WorldWideScience

Sample records for surface deformation measurements

  1. Seasonal slope surface deformation measured with TLS

    International Nuclear Information System (INIS)

    Fan, L; Smethurst, J; Powrie, W; Sellaiya, A

    2014-01-01

    In temperate European climates, soil water removal due to vegetation transpiration peaks in summer and soil rewetting from higher levels of precipitation occurs in winter. In clays of high plasticity, the seasonal cycles of drying and wetting cause the soil to experience a volumetric change, resulting in seasonal shrinking and swelling. For a clay slope exhibiting volume change, such behaviour can lead to excessive deformation and could contribute to strain-softening and progressive slope failure. This can in turn cause traffic disruption and loss of life if roads and railways are founded on or surrounded by such slopes. This paper discusses the driving forces of seasonal surface movement, in particular the role of vegetation, and presents the use of Terrestrial Laser Scanning (TLS) to measure the surface movement of a lightly vegetated London Clay slope near Newbury, UK. Two TLS scans were carried out in early and late summer respectively, representing relative wet and dry conditions of the slope. Continuous field measurements of soil water content in upper layers of the slope were obtained from TDR ThetaProbes already installed at the site. The water content data are used to support the results obtained from TLS by indicating the likely volumetric change in the soil due to loss of water

  2. Plastic Deformations of Measured Object Surface in Contact with Undeformable Surface of Measuring Tool

    Directory of Open Access Journals (Sweden)

    Kowalik Marek

    2016-10-01

    Full Text Available Measuring errors caused by deformation (flattening of a measured object appear under the influence of pressure force and weight of the measured object. Plastic strain, arising at the contact of a measured object and an undeformable contact tip of a measuring device, can be calculated by applying the Hertz plastic solution and the hypothesis of plastic strain. In a small area of contact between two bodies pressing against one another with force F, there appears the so-called contact stress. It can sometime reach very high values, exceeding the yield point, even when the contact pressure is relatively small. In the present work, the authors describe a theoretical solution to the problem of plastic strain between two bodies. The derived relationships enable to calculate force F during measurements of a deformable object by means of an instrument with an undeformable, spherical measuring tip. By applying the τmax hypothesis, a solution was obtained for the force F in an inexplicit form. The theoretical solution was verified with the digital simulation and experimental measurement. With the FEM method, the limit length gage was modeled in interaction with the measured shaft of a diameter d larger than the nominal one of Δl value.

  3. Plastic Deformations of Measured Object Surface in Contact with Undeformable Surface of Measuring Tool

    Science.gov (United States)

    Kowalik, Marek; Rucki, Mirosław; Paszta, Piotr; Gołębski, Rafał

    2016-10-01

    Measuring errors caused by deformation (flattening) of a measured object appear under the influence of pressure force and weight of the measured object. Plastic strain, arising at the contact of a measured object and an undeformable contact tip of a measuring device, can be calculated by applying the Hertz plastic solution and the hypothesis of plastic strain. In a small area of contact between two bodies pressing against one another with force F, there appears the so-called contact stress. It can sometime reach very high values, exceeding the yield point, even when the contact pressure is relatively small. In the present work, the authors describe a theoretical solution to the problem of plastic strain between two bodies. The derived relationships enable to calculate force F during measurements of a deformable object by means of an instrument with an undeformable, spherical measuring tip. By applying the τmax hypothesis, a solution was obtained for the force F in an inexplicit form. The theoretical solution was verified with the digital simulation and experimental measurement. With the FEM method, the limit length gage was modeled in interaction with the measured shaft of a diameter d larger than the nominal one of Δl value.

  4. An Experimental Comparison of Similarity Assessment Measures for 3D Models on Constrained Surface Deformation

    Science.gov (United States)

    Quan, Lulin; Yang, Zhixin

    2010-05-01

    To address the issues in the area of design customization, this paper expressed the specification and application of the constrained surface deformation, and reported the experimental performance comparison of three prevail effective similarity assessment algorithms on constrained surface deformation domain. Constrained surface deformation becomes a promising method that supports for various downstream applications of customized design. Similarity assessment is regarded as the key technology for inspecting the success of new design via measuring the difference level between the deformed new design and the initial sample model, and indicating whether the difference level is within the limitation. According to our theoretical analysis and pre-experiments, three similarity assessment algorithms are suitable for this domain, including shape histogram based method, skeleton based method, and U system moment based method. We analyze their basic functions and implementation methodologies in detail, and do a series of experiments on various situations to test their accuracy and efficiency using precision-recall diagram. Shoe model is chosen as an industrial example for the experiments. It shows that shape histogram based method gained an optimal performance in comparison. Based on the result, we proposed a novel approach that integrating surface constrains and shape histogram description with adaptive weighting method, which emphasize the role of constrains during the assessment. The limited initial experimental result demonstrated that our algorithm outperforms other three algorithms. A clear direction for future development is also drawn at the end of the paper.

  5. Study on dynamic deformation synchronized measurement technology of double-layer liquid surfaces

    Science.gov (United States)

    Tang, Huiying; Dong, Huimin; Liu, Zhanwei

    2017-11-01

    Accurate measurement of the dynamic deformation of double-layer liquid surfaces plays an important role in many fields, such as fluid mechanics, biomechanics, petrochemical industry and aerospace engineering. It is difficult to measure dynamic deformation of double-layer liquid surfaces synchronously for traditional methods. In this paper, a novel and effective method for full-field static and dynamic deformation measurement of double-layer liquid surfaces has been developed, that is wavefront distortion of double-wavelength transmission light with geometric phase analysis (GPA) method. Double wavelength lattice patterns used here are produced by two techniques, one is by double wavelength laser, and the other is by liquid crystal display (LCD). The techniques combine the characteristics such as high transparency, low reflectivity and fluidity of liquid. Two color lattice patterns produced by laser and LCD were adjusted at a certain angle through the tested double-layer liquid surfaces simultaneously. On the basis of the refractive indexes difference of two transmitted lights, the double-layer liquid surfaces were decoupled with GPA method. Combined with the derived relationship between phase variation of transmission-lattice patterns and out-of plane heights of two surfaces, as well as considering the height curves of the liquid level, the double-layer liquid surfaces can be reconstructed successfully. Compared with the traditional measurement method, the developed method not only has the common advantages of the optical measurement methods, such as high-precision, full-field and non-contact, but also simple, low cost and easy to set up.

  6. A Review of Surface Deformation and Strain Measurement Using Two-Dimensional Digital Image Correlation

    Directory of Open Access Journals (Sweden)

    Khoo Sze-Wei

    2016-09-01

    Full Text Available Among the full-field optical measurement methods, the Digital Image Correlation (DIC is one of the techniques which has been given particular attention. Technically, the DIC technique refers to a non-contact strain measurement method that mathematically compares the grey intensity changes of the images captured at two different states: before and after deformation. The measurement can be performed by numerically calculating the displacement of speckles which are deposited on the top of object’s surface. In this paper, the Two-Dimensional Digital Image Correlation (2D-DIC is presented and its fundamental concepts are discussed. Next, the development of the 2D-DIC algorithms in the past 33 years is reviewed systematically. The improvement of 2DDIC algorithms is presented with respect to two distinct aspects: their computation efficiency and measurement accuracy. Furthermore, analysis of the 2D-DIC accuracy is included, followed by a review of the DIC applications for two-dimensional measurements.

  7. Deformations of surface singularities

    CERN Document Server

    Szilárd, ágnes

    2013-01-01

    The present publication contains a special collection of research and review articles on deformations of surface singularities, that put together serve as an introductory survey of results and methods of the theory, as well as open problems, important examples and connections to other areas of mathematics. The aim is to collect material that will help mathematicians already working or wishing to work in this area to deepen their insight and eliminate the technical barriers in this learning process. This also is supported by review articles providing some global picture and an abundance of examples. Additionally, we introduce some material which emphasizes the newly found relationship with the theory of Stein fillings and symplectic geometry.  This links two main theories of mathematics: low dimensional topology and algebraic geometry. The theory of normal surface singularities is a distinguished part of analytic or algebraic geometry with several important results, its own technical machinery, and several op...

  8. Universal deformation of soft substrates near a contact line and the direct measurement of solid surface stresses.

    Science.gov (United States)

    Style, Robert W; Boltyanskiy, Rostislav; Che, Yonglu; Wettlaufer, J S; Wilen, Larry A; Dufresne, Eric R

    2013-02-08

    Droplets deform soft substrates near their contact lines. Using confocal microscopy, we measure the deformation of silicone gel substrates due to glycerol and fluorinated-oil droplets for a range of droplet radii and substrate thicknesses. For all droplets, the substrate deformation takes a universal shape close to the contact line that depends on liquid composition, but is independent of droplet size and substrate thickness. This shape is determined by a balance of interfacial tensions at the contact line and provides a novel method for direct determination of the surface stresses of soft substrates. Moreover, we measure the change in contact angle with droplet radius and show that Young's law fails for small droplets when their radii approach an elastocapillary length scale. For larger droplets the macroscopic contact angle is constant, consistent with Young's law.

  9. Enhanced interfacial deformation in a Marangoni flow: A measure of the dynamical surface tension

    Science.gov (United States)

    Leite Pinto, Rodrigo; Le Roux, Sébastien; Cantat, Isabelle; Saint-Jalmes, Arnaud

    2018-02-01

    We investigate the flows and deformations resulting from the deposition of a water soluble surfactant at a bare oil-water interface. Once the surfactant is deposited, we show that the oil-water interface is deformed with a water bump rising upward into the oil. For a given oil, the maximal deformation—located at the surfactant deposition point—decreases with the oil-layer thickness. We also observe a critical oil-layer thickness below which the deformation becomes as large as the oil layer, leading to the rupture of this layer and an oil-water dewetting. Experimentally, it is found that this critical thickness depends on the oil density and viscosity. We then provide an analytical modelization that explains quantitatively all these experimental features. In particular, our analysis allows us to derive an analytical relationship between the vertical profile of the oil-water interface and the in-plane surface tension profile. Therefore, we propose that the monitoring of the interface vertical shape can be used as a new spatially resolved tensiometry technique.

  10. Plastic Deformation of Metal Surfaces

    DEFF Research Database (Denmark)

    Hansen, Niels; Zhang, Xiaodan; Huang, Xiaoxu

    2013-01-01

    Plastic deformation of metal surfaces by sliding and abrasion between moving parts can be detrimental. However, when the plastic deformation is controlled for example by applying different peening techniques hard surfaces can be produced which can increase the fracture resistance and fatigue life...

  11. Longwall mining and surface deformation – lessons learned from dInSAR measurements

    CSIR Research Space (South Africa)

    Engelbrecht, Jeanine

    2016-08-01

    Full Text Available including 1) subsidence related to mining and groundwater abstraction, 2) deformation following earthquake events, 3) monitoring of landslides and slope stability, 4) monitoring the stability of infrastructure and large engineering works, and 5) monitoring...

  12. Covariance estimation for dInSAR surface deformation measurements in the presence of anisotropic atmospheric noise

    KAUST Repository

    Knospe, Steffen H G

    2010-04-01

    We study anisotropic spatial autocorrelation in differential synthetic aperture radar interferometric (dInSAR) measurements and its impact on geophysical parameter estimations. The dInSAR phase acquired by the satellite sensor is a superposition of different contributions, and when studying geophysical processes, we are usually only interested in the surface deformation part of the signal. Therefore, to obtain high-quality results, we would like to characterize and/or remove other phase components. A stochastic model has been found to be appropriate to describe atmospheric phase delay in dInSAR images. However, these phase delays are usually modeled as being isotropic, which is a simplification, because InSAR images often show directional atmospheric anomalies. Here, we analyze anisotropic structures and show validation results using both real and simulated data. We calculate experimental semivariograms of the dInSAR phase in several European Remote Sensing satellite-1/2 tandem interferograms. Based on the theory of random functions (RFs), we then fit anisotropic variogram models in the spatial domain, employing Matérn-and Bessel-family correlation functions in nested models to represent complex dInSAR covariance structures. The presented covariance function types, in the statistical framework of stationary RFs, are consistent with tropospheric delay models. We find that by using anisotropic data covariance information to weight dInSAR measurements, we can significantly improve both the precision and accuracy of geophysical parameter estimations. Furthermore, the improvement is dependent on how similar the deformation pattern is to the dominant structure of the anisotropic atmospheric signals. © 2009 IEEE.

  13. Surface deformation measured with interferometric synthetic aperture radar: Case studies of basin and range and Garlock-San Andreas fault

    Science.gov (United States)

    Greene, Fernando

    Interferometric Synthetic Aperture Radar (InSAR) and Global Positioning System (GPS) is widely used to detect ground deformation from varieties of geophysical origins. However, most studies lack the spatial and temporal resolutions to better characterize such observations. The purpose of this research is to use multi-track satellite radar imagery to generate time series to study and monitor vertical ground deformation over large regions such as the Nevada portion of the Basin and Range Province and the western end of the Mojave Desert. We developed an innovative method to remove horizontal movements from InSAR line-of-sight (LOS) observations using a GPS velocity field and subsequently combine the multi-track imagery resulting in one single high spatial resolution map of observed vertical crustal and surface movements. By implementing this technique we detect vertical deformation signals with short and intermediate wavelength signals associated to tectonic processes such as interseismic and postseismic deformation. In Central Nevada Seismic Belt we detect in three independent orbits a broad area of uplift that confirms results of previous studies that associate the origin of this signal to post-seimic deformation of the historic earthquakes at this region. In south-central Nevada we detect several valleys that show a gradual eastward tilt of the valley floors due to deep geodynamical processes. The valleys located at the eastern side of Ruby Mountains show a range decrease that could indicate uplift related to magma intrusion or post-seismic deformation due to older, unrecognized earthquakes. In the Big Bend segment in southern California we detect vertical uplift as expected by mechanical models of interseismic deformation. Additionaly all our velocity maps reveal small wavelength deformation signals of anthropogenic origin.

  14. Ocean tidal loading affecting precise geodetic observations on Greenland: Error account of surface deformations by tidal gravity measurements

    DEFF Research Database (Denmark)

    Jentzsch, G.; Knudsen, Per; Ramatschi, M.

    2000-01-01

    Air-borne and satellite based altimetry are used to monitor the Greenland ice-cap. Since these measurements are related to fiducial sites at the coast, the robustness of the height differences depends on the stability of these reference points. To benefit from the accuracy of these methods...... on the centimeter level, station corrections regarding the Earth tides and the ocean tidal loading have to be applied. Models for global corrections esp. for the body tides are available and sufficient, but local corrections regarding the effect of the adjacent shelf area still have to be inferred from additional...... observations. Near the coast ocean tidal loading causes additional vertical deformations in the order of 1 to 10 cm Therefore, tidal gravity measurements were carried out at four fiducial sites around Greenland in order to provide corrections for the kinematic part of the coordinates of these sites. Starting...

  15. Uncovering deformation processes from surface displacements

    Science.gov (United States)

    Stramondo, Salvatore

    2013-04-01

    The aim of this talk is to provide an overview about the most recent outcomes in Earth Sciences, describe the role of satellite remote sensing, together with GPS, ground measurement and further data, for geophysical parameter retrieval in well known case studies where the combined approach dealing with the use of two or more techniques/datasets have demonstrated their effectiveness. The Earth Sciences have today a wide availability of instruments and sensors able to provide scientists with an unprecedented capability to study the physical processes driving earthquakes, volcanic eruptions, landslides, and other dynamic Earth systems. Indeed measurements from satellites allow systematic observation of the Earth surface covering large areas, over a long time period and characterized by growing sample intervals. Interferometric Synthetic Aperture Radar (InSAR) technique has demonstrated its effectiveness to investigate processes responsible for crustal faulting stemming from the detection of surface deformation patterns. Indeed using satellite data along ascending and descending orbits, as well as different incident angles, it is possible in principle to retrieve the full 3D character of the ground motion. To such aim the use of GPS stations providing 3D displacement components is a reliable complementary instrument. Finally, offset tracking techniques and Multiple Aperture Interferometry (MAI) may provide a contribution to the analysis of horizontal and NS deformation vectors. The estimation of geophysical parameters using InSAR has been widely discussed in seismology and volcanology, and also applied to deformation associated with groundwater and other subsurface fluids. These applications often involve the solution of an inverse problem, which means the retrieval of optimal source parameters at depth for volcanoes and earthquakes, from the knowledge of surface deformation from InSAR. In recent years, InSAR measurements combined with traditional seismological and

  16. Optical 3D Deformation Measurement Utilizing Non-planar Surface for the Development of an “Intelligent Tire”

    Science.gov (United States)

    Matsuzaki, Ryosuke; Hiraoka, Naoki; Todoroki, Akira; Mizutani, Yoshihiro

    Intelligent tires, also known as smart tires, are equipped with sensors to monitor the strain of the interior surface and the rolling radius of tire, and are expected to improve the reliability of tires and tire control systems such as anti-lock braking systems (ABS). However, the high stiffness of an attached sensor like a strain gauge causes sensors to debond from the tire rubber. In the present study, a novel optical method is used for the concurrent monitoring of in-plane strain and out-of-plane displacement (rolling radius) utilizing the non-planar surface of the monitoring object. The optical method enables noncontact measurement of strain distribution. The in-plane strain and out-of-plane displacement are calculated by using image processing with an image of the interior surface of a tire that is taken with a single CCD camera fixed on the wheel rim. This new monitoring system is applied to an aluminum beam and a commercially available radial tire. As a result, the monitoring system provides concurrent measurement of in-plane strain, out-of-plane displacement and tire pressure, and is shown to be an effective monitoring system for intelligent tires.

  17. Satellite-based measurements of surface deformation reveal fluid flow associated with the geological storage of carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Vasco, D.W.; Rucci, A.; Ferretti, A.; Novali, F.; Bissell, R.; Ringrose, P.; Mathieson, A.; Wright, I.

    2009-10-15

    Interferometric Synthetic Aperture Radar (InSAR), gathered over the In Salah CO{sub 2} storage project in Algeria, provides an early indication that satellite-based geodetic methods can be effective in monitoring the geological storage of carbon dioxide. An injected volume of 3 million tons of carbon dioxide, from one of the first large-scale carbon sequestration efforts, produces a measurable surface displacement of approximately 5 mm/year. Using geophysical inverse techniques we are able to infer flow within the reservoir layer and within a seismically detected fracture/ fault zone intersecting the reservoir. We find that, if we use the best available elastic Earth model, the fluid flow need only occur in the vicinity of the reservoir layer. However, flow associated with the injection of the carbon dioxide does appear to extend several kilometers laterally within the reservoir, following the fracture/fault zone.

  18. Nanoscale deformation of a liquid surface.

    Science.gov (United States)

    Ledesma-Alonso, Rene; Legendre, Dominique; Tordjeman, Philippe

    2012-03-09

    We study the interaction between a solid particle and a liquid interface. A semianalytical solution of the nonlinear equation that describes the interface deformation points out the existence of a bifurcation behavior for the apex deformation as a function of the distance. We show that the apex curvature obeys a simple power-law dependency on the deformation. Relationships between physical parameters disclose the threshold distance at which the particle can approach the liquid before capillarity provokes a "jump to contact." A prediction of the interface original position before deformation takes place, as well as the attraction force measured by an approaching probe, are produced. The results of our analysis agree with the force curves obtained from atomic force microscopy experiments over a liquid puddle.

  19. Surface tension and deformation in soft adhesion

    Science.gov (United States)

    Jensen, Katharine

    Modern contact mechanics was originally developed to account for the competition between adhesion and elasticity for relatively stiff deformable materials like rubber, but much softer sticky materials are ubiquitous in biology, engineering, and everyday consumer products. In such soft materials, the solid surface tension can also play an important role in resisting shape change, and significantly modify the physics of contact with soft matter. We report indentation and pull-off experiments that bring small, rigid spheres into adhesive contact with compliant silicone gel substrates, varying both the surface functionalization of the spheres and the bulk elastic properties of the gels. We map the resulting deformation profiles using optical microscopy and image analysis. We examine the substrate geometry in light of capillary and elastic theories in order to explore the interplay of surface tension and bulk elasticity in governing soft adhesion.

  20. Ocean tidal loading affecting precise geodetic observations on Greenland: Error account of surface deformations by tidal gravity measurements

    DEFF Research Database (Denmark)

    Jentzsch, G.; Knudsen, Per; Ramatschi, M.

    2000-01-01

    Air-borne and satellite based altimetry are used to monitor the Greenland ice-cap. Since these measurements are related to fiducial sites at the coast, the robustness of the height differences depends on the stability of these reference points. To benefit from the accuracy of these methods on the...

  1. On infinitesimal conformai deformations of surfaces

    Directory of Open Access Journals (Sweden)

    Юлия Степановна Федченко

    2014-11-01

    Full Text Available A new form of basic equations for conformai deformations is found. The equations involve tensor fields of displacement vector only. Conditions for trivial deformations as well as infinitesimal conformai deformations are studied.

  2. Surface deformation of the secondary former mining areas

    Directory of Open Access Journals (Sweden)

    Tadeusz Głowacki

    2013-09-01

    Full Text Available The paper discuss the problem of secondary deformation observed on the surface of the land in the area of the old, non-existent copper and coal mines. The authors discuss the formation of the deformation in the final period of the mine, and after his arrest, after the close of any work of protecting the surface area of influence of mining activities. Discusses the reduction of the surface of the example of two disused mines: mining copper “Konrad” in Iwiny and “Thorez” in Walbrzych, an old coal mine. In the first part of the paper discusses a brief history of the creation of old copper basin and the Lower Silesian coal basin. It then discusses the formation of deformation processes in mining areas. Conducting continuous surveying allows you to monitor changes in the formation of land, in the paper indicate the source of the vertical displacements after ending of operation, the closure of the mine and stopped all work safety. In the area of Lower Silesia there are many remnants of disused mines, surface geodetic measurements show a constant activity in post-mining areas and the need to control the formation of the surface.

  3. Measurement of Microscopic Deformations Using Double-Exposure Holographic Interferometry and the Fourier Transform Method

    Directory of Open Access Journals (Sweden)

    Percival Almoro

    1998-12-01

    Full Text Available Microscopic deformations on the surface of a circular diaphragm were measured using double exposure holographic interferometry and Fourier transform method (FTM. The three-dimensional surface deformations were successfully visualized by applying FTM to holographic interferogram analysis. The minimum surface displacement measured was 0.317 µm. This was calibrated via the Michelson interferometry technique.

  4. Surface deformation of Taipei basin detected by Differential SAR Interferometry

    Science.gov (United States)

    Chen, Y.; Chang, C.; Yen, J.; Lin, M.

    2006-12-01

    Taiwan island is located between the southeastern periphery of the Eurasian plate and the Philippine Sea plate. The two converging plates produced very active tectonics, and can be seen by the high seismicity and deformation rate. Taipei, the highest populated area, center of politics, and economics in Taiwan, is in Taipei basin at the northern part of the island. There are several faults in and surrounding the basin, and the city is threatened with a high geological hazard potential that we should keep monitoring the crustal deformation to prevent and mitigate the disaster effect. The aims of our study is to apply the DInSAR technique to determine the surface deformation of Taipei basin area, and discussing the relation between the manifestation of deformation and the tectonically active region, Shanjiao fault. In the past few years, Differential SAR Interferometry (DInSAR) has been proved to be a powerful technique for monitoring the neotectonic activities and natural hazards. High spatial sampling rate of DInSAR technique allows studies of surface deformations with centimeter accuracy. In this area, we used ERS-1/2 SAR images acquired from 1993 to 2005 to generate 10 differential interferograms and processed the data using DIAPASON developed by CNES and SRTM global DEM.From our results, the deformation rate in Taipei is generally high in the western end of the basin along the Shanjiao fault and decrease eastward, while the subsidence center often appeared in the center of the Taipei basin. The neotectonic activity of the Shanjiao fault appeared to be insignificant by itself but it seemed to separate the subsiding basin from the surrounding areas. Further comparison between our DInSAR results and isopach of the Taipei basin revealed that the subsidence centers appeared in the interferograms did not coincide with the location where the sediments are thickest. Our results from differential interferometry will be compared to other geodetic measurements such as the

  5. Surface Slope Metrology on Deformable Soft X-ray Mirrors

    International Nuclear Information System (INIS)

    Yuan, Sheng; Yashchuk, Valeriy V.; Goldberg, Kenneth A.; Celestre, Rich; Church, Matthew; McKinney, Wayne R.; Morrison, Greg; Warwick, Tony

    2010-01-01

    We report on the current state of surface slope metrology on deformable mirrors for soft x-rays at the Advanced Light Source (ALS). While we are developing techniques for in situ at-wavelength tuning, we are refining methods of ex situ visible-light optical metrology to achieve sub-100-nrad accuracy. This paper reports on laboratory studies, measurements and tuning of a deformable test-KB mirror prior to its use. The test mirror was bent to a much different optical configuration than its original design, achieving a 0.38 micro-radian residual slope error. Modeling shows that in some cases, by including the image conjugate distance as an additional free parameter in the alignment, along with the two force couples, fourth-order tangential shape errors (the so-called bird shape) can be reduced or eliminated.

  6. Surface Slope Metrology on Deformable Soft X-ray Mirrors

    International Nuclear Information System (INIS)

    Yuan, S.; Yashchuk, V.V.; Goldberg, K.A.; Celestre, R.; Church, M.; McKinney, W.R.; Morrison, G.; Warwick, T.

    2009-01-01

    We report on the current state of surface slope metrology on deformable mirrors for soft x-rays at the Advanced Light Source (ALS). While we are developing techniques for in situ at-wavelength tuning, we are refining methods of ex situvisible-light optical metrology to achieve sub-100-nrad accuracy. This paper reports on laboratory studies, measurements and tuning of a deformable test-KB mirror prior to its use. The test mirror was bent to a much different optical configuration than its original design, achieving a 0.38 micro-radian residual slope error. Modeling shows that in some cases, by including the image conjugate distance as an additional free parameter in the alignment, along with the two force couples, fourth-order tangential shape errors (the so-called bird shape) can be reduced or eliminated.

  7. Bridge continuous deformation measurement technology based on fiber optic gyro

    Science.gov (United States)

    Gan, Weibing; Hu, Wenbin; Liu, Fang; Tang, Jianguang; Li, Sheng; Yang, Yan

    2016-03-01

    Bridge is an important part of modern transportation systems and deformation is a key index for bridge's safety evaluation. To achieve the long span bridge curve measurement rapidly and timely and accurately locate the bridge maximum deformation, the continuous deformation measurement system (CDMS) based on inertial platform is presented and validated in this paper. Firstly, based on various bridge deformation measurement methods, the method of deformation measurement based on the fiber optic gyro (FOG) is introduced. Secondly, the basic measurement principle based on FOG is presented and the continuous curve trajectory is derived by the formula. Then the measurement accuracy is analyzed in theory and the relevant factors are presented to ensure the measurement accuracy. Finally, the deformation measurement experiments are conducted on a bridge across the Yangtze River. Experimental results show that the presented deformation measurement method is feasible, practical, and reliable; the system can accurately and quickly locate the maximum deformation and has extensive and broad application prospects.

  8. Target Recognition Using Neural Networks for Model Deformation Measurements

    Science.gov (United States)

    Ross, Richard W.; Hibler, David L.

    1999-01-01

    Optical measurements provide a non-invasive method for measuring deformation of wind tunnel models. Model deformation systems use targets mounted or painted on the surface of the model to identify known positions, and photogrammetric methods are used to calculate 3-D positions of the targets on the model from digital 2-D images. Under ideal conditions, the reflective targets are placed against a dark background and provide high-contrast images, aiding in target recognition. However, glints of light reflecting from the model surface, or reduced contrast caused by light source or model smoothness constraints, can compromise accurate target determination using current algorithmic methods. This paper describes a technique using a neural network and image processing technologies which increases the reliability of target recognition systems. Unlike algorithmic methods, the neural network can be trained to identify the characteristic patterns that distinguish targets from other objects of similar size and appearance and can adapt to changes in lighting and environmental conditions.

  9. Surface deformation recovery algorithm for reflector antennas based on geometric optics.

    Science.gov (United States)

    Huang, Jianhui; Jin, Huiliang; Ye, Qian; Meng, Guoxiang

    2017-10-02

    Surface deformations of large reflector antennas highly depend on elevation angle. This paper adopted a scheme with the ability to conduct measurement at any elevation angle: carrying an emission source, an unmanned aerial vehicle (UAV) scans the antenna on a near-field plane, meanwhile the antenna stays stationary. Near-field amplitude is measured in the scheme. To recover the deformation from the measured amplitude, this paper proposed a novel algorithm by deriving the deformation-amplitude equation, which reveals the relation between the surface deformation and the near-field amplitude. By the algorithm, a precise deformation recovery can be reached at a low frequency (<1GHz) through single near-field amplitude. Simulation results showed the high accuracy and adaptability of the algorithm.

  10. Investigation of surface deformations by double exposure holographic interferometry

    International Nuclear Information System (INIS)

    Ecevit, F.N.; Guven, H.; Aydin, R.

    1990-01-01

    Surface deformations of rigid bodies produced by thermal as well as mechanical strains have been investigated using double-exposure holographic interferometry. The recorded interference fringes have been discussed qualitatively. (author). 9 refs, 4 figs

  11. Validation of a simple method for measuring cranial deformities (plagiocephalometry)

    NARCIS (Netherlands)

    van Adrichem, Léon N. A.; van Vlimmeren, Leo A.; Cadanová, Dominika; Helders, Paul J. M.; Engelbert, Raoul H. H.; van Neck, Han J. W.; Koning, Anton H. J.

    2008-01-01

    Craniofacial measuring is essential for diagnosis or evaluation of growth and therapies. Skull deformities in children are mainly caused by craniosynostosis or by external pressure in positional skull deformations. Traditional anthropometry does not sufficiently analyze craniofacial shape. In

  12. Postseismic surface deformations due to lithospheric and asthenospheric viscoelasticity

    Science.gov (United States)

    Cohen, S. C.

    1979-01-01

    This paper proposes a model for postseismic surface deformations by attributing them to lithospheric and asthenospheric viscoelasticity. The model predicts that the deformations due to lithospheric viscoelasticity depend on the decrease in the effective shear modulus acting long after the lithospheric relaxation compared to that acting immediately following the earthquake. While such deformations are generally smaller than those associated with asthenospheric viscoelasticity, they occur on a shorter time scale and may be in opposite direction to both the motion occurring at the time of the earthquake and that occurring as the asthenospheric relaxation occurs.

  13. 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

  14. Measurements and calculations of nuclear deformations

    International Nuclear Information System (INIS)

    Quentin, P.

    1975-01-01

    Main sources of experimental data pertaining to equilibrium deformation properties are shortly reviewed. Different approximations and methods relevant to their systematical calculations are discussed and compared. Finally, a rapid survey of some open problems is undertaken [fr

  15. GRINDING OF SURFACES WITH COATINGS FORMED BY ELECTROMAGNETIC FACING WITH SURFACE PLASTIC DEFORMATION

    Directory of Open Access Journals (Sweden)

    Zh. A. Mrochek

    2011-01-01

    Full Text Available The paper presents investigation results on machining of surfaces having a coating formed by electromagnetic facing with surface plastic deformation and using abrasive and diamond wheels having a porous metal binder with orientated drains.

  16. Tip-force induced surface deformation in the layered commensurate tellurides NbA xTe 2 (A = Si, Ge) during atomic force microscopy measurements

    Science.gov (United States)

    Bengel, H.; Cantow, H.-J.; Magonov, S. N.; Monconduit, L.; Evain, M.; Whangbo, M.-H.

    1994-12-01

    The Te-atom surfaces of commensurate layered tellurides NbA xTe 2 ( A = Si, x = {1}/{2}; A = Ge, x = {1}/{3}, {2}/{5}, {3}/{7}) were examined by atomic force microscopy (AFM) at different applied forces. Although the bulk crystal structures show a negligible height corrugation in the surface Te-atom sheets, the AFM images exhibit dark linear patterns that become strongly pronounced at high applied forces (several hundreds nN). This feature comes about because the tip-sample force interactions induce a surface corrugation according to the local hardness variation of the surface.

  17. Ground Surface Deformation around Tehran due to Groundwater Recharge: InSAR Monitoring.

    Science.gov (United States)

    Gourmelen, N.; Peyret, M.; Fritz, J. F.; Cherry, J.

    2003-04-01

    Tehran is located on an active tectonic and seismic zone. The surface deformation monitoring provides a powerful tool for getting a better understanding of faults kinematics and mechanisms. Used in conjunction with GPS networks, InSAR (Interferometric Synthetic Aperture Radar) provides dense and precise deformation measurements which are essential for mapping complex heterogeneous deformation fields. Moreover, urban and arid areas preserve interferometric phase coherence. The archived acquisitions of ERS that span 9 months between September 1998 and June 1999 reveal wide areas of surface uplift (by as much as 9 cm). This vertical deformation (gradual in time) has probably no tectonic meaning but is rather the ground response to ground water recharge. These zones are all located dowstream of large alluvial fans like the one of Karaj. The variation of effective stress caused by intersticial water draining could explain such surface deformation. It can also be noticed that some faults act as boundary for these deformation zones and fluid motion. The understanding of this deformation is relevant for groundwater monitoring and urban developement management. It is also necessary for discriminating it from tectonic deformation that also occurs on this zone. Due to the lack of attitude control of satellite ERS-2 since February 2001, the last images acquired could not be combined with the former acquisitions. Nevertheless, we expect to be able to enrich our set of images in order to map tectonic deformation on a longer period and to monitor in a more continuous way the deformation due to groundwater evolution. This would allow to quantify the permanent and reversible part of this signal.

  18. Surface deformation during an action potential in pearled cells

    Science.gov (United States)

    Mussel, Matan; Fillafer, Christian; Ben-Porath, Gal; Schneider, Matthias F.

    2017-11-01

    Electric pulses in biological cells (action potentials) have been reported to be accompanied by a propagating cell-surface deformation with a nanoscale amplitude. Typically, this cell surface is covered by external layers of polymer material (extracellular matrix, cell wall material, etc.). It was recently demonstrated in excitable plant cells (Chara braunii) that the rigid external layer (cell wall) hinders the underlying deformation. When the cell membrane was separated from the cell wall by osmosis, a mechanical deformation, in the micrometer range, was observed upon excitation of the cell. The underlying mechanism of this mechanical pulse has, to date, remained elusive. Herein we report that Chara cells can undergo a pearling instability, and when the pearled fragments were excited even larger and more regular cell shape changes were observed (˜10 -100 μ m in amplitude). These transient cellular deformations were captured by a curvature model that is based on three parameters: surface tension, bending rigidity, and pressure difference across the surface. In this paper these parameters are extracted by curve-fitting to the experimental cellular shapes at rest and during excitation. This is a necessary step to identify the mechanical parameters that change during an action potential.

  19. Measurement of copper vapour laser-induced deformation of ...

    Indian Academy of Sciences (India)

    2014-02-14

    Feb 14, 2014 ... Abstract. AMichelson interferometer-based technique has been used to measure the deformation of dielectric-coated mirror, caused by an incident repetitive pulsed laser beam with high average power. Minimum measurable deformation of 17 nm is reported.

  20. Berry's phase, chaos, and the deformations of Riemann surfaces

    Science.gov (United States)

    Lévay, Péter

    1997-11-01

    Parametrized families of Landau Hamiltonians on compact Riemann surfaces corresponding to classically chaotic families of geodesic motion are investigated. The parameters describe deformations of such surfaces with genus g>=1. It is shown that the adiabatic curvature (responsible for Berry's phase) of the lowest Landau level for g>1 is the sum of two terms. The first term is proportional to the natural symplectic form on deformation space, and the second is a fluctuating term reflecting the chaos of the geodesic motion for g>1. For g=1 (integrable motion on the torus) we have no fluctuating term. We propose our result to be interpreted as a curvature analog of the well-known semiclassical trace formulas. Connections with the viscosity properties of quantum Hall fluids on such surfaces are also pointed out. An interesting possibility in this respect is the fractional quantization of certain components of the viscosity tensor of such fluids.

  1. Correlations of Surface Deformation and 3D Flow Field in a Compliant Wall Turbulent Channel Flow.

    Science.gov (United States)

    Wang, Jin; Zhang, Cao; Katz, Joseph

    2015-11-01

    This study focuses on the correlations between surface deformation and flow features, including velocity, vorticity and pressure, in a turbulent channel flow over a flat, compliant Polydimethylsiloxane (PDMS) wall. The channel centerline velocity is 2.5 m/s, and the friction Reynolds number is 2.3x103. Analysis is based on simultaneous measurements of the time resolved 3D velocity and surface deformation using tomographic PIV and Mach-Zehnder Interferometry. The volumetric pressure distribution is calculated plane by plane by spatially integrating the material acceleration using virtual boundary, omni-directional method. Conditional sampling based on local high/low pressure and deformation events reveals the primary flow structures causing the deformation. High pressure peaks appear at the interface between sweep and ejection, whereas the negative deformations peaks (dent) appear upstream, under the sweeps. The persistent phase lag between flow and deformations are presumably caused by internal damping within the PDMS. Some of the low pressure peaks and strong ejections are located under the head of hairpin vortices, and accordingly, are associated with positive deformation (bump). Others bumps and dents are correlated with some spanwise offset large inclined quasi-streamwise vortices that are not necessarily associated with hairpins. Sponsored by ONR.

  2. Measurement of copper vapour laser-induced deformation of ...

    Indian Academy of Sciences (India)

    2014-02-14

    Feb 14, 2014 ... of dielectric-coated mirror, caused by an incident repetitive pulsed laser beam with high average power. Minimum measurable deformation of 17 nm is reported. Keywords. Michelson interferometer; interferogram; high reflectivity mirror; nanoscale deformation. PACS Nos 68.47.Mn; 42.79.–e. 1. Introduction.

  3. Surface cleanliness measurement procedure

    Science.gov (United States)

    Schroder, Mark Stewart; Woodmansee, Donald Ernest; Beadie, Douglas Frank

    2002-01-01

    A procedure and tools for quantifying surface cleanliness are described. Cleanliness of a target surface is quantified by wiping a prescribed area of the surface with a flexible, bright white cloth swatch, preferably mounted on a special tool. The cloth picks up a substantial amount of any particulate surface contamination. The amount of contamination is determined by measuring the reflectivity loss of the cloth before and after wiping on the contaminated system and comparing that loss to a previous calibration with similar contamination. In the alternative, a visual comparison of the contaminated cloth to a contamination key provides an indication of the surface cleanliness.

  4. a Research on Monitoring Surface Deformation and Relationships with Surface Parameters in Qinghai Tibetan Plateau Permafrost

    Science.gov (United States)

    Mi, S. J.; Li, Y. T.; Wang, F.; Li, L.; Ge, Y.; Luo, L.; Zhang, C. L.; Chen, J. B.

    2017-09-01

    The Qinghai Tibetan Plateau permafrost has been the largest permafrost region in middle-low latitude in the world for its high altitude. For the large area permafrost, especially surface deformation brought by it, have serious influence on the road engineering, road maintaining and regional economic development. Consequently, it is essential to monitor the surface deformation and study factors that influent it. We monitored an area named Wudaoliang from July 25, 2015 to June 1, 2016 and 15 Sentinel images were obtained during this time. The area we chose is about 35 kilometers long and 2 kilometers wide, and the national road 109 of China passes through the area. The traditional PS-INSAR (Persistent Scatterer Interferometric Synthetic Aperture Radar) method is not suitable because less historical images in the research area and leading to the number of PS (Persistent Scatterer) points is not enough to obtain accurate deformation results. Therefore, in this paper, we used another method which named QUASI-PSInSAR (QUASI Persistent Scatterer Interferometric Synthetic Aperture Radar) to acquire deformation for it has the advantage to weaken or eliminate the effects of spatial and temporal correlation, which has proved by other scholar. After processing 15 images in the SARproz software, we got the conclusions that, 1) the biggest deformation velocity in the whole area was about 127.9mm/year and about 109.3 mm/year in the road; 2) apparent deformation which have surface deformation more than 30mm/year was about 1.7Km in the road. Meanwhile, soil moisture(SM), Land surface temperature (LST) and surface water(SW), which are primary parameters of the land surface over the same time were reversed by using Sentinel data, Landsat data and ZY-3 data, respectively. After analyzing SM, LST , SW and deformation, we obtained that wet areas which had bigger SM, lower LST and more SW, had greater percentage of severe deformation than arid areas; besides, deformation pattern were

  5. Improvement of heterogeneous deformation measurement in digital image correlation

    Science.gov (United States)

    Shen, Huan; Liang, Zhonghan; Cheng, Baishun

    2017-07-01

    Heterogeneous deformation measurement using traditional digital image correlation (DIC) has times error of homogeneous deformation due to localized complexity. In case of small strain window, displacement field error will substantially corrupt the derived strain. On the contrary, large strain window will induce a reasonable information reduction in particular of heterogeneous deformation. In this paper, a novel parameter was put forward to correct displacement field and select strain subset size dynamically. This parameter was determined by localized displacement field that is called the localized displacement non-uniform intensity (λ). In addition, there is a simple and effective method to eliminate the rigid body rotation impact on strain measurement. A series of speckle images containing different heterogeneous deformation are simulated finally. Results show that the accuracy on the displacement and strain field can be substantially improved especially in heterogeneous deformation fields.

  6. Analysis of Shift and Deformation of Planar Surfaces Using the Least Squares Plane

    Directory of Open Access Journals (Sweden)

    Hrvoje Matijević

    2006-12-01

    Full Text Available Modern methods of measurement developed on the basis of advanced reflectorless distance measurement have paved the way for easier detection and analysis of shift and deformation. A large quantity of collected data points will often require a mathematical model of the surface that fits best into these. Although this can be a complex task, in the case of planar surfaces it is easily done, enabling further processing and analysis of measurement results. The paper describes the fitting of a plane to a set of collected points using the least squares distance, with previously excluded outliers via the RANSAC algorithm. Based on that, a method for analysis of the deformation and shift of planar surfaces is also described.

  7. Monitoring of surface deformation via InSAR imaging for petroleum engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Y.; Zhang, X. [National Key Lab of LIESMARS, (China)

    2004-07-01

    Interferometric synthetic aperture radar imaging (InSAR) is emerging as a method of monitoring minute deformations of the ground surface. Inversion of the surface deformation is also being developed to understand the casual effect underground. These techniques therefore have potential applications in petroleum engineering, in such fields as reservoir management, monitoring of subsurface waste re-injection, subsidence monitoring and overburden/casing integrity assessment. In-situ bitumen recovery from Canadian oil sands reservoirs, including cyclic steam stimulation or the SAGD process, is one area that could potentially utilize the new technology. InSAR yields an area view of the deformation in contrast to discrete point-based measurements provided by existing methods. Resolution down to the centimeter or sub-centimeter level is possible. This paper discusses these two new techniques along with typical examples.

  8. Measurement of shape and deformation of insect wing

    Science.gov (United States)

    Yin, Duo; Wei, Zhen; Wang, Zeyu; Zhou, Changqiu

    2018-01-01

    To measure the shape and deformation of an insect wing, a scanning setup adopting laser triangulation and image matching was developed. Only one industry camera with two light sources was employed to scan the transparent insect wings. 3D shape and point to point full field deformation of the wings could be obtained even when the wingspan is less than 3 mm. The venation and corrugation could be significantly identified from the results. The deformation of the wing under pin loading could be seen clearly from the results as well. Calibration shows that the shape and deformation measurement accuracies are no lower than 0.01 mm. Laser triangulation and image matching were combined dexterously to adapt wings' complex shape, size, and transparency. It is suitable for insect flight research or flapping wing micro-air vehicle development.

  9. Mapping three-dimensional surface deformation caused by the 2010 Haiti earthquake using advanced satellite radar interferometry.

    Directory of Open Access Journals (Sweden)

    Hyung-Sup Jung

    Full Text Available Mapping three-dimensional (3D surface deformation caused by an earthquake is very important for the environmental, cultural, economic and social sustainability of human beings. Synthetic aperture radar (SAR systems made it possible to measure precise 3D deformations by combining SAR interferometry (InSAR and multiple aperture interferometry (MAI. In this paper, we retrieve the 3D surface deformation field of the 2010 Haiti earthquake which occurred on January 12, 2010 by a magnitude 7.0 Mw by using the advanced interferometric technique that integrates InSAR and MAI data. The surface deformation has been observed by previous researchers using the InSAR and GPS method, but 3D deformation has not been measured yet due to low interferometric coherence. The combination of InSAR and MAI were applied to the ALOS PALSAR ascending and descending pairs, and were validated with the GPS in-situ measurements. The archived measurement accuracy was as little as 1.85, 5.49 and 3.08 cm in the east, north and up directions, respectively. This result indicates that the InSAR/MAI-derived 3D deformations are well matched with the GPS deformations. The 3D deformations are expected to allow us to improve estimation of the area affected by the 2010 Haiti earthquake.

  10. Mapping three-dimensional surface deformation caused by the 2010 Haiti earthquake using advanced satellite radar interferometry.

    Science.gov (United States)

    Jung, Hyung-Sup; Hong, Soo-Min

    2017-01-01

    Mapping three-dimensional (3D) surface deformation caused by an earthquake is very important for the environmental, cultural, economic and social sustainability of human beings. Synthetic aperture radar (SAR) systems made it possible to measure precise 3D deformations by combining SAR interferometry (InSAR) and multiple aperture interferometry (MAI). In this paper, we retrieve the 3D surface deformation field of the 2010 Haiti earthquake which occurred on January 12, 2010 by a magnitude 7.0 Mw by using the advanced interferometric technique that integrates InSAR and MAI data. The surface deformation has been observed by previous researchers using the InSAR and GPS method, but 3D deformation has not been measured yet due to low interferometric coherence. The combination of InSAR and MAI were applied to the ALOS PALSAR ascending and descending pairs, and were validated with the GPS in-situ measurements. The archived measurement accuracy was as little as 1.85, 5.49 and 3.08 cm in the east, north and up directions, respectively. This result indicates that the InSAR/MAI-derived 3D deformations are well matched with the GPS deformations. The 3D deformations are expected to allow us to improve estimation of the area affected by the 2010 Haiti earthquake.

  11. Measurement of Dam Deformations: Case Study of Obruk Dam (Turkey)

    Science.gov (United States)

    Gulal, V. Engin; Alkan, R. Metin; Alkan, M. Nurullah; İlci, Veli; Ozulu, I. Murat; Tombus, F. Engin; Kose, Zafer; Aladogan, Kayhan; Sahin, Murat; Yavasoglu, Hakan; Oku, Guldane

    2016-04-01

    In the literature, there is information regarding the first deformation and displacement measurements in dams that were conducted in 1920s Switzerland. Todays, deformation measurements in the dams have gained very different functions with improvements in both measurement equipment and evaluation of measurements. Deformation measurements and analysis are among the main topics studied by scientists who take interest in the engineering measurement sciences. The Working group of Deformation Measurements and Analysis, which was established under the International Federation of Surveyors (FIG), carries out its studies and activities with regard to this subject. At the end of the 1970s, the subject of the determination of fixed points in the deformation monitoring network was one of the main subjects extensively studied. Many theories arose from this inquiry, as different institutes came to differing conclusions. In 1978, a special commission with representatives of universities has been established within the FIG 6.1 working group; this commission worked on the issue of determining a general approach to geometric deformation analysis. The results gleaned from the commission were discussed at symposiums organized by the FIG. In accordance with these studies, scientists interested in the subject have begun to work on models that investigate cause and effect relations between the effects that cause deformation and deformation. As of the scientist who interest with the issue focused on different deformation methods, another special commission was established within the FIG engineering measurements commission in order to classify deformation models and study terminology. After studying this material for a long time, the official commission report was published in 2001. In this prepared report, studies have been carried out by considering the FIG Engineering Surveying Commission's report entitled, 'MODELS AND TERMINOLOGY FOR THE ANALYSIS OF GEODETIC MONITORING OBSERVATIONS

  12. SU-E-J-87: Lung Deformable Image Registration Using Surface Mesh Deformation for Dose Distribution Combination

    International Nuclear Information System (INIS)

    Labine, A; Carrier, J; Bedwani, S; Chav, R; DeGuise, J

    2014-01-01

    Purpose: To allow a reliable deformable image registration (DIR) method for dose calculation in radiation therapy. This work proposes a performance assessment of a morphological segmentation algorithm that generates a deformation field from lung surface displacements with 4DCT datasets. Methods: From the 4DCT scans of 15 selected patients, the deep exhale phase of the breathing cycle is identified as the reference scan. Varian TPS EclipseTM is used to draw lung contours, which are given as input to the morphological segmentation algorithm. Voxelized contours are smoothed by a Gaussian filter and then transformed into a surface mesh representation. Such mesh is adapted by rigid and elastic deformations to match each subsequent lung volumes. The segmentation efficiency is assessed by comparing the segmented lung contour and the TPS contour considering two volume metrics, defined as Volumetric Overlap Error (VOE) [%] and Relative Volume Difference (RVD) [%] and three surface metrics, defined as Average Symmetric Surface Distance (ASSD) [mm], Root Mean Square Symmetric Surface Distance (RMSSD) [mm] and Maximum Symmetric Surface Distance (MSSD) [mm]. Then, the surface deformation between two breathing phases is determined by the displacement of corresponding vertices in each deformed surface. The lung surface deformation is linearly propagated in the lung volume to generate 3D deformation fields for each breathing phase. Results: The metrics were averaged over the 15 patients and calculated with the same segmentation parameters. The volume metrics obtained are a VOE of 5.2% and a RVD of 2.6%. The surface metrics computed are an ASSD of 0.5 mm, a RMSSD of 0.8 mm and a MSSD of 6.9 mm. Conclusion: This study shows that the morphological segmentation algorithm can provide an automatic method to capture an organ motion from 4DCT scans and translate it into a volume deformation grid needed by DIR method for dose distribution combination

  13. 6. International FIG-symposium on deformation measurements. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Pelzer, H.; Heer, R. [eds.

    1996-12-31

    Due to the diversified fields of specialization of the authors, the papers span a very wide spectrum of theories, applications and case studies, concerning various problems of deformation studies in structural, geotechnical and mining engineering, in rock mechanics and earth crustal movements, covering such topics as: Design and analysis of deformations surveys; Integration of terrestrial, and space measurement techniques; New instrumental developements for automatic, continuous and telemetric data-acquisition with respect to geotechnical and geodetic applications; Monitoring and prediction of ground subsidence in mining areas, land slides and tectonic movements; Modeling and computation of deformations by Kalman-filtering techniques, finite element analysis and a special view to continuum mechanics; Application of expert systems and artificial intelligence; Description and analysis of dynamical deformation problems; special views in rock- and groundmechanics; Demonstration of mechanical engineering problems with respect to the supervision of industrial production and quality control. (orig.)

  14. Asperity Interaction and Substrate Deformation in Statistical Summation Models of Contact Between Rough Surfaces

    NARCIS (Netherlands)

    Vakis, Antonis I.

    A method is proposed to account for asperity interaction and bulk substrate deformation in models that utilize statistical summation of asperity forces to characterize contact between rough surfaces. Interaction deformations of noncontacting asperities are calculated based on the probability that

  15. Local deformation method for measuring element tension in space deployable structures

    Directory of Open Access Journals (Sweden)

    Belov Sergey

    2017-01-01

    Full Text Available The article describes the local deformation method to determine the tension of cord and thin membrane elements in space deployable structure as antenna reflector. Possible measuring instrument model, analytical and numerical solutions and experimental results are presented. The boundary effects on measurement results of metallic mesh reflector surface tension are estimated. The study case depicting non-uniform reflector surface tension is considered.

  16. Nanoscale deformation measurements for reliability assessment of material interfaces

    Science.gov (United States)

    Keller, Jürgen; Gollhardt, Astrid; Vogel, Dietmar; Michel, Bernd

    2006-03-01

    With the development and application of micro/nano electronic mechanical systems (MEMS, NEMS) for a variety of market segments new reliability issues will arise. The understanding of material interfaces is the key for a successful design for reliability of MEMS/NEMS and sensor systems. Furthermore in the field of BIOMEMS newly developed advanced materials and well known engineering materials are combined despite of fully developed reliability concepts for such devices and components. In addition the increasing interface-to volume ratio in highly integrated systems and nanoparticle filled materials are challenges for experimental reliability evaluation. New strategies for reliability assessment on the submicron scale are essential to fulfil the needs of future devices. In this paper a nanoscale resolution experimental method for the measurement of thermo-mechanical deformation at material interfaces is introduced. The determination of displacement fields is based on scanning probe microscopy (SPM) data. In-situ SPM scans of the analyzed object (i.e. material interface) are carried out at different thermo-mechanical load states. The obtained images are compared by grayscale cross correlation algorithms. This allows the tracking of local image patterns of the analyzed surface structure. The measurement results are full-field displacement fields with nanometer resolution. With the obtained data the mixed mode type of loading at material interfaces can be analyzed with highest resolution for future needs in micro system and nanotechnology.

  17. Modeling the mechanical deformation of nickel foils for nanoimprint lithography on double-curved surfaces

    DEFF Research Database (Denmark)

    Sonne, Mads Rostgaard; Cech, Jiri; Hattel, Jesper Henri

    2013-01-01

    on an aluminium substrate with three different radii; 500 μm, 1000 μm and 2000 μm, respectively. The nano imprint is performed using a 50 μm thick nickel foil, manufactured using electroforming. During the imprinting process, the nickel foil is stretched due to the curved surface of the aluminium substrate....... Experimentally, it is possible to address this stretch by counting the periods of the cross-gratings via SEM characterization. A model for the deformation of the nickel foil during nanoimprint is developed, utilizing non-linear material and geometrical behaviour. Good agreement between measured and numerically...... calculated stretch ratios on the surface of the deformed nickel foil is found, and it is shown, that from the model it is also possible to predict the geometrical extend of the nano-structured area on the curved surfaces....

  18. An application of the ground laser scanning to recognise terrain surface deformation over a shallowly located underground excavation

    Science.gov (United States)

    Pilecka, Elżbieta; Szwarkowski, Dariusz

    2017-11-01

    In the Upper Silesian Coal Basin area, there are post-mining sites of shallow exploitation of metal ores and hard coal deposits that reveal discontinuous deformations. Most often, these areas are heavily urbanised and the appearing deformations may be dangerous to the existing building infrastructure. The work, described in this article, presents the results of the research, which aimed to rate the usefulness of laser scanning to recognize discontinuous deformations on surface areas located over shallow mining excavations. Two laser scanning measurements were taken over the course of a few months. The surface area images were compared to identify changes in its deformation, especially those areas located above mining excavations. The tests carried out by the laser scanning method showed that some of the identified discontinuous deformations could have been connected to the shallowly located mining excavations.

  19. Two strategies of lowering surface deformations of internally cooled X-ray optics

    International Nuclear Information System (INIS)

    Oberta, P.; Áč, V.; Hrdý, J.

    2013-01-01

    Internally cooled X-ray optics, like X-ray monochromators and reflecting X-ray mirrors, play a crucial role in defining a beamlines resolution, degree of coherence and flux. A great effort is invested in the development of these optical components. An important aspect of the functionality of high heat load optics is its cooling and its influence on surface deformation. The authors present a study of two different geometrical cooling approaches. Its influence on beam inhomogeneity due to the strain from the manufacturing process is presented. X-ray topographic images and FWHM measurements are presented. FEA simulations of cooling efficiency and surface deformations were performed. The best achieved results are under an enlargement of 0.4μrad of the measured rocking curve

  20. Speckle photography applied to measure deformations of very large structures

    Science.gov (United States)

    Conley, Edgar; Morgan, Chris K.

    1995-04-01

    Fundamental principles of mechanics have recently been brought to bear on problems concerning very large structures. Fields of study include tectonic plate motion, nuclear waste repository vault closure mechanisms, the flow of glacier and sea ice, and highway bridge damage assessment and residual life prediction. Quantitative observations, appropriate for formulating and verifying models, are still scarce however, so the need to adapt new methods of experimental mechanics is clear. Large dynamic systems often exist in environments subject to rapid change. Therefore, a simple field technique that incorporates short time scales and short gage lengths is required. Further, the measuring methods must yield displacements reliably, and under oft-times adverse field conditions. Fortunately, the advantages conferred by an experimental mechanics technique known as speckle photography nicely fulfill this rather stringent set of performance requirements. Speckle seemed to lend itself nicely to the application since it is robust and relatively inexpensive. Experiment requirements are minimal -- a camera, high resolution film, illumination, and an optically rough surface. Perhaps most important is speckle's distinct advantage over point-by-point methods: It maps the two dimensional displacement vectors of the whole field of interest. And finally, given the method's high spatial resolution, relatively short observation times are necessary. In this paper we discuss speckle, two variations of which were used to gage the deformation of a reinforced concrete bridge structure subjected to bending loads. The measurement technique proved to be easily applied, and yielded the location of the neutral axis self consistently. The research demonstrates the feasibility of using whole field techniques to detect and quantify surface strains of large structures under load.

  1. Measurement of full-field deformation induced by a dc electrical field in organic insulator films

    Directory of Open Access Journals (Sweden)

    Boudou L.

    2010-06-01

    Full Text Available Digital image correlation method (DIC using the correlation coefficient curve-fitting for full-field surface deformation measurements of organic insulator films is investigated in this work. First the validation of the technique was undertaken. The computer-generated speckle images and the measurement of coefficient of thermal expansion (CTE of aluminium are used to evaluate the measurement accuracy of the technique. In a second part the technique is applied to measure the mechanical deformation induced by electrical field application to organic insulators. For that Poly(ethylene naphthalene 2,6-dicarboxylate (PEN thin films were subjected to DC voltage stress and DIC provides the full-field induced deformations of the test films. The obtained results show that the DIC is a practical and robust tool for better comprehension of mechanical behaviour of the organic insulator films under electrical stress.

  2. Intelligent Tires Based on Measurement of Tire Deformation

    Science.gov (United States)

    Matsuzaki, Ryosuke; Todoroki, Akira

    From a traffic safety point-of-view, there is an urgent need for intelligent tires as a warning system for road conditions, for optimized braking control on poor road surfaces and as a tire fault detection system. Intelligent tires, equipped with sensors for monitoring applied strain, are effective in improving reliability and control systems such as anti-lock braking systems (ABSs). In previous studies, we developed a direct tire deformation or strain measurement system with sufficiently low stiffness and high elongation for practical use, and a wireless communication system between tires and vehicle that operates without a battery. The present study investigates the application of strain data for an optimized braking control and road condition warning system. The relationships between strain sensor outputs and tire mechanical parameters, including braking torque, effective radius and contact patch length, are calculated using finite element analysis. Finally, we suggested the possibility of optimized braking control and road condition warning systems. Optimized braking control can be achieved by keeping the slip ratio constant. The road condition warning would be actuated if the recorded friction coefficient at a certain slip ratio is lower than a ‘safe’ reference value.

  3. Real-time deformation measurement using a transportable shearography system

    Science.gov (United States)

    Weijers, A. L.; van Brug, Hedser H.; Frankena, Hans J.

    1997-03-01

    A new system for deformation visualization has been developed, being a real time phase stepped shearing speckle interferometer. This system provides the possibility to measure quantitatively deformations of diffusely reflecting objects in an industrial environment. The main characteristics of this interferometer are its speed of operation and its reduced sensitivity to external disturbances. Apart from its semiconductor laser source, this system has a shoe-box size and is mounted on a tripod for easy handling during inspection. This paper describes the shearing speckle interferometry set-up, as it is developed at our laboratory and its potential for detecting defects.

  4. Time dependent deformation in prestressed concrete girder: Measurement and prediction

    Science.gov (United States)

    Sokal, Y. J.; Tyrer, P.

    1981-11-01

    Prestressed concrete girders which are intended for composite construction in bridges and other similar structures are often stored unloaded for some time before being placed in their final positions where top deck is being poured over. During that free storage the girders are subjected to creep and shrinkage which manifests itself through increased upward deformation usually defined as camber. The analytical estimation of this deformation is important as it controls the minimum thickness of the top deck. An attempt was made to correlate on site measurements with continuous computer modeling of the time-dependent behavior using data from recently adopted international standard for concrete structures.

  5. Experimental Investigation of Compliant Wall Surface Deformation in Turbulent Boundary Layer

    Science.gov (United States)

    Wang, Jin; Agarwal, Karuna; Katz, Joseph

    2017-11-01

    On-going research integrates Tomographic PIV (TPIV) with Mach-Zehnder Interferometry (MZI) to measure the correlations between deformation of a compliant wall and a turbulent channel flow or a boundary layer. Aiming to extend the scope to two-way coupling, in the present experiment the wall properties have been designed, based on a theoretical analysis, to increase the amplitude of deformation to several μm, achieving the same order of magnitude as the boundary layer wall unit (5-10 μm). It requires higher speeds and a softer surface that has a Young's modulus of 0.1MPa (vs. 1Mpa before), as well as proper thickness (5 mm) that maximize the wall response to excitation at scales that fall within the temporal and spatial resolution of the instruments. The experiments are performed in a water tunnel extension to the JHU refractive index matched facility. The transparent compliant surface is made of PDMS molded on the tunnel window, and measurements are performed at friction velocity Reynolds numbers in the 1000-7000 range. MZI measures the 2D surface deformation as several magnifications. The time-resolved 3D pressure distribution is determined by calculating to spatial distribution of material acceleration from the TPIV data and integrating it using a GPU-based, parallel-line, omni-directional integration method. ONR.

  6. Orientation and deformation of mineral crystals in tooth surfaces.

    Science.gov (United States)

    Fujisaki, Kazuhiro; Todoh, Masahiro; Niida, Atsushi; Shibuya, Ryota; Kitami, Shunsuke; Tadano, Shigeru

    2012-06-01

    Tooth enamel is the hardest material in the human body, and it is mainly composed of hydroxyapatite (HAp)-like mineral particles. As HAp has a hexagonal crystal structure, X-ray diffraction methods can be used to analyze the crystal structure of HAp in teeth. Here, the X-ray diffraction method was applied to the surface of tooth enamel to measure the orientation and strain of the HAp crystals. The c-axis of the hexagonal crystal structure of HAp was oriented to the surface perpendicular to the tooth enamel covering the tooth surface. Thus, the strain of HAp at the surface of teeth was measured by X-ray diffraction from the (004) lattice planes aligned along the c-axis. The X-ray strain measurements were conducted on tooth specimens with intact surfaces under loading. Highly accurate strain measurements of the surface of tooth specimens were performed by precise positioning of the X-ray irradiation area during loading. The strains of the (004) lattice plane were measured at several positions on the surface of the specimens under compression along the tooth axis. The strains were obtained as tensile strains at the labial side of incisor tooth specimens. In posterior teeth, the strains were different at different measurement positions, varying from tensile to compressive types. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Monitoring of Land-Surface Deformation in the Karamay Oilfield, Xinjiang, China, Using SAR Interferometry

    Directory of Open Access Journals (Sweden)

    Yusupujiang Aimaiti

    2017-07-01

    Full Text Available Synthetic Aperture Radar (SAR interferometry is a technique that provides high-resolution measurements of the ground displacement associated with various geophysical processes. To investigate the land-surface deformation in Karamay, a typical oil-producing city in the Xinjiang Uyghur Autonomous Region, China, Advanced Land Observing Satellite (ALOS Phased Array L-band Synthetic Aperture Radar (PALSAR data were acquired for the period from 2007 to 2009, and a two-pass differential SAR interferometry (D-InSAR process was applied. The experimental results showed that two sites in the north-eastern part of the city exhibit a clear indication of land deformation. For a further evaluation of the D-InSAR result, the Persistent Scatterer (PS and Small Baseline Subset (SBAS-InSAR techniques were applied for 21 time series Environmental Satellite (ENVISAT C-band Advanced Synthetic Aperture Radar (ASAR data from 2003 to 2010. The comparison between the D-InSAR and SBAS-InSAR measurements had better agreement than that from the PS-InSAR measurement. The maximum deformation rate attributed to subsurface water injection for the period from 2003 to 2010 was up to approximately 33 mm/year in the line of sight (LOS direction. The interferometric phase change from November 2007 to June 2010 showed a clear deformation pattern, and the rebound center has been expanding in scale and increasing in quantity.

  8. Large deformation and instability of soft hollow cylinder with surface effects

    OpenAIRE

    Wu, Jian; Liu, Mingchao; Wang, Zhenyu; Chen, C. Q.

    2017-01-01

    Surface stress, which is always neglected in classical elastic theories, has recently emerged as a key role in the mechanics of highly deformable soft solids. In this paper, the effect of surface stress on the deformation and instability of soft hollow cylinder are analyzed. By incorporating surface energy density function into the constitutive model of a hyper-elastic theory, explicit solutions are obtained for the deformation of soft hollow cylinder under the conditions of uniform pressure ...

  9. Measuring co-seismic deformation of the Sichuan earthquake by satellite differential INSAR

    Science.gov (United States)

    Zhang, Yonghong; Gong, Wenyu; Zhang, Jixian

    2008-12-01

    The Sichuan Earthquake, occurred on May 12, 2008, is the strongest earthquake to hit China since the 1976 Tangshan earthquake. The earthquake had a magnitude of M 8.0, and caused surface deformation greater than 3 meters. This paper presents the research work of measuring the co-seismic deformations of the earthquake with satellite differential interferometric SAR technique. Four L-band SAR images were used to form the interferogram with 2 pre- scenes imaged on Feb 17, 2008 and 2 post- scenes on May 19, 2008. The Digital Elevation Models extracted from 1:50,000-scale national geo-spatial database were used to remove the topographic contribution and form a differential interferogram. The interferogram presents very high coherence in most areas, although the pre- and post- images were acquired with time interval of 92 days. This indicates that the L-band PALSAR sensor is very powerful for interferometry applications. The baseline error is regarded as the main phase error source in the differential interferogram. Due to the difficulties of doing field works immediately after the earthquake, only one deformation measurement recorded by a permanent GPS station is obtained for this research. An approximation method is proposed to eliminate the orbital phase error with one control point. The derived deformation map shows similar spatial pattern and deformation magnitude compared with deformation field generated by seismic inversion method.

  10. Measurement of blockage in deformed LWR multi-rod arrays

    International Nuclear Information System (INIS)

    Hindle, E.D.; Jones, C.; Whitty, S.

    1983-01-01

    This paper critically reviews the current methods used for measuring blockage in multi-rod arrays and discusses their application. A new definition which overcomes the deficiencies of the previous methods is proposed. Also examples of the application of automatic computerised techniques to directly measure rod strain, blockage, sub-channel blockage and perimeter changes from photographs of sections through deformed arrays are presented. (author)

  11. Quartz Crystal Microbalance Model for Quantitatively Probing the Deformation of Adsorbed Particles at Low Surface Coverage.

    Science.gov (United States)

    Gillissen, Jurriaan J J; Jackman, Joshua A; Tabaei, Seyed R; Yoon, Bo Kyeong; Cho, Nam-Joon

    2017-11-07

    Characterizing the deformation of nanoscale, soft-matter particulates at solid-liquid interfaces is a demanding task, and there are limited experimental options to perform quantitative measurements in a nonperturbative manner. Previous attempts, based on the quartz crystal microbalance (QCM) technique, focused on the high surface coverage regime and modeled the adsorbed particles as a homogeneous film, while not considering the coupling between particles and surrounding fluid and hence resulting in an underestimation of the known particle height. In this work, we develop a model for the hydrodynamic coupling between adsorbed particles and surrounding fluid in the limit of a low surface coverage, which can be used to extract shape information from QCM measurement data. We tackle this problem by using hydrodynamic simulations of an ellipsoidal particle on an oscillating surface. From the simulation results, we derived a phenomenological relation between the aspect ratio r of the absorbed particles and the slope and intercept of the line that fits instantaneous, overtone-dependent QCM data on (δ/a, -Δf/n) coordinates where δ is the viscous penetration depth, a is the particle radius, Δf is the QCM frequency shift, and n is the overtone number. The model was applied to QCM measurement data pertaining to the adsorption of 34 nm radius, fluid-phase and gel-phase liposomes onto a titanium oxide-coated surface. The osmotic pressure across the liposomal bilayer was varied to induce shape deformation. By combining these results with a membrane bending model, we determined the membrane bending energy for the gel-phase liposomes, and the results are consistent with literature values. In summary, a phenomenological model is presented and validated in order to show for the first time that QCM experiments can quantitatively measure the deformation of adsorbed particles at low surface coverage.

  12. Application of image analysis method for measurement of fabric stretch deformation

    Science.gov (United States)

    Jariyapunya, N.; Baheti, S.

    2017-10-01

    For design of comfortable knitted fabric garments, it is necessary to know their distribution of elastic properties under the deformation. The standard tensile testing methods are not sufficient to explain distribution of these stretch properties. However, digital image analysis technique adjusted to the standard tensile test method can perform detailed study on distribution of local elastic deformation properties. The aim of this research was to develop a new method for the measurement of the local deformations between dots of stretch knitted fabrics during tensile testing. The image analysis approach was selected to calculate the gradient deformation tensor under the extension ranging from 10 %, 20%, 30% and 40 % in respective course, wale and bias directions. Moreover, this method was applied to know the deformation distribution on cylindrical surface as well by stretching the fabric under different extension. Subsequently the analysis of the deformation distribution by image processing system in MATLAB was carried out to determine the compression between cylindrical model and specimens. The results of image analysis were compared with ASTM D4964-96 standard and the actual obtained experimental results.

  13. Ceres' deformational surface features compared to other planetary bodies.

    Science.gov (United States)

    von der Gathen, Isabel; Jaumann, Ralf; Krohn, Katrin; Buczkowski, Debra L.; Elgner, Stephan; Kersten, Elke; Matz, Klaus-Dieter; Nass, Andrea; Otto, Katharina; Preusker, Frank; Roatsch, Thomas; Schröder, Stefanus E.; Schulzeck, Franziska; Stephan, Katrin; Wagner, Roland; De Sanctis, Maria C.; Schenk, Paul; Scully, Jennifer E. C.; Williams, Dave A.; Raymond, Carol A.

    2016-04-01

    On March 2015, NASA's Dawn spacecraft arrived at the dwarf planet Ceres and has been providing images of its surface. Based on High Altitude Mapping Orbiter (HAMO) clear filter images (140 m/px res.), a Survey mosaic (~400 m/px) and a series of Low Altitude Mapping Orbiter (LAMO) clear filter images (35 m/px) of the Dawn mission [1], deformational features are identified on the surface of Ceres. In order to further our knowledge about the nature and origin of these features, we start a comparative analysis of similar features on different planetary bodies, like Enceladus, Ganymede and the Moon, based on images provided by the Cassini, Galileo and Lunar Orbiter mission. This study focuses on the small scale fractures, mostly located on Ceres' crater floors, in comparison with crater fractures on the planetary bodies named above. The fractures were analyzed concerning the morphology and shape, the distribution, orientation and possible building mechanisms. On Ceres, two different groups of fractures are distinct. The first one includes fractures, normally arranged in subparallel pattern, which are usually located on crater floors, but also on crater rims. Their sense of direction is relatively uniform but in some cases they get deformed by shearing. The second group consists of joint systems, which spread out of one single location, sometimes arranged concentric to the crater rim. They were likely formed by cooling-melting processes linked to the impact process or up doming material. Fractures located on crater floors are also common on the icy satellite Enceladus [3]. While Enceladus' fractures don't seem to have a lot in common compared to those on Ceres, we assume that similar fracture patterns and therefore similar building mechanism can be found e.g. on Ganymede and especially on the Moon [2]. Further work will include the comparison of the fractures with additional planetary bodies and the trial to explain why fracturing e.g. on Enceladus differs from that on

  14. EM Bias-Correction for Ice Thickness and Surface Roughness Retrievals over Rough Deformed Sea Ice

    Science.gov (United States)

    Li, L.; Gaiser, P. W.; Allard, R.; Posey, P. G.; Hebert, D. A.; Richter-Menge, J.; Polashenski, C. M.

    2016-12-01

    The very rough ridge sea ice accounts for significant percentage of total ice areas and even larger percentage of total volume. The commonly used Radar altimeter surface detection techniques are empirical in nature and work well only over level/smooth sea ice. Rough sea ice surfaces can modify the return waveforms, resulting in significant Electromagnetic (EM) bias in the estimated surface elevations, and thus large errors in the ice thickness retrievals. To understand and quantify such sea ice surface roughness effects, a combined EM rough surface and volume scattering model was developed to simulate radar returns from the rough sea ice `layer cake' structure. A waveform matching technique was also developed to fit observed waveforms to a physically-based waveform model and subsequently correct the roughness induced EM bias in the estimated freeboard. This new EM Bias Corrected (EMBC) algorithm was able to better retrieve surface elevations and estimate the surface roughness parameter simultaneously. In situ data from multi-instrument airborne and ground campaigns were used to validate the ice thickness and surface roughness retrievals. For the surface roughness retrievals, we applied this EMBC algorithm to co-incident LiDAR/Radar measurements collected during a Cryosat-2 under-flight by the NASA IceBridge missions. Results show that not only does the waveform model fit very well to the measured radar waveform, but also the roughness parameters derived independently from the LiDAR and radar data agree very well for both level and deformed sea ice. For sea ice thickness retrievals, validation based on in-situ data from the coordinated CRREL/NRL field campaign demonstrates that the physically-based EMBC algorithm performs fundamentally better than the empirical algorithm over very rough deformed sea ice, suggesting that sea ice surface roughness effects can be modeled and corrected based solely on the radar return waveforms.

  15. Monitor the Surface Deformation in Metropolitan Taipei Basin by Using PS-InSAR Techniques

    Science.gov (United States)

    Chang, Yan-Ru; Tung, Hsin; Hu, Jyr-Ching

    2015-04-01

    Taipei is the most densely populated area and the center of politics and economics in Taiwan. However, the composite geohazards might occur in Taipei area, in which the active Shanchiao fault located in the western margin of Taipei basin and the active Tatun volcano group located 15 km to the north of the basin. Therefore, it is not only an important scientific topic but also a crucial social issue to better understand the assessment and mitigation of geological hazard in the metropolitan Taipei city. We use Persistent Scatterers interferometric synthetic aperture radar (PSInSAR) and small baseline methods to calculate the surface deformation rate with the constraints of continuous GPS and precise leveling measurements. The advantages of PSInSAR technique are wide, periodic, and stable in the temporal and spatial pattern of deformation. In this study C-band ERS-1/2 (1996/1-1999/9), ENVISAT (2003/1-2008/3) and L-band ALOS (2007/4-2011/6) SAR images are used to carry out the surface deformation in three periods. Based on the results of different periods of PS-InSAR, the slant range displacement (SRD) was variable via time which might be related to the deformation in different depth of loose deposits in Taipei basin. Previous study suggested that some factors influence the surface deformation change, including soil compaction, water-table change and tectonic movement. Consequently the assessment in activity of the Shanchiao fault, the induced deformation due to the fluctuation of the water table and the soil compaction should be removed. In general, the average SRD rate in the footwall and hanging wall of the Shanchiao Fault was about 12.2 mm/yr and 9.1 mm/yr, 1.5 mm/yr and 4.0 mm/yr, respectively with descending mode ERS-1/2 an ENVISAT radar images. For the ascending ALOS radar image, the average SRD rate in the footwall and hanging wall of the Shanchiao Fault was about -9.5 and -11.3 mm/yr, respectively. These results suggests that the slight uplift observed in the

  16. Formation of nanocrystalline surface layers in various metallic materials by near surface severe plastic deformation

    Directory of Open Access Journals (Sweden)

    Masahide Sato, Nobuhiro Tsuji, Yoritoshi Minamino and Yuichiro Koizumi

    2004-01-01

    Full Text Available The surface of the various kinds of metallic materials sheets were severely deformed by wire-brushing at ambient temperature to achieve nanocrystalline surface layer. The surface layers of the metallic materials developed by the near surface severe plastic deformation (NS-SPD were characterized by means of TEM. Nearly equiaxed nanocrystals with grain sizes ranging from 30 to 200 nm were observed in the near surface regions of all the severely scratched metallic materials, which are Ti-added ultra-low carbon interstitial free steel, austenitic stainless steel (SUS304, 99.99 wt.%Al, commercial purity aluminum (A1050 and A1100, Al–Mg alloy (A5083, Al-4 wt.%Cu alloy, OFHC-Cu (C1020, Cu–Zn alloy (C2600 and Pb-1.5%Sn alloy. In case of the 1050-H24 aluminum, the depth of the surface nanocrystalline layer was about 15 μm. It was clarified that wire-brushing is an effective way of NS-SPD, and surface nanocrystallization can be easily achieved in most of metallic materials.

  17. UAVSAR: An Airborne Window on Earth Surface Deformation

    Science.gov (United States)

    Hensley, Scott

    2011-01-01

    This study demonstrates that UAVSAR's precision autopilot and electronic steering have allowed for the reliable collection of airborne repeat pass radar interferometric data for deformation mapping. Deformation maps from temporal scales ranging from hours to months over a variety of signals of geophysical interest illustrate the utility of UAVSAR airborne repeat pass interferometry to these studies.

  18. Deformation of the Pannonian lithosphere and related tectonic topography: a depth-to-surface analysis

    NARCIS (Netherlands)

    Dombrádi, E.

    2012-01-01

    Fingerprints of deep-seated, lithospheric deformation are often recognised on the surface, contributing to topographic evolution, drainage organisation and mass transport. Interactions between deep and surface processes were investigated in the Carpathian-Pannonian region. The lithosphere beneath

  19. Three-dimensional surface deformation derived from airborne interferometric UAVSAR: Application to the Slumgullion Landslide

    Science.gov (United States)

    Delbridge, Brent G.; Burgmann, Roland; Fielding, Eric; Hensley, Scott; Schulz, William

    2016-01-01

    In order to provide surface geodetic measurements with “landslide-wide” spatial coverage, we develop and validate a method for the characterization of 3-D surface deformation using the unique capabilities of the Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) airborne repeat-pass radar interferometry system. We apply our method at the well-studied Slumgullion Landslide, which is 3.9 km long and moves persistently at rates up to ∼2 cm/day. A comparison with concurrent GPS measurements validates this method and shows that it provides reliable and accurate 3-D surface deformation measurements. The UAVSAR-derived vector velocity field measurements accurately capture the sharp boundaries defining previously identified kinematic units and geomorphic domains within the landslide. We acquired data across the landslide during spring and summer and identify that the landslide moves more slowly during summer except at its head, presumably in response to spatiotemporal variations in snowmelt infiltration. In order to constrain the mechanics controlling landslide motion from surface velocity measurements, we present an inversion framework for the extraction of slide thickness and basal geometry from dense 3-D surface velocity fields. We find that the average depth of the Slumgullion Landslide is 7.5 m, several meters less than previous depth estimates. We show that by considering a viscoplastic rheology, we can derive tighter theoretical bounds on the rheological parameter relating mean horizontal flow rate to surface velocity. Using inclinometer data for slow-moving, clay-rich landslides across the globe, we find a consistent value for the rheological parameter of 0.85 ± 0.08.

  20. In situ measurement on TSV-Cu deformation with hotplate system based on sheet resistance

    Science.gov (United States)

    Sun, Yunna; Wang, Bo; Wang, Huiying; Wu, Kaifeng; Yang, Shengyong; Wang, Yan; Ding, Guifu

    2017-12-01

    The in situ measurement of TSVs deformation at different temperature is meaningful for learning more about the thermal deformation schemes of 3D TSVs in the microelectronic devices. An efficient and smart hotplate based on sheet resistance is designed for offering more heat, producing a uniform temperature distribution, relieving thermal stress and heat concentration issues, and reducing room space, which was optimized by the finite element method (FEM). The fabricated hotplate is efficient and smart (2.5 cm  ×  2.0 cm  ×  0.5 cm) enough to be located in the limited space during measuring. The thermal infrared imager was employed as the temperature sensor for monitoring the temperature distribution of TSVs sample. The 3D profilometry was adopted as the observer for TSVs profiles survey. The in situ 2D top surface profiles and 3D displacement profiles of TSVs sample at the different temperature were measured by 3D profilometer. The in situ average relative deformation and effective plastic deformation of the TSV sample were measured. With optical measurement method, 3D profilometry, the TSV sample can be tested repeatedly.

  1. Die Deformation Measurement System during Sheet Metal Forming

    Science.gov (United States)

    Funada, J.; Takahashi, S.; Fukiharu, H.

    2011-08-01

    In order to reduce affection to the earth environment, it is necessary to lighten the vehicles. For this purpose, high tensile steels are applied. Because of high strength, high forming force is required for producing automotive sheet metal parts. In this situation, since the dies are elastic, they are deformed during forming parts. For reducing die developing period, sheet metal forming simulation is widely applied. In the numerical simulation, rigid dies are usually used for shortening computing time. It means that the forming conditions in the actual forming and the simulation are different. It will make large errors in the results between actual forming and simulation. It can be said that if contact pressure between dies and a sheet metal in the simulation can be reproduced in the actual forming, the differences of forming results between them can also been reduced. The basic idea is to estimate die shape which can produce the same distribution as computed from simulation with rigid dies. In this study, die deformation analyses with Finite Element Method as basic technologies are evaluated. For example, simple shape and actual dies elastic contact problems were investigated. The contact width between simple shape dies was investigated. The computed solutions were in good agreement with experimental results. The one case of the actual dies in two cases was also investigated. Bending force was applied to the blank holder with a mechanical press machine. The methodology shown with applying inductive displacement sensor for measuring die deformation during applying force was also proposed.

  2. Uncovering the Contribution of Microchannel Deformation to Impedance-Based Flow Rate Measurements.

    Science.gov (United States)

    Niu, Pengfei; Nablo, Brian J; Bhadriraju, Kiran; Reyes, Darwin R

    2017-11-07

    Changes in electrical impedance have previously been used to measure fluid flow rate in microfluidic channels. Ionic redistribution within the electrical double layer by fluid flow has been considered to be the primary mechanism underlying such impedance based microflow sensors. Here we describe a previously unappreciated contribution of microchannel deformation to such measurements. We found that flow-induced microchannel deformation contributes significantly to the change in electrical impedance of solutions, in particular to those solutions producing an electrical double layer in the order of a few tens of nanometers (i.e., containing relatively high ionic strength). Since the flow velocity at the measurement surface is near zero, due to the laminar nature of the flow, the contribution of the double layer under the conditions mentioned above should be negligible. In contrast, an increase in the fluid flow rate results in an increase in the microchannel cross-sectional area (because of higher local pressure), therefore, producing a decrease in solution resistance between the two electrodes. Our results suggest that microflow sensors based on the concept of elastic deformation could be designed for in situ monitoring and fine control of fluid flow in flexible microfluidics. Finally, we show that purposefully engineering a larger deformability of the microchannel, by changing the geometry and the Young's modulus of the microchannel, enhances the sensitivity of this flow rate measurement.

  3. Monitoring of the Earth's surface deformation in the area of water dam Zarnowiec

    Science.gov (United States)

    Mojzes, Marcel; Wozniak, Marek; Habel, Branislav; Macak, Marek

    2017-04-01

    Mathematical and physical research directly motivates geodetic community which can provide very accurate measurements for testing of the proposed models Earth's surface motion near the water dams should be monitored due to the security of the area. This is a process which includes testing of existing models and their physical parameters. Change of the models can improve the practical results for analyzing the trends of motion in the area of upper reservoir of water dam Zarnowiec. Since 1998 Warsaw University of Technology realized a research focused on the horizontal displacements of the upper reservoir of water dam Zarnowiec. The 15 selected control points located on the upper reservoir crown of the water dam were monitored by classical distance measurements. It was found out that changes in the object's geometry occur due to the variation of the water level. The control measurements of the changes in the object's geometry occurring during the process of emptying and filling of the upper reservoir of water dam were compared with the deformations computed using improved Boussinesqués method programmed in the software MATLAB and ANSYS for elastic and isotropic half space as derivation of suitable potentials extended to the loaded region. The details and numerical results of this process are presented This presentation was prepared within the project "National Centre for Diagnostic of the Earth's Surface Deformations in the Area of Slovakia", ITMS code: 26220220108.

  4. Surface micromachined MEMS deformable mirror based on hexagonal parallel-plate electrostatic actuator

    Science.gov (United States)

    Ma, Wenying; Ma, Changwei; Wang, Weimin

    2018-03-01

    Deformable mirrors (DM) based on microelectromechanical system (MEMS) technology are being applied in adaptive optics (AO) system for astronomical telescopes and human eyes more and more. In this paper a MEMS DM with hexagonal actuator is proposed and designed. The relationship between structural design and performance parameters, mainly actuator coupling, is analyzed carefully and calculated. The optimum value of actuator coupling is obtained. A 7-element DM prototype is fabricated using a commercial available standard three-layer polysilicon surface multi-user-MEMS-processes (PolyMUMPs). Some key performances, including surface figure and voltage-displacement curve, are measured through a 3D white light profiler. The measured performances are very consistent with the theoretical values. The proposed DM will benefit the miniaturization of AO systems and lower their cost.

  5. Cytocompatibility evaluation and surface characterization of TiNi deformed by high-pressure torsion

    Energy Technology Data Exchange (ETDEWEB)

    Awang Shri, Dayangku Noorfazidah, E-mail: AWANGSHRI.Dayangku@nims.go.jp [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Structural Materials Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Tsuchiya, Koichi [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Structural Materials Unit, National Institute for Materials Science, Tsukuba, Ibaraki 305-0047 (Japan); Yamamoto, Akiko [Biomaterials Unit, International Center for Material Nanoarchitectonics (WPI-MANA), National Institute for Materials Science, Namiki 1-1, Tsukuba, Ibaraki 305-0044 (Japan)

    2014-10-01

    Effect of high-pressure torsion (HPT) deformation on biocompatibility and surface chemistry of TiNi was systematically investigated. Ti–50 mol% Ni was subjected to HPT straining for different numbers of turns, N = 0.25, 0.5, 1, 5 and 10 at a rotation speed of 1 rpm. X-ray photoelectron spectroscopy observations after 7 days of cell culture revealed the changes in the surface oxide composition, enrichment of Ti and detection of nitrogen derived from organic molecules in the culture medium. Plating efficiency of L929 cells was slightly increased by HPT deformation though no significant difference was observed. Albumin adsorption was higher in HPT-deformed samples, while vitronectin adsorption was peaked at N = 1. HPT deformation was also found to effectively suppress the Ni ion release from the TiNi samples into the cell culture medium even after the low degree of deformation at N = 0.25. - Highlights: • Nanostructured Ti–50 mol%Ni alloy was produced using high-pressure torsion. • HPT deformation improved L929 growth on TiNi samples. • Changes in surface chemistry were observed in HPT deformed samples. • Protein adsorption behavior was influenced by the surface chemistry. • Ni ion release was suppressed in HPT deformed samples.

  6. Surface Impedance of Copper MOB Depending on the Annealing Temperature and Deformation Degree

    International Nuclear Information System (INIS)

    Kutovoj, V.A.; Nikolaenko, A.A.; Stoev, P.I.; Vinogradov, D.V.

    2006-01-01

    Results of researches of influence of annealing temperature and deformation degree on mechanical features of copper MOB are presented. It is shown that minimal surface resistance is observed in copper samples that were subject to pre-deformation and were annealed in the range of temperatures 873...923 K

  7. Subsurface deformation and the role of surface texture—A study with ...

    Indian Academy of Sciences (India)

    2Department of Mechanical Engineering, Indian Institute of Science,. Bangalore 560 012 e-mail: lancy@mecheng.iisc.ernet.in. Abstract. The extent of subsurface deformation below the worn surface influences friction and transfer layer formation during sliding. Thus, in this study, the extent of plastic deformation and strain ...

  8. Deformation of the surface of gallium arsenide during the deposition of gold

    International Nuclear Information System (INIS)

    Briantseva, T. A.; Lioubtchenko, D. V.; Markov, I. A.; Ten, Yu. A.

    2011-01-01

    Deformation phenomena of near-surface GaAs layers are studied using surface acoustic waves during the deposition of Au and the irradiation of the semiconductor surface by the light of a heated evaporator. It is shown that, in the case of Au deposition, the near-surface layers are plasticized due to the phase transformations in the Au-Ga-As system, while upon irradiation of the GaAs surface with light, a coarse-grained layer with liquid-like interlayers is formed. As a result, the type of surface deformations and their relaxation time change. The integral temporal characteristics of the surface acoustic wave, such as the variation integrals of its rate and dissipated power, reflect the processes occurring on the surface in the real-time mode. In summary, they reflect the current magnitude of the resulting deformation. The parameters of occurring processes such as activation energy and relaxation time are determined.

  9. Radiography used to measure internal spinal cord deformation in an in vivo rat model.

    Science.gov (United States)

    Lucas, E; Whyte, T; Liu, J; Tetzlaff, W; Cripton, P A

    2018-04-11

    Little is known about the internal mechanics of the in vivo spinal cord during injury. The objective of this study was to develop a method of tracking internal and surface deformation of in vivo rat spinal cord during compression using radiography. Since neural tissue is radio-translucent, radio-opaque markers were injected into the spinal cord. Two tantalum beads (260 µm) were injected into the cord (dorsal and ventral) at C5 of nine anesthetized rats. Four beads were glued to the lateral surface of the cord, caudal and cranial to the injection site. A compression plate was displaced 0.5 mm, 2 mm, and 3 mm into the spinal cord and lateral X-ray images were taken before, during, and after each compression for measuring bead displacements. Potential bead migration was monitored for by comparing displacements of the internal and glued surface beads. Dorsal beads moved significantly more than ventral beads with a range in averages of 0.57-0.71 mm and 0.31-0.35 mm respectively. Bead displacements during 0.5 mm compressions were significantly lower than 2 mm and 3 mm compressions. There was no statistically significant migration of the internal beads. The results indicate the merit of this technique for measuring in vivo spinal cord deformation. The pattern of bead displacements illustrates the complex internal and surface deformations of the spinal cord during transverse compression. This information is needed for validating physical and finite element spinal cord surrogates and to define relationships between loading parameters, internal cord deformation, and biological and functional outcomes. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Near-surface neotectonic deformation associated with seismicity in the northeastern United States

    International Nuclear Information System (INIS)

    Alexander, S.S.; Gold, D.P.; Gardner, T.W.; Slingerland, R.L.; Thornton, C.P.

    1989-10-01

    For the Lancaster, PA seismic zone a multifaceted investigation revealed several manifestations of near-surface, neotectonic deformation. Remote sensing data together with surface geological and geophysical observations, and recent seismicity reveal that the neotectonic deformation is concentrated in a NS-trending fault zone some 50 km in length and 10--20 km in width. Anomalies associated with this zone include distinctive lineament and surface erosional patterns; geologically recent uplift evidenced by elevations of stream terraces along the Susquehanna River; and localized contemporary travertine deposits in streams down-drainage from the inferred active fault zone. In the Moodus seismic zone the frequency of tectonically-controlled lineaments was observed to increase in the Moodus quadrangle compared to adjacent areas and dominant lineament directions were observed that are perpendicular and parallel to the orientation of the maximum horizontal stress direction (N80-85E) recently determined from in-situ stress measurements in a 1.5 km-deep borehole in the seismic zone and from well-constrained earthquake focal mechanisms. 284 refs., 33 figs

  11. Near-surface neotectonic deformation associated with seismicity in the northeastern United States

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, S.S.; Gold, D.P.; Gardner, T.W.; Slingerland, R.L.; Thornton, C.P. (Pennsylvania State Univ., University Park, PA (USA). Dept. of Geosciences)

    1989-10-01

    For the Lancaster, PA seismic zone a multifaceted investigation revealed several manifestations of near-surface, neotectonic deformation. Remote sensing data together with surface geological and geophysical observations, and recent seismicity reveal that the neotectonic deformation is concentrated in a NS-trending fault zone some 50 km in length and 10--20 km in width. Anomalies associated with this zone include distinctive lineament and surface erosional patterns; geologically recent uplift evidenced by elevations of stream terraces along the Susquehanna River; and localized contemporary travertine deposits in streams down-drainage from the inferred active fault zone. In the Moodus seismic zone the frequency of tectonically-controlled lineaments was observed to increase in the Moodus quadrangle compared to adjacent areas and dominant lineament directions were observed that are perpendicular and parallel to the orientation of the maximum horizontal stress direction (N80-85E) recently determined from in-situ stress measurements in a 1.5 km-deep borehole in the seismic zone and from well-constrained earthquake focal mechanisms. 284 refs., 33 figs.

  12. Surface deformation monitoring using synthetic aperture radar data

    African Journals Online (AJOL)

    CGS

    deformation basins over time was recognised and is consistent with the advance of the working face of the mine during the .... Several advanced algorithms have been developed to overcome the limitations due to phase noise. ... or both. Likewise, the antenna can receive either vertically or horizontally polarized waves. The.

  13. Modeling and simulation of the deformation process of PTFE flexiblestamps for nanoimprint lithography on curved surfaces

    DEFF Research Database (Denmark)

    Sonne, Mads Rostgaard; Smistrup, K.; Hannibal, Morten

    2015-01-01

    In the presented work, simulations of the deformation process of flexible stamps used for nanoimprint lithographron curved surfaces are presented. The material used for the flexible stamps was polytetrafluoroethylene (PTFE) whose material behavior was found to be viscoelastic-viscoplastic. This b......In the presented work, simulations of the deformation process of flexible stamps used for nanoimprint lithographron curved surfaces are presented. The material used for the flexible stamps was polytetrafluoroethylene (PTFE) whose material behavior was found to be viscoelastic...

  14. Corrosion Resistance of Steel 45 Subjected to Electromechanical Treatment and Surface Plastic Deformation

    Science.gov (United States)

    Dudkina, N. G.

    2018-01-01

    The corrosion properties of normalized steel 45 are studied after a combined hardening of its surface layer, which consists of electromechanical treatment and surface plastic deformation (EMT + SPD). The effect of different aggressive environments on the structure, microhardness and corrosion rate of the hardened surface layer is determined.

  15. Deformations of constant mean curvature surfaces preserving symmetries and the Hopf differential

    DEFF Research Database (Denmark)

    Brander, David; Dorfmeister, Josef

    2015-01-01

    We define certain deformations between minimal and non-minimal constant mean curvature (CMC) surfaces in Euclidean space E3 which preserve the Hopf differential. We prove that, given a CMC H surface f, either minimal or not, and a fixed basepoint z0 on this surface, there is a naturally defined...

  16. DigiWarp: a method for deformable mouse atlas warping to surface topographic data

    International Nuclear Information System (INIS)

    Joshi, Anand A; Shattuck, David W; Toga, Arthur W; Chaudhari, Abhijit J; Li Changqing; Cherry, Simon R; Dutta, Joyita; Leahy, Richard M

    2010-01-01

    For pre-clinical bioluminescence or fluorescence optical tomography, the animal's surface topography and internal anatomy need to be estimated for improving the quantitative accuracy of reconstructed images. The animal's surface profile can be measured by all-optical systems, but estimation of the internal anatomy using optical techniques is non-trivial. A 3D anatomical mouse atlas may be warped to the estimated surface. However, fitting an atlas to surface topography data is challenging because of variations in the posture and morphology of imaged mice. In addition, acquisition of partial data (for example, from limited views or with limited sampling) can make the warping problem ill-conditioned. Here, we present a method for fitting a deformable mouse atlas to surface topographic range data acquired by an optical system. As an initialization procedure, we match the posture of the atlas to the posture of the mouse being imaged using landmark constraints. The asymmetric L 2 pseudo-distance between the atlas surface and the mouse surface is then minimized in order to register two data sets. A Laplacian prior is used to ensure smoothness of the surface warping field. Once the atlas surface is normalized to match the range data, the internal anatomy is transformed using elastic energy minimization. We present results from performance evaluation studies of our method where we have measured the volumetric overlap between the internal organs delineated directly from MRI or CT and those estimated by our proposed warping scheme. Computed Dice coefficients indicate excellent overlap in the brain and the heart, with fair agreement in the kidneys and the bladder.

  17. Tools for measuring surface cleanliness

    Energy Technology Data Exchange (ETDEWEB)

    Schroder, Mark Stewart (Hendersonville, NC); Woodmansee, Donald Ernest (Simpsonville, SC); Beadie, Douglas Frank (Greenville, SC)

    2002-01-01

    A procedure and tools for quantifying surface cleanliness are described. Cleanliness of a target surface is quantified by wiping a prescribed area of the surface with a flexible, bright white cloth swatch, preferably mounted on a special tool. The cloth picks up a substantial amount of any particulate surface contamination. The amount of contamination is determined by measuring the reflectivity loss of the cloth before and after wiping on the contaminated system and comparing that loss to a previous calibration with similar contamination. In the alternative, a visual comparison of the contaminated cloth to a contamination key provides an indication of the surface cleanliness.

  18. Surface Deformation and Direct Field Observation to Constrain Conceptual Models of Hydraulic Fracture Growth and Form

    Science.gov (United States)

    Slack, W.; Murdoch, L.

    2016-12-01

    Hydraulic fractures can be created in shallow soil or bedrock to promote processes that destroy or remove chemical contaminants. The form of the fracture plays an important role in how it is used in such applications. We created more than 4500 environmental hydraulic fractures at approximately 300 sites since 1990, and we measured surface deformation at many. Several of these sites subsequently were excavated to evaluate fracture form in detail. In one recent example, six hydraulic fractures were created at 1.5m depth while we measured upward displacement and tilt at 15 overlying locations. We excavated in the vicinities of two of the fractures and mapped the exposed fractures. Tilt vectors were initially symmetric about the borehole but radiated from a point that moved southwest with time. Upward displacement of as much as 2.5 cm covered a region 5m to 6m across. The maximum displacement was roughly at the center of the deformed region but was 2m southwest of the borehole, consistent with the tilt data. Excavation revealed an oblong, proppant-filled fracture over 4.2 m in length with a maximum thickness of 1 cm, so the proppant covers a region that is smaller than the uplifted area and the proppant thickness is roughly half of the uplift. The fracture was shaped like a shallow saucer with maximum dips of approximately 15o at the southwestern end. The pattern of tilt and uplift generally reflect the aperture of the underlying pressurized fracture, but the deformation extends beyond the extent of the sand proppant so a quantitative interpretation requires inversion. Inversion of the tilt data using a simple double dislocation model under-estimates the extent but correctly predicts the depth, orientation, and off-centered location. Inversion of uplift using a model that assumes the overburden deforms like a plate over-estimates the extent. Neither can characterize the curved shape. A forward model using FEM analysis capable of representing 3D shapes is capable of

  19. Identifying deformation mechanisms in the NEEM ice core using EBSD measurements

    Science.gov (United States)

    Kuiper, Ernst-Jan; Weikusat, Ilka; Drury, Martyn R.; Pennock, Gill M.; de Winter, Matthijs D. A.

    2015-04-01

    Deformation of ice in continental sized ice sheets determines the flow behavior of ice towards the sea. Basal dislocation glide is assumed to be the dominant deformation mechanism in the creep deformation of natural ice, but non-basal glide is active as well. Knowledge of what types of deformation mechanisms are active in polar ice is critical in predicting the response of ice sheets in future warmer climates and its contribution to sea level rise, because the activity of deformation mechanisms depends critically on deformation conditions (such as temperature) as well as on the material properties (such as grain size). One of the methods to study the deformation mechanisms in natural materials is Electron Backscattered Diffraction (EBSD). We obtained ca. 50 EBSD maps of five different depths from a Greenlandic ice core (NEEM). The step size varied between 8 and 25 micron depending on the size of the deformation features. The size of the maps varied from 2000 to 10000 grid point. Indexing rates were up to 95%, partially by saving and reanalyzing the EBSP patterns. With this method we can characterize subgrain boundaries and determine the lattice rotation configurations of each individual subgrain. Combining these observations with arrangement/geometry of subgrain boundaries the dislocation types can be determined, which form these boundaries. Three main types of subgrain boundaries have been recognized in Antarctic (EDML) ice core¹². Here, we present the first results obtained from EBSD measurements performed on the NEEM ice core samples from the last glacial period, focusing on the relevance of dislocation activity of the possible slip systems. Preliminary results show that all three subgrain types, recognized in the EDML core, occur in the NEEM samples. In addition to the classical boundaries made up of basal dislocations, subgrain boundaries made of non-basal dislocations are also common. ¹Weikusat, I.; de Winter, D. A. M.; Pennock, G. M.; Hayles, M

  20. Quantifying cortical surface harmonic deformation with stereovision during open cranial neurosurgery

    Science.gov (United States)

    Ji, Songbai; Fan, Xiaoyao; Roberts, David W.; Paulsen, Keith D.

    2012-02-01

    Cortical surface harmonic motion during open cranial neurosurgery is well observed in image-guided neurosurgery. Recently, we quantified cortical surface deformation noninvasively with synchronized blood pressure pulsation (BPP) from a sequence of stereo image pairs using optical flow motion tracking. With three subjects, we found the average cortical surface displacement can reach more than 1 mm and in-plane principal strains of up to 7% relative to the first image pair. In addition, the temporal changes in deformation and strain were in concert with BPP and patient respiration [1]. However, because deformation was essentially computed relative to an arbitrary reference, comparing cortical surface deformation at different times was not possible. In this study, we extend the technique developed earlier by establishing a more reliable reference profile of the cortical surface for each sequence of stereo image acquisitions. Specifically, fast Fourier transform (FFT) was applied to the dynamic cortical surface deformation, and the fundamental frequencies corresponding to patient respiration and BPP were identified, which were used to determine the number of image acquisitions for use in averaging cortical surface images. This technique is important because it potentially allows in vivo characterization of soft tissue biomechanical properties using intraoperative stereovision and motion tracking.

  1. Armor Plate Surface Roughness Measurements

    National Research Council Canada - National Science Library

    Stanton, Brian; Coburn, William; Pizzillo, Thomas J

    2005-01-01

    ...., surface texture and coatings) that could become important at high frequency. We measure waviness and roughness of various plates to know the parameter range for smooth aluminum and rolled homogenous armor (RHA...

  2. FTIR measurements of OH in deformed quartz and feldspars of the South Tibetan Detachment, Greater Himalaya

    Science.gov (United States)

    Jezek, L.; Law, R. D.; Jessup, M. J.; Searle, M. P.; Kronenberg, A. K.

    2017-12-01

    OH absorption bands due to water in deformed quartz and feldspar grains of mylonites from the low-angle Lhotse Detachment (of the South Tibetan Detachment System, Rongbuk Valley north of Mount Everest) have been measured by Fourier Transform Infrared (FTIR) Spectroscopy. Previous microstructural studies have shown that these rocks deformed by dislocation creep at high temperature conditions in the middle crust (lower - middle amphibolite facies), and oxygen isotope studies suggest significant influx of meteoric water. OH absorption bands at 3400 cm-1 of quartz mylonites from the footwall of the Lhotse Detachment Fault are large, with the character of the molecular water band due to fluid inclusions in milky quartz. Mean water contents depend on structural position relative to the core of the Lhotse Detachment, from 1000 ppm (OH/106 Si) at 420 m below the fault to 11,350 (+/-1095) ppm near its center. The gradient in OH content shown by quartz grains implies influx of meteoric water along the Lhotse Detachment from the Tibetan Plateau ground surface to middle crustal depths, and significant fluid penetration into the extruding Himalayan slab by intergranular, permeable fluid flow processes. Feldspars of individual samples have comparable water contents to those of quartz and some are wetter. Large water contents of quartz and feldspar may have contributed to continued deformation and strain localization on the South Tibetan Detachment System. Dislocation creep in quartz is facilitated by water in laboratory experiments, and the water contents of the Lhotse fault rocks are similar to (and even larger than) water contents of quartz experimentally deformed during water weakening. Water contents of feldspars are comparable to those of plagioclase aggregates deformed experimentally by dislocation and diffusion creep under wet conditions.

  3. Estimating the Parameters of Deformation Action by Ultrasonic Surface Hardening of Metals

    Science.gov (United States)

    Rakhimyanov, Kharis M.; Rakhimyanov, Konstantin Kh; Rakhimyanov, Andrey Kh

    2017-10-01

    Developing the effective technologies of detail machining greatly depends on understanding the processes laid down in their basis. The technological methods based on electro-physical processes are considered to be attractive. These are the methods of surface plastic deforming which use the energy of ultrasonic oscillations. The peculiarities of these methods are characterized by high intensity and impulse character of the ultrasonic action. The paper presents the results of mathematical modeling of deformation processes under the impact of the ultrasonic tool on the surface layer of metals and alloys. The theoretical approach to studying the process of ultrasonic deforming allowed us to determine the mode parameters of impact and their quantitative correlations with the main characteristics of the deformation process.

  4. Measuring hull girder deformations on a 9300 TEU containership

    Directory of Open Access Journals (Sweden)

    Koning Jos

    2014-12-01

    Full Text Available A 9300 TEU container carrier was equipped in 2006 with instrumentation aimed at wave induced accelerations, and motions. In 2010 the system was extended with strain sensors to include structural loads. Section loads for vertical bending could be readily obtained but the originally intended derivation of horizontal bending and torsion from the measured strains was found to be unreliable. This paper addresses an alternative approach that was adopted in the post processing of results. In particular the concept to use acceleration sensors to capture global hull deformations along the length of the hull, and the use of a data fusion procedure to obtain section loads from combined sensor data and finite element calculations. The approach is illustrated by comparison of actually measured accelerations and local strains with values obtained from the data fusion model. It is concluded that the approach is promising but in need of further validation and development. In particular the number and shapes of the modes used may not have been sufficient to represent the true deflection and thus strain distributions along the high loaded areas.

  5. Measuring hull girder deformations on a 9300 TEU containership

    Science.gov (United States)

    Koning, Jos; Schiere, Marcus

    2014-12-01

    A 9300 TEU container carrier was equipped in 2006 with instrumentation aimed at wave induced accelerations, and motions. In 2010 the system was extended with strain sensors to include structural loads. Section loads for vertical bending could be readily obtained but the originally intended derivation of horizontal bending and torsion from the measured strains was found to be unreliable. This paper addresses an alternative approach that was adopted in the post processing of results. In particular the concept to use acceleration sensors to capture global hull deformations along the length of the hull, and the use of a data fusion procedure to obtain section loads from combined sensor data and finite element calculations. The approach is illustrated by comparison of actually measured accelerations and local strains with values obtained from the data fusion model. It is concluded that the approach is promising but in need of further validation and development. In particular the number and shapes of the modes used may not have been sufficient to represent the true deflection and thus strain distributions along the high loaded areas.

  6. Multilayer Steel Materials Deformation Resistance and Roll Force Measurement

    Directory of Open Access Journals (Sweden)

    A. G. Kolesnikov

    2014-01-01

    Full Text Available To create new types of cars, raise their reliability, gain operational life, and decrease in metal consumption of products it is necessary to improve mechanical, physical, and also special properties of the constructional materials applied in mechanical engineering. Presently, there are intensive researches and developments under way to create materials with ultrafine-grained structure (the sizes of grains in their crystal lattice make less than 1 micron in one of the measurements.BMSTU developed a manufacturing technology of multilayer steel sheets with steady ultrafine-grained structure based on the multiple hot rolling of billet as a composition consisting of the alternating metal sheets. A principled condition for implementation of such technology is existence of different crystallographic modifications in the adjoining sheets of the composition at specified temperature of rolling.Power parameters of rolling are important technical characteristics of the process. Usually, to determine a deformation resistance value when rolling the diverse multilayer materials, is used the actual resistance value averaging in relation to the components of the composition. The aim of this work is a comparative analysis of known calculated dependences with experimental data when rolling the 100-layer samples. Objects of research were the 100-layer compositions based on the alternating layers of steel 08H18N10 and U8.Experimental samples represented the vacuumized capsules with height, width, and length of 53 mm x 53 mm x 200 mm, respectively, in which there were the 100-layer packs from sheets, each of 0.5 mm, based on the composition of steels (U8+08H18N10. Rolling was made on the double-high mill with rolls of 160 mm in diameter during 19 passes to the thickness of 7 mm with the speed of 0,1 m/s. Relative sinking in each pass was accepted to be equal 10±2,5%. Rolling forces were measured by the strain-gauging method using the measuring cells, located under

  7. Influence of Plastic Deformation on Low Temperature Surface Hardening of Austenitic Stainless Steel by Gaseous Nitriding

    DEFF Research Database (Denmark)

    Bottoli, Federico; Winther, Grethe; Christiansen, Thomas Lundin

    2015-01-01

    This article addresses an investigation of the influence of plastic deformation on low temperature surface hardening by gaseous nitriding of two commercial austenitic stainless steels: AISI 304 and EN 1.4369. The materials were plastically deformed to different equivalent strains by uniaxial...... tension. Gaseous nitriding of the strained material was performed in ammonia gas at atmospheric pressure at 703 K. Microstructural characterization of the as-deformed states and the nitrided case produced included X-ray diffraction analysis, reflected light microscopy, microhardness testing. The results...

  8. Low temperature surface hardening of stainless steel; the role of plastic deformation

    DEFF Research Database (Denmark)

    Bottoli, Federico; Jespersen, Freja Nygaard; Hattel, Jesper Henri

    2016-01-01

    Thermochemical surface engineering by nitriding of austenitic stainless steel transforms the surface zone into expanded austenite, which improves the wear resistance of the stainless steel while preserving the stainless behavior. As a consequence of the thermochemical surface engineering, huge......: - plastic deformation of metastable austenitic stainless steels leads to the development of strain-induced martensite, which compromises the uniformity and the homogeneity of the expanded austenite zone. - during low temperature surface engineering composition and stress profiles develop. On numerical...

  9. Long-term monitoring of geodynamic surface deformation using SAR interferometry

    Science.gov (United States)

    Gong, Wenyu

    Synthetic Aperture Radar Interferometry (InSAR) is a powerful tool to measure surface deformation and is well suited for surveying active volcanoes using historical and existing satellites. However, the value and applicability of InSAR for geodynamic monitoring problems is limited by the influence of temporal decorrelation and electromagnetic path delay variations in the atmosphere, both of which reduce the sensitivity and accuracy of the technique. The aim of this PhD thesis research is: how to optimize the quantity and quality of deformation signals extracted from InSAR stacks that contain only a low number of images in order to facilitate volcano monitoring and the study of their geophysical signatures. In particular, the focus is on methods of mitigating atmospheric artifacts in interferograms by combining time-series InSAR techniques and external atmospheric delay maps derived by Numerical Weather Prediction (NWP) models. In the first chapter of the thesis, the potential of the NWP Weather Research & Forecasting (WRF) model for InSAR data correction has been studied extensively. Forecasted atmospheric delays derived from operational High Resolution Rapid Refresh for the Alaska region (HRRR-AK) products have been compared to radiosonding measurements in the first chapter. The result suggests that the HRRR-AK operational products are a good data source for correcting atmospheric delays in spaceborne geodetic radar observations, if the geophysical signal to be observed is larger than 20 mm. In the second chapter, an advanced method for integrating NWP products into the time series InSAR workflow is developed. The efficiency of the algorithm is tested via simulated data experiments, which demonstrate the method outperforms other more conventional methods. In Chapter 3, a geophysical case study is performed by applying the developed algorithm to the active volcanoes of Unimak Island Alaska (Westdahl, Fisher and Shishaldin) for long term volcano deformation

  10. A review of the trunk surface metrics used as Scoliosis and other deformities evaluation indices

    Directory of Open Access Journals (Sweden)

    Aggouris Costas

    2010-06-01

    Full Text Available Abstract Background Although scoliosis is characterized by lateral deviation of the spine, a 3D deformation actually is responsible for geometric and morphologic changes in the trunk and rib cage. In a vast related medical literature, one can find quite a few scoliosis evaluation indices, which are based on back surface data and are generally measured along three planes. Regardless the large number of such indices, the literature is lacking a coherent presentation of the underlying metrics, the involved anatomic surface landmarks, the definition of planes and the definition of the related body axes. In addition, the long list of proposed scoliotic indices is rarely presented in cross-reference to each other. This creates a possibility of misunderstandings and sometimes irrational or even wrong use of these indices by the medical society. Materials and methods It is hoped that the current work contributes in clearing up the issue and gives rise to innovative ideas on how to assess the surface metrics in scoliosis. In particular, this paper presents a thorough study on the scoliosis evaluation indices, proposed by the medical society. Results More specifically, the referred indices are classified, according to the type of asymmetry they measure, according to the plane they refer to, according to the importance, and relevance or the level of scientific consensus they enjoy. Conclusions Surface metrics have very little correlation to Cobb angle measurements. Indices measured on different planes do not correlate to each other. Different indices exhibit quite diverging characteristics in terms of observer-induced errors, accuracy, sensitivity and specificity. Complicated positioning of the patient and ambiguous anatomical landmarks are the major error sources, which cause observer variations. Principles that should be followed when an index is proposed are presented.

  11. Study on municipal road cracking and surface deformation based on image recognition

    Science.gov (United States)

    Yuan, Haitao; Wang, Shuai; Tan, Jizong

    2017-05-01

    In recent years, the digital image recognition technology of concrete structure cracks and deformation of binocular vision technology detection of civil engineering structure have made substantial development. As a result, people's understanding of the road engineering structure cracking and surface deformation recognition gives rise to a new situation. For the research on digital image concrete structure cracking and masonry structure surface deformation recognition technology, the key is to break through in the method, and to improve the traditional recognition technology and mode. Only in this way can we continuously improve the security level of the highway, to adapt to the new requirements of the development of new urbanization and modernization. This thesis focuses on and systematically analyzes the digital image road engineering structure cracking and key technologies of surface deformation recognition and its engineering applications. In addition, we change the concrete structure cracking and masonry structure surface deformation recognition pattern, and realize the breakthrough and innovation of the road structure safety testing means and methods.

  12. Surface deformation induced by water pumping for construction of Mass Rapid Transportation in Taipei basin

    Science.gov (United States)

    Hu, J. C.; Wu, P. C.; Tung, H.; Tsai, M. C.

    2017-12-01

    In 1968, there were 2,200 wells in the Taipei Basin used for water supply to meet the requirement of high population density. The overuse of ground water lead to the land subsidence rate up to 5 cm/yr. Although the government had already begun to limit groundwater pumping since 1968, the groundwater in the Taipei Basin demonstrated temporary fluctuation induced by pumping water for large deep excavation site or engineering usage. The previous study based on precise leveling suggested that the surface deformation was highly associated with the recovery of water level. In 1989, widespread uplift dominated in Taipei basin due to the recovery of ground water Table. In this study, we use 37 high-resolution X-band COSMO-SkyMed radar images from May 2011 to April 2015 to characterize deformation pattern in the period of construction of Mass Rapid Transportation (MRT). We also use 30 wells and 380 benchmarks of precise leveling in Taipei basin to study the correlation of surface deformation and change of ground water table. The storability is roughly constant across most of the aquifer with values between 0.8 x 10-4 and 1.3 x 10-3. Moreover, the high water pumping in two major aquifers, Jignme and Wuku Foramtions, before the underground construction for MRT led to inflict surface deformation and no time delay observed for surface deformation during the water pumping. It implies that the poro-elastic effect dominates in major aquifers in Taipei basin.

  13. Ra and the average effective strain of surface asperities deformed in metal-working processes

    DEFF Research Database (Denmark)

    Bay, Niels; Wanheim, Tarras; Petersen, A. S

    1975-01-01

    Based upon a slip-line analysis of the plastic deformation of surface asperities, a theory is developed determining the Ra-value (c.l.a.) and the average effective strain in the surface layer when deforming asperities in metal-working processes. The ratio between Ra and Ra0, the Ra-value after...... and before deformation, is a function of the nominal normal pressure and the initial slope γ0 of the surface asperities. The last parameter does not influence Ra significantly. The average effective strain View the MathML sourcege in the deformed surface layer is a function of the nominal normal pressure...... and γ0. View the MathML sourcege is highly dependent on γ0, View the MathML sourcege increasing with increasing γ0. It is shown that the Ra-value and the strain are hardly affected by the normal pressure until interacting deformation of the asperities begins, that is until the limit of Amonton's law...

  14. The Research of Phase Retrieval Holography Method Based on the Active Deformation of the Active Reflector Surface

    Science.gov (United States)

    Wang, Z. Q.; Chen, M. Z.; Pei, X.; Wang, J.

    2017-09-01

    The surface accuracy of a large reflector radio telescope is one of the important factors influencing the performance of the antenna. The effects of panel processing, installation, as well as gravity, temperature, and wind load, will greatly limit the observation efficiency of the antenna. Focused on the technology of active surface which is more accurately controllable than the minor reflector surface of six-ploe, the continuous distribution of active deformation phase factor described by Zernike polynomials is adopted for the first time. Only getting the far field amplitude through adjusting the active surface, the surface error can be detected. By building the models of numerical simulation, the retrieval error of arbitrary surface deformation is calculated, and the retrieval results of surface deformation in a variety of continuous active surface deformation is also studied. It is indicated that this method can stably and accurately detect surface deformation, and can also improve the efficiency of radio telescope observations effectively.

  15. Noninvasive, three-dimensional full-field body sensor for surface deformation monitoring of human body in vivo.

    Science.gov (United States)

    Chen, Zhenning; Shao, Xinxing; He, Xiaoyuan; Wu, Jialin; Xu, Xiangyang; Zhang, Jinlin

    2017-09-01

    Noninvasive, three-dimensional (3-D), full-field surface deformation measurements of the human body are important for biomedical investigations. We proposed a 3-D noninvasive, full-field body sensor based on stereo digital image correlation (stereo-DIC) for surface deformation monitoring of the human body in vivo. First, by applying an improved water-transfer printing (WTP) technique to transfer optimized speckle patterns onto the skin, the body sensor was conveniently and harmlessly fabricated directly onto the human body. Then, stereo-DIC was used to achieve 3-D noncontact and noninvasive surface deformation measurements. The accuracy and efficiency of the proposed body sensor were verified and discussed by considering different complexions. Moreover, the fabrication of speckle patterns on human skin, which has always been considered a challenging problem, was shown to be feasible, effective, and harmless as a result of the improved WTP technique. An application of the proposed stereo-DIC-based body sensor was demonstrated by measuring the pulse wave velocity of human carotid artery. (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  16. Noninvasive, three-dimensional full-field body sensor for surface deformation monitoring of human body in vivo

    Science.gov (United States)

    Chen, Zhenning; Shao, Xinxing; He, Xiaoyuan; Wu, Jialin; Xu, Xiangyang; Zhang, Jinlin

    2017-09-01

    Noninvasive, three-dimensional (3-D), full-field surface deformation measurements of the human body are important for biomedical investigations. We proposed a 3-D noninvasive, full-field body sensor based on stereo digital image correlation (stereo-DIC) for surface deformation monitoring of the human body in vivo. First, by applying an improved water-transfer printing (WTP) technique to transfer optimized speckle patterns onto the skin, the body sensor was conveniently and harmlessly fabricated directly onto the human body. Then, stereo-DIC was used to achieve 3-D noncontact and noninvasive surface deformation measurements. The accuracy and efficiency of the proposed body sensor were verified and discussed by considering different complexions. Moreover, the fabrication of speckle patterns on human skin, which has always been considered a challenging problem, was shown to be feasible, effective, and harmless as a result of the improved WTP technique. An application of the proposed stereo-DIC-based body sensor was demonstrated by measuring the pulse wave velocity of human carotid artery.

  17. Entanglement entropy of singular surfaces under relevant deformations in holography

    Science.gov (United States)

    Ghasemi, Mostafa; Parvizi, Shahrokh

    2018-02-01

    In the vacuum state of a CFT, the entanglement entropy of singular surfaces contains a logarithmic universal term which is only due to the singularity of the entangling surface. We consider the relevant perturbation of a three dimensional CFT for singular entangling surface. We observe that in addition to the universal term due to the entangling surface, there is a new logarithmic term which corresponds to a relevant perturbation of the conformal field theory with a coefficient depending on the scaling dimension of the relevant operator. We also find a new power law divergence in the holographic entanglement entropy. In addition, we study the effect of a relevant perturbation in the Gauss-Bonnet gravity for a singular entangling surface. Again a logarithmic term shows up. This new term is proportional to both the dimension of the relevant operator and the Gauss-Bonnet coupling. We also introduce the renormalized entanglement entropy for a kink region which in the UV limit reduces to a universal positive finite term.

  18. Deformation Measurements of Gabion Walls Using Image Based Modeling

    Directory of Open Access Journals (Sweden)

    Marek Fraštia

    2014-06-01

    Full Text Available The image based modeling finds use in applications where it is necessary to reconstructthe 3D surface of the observed object with a high level of detail. Previous experiments showrelatively high variability of the results depending on the camera type used, the processingsoftware, or the process evaluation. The authors tested the method of SFM (Structure fromMotion to determine the stability of gabion walls. The results of photogrammetricmeasurements were compared to precise geodetic point measurements.

  19. Experimental Constraints on Forecasting the Location of Volcanic Eruptions from Pre-eruptive Surface Deformation

    Directory of Open Access Journals (Sweden)

    Frank Guldstrand

    2018-02-01

    Full Text Available Volcanic eruptions pose a threat to lives and property when volcano flanks and surroundings are densely populated. The local impact of an eruption depends firstly on its location, whether it occurs near a volcano summit, or down on the flanks. Then forecasting, with a defined accuracy, the location of a potential, imminent eruption would significantly improve the assessment and mitigation of volcanic hazards. Currently, the conventional volcano monitoring methods based on the analysis of surface deformation assesses whether a volcano may erupt but are not implemented to locate imminent eruptions in real time. Here we show how surface deformation induced by ascending eruptive feeders can be used to forecast the eruption location through a simple geometrical analysis. Our analysis builds on the results of 33 scaled laboratory experiments simulating the emplacement of viscous magma intrusions in a brittle, cohesive Coulomb crust under lithostatic stress conditions. The intrusion-induced surface deformation was systematically monitored at high spatial and temporal resolution. In all the experiments, surface deformation preceding the eruptions resulted in systematic uplift, regardless of the intrusion shape. The analysis of the surface deformation patterns leads to the definition of a vector between the center of the uplifted area and the point of maximum uplift, which systematically acted as a precursor to the eruption's location. The temporal evolution of this vector indicated the direction in which the subsequent eruption would occur and ultimately the location itself, irrespective of the feeder shapes. Our findings represent a new approach on how surface deformation on active volcanoes that are not in active rifts could be analysed and used prior to an eruption with a real potential to improve hazard mitigation.

  20. Experimental constraints on forecasting the location of volcanic eruptions from pre-eruptive surface deformation

    Science.gov (United States)

    Guldstrand, Frank; Galland, Olivier; Hallot, Erwan; Burchardt, Steffi

    2018-02-01

    Volcanic eruptions pose a threat to lives and property when volcano flanks and surroundings are densely populated. The local impact of an eruption depends firstly on its location, whether it occurs near a volcano summit, or down on the flanks. Then forecasting, with a defined accuracy, the location of a potential, imminent eruption would significantly improve the assessment and mitigation of volcanic hazards. Currently, the conventional volcano monitoring methods based on the analysis of surface deformation assesses whether a volcano may erupt but are not implemented to locate imminent eruptions in real time. Here we show how surface deformation induced by ascending eruptive feeders can be used to forecast the eruption location through a simple geometrical analysis. Our analysis builds on the results of 33 scaled laboratory experiments simulating magma intrusions in a brittle crust, during which the intrusion-induced surface deformation was systematically monitored at high spatial and temporal resolution. In all the experiments, surface deformation preceding the eruptions resulted in systematic uplift, regardless of the intrusion shape. The analysis of the surface deformation patterns leads to the definition of a vector between the centre of the uplifted zone and the point of maximum uplift, which systematically acted as a precursor to the eruption’s location. The temporal evolution of this vector indicated the direction in which the subsequent eruption would occur and ultimately the location itself, irrespective of the feeder shapes. Our findings represent a new approach on how surface deformation on active volcanoes could be analysed and used prior to an eruption with a real potential to improve hazard mitigation.

  1. ANALYSIS OF DEFORMATION PROCESSES IN THE LITHOSPHERE FROM GEODETIC MEASUREMENTS BASED ON THE EXAMPLE OF THE SAN ANDREAS FAULT

    Directory of Open Access Journals (Sweden)

    Yury V. Gabsatarov

    2012-01-01

    Full Text Available Analysis of data from permanent GPS observation stations located in tectonically active regions provides for direct observation of deformation processes of the earth's surface which result from elastic interaction of the lithospheric plates and also occur when accumulated stresses are released by seismic events and postseismic processes.This article describes the methodology of applying the regression analysis of time series of data from GPS-stations for identification of individual components of the stations’ displacements caused by the influence of various deformation processes. Modelling of the stations’ displacements caused only by deformations of the marginal zone, wherein the lithospheric plates interact, allows us to study variations of the steady-state deformation in the marginal zone.he proposed methodology is applied to studies of variations of fields of cumulative surface displacements, surface displacement velocity and maximum shear strain velocity which are determined from the GPS data recorded prior to the Parkfield earthquake of 28 September 2004 (Mw=6.0.Combined analysis of the variations of the above-mentioned fields shows that measurable anomalies of the elastic deformation of the transform fault’s edge took place prior to the seismic event of 28 September 2004, and such anomalies were coincident in space and time with the focal area of the future seismic event.

  2. Microstructure refinement of tungsten by surface deformation for irradiation damage resistance

    International Nuclear Information System (INIS)

    Efe, Mert; El-Atwani, Osman; Guo, Yang; Klenosky, Daniel R.

    2014-01-01

    Surface deformation by machining is demonstrated as a way to engineer microstructures of pure tungsten for extreme irradiation environments. Thermomechanical conditions are established for microstructure refinement in the chips and the workpiece subsurface. Ultrafine grains are observed both in the chip and the subsurface, at depths relevant to the typical thickness of the irradiation-induced damage. Guidelines for producing a uniform, ultrafine-grained structure via machining and other surface deformation processes are discussed along with the implications of such microstructures for damage resistance

  3. Macro-carriers of plastic deformation of steel surface layers detected by digital image correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kopanitsa, D. G., E-mail: kopanitsa@mail.ru; Ustinov, A. M., E-mail: artemustinov@mail.ru [Tomsk State University of Architecture and Building, 2 Solyanaya Sq, Tomsk, 634003 (Russian Federation); Potekaev, A. I., E-mail: potekaev@spti.tsu.ru [National Research Tomsk State University, 36 Lenin Ave., Tomsk, 634050 (Russian Federation); Klopotov, A. A., E-mail: klopotovaa@tsuab.ru [Tomsk State University of Architecture and Building, 2 Solyanaya Sq, Tomsk, 634003 (Russian Federation); National Research Tomsk State University, 36 Lenin Ave., Tomsk, 634050 (Russian Federation); Kopanitsa, G. D., E-mail: georgy.kopanitsa@mail.com [National Research Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation)

    2016-01-15

    This paper presents a study of characteristics of an evolution of deformation fields in surface layers of medium-carbon low-alloy specimens under compression. The experiments were performed on the “Universal Testing Machine 4500” using a digital stereoscopic image processing system Vic-3D. A transition between stages is reflected as deformation redistribution on the near-surface layers. Electronic microscopy shows that the structure of the steel is a mixture of pearlite and ferrite grains. A proportion of pearlite is 40% and ferrite is 60%.

  4. Continuous monitoring of surface deformation at Long Valley Caldera, California, with GPS

    Science.gov (United States)

    Dixon, T.H.; Mao, A.; Bursik, M.; Heflin, M.; Langbein, J.; Stein, R.; Webb, F.

    1997-01-01

    Continuous Global Positioning System (GPS) measurements at Long Valley Caldera, an active volcanic region in east central California, have been made on the south side of the resurgent dome since early 1993. A site on the north side of the dome was added in late 1994. Special adaptations for autonomous operation in remote regions and enhanced vertical precision were made. The data record ongoing volcanic deformation consistent with uplift and expansion of the surface above a shallow magma chamber. Measurement precisions (1 standard error) for "absolute" position coordinates, i.e., relative to a global reference frame, are 3-4 mm (north), 5-6 mm (east), and 10-12 mm (vertical) using 24 hour solutions. Corresponding velocity uncertainties for a 12 month period are about 2 mm/yr in the horizontal components and 3-4 mm/yr in the vertical component. High precision can also be achieved for relative position coordinates on short (Comparison of baseline length changes across the resurgent dome between the two GPS sites and corresponding two-color electronic distance measurements indicates similar extension rates within error (???2 mm/yr) once we account for a random walk noise component in both systems that may reflect spurious monument motion. Both data sets suggest a pause in deformation for a 3.5 month period in mid-1995, when the extension rate across the dome decreased essentially to zero. Three dimensional positioning data from the two GPS stations suggest a depth (5.8??1.6 km) and location (west side of the resurgent dome) of a major inflation center, in agreement with other geodetic techniques, near the top of a magma chamber inferred from seismic data. GPS systems similar to those installed at Long Valley can provide a practical method for near real-time monitoring and hazard assessment on many active volcanoes.

  5. Complex surface deformation of Akutan volcano, Alaska revealed from InSAR time series

    Science.gov (United States)

    Wang, Teng; DeGrandpre, Kimberly; Lu, Zhong; Freymueller, Jeffrey T.

    2018-02-01

    Akutan volcano is one of the most active volcanoes in the Aleutian arc. An intense swarm of volcano-tectonic earthquakes occurred across the island in 1996. Surface deformation after the 1996 earthquake sequence has been studied using Interferometric Synthetic Aperture Radar (InSAR), yet it is hard to determine the detailed temporal behavior and spatial extent of the deformation due to decorrelation and the sparse temporal sampling of SAR data. Atmospheric delay anomalies over Akutan volcano are also strong, bringing additional technical challenges. Here we present a time series InSAR analysis from 2003 to 2016 to reveal the surface deformation in more detail. Four tracks of Envisat data acquired from 2003 to 2010 and one track of TerraSAR-X data acquired from 2010 to 2016 are processed to produce high-resolution surface deformation, with a focus on studying two transient episodes of inflation in 2008 and 2014. For the TerraSAR-X data, the atmospheric delay is estimated and removed using the common-master stacking method. These derived deformation maps show a consistently uplifting area on the northeastern flank of the volcano. From the TerraSAR-X data, we quantify the velocity of the subsidence inside the caldera to be as high as 10 mm/year, and identify another subsidence area near the ground cracks created during the 1996 swarm.

  6. Bayesian estimation of regularization parameters for deformable surface models

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, G.S.; Lehovich, A.; Hanson, K.M.

    1999-02-20

    In this article the authors build on their past attempts to reconstruct a 3D, time-varying bolus of radiotracer from first-pass data obtained by the dynamic SPECT imager, FASTSPECT, built by the University of Arizona. The object imaged is a CardioWest total artificial heart. The bolus is entirely contained in one ventricle and its associated inlet and outlet tubes. The model for the radiotracer distribution at a given time is a closed surface parameterized by 482 vertices that are connected to make 960 triangles, with nonuniform intensity variations of radiotracer allowed inside the surface on a voxel-to-voxel basis. The total curvature of the surface is minimized through the use of a weighted prior in the Bayesian framework, as is the weighted norm of the gradient of the voxellated grid. MAP estimates for the vertices, interior intensity voxels and background count level are produced. The strength of the priors, or hyperparameters, are determined by maximizing the probability of the data given the hyperparameters, called the evidence. The evidence is calculated by first assuming that the posterior is approximately normal in the values of the vertices and voxels, and then by evaluating the integral of the multi-dimensional normal distribution. This integral (which requires evaluating the determinant of a covariance matrix) is computed by applying a recent algorithm from Bai et. al. that calculates the needed determinant efficiently. They demonstrate that the radiotracer is highly inhomogeneous in early time frames, as suspected in earlier reconstruction attempts that assumed a uniform intensity of radiotracer within the closed surface, and that the optimal choice of hyperparameters is substantially different for different time frames.

  7. Plate Like Convection with Viscous Strain Weakening and Corresponding Surface Deformation Pattern

    Science.gov (United States)

    Fuchs, L.; Becker, T. W.

    2017-12-01

    How plate tectonic surface motions are generated by mantle convection on Earth and possibly other terrestrial type planets has recently become more readily accessible with fully dynamic convection computations. However, it remains debated how plate-like the behavior in such models truly is, and in particular how the well plate boundary dynamics are captured in models which typically exclude the effects of deformation history and memory. Here, we analyze some of the effects of viscous strain weakening on plate behavior and the interactions between interior convection dynamics and surface deformation patterns. We use the finite element code CitcomCU to model convection in a 3D Cartesian model setup. The models are internally heated, with an Arrhenius-type temperature dependent viscosity including plastic yielding and viscous strain weakening (VSW) and healing (VSWH). VSW can mimic first order features of more complex damage mechanisms such as grain-size dependent rheology. Besides plate diagnostic parameters (Plateness, Mobility, and Toroidal: Poloidal ratio) to analyze the tectonic behavior our models, we also explore how "plate boundaries" link to convective patterns. In a first model series, we analyze general surface deformation patterns without VSW. In the early stages, deformation patterns are clearly co-located with up- and downwelling limbs of convection. Along downwellings strain-rates are high and localized, whereas upwellings tend to lead to broad zones of high deformation. At a more advanced stage, however, the plates' interior is highly deformed due to continuous strain accumulation and resurfaced inherited strain. Including only VSW leads to more localized deformation along downwellings. However, at a more advanced stage plate-like convection fails due an overall weakening of the material. This is prevented including strain healing. Deformation pattern at the surface more closely coincide with the internal convection patterns. The average surface

  8. A connectionist-geostatistical approach for classification of deformation types in ice surfaces

    Science.gov (United States)

    Goetz-Weiss, L. R.; Herzfeld, U. C.; Hale, R. G.; Hunke, E. C.; Bobeck, J.

    2014-12-01

    Deformation is a class of highly non-linear geophysical processes from which one can infer other geophysical variables in a dynamical system. For example, in an ice-dynamic model, deformation is related to velocity, basal sliding, surface elevation changes, and the stress field at the surface as well as internal to a glacier. While many of these variables cannot be observed, deformation state can be an observable variable, because deformation in glaciers (once a viscosity threshold is exceeded) manifests itself in crevasses.Given the amount of information that can be inferred from observing surface deformation, an automated method for classifying surface imagery becomes increasingly desirable. In this paper a Neural Network is used to recognize classes of crevasse types over the Bering Bagley Glacier System (BBGS) during a surge (2011-2013-?). A surge is a spatially and temporally highly variable and rapid acceleration of the glacier. Therefore, many different crevasse types occur in a short time frame and in close proximity, and these crevasse fields hold information on the geophysical processes of the surge.The connectionist-geostatistical approach uses directional experimental (discrete) variograms to parameterize images into a form that the Neural Network can recognize. Recognizing that each surge wave results in different crevasse types and that environmental conditions affect the appearance in imagery, we have developed a semi-automated pre-training software to adapt the Neural Net to chaining conditions.The method is applied to airborne and satellite imagery to classify surge crevasses from the BBGS surge. This method works well for classifying spatially repetitive images such as the crevasses over Bering Glacier. We expand the network for less repetitive images in order to analyze imagery collected over the Arctic sea ice, to assess the percentage of deformed ice for model calibration.

  9. Bone surface extraction from MR images of a temporomandibular joint using deformable modeling technique

    International Nuclear Information System (INIS)

    Miura, Amane; Hattori, Yoshinori; Watanabe, Makoto; Tsukahara, Yasuo

    1999-01-01

    This paper presents a two-step method, based on magnetic resonance (MR) images, for three-dimensional reconstruction of osseous components of a temporomandibular joint (TMJ), the mandibular condyle and the fossa. In the first step, images were segmented in order to extract the bony outline (contour) by using a two-dimensional deformable model. An object in the model was extracted by deforming the initial contour located near the object of the image. In the second step, using the surface reconstructed from the extracted contour as the initial surface, a three-dimensional deformable model was applied in order to extract the surface of the object. These procedures were handled semi-automatically. Multi-section 1-mm-thick sagittal images of the right normal TMJ were obtained with a 1.5-T MR system and surface coils by using a FLASH-3D sequence (TR=50 ms, TE=11 ms) from an asymptomatic volunteer (male, age 31 years). From these images, the bony surfaces of TMJ were extracted using the above-mentioned method. Even though the extracted surfaces were a little smaller than the surface traced by experienced dentists, they showed the normal, anatomical form of TMJ. (author)

  10. The design procedures on brick building against surface ground deformations due to mining and earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, J.; Yang, S. (China University of Mining and Technology (China))

    1992-05-01

    By analysing the effects of ground motion and deformation on surface buildings, and drawing on the experience of damages caused by the Tangshan and Chenhai earthquakes, the authors discuss the design of brick and concrete buildings which are protected against the damaging effects of both earthquakes and mining activities. 5 figs.

  11. Surface layers' real structure of metals exposed to inhomogeneous thermal fields and plastic deformation

    Czech Academy of Sciences Publication Activity Database

    Pala, Z.; Ganev, N.; Drahokoupil, Jan; Sveshnikov, Alexey

    2010-01-01

    Roč. 163, - (2010), s. 59-63 ISSN 1012-0394. [21st Conference on Applied Crystallography. Zakopane, 20.09.2009-24.09.2009] Institutional research plan: CEZ:AV0Z10100520; CEZ:AV0Z10100521 Keywords : residual stress * grain size * surface treatment * thermal fields * plastic deformation Subject RIV: BM - Solid Matter Physics ; Magnetism

  12. Influence of plastic deformation on low temperature surface hardening of stainless steel by gaseous nitriding

    DEFF Research Database (Denmark)

    Bottoli, Federico; Winther, Grethe; Christiansen, Thomas Lundin

    2015-01-01

    This article addresses an investigation of the influence of plastic deformation on low temperature surface hardening by gaseous nitriding of three commercial austenitic stainless steels: AISI 304, EN 1.4369 and Sandvik Nanoflex® with various degrees of austenite stability. The materials were plas...

  13. Adhesion, Deformation, Rolling, and Detachment of a Liquid Capsule on An Adhesive Surface In Shear Flow

    Science.gov (United States)

    Pappu, Vijay; Bagchi, Prosenjit

    2008-11-01

    3D computational modeling and simulation are presented on adhesion, deformation, rolling and detachment of a liquid capsule on adhesive surfaces in shear flow with an objective to understand the adhesive rolling motion of biological cells, such as leukocyte and cancel cells, and the coupling between cell deformation and biophysics of the adhesive bonds. The computational model is based on an immersed boundary method for deformable capsules, and a finite difference-Fourier transform technique for solving the complete Navier-Stokes equations. The flow solver is coupled with a Monte Carlo simulation representing random process for bond formation and breakage between the capsule and the adhesive surface. Becuase of the stochastic process of bond formation and breakage, the roling motion is comprised of intermittent ``stops-and-runs'' which is well-known for biological cells such as leukocytes, which is reproduced in our simulations. The major objective of this talk is to present phase diagrams for cell adhesion which are obtained in terms of the critical bond strength as a function of cell deformability and biophysical parameters of the adhesion bonds. Through these phase diagrams, we elucidate the role of the hydrodynamic lift force, that exists on an wall- bounded deformable particle in shear flow, in the process of cell capture. Funded by NSF (BES-0603035 and CTS-0625936).

  14. Real-time 3D visualization of the thoraco-abdominal surface during breathing with body movement and deformation extraction

    International Nuclear Information System (INIS)

    Povšič, K; Jezeršek, M; Možina, J

    2015-01-01

    Real-time 3D visualization of the breathing displacements can be a useful diagnostic tool in order to immediately observe the most active regions on the thoraco-abdominal surface. The developed method is capable of separating non-relevant torso movement and deformations from the deformations that are solely related to breathing. This makes it possible to visualize only the breathing displacements. The system is based on the structured laser triangulation principle, with simultaneous spatial and color data acquisition of the thoraco-abdominal region. Based on the tracking of the attached passive markers, the torso movement and deformation is compensated using rigid and non-rigid transformation models on the three-dimensional (3D) data. The total time of 3D data processing together with visualization equals 20 ms per cycle.In vitro verification of the rigid movement extraction was performed using the iterative closest point algorithm as a reference. Furthermore, a volumetric evaluation on a live subject was performed to establish the accuracy of the rigid and non-rigid model. The root mean square deviation between the measured and the reference volumes shows an error of  ±0.08 dm 3 for rigid movement extraction. Similarly, the error was calculated to be  ±0.02 dm 3 for torsional deformation extraction and  ±0.11 dm 3 for lateral bending deformation extraction. The results confirm that during the torso movement and deformation, the proposed method is sufficiently accurate to visualize only the displacements related to breathing. The method can be used, for example, during the breathing exercise on an indoor bicycle or a treadmill. (paper)

  15. Finite-element analysis of the deformation of thin Mylar films due to measurement forces.

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Michael Sean; Robinson, Alex Lockwood; Tran, Hy D.

    2012-01-01

    Significant deformation of thin films occurs when measuring thickness by mechanical means. This source of measurement error can lead to underestimating film thickness if proper corrections are not made. Analytical solutions exist for Hertzian contact deformation, but these solutions assume relatively large geometries. If the film being measured is thin, the analytical Hertzian assumptions are not appropriate. ANSYS is used to model the contact deformation of a 48 gauge Mylar film under bearing load, supported by a stiffer material. Simulation results are presented and compared to other correction estimates. Ideal, semi-infinite, and constrained properties of the film and the measurement tools are considered.

  16. Deformation of the Pannonian lithosphere and related tectonic topography: a depth-to-surface analysis

    OpenAIRE

    Dombrádi, E.

    2012-01-01

    Fingerprints of deep-seated, lithospheric deformation are often recognised on the surface, contributing to topographic evolution, drainage organisation and mass transport. Interactions between deep and surface processes were investigated in the Carpathian-Pannonian region. The lithosphere beneath the Pannonian basin has formerly been extended, significantly stretched and heated up and thus became extremely weak from a rheological point of view. From Pliocene times onward the ‘crème brulee’ ty...

  17. Measurement of Rotorcraft Blade Deformation Using Projection Moiré Interferometry

    Directory of Open Access Journals (Sweden)

    Gary A. Fleming

    2000-01-01

    Full Text Available Projection Moiré Interferometry (PMI has been used to obtain near instantaneous, quantitative blade deformation measurements of a generic rotorcraft model at several test conditions. These laser-based measurements provide quantitative, whole field, dynamic blade deformation profiles conditionally sampled as a function of rotor azimuth. The instantaneous nature of the measurements permits computation of the mean and unsteady blade deformation, blade bending, and twist. The PMI method is presented, and the image processing steps required to obtain quantitative deformation profiles from PMI interferograms are described. Experimental results are provided which show blade bending, twist, and unsteady motion. This initial proof-of-concept test has demonstrated the capability of PMI to acquire accurate, full field rotorcraft blade deformation data.

  18. Analyzing the Potential for Unmanned Aerial Systems (UAS) Photogrammetry in Estimating Surface Deformations at a Geothermal Fiel

    Science.gov (United States)

    Pai, H.; Burnett, J.; Sladek, C.; Wing, M.; Feigl, K. L.; Selker, J. S.; Tyler, S.; Team, P.

    2016-12-01

    UAS systems equipped with a variety of spectral imaging devices are increasingly incorporated in spatial environmental assessments of continental surfaces (e.g., digital elevation maps, vegetative coverage classifications, surface temperatures). This presented work performed by the UAS team at the Center for Transformative Environmental Monitoring Programs (AirCTEMPS) examines the potential to measure small (sub-cm) deformation from a geothermal injection experiment at Brady's geothermal field in western Nevada (USA). Areal mapping of the 700 x 270 m area of interest was conducted with a nadir pointing Sony A5100 digital camera onboard an autopiloted quadcopter. A total of 16 ground control points were installed using a TopCon GR3 GPS receiver. Two such mapping campaigns were conducted with one before and one after an anticipated surface deformation event. A digital elevation map (DEM) for each time period was created from over 1500 images having 80% overlap/sidelap by using structure from motion (SfM) via Agisoft Photoscan software. The resulting DEM resolution was 8 mm/pixel with residual aerial triangulation errors was < 5 mm. We present preliminary results from an optimized workflow which achieved errors and average differential DEM heights between campaigns at the cm-scale which is broader than the maximum expected deformation. Despite the disconnect between error and deformation severity, this study presents a unique application of sub-cm UAS-based DEMs and further distinguishes itself by comparing results to concurrent Interferometric Synthetic Radar (InSAR). The intent of our study and presentation of results is to streamline, cross-validate, and share methods to encourage further adoption of UAS imagery into the standard toolkit for environmental surface sensing across spatial scales.

  19. Optical coherence elastography for measuring the deformation within glass fiber composite

    NARCIS (Netherlands)

    Liu, P.; Groves, R.M.; Benedictus, R.

    2014-01-01

    Optical coherence elastography (OCE) has been applied to the study of microscopic deformation in biological tissue under compressive stress for more than a decade. In this paper, OCE has been extended for the first time, to the best of our knowledge, to deformation measurement in a glass fiber

  20. Surface Plastic Deformation and Nanocrystallization Mechanism of Welded Joint of 16MnR Steel Treated by Ultrasonic Impact

    Directory of Open Access Journals (Sweden)

    Yingxia YU

    2015-11-01

    Full Text Available The welded joint surfaces of 16MnR steel were treated using an ultrasonic impact machine. The effects of ultrasonic impact treating (UIT on the plastic deformation and nanocrystallization mechanism of the welded joints of 16MnR steel were studied. The micro-structural features of the surface layer produced by UIT were observed by scanning electron microscopy (SEM and high resolution transmission electron microscopy (HRTEM, and micro-hardness measurements were performed. Experimental results showed that the thickness of the plastic deformation layer was approximately 80 μm. It was found that grains in the surfaces of the welded joints of 16MnR were greatly refined by UIT. Obvious grain refinement was observed, with resultant gain sizes less than 100nm. The micro-hardness of the treated surface layer of the welded joint was enhanced significantly compared to that of the un-treated sample. The micro-hardness on the treated surface of the welded joint was 62.3% higher than that of the un-treated surface.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9563

  1. SBAS Analysis of Induced Ground Surface Deformation from Wastewater Injection in East Central Oklahoma, USA

    Directory of Open Access Journals (Sweden)

    Elizabeth Loesch

    2018-02-01

    Full Text Available The state of Oklahoma has experienced a dramatic increase in the amount of measurable seismic activities over the last decade. The needs of a petroleum-driven world have led to increased production utilizing various technologies to reach energy reserves locked in tight formations and stimulate end-of-life wells, creating significant amounts of undesirable wastewater ultimately injected underground for disposal. Using Phased Array L-band Synthetic Aperture Radar (PALSAR data, we performed a differential Synthetic Aperture Radar Interferometry (InSAR technique referred to as the Small BAseline Subset (SBAS-based analysis over east central Oklahoma to identify ground surface deformation with respect to the location of wastewater injection wells for the period of December 2006 to January 2011. Our results show broad spatial correlation between SBAS-derived deformation and the locations of injection wells. We also observed significant uplift over Cushing, Oklahoma, the largest above ground crude oil storage facility in the world, and a key hub of the Keystone Pipeline. This finding has significant implications for the oil and gas industry due to its close proximity to the zones of increased seismicity attributed to wastewater injection. Results southeast of Drumright, Oklahoma represent an excellent example of the potential of InSAR, identifying a fault bordered by an area of subduction to the west and uplift to the east. This differentiated movement along the fault may help explain the lack of any seismic activity in this area, despite the large number of wells and high volume of fluid injected.

  2. A preliminary study on surface ground deformation near shallow foundation induced by strike-slip faulting

    Science.gov (United States)

    Wong, Pei-Syuan; Lin, Ming-Lang

    2016-04-01

    According to investigation of recent earthquakes, ground deformation and surface rupture are used to map the influenced range of the active fault. The zones of horizontal and vertical surface displacements and different features of surface rupture are investigated in the field, for example, the Greendale Fault 2010, MW 7.1 Canterbury earthquake. The buildings near the fault rotated and displaced vertically and horizontally due to the ground deformation. Besides, the propagation of fault trace detoured them because of the higher rigidity. Consequently, it's necessary to explore the ground deformation and mechanism of the foundation induced by strike-slip faulting for the safety issue. Based on previous study from scaled analogue model of strike-slip faulting, the ground deformation is controlled by material properties, depth of soil, and boundary condition. On the condition controlled, the model shows the features of ground deformation in the field. This study presents results from shear box experiment on small-scale soft clay models subjected to strike-slip faulting and placed shallow foundations on it in a 1-g environment. The quantifiable data including sequence of surface rupture, topography and the position of foundation are recorded with increasing faulting. From the result of the experiment, first en echelon R shears appeared. The R shears rotated to a more parallel angle to the trace and cracks pulled apart along them with increasing displacements. Then the P shears crossed the basement fault in the opposite direction appears and linked R shears. Lastly the central shear was Y shears. On the other hand, the development of wider zones of rupture, higher rising surface and larger the crack area on surface developed, with deeper depth of soil. With the depth of 1 cm and half-box displacement 1.2 cm, en echelon R shears appeared and the surface above the fault trace elevated to 1.15 mm (Dv), causing a 1.16 cm-wide zone of ground-surface rupture and deformation

  3. SURFACE DEFORMATIONS NEAR THE BAIKAL–AMUR RAILWAY FROM DIFFERENTIAL SAR INTERFEROMETRY DATA

    Directory of Open Access Journals (Sweden)

    M. A. Lebedeva

    2016-01-01

    Full Text Available This paper presents SAR interferometric data obtained in the study of surface deformations of different origin within the Upper Angara-Muya interbasin link of the northeastern segment of the Baikal rift system, Russia. Differential SAR interferometry using images with small perpendicular baselines was applied in this geodynamical study. The potential of using ENVISAT/ASAR and ALOS/PALSAR data is discussed. New geodynamical data on recent strain patterns were obtained. The endogenous linear-localized and areal deformations were revealed in the influence zone of the active Muyakan fault. The origin of these deformations is discussed. The landslide that negatively affects the Baikal-Amur railway facilities is also studied. The use of SAR data for detailed study and monitoring of the landslide is discussed. It is confirmed that natural hazard in the study area is growing due to the ongoing landsliding.

  4. Subsurface deformation measurements during a fast shallow landslide triggered by rainfall

    Science.gov (United States)

    Askarinejad, Amin; Springman, Sarah M.; Akca, Devrim; Bleiker, Ernst; Gruen, Armin

    2010-05-01

    A forested area in Ruedlingen, northern Switzerland, was selected to investigate the geotechnical and hydrological response of a steep slope prior to a rainfall induced failure. Artificial rainfall was applied according to a pre-planned schedule and parameters such as pore water pressure, volumetric water content, horizontal soil pressure, temperature, piezometric water level and subsurface deformations were monitored. The latter were determined from four deformation probes that were developed in the Institute for Geotechnical Engineering, ETHZ. Strain gauges have been attached at a regular spacing along a long, slender, flexible plate to enable measurements of bending strain to be made at different points along it. The strain gauges were connected as 'half bridges' to minimize the temperature effects. A biaxial inclinometer was also installed on the top of the plate, 20 cm above the soil surface, to measure the tilt above ground level, providing more boundary conditions to determine the deformed shape of the probe. The probe is installed vertically inside the soil, while the lowest part is grouted into the stiffer layer under the topsoil, and is assumed to be stable and without any rotation. Bending strains and the inclination at the top of the probe are sampled at a frequency of 100 Hz. These are input into an algorithm to determine a polynomial relationship of deformations and rotations with depth, so that the initiation of slow movements and propagation of failure during fast soil mass movements can be examined. A 4-camera arrangement was used for the image acquisition to monitor surface movements using photogrammetric analyses. Approximately 250 white ping-pong balls were attached to the ground and used as target points. Using a network simulation tool that was developed in-house, an a priori point positioning accuracy of the ping-pong balls was estimated to be ± 10.3 mm along the horizontal direction and ± 3.5 mm in the vertical direction. The cameras

  5. Fermi surface deformation in a simple iron-based superconductor, FeSe

    Science.gov (United States)

    Coldea, Amalia; Watson, Matthew; Kim, Timur; Haghighirad, Amir; McCollam, Alix; Hoesch, Moritz; Schofield, Andrew

    2015-03-01

    One of the outstanding problems in the field superconductivity is the identification of the normal state out of which superconductivity emerges. FeSe is one of the simplest and most intriguing iron-based superconductors, since in its bulk form it undergoes a structural transition before it becomes superconducting, whereas its single-layer form is believed to be a high-temperature superconductor. The nature of the structural transition, occurring in the absence of static magnetism, is rather unusual and how the electronic structure is stabilized by breaking of the rotational symmetry is the key to understand the superconductivity in bulk FeSe. Here we report angle-resolved photoemission spectroscopy measurements on FeSe that gives direct access to the band structure and orbital-dependent effects. We complement our studies on bulk FeSe with low-temperature angular-dependent quantum oscillation measurements using applied magnetic fields that are sufficiently strong to suppress superconductivity and reach the normal state. These studies reveal a strong deformation of Fermi surface through the structural transition driven by electronic correlations and orbital-dependent effects. . This work was supported by EPSRC, UK (EP/I004475/1), Diamond Light Source, UK and HFML, Nijmegen.

  6. Dynamic surface deformation of silicone elastomers for management of marine biofouling: laboratory and field studies using pneumatic actuation.

    Science.gov (United States)

    Shivapooja, Phanindhar; Wang, Qiming; Szott, Lizzy M; Orihuela, Beatriz; Rittschof, Daniel; Zhao, Xuanhe; López, Gabriel P

    2015-01-01

    Many strategies have been developed to improve the fouling release (FR) performance of silicone coatings. However, biofilms inevitably build on these surfaces over time. Previous studies have shown that intentional deformation of silicone elastomers can be employed to detach biofouling species. In this study, inspired by the methods used in soft-robotic systems, controlled deformation of silicone elastomers via pneumatic actuation was employed to detach adherent biofilms. Using programmed surface deformation, it was possible to release > 90% of biofilm from surfaces in both laboratory and field environments. A higher substratum strain was required to remove biofilms accumulated in the field environment as compared with laboratory-grown biofilms. Further, the study indicated that substratum modulus influences the strain needed to de-bond biofilms. Surface deformation-based approaches have potential for use in the management of biofouling in a number of technological areas, including in niche applications where pneumatic actuation of surface deformation is feasible.

  7. Measurement of Local Deformations in Steel Monostrands Using Digital Image Correlation

    DEFF Research Database (Denmark)

    Winkler, Jan; Fischer, Gregor; Georgakis, Christos T.

    2014-01-01

    , difficulties with the placement of strain gauges in the vicinity of the anchorage, and, most importantly, the relatively small magnitude of deformation occurring in the monostrand. This paper focuses on the measurement of localized deformations in high-strength steel monostrands using the digital image......The local deformation mechanisms in steel monostrands have a significant influence on their fatigue life and failure mode. However, the observation and quantification of deformations in monostrands experiencing axial and transverse deformations is challenging because of their complex geometry....... To validate the proposed image-based measurement method, two different tests were performed, with the one correlation method showing good agreement. Data collected from the DIC technique creates a basis for the analysis of the fretting and localized bending behavior of the monostrand and provides relevant...

  8. Utilization of InSAR differential interferometry for surface deformation detection caused by mining

    Energy Technology Data Exchange (ETDEWEB)

    Yang, F. [Liaoning Technical Univ., Fuxin (China). School of Geomatics; Shao, Y. [Liaoning Technical Univ., Fuxin (China). Dept. of Foreign Language; Guichen, M. [Gifu Univ., Yanagido, Gifu (Japan). Dept. of Civil Engineering

    2010-07-01

    In China, the surface deformation of ground has been a significant geotechnical problem as a result of cracks in the ground surface, collapsing of house, and subsidence of roads. A powerful technology for detecting surface deformation in the ground is differential interferometry using synthetic aperture radar (INSAR). The technology enables the analysis from different phase of micro-wave between two observed data by synthetic aperture radar (SAR) of surface deformation of ground such as ground subsidence, land slide, and slope failure. In January 2006, the advanced land observing satellite was launched by the Japan Aerospace Exploration Agency. This paper presented an analytical investigation to detect ground subsidence or change caused by mining, overuse of ground water, and disaster. Specifically, the paper discussed the INSAR monitoring technology of the mine slope, including INSAR data sources and processing software; the principle of synthetic aperture radar interferometry; principles of differential SAR interferometry; and INSAR technology to slope monitoring of the Haizhou open pit mine. The paper also discussed the Haizhou strip mine side slope INSAR monitoring results and tests. It was concluded that the use of synthetic aperture radar interferometer technique was the optimal technique to provide three-dimensional spatial information and minimal change from ground surface by spatial remote sensing device. 18 refs., 5 figs.

  9. Dynamics of a slowly evaporating solvent-polymer mixture with a deformable upper surface

    KAUST Repository

    Hennessy, M. G.

    2014-06-17

    This paper examines how surface deformations affect the stability of a slowly evaporating solvent-polymer mixture. The destabilizing effect of surface-tension variations arising from evaporation-induced concentration gradients and the counteracting influence of mean gravity and surface tension are incorporated into the mathematical model. A linear stability analysis that takes advantage of the separation between the characteristic time scales of the slowly evolving base state and the perturbations is carried out in combination with numerical solutions of the linearized system. It is shown that the onset of instability can occur for Marangoni numbers that are much lower than the critical value for a non-deformable surface. Moreover, two types of Marangoni instabilities appear in the system: one is associated with the traditional stationary instability, and the other is an oscillatory instability that is not present for a non-deformable liquid surface. A region of the parameter space where the oscillatory instability dominates is identified and used to formulate appropriate conditions for future experiments. © 2014 The authors 2014. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

  10. Surface severe plastic deformation of AISI 304 via conventional shot peening, severe shot peening and repeening

    Energy Technology Data Exchange (ETDEWEB)

    Unal, Okan, E-mail: unalokan78@gmail.com [Mechanical Engineering Department, Bartın University, Bartın 74100 (Turkey); Varol, Remzi [Mechanical Engineering Department, Suleyman Demirel University, Isparta 32200 (Turkey)

    2015-10-01

    Highlights: • CSP and SSP treatments transform austenite to metastable martensite structure. • Nanograin layer thickness after CSP and SSP is 8 μm and 22 μm, respectively. • Shot peening leads to carbon segregation from coarse to nano grain layer. • Repeening is an effective way to reduce surface roughness. - Abstract: Air blast conventional shot peening (CSP), severe shot peening (SSP) and repeening (RP) as a severe plastic deformation applications on AISI 304 austenitic stainless steel is addressed. Shot peened specimens are investigated based on optical, FESEM and digital microscope. The investigations present the austenite transformation to metastable martensite via mechanical twinning due to plastic deformation with high strain rates. It is found that SSP induces thicker nanograin layer with compared to CSP. In XRD studies, the austenite peaks broaden by means of severe shot peening and FWHM increase reveals the grain size reduction below 25 nm regimes on the surface. In EDAX line analysis of CSP specimen, carbon content increase has been detected from deformed layer through the nanocrystalline layer then the content reduces. The carbon segregation takes place due to the energy level distinction between dislocations and Fe−C bonds. 3d contour digital microscope studies and roughness investigations reveal that SSP has deleterious side effect on the surface roughness and surface flatness. However, RP is an effective way to reduce the surface roughness to reasonable values.

  11. Roughness parameters as the elements of surface condition and deformation assessment based on the results of TLS scanning

    Directory of Open Access Journals (Sweden)

    Kowalska Maria E.

    2017-03-01

    Full Text Available Roughness parameters as the elements of surface condition and deformation assessment based on the results of TLS scanning. Roughness is the attribute of a surface that can be defined as a collection of small surface unevennesses that can be identified optically or detected mechanically which do not result from the surface’s shape and their size depends on a material type as well as on undergone processing. The most often utilised roughness parameters are: Ra - mean distance value of the points on the observed profile from the average line on the sampling length, and Rz - difference between arithmetic mean height of the five highest peaks and arithmetic mean depth of the five deepest valleys regarding to the average line on the length of the measured fragment. In practice, roughness parameters are most often defined for surface elements that require relevant manufacturing or processing through grinding, founding or polishing in order to provide the expected surface roughness. To measure those parameters for the produced elements profilometers are used. In this paper the authors present an alternative approach of determining and utilising such parameters. Instead of the utilising methods based on sampling length measurement, roughness parameters are determined on the basis of point clouds, that represent a surface of rough concrete, obtained through terrestrial laser scanning. The authors suggest using the surface roughness parameter data acquired in this way as a supplementary data in the condition assessment (erosion rate of surfaces being a part of engineering constructions made of concrete.

  12. In situ measurement of grain rotation during deformation of polycrystals

    DEFF Research Database (Denmark)

    Margulies, L.; Winther, G.; Poulsen, H.F.

    2001-01-01

    Texture evolution governs many of the physical, chemical, and mechanical properties of polycrystalline materials, but texture models have only been tested on the macroscopic Level, which makes it hard to distinguish between approaches that are conceptually very different. Here, we present...... a universal method for providing data on the underlying structural dynamics at the grain and subgrain Level. The method is based on diffraction with focused hard x-rays, First results relate to the tensile deformation of pure aluminum. Experimental grain rotations are inconsistent with the classical Taylor...

  13. TH-CD-207A-05: Lung Surface Deformation Vector Fields Prediction by Monitoring Respiratory Surrogate Signals

    International Nuclear Information System (INIS)

    Nasehi Tehrani, J; Wang, J; McEwan, A

    2016-01-01

    Purpose: In this study, we developed and evaluated a method for predicting lung surface deformation vector fields (SDVFs) based on surrogate signals such as chest and abdomen motion at selected locations and spirometry measurements. Methods: A Patient-specific 3D triangular surface mesh of the lung region at end-expiration (EE) phase was obtained by threshold-based segmentation method. For each patient, a spirometer recorded the flow volume changes of the lungs; and 192 selected points at a regular spacing of 2cm X 2cm matrix points over a total area of 34cm X 24cm on the surface of chest and abdomen was used to detect chest wall motions. Preprocessing techniques such as QR factorization with column pivoting (QRCP) were employed to remove redundant observations of the chest and abdominal area. To create a statistical model between the lung surface and the corresponding surrogate signals, we developed a predictive model based on canonical ridge regression (CRR). Two unique weighting vectors were selected for each vertex on the surface of the lung, and they were optimized during the training process using the all other phases of 4D-CT except the end-inspiration (EI) phase. These parameters were employed to predict the vertices locations of a testing data set, which was the EI phase of 4D-CT. Results: For ten lung cancer patients, the deformation vector field of each vertex of lung surface mesh was estimated from the external motion at selected positions on the chest wall surface plus spirometry measurements. The average estimation of 98th percentile of error was less than 1 mm (AP= 0.85, RL= 0.61, and SI= 0.82). Conclusion: The developed predictive model provides a non-invasive approach to derive lung boundary condition. Together with personalized biomechanical respiration modelling, the proposed model can be used to derive the lung tumor motion during radiation therapy accurately from non-invasive measurements.

  14. TH-CD-207A-05: Lung Surface Deformation Vector Fields Prediction by Monitoring Respiratory Surrogate Signals

    Energy Technology Data Exchange (ETDEWEB)

    Nasehi Tehrani, J; Wang, J [UT Southwestern Medical Center, Dallas, TX (United States); McEwan, A [The University of Sydney, Sydney, New South Wales (Australia)

    2016-06-15

    Purpose: In this study, we developed and evaluated a method for predicting lung surface deformation vector fields (SDVFs) based on surrogate signals such as chest and abdomen motion at selected locations and spirometry measurements. Methods: A Patient-specific 3D triangular surface mesh of the lung region at end-expiration (EE) phase was obtained by threshold-based segmentation method. For each patient, a spirometer recorded the flow volume changes of the lungs; and 192 selected points at a regular spacing of 2cm X 2cm matrix points over a total area of 34cm X 24cm on the surface of chest and abdomen was used to detect chest wall motions. Preprocessing techniques such as QR factorization with column pivoting (QRCP) were employed to remove redundant observations of the chest and abdominal area. To create a statistical model between the lung surface and the corresponding surrogate signals, we developed a predictive model based on canonical ridge regression (CRR). Two unique weighting vectors were selected for each vertex on the surface of the lung, and they were optimized during the training process using the all other phases of 4D-CT except the end-inspiration (EI) phase. These parameters were employed to predict the vertices locations of a testing data set, which was the EI phase of 4D-CT. Results: For ten lung cancer patients, the deformation vector field of each vertex of lung surface mesh was estimated from the external motion at selected positions on the chest wall surface plus spirometry measurements. The average estimation of 98th percentile of error was less than 1 mm (AP= 0.85, RL= 0.61, and SI= 0.82). Conclusion: The developed predictive model provides a non-invasive approach to derive lung boundary condition. Together with personalized biomechanical respiration modelling, the proposed model can be used to derive the lung tumor motion during radiation therapy accurately from non-invasive measurements.

  15. Autocollimation system for measuring angular deformations with reflector designed by quaternionic method

    Science.gov (United States)

    Hoang, Phong V.; Konyakhin, Igor A.

    2017-06-01

    Autocollimators are widely used for angular measurements in instrument-making and the manufacture of elements of optical systems (wedges, prisms, plane-parallel plates) to check their shape parameters (rectilinearity, parallelism and planarity) and retrieve their optical parameters (curvature radii, measure and test their flange focusing). Autocollimator efficiency is due to the high sensitivity of the autocollimation method to minor rotations of the reflecting control element or the controlled surface itself. We consider using quaternions to optimize reflector parameters during autocollimation measurements as compared to the matrix technique. Mathematical model studies have demonstrated that the orthogonal positioning of the two basic unchanged directions of the tetrahedral reflector of the autocollimator is optimal by the criterion of reducing measurement errors where the axis of actual rotation is in a bisecting position towards them. Computer results are presented of running quaternion models that yielded conditions for diminishing measurement errors provided apriori information is available on the position of rotation axis. A practical technique is considered for synthesizing the parameters of the tetrahedral reflector that employs the newly-retrieved relationships. Following the relationships found between the angles of the tetrahedral reflector and the angles of the parameters of its initial orientation, an applied technique was developed to synthesize the control element for autocollimation measurements in case apriori information is available on the axis of actual rotation during monitoring measurements of shaft or pipeline deformation.

  16. A Computational Study of Plastic Deformation in AISI 304 Induced by Surface Mechanical Attrition Treatment

    Science.gov (United States)

    Zhang, X. C.; Lu, J.; Shi, S. Q.

    2010-05-01

    As a technique of grain refinement process by plastic deformation, surface mechanical attrition treatment (SMAT) has been developed to be one of the most effective ways to optimize the mechanical properties of various materials including pure metals and alloys. SMAT can significantly reduce grain size into nanometer regime in the surface layer of bulk materials, providing tremendous opportunities for improving physical, chemical and mechanical properties of the materials. In this work, a computational modeling of the surface mechanical attrition treatment (SMAT) process is presented, in which Johnson-Cook plasticity model and the finite element method were employed to study the high strain rate, elastic-plastic dynamic process of ball impact on a metallic target. AISI 304 steel with low stacking fault energy was chosen as the target material. First, a random impact model was used to analyze the statistic characteristics of ball impact, and then the plastic deformation behavior and residual stress distribution in AISI 304 stainless steel during SMAT were studied. The simulation results show that the compressive residual stress and vertical deformation of the surface structures were directly affected by ball impact frequency, incident impact angle and ball diameter used in SMAT process.

  17. Stress partitioning behavior of multilayered steels during tensile deformation measured by in situ neutron diffraction

    International Nuclear Information System (INIS)

    Ojima, M.; Inoue, J.; Nambu, S.; Xu, P.; Akita, K.; Suzuki, H.; Koseki, T.

    2012-01-01

    Stress partitioning in multilayered steels consisting of martensitic and austenitic layers was measured during tensile deformation by in situ neutron diffraction measurements to investigate the mechanism of the improved strength–elongation balance. The deformation mode can be classified into three stages, and the results indicate that the applied stress is effectively transferred to the martensitic phase, because no stress concentration sites exist, owing to the multilayered structure. Hence, even as-quenched martensite deformed uniformly, resulting in improved strength–elongation balance in multilayered steels.

  18. Shape and deformation measurements of 3D objects using volume speckle field and phase retrieval

    DEFF Research Database (Denmark)

    Anand, A; Chhaniwal, VK; Almoro, Percival

    2009-01-01

    Shape and deformation measurement of diffusely reflecting 3D objects are very important in many application areas, including quality control, nondestructive testing, and design. When rough objects are exposed to coherent beams, the scattered light produces speckle fields. A method to measure the ......-sized deformation induced on a metal sheet was obtained upon subtraction of the phase, corresponding to unloaded and loaded states. Results from computer simulations confirm the experiments. (C) 2009 Optical Society of America....

  19. Measurements of residual deformations of steel-aluminum conductors in operating overhead lines

    Energy Technology Data Exchange (ETDEWEB)

    Durov, E.V.; Kesel' man, L.M.; Treiger, A.S.

    1982-12-01

    Experience in the operation of overhead power lines using steel-aluminum conductors is presented. Measurements were taken on the residual deformation of the steel-aluminum lines to determine the amount of sag increase and to forecast this increase for the entire period of operation. It is recommended that the work on measuring the residual deformation in the power lines be extended to a broader range of operating conditions such as conductors, spans, and climate conditions.

  20. 2011-2012 Campaign GPS Geodetic Monitoring of Surface Deformation, Dominica, Lesser Antilles

    Science.gov (United States)

    Miller, J. A.; Mattioli, G. S.; James, S. A.

    2012-12-01

    Over the last decade, ongoing campaign style geodetic surveys have been conducted on the volcanic island of Dominica in central portion of the Lesser Antilles island arc. An increase in shallow seismicity on the island, the first concentrated in the south from 1998-2000 and the second in the north in 2003, motivated initial measurements in 2001 at 9 sites distributed across Dominica. Subsequent GPS campaigns were conducted in 2003, 2004 and 2007, during which 18 new sites were added to the original network. In 2007, a total of 27 sites were occupied. The most recent data were collected from 13 sites in 2011 and 9 sites in 2012. Out of the 27 sites on the Island, 5 were not occupied during the 2011/2012 field seasons due to accessibility issues. All GPS data have been reprocessed using GIPSY-OASIS II (v. 6) with final, precise IGS08 orbits, clocks, and earth orientation parameters using an absolute point positioning strategy. The purpose of our study is to examine spatial and temporal changes in surface deformation, constrained by GPS, and to investigate the relationship between the recent seismic swarms and shallow volcanic processes.

  1. Progress Report On Techniques Deriving Land Cover And Earth Surface Deformation Information From Polarimetric SAR Interferometry

    Science.gov (United States)

    Pottier, E.; Chen, E.; Li, Z.; Hong, W.; Xiang, M.; Cloude, S. R.; Papathanassiou, K.; Cao, F.; Zhang, H.

    2010-10-01

    In this paper we provide an up-date of activities carried out under the DRAGON collaborative program in a project concerned with the application of Pol-InSAR to deriving land cover and Earth Surface deformation information. This project (ID. 5344) is based around four main scientific topics: Land Cover Analysis, Earth Surface Deformation Monitoring and DEM Extraction, Forest V ertical Structure Parameters Extraction and PolSARpro Software Development. We propose a brief summary of the project objectives and progress to date of each Work Packages, concentrating on different recent developments, original results and important highlights that have been presented during the Dragon2 Mid-Term Results Symposium, that was held on 17-21 May 2010, in Yangshuo, Guilin, P.R. China

  2. A study on the degradation evaluation for Cr-Mo steel in power plants by grain deformation measuring and ultrasonic method

    International Nuclear Information System (INIS)

    Lee, Sang Guk

    2002-01-01

    Boiler high-temperature pipelines such as main steam pipe, header and steam drum in fossil power plants are degraded by creep and thermal fatigue damage due to severe operating conditions such as high temperature and high pressure for an extended period time. Conventional measurement techniques for measuring creep damage have low practicality and applied only to component surfaces with good accessibility. In this paper, the grain deformation and ultrasonic measurement for degraded specimens were carried out for the purpose of a practical evaluation for creep damage. Relationships between the grain deformation and ultrasonic properties for material degradation were established through these two measuring methods. As a result of grain deformation and ultrasonic tests for crept specimens, we conformed that deformation index and sound velocity linearly decreased, and also attenuation coefficient and ultrasonic noise linearly increased in proportion to the increase of creep degradation, respectively.

  3. Surface Deformation Caused by a Shallow Magmatic Source at Okmok Volcano, Aleutian Arc

    Science.gov (United States)

    Miyagi, Y.; Freymueller, J. T.; Kimata, F.; Sato, T.; Mann, D.; Kasahara, M.

    2001-12-01

    Okmok Volcano, located on Umnak Island in the eastern Aleutian arc, last erupted in 1997. Okmok consists of a 10 km wide caldera with several cones located inside. Significant surface deformation before, during and after the eruption has been measured using InSAR. However, the area of coherent data has been limited to the northern part of the caldera, with some additional coherent areas along the outer flanks of the volcano. With support from NASDA (National Space Development Agency of Japan) and the International Arctic Research Center, we carried out GPS campaigns in 2000 and 2001 to supplement the InSAR data with 3D measurements of deformation at well-distributed points. We surveyed 24 sites on and around Okmok in 2000, and 31 sites in 2001. As of this date, no SAR data from suitable passes has been acquired in the summer of 2001; if any are acquired, we will also analyze this data. InSAR data for the period 1997-2000 show what appears to be a radially-symmetric pattern of displacements, consistent with the inflation of a shallow (3-4 km) pressure (Mogi) source located beneath the geoemtric center of the caldera. A deflation source at the same location and depth was inferred from an interferogram spanning the eruption. The 2000-2001 GPS data, on the other hand, show evidence for rapid horizontal extension between sites in center of the caldera. This signal cannot be explained by a Mogi source, and may represent the intrusion of a shallow dike. In addition to this probable dike source, it appears that overall inflation of the volcano continues. The proposed dike extends from roughly the center of the caldera toward the 1997 eruptive vent. In May 2001, a swarm of micro-earthquakes occurred somewhere close to Okmok Volcano (location errors are very large as the closest permanent seismic site is ~100 km from Okmok). It is possible that this small earthquake swarm could have been associated with the intrusion of the shallow dike.

  4. A model of short term surface deformation of Soufriere Hills Volcano, Montserrat, constrained by GPS geodesy

    Science.gov (United States)

    McPherson, E. E.; Mattioli, G. S.

    2013-05-01

    Soufriere Hills Volcano (SHV), Montserrat, in the Lesser Antilles island arc, became active in 1995, and for nearly two decades, ground breaking geodetic surveys have been conducted using both continuous GPS and campaign GPS sites. Data have been collected and processed using the latest and most advanced geodetic instruments and technique available. The NSF- funded CALIPSO and SEA-CALIPSO projects have allowed for some of the most in depth studies of the ongoing SHV eruptions to date, and many models for surface deformation and magmatic chamber configuration have resulted. Research for this study is constrained to data gathered from the early stages of eruption in 1996 through 2010 from two continuous GPS sites, Hermitage Peak (HERM - located ~1.6 km from the vent) and Montserrat Volcano Observatory 1 (MVO1- located ~7.6 km away from the vent) and have been reprocessed using GIPSY-OASIS II (v. 6.1.2) with final, precise IGS08 orbits, clocks, and earth orientation parameters using an absolute point positioning (APP) strategy. Our study is being conducted to re-examine spatial and temporal changes in surface deformation, constrained by GPS, and to better illuminate the short term (i.e. sub-daily to weekly) deformation signals noted amongst the longer, cyclic deformation signals (i.e. monthly to annually) that have been previously reported and modeled. The reprocessed time-series show lower variance for daily APP solutions over the entire temporal data set; trends in the long-term inflation and deflation patterns are similar to those previously published (e.g. Elsworth et al., 2008; Mattioli et al., 2010; Odbert et al., 2012), but now superimposed, shorter term signals are more clearly visible. New elastic deformation models are being developed and will be presented for these short-term signals.

  5. Equipment for measuring autogenous RH-change and autogenous deformation in cement paste and concrete

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Jensen, Ole Mejlhede

    1997-01-01

    Equipment for measuring autogenous RH-change and autogenous deformation in cement paste and concrete are presented. The equipment consists of a Rotronic Hygroskop DT including a measuring chamber for measuring autogenous RH-change in cement paste and concrete, a paste dilatometer for measuring...

  6. A novel surface mesh deformation method for handling wing-fuselage intersections

    Directory of Open Access Journals (Sweden)

    Mario Jaime Martin-Burgos

    2017-02-01

    Full Text Available This paper describes a method for mesh adaptation in the presence of intersections, such as wing-fuselage. Automatic optimization tools, using Computational Fluid Dynamics (CFD simulations, face the problem to adapt the computational grid upon deformations of the boundary surface. When mesh regeneration is not feasible, due to the high cost to build up the computational grid, mesh deformation techniques are considered a cheap approach to adapt the mesh to changes on the geometry. Mesh adaptation is a well-known subject in the literature; however, there is very little work which deals with moving intersections. Without a proper treatment of the intersections, the use of automatic optimization methods for aircraft design is limited to individual components. The proposed method takes advantage of the CAD description, which usually comes in the form of Non-Uniform Rational B-Splines (NURBS patches. This paper describes an algorithm to recalculate the intersection line between two parametric surfaces. Then, the surface mesh is adapted to the moving intersection in parametric coordinates. Finally, the deformation is propagated through the volumetric mesh. The proposed method is tested with the DLR F6 wing-body configuration.

  7. A Feasibility Study of Sea Ice Motion and Deformation Measurements Using Multi-Sensor High-Resolution Optical Satellite Images

    Directory of Open Access Journals (Sweden)

    Chang-Uk Hyun

    2017-09-01

    Full Text Available Sea ice motion and deformation have generally been measured using low-resolution passive microwave or mid-resolution radar remote sensing datasets of daily (or few days intervals to monitor long-term trends over a wide polar area. This feasibility study presents an application of high-resolution optical images from operational satellites, which have become more available in polar regions, for sea ice motion and deformation measurements. The sea ice motion, i.e., Lagrangian vector, is measured by using a maximum cross-correlation (MCC technique and multi-temporal high-resolution images acquired on 14–15 August 2014 from multiple spaceborne sensors on board Korea Multi-Purpose Satellites (KOMPSATs with short acquisition time intervals. The sea ice motion extracted from the six image pairs of the spatial resolutions were resampled to 4 m and 15 m yields with vector length measurements of 57.7 m root mean square error (RMSE and −11.4 m bias and 60.7 m RMSE and −13.5 m bias, respectively, compared with buoy location records. The errors from both resolutions indicate more accurate measurements than from conventional sea ice motion datasets from passive microwave and radar data in ice and water mixed surface conditions. In the results of sea ice deformation caused by interaction of individual ice floes, while free drift patterns of ice floes were delineated from the 4 m spatial resolution images, the deformation was less revealing in the 15 m spatial resolution image pairs due to emphasized discretization uncertainty from coarser pixel sizes. The results demonstrate that using multi-temporal high-resolution optical satellite images enabled precise image block matching in the melting season, thus this approach could be used for expanding sea ice motion and deformation dataset, with an advantage of frequent image acquisition capability in multiple areas by means of many operational satellites.

  8. Measurement of curvature and twist of a deformed object using digital holography

    International Nuclear Information System (INIS)

    Chen Wen; Quan Chenggen; Cho Jui Tay

    2008-01-01

    Measurement of curvature and twist is an important aspect in the study of object deformation. In recent years, several methods have been proposed to determine curvature and twist of a deformed object using digital shearography. Here we propose a novel method to determine the curvature and twist of a deformed object using digital holography and a complex phasor. A sine/cosine transformation method and two-dimensional short time Fourier transform are proposed subsequently to process the wrapped phase maps. It is shown that high-quality phase maps corresponding to curvature and twist can be obtained. An experiment is conducted to demonstrate the validity of the proposed method

  9. Measurements of Active Tectonic Deformation on the Guerrero Coast, Mexico

    Science.gov (United States)

    Ramirez, T.; Cundy, A.; Carranza-Edwards, A.; Morales, E.; Kostoglodov, V.; Urrutia-Fucugauchi, J.

    2004-12-01

    The study of tectonic deformation rates using displaced shoreline features is relatively well-established, and has provided much useful information on seismic hazard. Such studies have frequently been complemented by analysis of the coastal sedimentary record, where past marine to terrestrial environmental changes (and vice versa) may be recorded by clear changes in stratigraphy. Studies of this type are particularly valuable for tectonically-active areas where the preservation of former shoreline features is poor, or where long-term subsidence has resulted in their erosion, drowning or burial. The specific objective of this study is to derive rates of tectonic deformation from geomorphic and stratigraphic studies of the Guerrero coastal area, and to examine the feasibility of this stratigraphic approach in the coastal lagoons of the Mexican Pacific coast, in the Guerrero gap. The Guerrero gap coastal area, where a major earthquake is expected to occur, parallels the Cocos plate subduction zone. Here convergence rates vary from 5.2 cm/yr to 5.8 cm/yr. The Guerrero gap has experienced several historical earthquakes, notably the 1911 (7.8 Ms). However, no large magnitude events since the 1911 earthquake and only a few Ms~6 events have occurred near the Guerrero gap edges. It is expected that a major interplate earthquake of estimated magnitude Mw=8.1 to 8.4 has a high probability to occur. Landforms within the Guerrero gap indicate that the coast is subsiding. A series of key indicators such as elongated islands reminiscent of ancient barriers, submerged barriers island, extensive marshy environments, increased depths in the lagoons, and submerged anthropogenic features (shell mounds), among others, suggest active tectonic subsidence of the coast. In contrast, the adjacent northwest area off the Guerrero gap exhibits landforms characteristic of tectonic uplift (marine terraces and uplifted beach ridges), indicating a different seismo-tectonic regime northwest of the

  10. Measurement of copper vapour laser-induced deformation of ...

    Indian Academy of Sciences (India)

    2014-02-14

    coated mirror surface by Michelson interferometer. A WAHID. ∗. , S KUNDU, J S B SINGH, A K SINGH, A KHATTAR,. S K MAURYA, J S DHUMAL and K DASGUPTA. Laser & Plasma Technology Division, Beam Technology ...

  11. On the effectiveness of surface severe plastic deformation by shot peening at cryogenic temperature

    Science.gov (United States)

    Novelli, M.; Fundenberger, J.-J.; Bocher, P.; Grosdidier, T.

    2016-12-01

    The effect of cryogenic temperature (CT) on the graded microstructures obtained by severe shot peening using surface mechanical attrition treatment (SMAT) was investigated for two austenitic steels that used different mechanisms for assisting plastic deformation. For the metastable 304L steel, the depth of the hardened region increases because CT promotes the formation of strain induced martensite. Comparatively, for the 310S steel that remained austenitic, the size of the subsurface affected region decreases because of the improved strength of the material at CT but the fine twinned nanostructures results in significant top surface hardening.

  12. Experimental Investigation of Aeroelastic Deformation of Slender Wings at Supersonic Speeds Using a Video Model Deformation Measurement Technique

    Science.gov (United States)

    Erickson, Gary E.

    2013-01-01

    A video-based photogrammetric model deformation system was established as a dedicated optical measurement technique at supersonic speeds in the NASA Langley Research Center Unitary Plan Wind Tunnel. This system was used to measure the wing twist due to aerodynamic loads of two supersonic commercial transport airplane models with identical outer mold lines but different aeroelastic properties. One model featured wings with deflectable leading- and trailing-edge flaps and internal channels to accommodate static pressure tube instrumentation. The wings of the second model were of single-piece construction without flaps or internal channels. The testing was performed at Mach numbers from 1.6 to 2.7, unit Reynolds numbers of 1.0 million to 5.0 million, and angles of attack from -4 degrees to +10 degrees. The video model deformation system quantified the wing aeroelastic response to changes in the Mach number, Reynolds number concurrent with dynamic pressure, and angle of attack and effectively captured the differences in the wing twist characteristics between the two test articles.

  13. Minimising the effect of nanoparticle deformation in intermittent contact amplitude modulation atomic force microscopy measurements

    International Nuclear Information System (INIS)

    Babic, Bakir; Lawn, Malcolm A.; Coleman, Victoria A.; Jämting, Åsa K.; Herrmann, Jan

    2016-01-01

    The results of systematic height measurements of polystyrene (PS) nanoparticles using intermittent contact amplitude modulation atomic force microscopy (IC-AM-AFM) are presented. The experimental findings demonstrate that PS nanoparticles deform during AFM imaging, as indicated by a reduction in the measured particle height. This deformation depends on the IC-AM-AFM imaging parameters, material composition, and dimensional properties of the nanoparticles. A model for nanoparticle deformation occurring during IC-AM-AFM imaging is developed as a function of the peak force which can be calculated for a particular set of experimental conditions. The undeformed nanoparticle height can be estimated from the model by extrapolation to zero peak force. A procedure is proposed to quantify and minimise nanoparticle deformation during IC-AM-AFM imaging, based on appropriate adjustments of the experimental control parameters.

  14. InSAR observations of ground surface deformation and lava flow emplacement at Pacaya volcano, Guatemala

    Science.gov (United States)

    Schaefer, L. N.; Lu, Z.; Oommen, T.

    2015-12-01

    Pacaya volcano is a persistently active basaltic cone complex located in the Central American Volcanic Arc in Guatemala. In May, 2010, violent VEI-3 eruptions caused significant topographic changes to the edifice, including the dispersion of ~20 cm of tephra and ash on the cone, the emplacement of a ~5.4 km long lava flow, and 3 m of co-eruptive movement of the southwest flank. For this study, Interferometric Synthetic Aperture Radar (InSAR) images (interferograms) processed from both spaceborne Advanced Land Observing Satellite (ALOS) and aerial Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) data were used to measure post-eruptive deformation events. Interferograms suggest four distinct deformation processes after the May 2010 eruption: (1) magma intrusion near the vents of the 2010 lava flow; (2) subsidence of the 2010 lava flow; (3) slow deflation of an elongated magma source near the summit, and; (4) settlement of the material involved in the co-eruptive slope movement. Our results provide insights into Pacaya's complex magmatic plumbing system and the postemplacement behavior of lava flows. The detection of several different deformation events emphasizes the utility of measuring volcanic deformation using high-resolution remote sensing techniques with broad spatial coverage.

  15. Optimization of freeform surfaces using intelligent deformation techniques for LED applications

    Science.gov (United States)

    Isaac, Annie Shalom; Neumann, Cornelius

    2018-04-01

    For many years, optical designers have great interests in designing efficient optimization algorithms to bring significant improvement to their initial design. However, the optimization is limited due to a large number of parameters present in the Non-uniform Rationaly b-Spline Surfaces. This limitation was overcome by an indirect technique known as optimization using freeform deformation (FFD). In this approach, the optical surface is placed inside a cubical grid. The vertices of this grid are modified, which deforms the underlying optical surface during the optimization. One of the challenges in this technique is the selection of appropriate vertices of the cubical grid. This is because these vertices share no relationship with the optical performance. When irrelevant vertices are selected, the computational complexity increases. Moreover, the surfaces created by them are not always feasible to manufacture, which is the same problem faced in any optimization technique while creating freeform surfaces. Therefore, this research addresses these two important issues and provides feasible design techniques to solve them. Finally, the proposed techniques are validated using two different illumination examples: street lighting lens and stop lamp for automobiles.

  16. Olopatadine Inhibits Exocytosis in Rat Peritoneal Mast Cells by Counteracting Membrane Surface Deformation

    Directory of Open Access Journals (Sweden)

    Asuka Baba

    2015-01-01

    Full Text Available Backgroud/Aims: Besides its anti-allergic properties as a histamine receptor antagonist, olopatadine stabilizes mast cells by inhibiting the release of chemokines. Since olopatadine bears amphiphilic features and is preferentially partitioned into the lipid bilayers of the plasma membrane, it would induce some morphological changes in mast cells and thus affect the process of exocytosis. Methods: Employing the standard patch-clamp whole-cell recording technique, we examined the effects of olopatadine and other anti-allergic drugs on the membrane capacitance (Cm in rat peritoneal mast cells during exocytosis. Using confocal imaging of a water-soluble fluorescent dye, lucifer yellow, we also examined their effects on the deformation of the plasma membrane. Results: Low concentrations of olopatadine (1 or 10 µM did not significantly affect the GTP-γ-S-induced increase in the Cm. However, 100 µM and 1 mM olopatadine almost totally suppressed the increase in the Cm. Additionally, these doses completely washed out the trapping of the dye on the cell surface, indicating that olopatadine counteracted the membrane surface deformation induced by exocytosis. As shown by electron microscopy, olopatadine generated inward membrane bending in mast cells. Conclusion: This study provides electrophysiological evidence for the first time that olopatadine dose-dependently inhibits the process of exocytosis in rat peritoneal mast cells. Such mast cell stabilizing properties of olopatadine may be attributed to its counteracting effects on the plasma membrane deformation in degranulating mast cells.

  17. Surface deformation and friction characteristic of nano scratch at ductile-removal regime for optical glass BK7.

    Science.gov (United States)

    Li, Chen; Zhang, Feihu; Ding, Ye; Liu, Lifei

    2016-08-20

    Nano scratch for optical glass BK7 based on the ductile-removal regime was carried out, and the influence rule of scratch parameters on surface deformation and friction characteristic was analyzed. Experimental results showed that, with increase of normal force, the deformation of burrs in the edge of the scratch was more obvious, and with increase of the scratch velocity, the deformation of micro-fracture and burrs in the edge of the scratch was more obvious similarly. The residual depth of the scratch was measured by atomic force microscope. The experimental results also showed that, with increase of normal force, the residual depth of the scratch increased linearly while the elastic recovery rate decreased. Furthermore, with increase of scratch velocity, the residual depth of the scratch decreased while the elastic recovery rate increased. The scratch process of the Berkovich indenter was divided into the cutting process of many large negative rake faces based on the improved cutting model, and the friction characteristic of the Berkovich indenter and the workpiece was analyzed. The analysis showed that the coefficient of friction increased and then tended to be stable with the increase of normal force. Meanwhile, the coefficient of friction decreased with the increase of scratch velocity, and the coefficients, k ln(v) and μ0, were introduced to improve the original formula of friction coefficient.

  18. Transient Surface Deformation of Northern Taiwan, 2007-2011, Using Persistent Scattered InSAR with ALOS Data

    Science.gov (United States)

    Wang, C.; Chang, W.; Chang, C.

    2013-12-01

    The Taipei basin, triangular in shape and located in the northern Taiwan, is now developed into the most densely populated area and also the capital of politics and economics in Taiwan. North of the Taipei basin, the Tatun volcano group was proposed to be the cause of extensional collapse during the Pleistocene following the collision between the Luzon volcanic arc and the Eurasian continental margin at about 5 Ma. We investigated the contemporary surface deformation of the northern Taiwan using ALOS images that cover the Taipei basin and its surrounding mountainous area. The Differential Interferometric Synthetic Aperture Radar (DInSAR) technique has been widely used in the past ten years. However, the mountainous areas surrounding the basin are mostly covered with densely various vegetations that reduce signal-to-noise ratio in the interferograms. Therefore, the DInSAR technique is not effective for measuring the surface deformation in and around the Taipei basin, including the Tatun volcano area, and consequently the Persistent Scatterer (PS) and small baseline (SB) InSAR techniques have been employed to extract phase signals of the chosen PS points. In this study, we aim to measure the ground deformation of northern Taiwan by processing the spaceborne radar interferometry data of ALOS acquired from 2007 to 2011 using PSInSAR and SBInSAR techniques. Compared with the Envisat and ERS images used by previous studies, L-band PALSAR images can produce more PS points in the region covered by dense vegetation so that our results reveal a higher resolution of ground deformation. The mean Line of Sight (LOS) velocity field of up to 8 mm/yr in the central Tatun volcanic area, and up to 5 mm/yr in the Taipei basin with higher rate at the hanging wall of the Sanchiao fault than the footwall. (See the Figure.) While previous studies indicated that the Taipei basin had experienced ground uplift from 1993 to 2001 and subsidence from 2003 to 2008, our results show a return to

  19. Measurements of Near Sea Surface Infrared Propagation

    National Research Council Canada - National Science Library

    Frost, Shaun

    1999-01-01

    .... Measurements have been made of the atmospheric infrared transmission near the sea surface. Spectral transmission profiles were measured for a number of ranges using a fourier transform spectrometer...

  20. The measurement of surface gravity

    International Nuclear Information System (INIS)

    Crossley, David; Hinderer, Jacques; Riccardi, Umberto

    2013-01-01

    This review covers basic theory and techniques behind the use of ground-based gravimetry at the Earth's surface. The orientation is toward modern instrumentation, data processing and interpretation for observing surface, land-based, time-variable changes to the geopotential. The instrumentation side is covered in some detail, with specifications and performance of the most widely used models of the three main types: the absolute gravimeters (FG5, A10 from Micro-g LaCoste), superconducting gravimeters (OSG, iGrav from GWR instruments), and the new generation of spring instruments (Micro-g LaCoste gPhone, Scintrex CG5 and Burris ZLS). A wide range of applications is covered, with selected examples from tides and ocean loading, atmospheric effects on gravity, local and global hydrology, seismology and normal modes, long period and tectonics, volcanology, exploration gravimetry, and some examples of gravimetry connected to fundamental physics. We show that there are only a modest number of very large signals, i.e. hundreds of µGal (10 −8 m s −2 ), that are easy to see with all gravimeters (e.g. tides, volcanic eruptions, large earthquakes, seasonal hydrology). The majority of signals of interest are in the range 0.1–5.0 µGal and occur at a wide range of time scales (minutes to years) and spatial extent (a few meters to global). Here the competing effects require a careful combination of different gravimeter types and measurement strategies to efficiently characterize and distinguish the signals. Gravimeters are sophisticated instruments, with substantial up-front costs, and they place demands on the operators to maximize the results. Nevertheless their performance characteristics such as drift and precision have improved dramatically in recent years, and their data recording ability and ruggedness have seen similar advances. Many subtle signals are now routinely connected with known geophysical effects such as coseismic earthquake displacements, post

  1. The measurement of surface gravity

    Science.gov (United States)

    Crossley, David; Hinderer, Jacques; Riccardi, Umberto

    2013-04-01

    This review covers basic theory and techniques behind the use of ground-based gravimetry at the Earth's surface. The orientation is toward modern instrumentation, data processing and interpretation for observing surface, land-based, time-variable changes to the geopotential. The instrumentation side is covered in some detail, with specifications and performance of the most widely used models of the three main types: the absolute gravimeters (FG5, A10 from Micro-g LaCoste), superconducting gravimeters (OSG, iGrav from GWR instruments), and the new generation of spring instruments (Micro-g LaCoste gPhone, Scintrex CG5 and Burris ZLS). A wide range of applications is covered, with selected examples from tides and ocean loading, atmospheric effects on gravity, local and global hydrology, seismology and normal modes, long period and tectonics, volcanology, exploration gravimetry, and some examples of gravimetry connected to fundamental physics. We show that there are only a modest number of very large signals, i.e. hundreds of µGal (10-8 m s-2), that are easy to see with all gravimeters (e.g. tides, volcanic eruptions, large earthquakes, seasonal hydrology). The majority of signals of interest are in the range 0.1-5.0 µGal and occur at a wide range of time scales (minutes to years) and spatial extent (a few meters to global). Here the competing effects require a careful combination of different gravimeter types and measurement strategies to efficiently characterize and distinguish the signals. Gravimeters are sophisticated instruments, with substantial up-front costs, and they place demands on the operators to maximize the results. Nevertheless their performance characteristics such as drift and precision have improved dramatically in recent years, and their data recording ability and ruggedness have seen similar advances. Many subtle signals are now routinely connected with known geophysical effects such as coseismic earthquake displacements, post-glacial rebound

  2. Point-Connecting Measurements of the Hallux Valgus Deformity: A New Measurement and Its Clinical Application

    Science.gov (United States)

    Seo, Jeong-Ho; Boedijono, Dimas

    2016-01-01

    Purpose The aim of this study was to investigate new point-connecting measurements for the hallux valgus angle (HVA) and the first intermetatarsal angle (IMA), which can reflect the degree of subluxation of the first metatarsophalangeal joint (MTPJ). Also, this study attempted to compare the validity of midline measurements and the new point-connecting measurements for the determination of HVA and IMA values. Materials and Methods Sixty feet of hallux valgus patients who underwent surgery between 2007 and 2011 were classified in terms of the severity of HVA, congruency of the first MTPJ, and type of chevron metatarsal osteotomy. On weight-bearing dorsal-plantar radiographs, HVA and IMA values were measured and compared preoperatively and postoperatively using both the conventional and new methods. Results Compared with midline measurements, point-connecting measurements showed higher inter- and intra-observer reliability for preoperative HVA/IMA and similar or higher inter- and intra-observer reliability for postoperative HVA/IMA. Patients who underwent distal chevron metatarsal osteotomy (DCMO) had higher intraclass correlation coefficient for inter- and intra-observer reliability for pre- and post-operative HVA and IMA measured by the point-connecting method compared with the midline method. All differences in the preoperative HVAs and IMAs determined by both the midline method and point-connecting methods were significant between the deviated group and subluxated groups (p=0.001). Conclusion The point-connecting method for measuring HVA and IMA in the subluxated first MTPJ may better reflect the severity of a HV deformity with higher reliability than the midline method, and is more useful in patients with DCMO than in patients with proximal chevron metatarsal osteotomy. PMID:26996576

  3. Point-Connecting Measurements of the Hallux Valgus Deformity: A New Measurement and Its Clinical Application.

    Science.gov (United States)

    Seo, Jeong-Ho; Ahn, Ji-Yong; Boedijono, Dimas

    2016-05-01

    The aim of this study was to investigate new point-connecting measurements for the hallux valgus angle (HVA) and the first intermetatarsal angle (IMA), which can reflect the degree of subluxation of the first metatarsophalangeal joint (MTPJ). Also, this study attempted to compare the validity of midline measurements and the new point-connecting measurements for the determination of HVA and IMA values. Sixty feet of hallux valgus patients who underwent surgery between 2007 and 2011 were classified in terms of the severity of HVA, congruency of the first MTPJ, and type of chevron metatarsal osteotomy. On weight-bearing dorsal-plantar radiographs, HVA and IMA values were measured and compared preoperatively and postoperatively using both the conventional and new methods. Compared with midline measurements, point-connecting measurements showed higher inter- and intra-observer reliability for preoperative HVA/IMA and similar or higher inter- and intra-observer reliability for postoperative HVA/IMA. Patients who underwent distal chevron metatarsal osteotomy (DCMO) had higher intraclass correlation coefficient for inter- and intra-observer reliability for pre- and post-operative HVA and IMA measured by the point-connecting method compared with the midline method. All differences in the preoperative HVAs and IMAs determined by both the midline method and point-connecting methods were significant between the deviated group and subluxated groups (p=0.001). The point-connecting method for measuring HVA and IMA in the subluxated first MTPJ may better reflect the severity of a HV deformity with higher reliability than the midline method, and is more useful in patients with DCMO than in patients with proximal chevron metatarsal osteotomy.

  4. Measuring medial longitudinal arch deformation during gait. A reliability study

    DEFF Research Database (Denmark)

    Bencke, Jesper; Christiansen, Ditte; Jensen, Anne Kathrine Bendrup

    2012-01-01

    during gait and to compare this method with a static measure and a 2D dynamic method. Fifty-two feet (26 healthy male participants) were tested twice 4-9 days apart in a biomechanical gait analysis laboratory using a 3D three-marker foot model, a 2D video-based model for the measurement of MLAD during...

  5. Repeated absolute gravity measurements for monitoring slow intraplate vertical deformation in Western Europe

    Science.gov (United States)

    Van Camp, M. J.; de Viron, O.; Scherneck, H.; Hinzen, K. G.; Williams, S. D.; Lecocq, T.; Quinif, Y.; Camelbeeck, T.

    2011-12-01

    In continental plate interiors, ground surface movements are at the limit of the noise level and close to or below the accuracy of current geodetic techniques. Absolute gravity measurements are valuable to quantify slow vertical movements, as this instrument is drift free and, unlike GPS, independent of the terrestrial reference frame. Repeated absolute gravity (AG) measurements have been performed in Oostende (Belgian coastline) and at 8 stations along a southwest-northeast profile across the Belgian Ardennes and the Roer Valley Graben (Germany), in order to estimate the tectonic deformation in the area. The AG measurements, repeated once or twice a year, can resolve elusive gravity changes with a precision better than 3.7 nm/s2/yr (95% confidence interval) after 11 years, even in difficult conditions. After 8-15 years (depending on the station), we find that the gravity rates of change lie in the [-3.1, 8.1] nm/s2/yr interval and result from a combination of anthropogenic, climatic, tectonic, and Glacial Isostatic Adjustment (GIA) effects. After correcting for the GIA, the inferred gravity rates and consequently, the vertical land movements, reduce to zero within the uncertainty level at all stations except Jülich (due to man-induced subsidence) and Sohier (possibly, an artefact due to the shortness of the time series at that station).

  6. A thermal comparator sensor for measuring autogenous deformation in hardening Portland cement paste

    DEFF Research Database (Denmark)

    Østergaard, Thomas; Jensen, Ole Mejlhede

    2003-01-01

    This paper describes a simple and accurate experimental device specially developed to measure autogenous deformation in hardening cement-based materials. The measuring system consists of a so-called thermal comparator sensor and a modular thermostatically controlled system. The operating principle...... of the thermal comparator is based on thermal expansion of aluminium. A particular characteristic of the measuring system is the fixation of the thermal comparator sensor to the deforming specimen. The modular system ensures effective thermostatic control of the hydrating cement paste samples. The technique...

  7. Surface deformation in the Western Coastal Plain of Taiwan after removal of groundwater withdrawal effects

    Science.gov (United States)

    Chen, K.; Ching, K.

    2012-12-01

    The effect of widespread groundwater pumping has been proposed to be able to obscure the tectonic signals resulted from the movement of blind thrust faults, such as the metropolitan Los Angeles. In Taiwan, the tip of westward-propagating frontal blind thrust has been suggested to be located beneath the Western Coastal Plain by analyses of the horizontal GPS velocities and the geological uplift rates due to the convergence between the Philippine Sea and the Eurasian plates. However, the serious land subsidence has been consistently occurred in the Western Coastal Plain because of the artificial groundwater pumping for the development of agriculture. The most significant subsidence rate is observed up to 109.4 mm/yr. This effect may disturb the pattern of the surface horizontal velocities caused by the movement of blind thrust. As a result, ignoring the groundwater withdrawal effects will make misunderstandings on the assessment of location and kinematic characteristics of the blind thrust in western Taiwan by analysis of horizontal velocities only. In this study, to obtain a reasonable horizontal velocity field for evaluating the fault behavior in western Taiwan, we therefore used more than 704 precise leveling measurements and 20 continuous GPS observations between 2000 and 2008 in the Western Coastal Plain of Taiwan to estimate and correct the effects of groundwater pumping from horizontal velocities. The distribution of subsidence rates in this area shows a concentric-circle-like pattern with the peak subsidence rates of over 80 and 90 mm/yr at the northeastern and center area of the plain. Next, we will invert the vertical velocities for the land subsidence rate resulted from the groundwater withdrawal, using a dislocation model and a tentative mogi-source model in an elastic half-space material. The accuracy of these tentative models will also be assessed in this study. Then the corrections of horizontal velocities will be provided from this model to help us

  8. Rates and patterns of surface deformation from laser scanning following the South Napa earthquake, California

    Science.gov (United States)

    DeLong, Stephen B.; Lienkaemper, James J.; Pickering, Alexandra J; Avdievitch, Nikita N.

    2015-01-01

    The A.D. 2014 M6.0 South Napa earthquake, despite its moderate magnitude, caused significant damage to the Napa Valley in northern California (USA). Surface rupture occurred along several mapped and unmapped faults. Field observations following the earthquake indicated that the magnitude of postseismic surface slip was likely to approach or exceed the maximum coseismic surface slip and as such presented ongoing hazard to infrastructure. Using a laser scanner, we monitored postseismic deformation in three dimensions through time along 0.5 km of the main surface rupture. A key component of this study is the demonstration of proper alignment of repeat surveys using point cloud–based methods that minimize error imposed by both local survey errors and global navigation satellite system georeferencing errors. Using solid modeling of natural and cultural features, we quantify dextral postseismic displacement at several hundred points near the main fault trace. We also quantify total dextral displacement of initially straight cultural features. Total dextral displacement from both coseismic displacement and the first 2.5 d of postseismic displacement ranges from 0.22 to 0.29 m. This range increased to 0.33–0.42 m at 59 d post-earthquake. Furthermore, we estimate up to 0.15 m of vertical deformation during the first 2.5 d post-earthquake, which then increased by ∼0.02 m at 59 d post-earthquake. This vertical deformation is not expressed as a distinct step or scarp at the fault trace but rather as a broad up-to-the-west zone of increasing elevation change spanning the fault trace over several tens of meters, challenging common notions about fault scarp development in strike-slip systems. Integrating these analyses provides three-dimensional mapping of surface deformation and identifies spatial variability in slip along the main fault trace that we attribute to distributed slip via subtle block rotation. These results indicate the benefits of laser scanner surveys along

  9. Contemporaneous ring fault activity and surface deformation at subsiding calderas studied using analogue experiments

    Science.gov (United States)

    Liu, Yuan-Kai; Ruch, Joël; Vasyura-Bathke, Hannes; Jónsson, Sigurjón

    2017-04-01

    Ground deformation analyses of several subsiding calderas have shown complex and overlapping deformation signals, with a broad deflation signal that affects the entire volcanic edifice and localized subsidence focused within the caldera. However, the relation between deep processes at subsiding calderas, including magmatic sources and faulting, and the observed surface deformation is still debated. Several recent examples of subsiding calderas in the Galápagos archipelago and at the Axial seamount in the Pacific Ocean indicate that ring fault activity plays an important role not only during caldera collapse, but also during initial stages of caldera subsidence. Nevertheless, ring fault activity has rarely been integrated into numerical models of subsiding calderas. Here we report on sandbox analogue experiments that we use to study the processes involved from an initial subsidence to a later collapse of calderas. The apparatus is composed of a subsiding half piston section connected to the bottom of a glass box and driven by a motor to control its subsidence. We analyze at the same time during the subsidence the 3D displacement at the model surface with a laser scanner and the 2D ring fault evolution on the side of the model (cross-section) with a side-view digital camera. We further use PIVLab, a time-resolved digital image correlation software tool, to extract strain and velocity fields at both the surface and in cross-section. This setup allows to track processes acting at depth and assess their relative importance as the collapse evolves. We further compare our results with the examples observed in nature as well as with numerical models that integrate ring faults.

  10. Investigation on coupling error characteristics in angular rate matching based ship deformation measurement approach

    Science.gov (United States)

    Yang, Shuai; Wu, Wei; Wang, Xingshu; Xu, Zhiguang

    2018-01-01

    The coupling error in the measurement of ship hull deformation can significantly influence the attitude accuracy of the shipborne weapons and equipments. It is therefore important to study the characteristics of the coupling error. In this paper, an comprehensive investigation on the coupling error is reported, which has a potential of deducting the coupling error in the future. Firstly, the causes and characteristics of the coupling error are analyzed theoretically based on the basic theory of measuring ship deformation. Then, simulations are conducted for verifying the correctness of the theoretical analysis. Simulation results show that the cross-correlation between dynamic flexure and ship angular motion leads to the coupling error in measuring ship deformation, and coupling error increases with the correlation value between them. All the simulation results coincide with the theoretical analysis.

  11. Geodetic measurement of deformation in the Ventura basin region, southern California

    Science.gov (United States)

    Donnellan, Andrea; Hager, Bradford H.; King, Robert W.; Herring, Thomas A.

    1993-12-01

    We have measured the deformation in the Ventura basin region, southern California, with Global Positioning System (GPS) measurements carried out over 4.6 years between 1987 and 1992. The deformation within our network is spatically variable on scales of tens of kilometers, with strain rates reaching 0.6 +/- 1 micro-rad/yr in the east-central basin. Blocklike rotations are observed south and northwest of the basin where the maximum shear strain rates are an order of magnitude lower (0.06 +/- 1 micro-rad/yr to the south). We also observed clockwise rotations of 1 deg - 7 deg/m.y. Shear strain rates determined by comparing angle changes from historical triangulation spanning several decades and GPS measurements give consistent, though less precise, results. The geodetic rates of shortening across the basin and Western Transverse Ranges are lower than those estimated from geological observations, but the patterns of deformation from the two methods agree qualitatively.

  12. Real-time GPU surface curvature estimation on deforming meshes and volumetric data sets.

    Science.gov (United States)

    Griffin, Wesley; Wang, Yu; Berrios, David; Olano, Marc

    2012-10-01

    Surface curvature is used in a number of areas in computer graphics, including texture synthesis and shape representation, mesh simplification, surface modeling, and nonphotorealistic line drawing. Most real-time applications must estimate curvature on a triangular mesh. This estimation has been limited to CPU algorithms, forcing object geometry to reside in main memory. However, as more computational work is done directly on the GPU, it is increasingly common for object geometry to exist only in GPU memory. Examples include vertex skinned animations and isosurfaces from GPU-based surface reconstruction algorithms. For static models, curvature can be precomputed and CPU algorithms are a reasonable choice. For deforming models where the geometry only resides on the GPU, transferring the deformed mesh back to the CPU limits performance. We introduce a GPU algorithm for estimating curvature in real time on arbitrary triangular meshes. We demonstrate our algorithm with curvature-based NPR feature lines and a curvature-based approximation for an ambient occlusion. We show curvature computation on volumetric data sets with a GPU isosurface extraction algorithm and vertex-skinned animations. We present a graphics pipeline and CUDA implementation. Our curvature estimation is up to ~18x faster than a multithreaded CPU benchmark.

  13. Surface deformation associated with the November 23, 1977, Caucete, Argentina, earthquake sequence

    Science.gov (United States)

    Kadinsky-Cade, K.; Reilinger, R.; Isacks, B.

    1985-01-01

    The 1977 Caucete (San Juan) earthquake considered in the present paper occurred near the Sierra Pie de Palo in the Sierras Pampeanas tectonic province of western Argentina. In the study reported, coseismic surface deformation is combined with seismic observations (main shock and aftershocks, both teleseismic and local data) to place constraints on the geometry and slip of the main fault responsible for the 1977 earthquake. The implications of the 1977 event for long-term crustal shortening and earthquake recurrence rates in this region are also discussed. It is concluded that the 1977 Caucete earthquake was accompanied by more than 1 m of vertical uplift.

  14. Electrostatic Deformation of Liquid Surfaces by a Charged Rod and a Van de Graaff Generator

    OpenAIRE

    Slisko, Josip; García Molina, Rafael; Abril Sánchez, Isabel

    2014-01-01

    Authors of physics textbooks frequently use the deflection of a thin, vertically falling water jet by a charged balloon, 1–3 comb, 4–6 or rod 7–9 as a visually appealing and conceptually relevant example of electrostatic attraction. Nevertheless, no attempts are made to explore whether these charged bodies could cause visible deformation of a horizontal water surface. That being so, we were quite surprised when we discovered that a 19th-century French book 10 contained a drawing showing an ap...

  15. Three-Dimensional Dynamic Deformation Measurements Using Stereoscopic Imaging and Digital Speckle Photography

    International Nuclear Information System (INIS)

    Prentice, H. J.; Proud, W. G.

    2006-01-01

    A technique has been developed to determine experimentally the three-dimensional displacement field on the rear surface of a dynamically deforming plate. The technique combines speckle analysis with stereoscopy, using a modified angular-lens method: this incorporates split-frame photography and a simple method by which the effective lens separation can be adjusted and calibrated in situ. Whilst several analytical models exist to predict deformation in extended or semi-infinite targets, the non-trivial nature of the wave interactions complicates the generation and development of analytical models for targets of finite depth. By interrogating specimens experimentally to acquire three-dimensional strain data points, both analytical and numerical model predictions can be verified more rigorously. The technique is applied to the quasi-static deformation of a rubber sheet and dynamically to Mild Steel sheets of various thicknesses

  16. Measurements of very large deformations in potash salt in conjunction with an ongoing mining operation

    International Nuclear Information System (INIS)

    Sattler, A.R.; Christensen, C.L.

    1980-01-01

    Room and pillar deformation were measured in conjunction with a relatively new type of mining operation in a southeastern New Mexico potash mine. The extraction ration was approximately 90 percent in a first mining operation. Due to severe deformations encountered, instrumentation had to be developed/modified for these measurements. This paper concentrates on experiment design, design of special instrumentation, field installation of equipment, and presentation of the data. Measurements made include extensometers in the pillar, in the floor and ceiling in the room between pillars, absolute level measurements, floor ceiling closure, and stress (strain) measurements. Associated laboratory rock mechanics measurements of samples from the mine are being done separately. Two separate room pillar complexes were instrumented. In the first complex, floor-ceiling deformations of approximately 1 inch/day and pillar deformations around 1/2 inch/day were measured. In the second complex, instrumentation was installed while the pillar was a part of a long wall and the subsequent sequential mining (long wall-pillar with only one adjoining room on one side - pillar in the middle of room pillar complex) was observed. Data return from this operation was good

  17. Numerical simulation of sloshing with large deforming free surface by MPS-LES method

    Science.gov (United States)

    Pan, Xu-jie; Zhang, Huai-xin; Sun, Xue-yao

    2012-12-01

    Moving particle semi-implicit (MPS) method is a fully Lagrangian particle method which can easily solve problems with violent free surface. Although it has demonstrated its advantage in ocean engineering applications, it still has some defects to be improved. In this paper, MPS method is extended to the large eddy simulation (LES) by coupling with a sub-particle-scale (SPS) turbulence model. The SPS turbulence model turns into the Reynolds stress terms in the filtered momentum equation, and the Smagorinsky model is introduced to describe the Reynolds stress terms. Although MPS method has the advantage in the simulation of the free surface flow, a lot of non-free surface particles are treated as free surface particles in the original MPS model. In this paper, we use a new free surface tracing method and the key point is "neighbor particle". In this new method, the zone around each particle is divided into eight parts, and the particle will be treated as a free surface particle as long as there are no "neighbor particles" in any two parts of the zone. As the number density parameter judging method has a high efficiency for the free surface particles tracing, we combine it with the neighbor detected method. First, we select out the particles which may be mistreated with high probabilities by using the number density parameter judging method. And then we deal with these particles with the neighbor detected method. By doing this, the new mixed free surface tracing method can reduce the mistreatment problem efficiently. The serious pressure fluctuation is an obvious defect in MPS method, and therefore an area-time average technique is used in this paper to remove the pressure fluctuation with a quite good result. With these improvements, the modified MPS-LES method is applied to simulate liquid sloshing problems with large deforming free surface. Results show that the modified MPS-LES method can simulate the large deforming free surface easily. It can not only capture

  18. Optical microscope for three-dimensional surface displacement and shape measurements at the microscale.

    Science.gov (United States)

    Xia, Shuman; Pan, Zhipeng; Zhang, Jingwen

    2014-07-15

    We report a novel optical microscope for full-field, noncontact measurements of three-dimensional (3D) surface deformation and topography at the microscale. The microscope system is based on a seamless integration of the diffraction-assisted image correlation (DAIC) method with fluorescent microscopy. We experimentally demonstrate the microscope's capability for 3D measurements with submicrometer spatial resolution and subpixel measurement accuracy.

  19. Sequential combination of multi-source satellite observations for separation of surface deformation associated with serial seismic events

    Science.gov (United States)

    Chen, Qiang; Xu, Qian; Zhang, Yijun; Yang, Yinghui; Yong, Qi; Liu, Guoxiang; Liu, Xianwen

    2018-03-01

    Single satellite geodetic technique has weakness for mapping sequence of ground deformation associated with serial seismic events, like InSAR with long revisiting period readily leading to mixed complex deformation signals from multiple events. It challenges the observation capability of single satellite geodetic technique for accurate recognition of individual surface deformation and earthquake model. The rapidly increasing availability of various satellite observations provides good solution for overcoming the issue. In this study, we explore a sequential combination of multiple overlapping datasets from ALOS/PALSAR, ENVISAT/ASAR and GPS observations to separate surface deformation associated with the 2011 Mw 9.0 Tohoku-Oki major quake and two strong aftershocks including the Mw 6.6 Iwaki and Mw 5.8 Ibaraki events. We first estimate the fault slip model of major shock with ASAR interferometry and GPS displacements as constraints. Due to the used PALSAR interferogram spanning the period of all the events, we then remove the surface deformation of major shock through forward calculated prediction thus obtaining PALSAR InSAR deformation associated with the two strong aftershocks. The inversion for source parameters of Iwaki aftershock is conducted using the refined PALSAR deformation considering that the higher magnitude Iwaki quake has dominant deformation contribution than the Ibaraki event. After removal of deformation component of Iwaki event, we determine the fault slip distribution of Ibaraki shock using the remained PALSAR InSAR deformation. Finally, the complete source models for the serial seismic events are clearly identified from the sequential combination of multi-source satellite observations, which suggest that the major quake is a predominant mega-thrust rupture, whereas the two aftershocks are normal faulting motion. The estimated seismic moment magnitude for the Tohoku-Oki, Iwaki and Ibaraki evens are Mw 9.0, Mw 6.85 and Mw 6.11, respectively.

  20. Deformation Measurement Of Lumbar Vertebra By Holographic Interferometry

    Science.gov (United States)

    Matsumoto, Toshiro; Kojima, Arata; Ogawa, Ryoukei; Iwata, Koichi; Nagata, Ryo

    1988-01-01

    The mechanical properties of normal lumbar vertebra and one with the interarticular part cut off to simulate hemi-spondylolysis were measured by the double exposure holographic interferometry. In the normal lumbar vertebra, displacement due to the load applied to the inferior articular process was greater than that of superior articular process under the same load. The interarticular part was subjected to the high stress. From these points, one of the valuable data to consider the cause of spondylolysis was obtained.

  1. Measuring Surface Combatant Fleet Effectiveness

    National Research Council Canada - National Science Library

    Crary, Michael

    1999-01-01

    ...? While Measures of Effectiveness for an individual ship can include its number of missiles, speed, and endurance, it is difficult to find a Measure of Effectiveness credible to experienced warplanners...

  2. Elastic strains of cementite in a pearlite steel during tensile deformation measured by neutron diffraction

    International Nuclear Information System (INIS)

    Kanie, A.; Tomota, Y.; Torii, S.; Kamiyama, T.

    2004-01-01

    Lattice plane strain, i.e., elastic strain, in cementite plates embedded in the ferrite matrix was measured by in situ neutron diffraction during tensile deformation for a hypereutectoid pearlite steel. The employment of time-of-flight method and microstructure control enable us to measure the shift of cementite peaks along tensile and transverse directions at the applied stress up to 1.6 GPa. The highest elastic strains of cementite determined was approximately 0.015. Heterogeneous plastic deformation between ferrite and cementite as well as among ferrite blocks are discussed. (author)

  3. Holographic otoscope for nanodisplacement measurements of surfaces under dynamic excitation.

    Science.gov (United States)

    Flores-Moreno, J M; Furlong, Cosme; Rosowski, John J; Harrington, Ellery; Cheng, Jeffrey T; Scarpino, C; Santoyo, F Mendoza

    2011-01-01

    We describe a novel holographic otoscope system for measuring nanodisplacements of objects subjected to dynamic excitation. Such measurements are necessary to quantify the mechanical deformation of surfaces in mechanics, acoustics, electronics, biology, and many other fields. In particular, we are interested in measuring the sound-induced motion of biological samples, such as an eardrum. Our holographic otoscope system consists of laser illumination delivery (IS), optical head (OH), and image processing computer (IP) systems. The IS delivers the object beam (OB) and the reference beam (RB) to the OH. The backscattered light coming from the object illuminated by the OB interferes with the RB at the camera sensor plane to be digitally recorded as a hologram. The hologram is processed by the IP using the Fresnel numerical reconstruction algorithm, where the focal plane can be selected freely. Our holographic otoscope system is currently deployed in a clinic, and is packaged in a custom design. It is mounted in a mechatronic positioning system to increase its maneuverability degrees to be conveniently positioned in front of the object to be measured. We present representative results highlighting the versatility of our system to measure deformations of complex elastic surfaces in the wavelength scale including a copper foil membrane and postmortem tympanic membrane. SCANNING 33: 342-352, 2011. © 2011 Wiley Periodicals, Inc. Copyright © 2011 Wiley Periodicals, Inc.

  4. The analysis of the bedrock deformation in Olkiluoto using precise levelling measurements

    International Nuclear Information System (INIS)

    Saaranen, V.; Rouhiainen, P.; Suurmaeki, H.

    2014-01-01

    In order to research vertical bedrock deformations in the Olkiluoto area, Posiva Oy and the Finnish Geodetic Institute began monitoring with precise levelling in 2003. At the moment, the measuring plan includes a loop between the monitoring GPS stations around the island, a levelling line from the island to the mainland, levelling loops to ONKALO, the final disposal site, and VLJ, the low and intermediate level waste repository there. The levelling to the mainland has been performed every fourth year and the levelling of the GPS stations every second year. The micro loops (ONKALO and VLJ) have been measured annually. In this report, we use three-step method to research a vertical deformation of the Olkiluoto area. Firstly, the linear deformation rate in the area has been determined by the least squares adjustment of the levelling data. It varies from -0.2 mm/yr to +0.2 mm/yr. Secondly, local deformations have been analysed by comparing the height differences for different years. In this comparison a starting value for the yearly adjustment has been corrected for land uplift. Using this method the elevation changes are relative to the whole network. For a fixed benchmark, we correct its yearly deformation. Thirdly, the fault lines have been analysed by comparing the elevation changes between the successive benchmarks from one observation epoch to another. The results show that ONKALO and Lapijoki are in the subsidence area of the network, and VLJ has small uplift rate. On the island some deformations exist, but elevation difference from 2003 to 2011 is less than one millimetre at every benchmarks. The measurements in the Lapijoki-Olkiluoto line in 2003, 2007 and 2011 show that linear elevation change between the mainland and Olkiluoto island is a little since 2003. The elevation differences, from Olkiluoto to Lapijoki, measured in 2003 and 2011 differ less than one millimetre each other, but the 2007 observation differs three millimetres from the other measurements

  5. Influence of slip-surface geometry on earth-flow deformation, Montaguto earth flow, southern Italy

    Science.gov (United States)

    Guerriero, L.; Coe, Jeffrey A.; Revellio, P.; Grelle, G.; Pinto, F.; Guadagno, F.

    2016-01-01

    We investigated relations between slip-surface geometry and deformational structures and hydrologic features at the Montaguto earth flow in southern Italy between 1954 and 2010. We used 25 boreholes, 15 static cone-penetration tests, and 22 shallow-seismic profiles to define the geometry of basal- and lateral-slip surfaces; and 9 multitemporal maps to quantify the spatial and temporal distribution of normal faults, thrust faults, back-tilted surfaces, strike-slip faults, flank ridges, folds, ponds, and springs. We infer that the slip surface is a repeating series of steeply sloping surfaces (risers) and gently sloping surfaces (treads). Stretching of earth-flow material created normal faults at risers, and shortening of earth-flow material created thrust faults, back-tilted surfaces, and ponds at treads. Individual pairs of risers and treads formed quasi-discrete kinematic zones within the earth flow that operated in unison to transmit pulses of sediment along the length of the flow. The locations of strike-slip faults, flank ridges, and folds were not controlled by basal-slip surface topography but were instead dependent on earth-flow volume and lateral changes in the direction of the earth-flow travel path. The earth-flow travel path was strongly influenced by inactive earth-flow deposits and pre-earth-flow drainages whose positions were determined by tectonic structures. The implications of our results that may be applicable to other earth flows are that structures with strikes normal to the direction of earth-flow motion (e.g., normal faults and thrust faults) can be used as a guide to the geometry of basal-slip surfaces, but that depths to the slip surface (i.e., the thickness of an earth flow) will vary as sediment pulses are transmitted through a flow.

  6. Deformation and breakup behavior of a small droplet impinging upon a hot surface

    International Nuclear Information System (INIS)

    Senda, Jiro; Takeuchi, Kiichiro; Miki, Hideo; Yamada, Koji.

    1986-01-01

    The phenomenon of a small droplet impinging upon a hot surface is applied in various industries. Such applications are divided into those employing atomization by the impingement of the droplet and those employing the heat transfer from surface to the droplet. The purpose of this paper is to obtain fundamental information concerning the heat transfer process and breakup behavior characteristics of individual small droplets impinging upon a hot surface. A uniform sized water droplets array at room temperature under atmospheric pressure was produced by the vibratory method to impinge upon a heated flat copper surface. And then, the deformation and the breakup behavior owing to the impingement of the droplet in observed by means of a drum camera recording highspeed microscopic photographs. The transient change in the diameter of the radial film which is formed after the droplet impinges on a surface is adjusted with the Weber number, and it is revealed that contact resistance in solid-liquid interface varies with surface temperature. The breakup form of the impinged droplet is classified into 7 types : R, RB, B, N, H, V, and F. The changes in the Sauter mean diameter of breakup droplets and the volume distribution of breakup droplets are examined. (author)

  7. Transient and microscale deformations and strains measured under exogenous loading by noninvasive magnetic resonance.

    Directory of Open Access Journals (Sweden)

    Deva D Chan

    Full Text Available Characterization of spatiotemporal deformation dynamics and material properties requires non-destructive methods to visualize mechanics of materials and biological tissues. Displacement-encoded magnetic resonance imaging (MRI has emerged as a noninvasive and non-destructive technique used to quantify deformation and strains. However, the techniques are not yet applicable to a broad range of materials and load-bearing tissues. In this paper, we visualize transient and internal material deformation through the novel synchrony of external mechanical loading with rapid displacement-encoded MRI. We achieved deformation measurements in silicone gel materials with a spatial resolution of 100 µm and a temporal resolution (of 2.25 ms, set by the repetition time (TR of the rapid MRI acquisition. Displacement and strain precisions after smoothing were 11 µm and 0.1%, respectively, approaching cellular length scales. Short (1/2 TR echo times enabled visualization of in situ deformation in a human tibiofemoral joint, inclusive of multiple variable T(2 biomaterials. Moreover, the MRI acquisitions achieved a fivefold improvement in imaging time over previous technology, setting the stage for mechanical imaging in vivo. Our results provide a general approach for noninvasive and non-destructive measurement, at high spatial and temporal resolution, of the dynamic mechanical response of a broad range of load-bearing materials and biological tissues.

  8. Validation of an optical system to measure acetabular shell deformation in cadavers.

    Science.gov (United States)

    Dold, Philipp; Bone, Martin C; Flohr, Markus; Preuss, Roman; Joyce, Tom J; Deehan, David; Holland, James

    2014-08-01

    Deformation of the acetabular shell at the time of surgery can result in poor performance and early failure of the hip replacement. The study aim was to validate an ATOS III Triple Scan optical measurement system against a co-ordinate measuring machine using in vitro testing and to check repeatability under cadaver laboratory conditions. Two sizes of custom-made acetabular shells were deformed using a uniaxial/two-point loading frame and measured at different loads. Roundness measurements were performed using both the ATOS III Triple Scan optical system and a co-ordinate measuring machine and then compared. The repeatability was also tested by measuring shells pre- and post-insertion in a cadaver laboratory multiple times. The in vitro comparison with the co-ordinate measuring machine demonstrated a maximum difference of 5 µm at the rim and 9 µm at the measurement closest to the pole of the shell. Maximum repeatability was below 1 µm for the co-ordinate measuring machine and 3 µm for the ATOS III Triple Scan optical system. Repeatability was comparable between the pre-insertion (below 2 µm) and post-insertion (below 3 µm) measurements in the cadaver laboratory. This study supports the view that the ATOS III Triple Scan optical system fulfils the necessary requirements to accurately measure shell deformation in cadavers. © IMechE 2014.

  9. Investigating the effects of membrane deformability on artificial capsule adhesion to the functionalized surface.

    Science.gov (United States)

    Balsara, Hiren D; Banton, Rohan J; Eggleton, Charles D

    2016-10-01

    Understanding, manipulating and controlling cellular adhesion processes can be critical in developing biomedical technologies. Adhesive mechanisms can be used to the target, pattern and separate cells such as leukocytes from whole blood for biomedical applications. The deformability response of the cell directly affects the rolling and adhesion behavior under viscous linear shear flow conditions. To that end, the primary objective of the present study was to investigate numerically the influence of capsule membrane's nonlinear material behavior (i.e. elastic-plastic to strain hardening) on the rolling and adhesion behavior of representative artificial capsules. Specifically, spherical capsules with radius of [Formula: see text] were represented using an elastic membrane governed by a Mooney-Rivlin strain energy functions. The surfaces of the capsules were coated with P-selectin glycoprotein-ligand-1 to initiate binding interaction with P-selectin-coated planar surface with density of [Formula: see text] under linear shear flow varying from 100 to [Formula: see text]. The numerical model is based on the Immersed Boundary Method for rolling of deformable capsule in shear flow coupled with Monte Carlo simulation for receptor/ligand interaction modeled using Bell model. The results reveal that the mechanical properties of the capsule play an important role in the rolling behavior and the binding kinetics between the capsule contact surface and the substrate. The rolling behavior of the strain hardening capsules is relatively smoother and slower compared to the elastic-plastic capsules. The strain hardening capsules exhibits higher contact area at any given shear rate compared to elastic-plastic capsules. The increase in contact area leads to decrease in rolling velocity. The capsule contact surface is not in complete contact with the substrate because of thin lubrication film that is trapped between the capsule and substrate. This creates a concave shape on the bottom

  10. A test case of the deformation rate analysis (DRA) stress measurement method

    Energy Technology Data Exchange (ETDEWEB)

    Dight, P.; Hsieh, A. [Australian Centre for Geomechanics, Univ. of WA, Crawley (Australia); Johansson, E. [Saanio and Riekkola Oy, Helsinki (Finland); Hudson, J.A. [Rock Engineering Consultants (United Kingdom); Kemppainen, K.

    2012-01-15

    As part of Posiva's site and ONKALO investigations, the in situ rock stress has been measured by a variety of techniques, including hydraulic fracturing, overcoring, and convergence measurements. All these techniques involve direct measurements in a drillhole or at the rock surface. An alternative method is to test drillhole core in a way that enables estimation of the magnitudes and orientations of the in situ rock stress. The Kaiser Effect (KE) and Deformation Rate Analysis (DRA) are two ways to do this. In the work reported here, a 'blind' DRA test was conducted on core obtained from the POSE (Posiva's Olkiluoto Spalling Experiment) niche in the ONKALO. The term 'blind' means that the two first authors of this report, who conducted the tests at the Australian Centre for Geomechanics, did not know the depths below surface at which the cores had been obtained. The results of this DRA Test Case are presented, together with an explanation of the DRA procedure. Also, additional information that would help in such DRA testing and associated analysis is explained. One of the problems in comparing the DRA results with the known Olkiluoto stress field is that the latter is highly variable across the site, as experienced by the previous in situ stress measurements and as predicted by numerical analysis. The variability is mainly caused by the presence of the large brittle deformation zones which perturb the local stress state. However, this variability reduces with depth and the stress field becomes more stable at the {approx} 350 m at which the drillhole cores were obtained. Another compounding difficulty is that the stress quantity, being a second order tensor, requires six independent components for its specification. In other words, comparison of the DRA results and the known stress field requires comparison of six different quantities. In terms of the major principal stress orientation, the DRA results predict an orientation completely

  11. A test case of the deformation rate analysis (DRA) stress measurement method

    International Nuclear Information System (INIS)

    Dight, P.; Hsieh, A.; Johansson, E.; Hudson, J.A.; Kemppainen, K.

    2012-01-01

    As part of Posiva's site and ONKALO investigations, the in situ rock stress has been measured by a variety of techniques, including hydraulic fracturing, overcoring, and convergence measurements. All these techniques involve direct measurements in a drillhole or at the rock surface. An alternative method is to test drillhole core in a way that enables estimation of the magnitudes and orientations of the in situ rock stress. The Kaiser Effect (KE) and Deformation Rate Analysis (DRA) are two ways to do this. In the work reported here, a 'blind' DRA test was conducted on core obtained from the POSE (Posiva's Olkiluoto Spalling Experiment) niche in the ONKALO. The term 'blind' means that the two first authors of this report, who conducted the tests at the Australian Centre for Geomechanics, did not know the depths below surface at which the cores had been obtained. The results of this DRA Test Case are presented, together with an explanation of the DRA procedure. Also, additional information that would help in such DRA testing and associated analysis is explained. One of the problems in comparing the DRA results with the known Olkiluoto stress field is that the latter is highly variable across the site, as experienced by the previous in situ stress measurements and as predicted by numerical analysis. The variability is mainly caused by the presence of the large brittle deformation zones which perturb the local stress state. However, this variability reduces with depth and the stress field becomes more stable at the ∼ 350 m at which the drillhole cores were obtained. Another compounding difficulty is that the stress quantity, being a second order tensor, requires six independent components for its specification. In other words, comparison of the DRA results and the known stress field requires comparison of six different quantities. In terms of the major principal stress orientation, the DRA results predict an orientation completely different to the NW-SE regional

  12. Corrosion mechanism of a Ni-based alloy in supercritical water: Impact of surface plastic deformation

    International Nuclear Information System (INIS)

    Payet, Mickaël; Marchetti, Loïc; Tabarant, Michel; Chevalier, Jean-Pierre

    2015-01-01

    Highlights: • The dissolution of Ni and Fe cations occurs during corrosion of Ni-based alloys in SCW. • The nature of the oxide layer depends locally on the alloy microstructure. • The corrosion mechanism changes when cold-work increases leading to internal oxidation. - Abstract: Ni–Fe–Cr alloys are expected to be a candidate material for the generation IV nuclear reactors that use supercritical water at temperatures up to 600 °C and pressures of 25 MPa. The corrosion resistance of Alloy 690 in these extreme conditions was studied considering the surface finish of the alloy. The oxide scale could suffer from dissolution or from internal oxidation. The presence of a work-hardened zone reveals the competition between the selective oxidation of chromium with respect to the oxidation of nickel and iron. Finally, corrosion mechanisms for Ni based alloys are proposed considering the effects of plastically deformed surfaces and the dissolution.

  13. Surface deformation on the west portion of the Chapala lake basin: uncertainties and facts

    Directory of Open Access Journals (Sweden)

    M. Hernandez-Marin

    2015-11-01

    Full Text Available In this study we investigate different aspects of land subsidence and ground failures occurring in the west portion of Chapala lake basin. Currently, surface discontinuities seem to be associated with subsiding bowls. In an effort to understand some of the conditioning factors to surface deformation, two sounding cores from the upper sequence (11 m depth were extracted for analyzing physical and mechanical properties. The upper subsoil showed a predominant silty composition and several lenses of pumice pyroclastic sand. Despite the relative predominance of fine soil, the subsoil shows mechanical properties with low clay content, variable water content, low plasticity and variable compressibility index, amongst some others. Some of these properties seem to be influenced by the sandy pyroclastic lenses, therefore, a potential source of the ground failure could be heterogeneities in the upper soil.

  14. Induced surface deformation and seismicity during 2011-2012 at the Húsmúli reinjection site, Iceland

    Science.gov (United States)

    Juncu, Daniel; Árnadóttir, Thóra; Geirsson, Halldór; Guðmundsson, Gunnar; Gunnarsson, Gunnar; Hooper, Andy; Hreinsdóttir, Sigrún; Michalczewska, Karolina

    2017-04-01

    While induced seismicity related to fluid injection is a common occurrence, deformation due to injection is rarely observed. At the Hellisheidi power plant in SW Iceland we detect both induced seismicity and deformation during the initial phase of geothermal wastewater reinjection. The largest seismic events in the sequence were two earthquakes of M3.8 and M4.0 on 15 October 2011, after reinjection was started in September 2011 with a flow rate of around 550 l/s. After the intense induced seismicity started, a few GNSS sites in the area were operated semi-continuously, as there was no continuous station nearby. The GNSS data reveal a transient signal which indicates that most of the deformation occured in the first months after the injection started. Surface deformation is also evident in SAR interferograms in the time interval of June 2011 to May 2012. We use an inverse modeling approach and simulate the geodetic data (InSAR and GNSS) to find the most plausible source for the deformation signal. We test whether the deformation was caused by co-seismic motion on N-S right-lateral strike slip faults due to the largest events in October 2011. We also examine other source models that may explain the deformation. Finally, we estimate Coulomb stress changes in the area to test what processes could have activated slip on pre-existing faults to examine the causal relationship between the deformation and the induced seismicity.

  15. Inter- and intrarater reliability of ulna variance versus lunate subsidence measurements in Madelung deformity.

    Science.gov (United States)

    Farr, Sebastian; Bae, Donald S

    2015-01-01

    To assess inter- and intrarater reliability of both ulna variance and lunate subsidence measurement methods in a large consecutive series of children with Madelung deformity. Ulnar variance and lunate subsidence were measured on 41 standard anteroposterior wrist radiographs from 31 patients with Madelung deformity. The patients had a mean age of 13 years (range, 5-25) at the time of presentation. Two pediatric orthopedic hand/upper limb surgeons evaluated all radiographs twice in a 4-week interval using standard digital imaging software. Intraclass correlation coefficients (ICCs) were calculated for inter- and intrarater reliability, and results were reported using the Landis and Koch criteria. The interrater ICC for the ulna variance measurements was substantial, and for the lunate subsidence almost perfect. The intrarater ICC for ulna variance was substantial for both raters. In contrast, the intrarater ICC for lunate subsidence was almost perfect for both raters. Measurement of lunate subsidence showed both superior interrater and intrarater reliability compared with the ulnar variance method. Whenever relative ulna length is assessed in children and adolescents with Madelung deformity, the lunate subsidence should be the preferred method to characterize deformity. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  16. Surface charge measurement by the Pockels effect

    CERN Document Server

    Sam, Y L

    2001-01-01

    have been observed by applying both impulse and AC voltages to a needle electrode in direct contact with the BSO. AC surface discharge behaviour of polymeric materials bonded to the BSO has also been investigated. The effect of the surrounding environment has been experimentally examined by placing the cell inside a vacuum chamber. Surface charge measurements have been made at various atmospheric pressures. The effect of an electro-negative gas (Sulphur Hexafluoride) on the surface charge distribution has also been investigated. This thesis is concerned with the design and development of a surface charge measurement system using Pockels effect. The measurement of surface charge is important in determining the electrical performance of high voltage insulation materials. The method proposed allows on-line measurement of charge and can generate two-dimensional images that represent the charge behaviour on the surface of the material under test. The measurement system is optical and uses a Pockels crystal as the ...

  17. Influence of Plastic Deformation on Low-Temperature Surface Hardening of Austenitic Stainless Steel by Gaseous Nitriding

    DEFF Research Database (Denmark)

    Bottoli, Federico; Winther, Grethe; Christiansen, Thomas Lundin

    2015-01-01

    This article addresses an investigation of the influence of plastic deformation on low-temperature surface hardening by gaseous nitriding of two commercial stainless steels: EN 1.4369 and AISI 304. The materials were plastically deformed to several levels of equivalent strain by conventional...... tensile straining, plane strain compression, and shear. Gaseous nitriding of the strained material was performed in ammonia gas at atmospheric pressure at various temperatures. Microstructural characterization of the as-deformed state and the nitrided case produced included X-ray diffraction analysis...

  18. Modeling of the anode surface deformation in high-current vacuum arcs with AMF contacts

    International Nuclear Information System (INIS)

    Huang, Xiaolong; Wang, Lijun; Deng, Jie; Jia, Shenli; Qin, Kang; Shi, Zongqian

    2016-01-01

    A high-current vacuum arc subjected to an axial magnetic field is maintained in a diffuse status. With an increase in arc current, the energy carried by the arc column to the anode becomes larger and finally leads to the anode temperature exceeding the melting point of the anode material. When the anode melting pool is formed, and the rotational plasma of the arc column delivers its momentum to the melting pool, the anode melting pool starts to rotate and also flow outwards along the radial direction, which has been photographed by some researchers using high-speed cameras. In this paper, the anode temperature and melting status is calculated using the melting and solidification model. The swirl flow of the anode melting pool and deformation of the anode is calculated using the magneto-hydrodynamic (MHD) model with the volume of fraction (VOF) method. All the models are transient 2D axial-rotational symmetric models. The influence of the impaction force of the arc plasma, electromagnetic force, viscosity force, and surface tension of the liquid metal are all considered in the model. The heat flux density injected into the anode and the arc pressure are obtained from the 3D numerical simulation of the high-current vacuum arc using the MHD model, which gives more realistic parameters for the anode simulation. Simulation results show that the depth of the anode melting pool increases with an increase in the arc current. Some droplets sputter out from the anode surface, which is caused by the inertial centrifugal force of the rotational melting pool and strong plasma pressure. Compared with the previous anode melting model without consideration of anode deformation, when the deformation and swirl flow of the anode melting pool are considered, the anode temperature is relatively lower, and just a little more than the melting point of Cu. This is because of liquid droplets sputtering out of the anode surface taking much of the energy away from the anode surface. The

  19. Measurement of deforming mode of lattice truss structures under impact loading

    Directory of Open Access Journals (Sweden)

    Zhao H.

    2012-08-01

    Full Text Available Lattice truss structures, which are used as a core material in sandwich panels, were widely investigated experimentally and theoretically. However, explanation of the deforming mechanism using reliable experimental results is almost rarely reported, particularly for the dynamic deforming mechanism. The present work aimed at the measurement of the deforming mode of lattice truss structures. Indeed, quasi-static and Split Hopkinson Pressure Bar (SHPB tests have been performed on the tetrahedral truss cores structures made of Aluminum 3003-O. Global values such as crushing forces and displacements between the loading platens are obtained. However, in order to understand the deforming mechanism and to explain the observed impact strength enhancement observed in the experiments, images of the truss core element during the tests are recorded. A method based on the edge detection algorithm is developed and applied to these images. The deforming profiles of one beam are extracted and it allows for calculating the length of beam. It is found that these lengths diminish to a critical value (due to compression and remain constant afterwards (because of significant bending. The comparison between quasi-static and impact tests shows that the beam were much more compressed under impact loading, which could be understood as the lateral inertia effect in dynamic bucking. Therefore, the impact strength enhancement of tetrahedral truss core sandwich panel can be explained by the delayed buckling of beam under impact (more compression reached, together with the strain hardening of base material.

  20. Reducing the Surface Performance Requirements of a Primary Mirror by Adding a Deformable Mirror in its Optical Path

    Science.gov (United States)

    2015-12-01

    REQUIREMENTS OF A PRIMARY MIRROR BY ADDING A DEFORMABLE MIRROR IN ITS OPTICAL PATH by Ernesto R. Villalba December 2015 Thesis Advisor: Brij...TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE REDUCING THE SURFACE PERFORMANCE REQUIREMENTS OF A PRIMARY MIRROR BY ADDING A...DEFORMABLE MIRROR IN ITS OPTICAL PATH 5. FUNDING NUMBERS 6. AUTHOR(S) Ernesto R. Villalba 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval

  1. Surface deformation induced by magmatic processes at Pacaya Volcano, Guatemala revealed by InSAR

    Science.gov (United States)

    Wnuk, K.; Wauthier, C.

    2017-09-01

    Pacaya Volcano, Guatemala is a continuously active, basaltic volcano with an unstable western flank. Despite continuous activity since 1961, a lack of high temporal resolution geodetic surveying has prevented detailed modeling of Pacaya's underlying magmatic plumbing system. A new, temporally dense dataset of Interferometric Synthetic Aperture Radar (InSAR) RADARSAT-2 images, spanning December 2012 to March 2014, show magmatic deformation before and during major eruptions in January and March 2014. Inversion of InSAR surface displacements using simple analytical forward models suggest that three magma bodies are responsible for the observed deformation: (1) a 4 km deep spherical reservoir located northwest of the summit, (2) a 0.4 km deep spherical source located directly west of the summit, and (3) a shallow dike below the summit. Periods of heightened volcanic activity are instigated by magma pulses at depth, resulting in rapid inflation of the edifice. We observe an intrusion cycle at Pacaya that consists of deflation of one or both magma reservoirs followed by dike intrusion. Intrusion volumes are proportional to reservoir volume loss and do not always result in an eruption. Periods of increased activity culminate with larger dike-fed eruptions. Large eruptions are followed by inter-eruptive periods marked by a decrease in crater explosions and a lack of detected deformation. Co-eruptive flank motion appears to have initiated a new stage of volcanic rifting at Pacaya defined by repeated NW-SE oriented dike intrusions. This creates a positive feedback relationship whereby magmatic forcing from eruptive dike intrusions induce flank motion.

  2. Microstructure and Texture in Surface Deformation Layer of Al-Zn-Mg-Cu Alloy Processed by Milling

    Directory of Open Access Journals (Sweden)

    CHEN Yanxia

    2017-12-01

    Full Text Available The microstructural and crystallographic features of the surface deformation layer in Al-Zn-Mg-Cu alloy induced by milling were investigated by means of transmission electron microscopy (TEM and precession electron diffraction (PED assisted nanoscale orientation mapping. The result shows that the surface deformation layer is composed by the top surface of equiaxed nanograins/ultrafine grains and the subsurface of lamellar nanograins/ultrafine grains surrounded by coarse grain boundary precipitates (GBPs. The recrystallized nanograins/ultrafine grains in the deformation layer show direct evidence that dynamic recrystallization plays an important role in grain refining process. The GBPs and grain interior precipitates (GIPs show a great difference in size and density with the matrix due to the thermally and mechanically induced precipitate redistribution. The crystallographic texture of the surface deformation layer is proved to be a mixture of approximate copper{112}, rotated cube{001} and F {111}. The severe shear deformation of the surface induced by milling is responsible for the texture evolution.

  3. Deformations on Hole and Projectile Surfaces Caused By High Velocity Friction During Ballistic Impact

    Science.gov (United States)

    Karamış, M. B.

    2018-01-01

    In this study, the deformations caused by the ballistic impact on the MM composites and on projectile surfaces are examined. The hole section and grain deformation of unreinforced targets are also examined after impact. The relatively high complexity of impact problems is caused by the large number of intervening parameters like relative velocity of projectile and target, shape of colliding objects, relative stiffness and masses, time-dependent surface of contact, geometry and boundary conditions and material characteristics. The material used in this investigation are 2024 and 7075 aluminum alloys as matrix reinforced with SiC and Al2O3 particles. The matrix materials are extensively used in defense applications due to its favorable ballistic properties, moderate strength, high corrosion resistance and super plastic potential. Two different composites were produced; one by casting and the other by lamination. The ballistic tests of the composite targets were carried out according to NIJ Standard-0101.04, Temperature 21 °C, RH=65% with 7.62 mm projectiles. The bullet weight was 9.6 g and their muzzle velocities were in the range of 770–800 m/s. The projectiles consisted of a steel core, copper jacket and lead material. The composite targets were positioned 15 m from the rifle. The interaction between projectiles and the target hole created after impact were examined by light microscopy and photography. Different damage and failure mechanisms such as petalling, cracking, spalling, dishing, etc., were observed on the target body. On the other hand, dramatic wear and damages on the projectile surface were also observed. The targets were supported with Al-5083 backing blocks having 40 mm thickness.

  4. Modelling the deformations during the manufacturing of nanostructures on non-planar surfaces for injection moulding tool inserts

    DEFF Research Database (Denmark)

    Sonne, M. R.; Cech, J.; Pranov, H.

    2016-01-01

    This paper presents a new manufacturing process for transferring nanostructures from a glass wafer to a curved aluminium insert for polymer injection moulding. A nanostructure consisting of sinusoidal cross-gratings with a period of 426 nm is successfully transferred to hemispheres with different...... radii via an embossing process. The embossing is done into a glass-like resist called HSQ, using a 50 μm thick nickel foil, manufactured with electroforming. During the imprinting process the nickel foil is stretched due to the curved surface of the aluminium substrate and it is experimentally possible...... to characterize this stretch by counting the periods of the cross-gratings via SEM characterization. A numerical model for simulating the deformation of the nickel foil during nanoimprint is also developed, utilizing non-linear material and geometrical behaviour. Good agreement between measured and numerically...

  5. 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....

  6. A Quantitative Assessment of DInSAR Measurements of Interseismic Deformation: The Southern San Andreas Fault Case Study

    Science.gov (United States)

    Manzo, Mariarosaria; Fialko, Yuri; Casu, Francesco; Pepe, Antonio; Lanari, Riccardo

    2012-08-01

    We investigate the capabilities and limitations of the Differential Interferometric Synthetic Aperture Radar (DInSAR) techniques, in particular of the Small BAseline Subset (SBAS) approach, to measure surface deformation in active seismogenetic areas. The DInSAR analysis of low-amplitude, long-wavelength deformation, such as that due to interseismic strain accumulation, is limited by intrinsic trade-offs between deformation signals and orbital uncertainties of SAR platforms in their contributions to the interferometric phases, the latter being typically well approximated by phase ramps. Such trade-offs can be substantially reduced by employing auxiliary measurements of the long-wavelength velocity field. We use continuous Global Positioning System (GPS) measurements from a properly distributed set of stations to perform a pre-filtering operation of the available DInSAR interferograms. In particular, the GPS measurements are used to estimate the secular velocity signal, approximated by a spatial ramp within the azimuth-range radar imaging plane; the phase ramps derived from the GPS data are then subtracted from the available set of DInSAR interferograms. This pre-filtering step allows us to compensate for the major component of the long-wavelength range change that, within the SBAS procedure, might be wrongly interpreted and filtered out as orbital phase ramps. With this correction, the final results are obtained by simply adding the pre-filtered long-wavelength deformation signal to the SBAS retrieved time series. The proposed approach has been applied to a set of ERS-1/2 SAR data acquired during the 1992-2006 time interval over a 200 × 200 km area around the Coachella Valley section of the San Andreas Fault in Southern California, USA. We present results of the comparison between the SBAS and the Line Of Sight (LOS)—projected GPS time series of the USGC/PBO network, as well as the mean LOS velocity fields derived using SBAS, GPS and stacking techniques. Our

  7. Reliability and validity of measures of hammer toe deformity angle and tibial torsion.

    Science.gov (United States)

    Kwon, O Y; Tuttle, L J; Commean, P K; Mueller, M J

    2009-09-01

    Measures of second-fourth metatarsophalangeal joint (MTPJ) angle (indicator of hammer toe deformity) and clinical measures of tibial torsion have limited evidence for validity and reliability. The purposes of this study are to determine: (1) reliability of using a 3D digitizer (Metrecom) and computed tomography (CT) to measure MTPJ angle for toes 2-4; (2) reliability of goniometer, 3D digitizer, and CT to measure tibial torsion; (3) validity of MTPJ angle measures for toes 2-4 using goniometry and 3D digitizer compared to CT (gold standard) and (4) validity of tibial torsion measures using goniometry and 3D digitizer (Metrecom) compared to CT (gold standard). Twenty-nine subjects participated in this study. 27 feet with hammer toe deformity and 31 feet without hammer toe deformity were tested using standardized gonimetric, 3D digitizer and CT methods. ICCs (3,1), standard error of the measurement (SEM) values, and difference measures were used to characterize intrarater reliability. Pearson correlation coefficients and an analysis of variance were used to determine associations and differences between the measurement techniques. 3D digitizer and CT measures of MTPJ angle had high test-retest reliability (ICC = 0.95-0.96 and 0.98-0.99, respectively; SEM = 2.64-3.35 degrees and 1.42-1.47 degrees, respectively). Goniometry, 3D digitizer, and CT measures of tibial torsion had good test-retest reliability (ICC = 0.75, 0.85, and 0.98, respectively; SEM = 2.15 degrees, 1.74 degrees, and 0.72 degree, respectively). Both goniometric and 3D digitizer measures of MTPJ angle were highly correlated with CT measures of MTPJ angle (r = 0.84-0.90, r = 0.84-0.88, respectively) and tibial torsion (r = 0.72, r = 0.83). Goniometry, 3D digitizer, and CT measures were all different from each other for measures of hammer toe deformity (p Goniometry measures were different from CT measures and 3D digitizer measures of tibial torsion (p reliable. Goniometer and 3D digitizer measures of

  8. Surface deformation of active volcanic areas retrieved with the SBAS-DInSAR technique: an overview

    Directory of Open Access Journals (Sweden)

    G. Zeni

    2008-06-01

    Full Text Available This paper presents a comprehensive overview of the surface deformation retrieval capability of the Differential Synthetic Aperture Radar Interferometry (DInSAR algorithm, referred to as Small BAseline Subset (SBAS technique, in the context of active volcanic areas. In particular, after a brief description of the algorithm some experiments relevant to three selected case-study areas are presented. First, we concentrate on the application of the SBAS algorithm to a single-orbit scenario, thus considering a set of SAR data composed by images acquired on descending orbits by the European Remote Sensing (ERS radar sensors and relevant to the Long Valley caldera (eastern California area. Subsequently, we address the capability of the SBAS technique in a multipleorbit context by referring to Mt. Etna volcano (southern Italy test site, with respect to which two different ERS data set, composed by images acquired both on ascending and descending orbits, are available. Finally, we take advantage of the capability of the algorithm to work in a multi-platform scenario by jointly exploiting two different sets of SAR images collected by the ERS and the Environment Satellite (ENVISAT radar sensors in the Campi Flegrei caldera (southern Italy area. The presented results demonstrate the effectiveness of the algorithm to investigate the deformation field in active volcanic areas and the potential of the DInSAR methodologies within routine surveillance scenario.

  9. Threshold voltages and optical retardation of deformed flexoelectric nematic layers with asymmetric surface anchoring

    Science.gov (United States)

    Derfel, G.; Buczkowska, M.

    2013-06-01

    Deformations of homeotropically aligned flexoelectric nematic layers induced by dc electric fields were simulated numerically. Two different anchoring strengths on the limiting surfaces were assumed. Nematic material was characterised by negative dielectric anisotropy. Both signs of the sum of flexoelectric coefficients were taken into account. The electric properties of the layer were described in terms of a weak electrolyte model. Mobility of cations was assumed to be one order of magnitude lower than that of anions. Quasi-blocking electrode contacts were assumed. The threshold voltages for deformations were determined by means of calculations of the phase difference Φ between ordinary and extraordinary light rays passing through a layer placed between crossed polarisers. The threshold values depended on the polarity of the bias voltage U. When the threshold value was exceeded, the phase difference increased with the voltage. Two different Φ(U/Uthreshold) dependencies for the two polarities of the voltage were found for each layer if the nematic possessed the flexoelectric properties. The possibility of using this effect to detect the flexoelectricity in the nematic was explored by simulated experiments. The effectiveness of the proposed method is discussed.

  10. Deformation vector measurement by means of ground based interferometric radar system

    Science.gov (United States)

    Michelini, Alberto; Coppi, Francesco

    2017-10-01

    Ground Based Interferometric Radar (GBInRad) is a class of terrestrial remote sensing imaging system, based on microwave interferometric techniques. The principal application of GBInRad system is deformation monitoring, since respect to other techniques they can provide remote sensing, high sensitivity to small deformations, long range of measurements, imaging capability and fast scan time. The main limitation of standard GBInRad system is their capability of detecting movements only along the Line of Sight (LoS) of the sensor, although actual targets may show deformations in any direction of space; this represents an important limitation with respect to other techniques able to estimate the full 3D deformation vector. If the displacement direction is not known a priori, combining together LoS displacement measured from different spatial positions, it is possible to reconstruct the actual 3D displacement vector of monitored targets. In this paper are introduced and analysed the various aspect of the displacement vector measurement with multiple GBInRad system that work both in a monostatic and in a bistatic configuration. In the monostatic configuration every system transmits and receives the signal independently from the others; this approach requires multiple GBInRad system deployed to monitoring the same scenario and therefore its main limitations lie in the costs, power consumption and maintenance. A possible cost-effective evolution of the monostatic configuration is to exploit GBInRad system in a multiple bistatic configuration; a multiple bistatic Radar is a system in which a transmitter operates together with multiple receivers located in different positions in space. In this paper, the deformation vector measurement by means of bistatic GBInRad is proposed.

  11. Deformation measurements of materials at low temperatures using laser speckle photography method

    International Nuclear Information System (INIS)

    Sumio Nakahara; Yukihide Maeda; Kazunori Matsumura; Shigeyoshi Hisada; Takeyoshi Fujita; Kiyoshi Sugihara

    1992-01-01

    The authors observed deformations of several materials during cooling down process from room temperature to liquid nitrogen temperature using the laser speckle photography method. The in-plane displacements were measured by the image plane speckle photography and the out-of-plane displacement gradients by the defocused speckle photography. The results of measurements of in-plane displacement are compared with those of FEM analysis. The applicability of laser speckle photography method to cryogenic engineering are also discussed

  12. A Method to Measure Thermal Deformation of Superconducting Magnet Cross Sections

    OpenAIRE

    Grau-Carles, A; García-Tabarés, L; Todesco, Ezio; Tommasini, D; Siegel, N

    1999-01-01

    The precision measurement of the cable positioning in superconducting coils is of great interest both at room and liquid nitrogen temperatures because mechanical and thermal deformations affect the quality of the magnetic field. The paper describes a new two-coordinate measuring device, which is able to obtain scanned images of flat composite samples at liquid nitrogen temperature. The sample is cooled at 77 K into a flat quartz tray to permit the optical access to the sample from the bottom....

  13. Impact of acoustic velocity structure to measurement of ocean bottom crustal deformation

    Science.gov (United States)

    Ikuta, R.; Tadokoro, K.; Okuda, T.; Sugimoto, S.; Watanabe, T.; Eto, S.; Ando, M.

    2010-12-01

    We are developing a geodetic method of monitoring crustal deformation under the ocean using kinematic GPS and acoustic ranging. The goal of our research is to achieve sub-centimeter accuracy in measuring oceanic crustal deformation by a very short-time measurement like 10 hours. In this study, we focused on lateral variation of acoustic velocity structure in seawater and introduced an inclined acoustic velocity structure model to improve accuracy of the measurement. We have a few measurement sites along Nankai trough, Japan. In each sites, we deployed a trio of transponders on ocean floor (seafloor benchmark units) within distance comparable with the depth. An ultrasonic signal is generated from a surface vessel drifting over the benchmark unit, which is received and replied by the benchmark unit. In this system, both acoustic velocity structure and the benchmark unit positions were determined simultaneously for the each measurement using a tomographic technique. This tomographic technique was adopted on an assumption that the acoustic velocity structure is horizontally layered and changes only in time, not in space. Ikuta et al., (AGU fall meeting 2009) reported an approach to improve accuracy of benchmark positioning using a new additional assumption. The additional assumption was that the configuration of the transponders trio constituting one benchmark unit does not change. They determined the time evolution of weight center for the fixed transponder triangle between different measurements using all repetitively obtained data sets at once. This is contrasting to the previous method in which each data set for different measurement was solved independently. This assumption worked well in reducing number of unknown parameters. As a result, repeatability of benchmark positioning improved from 5 cm to 3 cm. We conducted numerical experiments synthesizing acoustic travel-time data to evaluate the robustness of this new approach. When acoustic travel-time data is

  14. Simultaneous shape and deformation measurements in a blood vessel model by two wavelength interferometry

    Science.gov (United States)

    Andrés, Nieves; Pinto, Cristina; Lobera, Julia; Palero, Virginia; Arroyo, M. Pilar

    2017-06-01

    Holographic techniques have been used to measure the shape and the radial deformation of a blood vessel model and a real sheep aorta. Measurements are obtained from several holograms recorded for different object states. For each object state, two holograms with two different wavelengths are multiplexed in the same digital recording. Thus both holograms are simultaneously recorded but the information from each of them is separately obtained. The shape analysis gives a wrapped phase map whose fringes are related to a synthetic wavelength. After a filtering and unwrapping process, the 3D shape can be obtained. The shape data for each line are fitted to a circumference in order to determine the local vessel radius and center. The deformation analysis also results in a wrapped phase map, but the fringes are related to the laser wavelength used in the corresponding hologram. After the filtering and unwrapping process, a 2D map of the deformation in an out-of-plane direction is reconstructed. The radial deformation is then calculated by using the shape information.

  15. Inferring field-scale properties of a fractured aquifer from ground surface deformation during a well test

    Science.gov (United States)

    Schuite, Jonathan; Longuevergne, Laurent; Bour, Olivier; Boudin, Frédérick; Durand, Stéphane; Lavenant, Nicolas

    2015-12-01

    Fractured aquifers which bear valuable water resources are often difficult to characterize with classical hydrogeological tools due to their intrinsic heterogeneities. Here we implement ground surface deformation tools (tiltmetry and optical leveling) to monitor groundwater pressure changes induced by a classical hydraulic test at the Ploemeur observatory. By jointly analyzing complementary time constraining data (tilt) and spatially constraining data (vertical displacement), our results strongly suggest that the use of these surface deformation observations allows for estimating storativity and structural properties (dip, root depth, and lateral extension) of a large hydraulically active fracture, in good agreement with previous studies. Hence, we demonstrate that ground surface deformation is a useful addition to traditional hydrogeological techniques and opens possibilities for characterizing important large-scale properties of fractured aquifers with short-term well tests as a controlled forcing.

  16. Investigation of graded strengthened hyper-deformed surfaces by impact treatment: micro-percussion testing

    Science.gov (United States)

    Tumbajoy-Spinel, David; Descartes, Sylvie; Bergheau, Jean-Michel; Al-Baida, Halim; Langlade, Cécile; Kermouche, Guillaume

    2017-05-01

    In the industry, mechanical surface treatments could improve the mechanical behaviour of materials by the means of local hyper-deformation and graded strengthening. Micro-percussion test represents an interesting case scenario to emulate these kinds of conventional treatments (shot-peening, SMAT, roller-burnishing, etc) and go further on microstructural and mechanical characterization at local and global scales. For this technique, every impact is made at the same position by a rigid conical indenter, controlling the number, angle and velocity of impacts. The main issue of this work is to establish a complete description of the transformed microstructures; to understand the mechanisms involved on the formation and growth of refined structures; to make a parametric sensitivity analysis of different impact conditions.

  17. Isolated, slowly evolving, and dynamical trapping horizons: Geometry and mechanics from surface deformations

    International Nuclear Information System (INIS)

    Booth, Ivan; Fairhurst, Stephen

    2007-01-01

    We study the geometry and dynamics of both isolated and dynamical trapping horizons by considering the allowed variations of their foliating two-surfaces. This provides a common framework that may be used to consider both their possible evolutions and their deformations as well as derive the well-known flux laws. Using this framework, we unify much of what is already known about these objects as well as derive some new results. In particular we characterize and study the ''almost isolated'' trapping horizons known as slowly evolving horizons. It is for these horizons that a dynamical first law holds and this is analogous and closely related to the Hawking-Hartle formula for event horizons

  18. Measurement errors induced by deformation of optical axes of achromatic waveplate retarders in RRFP Stokes polarimeters.

    Science.gov (United States)

    Dong, Hui; Tang, Ming; Gong, Yandong

    2012-11-19

    The optical axes of achromatic waveplate retarders (AWR) may deform from ideal linear eigenpolarizations and be frequency-dependent owing to the imperfect design and fabrication. Such deformations result in the ellipticity error and the orientation error of an AWR away from the nominal values. In this paper, we address the measurement errors of Stokes parameters induced by deformation of optical axes of AWRs in roatatable retarder fixed polarizer (RRFP) Stokes polarimeters. A set of theoretical formulas is derived to reveal that such measurement errors actually depend on both retardance and angular orientations of the AWR in use, as well as the state of polarization (SOP) under test. We demonstrate that,by rotating the AWR to N (N≥5) uniformly spaced angles with the angle step of 180°/N or 360°/N, the measurement errors of Stokes parameters induced by the ellipticity error of the AWR can be suppressed compared with the result using any set of four specific angles, especially when the SOP under test is nearly circular. On the other hand, the measurement errors induced by the orientation error of the AWR have more complicated relationships with the angular orientations of the AWR: 1) when the SOP under test is nearly circular, above-mentioned N (N≥5) uniformly spaced angles also lead to much smaller measurement errors than any set of four specific angles; 2) when the SOP under test is nearly linear, N (N≥5) uniformly spaced angles result in smaller or larger measurement errors, depending on the SOP under test, compared with the usually-recommended sets of four specific angles. By theoretical calculations and numerical simulations, we can conclude that the RRFP Stokes polarimeters employing angle sets of N (N≥5) uniformly spaced angles, ( ± 90°, -54°, -18°, 18°, 54°) for instance, can effectively reduce the measurement errors of Stokes parameters induced by the optical axes deformation of the AWR.

  19. The Surface Layer Mechanical Condition and Residual Stress Forming Model in Surface Plastic Deformation Process with the Hardened Body Effect Consideration

    Science.gov (United States)

    Mahalov, M. S.; Blumenstein, V. Yu

    2017-10-01

    The mechanical condition and residual stresses (RS) research and computational algorithms creation in complex types of loading on the product lifecycle stages relevance is shown. The mechanical state and RS forming finite element model at surface plastic deformation strengthening machining, including technological inheritance effect, is presented. A model feature is the production previous stages obtained transformation properties consideration, as well as these properties evolution during metal particles displacement through the deformation space in the present loading step.

  20. The Virtual Fields Method Extracting Constitutive Mechanical Parameters from Full-field Deformation Measurements

    CERN Document Server

    Pierron, Fabrice

    2012-01-01

    The Virtual Fields Method: Extracting Constitutive Mechanical Parameters from Full-field Deformation Measurements is the first book on the Virtual Fields Method (VFM), a technique to identify materials mechanical properties from full-field measurements. Firmly rooted with extensive theoretical description of the method, the book presents numerous examples of application to a wide range of materials (composites, metals, welds, biomaterials) and situations (static, vibration, high strain rate). The authors give a detailed training section with examples of progressive difficulty to lead the reader to program the VFM and include a set of commented Matlab programs as well as GUI Matlab-based software for more general situations. The Virtual Fields Method: Extracting Constitutive Mechanical Parameters from Full-field Deformation Measurements is an ideal book for researchers, engineers, and students interested in applying the VFM to new situations motivated by their research.  

  1. Surface texture measurement for dental wear applications

    Science.gov (United States)

    Austin, R. S.; Mullen, F.; Bartlett, D. W.

    2015-06-01

    The application of surface topography measurement and characterization within dental materials science is highly active and rapidly developing, in line with many modern industries. Surface measurement and structuring is used extensively within oral and dental science to optimize the optical, tribological and biological performance of natural and biomimetic dental materials. Although there has historically been little standardization in the use and reporting of surface metrology instrumentation and software, the dental industry is beginning to adopt modern areal measurement and characterization techniques, especially as the dental industry is increasingly adopting digital impressioning techniques in order to leverage CAD/CAM technologies for the design and construction of dental restorations. As dental treatment becomes increasingly digitized and reliant on advanced technologies such as dental implants, wider adoption of standardized surface topography and characterization techniques will become evermore essential. The dental research community welcomes the advances that are being made in surface topography measurement science towards realizing this ultimate goal.

  2. Historical coseismic surface deformation of fluvial gravel deposits, Schafberg fault, Lower Rhine Graben, Germany

    Science.gov (United States)

    Kübler, Simon; Friedrich, Anke M.; Gold, Ryan D.; Strecker, Manfred R.

    2018-03-01

    Intraplate earthquakes pose a significant seismic hazard in densely populated rift systems like the Lower Rhine Graben in Central Europe. While the locations of most faults in this region are well known, constraints on their seismogenic potential and earthquake recurrence are limited. In particular, the Holocene deformation history of active faults remains enigmatic. In an exposure excavated across the Schafberg fault in the southwestern Lower Rhine Graben, south of Untermaubach, in the epicentral region of the 1756 Düren earthquake ( M L 6.2), we mapped a complex deformation zone in Holocene fluvial sediments. We document evidence for at least one paleoearthquake that resulted in vertical surface displacement of 1.2 ± 0.2 m. The most recent earthquake is constrained to have occurred after 815 AD, and we have modeled three possible earthquake scenarios constraining the timing of the latest event. Coseismic deformation is characterized by vertical offset of sedimentary contacts distributed over a 10-m-wide central damage zone. Faults were identified where they fracture and offset pebbles in the vertically displaced gravel layers and fracture orientation is consistent with the orientation of the Schafberg fault. This study provides the first constraint on the most recent surface-rupturing earthquake on the Schafberg fault. We cannot rule out that this fault acted as the source of the 1756 Düren earthquake. Our study emphasizes the importance of, and the need for, paleoseismic studies in this and other intracontinental regions, in particular on faults with subtle geomorphic expression that would not typically be recognized as being potentially seismically active. Our study documents textural features in unconsolidated sediment that formed in response to coseismic rupturing of the underlying bedrock fault. We suggest that these features, e.g., abundant oriented transgranular fractures in their context, should be added to the list of criteria used to identify a fault

  3. Technique for measuring very high surface velocities

    International Nuclear Information System (INIS)

    Maron, Y.

    1977-01-01

    An interferometric technique for measuring displacements of surfaces moving at velocities in the range of a few millimeters per microsecond is presented. The Doppler shift of frequency of light scattered from such surfaces is too high to be detectable by known devices. The present technique is based upon monitoring the signal resulting from the interference between two beams reflected from the surface at different incidence angles. Measurement systems for specularly as well as diffusely reflecting surfaces are described. Light source with very modest temporal coherence delivering about 100 mw power is required. The accuracy of the technique is discussed. (author)

  4. Influence of Plastic Deformation on Low-Temperature Surface Hardening of Austenitic Stainless Steel by Gaseous Nitriding

    Science.gov (United States)

    Bottoli, Federico; Winther, Grethe; Christiansen, Thomas L.; Somers, Marcel A. J.

    2015-06-01

    This article addresses an investigation of the influence of plastic deformation on low-temperature surface hardening by gaseous nitriding of two commercial stainless steels: EN 1.4369 and AISI 304. The materials were plastically deformed to several levels of equivalent strain by conventional tensile straining, plane strain compression, and shear. Gaseous nitriding of the strained material was performed in ammonia gas at atmospheric pressure at various temperatures. Microstructural characterization of the as-deformed state and the nitrided case produced included X-ray diffraction analysis, reflected-light microscopy, and microhardness testing. The results demonstrate that a case of expanded austenite develops and that the presence of plastic deformation has a significant influence on the morphology of the nitrided case. The presence of strain-induced martensite favors the formation of CrN, while a high dislocation density in a fully austenitic structure does not lead to such premature nucleation of CrN.

  5. Surface texture measurement for additive manufacturing

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  6. Model Deformation Measurements of Sonic Boom Models in the NASA Ames 9- by 7-Ft Supersonic Wind Tunnel

    Science.gov (United States)

    Schairer, Edward T.; Kushner, Laura K.; Garbeff, Theodore J.; Heineck, James T.

    2015-01-01

    The deformations of two sonic-boom models were measured by stereo photogrammetry during tests in the 9- by 7-Ft Supersonic Wind Tunnel at NASA Ames Research Center. The models were geometrically similar but one was 2.75 times as large as the other. Deformation measurements were made by simultaneously imaging the upper surfaces of the models from two directions by calibrated cameras that were mounted behind windows of the test section. Bending and twist were measured at discrete points using conventional circular targets that had been marked along the leading and trailing edges of the wings and tails. In addition, continuous distributions of bending and twist were measured from ink speckles that had been applied to the upper surfaces of the model. Measurements were made at wind-on (M = 1.6) and wind-off conditions over a range of angles of attack between 2.5 deg. and 5.0 deg. At each condition, model deformation was determined by comparing the wind-off and wind-on coordinates of each measurement point after transforming the coordinates to reference coordinates tied to the model. The necessary transformations were determined by measuring the positions of a set of targets on the rigid center-body of the models whose model-axes coordinates were known. Smoothly varying bending and twist measurements were obtained at all conditions. Bending displacements increased in proportion to the square of the distance to the centerline. Maximum deflection of the wingtip of the larger model was about 5 mm (2% of the semispan) and that of the smaller model was 0.9 mm (1% of the semispan). The change in wing twist due to bending increased in direct proportion to distance from the centerline and reached a (absolute) maximum of about -1? at the highest angle of attack for both models. The measurements easily resolved bending displacements as small as 0.05 mm and bending-induced changes in twist as small as 0.05 deg.

  7. Interseismic and coseismic surface deformation deduced from space geodetic observations : with inferences on seismic hazard, tectonic processes, earthquake complexity, and slip distribution

    NARCIS (Netherlands)

    Bos, A.G. (Annemarie Gerredina)

    2003-01-01

    In this thesis I am concerned with modeling the kinematics of surface deformation using space geodetic observations in order to advance insight in both interseismic and coseismic surface response. To model the surface deformation field I adopt the method of Spakman and Nyst (2002) which resolves the

  8. Constructing invariant fairness measures for surfaces

    DEFF Research Database (Denmark)

    Gravesen, Jens; Ungstrup, Michael

    2002-01-01

    The paper proposes a rational method to derive fairness measures for surfaces. It works in cases where isophotes, reflection lines, planar intersection curves, or other curves are used to judge the fairness of the surface. The surface fairness measure is derived by demanding that all the given cu...... of curves. Six basic third order invariants by which the fairing measures can be expressed are defined. Furthermore, the geometry of a plane intersection curve is studied, and the variation of the total, the normal, and the geodesic curvature and the geodesic torsion is determined....

  9. A new theory for the static contact between rough, unmated surfaces in non-elastically deforming rock and its implications for rock friction

    Science.gov (United States)

    Stesky, R. M.; Hannan, S. S.

    The closure behavior of fractures in marble and alabaster is markedly different from that in quartzite. The aperture decreases considerably more under normal stress and remains permanently reduced, for the same ratio of normal stress to unconfined compressive strength. Also, a larger permanent relative contact area develops between the surfaces of marble and alabaster than it does between surfaces of quartzite. The permanent contact area increases at an increasing rate with normal stress in marble and alabaster, unlike the nearly linear increase in quartzite. The failure of surface asperities of calcite and gypsum during closure accounts for these differences. We modeled this process by considering the surfaces to consist of paraboloids lying on a flat plane and having a range of initial heights. Closure occurs by pressing a plane rigid surface against the 'hills', flattening their peaks, keeping the base area of the hills constant. To allow for a changing resistance to deformation, the contact stress is assumed to vary linearly with the shortening strain, to a first approximation. This model was tested against measurements of fracture closure and contact area of rough surfaces of calcite marble with a known initial height distribution of surface peaks. The fit to the data is quite good. In all cases, the model shows that closure is accompanied by a decrease in contact strength of deforming asperities, suggested also by the cataclastic deformation observed petrographically. The number of contact spots and the total length of contact seen in profile are also reasonably well modeled. These results have important implications for our understanding of frictional strength of fractures. The overall resistance to shear along rough surfaces depends upon the product of the shear strength and true area of the contacts, both of which are affected by normal stress. Application of this model approach shows that the initial frictional resistance of some fractures in ductile

  10. [Posttraumatic torsional deformities of the forearm : Methods of measurement and decision guidelines for correction].

    Science.gov (United States)

    Blossey, R D; Krettek, C; Liodakis, E

    2018-03-01

    Forearm fractures are common in all age groups. Even if the adjacent joints are not directly involved, these fractures have an intra-articular character. One of the most common complications of these injuries is a painful limitation of the range of motion and especially of pronation and supination. This is often due to an underdiagnosed torsional deformity; however, in recent years new methods have been developed to make these torsional differences visible and quantifiable through the use of sectional imaging. The principle of measurement corresponds to that of the torsion measurement of the lower limbs. Computed tomography (CT) or magnetic resonance imaging (MRI) scans are created at defined heights. By searching for certain landmarks, torsional angles are measured in relation to a defined reference line. A new alternative is the use of 3D reformation models. The presence of a torsional deformity, especial of the radius, leads to an impairment of the pronation and supination of the forearm. In the presence of torsional deformities, radiological measurements can help to decide if an operation is needed or not. Unlike the lower limbs, there are still no uniform cut-off values as to when a correction is indicated. Decisions must be made together with the patient by taking the clinical and radiological results into account.

  11. Surface tension measurements with a smartphone

    Science.gov (United States)

    Goy, Nicolas-Alexandre; Denis, Zakari; Lavaud, Maxime; Grolleau, Adrian; Dufour, Nicolas; Deblais, Antoine; Delabre, Ulysse

    2017-11-01

    Smartphones are increasingly used in higher education and at university in mechanics, acoustics, and even thermodynamics as they offer a unique way to do simple science experiments. In this article, we show how smartphones can be used in fluid mechanics to measure surface tension of various liquids, which could help students understand the concept of surface tension through simple experiments.

  12. Constructing Invariant Fairness Measures for Surfaces

    DEFF Research Database (Denmark)

    Gravesen, Jens; Ungstrup, Michael

    1998-01-01

    This paper presents a general method which from an invariant curve fairness measure constructs an invariant surface fairness measure. Besides the curve fairness measure one only needs a class of curves on the surface for which one wants to apply the curve measure. The surface measure at a point...... variation.The method is extended to the case where one considers, not the fairness of one curve, but the fairness of a one parameter family of curves. Such a family is generated by the flow of a vector field, orthogonal to the curves. The first, respectively the second order derivative along the curve...... of the size of this vector field is used as the fairness measure on the family.Six basic 3rd order invariants satisfying two quadratic equations are defined. They form a complete set in the sense that any invariant 3rd order function can be written as a function of the six basic invariants together...

  13. Experimental evaluation of a polycrystal deformation modeling scheme using neutron diffraction measurements

    DEFF Research Database (Denmark)

    Clausen, Bjørn; Lorentzen, Torben

    1997-01-01

    The uniaxial behavior of aluminum polycrystals is simulated using a rate-independent incremental self-consistent elastic-plastic polycrystal deformation model, and the results are evaluated by neutron diffraction measurements. The elastic strains deduced from the model show good agreement...... with the experimental results for the 111 and 220 reflections, whereas the predicted elastic strain level for the 200 reflection is, in general, approximately 10 pct too low in the plastic regime....

  14. Preparation of stable silica surfaces for surface forces measurement

    Science.gov (United States)

    Ren, Huai-Yin; Mizukami, Masashi; Kurihara, Kazue

    2017-09-01

    A surface forces apparatus (SFA) measures the forces between two surfaces as a function of the surface separation distance. It is regarded as an essential tool for studying the interactions between two surfaces. However, sample surfaces used for the conventional SFA measurements have been mostly limited to thin (ca. 2-3 μm) micas, which are coated with silver layers (ca. 50 nm) on their back, due to the requirement of the distance determination by transmission mode optical interferometry called FECO (fringes of equal chromatic order). The FECO method has the advantage of determining the absolute distance, so it should be important to increase the availability of samples other than mica, which is chemically nonreactive and also requires significant efforts for cleaving. Recently, silica sheets have been occasionally used in place of mica, which increases the possibility of surface modification. However, in this case, the silver layer side of the sheet is glued on a cylindrical quartz disc using epoxy resin, which is not stable in organic solvents and can be easily swollen or dissolved. The preparation of substrates more stable under severe conditions, such as in organic solvents, is necessary for extending application of the measurement. In this study, we report an easy method for preparing stable silica layers of ca. 2 μm in thickness deposited on gold layers (41 nm)/silica discs by sputtering, then annealed to enhance the stability. The obtained silica layers were stable and showed no swelling in organic solvents such as ethanol and toluene.

  15. Calculation of rectal dose surface histograms in the presence of time varying deformations

    International Nuclear Information System (INIS)

    Roeske, John C.; Spelbring, Danny R.; Vijayakumar, S.; Forman, Jeffrey D.; Chen, George T.Y.

    1996-01-01

    Purpose: Dose volume (DVH) and dose surface histograms (DSH) of the bladder and rectum are usually calculated from a single treatment planning scan. These DVHs and DSHs will eventually be correlated with complications to determine parameters for normal tissue complication probabilities (NTCP). However, from day to day, the size and shape of the rectum and bladder may vary. The purpose of this study is to compare a more accurate estimate of the time integrated DVHs and DSHs of the rectum (in the presence of daily variations in rectal shape) to initial DVHs/DSHs. Methods: 10 patients were scanned once per week during the course of fractionated radiotherapy, typically accumulating a total of six scans. The rectum and bladder were contoured on each of the studies. The model used to assess effects of rectal contour deformation is as follows: the contour on a given axial slice (see figure) is boxed within a rectangle. A line drawn parallel to the AP axis through the rectangle equally partitions the box. Starting at the intersection of the vertical line and the rectal contour, points on the contour are marked off representing the same rectal dose point, even in the presence of distortion. Corresponding numbered points are used to sample the dose matrix and create a composite DSH. The model assumes uniform stretching of the rectal contour for any given axial cut, and no twist of the structure or vertical displacement. A similar model is developed for the bladder with spherical symmetry. Results: Normalized DSHs (nDSH) for each CT scan were calculated as well as the time averaged nDSH over all scans. These were compared with the nDSH from the initial planning scan. Individual nDSHs differed by 8% surface area irradiated at the 80% dose level, to as much as 20% surface area in the 70-100% dose range. DSH variations are due to position and shape changes in the rectum during different CT scans. The spatial distribution of dose is highly variable, and depends on the field

  16. The African Surface (85-45 Ma): a Record of Mantle Deformations Since 35 Ma

    Science.gov (United States)

    Guillocheau, Francois; Simon, Brendan; Baby, Guillaume; Robin, Cécile

    2016-04-01

    Africa is characterized by a bimodal topography with long (x100 km) to very long (x1000 km) wavelength plateaus and domes. The 300-400 m topographic mode corresponds to the Sahara on which is superimposed swells (Hoggar, Tibesti..) and the Congo Interior Basin. The 900-1100 m mode corresponds to the Southern African (Kalahari) Plateau and the East African and Ethiopian Domes. The landforms responsible of the African topography are of three types (1) etchplains (mantled or stripped), (2) pediments and pediplains and (3) incised valleys. Those different landforms are stepped with mantled etchplains at higher elevation and pediments/stripped etchplains are lower elevation. Some of those landforms can be dated using either direct geochronological evidences on lateritic weathering profiles or geological evidences such as the relationship between landforms and dated magmatism or sediments. We used the stepping of successive pediments as a proxy of deformation, making sure that they record successive base level fall. We mapped at Africa-scale, a major widespread etchplain known as the African Surface (King, 1949; Burke & Gunnel, 2008). This surface was dated both by geochronology (e.g. Beauvais et al., 2008 in Burkina, Deller, 2012 in North Ethiopia) and on geological evidences (interfingering or reworking of laterites in sedimentary basins such as Iullemmeden Basin or the Tanzanian Margin). The paroxysm of weathering was during Early Eocene times (EOCM) but started earlier in Late Cretaceous with more or less younger ages according to its location in Africa. Geometrical restorations of pediments indicate that this surface was (1) at sea level in northern and central Africa with unknown upstream gradients and (2) superimposed on a Late Cretaceous plateau in southern Africa. The main period of very long wavelenghth deformation occurred around the Oligocene-Eocene boundary with the uplift of northern Africa or the beginning of the growth the East African dome. Some other

  17. Elastic particle deformation in rectangular channel flow as a measure of particle stiffness.

    Science.gov (United States)

    Hwang, Margaret Y; Kim, Seo Gyun; Lee, Heon Sang; Muller, Susan J

    2018-01-03

    In this study, we experimentally observed and characterized soft elastic particle deformation in confined flow in a microchannel with a rectangular cross-section. Hydrogel microparticles of pNIPAM were produced using two different concentrations of crosslinker. This resulted in particles with two different shear moduli of 13.3 ± 5.5 Pa and 32.5 ± 15.7 Pa and compressive moduli of 66 ± 10 Pa and 79 ± 15 Pa, respectively, as measured by capillary micromechanics. Under flow, the particle shapes transitioned from circular to egg, triangular, arrowhead, and ultimately parachute shaped with increasing shear rate. The shape changes were reversible, and deformed particles relaxed back to circular/spherical in the absence of flow. The thresholds for each shape transition were quantified using a non-dimensional radius of curvature at the tip, particle deformation, circularity, and the depth of the concave dimple at the trailing edge. Several of the observed shapes were distinct from those previously reported in the literature for vesicles and capsules; the elastic particles had a narrower leading tip and a lower circularity. Due to variations in the shear moduli between particles within a batch of particles, each flow rate corresponded to a small but finite range of capillary number (Ca) and resulted in a series of shapes. By arranging the images on a plot of Ca versus circularity, a direct correlation was developed between shape and Ca and thus between particle deformation and shear modulus. As the shape was very sensitive to differences in shear modulus, particle deformation in confined flow may allow for better differentiation of microparticle shear modulus than other methods.

  18. Interseismic Deformation along the Red River Fault from InSAR Measurements

    Science.gov (United States)

    Chen, J.; Li, Z.; Clarke, P. J.

    2017-12-01

    The Red River Fault (RRF) zone is a profound geological discontinuity separating South China from Indochina. Right lateral movements along this >900 km fault are considered to accommodate the extrusion of SE China. Crustal deformation monitoring at high resolution is the key to understand the present-day mode of deformation in this zone and its interaction with the adjacent regions. This is the first study to measure the interseismic deformation of the entire fault with ALOS-1/2 and Sentinel-1 observations. Nine ascending tracks of ALOS-1 data between 2007 and 2011 are collected from the Alaska Satellite Facility (ASF), four descending tracks of Sentinel-1 data are acquired every 24 days since October 2014, and ALOS-2 data are being systematically acquired since 2014. The long wavelength (L-band) of ALOS-1/2 and short temporal baseline of Sentinel-1 ensure good coherence to overcome the limitations of heavy vegetation and variable climate in the region. Stacks of interferograms are generated by our automatic processing chain based on the InSAR Scientific Computing Environment (ISCE) software, ionospheric errors are estimated and corrected using the split-spectrum method (Fattahi et al., IEEE Trans. Geosci. Remote Sens., 2017) and the tropospheric delays are calibrated using the Generic Atmospheric Correction Online Service for InSAR (GACOS: http://ceg-research.ncl.ac.uk/v2/gacos) with high-resolution ECMWF products (Yu et al., J. Geophys. Res., 2017). Time series analysis is performed to determine the interseismic deformation rate of the RRF using the in-house InSAR time series with atmospheric estimation model (InSAR TS + AEM) package based on the Small Baseline Subset (SBAS) algorithm. Our results reveal the decrease of slip rate from north to south. We map the interseismic strain rate field to characterize the deformation patterns and seismic hazard throughout the RRF zone.

  19. Deformation of Olivine at Subduction Zone Conditions Determined from In situ Measurements with Synchrotron Radiation

    Energy Technology Data Exchange (ETDEWEB)

    H Long; D Weidner; L Li; J Chen; L Wang

    2011-12-31

    We report measurements of the deformation stress for San Carlos olivine at pressures of 3-5 GPa, temperatures of 25-1150 C, and strain rates of 10{sup -7}-10{sup -5} s{sup -1}. We determine a deformation stress of approximately 2.5 GPa that is relatively temperature and strain rate independent in the temperature range of 400-900 C. The deformation experiments have been carried out on a deformation DIA (D-DIA) apparatus, Sam85, at X17B2, NSLS. Powder samples are used in these experiments. Enstatite (MgSiO{sub 3}) (3-5% total quality of sample) is used as the buffer to control the activity of silica. Ni foil is used in some experiments to buffer the oxygen fugacity. Water content is confirmed by IR spectra of the recovered samples. Samples are compressed at room temperature and are then annealed at 1200 C for at least 2 h before deformation. The total (plastic and elastic) strains (macroscopic) are derived from the direct measurements of the images taken by X-ray radiograph technique. The differential stresses are derived from the diffraction determined elastic strains. In the regime of 25-400 C, there is a small decrease of stress at steady state as temperature increases; in the regime of 400 C to the 'transition temperature', the differential stress at steady state ({approx}2.5 GPa) is relatively insensitive to the changes of temperature and strain rate; however, it drastically decreases to about 1 GPa and becomes temperature-dependent above the transition temperature and thereafter. The transition temperature is near 900 C. Above the transition temperature, the flow agrees with power law creep measurements of previous investigations. The anisotropy of differential stress in individual planes indicates that the deformation of olivine at low temperature is dominated by [0 0 1](1 0 0). Accounting to a slower strain rate in the natural system, the transition temperature for the olivine in the slab is most likely in the range of 570-660 C.

  20. Automatic method of analysis and measurement of additional parameters of corneal deformation in the Corvis tonometer.

    Science.gov (United States)

    Koprowski, Robert

    2014-11-19

    The method for measuring intraocular pressure using the Corvis tonometer provides a sequence of images of corneal deformation. Deformations of the cornea are recorded using the ultra-high-speed Scheimpflug camera. This paper presents a new and reproducible method of analysis of corneal deformation images that allows for automatic measurements of new features, namely new three parameters unavailable in the original software. The images subjected to processing had a resolution of 200 × 576 × 140 pixels. They were acquired from the Corvis tonometer and simulation. In total 14,000 2D images were analysed. The image analysis method proposed by the author automatically detects the edge of the cornea and sclera fragments. For this purpose, new methods of image analysis and processing proposed by the author as well as those well-known, such as Canny filter, binarization, median filtering etc., have been used. The presented algorithms were implemented in Matlab (version 7.11.0.584-R2010b) with Image Processing toolbox (version 7.1-R2010b) using both known algorithms for image analysis and processing and those proposed by the author. Owing to the proposed algorithm it is possible to determine three parameters: (1) the degree of the corneal reaction relative to the static position; (2) the corneal length changes; (3) the ratio of amplitude changes to the corneal deformation length. The corneal reaction is smaller by about 30.40% compared to its static position. The change in the corneal length during deformation is very small, approximately 1% of its original length. Parameter (3) enables to determine the applanation points with a correlation of 92% compared to the conventional method for calculating corneal flattening areas. The proposed algorithm provides reproducible results fully automatically within a few seconds/per patient using Core i7 processor. Using the proposed algorithm, it is possible to measure new, additional parameters of corneal deformation, which

  1. Influence of Near-Surface Severe Plastic Deformation of Mild Steel on the Inhibition Performance of Sodium Molybdate and 1H-Benzotriazole in Artificial Sea Water

    Science.gov (United States)

    Sabet Bokati, Kazem; Dehghanian, Changiz; Babaei, Mahdi

    2018-02-01

    The effects of near-surface severe plastic deformation (NS-SPD) on the inhibition performance of sodium molybdate (SM) and 1H-benzotriazole (BTA) for mild steel were investigated using weight loss, polarization and electrochemical impedance spectroscopy measurements. The crystal grain size of NS-SPD-processed surface was analyzed by x-ray diffractometry and field emission scanning electron microscopy. A deformed layer with thickness of 20 ± 5 µm was produced on mild steel surface after NS-SPD process due to accumulated strains. The NS-SPD process caused more effective adsorption of corrosion inhibitors due to the fabrication of a surface with a high density of preferential adsorption sites. However, the stability of protective layer was predominantly influenced by the effect of NS-SPD process on inhibition efficiency. The fairly good persistence of protective layer formed on the surface by SM-containing solution and also positive effect of NS-SPD process on adsorption of molybdate ions caused higher inhibition performance for sodium molybdate. However, NS-SPD process encouraged deterioration of protective layer formed on steel surface in the presence of BTA inhibitor. It was ascribed to partial coverage of surface, low stability of adsorbed layer and thus more adsorption of aggressive ions on unprotected area which was uncovered during immersion time.

  2. Influence of Plastic Deformation on Low Temperature Surface Hardening of Austenitic and Precipitation Hardening Stainless Steels by Gaseous Nitriding

    DEFF Research Database (Denmark)

    Bottoli, Federico; Winther, Grethe; Christiansen, Thomas Lundin

    2015-01-01

    This article addresses an investigation of the influence of plastic deformation on low temperature surface hardening by gaseous nitriding of three commercial austenitic stainless steels: AISI 304, EN 1.4369 and Sandvik Nanoflex® with various degrees of austenite stability. The materials were...

  3. Control and dynamics study for the satellite power system. Volume 1: MPTS/SPS collector dynamic analysis and surface deformation

    Science.gov (United States)

    Wang, S. J.

    1980-01-01

    The basic dynamic properties and performance characteristics of the microwave power transmission satellite antenna were analyzed in an effort to develop criteria, requirements, and constraints for the control and structure design. The vibrational properties, the surface deformation, and the corresponding scan loss under the influence of disturbances are considered.

  4. Fully automatic measurements of axial vertebral rotation for assessment of spinal deformity in idiopathic scoliosis

    Science.gov (United States)

    Forsberg, Daniel; Lundström, Claes; Andersson, Mats; Vavruch, Ludvig; Tropp, Hans; Knutsson, Hans

    2013-03-01

    Reliable measurements of spinal deformities in idiopathic scoliosis are vital, since they are used for assessing the degree of scoliosis, deciding upon treatment and monitoring the progression of the disease. However, commonly used two dimensional methods (e.g. the Cobb angle) do not fully capture the three dimensional deformity at hand in scoliosis, of which axial vertebral rotation (AVR) is considered to be of great importance. There are manual methods for measuring the AVR, but they are often time-consuming and related with a high intra- and inter-observer variability. In this paper, we present a fully automatic method for estimating the AVR in images from computed tomography. The proposed method is evaluated on four scoliotic patients with 17 vertebrae each and compared with manual measurements performed by three observers using the standard method by Aaro-Dahlborn. The comparison shows that the difference in measured AVR between automatic and manual measurements are on the same level as the inter-observer difference. This is further supported by a high intraclass correlation coefficient (0.971-0.979), obtained when comparing the automatic measurements with the manual measurements of each observer. Hence, the provided results and the computational performance, only requiring approximately 10 to 15 s for processing an entire volume, demonstrate the potential clinical value of the proposed method.

  5. Nuclear moments and deformation changes in the lightest Pt isotopes measured by laser spectroscopy

    CERN Document Server

    Roussière, B; Crawford, J; Duong, H T; Genevey, J; Girod, M; Huber, G; Ibrahim, F; Krieg, M; Le Blanc, F; Lee, J K P; Obert, J; Oms, J; Peru, S; Pinard, J; Putaux, J C; Sauvage, J; Sebastian, V; Zemlyanoi, S G; Forkel-Wirth, Doris; Lettry, Jacques

    1999-01-01

    Laser spectroscopy measurements are performed with the lightest neutron-deficient platinum isotopes using the experimental setup COMPLIS installed at the ISOLDE-Booster facility. The hyperfine spectra of /sup 182-178/Pt and /sup 183m/Pt are recorded for the first time from the optical transition 5d/sup 9/6s/sup 3/D/sub 3/ to 5d/sup 9/6p/sup 3/P/sub 2/. The variation in the mean-square charge radius of these nuclei and the magnetic and quadrupole (for I>or=1) moments of the odd isotope nuclei are found. A large deformation change between the /sup 183g/Pt and /sup 183m/Pt nuclei, quite large inverted odd-even staggering of the charge radius around the neutron midshell N=104, and a nuclear deformation drop in the region A=179 are revealed. All the results are discussed in terms of nuclear shape variation and are compared with the results of Hartree-Fock- Bogoliubov calculations involving the Gogny force. Comparison of the deformation measured from /sup 183g, m/Pt to the odd-odd isotone /sup 184g, m/Au shows that...

  6. Novel Angular Measures of Cervical Deformity Account for Upper Cervical Compensation and Sagittal Alignment.

    Science.gov (United States)

    Protopsaltis, Themistocles S; Lafage, Renaud; Vira, Shaleen; Sciubba, Daniel; Soroceanu, Alex; Hamilton, Kojo; Smith, Justin; Passias, Peter G; Mundis, Gregory; Hart, Robert; Schwab, Frank; Klineberg, Eric; Shaffrey, Christopher; Lafage, Virginie; Ames, Christopher

    2017-08-01

    This is a retrospective review of a prospective multicenter database. This study introduces 2 new cervical alignment measures accounting for both cervical deformity (CD) and upper cervical compensation. Current descriptions of CD like the C2-C7 sagittal vertical axis (cSVA) do not account for compensatory mechanisms such as C0-C2 lordosis and pelvic tilt, which makes surgical planning difficult. The craniocervical angle (CCA) combines the slope of McGregor's line and the inclination from C7 to the hard palate. The C2-pelvic tilt (CPT) combines C2 tilt and pelvic tilt. Like the T1 pelvic angle, CPT is less affected by lower extremity and pelvic compensation. Novel and existing CD measures were correlated in 781 patients from a thoracolumbar deformity (TLD) database and 61 patients from a prospective CD database. CD patients were subanalyzed by region of deformity driver: cervical or cervico-thoracic junction. TLD patients were substratified according to whether or not they had CD as well, where CD was defined as cSVA>4 cm or T1 slope minus cervical lordosis mismatch (TS-CL) >20. TLD cohort: mean cSVA was 31.7±17.8 mm. Subanalysis of TLD patients with CD versus no-CD demonstrated significant differences in CCA (56.2 vs. 60.6, Paccount for both cervical sagittal alignment and upper cervical compensation and can be utilized in assessment of cervical alignment.

  7. Optomechanical measurement of the role of lamins in whole cell deformability.

    Science.gov (United States)

    Kolb, Thorsten; Kraxner, Julia; Skodzek, Kai; Haug, Michael; Crawford, Dean; Maaß, Kendra K; Aifantis, Katerina E; Whyte, Graeme

    2017-12-01

    There is mounting evidence that the nuclear envelope, and particularly the lamina, plays a critical role in the mechanical and regulation properties of the cell and changes to the lamina can have implications for the physical properties of the whole cell. In this study we demonstrate that the optical stretcher can measure changes in the time-dependent mechanical properties of living cells with different levels of A-type lamin expression. Results from the optical stretcher shows a decrease in the deformability of cells as the levels of lamin A increases, for cells which grow both adherently and in suspension. Further detail can be probed by combining the optical stretcher with fluorescence microscopy to investigate the nuclear mechanical properties which show a larger decrease in deformability than for the whole cell. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Cell visco-elasticity measured with AFM and optical trapping at sub-micrometer deformations.

    Directory of Open Access Journals (Sweden)

    Schanila Nawaz

    Full Text Available The measurement of the elastic properties of cells is widely used as an indicator for cellular changes during differentiation, upon drug treatment, or resulting from the interaction with the supporting matrix. Elasticity is routinely quantified by indenting the cell with a probe of an AFM while applying nano-Newton forces. Because the resulting deformations are in the micrometer range, the measurements will be affected by the finite thickness of the cell, viscous effects and even cell damage induced by the experiment itself. Here, we have analyzed the response of single 3T3 fibroblasts that were indented with a micrometer-sized bead attached to an AFM cantilever at forces from 30-600 pN, resulting in indentations ranging from 0.2 to 1.2 micrometer. To investigate the cellular response at lower forces up to 10 pN, we developed an optical trap to indent the cell in vertical direction, normal to the plane of the coverslip. Deformations of up to two hundred nanometers achieved at forces of up to 30 pN showed a reversible, thus truly elastic response that was independent on the rate of deformation. We found that at such small deformations, the elastic modulus of 100 Pa is largely determined by the presence of the actin cortex. At higher indentations, viscous effects led to an increase of the apparent elastic modulus. This viscous contribution that followed a weak power law, increased at larger cell indentations. Both AFM and optical trapping indentation experiments give consistent results for the cell elasticity. Optical trapping has the benefit of a lower force noise, which allows a more accurate determination of the absolute indentation. The combination of both techniques allows the investigation of single cells at small and large indentations and enables the separation of their viscous and elastic components.

  9. A Method to Measure Thermal Deformation of Superconducting Magnet Cross Sections

    CERN Document Server

    Grau-Carles, A; Todesco, Ezio; Tommasini, D; Siegel, N

    1999-01-01

    The precision measurement of the cable positioning in superconducting coils is of great interest both at room and liquid nitrogen temperatures because mechanical and thermal deformations affect the quality of the magnetic field. The paper describes a new two-coordinate measuring device, which is able to obtain scanned images of flat composite samples at liquid nitrogen temperature. The sample is cooled at 77 K into a flat quartz tray to permit the optical access to the sample from the bottom. The comparison of the images taken at room and liquid nitrogen temperatures by a high-resolution flatbed scanner gives the thermal contraction of the components.

  10. Episodic inflation and complex surface deformation of Akutan volcano, Alaska revealed from GPS time-series

    Science.gov (United States)

    DeGrandpre, Kimberly; Wang, Teng; Lu, Zhong; Freymueller, Jeffrey T.

    2017-11-01

    Akutan is one of the most active volcanoes in the Aleutian island arc. Studies involving seismic, GPS, and InSAR data have observed activity and deformation on the island since 1996. In this study we inverted measurements of volcanic deformation, observed using three components of motions at 12 continuous GPS sites to define magma source parameters using Mogi point source, Okada dislocation, and Yang spheroid and ellipsoid models. In order to analyze the evolution of this magma source we split the GPS data into five consecutive time periods, and one period that incorporates all available data. These time periods were designed around two inflation events in 2008 and 2014, when a sudden and significant increase in vertical velocity was observed. Inversion of these time periods independently allowed us to create a magma volume time-series that is related to the physical migration of magma defined by the estimated source parameters. The best fit model parameters resulting from these inversions describes magma storage in the form of an oblate spheroid centered on the northeastern rim of the caldera of Akutan volcano, extending from a depth of 7 km to 8 km, with a length of 3.5 km, a strike of N165°E, and a dip of 63° from the horizontal to the southwest. Our model results were compared with seismic studies and found to support previous interpretations of episodic inflation beneath Akutan volcano with complicated magma storage at intermediate depths. The inflation event observed in 2008 was estimated to be the result of an injection of magma of 0.08 km3 that was followed in 2014 by an additional increase in volume of 0.06 km3. No periods of deflation were observed in the GPS data after these events, and we believe the total volume of magma accumulated in this region, 0.2 km3, remains in a shallow storage system beneath Akutan Volcano.

  11. Accurate fluid force measurement based on control surface integration

    Science.gov (United States)

    Lentink, David

    2018-01-01

    Nonintrusive 3D fluid force measurements are still challenging to conduct accurately for freely moving animals, vehicles, and deforming objects. Two techniques, 3D particle image velocimetry (PIV) and a new technique, the aerodynamic force platform (AFP), address this. Both rely on the control volume integral for momentum; whereas PIV requires numerical integration of flow fields, the AFP performs the integration mechanically based on rigid walls that form the control surface. The accuracy of both PIV and AFP measurements based on the control surface integration is thought to hinge on determining the unsteady body force associated with the acceleration of the volume of displaced fluid. Here, I introduce a set of non-dimensional error ratios to show which fluid and body parameters make the error negligible. The unsteady body force is insignificant in all conditions where the average density of the body is much greater than the density of the fluid, e.g., in gas. Whenever a strongly deforming body experiences significant buoyancy and acceleration, the error is significant. Remarkably, this error can be entirely corrected for with an exact factor provided that the body has a sufficiently homogenous density or acceleration distribution, which is common in liquids. The correction factor for omitting the unsteady body force, {{{ {ρ f}} {1 - {ρ f} ( {{ρ b}+{ρ f}} )}.{( {{{{ρ }}b}+{ρ f}} )}}} , depends only on the fluid, {ρ f}, and body, {{ρ }}b, density. Whereas these straightforward solutions work even at the liquid-gas interface in a significant number of cases, they do not work for generalized bodies undergoing buoyancy in combination with appreciable body density inhomogeneity, volume change (PIV), or volume rate-of-change (PIV and AFP). In these less common cases, the 3D body shape needs to be measured and resolved in time and space to estimate the unsteady body force. The analysis shows that accounting for the unsteady body force is straightforward to non

  12. Effect of friction-induced deformation and oxidation on the structure and microhardness of surface aluminum and silumin layers

    Science.gov (United States)

    Korshunov, L. G.; Chernenko, N. L.; Brodova, I. G.; Shirinkina, I. G.

    2017-11-01

    Metallography, electron microscopy, and X-ray diffraction have been used to investigate structural transformations that take place in a 10-μm-thick surface layer in aluminum and Al-17% Si alloy under conditions of sliding friction and subsequent oxidation at 100 and 200°C for 1 h. Friction-induced deformation has been carried out at room temperature in air and at-196°C in liquid nitrogen by reciprocating sliding of a cylindrical indenter made of cubic boron nitride at a rate of 0.014 m/s and a load of 98 N. It is shown that deformation under these conditions forms nanocrystalline structures in the surface layer in aluminum and Al-17% Si alloy and increases their microhardness by a factor of 1.8-3.5. A high contact deformation and a high affinity of oxygen to aluminum and silicon cause the formation of anomalously supersaturated solid solutions of oxygen in aluminum and silicon in the surface layer of the alloy during friction. Oxidation at 100°C (1 h) of the deformed Al-17% Si alloy increases its microhardness due to the decomposition of anomalously supersaturated solid solutions of oxygen in aluminum and silicon and the formation of their oxides.

  13. Real-time structured light-based otoscopy for quantitative measurement of eardrum deformation

    Science.gov (United States)

    Van der Jeught, Sam; Dirckx, Joris J. J.

    2017-01-01

    An otological profilometry device based on real-time structured light triangulation is presented. A clinical otoscope head is mounted onto a custom-handheld unit containing both a small digital light projector and a high-speed digital camera. Digital fringe patterns are projected onto the eardrum surface and are recorded at a rate of 120 unique frames per second. The relative angle between projection and camera axes causes the projected patterns to appear deformed by the eardrum shape, allowing its full-field three-dimensional (3-D) surface map to be reconstructed. By combining hardware triggering between projector and camera with a dedicated parallel processing pipeline, the proposed system is capable of acquiring a live stream of point clouds of over 300,000 data points per frame at a rate of 40 Hz. Real-time eardrum profilometry adds an additional dimension of depth to the standard two-dimensional otoscopy image and provides a noninvasive tool to enhance the qualitative depth perception of the clinical operator with quantitative 3-D data. Visualization of the eardrum from different perspectives can improve the diagnosis of existing and the detection of impending middle ear pathology. The capability of the device to detect small middle ear pressure changes by monitoring eardrum deformation in real time is demonstrated.

  14. Microscopic Measurements of Axial Accumulation of Red Blood Cells in Capillary Flows Effects of Deformability

    Science.gov (United States)

    Sasaki, Takahiro; Seki, Junji; Itano, Tomoaki; Sugihara-Seki, Masako

    2017-11-01

    In the microcirculation, red blood cells (RBCs) are known to accumulate in the region near the central axis of microvessels, which is called the ``axial accumulation''. Although this behavior of RBCs is considered to originate from high deformability of RBCs, there have been few experimental studies on the mechanism. In order to elucidate the effect of RBC deformability on the axial accumulation, we measured the cross-sectional distributions of RBCs flowing through capillary tubes with a high spatial resolution by a newly devised observation system for intact and softened RBCs as well as hardened RBCs to various degrees. It was found that the intact and softened RBCs are concentrated in the small area centered on the tube axis, whereas the hardened RBCs are dispersed widely over the tube cross section dependent on the degree of hardness. These results demonstrate clearly the essential role of the deformability of RBCs in the ``axial accumulation'' of RBCs. JSPS KAKENHI Grant Number 17H03176, Kansai University ORDIST group funds.

  15. Geodetic Measurements and Numerical Models of Deformation at Coso Geothermal Field, California, USA

    Science.gov (United States)

    Ali, S. T.; Reinisch, E. C.; Feigl, K. L.; Davatzes, N. C.

    2016-12-01

    We measure transient deformation at the Coso geothermal field in south-central California using interferometric synthetic aperture data acquired between 2004 and 2016 by the Envisat and Sentinel-1A satellite missions. All well-correlated interferometric pairs show subsidence, with rates as high as 30 mm/year, over a large 75 km2 circular area surrounding the field below which most of the seismicity associated with geothermal production is located. The deformation signature remains in the same location throughout the 12 year interval. Time-series analysis of multiple interferometric pairs reveals continuous subsidence. A decrease in the subsidence rate after 2010 corresponds to a decrease in the net production rate. Using three-dimensional, fully numerical, multiphysics models, we explore the coupling between deformation and geothermal production. We seek to distinguish between two possible mechanisms: (i) decreasing pore-pressure following net extraction of fluids, or (ii) decrease in temperature of presumably fractured reservoir rock. Irrespective of the mechanism, a contracting ellipsoidal reservoir located at a depth of 2 km, with a volume of 80 km3 or less is required to explain the geodetic observations. Almost 90% of the seismicity beneath the field occurs within this 80 km3 ellipsoid.

  16. Complex surface deformation monitoring and mechanism inversion over Qingxu-Jiaocheng, China with multi-sensor SAR images

    Science.gov (United States)

    Liu, Yuanyuan; Zhao, Chaoying; Zhang, Qin; Yang, Chengsheng

    2018-02-01

    Qingxu-Jiaocheng, China has been suffering severe land subsidence along with the development of ground fissure, which are controlled by local fault and triggered by groundwater withdrawal. With multi-sensor SAR images, we study the spatiotemporal evolution of ground deformation over Qingxu-Jiaocheng with an IPTA InSAR technique and assess the role of groundwater withdrawal to the observed deformation. Discrete GPS measurements are applied to verify the InSAR results. The RMSE of the differences between InSAR and GPS, i.e. ALOS and GPS and Envisat and GPS, are 5.7 mm and 6.3 mm in the LOS direction, respectively. The east-west and vertical components of the observed deformation from 2007 to 2010 are decomposed by using descending-track Envisat and ascending-track ALOS interferograms, indicating that the east-west component cannot be neglected when the deformation is large or the ground fissure is active. Four phases of land subsidence in the study region are successfully retrieved, and its spatiotemporal evolution is quantitatively analyzed. Lastly, a flat lying sill model with distributed contractions is implemented to model the InSAR deformation over Qingxu-Jiaocheng, which manifests that the ground deformation is mainly caused by groundwater withdrawal. This research provides new insights into the land subsidence monitoring and its mechanism inversion over Qingxu-Jiaocheng region.

  17. Measurement of Gas-Surface Accommodation

    Science.gov (United States)

    Trott, W. M.; Rader, D. J.; Castañeda, J. N.; Torczynski, J. R.; Gallis, M. A.

    2008-12-01

    Thermal accommodation coefficients have been determined for a variety of gas-surface combinations using an experimental apparatus developed to measure both the pressure dependence of the conductive heat flux and the variation of gas density between parallel plates separated by a gas-filled gap. Effects of gas composition, surface roughness and surface contamination have been examined with this system, and the behavior of gas mixtures has also been explored. Results are discussed in comparison with previous parallel-plate experimental studies as well as numerical simulations.

  18. Holographic otoscope for nano-displacement measurements of surfaces under dynamic excitation

    OpenAIRE

    Flores-Moreno, J. M.; Furlong, Cosme; Rosowski, John J.; Harrington, Ellery; Cheng, Jeffrey T.; Scarpino, C.; Santoyo, F. Mendoza

    2011-01-01

    We describe a novel holographic otoscope system for measuring nano-displacements of objects subjected to dynamic excitation. Such measurements are necessary to quantify the mechanical deformation of surfaces in mechanics, acoustics, electronics, biology and many other fields. In particular, we are interested in measuring the sound-induced motion of biological samples, such as an eardrum. Our holographic otoscope system consists of laser illumination delivery (IS), optical head (OH), and image...

  19. Measurement of Strain in the Left Ventricle during Diastole withcine-MRI and Deformable Image Registration

    Energy Technology Data Exchange (ETDEWEB)

    Veress, Alexander I.; Gullberg, Grant T.; Weiss, Jeffrey A.

    2005-07-20

    The assessment of regional heart wall motion (local strain) can localize ischemic myocardial disease, evaluate myocardial viability and identify impaired cardiac function due to hypertrophic or dilated cardiomyopathies. The objectives of this research were to develop and validate a technique known as Hyperelastic Warping for the measurement of local strains in the left ventricle from clinical cine-MRI image datasets. The technique uses differences in image intensities between template (reference) and target (loaded) image datasets to generate a body force that deforms a finite element (FE) representation of the template so that it registers with the target image. To validate the technique, MRI image datasets representing two deformation states of a left ventricle were created such that the deformation map between the states represented in the images was known. A beginning diastoliccine-MRI image dataset from a normal human subject was defined as the template. A second image dataset (target) was created by mapping the template image using the deformation results obtained from a forward FE model of diastolic filling. Fiber stretch and strain predictions from Hyperelastic Warping showed good agreement with those of the forward solution. The technique had low sensitivity to changes in material parameters, with the exception of changes in bulk modulus of the material. The use of an isotropic hyperelastic constitutive model in the Warping analyses degraded the predictions of fiber stretch. Results were unaffected by simulated noise down to an SNR of 4.0. This study demonstrates that Warping in conjunction with cine-MRI imaging can be used to determine local ventricular strains during diastole.

  20. Modelling of deformation process for the layer of elastoviscoplastic media under surface action of periodic force of arbitrary type

    Science.gov (United States)

    Mikheyev, V. V.; Saveliev, S. V.

    2018-01-01

    Description of deflected mode for different types of materials under action of external force plays special role for wide variety of applications - from construction mechanics to circuits engineering. This article con-siders the problem of plastic deformation of the layer of elastoviscolastic soil under surface periodic force. The problem was solved with use of the modified lumped parameters approach which takes into account close to real distribution of normal stress in the depth of the layer along with changes in local mechanical properties of the material taking place during plastic deformation. Special numeric algorithm was worked out for computer modeling of the process. As an example of application suggested algorithm was realized for the deformation of the layer of elasoviscoplastic material by the source of external lateral force with the parameters of real technological process of soil compaction.

  1. Magnetic Fluid-Based Squeeze Film Performance in Rotating Curved Porous Circular Plates: The Effect of Deformation and Surface Roughness

    Directory of Open Access Journals (Sweden)

    M.E. Shimpi

    2012-06-01

    Full Text Available This investigation aims at analyzing the behaviour of a magnetic fluid based squeeze film between two rotating transversely rough porous circular plates taking bearing deformation into consideration. The results presented in graphical form inform that the transverse surface roughness introduces an adverse effect on the performance characteristics while the magnetic fluid lubricant turn in an improved performance. It is found that the combined effect of rotation and deformation causes significantly reduced load carrying capacity. However, this investigation establishes that the adverse effect of porosity, deformation and standard deviation can be compensated up to some extent by the positive effect of magnetic fluid lubricant in the case of negatively skewed roughness by choosing curvature parameters. To compensate, the rotational inertia needs to have smaller values.

  2. Using PSInSAR to Investigate the Surface Deformation Induced by Ground Water Variation in Taipei Basin

    Science.gov (United States)

    Wu, P. C.; Hu, J. C.

    2016-12-01

    Soil liquefaction induced from shaking of earthquake is a crucial issue for seismic hazards in urban area. Since 1975, the water pumping was prohibited in Taipei basin due to severe land subsidence with ground water level of about 60-70 m below sea level, consequently the ground water level recover to a high level of about 5-10 m below sea level which high potential soil liquefaction area should happen in think sediments area of Taipei basin. However, the anthropogenic pumping ground water still happened for construction of Taipei Rapid Transit System since 1993. In this study, we use persistent scatterer interferometry (PSI) technique for processing 37 high resolution X-band synthetic aperture radar (SAR) images archived from COSMO-SkyMed (CSK) constellation to get precise deformation map in the period from May 2011 to April 2015. The surface deformation rate along line of sight (LOS) toward to the satellite will be constrained by 3-D deformation rate from continuous GPS projected to the LOS. In addition, the vertical deformation rate from precise levelling across the Taipei basin will be compared to the deformation trend of PSI. In average, a subsidence rate of 5 mm/yr near the Banqiao station. Moreover, the high correlation between LOS rate and ground water table in Wuku station. The previous study suggested that the transient deformation in LOS of PSInSAR in Taipei Basin is highly related to the confined aquifer deformation of Jingmei formation. The storativity is roughly constant across most of the aquifer with values between 0.8 x 10-4 and 1.3 x 10-3. Thus, the storativity can be calculated to specific storage and values of aquifer compressibility for water resources management in Taipei basin.

  3. Interpreting the probe-surface interaction of surface measuring instruments, or what is a surface?

    Science.gov (United States)

    Leach, Richard; Weckenmann, Albert; Coupland, Jeremy; Hartmann, Wito

    2014-09-01

    When using dimensional measuring instruments it is assumed that there is a property of the object, which we call surface, that is present before during and after the measurement, i.e. the surface is a fundamental property of an object that can, by appropriate means, be used to measure geometry. This paper will attempt to show that the fundamental property ‘surface’ does not exist in any simple form and that all the information we can have about a surface is the measurement data, which will include measurement uncertainty. Measurement data, or what will be referred to as the measured surface, is all that really exists. In this paper the basic physical differences between mechanically, electromagnetically and electrically measured surfaces are highlighted and discussed and accompanied by measurement results on a roughness artefact.

  4. Interpreting the probe-surface interaction of surface measuring instruments, or what is a surface?

    International Nuclear Information System (INIS)

    Leach, Richard; Weckenmann, Albert; Hartmann, Wito; Coupland, Jeremy

    2014-01-01

    When using dimensional measuring instruments it is assumed that there is a property of the object, which we call surface, that is present before during and after the measurement, i.e. the surface is a fundamental property of an object that can, by appropriate means, be used to measure geometry. This paper will attempt to show that the fundamental property ‘surface’ does not exist in any simple form and that all the information we can have about a surface is the measurement data, which will include measurement uncertainty. Measurement data, or what will be referred to as the measured surface, is all that really exists. In this paper the basic physical differences between mechanically, electromagnetically and electrically measured surfaces are highlighted and discussed and accompanied by measurement results on a roughness artefact. (paper)

  5. The effect of modified benchmark on the accuracy of measuring the deformation at Muria

    International Nuclear Information System (INIS)

    Ari Nugroho

    2013-01-01

    The monitoring of deformation surrounding the Muria mountain is recommended by The IAEA (International Atomic Energy Agency). In addition, this study also to provide the data of deformation caused by the volcanic activity of Mount Muria, as a basic study in analyzing the volcanic hazard toward the NPP (Nuclear Power Plant). The main purpose of this study is to discover the accuracy between the two measurements by using the different BM (Benchmark). This study uses geodetic GPS (Global Positioning System) Trimble R7 GNSS. The measurement in the month of April to July 2011 used the standard BM and conducted in eight BM which are BKI (Bopkri), UJW (Ujung Watu), PDP (Perdopo), RTW (Rahtawu), RGG (Rengging), KTP (Ketek Putih), CRG (Cranggang), DM (Danyang Mulyo) and refer to one reference BM named Mijen. The measurement in the month of November 2011 used the modified BM and conducted in six BM which are BKI, PDP, RTW, RGG, KTP, CRG referred to the same reference BM named Mijen. These measurements resulted data in the range of 4-7 mm (horizontal), 16-28 mm (vertical), and in the range of 0.6 mm - 1.3 mm (horizontal), 0.3 mm – 0.6 mm, respectively. (author)

  6. A new analytical method for stress intensity factors based on insitu measurement of crack deformation under biaxial tension

    International Nuclear Information System (INIS)

    Wang, J.G.; Ju, D.Y.; Sun, M.J.; Li, S.L.

    2011-01-01

    A new approach for the calculation of stress intensity factors (SIF) for isotropic and orthotropic materials under biaxial tension loading was proposed in this paper. In order to determine SIF from the full-field displacement data, an asymptotic expansion of the crack tip displacement field was performed. The deforming shape and surface residual stress of the crack tip was obtained at the early extended stage of the loading process by using optical microscope and X-ray diffraction measurement. During this stage, a modified Dugdale Model, which takes into account the coupled effect at the crack tip, was proposed for the open displacement of the crack tip. In this paper, the SIFs of two types of silicon steel sheet with isotropic and orthotropic properties were calculated using the modified Dugdale Model based on the biaxial tension experimental data. From the results, it was found that analysis using the modified Dugdale Model is an effective way to evaluate SIF under biaxial stress.

  7. Damage visualization and deformation measurement in glass laminates during projectile penetration

    Directory of Open Access Journals (Sweden)

    Elmar Strassburger

    2014-06-01

    Full Text Available Transparent armor consists of glass-polymer laminates in most cases. The formation and propagation of damage in the different glass layers has a strong influence on the ballistic resistance of such laminates. In order to clarify the course of events during projectile penetration, an experimental technique was developed, which allows visualizing the onset and propagation of damage in each single layer of the laminate. A telecentric objective lens was used together with a microsecond video camera that allows recording 100 frames at a maximum rate of 1 MHz in a backlit photography set-up. With this technique, the damage evolution could be visualized in glass laminates consisting of four glass layers with lateral dimensions 500 mm × 500 mm. Damage evolution was recorded during penetration of 7.62 mm AP projectiles with tungsten carbide core and a total mass of 11.1 g in the impact velocity range from 800 to 880 m/s. In order to measure the deformation of single glass plates within the laminates, a piece of reflecting tape was attached to the corresponding glass plate, and photonic Doppler velocimetry (PDV was applied. With the photonic Doppler velocimeter, an infrared laser is used to illuminate an object to be measured and the Doppler-shifted light is superimposed to a reference light beam at the detector. The simultaneous visualization and PDV measurement of the glass deformation allow determining the deformation at the time of the onset of fracture. The analysis of the experimental data was supported by numerical simulations, using the AUTODYN commercial hydro-code.

  8. A new method for measuring AFO deformation, tibial and footwear movement in three dimensional gait analysis.

    Science.gov (United States)

    Ridgewell, Emily; Sangeux, Morgan; Bach, Timothy; Baker, Richard

    2013-09-01

    Solid ankle-foot orthoses (AFOs) are designed to immobilise the ankle but numerous studies have measured a considerable ankle range of motion (ROM) in AFO users. Measurement of ankle kinematics may be affected by soft-tissue artefact (STA) of the knee marker, deformation of the AFO or tibial movement within the AFO. A new model based on the Conventional Gait Model (CGM) was developed to calculate these effects. Although movement of the AFO within the shoe should not affect the measured ankle joint angle the model also allows an estimation of this movement. Seven children (13 limbs) with spastic diplegic cerebral palsy were assessed to present the benefits of the new model compared to the CGM. STA of the knee marker was estimated to result in a 1.5° overestimation of total ankle ROM (from 8.2° to 9.7°). STA error was strongly related to angle of knee flexion (r=0.82) with an average maximum error of 3.8°. AFO deformation contributed approximately two thirds of the ankle ROM (6.0±4.3°) with the remaining third from tibial movement relative to the AFO (2.8±0.9°). Movement of the AFO within the footwear was very small (1.8±0.8°). A strong positive relationship (r=0.9) was found between body mass (kg) and AFO deformation which was statistically significant (pAFOs. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. General considerations for a Sentinel-1 constellation InSAR time series processing chain for ground deformation measurements

    Science.gov (United States)

    Gonzalez, P. J.; Wright, T. J.; Hooper, A. J.; Walters, R. J.

    2014-12-01

    Sentinel-1A was launched on April 3rd, 2014. It is the first satellite of a European Space Agency (ESA) constellation that promises to revolutionize measurement of deformation of the Earth's surface. The constellation is designed to acquire data globally as frequently as every 6 days on the same orbital pass, and every 3 days in alternating ascending and descending orbits over the same regions. This data acquisition plan is possible due to a much larger swath coverage than previous SAR (Synthetic Aperture Radar) sensors. In addition, all observations from Copernicus, the European Commission Earth Observation program, have a liberal data policy, which will enable full exploitation of the archived Sentinel-1 big data, both for scientific and commercial use.Sentinel-1, and similar future constellations, shape a new landscape in the way that InSAR data have traditionally been processed. We have started to develop a completely new re-engineered and adapted InSAR time series processing approach, which efficiently processes the data from this new type of SAR constellation, with the goal to deliver ground deformation products with the highest possible precision. In summary, the proposed system approach will require the development of an automatic, almost unsupervised, system that integrates methods to obtain time-dependent surface deformation estimates and correction products for atmospheric noise and refined orbits. The ground velocity maps will ideally meet the desired precision of 1 mm/yr / 100 km to measure strain-rates (10 nanostrain/yr) at a comparable level of precision to current existing sparse regional GPS measurement networks.In this communication, we describe the different steps we have adopted to partially solve: 1) coregistration of TOPS (Terrain Observation with Progressive Scans) SAR images to enable interferometry, 2) how to manage the ambiguity between ground motion in azimuth and in line-of-sight for TOPS InSAR, 3) how to process efficiently newly

  10. Surface resistivity measurement of plasma treated polymers

    International Nuclear Information System (INIS)

    Simon, D.; Pigram, P.J.; Liesegang, J.

    2000-01-01

    Full text: Resistivity of insulators is an important property of materials used within the integrated circuit and packaging industries. The measurement of electrical resistivity of insulator materials in the surface region in this work is interpreted through observations of surface charge decay. A self-field driven and diffusion charge transport theory is used to model the process and resistivity values obtained computationally. Data for the charge decay of surface charged samples are collected by suspending them inside a coaxial cylinder connected to an electrometer. Samples used have been low density polyethylene LDPE sheet, both pristine and surface treated. Some samples have been treated by air plasma at low vacuum pressures for different periods of time; others have been washed in ethyl acetate and then plasma treated before the resistivity measurement. The sets of resistivity measurements form the various treatments are compared below. X-ray photoelectron spectroscopy (XPS) has also been used to investigate and account for the observed variations in surface resistivity

  11. On-resonance deformation effect measurements: A probe of order within chaos in the nucleus

    International Nuclear Information System (INIS)

    Davis, E.D.; Gould, C.R.; Gould, C.R.

    1998-01-01

    The statistics of on-resonance measurements of the deformation effect cross section σ 02 in unpolarized neutron transmission through an aligned 165 Ho target is discussed. Under the standard Porter-Thomas assumption about reduced partial width amplitudes, the sign of σ 02 is random at s-wave resonances with d-wave admixtures. Motivated by the observation of sign correlations in epithermal parity-violation studies, conditions under which a doorway state will give rise to σ 02 close-quote s of nonrandom sign are identified. Oblate shape isomers lying at excitation energies in the isolated resonance regime could meet these conditions. copyright 1998 The American Physical Society

  12. Earth surface deformation in the North China Plain detected by joint analysis of GRACE and GPS data.

    Science.gov (United States)

    Liu, Renli; Li, Jiancheng; Fok, Hok Sum; Shum, C K; Li, Zhao

    2014-10-22

    Mass redistribution of the Earth causes variable loading that deforms the solid Earth. While most recent studies using geodetic techniques focus on regions (such as the Amazon basin and the Nepal Himalayas) with large seasonal deformation amplitudes on the order of 1-4 cm due to hydrologic loading, few such studies have been conducted on the regions where the seasonal deformation amplitude is half as large. Here, we use joint GPS and GRACE data to investigate the vertical deformation due to hydrologic loading in the North China Plain, where significant groundwater depletion has been reported. We found that the GPS- and GRACE-derived secular trends and seasonal signals are in good agreement, with an uplift magnitude of 1-2 mm/year and a correlation of 85.0%-98.5%, respectively. This uplift rate is consistent with groundwater depletion rate estimated from GRACE data and in-situ groundwater measurements from earlier report studies; whereas the seasonal hydrologic variation reflects human behavior of groundwater pumping for agriculture irrigation in spring, leading to less water storage in summer than that in the winter season. However, less than 20% of weighted root-mean-squared (WRMS) reductions were detected for all the selected GPS stations when GRACE-derived seasonal deformations were removed from detrended GPS height time series. This discrepancy is probably because the GRACE-derived seasonal signals are large-scale, while the GPS-derived signals are local point measurements.

  13. Fiber-Laden Proppant Placement in a Deformable Fracture: Influence of Fracture-Surface Roughness

    Science.gov (United States)

    Medina, R.; Detwiler, R. L.; Prioul, R.; Xu, W.; Ortega, J. A.

    2016-12-01

    During the shut-in stage of hydraulic fracturing, aperture decreases and proppant is trapped between the fracture walls. The amount and distribution of the trapped proppant determines the fracture permeability after fracture closure. Conventional fluids used in hydraulic fracturing typically form a uniform distribution of proppant within the fracture, i.e. proppant pack, and the fracture permeability is that of the proppant pack. In recent experiments, the addition of fibers to proppant mixtures has been shown to result in the formation of proppant-fiber islands surrounded by solids-free regions. The formation of such proppant-fiber islands has the potential to increase fracture permeability, however, the behavior of these islands when subjected to an applied stress is unknown. We present preliminary results from a series of experiments of fiber-proppant settling inside a deformable fracture with both smooth and rough walls. The experimental system consists of a 15cm x 15cm fracture cell that allows the direct application of a normal stress to the fracture surfaces while the entire flow field is imaged using a high-resolution CCD camera. The proppant mixture was prepared by adding 17.7% v/v of quartz sand and 0.4% v/v of polymeric fibers to a highly shear-thinning viscous fluid (0.48% w/w guar-water). The proppant mixture was injected into the fracture and allowed to settle uninterrupted for two hours before we incrementally increased the normal stress applied to the fracture surfaces from 0 to 90 kPa. The results for both smooth- and rough-walled fractures demonstrate the development of isolated proppant-fiber islands with some interconnected proppant-free regions. In the smooth-walled fracture, the isolated proppant islands settled towards the bottom of the fracture that resulted in some consolidation of the proppant mixture in the lower portion of the fracture. The proppant islands in the rough-walled fracture show a reduced amount of settling, resulting in

  14. Comparison between deformation modulus of rock mass measured by plate jacking and dilatometer tests

    Directory of Open Access Journals (Sweden)

    Mohsen Rezaei

    2017-09-01

    Full Text Available For determination of the in-situ deformation modulus of rock mass at Bakhtiari Dam site, located in south-west of Iran, plate jacking tests (PJT and dilatometer tests (DLT carried out during the geotechnical investigations. In this study, the results of PJTs and DLTs were compared. This comparison involves 89 vertical and horizontal PJTs and 83 DLTs carried out in 6 rock units of Sarvak formation. Although, both PJTs and DLTs in the Bakhtiari Dam site were performed in same geological and geotechnical conditions, but there are not sufficient side by side data to make a paired two samples correlation. Therefore, the mean of in-situ data was compared at each rock unit. Besides Mann–Whitney U tests were performed to compare in-situ test results. The comparison shows that the deformation modulus measured by both methods has no significant differences. However, in low quality rock masses the moduli measured by the use of DLTs were greater than the modulus measured by PJTs. Conversely, in high quality rock masses the results of PJTs were greater than DLT’s.

  15. Surface Tension Measurements with a Smartphone

    Science.gov (United States)

    Goy, Nicolas-Alexandre; Denis, Zakari; Lavaud, Maxime; Grolleau, Adrian; Dufour, Nicolas; Deblais, Antoine; Delabre, Ulysse

    2017-01-01

    Smartphones are increasingly used in higher education and at university in mechanics, acoustics, and even thermodynamics as they offer a unique way to do simple science experiments. In this article, we show how smartphones can be used in fluid mechanics to measure surface tension of various liquids, which could help students understand the concept…

  16. Surface charge measurement using an electrostatic probe

    DEFF Research Database (Denmark)

    Crichton, George C; McAllister, Iain Wilson

    1998-01-01

    During the 1960s, the first measurements of charge on dielectric surfaces using simple electrostatic probes were reported. However it is only within the last 10 years that a proper understanding of the probe response has been developed. This situation arose as a consequence of the earlier studies...

  17. Optical measurement of surface roughness in manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Brodmann, R.

    1984-11-01

    The measuring system described here is based on the light-scattering method, and was developed by Optische Werke G. Rodenstock, Munich. It is especially useful for rapid non-contact monitoring of surface roughness in production-related areas. This paper outlines the differences between this system and the common stylus instrument, including descriptions of some applications in industry.

  18. Development of Chinese reference man deformable surface phantom and its application to the influence of physique on electromagnetic dosimetry.

    Science.gov (United States)

    Yu, D; Wang, M; Liu, Q

    2015-09-07

    A reference man is a theoretical individual that represents the average anatomical structure and physiological and metabolic features of a specific group of people and has been widely used in radiation safety research. With the help of an advantage in deformation, the present work proposed a Chinese reference man adult-male polygon-mesh surface phantom based on the Visible Chinese Human segment image dataset by surface rendering and deforming. To investigate the influence of physique on electromagnetic dosimetry in humans, a series of human phantoms with 10th, 50th and 90th body mass index and body circumference percentile physiques for Chinese adult males were further constructed by deforming the Chinese reference man surface phantom. All the surface phantoms were then voxelized to perform electromagnetic field simulation in a frequency range of 20 MHz to 3 GHz using the finite-difference time-domain method and evaluate the whole-body average and organ average specific absorption rate and the ratios of absorbed energy in skin, fat and muscle to the whole body. The results indicate thinner physique leads to higher WBSAR and the volume of subcutaneous fat, the penetration depth of the electromagnetic field in tissues and standing-wave occurrence may be the influence factors of physique on electromagnetic dosimetry.

  19. Rayleigh-Bénard-Marangoni convection in a weakly non-Boussinesq fluid layer with a deformable surface

    Science.gov (United States)

    Lyubimov, D. V.; Lyubimova, T. P.; Lobov, N. I.; Alexander, J. I. D.

    2018-02-01

    The influence of surface deformations on the Rayleigh-Bénard-Marangoni instability of a uniform layer of a non-Boussinesq fluid heated from below is investigated. In particular, the stability of the conductive state of a horizontal fluid layer with a deformable surface, a flat isothermal rigid lower boundary, and a convective heat transfer condition at the upper free surface is considered. The fluid is assumed to be isothermally incompressible. In contrast to the Boussinesq approximation, density variations are accounted for in the continuity equation and in the buoyancy and inertial terms of the momentum equations. Two different types of temperature dependence of the density are considered: linear and exponential. The longwave instability is studied analytically, and instability to perturbations with finite wavenumber is examined numerically. It is found that there is a decrease in stability of the system with respect to the onset of longwave Marangoni convection. This result could not be obtained within the framework of the conventional Boussinesq approximation. It is also shown that at Ma = 0 the critical Rayleigh number increases with Ga (the ratio of gravity to viscous forces or Galileo number). At some value of Ga, the Rayleigh-Bénard instability vanishes. This stabilization occurs for each of the density equations of state. At small values of Ga and when deformation of the free surface is important, it is shown that there are significant differences in stability behavior as compared to results obtained using the Boussinesq approximation.

  20. Characterisation of polycrystal deformation by numerical modelling and neutron diffraction measurements

    DEFF Research Database (Denmark)

    Clausen, Bjørn

    , that the effect of the elastic anisotropy is limited to the very early stages of plasticity (εP neutron diffraction mea-surements of elastic lattice strains...... reflections. The self-consistent model is used to determine the most suitable reflection for technological applications of neutron diffraction, where focus is on the volume av-erage stress state in engineering components. To be able to successfully convert the measured elastic lattice strains for a specific...... the smallest build-up of residual lattice strains. Below 5% deforma-tion the deviations from linearity and the residual strains are below the normal strain resolution of a neutron diffraction measurement. The model predictions have pinpointed, that the selection of the reflection is crucial for the validity...

  1. Surface dose extrapolation measurements with radiographic film

    International Nuclear Information System (INIS)

    Butson, Martin J; Cheung Tsang; Yu, Peter K N; Currie, Michael

    2004-01-01

    Assessment of surface dose delivered from radiotherapy x-ray beams for optimal results should be performed both inside and outside the prescribed treatment fields. An extrapolation technique can be used with radiographic film to perform surface dose assessment for open field high energy x-ray beams. This can produce an accurate two-dimensional map of surface dose if required. Results have shown that the surface percentage dose can be estimated within ±3% of parallel plate ionization chamber results with radiographic film using a series of film layers to produce an extrapolated result. Extrapolated percentage dose assessment for 10 cm, 20 cm and 30 cm square fields was estimated to be 15% ± 2%, 29% ± 3% and 38% ± 3% at the central axis and relatively uniform across the treatment field. The corresponding parallel plate ionization chamber measurements are 16%, 27% and 37%, respectively. Surface doses are also measured outside the treatment field which are mainly due to scattered electron contamination. To achieve this result, film calibration curves must be irradiated to similar x-ray field sizes as the experimental film to minimize quantitative variations in film optical density caused by varying x-ray spectrum with field size. (note)

  2. Novel surface measurement system reading cost savings

    Energy Technology Data Exchange (ETDEWEB)

    Sword, M.

    1996-05-01

    A new state-of-the-art data acquisition system for the oil and natural gas industries is being marketed by OPSCO`92 Industries Ltd. The unit is portable, it measures surface data which is calibrated to bottom-hole conditions and designed to measure temperature and pressure information without the necessity of sending testing equipment downhole. The Surface Data System (SDS) uses silicon-crystal technology, is mounted in a suitcase size carrying case, and runs off a 12-volt battery enclosure which can be backed up by a small solar panel. The first generation system can handle 16 different channels of information input on a laptop computer. Pressure, pressure differential, temperature, frequency and pulse signals for flow meter measurements are handled by standard sensors. Areas of application include build-up and fall-off tests, pipeline evaluation, pre-frac tests, underbalanced drilling and gas well evaluation. 1 fig., 1 photo.

  3. Pressure sources versus surface loads : Analyzing volcano deformation signal composition with an application to Hekla volcano, Iceland

    NARCIS (Netherlands)

    Grapenthin, R.; Ófeigsson, B.G.; Sigmundsson, F.; Sturkell, E.; Hooper, A.J.

    2010-01-01

    The load of lava emplaced over periods of decades to centuries induces a gradual viscous response of the Earth resulting in measurable deformation. This effect should be considered in source model inversions for volcanic areas with large lava production and flow emplacement in small centralized

  4. Atom probe study on microstructure change in severely deformed pearlitic steels: application to rail surfaces and drawn wires

    Science.gov (United States)

    Takahashi, Jun

    2017-07-01

    Pearlitic steel is used as the material for high tensile steel wires, rails and wheels due to its high work hardening and wear resistance. These properties arise from a layered structure comprising deformable lamellar ferrite and hard lamellar cementite. This paper reviews the microstructural change in heavily drawn pearlitic steels wires and worn surfaces of pearlitic rails using atom probe tomography analysis. The cementite decomposition mechanism was elucidated for heavily drawn pearlitic steel wires. For pearlitic rail steels, atomic scale characterization of worn surfaces and of the white etching layer (WEL) were performed, and a mechanism for the formation of the WEL was proposed. The differences and similarities in microstructure and in the state of the cementite in these severely deformed pearlitic steels are discussed.

  5. Deformation responses of slow moving landslides to seasonal rainfall in the Northern Apennines, measured by InSAR

    Science.gov (United States)

    Bayer, Benedikt; Simoni, Alessandro; Mulas, Marco; Corsini, Alessandro; Schmidt, David

    2018-05-01

    Slow moving landslides are widespread geomorphological features in the Northern Apennines of Italy where they represent one of the main landscape forming processes. The lithology of the Northern Apennines fold and thrust belt is characterized by alternations of sandstone, siltstone and clayshales, also known as flysch, and clay shales with a chaotic block in matrix fabric, which are often interpreted as tectonic or sedimentary mélanges. While flysch rocks with a high pelitic fraction host earthslides that occasionally evolve into flow like movements, earthflows are the dominant landslide type in chaotic clay shales. In the present work, we document the kinematic response to rainfall of landslides in these different lithologies using radar interferometry. The study area includes three river catchments in the Northern Apennines. Here, the Mediterranean climate is characterized by two wet seasons during autumn and spring respectively, separated by dry summers and winters with moderate precipitation. We use SAR imagery from the X-band satellite COSMO SkyMed and from the C-band satellite Sentinel 1 to retrieve spatial displacement measurements between 2009 and 2016 for 25 landslides in our area of interest. We also document detailed temporal and spatial deformation signals for eight representative landslides, although the InSAR derived deformation signal is only well constrained by our dataset during the years 2013 and 2015. In spring 2013, long enduring rainfalls struck the study area and numerous landslide reactivations were documented by the regional authorities. During 2013, we measured higher displacement rates on the landslides in pelitic flysch formations compared to the earthflows in the clay shales. Slower mean velocities were measured on most landslides during 2015. We analyse the temporal deformation signal of our eight representative landslides and compare the temporal response to precipitation. We show that earthslides in pelitic flysch formations

  6. Time-series analysis of surface deformation at Brady Hot Springs geothermal field (Nevada) using interferometric synthetic aperture radar

    Energy Technology Data Exchange (ETDEWEB)

    Ali, S. T. [Univ. of Wisconsin, Madison, WI (United States); Akerley, J. [Ormat Technologies Inc., Reno, NV (United States); Baluyut, E. C. [Univ. of Wisconsin, Madison, WI (United States); Cardiff, M. [Univ. of Wisconsin, Madison, WI (United States); Davatzes, N. C. [Temple Univ., Philadelphia, PA (United States). Dept. of Earth and Environmental Science; Feigl, K. L. [Univ. of Wisconsin, Madison, WI (United States); Foxall, W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Fratta, D. [Univ. of Wisconsin, Madison, WI (United States); Mellors, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Spielman, P. [Ormat Technologies Inc., Reno, NV (United States); Wang, H. F. [Univ. of Wisconsin, Madison, WI (United States); Zemach, E. [Ormat Technologies Inc., Reno, NV (United States)

    2016-05-01

    We analyze interferometric synthetic aperture radar (InSAR) data acquired between 2004 and 2014, by the ERS-2, Envisat, ALOS and TerraSAR-X/TanDEM-X satellite missions to measure and characterize time-dependent deformation at the Brady Hot Springs geothermal field in western Nevada due to extraction of fluids. The long axis of the ~4 km by ~1.5 km elliptical subsiding area coincides with the strike of the dominant normal fault system at Brady. Within this bowl of subsidence, the interference pattern shows several smaller features with length scales of the order of ~1 km. This signature occurs consistently in all of the well-correlated interferometric pairs spanning several months. Results from inverse modeling suggest that the deformation is a result of volumetric contraction in shallow units, no deeper than 600 m, likely associated with damaged regions where fault segments mechanically interact. Such damaged zones are expected to extend downward along steeply dipping fault planes, providing a high permeability conduit to the production wells. Using time series analysis, we test the hypothesis that geothermal production drives the observed deformation. We find a good correlation between the observed deformation rate and the rate of production in the shallow wells. We also explore mechanisms that could potentially cause the observed deformation, including thermal contraction of rock, decline in pore pressure and dissolution of minerals over time.

  7. Oblique interaction of a laminar vortex ring with a non-deformable free surface: Vortex reconnection and breakdown

    International Nuclear Information System (INIS)

    Balakrishnan, S K; Thomas, T G; Coleman, G N

    2011-01-01

    Direct Numerical Simulation (DNS) is used to study the interaction of a laminar vortex ring with a non-deformable, free-slip surface at an oblique angle of incidence. The interaction leads to the well-known phenomenon of vortex reconnection. It was found that the reconnection process leads to rapid production of small-scale vortical structures. This phenomenon was found to be related to the kinematics of the reconection process.

  8. Detection of hidden stationary deformations of vibrating surfaces by use of time-averaged digital holographic interferometry.

    Science.gov (United States)

    Demoli, Nazif; Vukicevic, Dalibor

    2004-10-15

    A method of detecting displacements of a surface from its steady-state position to its equilibrium position while it is vibrating has been developed by use of time-average digital holographic interferometry. This method permits extraction of such a hidden deformation by creating two separated systems of interferogram fringes: one corresponding to a time-varying resonantly oscillating optical phase, the other to the stationary phase modification. A mathematical description of the method and illustrative results of experimental verification are presented.

  9. Minimizing Uncertainty in Cryogenic Surface Figure Measurement

    Science.gov (United States)

    Blake, Peter; Mink, Ronald G.; Chambers, John; Robinson, F. David; Content, David; Davila, Pamela

    2005-01-01

    A new facility at the Goddard Space Flight Center is designed to measure with unusual accuracy the surface figure of mirrors at cryogenic temperatures down to 12 K. The facility is currently configured for spherical mirrors with a radius of curvature (ROC) of 600 mm, and apertures of about 150 mm or less. The goals of the current experiment were to 1) Obtain the best possible estimate of test mirror surface figure, S(x,y) at 87 K and 20 K; 2) Obtain the best estimate of the cryo-change, Delta (x,y): the change in surface figure between room temperature and the two cryo-temperatures; and 3) Determine the uncertainty of these measurements, using the definitions and guidelines of the ISO Guide to the Expression of Uncertainty in Measurement. A silicon mirror was tested, and the cry-change from room temperature to 20K was found to be 3.7 nm rms, with a standard uncertainty of 0.23 nm in the rms statistic. Both the cryo-change figure and the uncertainty are among the lowest such figures yet published. This report describes the facilities, experimental methods, and uncertainty analysis of the measurements.

  10. Onsets of nuclear deformation from measurements with the Isoltrap mass spectrometer

    International Nuclear Information System (INIS)

    Naimi, S.

    2010-10-01

    Mass measurements provide important information concerning nuclear structure. This work presents results from the pioneering Penning trap spectrometer Isoltrap at CERN-Isolde. High-precision mass measurements of neutron-rich manganese ( 58 - 66 Mn) and krypton isotopes ( 96, 97 Kr) are presented, of which the 66 Mn and 96, 97 Kr masses are measured for the first time. In particular, the mass of 97 Kr was measured using the preparation trap and required the definition of a new fit function. In the case of the manganese isotopes, the N=40 shell closure is addressed. The two-neutron-separation energies calculated from the new masses show no shell closure at N=40 but give an estimation of the proton-neutron interaction (around 0.5 MeV) responsible for the increase of collectivity and nuclear deformation in this mass region. The new krypton masses show behavior in sharp contrast with heavier neighbors where sudden and intense deformation is present, interpreted as the establishment of a nuclear quantum shape/phase transition critical-point boundary. The new masses confirm findings from nuclear mean-square charge-radius measurements up to N=60 but are at variance with conclusions from recent gamma-ray spectroscopy. Another part of this work was the design of new decay spectroscopy system behind the Isoltrap mass spectrometer. The beam purity achievable with Isoltrap will allow decay studies with γ and β detection coupled to a tape-station. This system has been mounted and commissioned with the radioactive beam 80 Rb. (author)

  11. Quantifying the short- and long-term controls exerted by the basal and lateral boundaries of the Slumgullion Landslide from creepmeters and 3-D surface deformation

    Science.gov (United States)

    Delbridge, B. G.; Bilham, R. G.; Wang, T.; Fielding, E. J.; Burgmann, R.

    2017-12-01

    The Slumgullion landslide is 3.9 km long, moves persistently with peak rates of up to 2 cm/day, and exhibits daily, seasonal, and decadal accelerations. In this study, we provide geodetic observations needed to test whether the short- and long-term variations are governed by the same physical mechanisms. Specific focus is placed on disentangling the roles played by the lateral and basal landslide surfaces. In order to provide surface geodetic measurements with dense spatial resolution (pixel spacing parallel to- (azimuth) the along-track direction of flight. To examine deformation rates spanning minutes to days we have installed a surface creepmeter, similar to those currently monitoring actively creeping faults such as the Hayward Fault. A tensioned flexible wire is fastened obliquely across the lateral bounding fault and wrapped around a 100 mm wheel wheel whose angular position is monitored by a Hall effect sensor, resulting in resolution of 8 microns and with a 5 m range.

  12. Topography and structural heterogeneities in surface ground deformation: a simulation test for Somma-Vesuvius volcano

    Science.gov (United States)

    Tammaro, Umberto; Riccardi, Umberto; Romano, Vittorio; Meo, Michele; Capuano, Paolo

    2017-04-01

    Through a 3D finite element code we simulate, the deformation of Somma-Vesuvius volcano caused by some overpressure sources. Under the assumption of linear elastic isotropic material behavior, the volcano deformation sources are located at various depths and their geometry (shape and lateral extension) is mainly constrained by the results of recent seismic tomography studies. These simulations have the objective to inquire about the influence of topography and structural heterogeneity on ground deformation. Structural heterogeneities have been modeled in terms of dynamical elastic parameters (Young's modulus) accounting for previous seismic tomography and gravity studies. Topography of Somma-Vesuvius is taken into account, using a digital terrain model. The main outcomes of this study is a strong deviation from axially symmetric pattern of the displacement field, which is quietly unaccounted by simplistic Mogi modeling in homogeneous medium with simplified topography. These results demonstrate that real topography and structural heterogeneities are key factors controlling the pattern of ground deformations, i.e. one of the most relevant problem in volcano monitoring. Moreover, an improved knowledge of deformation patterns can significantly help in the location of monitoring sensors as well as in the design of an efficient geodetic network.

  13. Radioimmunoassay to quantitatively measure cell surface immunoglobulins

    International Nuclear Information System (INIS)

    Krishman, E.C.; Jewell, W.R.

    1975-01-01

    A radioimmunoassay techniques developed to quantitatively measure the presence of immunoglobulins on the surface of cells, is described. The amount of immunoglobulins found on different tumor cells varied from 200 to 1140 ng/10 6 cells. Determination of immunoglobulins on the peripheral lymphocytes obtained from different cancer patients varied between 340 to 1040 ng/10 6 cells. Cultured tumor cells, on the other hand, were found to contain negligible quantities of human IgG [pt

  14. Description of measurement techniques for surface contaminations

    International Nuclear Information System (INIS)

    Bourrez, E.

    2001-01-01

    The needs of evaluation of the surface contamination are numerous in the processes of production and management of radioactive waste. The market of radiation protection materials proposes a lot of devices answering to the almost all these needs. These device have however their conditions and particular limits for use. To realize correct measurements it is use the device, the technique and the methods adapted to the need, by taking into account the optimization of economical aspect. (N.C.)

  15. Development of AN Open-Source Automatic Deformation Monitoring System for Geodetical and Geotechnical Measurements

    Science.gov (United States)

    Engel, P.; Schweimler, B.

    2016-04-01

    The deformation monitoring of structures and buildings is an important task field of modern engineering surveying, ensuring the standing and reliability of supervised objects over a long period. Several commercial hardware and software solutions for the realization of such monitoring measurements are available on the market. In addition to them, a research team at the Neubrandenburg University of Applied Sciences (NUAS) is actively developing a software package for monitoring purposes in geodesy and geotechnics, which is distributed under an open source licence and free of charge. The task of managing an open source project is well-known in computer science, but it is fairly new in a geodetic context. This paper contributes to that issue by detailing applications, frameworks, and interfaces for the design and implementation of open hardware and software solutions for sensor control, sensor networks, and data management in automatic deformation monitoring. It will be discussed how the development effort of networked applications can be reduced by using free programming tools, cloud computing technologies, and rapid prototyping methods.

  16. A Constellation of CubeSat InSAR Sensors for Rapid-Revisit Surface Deformation Studies

    Science.gov (United States)

    Wye, L.; Lee, S.; Yun, S. H.; Zebker, H. A.; Stock, J. D.; Wicks, C. W., Jr.; Doe, R.

    2016-12-01

    The 2007 NRC Decadal Survey for Earth Sciences highlights three major Earth surface deformation themes: 1) solid-earth hazards and dynamics; 2) human health and security; and 3) land-use change, ecosystem dynamics and biodiversity. Space-based interferometric synthetic aperture radar (InSAR) is a key change detection tool for addressing these themes. Here, we describe the mission and radar payload design for a constellation of S-band InSAR sensors specifically designed to provide the global, high temporal resolution, sub-cm level deformation accuracy needed to address some of the major Earth system goals. InSAR observations with high temporal resolution are needed to properly monitor certain nonlinearly time-varying features (e.g., unstable volcanoes, active fault lines, and heavily-used groundwater or hydrocarbon reservoirs). Good temporal coverage is also needed to reduce atmospheric artifacts by allowing multiple acquisitions to be averaged together, since each individual SAR measurement is corrupted by up to several cm of atmospheric noise. A single InSAR platform is limited in how often it can observe a given scene without sacrificing global spatial coverage. Multiple InSAR platforms provide the spatial-temporal flexibility required to maximize the science return. However, building and launching multiple InSAR platforms is cost-prohibitive for traditional satellites. SRI International (SRI) and our collaborators are working to exploit developments in nanosatellite technology, in particular the emergence of the CubeSat standard, to provide high-cadence InSAR capabilities in an affordable package. The CubeSat Imaging Radar for Earth Science (CIRES) subsystem, a prototype SAR elec­tronics package developed by SRI with support from a 2014 NASA ESTO ACT award, is specifically scaled to be a drop-in radar solution for resource-limited delivery systems like CubeSats and small airborne vehicles. Here, we present our mission concept and flow-down requirements for a

  17. Acoustic Impedance Measurement for Underground Surfaces.

    Science.gov (United States)

    Cockcroft, Paul William

    Available from UMI in association with The British Library. Requires signed TDF. This thesis investigates the measurement of acoustic impedance for surfaces likely to be found in underground coal mines. By introducing the concepts of industrial noise, the effects of noise on the ear and relevant legislation the need for the protection of workers can be appreciated. Representative acoustic impedance values are vital as input for existing computer models that predict sound levels in various underground environments. These enable the mining engineer to predict the noise level at any point within a mine in the vicinity of noisy machinery. The concepts of acoustic intensity and acoustic impedance are investigated and different acoustic impedance measurement techniques are detailed. The possible use of either an impedance tube or an intensity meter for these kinds of measurements are suggested. The problems with acoustic intensity and acoustic impedance measurements are discussed with reference to the restraints that an underground environment imposes on any measurement technique. The impedance tube method for work in an acoustics laboratory is shown and the theory explained, accompanied by a few representative results. The use of a Metravib intensity meter in a soundproof chamber to gain impedance values is explained in detail. The accompanying software for the analysis of the two measured pressure signals is shown as well as the actual results for a variety of test surfaces. The use of a Nagra IV-SJ tape recorder is investigated to determine the effect of recording on the measurement and subsequent analysis of the input signals, particularly with reference to the phase difference introduced between the two simultaneous pressure signals. The subsequent use of a Norwegian Electronic intensity meter, including a proposal for underground work, is shown along with results for tests completed with this piece of equipment. Finally, recommendations are made on how to link up

  18. Estimating Actual 2D Ground Deformations Induced by Underground Activities with Cross-Heading InSAR Measurements

    Directory of Open Access Journals (Sweden)

    Xiaoying Yu

    2017-01-01

    Full Text Available InSAR can only monitor relative ground deformations with respect to a reference area. In order to obtain actual deformations, GCPs or stable area is required in the study area, which, however, may be unavailable in the investigating of geohazards associated with underground activities (i.e., groundwater pumping, underground mining, and oil/gas exploitation. We propose a novel approach to estimate actual 2D deformations based on the InSAR relative LOS measurements acquired from cross-heading datasets. The errors induced by the arbitrary selection of reference areas can thus be avoided. The performance of the proposed approach is validated by a series of simulations. By providing the ascending and descending measurements with errors of 2 and 1.5 mm/year STDs, respectively, the RMSEs are 2.1 and 2.6 mm/year for the estimated vertical and east deformations, respectively. A case study is carried out in Cangzhou, China, for estimating the actual 2D ground deformations associated with groundwater pumping. By integrating ALOS ascending and ENVISAT descending datasets acquired between 2007 and 2010, we found that the Cangzhou area experienced ground subsidence of up to 23.4 mm/year in the suburbs but ground uplift of up to 20.9 mm/year in the urban area, both of which are accompanied by considerable lateral deformations.

  19. Measurement of Flat Slab Deformations by the Multi-Image Photogrammetry Method

    Science.gov (United States)

    Marčiš, Marián; Fraštia, Marek; Augustín, Tomáš

    2017-12-01

    The use of photogrammetry during load tests of building components is a common practise all over the world. It is very effective thanks to its contactless approach, 3D measurement, fast data collection, and partial or full automation of image processing; it can deliver very accurate results. Multi-image convergent photogrammetry supported by artificial coded targets is the most accurate photogrammetric method when the targets are detected in an image with a higher degree of accuracy than a 0.1 pixel. It is possible to achieve an accuracy of 0.03 mm for all the points measured on the object observed if the camera is close enough to the object, and the positions of the camera and the number of shots are precisely planned. This contribution deals with the design of a special hanging frame for a DSLR camera used during the photogrammetric measurement of the deformation of flat concrete slab. The results of the photogrammetric measurements are compared to the results from traditional contact measurement techniques during load tests.

  20. Electrostatic Deformation of Liquid Surfaces by a Charged Rod and a Van De Graaff Generator

    Science.gov (United States)

    Slisko, Josip; García-Molina, Rafael; Abril, Isabel

    2014-01-01

    Authors of physics textbooks frequently use the deflection of a thin, vertically falling water jet by a charged balloon, comb, or rod as a visually appealing and conceptually relevant example of electrostatic attraction. Nevertheless, no attempts are made to explore whether these charged bodies could cause visible deformation of a horizontal water…

  1. Modeling viscoelastic deformation of the earth due to surface loading by commercial finite element package - ABAQUS

    Science.gov (United States)

    Kit Wong, Ching; Wu, Patrick

    2017-04-01

    Wu (2004) developed a transformation scheme to model viscoelatic deformation due to glacial loading by commercial finite element package - ABAQUS. Benchmark tests confirmed that this method works extremely well on incompressible earth model. Bangtsson & Lund (2008),however, showed that the transformation scheme would lead to incorrect results if compressible material parameters are used. Their study implies that Wu's method of stress transformation is inadequate to model the load induced deformation of a compressible earth under the framework of ABAQUS. In light of this, numerical experiments are carried out to find if there exist other methods that serve this purpose. All the tested methods are not satisfying as the results failed to converge through iterations, except at the elastic limit. Those tested methods will be outlined and the results will be presented. Possible reasons of failure will also be discussed. Bängtsson, E., & Lund, B. (2008). A comparison between two solution techniques to solve the equations of glacially induced deformation of an elastic Earth. International journal for numerical methods in engineering, 75(4), 479-502. Wu, P. (2004). Using commercial finite element packages for the study of earth deformations, sea levels and the state of stress. Geophysical Journal International, 158(2), 401-408.

  2. Solid surface tension measured by a liquid drop under a solid film.

    Science.gov (United States)

    Nadermann, Nichole; Hui, Chung-Yuen; Jagota, Anand

    2013-06-25

    We show that a drop of liquid a few hundred microns in diameter placed under a solid, elastic, thin film (∼10 μm thick) causes it to bulge by tens of microns. The deformed shape is governed by equilibrium of tensions exerted by the various interfaces and the solid film, a form of Neumann's triangle. Unlike Young's equation, which specifies the contact angles at the junction of two fluids and a (rigid) solid, and is fundamentally underdetermined, both tensions in the solid film can be determined here if the liquid-vapor surface tension is known independently. Tensions in the solid film have a contribution from elastic stretch and a constant residual component. The residual component, extracted by extrapolation to films of vanishing thickness and supported by analysis of the elastic deformation, is interpreted as the solid-fluid surface tension, demonstrating that compliant thin-film structures can be used to measure solid surface tensions.

  3. First-principles approaches to intrinsic strength and deformation of materials: perfect crystals, nano-structures, surfaces and interfaces

    International Nuclear Information System (INIS)

    Ogata, Shigenobu; Umeno, Yoshitaka; Kohyama, Masanori

    2009-01-01

    First-principles studies on the intrinsic mechanical properties of various materials and systems through ab initio tensile and shear testing simulations based on density-functional theory are reviewed. For various materials, ideal tensile and shear strength and features of the deformation of bulk crystals without any defects have been examined, and the relation with the bonding nature has been analyzed. The surfaces or low-dimensional nano-structures reveal peculiar strength and deformation behavior due to local different bonding nature. For grain boundaries and metal/ceramic interfaces, tensile and shear behaviors depend on the interface bonding, which impacts on the research of real engineering materials. Remaining problems and future directions in this research field are discussed. (topical review)

  4. Dynamic deformation image de-blurring and image processing for digital imaging correlation measurement

    Science.gov (United States)

    Guo, X.; Li, Y.; Suo, T.; Liu, H.; Zhang, C.

    2017-11-01

    This paper proposes a method for de-blurring of images captured in the dynamic deformation of materials. De-blurring is achieved based on the dynamic-based approach, which is used to estimate the Point Spread Function (PSF) during the camera exposure window. The deconvolution process involving iterative matrix calculations of pixels, is then performed on the GPU to decrease the time cost. Compared to the Gauss method and the Lucy-Richardson method, it has the best result of the image restoration. The proposed method has been evaluated by using the Hopkinson bar loading system. In comparison to the blurry image, the proposed method has successfully restored the image. It is also demonstrated from image processing applications that the de-blurring method can improve the accuracy and the stability of the digital imaging correlation measurement.

  5. Neighborhood binary speckle pattern for deformation measurements insensitive to local illumination variation by digital image correlation.

    Science.gov (United States)

    Zhao, Jian; Yang, Ping; Zhao, Yue

    2017-06-01

    Speckle pattern-based characteristics of digital image correlation (DIC) restrict its application in engineering fields and nonlaboratory environments, since serious decorrelation effect occurs due to localized sudden illumination variation. A simple and efficient speckle pattern adjusting and optimizing approach presented in this paper is aimed at providing a novel speckle pattern robust enough to resist local illumination variation. The new speckle pattern, called neighborhood binary speckle pattern, derived from original speckle pattern, is obtained by means of thresholding the pixels of a neighborhood at its central pixel value and considering the result as a binary number. The efficiency of the proposed speckle pattern is evaluated in six experimental scenarios. Experiment results indicate that the DIC measurements based on neighborhood binary speckle pattern are able to provide reliable and accurate results, even though local brightness and contrast of the deformed images have been seriously changed. It is expected that the new speckle pattern will have more potential value in engineering applications.

  6. Measuring the Valence of Nanocrystal Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Owen, Jonathan Scharle [Columbia Univ., New York, NY (United States)

    2016-11-30

    The goal of this project is to understand and control the interplay between nanocrystal stoichiometry, surface ligand binding and exchange, and the optoelectronic properties of semiconductor nanocrystals in solution and in thin solid films. We pursued three research directions with this goal in mind: 1) We characterized nanocrystal stoichiometry and its influence on the binding of L-type and X-type ligands, including the thermodynamics of binding and the kinetics of ligand exchange. 2) We developed a quantitative understanding of the relationship between surface ligand passivation and photoluminescence quantum yield. 3) We developed methods to replace the organic ligands on the nanocrystal with halide ligands and controllably deposit these nanocrystals into thin films, where electrical measurements were used to investigate the electrical transport and internanocrystal electronic coupling.

  7. Measured ground-surface movements, Cerro Prieto geothermal field

    Energy Technology Data Exchange (ETDEWEB)

    Massey, B.L.

    1981-01-01

    The Cerro Prieto geothermal area in the Mexicali Valley, 30 kilometers southeast of Mexicali, Baja California, incurred slight deformation because of the extraction of hot water and steam, and probably, active tectonism. During 1977 to 1978, the US Geological Survey established and measured two networks of horizontal control in an effort to define both types of movement. These networks consisted of: (1) a regional trilateration net brought into the mountain ranges west of the geothermal area from stations on an existing US Geological Survey crustal-strain network north of the international border; and (2) a local net tied to stations in the regional net and encompassing the present and planned geothermal production area. Electronic distance measuring instruments were used to measure the distances between stations in both networks in 1978, 1979 and 1981. Lines in the regional net averaged 25 km. in length and the standard deviation of an individual measurement is estimated to be approx. 0.3 part per million of line length. The local network was measured using different instrumentation and techniques. The average line length was about 5 km. and the standard deviation of an individual measurement approached 3 parts per million per line length. Ground-surface movements in the regional net, as measured by both the 1979 and 1981 resurveys, were small and did not exceed the noise level. The 1979 resurvey of the local net showed an apparent movement of 2 to 3 centimeters inward toward the center of the production area. This apparent movement was restricted to the general limits of the production area. The 1981 resurvey of the local net did not show increased movement attributable to fluid extraction.

  8. Design and Testing of the Strain Transducer for Measuring Deformations of Pipelines Operating in the Mining-deformable Ground Environment

    Directory of Open Access Journals (Sweden)

    Gawedzki Waclaw

    2015-10-01

    Full Text Available Design and laboratory test results of the strain transducer intended for monitoring and assessing stress states of pipelines sited in mining areas are presented in this paper. This transducer allows measuring strains of pipelines subjected to external forces - being the mining operations effect. Pipeline strains can have a direct influence on a tightness loss and penetration of the transported fluid into the environment. The original strain gauge transducer was proposed for performing measurements of strains. It allows measuring circumferential strains and determining the value and direction of the main longitudinal strain. This strain is determined on the basis of measuring component longitudinal strains originating from axial forces and the resultant bending moment. The main purpose of investigations was the experimental verification of the possibility of applying the strain transducer for measuring strains of polyethylene pipelines. The obtained results of the transducer subjected to influences of tensile and compression forces are presented and tests of relaxation properties of polyethylene are performed.

  9. Validity of a smartphone protractor to measure sagittal parameters in adult spinal deformity.

    Science.gov (United States)

    Kunkle, William Aaron; Madden, Michael; Potts, Shannon; Fogelson, Jeremy; Hershman, Stuart

    2017-10-01

    Smartphones have become an integral tool in the daily life of health-care professionals (Franko 2011). Their ease of use and wide availability often make smartphones the first tool surgeons use to perform measurements. This technique has been validated for certain orthopedic pathologies (Shaw 2012; Quek 2014; Milanese 2014; Milani 2014), but never to assess sagittal parameters in adult spinal deformity (ASD). This study was designed to assess the validity, reproducibility, precision, and efficiency of using a smartphone protractor application to measure sagittal parameters commonly measured in ASD assessment and surgical planning. This study aimed to (1) determine the validity of smartphone protractor applications, (2) determine the intra- and interobserver reliability of smartphone protractor applications when used to measure sagittal parameters in ASD, (3) determine the efficiency of using a smartphone protractor application to measure sagittal parameters, and (4) elucidate whether a physician's level of experience impacts the reliability or validity of using a smartphone protractor application to measure sagittal parameters in ASD. An experimental validation study was carried out. Thirty standard 36″ standing lateral radiographs were examined. Three separate measurements were performed using a marker and protractor; then at a separate time point, three separate measurements were performed using a smartphone protractor application for all 30 radiographs. The first 10 radiographs were then re-measured two more times, for a total of three measurements from both the smartphone protractor and marker and protractor. The parameters included lumbar lordosis, pelvic incidence, and pelvic tilt. Three raters performed all measurements-a junior level orthopedic resident, a senior level orthopedic resident, and a fellowship-trained spinal deformity surgeon. All data, including the time to perform the measurements, were recorded, and statistical analysis was performed to

  10. Importance of methodological standardization for the ektacytometric measures of red blood cell deformability in sickle cell anemia.

    Science.gov (United States)

    Renoux, Céline; Parrow, Nermi; Faes, Camille; Joly, Philippe; Hardeman, Max; Tisdale, John; Levine, Mark; Garnier, Nathalie; Bertrand, Yves; Kebaili, Kamila; Cuzzubbo, Daniela; Cannas, Giovanna; Martin, Cyril; Connes, Philippe

    2016-01-01

    Red blood cell (RBC) deformability is severely decreased in patients with sickle cell anemia (SCA), which plays a role in the pathophysiology of the disease. However, investigation of RBC deformability from SCA patients demands careful methodological considerations. We assessed RBC deformability by ektacytometry (LORRCA MaxSis, Mechatronics, The Netherlands) in 6 healthy individuals and 49 SCA patients and tested the effects of different heights of the RBC diffraction patterns, obtained by altering the camera gain of the LORRCA, on the result of RBC deformability measurements, expressed as Elongation Index (EI). Results indicate that the pattern of RBCs from control subjects adopts an elliptical shape under shear stress, whereas the pattern of RBCs from individuals with SCA adopts a diamond shape arising from the superposition of elliptical and circular patterns. The latter represent rigid RBCs. While the EI measures did not change with the variations of the RBC diffraction pattern heights in the control subjects, we observed a decrease of EI when the RBC diffraction pattern height is increased in the SCA group. The differences in SCA EI values measured at 5 Pa between the different diffraction pattern heights correlated with the percent of hemoglobin S and the percent of sickled RBC observed by microscopy. Our study confirms that the camera gain or aperture of the ektacytometer should be used to standardize the size of the RBC diffraction pattern height when measuring RBC deformability in sickle cell patients and underscores the potential clinical utility of this technique.

  11. Evaluation of Arctic broadband surface radiation measurements

    Directory of Open Access Journals (Sweden)

    N. Matsui

    2012-02-01

    Full Text Available The Arctic is a challenging environment for making in-situ surface radiation measurements. A standard suite of radiation sensors is typically designed to measure incoming and outgoing shortwave (SW and thermal infrared, or longwave (LW, radiation. Enhancements may include various sensors for measuring irradiance in narrower bandwidths. Many solar radiation/thermal infrared flux sensors utilize protective glass domes and some are mounted on complex mechanical platforms (solar trackers that keep sensors and shading devices trained on the sun along its diurnal path. High quality measurements require striking a balance between locating stations in a pristine undisturbed setting free of artificial blockage (such as from buildings and towers and providing accessibility to allow operators to clean and maintain the instruments. Three significant sources of erroneous data in the Arctic include solar tracker malfunctions, rime/frost/snow deposition on the protective glass domes of the radiometers and operational problems due to limited operator access in extreme weather conditions. In this study, comparisons are made between the global and component sum (direct [vertical component] + diffuse SW measurements. The difference between these two quantities (that theoretically should be zero is used to illustrate the magnitude and seasonality of arctic radiation flux measurement problems. The problem of rime/frost/snow deposition is investigated in more detail for one case study utilizing both SW and LW measurements. Solutions to these operational problems that utilize measurement redundancy, more sophisticated heating and ventilation strategies and a more systematic program of operational support and subsequent data quality protocols are proposed.

  12. Calibration of areal surface topography measuring instruments

    Science.gov (United States)

    Seewig, J.; Eifler, M.

    2017-06-01

    The ISO standards which are related to the calibration of areal surface topography measuring instruments are the ISO 25178-6xx series which defines the relevant metrological characteristics for the calibration of different measuring principles and the ISO 25178-7xx series which defines the actual calibration procedures. As the field of areal measurement is however not yet fully standardized, there are still open questions to be addressed which are subject to current research. Based on this, selected research results of the authors in this area are presented. This includes the design and fabrication of areal material measures. For this topic, two examples are presented with the direct laser writing of a stepless material measure for the calibration of the height axis which is based on the Abbott- Curve and the manufacturing of a Siemens star for the determination of the lateral resolution limit. Based on these results, as well a new definition for the resolution criterion, the small scale fidelity, which is still under discussion, is presented. Additionally, a software solution for automated calibration procedures is outlined.

  13. Low temperature surface hardening of stainless steel; the role of plastic deformation

    DEFF Research Database (Denmark)

    Bottoli, Federico; Jespersen, Freja Nygaard; Hattel, Jesper Henri

    2016-01-01

    Thermochemical surface engineering by nitriding of austenitic stainless steel transforms the surface zone into expanded austenite, which improves the wear resistance of the stainless steel while preserving the stainless behavior. As a consequence of the thermochemical surface engineering, huge re...

  14. Optical measurement of thermal deformation of multilayer optics under synchrotron radiation

    International Nuclear Information System (INIS)

    Revesz, P.; Kazimirov, A.; Bazarov, I.

    2007-01-01

    An in situ optical technique to visualize surface distortions of the first monochromator crystal under synchrotron beam heat loading has been developed and applied to measure surface profiles of multilayer optics under white wiggler beam at the CHESS A2 beamline. Two identical multilayer structures deposited on Si and SiC substrates have been tested. Comparison of the reconstructed 3D heatbump profiles showed the surface distortions of the multilayer on SiC a factor of two smaller than the same multilayer on a Si substrate

  15. An automated in vitro model for the evaluation of ultrasound modalities measuring myocardial deformation

    Directory of Open Access Journals (Sweden)

    Stigö Albin

    2010-09-01

    Full Text Available Abstract Background Echocardiography is the method of choice when one wishes to examine myocardial function. Qualitative assessment of the 2D grey scale images obtained is subjective, and objective methods are required. Speckle Tracking Ultrasound is an emerging technology, offering an objective mean of quantifying left ventricular wall motion. However, before a new ultrasound technology can be adopted in the clinic, accuracy and reproducibility needs to be investigated. Aim It was hypothesized that the collection of ultrasound sample data from an in vitro model could be automated. The aim was to optimize an in vitro model to allow for efficient collection of sample data. Material & Methods A tissue-mimicking phantom was made from water, gelatin powder, psyllium fibers and a preservative. Sonomicrometry crystals were molded into the phantom. The solid phantom was mounted in a stable stand and cyclically compressed. Peak strain was then measured by Speckle Tracking Ultrasound and sonomicrometry. Results We succeeded in automating the acquisition and analysis of sample data. Sample data was collected at a rate of 200 measurement pairs in 30 minutes. We found good agreement between Speckle Tracking Ultrasound and sonomicrometry in the in vitro model. Best agreement was 0.83 ± 0.70%. Worst agreement was -1.13 ± 6.46%. Conclusions It has been shown possible to automate a model that can be used for evaluating the in vitro accuracy and precision of ultrasound modalities measuring deformation. Sonomicrometry and Speckle Tracking Ultrasound had acceptable agreement.

  16. Longer-Term Postcure Measurement of Cuspal Deformation Induced by Dimensional Changes in Dental Materials

    Science.gov (United States)

    Falsafi, A.; Oxman, J. D.; Tse, P.-H.; Ton, T. T.

    2015-01-01

    Aim. This paper presents a simple, versatile in vitro methodology that enables indirect quantification of shrinkage and expansion stresses under clinically relevant conditions without the need for a dedicated instrument. Methods. For shrinkage effects, resulting cusp deformation of aluminum blocks with MOD type cavity, filled with novel filling compositions and commercial cements, has been measured using a bench-top micrometer and a Linear Variable Differential Transformer (LVDT, a displacement transducer) based instrument. Results. The results demonstrated the validity of the proposed simple methodology. The technique was successfully used in longer-term measurements of shrinkage and expansion stress for several dental compositions. Conclusions. In contrast to in situ techniques where a measuring instrument is dedicated to the sample and its data collection, the proposed simple methodology allows for transfer of the samples to the environment of choice for storage and conditioning. The presented technique can be reliably used to quantify stress development of curing materials under clinically relevant (oral) conditions. This enables direct examination and comparison of structural properties corresponding to the final stage of formed networks. The proposed methodology is directly applicable to the study of self-curing systems as they require mouth-type conditions (temperature and humidity) to achieve their designed kinetics and reactions. PMID:26257783

  17. First 3D measurements of proton beams in a deformable silicone-based dosimeter

    Science.gov (United States)

    Høye, E. M.; Sadel, M.; Kaplan, L.; Skyt, P. S.; Muren, L. P.; Petersen, J. B. B.; Swakoń, J.; Mierzwińska, G.; Rydygier, M.; Malinowski, L.; Balling, P.

    2017-05-01

    3D dosimetry provides high-resolution dose information of radiation therapy (RT), and is explored to enable and secure high-quality delivery of advanced RT modalities, including proton therapy. We present the first 3D measurements of spot-scanning proton plans in a silicone-based, radiochromic dosimeter with deformation properties. The dose information was read-out by optical CT-scanning. We found that the dosimeter signal was quenched close to the Bragg peak, and that this had a large impact on a measured spread-out Bragg peak. The dose response was linear both in the entrance region and in the Bragg peak, however, the dose response significantly reduced in the Bragg peak. Quenching was attributed to a linear-energy-transfer dependent dose response. Linear energy transfer distributions for each proton treatment plan will provide a means for calibrating the optical measurement to linear energy transfer, as well as dose. This might enable use of the silicone-dosimeter in quality assurance of proton beams.

  18. 3D shape, deformation, and vibration measurements using infrared Kinect sensors and digital image correlation.

    Science.gov (United States)

    Nguyen, Hieu; Wang, Zhaoyang; Jones, Patrick; Zhao, Bing

    2017-11-10

    Consumer-grade red-green-blue and depth (RGB-D) sensors, such as the Microsoft Kinect and the Asus Xtion, are attractive devices due to their low cost and robustness for real-time sensing of depth information. These devices provide the depth information by detecting the correspondences between the captured infrared (IR) image and the initial image sent to the IR projector, and their essential limitation is the low accuracy of 3D shape reconstruction. In this paper, an effective technique that employs the Kinect sensors for accurate 3D shape, deformation, and vibration measurements is introduced. The technique involves using the RGB-D sensors, an accurate camera calibration scheme, and area- and feature-based image-matching algorithms. The IR speckle pattern projected from the Kinect projector considerably facilitates the digital image correlation analysis in the regions of interest with enhanced accuracy. A number of experiments have been carried out to demonstrate the validity and effectiveness of the proposed technique and approach. It is shown that the technique can yield measurement accuracy at the 10 μm level for a typical field of view. The real-time capturing speed of 30 frames per second makes the proposed technique suitable for certain motion and vibration measurements, such as non-contact monitoring of respiration and heartbeat rates.

  19. Influence of steel composition and plastic deformation on the surface properties induced by low temperature thermochemical processing

    DEFF Research Database (Denmark)

    Bottoli, Federico

    products. The activities carried out encompass the study and the characterization of the following aspects: ‐ Influence of plastic deformation prior to the low-temperature thermochemical process ‐ Influence of initial phase composition on the properties and morphology of thenitrided/nitrocarburized surface......Low-temperature thermochemical surface hardening by nitriding, carburizing and nitrocarburizing is used to improve the performance of stainless steels with respect to wear, fatigue and corrosion resistance.The dissolution of nitrogen and/or carbon atoms in the materials surface leads...... with the improvement of these properties, the corrosion resistance of the stainless steel is fully maintained or even enhanced. Despite low-temperature thermochemical processing of austenitic stainless steels has been widely studied in literature, other stainless steel classes and the influence of steel´s initial...

  20. Using PS-InSAR to detect surface deformation in geothermal areas of West Java in Indonesia

    Science.gov (United States)

    Maghsoudi, Yasser; van der Meer, Freek; Hecker, Christoph; Perissin, Daniele; Saepuloh, Asep

    2018-02-01

    In this paper, the Persistent Scatterer InSAR (PS-InSAR) technique is applied in order to investigate the ground deformation in and around two geothermal areas in West Java, Indonesia. Two time-series of ALOS PALSAR and Sentinel-1A acquisitions, covering the period from 2007 to 2009 and 2015-2016, are analysed. The first case study examines the Wayang Windu geothermal zone where the PS-InSAR analysis provides an overview of the surface deformation around a geothermal reservoir. Uplift is observed around the injection wells in the area. The second example involves the use of the PS-InSAR technique over a more recent geothermal system in Patuha field. Again, a pattern of uplift was observed around the only available injection well in the area. Due to the dense vegetation coverage of the geothermal areas in West Java, the longer wavelength ALOS PALSAR data is provides better results by identifying a larger number of PS points. Additionally, experiments have been carried out to compare the resulting deformation with another example of the fluid migration process i.e. water extraction in Bandung basin. The potential of sentinel-1A and ALOS PALSR data are compared in all the experiments.

  1. Preliminary results of continuous GPS monitoring of surface deformation at the Aquistore underground CO2 storage site

    Science.gov (United States)

    Craymer, M. R.; Henton, J. A.; Piraszewski, M.; Silliker, J.; Samsonov, S. V.

    2013-12-01

    Aquistore is a demonstration project for the underground storage of CO2 at a depth of ~3350 m near Estevan, Saskatchewan, Canada. An objective of the project is to design, adapt, and test non-seismic monitoring methods that have not been systematically utilized to date for monitoring CO2 storage projects, and to integrate the data from these various monitoring tools to obtain quantitative estimates of the change in subsurface fluid distributions, pressure changes and associated surface deformation. Monitoring methods being applied include satellite-, surface- and wellbore-based monitoring systems and comprise natural- and controlled-source electromagnetic methods, gravity monitoring, GPS, synthetic aperture radar interferometry (InSAR), tiltmeter array analysis, and chemical tracer studies. Here we focus on the GPS monitoring of surface deformation. Five of the planned thirteen GPS monitoring stations were installed in November 2012 and results subsequently processed on a weekly basis. The first GPS results prior to CO2 injection have just been determined using both precise point positioning (PPP) and baseline processing with the Bernese GPS Software. The time series of the five sites are examined, compared and analysed with respect to monument stability, seasonal signals and estimates of expected regional ground motion. The individual weekly network solutions are combined together in a cumulative 4D network solution to provide a preliminary local velocity field in the immediately vicinity of the injection well. The results are compared to those from InSAR.

  2. The fundamental relationships between grain orientation, deformation-induced surface roughness and strain localization in an aluminum alloy

    International Nuclear Information System (INIS)

    Stoudt, M.R.; Levine, L.E.; Creuziger, A.; Hubbard, J.B.

    2011-01-01

    Highlights: ► AA6022 samples are characterized in situ during tensile deformation. ► Scanning laser confocal images and electron backscatter diffraction results are overlaid. ► Strain localization is correlated with Taylor factors, grain orientations, and grain sizes. - Abstract: Polycrystalline AA6022 tensile specimens were cut from sheet stock, mechanically polished, and uniaxially strained in situ under a scanning laser confocal microscope (SLCM) using a sub-sized universal testing apparatus. Prior to deformation, electron backscatter diffraction (EBSD) was performed on the gauge sections of one specimen in the rolling direction of the sheet and one in the transverse direction. Maps of the largest displacements in the surface morphology were constructed from the SLCM data and overlaid onto maps derived from the crystallographic orientation data to examine the strength of the influence that grain orientation effects have on critical strain localization. The roles of Taylor factors, grain boundary misorientation, largest Schmid factors, grain sizes, coincident site lattice orientations, and local grain breakup were considered. The largest surface displacements were observed to be concentrated at triple junctions where there is a large difference between the Taylor factors of the individual grains. The high degree of correlation between the density and location of these large surface displacements and the local plasticity conditions indicate that a critical localization event is most likely to initiate in grain boundary regions where unfavorable slip interactions produce the largest plastic strains.

  3. Effects of size reduction on deformation, microstructure, and surface roughness of micro components for micro metal injection molding

    Science.gov (United States)

    Liu, Lin; Wang, Xin-da; Li, Xiang; Qi, Xiao-tong; Qu, Xuan-hui

    2017-09-01

    The fabrication of 17-4PH micro spool mandrils by micro metal injection molding was described here. The effects of size reduction on deformation, microstructure and surface roughness were studied by comparing a ϕ500 μm micro post and a ϕ1.7 mm cylinder after debinding and sintering. Experimental results show that slumping of the micro posts occurred due to a dramatic increase in outlet vapor pressure initiated at the thermal degradation onset temperature and the moment of gravity. Asymmetrical stress distribution within the micro component formed during the cooling stage may cause warping. Prior solvent debinding and adjustment in a thermal debinding scheme were useful for preventing the deformation of the micro components. Smaller grain size and higher micro hardness due to impeded grain growth were observed for the micro posts compared with the ϕ1.7 mm cylinder. Surface roughness increased with distance from the gate of the micro spool mandril due to melt front advancement during mold filling and the ensuing pressure distribution. At each position, surface roughness was dictated by injection molding and increased slightly after sintering.

  4. Long-term geodetic measurements of large scale deformation at Iwo-jima caldera, Japan

    Science.gov (United States)

    Ukawa, M.; Fujita, E.; Ueda, H.; Kumagai, T.; Nakajima, H.; Morita, H.

    2006-02-01

    Iwo-jima is a volcanic caldera located 1250 km south of Tokyo, and is part of the Izu-Ogasawara arc. An extremely high uplift rate (averaging 0.25 m/a over several hundred years) characterizes the volcanic activity of Iwo-jima. This deformation is believed to be due to post caldera uplift. To investigate the mechanisms contributing to the high uplift rate, we have repeatedly conducted leveling and trilateration surveys from 1976 to 1995, and GPS surveys from 1996 to 2002. These observations have detected two patterns of continuous crustal deformation: concentric subsidence around Motoyama at the center of the Iwo-jima caldera and uplift surrounding the subsiding area. During the period from 1977 to 1995, subsidence at Motoyama reached 0.54 m and uplift in the southwestern part of the island exceeded 3 m. In addition, the island has experienced broad, episodic uplift, which amounted to more than 1 m during volcanic unrest both in 1982 and 2001. Horizontal displacements around Motoyama exhibit contraction due to the concentric subsidence, indicating the presence of a deflating source at depth. Vertical deformation dominates the displacement field during periods of broad episodic uplift, suggesting a deeper and/or more extensive source. Focusing the Motoyama area, we modeled the subsidence source simultaneously with the broad episodic uplift, which is approximated by deformation with a planar gradient, for 14 times between 1976 and 2002, using a grid search combined with a least-squares method. By assuming the subsidence source could be located at any grid point, we applied the least-squares method to calculate the intensity of subsidence source and the parameters for the uplift with a planar gradient and then selected the best-fitting source location. The best-fitting subsidence source geometries for 1998-2000 and 2000-2002 (the two time periods with GPS results) are horizontal, squared-shaped sills with side lengths of 4 and 5 km, respectively. Adopting the

  5. Simultaneous Boundary-Layer Transition, Tip Vortex, and Blade Deformation Measurements of a Rotor in Hover

    Science.gov (United States)

    Heineck, James; Schairer, Edward; Ramasamy, Manikandan; Roozeboom, Nettie

    2016-01-01

    This paper describes simultaneous optical measurements of a sub-scale helicopter rotor in the U.S. Army Hover Chamber at NASA Ames Research Center. The measurements included thermal imaging of the rotor blades to detect boundary layer transition; retro-reflective background-oriented schlieren (RBOS) to visualize vortices; and stereo photogrammetry to measure displacements of the rotor blades, to compute spatial coordinates of the vortices from the RBOS data, and to map the thermal imaging data to a three-dimensional surface grid. The test also included an exploratory effort to measure flow near the rotor tip by tomographic particle image velocimetry (tomo PIV)an effort that yielded valuable experience but little data. The thermal imaging was accomplished using an image-derotation method that allowed long integration times without image blur. By mapping the thermal image data to a surface grid it was possible to accurately locate transition in spatial coordinates along the length of the rotor blade.

  6. Automatic centroid detection and surface measurement with a digital Shack–Hartmann wavefront sensor

    International Nuclear Information System (INIS)

    Yin, Xiaoming; Zhao, Liping; Li, Xiang; Fang, Zhongping

    2010-01-01

    With the breakthrough of manufacturing technologies, the measurement of surface profiles is becoming a big issue. A Shack–Hartmann wavefront sensor (SHWS) provides a promising technology for non-contact surface measurement with a number of advantages over interferometry. The SHWS splits the incident wavefront into many subsections and transfers the distorted wavefront detection into the centroid measurement. So the accuracy of the centroid measurement determines the accuracy of the SHWS. In this paper, we have presented a new centroid measurement algorithm based on an adaptive thresholding and dynamic windowing method by utilizing image-processing techniques. Based on this centroid detection method, we have developed a digital SHWS system which can automatically detect centroids of focal spots, reconstruct the wavefront and measure the 3D profile of the surface. The system has been tested with various simulated and real surfaces such as flat surfaces, spherical and aspherical surfaces as well as deformable surfaces. The experimental results demonstrate that the system has good accuracy, repeatability and immunity to optical misalignment. The system is also suitable for on-line applications of surface measurement

  7. Sea Surface Temperatures (SST): Significance and Measurement

    Science.gov (United States)

    Singer, S. F.

    2006-05-01

    Oceans cover 71 percent of Earth's surface and control the global climate. Quoted global mean temperature values and trends, largely based on land thermometers, differ substantially -" mainly because of uncertainties about SST. The ongoing controversy about the relative importance of natural climate changes and Anthropogenic Global Warming (AGW) revolves mainly around disparities between temperature trends of the atmosphere and surface (in the tropics and SH, i.e. mostly SST). Accurate measurement of SST is difficult. Geographic coverage is poor and there are many different techniques, each with its own problems and uncertainties: Water temperatures from buckets and ship-engine inlets; fixed and floating buoys; air temperatures from shipboard and island stations; and remote sensing from satellites using IR and microwaves. As is evident, each technique refers to a different level below the air-water interface. Drifter buoys (at around 50 cm) measure temperatures in the euphotic layers that are generally warmer than the bulk mixed layer sampled by ships (typically around 10 m). The IR emission arises from a 10-micron-thick skin that interacts dynamically with the underlying "mixed layer." The microwave data depend also on emissivity and therefore on surface roughness and sea state. SST data derived from corals provide some support for instrumental data but are not conclusive. The majority of corals show a warming trend since 1979; others show cooling or are ambiguous. There are different ways of interpreting this result. Physical optics dictates that the downwelling IR radiation from atmospheric greenhouse gases is absorbed in the first instance within the skin. Only direct measurements can establish how much of this energy is shared with the bulk mixed layer (to which the usual SST values refer.). SST controls evaporation and therefore global precipitation. SST influences tropical cyclones and sea-level rise; but there is lively debate on those issues. Changes in

  8. Quadrotor helicopter for surface hydrological measurements

    Science.gov (United States)

    Pagano, C.; Tauro, F.; Porfiri, M.; Grimaldi, S.

    2013-12-01

    Surface hydrological measurements are typically performed through user-assisted and intrusive field methodologies which can be inadequate to monitor remote and extended areas. In this poster, we present the design and development of a quadrotor helicopter equipped with digital acquisition system and image calibration units for surface flow measurements. This custom-built aerial vehicle is engineered to be lightweight, low-cost, highly customizable, and stable to guarantee optimal image quality. Quadricopter stability guarantees minimal vibrations during image acquisition and, therefore, improved accuracy in flow velocity estimation through large scale particle image velocimetry algorithms or particle tracking procedures. Stability during the vehicle pitching and rolling is achieved by adopting large arm span and high-wing configurations. Further, the vehicle framework is composed of lightweight aluminum and durable carbon fiber for optimal resilience. The open source Ardupilot microcontroller is used for remote control of the quadricopter. The microcontroller includes an inertial measurement unit (IMU) equipped with accelerometers and gyroscopes for stable flight through feedback control. The vehicle is powered by a 3 cell (11.1V) 3000 mAh Lithium-polymer battery. Electronic equipment and wiring are hosted into the hollow arms and on several carbon fiber platforms in the waterproof fuselage. Four 35A high-torque motors are supported at the far end of each arm with 10 × 4.7 inch propellers. Energy dissipation during landing is accomplished by four pivoting legs that, through the use of shock absorbers, prevent the impact energy from affecting the frame thus causing significant damage. The data capturing system consists of a GoPro Hero3 camera and in-house built camera gimbal and shock absorber damping device. The camera gimbal, hosted below the vehicle fuselage, is engineered to maintain the orthogonality of the camera axis with respect to the water surface by

  9. Definition of criteria for estimating alternative technologies of increasing quality of rotor shaft neck by electroerosive alloying and surface plastic deformation methods

    Science.gov (United States)

    Martsynkovskyy, V.; Kirik, G.; Tarelnyk, V.; Zharkov, P.; Konoplianchenko, Ie; Dovzhyk, M.

    2017-08-01

    There are represented the results of influence of the surface plastic deformation (SPD) methods, namely, diamond smoothing (DS) and ball-rolling surface roughness generation (BSRG) ones on the qualitative parameters (residual stresses, fatigue strength and wear resistance values) of the steel substrate surface layers formed by the electroerosive alloying (EEA) method. There are proposed the most rational methods of deformation and also the composition for electroerosive coatings providing the presence of the favorable residual compressive stresses in the surface layer, increasing fatigue strength and wear resistance values. There are stated the criteria for estimating the alternative variants of the combined technologies and choosing the most rational ones thereof.

  10. Dynamic measurement of surface strain distribution on the foot during walking.

    Science.gov (United States)

    Ito, Kohta; Maeda, Kosuke; Fujiwara, Ikumi; Hosoda, Koh; Nagura, Takeo; Lee, Taeyong; Ogihara, Naomichi

    2017-05-01

    To clarify the mechanism underlying the development of foot disorders such as diabetic ulcers and deformities, it is important to understand how the foot surface elongates and contracts during gait. Such information is also helpful for improving the prevention and treatment of foot disorders. We therefore measured temporal changes in the strain distribution on the foot surface during human walking. Five adult male participants walked across a glass platform placed over an angled mirror set in a wooden walkway at a self-selected speed and the dorsolateral and plantar surfaces of the foot were filmed using two pairs of synchronized high-speed cameras. Three-dimensional (3D) digital image correlation was used to quantify the spatial strain distribution on the foot surface with respect to that during quiet standing. Using the proposed method, we observed the 3D patterns of foot surface strain distribution during walking. Large strain was generated around the ball on the plantar surface of the foot throughout the entire stance phase, due to the windlass mechanism. The dorsal surface around the cuboid was stretched in the late stance phase, possibly due to lateral protruding movement of the cuboid. It may be possible to use this technique to non-invasively estimate movements of the foot bones under the skin using the surface strain distribution. The proposed technique may be an effective tool with which to analyze foot deformation in the fields of diabetology, clinical orthopedics, and ergonomics. Copyright © 2017. Published by Elsevier Ltd.

  11. Interfacial characterization of soil-embedded optical fiber for ground deformation measurement

    International Nuclear Information System (INIS)

    Zhang, Cheng-Cheng; Zhu, Hong-Hu; Shi, Bin; She, Jun-Kuan

    2014-01-01

    Recently fiber-optic sensing technologies have been applied for performance monitoring of geotechnical structures such as slopes, foundations, and retaining walls. However, the validity of measured data from soil-embedded optical fibers is strongly influenced by the properties of the interface between the sensing fiber and the soil mass. This paper presents a study of the interfacial properties of an optical fiber embedded in soil with an emphasis on the effect of overburden pressure. Laboratory pullout tests were conducted to investigate the load-deformation characteristics of a 0.9 mm tight-buffered optical fiber embedded in soil. Based on a tri-linear interfacial shear stress-displacement relationship, an analytical model was derived to describe the progressive pullout behavior of an optical fiber from soil matrix. A comparison between the experimental and predicted results verified the effectiveness of the proposed pullout model. The test results are further interpreted and discussed. It is found that the interfacial bond between an optical fiber and soil is prominently enhanced under high overburden pressures. The apparent coefficients of friction of the optical fiber/soil interface decrease as the overburden pressure increases, due to the restrained soil dilation around the optical fiber. Furthermore, to facilitate the analysis of strain measurement, three working states of a soil-embedded sensing fiber were defined in terms of two characteristic displacements. (paper)

  12. Status of a UAVSAR designed for repeat pass interferometry for deformation measurements

    Science.gov (United States)

    Hensley, Scott; Wheeler, Kevin; Sadowy, Greg; Miller, Tim; Shaffer, Scott; Muellerschoen, Ron; Jones, Cathleen; Zebker, Howard; Madsen, Soren; Paul, Rose

    2005-01-01

    NASA's Jet Propulsion Laboratory is currently implementing a reconfigurable polarimetric L-band synthetic aperture radar (SAR), specifically designed to acquire airborne repeat track interferometric (RTI) SAR data, also known as differential interferometric measurements. Differential interferometry can provide key deformation measurements, important for the scientific studies of Earthquakes and volcanoes. Using precision real-time GPS and a sensor controlled flight management system, the system will be able to fly predefined paths with great precision. The expected performance of the flight control system will constrain the flight path to be within a 10 m diameter tube about the desired flight track. The radar wilI be designed to operate on a UAV (Unpiloted Aria1 Vehicle) but will initially be demonstrated on a minimally piloted vehicle (MPV), such as the Proteus buitt by Scaled Composites or on a NASA Gulfstream III. The radar design is a fully polarimetric with an 80 MHz bandwidth (2 m range resolution) and 16 km range swath. The antenna is an electronically steered along track to assure that the actual antenna pointing can be controlled independent of the wind direction and speed. Other features supported by the antenna include an elevation monopulse option and a pulse-to-pulse resteering capability that will enable some novel modes of operation. The system will nominally operate at 45,000 ft (13800 m). The program began out as an Instrument Incubator Project (IIP) funded by NASA Earth Science and Technology Office (ESTO).

  13. Onsets of nuclear deformation from measurements with the Isoltrap mass spectrometer; Apparitions de deformation nucleaire a partir de mesures avec le spectrometre de masse isoltrap

    Energy Technology Data Exchange (ETDEWEB)

    Naimi, S.

    2010-10-15

    Mass measurements provide important information concerning nuclear structure. This work presents results from the pioneering Penning trap spectrometer Isoltrap at CERN-Isolde. High-precision mass measurements of neutron-rich manganese ({sup 58}-{sup 66}Mn) and krypton isotopes ({sup 96,} {sup 97}Kr) are presented, of which the {sup 66}Mn and {sup 96,} {sup 97}Kr masses are measured for the first time. In particular, the mass of {sup 97}Kr was measured using the preparation trap and required the definition of a new fit function. In the case of the manganese isotopes, the N=40 shell closure is addressed. The two-neutron-separation energies calculated from the new masses show no shell closure at N=40 but give an estimation of the proton-neutron interaction (around 0.5 MeV) responsible for the increase of collectivity and nuclear deformation in this mass region. The new krypton masses show behavior in sharp contrast with heavier neighbors where sudden and intense deformation is present, interpreted as the establishment of a nuclear quantum shape/phase transition critical-point boundary. The new masses confirm findings from nuclear mean-square charge-radius measurements up to N=60 but are at variance with conclusions from recent gamma-ray spectroscopy. Another part of this work was the design of new decay spectroscopy system behind the Isoltrap mass spectrometer. The beam purity achievable with Isoltrap will allow decay studies with {gamma} and {beta} detection coupled to a tape-station. This system has been mounted and commissioned with the radioactive beam {sup 80}Rb. (author)

  14. Measurements of red cell deformability and hydration reflect HbF and HbA2 in blood from patients with sickle cell anemia.

    Science.gov (United States)

    Parrow, Nermi L; Tu, Hongbin; Nichols, James; Violet, Pierre-Christian; Pittman, Corinne A; Fitzhugh, Courtney; Fleming, Robert E; Mohandas, Narla; Tisdale, John F; Levine, Mark

    2017-06-01

    Decreased erythrocyte deformability, as measured by ektacytometry, may be associated with disease severity in sickle cell anemia (SCA). Heterogeneous populations of rigid and deformable cells in SCA blood result in distortions of diffraction pattern measurements that correlate with the concentration of hemoglobin S (HbS) and the percentage of irreversibly sickled cells. We hypothesize that red cell heterogeneity, as well as deformability, will also be influenced by the concentration of alternative hemoglobins such as fetal hemoglobin (HbF) and the adult variant, HbA 2 . To test this hypothesis, we investigate the relationship between diffraction pattern distortion, osmotic gradient ektacytometry parameters, and the hemoglobin composition of SCA blood. We observe a correlation between the extent of diffraction pattern distortions and percentage of HbF and HbA 2 . Osmotic gradient ektacytometry data indicate that minimum elongation in the hypotonic region is positively correlated with HbF, as is the osmolality at which it occurs. The osmolality at both minimum and maximum elongation is inversely correlated with HbS and HbA 2 . These data suggest that HbF may effectively improve surface-to-volume ratio and osmotic fragility in SCA erythrocytes. HbA 2 may be relatively ineffective in improving these characteristics or cellular hydration at the levels found in this patient cohort. Copyright © 2017. Published by Elsevier Inc.

  15. In Situ Tensile Deformation and Residual Stress Measurement by Neutron Diffraction in Modified 9Cr-1Mo Steel

    Science.gov (United States)

    Shrestha, Triratna; Charit, Indrajit; Potirniche, Gabriel

    2015-12-01

    The deformation behavior of monolithic modified 9Cr-1Mo (Grade 91) steel during uniaxial tensile loading was studied using the in situ neutron diffraction technique. The residual stress distribution across gas tungsten arc welds in the Grade 91 steel was measured by the time-of-flight neutron diffraction method using the SMARTS diffractometer at Lujan Neutron Scattering Center, Los Alamos National Laboratory. Grade 91 plates were welded using the gas tungsten arc welding (GTAW) technique. The load sharing by different grain orientations was observed during the tensile loading. The residual stresses along three orthogonal directions were determined at the mid-thickness, 4.35 and 2.35 mm below the surface of both the as-welded and post-weld heat-treated plates. The residual stresses of the as-welded plates were compared with those of the post-weld heat-treated plates. The post-weld heat treatment significantly reduced the residual stress level in the base metal, the heat-affected zone, and the weld zone. Vickers microhardness across the weld zone of the as-welded and post-weld heat-treated specimens was evaluated and correlated with the observed residual stress profile and microstructure.

  16. Composition, Alteration, and Texture of Fault-Related Rocks from Safod Core and Surface Outcrop Analogs: Evidence for Deformation Processes and Fluid-Rock Interactions

    Science.gov (United States)

    Bradbury, Kelly K.; Davis, Colter R.; Shervais, John W.; Janecke, Susanne U.; Evans, James P.

    2015-05-01

    We examine the fine-scale variations in mineralogical composition, geochemical alteration, and texture of the fault-related rocks from the Phase 3 whole-rock core sampled between 3,187.4 and 3,301.4 m measured depth within the San Andreas Fault Observatory at Depth (SAFOD) borehole near Parkfield, California. This work provides insight into the physical and chemical properties, structural architecture, and fluid-rock interactions associated with the actively deforming traces of the San Andreas Fault zone at depth. Exhumed outcrops within the SAF system comprised of serpentinite-bearing protolith are examined for comparison at San Simeon, Goat Rock State Park, and Nelson Creek, California. In the Phase 3 SAFOD drillcore samples, the fault-related rocks consist of multiple juxtaposed lenses of sheared, foliated siltstone and shale with block-in-matrix fabric, black cataclasite to ultracataclasite, and sheared serpentinite-bearing, finely foliated fault gouge. Meters-wide zones of sheared rock and fault gouge correlate to the sites of active borehole casing deformation and are characterized by scaly clay fabric with multiple discrete slip surfaces or anastomosing shear zones that surround conglobulated or rounded clasts of compacted clay and/or serpentinite. The fine gouge matrix is composed of Mg-rich clays and serpentine minerals (saponite ± palygorskite, and lizardite ± chrysotile). Whole-rock geochemistry data show increases in Fe-, Mg-, Ni-, and Cr-oxides and hydroxides, Fe-sulfides, and C-rich material, with a total organic content of >1 % locally in the fault-related rocks. The faults sampled in the field are composed of meters-thick zones of cohesive to non-cohesive, serpentinite-bearing foliated clay gouge and black fine-grained fault rock derived from sheared Franciscan Formation or serpentinized Coast Range Ophiolite. X-ray diffraction of outcrop samples shows that the foliated clay gouge is composed primarily of saponite and serpentinite, with localized

  17. Myocardial Deformation Measured by 3-Dimensional Speckle Tracking in Children and Adolescents With Systemic Arterial Hypertension.

    Science.gov (United States)

    Navarini, Susanne; Bellsham-Revell, Hannah; Chubb, Henry; Gu, Haotian; Sinha, Manish D; Simpson, John M

    2017-12-01

    Systemic arterial hypertension predisposes children to cardiovascular risk in childhood and adult life. Despite extensive study of left ventricular (LV) hypertrophy, detailed 3-dimensional strain analysis of cardiac function in hypertensive children has not been reported. The aim of this study was to evaluate LV mechanics (strain, twist, and torsion) in young patients with hypertension compared with a healthy control group and assess factors associated with functional measurements. Sixty-three patients (26 hypertension and 37 normotensive) were enrolled (mean age, 14.3 and 11.4 years; 54% men and 41% men, respectively). All children underwent clinical evaluation and echocardiographic examination, including 3-dimensional strain. There was no difference in LV volumes and ejection fraction between the groups. Myocardial deformation was significantly reduced in those with hypertension compared with controls. For hypertensive and normotensive groups, respectively, global longitudinal strain was -15.1±2.3 versus -18.5±1.9 ( P hypertensive and normotensive children, but children with hypertension had significantly lower strain indices. Whether reduced strain might predict future cardiovascular risk merits further longitudinal study. © 2017 American Heart Association, Inc.

  18. Real-time detection of antibiotic activity by measuring nanometer-scale bacterial deformation

    Science.gov (United States)

    Iriya, Rafael; Syal, Karan; Jing, Wenwen; Mo, Manni; Yu, Hui; Haydel, Shelley E.; Wang, Shaopeng; Tao, Nongjian

    2017-12-01

    Diagnosing antibiotic-resistant bacteria currently requires sensitive detection of phenotypic changes associated with antibiotic action on bacteria. Here, we present an optical imaging-based approach to quantify bacterial membrane deformation as a phenotypic feature in real-time with a nanometer scale (˜9 nm) detection limit. Using this approach, we found two types of antibiotic-induced membrane deformations in different bacterial strains: polymyxin B induced relatively uniform spatial deformation of Escherichia coli O157:H7 cells leading to change in cellular volume and ampicillin-induced localized spatial deformation leading to the formation of bulges or protrusions on uropathogenic E. coli CFT073 cells. We anticipate that the approach will contribute to understanding of antibiotic phenotypic effects on bacteria with a potential for applications in rapid antibiotic susceptibility testing.

  19. Crustal deformation pattern of the Morocco-Iberian area: constraints from 14 years of GPS measurements

    Science.gov (United States)

    Palano, Mimmo; González, Pablo; Fernandez, Josè

    2014-05-01

    We present an improved rendition of crustal motion field of the Morocco-Iberian area, based on an extensive GPS dataset covering about 14 years of observations from 1999.00 up to 2013.79 in order to provide a detailed spatial resolution of geodetic velocity and strain-rate fields. In particular, we included all available data from public continuous GPS stations, considering also data coming from networks developed mainly for mapping, engineering and cadastre purposes. In addition to continuous GPS sites, we included data from 31 episodic GPS sites located in Morocco with surveys spanning the 1999-2006 time interval, whose data are available through the UNAVCO archive (www.unavco.org). All GPS data were processed by using the GAMIT/GLOBK software, taking into account precise ephemerides from the IGS (International GNSS Service; http://igscb.jpl.nasa.gov) and Earth orientation parameters from the International Earth Rotation Service (http://www.iers.org). To improve the overall configuration of the network and tie the regional measurements to an external global reference frame, data coming from more than 25 continuously operating global tracking stations, largely from the IGS and EUREF permanent networks, were introduced in the processing. All stations were organized (and processed) into seven sub-networks of about 40-50 sites each, on average, sharing a few common sites to provide ties between them. Finally, by using the GLORG module of GLOBK, the GAMIT-solutions and their full covariance matrices were combined to estimated a consistent set of positions and velocities in the ITRF2008 reference frame by minimizing the horizontal velocity of the continuously operating global tracking stations mentioned above. To adequately investigate the crustal deformation pattern over the study area, we aligned our estimated GPS velocities to an Eurasian and a Nubian fixed reference frames. In addition, by taking into account the observed GPS horizontal velocity field and

  20. Kinematic analyses of a cross-slot microchannel applicable to cell deformability measurement under inertial or viscoelastic flow

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ju Min [Ajou University, Suwon (Korea, Republic of)

    2015-12-15

    A cross-slot microchannel has been harnessed for a wide range of applications, such as label-free measurements of cell deformability and rheological characterization of complex fluids. This work investigates flow kinematics in a cross-slot microchannel used for the measurements of cell deformability utilizing finite element method (FEM)- based numerical simulation. In a cross-slot microchannel, the cell is stretched near the stagnation of the cross-slot channel, and cell deformation is significantly affected by its trajectory. Two passive methods, inertia- and viscoelasticitybased, which do not rely on any external force such as an electric field, have been applied to focus particles along the channel centerline so that the cell trajectories are unified. However, it is not well understood how the flow kinematics inside the cross-slot channel is altered by the inertial or viscoelastic effect when these two methods are employed. This work demonstrates that the flow kinematics such as the distributions of flow type and strain rate is notably changed with an increase in the Reynolds number when an inertia-based method is employed. On the other hand, flow kinematics does not significantly deviate from that of an inertia-less Newtonian fluid irrespective of the Weissenberg numbers when a viscoelasticity-based method is used. The current work will be helpful for the design and operation of a cross-slot microdevice for measuring cell deformability.

  1. Evolution of surface-based deformable image registration for adaptive radiotherapy of non-small cell lung cancer (NSCLC

    Directory of Open Access Journals (Sweden)

    Richter Anne

    2009-12-01

    Full Text Available Abstract Background To evaluate the performance of surface-based deformable image registration (DR for adaptive radiotherapy of non-small cell lung cancer (NSCLC. Methods Based on 13 patients with locally advanced NSCLC, CT images acquired at treatment planning, midway and the end of the radio- (n = 1 or radiochemotherapy (n = 12 course were used for evaluation of DR. All CT images were manually [gross tumor volume (GTV] and automatically [organs-at-risk (OAR lung, spinal cord, vertebral spine, trachea, aorta, outline] segmented. Contours were transformed into 3D meshes using the Pinnacle treatment planning system and corresponding mesh points defined control points for DR with interpolation within the structures. Using these deformation maps, follow-up CT images were transformed into the planning images and compared with the original planning CT images. Results A progressive tumor shrinkage was observed with median GTV volumes of 170 cm3 (range 42 cm3 - 353 cm3, 124 cm3 (19 cm3 - 325 cm3 and 100 cm3 (10 cm3 - 270 cm3 at treatment planning, mid-way and at the end of treatment. Without DR, correlation coefficients (CC were 0.76 ± 0.11 and 0.74 ± 0.10 for comparison of the planning CT and the CT images acquired mid-way and at the end of treatment, respectively; DR significantly improved the CC to 0.88 ± 0.03 and 0.86 ± 0.05 (p = 0.001, respectively. With manual landmark registration as reference, DR reduced uncertainties on the GTV surface from 11.8 mm ± 5.1 mm to 2.9 mm ± 1.2 mm. Regarding the carina and intrapulmonary vessel bifurcations, DR reduced uncertainties by about 40% with residual errors of 4 mm to 6 mm on average. Severe deformation artefacts were observed in patients with resolving atelectasis and pleural effusion, in one patient, where the tumor was located around large bronchi and separate segmentation of the GTV and OARs was not possible, and in one patient, where no clear shrinkage but more a decay of the tumor was observed

  2. Surface deformation time-series analysis at Ischia Island (South Italy) carried out via multi-platform monitoring systems

    Science.gov (United States)

    Manzo, Mariarosaria; Del Gaudio, Carlo; De Martino, Prospero; Ricco, Ciro; Tammaro, Umberto; Castaldo, Raffaele; Tizzani, Pietro; Lanari, Riccardo

    2014-05-01

    Ischia Island, located at the North-Western corner of the Gulf of Napoli (South Italy), is a volcanic area, whose state of activity is testified from eruptions (the last one occurred in 1302), earthquakes (the most disastrous in 1881 and 1883), hydrothermal manifestations and ground deformation. In this work we present the state of the art of the Ischia Island ground deformation phenomena through the joint analysis of data collected via different monitoring methodologies (leveling, GPS, and Differential SAR Interferometry) during the last twenty years. In particular, our analysis benefits from the large amount of periodic and continuous geodetic measurements collected by the 257 leveling benchmarks and the 20 (17 campaign and 3 permanent) GPS stations deployed on the island. Moreover, it takes advantage from the large archives of C-band SAR data (about 300 ascending and descending ERS-1/2 and ENVISAT images) acquired over the island since 1992 and the development of the advanced Differential SAR Interferometry (DInSAR) technique referred to as Small BAseline Subset (SBAS). The latter, allows providing space-time information on the ground displacements measured along the radar line of sight (LOS), and thanks to the availability of multi-orbit SAR data, permits to discriminate the vertical and east-west components of the detected displacements. Our integrated analysis reveals a complex deformative scenario; in particular, it identifies a spatially extended subsidence pattern, which increases as we move to higher heights, with no evidence of any uplift phenomena. This broad effect involve the Northern, Eastern, Southern and South-Western sectors of the island where we measure velocity values not exceeding -6 mm/year; moreover, we identify a more localized phenomenon affecting the North-Western area in correspondence to the Fango zone, where velocity values up to -10 mm/year are retrieved. In addition, our study shows a migration of the Eastern sector of the island

  3. The effect of time duration in the network and radial method toward the accuracy in measuring the deformation at Muria

    International Nuclear Information System (INIS)

    Ari Nugroho and Hadi Suntoko

    2011-01-01

    The Deformation monitoring activities in the vicinity of Mount Muria are recommended by the IAEA (International Atomic Energy Agency) to be done for 5 years. The purpose of these activities is to determine the rate of the deformation caused by the volcanic activity of Mount Muria, as a basic study in analyzing the volcanic hazard toward the NPP (Nuclear Power Plant). The whole coordinate points measured encompass the district of Jepara, Pati, Demak, and Kudus. In 2010 deformation measurements were periodically conducted for 4 times a year using two geodetic GPS units of Trimble R7 GNSS type through the network method. The measurements were carried out at seven points of interest and at one reference point in March, April, May and December. Each session of the measurements was performed for 2.5 hours. In 2011 the deformation measurements were periodically conducted for 4 times a year by means of the radial method. The measurements were made at eight points of interest and at one reference point in April and May, June and July. Each session of measurements was performed for 10 hours. Based on the results of the measurements by means of the network method in 2010, it was concluded that the range of horizontal and vertical accuracy is between 6-10 mm and 25-46 mm, while the results of the measurements of the radial method in 2011 is 4-7 mm, and 16-28 mm respectively. Furthermore, it provides the evidence that the radial method tends to has better result than the network method if it is applied 4 times longer than the network method, resulting the accuracy below 7 mm and 28 mm for horizontal and vertical respectively. (author)

  4. An automatic rat brain extraction method based on a deformable surface model.

    Science.gov (United States)

    Li, Jiehua; Liu, Xiaofeng; Zhuo, Jiachen; Gullapalli, Rao P; Zara, Jason M

    2013-08-15

    The extraction of the brain from the skull in medical images is a necessary first step before image registration or segmentation. While pre-clinical MR imaging studies on small animals, such as rats, are increasing, fully automatic imaging processing techniques specific to small animal studies remain lacking. In this paper, we present an automatic rat brain extraction method, the Rat Brain Deformable model method (RBD), which adapts the popular human brain extraction tool (BET) through the incorporation of information on the brain geometry and MR image characteristics of the rat brain. The robustness of the method was demonstrated on T2-weighted MR images of 64 rats and compared with other brain extraction methods (BET, PCNN, PCNN-3D). The results demonstrate that RBD reliably extracts the rat brain with high accuracy (>92% volume overlap) and is robust against signal inhomogeneity in the images. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Rotating Rig Development for Droplet Deformation/Breakup and Impact Induced by Aerodynamic Surfaces

    Science.gov (United States)

    Feo, A.; Vargas, M.; Sor, A.

    2012-01-01

    This work presents the development of a Rotating Rig Facility by the Instituto Nacional de Tecnica Aeroespacial (INTA) in cooperation with the NASA Glenn Research Center. The facility is located at the INTA installations near Madrid, Spain. It has been designed to study the deformation, breakup and impact of large droplets induced by aerodynamic bodies. The importance of these physical phenomena is related to the effects of Supercooled Large Droplets in icing clouds on the impinging efficiency of the droplets on the body, that may change should these phenomena not be taken into account. The important variables and the similarity parameters that enter in this problem are presented. The facility's components are described and some possible set-ups are explained. Application examples from past experiments are presented in order to indicate the capabilities of the new facility.

  6. Global positioning system measurements of ground deformation caused by magma intrusion and lava discharge: the 1990 1995 eruption at Unzendake volcano, Kyushu, Japan

    Science.gov (United States)

    Nishi, K.; Ono, H.; Mori, H.

    1999-04-01

    Global positioning system (GPS) measurements made around Unzendake volcano, Kyushu, Japan, since January 1991 have detected ground deformation caused by magma intrusion and lava discharge. In the intermittent phreatic and phreatomagmatic eruption stage, the ground was inflating. After growth of the lava dome and following frequent pyroclastic flows at Unzendake volcano, the ground began deflating. These ground deformations are explained by the inflation and deflation of a Mogi's source model (a point source model) located about 6 km west of the active crater at a depth of 11 km, at an aseismic region. The observed horizontal displacement vectors pointed radially away from the estimated pressure source during inflation and pointed to the pressure source during deflation. The horizontal displacements at the reference GPS station calculated from contraction of the estimated pressure source coincide well with the actual horizontal displacements observed from other GPS baseline systems. These observations validate our estimates for the pressure source. Based on the relation between the deformation volume of the ground surface and the discharged volume of the lava, it is estimated that during the eruption there was magma supply from the deeper portion as well as magma discharge at the crater. Magma is estimated to be supplied to the reservoir at an average rate of 1.1×10 5 m 3/day; magma intrusion began in December 1989 at the latest and continued for 1.9×10 3 days.

  7. Measurement of free-surface of liquid metal lithium jet for IFMIF target

    International Nuclear Information System (INIS)

    Hiroo Kondo; Nobuo Yamaoka; Takuji Kanemura; Seiji Miyamoto; Hiroshi Horiike; Mizuho Ida; Hiroo Nakamura; Izuru Matsushita; Takeo Muroga

    2006-01-01

    This reports an experimental study on flow characteristics of a lithium target flow of International Fusion Materials Irradiation Facility (IFMIF). Surface shapes of the target were tried to measure by pattern projection method that is a three dimensional image measurement method. Irregularity of the surface shape caused by surface wakes was successfully measured by the method. IFMIF liquid lithium target is formed a flat plane jet of 25 mm in depth and 260 mm in width, and flows in a flow velocity range of 10 to 20 m/s. Aim of this study is to develop measurement techniques for monitoring of the target when IFMIF is in operation. The lithium target flow is high speed jet and the temperature high is more than 500 K. Also, light is not transmitted into liquid metal lithium. Therefore, almost of all flow measurement techniques developed for water are not used for lithium flow. In this study, pattern projection method was employed to measure the surface irregularity of the target. In the method, stripe patterns are projected onto the flow surface. The projected patterns are deformed according the surface shape. Three-dimensional surface shape is measured by analyzing the deformed patterns recorded using a CCD camera. The method uses the property that lithium dose not transmit visible lights. The experiments were carried out using a lithium loop at Osaka University. In this facility, lithium plane jet of 10 mm in depth and 70 mm width is obtained in the velocity range of less than 15 m/s using a two contractions nozzle. The pattern projection method was used to measure the amplitude of surface irregularity caused by surface wakes. The surface wakes were generated from small damaged at the nozzle edge caused by erosion, and those were successfully measured by the method. The measurement results showed the amplitude of the surface wakes were approximately equal to a size of damage of a nozzle. The amplitude was decreasing with distance to down stream and with decreasing

  8. First Results of Continuous GPS Monitoring of Surface Deformation at the Aquistore Underground CO2 Storage Site

    Science.gov (United States)

    Craymer, M. R.; Ferland, R.; Piraszewski, M.; Samsonov, S. V.; Czarnogorska, M.

    2014-12-01

    Aquistore is a demonstration project for the underground storage of CO2 at a depth of ~3350 m near Estevan, Saskatchewan, Canada. An objective of the project is to design, adapt, and test non-seismic monitoring methods that have not been systematically utilized to date for monitoring CO2 storage projects, and to integrate the data from these various monitoring tools to obtain quantitative estimates of the change in subsurface fluid distributions, pressure changes and associated surface deformation. Monitoring methods being applied include satellite-, surface- and wellbore-based monitoring systems and comprise natural- and controlled-source electromagnetic methods, gravity monitoring, GPS, synthetic aperture radar interferometry (InSAR), tiltmeter array analysis, and chemical tracer studies. Here we focus on the GPS monitoring of surface deformation. Five GPS monitoring stations were installed in 2012 and another six in 2013, some collocated on top of InSAR retroreflectors. The GPS data from these stations have been processed on a weekly basis in both baseline processing mode using the Bernese GPS Software and precise point positioning mode using CSRS-PPP. Here we present the first complete results with 1-2 years of data at all sites prior to CO2 injection. The time series of these sites are examined, compared and analysed with respect to monument stability, seasonal signals and estimates of expected regional ground motion. The individual weekly network solutions have also been combined together in a cumulative 4D network solution to provide a preliminary local velocity field in the immediately vicinity of the injection well. These results are also compared to those obtained independently from InSAR, in particular the direct comparison of GPS and InSAR at the retroreflectors.

  9. Documenting feedbacks between surface processes and structural deformation in East Timor using stream profile and drainage network analysis

    Science.gov (United States)

    Tate, G. W.; Willett, S.; McQuarrie, N.; Goren, L.; Fox, M.

    2013-12-01

    While river profile analyses have long been used to evaluate the development of landforms, recent advances in analyzing drainage networks have significantly improved the ability to positively link stream profiles with surface uplift. In one such method, Perron and Royden (2012) define the value chi, an integral quantity based on the steady-state stream power equation which aids in determining the conformity of rivers and drainage basins to steady-state behavior. East Timor is an ideal location to test new methods using chi, as it is an active and unglaciated orogen with independent constraints of the deformational history through thermochronology and structural geology. We utilize the calculation of chi in our analyses of the drainage network to provide new constraints on the most recent uplift history of the island of Timor. Discontinuities in chi across drainage divides imply different steady state baselevel for hillslopes and therefore active migration of the divide. We confirm this by noting visible landslides in satellite images and asymmetries in hillslope steepness. Analyses of chi and elevation reveal in some locations that tributaries within a single basin have experienced distinctly different histories, documenting instances where previous river capture has occurred. In other locations the relationships between chi and elevation along single rivers denote spatial changes in surface uplift rate. Many of these observations from the drainage network correspond well to patterns of recent exhumation identified from thermochronologic analyses as well as structural constraints from field mapping and balanced cross-sections. Much of the fastest exhumation on the island (as indicated by zircon (U-Th)/He ages of 1.5-3.8 Ma and modeled exhumation rates of 1-3 mm/yr) is in the hinterland slate belt, which also contains the most stream profile remnants of paleo-capture events. Many locations of active river capture correspond well to independently constrained

  10. Post-Eruption Deformation Processes Measured Using ALOS-1 and UAVSAR InSAR at Pacaya Volcano, Guatemala

    Directory of Open Access Journals (Sweden)

    Lauren N. Schaefer

    2016-01-01

    Full Text Available Pacaya volcano is a persistently active basaltic cone complex located in the Central American Volcanic Arc in Guatemala. In May of 2010, violent Volcanic Explosivity Index-3 (VEI-3 eruptions caused significant topographic changes to the edifice, including a linear collapse feature 600 m long originating from the summit, the dispersion of ~20 cm of tephra and ash on the cone, the emplacement of a 5.4 km long lava flow, and ~3 m of co-eruptive movement of the southwest flank. For this study, Interferometric Synthetic Aperture Radar (InSAR images (interferograms processed from both spaceborne Advanced Land Observing Satellite-1 (ALOS-1 and aerial Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR data acquired between 31 May 2010 and 10 April 2014 were used to measure post-eruptive deformation events. Interferograms suggest three distinct deformation processes after the May 2010 eruptions, including: (1 subsidence of the area involved in the co-eruptive slope movement; (2 localized deformation near the summit; and (3 emplacement and subsequent subsidence of about a 5.4 km lava flow. The detection of several different geophysical signals emphasizes the utility of measuring volcanic deformation using remote sensing techniques with broad spatial coverage. Additionally, the high spatial resolution of UAVSAR has proven to be an excellent compliment to satellite data, particularly for constraining motion components. Measuring the rapid initiation and cessation of flank instability, followed by stabilization and subsequent influence on eruptive features, provides a rare glimpse into volcanic slope stability processes. Observing these and other deformation events contributes both to hazard assessment at Pacaya and to the study of the stability of stratovolcanoes.

  11. Creating flat-top X-ray beams by applying surface profiles of alternating curvature to deformable piezo bimorph mirrors.

    Science.gov (United States)

    Sutter, John P; Alcock, Simon G; Kashyap, Yogesh; Nistea, Ioana; Wang, Hongchang; Sawhney, Kawal

    2016-11-01

    Beam shaping is becoming increasingly important for synchrotron X-ray applications. Although routine for visible light lasers, this is challenging for X-rays due to the limited source coherence and extreme optical tolerances required for the shaping mirrors. In deliberate defocusing, even surface errors mirrors of fixed curvature. Such optics are useful for providing a fixed size of X-ray beam, but do not provide the adaptability required by many experiments. In contrast, deformable piezo bimorph mirrors permit a continuous range of X-ray beam sizes and shapes. A new theory is developed for applying non-periodic modifications of alternating curvature to optical surfaces. The position and length of the segments may be freely chosen. For the first time, surface modifications of alternating curvature are applied to bimorph mirrors to generate non-Gaussian X-ray beam profiles of specified width. The new theory's freedom is exploited to choose the segments to match the polishing errors of medium wavelength (>10 mm) and the piezos' influence on the mirror's figure. Five- and seven-segment modifications of alternating curvature are calculated and verified by visible light and X-ray metrology. The latter yields beam profiles with less striation than those made by defocusing. Remaining beam striations are explained by applying geometrical optics to the deviations from the ideal surface modifications of alternating curvature.

  12. Surface chemical treatment of ultrafine-grained Ti–6Al–7Nb alloy processed by severe plastic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, D.P., E-mail: dpedreira@ufscar.br [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, km 235, São Carlos 13565-905, SP (Brazil); Prokofiev, E. [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, km 235, São Carlos 13565-905, SP (Brazil); Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, 12 K. Marx Str., Ufa 450000 (Russian Federation); Sanches, L.F.R. [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, km 235, São Carlos 13565-905, SP (Brazil); Polyakova, V. [Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, 12 K. Marx Str., Ufa 450000 (Russian Federation); Valiev, R.Z., E-mail: rzvaliev@mail.rb.ru [Institute of Physics of Advanced Materials, Ufa State Aviation Technical University, 12 K. Marx Str., Ufa 450000 (Russian Federation); Botta, W.J.; Junior, A.M.J.; Bolfarini, C. [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, km 235, São Carlos 13565-905, SP (Brazil)

    2015-09-15

    Highlights: • Ultrafine-grained titanium alloys is a good choice for biomedical applications. • Acid phosphoric treatment enhances bioactivity of Ti–6Al–7Nb alloy. • Apatite precipitation was increased in ultrafine-grained after surface modification. - Abstract: Ti–6Al–7Nb containing harmless for tissues niobium can be a good choice replacing Ti–6Al–4V for orthopedic implants application. Formation of ultrafine-grained (UFG) structure in metals and alloys by severe plastic deformation (SPD) techniques allows for achieving unique mechanical properties. Using equal channel angular pressing (ECAP) UFG structure in Ti–6Al–7Nb alloy with an average size of grains/subgrains of 200 nm was obtained. This UFG Ti–6Al–7Nb alloy has high mechanical (ultimate tensile strength 1470 MPa) and fatigue properties, suitable for practical application. Additionally, surface modifications of titanium alloys aim induce specific responses on osteoblastic cells after implantation. Chemical surface treatments are simple methods to obtain a bioactive for apatite precipitation surface. Phosphoric acid etching combined or not with alkaline treatment presented bioactivity after seven days soaked in simulated body fluid (SBF) solution.

  13. Measurement of the force–displacement response of in vivo human skin under a rich set of deformations

    KAUST Repository

    Flynn, Cormac

    2011-06-01

    The non-linear, anisotropic, and viscoelastic properties of human skin vary according to location on the body, age, and individual. The measurement of skin\\'s mechanical properties is important in several fields including medicine, cosmetics, and forensics. In this study, a novel force-sensitive micro-robot applied a rich set of three-dimensional deformations to the skin surface of different areas of the arms of 20 volunteers. The force-displacement response of each area in different directions was measured. All tested areas exhibited a non-linear, viscoelastic, and anisotropic force-displacement response. There was a wide quantitative variation in the stiffness of the response. For the right anterior forearm, the ratio of the maximum probe reaction force to maximum probe displacement ranged from 0.44Nmm-1 to 1.45Nmm-1. All volunteers exhibited similar qualitative anisotropic characteristics. For the anterior right forearm, the stiffest force-displacement response was when the probe displaced along the longitudinal axis of the forearm. The response of the anterior left forearm was stiffest in a direction 20° to the longitudinal axis of the forearm. The posterior upper arm was stiffest in a direction 90° to the longitudinal axis of the arm. The averaged posterior upper arm response was less stiff than the averaged anterior forearm response. The maximum probe force at 1.3mm probe displacement was 0.69N for the posterior upper arm and 1.1N for the right anterior forearm. The average energy loss during the loading-unloading cycle ranged from 11.9% to 34.2%. This data will be very useful for studying the non-linear, anisotropic, and viscoelastic behaviour of skin and also for generating material parameters for appropriate constitutive models. © 2011 IPEM.

  14. Characteristics of lateral electrical surface stimulation (LESS) and its effect on the degree of spinal deformity in idiopathic scoliosis

    Science.gov (United States)

    Kowalski, Ireneusz M.; Palko, Tadeusz; Pasniczek, Roman; Szarek, Jozef

    2009-01-01

    Clinical studies were carried out in the period of 2003-2006 at the Provincial Children's Rehabilitation Hospital in Ameryka near Olsztyn (Poland). The study involved a group of children and youth exhibiting spinal deformity progression in idiopathic scoliosis (IS) of more than 5° per year according to the Cobb scale. Four hundred and fifty patients between 4 and 15 years of age were divided into three groups (n = 150). Group I and group II received 2-hour and 9-hour lateral electrical surface stimulation (LESS), respectively, whereas group III (control) was treated only with corrective exercises for 30 minutes twice a day. LESS was performed with the use of a battery-operated SCOL-2 stimulator manufactured by Elmech, Warsaw, Poland. The effectiveness of this method was confirmed in the treatment of spinal IS in children and youth, especially when the initial spinal deformity did not exceed 20° according to the Cobb scale. A short-duration electrostimulation (2 hours daily) was found to produce results similar to those obtained after overnight (9 h) electrostimulation. Moreover, the analysis of the Harrington prognostic index F confirms the positive effect of LESS in both groups of patients (2 h and 9 h of LESS).

  15. Deformation and instabilities at a free surface of liquid subject to a local rapid evaporation

    International Nuclear Information System (INIS)

    Marechal, Anne

    1993-01-01

    This research thesis first addresses theoretical aspects related to the study of stationary system (the deformation of the liquid-vapour interface) and to the study of the linear stability of this interface, and more particularly the study of the liquid-vapour interface of a fluid heated by electron bombardment in a vacuum enclosure. The author reports the analysis of Landau and Palmer systems, reports the study of the marginal stability of a simplified SILVA (isotopic separation by laser on atomic vapour) system which allows the identification of destabilizing mechanisms, and the comparison between a liquid system heated from underneath with liquid system heated from above. Results are then validated by experimental results. In the next part, the author sets the equations of a SILVA system closer to reality by addressing vapour in a more realistic way. Results of conventional kinetic theory are studied again by analysing sonic evaporation of a liquid. The author reports a study of the linear stability of this system, and reports an attempt to analyse the obtained results [fr

  16. Measurement and interpretation of subtle deformation signals at Unimak Island from 2003 to 2010 using weather model-assisted time series InSAR

    Science.gov (United States)

    Gong, W.; Meyer, F. J.; Lee, C.-W.; Lu, Z.; Freymueller, J.

    2015-02-01

    A 7 year time series of satellite radar images over Unimak Island, Alaska—site of Westdahl Volcano, Fisher Caldera, and Shishaldin Volcano—was processed using a model-free Persistent Scatterer Interferometry technique assisted by numerical weather prediction model. The deformation-only signals were optimally extracted from atmosphere-contaminated phase records. The reconstructed deformation time series maps are compared with campaign and continuous Global Positioning System (GPS) measurements as well as Small Baseline Subset interferometric synthetic aperture radar (InSAR) results for quality assessment and geophysical interpretation. We observed subtle surface inflation at Westdahl Volcano that can be fit by a Mogi source located at approximately 3.6 km north of Westdahl peak and at depth of about 6.9 km that is consistent with the GPS-estimated depth for the 1998 to 2001 time period. The magma chamber volume change decays during the period of 2003 to 2010. The deformation field over Fisher Caldera is steadily subsiding over time. Its best fit analytical model is a sill source that is about 7.9 km in length, 0.54 km in width, and located at about 5.5 km below sea level underneath the center of Fisher Caldera with strike angle of N52°E. Very little deformation was detected near Shishaldin peak; however, a region approximately 15 km east of Shishaldin, as well as an area at the Tugamak range at about 30 km northwest of Shishaldin, shows evidence for movement toward the satellite, with a temporal signature correlated with the 2004 Shishaldin eruption. The cause of these movements is unknown.

  17. Strain-induced phase transformation at the surface of an AISI-304 stainless steel irradiated to 4.4 dpa and deformed to 0.8% strain

    Science.gov (United States)

    Gussev, M. N.; Field, K. G.; Busby, J. T.

    2014-03-01

    Surface relief due to localized deformation in a 4.4-dpa neutron-irradiated AISI 304 stainless steel was investigated using scanning electron microscopy coupled with electron backscattering diffraction and scanning transmission electron microscopy. It was found a body-centered-cubic (BCC) phase (deformation-induced martensite) had formed at the surface of the deformed specimen along the steps generated from dislocation channels. Martensitic hill-like formations with widths of ˜1 μm and depths of several microns were observed at channels with heights greater than ˜150 nm above the original surface. Martensite at dislocation channels was observed in grains along the [0 0 1]-[1 1 1] orientation but not in those along the [1 0 1] orientation.

  18. PAF: A software tool to estimate free-geometry extended bodies of anomalous pressure from surface deformation data

    Science.gov (United States)

    Camacho, A. G.; Fernández, J.; Cannavò, F.

    2018-02-01

    We present a software package to carry out inversions of surface deformation data (any combination of InSAR, GPS, and terrestrial data, e.g., EDM, levelling) as produced by 3D free-geometry extended bodies with anomalous pressure changes. The anomalous structures are described as an aggregation of elementary cells (whose effects are estimated as coming from point sources) in an elastic half space. The linear inverse problem (considering some simple regularization conditions) is solved by means of an exploratory approach. This software represents the open implementation of a previously published methodology (Camacho et al., 2011). It can be freely used with large data sets (e.g. InSAR data sets) or with data coming from small control networks (e.g. GPS monitoring data), mainly in volcanic areas, to estimate the expected pressure bodies representing magmatic intrusions. Here, the software is applied to some real test cases.

  19. Model Deformation and Optical Angle of Attack Measurement System in the NASA Ames Unitary Plan Wind Tunnel

    Science.gov (United States)

    Kushner, Laura K.; Drain, Bethany A.; Schairer, Edward T.; Heineck, James T.; Bell, James H.

    2017-01-01

    Both AoA and MDM measurements can be made using an optical system that relies on photogrammetry. Optical measurements are being requested by customers in wind tunnels with increasing frequency due to their non-intrusive nature and recent hardware and software advances that allow measurements to become near real time. The NASA Ames Research Center Unitary Plan Wind Tunnel is currently developing a system based on photogrammetry to measure model deformation and model angle of attack. This paper describes the new system, its development, its use on recent tests and plans to further develop the system.

  20. [Measuring microhardness of laser exposed tooth surface].

    Science.gov (United States)

    Florin, R; Herrmann, C; Bernhardt, W

    1990-02-01

    In principle it is possible to homogenize the enamel surface by melting structural elements with the continuous wave CO2 laser. Using the precision instrument NEOPHOT 2 (Carl Zeiss JENA) the microhardness of extracted laserexposed premolares were tested so as to clarify the functional strain capasity and the mechanical characteristics of laserexposed regions of enamel surfaces. The proven higher hardness in the centre of the laserinduced fusing zones (in comparison with adjacent enamel) objectify an attainable refining of the enamel surface that probably causes an increase in the caries-preventive resistance.

  1. Time Series Surface Deformation using Multi-Temporal InSAR Technique at Mount Sinabung Eruption in North Sumatra, Indonesia

    Science.gov (United States)

    Hwang, Eui-Hong; Lee, ChangWook; Jo, Eunyoung; Lee, SeulKi; Kim, KiYeon

    2014-05-01

    Sinabung volcano in Indonesia is a part of the Pacific Ring of Fire, formed due to the subduction between the Eurasian and the Indo-Australian plate. After about 400-year dormancy, Sinabung volcano erupted on August 29, 2010 and January 4, 2014, recently. We study the surface deformation of Sinabung volcano using ALOS/PALSAR and RADARSAT-2 interferometric synthetic aperture radar (InSAR) images acquired from February 2007 to September 2013. Based on multi-temporal InSAR processing, we can generate the ground surface deformation map due to the 2010 eruption. During the 3 years before the 2010 eruption, the volcano inflated at an average rate ~1.7 cm/yr with marked higher rate of 6.6 cm/year during the 6 months prior to the 2010 eruption. The inflation is constrained to the top of the volcano. Since the 2010 eruption to January 2011, the volcano has subsided for about 3 cm (or about 6 cm/yr). The observed inflation and deflation are modeled with a Mogi and Prolate spheroid source. The source of inflation is located about 0.3 - 1.3 km below sea level directly underneath the crater. On the other hand, deflation source is modeled about 0.6-1.0 km with coeruption period. The average volumetric change was about from 1.9x10-6 to -2.7x10-5 km3/yr during the eruption event using ALOS/PALSAR images. Recently, RADARSAT-2 SAR data were applied to new eruption event from September 2013 to January 2014 for frequently eruption during short time period. We interpret the inflation was due to magma accumulation at a shallow reservoir beneath the Sinabung volcano. The deflation was due to the magma withdrawal from the shallow reservoir during the eruption as well as thermo-elastic compaction of erupted material.

  2. Measurement of Slip, Force and Deformation Using Hybrid Tactile Sensor System for Robot Hand Gripping an Object

    Directory of Open Access Journals (Sweden)

    Takuya Kawamura

    2013-01-01

    Full Text Available A hybrid tactile sensor system is proposed for a robot hand to hold and grip an object adaptively as the sensor system measures the slip of an object, the gripping force, and the deformation of its silicon rubber sensor element. A hybrid tactile sensor system consists of a Carbon Micro-Coil (CMC touch sensor and a force sensor. The CMC sensor element is made of silicon rubber containing CMCs several micrometres in diameter. It is considered that the sensor element constitutes an LCR circuit, and the CMC touch sensor, deformed mechanically, produces signals due to the modification of the circuit. In this study, a dome-shaped CMC sensor element similar to the shape of a human fingertip was used. This paper first examines the characteristics of the CMC sensor in terms of slip detection when the sensor system held and released an object. Next, the characteristics of the CMC element are clarified with respect to the compression force and deformation when the CMC element was compressed vertically. Finally, methods using the hybrid tactile sensor system are developed to detect the slip of an object and estimate the magnitude of deformation of the CMC element.

  3. Lifetime measurements of the first 2+ states in 104,106Zr: Evolution of ground-state deformations

    Directory of Open Access Journals (Sweden)

    F. Browne

    2015-11-01

    Full Text Available The first fast-timing measurements from nuclides produced via the in-flight fission mechanism are reported. The lifetimes of the first 2+ states in 104,106Zr nuclei have been measured via β-delayed γ-ray timing of stopped radioactive isotope beams. An improved precision for the lifetime of the 21+ state in 104Zr was obtained, τ(21+=2.90−20+25 ns, as well as a first measurement of the 21+ state in 106Zr, τ(21+=2.60−15+20 ns, with corresponding reduced transition probabilities of B(E2;21+→0g.s.+=0.39(2 e2b2 and 0.31(1 e2b2, respectively. Comparisons of the extracted ground-state deformations, β2=0.39(1 (104Zr and β2=0.36(1 (106Zr with model calculations indicate a persistence of prolate deformation. The data show that 104Zr is the most deformed of the neutron-rich Zr isotopes measured so far.

  4. Effect of machining on the deformability of steel in surface-active medium at lower temperatures

    International Nuclear Information System (INIS)

    Gusti, E.Ya.; Babej, Yu.I.

    1977-01-01

    The effect of some machining methods of carbon steel, chromium steel, and chromium nickel steel, and that of low temperatures on the principle characteristics of formability during impact bending in air and a surface-active environment have been studied. The temperature decrease from the ambient to -80 deg is shown to reduce steel formability as evaluated by deflection (f) and to increase the forming force. The variation of these characteristics with lowering temperature, however, is greatly affected by machining process conditions. The FRHT (Friction-Hardening Treatment) on the white layer assures minimum ductility losses, and increases steel strength at low temperatures both in air and in the surface-active environment

  5. Joint surface reconstruction and 4D deformation estimation from sparse data and prior knowledge for marker-less Respiratory motion tracking.

    Science.gov (United States)

    Berkels, Benjamin; Bauer, Sebastian; Ettl, Svenja; Arold, Oliver; Hornegger, Joachim; Rumpf, Martin

    2013-09-01

    The intraprocedural tracking of respiratory motion has the potential to substantially improve image-guided diagnosis and interventions. The authors have developed a sparse-to-dense registration approach that is capable of recovering the patient's external 3D body surface and estimating a 4D (3D + time) surface motion field from sparse sampling data and patient-specific prior shape knowledge. The system utilizes an emerging marker-less and laser-based active triangulation (AT) sensor that delivers sparse but highly accurate 3D measurements in real-time. These sparse position measurements are registered with a dense reference surface extracted from planning data. Thereby a dense displacement field is recovered, which describes the spatio-temporal 4D deformation of the complete patient body surface, depending on the type and state of respiration. It yields both a reconstruction of the instantaneous patient shape and a high-dimensional respiratory surrogate for respiratory motion tracking. The method is validated on a 4D CT respiration phantom and evaluated on both real data from an AT prototype and synthetic data sampled from dense surface scans acquired with a structured-light scanner. In the experiments, the authors estimated surface motion fields with the proposed algorithm on 256 datasets from 16 subjects and in different respiration states, achieving a mean surface reconstruction accuracy of ± 0.23 mm with respect to ground truth data-down from a mean initial surface mismatch of 5.66 mm. The 95th percentile of the local residual mesh-to-mesh distance after registration did not exceed 1.17 mm for any subject. On average, the total runtime of our proof of concept CPU implementation is 2.3 s per frame, outperforming related work substantially. In external beam radiation therapy, the approach holds potential for patient monitoring during treatment using the reconstructed surface, and for motion-compensated dose delivery using the estimated 4D surface motion field in

  6. Subsurface deformation and the role of surface texture—A study with ...

    Indian Academy of Sciences (India)

    Moore M A, Richardson R C D, Attwood D G 1972 The limiting strength of worn metal surfaces. Metall. Trans. 3: 2485–2491. Petryk H 1987 Slip line field solutions for sliding contact. Proc. Inst. Mech. Eng. Int. Conf., Tribology. Friction, Lubrication and Wear 50 years on, vol II, London pp 987–994. Rice S L, Nowotny H, Wayne ...

  7. Early results of micro-deformation measurements in Magdalena Jama (Slovenia) by a vertical static pendulum

    Czech Academy of Sciences Publication Activity Database

    Kalenda, Pavel; Neumann, L.; Šebela, S.

    2013-01-01

    Roč. 42, č. 1 (2013), s. 143-154 ISSN 0583-6050 Institutional support: RVO:67985891 Keywords : tilt * pendulum * deformations * earthquakes Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.710, year: 2013 http://ojs.zrc-sazu.si/carsologica/article/view/635

  8. Evaluation of material's state during deformation process by means of thermographic measurement

    Czech Academy of Sciences Publication Activity Database

    Žďárský, M.; Valach, Jaroslav; Kytýř, D.

    2012-01-01

    Roč. 17, č. 10 (2012), s. 102-107 ISSN 1435-4934. [Quantitative infrared thermotheraphy /11./. Naples, 11.06.2012-14.06.2012] R&D Projects: GA ČR(CZ) GA103/09/2101 Institutional support: RVO:68378297 Keywords : thermography * ductile crack * plastic deformation Subject RIV: JL - Materials Fatigue, Friction Mechanics www.ndt.net/?id=13389

  9. Nanoscale deformation measurement of microscale interconnection assemblies by a digital image correlation technique

    International Nuclear Information System (INIS)

    Sun Yaofeng; Pang, John H L; Fan Wei

    2007-01-01

    The continuous miniaturization of microelectronic devices and interconnections demand more and more experimental strain/stress analysis of micro- and nanoscale components for material characterization and structure reliability analysis. The digital image correlation (DIC) technique, with the aid of scanning probe microscopes, has become a very promising tool to meet this demand. In this study, an atomic force microscope (AFM) was used to scan and digitally image micro-interconnection assemblies in a micro-thermoelectric cooler. AFM images of the scan region of interest were obtained separately when the microelectronic device was operated before and after the cooling and heating stages. The AFM images were then used to obtain the in-plane deformation fields in the observed region of the micro-assembly. AFM image correlation is performed for nanoscale deformation analysis using the authors' AFM-DIC program. The results show that the observed region was subjected to cyclic strains when the device worked between its cooling and heating stages, and cyclic strain in the vertical direction was found to be a significant deformation mode. The thermally induced deformation behavior of the micro-assembly device was modeled by finite element analysis (FEA). Both thermal-electric analysis and thermal stress analysis were conducted on a 3D finite element model of the device. It is shown that the experimental results were able to validate the finite element analysis results

  10. Surface texturing of crystalline silicon and effective area measurement

    Science.gov (United States)

    Sun, Tietun; Chen, Dong; Chui, Rongqiang

    2000-11-01

    In this paper, the surface area of solar cell is determined by the capacitance measurements of MOS structure. The texture etching technology can be controlled according to the change of silicon surface area, furthermore, the textured silicon surface and interface characteristic of solar cell can be studied by measuring the relationship of capacitance and voltage for MOS structure.

  11. Relation between self-image score of SRS-22 with deformity measures in female adolescent idiopathic scoliosis patients.

    Science.gov (United States)

    Wang, L; Wang, Y P; Yu, B; Zhang, J G; Shen, J X; Qiu, G X; Li, Y

    2014-11-01

    Adolescent idiopathic scoliosis (AIS) is a pathology which affects the individual's functioning in the widely understood physical, psychic, and social aspects. More attention should be paid to patients' perception of self-image when evaluating the spine deformity. The present retrospective study evaluated the associations between the deformity measures and self-image score as determined by the SRS-22 questionnaire in Chinese female AIS patients. The self-image score correlates significantly with deformity measures. The location of main curve apex and the number of curve could affect the self-image score. We retrospectively reviewed the records of 202 female patients, collected data on patient's age, body mass index, radiographic and physical measures and self-image score of SRS-22 questionnaire. According to the location of main curve apex and the number of curve, the patients were divided to different subgroups. Correlations between deformity measures and self-image score of different groups were evaluated by the Spearman correlation test. The self-image score correlated negatively with the main Cobb angle, apical vertebral translation (AVT), and razor hump height. There is no significant difference of self-image score between thoracic curve (TC) and thoracolumbar curve (TL/LC) subgroups. And the self-image scores of one-curve, two-curve and three-curve subgroups are similar. For Chinese female AIS patients in our study, self-image was found to correlate negatively with the main Cobb angle, AVT and razor hump height. And the location of scoliosis apex and the number of curve are not influencing factors of self-image perception. Level IV, retrospective study. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  12. Spatial features of dose-surface maps from deformably-registered plans correlate with late gastrointestinal complications

    Science.gov (United States)

    Moulton, Calyn R.; House, Michael J.; Lye, Victoria; Tang, Colin I.; Krawiec, Michele; Joseph, David J.; Denham, James W.; Ebert, Martin A.

    2017-05-01

    This study investigates the associations between spatial distribution of dose to the rectal surface and observed gastrointestinal toxicities after deformably registering each phase of a combined external beam radiotherapy (EBRT)/high-dose-rate brachytherapy (HDRBT) prostate cancer treatment. The study contains data for 118 patients where the HDRBT CT was deformably-registered to the EBRT CT. The EBRT and registered HDRBT TG43 dose distributions in a reference 2 Gy/fraction were 3D-summed. Rectum dose-surface maps (DSMs) were obtained by virtually unfolding the rectum surface slice-by-slice. Associations with late peak gastrointestinal toxicities were investigated using voxel-wise DSM analysis as well as parameterised spatial patterns. The latter were obtained by thresholding DSMs from 1-80 Gy (increment  =  1) and extracting inferior-superior extent, left-right extent, area, perimeter, compactness, circularity and ellipse fit parameters. Logistic regressions and Mann-Whitney U-tests were used to correlate features with toxicities. Rectal bleeding, stool frequency, diarrhoea and urgency/tenesmus were associated with greater lateral and/or longitudinal spread of the high doses near the anterior rectal surface. Rectal bleeding and stool frequency were also influenced by greater low-intermediate doses to the most inferior 20% of the rectum and greater low-intermediate-high doses to 40-80% of the rectum length respectively. Greater low-intermediate doses to the superior 20% and inferior 20% of the rectum length were associated with anorectal pain and urgency/tenesmus respectively. Diarrhoea, completeness of evacuation and proctitis were also related to greater low doses to the posterior side of the rectum. Spatial features for the intermediate-high dose regions such as area, perimeter, compactness, circularity, ellipse eccentricity and confinement to ellipse fits were strongly associated with toxicities other than anorectal pain. Consequently, toxicity is

  13. Holographic otoscope for nano-displacement measurements of surfaces under dynamic excitation

    Science.gov (United States)

    Flores-Moreno, J. M.; Furlong, Cosme; Rosowski, John J.; Harrington, Ellery; Cheng, Jeffrey T.; Scarpino, C.; Santoyo, F. Mendoza

    2011-01-01

    Summary We describe a novel holographic otoscope system for measuring nano-displacements of objects subjected to dynamic excitation. Such measurements are necessary to quantify the mechanical deformation of surfaces in mechanics, acoustics, electronics, biology and many other fields. In particular, we are interested in measuring the sound-induced motion of biological samples, such as an eardrum. Our holographic otoscope system consists of laser illumination delivery (IS), optical head (OH), and image processing computer (IP) systems. The IS delivers the object beam (OB) and the reference beam (RB) to the OH. The backscattered light coming from the object illuminated by the OB interferes with the RB at the camera sensor plane to be digitally recorded as a hologram. The hologram is processed by the IP using Fresnel numerical reconstruction algorithm, where the focal plane can be selected freely. Our holographic otoscope system is currently deployed in a clinic, and is packaged in a custom design. It is mounted in a mechatronic positioning system to increase its maneuverability degrees to be conveniently positioned in front of the object to be measured. We present representative results highlighting the versatility of our system to measure deformations of complex elastic surfaces in the wavelength scale including a copper foil membrane and postmortem tympanic membrane (TM). PMID:21898459

  14. Phase change in subducted lithosphere, impulse, and quantizing Earth surface deformations

    Science.gov (United States)

    Bowin, C. O.; Yi, W.; Rosson, R. D.; Bolmer, S. T.

    2015-09-01

    conservation of angular momentum. Since mountain building we now know results from changes in momentum, we have calculated an experimental deformation index value (1-1000) based on a world topographic grid at 5 arcmin spacing and displayed those results for viewing.

  15. Vocanic Deformations During Repose Interval Revealed by GPS Measurements, Batur Volcano, Indonesia

    Science.gov (United States)

    Nishimae, K.; Fujii, N.; Kimata, F.; Murase, M.; Suganda, O. K.; Abidin, H. Z.

    2005-12-01

    Batur volcano is located north west of Bali Island in Indonesia.This volcano has two calderas with more than 10 km in diameter. Recent eruptions with lava flow occurred in 1963 and 1974. No effusion of lava has been observed since 1990, although steam explosions occurred August 1994, November 1997 and June 1998.This suggests that magmatic activity of this volcano would keep its high level since 1994.GPS observation network of this volcano has been kept by Institute Technology of Bandung (ITB) and Volcano Survey of Indonesia (VSI).The network was consisted of 10 observation points at the beginning in 1999, and now it becomes 23 observation points. We have made GPS campaign observations about five times from 2003 to 2005. Each campaign observation consisted of a couple of days of measurements for each observation point. In order to keep the quality of data as high as possible, observations have been made at least 12 hours of continuous data for each point. In this report, results of two campaign observations (December 2004 and July 2005) are used for the analysis. The data thus obtained are fitted to the Mogi source (i.e. a point source model) to locate the depth and amount of volume changes for 7 months. Location of the Mogi source was obtained about 4km southeast of the summit of central cone, and 3km depth with deflation volume change of 1.3_~106 m3 for about 7months. For the period from 1999 to 2004, estimated volume change suggests a continuous deflation throughout this period, although the reliability of data was not so high. Continuous deflations might be likely after the last effusive eruption in 1974, would suggest that shallow part of magma beneath the central cone would probably be drained down to further deep, or shrinkage of magma associated with the cooling or solidification. Further data are obviously needed to discriminate the mechanisms of the deformation process during the repose period in this volcano.

  16. High speed machined surface roughness measurement ...

    African Journals Online (AJOL)

    Surface roughness monitoring techniques using non-contact methods based on computer vision technology are becoming popular and cost effective. An evolvable hardware configuration using reconfigurable Xilinx Virtex FPGA xcv1000 architecture with capability to compensate for poor illumination environment is ...

  17. Simultaneous measurement of erythrocyte deformability and blood viscoelasticity using micropillars and co-flowing streams under pulsatile blood flows.

    Science.gov (United States)

    Kang, Yang Jun

    2017-01-01

    The biophysical properties of blood provide useful information on the variation in hematological disorders or diseases. In this study, a simultaneous measurement method of RBC (Red Blood Cell) deformability and blood viscoelasticity is proposed by evaluating hemodynamic variations through micropillars and co-flowing streams under sinusoidal blood flow. A disposable microfluidic device is composed of two inlets and two outlets, two upper side channels, and two lower side channels connected to one bridge channel. First, to measure the RBC deformability, the left-lower side channel has a deformability assessment chamber (DAC) with narrow-sized micropillars. Second, to evaluate the blood viscoelasticity in co-flowing streams, a phosphate buffered saline solution is supplied at a constant flow rate. By closing or opening a pinch valve connected to the outlet of DAC, blood flows in forward or back-and-forth mode. A time-resolved micro-particle image velocimetry technique and a digital image processing technique are used to quantify the blood velocity and image intensity. Then, RBC deformability is evaluated by quantifying the blood volume passing through the DAC under forward flow, and quantifying the variations of blood velocity and image intensity in the DAC under back-and-forth flow. Using a discrete circuit model, blood viscoelasticity is obtained by evaluating variations of blood velocity and co-flowing streams. The effect of several factors (period, hematocrit, and base solution) on the performance is quantitatively evaluated. Based on the experimental results, the period of sinusoidal flow and hematocrit are fixed at 30 s and 50%, respectively. As a performance demonstration, the proposed method is employed to detect the homogeneous and heterogeneous blood composed of normal RBCs and hardened RBCs. These experimental results show that the RBC deformability is more effective to detect minor subpopulations of heterogeneous bloods, compared with blood viscoelasticity

  18. Implications of ground-deformation measurements across earth fissures in subsidence areas in the southwestern USA

    Science.gov (United States)

    Holzer, Thomas L.

    2010-01-01

    Ground deformation was monitored at earth fissures in areas of land subsidence induced by groundwater extraction in the southwestern United States. The ground deformation is consistent with the mechanism that fissures are caused by horizontal strains generated by bending of overburden in response to localized differential compaction. Subsidence profiles indicated that localized differential subsidence occurred across the fissures and that maximum convex-upward curvature was at the fissure. The overall shape of the profile stayed similar with time, and maximum curvature remained stationary at the fissure. Horizontal displacements were largest near the fissure, and generally were small to negligible away from the fissure. Maximum tensile horizontal strains were at the fissure and coincided with maximum curvature in the subsidence profiles. Horizontal tensile strain continued to accumulate at fissures after they formed with rates of opening ranging from 30 to 120 microstrain/year at fissures in Arizona.

  19. Identification of tectonic deformations on the south polar surface of the moon

    Science.gov (United States)

    Mukherjee, Saumitra; Singh, Priyadarshini

    2015-07-01

    Recent extensional and contractional tectonic features present globally over the lunar surface have been studied to infer lunar crustal tectonism. Investigation of indicators of recent crustal tectonics, such as fault lines, thrust fault scarps, and dislocation of debris along the identified fault planes, primarily using data from the miniature-synthetic aperture radar (mini-SAR) aboard CHANDRAYAAN-1 mission and Narrow angle camera (NAC) images, are the focus of this study. Spatial orientation of these tectonic features helps to elucidate the change in the interior geological dynamics of any planetary body with time. The ability of microwave sensors to penetrate the lunar regolith, along with application of m-χ decomposition method on Mini-SAR data has been used to reveal unique features indicative of hidden tectonics. The m-χ decomposition derived radar images expose hidden lineaments and lobate scarps present within shadowed crater floors as well as over the illuminated regions of the lunar surface. The area around and within Cabeus B crater in the South Polar Region contains lobate scarps, hidden lineaments and debris avalanches (associated with the identified lineaments) indicative of relatively recent crustal tectonism.

  20. The prediction of BRDFs from surface profile measurements

    International Nuclear Information System (INIS)

    Church, E.L.; Takacs, P.Z.; Leonard, T.A.

    1989-01-01

    This paper discusses methods of predicting the BRDF of smooth surfaces from profile measurements of their surface finish. The conversion of optical profile data to the BRDF at the same wavelength is essentially independent of scattering models, while the conversion of mechanical measurements, and wavelength scaling in general, are model dependent. Procedures are illustrated for several surfaces, including two from the recent HeNe BRDF round robin, and results are compared with measured data. Reasonable agreement is found except for surfaces which involve significant scattering from isolated surface defects which are poorly sampled in the profile data

  1. Microthermal Instrument for Measuring Surface Layer Seeing

    Science.gov (United States)

    Li, Xue-Bao; Zheng, Yan-Fang; Deng, Lin Hua; Xu, Guang

    2012-02-01

    Microthermal fluctuations are introduced by atmospheric turbulence very near the ground. In order to detect microthermal fluctuations at Fuxian Solar Observatory (FSO), a microthermal instrument has been developed. The microthermal instrument consists of a microthermal sensor, which is based on a Wheatstone bridge circuit and uses fine tungsten filaments as resistance temperature detectors, an associated signal processing unit, and a data collection, & communication subsystem. In this paper, after a brief introduction to surface layer seeing, we discuss the instrumentation behind the microthermal detector we have developed and then present the results obtained. The results of the evaluation indicate that the effect of the turbulent surface boundary layer to astronomical seeing would become sufficiently small when installing a telescope at a height of 16m or higher from the ground at FSO.

  2. Rivited panel surface measurement using photogrammetry

    Science.gov (United States)

    Merrick, W. D.; Lobb, V. B.; Lansing, F. L.; Stoller, F. W.

    1986-01-01

    Two riveted antenna panels on rings number 3 and 9 were removed from the 34m antenna at DSS-15, fixed in the leveled position and the surface was photographed indoors. The results from this pilot photogrammetric demonstration and diagnostics of panel surface contours, are presented. The photogrammetric network for each panel incorporated eight photographs, two from each of four camera stations and observed over 200 targets. The accuracy (1 sigma) of the XYZ coordinates for the error ellipsoids was + or - 0.013 mm (0.0005 inch). This level of precision relative to the object size corresponds roughly to 1 part in 250,000 which is superior to conventional dial sweep-arm template techniques by at least a factor of 4.

  3. Surface Temperature Measurement Using Hematite Coating

    Science.gov (United States)

    Bencic, Timothy J. (Inventor)

    2015-01-01

    Systems and methods that are capable of measuring temperature via spectrophotometry principles are discussed herein. These systems and methods are based on the temperature dependence of the reflection spectrum of hematite. Light reflected from these sensors can be measured to determine a temperature, based on changes in the reflection spectrum discussed herein.

  4. Determination of stamp deformation during imprinting on semi-spherical surfaces

    DEFF Research Database (Denmark)

    Kafka, Jan; Matschuk, Maria; Pranov, Henrik

    of sol-gel was applied onto spherical injection mold inserts and subsequently imprinted using a flexible stamp. A hard curing step transformed the sol-gel into a quartz-like and durable material. As an example, we present theory and results regarding the imprint of pillar nanostructures on semi......-spherical mold surfaces. Imprints were realized on three different radii of circumferenceof the spherical mold: R = 0.5 mm, R = 1.0 mm, and R = 2 mm. After hard-curing of theimprinted sol-gel, the inserts were used for cold-mold as well as vario-therm injection molding.The polymer replicas and the inserts were...

  5. Evaluating links between deformation, topography and surface temperature at volcanic domes: Results from a multi-sensor study at Volcán de Colima, Mexico

    Science.gov (United States)

    Salzer, Jacqueline T.; Milillo, Pietro; Varley, Nick; Perissin, Daniele; Pantaleo, Michele; Walter, Thomas R.

    2017-12-01

    Dome building activity is common at many volcanoes and due to the gravitational instability, a dome represents one of the most hazardous volcanic phenomena. Shallow volcanic processes as well as rheological and structural changes of the dome affecting the fluid transport have been linked to transitions in eruptive activity. Also, hydrothermal alteration may affect the structural integrity of the dome, increasing the potential for collapse. However, mapping the deformation and details of fluid escape at the summit of steep sloped volcanoes and integrating these with other types of data is challenging due to difficult access and poor coverage. Here we present for the first time the near-vertical and near-horizontal surface deformation field of a quiescent summit dome and the relationships with degassing and topographic patterns. Our results are derived from high resolution satellite radar interferometry (InSAR) time series based on a year of TerraSAR-X SpotLight acquisitions and Structure from Motion (SfM) processing of overflight infrared data at Volcán de Colima, Mexico. The identified deformation is dominated by localized heterogeneous subsidence of the summit dome exceeding rates of 15 cm/yr, and strongly decreasing over the year 2012, up to the renewal of explosive and extrusive activity in early 2013. We tentatively attribute the deformation to the degassing, cooling and contraction of the dome and shallow conduit material. We also find that the results strongly differ depending on the chosen InSAR time series method, which potentially overprints the true physical complexities of small scale, shallow deformation processes. The combined interpretation of the deformation and infrared data reveals a complex spatial relationship between the degassing pathways and the deformation. While we observe no deformation across the crater rim fumaroles, discontinuities in the deformation field are more commonly observed around the dome rim fumaroles and occasionally on the

  6. Axisymmetric flow in a cylindrical tank over a rotating bottom. Part II. Deformation of the water surface and experimental verification of the theory

    Science.gov (United States)

    Iga, Keita; Yokota, Sho; Watanabe, Shunichi; Ikeda, Takashi; Niino, Hiroshi; Misawa, Nobuhiko

    2017-12-01

    The theory of axisymmetric flow in a cylindrical container with a rotating bottom, as described in Part I, is validated against the results of previous and our own laboratory experiments. First, deformation of the water surface is derived using the velocity distribution of the axisymmetric flow obtained by the theory. The form of the water surface is classified into three regimes, and the rotation rates of the transitions between these regimes are determined. The parameters predicted from this theory are compared with the results measured in laboratory experiments and also with data from previous experimental studies. The theory predicts the experimental data well, but a slight difference was found in the narrow region close to the side wall. Corrections estimated by considering the fluid behavior around the side wall boundary layer successfully explain most of the discrepancies. This theory appears to predict the results of the laboratory experiments very well, much better than a theory using an assumption of quadratic drag as a model of turbulent boundary layers.

  7. Looking for Off-Fault Deformation and Measuring Strain Accumulation During the Past 70 years on a Portion of the Locked San Andreas Fault

    Science.gov (United States)

    Vadman, M.; Bemis, S. P.

    2017-12-01

    Even at high tectonic rates, detection of possible off-fault plastic/aseismic deformation and variability in far-field strain accumulation requires high spatial resolution data and likely decades of measurements. Due to the influence that variability in interseismic deformation could have on the timing, size, and location of future earthquakes and the calculation of modern geodetic estimates of strain, we attempt to use historical aerial photographs to constrain deformation through time across a locked fault. Modern photo-based 3D reconstruction techniques facilitate the creation of dense point clouds from historical aerial photograph collections. We use these tools to generate a time series of high-resolution point clouds that span 10-20 km across the Carrizo Plain segment of the San Andreas fault. We chose this location due to the high tectonic rates along the San Andreas fault and lack of vegetation, which may obscure tectonic signals. We use ground control points collected with differential GPS to establish scale and georeference the aerial photograph-derived point clouds. With a locked fault assumption, point clouds can be co-registered (to one another and/or the 1.7 km wide B4 airborne lidar dataset) along the fault trace to calculate relative displacements away from the fault. We use CloudCompare to compute 3D surface displacements, which reflect the interseismic strain accumulation that occurred in the time interval between photo collections. As expected, we do not observe clear surface displacements along the primary fault trace in our comparisons of the B4 lidar data against the aerial photograph-derived point clouds. However, there may be small scale variations within the lidar swath area that represent near-fault plastic deformation. With large-scale historical photographs available for the Carrizo Plain extending back to at least the 1940s, we can potentially sample nearly half the interseismic period since the last major earthquake on this portion of

  8. Interferometric Surface Relief Measurements with Subnano/Picometer Height Resolution

    Science.gov (United States)

    Sysoev, Evgeny; Kosolobov, Sergey; Kulikov, Rodion; Latyshev, Alexander; Sitnikov, Sergey; Vykhristyuk, Ignat

    2017-10-01

    We present an optical interference system nanoprofiler MNP-1 designed for high-precision noncontact measurement of surface relief with subnanometer resolution (root mean square of measured values), based on partial scanning of interference signal. The paper describes the construction of the measurement system with Linnik interferometer and the algorithm for nanorelief surface reconstruction. Experimental measurement results of silicon sample with profile height of surface structure of one interatomic distance obtained by MNP-1 are shown. It was proposed to use an atomically smooth surface as the reference mirror in the interferometer MNP-1 that allowed us to measure monatomic steps of the presented silicon sample. Monatomic steps of 0.31 nm in height on silicon (111) surface were measured with resolution up to 5 pm.

  9. Comparison between different speckle tracking and color tissue Doppler techniques to measure global and regional myocardial deformation in children.

    Science.gov (United States)

    Koopman, Laurens P; Slorach, Cameron; Hui, Wei; Manlhiot, Cedric; McCrindle, Brian W; Friedberg, Mark K; Jaeggi, Edgar T; Mertens, Luc

    2010-09-01

    Myocardial deformation parameters obtained by speckle-tracking echocardiography (STE) and color Doppler tissue imaging (CDTI) using two different ultrasound systems and three different software packages were compared. Apical four-chamber, short-axis grayscale, and color Doppler tissue images were prospectively acquired using Vivid 7 and iE33 ultrasound systems in 34 children and then analyzed using EchoPAC and QLAB (STE) and SPEQLE (CDTI). Measurement of myocardial deformation was feasible for all three modalities. Longitudinal strain (epsilon) measurements showed the lowest intraobserver and interobserver variability (intraobserver and interobserver coefficients of variation, 9% and 8% for EchoPAC, 5% and 6% for QLAB, and 14% and 16% for SPEQLE). In addition, longitudinal epsilon had a small bias and narrow limits of agreement when comparing different techniques. The coefficients of variation of circumferential epsilon by EchoPAC and QLAB were 12% and 11% (intraobserver) and 9% and 13% (interobserver), respectively. Circumferential epsilon by STE had a small systematic bias but relatively narrow limits of agreement. The reproducibility of radial epsilon measurements using STE was low, while CDTI epsilon provided better performance (intraobserver and interobserver coefficients of variation for radial posterior epsilon, 12% and 24% for EchoPAC, 39% and 56% for QLAB, and 12% and 14% for SPEQLE). Radial epsilon was on average 50% lower using QLAB compared with EchoPAC and SPEQLE. Systolic strain rate values obtained by STE were lower compared with CDTI-derived values. The limits of agreement for strain rate values among the three modalities were wide, and intraobserver and interobserver variability was poor for all three modalities. Some deformation measurements (e.g., longitudinal and circumferential epsilon) are comparable among different ultrasound machines and software packages, whereas others are significantly different (e.g., radial epsilon and strain rate

  10. History Matching and Parameter Estimation of Surface Deformation Data for a CO2 Sequestration Field Project Using Ensemble-Based Algorithms

    Science.gov (United States)

    Tavakoli, Reza; Srinivasan, Sanjay; Wheeler, Mary

    2015-04-01

    The application of ensemble-based algorithms for history matching reservoir models has been steadily increasing over the past decade. However, the majority of implementations in the reservoir engineering have dealt only with production history matching. During geologic sequestration, the injection of large quantities of CO2 into the subsurface may alter the stress/strain field which in turn can lead to surface uplift or subsidence. Therefore, it is essential to couple multiphase flow and geomechanical response in order to predict and quantify the uncertainty of CO2 plume movement for long-term, large-scale CO2 sequestration projects. In this work, we simulate and estimate the properties of a reservoir that is being used to store CO2 as part of the In Salah Capture and Storage project in Algeria. The CO2 is separated from produced natural gas and is re-injected into downdip aquifer portion of the field from three long horizontal wells. The field observation data includes ground surface deformations (uplift) measured using satellite-based radar (InSAR), injection well locations and CO2 injection rate histories provided by the operators. We implement variations of ensemble Kalman filter and ensemble smoother algorithms for assimilating both injection rate data as well as geomechanical observations (surface uplift) into reservoir model. The preliminary estimation results of horizontal permeability and material properties such as Young Modulus and Poisson Ratio are consistent with available measurements and previous studies in this field. Moreover, the existence of high-permeability channels (fractures) within the reservoir; especially in the regions around the injection wells are confirmed. This estimation results can be used to accurately and efficiently predict and quantify the uncertainty in the movement of CO2 plume.

  11. History matching and parameter estimation of surface deformation data for a CO2 sequestration field project using ensemble-based algorithm

    Science.gov (United States)

    Ping, J.; Tavakoli, R.; Min, B.; Srinivasan, S.; Wheeler, M. F.

    2015-12-01

    Optimal management of subsurface processes requires the characterization of the uncertainty in reservoir description and reservoir performance prediction. The application of ensemble-based algorithms for history matching reservoir models has been steadily increasing over the past decade. However, the majority of implementations in the reservoir engineering have dealt only with production history matching. During geologic sequestration, the injection of large quantities of CO2 into the subsurface may alter the stress/strain field which in turn can lead to surface uplift or subsidence. Therefore, it is essential to couple multiphase flow and geomechanical response in order to predict and quantify the uncertainty of CO2 plume movement for long-term, large-scale CO2 sequestration projects. In this work, we simulate and estimate the properties of a reservoir that is being used to store CO2 as part of the In Salah Capture and Storage project in Algeria. The CO2 is separated from produced natural gas and is re-injected into downdip aquifer portion of the field from three long horizontal wells. The field observation data includes ground surface deformations (uplift) measured using satellite-based radar (InSAR), injection well locations and CO2 injection rate histories provided by the operators. We implement ensemble-based algorithms for assimilating both injection rate data as well as geomechanical observations (surface uplift) into reservoir model. The preliminary estimation results of horizontal permeability and material properties such as Young Modulus and Poisson Ratio are consistent with available measurements and previous studies in this field. Moreover, the existence of high-permeability channels/fractures within the reservoir; especially in the regions around the injection wells are confirmed. This estimation results can be used to accurately and efficiently predict and monitor the movement of CO2 plume.

  12. Measurements of skin friction in water using surface stress sensitive films

    International Nuclear Information System (INIS)

    Crafton, J W; Fonov, S D; Jones, E G; Goss, L P; Forlines, R A; Fontaine, A

    2008-01-01

    The measurement of skin friction on hydrodynamic surfaces is of significant value for the design of advanced naval technology, particularly at high Reynolds numbers. Here we report on the development of a new sensor for measurement of skin friction and pressure that operates in both air and water. This sensor is based on an elastic polymer film that deforms under the action of applied normal and tangential loads. Skin friction and pressure gradients are determined by monitoring these deformations and then solving an inverse problem using a finite element model of the elastic film. This technique is known as surface stress sensitive films. In this paper, we describe the development of a sensor package specifically designed for two-dimensional skin friction measurements at a single point. The package has been developed with the goal of making two-dimensional measurements of skin friction in water. Quantitative measurements of skin friction are performed on a high Reynolds number turbulent boundary layer in the 12 inch water tunnel at Penn State University. These skin friction measurements are verified by comparing them to measurements obtained with a drag plate as well as by performing two-dimensional velocity measurements above the sensor using a laser Doppler velocimetry system. The results indicate that the sensor skin friction measurements are accurate to better than 5% and repeatable to better than 2%. The directional sensitivity of the sensor is demonstrated by positioning the sensor at several orientations to the flow. A final interesting feature of this sensor is that it is sensitive to pressure gradients, not to static pressure changes. This feature should prove useful for monitoring the skin friction on a seafaring vessel as the operating depth is changed

  13. Radioactivity Measurements on Glazed Ceramic Surfaces

    OpenAIRE

    Hobbs, Thomas G.

    2000-01-01

    A variety of commonly available household and industrial ceramic items and some specialty glass materials were assayed by alpha pulse counting and ion chamber voltage measurements for radioactivity concentrations. Identification of radionuclides in some of the items was performed by gamma spectroscopy. The samples included tableware, construction tiles and decorative tiles, figurines, and other products with a clay based composition. The concentrations of radioactivity ranged from near backgr...

  14. Piezotransistive GaN microcantilevers based surface work function measurements

    Science.gov (United States)

    Bayram, Ferhat; Khan, Digangana; Li, Hongmei; Maksudul Hossain, Md.; Koley, Goutam

    2018-04-01

    Surface work function (SWF) measurements using a piezotransistive III–nitride cantilever has been demonstrated on multiple surfaces. The minimum detectable surface potential change of 10 mV was achieved with a signal to noise ratio of 3. This method was applied to determine the surface potential changes due to exposure of 5 ppm NO2 in graphene and In2O3 thin film, simultaneously with conductivity changes. The potentiometric measurements yielded 100 and 80 mV potential changes in SWFs of graphene and In2O3 respectively, which matches very well with experimental data published earlier indicating the efficacy of this readily miniaturizable measurement technique.

  15. Comparative analyses of measured evapotranspiration for various land surfaces

    Science.gov (United States)

    Suat Irmak

    2016-01-01

    There is a significant lack of continuously measured ET data for multiple land surfaces in the same area to be able to make comparisons of water use rates of different agroecosystems. This research presentation will provide continuous evapotranspiration and other surface energy balance variables measured above multiple land use and management practices.

  16. Specific surface as a measure of burial diagenesis of chalk

    DEFF Research Database (Denmark)

    Borre, Mai Kirstine; Lind, Ida; Mortensen, Jeanette

    1997-01-01

    the relative importance of the three processes, simple models have been established to illustrate changes in pore space, particle size and -shape and the resulting trends in the specific surface. Specific surface and porosity of the samples were measured using image analysis on electron micrographs of polished...... sections. Using these simple models, trends in the measured specific surface can be interpred throughout the majority of the geological sequence....

  17. Development of material measures for performance verifying surface topography measuring instruments

    International Nuclear Information System (INIS)

    Leach, Richard; Giusca, Claudiu; Rickens, Kai; Riemer, Oltmann; Rubert, Paul

    2014-01-01

    The development of two irregular-geometry material measures for performance verifying surface topography measuring instruments is described. The material measures are designed to be used to performance verify tactile and optical areal surface topography measuring instruments. The manufacture of the material measures using diamond turning followed by nickel electroforming is described in detail. Measurement results are then obtained using a traceable stylus instrument and a commercial coherence scanning interferometer, and the results are shown to agree to within the measurement uncertainties. The material measures are now commercially available as part of a suite of material measures aimed at the calibration and performance verification of areal surface topography measuring instruments

  18. GBIS (Geodetic Bayesian Inversion Software): Rapid Inversion of InSAR and GNSS Data to Estimate Surface Deformation Source Parameters and Uncertainties

    Science.gov (United States)

    Bagnardi, M.; Hooper, A. J.

    2017-12-01

    Inversions of geodetic observational data, such as Interferometric Synthetic Aperture Radar (InSAR) and Global Navigation Satellite System (GNSS) measurements, are often performed to obtain information about the source of surface displacements. Inverse problem theory has been applied to study magmatic processes, the earthquake cycle, and other phenomena that cause deformation of the Earth's interior and of its surface. Together with increasing improvements in data resolution, both spatial and temporal, new satellite missions (e.g., European Commission's Sentinel-1 satellites) are providing the unprecedented opportunity to access space-geodetic data within hours from their acquisition. To truly take advantage of these opportunities we must become able to interpret geodetic data in a rapid and robust manner. Here we present the open-source Geodetic Bayesian Inversion Software (GBIS; available for download at http://comet.nerc.ac.uk/gbis). GBIS is written in Matlab and offers a series of user-friendly and interactive pre- and post-processing tools. For example, an interactive function has been developed to estimate the characteristics of noise in InSAR data by calculating the experimental semi-variogram. The inversion software uses a Markov-chain Monte Carlo algorithm, incorporating the Metropolis-Hastings algorithm with adaptive step size, to efficiently sample the posterior probability distribution of the different source parameters. The probabilistic Bayesian approach allows the user to retrieve estimates of the optimal (best-fitting) deformation source parameters together with the associated uncertainties produced by errors in the data (and by scaling, errors in the model). The current version of GBIS (V1.0) includes fast analytical forward models for magmatic sources of different geometry (e.g., point source, finite spherical source, prolate spheroid source, penny-shaped sill-like source, and dipping-dike with uniform opening) and for dipping faults with uniform

  19. Comparison of Experimentally Measured Deformation of the Plate on the Subsoil and the Results of 3D Numerical Model

    Directory of Open Access Journals (Sweden)

    Labudková Jana

    2014-06-01

    Full Text Available The purpose of this paper is to compare the measured subsidence of the foundation in experiments and subsidence obtained from FEM calculations. When using 3D elements for creation of a 3D model, it is, in particular, essential to choose correctly the size of the modelled area which represents the subsoil, the boundary conditions and the size of the finite element network. The parametric study evaluates impacts of those parameters on final deformation. The parametric study is conducted of 168 variant models.

  20. Resolving spatial heterogeneities in exhumation and surface uplift in Timor-Leste : Constraints on deformation processes in young orogens

    NARCIS (Netherlands)

    Tate, Garrett W.; McQuarrie, Nadine; van Hinsbergen, D.J.J.|info:eu-repo/dai/nl/269263624; Bakker, Richard R.; Harris, Ron; Willett, Sean; Reiners, Peter W.; Fellin, Maria Giuditta; Ganerød, Morgan; Zachariasse, Willem Jan|info:eu-repo/dai/nl/413577368

    Although exhumation and surface uplift are important parameters in understanding orogenesis, the opportunity to measure both in close proximity is rare. In Timor-Leste (East Timor), deeply exhumed metamorphic rocks and piggyback deepwater synorogenic basins are only tens of kilometers apart,

  1. Radioactivity Measurements on Glazed Ceramic Surfaces.

    Science.gov (United States)

    Hobbs, T G

    2000-01-01

    A variety of commonly available household and industrial ceramic items and some specialty glass materials were assayed by alpha pulse counting and ion chamber voltage measurements for radioactivity concentrations. Identification of radionuclides in some of the items was performed by gamma spectroscopy. The samples included tableware, construction tiles and decorative tiles, figurines, and other products with a clay based composition. The concentrations of radioactivity ranged from near background to about four orders of magnitude higher. Almost every nuclide identification test demonstrated some radioactivity content from one or more of the naturally occurring radionuclide series of thorium or uranium. The glazes seemed to contribute most of the activity, although a sample of unglazed pottery greenware showed some activity. Samples of glazing paints and samples of deliberately doped glass from the World War II era were included in the test, as was a section of foam filled poster board. A glass disc with known (232)Th radioactivity concentration was cast for use as a calibration source. The results from the two assay methods are compared, and a projection of sensitivity from larger electret ion chamber devices is presented.

  2. SGP Cloud and Land Surface Interaction Campaign (CLASIC): Measurement Platforms

    Energy Technology Data Exchange (ETDEWEB)

    MA Miller; R Avissar; LK Berg; SA Edgerton; ML Fischer; TJ Jackson; B. Kustas; PJ Lamb; G McFarquhar; Q Min; B Schmid; MS Torn; DD Tuner

    2007-06-01

    The Cloud and Land Surface Interaction Campaign (CLASIC) will be conducted from June 8 to June 30, 2007, at the U.S. Department of Energy’s Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) Southern Great Plains (SGP) site. Data will be collected using eight aircraft equipped with a variety of specialized sensors, four specially instrumented surface sites, and two prototype surface radar systems. The architecture of CLASIC includes a high-altitude surveillance aircraft and enhanced vertical thermodynamic and wind profile measurements that will characterize the synoptic scale structure of the clouds and the land surface within the ACRF SGP site. Mesoscale and microscale structures will be sampled with a variety of aircraft, surface, and radar observations. An overview of the measurement platforms that will be used during the CLASIC are described in this report. The coordination of measurements, especially as it relates to aircraft flight plans, will be discussed in the CLASIC Implementation Plan.

  3. A Study on 3-Dimensional Surface Measurement using Confocal Principle

    International Nuclear Information System (INIS)

    Kang, Young June; Song, Dae Ho; You, Weon Jae

    2001-01-01

    In modern industry, the accuracy and the sulfate-finish requirements for machined parts have been becoming ever more stringent. In addition, the measurement and understanding of surface topography is rapidly attracting the attention of the physicist and chemist as well as the engineer. Optical measuring method is used in vibration measurement, crack and defect detection with the advent of opto-mechatronics, and it is expected to play an important role in surface topography. In this study, the principle of confocal microscope is described, and the advanced 3-D surface measuring system that has better performance than the traditional confocal microscope is developed. Suitable fixtures arc developed and integrated with the computer system for generating 3-D surface and form data. Software for data acquisition and analysis of various parameters in surface geometrical features has been developed

  4. ROUGHNESS ON WOOD SURFACES AND ROUGHNESS MEASUREMENT METHODS

    Directory of Open Access Journals (Sweden)

    İsmail Aydın

    2003-04-01

    Full Text Available Some visual characteristics of wood such as color, pattern and texture determine the quality of manufactured products. Surface properties of wood material are important both in production and marketing after production. Initial studies related to the roughness of wood surface were begun in early 1950’s. However, no general agreed standardization can not have been developed for wood surfaces. Surface roughness of wood is function of the production process, product type and the natural anatomical properties of wood. Contact and non-contact tracing methods are used to measure of wood surface roughness. Surface roughness also affects the gluability and wettability of wood surfaces. The success in finishing also depends on the surface roughness of wood.

  5. The nuclear deformations of 148Sm, 150Sm, 152Sm and 154Sm determined from neutron scattering measurements

    International Nuclear Information System (INIS)

    Shamu, R.; Haouat, G.; Lachkar, J.; Lagrange, C.; McEllistrem, M.; Patin, Y.; Sigaud, J.; Cocu, F.; Bernstein, E.; Ramirez, J.

    1975-01-01

    The neutron total cross section for 148 Sm and total cross section differences for ( 150 Sm, 148 Sm) and ( 152 Sm, 148 Sm) and ( 154 Sm, 148 Sm) were measured from 0.7 to 15MeV neutron energy and differential cross sections for 148 Sm, 150 Sm, 152 Sm and 154 Sm were measured at 7.0MeV neutron energy. The quadrupole deformation parameter of the nuclear potential, β2, was determined for each of the 148 Sm, 150 Sm, 152 Sm, 154 Sm nuclei from these measurements using nonspherical optical-potential coupled-channel calculations. The β2 values deduced for 152 Sm and 154 Sm are in good agreement with values determined from proton and α-particle scattering, but about 10% lower than β2 values of the nuclear charge distribution obtained from Coulomb excitation, electron scattering, and μ-meson scattering experiments [fr

  6. Partial compensation interferometry for measurement of surface parameter error of high-order aspheric surfaces

    Science.gov (United States)

    Hao, Qun; Li, Tengfei; Hu, Yao

    2018-01-01

    Surface parameters are the properties to describe the shape characters of aspheric surface, which mainly include vertex radius of curvature (VROC) and conic constant (CC). The VROC affects the basic properties, such as focal length of an aspheric surface, while the CC is the basis of classification for aspheric surface. The deviations of the two parameters are defined as surface parameter error (SPE). Precisely measuring SPE is critical for manufacturing and aligning aspheric surface. Generally, SPE of aspheric surface is measured directly by curvature fitting on the absolute profile measurement data from contact or non-contact testing. And most interferometry-based methods adopt null compensators or null computer-generated holograms to measure SPE. To our knowledge, there is no effective way to measure SPE of highorder aspheric surface with non-null interferometry. In this paper, based on the theory of slope asphericity and the best compensation distance (BCD) established in our previous work, we propose a SPE measurement method for high-order aspheric surface in partial compensation interferometry (PCI) system. In the procedure, firstly, we establish the system of two element equations by utilizing the SPE-caused BCD change and surface shape change. Then, we can simultaneously obtain the VROC error and CC error in PCI system by solving the equations. Simulations are made to verify the method, and the results show a high relative accuracy.

  7. Automatic Measurement of Low Level Contamination on Concrete Surfaces

    International Nuclear Information System (INIS)

    Tachibana, M.; Itoh, H.; Shimada, T.; Yanagihara, S.

    2002-01-01

    Automatic measurement of radioactivity is necessary for considering cost effectiveness in final radiological survey of building structures in decommissioning nuclear facilities. The RAPID (radiation measuring pilot device for surface contamination) was developed to be applied to automatic measurement of low level contamination on concrete surfaces. The RAPID has a capability to measure contamination with detection limit of 0.14 Bq/cm2 for 60Co in 30 seconds of measurement time and its efficiency is evaluated to be 5 m2/h in a normal measurement option. It was confirmed that low level contamination on concrete surfaces could be surveyed by the RAPID efficiently compared with direct measurement by workers through its actual application

  8. Application of the global positioning system to crustal deformation measurements: 3. Result from the southern California borderlands

    Science.gov (United States)

    Larson, Kristine M.

    1993-12-01

    Five years of measurements from the Global Positioning System (GPS) satellites collected between 1986 and 1991 are used to investigate deformation in the offshore regions of southern California. GPS provides the first practical technique to make precise geodetic measurements in the region. The geodetic network is situated along the California coastline from Vandenberg (120.6°W, 34.6°N) to San Diego, with additional sites on Santa Cruz, San Nicolas, Santa Catalina, Santa Rosa, and San Clemente Islands. The precision of horizontal interstation vectors is subcentimeter, and the interstation vector rate between OVRO and Vandenberg agrees with the very long baseline interferometry derived rate to within one standard deviation. No significant motion is observed in the western Santa Barbara Channel between Vandenberg and Santa Rosa Island, 0.5 ± 1.6 mm/yr, where the quoted uncertainties are one standard deviation. Motions in the eastern Santa Barbara Channel are consistent with compressional deformation of 6 ± 1 mm/yr at N16 ± 3°E. This motion is in agreement with seismicity and an independent geodetic analysis for the period 1971-1987 (Larsen, 1991). San Clemente Island is moving relative to San Diego at the rate of 5.9 ± 1.8 mm/yr at a direction of N38 ± 20°W. The motion between San Nicolas Island and San Clemente Island, 0.8 ± 1.5 mm/yr, is insignificant.

  9. Style of the surface deformation by the 1999 Chichi earthquake at the central segment of Chelungpu fault, Taiwan, with special reference to the presence of the main and subsidiary faults and their progressive deformation in the Tsauton area

    Science.gov (United States)

    Ota, Y.; Watanabe, M.; Suzuki, Y.; Yanagida, M.; Miyawaki, A.; Sawa, H.

    2007-11-01

    We describe the style of surface deformation in the 1999 Chichi earthquake in the central segment of the Chelungpu Fault. The study covers the Kung-fu village, north of Han River, to the south of Tsauton area. A characteristic style of the surface deformation is a convex scarp in profile and sinuous plan view, due to the low angle thrust fault. Two subparallel faults, including the west facing Tsauton West fault, and the east facing Tsauton East fault, limit the western and eastern margin of the Tsauton terraced area. The Tsauton West fault is the continuation of the main Chelungpu fault and the Tsauton East fault is located about 2 km apart. Both faults record larger amounts of vertical displacement on the older terraces. The 1999 surface rupture occurred exactly on a pre-existing fault scarp of the Tsauton West and East faults. Thus, repeated activities of these two faults during the Holocene, possibly since the late Quaternary, are confirmed. The amount of vertical offset of the Tsauton East fault is smaller, and about 40-50% of that of the Tsauton West fault for the pre-existing fault. This indicates that the Tsauton East fault is a subsidiary fault and moved together with the main fault, but accommodated less amount.

  10. Open questions in surface topography measurement: a roadmap

    International Nuclear Information System (INIS)

    Leach, Richard; Evans, Christopher; He, Liangyu; Davies, Angela; Duparré, Angela; Henning, Andrew; Jones, Christopher W; O’Connor, Daniel

    2015-01-01

    Control of surface topography has always been of vital importance for manufacturing and many other engineering and scientific disciplines. However, despite over one hundred years of quantitative surface topography measurement, there are still many open questions. At the top of the list of questions is ‘Are we getting the right answer?’ This begs the obvious question ‘How would we know?’ There are many other questions relating to applications, the appropriateness of a technique for a given scenario, or the relationship between a particular analysis and the function of the surface. In this first ‘open questions’ article we have gathered together some experts in surface topography measurement and asked them to address timely, unresolved questions about the subject. We hope that their responses will go some way to answer these questions, address areas where further research is required, and look at the future of the subject. The first section ‘Spatial content characterization for precision surfaces’ addresses the need to characterise the spatial content of precision surfaces. Whilst we have been manufacturing optics for centuries, there still isn’t a consensus on how to specify the surface for manufacture. The most common three methods for spatial characterisation are reviewed and compared, and the need for further work on quantifying measurement uncertainties is highlighted. The article is focussed on optical surfaces, but the ideas are more pervasive. Different communities refer to ‘figure, mid-spatial frequencies, and finish’ and ‘form, waviness, and roughness’, but the mathematics are identical. The second section ‘Light scattering methods’ is focussed on light scattering techniques; an important topic with in-line metrology becoming essential in many manufacturing scenarios. The potential of scattering methods has long been recognized; in the ‘smooth surface limit’ functionally significant relationships can be derived from first

  11. Measurement of Dynamic Friction Coefficient on the Irregular Free Surface

    International Nuclear Information System (INIS)

    Yeom, S. H.; Seo, K. S.; Lee, J. H.; Lee, K. H.

    2007-01-01

    A spent fuel storage cask must be estimated for a structural integrity when an earthquake occurs because it freely stands on ground surface without a restriction condition. Usually the integrity estimation for a seismic load is performed by a FEM analysis, the friction coefficient for a standing surface is an important parameter in seismic analysis when a sliding happens. When a storage cask is placed on an irregular ground surface, measuring a friction coefficient of an irregular surface is very difficult because the friction coefficient is affected by the surface condition. In this research, dynamic friction coefficients on the irregular surfaces between a concrete cylinder block and a flat concrete slab are measured with two methods by one direction actuator

  12. Measurement of near neighbor separations of surface atoms

    International Nuclear Information System (INIS)

    Cohen, P.I.

    Two techniques are being developed to measure the nearest neighbor distances of atoms at the surfaces of solids. Both measures extended fine structure in the excitation probability of core level electrons which are excited by an incident electron beam. This is an important problem because the structures of most surface systems are as yet unknown, even though the location of surface atoms is the basis for any quantitative understanding of the chemistry and physics of surfaces and interfaces. These methods would allow any laboratory to make in situ determinations of surface structure in conjunction with most other laboratory probes of surfaces. Each of these two techniques has different advantages; further, the combination of the two will increase confidence in the results by reducing systematic error in the data analysis

  13. Surface deposition measurements of the TMI-2 gross decontamination experiment

    International Nuclear Information System (INIS)

    McIssac, C.V.; Hetzer, D.C.

    1982-01-01

    In order to measure the effectiveness of the gross decontamination experiment (principally a water spray technique) performed in the TMI-2 reactor building, the Technical Information and Examination Program's Radiation and Environment personnel made surface activity measurements before and after the experiment. In conjunction with surface sampling, thermoluminescent dosimeter (TLD) and gamma spectrometry measurements were also performed to distinguish between radiation fields and contamination. The surface sampler used to collect samples from external surfaces within the reactor building is a milling tool having four major components: a 1.27-cm constant-speed drill; a drill support assembly that allows setting sample penetration depth; filter cartridges for intake air purification and sample collection; and an air pump that forces air across the surface being sampled and through the sample filter cartridge

  14. Deformation of the free surface of a conducting fluid in the magnetic field of current-carrying linear conductors

    Energy Technology Data Exchange (ETDEWEB)

    Zubarev, N.M. [Institute of Electrophysics, UB RAS, Ekaterinburg (Russian Federation); P.N. Lebedev Physical Institute, RAS, Moscow (Russian Federation); Zubareva, O.V., E-mail: olga@iep.uran.ru [Institute of Electrophysics, UB RAS, Ekaterinburg (Russian Federation)

    2017-06-01

    The magnetic shaping problem is studied for the situation where a cylindrical column of a perfectly conducting fluid is deformed by the magnetic field of a system of linear current-carrying conductors. Equilibrium is achieved due to the balance of capillary and magnetic pressures. Two two-parametric families of exact solutions of the problem are obtained with the help of conformal mapping technique. In accordance with them, the column essentially deforms in the cross section up to its disintegration.

  15. Surface and interfacial tension measurement, theory, and applications

    CERN Document Server

    Hartland, Stanley

    2004-01-01

    This edited volume offers complete coverage of the latest theoretical, experimental, and computer-based data as summarized by leading international researchers. It promotes full understanding of the physical phenomena and mechanisms at work in surface and interfacial tensions and gradients, their direct impact on interface shape and movement, and their significance to numerous applications. Assessing methods for the accurate measurement of surface tension, interfacial tension, and contact angles, Surface and Interfacial Tension presents modern simulations of complex interfacial motions, such a

  16. NASA's Space Lidar Measurements of Earth and Planetary Surfaces

    Science.gov (United States)

    Abshire, James B.

    2010-01-01

    A lidar instrument on a spacecraft was first used to measure planetary surface height and topography on the Apollo 15 mission to the Moon in 1971, The lidar was based around a flashlamp-pumped ruby laser, and the Apollo 15-17 missions used them to make a few thousand measurements of lunar surface height from orbit. With the advent of diode pumped lasers in the late 1980s, the lifetime, efficiency, resolution and mass of lasers and space lidar all improved dramatically. These advances were utilized in NASA space missions to map the shape and surface topography of Mars with > 600 million measurements, demonstrate initial space measurements of the Earth's topography, and measured the detailed shape of asteroid. NASA's ICESat mission in Earth orbit just completed its polar ice measurement mission with almost 2 billion measurements of the Earth's surface and atmosphere, and demonstrated measurements to Antarctica and Greenland with a height resolution of a few em. Space missions presently in cruise phase and in operation include those to Mercury and a topographic mapping mission of the Moon. Orbital lidar also have been used in experiments to demonstrate laser ranging over planetary distances, including laser pulse transmission from Earth to Mars orbit. Based on the demonstrated value of the measurements, lidar is now the preferred measurement approach for many new scientific space missions. Some missions planned by NASA include a planetary mission to measure the shape and dynamics of Europa, and several Earth orbiting missions to continue monitoring ice sheet heights, measure vegetation heights, assess atmospheric CO2 concentrations, and to map the Earth surface topographic heights with 5 m spatial resolution. This presentation will give an overview of history, ongoing work, and plans for using space lidar for measurements of the surfaces of the Earth and planets.

  17. Importance of methodological standardization for the ektacytometric measures of red blood cell deformability in sickle cell anemia

    NARCIS (Netherlands)

    Renoux, Céline; Parrow, Nermi; Faes, Camille; Joly, Philippe; Hardeman, Max; Tisdale, John; Levine, Mark; Garnier, Nathalie; Bertrand, Yves; Kebaili, Kamila; Cuzzubbo, Daniela; Cannas, Giovanna; Martin, Cyril; Connes, Philippe

    2016-01-01

    Red blood cell (RBC) deformability is severely decreased in patients with sickle cell anemia (SCA), which plays a role in the pathophysiology of the disease. However, investigation of RBC deformability from SCA patients demands careful methodological considerations. We assessed RBC deformability by

  18. A computer-aided surface roughness measurement system

    International Nuclear Information System (INIS)

    Hughes, F.J.; Schankula, M.H.

    1983-11-01

    A diamond stylus profilometer with computer-based data acquisitions/analysis system is being used to characterize surfaces of reactor components and materials, and to examine the effects of surface topography on thermal contact conductance. The current system is described; measurement problems and system development are discussed in general terms and possible future improvements are outlined

  19. Measuring Forces between Oxide Surfaces Using the Atomic Force Microscope

    DEFF Research Database (Denmark)

    Pedersen, Henrik Guldberg; Høj, Jakob Weiland

    1996-01-01

    The interactions between colloidal particles play a major role in processing of ceramics, especially in casting processes. With the Atomic Force Microscope (AFM) it is possible to measure the inter-action force between a small oxide particle (a few micron) and a surface as function of surface...

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

    Science.gov (United States)

    Guilizzoni, Manfredo

    2011-12-01

    The shape and contact angles of drops on curved surfaces is experimentally investigated. Image processing, spline fitting and numerical integration are used to extract the drop contour in a number of cross-sections. The three-dimensional surfaces which describe the surface-air and drop-air interfaces can be visualized and a simple procedure to determine the equilibrium contact angle starting from measurements on curved surfaces is proposed. Contact angles on flat surfaces serve as a reference term and a procedure to measure them is proposed. Such procedure is not as accurate as the axisymmetric drop shape analysis algorithms, but it has the advantage of requiring only a side view of the drop-surface couple and no further information. It can therefore be used also for fluids with unknown surface tension and there is no need to measure the drop volume. Examples of application of the proposed techniques for distilled water drops on gemstones confirm that they can be useful for drop shape analysis and contact angle measurement on three-dimensional sculptured surfaces. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Device for radiometric measurement, e.g. of surface density

    International Nuclear Information System (INIS)

    Gregor, J.; Kopl, F.

    1973-01-01

    A design is described of a device for radiometric measurements, such as of material surface density, thickness of coating layers, surface moisture, and for the analysis of chemical composition. The device uses backscattered radiation indicated by two ionization chambers with gas filling; the radiation source is placed in between the chambers. (J.K.)

  2. Laboratory measurements of dusty surface charging in plasma.

    Science.gov (United States)

    Chou, Kevin; Wang, Joseph

    2017-09-01

    A novel method is developed to study the charging of a conducting surface covered by a thin dust layer in plasma. The potential profile in the dust layer and the floating potential of the surface underneath are measured directly by embedding conducting wires in the dust and connecting the wires to a measurement plate outside the vacuum chamber, where a Trek non-contacting electrostatic voltmeter measures the floating potential of the measurement plate. Laboratory experiments are carried out to study plasma charging of a conducting plate covered by lunar dust simulant, JSC-1A. The results show that the plate potential is dependent on both the ambient plasma condition and the dust layer thickness. The current balance condition controls the floating potential of the dust surface while the dust layer acts as a capacitor and controls the potential of the plate with respect to the dust surface. Hence, a dust covered conducting plate will be charged more negatively than a clean plate.

  3. Vertebral deformities and fractures are associated with MRI and pQCT measures obtained at the distal tibia and radius of postmenopausal women

    Science.gov (United States)

    Rajapakse, C. S.; Phillips, E. A.; Sun, W.; Wald, M. J.; Magland, J. F.; Snyder, P. J.; Wehrli, F. W.

    2016-01-01

    Summary We investigated the association of postmenopausal vertebral deformities and fractures with bone parameters derived from distal extremities using MRI and pQCT. Distal extremity measures showed variable degrees of association with vertebral deformities and fractures, highlighting the systemic nature of postmenopausal bone loss. Introduction Prevalent vertebral deformities and fractures are known to predict incident further fractures. However, the association of distal extremity measures and vertebral deformities in postmenopausal women has not been fully established. Methods This study involved 98 postmenopausal women (age range 60–88 years, mean 70 years) with DXA BMD T-scores at either the hip or spine in the range of −1.5 to −3.5. Wedge, biconcavity, and crush deformities were computed on the basis of spine MRI. Vertebral fractures were assessed using Eastell's criterion. Distal tibia and radius stiffness was computed using MRI-based finite element analysis. BMD at the distal extremities were obtained using pQCT. Results Several distal extremity MRI and pQCT measures showed negative association with vertebral deformity on the basis of single parameter correlation (r up to 0.67) and two-parameter regression (r up to 0.76) models involving MRI stiffness and pQCT BMD. Subjects who had at least one prevalent vertebral fracture showed decreased MRI stiffness (up to 17.9 %) and pQCT density (up to 34.2 %) at the distal extremities compared to the non-fracture group. DXA lumbar spine BMD T-score was not associated with vertebral deformities. Conclusions The association between vertebral deformities and distal extremity measures supports the notion of postmenopausal osteoporosis as a systemic phenomenon. PMID:24221453

  4. Surface Laser Scanning Measurements for the n_TOF spallation target

    CERN Document Server

    Vlachoudis, V; Cennini, P; Lebbos, E; Lettry, J

    2010-01-01

    The n_TOF spallation target is made of pure lead immersed into cooling water. The target was operating normally from 2001 until august 2004, when an increased transfer of radioactive products from the spallation target to the cooling circuit has been observed. The target was considered damaged by the safety commission (SC/RP), and an investigation campaign started to verify the actual status of the target. According to FLUKA and Ansys calculations the target was working in the elastoplastic regime of the lead material, therefore a deformation might be expected. The present paper describes a laser photographic method and the results of a possible such deformation. The target had a surface activity of the order of 20 mSv/h, therefore we were forced to perform the measurement from distance. The used method, is based on a linelaser and a high resolution digital camera for retrieving the 3D position of the surface of the lead target. Similar methods are used in the film industry and animation studios for scanning ...

  5. Accuracy of Surface Plate Measurements - General Purpose Software for Flatness Measurement

    NARCIS (Netherlands)

    Meijer, J.; Heuvelman, C.J.

    1990-01-01

    Flatness departures of surface plates are generally obtained from straightness measurements of lines on the surface. A computer program has been developed for on-line measurement and evaluation, based on the simultaneous coupling of measurements in all grid points. Statistical methods are used to

  6. Surface Roughness and Elastic Deformation Effects on the Behaviour of the Magnetic Fluid Based Squeeze Film Between Rotating Porous Circular Plates with Concentric Circular Pockets

    Directory of Open Access Journals (Sweden)

    M. E. Shimpi

    2010-06-01

    Full Text Available An attempt has been made to study and analyze the performance of a magnetic fluid based squeeze film between rotating porous transversely rough circular plates with concentric circular pockets. The porous housing is considered to be elastically negligibly deformable with its contact surface transversely rough. The stochastic film thickness characterizing the random roughness is assumed to be asymmetric with non zero mean and variance. The pressure distribution is obtained by solving the associated stochastically averaged Reynolds equation with appropriate boundary conditions. This results in the calculation of the load carrying capacity. All the results in graphical form establish that the transverse roughness in conjunction with the deformation has a strong negative effect on the performance of the bearing system. The bearing suffers on account of transverse surface roughness in general which probably is due to the fact that the roughness of the bearing surfaces tends to retard the motion of the lubricant resulting in decreased load carrying capacity. However, this negative effect of roughness, porosity and deformation can be minimized by the positive effect of the magnetization parameter in the case of negatively skewed roughness by choosing a suitable combination of pocket radius and rotational inertia. Lastly, the effect of radii ratio is noted to be quite significant.

  7. Cantilever measurements of surface stress, surface reconstruction, film stress and magnetoelastic stress of monolayersc

    Directory of Open Access Journals (Sweden)

    Jürgen Kirschner

    2008-07-01

    Full Text Available We review the application of cantilever-based stress measurements in surface science and magnetism. The application of thin (thickness appr. 0.1 mm single crystalline substrates as cantilevers has been used successfully to measure adsorbate-induced surface stress changes, lattice misfit induced film stress, and magneto-elastic stress of ferromagnetic monolayers. Surface stress changes as small as 0.01 N/m can be readily measured, and this translates into a sensitivity for adsorbate-coverage well below 0.01 of one layer. Stress as large as several GPa, beyond the elasticity limits of high strength materials, is measured, and it is ascribed to the lattice misfit between film and substrate. Our results point at the intimate relation between surface stress and surface reconstruction, stress-induced structural changes in epitaxially strained films, and strain-induced modifications of the magneto-elastic coupling in ferromagnetic monolayers.

  8. Cantilever measurements of surface stress, surface reconstruction, film stress and magnetoelastic stress of monolayers.

    Science.gov (United States)

    Sander, Dirk; Tian, Zhen; Kirschner, Jürgen

    2008-07-29

    We review the application of cantilever-based stress measurements in surface science and magnetism. The application of thin (thickness appr. 0.1 mm) single crystalline substrates as cantilevers has been used successfully to measure adsorbate-induced surface stress changes, lattice misfit induced film stress, and magneto-elastic stress of ferromagnetic monolayers. Surface stress changes as small as 0.01 N/m can be readily measured, and this translates into a sensitivity for adsorbate-coverage well below 0.01 of one layer. Stress as large as several GPa, beyond the elasticity limits of high strength materials, is measured, and it is ascribed to the lattice misfit between film and substrate. Our results point at the intimate relation between surface stress and surface reconstruction, stress-induced structural changes in epitaxially strained films, and strain-induced modifications of the magneto-elastic coupling in ferromagnetic monolayers.

  9. Mapping and Measuring the Microrelief of Slope Deformations Using Modern Contactless Technologies and Practical Application in Territorial Planning

    Science.gov (United States)

    Chudý, František; Slámová, Martina; Tomaštík, Julián; Kardoš, Miroslav; Tunák, Daniel; Saloň, Šimon

    2017-04-01

    Slope deformations are risks limiting economic land use potential. A national database system keeps records of slope disturbances and deformations, however, it is important to update the information mainly from the point of view of practical territorial planning, especially in the high-risk areas presented in the study. The paper explains the possibilities of applying modern methods of mapping the microrelief of slope deformations of a lower extent (up to several hundreds of m2) and using not very well known contactless technologies, which could be applied in practice due to their low-cost and low-time consuming nature. In order to create a digital model of the microrelief used to carry out the measurements we applied the method of terrestrial photogrammetry, terrestrial scanning using Lenovo Phab 2Pro. It is the first device available for users that uses the Google Tango technology. So far there have been only prototypes of devices available for the developers only. The Tango technology consists of 3 partial technologies - "depth perception" (measuring the distance to objects, nowadays it uses mainly infrared radiation), "motion tracking" (tracking the position and motion of the device using embedded sensors) and "area learning" (simply learning the area, where the device looks for same objects within already existing 3D models and real space). Even though the technology utilisation is nowadays presented mainly in the field of augmented reality and navigation in the interior, there are already some applications for collecting the point clouds in real time, which can be used in a wide spectrum of applications in exterior, which was also applied in our research. Data acquired this way can be processed in readily available software products, what enabled a high degree of automation also in our case. After comparing with the reference point field that was measured using GNSS and electronic tachymeter, we reached accuracy of point position determination from a digital

  10. Summations over equilaterally triangulated surfaces and the critical string measure

    Science.gov (United States)

    Smit, Dirk-Jan

    1992-01-01

    We propose a new approach to the summation over dynamically triangulated Riemann surfaces which does not rely on properties of the potential in a matrix model. Instead, we formulate a purely algebraic discretization of critical string path integral. This is combined with a technique which assigns to each equilateral triangulation of a two-dimensional surface a Riemann surface defined over a certain finite extension of the field of rational numbers, i.e. an arthmetic surface. Thus we establish a new formulation in which the sum over randomly triangulated surfaces defines an invariant measure on the moduli space of arithmetic surfaces. It is shown that because of this it is far from obvious that this measure for large genera approximates the measure defined by the continuum theory, i.e. Liouville theory or critical string theory. In low genus this subtlety does not exist. In the case of critical string theory we explicity compute the volume of the moduli space of arithmetic surfaces in terms of the modular height function and show that for low genus it approximates correctly the continuum measure. We also discuss a continuum limit which bears some resemblance with a double scaling limit in matrix models.

  11. Summations over equilaterally triangulated surfaces and the critical string measure

    International Nuclear Information System (INIS)

    Smit, D.J.; Lawrence Berkeley Lab., CA

    1992-01-01

    We propose a new approach to the summation over dynamically triangulated Riemann surfaces which does not rely on properties of the potential in a matrix model. Instead, we formulate a purely algebraic discretization of critical string path integral. This is combined with a technique which assigns to each equilateral triangulation of a two-dimensional surface a Riemann surface defined over a certain finite extension of the field of rational numbers, i.e. an arithmetic surface. Thus we establish a new formulated in which the sum over randomly triangulated surfaces defines an invariant measure on the moduli space of arithmetic surfaces. It is shown that because of this it is far from obvious that this measure for large genera approximates the measure defined by the continuum theory, i.e. Liouville theory or critical string theory. In low genus this subtlety does not exist. In the case of critical string theory we explicitly compute the volume of the moduli space of arithmetic surfaces in terms of the modular height function and show that for low genus it approximates correctly the continuum measure. We also discuss a continuum limit which bears some resemblance with a double scaling limit in matrix models. (orig.)

  12. Tumor Tracking Method Based on a Deformable 4D CT Breathing Motion Model Driven by an External Surface Surrogate

    Energy Technology Data Exchange (ETDEWEB)

    Fassi, Aurora, E-mail: aurora.fassi@mail.polimi.it [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Schaerer, Joël; Fernandes, Mathieu [CREATIS, CNRS UMR 5220, INSERM U1044, Université Lyon 1, INSA-Lyon, Villeurbanne (France); Department of Radiotherapy, Centre Léon Bérard, Lyon (France); Riboldi, Marco [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit, CNAO Foundation, Pavia (Italy); Sarrut, David [CREATIS, CNRS UMR 5220, INSERM U1044, Université Lyon 1, INSA-Lyon, Villeurbanne (France); Department of Radiotherapy, Centre Léon Bérard, Lyon (France); Baroni, Guido [Dipartimento di Elettronica, Informazione e Bioingegneria, Politecnico di Milano, Milano (Italy); Bioengineering Unit, CNAO Foundation, Pavia (Italy)

    2014-01-01

    Purpose: To develop a tumor tracking method based on a surrogate-driven motion model, which provides noninvasive dynamic localization of extracranial targets for the compensation of respiration-induced intrafraction motion in high-precision radiation therapy. Methods and Materials: The proposed approach is based on a patient-specific breathing motion model, derived a priori from 4-dimensional planning computed tomography (CT) images. Model parameters (respiratory baseline, amplitude, and phase) are retrieved and updated at each treatment fraction according to in-room radiography acquisition and optical surface imaging. The baseline parameter is adapted to the interfraction variations obtained from the daily cone beam (CB) CT scan. The respiratory amplitude and phase are extracted from an external breathing surrogate, estimated from the displacement of the patient thoracoabdominal surface, acquired with a noninvasive surface imaging device. The developed method was tested on a database of 7 lung cancer patients, including the synchronized information on internal and external respiratory motion during a CBCT scan. Results: About 30 seconds of simultaneous acquisition of CBCT and optical surface images were analyzed for each patient. The tumor trajectories identified in CBCT projections were used as reference and compared with the target trajectories estimated from surface displacement with the a priori motion model. The resulting absolute differences between the reference and estimated tumor motion along the 2 image dimensions ranged between 0.7 and 2.4 mm; the measured phase shifts did not exceed 7% of the breathing cycle length. Conclusions: We investigated a tumor tracking method that integrates breathing motion information provided by the 4-dimensional planning CT with surface imaging at the time of treatment, representing an alternative approach to point-based external–internal correlation models. Although an in-room radiograph-based assessment of the

  13. Inverse measurement of wall pressure field in flexible-wall wind tunnels using global wall deformation data

    Science.gov (United States)

    Brown, Kenneth; Brown, Julian; Patil, Mayuresh; Devenport, William

    2018-02-01

    The Kevlar-wall anechoic wind tunnel offers great value to the aeroacoustics research community, affording the capability to make simultaneous aeroacoustic and aerodynamic measurements. While the aeroacoustic potential of the Kevlar-wall test section is already being leveraged, the aerodynamic capability of these test sections is still to be fully realized. The flexibility of the Kevlar walls suggests the possibility that the internal test section flow may be characterized by precisely measuring small deflections of the flexible walls. Treating the Kevlar fabric walls as tensioned membranes with known pre-tension and material properties, an inverse stress problem arises where the pressure distribution over the wall is sought as a function of the measured wall deflection. Experimental wall deformations produced by the wind loading of an airfoil model are measured using digital image correlation and subsequently projected onto polynomial basis functions which have been formulated to mitigate the impact of measurement noise based on a finite-element study. Inserting analytic derivatives of the basis functions into the equilibrium relations for a membrane, full-field pressure distributions across the Kevlar walls are computed. These inversely calculated pressures, after being validated against an independent measurement technique, can then be integrated along the length of the test section to give the sectional lift of the airfoil. Notably, these first-time results are achieved with a non-contact technique and in an anechoic environment.

  14. Deformation and velocity measurements at elevated temperature in a fractured 0.5 M block of tuff

    International Nuclear Information System (INIS)

    Blair, S.C.; Berge, P.A.

    1996-01-01

    This paper presents preliminary results of laboratory tests conducted on small block samples of Topopah Spring tuff, in support of the Yucca Mountain Site Characterization Project. The overall objective of these tests is to investigate the thermal-mechanical, thermal-hydrological, and thermal-chemical response of the rock to conditions similar to the near-field environment (NFE) of a potential nuclear waste repository. We present preliminary results of deformation and elastic wave velocity measurements on a 0.5-m-scale block of Topopah Spring tuff tested in uniaxial compression to 8.5 MPa and at temperatures to 85 degree C. The Young's modulus was found to be about 7 to 31 GPa for vertical measurements parallel to the stress direction across parts of the block containing no fractures or a few fractures, and 0.5 to 0.9 GPA for measurements across individual fractures, at ambient temperature and 8.5 MPa maximum stress. During stress cycles between 5 and 8.5 MPa, the deformation modulus values for the matrix with fractures were near 15-20 GPa at ambient temperature but dropped to about 10 GPa at 85 degree C. Compressional wave velocities were found to be about 3.6 to 4.7 km/s at ambient temperature and stress. After the stress was cycled, velocities dropped to values as low as 2.6 km/s in the south end of the block where vertical cracks developed. Heating the block to about 85 degree C raised velocities to as much as 5.6 km/s in the upper third of the block

  15. The reliability of measurements taken from radiographs in the assessment of paediatric flat foot deformity.

    Science.gov (United States)

    Metcalfe, Stuart A; Bowling, Frank L; Baltzopoulos, V; Maganaris, C; Reeves, Neil D

    2012-09-01

    Radiographic charted values are widely applied in the assessment of paediatric flat foot and as quantitative markers of intervention success. Nearly all literature pertaining to the reliability of these measures relates to the adult foot. In view of the importance placed on these charted values we assessed the inter and intra-rater reliability of 10 key radiographic measures in children aged 7-14 years. We present the reliability of these measures in terms of intra class correlation and standard error based on repeated measures of 50 radiographs across five independent trained observers. Two new detailed methods are presented for the calculation of lateral and dorso-plantar talo-calcaneal overlap in an attempt to better define the talo-calcaneal inter-relationship. The results demonstrate wide variation of measurement reliability, with some measures being highly reproducible and others showing poor reproducibility. A strong negative correlation between reliability and the number of steps required for the measurement was demonstrated. Consistent with other studies intra-rater reliability tended to be higher than that of inter-rater reliability. In conclusion, we have provided evidence as to which radiographic charted measures may be reliably used in evaluating the paediatric flat foot in children aged 7-14 years, and which measures are not reliable and we advise against their application. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Surface deformation induced by ground water pumping in Taipei Basin: A case study in rban underground construction of Taipei metro station

    Science.gov (United States)

    Wu, Pei-Chin; Hu, Jyr-Ching

    2017-04-01

    Since 1955, the rapid development of population has requested for large amount of water usage in Taipei city. Thus, the overuse of ground water leads to the land subsidence rate up to 5 cm/yr. In 1989, the government stated to put restrictions on water pumping. Consequently, ground water recovered and resulted in the a wideapred uplift in Taipei basin. Due to the underground transportation and wiring, ground water were massively pumped for the safety of construction sites. In this study, persistent scatterer interferometry technique is used for processing 37 high resolution X-band radar images to characterize deformation map in the period from May 2011 to April 2015. From the ground table records of 30 wells in Taipei basin, the results indicated that the main factor to the surface deformation of Taipei basin is the elevation change of water table. In the case of Wuku groundwater well, the elevation change of the ground water table is about 15 m during September 2011 to April 2015. In the same period of the time, the change of surface deformation within 100 m of Wuku groundwater well is consistent to the elevation change of ground water table, and is more than 5 cm along line of sight. The storability is roughly constant across most of the aquifer with values between 0.8 x 10-4 and 1.3 x 10-3. Moreover, in the case of Taipei metro construction, according to the analytical results of radar image and the 380 vertical control points of Taipei, the high water pumping before the underground construction project will inflict surface deformation. It is noticeable that, the Jingmei Formation and the Wuku Formation are composed of the sediments with high porosity. Thus, the actual land subsidence caused by water pumping would be five times than the underground construction areas.

  17. Surface deformation in areas of abandoned mining: a case study of InSAR applied in the Northumberland region of the UK

    Science.gov (United States)

    Mccormack, Harry; Bateson, Luke; Banton, Carl; Holley, Rachel; Lawrence, David; Cigna, Francesca; Watson, Ian; Burren, Richard

    2013-04-01

    The United Kingdom has a rich history of coal mining probably dating back to Roman times, and this was a driving force behind the industrial revolution. Although the amount of mining has decreased significantly in recent years, the effects of mining on ground stability are widespread, complex and under-monitored. The Coal Authority is responsible for protecting the public and environment in coal mining areas. Particularly they are responsible for administering coal mining subsidence damage claims and preventing problems due to rising groundwater in old mining areas. Drawing on the expertise of Fugro NPA (FNPA) and the British Geological Survey (BGS), the aim of this project was to show how a wide-area ground stability dataset with associated geological interpretation could help the Coal Authority better administer their subsidence claims and groundwater management. This work was performed within the Terrafirma project. The study area chosen was the Northumberland and Durham coalfield where the last active mine closed in 2005. More than 20 seams have been mined and as depths increased this led to the need to pump water to prevent the mines from flooding. As the mines shut down the pumping stopped, causing the water level to rise and recover. Using interferometric synthetic aperture radar (InSAR) techniques FNPA produced a surface deformation dataset which was interpreted by BGS to add value in the form of geological interpretation. The dataset covers two epochs; 1995-2000 and 2002-2008. During the earlier epoch eight to nine 'hotspots' of subsidence were identified, mainly in the south of the study area. All but one of the subsidence areas shows a strong spatial correlation with areas of past mining. However there is a discrepancy in the timing of InSAR deformations and the timing of subsidence that would be expected given the type of workings. It is suspected that the spatial and temporal pattern of deformation relates not only to material extraction but also to

  18. Indirect deformation (strain) measurements and calibrations in Sandia triaxial apparatus for rock testing to 2500C

    International Nuclear Information System (INIS)

    Wawersik, W.R.

    1979-09-01

    Indirect procedures for axial and radial strain measurements on rock in triaxial tests to 250 0 C are presented. The description of techniques includes discussions of all calibrations and of the accuracies of measurements. In addition, two examples are given to show how the techniques are implemented in triaxial compression and triaxial extension experiments. 10 figures

  19. Measuring evaporation from soil surfaces for environmental and ...

    African Journals Online (AJOL)

    ... in many aspects of environmental geotechnics and waste management. The paper describes the measurements made to assess the surface energy balance as well as its analysis, and presents the results of typical measurements. It also presents numerical values of the parameters and constants needed for the analysis.

  20. Sensitivity of surface resistance measurement of HTS thin films by ...

    Indian Academy of Sciences (India)

    field distribution in the resonators. The microwave surface resistance of the superconducting sample is then extracted from the measured Q value as a function of temperature. The sensitivity of the Rs measurement, that is, the relative change in the Q value with the change in the Rs value is determined for each resonator.

  1. Measurement of tendon reflexes by surface electromyography in normal subjects

    NARCIS (Netherlands)

    Stam, J.; van Crevel, H.

    1989-01-01

    A simple method for measuring the tendon reflexes was developed. A manually operated, electronic reflex hammer was applied that enabled measurement of the strength of tendon taps. Reflex responses were recorded by surface electromyography. Stimulus-response relations and latencies of tendon reflexes

  2. Estimating the breast surface using UWB microwave monostatic backscatter measurements.

    Science.gov (United States)

    Winters, David W; Shea, Jacob D; Madsen, Ernest L; Frank, Gary R; Van Veen, Barry D; Hagness, Susan C

    2008-01-01

    This paper presents an algorithm for estimating the location of the breast surface from scattered ultrawideband (UWB) microwave signals recorded across an antenna array. Knowing the location of the breast surface can improve imaging performance if incorporated as a priori information into recently proposed microwave imaging algorithms. These techniques transmit low-power microwaves into the breast using an antenna array, which in turn measures the scattered microwave signals for the purpose of detecting anomalies or changes in the dielectric properties of breast tissue. Our proposed surface identification algorithm consists of three procedures, the first of which estimates M points on the breast surface given M channels of measured microwave backscatter data. The second procedure applies interpolation and extrapolation to these M points to generate N > M points that are approximately uniformly distributed over the breast surface, while the third procedure uses these N points to generate a 3-D estimated breast surface. Numerical as well as experimental tests indicate that the maximum absolute error in the estimated surface generated by the algorithm is on the order of several millimeters. An error analysis conducted for a basic microwave radar imaging algorithm (least-squares narrowband beamforming) indicates that this level of error is acceptable. A key advantage of the algorithm is that it uses the same measured signals that are used for UWB microwave imaging, thereby minimizing patient scan time and avoiding the need for additional hardware.

  3. Composite Match Index with Application of Interior Deformation Field Measurement from Magnetic Resonance Volumetric Images of Human Tissues

    Directory of Open Access Journals (Sweden)

    Penglin Zhang

    2012-01-01

    Full Text Available Whereas a variety of different feature-point matching approaches have been reported in computer vision, few feature-point matching approaches employed in images from nonrigid, nonuniform human tissues have been reported. The present work is concerned with interior deformation field measurement of complex human tissues from three-dimensional magnetic resonance (MR volumetric images. To improve the reliability of matching results, this paper proposes composite match index (CMI as the foundation of multimethod fusion methods to increase the reliability of these various methods. Thereinto, we discuss the definition, components, and weight determination of CMI. To test the validity of the proposed approach, it is applied to actual MR volumetric images obtained from a volunteer’s calf. The main result is consistent with the actual condition.

  4. Mapping surface soil moisture with L-band radiometric measurements

    Science.gov (United States)

    Wang, James R.; Shiue, James C.; Schmugge, Thomas J.; Engman, Edwin T.

    1989-01-01

    A NASA C-130 airborne remote sensing aircraft was used to obtain four-beam pushbroom microwave radiometric measurements over two small Kansas tall-grass prairie region watersheds, during a dry-down period after heavy rainfall in May and June, 1987. While one of the watersheds had been burned 2 months before these measurements, the other had not been burned for over a year. Surface soil-moisture data were collected at the time of the aircraft measurements and correlated with the corresponding radiometric measurements, establishing a relationship for surface soil-moisture mapping. Radiometric sensitivity to soil moisture variation is higher in the burned than in the unburned watershed; surface soil moisture loss is also faster in the burned watershed.

  5. Measuring the Deformation of a Flat Die by Applying a Laser Beam on a Reflecting Surface

    NARCIS (Netherlands)

    Assaad, W.; Geijselaers, Hubertus J.M.; Nilsen, K.E.

    2009-01-01

    The design of extrusion dies depends on the experience of the designer. After the die has been manufactured, it is tested during an extrusion process and machined several times until it works properly. The die is designed by a trial and error method which is expensive interms of time consumption and

  6. Indirect measurement of near-surface velocity and pressure fields based on measurement of moving free surface profiles

    International Nuclear Information System (INIS)

    Sibamoto, Yasuteru; Nakamura, Hideo

    2005-01-01

    A non-intrusive technique for measurement of the velocity and pressure fields adjacent to a moving fluid surface is developed. The technique is based on the measurement of fluid surface profile. The velocity and pressure fields are derived with use of the boundary element method (BEM) by seeking for an incompressible flow field that satisfies the kinematic boundary condition imposed by the time-dependent fluid surface profile. The proposed technique is tested by deriving the velocity and pressure fields inversely from the fluid surface profiles obtained by a forward BEM calculation of fluid surface response to externally-imposed pressure. The inverse calculation results show good agreement with the imposed pressure distribution in the forward calculation. (author)

  7. Advancing a smart air cushion system for preventing pressure ulcers using projection Moiré for large deformation measurements

    Science.gov (United States)

    Cheng, Sheng-Lin; Tsai, Tsung-Heng; Lee, Carina Jean-Tien; Hsu, Yu-Hsiang; Lee, Chih-Kung

    2016-03-01

    A pressure ulcer is one of the most important concerns for wheelchair bound patients with spinal cord injuries. A pressure ulcer is a localized injury near the buttocks that bear ischial tuberosity oppression over a long period of time. Due to elevated compression to blood vessels, the surrounding tissues suffer from a lack of oxygen and nutrition. The ulcers eventually lead to skin damage followed by tissue necrosis. The current medical strategy is to minimize the occurrence of pressure ulcers by regularly helping patients change their posture. However, these methods do not always work effectively or well. As a solution to fundamentally prevent pressure ulcers, a smart air cushion system was developed to detect and control pressure actively. The air cushion works by automatically adjusting a patient's sitting posture to effectively relieve the buttock pressure. To analyze the correlation between the dynamic pressure profiles of an air cell with a patient's weight, a projection Moiré system was adopted to measure the deformation of an air cell and its associated stress distribution. Combining a full-field deformation imaging with air pressure measured within an air cell, the patient's weight and the stress distribution can be simultaneously obtained. By integrating a full-field optical metrology with a time varying pressure sensor output coupled with different active air control algorithms for various designs, we can tailor the ratio of the air cells. Our preliminary data suggests that this newly developed smart air cushion has the potential to selectively reduce localized compression on the tissues at the buttocks. Furthermore, it can take a patient's weight which is an additional benefit so that medical personnel can reference it to prescribe the correct drug dosages.

  8. Roughness in Surface Force Measurements: Extension of DLVO Theory To Describe the Forces between Hafnia Surfaces.

    Science.gov (United States)

    Eom, Namsoon; Parsons, Drew F; Craig, Vincent S J

    2017-07-06

    The interaction between colloidal particles is commonly viewed through the lens of DLVO theory, whereby the interaction is described as the sum of the electrostatic and dispersion forces. For similar materials acting across a medium at pH values remote from the isoelectric point the theory typically involves an electrostatic repulsion that is overcome by dispersion forces at very small separations. However, the dominance of the dispersion forces at short separations is generally not seen in force measurements, with the exception of the interaction between mica surfaces. The discrepancy for silica surfaces has been attributed to hydration forces, but this does not explain the situation for titania surfaces where the dispersion forces are very much larger. Here, the interaction forces between very smooth hafnia surfaces have been measured using the colloid probe technique and the forces evaluated within the DLVO framework, including both hydration forces and the influence of roughness. The measured forces across a wide range of pH at different salt concentrations are well described with a single parameter for the surface roughness. These findings show that even small degrees of surface roughness significantly alter the form of the interaction force and therefore indicate that surface roughness needs to be included in the evaluation of surface forces between all surfaces that are not ideally smooth.

  9. METHODS FOR LOCAL CHANGES IN THE PLASTIC DEFORMATION DIAGNOSTICS ON THE WORK FUNCTION

    Directory of Open Access Journals (Sweden)

    K. V. Panteleyev

    2015-01-01

    Full Text Available The paper describes the electronic work function measurements by the contact potential difference technique, and experimental demonstration of the possibility of these methods application for the stress-strain state of the surface layer of the metals and alloys. The techniques end examples of their application of localization of plastic deformation studies using the Kelvin probe are developed and present. The study topology of work function the deformed surface possible to determine the type of deformation and dynamics of

  10. Measuring and modeling surface sorption dynamics of organophosphate flame retardants on impervious surfaces

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data presented in this data file is a product of a journal publication. The dataset contains measured and model predicted OPFRs gas-phase and surface-phase...

  11. Surface Moisture Measurement System Operation and Maintenance Manual

    International Nuclear Information System (INIS)

    Ritter, G.A.; Pearce, K.L.; Stokes, T.L.

    1995-12-01

    This operations and maintenance manual addresses deployment, equipment and field hazards, operating instructions, calibration verification, removal, maintenance, and other pertinent information necessary to safely operate and store the Surface Moisture Measurement System (SMMS) and Liquid Observation Well Moisture Measurement System (LOWMMS). These systems were developed primarily in support of Tank Waste Remediation System (TWRS) Safety Programs for moisture measurement in organic and ferrocyanide watch list tanks

  12. Practical aspects of tritium measurement in ground and surface waters

    Energy Technology Data Exchange (ETDEWEB)

    Nitzsche, O. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Angewandte Physik; Hebert, D. [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Angewandte Physik

    1997-03-01

    Tritium measurements are a powerful tool in hydrological and hydrogeological investigations for detecting mean residence times of several water reservoirs. Due to the low tritium activities in precipitation, ground and surface waters a low level measurement is necessary. Therefore often the liquid scintillation counting after an electrolytic enrichment of water is used. In this paper some practical aspects and problems of measurement are discussed and the problem of contamination in low level laboratories is shown. (orig.)

  13. Measurement of installation deformation of the acetabulum during prosthetic replacement of a hip joint using digital image correlation

    Science.gov (United States)

    Lei, Dong; Bai, Pengxiang; Zhu, Feipeng

    2018-01-01

    Nowadays, acetabulum prosthesis replacement is widely used in clinical medicine. However, there is no efficient way to evaluate the implantation effect of the prosthesis. Based on a modern photomechanics technique called digital image correlation (DIC), the evaluation method of the installation effect of the acetabulum was established during a prosthetic replacement of a hip joint. The DIC method determines strain field by comparing the speckle images between the undeformed sample and the deformed counterpart. Three groups of experiments were carried out to verify the feasibility of the DIC method on the acetabulum installation deformation test. Experimental results indicate that the installation deformation of acetabulum generally includes elastic deformation (corresponding to the principal strain of about 1.2%) and plastic deformation. When the installation angle is ideal, the plastic deformation can be effectively reduced, which could prolong the service life of acetabulum prostheses.

  14. Interferometric method for measuring high velocities of diffuse surfaces

    International Nuclear Information System (INIS)

    Maron, Y.

    1978-01-01

    An interferometric method for measuring the displacement of diffuse surfaces moving with velocities of a few microsecond is presented. The method utilizes the interference between two light beams reflected from a constant area of the moving surface at two different angles. It enables the detection of high rate velocity variations. Light source of a fairly low temporal coherence and power around 100mW is needed. (author)

  15. An instrument for the measurement of road surface reflection properties

    DEFF Research Database (Denmark)

    Corell, Dennis Dan; Sørensen, K.

    2017-01-01

    Road surface reflection data in the form of standard r-tables serve as input for design calculations of road lighting installations on traffic roads. However, in several countries the use of the standard r-tables has not been verified by measurement in a long period of time, while the types of road...... surfaces in use have changed - for instance to road surface types with less noise from wheel passages. Because of this, a co-operation between the road administrations of the Nordic countries (abbreviated NMF) decided to construct a portable instrument to be used on selections of traffic roads within...

  16. Experimental Method for Measuring Dust Load on Surfaces in Rooms

    DEFF Research Database (Denmark)

    Lengweiler, Philip; Nielsen, Peter V.; Moser, Alfred

    , there is a need for better understanding of the mechanism of dust deposition and resuspension. With the presented experimental setup, the dust load on surfaces in a channel can be measured as a function of the environmental and surface conditions and the type of particles under controlled laboratory conditions.......A new experimental setup to investigate the physical process of dust deposition and resuspension on and from surfaces is introduced. Dust deposition can reduce the airborne dust concentration considerably. As a basis for developing methods to eliminate dust-related problems in rooms...

  17. Reporting central tendencies of chamber measured surface emission and oxidation.

    Science.gov (United States)

    Abichou, Tarek; Clark, Jeremy; Chanton, Jeffery

    2011-05-01

    Methane emissions, concentrations, and oxidation were measured on eleven MSW landfills in eleven states spanning from California to Pennsylvania during the three year study. The flux measurements were performed using a static chamber technique. Initial concentration samples were collected immediately after placement of the flux chamber. Oxidation of the emitted methane was evaluated using stable isotope techniques. When reporting overall surface emissions and percent oxidation for a landfill cover, central tendencies are typically used to report "averages" of the collected data. The objective of this study was to determine the best way to determine and report central tendencies. Results showed that 89% of the data sets of collected surface flux have lognormal distributions, 83% of the surface concentration data sets are also lognormal. Sixty seven percent (67%) of the isotope measured percent oxidation data sets are normally distributed. The distribution of data for all eleven landfills provides insight of the central tendencies of emissions, concentrations, and percent oxidation. When reporting the "average" measurement for both flux and concentration data collected at the surface of a landfill, statistical analyses provided insight supporting the use of the geometric mean. But the arithmetic mean can accurately represent the percent oxidation, as measured with the stable isotope technique. We examined correlations between surface CH(4) emissions and surface air CH(4) concentrations. Correlation of the concentration and flux values using the geometric mean proved to be a good fit (R(2)=0.86), indicating that surface scans are a good way of identifying locations of high emissions. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. Horizontal and vertical deformation field in New Caledonia, South West Pacific, derived from more than 20 years of GNSS measurements

    Science.gov (United States)

    Ballu, V.; Calmant, S.; Valty, P.; Gravelle, M.; Sakic, P.; Aucan, J.; Pelletier, B.

    2015-12-01

    New Caledonia is located in the South West Pacific Ocean, on the Australian Plate just before its subduction under the North Fiji Basin. Because it is on the subducting side of the plate interface, New Caledonia is considered to be stable to first order and not to undergo rapid deformation. However, moderate seismicity is recorded close to the plate interface, in the southern part of the main land and along the Loyalty ridge. In addition, the main island and Loyalty ridge are subjected to long-term vertical deformation due to the flexure of the plate entering subduction. A geodetic network was installed since the early days of GPS (~1990) and has been further developed and occasionally measured since. Due to the low number of global GNSS recording stations in the early 1990s, the positioning accuracy that can be achieved with these data is poor compared to present-day standards, and expected movements are slow (possibly less than 1 mm/yr). However, the >20 year length of the time series may allow us to determine the current deformation field in New Caledonia and Loyalty Ridge. We pay special care in using older GNSS data for characterizing ground motions, reprocessing all available data using a range of different processing strategies and products. We calculated daily positions from double-differenced ionosphere-free carrier phase data in a global network using the GAMIT software and combined and aligned the results on the ITRF2008 using the CATREF software, according to the processing strategy developed as part of the current ULR6 (www.sonel.org) reprocessing campaign for IGS. We compare the double difference results with those obtained in PPP mode using JPL GIPSY software as well as CNES GINS software and different products (MIT, JPL and GRG orbits and clocks provided in the framework of the IGS2 reprocessing campaign). We present both the results for New Caledonia and an analysis of the applicability of these different processing strategies to older GNSS

  19. Inverse analysis of inner surface temperature history from outer surface temperature measurement of a pipe

    International Nuclear Information System (INIS)

    Kubo, S; Ioka, S; Onchi, S; Matsumoto, Y

    2010-01-01

    When slug flow runs through a pipe, nonuniform and time-varying thermal stresses develop and there is a possibility that thermal fatigue occurs. Therefore it is necessary to know the temperature distributions and the stress distributions in the pipe for the integrity assessment of the pipe. It is, however, difficult to measure the inner surface temperature directly. Therefore establishment of the estimation method of the temperature history on inner surface of pipe is needed. As a basic study on the estimation method of the temperature history on the inner surface of a pipe with slug flow, this paper presents an estimation method of the temperature on the inner surface of a plate from the temperature on the outer surface. The relationship between the temperature history on the outer surface and the inner surface is obtained analytically. Using the results of the mathematical analysis, the inverse analysis method of the inner surface temperature history estimation from the outer surface temperature history is proposed. It is found that the inner surface temperature history can be estimated from the outer surface temperature history by applying the inverse analysis method, even when it is expressed by the multiple frequency components.

  20. Intelligent sampling for the measurement of structured surfaces

    International Nuclear Information System (INIS)

    Wang, J; Jiang, X; Blunt, L A; Scott, P J; Leach, R K

    2012-01-01

    Uniform sampling in metrology has known drawbacks such as coherent spectral aliasing and a lack of efficiency in terms of measuring time and data storage. The requirement for intelligent sampling strategies has been outlined over recent years, particularly where the measurement of structured surfaces is concerned. Most of the present research on intelligent sampling has focused on dimensional metrology using coordinate-measuring machines with little reported on the area of surface metrology. In the research reported here, potential intelligent sampling strategies for surface topography measurement of structured surfaces are investigated by using numerical simulation and experimental verification. The methods include the jittered uniform method, low-discrepancy pattern sampling and several adaptive methods which originate from computer graphics, coordinate metrology and previous research by the authors. By combining the use of advanced reconstruction methods and feature-based characterization techniques, the measurement performance of the sampling methods is studied using case studies. The advantages, stability and feasibility of these techniques for practical measurements are discussed. (paper)

  1. Can foot anthropometric measurements predict dynamic plantar surface contact area?

    Directory of Open Access Journals (Sweden)

    Collins Natalie

    2009-10-01

    Full Text Available Abstract Background Previous studies have suggested that increased plantar surface area, associated with pes planus, is a risk factor for the development of lower extremity overuse injuries. The intent of this study was to determine if a single or combination of foot anthropometric measures could be used to predict plantar surface area. Methods Six foot measurements were collected on 155 subjects (97 females, 58 males, mean age 24.5 ± 3.5 years. The measurements as well as one ratio were entered into a stepwise regression analysis to determine the optimal set of measurements associated with total plantar contact area either including or excluding the toe region. The predicted values were used to calculate plantar surface area and were compared to the actual values obtained dynamically using a pressure sensor platform. Results A three variable model was found to describe the relationship between the foot measures/ratio and total plantar contact area (R2 = 0.77, p R2 = 0.76, p Conclusion The results of this study indicate that the clinician can use a combination of simple, reliable, and time efficient foot anthropometric measurements to explain over 75% of the plantar surface contact area, either including or excluding the toe region.

  2. Accuracy and reliability of three-dimensional surface reconstruction measurement

    International Nuclear Information System (INIS)

    Mizukami, Chikashi; Yamamoto, Etsuo; Ohmura, Masaki; Oiki, Hiroyuki; Tsuji, Jun; Muneta, Yuki; Tanabe, Makito; Hakuba, Nobuhiro; Azemoto, Syougo.

    1993-01-01

    We are using a new three-dimensional (3-D) surface reconstruction system to measure the temporal bones. This system offers the advantage of observation of the external aperture of the vestibular aqueduct and the porus acusticus internus in living subjects. However, its accuracy has not been confirmed. To investigate the accuracy of this new system, we measured the length of an in situ ceramic ossicular replacement prosthesis (CORP) of known length of 6.0 mm using 3-D surface reconstruction, conventional plain X-ray and polytomography. The CORP was scanned in the axial, sagittal and oblique directions. The mean measured length obtained with the 3-D surface reconstruction images was 5.94±0.21 on vertical scans, 5.91±0.27 on horizontal scans, and 6.01±0.25 on oblique scans. There were no significant differences among the measured lengths obtained in the three directions. Therefore, this 3-D surface reconstruction measurement system is considered to be reliable. Conversely, the mean measured length obtained by plain X-ray was 7.98±0.20, and by polytomography it was 7.94±0.23. These conventional methods have the inherent disadvantage of magnification of size which consequently requires correction. (author)

  3. Deformation measurement in the wind tunnel for an UAV leading edge with a morphing mechanism

    NARCIS (Netherlands)

    Radestock, M.; Riemenschneider, J.; Monner, H.P.; Huxdorf, O.; Werter, N.P.M.; De Breuker, R.

    2016-01-01

    In a wind tunnel experiment a morphing wing with span extension and camber morphing was investigated. The considered aircraft is an unmanned aerial vehicle (UAV) with a span of 4 m. During the investigations a half wing model was analysed with pressure and structural measurement. The half wing model

  4. Calibration of Surveying Instruments and Tools – Means to the Quality Increase of Deformation Measurements

    Directory of Open Access Journals (Sweden)

    Ján Ježko

    2014-01-01

    Originality/value: The use of a laser interferometer (laser measurement system XL 10 f. RENISHAW for the calibration of the code leveling rod, respectively of the system calibration (digital leveling device - code late prepared by the Department of Geodesy, SUT Bratislava with the help of European projects, will then be implemented in a unique facility in the Slovak Republic.

  5. An atmospheric turbulence power factor to improve the estimation of surface deformation and atmosphere phase screen using SAR interferometry

    Science.gov (United States)

    Mulder, G.; van Leijen, F. J.; Barkmeijer, J.; Haan, de, S.; Hanssen, R. F.

    2017-12-01

    Differential atmospheric delays in (time series) InSAR data are still a main cause for uncertainties and errors in deformation estimates. Particularly when deformation signals cannot be parameterized with steady-state models, it is hard to distinguish spatial anomalies due to deformation or atmosphere, often occurring at the same spatial scales. Most approaches for atmospheric mitigation are based on the assumption that the atmospheric signal can be `averaged out' by using tens of SAR acquisitions. Implicitly, this also assumes that the magnitude of the atmospheric signal is rather constant over time. The analysis of the atmospheric phase screen related to a wide range of weather events has shown that the atmospheric signal due to turbulent mixing always follows a distinct multi-scale power-law behavior, where a single power factor can be used to differentiate various weather types. In this study we estimate and use this power factor to optimally weight the InSAR observations in a time-series based on atmospheric turbulence. Our method uses the phase variation in interferograms on different length scales to characterize the turbulence with one turbulence power factor, following Kolmogorov turbulence theory. This is done by fitting a -5/3 to -8/3 power function through the power spectrum of our data, which gives an indication of the total turbulence strength in the whole image. The strength of this method is that the power factor metric is robust for most wide- and small-scale deformations and can be summarized with a single number for each interferogram. We show how the application of power law scaling is beneficial both for optimal deformation signal estimation as well as atmospheric phase screen estimation to operationally assimilate InSAR atmospheric data in weather models.

  6. DEVELOPMENT OF THE LOAD MEASURING DEVICES TO DETERMINE THE RESIDUAL DEFORMATION OF THE ELASTIC SENSING ELEMENT

    Directory of Open Access Journals (Sweden)

    Ivan V. Antonets

    2018-01-01

    Full Text Available The main focus in the design of weighing and batching devices is to create a gravimetric technique, capable of providing not only mass measurement – weighing with the required accuracy and speed, but also automatic control of technological processes and their control and regulation. In this case, the opportunity of two-way communication with a computer when designing the load measuring devices is realized, allowing remote monitoring and solution of logical problems associated with the management process. Modern automatic weighing and batching devices are important parts of comprehensive automation in different branches of industry. Existing developments of electrical, electronic, computing and other branches of instrument engineering techniques allow to implement transformations of the measured quantity with a very high degree of accuracy. However, if the measured quantity in the weighing process is perceived by the elastic sensing element of low quality, then no matter how high the accuracy of further changes is; the characteristics of the elastic element will limit the accuracy of the instrument as a whole. Although the elastic elements are simple mechanical parts, and many types of elastic elements are known and are widely used for many decades, their performance often does not meet the requirements, and hampers the device creation of high accuracy classes. Growing requirements for primary transformer makes actual the problem solution of improving the quality of elastic sensing elements not only in the manufacture but in the design. This led to the appearance of projects aimed at the development of computational and experimental methods that have altered the methodology for the design of force measuring devices.

  7. Surface temperature measurement of plasma facing components in tokamaks

    International Nuclear Information System (INIS)

    Amiel, Stephane

    2014-01-01

    During this PhD, the challenges on the non-intrusive surface temperature measurements of metallic plasma facing components in tokamaks are reported. Indeed, a precise material emissivity value is needed for classical infrared methods and the environment contribution has to be known particularly for low emissivities materials. Although methods have been developed to overcome these issues, they have been implemented solely for dedicated experiments. In any case, none of these methods are suitable for surface temperature measurement in tokamaks.The active pyrometry introduced in this study allows surface temperature measurements independently of reflected flux and emissivities using pulsed and modulated photothermal effect. This method has been validated in laboratory on metallic materials with reflected fluxes for pulsed and modulated modes. This experimental validation is coupled with a surface temperature variation induced by photothermal effect and temporal signal evolvement modelling in order to optimize both the heating source characteristics and the data acquisition and treatment. The experimental results have been used to determine the application range in temperature and detection wavelengths. In this context, the design of an active pyrometry system on tokamak has been completed, based on a bicolor camera for a thermography application in metallic (or low emissivity) environment.The active pyrometry method introduced in this study is a complementary technique of classical infrared methods used for thermography in tokamak environment which allows performing local and 2D surface temperature measurements independently of reflected fluxes and emissivities. (author) [fr

  8. Reproducibility of digital measurements of lower-limb deformity on plain radiographs and agreement with CT measurements.

    Science.gov (United States)

    Sorin, G; Pasquier, G; Drumez, E; Arnould, A; Migaud, H; Putman, S

    2016-06-01

    Five angles (HKA, HKS, alpha, beta, tibial slope) are used for goniometry in total knee arthroplasty. The reproducibility of the measurement of these angles has been assessed on plain and digitized x-rays, but to our knowledge, this has not been confirmed on x-rays taken on the PACS system and they have not been compared to computed tomography (CT) measurements, the reference for angle measurement. This prospective study aimed to: (1) evaluate the inter- and intrarater reliability of the measurement of these angles on digital x-rays taken on a PACS; (2) determine the agreement of these measurements with those obtained using a CT protocol. The measurements of these five angles on digitized radiographs are reproducible and in agreement with CT values. Forty-two patients suffering from knee osteoarthritis and scheduled for total knee arthroplasty were included in the study. Each patient had a PACS digitized x-ray and a CT intended to produce patient-specific instrumentation (Symbios, Yverdon, Switzerland) including measurements of the angles evaluated. Four senior orthopaedic surgeon-raters measured all the angles twice. Inter- and intrarater reliability was then calculated as well as the agreement between the second measurement of each rater and the CT measurement using interclass correlation and kappa coefficients (data provided as means and 95% confidence intervals). The inter- and intrarater reliability values were excellent for the HKA, alpha, and beta angles (with, respectively, a coefficient of 0.99 [0.97-0.99], 0.84 [0.76-0.9], and 0.94 [0.86-0.96] interrater reliability and 0.98 [0.96-0.99], 0.86 [0.75-0.92], and 0.65 [0.44-0.8] intrarater reliability). Interrater reliability was low for HKS and tibial slope angles (coefficients allreliability and reliability). The x-ray/CT agreement was very good for the HKA, alpha, and beta angles (0.81 [0.67-0.99], 0.74 [0.56-0.91], and 0.74 [0.45-0.92], respectively) and low for the HKS and tibial slope angles (all<0

  9. RNGCHN: a program to calculate displacement components from dislocations in an elastic half-space with applications for modeling geodetic measurements of crustal deformation

    Science.gov (United States)

    Feigl, Kurt L.; Dupré, Emmeline

    1999-07-01

    The RNGCHN program calculates a single component of the displacement field due to a finite or point-source dislocation buried in an elastic half space. This formulation approximates the surface movements produced by earthquake faulting or volcanic intrusion. As such, it is appropriate for modeling crustal deformation measured by geodetic surveying techniques, such as spirit leveling, trilateration, Very Long Baseline Interferometry (VLBI), Global Positioning System (GPS), or especially interferometric analysis of synthetic aperture radar (SAR) images. Examples suggest that this model can fit simple coseismic earthquake signatures to within their measurement uncertainties. The program's input parameters include fault position, depth, length, width, strike, dip, and three components of slip. The output consists of displacement components in the form of an ASCII list or a rectangular array of binary integers. The same program also provides partial derivatives of the displacement component with respect to all 10 input parameters. The FORTRAN source code for the program