrew J

    2010-08-01

    We review the context of the environment of care in the intensive care unit setting in relation to patient safety and quality, specifically addressing healthcare-associated infection issues and solutions involving interdisciplinary teams. Issues addressed include current and future architectural design and layout trends, construction trends affecting intensive care units, and prevention of construction-associated healthcare-associated infections related to airborne and waterborne risks and design solutions. Specific elements include single-occupancy, acuity-scalable intensive care unit rooms; environmental aspects of hand hygiene, such as water risks, sink design/location, human waste management, surface selection (floor covering, countertops, furniture, and equipment) and cleaning, antimicrobial-treated or similar materials, ultraviolet germicidal irradiation, specialized rooms (airborne infection isolation and protective environments), and water system design and strategies for safe use of potable water and mitigation of water intrusion. Effective design and operational use of the intensive care unit environment of care must engage critical care personnel from initial planning and design through occupancy of the new/renovated intensive care unit as part of the infection control risk assessment team. The interdisciplinary infection control risk assessment team can address key environment of care design features to enhance the safety of intensive care unit patients, personnel, and visitors. This perspective will ensure the environment of care supports human factors and behavioral aspects of the interaction between the environment of care and its occupants.

  1. Low energy intense electron beams with extra-low energy spread

    International Nuclear Information System (INIS)

    Aleksandrov, A.V.; Calabrese, R.; Ciullo, G.; Dikansky, N.S.; Guidi, V.; Kot, N.C.; Kudelainen, V.I.; Lamanna, G.; Lebedev, V.A.; Logachov, P.V.; Tecchio, L.; Yang, B.

    1994-01-01

    Maximum achievable intensity for low energy electron beams is a feature that is not very often compatible with low energy spread. We show that a proper choice of the source and the acceleration optics allows one to match them together. In this scheme, a GaAs photocathode excited by a single-mode infrared laser and adiabatic acceleration in fully magnetised optics enables the production of a low-energy-spread electron beam with relatively high intensity. The technological problems associated with the method are discussed together with its limitations. (orig.)

  2. Zinc (hydr)oxide/graphite oxide/AuNPs composites: role of surface features in H₂S reactive adsorption.

    Science.gov (United States)

    Giannakoudakis, Dimitrios A; Bandosz, Teresa J

    2014-12-15

    Zinc hydroxide/graphite oxide/AuNPs composites with various levels of complexity were synthesized using an in situ precipitation method. Then they were used as H2S adsorbents in visible light. The materials' surfaces were characterized before and after H2S adsorption by various physical and chemical methods (XRD, FTIR, thermal analysis, potentiometric titration, adsorption of nitrogen and SEM/EDX). Significant differences in surface features and synergistic effects were found depending on the materials' composition. Addition of graphite oxide and the deposition of gold nanoparticles resulted in a marked increase in the adsorption capacity in comparison with that on the zinc hydroxide and zinc hydroxide/AuNP. Addition of AuNPs to zinc hydroxide led to a crystalline ZnO/AuNP composite while the zinc hydroxide/graphite oxide/AuNP composite was amorphous. The ZnOH/GO/AuNPs composite exhibited the greatest H2S adsorption capacity due to the increased number of OH terminal groups and the conductive properties of GO that facilitated the electron transfer and consequently the formation of superoxide ions promoting oxidation of hydrogen sulfide. AuNPs present in the composite increased the conductivity, helped with electron transfer to oxygen, and prevented the fast recombination of the electrons and holes. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. CosmoQuest - Mapping Surface Features Across the Inner Solar System

    Science.gov (United States)

    Grier, Jennifer A.; Richardson, Matthew; Gay, Pamela L.; Lehan, Cory; Owens, Ryan; Robbins, Stuart J.; DellaGiustina, Daniella; Bennett, Carina; Runco, Susan; Graff, Paige

    2017-10-01

    The CosmoQuest Virtual Research Facility allows research scientists to work together with citizen scientists in ‘big data’ investigations. Some research requires the examination of vast numbers of images - partnering with engaged and trained citizen scientists allows for that research to be completed in a thorough and timely manner. The techniques used by CosmoQuest to collect impact crater data have been validated to ensure robustness (Robbins et al., 2014), and include software tools that accurately identify crater clusters, and multiple crater identifications. CosmoQuest has current or up-and-coming projects that span much of the inner solar system. “Moon Mappers” gives the public a chance to learn about the importance of cratered surfaces, and investigate factors that effect the identification and measurement of impact craters such as incidence angle. In the “Mars Mappers” program citizens map small craters in valley networks. These will be used to estimate times of ancient water flow. In “Mercury Mappers” the public learns about other issues related to crater counting, such as secondaries. On Mercury, secondaries appear to dominate counts up to 10km. By mapping these craters, we will be able to better understand the maximum diameter of secondaries relative to the parent primary. The public encounters Vesta in “Vesta Mappers,” a project that contributes data to the overall crater counting efforts on that body. Asteroid investigations do not end there - the OSIRIS-REx team is collaborating with CosmoQuest to create a science campaign to generate boulder and crater counting datasets of the asteroid Bennu. This “Bennu Mappers” project will inform the final selection of the sample return site. The Earth is the target for the “Image Detective” project, which uses the 2 million images returned from crewed space flight. These images are rich in information about our changing Earth, as well as phenomena like aurora. Citizens tag these images

  4. Gender differences in psychopathologic features of agoraphobia with panic disorder

    Directory of Open Access Journals (Sweden)

    Latas Milan

    2006-01-01

    Full Text Available Background/Aim. To examine gender differences in the major psychopathologic features in agoraphobia with panic disorder. Method. The study was conducted as a clinical study. The sample consisted of 119 patients, 32 men (26.9% and 87 women (73.1% with the basic diagnosis of agoraphobia with panic disorder. All the patients were evaluated with the clinical instruments suitable for the assessment of various clinical features associated with agoraphobia with panic disorder - questionnaires (the Hopkins Symptom Checklist 90, the Panic Appraisal Inventory, the Fear Questionnaire, the Beck Anxiety Inventory, and the Beck Depression Inventory, and the clinical rating scale (the Panic and Agoraphobia Scale. After the data collection, the sample was divided into two groups by the gender. Then the groups were compared. Results. There were no differences between the genders in the global psychopathologic features (the age at the onset of a disorder, duration of a disorder, severity and frequency of panic attacks, intensity of general psychiatric symptoms, intensity of general anxiety and depression. The women, however, reported a subjective perception of a more severe agoraphobic avoidance and males were significantly more likely than the females to anticipate the serious somatic consequences of panic attacks and worry about somatic health. Conclusion. There were a few gender specific psychopathologic features in patients with agoraphobia with panic disorder, so further studies would be necessary to come to a more precise conclusion.

  5. Mid-thickness studies of the stress intensity factor in the bulk of bainitic steel

    Directory of Open Access Journals (Sweden)

    P. Lopez-Crespo

    2017-07-01

    Full Text Available The current work aims at estimating the stress intensity factor deep inside the bulk from elastic strain data measured by synchrotron X-ray diffraction. Key features affecting the evaluation of the stress intensity factor are the number of terms in the analytical model describing the crack tip field, the extension and position of the area of interest of the experimental data, the effect of the experimental data collected within the plastic zone and the number of elastic strain data points used. Here a parametric study of these features is presented in terms of their influence for the stress intensity factor determination. It was found that 3 or 4 terms in Williams’ expansion is often sufficient; the data should be collected from across the full range of angles around the crack tip; and the number of points/number of terms should be greater than 40.

  6. The new fabrication method of standard surface sources

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Yasushi E-mail: yss.sato@aist.go.jp; Hino, Yoshio; Yamada, Takahiro; Matsumoto, Mikio

    2004-04-01

    We developed a new fabrication method for standard surface sources by using an inkjet printer with inks in which a radioactive material is mixed to print on a sheet of paper. Three printed test patterns have been prepared: (1) 100 mmx100 mm uniformity-test patterns, (2) positional-resolution test patterns with different widths and intervals of straight lines, and (3) logarithmic intensity test patterns with different radioactive intensities. The results revealed that the fabricated standard surface sources had high uniformity, high positional resolution, arbitrary shapes and a broad intensity range.

  7. Intense charge transfer surface based on graphene and thymine-Hg(II)-thymine base pairs for detection of Hg(2.).

    Science.gov (United States)

    Li, Jiao; Lu, Liping; Kang, Tianfang; Cheng, Shuiyuan

    2016-03-15

    In this article, we developed an electrochemiluminescence (ECL) sensor with a high-intensity charge transfer interface for Hg(2+) detection based on Hg(II)-induced DNA hybridization. The sensor was fabricated by the following simple method. First, graphene oxide (GO) was electrochemically reduced onto a glassy carbon electrode through cyclic voltammetry. Then, amino-labeled double-stranded (ds)DNA was assembled on the electrode surface using 1-pyrenebutyric acid N-hydroxysuccinimide as a linker between GO and DNA. The other terminal of dsDNA, which was labeled with biotin, was linked to CdSe quantum dots via biotin-avidin interactions. Reduced graphene oxide has excellent electrical conductivity. dsDNA with T-Hg(II)-T base pairs exhibited more facile charge transfer. They both accelerate the electron transfer performance and sensitivity of the sensor. The increased ECL signals were logarithmically linear with the concentration of Hg(II) when Hg(2+) was present in the detection solution. The linear range of the sensor was 10(-11) to 10(-8)mol/L (R=0.9819) with a detection limit of 10(-11)mol/L. This biosensor exhibited satisfactory results when it was used to detect Hg(II) in real water samples. The biosensor with high-intense charge transfer performance is a prospect avenue to pursue more and more sensitive detection method. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. When intensions do not map onto extensions: Individual differences in conceptualization.

    Science.gov (United States)

    Hampton, James A; Passanisi, Alessia

    2016-04-01

    Concepts are represented in the mind through knowledge of their extensions (the class of items to which the concept applies) and intensions (features that distinguish that class of items). A common assumption among theories of concepts is that the 2 aspects are intimately related. Hence if there is systematic individual variation in concept representation, the variation should correlate between extensional and intensional measures. A pair of individuals with similar extensional beliefs about a given concept should also share similar intensional beliefs. To test this notion, exemplars (extensions) and features (intensions) of common categories were rated for typicality and importance respectively across 2 occasions. Within-subject consistency was greater than between-subjects consensus on each task, providing evidence for systematic individual variation. Furthermore, the similarity structure between individuals for each task was stable across occasions. However, across 5 samples, similarity between individuals for extensional judgments did not map onto similarity between individuals for intensional judgments. The results challenge the assumption common to many theories of conceptual representation that intensions determine extensions and support a hybrid view of concepts where there is a disconnection between the conceptual resources that are used for the 2 tasks. (c) 2016 APA, all rights reserved).

  9. Study on surface wave characteristics of free surface flow of liquid metal lithium for IFMIF

    International Nuclear Information System (INIS)

    Hoashi, Eiji; Sugiura, Hirokazu; Yoshihashi-Suzuki, Sachiko; Yamaoka, Nobuo; Horiike, Hiroshi; Kanemura, Takuji; Kondo, Hiroo

    2011-01-01

    The international fusion materials irradiation facility (IFMIF) presents an intense neutron source to develop fusion reactor materials. The free surface flow of a liquid metal Lithium (Li) is planned as a target irradiated by two deuteron beams to generate intense neutrons and it is thus important to obtain knowledge of the surface wave characteristic for the safety and the efficiency of system in the IFMIF. We have been studying on surface wave characteristics experimentally using the liquid metal Li circulation facility at Osaka University and numerically using computational fluid dynamics (CFD) code, FLUENT. This paper reports the results of the surface fluctuation, the wave height and the surface velocity in the free surface flow of the liquid metal Li examined experimentally and numerically. In the experiment, an electro-contact probe apparatus was used to obtain the surface fluctuation and the wave height, and a high speed video was used to measure the surface velocity. We resulted in knowledge of the surface wave growth mechanism. On the other hand, a CFD simulation was also conducted to obtain information on the relation of the free surface with the inner flow. In the simulation, the model included from a two-staged contraction nozzle to a flow channel with a free surface flow region and simulation results were compared with the experimental data. (author)

  10. Ultrastructural features of the internodes’ surface in horsetail (Equisetum arvense L.

    Directory of Open Access Journals (Sweden)

    Myroslava Stakhiv

    2013-04-01

    Full Text Available The ultrastructure of the outer surface of the common horsetail stem was studied. Through electron microscopic analysis we showed that silica plates on the surface of Equisetum arvense L. stem are distributed evenly, not tight, in thin layer. Thus, compact arrangement of particles on the internodes causes high mechanical strength and stiffness of the E. arvensestem and lateral branches.

  11. Correlation between phonon anomaly along [211] and the Fermi surface nesting features with associated electron-phonon interactions in Ni2FeGa: A first principles study

    International Nuclear Information System (INIS)

    Chabungbam, Satyananda; Sahariah, Munima B.

    2015-01-01

    First principles calculation reaffirms the presence of phonon anomaly along [211] direction in Ni 2 FeGa shape memory alloy supporting the experimental findings of J. Q. Li et al. Fermi surface scans have been performed in both austenite and martensite phase to see the possible Fermi nesting features in this alloy. The magnitude of observed Fermi surface nesting vectors in (211) plane exactly match the phonon anomaly wavevectors along [211] direction. Electron-phonon calculation in the austenite phase shows that there is significant electron-phonon coupling in this alloy which might arise out of the lattice coupling between lower acoustic modes and higher optical modes combined with the observed strong Fermi nesting features in the system. - Highlights: • Transverse acoustic (TA 2 ) modes show anomaly along [211] direction in Ni 2 FeGa. • The phonon anomaly wavevector has been correlated with the Fermi nesting vectors. • Electron-phonon coupling calculation shows significant coupling in this system. • Max. el-ph coupling occurs in transition frequencies from acoustic to optical modes

  12. Generation of intense high-order vortex harmonics.

    Science.gov (United States)

    Zhang, Xiaomei; Shen, Baifei; Shi, Yin; Wang, Xiaofeng; Zhang, Lingang; Wang, Wenpeng; Xu, Jiancai; Yi, Longqiong; Xu, Zhizhan

    2015-05-01

    This Letter presents for the first time a scheme to generate intense high-order optical vortices that carry orbital angular momentum in the extreme ultraviolet region based on relativistic harmonics from the surface of a solid target. In the three-dimensional particle-in-cell simulation, the high-order harmonics of the high-order vortex mode is generated in both reflected and transmitted light beams when a linearly polarized Laguerre-Gaussian laser pulse impinges on a solid foil. The azimuthal mode of the harmonics scales with its order. The intensity of the high-order vortex harmonics is close to the relativistic region, with the pulse duration down to attosecond scale. The obtained intense vortex beam possesses the combined properties of fine transversal structure due to the high-order mode and the fine longitudinal structure due to the short wavelength of the high-order harmonics. In addition to the application in high-resolution detection in both spatial and temporal scales, it also presents new opportunities in the intense vortex required fields, such as the inner shell ionization process and high energy twisted photons generation by Thomson scattering of such an intense vortex beam off relativistic electrons.

  13. Experimental surface charge density of the Si (100)-2x1H surface

    DEFF Research Database (Denmark)

    Ciston, J.; Marks, L.D.; Feidenhans'l, R.

    2006-01-01

    We report a three-dimensional charge density refinement from x-ray diffraction intensities of the Si (100) 2x1H surface. By paying careful attention to parameterizing the bulk Si bonding, we are able to locate the hydrogen atoms at the surface, which could not be done previously. In addition, we...

  14. Acute Exercise-Associated Skin Surface Temperature Changes after Resistance Training with Different Exercise Intensities

    Directory of Open Access Journals (Sweden)

    Martin Weigert

    2018-01-01

    Full Text Available Background: Studies showed, that changes in muscular metabolic-associated heat production and blood circulation during and after muscular work affect skin temperature (T but the results are inconsistent and the effect of exercise intensity is unclear. Objective: This study investigated the intensity-dependent reaction of T on resistance training. Methods: Ten male students participated. After acclimatization (15 min, the participants completed 3x10 repetitions of unilateral biceps curl with 30, 50 or 70% of their one-repetition-maximum (1RM in a randomized order. Skin temperature of the loaded and unloaded biceps was measured at rest (Trest, immediately following set 1, 2 and 3 (TS1,TS2,TS3 and 30 minutes post exercise (T1 - T30 with an infrared camera. Results: Two-way ANOVA detected a significant effect of the measuring time point on T (Trest to T30 of the loaded arm for 30% (Eta²=0.85, 50% (Eta²=0.88 and 70% 1RM (Eta²=0.85 and of the unloaded arm only for 30% 1RM (Eta²=0.41 (p0.05. The T values at the different measuring time points (Trest - T30 did not differ between the intensities at any time point. The loaded arm showed a mean maximum T rise to Trest of 1.8°C and on average, maximum T was reached approximately 5 minutes after the third set.  Conclusion: This study indicate a rise of T, which could be independent of the exercise intensity. Infrared thermography seems to be applicable to identify the primary used functional muscles in resistance training but this method seems not suitable to differentiate between exercise intensity from 30 to 70% 1RM.

  15. The Surface of Mars: A Post-Viking View.

    Science.gov (United States)

    Carr, Michael H.

    1983-01-01

    Highlights current information on the martian surface. Topics include a planetary overview (atmosphere, dust storms, water vapor/ice, soil analysis) and surface features (craters, volcanoes, canyons/channels, polar regions, wind-related features). Similarities/differences between Mars and Earth are also discussed. (JN)

  16. Numerical simulation of mesoscale surface pressure features with trailing stratiform squall lines using WRF -ARW model over Gangetic West Bengal region

    Science.gov (United States)

    Dawn, Soma; Satyanarayana, A. N. V.

    2018-01-01

    In the present study, an attempt has been made to investigate the simulation of mesoscale surface pressure patterns like pre-squall mesolow, mesohigh and wake low associated with leading convective line-trailing stratiform (TS) squall lines over Gangetic West Bengal (GWB). For this purpose, a two way interactive triple nested domain with high resolution WRF model having2 km grid length in the innermost domain is used. The model simulated results are compared with the available in-situ observations obtained as a part of Severe Thunderstorm: Observations and Regional Modeling (STORM) programme, reflectivity products of Doppler Weather Radar (DWR) Kolkata and TRMM rainfall. Three TS squall lines (15 May 2009, 5 May 2010 and 7 May 2010) are chosen during pre-monsoon thunderstorm season for this study. The model simulated results of diurnal variation of temperature, relative humidity, wind speed and direction at the station Kharagpur in GWB region reveal a sudden fall in temperature, increase in the amount of relative humidity and sudden rise in wind speed during the arrival of the storms. Such results are well comparable with the observations though there are some leading or lagging of time in respect of actual occurrences of such events. The study indicates that the model is able to predict the occurrences of three typical surface pressure features namely: pre-squall mesolow, meso high and wake low. The predicted surface parameters like accumulated rainfall, maximum reflectivity and vertical profiles (temperature, relative humidity and winds) are well accorded with the observations. The convective and stratiform precipitation region of the TS squall lines are well represented by the model. A strong downdraft is observed to be a contributory factor for formation of mesohigh in the convective region of the squall line. Wake low is observed to reside in the stratiform rain region and the descending dry air at this place has triggered the wake low through adiabatic

  17. The theory of development of surface morphology by sputter erosion processes

    International Nuclear Information System (INIS)

    Carter, G.; Nobes, M.J.

    1984-01-01

    When a surface is bombarded by an energetic ion flux a rich variety of surface structures are observed to develop at the atomic, microscopic and macroscopic scales. Such structures include elevated, with respect to the surrounding surface, features such as mesas or plateaux, ridges, cones and pyramids and depressed features such as etch pits and cavities. These elementary features may be isolated or in profusion and frequently repetitive patterns of coordinated pyramidal structures, etch pits, surface ledges or facets and ripple or wave-like structures occur. The majority of the features arise rather directly from the erosion action of the sputtering process, particularly from differential erosion processes at different surface localities. The authors outline a general approach to sputter erosion induced surface morphology development based on the concept of the surface as an advancing wave. (Auth.)

  18. Simulation of intense short-pulse laser-plasma interaction

    International Nuclear Information System (INIS)

    Yamagiwa, Mitsuru

    2000-01-01

    We have completed the massive parallelization of a 2-dimensional giga-particle code and have achieved a 530-fold acceleration rate with 512 processing elements (PE's). Using this we have implemented a simulation of the interaction of a solid thin film and a high intensity laser and have discovered a phenomenon in which high quality short pulses from the far ultraviolet to soft X-rays are generated at the back surface of the thin layer. We have also introduced the atomic process database code (Hullac) and have the possibility for high precision simulations of X-ray laser radiation. With respect to laser acceleration we have the possibility to quantitatively evaluate relativistic self-focusing assumed to occur in higher intensity fields. Ion acceleration from a solid target and an underdense plasma irradiated by an intense and an ultra intense laser, respectively, has also been studied by particle-in-cell (PIC) simulations. (author)

  19. A feature-based approach to modeling protein-protein interaction hot spots.

    Science.gov (United States)

    Cho, Kyu-il; Kim, Dongsup; Lee, Doheon

    2009-05-01

    Identifying features that effectively represent the energetic contribution of an individual interface residue to the interactions between proteins remains problematic. Here, we present several new features and show that they are more effective than conventional features. By combining the proposed features with conventional features, we develop a predictive model for interaction hot spots. Initially, 54 multifaceted features, composed of different levels of information including structure, sequence and molecular interaction information, are quantified. Then, to identify the best subset of features for predicting hot spots, feature selection is performed using a decision tree. Based on the selected features, a predictive model for hot spots is created using support vector machine (SVM) and tested on an independent test set. Our model shows better overall predictive accuracy than previous methods such as the alanine scanning methods Robetta and FOLDEF, and the knowledge-based method KFC. Subsequent analysis yields several findings about hot spots. As expected, hot spots have a larger relative surface area burial and are more hydrophobic than other residues. Unexpectedly, however, residue conservation displays a rather complicated tendency depending on the types of protein complexes, indicating that this feature is not good for identifying hot spots. Of the selected features, the weighted atomic packing density, relative surface area burial and weighted hydrophobicity are the top 3, with the weighted atomic packing density proving to be the most effective feature for predicting hot spots. Notably, we find that hot spots are closely related to pi-related interactions, especially pi . . . pi interactions.

  20. A feature-based approach to modeling protein–protein interaction hot spots

    Science.gov (United States)

    Cho, Kyu-il; Kim, Dongsup; Lee, Doheon

    2009-01-01

    Identifying features that effectively represent the energetic contribution of an individual interface residue to the interactions between proteins remains problematic. Here, we present several new features and show that they are more effective than conventional features. By combining the proposed features with conventional features, we develop a predictive model for interaction hot spots. Initially, 54 multifaceted features, composed of different levels of information including structure, sequence and molecular interaction information, are quantified. Then, to identify the best subset of features for predicting hot spots, feature selection is performed using a decision tree. Based on the selected features, a predictive model for hot spots is created using support vector machine (SVM) and tested on an independent test set. Our model shows better overall predictive accuracy than previous methods such as the alanine scanning methods Robetta and FOLDEF, and the knowledge-based method KFC. Subsequent analysis yields several findings about hot spots. As expected, hot spots have a larger relative surface area burial and are more hydrophobic than other residues. Unexpectedly, however, residue conservation displays a rather complicated tendency depending on the types of protein complexes, indicating that this feature is not good for identifying hot spots. Of the selected features, the weighted atomic packing density, relative surface area burial and weighted hydrophobicity are the top 3, with the weighted atomic packing density proving to be the most effective feature for predicting hot spots. Notably, we find that hot spots are closely related to π–related interactions, especially π · · · π interactions. PMID:19273533

  1. FEATURES OF GEODEFORMATION CHANGES OF NEAR SURFACE SEDIMENTARY ROCKS

    Directory of Open Access Journals (Sweden)

    I. A. Larionov

    2016-11-01

    Full Text Available The results of investigations of the deformation process in the near surface sedimentary rocks, which has been carried out in a seismically active region of Kamchatka peninsular since 2007,are presented. The peculiarity of the experiments on the registration of geodeformations is the application of a laser deformograph-interferometer constructed according to the Michelson interferometer scheme.

  2. Superhydrophobic surfaces fabricated by surface modification of alumina particles

    Science.gov (United States)

    Richard, Edna; Aruna, S. T.; Basu, Bharathibai J.

    2012-10-01

    The fabrication of superhydrophobic surfaces has attracted intense interest because of their widespread potential applications in various industrial fields. Recently, some attempts have been carried out to prepare superhydrophobic surfaces using metal oxide nanoparticles. In the present work, superhydrophobic surfaces were fabricated with low surface energy material on alumina particles with different sizes. It was found that particle size of alumina is an important factor in achieving stable superhydrophobic surface. It was possible to obtain alumina surface with water contact angle (WCA) of 156° and a sliding angle of Superhydrophobicity of the modified alumina is attributed to the combined effect of the micro-nanostructure and low surface energy of fatty acid on the surface. The surface morphology of the alumina powder and coatings was determined by FESEM. The stability of the coatings was assessed by conducting water immersion test. Effect of heat treatment on WCA of the coating was also studied. The transition of alumina from hydrophilic to superhydrophobic state was explained using Wenzel and Cassie models. The method is shown to have potential application for creating superhydrophobic surface on cotton fabrics.

  3. Discriminating Induced-Microearthquakes Using New Seismic Features

    Science.gov (United States)

    Mousavi, S. M.; Horton, S.

    2016-12-01

    We studied characteristics of induced-microearthquakes on the basis of the waveforms recorded on a limited number of surface receivers using machine-learning techniques. Forty features in the time, frequency, and time-frequency domains were measured on each waveform, and several techniques such as correlation-based feature selection, Artificial Neural Networks (ANNs), Logistic Regression (LR) and X-mean were used as research tools to explore the relationship between these seismic features and source parameters. The results show that spectral features have the highest correlation to source depth. Two new measurements developed as seismic features for this study, spectral centroids and 2D cross-correlations in the time-frequency domain, performed better than the common seismic measurements. These features can be used by machine learning techniques for efficient automatic classification of low energy signals recorded at one or more seismic stations. We applied the technique to 440 microearthquakes-1.7Reference: Mousavi, S.M., S.P. Horton, C. A. Langston, B. Samei, (2016) Seismic features and automatic discrimination of deep and shallow induced-microearthquakes using neural network and logistic regression, Geophys. J. Int. doi: 10.1093/gji/ggw258.

  4. Regularity of Minimal Surfaces

    CERN Document Server

    Dierkes, Ulrich; Tromba, Anthony J; Kuster, Albrecht

    2010-01-01

    "Regularity of Minimal Surfaces" begins with a survey of minimal surfaces with free boundaries. Following this, the basic results concerning the boundary behaviour of minimal surfaces and H-surfaces with fixed or free boundaries are studied. In particular, the asymptotic expansions at interior and boundary branch points are derived, leading to general Gauss-Bonnet formulas. Furthermore, gradient estimates and asymptotic expansions for minimal surfaces with only piecewise smooth boundaries are obtained. One of the main features of free boundary value problems for minimal surfaces is t

  5. Anomalous water dynamics at surfaces and interfaces: synergistic effects of confinement and surface interactions

    Science.gov (United States)

    Biswas, Rajib; Bagchi, Biman

    2018-01-01

    In nature, water is often found in contact with surfaces that are extended on the scale of molecule size but small on a macroscopic scale. Examples include lipid bilayers and reverse micelles as well as biomolecules like proteins, DNA and zeolites, to name a few. While the presence of surfaces and interfaces interrupts the continuous hydrogen bond network of liquid water, confinement on a mesoscopic scale introduces new features. Even when extended on a molecular scale, natural and biological surfaces often have features (like charge, hydrophobicity) that vary on the scale of the molecular diameter of water. As a result, many new and exotic features, which are not seen in the bulk, appear in the dynamics of water close to the surface. These different behaviors bear the signature of both water-surface interactions and of confinement. In other words, the altered properties are the result of the synergistic effects of surface-water interactions and confinement. Ultrafast spectroscopy, theoretical modeling and computer simulations together form powerful synergistic approaches towards an understanding of the properties of confined water in such systems as nanocavities, reverse micelles (RMs), water inside and outside biomolecules like proteins and DNA, and also between two hydrophobic walls. We shall review the experimental results and place them in the context of theory and simulations. For water confined within RMs, we discuss the possible interference effects propagating from opposite surfaces. Similar interference is found to give rise to an effective attractive force between two hydrophobic surfaces immersed and kept fixed at a separation of d, with the force showing an exponential dependence on this distance. For protein and DNA hydration, we shall examine a multitude of timescales that arise from frustration effects due to the inherent heterogeneity of these surfaces. We pay particular attention to the role of orientational correlations and modification of the

  6. Remote measurement of surface roughness, surface reflectance, and body reflectance with LiDAR.

    Science.gov (United States)

    Li, Xiaolu; Liang, Yu

    2015-10-20

    Light detection and ranging (LiDAR) intensity data are attracting increasing attention because of the great potential for use of such data in a variety of remote sensing applications. To fully investigate the data potential for target classification and identification, we carried out a series of experiments with typical urban building materials and employed our reconstructed built-in-lab LiDAR system. Received intensity data were analyzed on the basis of the derived bidirectional reflectance distribution function (BRDF) model and the established integration method. With an improved fitting algorithm, parameters involved in the BRDF model can be obtained to depict the surface characteristics. One of these parameters related to surface roughness was converted to a most used roughness parameter, the arithmetical mean deviation of the roughness profile (Ra), which can be used to validate the feasibility of the BRDF model in surface characterizations and performance evaluations.

  7. An improved high order texture features extraction method with application to pathological diagnosis of colon lesions for CT colonography

    Science.gov (United States)

    Song, Bowen; Zhang, Guopeng; Lu, Hongbing; Wang, Huafeng; Han, Fangfang; Zhu, Wei; Liang, Zhengrong

    2014-03-01

    Differentiation of colon lesions according to underlying pathology, e.g., neoplastic and non-neoplastic, is of fundamental importance for patient management. Image intensity based textural features have been recognized as a useful biomarker for the differentiation task. In this paper, we introduce high order texture features, beyond the intensity, such as gradient and curvature, for that task. Based on the Haralick texture analysis method, we introduce a virtual pathological method to explore the utility of texture features from high order differentiations, i.e., gradient and curvature, of the image intensity distribution. The texture features were validated on database consisting of 148 colon lesions, of which 35 are non-neoplastic lesions, using the random forest classifier and the merit of area under the curve (AUC) of the receiver operating characteristics. The results show that after applying the high order features, the AUC was improved from 0.8069 to 0.8544 in differentiating non-neoplastic lesion from neoplastic ones, e.g., hyperplastic polyps from tubular adenomas, tubulovillous adenomas and adenocarcinomas. The experimental results demonstrated that texture features from the higher order images can significantly improve the classification accuracy in pathological differentiation of colorectal lesions. The gain in differentiation capability shall increase the potential of computed tomography (CT) colonography for colorectal cancer screening by not only detecting polyps but also classifying them from optimal polyp management for the best outcome in personalized medicine.

  8. Fluorescence Imaging Reveals Surface Contamination

    Science.gov (United States)

    Schirato, Richard; Polichar, Raulf

    1992-01-01

    In technique to detect surface contamination, object inspected illuminated by ultraviolet light to make contaminants fluoresce; low-light-level video camera views fluorescence. Image-processing techniques quantify distribution of contaminants. If fluorescence of material expected to contaminate surface is not intense, tagged with low concentration of dye.

  9. Rethinking the intensive care environment: considering nature in nursing practice.

    Science.gov (United States)

    Minton, Claire; Batten, Lesley

    2016-01-01

    With consideration of an environmental concept, this paper explores evidence related to the negative impacts of the intensive care unit environment on patient outcomes and explores the potential counteracting benefits of 'nature-based' nursing interventions as a way to improve care outcomes. The impact of the environment in which a patient is nursed has long been recognised as one determinant in patient outcomes. Whilst the contemporary intensive care unit environment contains many features that support the provision of the intensive therapies the patient requires, it can also be detrimental, especially for long-stay patients. This narrative review considers theoretical and evidence-based literature that supports the adoption of nature-based nursing interventions in intensive care units. Research and theoretical literature from a diverse range of disciplines including nursing, medicine, psychology, architecture and environmental science were considered in relation to patient outcomes and intensive care nursing practice. There are many nature-based interventions that intensive care unit nurses can implement into their nursing practice to counteract environmental stressors. These interventions can also improve the environment for patients' families and nurses. Intensive care unit nurses must actively consider and manage the environment in which nursing occurs to facilitate the best patient outcomes. © 2015 John Wiley & Sons Ltd.

  10. Online feature selection with streaming features.

    Science.gov (United States)

    Wu, Xindong; Yu, Kui; Ding, Wei; Wang, Hao; Zhu, Xingquan

    2013-05-01

    We propose a new online feature selection framework for applications with streaming features where the knowledge of the full feature space is unknown in advance. We define streaming features as features that flow in one by one over time whereas the number of training examples remains fixed. This is in contrast with traditional online learning methods that only deal with sequentially added observations, with little attention being paid to streaming features. The critical challenges for Online Streaming Feature Selection (OSFS) include 1) the continuous growth of feature volumes over time, 2) a large feature space, possibly of unknown or infinite size, and 3) the unavailability of the entire feature set before learning starts. In the paper, we present a novel Online Streaming Feature Selection method to select strongly relevant and nonredundant features on the fly. An efficient Fast-OSFS algorithm is proposed to improve feature selection performance. The proposed algorithms are evaluated extensively on high-dimensional datasets and also with a real-world case study on impact crater detection. Experimental results demonstrate that the algorithms achieve better compactness and higher prediction accuracy than existing streaming feature selection algorithms.

  11. Synthesis of gold nanostars with fractal structure: application in surface-enhanced Raman scattering

    Science.gov (United States)

    Zhu, Jian; Liu, Mei-Jin; Li, Jian-Jun; Zhao, Jun-Wu

    2017-11-01

    Multi-branched gold nanostars with fractal feature were synthesized using the Triton X-100 participant seed-growth method. By increasing the amount of ascorbic acid, the branch length of gold nanostars could be greatly increased. It has been interesting to find that the secondary growth of new branches takes place from the elementary structure when the aspect ratio of the branches is greater than 8.0 and the corresponding plasmon absorption wavelength is greater than 900 nm. Raman activity of the gold nanostar films has been investigated by using the 4-mercaptobenzoic acid (4-MBA) as Raman active probe. Experimental results show that the surface-enhanced Raman scattering (SERS) ability of the gold nanostars could be efficiently improved when the fractal structure appears. The physical mechanism has been attributed to the intense increased secondary branch number and the increased "hot spots". These unique multi-branched gold nanostars with fractal feature and great SERS activity should have great potential in sensing applications.

  12. A high resolution photoemission study of surface core-level shifts in clean and oxygen-covered Ir(2 1 0) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Gladys, M.J.; Ermanoski, I.; Jackson, G.; Quinton, J.S.; Rowe, J.E.; Madey, T.E. E-mail: madey@physics.rutgers.edu

    2004-04-01

    High resolution soft X-ray photoemission electron spectroscopy (SXPS), using synchrotron radiation, is employed to investigate 4f core-level features of four differently-prepared Ir(2 1 0) surfaces: clean planar, oxygen-covered planar, oxygen-induced faceted, and clean faceted surfaces. Surface and bulk peak identifications are supported by measurements at different photon energies (thus probing different electron escape depths) and variable emission angles. Iridium 4f{sub 7/2} photoemission spectra are fitted with Doniach-Sunjic lineshapes. The surface components are identified with core levels positioned at lower binding energies than the bulk components, in contrast to previous reports of binding energy inversion on Ir(1 0 0) (1x1) and (5x1) surfaces. For clean planar Ir(2 1 0) three surface Ir 4f{sub 7/2} features are observed with core-level shifts of -765, -529, and -281 meV, with respect to the bulk; these are associated with the first, second and third layers of atoms, respectively, for atomically rough Ir(2 1 0). Adsorption of oxygen onto the planar Ir(2 1 0) surface is found to cause a suppression and shift of the surface features to higher binding energies. Annealing at T{>=}600 K in oxygen produces a faceted surface as verified by low energy electron diffraction (LEED). A comparison of planar and faceted oxygen-covered surfaces reveals minor differences in the normal emission SXPS spectra, while grazing emission spectra exhibit differences. The SXPS spectrum of the clean, faceted Ir(2 1 0) exhibits small differences in comparison to the clean planar case, with surface features having binding energy shifts of -710, -450, and -230 meV.

  13. Understanding Legacy Features with Featureous

    DEFF Research Database (Denmark)

    Olszak, Andrzej; Jørgensen, Bo Nørregaard

    2011-01-01

    Java programs called Featureous that addresses this issue. Featureous allows a programmer to easily establish feature-code traceability links and to analyze their characteristics using a number of visualizations. Featureous is an extension to the NetBeans IDE, and can itself be extended by third...

  14. Intensity of competition in the market of greenhouse vegetables

    Directory of Open Access Journals (Sweden)

    Oleg Ivanovich Botkin

    2012-03-01

    Full Text Available This paper reviews the competitive environment of the market greenhouse vegetables. Revealed specific features of the industry, determining the level of intensity of competition in the market greenhouse vegetables. Classified factors internal and external environment, identify indicators that affect the state of the market. The factors that determine the intensity of competition in the market greenhouse vegetables.The main competitors on the Russian market of greenhouse production.Identified indicators of the intensity level of competition, in particular: the level of monopolization of the market greenhouse vegetables, the level of concentration of production in the industry, the generalized index of the intensity of the competitive environment.Shows a comparative analysis of competitors’ market greenhouse vegetables in Udmurtia.Revealed competitive advantages which can help local producers to reduce the pressure of competition and intra-industry to occupy a leading position in the Russian market of greenhouse vegetable production.The dynamics of economic performance of Russian producers. Ways of improving the competitiveness of enterprises for the production of greenhouse vegetables

  15. A new procedure for characterizing textured surfaces with a deterministic pattern of valley features

    DEFF Research Database (Denmark)

    Godi, Alessandro; Kühle, A; De Chiffre, Leonardo

    2013-01-01

    , therefore some modifications are investigated. In particular the robust Gaussian regression filter has been modified providing an envelope first-guess in order to always fit the mean line through the plateau region. Starting from a filtered and aligned profile, the feature thresholds recognition...... a correctly aligned roughness profile and permitting comprehensive feature analyses....

  16. Performance of Multiplexed XY Resistive Micromegas detectors in a high intensity beam

    Science.gov (United States)

    Banerjee, D.; Burtsev, V.; Chumakov, A.; Cooke, D.; Depero, E.; Dermenev, A. V.; Donskov, S. V.; Dubinin, F.; Dusaev, R. R.; Emmenegger, S.; Fabich, A.; Frolov, V. N.; Gardikiotis, A.; Gninenko, S. N.; Hösgen, M.; Karneyeu, A. E.; Ketzer, B.; Kirsanov, M. M.; Konorov, I. V.; Kramarenko, V. A.; Kuleshov, S. V.; Levchenko, E.; Lyubovitskij, V. E.; Lysan, V.; Mamon, S.; Matveev, V. A.; Mikhailov, Yu. V.; Myalkovskiy, V. V.; Peshekhonov, V. D.; Peshekhonov, D. V.; Polyakov, V. A.; Radics, B.; Rubbia, A.; Samoylenko, V. D.; Tikhomirov, V. O.; Tlisov, D. A.; Toropin, A. N.; Vasilishin, B.; Arenas, G. Vasquez; Ulloa, P.; Crivelli, P.

    2018-02-01

    We present the performance of multiplexed XY resistive Micromegas detectors tested in the CERN SPS 100 GeV/c electron beam at intensities up to 3 . 3 × 105e- /(s ṡcm2) . So far, all studies with multiplexed Micromegas have only been reported for tests with radioactive sources and cosmic rays. The use of multiplexed modules in high intensity environments was not explored due to the effect of ambiguities in the reconstruction of the hit point caused by the multiplexing feature. For the specific mapping and beam intensities analyzed in this work with a multiplexing factor of five, more than 50% level of ambiguity is introduced due to particle pile-up as well as fake clusters due to the mapping feature. Our results prove that by using the additional information of cluster size and integrated charge from the signal clusters induced on the XY strips, the ambiguities can be reduced to a level below 2%. The tested detectors are used in the CERN NA64 experiment for tracking the incoming particles bending in a magnetic field in order to reconstruct their momentum. The average hit detection efficiency of each module was found to be ∼96% at the highest beam intensities. By using four modules a tracking resolution of 1.1% was obtained with ∼85% combined tracking efficiency.

  17. Large anterior temporal Virchow-Robin spaces: unique MR imaging features

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Anthony T. [Monash University, Neuroradiology Service, Monash Imaging, Monash Health, Melbourne, Victoria (Australia); Chandra, Ronil V. [Monash University, Neuroradiology Service, Monash Imaging, Monash Health, Melbourne, Victoria (Australia); Monash University, Department of Surgery, Faculty of Medicine, Nursing and Health Sciences, Melbourne (Australia); Trost, Nicholas M. [St Vincent' s Hospital, Neuroradiology Service, Melbourne (Australia); McKelvie, Penelope A. [St Vincent' s Hospital, Anatomical Pathology, Melbourne (Australia); Stuckey, Stephen L. [Monash University, Neuroradiology Service, Monash Imaging, Monash Health, Melbourne, Victoria (Australia); Monash University, Southern Clinical School, Faculty of Medicine, Nursing and Health Sciences, Melbourne (Australia)

    2015-05-01

    Large Virchow-Robin (VR) spaces may mimic cystic tumor. The anterior temporal subcortical white matter is a recently described preferential location, with only 18 reported cases. Our aim was to identify unique MR features that could increase prospective diagnostic confidence. Thirty-nine cases were identified between November 2003 and February 2014. Demographic, clinical data and the initial radiological report were retrospectively reviewed. Two neuroradiologists reviewed all MR imaging; a neuropathologist reviewed histological data. Median age was 58 years (range 24-86 years); the majority (69 %) was female. There were no clinical symptoms that could be directly referable to the lesion. Two thirds were considered to be VR spaces on the initial radiological report. Mean maximal size was 9 mm (range 5-17 mm); majority (79 %) had perilesional T2 or fluid-attenuated inversion recovery (FLAIR) hyperintensity. The following were identified as potential unique MR features: focal cortical distortion by an adjacent branch of the middle cerebral artery (92 %), smaller adjacent VR spaces (26 %), and a contiguous cerebrospinal fluid (CSF) intensity tract (21 %). Surgery was performed in three asymptomatic patients; histopathology confirmed VR spaces. Unique MR features were retrospectively identified in all three patients. Large anterior temporal lobe VR spaces commonly demonstrate perilesional T2 or FLAIR signal and can be misdiagnosed as cystic tumor. Potential unique MR features that could increase prospective diagnostic confidence include focal cortical distortion by an adjacent branch of the middle cerebral artery, smaller adjacent VR spaces, and a contiguous CSF intensity tract. (orig.)

  18. Critical features of coupling parameter in synchronization of small world neural networks

    International Nuclear Information System (INIS)

    Li Yanlong; Ma Jun; Xu Wenke; Li Hongbo; Wu Min

    2008-01-01

    The critical features of a coupling parameter in the synchronization of small world neural networks are investigated. A power law decay form is observed in this spatially extended system, the larger linked degree becomes, the larger critical coupling intensity. There exists maximal and minimal critical coupling intensity for synchronization in the extended system. An approximate synchronization diagram has been constructed. In the case of partial coupling, a primary result is presented about the critical coupling fraction for various linked degree of networks

  19. THE THOMSON SURFACE. I. REALITY AND MYTH

    International Nuclear Information System (INIS)

    Howard, T. A.; DeForest, C. E.

    2012-01-01

    The solar corona and heliosphere are visible via sunlight that is Thomson-scattered off free electrons and detected by coronagraphs and heliospheric imagers. It is well known that these instruments are most responsive to material at the 'Thomson surface', the sphere with a diameter passing through both the observer and the Sun. It is less well known that in fact the Thomson scattering efficiency is minimized on the Thomson surface. Unpolarized heliospheric imagers such as STEREO/HI are thus approximately equally responsive to material over more than a 90° range of solar exit angles at each given position in the image plane. We call this range of angles the 'Thomson plateau'. We observe that heliospheric imagers are actually more sensitive to material far from the Thomson surface than close to it, at a fixed radius from the Sun. We review the theory of Thomson scattering as applied to heliospheric imaging, feature detection in the presence of background noise, geometry inference, and feature mass measurement. We show that feature detection is primarily limited by observing geometry and field of view, that the highest sensitivity for detection of density features is to objects close to the observer, that electron surface density inference is independent of geometry across the Thomson plateau, and that mass inference varies with observer distance in all geometries. We demonstrate the sensitivity results with a few examples of features detected by STEREO, far from the Thomson surface.

  20. A novel approach to obtain highly intense self-activated photoluminescence emissions in hydroxyapatite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Thales R. [CDMF-UFSCar, Universidade Federal de São Carlos, P.O. Box 676, 13565-905 São Carlos, São Paulo (Brazil); QIO-UJI, Universitat Jaume I, 12071 Castellón (Spain); Sczancoski, Júlio C. [CDMF-UFSCar, Universidade Federal de São Carlos, P.O. Box 676, 13565-905 São Carlos, São Paulo (Brazil); Beltrán-Mir, Héctor [QIO-UJI, Universitat Jaume I, 12071 Castellón (Spain); Nogueira, Içamira C. [PPGEM-IFMA, Instituto Federal de Educação, Ciência e Tecnologia do Maranhão, 65030-005 São Luís, MA (Brazil); Li, Máximo S. [IFSC-USP, Universidade de São Paulo, P.O. Box 369, 13560-970 São Carlos, SP (Brazil); Andrés, Juan [QFA-UJI, Universitat Jaume I, 12071 Castellón (Spain); Cordoncillo, Eloisa [QIO-UJI, Universitat Jaume I, 12071 Castellón (Spain); Longo, Elson, E-mail: elson.liec@gmail.com [CDMF-UFSCar, Universidade Federal de São Carlos, P.O. Box 676, 13565-905 São Carlos, São Paulo (Brazil)

    2017-05-15

    Defect-related photoluminescence (PL) in materials have attracted interest for applications including near ultraviolet (NUV) excitable light-emitting diodes and in biomedical field. In this paper, hydroxyapatite [Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}] nanorods with intense PL bands (bluish- and yellowish-white emissions) were obtained when excited under NUV radiation at room temperature. These nanoparticles were synthesized via chemical precipitation at 90 °C followed by distinct heat treatments temperatures (200–800 °C). Intense and broad emission profiles were achieved at 350 °C (380–750 nm) and 400 °C (380–800 nm). UV–Vis spectroscopy revealed band gap energies (5.58–5.78 eV) higher than the excitation energies (~3.54 and ~2.98 eV at 350 and 415 nm, respectively), confirming the contribution of defect energy levels within the forbidden zone for PL emissions. The structural features were characterized by X-ray diffraction, Rietveld refinement, thermogravimetric analysis, and Fourier transform infrared spectroscopy. By means of these techniques, the relation between structural order-disorder induced by defects, chemical reactions at both lattice and surface of the materials as well as the PL, without activator centers, was discussed in details. - Graphical abstract: The self-activated photoluminescence emissions of chemically precipitated hydroxyapatite nanorods were improved by different heat treatment temperatures. - Highlights: • HA nanorods were synthesized with improved self-activated PL at room temperature. • PL profile and intensity dependents on the temperature of posterior heat treatments. • Bluish- and yellowish-white emissions under NUV excitation (350 and 415 nm). • Broad and intense profiles achieved at 350 °C (380–750 nm) and 400 °C (380–800 nm). • PL from the e′–h{sup •} recombination between defect energy levels within the band gap.

  1. Plasmonic metalens based on coupled resonators for focusing of surface plasmons

    KAUST Repository

    Xu, Quan

    2016-11-29

    As an essential functionality, flexible focusing of surface plasmons (SPs) is of particular interest in nonlinear optics and highly integrated plasmonic circuitry. Here, we developed a versatile plasmonic metalens, a metasurface comprised of coupled subwavelength resonators, whose optical responses exhibit a remarkable feature of electromagnetically induced transparency (EIT). We demonstrate numerically and experimentally how a proper spatial design of the unit elements steers SPs to arbitrary foci based on the holographic principles. More specifically, we show how to control the interaction between the constituent EIT resonators to efficiently manipulate the focusing intensity of SPs. We also demonstrated that the proposed metalens is capable of achieving frequency division multiplexing. The power and simplicity of the proposed design would offer promising opportunities for practical plasmonic devices.

  2. Particle physics in intense electromagnetic fields

    International Nuclear Information System (INIS)

    Kurilin, A.V.

    1999-01-01

    The quantum field theory in the presence of classical background electromagnetic field is reviewed giving a pedagogical introduction to the Feynman-Furry method of describing non-perturbative interactions with very strong electromagnetic fields. A particular emphasis is given to the case of the plane-wave electromagnetic field for which the charged particles' wave functions and propagators are presented. Some general features of quantum processes proceeding in the intense electromagnetic background are argued. The possibilities of searching new physics through the investigations of quantum phenomena induced by a strong electromagnetic environment are also discussed

  3. Impact of global warming on the typhoon intensities during 2015

    Science.gov (United States)

    Kang, N. Y.; Yang, S. H.; Elsner, J.; Chun, Y.

    2017-12-01

    The climate of 2015 was characterized by a strong El Nino, global warmth, and record setting tropical cyclone (TC) intensity for western North Pacific typhoons. In this study, the highest TC intensity in 32 years (1984-2015) is shown to be a consequence of above normal TC activity—following natural internal variation—and greater efficiency of intensity. The efficiency of intensity (EINT) is termed the `blasting effect' and refers to typhoon intensification at the expense of occurrence. Statistical models show that the EINT is mostly due to the anomalous warmth in the environment as indicated by global mean sea-surface temperature. In comparison, the EINT due to El Nino is negligibly small. This implies that the record-setting intensity of 2015 might not have occurred without environmental warming and suggests that a year with even greater TC intensity is possible in the near future when above normal activity coincides with another record EINT due to continuous warming.

  4. A savanna response to precipitation intensity.

    Directory of Open Access Journals (Sweden)

    Ryan S Berry

    Full Text Available As the atmosphere warms, precipitation events are becoming less frequent but more intense. A three-year experiment in Kruger National Park, South Africa, found that fewer, more intense precipitation events encouraged woody plant encroachment. To test whether or not these treatment responses persisted over time, here, we report results from all five years of that experiment. Grass growth, woody plant growth, total fine root number and area and hydrologic tracer uptake by grasses and woody plants were measured in six treated plots (8 m by 8 m and six control plots. Treatment effects on soil moisture were measured continuously in one treated and one control plot. During the fourth year, increased precipitation intensity treatments continued to decrease water flux in surface soils (0-10 cm, increase water flux in deeper soils (20+ cm, decrease grass growth and increase woody plant growth. Greater root numbers at 20-40 cm and greater woody plant uptake of a hydrological tracer from 45-60 cm suggested that woody plants increased growth by increasing root number and activity (but not root area in deeper soils. During the fifth year, natural precipitation events were large and intense so treatments had little effect on precipitation intensity or plant available water. Consistent with this effective treatment removal, there was no difference in grass or woody growth rates between control and treated plots, although woody plant biomass remained higher in treated than control plots due to treatment effects in the previous four years. Across the five years of this experiment, we found that 1 small increases in precipitation intensity can result in large increases in deep (20-130 cm soil water availability, 2 plant growth responses to precipitation intensity are rapid and disappear quickly, and 3 because woody plants accumulate biomass, occasional increases in precipitation intensity can result in long-term increases in woody plant biomass (i.e., shrub

  5. Image features dependant correlation-weighting function for efficient PRNU based source camera identification.

    Science.gov (United States)

    Tiwari, Mayank; Gupta, Bhupendra

    2018-04-01

    For source camera identification (SCI), photo response non-uniformity (PRNU) has been widely used as the fingerprint of the camera. The PRNU is extracted from the image by applying a de-noising filter then taking the difference between the original image and the de-noised image. However, it is observed that intensity-based features and high-frequency details (edges and texture) of the image, effect quality of the extracted PRNU. This effects correlation calculation and creates problems in SCI. For solving this problem, we propose a weighting function based on image features. We have experimentally identified image features (intensity and high-frequency contents) effect on the estimated PRNU, and then develop a weighting function which gives higher weights to image regions which give reliable PRNU and at the same point it gives comparatively less weights to the image regions which do not give reliable PRNU. Experimental results show that the proposed weighting function is able to improve the accuracy of SCI up to a great extent. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Detailed seismic intensity in Morioka area; Moriokashi ni okeru shosai shindo bunpu

    Energy Technology Data Exchange (ETDEWEB)

    Saito, T; Yamamoto, H; Settai, H [Iwate University, Iwate (Japan). Faculty of Engineering; Yamada, T [Obayashi Road Construction Co. Ltd., Tokyo (Japan)

    1996-10-01

    To reveal a seismic intensity distribution in individual areas, a large-scale detailed seismic intensity survey was conducted in Morioka City through questionnaire, as to the Hokkaido Toho-oki (HE) earthquake occurred on October 4, 1994 with a record of seismic intensity 4 at Morioka, and the Sanriku Haruka-oki (SH) earthquake occurred on December 28, 1994 with a record of seismic intensity 5 at Morioka. A relationship was also examined between the seismic intensity distribution and the properties of shallow basement in Morioka City. The range of seismic intensity was from 2.9 to 4.6 and the difference was 1.7 in the case of HE earthquake, and the range was from 3.1 to 5.0 and the difference was 1.9 in the case of SH earthquake. There were large differences in the seismic intensity at individual points. Morioka City has different geological structures in individual areas. There were differences in the S-wave velocity in the surface layer ranging from 150 to 600 m/sec, which were measured using a plate hammering seismic source at 76 areas in Morioka City. These properties of surface layers were in harmony with the seismic intensity distribution obtained from the questionnaire. For the observation of short frequency microtremors at about 490 points in the city, areas with large amplitudes, mean maximum amplitudes of vertical motion components more than 0.1 mkine were distributed in north-western region and a part of southern region. 4 refs., 9 figs., 1 tab.

  7. Generalizations of the subject-independent feature set for music-induced emotion recognition.

    Science.gov (United States)

    Lin, Yuan-Pin; Chen, Jyh-Horng; Duann, Jeng-Ren; Lin, Chin-Teng; Jung, Tzyy-Ping

    2011-01-01

    Electroencephalogram (EEG)-based emotion recognition has been an intensely growing field. Yet, how to achieve acceptable accuracy on a practical system with as fewer electrodes as possible is less concerned. This study evaluates a set of subject-independent features, based on differential power asymmetry of symmetric electrode pairs [1], with emphasis on its applicability to subject variability in music-induced emotion classification problem. Results of this study have evidently validated the feasibility of using subject-independent EEG features to classify four emotional states with acceptable accuracy in second-scale temporal resolution. These features could be generalized across subjects to detect emotion induced by music excerpts not limited to the music database that was used to derive the emotion-specific features.

  8. An intensity-monitoring technique for measuring ellipsometric transients

    NARCIS (Netherlands)

    Droog, J.M.M.; Bootsma, G.A.

    1979-01-01

    Intensity-monitoring techniques make possible the measurement of rapid changes in the ellipsometric parameters. Methods used hitherto have been suitable for measuring slight changes only and require prior knowledge of the Δ and Ψ values for the initial surface. It is shown that larger changes can

  9. Particle surface area and bacterial activity in recirculating aquaculture systems

    DEFF Research Database (Denmark)

    Pedersen, Per Bovbjerg; von Ahnen, Mathis; Fernandes, Paulo

    2017-01-01

    Suspended particles in recirculating aquaculture systems (RAS) provide surface area that can be colonized by bacteria. More particles accumulate as the intensity of recirculation increases thus potentially increasing the bacterial carrying capacity of the systems. Applying a recent, rapid, culture...... but may provide significant surface area. Hence, the study substantiates that particles in RAS provide surface area supporting bacterial activity, and that particles play a key role in controlling the bacterial carrying capacity at least in less intensive RAS. Applying fast, culture-independent techniques......-independent fluorometric detection method (Bactiquant®) for measuring bacterial activity, the current study explored the relationship between total particle surface area (TSA, derived from the size distribution of particles >5 μm) and bacterial activity in freshwater RAS operated at increasing intensity of recirculation...

  10. Structure and Function: Planning a New Intensive Care Unit to Optimize Patient Care

    Directory of Open Access Journals (Sweden)

    Jozef Kesecioğlu

    2014-08-01

    Full Text Available To survey the recent medical literature reporting effects of intensive care unit (ICU design on patients’ and family members’ well-being, safety and functionality. Features of ICU design linked to the needs of patients and their family are single-rooms, privacy, quiet surrounding, exposure to daylight, views of nature, prevention of infection, a family area and open visiting hours. Other features such as safety, working procedures, ergonomics and logistics have a direct impact on the patient care and the nursing and medical personnel. An organization structured on the needs of the patient and their family is mandatory in designing a new intensive care. The main aims in the design of a new department should be patient centered care, safety, functionality, innovation and a future-proof concept.

  11. A Methodological Approach to Quantifying Plyometric Intensity.

    Science.gov (United States)

    Jarvis, Mark M; Graham-Smith, Phil; Comfort, Paul

    2016-09-01

    Jarvis, MM, Graham-Smith, P, and Comfort, P. A Methodological approach to quantifying plyometric intensity. J Strength Cond Res 30(9): 2522-2532, 2016-In contrast to other methods of training, the quantification of plyometric exercise intensity is poorly defined. The purpose of this study was to evaluate the suitability of a range of neuromuscular and mechanical variables to describe the intensity of plyometric exercises. Seven male recreationally active subjects performed a series of 7 plyometric exercises. Neuromuscular activity was measured using surface electromyography (SEMG) at vastus lateralis (VL) and biceps femoris (BF). Surface electromyography data were divided into concentric (CON) and eccentric (ECC) phases of movement. Mechanical output was measured by ground reaction forces and processed to provide peak impact ground reaction force (PF), peak eccentric power (PEP), and impulse (IMP). Statistical analysis was conducted to assess the reliability intraclass correlation coefficient and sensitivity smallest detectable difference of all variables. Mean values of SEMG demonstrate high reliability (r ≥ 0.82), excluding ECC VL during a 40-cm drop jump (r = 0.74). PF, PEP, and IMP demonstrated high reliability (r ≥ 0.85). Statistical power for force variables was excellent (power = 1.0), and good for SEMG (power ≥0.86) excluding CON BF (power = 0.57). There was no significant difference (p > 0.05) in CON SEMG between exercises. Eccentric phase SEMG only distinguished between exercises involving a landing and those that did not (percentage of maximal voluntary isometric contraction [%MVIC] = no landing -65 ± 5, landing -140 ± 8). Peak eccentric power, PF, and IMP all distinguished between exercises. In conclusion, CON neuromuscular activity does not appear to vary when intent is maximal, whereas ECC activity is dependent on the presence of a landing. Force characteristics provide a reliable and sensitive measure enabling precise description of intensity

  12. [Ocular surface system integrity].

    Science.gov (United States)

    Safonova, T N; Pateyuk, L S

    2015-01-01

    The interplay of different structures belonging to either the anterior segment of the eye or its accessory visual apparatus, which all share common embryological, anatomical, functional, and physiological features, is discussed. Explanation of such terms, as ocular surface, lacrimal functional unit, and ocular surface system, is provided.

  13. Interpreting intensities in vibrational sum frequency generation (SFG) spectroscopy: CO adsorption on Pd surfaces

    Science.gov (United States)

    Morkel, M.; Unterhalt, H.; Klüner, T.; Rupprechter, G.; Freund, H.-J.

    2005-07-01

    The lineshape and intensity of SFG signals of CO adsorbed on supported Pd nanoparticles and Pd(1 1 1) are analyzed. For CO/Pd(1 1 1) nearly symmetric lorentzian lineshapes were observed. Applying two different visible wavelengths for excitation, asymmetric lineshapes observed for the CO/Pd/Al 2O 3/NiAl(1 1 0) system are explained by a lower resonant and a higher non-resonant SFG signal and a change in the phase between resonant and non-resonant signals, most likely originating from an interband transition in the NiAl substrate. The relative intensity of different CO species (hollow, bridge, on-top) was modeled by DFT calculations of IR transition moments and Raman activities. While the (experimental) sensitivity of SFG towards different CO species strongly varies, the calculated IR and Raman activities are rather similar. The inability to exactly reproduce experimental SFG intensities suggests a strong coverage dependence of Raman activities or that non-linear effects occur that can currently not be properly accounted for.

  14. Surface-confined [2 + 2] cycloaddition towards one-dimensional polymers featuring cyclobutadiene units

    NARCIS (Netherlands)

    Tran, Bay V.; Pham, Tuan Anh; Grunst, Michael; Kivala, Milan; Stöhr, Meike

    2017-01-01

    Surface-confined synthesis has been offering a wide range of opportunities for the construction of novel molecular nanostructures. Exploring new types of on-surface coupling reactions is considered essential for being able to deliberately tune the materials properties. Here, we report on the

  15. SPECIFIC FEATURES OF PSYCHOLOGICAL CARE FOR PATIENTS WITH PULMONARY TUBERCULOSIS DURING INTENSIVE CHEMOTHERAPY (IN THE HOSPITAL SETTING

    Directory of Open Access Journals (Sweden)

    V. V. Streltsov

    2014-01-01

    Full Text Available The psychological trauma of pulmonary tuberculosis and long-term treatment may cause the development and progression of different borderline neuropsychic disorders in patients, lower therapeutic effectiveness, and prematurely discontinue therapy. The main practical tasks of psychological rehabilitation during intensive treatment are to render care for a patient during his adaptation to the hospital setting, to correct inadequate attitude towards disease, and to motivate active cooperation with specialists. Competent psychological support of drug therapy promotes a reduction in the intensity of psychic and somatic experiences in the patient and an increase in his psychological resources. A respective microclimate in the tuberculosis control facility and a patient-centered doctorpatient model should be considered as the most important rehabilitation factors.

  16. Empirical evaluation of cross-site reproducibility in radiomic features for characterizing prostate MRI

    Science.gov (United States)

    Chirra, Prathyush; Leo, Patrick; Yim, Michael; Bloch, B. Nicolas; Rastinehad, Ardeshir R.; Purysko, Andrei; Rosen, Mark; Madabhushi, Anant; Viswanath, Satish

    2018-02-01

    The recent advent of radiomics has enabled the development of prognostic and predictive tools which use routine imaging, but a key question that still remains is how reproducible these features may be across multiple sites and scanners. This is especially relevant in the context of MRI data, where signal intensity values lack tissue specific, quantitative meaning, as well as being dependent on acquisition parameters (magnetic field strength, image resolution, type of receiver coil). In this paper we present the first empirical study of the reproducibility of 5 different radiomic feature families in a multi-site setting; specifically, for characterizing prostate MRI appearance. Our cohort comprised 147 patient T2w MRI datasets from 4 different sites, all of which were first pre-processed to correct acquisition-related for artifacts such as bias field, differing voxel resolutions, as well as intensity drift (non-standardness). 406 3D voxel wise radiomic features were extracted and evaluated in a cross-site setting to determine how reproducible they were within a relatively homogeneous non-tumor tissue region; using 2 different measures of reproducibility: Multivariate Coefficient of Variation and Instability Score. Our results demonstrated that Haralick features were most reproducible between all 4 sites. By comparison, Laws features were among the least reproducible between sites, as well as performing highly variably across their entire parameter space. Similarly, the Gabor feature family demonstrated good cross-site reproducibility, but for certain parameter combinations alone. These trends indicate that despite extensive pre-processing, only a subset of radiomic features and associated parameters may be reproducible enough for use within radiomics-based machine learning classifier schemes.

  17. Energetic particle pressure in intense ESP events

    Science.gov (United States)

    Lario, D.; Decker, R. B.; Roelof, E. C.; Viñas, A.-F.

    2015-09-01

    We study three intense energetic storm particle (ESP) events in which the energetic particle pressure PEP exceeded both the pressure of the background thermal plasma Pth and the pressure of the magnetic field PB. The region upstream of the interplanetary shocks associated with these events was characterized by a depression of the magnetic field strength coincident with the increase of the energetic particle intensities and, when plasma measurements were available, a depleted solar wind density. The general feature of cosmic-ray mediated shocks such as the deceleration of the upstream background medium into which the shock propagates is generally observed. However, for those shocks where plasma parameters are available, pressure balance is not maintained either upstream of or across the shock, which may result from the fact that PEP is not included in the calculation of the shock parameters.

  18. Damage Detection for Historical Architectures Based on Tls Intensity Data

    Science.gov (United States)

    Li, Q.; Cheng, X.

    2018-04-01

    TLS (Terrestrial Laser Scanner) has long been preferred in the cultural heritage field for 3D documentation of historical sites thanks to its ability to acquire the geometric information without any physical contact. Besides the geometric information, most TLS systems also record the intensity information, which is considered as an important measurement of the spectral property of the scanned surface. Recent studies have shown the potential of using intensity for damage detection. However, the original intensity is affected by scanning geometry such as range and incidence angle and other factors, thus making the results less accurate. Therefore, in this paper, we present a method to detect certain damage areas using the corrected intensity data. Firstly, two data-driven models have been developed to correct the range and incidence angle effect. Then the corrected intensity is used to generate 2D intensity images for classification. After the damage areas being detected, they are re-projected to the 3D point cloud for better visual representation and further investigation. The experiment results indicate the feasibility and validity of the corrected intensity for damage detection.

  19. Submesoscale features and their interaction with fronts and internal tides in a high-resolution coupled atmosphere-ocean-wave model of the Bay of Bengal

    Science.gov (United States)

    Jensen, Tommy G.; Shulman, Igor; Wijesekera, Hemantha W.; Anderson, Stephanie; Ladner, Sherwin

    2018-03-01

    Large freshwater fluxes into the Bay of Bengal by rainfall and river discharges result in strong salinity fronts in the bay. In this study, a high-resolution coupled atmosphere-ocean-wave model with comprehensive physics is used to model the weather, ocean circulation, and wave field in the Bay of Bengal. Our objective is to explore the submesoscale activity that occurs in a realistic coupled model that resolves mesoscales and allows part of the submesoscale field. Horizontal resolution in the atmosphere varies from 2 to 6 km and is 13 km for surface waves, while the ocean model is submesoscale permitting with resolutions as high as 1.5 km and a vertical resolution of 0.5 m in the upper 10 m. In this paper, three different cases of oceanic submesoscale features are discussed. In the first case, heavy rainfall and intense downdrafts produced by atmospheric convection are found to force submesoscale currents, temperature, and salinity anomalies in the oceanic mixed layer and impact the mesoscale flow. In a second case, strong solitary-like waves are generated by semidiurnal tides in the Andaman Sea and interact with mesoscale flows and fronts and affect submesoscale features generated along fronts. A third source of submesoscale variability is found further north in the Bay of Bengal where river outflows help maintain strong salinity gradients throughout the year. For that case, a comparison with satellite observations of sea surface height anomalies, sea surface temperature, and chlorophyll shows that the model captures the observed mesoscale eddy features of the flow field, but in addition, submesoscale upwelling and downwelling patterns associated with ageostrophic secondary circulations along density fronts are also captured by the model.

  20. Vibration Feature Extraction and Analysis for Fault Diagnosis of Rotating Machinery-A Literature Survey

    OpenAIRE

    Saleem Riaz; Hassan Elahi; Kashif Javaid; Tufail Shahzad

    2017-01-01

    Safety, reliability, efficiency and performance of rotating machinery in all industrial applications are the main concerns. Rotating machines are widely used in various industrial applications. Condition monitoring and fault diagnosis of rotating machinery faults are very important and often complex and labor-intensive. Feature extraction techniques play a vital role for a reliable, effective and efficient feature extraction for the diagnosis of rotating machinery. Therefore, deve...

  1. [Effects of intensive management on soil C and N pools and soil enzyme activities in Moso bamboo plantations.

    Science.gov (United States)

    Yang, Meng; Li, Yong Fu; Li, Yong Chun; Xiao, Yong Heng; Yue, Tian; Jiang, Pei Kun; Zhou, Guo Mo; Liu, Juan

    2016-11-18

    In order to elucidate the effects of intensive management on soil carbon pool, nitrogen pool, enzyme activities in Moso bamboo (Phyllostachys pubescens) plantations, we collected soil samples from the soil surface (0-20 cm) and subsurface (20-40 cm) layers in the adjacent Moso bamboo plantations with extensive and intensive managements in Sankou Township, Lin'an City, Zhejiang Province. We determined different forms of C, N and soil invertase, urease, catalase and acid phosphatase activities. The results showed that long-term intensive management of Moso bamboo plantations significantly decreased the content and storage of soil organic carbon (SOC), with the SOC storage in the soil surface and subsurface layers decreased by 13.2% and 18.0%, respectively. After 15 years' intensive management of Masoo bamboo plantations, the contents of soil water soluble carbon (WSOC), hot water soluble carbon (HWSOC), microbial carbon (MBC) and readily oxidizable carbon (ROC) were significantly decreased in the soil surface and subsurface layers. The soil N storage in the soil surface and subsurface layers in intensively managed Moso bamboo plantations increased by 50.8% and 36.6%, respectively. Intensive management significantly increased the contents of nitrate-N (NO 3 - -N) and ammonium-N (NH 4 + -N), but decreased the contents of water-soluble nitrogen (WSON) and microbial biomass nitrogen (MBN). After 15 years' intensive management of Masoo bamboo plantations, the soil invertase, urease, catalase and acid phosphatase activities in the soil surface layer were significantly decreased, the soil acid phosphatase activity in the soil subsurface layer were significantly decreased, and other enzyme activities in the soil subsurface layer did not change. In conclusion, long-term intensive management led to a significant decline of soil organic carbon storage, soil labile carbon and microbial activity in Moso bamboo plantations. Therefore, we should consider the use of organic

  2. Classification of Broken Rice Kernels using 12D Features

    Directory of Open Access Journals (Sweden)

    SUNDER ALI KHOWAJA

    2016-07-01

    Full Text Available Integrating the technological aspect for assessment of rice quality is very much needed for the Asian markets where rice is one of the major exports. Methods based on image analysis has been proposed for automated quality assessment by taking into account some of the textural features. These features are good at classifying when rice grains are scanned in controlled environment but it is not suitable for practical implementation. Rice grains are placed randomly on the scanner which neither maintains the uniformity in intensity regions nor the placement strategy is kept ideal thus resulting in false classification of grains. The aim of this research is to propose a method for extracting set of features which can overcome the said issues. This paper uses morphological features along-with gray level and Hough transform based features to overcome the false classification in the existing methods. RBF (Radial Basis function is used as a classification mechanism to classify between complete grains and broken grains. Furthermore the broken grains are classified into two classes? i.e. acceptable grains and non-acceptable grains. This research also uses image enhancement technique prior to the feature extraction and classification process based on top-hat transformation. The proposed method has been simulated in MATLAB to visually analyze and validate the results.

  3. Improved ion acceleration via laser surface plasma waves excitation

    Energy Technology Data Exchange (ETDEWEB)

    Bigongiari, A. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); TIPS/LULI, Université Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilée, 94200 Ivry-sur-Seine (France); Raynaud, M. [CEA/DSM/LSI, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Riconda, C. [TIPS/LULI, Université Paris 6, CNRS, CEA, Ecole Polytechnique, 3, rue Galilée, 94200 Ivry-sur-Seine (France); Héron, A. [CPHT, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2013-05-15

    The possibility of enhancing the emission of the ions accelerated in the interaction of a high intensity ultra-short (<100 fs) laser pulse with a thin target (<10λ{sub 0}), via surface plasma wave excitation is investigated. Two-dimensional particle-in-cell simulations are performed for laser intensities ranging from 10{sup 19} to 10{sup 20} Wcm{sup −2}μm{sup 2}. The surface wave is resonantly excited by the laser via the coupling with a modulation at the target surface. In the cases where the surface wave is excited, we find an enhancement of the maximum ion energy of a factor ∼2 compared to the cases where the target surface is flat.

  4. Container Surface Evaluation by Function Estimation

    Energy Technology Data Exchange (ETDEWEB)

    Wendelberger, James G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-08-03

    Container images are analyzed for specific surface features, such as, pits, cracks, and corrosion. The detection of these features is confounded with complicating features. These complication features include: shape/curvature, welds, edges, scratches, foreign objects among others. A method is provided to discriminate between the various features. The method consists of estimating the image background, determining a residual image and post processing to determine the features present. The methodology is not finalized but demonstrates the feasibility of a method to determine the kind and size of the features present.

  5. Cigarette Design Features: Effects on Emission Levels, User Perception, and Behavior.

    Science.gov (United States)

    Talhout, Reinskje; Richter, Patricia A; Stepanov, Irina; Watson, Christina V; Watson, Clifford H

    2018-01-01

    This paper describes the effects of non-tobacco, physical cigarette design features on smoke emissions, product appeal, and smoking behaviors - 3 factors that determine smoker's exposure and related health risks. We reviewed available evidence for the impact of filter ventilation, new filter types, and cigarettes dimensions on toxic emissions, smoker's perceptions, and behavior. For evidence sources we used scientific literature and websites providing product characteristics and marketing information. Whereas filter ventilation results in lower machine-generated emissions, it also leads to perceptions of lighter taste and relative safety in smokers who can unwittingly employ more intense smoking behavior to obtain the desired amount of nicotine and sensory appeal. Filter additives that modify smoke emissions can also modify sensory cues, resulting in changes in smoking behavior. Flavor capsules increase the cigarette's appeal and novelty, and lead to misperceptions of reduced harm. Slim cigarettes have lower yields of some smoke emissions, but smoking behavior can be more intense than with standard cigarettes. Physical design features significantly impact machine-measured emission yields in cigarette smoke, product appeal, smoking behaviors, and exposures in smokers. The influence of current and emerging design features is important in understanding the effectiveness of regulatory actions to reduce smoking-related harm.

  6. Modification of Surface Energy via Direct Laser Ablative Surface Patterning

    Science.gov (United States)

    Wohl, Christopher J., Jr. (Inventor); Belcher, Marcus A. (Inventor); Connell, John W. (Inventor); Hopkins, John W. (Inventor)

    2015-01-01

    Surface energy of a substrate is changed without the need for any template, mask, or additional coating medium applied to the substrate. At least one beam of energy directly ablates a substrate surface to form a predefined topographical pattern at the surface. Each beam of energy has a width of approximately 25 micrometers and an energy of approximately 1-500 microJoules. Features in the topographical pattern have a width of approximately 1-500 micrometers and a height of approximately 1.4-100 micrometers.

  7. Beyond Cassie equation: Local structure of heterogeneous surfaces determines the contact angles of microdroplets

    Science.gov (United States)

    Zhang, Bo; Wang, Jianjun; Liu, Zhiping; Zhang, Xianren

    2014-01-01

    The application of Cassie equation to microscopic droplets is recently under intense debate because the microdroplet dimension is often of the same order of magnitude as the characteristic size of substrate heterogeneities, and the mechanism to describe the contact angle of microdroplets is not clear. By representing real surfaces statistically as an ensemble of patterned surfaces with randomly or regularly distributed heterogeneities (patches), lattice Boltzmann simulations here show that the contact angle of microdroplets has a wide distribution, either continuous or discrete, depending on the patch size. The origin of multiple contact angles observed is ascribed to the contact line pinning effect induced by substrate heterogeneities. We demonstrate that the local feature of substrate structure near the contact line determines the range of contact angles that can be stabilized, while the certain contact angle observed is closely related to the contact line width. PMID:25059292

  8. Replication fidelity assessment of large area sub-μm structured polymer surfaces using scatterometry

    International Nuclear Information System (INIS)

    Calaon, M; Hansen, H N; Tosello, G; Madsen, M H; Weirich, J; Hansen, P E; Garnaes, J; Tang, P T

    2015-01-01

    The present study addresses one of the key challenges in the product quality control of transparent structured polymer substrates, the replication fidelity of sub-μm structures over a large area. Additionally the work contributes to the development of new techniques focused on in-line characterization of large nanostructured surfaces using scatterometry. In particular an approach to quantify the replication fidelity of high volume manufacturing processes such as polymer injection moulding is presented. Both periodic channels and semi-spherical structures were fabricated on nickel shims used for later injection moulding of Cyclic-olefin-copolymer (COC) substrate were the sub-μm features where ultimately transferred. The scatterometry system was validated using calibrated atomic force microscopy measurements and a model based on scalar diffraction theory employed to calculate the expected angular distribution of the reflected and the transmitted intensity for the nickel surfaces and structured COC and, respectively. (paper)

  9. Statistical Identification of Composed Visual Features Indicating High Likelihood of Grasp Success

    DEFF Research Database (Denmark)

    Thomsen, Mikkel Tang; Bodenhagen, Leon; Krüger, Norbert

    2013-01-01

    configurations of three 3D surface features that predict grasping actions with a high success probability. The strategy is based on first computing spatial relations between visual entities and secondly, exploring the cross-space of these relational feature space and grasping actions. The data foundation...... for identifying such indicative feature constellations is generated in a simulated environment wherein visual features are extracted and a large amount of grasping actions are evaluated through dynamic simulation. Based on the identified feature constellations, we validate by applying the acquired knowledge...

  10. Surface Behavior of Rhodamin and Tartrazine on Silica-Cellulose Sol-Gel Surfaces by Thin Layer Elution

    Directory of Open Access Journals (Sweden)

    Surjani Wonorahardjo

    2016-05-01

    Full Text Available Physical and chemical interactions are the principles for different types of separation systems as the equillibrium dynamics on surface plays a key-role. Surface modification is a way for selective separation at interfaces. Moreover, synthesis of gel silica by a sol-gel method is preferred due to the homogeneity and surface feature easily controlled. Cellulose can be added in situ to modified the silica features during the process. Further application for to study interaction of rhodamin and tartrazine in its surface and their solubilities in mobile phase explains the possibility for their separation. This paper devoted to evaluate the surface behavior in term of adsorption and desorption of tartrazine and rhodamin on silica-cellulose thin layer in different mobile phase. Some carrier liquids applied such as methanol, acetone, n-hexane and chloroform. The result proves tartrazine and rhodamin is separated and have different behavior in different mobile phase. The retardation factors (Rf of the mixtures suggest complexity behavior on silica-cellulose surface.

  11. Surface origin and control of resonance Raman scattering and surface band gap in indium nitride

    International Nuclear Information System (INIS)

    Alarcón-Lladó, Esther; Brazzini, Tommaso; Ager, Joel W

    2016-01-01

    Resonance Raman scattering measurements were performed on indium nitride thin films under conditions where the surface electron concentration was controlled by an electrolyte gate. As the surface condition is tuned from electron depletion to accumulation, the spectral feature at the expected position of the ( E 1 , A 1 ) longitudinal optical (LO) near 590 cm −1 shifts to lower frequency. The shift is reversibly controlled with the applied gate potential, which clearly demonstrates the surface origin of this feature. The result is interpreted within the framework of a Martin double resonance, where the surface functions as a planar defect, allowing the scattering of long wavevector phonons. The allowed wavevector range, and hence the frequency, is modulated by the electron accumulation due to band gap narrowing. A surface band gap reduction of over 500 meV is estimated for the conditions of maximum electron accumulation. Under conditions of electron depletion, the full InN bandgap ( E g   =  0.65 eV) is expected at the surface. The drastic change in the surface band gap is expected to influence the transport properties of devices which utilize the surface electron accumulation layer. (paper)

  12. Surface origin and control of resonance Raman scattering and surface band gap in indium nitride

    Science.gov (United States)

    Alarcón-Lladó, Esther; Brazzini, Tommaso; Ager, Joel W.

    2016-06-01

    Resonance Raman scattering measurements were performed on indium nitride thin films under conditions where the surface electron concentration was controlled by an electrolyte gate. As the surface condition is tuned from electron depletion to accumulation, the spectral feature at the expected position of the (E 1, A 1) longitudinal optical (LO) near 590 cm-1 shifts to lower frequency. The shift is reversibly controlled with the applied gate potential, which clearly demonstrates the surface origin of this feature. The result is interpreted within the framework of a Martin double resonance, where the surface functions as a planar defect, allowing the scattering of long wavevector phonons. The allowed wavevector range, and hence the frequency, is modulated by the electron accumulation due to band gap narrowing. A surface band gap reduction of over 500 meV is estimated for the conditions of maximum electron accumulation. Under conditions of electron depletion, the full InN bandgap (E g  =  0.65 eV) is expected at the surface. The drastic change in the surface band gap is expected to influence the transport properties of devices which utilize the surface electron accumulation layer.

  13. Stress intensity factors of corner cracks in two nozzle-cylinder intersections

    International Nuclear Information System (INIS)

    Kobayashi, A.S.; Polvanich, N.; Emery, A.F.; Love, W.J.

    1977-01-01

    In a recent paper, the authors presented the stress-intensity-magnification factors of a quarter-elliptical surface crack in a quarter-infinite solid and a circular crack approaching a reentry corner in a three-quarter infinite solid. These stress-intensity-magnification factors were used together with a curvature-correction factor to estimate the stress-intensity factor of a corner crack at a nozzle-cylinder intersection. Through appropriate superposition of the above stress-intensity-magnification factors, stress-intensity factors for hypothetical corner cracks at a nozzle-cylinder intersection subjected to internal pressure and transient thermal-stress loadings can be obtained. A description of a computer code based on this procedure as well as its applications in analyzing two corner-crack problems at a nozzle-cylinder intersection are discussed in this paper

  14. Stress intensity factors of corner cracks in two nozzle-cylinder interactions

    International Nuclear Information System (INIS)

    Kobayashi, A.S.; Polvanich, N.; Emery, A.F.; Love, W.J.

    1977-01-01

    In a recent paper, the authors presented the stress-intensity-magnification factors of a quarter-elliptical surface crack in a quarter-infinite solid and a circular crack approaching a reentry corner in a three-quarter infinite solid. These stress-intensity-magnification factors were used together with a curvature-correction factor to estimate the stress-intensity factor of a corner crack at a nozzle-cylinder interaction. Through appropriate superposition of the above stress-intensity-magnification factors, stress-intensity factors for hypothetical corner cracks at a nozzle-cylinder intersection subjected to internal pressure and transient thermal-stress loadings can be obtained. A description of a computer code based on this procedure as well as its applications in analyzing two corner-crack probems at a nozzle-cylinder intersection are discussed in this paper. (Auth.)

  15. Turbulence, aeration and bubble features of air-water flows in macro- and intermediate roughness conditions

    Directory of Open Access Journals (Sweden)

    Stefano Pagliara

    2011-06-01

    Full Text Available Free surface flows in macro- and intermediate roughness conditions have a high aeration potential causing the flow characteristics to vary with slopes and discharges. The underlying mechanism of two-phase flow characteristics in macro- and intermediate roughness conditions were analyzed in an experimental setup assembled at the Laboratory of Hydraulic Protection of the Territory (PITLAB of the University of Pisa, Italy. Crushed angular rocks and hemispherical boulders were used to intensify the roughness of the bed. Flow rates per unit width ranging between 0.03 m2/s and 0.09 m2/s and slopes between 0.26 and 0.46 were tested over different arrangements of a rough bed. Analyses were mainly carried out in the inner flow region, which consists of both bubbly and intermediate flow regions. The findings revealed that the two-phase flow properties over the rough bed were much affected by rough bed arrangements. Turbulence features of two-phase flows over the rough bed were compared with those of the stepped chute data under similar flow conditions. Overall, the results highlight the flow features in the inner layers of the two-phase flow, showing that the maximum turbulence intensity decreases with the relative submergence, while the bubble frequency distribution is affected by the rough bed elements.

  16. Surface topography and morphology characterization of PIII irradiated silicon surface

    International Nuclear Information System (INIS)

    Sharma, Satinder K.; Barthwal, Sumit

    2008-01-01

    The effect of plasma immersion ion implantation (PIII) treatment on silicon surfaces was investigated by micro-Raman and atomic force microscopy (AFM) technique. The surface damage was given by the implantation of carbon, nitrogen, oxygen and argon ions using an inductively coupled plasma (ICP) source at low pressure. AFM studies show that surface topography of the PIII treated silicon wafers depend on the physical and chemical nature of the implanted species. Micro-Raman spectra indicate that the significant reduction of intensity of Raman peak after PIII treatment. Plasma immersion ion implantation is a non-line-of-sight ion implantation method, which allows 3D treatment of materials. Therefore, PIII based surface modification and plasma immersion ion deposition (PIID) coatings are applied in a wide range of situations.

  17. Feature Detector and Descriptor for Medical Images

    Science.gov (United States)

    Sargent, Dusty; Chen, Chao-I.; Tsai, Chang-Ming; Wang, Yuan-Fang; Koppel, Daniel

    2009-02-01

    The ability to detect and match features across multiple views of a scene is a crucial first step in many computer vision algorithms for dynamic scene analysis. State-of-the-art methods such as SIFT and SURF perform successfully when applied to typical images taken by a digital camera or camcorder. However, these methods often fail to generate an acceptable number of features when applied to medical images, because such images usually contain large homogeneous regions with little color and intensity variation. As a result, tasks like image registration and 3D structure recovery become difficult or impossible in the medical domain. This paper presents a scale, rotation and color/illumination invariant feature detector and descriptor for medical applications. The method incorporates elements of SIFT and SURF while optimizing their performance on medical data. Based on experiments with various types of medical images, we combined, adjusted, and built on methods and parameter settings employed in both algorithms. An approximate Hessian based detector is used to locate scale invariant keypoints and a dominant orientation is assigned to each keypoint using a gradient orientation histogram, providing rotation invariance. Finally, keypoints are described with an orientation-normalized distribution of gradient responses at the assigned scale, and the feature vector is normalized for contrast invariance. Experiments show that the algorithm detects and matches far more features than SIFT and SURF on medical images, with similar error levels.

  18. TEMPO: an ESA-funded project for uncovering significant features of the South Atlantic Anomaly

    Science.gov (United States)

    Pavón-Carrasco, F. Javier; De Santis, Angelo

    2016-04-01

    In this work we provide the last results of the ESA (European Space Agency) funded project TEMPO ("Is The Earth's Magnetic field POtentially reversing? New insights from Swarm mission"). The mail goal of this project is to analyse the time and spatial evolution of one of the most important features of the present geomagnetic field, i.e. the South Atlantic Anomaly (SAA). The region covered by this anomaly is characterized by values of geomagnetic field intensity around 30% lower than expected for those latitudes and extends over a large area in the South Atlantic Ocean, South America, South Africa and the Eastern Pacific Ocean. This large depression of the geomagnetic field strength has its origin in a prominent patch of reversed polarity flux in the Earth's outer core. The study of the SAA is an important challenge nowadays not only for the geomagnetic and paleomagnetic community, but also for other areas focused on the Earth Observation due to the protective role of this potential field against the charged particles forming the solar wind. A further increase of the SAA surface extent could have dramatic consequences for human health and technologies because a larger number of solar charged particles could reach the Earth's surface.

  19. Intensive archaeological survey of the F/H Surface Enhancement Project Area, Savannah River Site, Aiken and Barnwell Counties, South Carolina

    Energy Technology Data Exchange (ETDEWEB)

    Sassaman, K.E.; Gillam, J.C.

    1993-08-01

    Twelve archaeological sites and four artifact occurrences were located by intensive survey of two tracts of land for the F and H Surface Enhancement Project on the Savannah River Site, Aiken and Barnwell Counties, South Carolina. Fieldwork in the 480-acre project area included surface reconnaissance of 3.6 linear kilometers of transects, 140 shovel tests along 4.2 linear kilometers of transects, an additional 162 shovel tests at sites and occurrences, and the excavation of six l {times} 2 m test units. All but one of the sites contained artifacts of the prehistoric era; the twelfth site consists of the remains of a twentieth-century home place. The historic site and six of the prehistoric sites consist of limited and/or disturbed contexts of archaeological deposits that have little research potential and are therefore considered ineligible for nomination to the National Register of Historic Places (NRHP). The remaining five sites have sufficient content and integrity to yield information important to ongoing investigations into upland site use. These sites (38AK146, 38AK535, 38AK539, 38AK541, and 38AK543) are thus deemed eligible for nomination to the NRHP and the Savannah River Archaeological Research Program (SRARP) recommends that they be preserved through avoidance or data recovery.

  20. MUREX: a land-surface field experiment to study the annual cycle of the energy and water budgets

    Directory of Open Access Journals (Sweden)

    J.-C. Calvet

    1999-06-01

    Full Text Available The MUREX (monitoring the usable soil reservoir experimentally experiment was designed to provide continuous time series of field data over a long period, in order to improve and validate the Soil-vegetation-Atmosphere Transfer (SVAT parameterisations employed in meteorological models. Intensive measurements were performed for more than three years over fallow farmland in southwestern France. To capture the main processes controlling land-atmosphere exchanges, the local climate was fully characterised, and surface water and energy fluxes, vegetation biomass, soil moisture profiles, surface soil moisture and surface and soil temperature were monitored. Additional physiological measurements were carried out during selected periods to describe the biological control of the fluxes. The MUREX data of 1995, 1996, and 1997 are presented. Four SVAT models are applied to the annual cycle of 1995. In general, they succeed in simulating the main features of the fallow functioning, although some shortcomings are revealed.Key words. Hydrology (evapotranspiration; soil moisture; water-energy interactions.