WorldWideScience

Sample records for surface deformation occurred

  1. 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...

  2. 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...

  3. Permanent deformation behavior of naturally occurring bituminous sands

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2008-01-01

    Full Text Available were compacted close to field densities and then tested for permanent deformation at two temperatures using a newly proposed test procedure. The procedure applied stress states and ratios determined from field-loading characteristics of haul trucks...

  4. 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.

  5. Characterizing volumetric deformation behavior of naturally occuring bituminous sand materials

    CSIR Research Space (South Africa)

    Anochie-Boateng, Joseph

    2009-05-01

    Full Text Available indicated that the considerable amount of bitumen in the oil sands, high applied loads from mining equipment and seasonal changes in temperature are major fac- tors that control the modulus and deformation behavior of oil sands (Joseph 2002). To date... angle and cohesion are the material properties used for modeling the strength and stiffness behavior. Bulk modulus is an important material property that describes the resistance to volume change when an element of soil is subjected to hydrostat- ic...

  6. 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

  7. Occurence of pharmaceuticals in surface water

    Directory of Open Access Journals (Sweden)

    Dajana Gašo-Sokač

    2017-01-01

    Full Text Available Pharmaceuticals constitute a large group of human and veterinary medicinal organic compounds which have long been used throughout the world. According to their therapeutic activity they are classified in several groups: antibiotics, analgesics/antipyretic, CNS (Central nervous system drugs, cardiovascular drugs, endocrinology treatments, diagnostic aid-adsorbable organic halogen compounds. Pharmaceuticals are designed to have a physiological effect on humans and animals in trace concentrations. Pharmaceuticals end up in soil, surface waters and eventually in ground water, which can be used as a source of drinking water, after their excretion (in unmetabolized form or as active metabolites from humans or animals via urine or faeces. The possible fates of pharmaceuticals once they get into the aquatic environment are mainly three: (i ultimately they are mineralized to carbon dioxide and water, (ii the compound does not degrade readily because it is lipophilic and is partially retained in the sedimentation sludge and (iii the compound metabolizes to a more hydrophilic molecule, passes through the wastewater treatment plant and ends up in receiving waters (which are surface waters, mainly rivers. These compounds exhibit the highest persistence in the environment. In recent years, and in particular after the use of the advanced measurement technologies, many pharmaceuticals have been identified worldwide and detected at ng/L levels (trace concentrations in the aquatic environment, and are considered as an emerging environmental problem due to their continuous input and persistence in the aquatic ecosystem even at low concentrations.

  8. 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.

  9. Field evidences of secondary surface ruptures occurred during the ...

    Indian Academy of Sciences (India)

    Surface rupture and source fault of the 20 February 1956 Eskişehir earthquake have been a matter of debate that potentially contributes towards the understanding of the active deformation and seismic risk in the highly populated NW Anatolia. Field observations on the two fault segments (namely Kavacık and Uludere ...

  10. 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

  11. 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.

  12. Modelling of deformations occurring in the city of Auckland, New Zealand and observed by Differential Synthetic Aperture Radar

    Science.gov (United States)

    Samsonov, S.; Tiampo, K.; Manville, V.; Jolly, G.

    2008-12-01

    Auckland is the largest city in New Zealand with a current population of over one million. It is situated on a basaltic volcanic field which consist of over 50 individual largely monogenetic volcanoes with a total area of 360 sq. km. The most recent and largest eruption occurred 600 years ago, and was witnessed by local inhabitants. It is anticipated that the chance of reawakening of a past volcano is very low; however, a new volcano could be created at any time in a new location within the field. In this work we present results of modelling of the deformations that occurred in the city of Auckland from 18 July 2003 to 9 November 2007. These deformations were observed by the Differential Synthetic Aperture Radar on ENVISAT satellite (Track 151, Frame 6442, IS2, VV). Stacking, Small Baseline Subset (SBAS) and Permanent Scatterers (PS) processing algorithms where used to determine spatial and temporal patterns of surface deformation as well as average rates. A number of localized deformation regions were consistently observed by all three techniques. Three regions of subsidence are believed to be caused by groundwater extraction. And three source of uplift are modeled here as volcanic sources, however, the volcanic nature of these uplifts has not been confirmed.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  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. 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. 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.

  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. 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

  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. 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. Field evidences of secondary surface ruptures occurred during the ...

    Indian Academy of Sciences (India)

    Some rock slides of several tens of meters in size that obviously require significantly high ground shaking were also developed on steep fault scarps. The orientation of the principal stress tensor as deduced from the surface rupture of the Eskisehir earthquake displays clear inconsistency with the geometry of prominent ...

  7. Field evidences of secondary surface ruptures occurred during the ...

    Indian Academy of Sciences (India)

    The orientation of the principal stress tensor as deduced from the surface rupture of the Eskisehir earthquake ... history extended back to late Oligocene exhuma- tion of the Uludag massif (Okay et al 2008) and the ensuing ... accepted this view estimating stress directions from slip measurements in the main bounding faults.

  8. Ground deformation occurring in the city of Auckland, New Zealand, and observed by Envisat interferometric synthetic aperture radar during 2003-2007

    Science.gov (United States)

    Samsonov, Sergey; Tiampo, Kristy; GonzáLez, Pablo J.; Manville, Vernon; Jolly, Gill

    2010-08-01

    In this study we present modeling results derived from ground deformation observed in the Auckland Volcanic Field (AVF) by the C-band Envisat Synthetic Aperture Radar. Auckland, the largest city in New Zealand with a current population of over one million, coincides with the AVF, which comprises about 50 individual, largely monogenetic, basaltic volcanoes distributed across a total area of 360 km2. The most recent and largest eruption there occurred 600 years ago. While it is anticipated that the chance of any existing volcano reawakening is very low, a new volcano could be created at any time in a new location within the field. The aim of this work is to evaluate the feasibility of interferometric synthetic aperture radar (InSAR) for mapping ground deformation associated with magma ascent, which would be a likely precursor to the onset of volcanic activity. For this study we acquired and processed 23 single look complex (SLC) images from the Envisat satellite (Track 151, Frame 6442, IS2, VV) spanning from July 2003 until November 2007. All possible combinations of differential interferograms were created. Stacking, Small Baseline Subset (SBAS) and Permanent Scatterers (PS) processing algorithms were used to determine spatial and temporal patterns of surface deformation as well as their average rates. A number of localized deformation regions were consistently observed by all three techniques. Due to a lack of evidence pointing toward a relationship with volcanic or tectonic sources it was assumed that they are produced by groundwater withdrawal and recharge. Three largest regions of subsidence (S1-S3) and also three largest regions of uplift (U1-U3) were modeled with the derivative-free simplex algorithms for location, depth and source volume change using a Mogi point source approximation. The results show that InSAR is a viable technique capable of detecting the scale, rate and spatial distribution of precursory deformation that would likely be associated with

  9. 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.

  10. 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.

  11. 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.

  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. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. Micro-structure and chemical composition of vateritic deformities occurring in the bivalve Corbicula fluminea (Müller, 1774).

    Science.gov (United States)

    Frenzel, Max; Harper, Elizabeth M

    2011-05-01

    Vateritic deformities occurring in the invasive heterodont bivalve Corbicula fluminea from several locations in the UK were characterised in detail for the first time using scanning electron microscopy, X-ray diffraction and different geochemical techniques (electron microprobe, ICP-AES, and mass spectrometry). Large volumes of vaterite are produced abnormally in the animals' shells in the form of yellow-green bulges. These are distinguished from the aragonitic parts of the shell by their characteristic micro-structures, content of organic material, trace elemental composition and carbon stable isotope signatures. The most commonly observed micro-structures include columnar vaterite, lamellar vaterite and different irregular structures occurring in all parts of the shell. There are indications that organic material is present largely as intracrystalline impurities or nano-scale phases and not as envelopes around microstructural units. These micro-structures are novel, nothing equivalent having yet been described for other vateritic systems. Euhedral vaterite crystals also occur occasionally. The vaterite has generally higher Mg/Ca and lower Na/Ca, K/Ca than the aragonite. In addition, δ¹³C is also always lower. Microstructural characteristics would suggest loss of biological control probably due to physiological stress(es) inducing the switch to vaterite production. The vaterite might be stabilised by its higher content of organic material and magnesium. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. 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 ...

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. [Deformations occurring in the apical third of curved root canals during biomechanical preparation using manual impulsion-traction techniques].

    Science.gov (United States)

    Roig Cayón, M; Basilio Monné, J; Canalda Sahli, C

    1990-01-01

    Apical deformations, specially zips and elbows, during instrumentation of the root canals, are studied. The authors study why do they appear, their effect on endodontic therapy, and the way of avoiding them.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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

  13. 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 ...

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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...

  19. Ground deformation occurring in the city of Auckland, New Zealand, and observed by Envisat interferometric synthetic aperture radar during 2003–2007

    OpenAIRE

    Samsonov, Sergey; Tiampo, Kristy F.; González Méndez, Pablo José; Manville, Vernon; Jolly, Gill

    2010-01-01

    In this study we present modeling results derived from ground deformation observed in the Auckland Volcanic Field (AVF) by the C-band Envisat Synthetic Aperture Radar. Auckland, the largest city in New Zealand with a current population of over one million, coincides with the AVF, which comprises about 50 individual, largely monogenetic, basaltic volcanoes distributed across a total area of 360 km2. The most recent and largest eruption there occurred 600 years ago. While it is anticipated that...

  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. 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.

  2. 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.

  3. 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.

  4. 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...

  5. 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...

  6. Modeling ground deformation associated with the destructive earthquakes occurring on Mt. Etna's southeastern flank in 1984

    Directory of Open Access Journals (Sweden)

    F. Cannavò

    2016-11-01

    Full Text Available The Timpe Fault System is the source of very shallow but destructive earthquakes that affect several towns and villages on the eastern flank of Mt. Etna (Italy. In 1984, several seismic events, and specifically on 19 and 25 October, caused one fatality, 12 injuries and produced serious damage in the Zafferana and Acireale territories. This seismicity was mainly related to the activity of the Fiandaca Fault, one of the structures belonging to the Timpe Fault System. We inverted ground deformation data collected by a geodimeter trilateration network set up in 1977 at a low altitude along the eastern side of the volcano in order to define the Timpe Fault System faulting mechanisms linked to the seismicity in 1984. We have found that in the period May 1980–October 1984, the Fiandaca Fault was affected by a strike-slip and normal dip-slip of about 20.4 and 12.7 cm respectively. This result is kinematically consistent with field observations of the coseismic ground ruptures along the fault but it is notably large compared to displacements estimated by seismicity, then suggesting that most of the slip over the fault plane was aseismic. The results once again confirm how seismicity and its relation with ground ruptures and creep displacement represent a very high hazard to the several towns and villages situated along the Timpe Fault System.

  7. 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.

  8. 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

  9. Following the correction of varus deformity of the knee through total knee arthroplasty, significant compensatory changes occur not only at the ankle and subtalar joint, but also at the foot.

    Science.gov (United States)

    Jeong, Bi O; Kim, Tae Yong; Baek, Jong Hun; Jung, Hyuk; Song, Seung Hyun

    2018-01-18

    This study aimed to assess radiological changes of the ankle joint, subtalar joint and foot following the correction of varus deformity of the knee with total knee arthroplasty (TKA). It was hypothesized that following the correction of varus deformity by TKA, compensatory reactions would occur at the subtalar joint in accordance with the extent of the correction. For this prospective study, 375 knees of patients who underwent TKA between 2011 and 2012 were enrolled. The varus angle of the knee, talar tilt of the ankle joint (TT), ground-talar dome angle of the foot (GD), anterior surface angle of the distal tibia and lateral surface angle of the distal tibia, heel alignment ratio (HR), heel alignment angle (HA), and heel alignment distance (HD) were measured on radiographs obtained pre-operatively and at post-operative 6 months. The mean correction angle in varus deformity of the knee was 10.8 ± 4.1°. TT and GD changed significantly from 0.4 ± 1.9° and 6.5 ± 3.1° pre-operatively to 0.1 ± 1.8° and 0.2 ± 2.1°, respectively (p = 0.007, p varus whereas GD was oriented in valgus. Following the correction of varus deformity of the knee through TKA, significant compensatory changes occurred not only at the ankle and subtalar joints, but also at the foot. The findings of this study are useful in predicting the orientation of changes in the ankle and subtalar joints and the foot following TKA, and in determining the sequence of surgery when both the ankle and knee have a problem. In other words, changes in the parts of the lower extremity below the ankle joint following the correction of varus deformity of the knee must be considered when TKA is planned and performed. Patients who have problems at the ankle, subtalar, and foot joints in addition to varus deformity of the knee are recommended to undergo knee joint correction first. II.

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  15. 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

  16. 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%.

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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)

  2. 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.

  3. 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.

  4. 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

  5. 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...

  6. 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).

  7. 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.

  8. 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...

  9. 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

  10. 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.

  11. 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.

  12. 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....

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  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. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Modeling Surface Processes Occurring on Moons of the Outer Solar System

    Science.gov (United States)

    Umurhan, O. M.; White, O. L.; Moore, J. M.; Howard, A. D.; Schenk, P.

    2016-12-01

    A variety of processes, some with familiar terrestrial analogs, are known to take place on moon surfaces in the outer solar system. In this talk, we discuss the observed features of mass wasting and surface transport seen on both Jupiter's moon Calisto and one of Saturn's Trojan moons Helene. We provide a number of numerical models using upgraded version of MARSSIM in support of several hypotheses suggested on behalf of the observations made regarding these objects. Calisto exhibits rolling plains of low albedo materials surrounding relatively high jutting peaks harboring high albedo deposits. Our modeling supports the interpretation that Calisto's surface is a record of erosion driven by the sublimation of CO2 and H2O contained in the bedrock. Both solar insolation and surface re-radiation drives the sublimation leaving behind debris which we interpret to be the observed darkened regolith and, further, the high albedo peaks are water ice deposits on surface cold traps. On the other hand, the 45 km scale Helene, being a milligravity environment, exhibits mysterious looking streaks and grooves of very high albedo materials extending for several kilometers with a down-sloping grade of 7o-9o. Helene's cratered terrain also shows evidence of narrowed septa. The observed surface features suggest some type of advective processes are at play in this system. Our modeling lends support to the suggestion that Helene's surface materials behave as a Bingham plastic material - our flow modeling with such rheologies can reproduce the observed pattern of streakiness depending upon the smoothness of the underlying bedrock; the overall gradients observed; and the narrowed septa of inter-crater regions.

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  3. 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

  4. 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.

  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. 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

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. 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

  13. 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...

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. 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.

  12. 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.

  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. 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...

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  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. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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...

  7. 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.

  8. 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)

  9. 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.

  10. 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.

  11. 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.

  12. 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).

  13. 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.

  14. 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

  15. 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.

  16. Ground surface deformation patterns, magma supply, and magma storage at Okmok volcano, Alaska, from InSAR analysis: 2. Coeruptive deflation, July-August 2008

    Science.gov (United States)

    Lu, Zhong; Dzurisin, Daniel

    2010-01-01

    A hydrovolcanic eruption near Cone D on the floor of Okmok caldera, Alaska, began on 12 July 2008 and continued until late August 2008. The eruption was preceded by inflation of a magma reservoir located beneath the center of the caldera and ∼3 km below sea level (bsl), which began immediately after Okmok's previous eruption in 1997. In this paper we use data from several radar satellites and advanced interferometric synthetic aperture radar (InSAR) techniques to produce a suite of 2008 coeruption deformation maps. Most of the surface deformation that occurred during the eruption is explained by deflation of a Mogi-type source located beneath the center of the caldera and 2–3 km bsl, i.e., essentially the same source that inflated prior to the eruption. During the eruption the reservoir deflated at a rate that decreased exponentially with time with a 1/e time constant of ∼13 days. We envision a sponge-like network of interconnected fractures and melt bodies that in aggregate constitute a complex magma storage zone beneath Okmok caldera. The rate at which the reservoir deflates during an eruption may be controlled by the diminishing pressure difference between the reservoir and surface. A similar mechanism might explain the tendency for reservoir inflation to slow as an eruption approaches until the pressure difference between a deep magma production zone and the reservoir is great enough to drive an intrusion or eruption along the caldera ring-fracture system.

  17. DEVELOPMENT OF DEFORMATION STRIPS WHILE STRETCHING OF CYLINDRICAL SAMPLES

    Directory of Open Access Journals (Sweden)

    Y. V. Vasilevich

    2011-01-01

    Full Text Available Deformation strips have been experimentally revealed and described while stretching of cylindrical samples by means of computer thermography. It has been established that temperature of shift strip surface grows smoothly up to the stage of crack origin in material defect. Sharp growth of surface temperature occurs when tensile stresses reach tensile strength. Change in surface temperature occurs wavy after destruction (while cooling the sample. Processes of material destruction origin and development  characterize temperature changes in deformation strips.

  18. 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

    The new paradigm of plate tectonics began in 1960 with Harry H. Hess's 1960 realization that new ocean floor was being created today and is not everywhere of Precambrian age as previously thought. In the following decades an unprecedented coming together of bathymetric, topographic, magnetic, gravity, seismicity, seismic profiling data occurred, all supporting and building upon the concept of plate tectonics. Most investigators accepted the premise that there was no net torque amongst the plates. Bowin (2010) demonstrated that plates accelerated and decelerated at rates 10-8 times smaller than plate velocities, and that globally angular momentum is conserved by plate tectonic motions, but few appeared to note its existence. Here we first summarize how we separate where different mass sources may lie within the Earth and how we can estimate their mass. The Earth's greatest mass anomalies arise from topography of the boundary between the metallic nickel-iron core and the silicate mantle that dominate the Earth's spherical harmonic degree 2 and 3 potential field coefficients, and overwhelm all other internal mass anomalies. The mass anomalies due to phase changes in olivine and pyroxene in subducted lithosphere are hidden within the spherical harmonic degree 4-10 packet, and are an order of magnitude smaller than those from the core-mantle boundary. Then we explore the geometry of the Emperor and Hawaiian seamount chains and the 60° bend between them that aids in documenting the slow acceleration during both the Pacific Plate's northward motion that formed the Emperor seamount chain and its westward motion that formed the Hawaiian seamount chain, but it decelerated at the time of the bend (46 Myr). Although the 60° change in direction of the Pacific Plate at of the bend, there appears to have been nary a pause in a passive spreading history for the North Atlantic Plate, for example. This, too, supports phase change being the single driver for plate tectonics and

  19. 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.

  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. 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.

  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. 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.

  5. 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.

  6. 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...

  7. 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.

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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).

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. 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

  10. 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 ...

  11. Naturally occurring mutations in large surface genes related to occult infection of hepatitis B virus genotype C.

    Directory of Open Access Journals (Sweden)

    Hong Kim

    Full Text Available Molecular mechanisms related to occult hepatitis B virus (HBV infection, particularly those based on genotype C infection, have rarely been determined thus far in the ongoing efforts to determine infection mechanisms. Therefore, we aim to elucidate the mutation patterns in the surface open reading frame (S ORF underlying occult infections of HBV genotype C in the present study. Nested PCRs were applied to 624 HBV surface antigen (HBsAg negative Korean subjects. Cloning and sequencing of the S ORF gene was applied to 41 occult cases and 40 control chronic carriers. Forty-one (6.6% of the 624 Korean adults with HBsAg-negative serostatus were found to be positive for DNA according to nested PCR tests. Mutation frequencies in the three regions labeled here as preS1, preS2, and S were significantly higher in the occult subjects compared to the carriers in all cases. A total of two types of deletions, preS1 deletions in the start codon and preS2 deletions as well as nine types of point mutations were significantly implicated in the occult infection cases. Mutations within the "a" determinant region in HBsAg were found more frequently in the occult subjects than in the carriers. Mutations leading to premature termination of S ORF were found in 16 occult subjects (39.0% but only in one subject from among the carriers (2.5%. In conclusion, our data suggest that preS deletions, the premature termination of S ORF, and "a" determinant mutations are associated with occult infections of HBV genotype C among a HBsAg-negative population. The novel mutation patterns related to occult infection introduced in the present study can help to broaden our understanding of HBV occult infections.

  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. 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.

  14. 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.

  15. Analysis of phase transformation occurring during deformation and recrystallization processes in Ti-Nb-Si alloys; Analise das transformacoes de fases ocorridas durante os processos de deformacao e recristalizacao em ligas de Ti-Nb-Si

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, H.J.R.; Batista, W.W.; Souza, S.A.; Dos Santos, D.F.D.; Lima, T.N.; Ramos, W.S., E-mail: helton_cabral@hotmail.com [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil)

    2014-07-01

    This paper presents an analysis of phase transformations in Ti-Nb-Si alloys. The alloys were produced in the arc furnace with a controlled atmosphere of argon and were then homogenized at 1000 ° for 8 hours and deformed by compression. The deformed alloys were recrystallized at the temperatures of 500, 600 and 700 ° C. Were used Optical Microscopy, Vickers Microhardness and X-ray Diffraction techniques in order to assess the effect of cold deformation and recrystallization processes in the hardness and phases present in the alloys. (author)

  16. 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...

  17. 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

  18. 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

  19. 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.

  20. 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.

  1. 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.

  2. Deformation processes within wheel-rail adhesion in contact area

    Science.gov (United States)

    Albagachiev, A. Yu; Keropyan, A. M.

    2018-03-01

    The study of working surface deformation during interaction of open-pit locomotive tires allowed defining outstanding features of phenomena occurring in the contact area of interacting surfaces. It was found that processes typical for plastic saturated contact occur in the area of wheel-rail interaction of industrial railway transport. In case of plastic deformation exposed to heavy loads typical for open-pit locomotives, upon all rough surfaces of the contour contact area being fully deformed, the frame on which they are found is exposed to plastic deformation. Plastic deformation of roughness within the contact area of interacting surfaces leads to the increase in the actual area of their contact and, therefore, increases the towing capacity of mining machines. Finally, the available data on deformation characteristics with regard to processes occurring in the contact area of wheel-rail interaction will allow making theoretical forecasts on the expected design value of friction coefficient and, therefore, the towing capacity of open-pit locomotives.

  3. Inactivation of lipoprotein lipase occurs on the surface of THP-1 macrophages where oligomers of angiopoietin-like protein 4 are formed

    International Nuclear Information System (INIS)

    Makoveichuk, Elena; Sukonina, Valentina; Kroupa, Olessia; Thulin, Petra; Ehrenborg, Ewa; Olivecrona, Thomas; Olivecrona, Gunilla

    2012-01-01

    Highlights: ► Lipoprotein lipase (LPL) activity is controlled by ANGPTL4 in THP-1 macrophages. ► Both LPL and ANGPTL4 bind to THP-1 macrophages in a heparin-releasable fashion. ► Only monomers of ANGPTL4 are present within THP-1 macrophages. ► Covalent oligomers of ANGPTL4 appear on cell surface and in medium. ► Inactivation of LPL coincide with ANGPTL4 oligomer formation on cell surfaces. -- Abstract: Lipoprotein lipase (LPL) hydrolyzes triglycerides in plasma lipoproteins causing release of fatty acids for metabolic purposes in muscles and adipose tissue. LPL in macrophages in the artery wall may, however, promote foam cell formation and atherosclerosis. Angiopoietin-like protein (ANGPTL) 4 inactivates LPL and ANGPTL4 expression is controlled by peroxisome proliferator-activated receptors (PPAR). The mechanisms for inactivation of LPL by ANGPTL4 was studied in THP-1 macrophages where active LPL is associated with cell surfaces in a heparin-releasable form, while LPL in the culture medium is mostly inactive. The PPARδ agonist GW501516 had no effect on LPL mRNA, but increased ANGPTL4 mRNA and caused a marked reduction of the heparin-releasable LPL activity concomitantly with accumulation of inactive, monomeric LPL in the medium. Intracellular ANGPTL4 was monomeric, while dimers and tetramers of ANGPTL4 were present in the heparin-releasable fraction and medium. GW501516 caused an increase in the amount of ANGPTL4 oligomers on the cell surface that paralleled the decrease in LPL activity. Actinomycin D blocked the effects of GW501516 on ANGPTL4 oligomer formation and prevented the inactivation of LPL. Antibodies against ANGPTL4 interfered with the inactivation of LPL. We conclude that inactivation of LPL in THP-1 macrophages primarily occurs on the cell surface where oligomers of ANGPTL4 are formed.

  4. Inactivation of lipoprotein lipase occurs on the surface of THP-1 macrophages where oligomers of angiopoietin-like protein 4 are formed

    Energy Technology Data Exchange (ETDEWEB)

    Makoveichuk, Elena; Sukonina, Valentina; Kroupa, Olessia [Department of Medical Biosciences, Physiological Chemistry Umea University, SE-901 87 Umea (Sweden); Thulin, Petra; Ehrenborg, Ewa [Atherosclerosis Research Unit, Department of Medicine, Karolinska Institutet, SE-171 76 Stockholm (Sweden); Olivecrona, Thomas [Department of Medical Biosciences, Physiological Chemistry Umea University, SE-901 87 Umea (Sweden); Olivecrona, Gunilla, E-mail: Gunilla.Olivecrona@medbio.umu.se [Department of Medical Biosciences, Physiological Chemistry Umea University, SE-901 87 Umea (Sweden)

    2012-08-24

    Highlights: Black-Right-Pointing-Pointer Lipoprotein lipase (LPL) activity is controlled by ANGPTL4 in THP-1 macrophages. Black-Right-Pointing-Pointer Both LPL and ANGPTL4 bind to THP-1 macrophages in a heparin-releasable fashion. Black-Right-Pointing-Pointer Only monomers of ANGPTL4 are present within THP-1 macrophages. Black-Right-Pointing-Pointer Covalent oligomers of ANGPTL4 appear on cell surface and in medium. Black-Right-Pointing-Pointer Inactivation of LPL coincide with ANGPTL4 oligomer formation on cell surfaces. -- Abstract: Lipoprotein lipase (LPL) hydrolyzes triglycerides in plasma lipoproteins causing release of fatty acids for metabolic purposes in muscles and adipose tissue. LPL in macrophages in the artery wall may, however, promote foam cell formation and atherosclerosis. Angiopoietin-like protein (ANGPTL) 4 inactivates LPL and ANGPTL4 expression is controlled by peroxisome proliferator-activated receptors (PPAR). The mechanisms for inactivation of LPL by ANGPTL4 was studied in THP-1 macrophages where active LPL is associated with cell surfaces in a heparin-releasable form, while LPL in the culture medium is mostly inactive. The PPAR{delta} agonist GW501516 had no effect on LPL mRNA, but increased ANGPTL4 mRNA and caused a marked reduction of the heparin-releasable LPL activity concomitantly with accumulation of inactive, monomeric LPL in the medium. Intracellular ANGPTL4 was monomeric, while dimers and tetramers of ANGPTL4 were present in the heparin-releasable fraction and medium. GW501516 caused an increase in the amount of ANGPTL4 oligomers on the cell surface that paralleled the decrease in LPL activity. Actinomycin D blocked the effects of GW501516 on ANGPTL4 oligomer formation and prevented the inactivation of LPL. Antibodies against ANGPTL4 interfered with the inactivation of LPL. We conclude that inactivation of LPL in THP-1 macrophages primarily occurs on the cell surface where oligomers of ANGPTL4 are formed.

  5. 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.

  6. Morphogenesis of respiratory syncytial virus in human primary nasal ciliated epithelial cells occurs at surface membrane microdomains that are distinct from cilia

    International Nuclear Information System (INIS)

    Jumat, Muhammad Raihan; Yan, Yan; Ravi, Laxmi Iyer; Wong, Puisan; Huong, Tra Nguyen; Li, Chunwei; Tan, Boon Huan; Wang, De Yun; Sugrue, Richard J.

    2015-01-01

    The distribution of cilia and the respiratory syncytial virus (RSV) nucleocapsid (N) protein, fusion (F) protein, attachment (G) protein, and M2-1 protein in human ciliated nasal epithelial cells was examined at between 1 and 5 days post-infection (dpi). All virus structural proteins were localized at cell surface projections that were distinct from cilia. The F protein was also trafficked into the cilia, and while its presence increased as the infection proceeded, the N protein was not detected in the cilia at any time of infection. The presence of the F protein in the cilia correlated with cellular changes in the cilia and reduced cilia function. At 5 dpi extensive cilia loss and further reduced cilia function was noted. These data suggested that although RSV morphogenesis occurs at non-cilia locations on ciliated nasal epithelial cells, RSV infection induces changes in the cilia body that leads to extensive cilia loss. - Highlights: • Respiratory syncytial virus (RSV) infects nasal ciliated epithelial cells. • Virus morphogenesis occurs within filamentous projections distinct from cilia. • The RSV N protein was not detected in the cilia at any time during infection. • Trafficking of the F protein into the cilia occurred early in infection. • Presence of the F protein in cilia correlated with impaired cilia function

  7. Morphogenesis of respiratory syncytial virus in human primary nasal ciliated epithelial cells occurs at surface membrane microdomains that are distinct from cilia

    Energy Technology Data Exchange (ETDEWEB)

    Jumat, Muhammad Raihan [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Yan, Yan [Department of Otolaryngology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore 119228 (Singapore); Ravi, Laxmi Iyer [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Wong, Puisan [Detection and Diagnostics Laboratory, DSO National Laboratories, 27 Medical Drive, Singapore 117510 (Singapore); Huong, Tra Nguyen [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Li, Chunwei [Department of Otolaryngology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore 119228 (Singapore); Tan, Boon Huan [Detection and Diagnostics Laboratory, DSO National Laboratories, 27 Medical Drive, Singapore 117510 (Singapore); Wang, De Yun [Department of Otolaryngology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore 119228 (Singapore); Sugrue, Richard J., E-mail: rjsugrue@ntu.edu.sg [School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore)

    2015-10-15

    The distribution of cilia and the respiratory syncytial virus (RSV) nucleocapsid (N) protein, fusion (F) protein, attachment (G) protein, and M2-1 protein in human ciliated nasal epithelial cells was examined at between 1 and 5 days post-infection (dpi). All virus structural proteins were localized at cell surface projections that were distinct from cilia. The F protein was also trafficked into the cilia, and while its presence increased as the infection proceeded, the N protein was not detected in the cilia at any time of infection. The presence of the F protein in the cilia correlated with cellular changes in the cilia and reduced cilia function. At 5 dpi extensive cilia loss and further reduced cilia function was noted. These data suggested that although RSV morphogenesis occurs at non-cilia locations on ciliated nasal epithelial cells, RSV infection induces changes in the cilia body that leads to extensive cilia loss. - Highlights: • Respiratory syncytial virus (RSV) infects nasal ciliated epithelial cells. • Virus morphogenesis occurs within filamentous projections distinct from cilia. • The RSV N protein was not detected in the cilia at any time during infection. • Trafficking of the F protein into the cilia occurred early in infection. • Presence of the F protein in cilia correlated with impaired cilia function.

  8. 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.

  9. Cosmetic and Functional Nasal Deformities

    Science.gov (United States)

    ... nasal complaints. Nasal deformity can be categorized as “cosmetic” or “functional.” Cosmetic deformity of the nose results in a less ... taste , nose bleeds and/or recurrent sinusitis . A cosmetic or functional nasal deformity may occur secondary to ...

  10. 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.

  11. 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.

  12. 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

  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. 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

  15. Twist deformation in anticlinic antiferroelectric structure in smectic B.sub.2./sub. imposed by the surface anchoring

    Czech Academy of Sciences Publication Activity Database

    Lejček, Lubor; Novotná, Vladimíra; Glogarová, Milada

    2008-01-01

    Roč. 35, č. 1 (2008), s. 11-19 ISSN 0267-8292 R&D Projects: GA ČR GA202/05/0431 Institutional research plan: CEZ:AV0Z10100520 Keywords : smectic liquid crystals * bent-shaped molecules * anticlinic antiferroelectric structure * ferroelectric structure * twist deformation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.132, year: 2008

  16. Physical model studies of seismically induced deformations in slopes

    Science.gov (United States)

    Wartman, Joseph

    Physical model experiments were conducted on a 1-g shaking table with the goals of: (1) investigating the mechanisms of seismically induced permanent deformations in slopes and embankments, (2) assessing the accuracy and applicability of the popular "Newmark-type" procedures for estimating deformations in slopes, and (3) developing a suite of fully defined "model-scale" case histories for calibration of existing numerical procedures for predicting seismic slope deformations and for the future development of advanced numerical analyses. The inclined plane experiments indicated that the Newmark (1965) sliding block procedure generally provides unconservative estimates of deformation when the predominant frequency of the input motion is 0.2 to 1.5 times the natural frequency of the sliding mass. Conversely, the procedure was found to be generally conservative when the frequency ratio is in the range of about 1.5 to 2.2. The inclined plane tests also suggest that one-dimensional decoupled deformation analyses are generally conservative, with decoupled analyses overpredicting measured deformations by about 10% to 20% for the tests analyzed. The model slopes were commonly observed to displace along two or more localized shear surfaces. The multiple shear surfaces were typically of the same orientation and generally located within relatively close proximity of each other. Surface deformations varied over the length of each model, with the largest displacements occurring at the toe or along the face of the slope. Newmark's (1965) assumption that deformation occurs along a single surface reasonably approximated the actual deformation behavior for tests where multiple shear surfaces developed in close proximity to each other. For approximately half the tests, however, the single surface assumption proved to be an oversimplification. Accuracy was improved when the Newmark (1965) procedure was modified by using the acceleration-time history recorded in the soil immediately

  17. 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.

  18. First-Principles Surface Stress Calculations and Multiscale Deformation Analysis of a Self-Assembled Monolayer Adsorbed on a Micro-Cantilever

    Directory of Open Access Journals (Sweden)

    Yu-Ching Shih

    2014-04-01

    Full Text Available Micro-cantilever sensors are widely used to detect biomolecules, chemical gases, and ionic species. However, the theoretical descriptions and predictive modeling of these devices are not well developed, and lag behind advances in fabrication and applications. In this paper, we present a novel multiscale simulation framework for nanomechanical sensors. This framework, combining density functional theory (DFT calculations and finite element method (FEM analysis, is capable of analyzing molecular adsorption-induced deformation and stress fields in the sensors from the molecular scale to the device scale. Adsorption of alkanethiolate self-assembled monolayer (SAM on the Au(111 surface of the micro-cantilever sensor is studied in detail to demonstrate the applicability of this framework. DFT calculations are employed to investigate the molecular adsorption-induced surface stress upon the gold surface. The 3D shell elements with initial stresses obtained from the DFT calculations serve as SAM domains in the adsorption layer, while FEM is employed to analyze the deformation and stress of the sensor devices. We find that the micro-cantilever tip deflection has a linear relationship with the coverage of the SAM domains. With full coverage, the tip deflection decreases as the molecular chain length increases. The multiscale simulation framework provides a quantitative analysis of the displacement and stress fields, and can be used to predict the response of nanomechanical sensors subjected to complex molecular adsorption.

  19. First-principles surface stress calculations and multiscale deformation analysis of a self-assembled monolayer adsorbed on a micro-cantilever.

    Science.gov (United States)

    Shih, Yu-Ching; Chen, Chuin-Shan; Wu, Kuang-Chong

    2014-04-23

    Micro-cantilever sensors are widely used to detect biomolecules, chemical gases, and ionic species. However, the theoretical descriptions and predictive modeling of these devices are not well developed, and lag behind advances in fabrication and applications. In this paper, we present a novel multiscale simulation framework for nanomechanical sensors. This framework, combining density functional theory (DFT) calculations and finite element method (FEM) analysis, is capable of analyzing molecular adsorption-induced deformation and stress fields in the sensors from the molecular scale to the device scale. Adsorption of alkanethiolate self-assembled monolayer (SAM) on the Au(111) surface of the micro-cantilever sensor is studied in detail to demonstrate the applicability of this framework. DFT calculations are employed to investigate the molecular adsorption-induced surface stress upon the gold surface. The 3D shell elements with initial stresses obtained from the DFT calculations serve as SAM domains in the adsorption layer, while FEM is employed to analyze the deformation and stress of the sensor devices. We find that the micro-cantilever tip deflection has a linear relationship with the coverage of the SAM domains. With full coverage, the tip deflection decreases as the molecular chain length increases. The multiscale simulation framework provides a quantitative analysis of the displacement and stress fields, and can be used to predict the response of nanomechanical sensors subjected to complex molecular adsorption.

  20. Deformed configurations, band structures and spectroscopic ...

    Indian Academy of Sciences (India)

    2014-03-20

    Mar 20, 2014 ... The deformed configurations and rotational band structures in =50 Ge and Se nuclei are studied by deformed Hartree–Fock with quadrupole constraint and angular momentum projection. Apart from the `almost' spherical HF solution, a well-deformed configuration occurs at low excitation. A deformed ...

  1. Surface deformation associated with the 2015 Mw 8.3 Illapel earthquake revealed by satellite-based geodetic observations and its implications for the seismic cycle

    Science.gov (United States)

    Feng, Wanpeng; Samsonov, Sergey; Tian, Yunfeng; Qiu, Qiang; Li, Peng; Zhang, Yong; Deng, Zhiguo; Omari, Khalid

    2017-02-01

    In this study, we present inter-, co- and post-seismic displacements observed in the 2015 Illapel earthquake area by Global Positioning System (GPS) and Synthetic Aperture Radar Interferometry (InSAR). RADARSAT-2, ALOS-2 and Sentinel-1A interferograms capture the co- and post-seismic displacements due to the Illapel earthquake. Based on a layered Earth structure, we modeled both co- and post-seismic faulting behaviors on the subduction interface of central Chile. The best-fit model shows that the coseismic rupture broke a 200 km × 200 km area with a maximum slip of 10 m at a depth of 20 km. Two distinct slip centers, likely controlled by local ramp-flat structure, are revealed. The total coseismic geodetic moment is 2.76 ×1021 N m, equivalent to a moment magnitude 8.3. The accumulated afterslip in the first two months after the mainshock is observed on both sides of the coseismic rupture zone with both ascending and descending Sentinel-1A interferograms. A limited overlap zone between co- and post-seismic slip models can be observed, suggesting partitioning of the frictional properties within the Illapel earthquake rupture zone. The total afterslip releases ∼ 5.0 ×1020 N m geodetic moment, which is equivalent to an earthquake of Mw 7.7. The 2010 Mw 8.8 Maule earthquake that occurred ∼400 km away from the Illapel earthquake epicenter could have exerted certain effects on the seismic cycle of the Illapel earthquake area. The seismic records from 2000 to 2015 imply that the rate of annual seismic moment release in the Illapel earthquake area dropped from 0.4 to 0.2 ×1019 N m /yr after the Maule earthquake. Based on the forward modeling with the best-fit slip models determined in this study, we reproduce the local surface displacements before, during and after the Illapel earthquake. A rough deformation cycle, 105 ± 29 yr, calculated by using the coseismic displacements and interseismic rate is basically identical with the revisit interval of M8 events in the

  2. Contemporary Surface Seasonal Oscillation and Vertical Deformation in Tibetan Plateau and Nepal Derived from the GPS, Leveling and GRACE Data

    Science.gov (United States)

    Shen, W.; Pan, Y.; Hwang, C.; Ding, H.

    2015-12-01

    We use 168 Continuous Global Positioning System (CGPS) stations distributed in the Tibetan Plateau (TP) and Nepal from lengths of 2.5 to 14 years to estimate the present-day velocity field in this area, including the horizontal and vertical deformations under the frame ITRF2008. We estimate and remove common mode errors in regional GPS time series using the principal component analysis (PCA), obtaining a time series with high signal to noise ratio. Following the maximum estimation analysis, a power law plus white noise stochastic model are adopted to estimate the velocity field. The highlight of Tibetan region is the crust vertical deformation. GPS vertical time series present seasonal oscillations caused by temporal mass loads, hence GRACE data from CSR are used to study the mass loads change. After removing the mass load deformations from GPS vertical rates, the results are improved. Leveling data about 48 years in this region are also used to estimate the rates of vertical movements. Our study suggests that the boundary of south Nepal is still sinking due to the fact that the India plate is crashing into the Eurasian plate. The uplift rates from south to north of TP reduce gradually. Himalayas region and north Nepal uplift around 6 mm/yr in average. The uplift rate along East TP in Qinhai is around 2.7 mm/yr in average. In contrast, the southeast of Tibetan Plateau, south Yunnan and Tarim in Xinjiang sink with different magnitudes. Our observation results suggest complicated mechanism of the mass migration in TP. This study is supported by National 973 Project China (grant Nos. 2013CB733302 and 2013CB733305), NSFC (grant Nos. 41174011, 41429401, 41210006, 41128003, 41021061).

  3. Producing a gradient-composition nanocrystalline structure on nitrided surfaces of invar-type Fe-Ni alloys using megaplastic deformation

    Science.gov (United States)

    Shabashov, V. A.; Borisov, S. V.; Litvinov, A. V.; Kataeva, N. V.; Afanas'ev, S. V.; Titova, S. G.

    2014-09-01

    A nanocrystalline Fe-Ni matrix strengthened by dispersed CrN and TiN nitrides has been produced on the ion-plasma-nitrided surfaces of the austenitic Fe-Ni38-Cr15 and Fe-Ni36-Ti4 alloys using cyclic "nitride dissolution-nitride precipitation" phase transformations induced by megaplastic deformation. The high-pressure torsion of the nitrided alloys has led to the dissolution of the CrN nitrides and Ni3Ti intermetallic compounds, which appeared in the matrix, in the surface layer and to the mechanical alloying of the nitrided subsurface layer and the unnitriderd bulk of the specimens. Subsequent annealing has resulted in the formation of secondary nitrides, which propagated to a depth substantially exceeding the thickness of the original nitrided layer.

  4. 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

  5. Surface tension determination using data of the evolution of thermocapillary deformations in a locally heated liquid layer

    Directory of Open Access Journals (Sweden)

    Barakhovskaia Ella

    2017-01-01

    Full Text Available Identifying liquids in chemical technologies and in the oil industry is an actual problem. Such identifications can be made using individual characteristics of thermocapillary flows and deformations in the horizontal layers of the investigated liquids. Numerical algorithms and calculating code have been developed for solving inverse problems for identifying properties of liquid. As additional information for inverse problem a function of thermocapillary response is used. The algorithm for solving inverse problem is based on solving problem of minimizing the residual function. The minimum is obtained numerically by the Newton’s method. Numerical calculations have been made for silicone oil. Thermocapillary responses have been calculated for different values of the coefficients. The developed algorithms have been tested on synthetic data, which have been obtained from the solution of direct problems. The developed algorithms have shown a good convergence and efficiency.

  6. 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...

  7. Quantitative analysis of surface deformation and ductile flow in complex analogue geodynamic models based on PIV method.

    Science.gov (United States)

    Krýza, Ondřej; Lexa, Ondrej; Závada, Prokop; Schulmann, Karel; Gapais, Denis; Cosgrove, John

    2017-04-01

    Recently, a PIV (particle image velocimetry) analysis method is optical method abundantly used in many technical branches where material flow visualization and quantification is important. Typical examples are studies of liquid flow through complex channel system, gas spreading or combustion problematics. In our current research we used this method for investigation of two types of complex analogue geodynamic and tectonic experiments. First class of experiments is aimed to model large-scale oroclinal buckling as an analogue of late Paleozoic to early Mesozoic evolution of Central Asian Orogenic Belt (CAOB) resulting from nortward drift of the North-China craton towards the Siberian craton. Here we studied relationship between lower crustal and lithospheric mantle flows and upper crustal deformation respectively. A second class of experiments is focused to more general study of a lower crustal flow in indentation systems that represent a major component of some large hot orogens (e.g. Bohemian massif). The most of simulations in both cases shows a strong dependency of a brittle structures shape, that are situated in upper crust, on folding style of a middle and lower ductile layers which is influenced by rheological, geometrical and thermal conditions of different parts across shortened domain. The purpose of PIV application is to quantify material redistribution in critical domains of the model. The derivation of flow direction and calculation of strain-rate and total displacement field in analogue experiments is generally difficult and time-expensive or often performed only on a base of visual evaluations. PIV method operates with set of images, where small tracer particles are seeded within modeled domain and are assumed to faithfully follow the material flow. On base of pixel coordinates estimation the material displacement field, velocity field, strain-rate, vorticity, tortuosity etc. are calculated. In our experiments we used velocity field divergence to

  8. Porosity reduction within shear deformation bands in unconsolidated Pleistocene sediments

    Science.gov (United States)

    Brandes, Christian; Tanner, David

    2016-04-01

    Deformation bands are important structural elements that occur in the upper crust and develop in porous sandstones and even in unconsolidated sands. In contrast to discrete surfaces such as faults, deformation bands represent tabular zones of continuous displacement over several centimeters (Fossen et al., 2007). We present an outcrop-based study on the internal fabric of shear deformation bands that developed in Pleistocene unconsolidated sands in northern Germany. The deformation bands formed in an extensional stress regime, have a normal sense of displacement in a range of centimeters to decimeters, and form conjugate sets that intersect at angles between 70° and 90° (Brandes & Tanner, 2012). Due to their near-surface position, they are a perfect target for the study of deformation band formation prior to burial and diagenesis. Thin section analysis show a significant pore space reduction from the host sediment to the shear deformation band. The boundary between the host sediment and the shear deformation bands can be very sharp. The grains within the deformation band are of the same grain size as the host sediment. Grain shape varies from angular to well-rounded. Many elliptic grains have a long-axis orientation parallel to the trend of the deformation band. The grains in the analysed thin sections are all intact, i.e., there is no evidence for cataclasis. We believe the shear deformation bands are created by a grain-sliding process that decreases the porosity and leads to a denser packing of the sand. This is a porosity reduction mechanism in sandstone that occurs prior to burial without cataclasis. This can have an impact on fluid-flow in unconsolidated sediments in the near-surface. References: Brandes, C. & Tanner, D.C. (2012) Three-dimensional geometry and fabric of shear deformation bands in unconsolidated Pleistocene sediments. Tectonophysics, 518-521, 84-92. Fossen, H., Schultz, R.A., Shipton, Z.K., & Mair, K. (2007) Deformation bands in sandstone: a

  9. Deformation microstructures

    DEFF Research Database (Denmark)

    Hansen, N.; Huang, X.; Hughes, D.A.

    2004-01-01

    Microstructural characterization and modeling has shown that a variety of metals deformed by different thermomechanical processes follows a general path of grain subdivision, by dislocation boundaries and high angle boundaries. This subdivision has been observed to very small structural scales...

  10. Deformation analysis of shallow penetration in clay

    Science.gov (United States)

    Sagaseta, C.; Whittle, A. J.; Santagata, M.

    1997-10-01

    A new method of analysis is described for estimating the deformations and strains caused by shallow undrained penetration of piles and caissons in clay. The formulation combines previous analyses for steady, deep penetration, with methods used to compute soil deformations due to near-surface ground loss, and is referred to as the Shallow Strain Path Method (SSPM). Complete analytical solutions for the velocity and strain rates are given for a planar wall, an axisymmetric, closed-ended pile and unplugged, open-ended pile geometries. In these examples, the analyses consider a single source penetrating through the soil at a constant rate, generating a family of penetrometers with rounded tips, referred to as simple wall, pile and tube geometries. Soil deformations and strains are obtained by integrating the velocity and strain rates along the particle paths.The transition from shallow to deep penetration is analysed in detail. Shallow penetration causes heave at the ground surface, while settlements occur only in a thin veneer of material adjacent to the shaft and in a bulb-shaped region around the tip. The size of this region increases with the embedment depth. Deformations inside an open-ended pile/caisson are affected significantly by details of the simple tube wall geometry.

  11. The August 24th 2016 Accumoli earthquake: surface faulting and Deep-Seated Gravitational Slope Deformation (DSGSD in the Monte Vettore area

    Directory of Open Access Journals (Sweden)

    Domenico Aringoli

    2016-11-01

    Full Text Available On August 24th 2016 a Mw=6.0 earthquake hit central Italy, with the epicenter located at the boundaries between Lazio, Marche, Abruzzi and Umbria regions, near the village of Accumoli (Rieti, Lazio. Immediately after the mainshock, this geological survey has been focused on the earthquake environmental effects related to the tectonic reactivation of the previously mapped active fault (i.e. primary, as well as secondary effects mostly related to the seismic shaking (e.g. landslides and fracturing in soil and rock.This paper brings data on superficial effects and some preliminary considerations about the interaction and possible relationship between surface faulting and the occurrence of Deep-Seated Gravitational Slope Deformation (DSGSD along the southern and western slope of Monte Vettore.

  12. 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

  13. 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

  14. Source model for the Copahue volcano magma plumbing system constrained by InSAR surface deformation observations

    Science.gov (United States)

    Lundgren, Paul; Nikkhoo, Mehdi; Samsonov, Sergey V.; Milillo, Pietro; Gil-Cruz, Fernando; Lazo, Jonathan

    2017-07-01

    Copahue volcano straddling the edge of the Agrio-Caviahue caldera along the Chile-Argentina border in the southern Andes has been in unrest since inflation began in late 2011. We constrain Copahue's source models with satellite and airborne interferometric synthetic aperture radar (InSAR) deformation observations. InSAR time series from descending track RADARSAT-2 and COSMO-SkyMed data span the entire inflation period from 2011 to 2016, with their initially high rates of 12 and 15 cm/yr, respectively, slowing only slightly despite ongoing small eruptions through 2016. InSAR ascending and descending track time series for the 2013-2016 time period constrain a two-source compound dislocation model, with a rate of volume increase of 13 × 106 m3/yr. They consist of a shallow, near-vertical, elongated source centered at 2.5 km beneath the summit and a deeper, shallowly plunging source centered at 7 km depth connecting the shallow source to the deeper caldera. The deeper source is located directly beneath the volcano tectonic seismicity with the lower bounds of the seismicity parallel to the plunge of the deep source. InSAR time series also show normal fault offsets on the NE flank Copahue faults. Coulomb stress change calculations for right-lateral strike slip (RLSS), thrust, and normal receiver faults show positive values in the north caldera for both RLSS and normal faults, suggesting that northward trending seismicity and Copahue fault motion within the caldera are caused by the modeled sources. Together, the InSAR-constrained source model and the seismicity suggest a deep conduit or transfer zone where magma moves from the central caldera to Copahue's upper edifice.

  15. 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,

  16. Fraktalnist deformational relief polycrystalline aluminum

    Directory of Open Access Journals (Sweden)

    М.В. Карускевич

    2006-02-01

    Full Text Available  The possibility of the fractal geometry method application for the analisys of surface deformation structures under cyclic loading is presented.It is shown, that deformation relief of the alclad aluminium alloyes meets the criteria of the fractality. For the fractal demention estimation the method of  “box-counting”can be applied.

  17. Deformation mechanisms in experimentally deformed Boom Clay

    Science.gov (United States)

    Desbois, Guillaume; Schuck, Bernhard; Urai, Janos

    2016-04-01

    Bulk mechanical and transport properties of reference claystones for deep disposal of radioactive waste have been investigated since many years but little is known about microscale deformation mechanisms because accessing the relevant microstructure in these soft, very fine-grained, low permeable and low porous materials remains difficult. Recent development of ion beam polishing methods to prepare high quality damage free surfaces for scanning electron microscope (SEM) is opening new fields of microstructural investigation in claystones towards a better understanding of the deformation behavior transitional between rocks and soils. We present results of Boom Clay deformed in a triaxial cell in a consolidated - undrained test at a confining pressure of 0.375 MPa (i.e. close to natural value), with σ1 perpendicular to the bedding. Experiments stopped at 20 % strain. As a first approximation, the plasticity of the sample can be described by a Mohr-Coulomb type failure envelope with a coefficient of cohesion C = 0.117 MPa and an internal friction angle ϕ = 18.7°. After deformation test, the bulk sample shows a shear zone at an angle of about 35° from the vertical with an offset of about 5 mm. We used the "Lamipeel" method that allows producing a permanent absolutely plane and large size etched micro relief-replica in order to localize and to document the shear zone at the scale of the deformed core. High-resolution imaging of microstructures was mostly done by using the BIB-SEM method on key-regions identified after the "Lamipeel" method. Detailed BIB-SEM investigations of shear zones show the following: the boundaries between the shear zone and the host rock are sharp, clay aggregates and clastic grains are strongly reoriented parallel to the shear direction, and the porosity is significantly reduced in the shear zone and the grain size is smaller in the shear zone than in the host rock but there is no evidence for broken grains. Comparison of microstructures

  18. INTERFACIAL FREE-ENERGY CHANGES OCCURRING DURING BSA ADSORPTION IN SOLUTION DROPLETS ON FEP-TEFLON SURFACES AS MEASURED BY ADSA-P

    NARCIS (Netherlands)

    BUSSCHER, HJ; VANDERVEGT, W; SCHAKENRAAD, JM; VANDERMEI, HC

    1991-01-01

    Axisymmetric drop shape analysis by profile (ADSA-P) was employed to determine the interfacial free energy changes occurring during bovine serum albumin (BSA) adsorption from solution droplets on fluoroethylenepropylene-Teflon (FEP-Teflon). 100-mu-l droplets of BSA solutions on FEP-Teflon were

  19. The weight of a storm: what observations of Earth surface deformation can tell us about Hurricane Harvey

    Science.gov (United States)

    Borsa, A. A.; Mencin, D.; van Dam, T. M.

    2017-12-01

    Hurricane Harvey was the first major hurricane to impact the USA in over a decade, making landfall southwest of Houston, TX on August 26, 2017. Although Harvey was downgraded to a tropical storm shortly after landfall, it dropped a record amount of rain and was responsible for epic flooding across much of southeast Texas. While precipitation from a large storm like Harvey can be estimated from in-situ rain gages and Doppler radar, the accompanying surface water changes that lead to flooding are imperfectly observed due to the limited coverage of existing stream and lake level gages and because floodwaters inundate areas that are typically unmonitored. Earth's response to changes in surface loading provides an opportunity to observe the local hydrological response to Hurricane Harvey, specifically the dramatic changes in water storage coincident with and following the storm. Continuous GPS stations in southeastern Texas observed an average drop in land surface elevations of 1.8 cm following Harvey's landfall, followed by a gradual recovery to pre-storm levels over the following month. We interpret this surface motion as Earth's elastic response to the weight of cumulative rainfall during the storm, followed by rebound as that weight was removed by runoff and evapotranspiration (ET). Using observations of surface displacements from GPS stations in the HoustonNET and Plate Boundary Observatory networks, we model the daily water storage changes across Texas and Louisiana associated with Harvey. Because Harvey's barometric pressure low caused surface uplift at the cm level which temporarily obscured the subsidence signal due to precipitation, we model and remove the effect of atmospheric loading from the GPS data prior to our analysis. We also consider the effect on GPS position time series of non-tidal ocean loading due to the hurricane storm surge, which at the coast was an order of magnitude larger than loads due to precipitation alone. Finally, we use our results to

  20. Dynamic soft tissue deformation estimation based on energy analysis

    Science.gov (United States)

    Gao, Dedong; Lei, Yong; Yao, Bin

    2016-10-01

    The needle placement accuracy of millimeters is required in many needle-based surgeries. The tissue deformation, especially that occurring on the surface of organ tissue, affects the needle-targeting accuracy of both manual and robotic needle insertions. It is necessary to understand the mechanism of tissue deformation during needle insertion into soft tissue. In this paper, soft tissue surface deformation is investigated on the basis of continuum mechanics, where a geometry model is presented to quantitatively approximate the volume of tissue deformation. The energy-based method is presented to the dynamic process of needle insertion into soft tissue based on continuum mechanics, and the volume of the cone is exploited to quantitatively approximate the deformation on the surface of soft tissue. The external work is converted into potential, kinetic, dissipated, and strain energies during the dynamic rigid needle-tissue interactive process. The needle insertion experimental setup, consisting of a linear actuator, force sensor, needle, tissue container, and a light, is constructed while an image-based method for measuring the depth and radius of the soft tissue surface deformations is introduced to obtain the experimental data. The relationship between the changed volume of tissue deformation and the insertion parameters is created based on the law of conservation of energy, with the volume of tissue deformation having been obtained using image-based measurements. The experiments are performed on phantom specimens, and an energy-based analytical fitted model is presented to estimate the volume of tissue deformation. The experimental results show that the energy-based analytical fitted model can predict the volume of soft tissue deformation, and the root mean squared errors of the fitting model and experimental data are 0.61 and 0.25 at the velocities 2.50 mm/s and 5.00 mm/s. The estimating parameters of the soft tissue surface deformations are proven to be useful

  1. The effects of subduction termination on the continental lithosphere: Linking volcanism, deformation, surface uplift, and slab tearing in central Anatolia

    Science.gov (United States)

    Delph, Jonathan R.; Abgarmi, Bijan; Ward, Kevin M.; Beck, Susan L.; Arda Ozacar, A.; Zandt, George; Sandvol, Eric; Turkelli, Niyazi; Kalafat, Dogan

    2017-04-01

    The lithospheric evolution of Anatolia is largely defined by processes associated with the terminal stages of subduction along its southern margin. Central Anatolia represents the transition from the subduction of oceanic lithosphere at the Aegean trench in the west to the Arabian - Eurasian continental collision in the east. In the overriding plate, this complicated transition is contemporaneous with uplift along the southern margin of central Anatolia (2 km in 6 Myr), voluminous felsic-intermediate ignimbrite eruptions (>1000 km3), extension, and tectonic deformation reflected by abundant low-magnitude seismic activity. The addition of 72 seismic stations as part of the Continental Dynamics - Central Anatolian Tectonics project, along with development of a new approach to the joint inversion of receiver functions and dispersion data, enables us obtain a high-resolution 3D shear wave velocity model of central Anatolia down to 150 km. This new velocity model has important implications for the complex interactions between the downgoing, segmenting African lithosphere and the overriding Anatolian Plate. These results reveal that the lithosphere of central Anatolia and the northern Arabian Plate is thin (4.5 km/s), indicating the presence of the Cyprean slab beneath central Anatolia. Thus, uplift of the Central Taurus Mountains may be due to slab rebound after the detachment of the oceanic portion of the Cyprean slab beneath Anatolia rather than the presence of shallow asthenospheric material. These fast velocities extend to the northern margin of the Central Taurus Mountains, giving way to a NE-SW trend of very slow upper mantle shear wave velocities (interpreted to be shallow, warm asthenosphere in which melt is present. The combination of a shallow asthenosphere and lithospheric-scale weaknesses associated with relict tectonic structures formed during the assembly of Anatolia are responsible for the spatial distribution of volcanism in the Central Anatolian

  2. Existence of quasi-stationary neutron and x-ray states near the surface of a deformed single crystal

    CERN Document Server

    Iolin, E

    1999-01-01

    The problem of x-ray or neutron multiply internally reflected inside a bent single crystal plate (Bragg geometry) is considered. It is found that such multiple reflections lead to the existence of quasi-stationary (QS) states. QS states are discrete and correspond to the resonance of motion of the tie point between the front surface and a 'turning place' inside a single crystal. (author)

  3. 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.

  4. Nanolaminate deformable mirrors

    Science.gov (United States)

    Papavasiliou, Alexandros P.; Olivier, Scot S.

    2009-04-14

    A deformable mirror formed out of two layers of a nanolaminate foil attached to a stiff substrate is introduced. Deformation is provided by an electrostatic force between two of the layers. The internal stiffness of the structure allows for high-spatial-frequency shapes. The nanolaminate foil of the present invention allows for a high-quality mirror surface. The device achieves high precision in the vertical direction by using foils with accurately controlled thicknesses, but does not require high precision in the lateral dimensions, allowing such mirrors to be fabricated using crude lithography techniques. Such techniques allow structures up to about the meter scale to be fabricated.

  5. Resolving spatial heterogeneities in exhumation and surface uplift in Timor-Leste: Constraints on deformation processes in young orogens

    Science.gov (United States)

    Tate, Garrett W.; McQuarrie, Nadine; van Hinsbergen, Douwe J. J.; Bakker, Richard R.; Harris, Ron; Willett, Sean; Reiners, Peter W.; Fellin, Maria Giuditta; Ganerød, Morgan; Zachariasse, Willem Jan

    2014-06-01

    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, permitting direct relation of uplift and exhumation by comparing micropaleontology to thermochronology interpreted through one-dimensional thermal modeling. Foraminifera in two deepwater synorogenic basins suggest basin uplift from depths of 1-2 km to depths of 350-1000 m between 3.35 and 1.88 Ma. Thermochronologic sampling was conducted in the central mountain belt between these basins. Of four muscovite 40Ar/39Ar samples, one provides a reset age of 7.13 ± 0.25 Ma in the Aileu high-grade belt that suggests 9-16 km of exhumation since that time. Eighteen zircon (U-Th)/He samples contain a group of reset ages in the Aileu Complex ranging from 4.4 to 1.5 Ma, which suggest exhumation rates of 1.0-3.1 mm/yr with 2.7-7.8 km of exhumation since these ages. Thirteen apatite (U-Th)/He ages in the Gondwana Sequence range from 5.5 to 1.4 Ma, suggesting 1-2 km of exhumation and defining a pattern of exhumation rates (ranging from 0.2 to 1.3 mm/yr) that positively correlates with average annual rainfall. Seven apatite fission track samples display varying degrees of partial resetting, with greatest resetting where apatite (U-Th)/He ages are youngest. Together, these data demonstrate extreme variability in surface uplift and exhumation over small spatial scales. We propose ongoing subsurface duplexing driven by subduction and underplating of Australian continental crust as the predominant driver for surface uplift and uplift-induced exhumation.

  6. Influence of synthesis methods on tungsten dispersion, structural deformation, and surface acidity in binary WO3-ZrO2 system.

    Science.gov (United States)

    Cortés-Jácome, M A; Toledo, J A; Angeles-Chavez, C; Aguilar, M; Wang, J A

    2005-12-08

    WO3-ZrO2 catalysts were synthesized by precipitating the aqueous solutions of zirconium oxynitrate and ammonium metatungstate with ammonium hydroxide. The white slurry precipitate was treated under three different conditions. In the as-made materials, the amorphous phase was formed in the aged and refluxed samples, while well-crystallized tetragonal and monoclinic phases were obtained in the hydrothermally treated sample. The real amount of tungsten loaded in the samples was similar for the three samples, independently of the treatments; however, the tungsten surface atomic density in the annealed WO3-ZrO2 samples varied between 6 and 9 W atoms/nm2. Two different contrast types of aggregates were determined by scanning electron microscopy, the white particles which are rich in W, and the gray ones which are rich in zirconium; both of them were formed in the calcined solids prepared under aging or reflux condition. A very high dispersion of tungsten species on the zirconia surface was achieved in the hydrothermally treated sample. The degree of the interaction between WO(x) and ZrO2 surface strongly modified the Zr-O bond lengths and bond angles in the structure of tetragonal zirconia as proved by X-ray diffraction analysis and the Rietveld refinement. The catalyst obtained under hydrothermal condition exhibited the highest dispersion of tungsten species in the zirconia, which in turn causes strong structural deformation of the tetragonal ZrO2 phase responsible of the strongest surface acidity and, consequently, the optimum catalytic activity for n-hexane isomerization.

  7. 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

  8. 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.

  9. APEX (Aqueous Photochemistry of Environmentally occurring Xenobiotics): a free software tool to predict the kinetics of photochemical processes in surface waters.

    Science.gov (United States)

    Bodrato, Marco; Vione, Davide

    2014-04-01

    The APEX software predicts the photochemical transformation kinetics of xenobiotics in surface waters as a function of: photoreactivity parameters (direct photolysis quantum yield and second-order reaction rate constants with transient species, namely ˙OH, CO₃(-)˙, (1)O₂ and the triplet states of chromophoric dissolved organic matter, (3)CDOM*), water chemistry (nitrate, nitrite, bicarbonate, carbonate, bromide and dissolved organic carbon, DOC), and water depth (more specifically, the optical path length of sunlight in water). It applies to well-mixed surface water layers, including the epilimnion of stratified lakes, and the output data are average values over the considered water column. Based on intermediate formation yields from the parent compound via the different photochemical pathways, the software can also predict intermediate formation kinetics and overall yield. APEX is based on a photochemical model that has been validated against available field data of pollutant phototransformation, with good agreement between model predictions and field results. The APEX software makes allowance for different levels of knowledge of a photochemical system. For instance, the absorption spectrum of surface water can be used if known, or otherwise it can be modelled from the values of DOC. Also the direct photolysis quantum yield can be entered as a detailed wavelength trend, as a single value (constant or average), or it can be defined as a variable if unknown. APEX is based on the free software Octave. Additional applications are provided within APEX to assess the σ-level uncertainty of the results and the seasonal trend of photochemical processes.

  10. Specific binding of a naturally occurring amyloidogenic fragment of Streptococcus mutans adhesin P1 to intact P1 on the cell surface characterized by solid state NMR spectroscopy.

    Science.gov (United States)

    Tang, Wenxing; Bhatt, Avni; Smith, Adam N; Crowley, Paula J; Brady, L Jeannine; Long, Joanna R

    2016-02-01

    The P1 adhesin (aka Antigen I/II or PAc) of the cariogenic bacterium Streptococcus mutans is a cell surface-localized protein involved in sucrose-independent adhesion and colonization of the tooth surface. The immunoreactive and adhesive properties of S. mutans suggest an unusual functional quaternary ultrastructure comprised of intact P1 covalently attached to the cell wall and interacting with non-covalently associated proteolytic fragments thereof, particularly the ~57-kDa C-terminal fragment C123 previously identified as Antigen II. S. mutans is capable of amyloid formation when grown in a biofilm and P1 is among its amyloidogenic proteins. The C123 fragment of P1 readily forms amyloid fibers in vitro suggesting it may play a role in the formation of functional amyloid during biofilm development. Using wild-type and P1-deficient strains of S. mutans, we demonstrate that solid state NMR (ssNMR) spectroscopy can be used to (1) globally characterize cell walls isolated from a Gram-positive bacterium and (2) characterize the specific binding of heterologously expressed, isotopically-enriched C123 to cell wall-anchored P1. Our results lay the groundwork for future high-resolution characterization of the C123/P1 ultrastructure and subsequent steps in biofilm formation via ssNMR spectroscopy, and they support an emerging model of S. mutans colonization whereby quaternary P1-C123 interactions confer adhesive properties important to binding to immobilized human salivary agglutinin.

  11. Specific binding of a naturally occurring amyloidogenic fragment of Streptococcus mutans adhesin P1 to intact P1 on the cell surface characterized by solid state NMR spectroscopy

    International Nuclear Information System (INIS)

    Tang, Wenxing; Bhatt, Avni; Smith, Adam N.; Crowley, Paula J.; Brady, L. Jeannine; Long, Joanna R.

    2016-01-01

    The P1 adhesin (aka Antigen I/II or PAc) of the cariogenic bacterium Streptococcus mutans is a cell surface-localized protein involved in sucrose-independent adhesion and colonization of the tooth surface. The immunoreactive and adhesive properties of S. mutans suggest an unusual functional quaternary ultrastructure comprised of intact P1 covalently attached to the cell wall and interacting with non-covalently associated proteolytic fragments thereof, particularly the ∼57-kDa C-terminal fragment C123 previously identified as Antigen II. S. mutans is capable of amyloid formation when grown in a biofilm and P1 is among its amyloidogenic proteins. The C123 fragment of P1 readily forms amyloid fibers in vitro suggesting it may play a role in the formation of functional amyloid during biofilm development. Using wild-type and P1-deficient strains of S. mutans, we demonstrate that solid state NMR (ssNMR) spectroscopy can be used to (1) globally characterize cell walls isolated from a Gram-positive bacterium and (2) characterize the specific binding of heterologously expressed, isotopically-enriched C123 to cell wall-anchored P1. Our results lay the groundwork for future high-resolution characterization of the C123/P1 ultrastructure and subsequent steps in biofilm formation via ssNMR spectroscopy, and they support an emerging model of S. mutans colonization whereby quaternary P1-C123 interactions confer adhesive properties important to binding to immobilized human salivary agglutinin

  12. Specific binding of a naturally occurring amyloidogenic fragment of Streptococcus mutans adhesin P1 to intact P1 on the cell surface characterized by solid state NMR spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Wenxing; Bhatt, Avni [University of Florida, Department of Biochemistry and Molecular Biology, College of Medicine (United States); Smith, Adam N. [University of Florida, Department of Chemistry, College of Liberal Arts and Sciences (United States); Crowley, Paula J.; Brady, L. Jeannine, E-mail: jbrady@dental.ufl.edu [University of Florida, Department of Oral Biology, College of Dentistry (United States); Long, Joanna R., E-mail: jrlong@ufl.edu [University of Florida, Department of Biochemistry and Molecular Biology, College of Medicine (United States)

    2016-02-15

    The P1 adhesin (aka Antigen I/II or PAc) of the cariogenic bacterium Streptococcus mutans is a cell surface-localized protein involved in sucrose-independent adhesion and colonization of the tooth surface. The immunoreactive and adhesive properties of S. mutans suggest an unusual functional quaternary ultrastructure comprised of intact P1 covalently attached to the cell wall and interacting with non-covalently associated proteolytic fragments thereof, particularly the ∼57-kDa C-terminal fragment C123 previously identified as Antigen II. S. mutans is capable of amyloid formation when grown in a biofilm and P1 is among its amyloidogenic proteins. The C123 fragment of P1 readily forms amyloid fibers in vitro suggesting it may play a role in the formation of functional amyloid during biofilm development. Using wild-type and P1-deficient strains of S. mutans, we demonstrate that solid state NMR (ssNMR) spectroscopy can be used to (1) globally characterize cell walls isolated from a Gram-positive bacterium and (2) characterize the specific binding of heterologously expressed, isotopically-enriched C123 to cell wall-anchored P1. Our results lay the groundwork for future high-resolution characterization of the C123/P1 ultrastructure and subsequent steps in biofilm formation via ssNMR spectroscopy, and they support an emerging model of S. mutans colonization whereby quaternary P1-C123 interactions confer adhesive properties important to binding to immobilized human salivary agglutinin.

  13. All Madelung deformities are not endocrine

    Directory of Open Access Journals (Sweden)

    Ajay Kumar

    2013-01-01

    Full Text Available Madelung deformity is a rare inherited disorder associated with endocrine disorders like Turner′s syndrome, pseudohypoparathyroidism, but can be seen with short stature homeobox deficiency conditions such as Leri-Weill dyschondrosteosis (LWD and Langers mesomelic dysplasia. It has also been reported following trauma to the distal radius epiphysis neoplasia mucopolysaccharidosis (MPS and achondroplasia. Madelung deformity is an abnormality of distal radial epiphysis where in progressive ulnar and volar tilt of the articular surface occurring in association with distal subluxation of ulna. A 13-year-old girl was referred to us for evaluation of bilateral deformity of wrist and short stature. There was ulnar deviation and dorsal tilt of bilateral hands without history of pain to the joint trauma and family history of similar illness. On X-ray, wrist showed malformed distal radial epiphysis with dorsal and ulnar shift and with increased length of phalanges suggestive of Madelung deformity. X-ray spine was normal. Ultrasound abdomen showed normal uterus and ovary and her follicle stimulating hormone. Luteinizing hormone was normal and so was urine MPS screening. Based on the above points the diagnosis of LWD was made.

  14. 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.

  15. 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.

  16. Mineralization of collagen may occur on fibril surfaces: evidence from conventional and high-voltage electron microscopy and three-dimensional imaging

    Science.gov (United States)

    Landis, W. J.; Hodgens, K. J.; Song, M. J.; Arena, J.; Kiyonaga, S.; Marko, M.; Owen, C.; McEwen, B. F.

    1996-01-01

    The interaction between collagen and mineral crystals in the normally calcifying leg tendons from the domestic turkey, Meleagris gallopavo, has been investigated at an ultrastructural level with conventional and high-voltage electron microscopy, computed tomography, and three-dimensional image reconstruction methods. Specimens treated by either aqueous or anhydrous techniques and resin-embedded were appropriately sectioned and regions of early tendon mineralization were photographed. On the basis of individual photomicrographs, stereoscopic pairs of images, and tomographic three-dimensional image reconstructions, platelet-shaped crystals may be demonstrated for the first time in association with the surface of collagen fibrils. Mineral is also observed in closely parallel arrays within collagen hole and overlap zones. The mineral deposition at these spatially distinct locations in the tendon provides insight into possible means by which calcification is mediated by collagen as a fundamental event in skeletal and dental formation among vertebrates.

  17. Mathematical modeling of deformation during hot rolling

    Energy Technology Data Exchange (ETDEWEB)

    Jin, D.; Stachowiak, R.G.; Samarasekera, I.V.; Brimacombe, J.K. [Univ. of British Columbia, Vancouver, British Columbia (Canada). Centre for Metallurgical Processing Engineering

    1994-12-31

    The deformation that occurs in the roll bite during the hot rolling of steel, particularly the strain-rate and strain distribution, has been mathematically modeled using finite-element analysis. In this paper three different finite-element models are compared with one another and with industrial measurements. The first model is an Eulerian analysis based on the flow formulation method, while the second utilizes an Updated Lagrangian approach. The third model is based on a commercially available program DEFORM which also utilizes a Lagrangian reference frame. Model predictions of strain and strain-rate distribution, particularly near the surface of the slab, are strongly influenced by the treatment of friction at the boundary and the magnitude of the friction coefficient or shear factor. Roll forces predicted by the model have been compared with industrial rolling loads from a seven-stand hot-strip mill.

  18. Hillslope surface deformation on chalky landscape under the influence of Quaternary tectonics coupled with periglacial processes, Picardy (NW France)

    Science.gov (United States)

    Duperret, Anne; Vandycke, Sara; Colbeaux, Jean-Pierre; Raimbault, Celine; Duguet, Timothée; Van vliet-lanoe, Brigitte

    2017-04-01

    Chalky hillslopes observed in Picardy region (NW Paris basin, France) evidence specific surficial ridges and steps, of several meters high and several ten-meters length, roughly parallel oriented to slopes on some dry valleys. They are locally named "rideaux" or strip-lynchets. Their origin is still discussed among the communities of geology, geography, archeology and pedology. Detailed observations of the Picardy coastal chalk cliffs using high resolution low-lying aerial LiDAR and field works allow us to precisely describe and understand ridges and steps formation. At Bois de Cise, a rectangular depression with ridges and steps was observed in 3D on the ground, due to its natural overlap by the cliff face. This structure proves to be a graben, controlled by conjugate normal faults, at the top of which the ridges and steps are developed. The set forms a "step-graben" composed of a system of faults in relay and ramps, involved in the superficial covering of quaternary loess. Steps formation will be discussed in relation with the tectonic context (paleo-constraint fields), the continental water circulation within the karst, the presence of break-up structures on the fault planes, the role of cryogenic processes during the last glacial epochs and the remobilization of loess surface deposits. Caves and temporary springs of fresh water along faults evidence a karstic behavior in the chalk and suggests step-graben structures as geological guides for hydrogeological circulation in the chalk of Picardy. In this context, chalky surficial step-structures appears as tectonically controlled and as the witness of a recent active tectonics in the NW european chalk basin. In addition, the field of steps developed on a coastal fossil cliff tends to prove the occurrence of a fractured system, developed according to a paleo-field of NW-SE extensive stresses. Data from the CROCOLIT-Leg1 (Duperret, 2013) campaign carried out on the offshore subtidal platform (shallow bathymetry, THR

  19. Radiological control in a mine with a naturally-occurring radioactive material -NORM: III assessment of removable surface contamination in a pilot plant

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, W.S.; Py Junior, D.A.; Silva, A.C.A.; Garcia Filho, O., E-mail: pereiraws@gmail.com [Industrias Nucleares do Brasil (INB), Pocos de Caldas, MG (Brazil). Unidade de Tratamento de Minerio. Grupo Multidisciplinar de Radioprotecao; Kelecom, A., E-mail: akelecom@id.uff.br [Universidade Federal Fluminense (GETA/LARARA-PLS/UFF), Niteroi, RJ, (Brazil). Grupo de Estudos em Temas Ambientais. Lab. de Radiobiologia e Radiometria; Pereira, J.R.S., E-mail: pereirarsj@gmail.com [Universidade Federal de Alfenas (UNIFAL), Pocos de Caldas, MG (Brazil)

    2013-07-01

    Ore Treatment Unit (OUT) possesses a process laboratory. Considering the uranium ore processing, this laboratory works in close cooperation with the Radiation Protection Service of the Unit. In the year of 2009 a pilot plant for the development of solvent uranium extraction from the phosphate ore of the mine of Santa Quiteria city, in Ceara State, Brazil was developed. In this kind of plant the surface contamination may cause contamination for Occupational Exposed Individuals (OEI). In order to control this kind of contamination and offer a safety work's condition for OEIs, a monitoring program of transferable contamination using swab samples was developed. 162 swabs were made. For the alpha emitters the monitoring results varied from 0.001 Bq cm{sup -2} to 0.014 Bq cm{sup -2}, with average value of 0.002 Bq cm{sup -2}. For beta emitters the results varied from 0.010 Bq cm{sup -2} to 0.031 Bq cm{sup -2} with average equal to 0.011 Bq cm{sup -2}. For alpha emitters, 87.65 % of the results were below 0.004 Bq cm{sup -2}, values that are one order of magnitude smaller than the limit and the maximum value stayed in 35 % of the limit for an object to be considered contaminated. For beta emitters, 90 % of the results were below 0.010 Bq cm{sup -2} that corresponds to 25 % of the limit and 100 % were below 0.031 Bq cm{sup -2} below the limit for an object to be considered contaminated. In both cases any object monitored during the operation, was not considered contaminated, proving the good practices employed in the laboratory, resultant of the good planning of the Radiation Protection Service for the operations' process. (author)

  20. Soil erosion and its impact on surface deformation studied in Nozhian, Iran: new insight from the analysis of Synthetic Aperture Radar (SAR) data

    Science.gov (United States)

    Motagh, Mahdi; Haghshenas-Haghighi, Mahmud; Ebrahimzadeh, Somayeh

    2014-05-01

    Soil erosion is one of the most serious environmental problems causing large damages and costs all over the world. Obtaining precise volumetric information for the amount of soil loss and/or deposition and sedimentation is a key parameter in modelling soil erosion processes. The use of SAR remote sensing observations for monitoring of rapidly eroded regions could be problematic due to phase decorrelation. In this study, we attempt to use observations from C-band and L-band SAR imagery to assess the impact of soil erosion on surface deformation in Nozhian region, central Iran. Nozhian is known as one of the most extreme cases of soil erosion in Iran due to the combination of relatively high intensity rainfall, steep topography and landslides. We use Envisat and ALOS data to evaluate the potential of SAR imagery for detecting areas of erosion and for estimating its volume at a regional scale. The InSAR results are compared with field data acquired in several gabions in the region for validation.

  1. Surface deformation time series and source modeling for a volcanic complex system based on satellite wide swath and image mode interferometry: The Lazufre system, central Andes

    Science.gov (United States)

    Anderssohn, J.; Motagh, M.; Walter, T. R.; Rosenau, M.; Kaufmann, H.; Oncken, O.

    2009-12-01

    The variable spatio-temporal scales of Earth's surface deformation in potentially hazardous volcanic areas pose a challenge for observation and assessment. Here we used Envisat data acquired in Wide Swath Mode (WSM) and Image Mode (IM) from ascending and descending geometry, respectively, to study time-dependent ground uplift at the Lazufre volcanic system in Chile and Argentina. A least-squares adjustment was performed on 65 IM interferograms that covered the time period of 2003-2008. We obtained a clear trend of uplift reaching 15-16 cm in this 5-year interval. Using a joint inversion of ascending and descending interferograms, we evaluated the geometry and time-dependent progression of a horizontally extended pressurized source beneath the Lazufre volcanic system. Our results hence indicate that an extended magma body at a depth between 10 and 15 km would account for most of the ground uplift. The maximum inflation reached up to ~40 cm during 2003-2008. The lateral propagation velocity of the intrusion was estimated to be nearly constant at 5-10 km/yr during the observation time, which has important implications for the physical understanding of magma intrusion processes.

  2. Grain orientation dependence of deformation twinning in pure Cu subjected to dynamic plastic deformation

    DEFF Research Database (Denmark)

    Hong, C.S.; Tao, N.R.; Lu, K.

    2009-01-01

    A clear grain orientation dependence of deformation twinning has been identified in coarse-grained copper subjected to dynamic plastic deformation. Deformation twins tend to occur in grains with orientations near the [0 0 1] corner but not in grains near the [1 0 1] corner, which can be explained...

  3. Surface deformation due to the M6.5 Lefkada earthquake (17 November 2015) exploiting SENTINEL-1 and GNSS observations. Implications for seismic hazard.

    Science.gov (United States)

    Elias, Panagiotis; Ganas, Athanassios; Briole, Pierre; Parcharidis, Isaak; Avallone, Antonio; Roukounakis, Nikos; Argyrakis, Panagiotis; Roger, Marine; Cheloni, Daniele; Tolomei, Cristiano; Mendonidis, Evangelos; Moraitini, Evelyn; Papanikolaou, Marios; Papastergios, Asterios

    2017-04-01

    The 17 November 2015 M=6.5 Lefkada earthquake in the Ionian sea, Greece, produced tens of centimetres of co-seismic motion in both Lefkada and Cephalonia islands. We present the full picture of the co-seismic displacements as mapped by space geodetic techniques, Sentinel 1A INSAR and permanent GNSS stations. We use this data together with the constraints from seismology to invert for fault localisation , size and slip distribution. We observed post-seismic displacements throughout most of southern Lefkada and northern Cephalonia islands recorded at the two NOA GNSS stations of PONT and SPAN and four additional permanent and six campaign GNSS stations established after the earthquake. Those displacements range from a few centimetres near the epicentre to a few millimetres far from the fault. We model the post-seismic displacements as due to uniform slip on the same fault plane that ruptured during the main event. The model shows a right-lateral afterslip along the fault but with slightly larger extension in comparison to the co-seismic slip, less shallow and deeper. This transient strain followed the main event during a short period of 80 days as modelled with an exponential law. Currently, the post-seismic deformation is being investigated by exploiting multi-temporal Sentinel 1A/B InSAR processed among others with ESA's Geohazards Exploitation Platform and SNAP software. The first challenging issue is the coherence which is not high in the area due to the vegetation cover. The second one is the correction of the tropospheric component. We estimate it using the tropospheric delay at the permanent GNSS stations and by using an meteorological model based on the WRF refined at the spatial resolution of 1 km. The earthquakes occurred in the Central Ionian area since 1983, studied both by seismology and space geodesy imply a seismic gap offshore NW Cephalonia that needs to be monitored.

  4. Investigating the relationship between seismicity and fluid injection in the Barnett Shale, Texas using coupled poroelastic model and surface deformation data

    Science.gov (United States)

    Zhai, G.; Shirzaei, M.

    2017-12-01

    Across the Barnett Shale, Texas a noticeable increase in seismic activity was observed during 2007 and 2015, which was accompanied by high volume injection at several nearby disposal wells. Many studies focused on the positive correlation between injection rate at individual wells and the adjacent seismicity, suggesting that seismicity is triggered or induced due to increased pore fluid pressure associated with fluid injection in hydraulically connected geological units. However, investigating temporal evolution of total volume of injected fluid and concurrent earthquakes in a larger area indicates more complex patterns, requiring a more comprehensive analysis of the spatiotemporal evolution of coupled poroelastic stress and pore fluid pressure. In this study, we created a coupled poroelastic model to simulate large scale spatiotemporal evolution of pore pressure, poroelastic stresses, and Coulomb failure stress in the Barnett Shale using injection time series of 96 high-volume injection wells spanning from 2007 to 2015. We additionally account for a layered poroelastic medium, where its parameters are set up using geological maps and seismic tomographic data sets. Fault orientations and relevant frictional properties are also extracted from published literatures. We further integrate observation of surface deformation obtained from interferometric processing of 16 ALOS L-Band SAR images to optimize rock hydraulic diffusivity and constrain the extent to which fluid may migrate. The preliminary modeling result shows that poroelastic stress is only 10% of pore pressure. However, the superimposition of these two effects is spatially and temporally responsible for the occurrence of earthquakes in the Barnett Shale. Also, not all area with increased Coulomb failure stress experiences elevated seismicity, suggesting possible heterogeneous background tectonic stresses, lacking pre-existing faults, and/or heterogeneous fault orientations.

  5. Nanoscale Deformable Optics

    Science.gov (United States)

    Strauss, Karl F.; Sheldon, Douglas J.

    2011-01-01

    Several missions and instruments in the conceptual design phase rely on the technique of interferometry to create detectable fringe patterns. The intimate emplacement of reflective material upon electron device cells based upon chalcogenide material technology permits high-speed, predictable deformation of the reflective surface to a subnanometer or finer resolution with a very high degree of accuracy. In this innovation, a layer of reflective material is deposited upon a wafer containing (perhaps in the millions) chalcogenic memory cells with the reflective material becoming the front surface of a mirror and the chalcogenic material becoming a means of selectively deforming the mirror by the application of heat to the chalcogenic material. By doing so, the mirror surface can deform anywhere from nil to nanometers in spots the size of a modern day memory cell, thereby permitting realtime tuning of mirror focus and reflectivity to mitigate aberrations caused elsewhere in the optical system. Modern foundry methods permit the design and manufacture of individual memory cells having an area of or equal to the Feature (F) size of the design (assume 65 nm). Fabrication rules and restraints generally require the instantiation of one memory cell to another no closer than 1.5 F, or, for this innovation, 90 nm from its neighbor in any direction. Chalcogenide is a semiconducting glass compound consisting of a combination of chalcogen ions, the ratios of which vary according to properties desired. It has been shown that the application of heat to cells of chalcogenic material cause a large alteration in resistance to the range of 4 orders of magnitude. It is this effect upon which chalcogenidebased commercial memories rely. Upon removal of the heat source, the chalcogenide rapidly cools and remains frozen in the excited state. It has also been shown that the chalcogenide expands in volume because of the applied heat, meaning that the coefficient of expansion of chalcogenic

  6. Anisotropic Ripple Deformation in Phosphorene.

    Science.gov (United States)

    Kou, Liangzhi; Ma, Yandong; Smith, Sean C; Chen, Changfeng

    2015-05-07

    Two-dimensional materials tend to become crumpled according to the Mermin-Wagner theorem, and the resulting ripple deformation may significantly influence electronic properties as observed in graphene and MoS2. Here, we unveil by first-principles calculations a new, highly anisotropic ripple pattern in phosphorene, a monolayer black phosphorus, where compression-induced ripple deformation occurs only along the zigzag direction in the strain range up to 10%, but not the armchair direction. This direction-selective ripple deformation mode in phosphorene stems from its puckered structure with coupled hinge-like bonding configurations and the resulting anisotropic Poisson ratio. We also construct an analytical model using classical elasticity theory for ripple deformation in phosphorene under arbitrary strain. The present results offer new insights into the mechanisms governing the structural and electronic properties of phosphorene crucial to its device applications.

  7. Localization of Plastic Deformation in Aluminum Single Crystals at Different Scale Levels

    Science.gov (United States)

    Bespalova, I. V.; Teplyakova, L. A.; Kunitsyna, T. S.

    2017-07-01

    The paper generalizes results of investigating the localization and fragmentation of plastic deformation in aluminum single crystals having a different orientation of the compression axis and lateral faces. The surface topography of the samples induced by plastic deformation includes such elements as deformation bands, folds and shear markings observed at different scale levels (macro, meso and micro). The morphological uniformity is identified for these elements in the aluminum single crystals. Depending on the resolution required, the quantification of the shear deformation markings is provided by the optical microscope and the scanning and transmission electron microscopes using the replication technique. The following parameters are obtained: the distance between the nearest shear deformation markings, width of shear markings, local shear; shear γ; the single-crystal volume fraction in which the shear deformation occurs at macro, meso, and micro-levels. The statistical examination of the shear deformation markings in aluminum single crystals with different geometry is performed at these three levels and allows us to conclude that the micro-scale level makes the main contribution to the shear deformation.

  8. An Incomplete Inventory of Suspected Human-Induced Surface Deformation in North America Detected by Satellite Interferometric Synthetic-Aperture Radar

    Directory of Open Access Journals (Sweden)

    Alana G. Semple

    2017-12-01

    Full Text Available We used satellite interferometric synthetic-aperture radar (InSAR data to document ground deformation across North America suspected to be caused by human activities. We showed that anthropogenic deformation can be measured from space across the continent and thus satellite observations should be collected routinely to characterize this deformation. We included results from the literature as well as new analysis of more than 5000 interferograms from the European Remote Sensing (ERS satellite, Envisat, the Advanced Land Observing Satellite (ALOS, and other satellites, collectively spanning the period 1992–2015. This compilation, while not complete in terms of spatial or temporal coverage nor uniform in quality over the region, contains 263 different areas of likely anthropogenic ground deformation, including 65 that were previously unreported. The sources can be attributed to groundwater extraction (50%, geothermal sites (6%, hydrocarbon production (20%, mining (21%, and other sources (3% such as lake level changes driven by human activities and tunneling. In a few areas, the source of deformation is ambiguous. We found at least 80 global positioning system (GPS stations within 20 km of of these areas that could be contaminated by the anthropogenic deformation. At sites where we performed a full time series analysis, we found a mix of steady and time-variable deformation rates. For example, at the East Mesa Geothermal Field in California, we found an area that changed from subsidence to uplift around 2006, even though publicly available records of pumping and injection showed no change during that time. We illustrate selected non-detections from wastewater injection in Oklahoma and eastern Texas, where we found that the detection threshold with available data is >0.5 cm/yr. This places into doubt previous results claiming detection below this threshold in eastern Texas. However, we found likely injection-induced uplift in a different area of

  9. Deformation mechanisms in cyclic creep and fatigue

    International Nuclear Information System (INIS)

    Laird, C.

    1979-01-01

    Service conditions in which static and cyclic loading occur in conjunction are numerous. It is argued that an understanding of cyclic creep and cyclic deformation are necessary both for design and for understanding creep-fatigue fracture. Accordingly a brief, and selective, review of cyclic creep and cyclic deformation at both low and high strain amplitudes is provided. Cyclic loading in conjunction with static loading can lead to creep retardation if cyclic hardening occurs, or creep acceleration if softening occurs. Low strain amplitude cyclic deformation is understood in terms of dislocation loop patch and persistent slip band behavior, high strain deformation in terms of dislocation cell-shuttling models. While interesting advances in these fields have been made in the last few years, the deformation mechanisms are generally poorly understood

  10. Thermal elastic deformations of the planet Mercury.

    Science.gov (United States)

    Liu, H.-S.

    1972-01-01

    The variation in solar heating due to the resonance rotation of Mercury produces periodic elastic deformations on the surface of the planet. The thermal stress and strain fields under Mercury's surface are calculated after certain simplifications. It is found that deformations penetrate to a greater depth than the variation of solar heating, and that the thermal strain on the surface of the planet pulsates with an amplitude of .004 and a period of 176 days.

  11. Tensión- Deformación durante la deformación Plástica Superficial con rodillo // Stress-deformation during the Surfaces Plastic deformation with roller.

    Directory of Open Access Journals (Sweden)

    T. Fernández-Columbié

    2009-09-01

    Full Text Available Se establece el procedimiento para el endurecimiento del acero 45 a través de la DeformaciónPlástica por rodadura con el empleo de un torno marca 16 D 20 y un rodillo como elementodeformante. En el trabajo se muestra la forma de sujeción de la pieza entre plato y punto, métodoempleado para evitar la flexión de la pieza durante el proceso de elaboración, se muestran lasvariables del diseño de experimento numero de revolución, avance y fuerza, las cuales permitenrealizar el procesamiento estadísticos de los datos, lo que luego son graficado para obtener elcomportamiento de las curvas de fuerza contra dureza y avance contra dureza y demostrar elincremento de la dureza superficial en la medida que se incrementa el valor de las variables. Sedescriben los pasos para la preparación metalografica de la probeta desde el corte de la misma conel empleo de cuchilla del tipo SANVIDK, hasta el pulido para la observación metalografica, donde sedetermina el comportamiento de la red cristalina por el tensionamiento de los granos y elendurecimiento por acritud.Palabras claves: deformación plástica, dureza superficial, rodadura, acritud._______________________________________________________________________________AbstractThe procedure settles down for the hardening of the steel 45 through the Plastic Deformation forrolling with the employment of a lathe 16 D 20 and a roller like element deformante. In the workthe form of subjection of the piece is shown between plate and point, method used to avoid theflexion of the piece during the trial of elaboration, the variables of the experiment design areshown I number of revolution, advance and it forces, which allow to carry out the statisticalprosecution of the data, that are graph to obtain the behavior of the curves of force againsthardness and advance against hardness and to demonstrate the increment of the superficialhardness in the measure that the value of the variables is increased. The steps are

  12. 3D modeling of unconstrained HPT process: role of strain gradient on high deformed microstructure formation

    Science.gov (United States)

    Ben Kaabar, A.; Aoufi, A.; Descartes, S.; Desrayaud, C.

    2017-05-01

    During tribological contact’s life, different deformation paths lead to the formation of high deformed microstructure, in the near-surface layers of the bodies. The mechanical conditions (high pressure, shear) occurring under contact, are reproduced through unconstrained High Pressure Torsion configuration. A 3D finite element model of this HPT test is developed to study the local deformation history leading to high deformed microstructure with nominal pressure and friction coefficient. For the present numerical study the friction coefficient at the interface sample/anvils is kept constant at 0.3; the material used is high purity iron. The strain distribution in the sample bulk, as well as the main components of the strain gradients according to the spatial coordinates are investigated, with rotation angle of the anvil.

  13. Zernike polynomial based Rayleigh-Ritz model of a piezoelectric unimorph deformable mirror

    CSIR Research Space (South Africa)

    Long, CS

    2012-04-01

    Full Text Available Piezoelectric bimorph- or unimorph-type deformable mirrors are commonly used in adaptive optics to correct for time-dependent phase aberrations. In the optics community, the surface deformations that deformable mirrors are required to achieve...

  14. Optimization of Kinematic GPS Data Analysis for Large Surface Deformation from the July 2003 Dome Collapse at Soufrière Hills Volcano, Montserrat

    Science.gov (United States)

    Medina, R. B.; Mattioli, G. S.; Braun, J.

    2013-12-01

    , since BGGY is subjected to the similar weather patterns but was unaffected by volcanic activity at SHV. The final stochastic parameters were selected to yield the lowest variance in the kinematic position time-series at BGGY, then, HERM was reprocessed using the same parameters. The apparent vertical movement at HERM has been reduced substantially, and now has a maximum of 2.5 cm with a variation of 30 cm in the zenith wet troposphere estimate. We conclude that the original default parameters used to process that GPS observations over-constrained possible atmospheric variation for this tropical environment, producing apparently large dynamic position changes. Our new results now reflect actual dynamic ground deformation during the massive dome collapse and may be used to develop improved models for volcanic processes that occur over time scales of minutes to hours at SHV and other tropical volcanoes.

  15. Deformation localization forming and destruction over a decompression zone.

    Science.gov (United States)

    Turuntaev, Sergey; Kondratyev, Viktor

    2017-04-01

    Development of a hydrocarbon field is accompanied by deformation processes in the surrounding rocks. In particular, a subsidence of oil strata cap above a decompression zone near producing wells causes changes in the stress-strain state of the upper rocks. It was shown previously, that the stress spatial changes form a kind of arch structures. The shear displacements along the arch surfaces can occur, and these displacements can cause a collapse of casing or even man-made earthquakes. We present here the results of laboratory simulation of such a phenomenon. A laboratory setup was made in the form of narrow box 30x30x5 cm3 in size with a hole (0.6 cm in diameter) in its bottom. As a model of porous strata, a foam-rubber layer of 4.0 -10.5cm in thick was used, which was saturated with water. The foam was sealed to the bottom of the box; the upper part of the box was filled by the dry sand. The sand was separated from the foam by thin polyethylene film to prevent the sand wetting. For visualization the sand deformations, the front wall of the box was made transparent and the sand was marked by horizontal strips of the colored sand. In the experiments, the water was pumped out the foam layer through the bottom hole. After pumping-out 50 ml of the water, the localization of sand deformations above the sink hole became noticeable; after pumping-out 100 ml of the water, the localized deformation forms an arch. At the same time, there was no displacement on the upper surface of the sand. To amplify the localization effect, the foam was additionally squeezed locally. In this case, three surfaces of the localized deformation appeared in the sand. The vertical displacements decreased essentially with height, but they reached the upper layers of the sand. An influence of vibration on arches forming was investigated. Several types of vibrators were used, they were placed inside the sand or on the front side of the box. Resulting accelerations were measured by the

  16. X-ray beam-shaping via deformable mirrors: surface profile and point spread function computation for Gaussian beams using physical optics.

    Science.gov (United States)

    Spiga, D

    2018-01-01

    X-ray mirrors with high focusing performances are commonly used in different sectors of science, such as X-ray astronomy, medical imaging and synchrotron/free-electron laser beamlines. While deformations of the mirror profile may cause degradation of the focus sharpness, a deliberate deformation of the mirror can be made to endow the focus with a desired size and distribution, via piezo actuators. The resulting profile can be characterized with suitable metrology tools and correlated with the expected optical quality via a wavefront propagation code or, sometimes, predicted using geometric optics. In the latter case and for the special class of profile deformations with monotonically increasing derivative, i.e. concave upwards, the point spread function (PSF) can even be predicted analytically. Moreover, under these assumptions, the relation can also be reversed: from the desired PSF the required profile deformation can be computed analytically, avoiding the use of trial-and-error search codes. However, the computation has been so far limited to geometric optics, which entailed some limitations: for example, mirror diffraction effects and the size of the coherent X-ray source were not considered. In this paper, the beam-shaping formalism in the framework of physical optics is reviewed, in the limit of small light wavelengths and in the case of Gaussian intensity wavefronts. Some examples of shaped profiles are also shown, aiming at turning a Gaussian intensity distribution into a top-hat one, and checks of the shaping performances computing the at-wavelength PSF by means of the WISE code are made.

  17. A Deformable Generic 3D Model of Haptoral Anchor of Monogenean

    Science.gov (United States)

    Teo, Bee Guan; Dhillon, Sarinder Kaur; Lim, Lee Hong Susan

    2013-01-01

    In this paper, a digital 3D model which allows for visualisation in three dimensions and interactive manipulation is explored as a tool to help us understand the structural morphology and elucidate the functions of morphological structures of fragile microorganisms which defy live studies. We developed a deformable generic 3D model of haptoral anchor of dactylogyridean monogeneans that can subsequently be deformed into different desired anchor shapes by using direct manipulation deformation technique. We used point primitives to construct the rectangular building blocks to develop our deformable 3D model. Point primitives are manually marked on a 2D illustration of an anchor on a Cartesian graph paper and a set of Cartesian coordinates for each point primitive is manually extracted from the graph paper. A Python script is then written in Blender to construct 3D rectangular building blocks based on the Cartesian coordinates. The rectangular building blocks are stacked on top or by the side of each other following their respective Cartesian coordinates of point primitive. More point primitives are added at the sites in the 3D model where more structural variations are likely to occur, in order to generate complex anchor structures. We used Catmull-Clark subdivision surface modifier to smoothen the surface and edge of the generic 3D model to obtain a smoother and more natural 3D shape and antialiasing option to reduce the jagged edges of the 3D model. This deformable generic 3D model can be deformed into different desired 3D anchor shapes through direct manipulation deformation technique by aligning the vertices (pilot points) of the newly developed deformable generic 3D model onto the 2D illustrations of the desired shapes and moving the vertices until the desire 3D shapes are formed. In this generic 3D model all the vertices present are deployed for displacement during deformation. PMID:24204903

  18. A deformable generic 3D model of haptoral anchor of Monogenean.

    Directory of Open Access Journals (Sweden)

    Bee Guan Teo

    Full Text Available In this paper, a digital 3D model which allows for visualisation in three dimensions and interactive manipulation is explored as a tool to help us understand the structural morphology and elucidate the functions of morphological structures of fragile microorganisms which defy live studies. We developed a deformable generic 3D model of haptoral anchor of dactylogyridean monogeneans that can subsequently be deformed into different desired anchor shapes by using direct manipulation deformation technique. We used point primitives to construct the rectangular building blocks to develop our deformable 3D model. Point primitives are manually marked on a 2D illustration of an anchor on a Cartesian graph paper and a set of Cartesian coordinates for each point primitive is manually extracted from the graph paper. A Python script is then written in Blender to construct 3D rectangular building blocks based on the Cartesian coordinates. The rectangular building blocks are stacked on top or by the side of each other following their respective Cartesian coordinates of point primitive. More point primitives are added at the sites in the 3D model where more structural variations are likely to occur, in order to generate complex anchor structures. We used Catmull-Clark subdivision surface modifier to smoothen the surface and edge of the generic 3D model to obtain a smoother and more natural 3D shape and antialiasing option to reduce the jagged edges of the 3D model. This deformable generic 3D model can be deformed into different desired 3D anchor shapes through direct manipulation deformation technique by aligning the vertices (pilot points of the newly developed deformable generic 3D model onto the 2D illustrations of the desired shapes and moving the vertices until the desire 3D shapes are formed. In this generic 3D model all the vertices present are deployed for displacement during deformation.

  19. A deformable generic 3D model of haptoral anchor of Monogenean.

    Science.gov (United States)

    Teo, Bee Guan; Dhillon, Sarinder Kaur; Lim, Lee Hong Susan

    2013-01-01

    In this paper, a digital 3D model which allows for visualisation in three dimensions and interactive manipulation is explored as a tool to help us understand the structural morphology and elucidate the functions of morphological structures of fragile microorganisms which defy live studies. We developed a deformable generic 3D model of haptoral anchor of dactylogyridean monogeneans that can subsequently be deformed into different desired anchor shapes by using direct manipulation deformation technique. We used point primitives to construct the rectangular building blocks to develop our deformable 3D model. Point primitives are manually marked on a 2D illustration of an anchor on a Cartesian graph paper and a set of Cartesian coordinates for each point primitive is manually extracted from the graph paper. A Python script is then written in Blender to construct 3D rectangular building blocks based on the Cartesian coordinates. The rectangular building blocks are stacked on top or by the side of each other following their respective Cartesian coordinates of point primitive. More point primitives are added at the sites in the 3D model where more structural variations are likely to occur, in order to generate complex anchor structures. We used Catmull-Clark subdivision surface modifier to smoothen the surface and edge of the generic 3D model to obtain a smoother and more natural 3D shape and antialiasing option to reduce the jagged edges of the 3D model. This deformable generic 3D model can be deformed into different desired 3D anchor shapes through direct manipulation deformation technique by aligning the vertices (pilot points) of the newly developed deformable generic 3D model onto the 2D illustrations of the desired shapes and moving the vertices until the desire 3D shapes are formed. In this generic 3D model all the vertices present are deployed for displacement during deformation.

  20. Microstructural evolution during tensile deformation of polypropylenes

    International Nuclear Information System (INIS)

    Dasari, A.; Rohrmann, J.; Misra, R.D.K.

    2003-01-01

    Tensile deformation processes occurring at varying strain rates in high and low crystallinity polypropylenes and ethylene-propylene di-block copolymers have been investigated by scanning electron microscopy. This is examined for both long and short chain polymeric materials. The deformation processes in different polymeric materials show striking dissimilarities in spite of the common propylene matrix. Additionally, the deformation behavior of long and their respective short chain polymers was different. Deformation mechanisms include crazing/tearing, wedging, ductile ploughing, fibrillation, and brittle fracture. The different modes of deformation are depicted in the form of strain rate-strain diagrams. At a constant strain rate, the strain to fracture follows the sequence: high crystallinity polypropylenes< low crystallinity polypropylenes< ethylene-propylene di-block copolymers, indicative of the trend in resistance to plastic deformation

  1. In vivo cartilage contact deformation in the healthy human tibiofemoral joint.

    Science.gov (United States)

    Bingham, J T; Papannagari, R; Van de Velde, S K; Gross, C; Gill, T J; Felson, D T; Rubash, H E; Li, G

    2008-11-01

    In vivo cartilage contact deformation is instrumental for understanding human joint function and degeneration. This study measured the total deformation of contacting articular cartilage in the human tibiofemoral joint during in vivo weight-bearing flexion. Eleven healthy knees were magnetic resonance (MR) scanned and imaged with a dual fluoroscopic system while the subject performed a weight-bearing single-leg lunge. The tibia, femur and associated articulating cartilage were constructed from the MR images and combined with the dual fluoroscopic images to determine in vivo cartilage contact deformation from full extension to 120 degrees of flexion. In both compartments, minimum peak compartmental contact deformation occurred at 30 degrees of flexion (24 +/- 6% medial, 17 +/- 7% lateral) and maximum peak compartmental deformation occurred at 120 degrees of flexion (30 +/- 13% medial, 30 +/- 10% lateral) during the weight-bearing flexion from full extension to 120 degrees. Average medial contact areas and peak contact deformations were significantly greater than lateral compartment values (P In addition, cartilage thickness in regions of contact was on average 1.4- and 1.1-times thicker than the average thickness of the tibial and femoral cartilage surfaces, respectively (P line knowledge for investigating the effects of various knee injuries on joint contact biomechanics and the aetiology of cartilage degeneration.

  2. Nonlinear continuum mechanics and large inelastic deformations

    CERN Document Server

    Dimitrienko, Yuriy I

    2010-01-01

    This book provides a rigorous axiomatic approach to continuum mechanics under large deformation. In addition to the classical nonlinear continuum mechanics - kinematics, fundamental laws, the theory of functions having jump discontinuities across singular surfaces, etc. - the book presents the theory of co-rotational derivatives, dynamic deformation compatibility equations, and the principles of material indifference and symmetry, all in systematized form. The focus of the book is a new approach to the formulation of the constitutive equations for elastic and inelastic continua under large deformation. This new approach is based on using energetic and quasi-energetic couples of stress and deformation tensors. This approach leads to a unified treatment of large, anisotropic elastic, viscoelastic, and plastic deformations. The author analyses classical problems, including some involving nonlinear wave propagation, using different models for continua under large deformation, and shows how different models lead t...

  3. Exploratory Data Analysis of Synthetic Aperture Radar (SAR Measurements to Distinguish the Sea Surface Expressions of Naturally-Occurring Oil Seeps from Human-Related Oil Spills in Campeche Bay (Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Gustavo de Araújo Carvalho

    2017-12-01

    Full Text Available An Exploratory Data Analysis (EDA aims to use Synthetic Aperture Radar (SAR measurements for discriminating between two oil slick types observed on the sea surface: naturally-occurring oil seeps versus human-related oil spills—the use of satellite sensors for this task is poorly documented in scientific literature. A long-term RADARSAT dataset (2008–2012 is exploited to investigate oil slicks in Campeche Bay (Gulf of Mexico. Simple Classification Algorithms to distinguish the oil slick type are designed based on standard multivariate data analysis techniques. Various attributes of geometry, shape, and dimension that describe the oil slick Size Information are combined with SAR-derived backscatter coefficients—sigma-(σo, beta-(βo, and gamma-(γo naught. The combination of several of these characteristics is capable of distinguishing the oil slick type with ~70% of overall accuracy, however, the sole and simple use of two specific oil slick’s Size Information (i.e., area and perimeter is equally capable of distinguishing seeps from spills. The data mining exercise of our EDA promotes a novel idea bridging petroleum pollution and remote sensing research, thus paving the way to further investigate the satellite synoptic view to express geophysical differences between seeped and spilled oil observed on the sea surface for systematic use.

  4. Thermoelastoplastic Deformation of a Multilayer Ball

    Science.gov (United States)

    Murashkin, E. V.; Dats, E. P.

    2017-09-01

    The problem of centrally symmetric deformation of a multilayer elastoplastic ball in the process of successive accretion of preheated layers to its outer surface is considered in the framework of small elastoplastic deformations. The problems of residual stress formation in the elastoplastic ball with an inclusion and a cavity are solved under various mechanical boundary conditions on the inner surface and for prescribed thermal compression distributions. The graphs of residual stress and displacement fields are constructed.

  5. An On-Demand Web Tool for the Unsupervised Retrieval of Earth’s Surface Deformation from SAR Data: The P-SBAS Service within the ESA G-POD Environment

    Directory of Open Access Journals (Sweden)

    Claudio De Luca

    2015-11-01

    Full Text Available This paper presents a web tool for the unsupervised retrieval of Earth’s surface deformation from Synthetic Aperture Radar (SAR satellite data. The system is based on the implementation of the Differential SAR Interferometry (DInSAR algorithm referred to as Parallel Small BAseline Subset (P-SBAS approach, within the Grid Processing on Demand (G-POD environment that is a part of the ESA’s Geohazards Exploitation Platform (GEP. The developed on-demand web tool, which is specifically addressed to scientists that are non-expert in DInSAR data processing, permits to set up an efficient on-line P-SBAS processing service to produce surface deformation mean velocity maps and time series in an unsupervised manner. Such results are obtained by exploiting the available huge ERS and ENVISAT SAR data archives; moreover, the implementation of the Sentinel-1 P-SBAS processing chain is in a rather advanced status and first results are already available. Thanks to the adopted strategy to co-locate both DInSAR algorithms and computational resources close to the SAR data archives, as well as the provided capability to easily generate the DInSAR results, the presented web tool may contribute to drastically expand the user community exploiting the DInSAR products and methodologies.

  6. Growth of contact area between rough surfaces under normal stress

    Science.gov (United States)

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

    1987-05-01

    The contact area between deforming rough surfaces in marble, alabaster, and quartz was measured from thin sections of surfaces bonded under load with low viscosity resin epoxy. The marble and alabaster samples had contact areas that increased with stress at an accelerating rate. This result suggests that the strength of the asperity contacts decreased progressively during the deformation, following some form of strain weakening relationship. This conclusion is supported by petrographic observation of the thin sections that indicate that much of the deformation was cataclastic, with minor twinning of calcite and kinking of gypsum. In the case of the quartz, the observed contact area was small and increased approximately linearly with normal stress. Only the irreversible cataclastic deformation was observed; however strain-induced birefringence and cracking of the epoxy, not observed with the other rocks, suggests that significant elastic deformation occurred, but recovered during unloading.

  7. Microstructure evolution of hot-deformed Nd-Fe-B anisotropic magnets

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J., E-mail: liu.jun@nims.go.jp; Hono, K. [Elements Strategy Initiative Center for Magnetic Materials, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8577 (Japan); Sepehri-Amin, H.; Ohkubo, T. [Elements Strategy Initiative Center for Magnetic Materials, National Institute for Materials Science, Tsukuba 305-0047 (Japan); Hioki, K.; Hattori, A. [Daido Steel Co. Ltd., Nagoya 457-8545 (Japan)

    2014-05-07

    The microstructural evolution of hot-deformed Nd-Fe-B magnets in each stage of hot-deformation process was studied using transmission electron microscopy and three dimensional atom probe (3DAP). The anisotropic growth of initially isotropic grains in rapidly solidified alloy occurs by annealing without pressing. 3DAP analyses showed a higher concentration of rare-earth elements in the intergranular phase parallel to the flat surface of platelet shaped Nd{sub 2}Fe{sub 14}B grains compared to that in the intergranular phase at the side of platelets.

  8. Investigating Corrosion, Wear Resistance and Friction of AA5454-O Series after its Severe Deformation by Rolling

    Directory of Open Access Journals (Sweden)

    Sinan SEZEK

    2017-02-01

    Full Text Available AA5454-O is an easily wrought, or in other words, a ductile aluminium alloy, however, its mechanical properties are inferior as compared to those of other alloys. The change taking place in corrosion resistance of AA5454-O alloy as a result of its severe plastic deformation (SPD by rolling has been investigated in this study. It has been observed that significant changes occurred in abrasion wear and corrosion resistances of AA5454-O alloy, which was severely deformed up to 80 % by rolling process. Corrosion resistance of the alloy that was severely deformed by rolling has increased. The effect of deformation rate on corrosion has been investigated by applying potentiodynamic test whereas on the other hand such change has been evidenced also through corrosion test. It has been observed that friction coefficient of severely deformed AA5454-O alloy varied by around 10 %, and that, associated with such change, its wear resistance also increased considerably. It has been determined that, as a result of severe deformation by rolling, hardness values rose in areas where the alloy was in contact with rolling surface. In this study, wear resistance of severely deformed alloy has been investigated as well. It has been observed that deformation value contributed positively to the increase in wear resistance.DOI: http://dx.doi.org/10.5755/j01.ms.23.1.14650

  9. 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.

  10. Transport-related mylonitic ductile deformation and shape change of alluvial gold, southern New Zealand

    Science.gov (United States)

    Kerr, Gemma; Falconer, Donna; Reith, Frank; Craw, Dave

    2017-11-01

    Gold is a malleable metal, and detrital gold particles deform via internal distortion. The shapes of gold particles are commonly used to estimate transport distances from sources, but the mechanisms of internal gold deformation leading to shape changes are poorly understood because of subsequent recrystallisation of the gold in situ in placer deposits, which creates a rim zone around the particles, with undeformed > 10 μm grains. This paper describes samples from southern New Zealand in which grain size reduction (to submicrometer scale) and mylonitic textures have resulted from internal ductile deformation. These textures have been preserved without subsequent recrystallisation after deposition in late Pleistocene-Holocene alluvial fan placers. These mylonitic textures were imposed by transport-related deformation on recrystallised rims that were derived from previous stages of fluvial transportation and deposition. This latest stage of fluvial transport and deformation has produced numerous elongated gold smears that are typically 100 μm long and 10-20 μm wide. These smears are the principal agents for transport-induced changes in particle shape in the studied placers. Focused ion beam (FIB) sectioning through these deformed zones combined with scanning electron microscopic (SEM) imaging show that the interior of the gold particles has undergone grain size reduction (to 500 nm) and extensive folding with development of a ductile deformation fabric that resembles textures typical of mylonites in silicate rocks. Relict pods of the pre-existing recrystallised rim zone are floating in this ductile deformation zone and these pods are irregular in shape and discontinuous in three dimensions. Micrometer scale biologically-mediated deposition from groundwater of overgrowth gold on particle surfaces occurs at all stages of placer formation, and some of this overgrowth gold has been incorporated into deformation zones. These examples provide a rare view into the nature

  11. Active deformation offshore the Western Transverse Ranges

    Science.gov (United States)

    Ucarkus, G.; Driscoll, N. W.; Brothers, D. S.; Kent, G.; Rockwell, T. K.

    2014-12-01

    The Transverse Ranges within the structural province of southern California, an east-west trending active fold and thrust belt system, has rapid uplift rates that are capable of generating large earthquakes and tsunamis. This system to the west consists of north and south dipping reverse faults offshore Santa Barbara and Ventura (i.e., Pitas Point fault, Red Mountain fault, Rincon Creek fault). Ventura Avenue Anticline (VAA) is one of the fastest uplifting structure within this system has experienced nearly 2.7 km of structural uplift since fold initiation about 200-300 thousand years ago, yielding an average uplift rate of 9-13 mm/yr. Mapped and dated Holocene marine terraces between Ventura and Carpenteria reveal that large uplift events occurred at 0.8 ka and 1.9 ka; a recurrence interval of approximately a thousand years. The VAA trends offshore to the west and is buried by sediment from Rincon Creek. This sediment completely obscures the surficial expression of the fold between Rincon Point and Punta Gorda, indicating that Holocene sedimentation has kept pace with fold growth. Given the high sedimentation rate, each uplift event should be captured by stratigraphic rotation and onlap, and formation of angular unconformities. With that perspective, we acquired ~240 km-long very high-resolution (decimeter) CHIRP seismic reflection data from offshore Santa Barbara in the west to Ventura in the east, in order to examine discrete folding/uplift events that are preserved in the Holocene sediment record. CHIRP data together with re-processed USGS sparker profiles provide new constraints on timing and architecture of deformation offshore. A transgressive surface that dates back to ~9.5 kyr B.P is identified in seismic reflection data and dips landward; bending of the transgressive surface appears to be due to active folding and faulting. Observed onlapping sediments together with the deformation of the transgressive surface mark the onset of deformation while periods

  12. Deformation Analysis of Fixed Bearing Inclined Plane Thrust Bearing

    Directory of Open Access Journals (Sweden)

    LI Yong--hai

    2017-02-01

    Full Text Available According to the theory of lubrication,Numerical simulation of the deformation of the thrust bearing of the fixed inclined plane was carried out,by finite element numerical analysis method and using the ANSYS software. The mathematical model of the oil film shape control equations about of the deformation and bearing is established. Analytical result showed that the force caused the tile surface generating concave deformation,and convex deformation increased with the height and the size of the load and bearing;Tile surface temperature generated convex deformation and increased with the height and the size of the temperature of bearing bush;The actual deformation of the tile surface is the superposition of the force and the thermal deformation. This conclusion can provide reference for the design and the application of thrust bearing,to reduce the tile surface,which is not conducive to the carrying capacity of the concave deformation.

  13. Biomechanical and biochemical outcomes of porcine temporomandibular joint disc deformation.

    Science.gov (United States)

    Matuska, Andrea M; Muller, Stephen; Dolwick, M Franklin; McFetridge, Peter S

    2016-04-01

    The structure-function relationship in the healthy temporomandibular joint (TMJ) disc has been well established, however the changes in dysfunctional joints has yet to be systematically evaluated. Due to the poor understanding of the etiology of temporomandibular disorders (TMDs) this study evaluated naturally occurring degenerative remodeling in aged female porcine temporomandibular joint (TMJ) discs in order to gain insight into the progression and effects on possible treatment strategies of TMDs. Surface and regional biomechanical and biochemical properties of discal tissues were determined in grossly deformed (≥Wilkes Stage 3) and morphologically normal (≤Wilkes Stage 2) TMJ discs. Compared to normal disc structure the deformed discs lacked a smooth biconcave shape and characteristic ECM organization. Reduction in tensile biomechanical integrity and increased compressive stiffness and cellularity was found in deformed discs. Regionally, the posterior and intermediate zones of the disc were most frequently affected along with the inferior surface. The frequency of degeneration observed on the inferior surface of the disc (predominantly posterior), suggests that a disruption in the disc-condyle relationship likely contributes to the progression of joint dysfunction more than the temporodiscal relationship. As such, the inferior joint space may be an important consideration in early clinical diagnosis and treatment of TMDs, as it is overlooked in techniques performed in the upper joint space, including arthroscopy and arthrocentesis. Furthermore, permanent damage to the disc mechanical properties would limit the ability to successfully reposition deformed discs, highlighting the importance of emerging therapies such as tissue engineering. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. 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.

  15. Plastic deformation in nano-scale multilayer materials — A biomimetic approach based on nacre

    Energy Technology Data Exchange (ETDEWEB)

    Lackner, Juergen M., E-mail: juergen.lackner@joanneum.at [JOANNEUM RESEARCH Forschungsges.m.b.H., Institute for Surface Technologies and Photonics, Functional Surfaces, Leobner Strasse 94, A-8712 Niklasdorf (Austria); Waldhauser, Wolfgang [JOANNEUM RESEARCH Forschungsges.m.b.H., Institute for Surface Technologies and Photonics, Functional Surfaces, Leobner Strasse 94, A-8712 Niklasdorf (Austria); Major, Boguslaw; Major, Lukasz [Polish Academy of Sciences, Institute of Metallurgy and Materials Sciences, IMIM-PAN, ul. Reymonta 25, PL-30059 Krakow (Poland); Kot, Marcin [University of Science and Technology, AGH, Aleja Adama Mickiewicza 30, 30-059 Krakow (Poland)

    2013-05-01

    The paper reports about a biomimetic based comparison of deformation in magnetron sputtered multilayer coatings based on titanium (Ti), titanium nitride (TiN) and diamond-like carbon (DLC) layers and the deformation mechanisms in nacre of mollusc shells. Nacre as highly mineralized tissue combines high stiffness and hardness with high toughness, enabling resistance to fracture and crack propagation during tensile loading. Such behaviour is based on a combination of load transmission by tensile stressed aragonite tablets and shearing in layers between the tablets. Shearing in these polysaccharide and protein interlayers demands hydrated conditions. Otherwise, nacre has similar brittle behaviour to aragonite. To prevent shear failure, shear hardening occurs by progressive tablet locking due to wavy dovetail-like surface geometry of the tablets. Similar effects by shearing and strain hardening mechanisms were found for Ti interlayers between TiN and DLC layers in high-resolution transmission electron microscopy studies, performed in deformed zones beneath spherical indentations. 7 nm thin Ti films are sufficient for strong toughening of the whole multi-layered coating structure, providing a barrier for propagation of cracks, starting from tensile-stressed, hard, brittle TiN or DLC layers. - Highlights: • Biomimetic approach to TiN-diamond-like carbon (DLC) multilayers by sputtering • Investigation of deformation in/around hardness indents by HR-TEM • Plastic deformation with shearing in 7-nm thick Ti interlayers in TiN–DLC multilayers • Biomimetically comparable to nacre deformation.

  16. The effect of deformation twinning on irradiation embrittlement in iron single crystals

    International Nuclear Information System (INIS)

    Kayano, Hideo; Tokutomi, Shoichiro; Yajima, Seishi; Takaku, Hiroshi.

    1978-01-01

    Single crystals of iron with the [100] crystal orientation were irradiated in JMTR with fast neutrons to a fluence of 8 x 10 18 n/cm 2 (E > 1 MeV). All samples were deformed in tension at temperatures from liquid nitrogen temperature to 200 0 C at different strain rates using an Instron-type tensile testing machine. Scanning electron microscopy of the fractured surfaces revealed that deformation twinning is difficult to occur in irradiated samples, and also that twins formed in both irradiated and unirradiated samples inhibit fracture nucleation and growth. From the results of tensile deformation of the irradiated samples deformed in tension a different strain rates at 159 0 K, it is conceived that twinning suppression is greater in the irradiated than in the unirradiated samples, and that the nucleation and growth of twins are not necessarily related to those of cracks. It is suggested that the irradiation-induced defects impede plastic deformation of the crystals and deformation twinning is suppressed by irradiation, thus causing the irradiation embrittlement. (auth.)

  17. Spatiotemporal deformations of reflectionless potentials

    Science.gov (United States)

    Horsley, S. A. R.; Longhi, S.

    2017-08-01

    Reflectionless potentials for classical or matter waves represent an important class of scatteringless systems encountered in different areas of physics. Here we mathematically demonstrate that there is a family of non-Hermitian potentials that, in contrast to their Hermitian counterparts, remain reflectionless even when deformed in space or time. These are the profiles that satisfy the spatial Kramers-Kronig relations. We start by considering scattering of matter waves for the Schrödinger equation with an external field, where a moving potential is observed in the Kramers-Henneberger reference frame. We then generalize this result to the case of electromagnetic waves, by considering a slab of reflectionless material that both is scaled and has its center displaced as an arbitrary function of position. We analytically and numerically demonstrate that the backscattering from these profiles remains zero, even for extreme deformations. Our results indicate the supremacy of non-Hermitian Kramers-Kronig potentials over reflectionless Hermitian potentials in keeping their reflectionless property under deformation and could find applications to, e.g., reflectionless optical coatings of highly deformed surfaces based on perfect absorption.

  18. Mounting with compliant cylinders for deformable mirrors.

    Science.gov (United States)

    Reinlein, Claudia; Goy, Matthias; Lange, Nicolas; Appelfelder, Michael

    2015-04-01

    A method is presented to mount large aperture unimorph deformable mirrors by compliant cylinders (CC). The CCs are manufactured from a soft silicone, and shear testing is performed in order to evaluate the Young's modulus. A scale mirror model is assembled to evaluate mount-induced change of piezoelectric deformation, and its applicability for tightly focusing mirrors. Experiments do not show any decrease of piezoelectric stroke. Further it is shown that the changes of surface fidelity by the attachment of the deformable mirror to its mount are neglectable.

  19. Deformation relief evolution during sliding friction of Hadfield steel single crystal

    Science.gov (United States)

    Lychagin, D. V.; Filippov, A. V.; Novitskaya, O. S.; Kolubaev, A. V.; Sizova, O. V.

    2017-12-01

    The paper deals with the evolution of the deformation relief formed on lateral faces of single crystals of Hadfield steel during dry sliding friction. The use of single crystals with the predetermined orientation enables to analyze the development of shear systems subject to the duration of tribological tests. As the test duration increases, slip bands are curved and thicken in the near-surface region. After 24 hours of friction, single crystals of Hadfield steel demonstrate the maximum hardening. Afterwards, the wear process begins, which is followed by the repeated strain hardening of the specimens. After 48 hours of friction, the height of the deformation relief nearly halves on all of the three faces, as compared to that observed after 24 hours of friction. Differences in the propagation height of slip bands on the faces occur due to the uneven running-in as well as the complex involvement pattern of shear systems into the deformation process.

  20. Combined effect of rapid nitriding and plastic deformation on the surface strength, toughness and wear resistance of steel 38CrMoAlA

    DEFF Research Database (Denmark)

    Wang, B.; Lv, Z.A.; Zhou, Z.A.

    2015-01-01

    The combined treatment of pressurized gas nitriding and cold rolling is proposed as a new approach to rapid preparation of a strong and tough nitrided layer for steel 38CrMoAlA. The microstructural characteristics and properties of the modified surface layer in comparison with those of the conven...

  1. Selected problems of the influence of underground mining on ground surface

    Energy Technology Data Exchange (ETDEWEB)

    Gren, K.; Popiolek, E.; Janusz, W.; Bartosik-Sroka, T.; Ostrowski, J.

    1980-01-01

    Problems associated with forecasting ground deformation caused by underground mining are discussed. Irregularities in surface deformations are described. Two cases of irregularities which occur in the Lower Silesian coal basin are presented. In the Nowa Ruda coal mine, irregularities accompany mining of coal seams located at a depth of about 400 m using pneumatic stowing. Mining geological conditions of working fronts are discussed. The mined coal seams are located in the protective pillar under Nowa Ruda. Zone of increased deformation is characterized by horizontal deformations 2.5 times higher than the maximum average deformation. The second case is associated with coal mining in the safety coal pillar of Nowe Miasto (a section of the town of Walbrzych). Irregularities in ground deformations occur on the rise side of mined coal seams: compression deformations are two times higher than the maximum compression beyond the zone and the three times higher than the maximum tension deformations. Ground deformations and the irregularities are shown in four diagrams. It is suggested that the described cases of deformation irregularities point out the need for individual analysis of geological and mining conditions of coal seams. (9 refs.) (In Polish)

  2. Deformations of superconformal theories

    International Nuclear Information System (INIS)

    Córdova, Clay; Dumitrescu, Thomas T.; Intriligator, Kenneth

    2016-01-01

    We classify possible supersymmetry-preserving relevant, marginal, and irrelevant deformations of unitary superconformal theories in d≥3 dimensions. Our method only relies on symmetries and unitarity. Hence, the results are model independent and do not require a Lagrangian description. Two unifying themes emerge: first, many theories admit deformations that reside in multiplets together with conserved currents. Such deformations can lead to modifications of the supersymmetry algebra by central and non-central charges. Second, many theories with a sufficient amount of supersymmetry do not admit relevant or marginal deformations, and some admit neither. The classification is complicated by the fact that short superconformal multiplets display a rich variety of sporadic phenomena, including supersymmetric deformations that reside in the middle of a multiplet. We illustrate our results with examples in diverse dimensions. In particular, we explain how the classification of irrelevant supersymmetric deformations can be used to derive known and new constraints on moduli-space effective actions.

  3. Mechanics of deformable bodies

    CERN Document Server

    Sommerfeld, Arnold Johannes Wilhelm

    1950-01-01

    Mechanics of Deformable Bodies: Lectures on Theoretical Physics, Volume II covers topics on the mechanics of deformable bodies. The book discusses the kinematics, statics, and dynamics of deformable bodies; the vortex theory; as well as the theory of waves. The text also describes the flow with given boundaries. Supplementary notes on selected hydrodynamic problems and supplements to the theory of elasticity are provided. Physicists, mathematicians, and students taking related courses will find the book useful.

  4. Diffeomorphic Statistical Deformation Models

    DEFF Research Database (Denmark)

    Hansen, Michael Sass; Hansen, Mads/Fogtman; Larsen, Rasmus

    2007-01-01

    In this paper we present a new method for constructing diffeomorphic statistical deformation models in arbitrary dimensional images with a nonlinear generative model and a linear parameter space. Our deformation model is a modified version of the diffeomorphic model introduced by Cootes et al....... The modifications ensure that no boundary restriction has to be enforced on the parameter space to prevent folds or tears in the deformation field. For straightforward statistical analysis, principal component analysis and sparse methods, we assume that the parameters for a class of deformations lie on a linear...

  5. Deformed Open Quantum Systems

    Science.gov (United States)

    Isar, A.

    2004-09-01

    A master equation for the deformed quantum harmonic oscillator interacting with a dissipative environment, in particular with a thermal bath, is obtained in the microscopic model, using perturbation theory. The coefficients of the master equation depend on the deformation function. The steady state solution of the equation for the density matrix in the number representation is derived and the equilibrium energy of the deformed harmonic oscillator is calculated in the approximation of small deformation. Note from Publisher: This article contains the abstract and references only.

  6. Faraday instability in deformable domains

    International Nuclear Information System (INIS)

    Pucci, G.

    2013-01-01

    Hydrodynamical instabilities are usually studied either in bounded regions or free to grow in space. In this article we review the experimental results of an intermediate situation, in which an instability develops in deformable domains. The Faraday instability, which consists in the formation of surface waves on a liquid experiencing a vertical forcing, is triggered in floating liquid lenses playing the role of deformable domains. Faraday waves deform the lenses from the initial circular shape and the mutual adaptation of instability patterns with the lens boundary is observed. Two archetypes of behaviour have been found. In the first archetype a stable elongated shape is reached, the wave vector being parallel to the direction of elongation. In the second archetype the waves exceed the response of the lens border and no equilibrium shape is reached. The lens stretches and eventually breaks into fragments that have a complex dynamics. The difference between the two archetypes is explained by the competition between the radiation pressure the waves exert on the lens border and its response due to surface tension.

  7. Application of TOPEX Altimetry for Solid Earth Deformation Studies

    Directory of Open Access Journals (Sweden)

    Hyongki Lee

    2008-01-01

    Full Text Available This study demonstrates the use of satellite radar altimetry to detect solid Earth deformation signals such as Glacial Isostatic Adjustment (GIA. Our study region covers moderately flat land surfaces seasonally covered by snow/ice/vegetation. The maximum solid Earth uplift of ~10 mm yr-1 is primarily due to the incomplete glacial isostatic rebound that occurs around Hudson Bay, North America. We use decadal (1992 - 2002 surface height measurements from TOPEX/POSEIDON radar altimetry to generate height changes time series for 12 selected locations in the study region. Due to the seasonally varying surface characteristics, we first perform radar waveform shape classification and have found that most of the waveforms are quasi-diffuse during winter/spring and specular during summer/fall. As a result, we used the NASA £]-retracker for the quasi-diffuse waveforms and the Offset Center of Gravity or the threshold retracker for the specular waveforms, to generate the surface height time series. The TOPEX height change time series exhibit coherent seasonal signals (higher amplitude during the winter and lower amplitude during the summer, and the estimated deformation rates agree qualitatively well with GPS vertical velocities, and with altimeter/tide gauge combined vertical velocities around the Great Lakes. The TOPEX observations also agree well with various GIA model predictions, especially with the ICE-5G (VM2 model with differences at 0.2 ¡_ 1.4 mm yr-1, indicating that TOPEX has indeed observed solid Earth deformation signals manifested as crustal uplift over the former Laurentide Ice Sheet region.

  8. Effect of vorticity on polycrystalline ice deformation

    Science.gov (United States)

    Llorens, Maria-Gema; Griera, Albert; Steinbach, Florian; Bons, Paul D.; Gomez-Rivas, Enrique; Jansen, Daniela; Lebensohn, Ricardo A.; Weikusat, Ilka

    2017-04-01

    Understanding ice sheet dynamics requires a good knowledge of how dynamic recrystallisation controls ice microstructures and rheology at different boundary conditions. In polar ice sheets, pure shear flattening typically occurs at the top of the sheets, while simple shearing dominates near their base. We present a series of two-dimensional microdynamic numerical simulations that couple ice deformation with dynamic recrystallisation of various intensities, paying special attention to the effect of boundary conditions. The viscoplastic full-field numerical modelling approach (VPFFT) (Lebensohn, 2001) is used to calculate the response of a polycrystalline aggregate that deforms purely by dislocation glide. This code is coupled with the ELLE microstructural modelling platform that includes recrystallisation in the aggregate by intracrystalline recovery, nucleation by polygonisation, as well as grain boundary migration driven by the reduction of surface and strain energies (Llorens et al., 2016a, 2016b, 2017). The results reveal that regardless the amount of DRX and ice flow a single c-axes maximum develops all simulations. This maximum is oriented approximately parallel to the maximum finite shortening direction and rotates in simple shear towards the normal to the shear plane. This leads to a distinctly different behaviour in pure and simple shear. In pure shear, the lattice preferred orientation (LPO) and shape-preferred orientation (SPO) are increasingly unfavourable for deformation, leading to hardening and an increased activity of non-basal slip. The opposite happens in simple shear, where the imposed vorticity causes rotation of the LPO and SPO to a favourable orientation, leading to strain softening. An increase of recrystallisation enhances the activity of the non-basal slip, due to the reduction of deformation localisation. In pure shear conditions, the pyramidal slip activity is thus even more enhanced and can become higher than the basal-slip activity. Our

  9. Intracrystalline deformation of calcite

    NARCIS (Netherlands)

    Bresser, J.H.P. de

    1991-01-01

    It is well established from observations on natural calcite tectonites that intracrystalline plastic mechanisms are important during the deformation of calcite rocks in nature. In this thesis, new data are presented on fundamental aspects of deformation behaviour of calcite under conditions where

  10. Passive sorting of capsules by deformability

    Science.gov (United States)

    Haener, Edgar; Juel, Anne

    We study passive sorting according to deformability of liquid-filled ovalbumin-alginate capsules. We present results for two sorting geometries: a straight channel with a half-cylindrical obstruction and a pinched flow fractioning device (PFF) adapted for use with capsules. In the half-cylinder device, the capsules deform as they encounter the obstruction, and travel around the half-cylinder. The distance from the capsule's centre of mass to the surface of the half-cylinder depends on deformability, and separation between capsules of different deformability is amplified by diverging streamlines in the channel expansion downstream of the obstruction. We show experimentally that capsules can be sorted according to deformability with their downstream position depending on capillary number only, and we establish the sensitivity of the device to experimental variability. In the PFF device, particles are compressed against a wall using a strong pinching flow. We show that capsule deformation increases with the intensity of the pinching flow, but that the downstream capsule position is not set by deformation in the device. However, when using the PFF device like a T-Junction, we achieve improved sorting resolution compared to the half-cylinder device.

  11. Rheological responses to plate boundary deformation at the Eastern Volcanic Zone in Iceland

    Science.gov (United States)

    Tariqul Islam, Md.; Sturkell, Erik

    2017-10-01

    Located on the mid-Atlantic ridge, Iceland allows for direct measurement of crustal deformation. Global Positioning System (GPS) data from the Eastern Volcanic Zone (EVZ), Iceland, and crustal deformation of the rift near its southern end at 64°N show a spreading rate of 13.8 ± 1.8 mm yr- 1. About 90% of the deformation occurs in an 80 to 90-km wide zone. To understand how the rheology of the lithosphere influences rifting, we applied a thermo-mechanical stretching model that includes thermal states in Iceland using temperature- and stress-dependent wet and dry olivine rheology. We attempt to reproduce the thermal structure of a rift by defining 700 °C from 5- to 15-km depth at the rift axis that leads to variation in rheological structure, and to estimate the layer (from surface to a depth of 700 °C) where the elastic deformation of the lithosphere is the greatest. At a fixed spreading rate, the deformation field is controlled by the sub-surface thermal state. The vertical subsidence rate at the ridge axis increases almost linearly as the half-velocity increases. The best fitted model suggests a thermal gradient of 54 °C km- 1 at depth below where 700 °C occurs at the ridge axis. The models have little sensitivity to the wet or dry olivine rheology. Estimated viscosity is 1 × 1019 Pa s at 20-km depth at the ridge axis and 1 × 1018 Pa s up to 100-km depth in the model. The spreading rate influences the tangential (non-linearity) shape of the deformation field, and a change in spreading rate affects the deformation field the most. After spreading velocity, the model's second most sensitive parameter is the location of the 700 °C at the rift axis. The thermomechanical model confirms that the rheological responses at the central part of the rift zone in the EVZ, Iceland caused of plate spreading is nonlinear, comparable with surface deformation observed by GPS measurement.

  12. 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.

  13. GEOPHYSICS. Layered deformation in the Taiwan orogen.

    Science.gov (United States)

    Huang, T-Y; Gung, Y; Kuo, B-Y; Chiao, L-Y; Chen, Y-N

    2015-08-14

    The underthrusting of continental crust during mountain building is an issue of debate for orogens at convergent continental margins. We report three-dimensional seismic anisotropic tomography of Taiwan that shows a nearly 90° rotation of anisotropic fabrics across a 10- to 20-kilometer depth, consistent with the presence of two layers of deformation. The upper crust is dominated by collision-related compressional deformation, whereas the lower crust of Taiwan, mostly the crust of the subducted Eurasian plate, is dominated by convergence-parallel shear deformation. We interpret this lower crustal shearing as driven by the continuous sinking of the Eurasian mantle lithosphere when the surface of the subducted plate is coupled with the orogen. The two-layer deformation clearly defines the role of subduction in the formation of the Taiwan mountain belt. Copyright © 2015, American Association for the Advancement of Science.

  14. Shapeable sheet without plastic deformation

    Science.gov (United States)

    Oppenheimer, Naomi; Witten, Thomas A.

    2015-11-01

    Randomly crumpled sheets have shape memory. In order to understand the basis of this form of memory, we simulate triangular lattices of springs whose lengths are altered to create a topography with multiple potential energy minima. We then deform these lattices into different shapes and investigate their ability to retain the imposed shape when the energy is relaxed. The lattices are able to retain a range of curvatures. Under moderate forcing from a state of local equilibrium, the lattices deform by several percent but return to their retained shape when the forces are removed. By increasing the forcing until an irreversible motion occurs, we find that the transitions between remembered shapes show cooperativity among several springs. For fixed lattice structures, the shape memory tends to decrease as the lattice is enlarged; we propose ways to counter this decrease by modifying the lattice geometry. We survey the energy landscape by displacing individual nodes. An extensive fraction of these nodes proves to be bistable; they retain their displaced position when the energy is relaxed. Bending the lattice to a stable curved state alters the pattern of bistable nodes. We discuss this shapeability in the context of other forms of material memory and contrast it with the shapeability of plastic deformation. We outline the prospects for making real materials based on these principles.

  15. A deformation model for non-rigid registration of the kidney

    Science.gov (United States)

    Ong, Rowena E.; Glisson, Courtenay L.; Herrell, S. Duke; Miga, Michael I.; Galloway, Robert

    2009-02-01

    The development of an image-guided renal surgery system may aid tumor resection during partial nephrectomies. This system would require the registration of pre-operative kidney CT or MR scans to the physical kidney; however, the amount of non-rigid deformation occurring during surgery and whether it can be corrected for in an image-guided system is unknown. One possible source of non-rigid deformation is a change in pressure within the kidney: during surgery, clamping of the renal artery and vein results in a loss of perfusion, such that the subsequent cutting of the kidney and fluid outflow may cause a decrease in intrarenal pressure. In this work, we attempt to characterize the deformation due to cutting of the kidney and subsequent changes in intrarenal pressure. To accomplish this, we perfused a resected porcine kidney at a physiologically realistic pressure, clamped the renal vessels, and cut the kidney using a tracked scalpel. The resulting deformation was tracked in a CT scanner using 15-20 glass bead fiducials attached to the kidney surface. A modified form of Biot's consolidation model was used to simulate the deformation, and the accuracy was assessed by calculating the target registration error and image similarity.

  16. Mechanisms of deformation and of recrystallization of imperfect uranium monocrystals

    International Nuclear Information System (INIS)

    Calais, D.

    1960-04-01

    The various means by which plastic deformations by slip, twinning or kinking are produced by tension of imperfect α uranium single crystals prepared by a β → α phase change, have been studied by X-rays and micrographic examination. Depending on the crystallographic orientation with respect to the direction of the applied tension, and depending on the magnitude of the change in length, the crystals are deformed either preferentially according to a single mechanism, for example twinning, or simultaneously according to two or three mechanisms. The results of a subsequent annealing of the deformed single in the α phase are studied with respect to the deformation mechanisms. In the case of a deformation due primarily to (010) [100], (011) [100] or (110) [001] sliding, there occurs recrystallization by crystal growth selectivity. If the deformation occurs via deformation bands, there is recrystallization by 'oriented nucleation'. The crystals deformed preponderantly by twinning give on recrystallization perfect crystals having optimum dimensions and having orientational characteristics closely related to those of the original crystal. Finally are discussed some criteria relating to the geometry and the dynamics with a view to explaining the occurrence of such and such a deformation mechanism of a single crystal with a given orientation. This study, in conclusion, must help to define the best conditions (crystalline orientation and process of deformation) which will promote the growth of large, perfect, single crystals. (author) [fr

  17. Calcaneo-valgus deformity.

    Science.gov (United States)

    Evans, D

    1975-08-01

    A discussion of the essential deformity in calcaneo-valgus feet develops a theme originally put forward in 1961 on the relapsed club foot (Evans 1961). Whereas in the normal foot the medial and lateral columns are about equal in length, in talipes equino-varus the lateral column is longer and in calcaneo-valgus shorter than the medial column. The suggestion is that in the treatment of both deformities the length of the columns be made equal. A method is described of treating calcaneo-valgus deformity by inserting cortical bone grafts taken from the tibia to elongate the anterior end of the calcaneus.

  18. In vitro deposition of hydroxyapatite on cortical bone collagen stimulated by deformation-induced piezoelectricity.

    Science.gov (United States)

    Noris-Suárez, Karem; Lira-Olivares, Joaquin; Ferreira, Ana Marina; Feijoo, José Luis; Suárez, Nery; Hernández, Maria C; Barrios, Esteban

    2007-03-01

    In the present work, we have studied the effect of the piezoelectricity of elastically deformed cortical bone collagen on surface using a biomimetic approach. The mineralization process induced as a consequence of the piezoelectricity effect was evaluated using scanning electron microscopy (SEM), thermally stimulated depolarization current (TSDC), and differential scanning calorimetry (DSC). SEM micrographs showed that mineralization occurred predominantly over the compressed side of bone collagen, due to the effect of piezoelectricity, when the sample was immersed in the simulated body fluid (SBF) in a cell-free system. The TSDC method was used to examine the complex collagen dielectric response. The dielectric spectra of deformed and undeformed collagen samples with different hydration levels were compared and correlated with the mineralization process followed by SEM. The dielectric measurements showed that the mineralization induced significant changes in the dielectric spectra of the deformed sample. DSC and TSDC results demonstrated a reduction of the collagen glass transition as the mineralization process advanced. The combined use of SEM, TSDC, and DSC showed that, even without osteoblasts present, the piezoelectric dipoles produced by deformed collagen can produce the precipitation of hydroxyapatite by electrochemical means, without a catalytic converter as occurs in classical biomimetic deposition.

  19. Looking into Vulcanian eruption through new analogue experiments and associated deformation patterns

    Science.gov (United States)

    Manta, F.; Taisne, B.

    2017-12-01

    The dynamic of Vulcanian eruptions is one of the most fascinating subjects in volcanology. Its characteristic pattern of inflation-deflation cycles has been observed through geodetic data at several volcanoes. Deformation can occur minutes before an explosion suggesting a rapid escalation of events happening in the shallow conduit region. Several numerical and theoretical models have been proposed to explain the relation between the observed deformation pattern and properties of the system. While all of them have their own way to simplify the complexity of the natural system, no comprehensive studies were done to estimate the uncertainties associated with such simplifications. This is a challenging task since no direct observations about the characteristics of the natural system (e.g. bubbles length, conduit radius, viscosity, density...) can be made. Available models can be used to invert the deformation pattern in order to estimate values of the controlling parameters. While taking into account the uncertainties on the data, limitation of the models are usually neglected. In order to quantify the uncertainties associated with the numerical models, we have performed analogue experiments that simulate surface deformation related to conduit processes. We reproduced a degassing volcanic system embedded into an elastic medium that has analogue elastic properties compared to the earth crust. By applying inversion techniques on the measured deformation data and knowing the values of the controlling parameters, we are able to estimate the uncertainties of the model. Through the experimental approach, we also aim to shed light on the triggering mechanism behind Vulcanian eruptions that is still subject of debate. To this end, we explored different scenarios of pressurization: from bubbly flow regime to gas overpressure below a viscous plug. Results will help to clarify what is the dynamic of Vulcanian eruptions and quantify how the properties of the system affect the

  20. In-situ electron microscopy studies on the tensile deformation mechanisms in aluminium 5083 alloy

    CSIR Research Space (South Africa)

    Motsi, G

    2014-10-01

    Full Text Available In this study tensile deformation mechanisms of aluminium alloy 5083 were investigated under observations made from SEM equipped with a tensile stage. Observations during tensile testing revealed a sequence of surface deformation events...

  1. Estudio del estado físico-mecánico de superficies tratadas por deformación plástica superficial. // Study of the mechanical and physical behavior of surfaces treated by superficial plastic deformation.

    Directory of Open Access Journals (Sweden)

    O. Boada Carrazana

    2003-05-01

    Full Text Available El presente trabajo aborda lo referente al estado del arte de la modelación y el comportamiento de las superficies tratadapor deformación plástica superficial (DPS. Se hace una breve descripción de la modelación elástica y plástica, de la teoríade la plasticidad y de las dislocaciones y se dan algunos resultados sobre la modelación del rodilado usando las técnicasde simulación y modelación, como el método de los elementos finitos, a partir del cual se obtienen los modelosmatemáticos para calcular las tensiones y deformaciones máximas.Palabras claves: deformación plástica superficial, rodilado, bruñido por rodillo, elementos finitos,modelación.____________________________________________________________________________Abstract.This paper deals with the state of the art of modelation and the behaviour of surfaces treated by superficial plasticdeformation. It is given a brief description of the elastic and plastic modelation, theory of plasticity and dislocations, andshowed some results about modelation of roller burnishing using simulation techniques like finite elements method toobtain the mathematics models in order to calculate the maximum stresses and strains.Key words: Superficial plastic deformation, roller burnishing, finite elements method, modelation.

  2. Extremely deformable structures

    CERN Document Server

    2015-01-01

    Recently, a new research stimulus has derived from the observation that soft structures, such as biological systems, but also rubber and gel, may work in a post critical regime, where elastic elements are subject to extreme deformations, though still exhibiting excellent mechanical performances. This is the realm of ‘extreme mechanics’, to which this book is addressed. The possibility of exploiting highly deformable structures opens new and unexpected technological possibilities. In particular, the challenge is the design of deformable and bi-stable mechanisms which can reach superior mechanical performances and can have a strong impact on several high-tech applications, including stretchable electronics, nanotube serpentines, deployable structures for aerospace engineering, cable deployment in the ocean, but also sensors and flexible actuators and vibration absorbers. Readers are introduced to a variety of interrelated topics involving the mechanics of extremely deformable structures, with emphasis on ...

  3. Vibrations in deformed nuclei

    International Nuclear Information System (INIS)

    Aprahamian, A.

    1992-01-01

    Quadrupole oscillations around a deformed shape give rise to vibrations in deformed nuclei. Single phonon vibrations of K = 0 (β) and K = 2 (γ) are a systematic feature in deformed nuclei, but the existence of multi-phonon vibrations had remained an open question until the recently reported results in 168 Er. In this nucleus, a two-phonon K = 4(γγ) band was observed at approximately 2.5 times the energy of the single γ vibration. The authors have studied several deformed rare-earth nuclei using the ( 4 He,2n) reaction in order to map out the systematic behavior of these multi-phonon vibrations. Recently, they have identified a similar K = 4 band in 154 Gd

  4. Description of soft sediment deformational structure of the Campano ...

    African Journals Online (AJOL)

    Several soft sediment deformational structures were identified during fieldwork survey carried out on exposures of Gombe Formation in the Gongola sub–basin of the Northern Benue Trough at Gombe and environs. These soft sediment deformational structures includes: simple internal cusps, which occur wide spread ...

  5. Recovery by triple junction motion in heavily deformed metals

    DEFF Research Database (Denmark)

    Yu, Tianbo; Hansen, Niels; Huang, Xiaoxu

    2015-01-01

    A number of processes may occur during recovery, which reduce the stored energy and coarsen the structure, paving the way for the nucleation of recrystallization. In this review, recovery is discussed based on the initial deformed structure. Recovery in samples deformed to low-to-medium strains i...

  6. The Spherical Deformation Model

    DEFF Research Database (Denmark)

    Hobolth, Asgar

    2003-01-01

    Miller et al. (1994) describe a model for representing spatial objects with no obvious landmarks. Each object is represented by a global translation and a normal deformation of a sphere. The normal deformation is defined via the orthonormal spherical-harmonic basis. In this paper we analyse the s...... a single central section of the object. We use maximum-likelihood-based inference for this purpose and demonstrate the suggested methods on real data....

  7. Theory of photoinduced deformation of molecular films

    DEFF Research Database (Denmark)

    Gaididei, Yuri B.; Christiansen, Peter Leth; Ramanujam, P.S.

    2002-01-01

    Azobenzene-containing polymers exhibit strong surface-relief features when irradiated with polarized light. Currently proposed theories do not explain all the observed features. Here we propose a theory based on elastic deformation of the polymer due to interaction between dipoles ordered through...

  8. Deformable nematic droplets in a magnetic field

    NARCIS (Netherlands)

    Otten, R.H.J.; van der Schoot, P. P. A. M.

    2012-01-01

    We present a Frank-Oseen elasticity theory for the shape and structure of deformable nematic droplets with homeotropic surface anchoring in the presence of a magnetic field. Inspired by recent experimental observations, we focus on the case where the magnetic susceptibility is negative, and find

  9. Stability of fluid flow through deformable tubes and channels: An ...

    Indian Academy of Sciences (India)

    S¯adhan¯a Vol. 40, Part 3, May 2015, pp. 925–943. c Indian Academy of Sciences. Stability of fluid flow through deformable tubes and channels: An overview ... tic solid models. All these studies predict several types of instabilities in flow past deformable surfaces. This paper will attempt to place the various theoretical ...

  10. Shell structure of octupole deformation

    International Nuclear Information System (INIS)

    Zhang Xizhen; Dong Baoguo

    1992-01-01

    A convenient definition of intrinsic frame of an octupole deformed shape was proposed recently. The octupole deformation potential was expanded on the bases of irreducible representations of group O h . Based on the parameterization given in previous paper, the shell structures of octupole deformation which cover all possible octupole deformed shapes were studied

  11. Typhoon-Induced Ground Deformation

    Science.gov (United States)

    Mouyen, M.; Canitano, A.; Chao, B. F.; Hsu, Y.-J.; Steer, P.; Longuevergne, L.; Boy, J.-P.

    2017-11-01

    Geodetic instruments now offer compelling sensitivity, allowing to investigate how solid Earth and surface processes interact. By combining surface air pressure data, nontidal sea level variations model, and rainfall data, we systematically analyze the volumetric deformation of the shallow crust at seven borehole strainmeters in Taiwan induced by 31 tropical cyclones (typhoons) that made landfall to the island from 2004 to 2013. The typhoon's signature consists in a ground dilatation due to air pressure drop, generally followed by a larger ground compression. We show that this compression phase can be mostly explained by the mass loading of rainwater that falls on the ground and concentrates in the valleys towards the strainmeter sensitivity zone. Further, our analysis shows that borehole strainmeters can help quantifying the amount of rainwater accumulating and flowing over a watershed during heavy rainfalls, which is a useful constraint for building hydrological models.

  12. Micromechanisms of deformation in shales

    Science.gov (United States)

    Bonnelye, A.; Gharbi, H.; Hallais, S.; Dimanov, A.; Bornert, M.; Picard, D.; Mezni, M.; Conil, N.

    2017-12-01

    One of the envisaged solutions for nuclear wastes disposal is underground repository in shales. For this purpose, the Callovo Oxfordian (Cox) argillaceous formation is extensively studied. The hydro-mechanical behavior of the argillaceous rock is complex, like the multiphase and multi-scale structured material itself. The argilaceous matrix is composed of interstratified illite-smectite particles, it contains detritic quartz and calcite, accessory pyrite, and the rock porosity ranges from micrometre to nanometre scales. Besides the bedding anisotropy, structural variabilities exist at all scales, from the decametric-metric scales of the geological formation to the respectively millimetric and micrometric scales of the aggregates of particles and clay particles Our study aims at understanding the complex mechanisms which are activated at the micro-scale and are involved in the macroscopic inelastic deformation of such a complex material. Two sets of experiments were performed, at two scales on three bedding orientations (90°, 45° and 0°). The first set was dedicated to uniaxial deformation followed with an optical set-up with a pixel resolution of 0.55µm. These experiments allowed us to see the fracture propagation with different patterns depending on the bedding orientation. For the second set of experiments, an experimental protocol was developed in order to perform uniaxial deformation experiment at controlled displacement rate, inside an environmental scanning electron microscope (ESEM), under controlled relative humidity, in order to preserve as much as possible the natural state of saturation of shales. We aimed at characterizing the mechanical anisotropy and the mechanisms involved in the deformation, with an image resolution below the micormeter. The observed sample surfaces were polished by broad ion beam in order to reveal the fine microstructures of the argillaceous matrix. In both cases, digital images were acquired at different loading stages during

  13. Effect of self-ion irradiation on the microstructural changes of alloy EK-181 in annealed and severely deformed conditions

    Science.gov (United States)

    Aydogan, E.; Chen, T.; Gigax, J. G.; Chen, D.; Wang, X.; Dzhumaev, P. S.; Emelyanova, O. V.; Ganchenkova, M. G.; Kalin, B. A.; Leontiva-Smirnova, M.; Valiev, R. Z.; Enikeev, N. A.; Abramova, M. M.; Wu, Y.; Lo, W. Y.; Yang, Y.; Short, M.; Maloy, S. A.; Garner, F. A.; Shao, L.

    2017-04-01

    EK-181 is a low-activation ferritic/martensitic steel that is an attractive candidate for in-core component materials for both fast reactors and fusion reactors. To assess the effect of microstructural engineering on radiation response, two variants of EK-181 were studied: one in an annealed condition and the other subject to severe plastic deformation. These specimens were irradiated with 3.5 MeV Fe self-ions up to 400 peak displacements per atom (dpa) at temperatures ranging from 400 °C to 500 °C. The deformation did not suppress swelling over the whole irradiated region. Instead, deformed samples showed higher swelling in the near-surface region. Void swelling was found to be correlated with grain boundary instability. Significant grain growth occurred when steady-state void growth started.

  14. Multiscale Finite Element Methods for Flows on Rough Surfaces

    KAUST Repository

    Efendiev, Yalchin

    2013-01-01

    In this paper, we present the Multiscale Finite Element Method (MsFEM) for problems on rough heterogeneous surfaces. We consider the diffusion equation on oscillatory surfaces. Our objective is to represent small-scale features of the solution via multiscale basis functions described on a coarse grid. This problem arises in many applications where processes occur on surfaces or thin layers. We present a unified multiscale finite element framework that entails the use of transformations that map the reference surface to the deformed surface. The main ingredients of MsFEM are (1) the construction of multiscale basis functions and (2) a global coupling of these basis functions. For the construction of multiscale basis functions, our approach uses the transformation of the reference surface to a deformed surface. On the deformed surface, multiscale basis functions are defined where reduced (1D) problems are solved along the edges of coarse-grid blocks to calculate nodalmultiscale basis functions. Furthermore, these basis functions are transformed back to the reference configuration. We discuss the use of appropriate transformation operators that improve the accuracy of the method. The method has an optimal convergence if the transformed surface is smooth and the image of the coarse partition in the reference configuration forms a quasiuniform partition. In this paper, we consider such transformations based on harmonic coordinates (following H. Owhadi and L. Zhang [Comm. Pure and Applied Math., LX(2007), pp. 675-723]) and discuss gridding issues in the reference configuration. Numerical results are presented where we compare the MsFEM when two types of deformations are used formultiscale basis construction. The first deformation employs local information and the second deformation employs a global information. Our numerical results showthat one can improve the accuracy of the simulations when a global information is used. © 2013 Global-Science Press.

  15. Mechanical controls on collision related compressional intraplate deformation.

    NARCIS (Netherlands)

    Ziegler, P.A.; van Wees, J.D.A.M.; Cloetingh, S.A.P.L.

    1998-01-01

    Intraplate compressional features, such as inverted extensional basins, upthrust basement blocks and whole lithospheric folds, play an important role in the structural framework of many cratons. Although compressional intraplate deformation can occur in a number of dynamic settings, stresses related

  16. Management of post burn hand deformities

    Directory of Open Access Journals (Sweden)

    Sabapathy S

    2010-10-01

    Full Text Available The hand is ranked among the three most frequent sites of burns scar contracture deformity. One of the major determinants of the quality of life in burns survivors is the functionality of the hands. Burns deformities, although largely preventable, nevertheless do occur when appropriate treatment is not provided in the acute situation or when they are part of a major burns. Reconstructive procedures can greatly improve the function of the hands. Appropriate choice of procedures and timing of surgery followed by supervised physiotherapy can be a boon for a burns survivor.

  17. Yeasts Occurring in Surface and Mouth Cavity of Two Chelonian Species, Podocnemis expansa Schweigger and P. unifilis Troschel (Reptilia: Chelonia: Pelomedusidae, in the Javaés River Border of Araguaia National Park in Brazil

    Directory of Open Access Journals (Sweden)

    Paula Benevides de Morais

    2010-01-01

    Full Text Available Thirty-eight specimens of free-ranging Podocnemis expansa (Amazon turtle and 22 of P. unifilis (Tracajá were screened for yeast isolation from surface (plastron, skin, and nails, eye, and mouth cavity. A hundred and eighteen yeast isolates belonging to 39 species were obtained. Debaryomyces hansenii, Candida galli, C. sake, and Rhodotorula mucilaginosa were the most frequent species isolated from these chelonians. Species diversity measured by Shannon's index was shown to be low and a degree of dominance could be detected as species known as potential pathogens were commonly isolated. The effective number of species in plastron of P. expansa was higher than in mouth samples, but not in P. unifilis probably due to dietary factors. P. expansa animals were captured on the beaches, and the superficial yeast populations may include terrestrial species. P. unifilis animals were captured in the water and the yeasts from superficial sites may represent species from river water.

  18. The thermal and mechanical deformation study of up-stream pumping mechanical seal

    International Nuclear Information System (INIS)

    Chen, H L; Xu, C; Zuo, M Z; Wu, Q B

    2015-01-01

    Taking the viscosity-temperature relationship of the fluid film into consideration, a 3-D numerical model was established by ANSYS software which can simulate the heat transfer between the upstream pumping mechanical seal stationary and rotational rings and the fluid film between them as well as simulate the thermal deformation, structure deformation and the coupling deformation of them. According to the calculation result, thermal deformation causes the seal face expansion and the maximum thermal deformation appears at the inside of the seal ring. Pressure results in a mechanical deformation, the maximum deformation occurs at the top of the spiral groove and the overall trend is inward the mating face, opposite to the thermal deformation. The coupling deformation indicate that the thermal deformation can be partly counteracted by pressure deformation. Using this model, the relationship between deformation and shaft speed and the sealing liquid pressure was studied. It's found that the shaft speed will both enhance the thermal and structure deformation and the fluid pressure will enhance the structure deformation but has little to do with the thermal deformation. By changing the sealing material, it's found that material with low thermal expansion coefficient and low elastic modulus will suffer less thermal-pressure deformation

  19. The thermal and mechanical deformation study of up-stream pumping mechanical seal

    Science.gov (United States)

    Chen, H. L.; Xu, C.; Zuo, M. Z.; Wu, Q. B.

    2015-01-01

    Taking the viscosity-temperature relationship of the fluid film into consideration, a 3-D numerical model was established by ANSYS software which can simulate the heat transfer between the upstream pumping mechanical seal stationary and rotational rings and the fluid film between them as well as simulate the thermal deformation, structure deformation and the coupling deformation of them. According to the calculation result, thermal deformation causes the seal face expansion and the maximum thermal deformation appears at the inside of the seal ring. Pressure results in a mechanical deformation, the maximum deformation occurs at the top of the spiral groove and the overall trend is inward the mating face, opposite to the thermal deformation. The coupling deformation indicate that the thermal deformation can be partly counteracted by pressure deformation. Using this model, the relationship between deformation and shaft speed and the sealing liquid pressure was studied. It's found that the shaft speed will both enhance the thermal and structure deformation and the fluid pressure will enhance the structure deformation but has little to do with the thermal deformation. By changing the sealing material, it's found that material with low thermal expansion coefficient and low elastic modulus will suffer less thermal-pressure deformation.

  20. Use of a Routh-Russel deformation map to achieve film formation of a latex with a high glass transition temperature.

    Science.gov (United States)

    Gonzalez, Edurne; Paulis, María; Barandiaran, María Jesús; Keddie, Joseph L

    2013-02-12

    In the film formation of latex, particle deformation can occur by processes of wet sintering, dry sintering, or capillary action. When latex films dry nonuniformly and when particles deform and coalesce while the film is still wet, a detrimental skin layer will develop at the film surface. In their process model, Routh and Russel proposed that the operative particle deformation mechanism can be determined by the values of control parameters on a deformation map. Here, the film formation processes of three methyl methacrylate/butyl acrylate copolymer latexes with high glass transition temperatures (T(g)), ranging from 45 to 64 °C, have been studied when heated by infrared radiation. Adjusting the infrared (IR) power density enables the film temperature, polymer viscosity, and evaporation rate during latex film formation to be controlled precisely. Different polymer particle deformation mechanisms have been demonstrated for the same latex under a variety of film formation process conditions. When the temperature is too high, a skin layer develops. On the other hand, when the temperature is too low, particles deform by dry sintering, and the process requires extended time periods. The deduced mechanisms can be interpreted and explained by the Routh-Russel deformation maps. Film formation of hard (high T(g)) coatings is achieved without using coalescing aids that emit volatile organic compounds (VOCs), which is a significant technical achievement.

  1. Poludnista Dorsa, Venus: History and context of a deformation belt

    Science.gov (United States)

    Young, D. A.; Hansen, V. L.

    2005-03-01

    Rolling lowlands comprise 80% of Venus's surface, and thus developing a geological understating of resurfacing and tectonism is critical for our understanding of Venus' evolution. In this paper, global, regional, and local approaches to interpreting Magellan synthetic aperture radar and altimetry radar data are used to constrain modes of lowland evolution, convection processes, and lithospheric structure. Detailed geologic mapping is combined with altimetry data test models of deformation belt evolution in Venus's lowlands. Poludnista Dorsa, a complex 2000-km-long deformation belt, is highly segmented and broadly time transgressive. Long-wavelength deformation is spatially independent of local short-wavelength deformation within the deformation belt and temporally predates regional deformation marked by wrinkle ridges. A mechanically layered lithosphere of regional extent is not required by the local geologic history; local lithospheric thinning or progressive regional thickening of the mechanical layer better explains the observed sequence of events.

  2. Autogenous Deformation of Concrete

    DEFF Research Database (Denmark)

    Autogenous deformation of concrete can be defined as the free deformation of sealed concrete at a constant temperature. A number of observed problems with early age cracking of high-performance concretes can be attributed to this phenomenon. During the last 10 years , this has led to an increased...... focus on autogenous deformation both within concrete practice and concrete research. Since 1996 the interest has been significant enough to hold international, yearly conferences entirely devoted to this subject. The papers in this publication were presented at two consecutive half-day sessions...... at the American Concrete Institute’s Fall Convention in Phoenix, Arizona, October 29, 2002. All papers have been reviewed according to ACI rules. This publication, as well as the sessions, was sponsored by ACI committee 236, Material Science of Concrete. The 12 presentations from 8 different countries indicate...

  3. Packings of deformable spheres

    Science.gov (United States)

    Mukhopadhyay, Shomeek; Peixinho, Jorge

    2011-07-01

    We present an experimental study of disordered packings of deformable spheres. Fluorescent hydrogel spheres immersed in water together with a tomography technique enabled the imaging of the three-dimensional arrangement. The mechanical behavior of single spheres subjected to compression is first examined. Then the properties of packings of a randomized collection of deformable spheres in a box with a moving lid are tested. The transition to a state where the packing withstands finite stresses before yielding is observed. Starting from random packed states, the power law dependence of the normal force versus packing fraction or strain at different velocities is quantified. Furthermore, a compression-decompression sequence at low velocities resulted in rearrangements of the spheres. At larger packing fractions, a saturation of the mean coordination number took place, indicating the deformation and faceting of the spheres.

  4. Angiodysplasia Occurring in Jejunal Diverticulosis

    OpenAIRE

    1990-01-01

    The first case of angiodysplasia occurring in acquired jejunal diverticulosis is reported. The patient presented with occult gastrointestinal bleeding and chronic anemia, and was created successfully by resection of a 25 cm long segment of jejunum. Possible pathogenetic mechanisms for both angiodysplasia and jejunal diverticulosis are discussed.

  5. Chromosomal rearrangements occurred repeatedly and ...

    African Journals Online (AJOL)

    Furthermore, molecular and/or chromosomal data indicate that Paroedura is a monophyletic genus, in which chromosome rearrangements occurred repeatedly and independently during the specific diversification. Moreover both P. bastardi and P. gracilis in current definitions are paraphyletic assemblages of several ...

  6. Texture and deformation mechanism of yttrium

    International Nuclear Information System (INIS)

    Adamesku, R.A.; Grebenkin, S.V.; Stepanenko, A.V.

    1992-01-01

    X-ray pole figure analysis was applied to study texture and deformation mechanism in pure and commercial polycrystalline yttrium on cold working. It was found that in cast yttrium the texture manifected itself weakly enough both for pure and commercial metal. Analysis of the data obtained made it possible to assert that cold deformation of pure yttrium in the initial stage occurred mainly by slip the role of which decreased at strains higher than 36%. The texture of heavily deformed commercial yttrium contained two components, these were an 'ideal' basic orientation and an axial one with the angle of inclination about 20 deg. Twinning mechanism was revealed to be also possible in commercial yttrium

  7. How the continents deform: The evidence from tectonic geodesy

    Science.gov (United States)

    Thatcher, Wayne R.

    2009-01-01

    Space geodesy now provides quantitative maps of the surface velocity field within tectonically active regions, supplying constraints on the spatial distribution of deformation, the forces that drive it, and the brittle and ductile properties of continental lithosphere. Deformation is usefully described as relative motions among elastic blocks and is block-like because major faults are weaker than adjacent intact crust. Despite similarities, continental block kinematics differs from global plate tectonics: blocks are much smaller, typically ∼100–1000 km in size; departures from block rigidity are sometimes measurable; and blocks evolve over ∼1–10 Ma timescales, particularly near their often geometrically irregular boundaries. Quantitatively relating deformation to the forces that drive it requires simplifying assumptions about the strength distribution in the lithosphere. If brittle/elastic crust is strongest, interactions among blocks control the deformation. If ductile lithosphere is the stronger, its flow properties determine the surface deformation, and a continuum approach is preferable.

  8. Experimental Elastic Deformation Characterization of a Flapping-Wing MAV Using Visual Image Correlation

    National Research Council Canada - National Science Library

    Stewart, Kelly; Albertani, Roberto

    2007-01-01

    .... By knowing the elastic deformation that occurs, researchers can better understand the mechanics and aerodynamic effects behind flexible, flapping wings and apply that knowledge to various design...

  9. Deformation and failure mechanism of slope in three dimensions

    Directory of Open Access Journals (Sweden)

    Yingfa Lu

    2015-04-01

    Full Text Available Understanding three-dimensional (3D slope deformation and failure mechanism and corresponding stability analyses are crucially important issues in geotechnical engineering. In this paper, the mechanisms of progressive failure with thrust-type and pull-type landslides are described in detail. It is considered that the post-failure stress state and the pre-peak stress state may occur at different regions of a landslide body with deformation development, and a critical stress state element (or the soil slice block exists between the post-failure stress state and the pre-peak stress state regions. In this regard, two sorts of failure modes are suggested for the thrust-type and three sorts for pull-type landslides, based on the characteristics of shear stress and strain (or tensile stress and strain. Accordingly, a new joint constitutive model (JCM is proposed based on the current stability analytical theories, and it can be used to describe the mechanical behaviors of geo-materials with softening properties. Five methods, i.e. CSRM (comprehensive sliding resistance method, MTM (main thrust method, CDM (comprehensive displacement method, SDM (surplus displacement method, and MPM (main pull method, for slope stability calculation are proposed. The S-shaped curve of monitored displacement vs. time is presented for different points on the sliding surface during progressive failure process of landslide, and the relationship between the displacement of different points on the sliding surface and height of landslide body is regarded as the parabolic curve. The comparisons between the predicted and observed load–displacement and displacement–time relations of the points on the sliding surface are conducted. The classification of stable/unstable displacement–time curves is proposed. The definition of the main sliding direction of a landslide is also suggested in such a way that the failure body of landslide (simplified as “collapse body” is only

  10. High temperature deformation behavior of gradually pressurized zircaloy-4 tubes

    International Nuclear Information System (INIS)

    Suzuki, Motoye

    1982-03-01

    In order to obtain preliminary perspectives on fuel cladding deformation behavior under changing temperature and pressure conditions in a hypothetical loss-of-coolant accident of PWR, a Zircaloy-4 tube burst test was conducted in both air and 99.97% Ar atomospheres. The tubes were directly heated by AC-current and maintained at various temperatures, and pressurized gradually until rupture occurred. Rupture circumferential strains were generally larger in Ar gas than in air and attained a maximum around 1100 K in both atmospheres. Some tube tested in air produced axially-extended long balloons, which proved not to be explained by such properties or ideas as effect of cooling on strain rate, superplasticity, geometrical plastic instability and stresses generated by surface oxide layer. A cause of the long balloon may be obtained in the anisotropy of the material structure. But even a qualitative analysis based on this property can not be made due to insufficient data of the anisotropy. (author)

  11. Deciphering the shape and deformation of secondary structures through local conformation analysis

    Directory of Open Access Journals (Sweden)

    Camproux Anne-Claude

    2011-02-01

    Full Text Available Abstract Background Protein deformation has been extensively analysed through global methods based on RMSD, torsion angles and Principal Components Analysis calculations. Here we use a local approach, able to distinguish among the different backbone conformations within loops, α-helices and β-strands, to address the question of secondary structures' shape variation within proteins and deformation at interface upon complexation. Results Using a structural alphabet, we translated the 3 D structures of large sets of protein-protein complexes into sequences of structural letters. The shape of the secondary structures can be assessed by the structural letters that modeled them in the structural sequences. The distribution analysis of the structural letters in the three protein compartments (surface, core and interface reveals that secondary structures tend to adopt preferential conformations that differ among the compartments. The local description of secondary structures highlights that curved conformations are preferred on the surface while straight ones are preferred in the core. Interfaces display a mixture of local conformations either preferred in core or surface. The analysis of the structural letters transition occurring between protein-bound and unbound conformations shows that the deformation of secondary structure is tightly linked to the compartment preference of the local conformations. Conclusion The conformation of secondary structures can be further analysed and detailed thanks to a structural alphabet which allows a better description of protein surface, core and interface in terms of secondary structures' shape and deformation. Induced-fit modification tendencies described here should be valuable information to identify and characterize regions under strong structural constraints for functional reasons.

  12. Marginally Deformed Starobinsky Gravity

    DEFF Research Database (Denmark)

    Codello, A.; Joergensen, J.; Sannino, Francesco

    2015-01-01

    We show that quantum-induced marginal deformations of the Starobinsky gravitational action of the form $R^{2(1 -\\alpha)}$, with $R$ the Ricci scalar and $\\alpha$ a positive parameter, smaller than one half, can account for the recent experimental observations by BICEP2 of primordial tensor modes....

  13. Soft swimming: exploiting deformable interfaces for low reynolds number locomotion.

    Science.gov (United States)

    Trouilloud, Renaud; Yu, Tony S; Hosoi, A E; Lauga, Eric

    2008-07-25

    Reciprocal movement cannot be used for locomotion at low Reynolds number in an infinite fluid or near a rigid surface. Here we show that this limitation is relaxed for a body performing reciprocal motions near a deformable interface. Using physical arguments and scaling relationships, we show that the nonlinearities arising from reciprocal flow-induced interfacial deformation rectify the periodic motion of the swimmer, leading to locomotion. Such a strategy can be used to move toward, away from, and parallel to any deformable interface as long as the length scales involved are smaller than intrinsic scales, which we identify. A macroscale experiment of flapping motion near a free surface illustrates this new result.

  14. Characteristic of Lokon Volcano Deformation of 2009 - 2011 Based on GPS Data

    Directory of Open Access Journals (Sweden)

    Estu Kriswati

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v7i4.147Precursor of Lokon Volcano eruptions in 2011 is believed to begin since December 2007 which was marked by increasing number of volcanic earthquakes and gas emission. To support this information, deformation method is used primarily to determine deformation characteristics of Lokon volcanic activity in the period of 2009-2011. The period of analysis is adapted to the presence of GPS data. Displacement rate of Lokon GPS observation points in the period of 2009 - 2011 ranged from 1.1 to 7 cm a year. Strain patterns that occur in the areas are compression surrounding Tompaluan crater and extension in the eastern slope. Location of the pressure source for August 2009 - March 2011 measurement was at a depth of 1800 m beneath Tompaluan crater. Deformation in the Lokon Volcano is characteristized by the compression zone in the summit and crater area caused by magma activity raised into the surface from a shallow magma source which is accompanied by a high release of volcanic gases. Accumulated pressure release and deformation rate as measured in the Lokon Volcano remain low.

  15. Deformation, Stress Relaxation, and Crystallization of Lithium Silicate Glass Fibers Below the Glass Transition Temperature

    Science.gov (United States)

    Ray, Chandra S.; Brow, Richard K.; Kim, Cheol W.; Reis, Signo T.

    2004-01-01

    The deformation and crystallization of Li(sub 2)O (center dot) 2SiO2 and Li(sub 2)O (center dot) 1.6SiO2 glass fibers subjected to a bending stress were measured as a function of time over the temperature range -50 to -150 C below the glass transition temperature (Tg). The glass fibers can be permanently deformed at temperatures about 100 C below T (sub)g, and they crystallize significantly at temperatures close to, but below T,, about 150 C lower than the onset temperature for crystallization for these glasses in the no-stress condition. The crystallization was found to occur only on the surface of the glass fibers with no detectable difference in the extent of crystallization in tensile and compressive stress regions. The relaxation mechanism for fiber deformation can be best described by a stretched exponential (Kohlrausch-Williams-Watt (KWW) approximation), rather than a single exponential model.The activation energy for stress relaxation, Es, for the glass fibers ranges between 175 and 195 kJ/mol, which is considerably smaller than the activation energy for viscous flow, E, (about 400 kJ/mol) near T, for these glasses at normal, stress-free condition. It is suspected that a viscosity relaxation mechanism could be responsible for permanent deformation and crystallization of the glass fibers below T,

  16. Deformation-Induced Precession of a Robot Moving on Curved Space

    Science.gov (United States)

    Li, Shengkai; Aydin, Yasemin; Lofaro, Olivia; Rieser, Jennifer; Goldman, Daniel

    Previous studies have demonstrated that passive particles rolling on a deformed surface can mimic aspects of general relativity [Ford et al, AJP, 2015]. However, these systems are dissipative. To explore steady-state dynamics, we study the movement of a self-propelled robot car on a large deformable elastic membrane: a spandex sheet stretched over a metal frame with a diameter of 2.5 m. Two wheels in the rear of the car are differentially-driven by a DC motor, and a caster in the front helps maintain directional stability; in the absence of curvature the car drives straight. A linear actuator attached below the membrane allows for controlled deformation at the center of the membrane. We find that closed elliptic orbits occur when the membrane is highly depressed ( 10 cm). However, when the center is only slightly indented, the elliptical orbits precess at a rate depending on the orbit shape and the depression. Remarkably, this dynamic is well described by the Schwarzschild metric solution, typically used to describe the effects of gravity on bodies orbiting a massive object. Experiments with multiple cars reveal complex interactions that are mediated through car-induced deformations of the membrane.

  17. Compression strain-induced folding at intersecting deformation macrobands on the copper single crystals

    Science.gov (United States)

    Chumaevskii, A. V.; Lychagin, D. V.; Tarasov, S. Yu.

    2017-12-01

    Compression strain-induced surface pattern on copper single crystal faces was studied by means of optical, confocal laser and scanning electron microscopies. It was shown that apart from work-hardening effect of previously formed deformation macrobands there is a pure geometrical (size) effect which serves for changing the conditions for further deformation within the deformation macroband zones by folded structure formation.

  18. Deformation dynamics study of a wrought magnesium alloy by real-time in situ neutron diffraction

    International Nuclear Information System (INIS)

    Wu, Wei; An, Ke; Huang, Lu; Lee, Soo Yeol; Liaw, Peter K.

    2013-01-01

    The deformation dynamics and the effect of deformation history on plastic deformation in a wrought magnesium alloy at room temperature have been studied by real-time in situ neutron diffraction measurements under a continuous loading condition. The experimental results reveal that no detwinning occurred during unloading after compression and even in an elastic region during reverse tension. It is found that the serration behavior is closely related to the twinning- and detwinning-dominated deformation

  19. 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.

  20. Formation and subdivision of deformation structures during plastic deformation

    DEFF Research Database (Denmark)

    Jakobsen, B.; Poulsen, H.F.; Lienert, U.

    2006-01-01

    of individual, deeply embedded dislocation structures. During tensile deformation of pure copper, dislocation-free regions were identified. They showed an unexpected intermittent dynamics, for example, appearing and disappearing with proceeding deformation and even displaying transient splitting behavior....... Insight into these processes is relevant for an understanding of the strength and work-hardening of deformed materials....

  1. Inelastic deformations of fault and shear zones in granitic rock

    International Nuclear Information System (INIS)

    Wilder, D.G.

    1986-02-01

    Deformations during heating and cooling of three drifts in granitic rock were influenced by the presence of faults and shear zones. Thermal deformations were significantly larger in sheared and faulted zones than where the rock was jointed, but neither sheared nor faulted. Furthermore, thermal deformations in faulted or sheared rock were not significantly recovered during subsequent cooling, thus a permanent deformation remained. This inelastic response is in contrast with elastic behavior identified in unfaulted and unsheared rock segments. A companion paper indicates that deformations in unsheared or unfaulted rock were effectively modeled as an elastic response. We conclude that permanent deformations occurred in fractures with crushed minerals and fracture filling or gouge materials. Potential mechanisms for this permanent deformation are asperity readjustments during thermal deformations, micro-shearing, asperity crushing and crushing of the secondary fracture filling minerals. Additionally, modulus differences in sheared or faulted rock as compared to more intact rock would result in greater deformations in response to the same thermal loads

  2. Early occurring and continuing effects

    International Nuclear Information System (INIS)

    Scott, B.R.; Hahn, F.F.

    1985-01-01

    This chapter deals with health-risk estimates for early and continuing effects of exposure to ionizing radiations that could be associated with light water nuclear power plants accidents. Early and continuing effects considered are nonneoplastic diseases and symptoms that normally occur soon after radiation exposure, but may also occur after years have passed. They are generally associated with relatively high (greater than 1 Gy) doses. For most of the effects considered, there is a practical dose threshold. Organs of primary interest, because of their high sensitivity or the likelihood of receiving a large radiation dose, are bone marrow, gastrointestinal tract, thyroid glands, lungs, skin, gonads, and eyes. In utero exposure of the fetus is also considered. New data and modeling techniques available since publication of the Reactor Safety Study (WASH 1400, 1975) were used along with data cited in the Study to develop improved health-risk models for morbidity and mortality. The new models are applicable to a broader range of accident scenarios, provide a more detailed treatment of dose protraction effects, and include morbidity effects not considered in the Reactor Safety Study. 115 references, 20 figures, 19 tables

  3. Postural deformities in Parkinson's disease

    NARCIS (Netherlands)

    Doherty, K.M.; Warrenburg, B.P.C. van de; Peralta, M.C.; Silveira-Moriyama, L.; Azulay, J.P.; Gershanik, O.S.; Bloem, B.R.

    2011-01-01

    Postural deformities are frequent and disabling complications of Parkinson's disease (PD) and atypical parkinsonism. These deformities include camptocormia, antecollis, Pisa syndrome, and scoliosis. Recognition of specific postural syndromes might have differential diagnostic value in patients

  4. An improved evaluation of the seismic/geodetic deformation-rate ratio for the Zagros Fold-and-Thrust collisional belt

    Science.gov (United States)

    Palano, Mimmo; Imprescia, Paola; Agnon, Amotz; Gresta, Stefano

    2018-04-01

    We present an improved picture of the ongoing crustal deformation field for the Zagros Fold-and-Thrust Belt continental collision zone by using an extensive combination of both novel and published GPS observations. The main results define the significant amount of oblique Arabia-Eurasia convergence currently being absorbed within the Zagros: right-lateral shear along the NW trending Main Recent fault in NW Zagros and accommodated between fold-and-thrust structures and NS right-lateral strike-slip faults on Southern Zagros. In addition, taking into account the 1909-2016 instrumental seismic catalogue, we provide a statistical evaluation of the seismic/geodetic deformation-rate ratio for the area. On Northern Zagros and on the Turkish-Iranian Plateau, a moderate to large fraction (˜49 and >60 per cent, respectively) of the crustal deformation occurs seismically. On the Sanandaj-Sirjan zone, the seismic/geodetic deformation-rate ratio suggests that a small to moderate fraction (seismically; locally, the occurrence of large historic earthquakes (M ≥ 6) coupled with the high geodetic deformation, could indicate overdue M ≥ 6 earthquakes. On Southern Zagros, aseismic strain dominates crustal deformation (the ratio ranges in the 15-33 per cent interval). Such aseismic deformation is probably related to the presence of the weak evaporitic Hormuz Formation which allows the occurrence of large aseismic motion on both subhorizontal faults and surfaces of décollement. These results, framed into the seismotectonic framework of the investigated region, confirm that the fold-and-thrust-dominated deformation is driven by buoyancy forces; by contrast, the shear-dominated deformation is primary driven by plate stresses.

  5. Ground Deformation Detection Using China’s ZY-3 Stereo Imagery in an Opencast Mining Area

    OpenAIRE

    Wenmin Hu; Lixin Wu; Wei Zhang; Bin Liu; Jiaxing Xu

    2017-01-01

    Detection and extraction of mining-induced ground deformation can be used to understand the deformation process and space distribution and to estimate the deformation laws and trends. This study focuses on the application of ground deformation detection and extraction combined with digital surface model (DSM), derived from China’s ZiYuan-3 (ZY-3) satellite stereo imagery and the advanced spaceborne thermal emission and reflection radiometer global digital elevation model (ASTER GDEM) data. A ...

  6. q-Deformed Kink solutions

    International Nuclear Information System (INIS)

    Lima, A.F. de

    2003-01-01

    The q-deformed kink of the λφ 4 -model is obtained via the normalisable ground state eigenfunction of a fluctuation operator associated with the q-deformed hyperbolic functions. The kink mass, the bosonic zero-mode and the q-deformed potential in 1+1 dimensions are found. (author)

  7. Synthetic Aperture Radar Interferometry Analysis of Ground Deformation within the Coso Geothermal Site, California

    Science.gov (United States)

    Brawner, Erik

    Earth's surface movement may cause as a potential hazard to infrastructure and people. Associated earthquake hazards pose a potential side effect of geothermal activity. Modern remote sensing techniques known as Interferometric Synthetic Aperture Radar (InSAR) can measure surface change with a high degree of precision to mm scale movements. Previous work has identified a deformation anomaly within the Coso Geothermal site in eastern California. Surface changes have not been analyzed since the 1990s, allowing a decade of geothermal production impact to occur since previously assessed. In this study, InSAR data was acquired and analyzed between the years 2005 and 2010. Acquired by the ENVISAT satellite from both ascending and descending modes. This provides an independent dataset from previous work. Incorporating data generated from a new sensor covering a more modern temporal study period. Analysis of this time period revealed a subsidence anomaly in correlation with the extents of the geothermal production area under current operation. Maximum subsidence rates in the region reached approximately 3.8 cm/yr. A similar rate assessed from previous work throughout the 1990s. The correlation of subsidence patterns suggests a linear source of deformation from measurements spanning multiple decades. Regions of subsidence branch out from the main anomaly to the North-Northeast and to the South where additional significant peaks of subsidence occurring. The extents of the deformation anomaly directly correlate with the dispersal of geothermal production well site locations. Depressurization within the geothermal system provides a leading cause to surface subsidence from excessive extraction of hydrothermal fluids. As a result of minimal reinjection of production fluids.

  8. The influence of strain hardening on cumulative plastic deformation in rolling and sliding line contact

    Science.gov (United States)

    Bower, A. F.; Johnson, K. L.

    THE INFLUENCE of strain hardening on the cumulative plastic deformation (ratchetting) which takes place in repeated rolling and sliding contacts has been assessed by the use of a non-linear kinematic hardening law proposed and tested by B OWER ( J. Mech. Phys. Solids37,455, 1989). Both the sub-surface flow, which occurs at low traction coefficients ( traction ( >0.25), have been investigated. Two materials have been studied: hard-drawn copper and rail steel. Good correlation was found for copper between the theory and rolling contact experiments.

  9. [Babies with cranial deformity].

    Science.gov (United States)

    Feijen, Michelle M W; Claessens, Edith A W M Habets; Dovens, Anke J Leenders; Vles, Johannes S; van der Hulst, Rene R W J

    2009-01-01

    Plagiocephaly was diagnosed in a baby aged 4 months and brachycephaly in a baby aged 5 months. Positional or deformational plagio- or brachycephaly is characterized by changes in shape and symmetry of the cranial vault. Treatment options are conservative and may include physiotherapy and helmet therapy. During the last two decades the incidence of positional plagiocephaly has increased in the Netherlands. This increase is due to the recommendation that babies be laid on their backs in order to reduce the risk of sudden infant death syndrome. We suggest the following: in cases of positional preference of the infant, referral to a physiotherapist is indicated. In cases of unacceptable deformity of the cranium at the age 5 months, moulding helmet therapy is a possible treatment option.

  10. Deformation Theory ( Lecture Notes )

    Czech Academy of Sciences Publication Activity Database

    Doubek, M.; Markl, Martin; Zima, P.

    2007-01-01

    Roč. 43, č. 5 (2007), s. 333-371 ISSN 0044-8753. [Winter School Geometry and Physics/27./. Srní, 13.01.2007-20.01.2007] R&D Projects: GA ČR GA201/05/2117 Institutional research plan: CEZ:AV0Z10190503 Keywords : deformation * Mauerer-Cartan equation * strongly homotopy Lie algebra Subject RIV: BA - General Mathematics

  11. Deformations of fractured rock

    International Nuclear Information System (INIS)

    Stephansson, O.

    1977-09-01

    Results of the DBM and FEM analysis in this study indicate that a suitable rock mass for repository of radioactive waste should be moderately jointed (about 1 joint/m 2 ) and surrounded by shear zones of the first order. This allowes for a gentle and flexible deformation under tectonic stresses and prevent the development of large cross-cutting failures in the repository area. (author)

  12. Root Surface Caries Occurence in Relation to Social and Dental ...

    African Journals Online (AJOL)

    Objective: To investigate the association between root caries and social and dental behaviour amongst adults in a selected suburband adult population. Methods: The setting, study design and root caries diagnosis were as described in the first part of this three part series. Subjects\\' social and dental health behaviour were ...

  13. Analysis of Severe Plastic Deformation by Large Strain Extrusion Machining

    Science.gov (United States)

    Sevier, M.; Yang, H. T. Y.; Moscoso, W.; Chandrasekar, S.

    2008-11-01

    Large strain extrusion machining (LSEM), a constrained chip formation process, is examined as a method of severe plastic deformation (SPD) at small deformation rates for production of ultra-fine-grained (UFG) materials. A finite element procedure is developed for prediction of deformation field parameters such as effective strain, strain rate, and their variation across the thickness of the chip for various cutting (extrusion) ratios. The cutting force (extrusion pressure) and hydrostatic pressures within the deformation zone are also analyzed. A consideration of the deformation occurring in chip formation suggests bounds on the extrusion ratios that can be realized. Implications of the results for production of bulk chip samples of controlled geometry and with an UFG microstructure are discussed.

  14. The effect of the mineral dissolution and deformation of slope stability on nature terrane

    Science.gov (United States)

    Choi, J.; Chae, B.

    2012-12-01

    A landslide on nature terrane is mainly occurred by rainfall, snowmelt, earthquakes and rock/soil weathering process. Especially, the role of rainfall and rock/soil weathering in slope stability is very important because it causes decreased in shear strength by reducing the soil cohesion. Quartz is the most abundant crust-forming mineral on earth. This mineral contributes to the formation of crystalline rocks such as granite, gneiss, and sandstone. Therefore, in case of the slope consisted by granite, gneiss, and sandstone, the slope stability can be affected by the mineral weathering process such as mineral dissolution and deformation because the shear strength, one of the key factors to calculate the slope stability, can be reduced by mineral weathering. That is, mineral weathering including dissolution and deformation between the minerals can reduce the soil cohesion on nature terrane. Many studies have found that quartz exhibits a notably slow rate of dissolution at room temperature. Therefore, to achieve rapid dissolution at room temperature, other methods should be considered, including 1) expanding the surface area of quartz to increase the reaction area and 2) applying high pressure to the contact area of crystals to increase the dissolution rate. However, dissolution of the surface of quartz is difficult to observe when using powdered quartz to maximize the surface area. Therefore, we used beads and single quartz crystals to observe and analyze the dissolution of the surface. The former can be used to maximize the surface area of quartz, and high-pressure conditions can be applied to the latter. A confocal laser scanning microscope (CLSM) was subsequently used to observe the dissolution patterns on the quartz surface. Numerical analyses using the finite element method (FEM) were also performed to quantify the deformation of the contact area. Quartz dissolution was observed in both experiments. This deformation was due to a concentrated compressive stress

  15. Sintering and deformation of nanocrystalline ceramics

    International Nuclear Information System (INIS)

    Hahn, H.; Averback, R.S.; Hofler, H.J.; Logas, J.

    1991-01-01

    Nanocrystalline ceramics have been produced by the method of inert gas condensation of ultra-small particles and in situ consolidation. Sintering characteristics and microstructural parameter such as grain size, porosity and pore size distributions have been investigated by a variety of techniques, including: X-ray diffraction, gravimetry, nitrogen adsorption, scanning electron microscopy and small angle neutron scattering. In pure TiO 2 , the sintering temperatures are drastically lowered compared to conventional ceramics, however, extensive grain growth occurs before full densification is achieved. High density, nanocrystalline ceramics can be prepared by pressure assisted sintering, doping and additions of second phases. High temperature microhardness and creep deformation in compression were measured and it was found that creep processes occur at lower temperatures than in ceramics with larger grain sizes. Nanocrystalline TiO 2 with densities >99% can be deformed plastically without fracture at temperatures below half the melting point. The total strains exceed 0.6 at strain rates as high as 10 -3 s -l . The stress exponent of the strain rate, n, is approximately 3 and the grain size dependence is G -q with q in the range of 1-1.5. In this paper it is concluded that the creep deformation occurs by an interface reaction controlled mechanism

  16. Optical Coherence Tomography for Tracking Canvas Deformation

    International Nuclear Information System (INIS)

    Targowski, P.; Gora, M.; Bajraszewski, T.; Szkulmowski, M.; Rouba, B.; Lekawa-Wyslouch, T.; Tyminska-Widmer, L.

    2006-01-01

    Preliminary results of the application of optical coherence tomography (OCT), in particular in its spectral mode (SOCT), to tracking of deformations in paintings on canvas caused by periodical humidity changes are presented. The setup is able to monitor the position of a chosen point at the surface of a painting with micrometre precision, simultaneously in three dimensions, every 100 seconds. This allows recording of deformations associated with crack formation. For the particular painting model examined, it was shown that the surface moves in-plane towards the corner, and bulges outwards (Z-direction) in response to a rise in humidity. Subsequent to the first humidification/drying cycle, translation in the Z-direction is decreased, whilst in-plane translations increase somewhat. It was also shown that the response of the painting on canvas begins immediately on changing the relative humidity in the surroundings.

  17. Does overtraining occur in triathletes?

    Directory of Open Access Journals (Sweden)

    I Margaritis

    2003-06-01

    Full Text Available 1. Objective: Long distance triathlon training is characterized by considerably high volume training loads. This volume can provoke an overtraining state. The aim of the study was to determine whether overtraining occurs in well-trained male triathletes in relation with their volume training loads. 2. Experimental design: A questionnaire investigation was completed two days before the Nice long-distance triathlon (October 1995: 4-km swim, 120-km bike ride and 30-km run. 3. Participants: Ninety-three well-trained male triathletes who took part in the triathlon race. 4. Measures: A questionnaire to relate clinical symptoms, which are known to appear in case of overtraining, was collected. 5. Results: 39.8% of the questioned triathletes reported a decrease in triathlon performances within the last month preceding the race. Moreover, these triathletes exhibited significantly more overtraining-relied symptoms than the others (5.9±3.8 vs 3.4±2.6, P<0.05. Surprisingly, the occurrence of overtraining in triathletes appears not to depend on the volume training loads. 6. Conclusions: These results suggest that overtraining has to be considered in the case of triathletes. This preliminary study evidences the need for further investigation in order to monitor triathletes training respond and prevent overtraining.

  18. Earl occurring and continuing effects

    International Nuclear Information System (INIS)

    Scott, B.R.; Hahn, F.F.

    1989-01-01

    This chapter develops health-risk models for early and continuing effects of exposure to beta or gamma radiation that could be associated with light water nuclear power plant accidents. The main purpose of the chapter is to provide details on each health-risk model and on the data used. Early and continuing effects considered are prodromal symptoms and nonneoplastic diseases that usually occur soon after a brief radiation exposure. These effects are generally associated with relatively high (greater than 1 Gy) absorbed organ doses. For most of the effects considered, there is an absorbed organ dose threshold below which no effects are seen. Some information is provided on health effects observed in victims of the Chernobyl power plant accident. Organs of primary interest, because of their high sensitivity or their potential for receiving large doses, are bone marrow, gastrointestinal tract, thyroid glands, lungs, skin, gonads, and eyes. Exposure of the fetus is also considered. Additional data and modeling techniques available since publication of the Reactor Safety Study were used to obtain models for morbidity and mortality

  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. Study of the deformation mechanism of the Gaoliying ground fissure

    Directory of Open Access Journals (Sweden)

    G. Cheng

    2015-11-01

    Full Text Available The Gaoliying ground fissure in Beijing has caused building cracking and road damage, and has seriously influenced city construction. Based on investigations and trenching, the influences of the fault and the variation of groundwater levels on the formation mechanism of the Gaoliying ground fissure were investigated by using FLAC3D. The results indicated that (1 the surface location of Gaoliying fissure is controlled by the underlying normal fault activity, and over pumping further exacerbates development of the ground fissure; (2 when the groundwater level declines, obvious differential settlement occurs at both sides of the ground fissure, in which greater settlement occurs in the vicinity of the hanging wall, the greater the distance from the hanging wall, the smaller the ground subsidence, however smaller ground subsidence occurs in the vicinity of the footwall, the greater the distance from the footwall, the greater the ground subsidence; (3 the vertical velocity of the ground fissure triggered by the fault activity and groundwater decline ranges from 15.5 to 18.3 mm a−1, which is basically in line with the monitoring data. The fault activity contributes about 28–39 %, and the groundwater contributes about 61–72 % to the deformation of the ground fissure, respectively.

  1. Effect of coseismic and postseismic deformation on homogeneous and layered half-space and spherical analysis: Model simulation of the 2006 Java, Indonesia, tsunami earthquake

    Science.gov (United States)

    Gunawan, Endra; Meilano, Irwan; Hanifa, Nuraini Rahma; Widiyantoro, Sri

    2017-12-01

    We simulate surface displacements calculated on homogeneous and layered half-space and spherical models as applied to the coseismic and postseismic (afterslip and viscoelastic relaxation) of the 2006 Java tsunami earthquake. Our analysis of coseismic and afterslip deformation suggests that the homogeneous half-space model generates a much broader displacement effect than the layered half-space and spherical models. Also, though the result for surface displacements is similar for the layered half-space and spherical models, noticeable displacements still occurred on top of the coseismic fault patches. Our displacement result in afterslip modeling suggests that significant displacements occurred on top of the main afterslip fault patches, differing from the viscoelastic relaxation model, which has displacements in the front region of coseismic fault patches. We propose this characteristic as one of the important features differentiating a postseismic deformation signal from afterslip and viscoelastic relaxation detected by geodetic data.

  2. Deformation of Taiwan from Continuous GPS Monitoring

    Science.gov (United States)

    Wu, F. T.; Kuo, L.; Kuo-Chen, H.

    2007-12-01

    As of 2006 there are more than 290 continuously recording GPS stations(1,2) now in and around Taiwan and its surrounding islands. We have determined horizontal and vertical velocity vectors, the areal strain rate, the shear strain rate and the volume strain rate. Because of the rapid convergence of Eurasian plate with the Philippine Sea plate (PSP) near Taiwan the trend in the GPS displacement time series is large enough to derive the above- mentioned quantities on a yearly basis and thus track their changes as a function of time. In the following discussions we shall use the Penghu island station (S01R) as reference when relevant. The overall patterns of the velocity vectors in Taiwan reflect the geometry of the plate convergence that created Taiwan. In the mature collision zone of central Taiwan, situated on the Eurasian plate, the velocities are largest on the eastern side and decreases toward the west to very small values in the Coastal Plain. In the south the western side of the Hengchun Peninsula is still moving westward or southwestward at about 50 mm/yr, apparently as a part of the PSP. In general, in central and northern Taiwan, the velocity vectors are oriented WNW but north of about 24ON the velocities become very slow because the PSP has subducted toward the north near that latitude so the collision takes place at depth and the deformation on the surface becomes small. The areal strain rate patterns derived from the horizontal velocities show that although much of Taiwan is under compression, two areas consistently show dilatation: one along the high Central Range and the other one in the northeast coastal area south of Ilan. In the Central Range the dilatation is probably related to the building of the mountain range and in the northeast the subduction of the PSP leaves the top portion a "free boundary". Although the noise level of the vertical time series is about 3 times higher than the corresponding horizontal measurements the continuous data show

  3. High temperature deformation mechanisms of cemented carbides and cermets

    OpenAIRE

    Buss, Katharina

    2004-01-01

    The motivation of this work derives from the need of the cutting tool industry to improve its products in order to support harder and harder working conditions, namely increasing cutting speeds and working on stronger modern materials. The lifetime of the tools is limited by plastic deformation that occurs at the cutting edge under working conditions, which involve high temperatures and stresses. The high temperature deformation of the materials that are used for the production of cutting too...

  4. Formation of Quenching Structures in the Steel 35 by Deform Cutting

    Directory of Open Access Journals (Sweden)

    A. G. Degtyareva

    2014-01-01

    Full Text Available In industry different methods of surface hardening are widely used to increase reliability and durability of friction unit parts. Among these methods are areas of focus based on deformcutting technology (DC i.e. method of chip-free mechanical treatment.It is shown that DC method allows us to produce through- or partial-hardening surface layers of a large thickness (0,4…1.5mm on steel with no additional heat sources. The standard metal-cutting equipment and common tools are used for deform-cutting process.The significant heat generation in the deform-cutting zone and mechanical effect from the tool allow us to heat undercut layers to the phase transformation point to have the hardening structure as a result of heat removal to the cold balk. The hardening structure formation occurs at significant heating and cooling rate (106C/c with large degrees and rates of strain.The deform-cutting modes and working face tool grinding determine the type and properties of the hardening structure. To produce the hardening structure would require the heat transfer and force action augmentation while treatment.These researches deal with through- and partial surface hardening samples produced by turning steel 35 shafts. While through hardening the phase transformation carry among the whole thickness of the undercut layer; while partial hardening the hardening interlayer formed on the side of the cutting tool contact.The depth of hardening zone of samples with through hardening layers is 0,5 mm; the depth of hardening zone of partial hardening samples is 0,8 mm. Micro-hardness of the through hardening layers is 653 HV0,1 and 485 HV0,1 for the partial hardening layers. The metallographic analysis shows that the hardening zone formed while deform cutting has disperse structure; there are ferrite ghosts in it.The tempering at temperatures of 200 – 700C showed that the micro-hardness of the hardening structures formed while deform cutting is larger than the micro

  5. Aeroelastic deformation of a perforated strip

    Science.gov (United States)

    Guttag, M.; Karimi, H. H.; Falcón, C.; Reis, P. M.

    2018-01-01

    We perform a combined experimental and numerical investigation into the static deformation of perforated elastic strips under uniform aerodynamic loading at high-Reynolds-number conditions. The static shape of the porous strips, clamped either horizontally or vertically, is quantified as they are deformed by wind loading, induced by a horizontal flow. The experimental profiles are compared to numerical simulations using a reduced model that takes into account the normal drag force on the deformed surface. For both configurations (vertical and horizontal clamping), we compute the drag coefficient of the strip, by fitting the experimental data to the model, and find that it decreases as a function of porosity. Surprisingly, we find that, for every value of porosity, the drag coefficients for the horizontal configuration are larger than those of the vertical configuration. For all data in both configurations, with the exception of the continuous strip clamped vertically, a linear relation is found between the porosity and drag. Making use of this linearity, we can rescale the drag coefficient in a way that it becomes constant as a function of the Cauchy number, which relates the force due to fluid loading on the elastic strip to its bending rigidity, independently of the material properties and porosity of the strip and the flow speed. Our findings on flexible strips are contrasted to previous work on rigid perforated plates. These results highlight some open questions regarding the usage of reduced models to describe the deformation of flexible structures subjected to aerodynamic loading.

  6. Canny edge-based deformable image registration.

    Science.gov (United States)

    Kearney, Vasant; Huang, Yihui; Mao, Weihua; Yuan, Baohong; Tang, Liping

    2017-02-07

    This work focuses on developing a 2D Canny edge-based deformable image registration (Canny DIR) algorithm to register in vivo white light images taken at various time points. This method uses a sparse interpolation deformation algorithm to sparsely register regions of the image with strong edge information. A stability criterion is enforced which removes regions of edges that do not deform in a smooth uniform manner. Using a synthetic mouse surface ground truth model, the accuracy of the Canny DIR algorithm was evaluated under axial rotation in the presence of deformation. The accuracy was also tested using fluorescent dye injections, which were then used for gamma analysis to establish a second ground truth. The results indicate that the Canny DIR algorithm performs better than rigid registration, intensity corrected Demons, and distinctive features for all evaluation matrices and ground truth scenarios. In conclusion Canny DIR performs well in the presence of the unique lighting and shading variations associated with white-light-based image registration.

  7. Deformable Simplicial Complexes

    DEFF Research Database (Denmark)

    Misztal, Marek Krzysztof

    triangles/tetrahedra marked as outside from those marked as inside. Such an approach allows for robust topological adaptivity. Among other advantages of the deformable simplicial complexes there are: space adaptivity, ability to handle and preserve sharp features, possibility for topology control. We....... One particular advantage of DSC is the fact that as an alternative to topology adaptivity, topology control is also possible. This is exploited in the construction of cut loci on tori where a front expands from a single point on a torus and stops when it self-intersects....

  8. 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

  9. Experiments of dike-induced deformation: Insights on the long-term evolution of divergent plate boundaries

    KAUST Repository

    Trippanera, D.

    2015-10-22

    The shallow transport of magma occurs through dikes causing surface deformation. Our understanding of the effects of diking at the surface is limited, especially on the long term, for repeated intrusive episodes. We use analogue models to study the upper crustal deformation induced by dikes. We insert metal plates within cohesive sand with three setups: in setup A, the intrusion rises upward with constant thickness and in setups B and C, the intrusion thickens at a fixed depth, with final rectangular (setup B) or triangular (setup C) shape in section. Setup A creates a doming delimited by reverse faults, with secondary apical graben, without close correspondence in nature. In setups B and C, a depression flanked by two uplifted areas is bordered by inward dipping normal faults propagating downward and, for deeper intrusions in setup B, also by inner faults, reverse at the surface; this deformation is similar to what is observed in nature, suggesting a consistent physical behavior. Dikes in nature initially propagate developing a mode I fracture at the tip, subsequently thickened by magma intrusion, without any host rock translation in the propagation direction (as in setup A). The deformation pattern in setups B and C depends on the intrusion depth and thickness, consistently to what is observed along divergent plate boundaries. The early deformation in setups B and C is similar to that from a single rifting episode (i.e., Lakagigar, Iceland, and Dabbahu, Afar), whereas the late stages resemble the structure of mature rifts (i.e., Krafla, Iceland), confirming diking as a major process in shaping divergent plate boundaries.

  10. The Whitham deformation of the Dijkgraaf-Vafa Theory

    International Nuclear Information System (INIS)

    Aoyama, Shogo; Masuda, Takahiro

    2004-01-01

    We discuss the Whitham deformation of the effective superpotential in the Dijkgraaf-Vafa (DV) theory. It amounts to discussing the Whitham deformation of an underlying (hyper)elliptic curve. Taking the elliptic case for simplicity we derive the Whitham equation for the period, which governs fowings of branch points on the Riemann surface. By studying the hodograph solution to the Whitham equation it is shown that the effective superpotential in the DV theory is realized by many different meromorphic differentials. Depending on which meromorphic differential to take, the effective superpotential undergoes different deformations. This aspect of the DV theory is discussed in detail by taking the N = 1* theory. (author)

  11. Void growth and coalescence in metals deformed at elevated temperature

    DEFF Research Database (Denmark)

    Klöcker, H.; Tvergaard, Viggo

    2000-01-01

    For metals deformed at elevated temperatures the growth of voids to coalescence is studied numerically. The voids are assumed to be present from the beginning of deformation, and the rate of deformation considered is so high that void growth is dominated by power law creep of the material, without...... any noticeable effect of surface diffusion. Axisymmetric unit cell model computations are used to study void growth in a material containing a periodic array of voids, and the onset of the coalescence process is defined as the stage where plastic flow localizes in the ligaments between neighbouring...

  12. The Finite Deformation Dynamic Sphere Test Problem

    Energy Technology Data Exchange (ETDEWEB)

    Versino, Daniele [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Brock, Jerry Steven [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-09-02

    In this manuscript we describe test cases for the dynamic sphere problem in presence of finite deformations. The spherical shell in exam is made of a homogeneous, isotropic or transverse isotropic material and elastic and elastic-plastic material behaviors are considered. Twenty cases, (a) to (t), are thus defined combining material types and boundary conditions. The inner surface radius, the outer surface radius and the material's density are kept constant for all the considered test cases and their values are ri = 10mm, ro = 20mm and p = 1000Kg/m3 respectively.

  13. A novel methodology for 3D deformable dosimetry

    International Nuclear Information System (INIS)

    Yeo, U. J.; Taylor, M. L.; Dunn, L.; Kron, T.; Smith, R. L.; Franich, R. D.

    2012-01-01

    three dimensions occurring as a result of the change in shape of the target between irradiations, even for a relatively simple deformation. Discrepancies of up to 30% of the maximum dose were evident from dose difference maps for three orthogonal planes taken through the isocenter of a stereotactic field. Conclusions: This paper describes the first use of a tissue-equivalent, 3D dose-integrating deformable phantom that yields integrated or redistributed dosimetric information. The proposed methodology readily yields three-dimensional (3D) dosimetric data from radiation delivery to the DEFGEL phantom in deformed and undeformed states. The impacts of deformation on dose distributions were readily seen in the isodose contours and line profiles from the three arrangements. It is demonstrated that the system is potentially capable of reproducibly emulating the physical deformation of an organ, and therefore can be used to evaluate absorbed doses to deformable targets and organs at risk in three dimensions and to validate deformation algorithms applied to dose distributions.

  14. A novel methodology for 3D deformable dosimetry.

    Science.gov (United States)

    Yeo, U J; Taylor, M L; Dunn, L; Kron, T; Smith, R L; Franich, R D

    2012-04-01

    Interfraction and intrafraction variation in anatomic structures is a significant challenge in contemporary radiotherapy. The objective of this work is to develop a novel tool for deformable structure dosimetry, using a tissue-equivalent deformable gel dosimeter that can reproducibly simulate targets subject to deformation. This will enable direct measurement of integrated doses delivered in different deformation states, and the verification of dose deforming algorithms. A modified version of the nPAG polymer gel has been used as a deformable 3D dosimeter and phantom to investigate doses delivered to deforming tissue-equivalent geometry. The deformable gel (DEFGEL) dosimeter/phantom is comprised of polymer gel in a latex membrane, moulded (in this case) into a cylindrical geometry, and deformed with an acrylic compressor. Fifteen aluminium fiducial markers (FM) were implanted into DEFGEL phantoms and the reproducibility of deformation was determined via multiple computed tomography (CT) scans in deformed and nondeformed states before and after multiple (up to 150) deformations. Dose was delivered to the DEFGEL phantom in three arrangements: (i) without deformation, (ii) with deformation, and (iii) cumulative exposures with and without deformation, i.e., dose integration. Irradiations included both square field and a stereotactic multiple dynamic arc treatment adapted from a patient plan. Doses delivered to the DEFGEL phantom were read out using cone beam optical CT. Reproducibility was verified by observation of interscan shifts of FM locations (as determined via CT), measured from an absolute reference point and in terms of inter-FM distance. The majority (76%) of points exhibited zero shift, with others shifting by one pixel size consistent with setup error as confirmed with a control sample. Comparison of dose profiles and 2D isodose distributions from the three arrangements illustrated complex spatial redistribution of dose in all three dimensions occurring as

  15. Deformations in closed string theory: canonical formulation and regularization

    International Nuclear Information System (INIS)

    Cederwall, M.; Von Gussich, A.; Sundell, P.

    1996-01-01

    We study deformations of closed string theory by primary fields of conformal weight (1,1), using conformal techniques on the complex plane. A canonical surface integral formalism for computing commutators in a non-holomorphic theory is constructed, and explicit formulae for deformations of operators are given. We identify the unique regularization of the arising divergences that respects conformal invariance, and consider the corresponding parallel transport. The associated connection is metric compatible and carries no curvature. (orig.)

  16. Nuclear fuel deformation phenomena

    International Nuclear Information System (INIS)

    Van Brutzel, L.; Dingreville, R.; Bartel, T.J.

    2015-01-01

    Nuclear fuel encounters severe thermomechanical environments. Its mechanical response is profoundly influenced by an underlying heterogeneous microstructure but also inherently dependent on the temperature and stress level histories. The ability to adequately simulate the response of such microstructures, to elucidate the associated macroscopic response in such extreme environments is crucial for predicting both performance and transient fuel mechanical responses. This chapter discusses key physical phenomena and the status of current modelling techniques to evaluate and predict fuel deformations: creep, swelling, cracking and pellet-clad interaction. This chapter only deals with nuclear fuel; deformations of cladding materials are discussed elsewhere. An obvious need for a multi-physics and multi-scale approach to develop a fundamental understanding of properties of complex nuclear fuel materials is presented. The development of such advanced multi-scale mechanistic frameworks should include either an explicit (domain decomposition, homogenisation, etc.) or implicit (scaling laws, hand-shaking,...) linkage between the different time and length scales involved, in order to accurately predict the fuel thermomechanical response for a wide range of operating conditions and fuel types (including Gen-IV and TRU). (authors)

  17. Rotary deformity in degenerative spondylolisthesis

    International Nuclear Information System (INIS)

    Kang, Sung Gwon; Kim, Jeong; Kho, Hyen Sim; Yun, Sung Su; Oh, Jae Hee; Byen, Ju Nam; Kim, Young Chul

    1994-01-01

    We studied to determine whether the degenerative spondylolisthesis has rotary deformity in addition to forward displacement. We have made analysis of difference of rotary deformity between the 31 study groups of symptomatic degenerative spondylolisthesis and 31 control groups without any symptom, statistically. We also reviewed CT findings in 15 study groups. The mean rotary deformity in study groups was 6.1 degree(the standard deviation is 5.20), and the mean rotary deformity in control groups was 2.52 degree(the standard deviation is 2.16)(p < 0.01). The rotary deformity can be accompanied with degenerative spondylolisthesis. We may consider the rotary deformity as a cause of symptomatic degenerative spondylolisthesis in case that any other cause is not detected

  18. Rotary deformity in degenerative spondylolisthesis

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sung Gwon; Kim, Jeong; Kho, Hyen Sim; Yun, Sung Su; Oh, Jae Hee; Byen, Ju Nam; Kim, Young Chul [Chosun University College of Medicine, Gwangju (Korea, Republic of)

    1994-05-15

    We studied to determine whether the degenerative spondylolisthesis has rotary deformity in addition to forward displacement. We have made analysis of difference of rotary deformity between the 31 study groups of symptomatic degenerative spondylolisthesis and 31 control groups without any symptom, statistically. We also reviewed CT findings in 15 study groups. The mean rotary deformity in study groups was 6.1 degree(the standard deviation is 5.20), and the mean rotary deformity in control groups was 2.52 degree(the standard deviation is 2.16)(p < 0.01). The rotary deformity can be accompanied with degenerative spondylolisthesis. We may consider the rotary deformity as a cause of symptomatic degenerative spondylolisthesis in case that any other cause is not detected.

  19. Neutron halo in deformed nuclei

    International Nuclear Information System (INIS)

    Zhou Shangui; Meng Jie; Ring, P.; Zhao Enguang

    2010-01-01

    Halo phenomena in deformed nuclei are investigated within a deformed relativistic Hartree Bogoliubov (DRHB) theory. These weakly bound quantum systems present interesting examples for the study of the interdependence between the deformation of the core and the particles in the halo. Contributions of the halo, deformation effects, and large spatial extensions of these systems are described in a fully self-consistent way by the DRHB equations in a spherical Woods-Saxon basis with the proper asymptotic behavior at a large distance from the nuclear center. Magnesium and neon isotopes are studied and detailed results are presented for the deformed neutron-rich and weakly bound nucleus 44 Mg. The core of this nucleus is prolate, but the halo has a slightly oblate shape. This indicates a decoupling of the halo orbitals from the deformation of the core. The generic conditions for the occurrence of this decoupling effects are discussed.

  20. Offshore Deformation Front in Miaoli Area

    Science.gov (United States)

    Chiang, P.; Gwo-shyn, S.

    2015-12-01

    Taiwan is located at the junction of the Eurasian Plate and the Philippine Sea Plate. It's because arc-continent collision occurs in the western Taiwan, resulting in the orogeny has formed a fold-and-thrust belt, developing a series of thrusts aligned in north-south direction. The thrust faults, locating in the central island, are the oldest and have almost inactive. Westward to the island, the faults become younger, dipping angles are smaller, and motions were stronger. On the west side, the foot of the Taiwan Western Foothill is considered the youngest thrust faults located along west Taiwan. Scholars recognized them as so-called the deformation front, and they also believed that the deformation front is located in between the compressive terrain uplifted area and the extensional subsidence area. Therefore, this front line is on the boundary of two different tectonic zones. This study investigates the trace of the deformation front in Miaoli area. Previous studies suggested that the west side of Miaoli collision zone should be fault-bounded, and is located in the seabed. However, in the geological map, there is no geologic evidence that appears on land and so-called active faults related with this deformation front. In the near coast seafloor, according to the reflection earthquakes data from the Institute of Oceanography of NTU, we can only see the offshore strata have been uplifted, and the data also shows that seabed is only covered by thin layer of sediments. This study indicates that in offshore place within three kilometers, shallow formations show a special layer of slime which was extruded to be corrugated transversely. Accordingly, we believe that this slime layer should be pressurized and filled with muddy water. Such features should be further investigated with other geological and geophysical survey data to check if they belong to the structural product of the deformation front.

  1. Elastic deformation of soft coatings due to lubrication forces.

    Science.gov (United States)

    Wang, Yumo; Tan, Matthew R; Frechette, Joelle

    2017-10-04

    Elastic deformation of rigid materials with soft coatings (stratified materials) due to lubrication forces can alter the interpretation of dynamic surface forces measurements and prevent contact formation between approaching surfaces. Understanding the role of elastic deformation on the process of fluid drainage is necessary, in particular for the case where one (or both) of the interacting materials consists of a rigid substrate with a soft coating. We combine lubrication theory and solid linear elasticity to describe the dynamic of fluid drainage past a compliant stratified boundary. The analysis presented covers the full range of coating thicknesses, from an elastic foundation to a half-space for an incompressible coating. We decouple the individual contributions of the coating thickness and material properties on the elastic deformation, hydrodynamic forces, and fluid film thickness. We obtain a simple expression for the shift in contact position during force measurements that is valid for many experimental conditions. We compare directly the effect of stratification on the out-of-contact deformation to the well-known effect of stratification on indentation. We show that corrections developed for stratification in contact mechanics are not applicable to elastohydrodynamic deformation. Finally, we provide generalized contour maps that can be employed directly to estimate the elastic deformation present in most dynamic surface force measurements.

  2. Adaptive soft tissue deformation for a virtual reality surgical trainer.

    Science.gov (United States)

    Jerabkova, Lenka; Wolter, Timm P; Pallua, Norbert; Kuhlen, Torsten

    2005-01-01

    Real time tissue deformation is an important aspect of interactive virtual reality (VR) environments such as medical trainers. Most approaches in deformable modelling use a fixed space discretization. A surgical trainer requires high plausibility of the deformations especially in the area close to the instrument. As the area of intervention is not known a priori, adaptive techniques have to be applied. We present an approach for real time deformation of soft tissue based on a regular FEM mesh of cube elements as opposed to a mesh of tetrahedral elements used by the majority of soft tissue simulators. A regular mesh structure simplifies the local refinement operation as the elements topology and stiffness are known implicitly. We propose an octree-based adaptive multiresolution extension of our basic approach. The volumetric representation of the deformed object is created automatically from medical images or by voxelization of a surface model. The resolution of the volumetric representation is independent of the surface geometry resolution. The surface is deformed according to the simulation performed on the underlying volumetric mesh.

  3. Radiologic evaluation of foot deformities

    International Nuclear Information System (INIS)

    Erlemann, R.; Fischedick, A.R.; Peters, P.E.

    1986-01-01

    In order to analyze foot deformities, the foot is divided into three compartments. Their normal and pathological positions are defined by the alignment of the bones' axes. The various foot deformities can be put down to a malalignment of the particular compartments. X-ray analysis of the malalignment allows a diagnosis to be made. The most important congenital and acquired foot deformities are discussed. (orig.) [de

  4. q-deformed Brownian motion

    CERN Document Server

    Man'ko, V I

    1993-01-01

    Brownian motion may be embedded in the Fock space of bosonic free field in one dimension.Extending this correspondence to a family of creation and annihilation operators satisfying a q-deformed algebra, the notion of q-deformation is carried from the algebra to the domain of stochastic processes.The properties of q-deformed Brownian motion, in particular its non-Gaussian nature and cumulant structure,are established.

  5. Sundew adhesive: a naturally occurring hydrogel.

    Science.gov (United States)

    Huang, Yujian; Wang, Yongzhong; Sun, Leming; Agrawal, Richa; Zhang, Mingjun

    2015-06-06

    Bioadhesives have drawn increasing interest in recent years, owing to their eco-friendly, biocompatible and biodegradable nature. As a typical bioadhesive, sticky exudate observed on the stalked glands of sundew plants aids in the capture of insects and this viscoelastic adhesive has triggered extensive interests in revealing the implied adhesion mechanisms. Despite the significant progress that has been made, the structural traits of the sundew adhesive, especially the morphological characteristics in nanoscale, which may give rise to the viscous and elastic properties of this mucilage, remain unclear. Here, we show that the sundew adhesive is a naturally occurring hydrogel, consisting of nano-network architectures assembled with polysaccharides. The assembly process of the polysaccharides in this hydrogel is proposed to be driven by electrostatic interactions mediated with divalent cations. Negatively charged nanoparticles, with an average diameter of 231.9 ± 14.8 nm, are also obtained from this hydrogel and these nanoparticles are presumed to exert vital roles in the assembly of the nano-networks. Further characterization via atomic force microscopy indicates that the stretching deformation of the sundew adhesive is associated with the flexibility of its fibrous architectures. It is also observed that the adhesion strength of the sundew adhesive is susceptible to low temperatures. Both elasticity and adhesion strength of the sundew adhesive reduce in response to lowering the ambient temperature. The feasibility of applying sundew adhesive for tissue engineering is subsequently explored in this study. Results show that the fibrous scaffolds obtained from sundew adhesive are capable of increasing the adhesion of multiple types of cells, including fibroblast cells and smooth muscle cells, a property that results from the enhanced adsorption of serum proteins. In addition, in light of the weak cytotoxic activity exhibited by these scaffolds towards a variety of

  6. Deformable paper origami optoelectronic devices

    KAUST Repository

    He, Jr-Hau

    2017-01-19

    Deformable optoelectronic devices are provided, including photodetectors, photodiodes, and photovoltaic cells. The devices can be made on a variety of paper substrates, and can include a plurality of fold segments in the paper substrate creating a deformable pattern. Thin electrode layers and semiconductor nanowire layers can be attached to the substrate, creating the optoelectronic device. The devices can be highly deformable, e.g. capable of undergoing strains of 500% or more, bending angles of 25° or more, and/or twist angles of 270° or more. Methods of making the deformable optoelectronic devices and methods of using, e.g. as a photodetector, are also provided.

  7. q-deformed Minkowski space

    International Nuclear Information System (INIS)

    Ogievetsky, O.; Pillin, M.; Schmidke, W.B.; Wess, J.; Zumino, B.

    1993-01-01

    In this lecture I discuss the algebraic structure of a q-deformed four-vector space. It serves as a good example of quantizing Minkowski space. To give a physical interpretation of such a quantized Minkowski space we construct the Hilbert space representation and find that the relevant time and space operators have a discrete spectrum. Thus the q-deformed Minkowski space has a lattice structure. Nevertheless this lattice structure is compatible with the operation of q-deformed Lorentz transformations. The generators of the q-deformed Lorentz group can be represented as linear operators in the same Hilbert space. (orig.)

  8. Deformation behaviour of turbine foundations

    International Nuclear Information System (INIS)

    Koch, W.; Klitzing, R.; Pietzonka, R.; Wehr, J.

    1979-01-01

    The effects of foundation deformation on alignment in turbine generator sets have gained significance with the transition to modern units at the limit of design possibilities. It is therefore necessary to obtain clarification about the remaining operational variations of turbine foundations. Static measurement programmes, which cover both deformation processes as well as individual conditions of deformation are described in the paper. In order to explain the deformations measured structural engineering model calculations are being undertaken which indicate the effect of limiting factors. (orig.) [de

  9. Leachability of naturally occurring radioactive materials

    International Nuclear Information System (INIS)

    Desideri, D.; Feduzi, L.; Meli, M.A.; Roselli, C.

    2006-01-01

    Naturally occurring radioactive materials (NORM) are present in the environment and can be concentrated by technical activities, particularly those involving natural resources. These NORM deposits are highly stable and very insoluble under environmental conditions at the earth's surface. However, reducing or oxidant conditions or pH changes may enable a fraction of naturally occurring radionuclides to eventually be released to the environment. Leachability of 210 Pb and 210 Po was determined in three samples coming from a refractories production plant (dust, sludge, finished product), in one dust sample from a steelwork and in one ash sample coming from an electric power station. A sequential extraction method consisting of five operationally-defined fractions was used. The average leaching potential observed in the samples from the refractory industry is very low (mean values: 5.8% for 210 Pb and 1.7% for 210 Po). The 210 Pb and 210 Po leachability increases for the ash sample coming from an electric power plant using carbon (17.8% for 210 Pb and 10.0% for 210 Po); for the dust sample coming from a steelwork, the percent soluble fraction is 41.1% for 210 Pb and 8.5% for 210 Po. For all samples the results obtained show that 210 Pb is slightly more soluble than 210 Po. (author)

  10. [Nasal septum cartilage-silica gel complex for repairing nasal deformities of unilateral cleft lip].

    Science.gov (United States)

    Li, Qingwei; Sheng, Zunqi; Tang, Shengjian; Yang, Biaobing; Yu, Xiaohua

    2009-07-01

    To evaluate the operative methods and therapeutic effects of nasal septum cartilage-silica gel complex for two-stage repair of nasal deformities of unilateral cleft lip. From June 2001 to June 2007, 38 cases of secondary nasal deformity and septum deviation of cleft lip were treated with transplanting nasal septum cartilage-silica gel complex. Among of them, there were 21 males and 17 females, aging 14-23 years with an average of 17.6 years. All cases were with nasal deformities of unilateral cleft lip, including 21 cases of complete cleft lip and 17 cases of incomplete cleft lip. The locations were left side in 26 cases and right side in 12 cases. Nasal deformities were columella nasi deflexion, flattened nasal tip, pteleorrhine and alanasi collapse. The patients received 1-4 times operations, and the interval of two operations was 3-10 years (mean 5.5 years). According to nasal deformity, the nasal septum cartilage of 1.8 cm x 1.2 cm was cut, and transplanted into the nose point phantom surface forming "the shield" to extend nose column and to raise the tip of the nose. At the same time the nasal tip fat-connective tissue flap graft with fat knot was given. After fixation, the nasal alar cartilage and soft tissues were reduced to normal position. Primary healing of the incisions was achieved in all cases. The nasal deformity was corrected. The postoperative follow-up period was 12-18 months with an average of 15.6 months. All the patients of regional cartilage scars had no complication. The figure of nose was slinky, the height of apex of nose and the shape of nose was natural, the apex of nose, nasal ala, nostrils and nasal columella were satisfactory [(the results were satisfactory in 30 cases (78.9%), general in 8 cases (21.1%)]. The nose department overall esthetics shape was improved in all the patients, no complications of the phantom sliding, shifting and exposure, hemorrhage and infection occurred. The nasal septum cartilage-silica gel complex to repair

  11. Coseismic and postseismic deformation of the great 2004 Sumatra-Andaman earthquake

    Science.gov (United States)

    Hughes, Kristin Leigh Hellem

    The 26 December 2004 M9.2 Sumatra-Andaman earthquake (SAE) induced a devastating tsunami when it ruptured over 1300 km of the boundary between the Indo-Australian plate and Burma microplate (Vigny et al., 2005; Bilek, 2007). Three months later on 28 March 2005, the M8.7 Nias earthquake (NE) ruptured over 400 km along the same trench overlapping and progressing to the south of the M9.2 rupture (Banerjee et al., 2007). The spatial and temporal proximity of these two earthquakes suggests that the SAE mechanically influenced the timing of the NE. I analyze the coseismic and postseismic deformation, stress, and pore pressure of the 2004 SAE using 3D finite element models (FEMs) in order to determine the mechanical coupling of the SAE and NE. The motivation for using FEMs is two-fold. First, FEMs allow me to honor the geologic structure of the Sumatra-Andaman subduction zone, and second, FEMs simulate the mechanical behavior of quasi-static coseismic and postseismic deformation systems (e.g., elastic, poroelastic, and viscoelastic materials). The results of my study include: (1) Coseismic slip distributions are incredibly sensitive to the distribution of material properties (Masterlark and Hughes, 2008), (2) Slip models derived from tsunami wave heights do not match slip models derived from GPS data (Hughes and Masterlark, 2008), (3) These FEMs predict postseismic poroelastic deformation and viscoelastic deformation simultaneously (Masterlark and Hughes, 2008), (4) Pore pressure changes induced by the SAE triggered the NE via fluid flow in the subducting oceanic crust and caused the NE to occur 7 years ahead of interseismic strain accumulation predictions (Hughes et al., 2010; Hughes et al., 2011), (5) Global Conductance Matrices provide a way to smooth an underdetermined FEM for arbitrarily irregular surfaces, and (6) FEMs are capable and desired to model subduction zone deformation built around the complexity of a subducting slab which is usually ignored in geodetic

  12. Layered Structures in Deformed Metals and Alloys

    DEFF Research Database (Denmark)

    Hansen, Niels; Zhang, Xiaodan; Huang, Xiaoxu

    2014-01-01

    Layered structures characterize metals and alloys deformed to high strain. The morphology is typical lamellar or fibrous and the interlamellar spacing can span several length scales down to the nanometer dimension. The layered structures can be observed in bulk or in surface regions, which is shown...... by the way of examples of different processing routes: friction, wire drawing, shot peening, high pressure torsion and rolling. The interlamellar spacing reaches from 5-10 nanometers to about one micrometer and the analysis will cover structural evolution, strengthening parameters and strength-structure...... relationships. Finally, the results will be discussed based on universal principles for the evolution of microstructure and properties during plastic deformation of metals and alloys from low to high strain....

  13. Analysis on Wetting Deformation Properties of Silty Clay

    Directory of Open Access Journals (Sweden)

    Xinrong Liu

    2014-06-01

    Full Text Available Changes in water level that cause deformation and stability problems often occur in foundation pit engineering. Water damage is one of the main problems that will lead to disasters in foundation pit engineering. Research findings with regard to properties of wetting deformation due to water damage can be applied not only in foundation pit engineering, slope engineering, hydraulic engineering, and mining engineering but also in related issues in the field of theoretical research and practice. In this study, the characteristics of silty clay deformation after wetting are examined from the perspective of the effect of wetting on the side wall of foundation pit, and wetting experiments on silty clay of a selected area’s stratum located in Chongqing Municipality are conducted under different confining pressures and stress levels through a multi-function triaxial apparatus. Then, laws of silty clay wetting deformation are obtained, and the relationship between wetting stress level and wetting deformation amount is also figured out. The study reveals that the maximum values of wetting deformation under different confining pressures have appear at a particular stress level; therefore, the related measures should be taken to avoid this deformation in the process of construction.

  14. Post- and interseismic deformation due to both localized and distributed creep at depth (Invited)

    Science.gov (United States)

    Hetland, E. A.; Zhang, G.; Hines, T.

    2013-12-01

    There are two end-member representations of the ductile lithosphere (i.e., the lower crust and uppermost mantle) commonly used in models of post- and interseismic deformation around strike-slip faults: either (1) laterally homogeneous ductile layers, with sharp contrasts in rheological properties between the layers, in which creep is distributed; or (2) discrete extensions of the fault at depth in which creep is fully localized. The most realistic representation of the ductile lithosphere on earthquake cycle time scales likely falls between these two end-members. Researchers have considered both distributed and localized creep when interpreting post- and interseismic deformation, although the two mechanisms are most commonly treated separately, with the localized creep often approximated by kinematic slip on planar faults. There are a few noteworthy models that considered the feedback between both distributed and localized creep, although those models were largely constrained to 2D geometries of infinite length faults. The thickness of shear zones in the ductile lithosphere may be comparable to the locking depth of the fault, and the existence of a deep shear zone does not preclude the possibility that some distributed creep occurs in the surrounding lithosphere. Furthermore, variations in rheology, including both rheological models and their parameters, may be more subtle than the discrete contrasts typically assumed. In this presentation, we consider models of postseismic deformation following a finite length, strike-slip fault, as well as models of interseismic deformation around an infinite length strike-slip fault. Both sets of models are capable of localized and distributed creep at depth, and use Maxwell viscoelasticity. We show that the horizontal surface velocities during the early postseismic period are most sensitive to the viscosity of the shear zone; however during much of the interseismic period the shear zone is not apparent from the surface

  15. Characterization of deformed pearlitic rail steel

    Science.gov (United States)

    Nikas, Dimitrios; Meyer, Knut Andreas; Ahlström, Johan

    2017-07-01

    Pearlitic steels are commonly used for railway rails because they combine good strength and wear properties. During service, the passage of trains results in a large accumulation of shear strains in the surface layer of the rail, leading to crack initiation. Knowledge of the material properties in this region is therefore important for fatigue life prediction. As the strain is limited to a thin surface layer, very large strain gradients can be found. This makes it very difficult to quantify changes in material behavior. In this study hardness measurements were performed close to the surface using the Knoop hardness test method. The orientation of the pearlitic lamellas was measured to give an overview of the deformed microstructure in the surface of the rail. Microstructural characterization of the material was done by optical microscopy and scanning electron microscopy to evaluate the changes in the microstructure due to the large deformation. A strong gradient can be observed in the top 50 μm of the rail, while deeper into the rail the microstructure of the base material is preserved.

  16. Robust brain ROI segmentation by deformation regression and deformable shape model.

    Science.gov (United States)

    Wu, Zhengwang; Guo, Yanrong; Park, Sang Hyun; Gao, Yaozong; Dong, Pei; Lee, Seong-Whan; Shen, Dinggang

    2018-01-01

    We propose a robust and efficient learning-based deformable model for segmenting regions of interest (ROIs) from structural MR brain images. Different from the conventional deformable-model-based methods that deform a shape model locally around the initialization location, we learn an image-based regressor to guide the deformable model to fit for the target ROI. Specifically, given any voxel in a new image, the image-based regressor can predict the displacement vector from this voxel towards the boundary of target ROI, which can be used to guide the deformable segmentation. By predicting the displacement vector maps for the whole image, our deformable model is able to use multiple non-boundary predictions to jointly determine and iteratively converge the initial shape model to the target ROI boundary, which is more robust to the local prediction error and initialization. In addition, by introducing the prior shape model, our segmentation avoids the isolated segmentations as often occurred in the previous multi-atlas-based methods. In order to learn an image-based regressor for displacement vector prediction, we adopt the following novel strategies in the learning procedure: (1) a joint classification and regression random forest is proposed to learn an image-based regressor together with an ROI classifier in a multi-task manner; (2) high-level context features are extracted from intermediate (estimated) displacement vector and classification maps to enforce the relationship between predicted displacement vectors at neighboring voxels. To validate our method, we compare it with the state-of-the-art multi-atlas-based methods and other learning-based methods on three public brain MR datasets. The results consistently show that our method is better in terms of both segmentation accuracy and computational efficiency. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Capillary Deformations of Bendable Films

    KAUST Repository

    Schroll, R. D.

    2013-07-01

    We address the partial wetting of liquid drops on ultrathin solid sheets resting on a deformable foundation. Considering the membrane limit of sheets that can relax compression through wrinkling at negligible energetic cost, we revisit the classical theory for the contact of liquid drops on solids. Our calculations and experiments show that the liquid-solid-vapor contact angle is modified from the Young angle, even though the elastic bulk modulus (E) of the sheet is so large that the ratio between the surface tension γ and E is of molecular size. This finding indicates a new elastocapillary phenomenon that stems from the high bendability of very thin elastic sheets rather than from material softness. We also show that the size of the wrinkle pattern that emerges in the sheet is fully predictable, thus resolving a puzzle in modeling "drop-on-a-floating-sheet" experiments and enabling a quantitative, calibration-free use of this setup for the metrology of ultrathin films. © 2013 American Physical Society.

  18. Rapid collision detection for deformable objects using inclusion-fields applied to cloth simulation

    Directory of Open Access Journals (Sweden)

    Asma A. ElBadrawy

    2012-07-01

    Full Text Available We introduce an inclusion-field technique for fast detection of collisions between a highly deformable object and another object with limited deformations. We mainly target the cloth simulation application where cloth (highly deformable collides with deforming skin of a moving human model (has limited deformation as skin stretches and compacts within finite spacial and temporal limits specified by the bending angle and speed. Our technique intermixes concepts from space voxelization and distance fields to make use of the limited deformation nature of human skin. The technique works by discretizing the space containing the object into cells, and giving each cell an inclusion property. This property specifies whether this cell lies inside, outside, or on the surface of the deforming object. As the object deforms, the cells’ inclusion properties are updated to maintain the correctness of the collision detection process. We tested our technique on a generally deforming Bezier surface, and on cloth simulation to detect collisions between cloth and several articulated and deforming human body parts. Results showed that the inclusion field allows real-time collision detection between cloth and limited deformable objects on a standard PC. The technique is simple and easy to implement.

  19. Characterization of the failure behavior of zinc coating on dual phase steel under tensile deformation

    International Nuclear Information System (INIS)

    Song Guiming; Sloof, Willem G.

    2011-01-01

    Highlights: → The microcracks and voids at the zinc grain boundaries are the initial sites for the coating cracking. → The crack spacing of the fragmentally fractured zinc coating is mainly determined by the zinc grain size. → Small zinc grain size and the c-axis direction of zinc grain parallel to the zinc surface are beneficial to the mitigation of the zinc coating delamination. - Abstract: The failure behavior of hot-dip galvanized zinc coatings on dual phase steels under tensile deformation is characterized with in situ scanning electron microscopy (SEM). Under tension, the pre-existed microcracks and voids at the zinc grain boundaries propagate along the zinc grain boundaries to form crack nets within the coating, leading to a segmented fracture of the zinc coating with the crack spacing approximately equal to the zinc grain size. With further loading, the coating segments partially delaminated along the interface between the top zinc layer and the inhibition layer instead of the interface between the inhibition layer and steel substrate. As the c-axis of zinc grains trends to be normal to the tensile loading direction, the twinning deformation became more noticeable, and meanwhile the coating delamination was diminished. The transverse and incline tunneling cracks occurred in the inhibition layer with tensile deformation. The existence of the brittle FeZn 13 particles on top of the inhibition layer was unfavorable to the coating adhesion.

  20. Timing of oceans on Mars from shoreline deformation

    Science.gov (United States)

    Citron, Robert I.; Manga, Michael; Hemingway, Douglas J.

    2018-03-01

    Widespread evidence points to the existence of an ancient Martian ocean. Most compelling are the putative ancient shorelines in the northern plains. However, these shorelines fail to follow an equipotential surface, and this has been used to challenge the notion that they formed via an early ocean and hence to question the existence of such an ocean. The shorelines’ deviation from a constant elevation can be explained by true polar wander occurring after the formation of Tharsis, a volcanic province that dominates the gravity and topography of Mars. However, surface loading from the oceans can drive polar wander only if Tharsis formed far from the equator, and most evidence indicates that Tharsis formed near the equator, meaning that there is no current explanation for the shorelines’ deviation from an equipotential that is consistent with our geophysical understanding of Mars. Here we show that variations in shoreline topography can be explained by deformation caused by the emplacement of Tharsis. We find that the shorelines must have formed before and during the emplacement of Tharsis, instead of afterwards, as previously assumed. Our results imply that oceans on Mars formed early, concurrent with the valley networks, and point to a close relationship between the evolution of oceans on Mars and the initiation and decline of Tharsis volcanism, with broad implications for the geology, hydrological cycle and climate of early Mars.

  1. Timing of oceans on Mars from shoreline deformation.

    Science.gov (United States)

    Citron, Robert I; Manga, Michael; Hemingway, Douglas J

    2018-03-29

    Widespread evidence points to the existence of an ancient Martian ocean. Most compelling are the putative ancient shorelines in the northern plains. However, these shorelines fail to follow an equipotential surface, and this has been used to challenge the notion that they formed via an early ocean and hence to question the existence of such an ocean. The shorelines' deviation from a constant elevation can be explained by true polar wander occurring after the formation of Tharsis, a volcanic province that dominates the gravity and topography of Mars. However, surface loading from the oceans can drive polar wander only if Tharsis formed far from the equator, and most evidence indicates that Tharsis formed near the equator, meaning that there is no current explanation for the shorelines' deviation from an equipotential that is consistent with our geophysical understanding of Mars. Here we show that variations in shoreline topography can be explained by deformation caused by the emplacement of Tharsis. We find that the shorelines must have formed before and during the emplacement of Tharsis, instead of afterwards, as previously assumed. Our results imply that oceans on Mars formed early, concurrent with the valley networks, and point to a close relationship between the evolution of oceans on Mars and the initiation and decline of Tharsis volcanism, with broad implications for the geology, hydrological cycle and climate of early Mars.

  2. Operating limits for subassembly deformation in EBR-II

    International Nuclear Information System (INIS)

    Bottcher, J.H.

    1977-01-01

    The deformation of a subassembly in response to the core environment is frequently the life limiting factor for that component in an LMFBR. Deformation can occur as diametral and axial growth or bowing of the subassembly. Such deformation has caused several handling problems in both the core and the storage basket of EBR-II and may also have contributed to reactivity anomalies during reactor operation. These problems generally affect plant availability but the reactivity anomalies could lead to a potential safety hazard. Because of these effects the deformation mechanisms must be understood and modeled. Diametral and axial growth of subassembly ducts in EBR-II is due to swelling and creep and is a function of temperature, neutron fluence and stress. The source of stress in a duct is the hydraulic pressure difference across the wall. By coupling the calculated subassembly growth rate to the available clearance in the core or storage basket a limiting neutron fluence, or exposure, can be established

  3. Effect of ionic charge on flexoelectric deformations in planar nematic layers

    Science.gov (United States)

    Felczak, Mariola; Derfel, Grzegorz

    2004-09-01

    Elastic deformations of nematic liquid crystal layers subjected to d.c. electric field were studied numerically. Nearly planar alignment with 1° tilt angle and with finite surface anchoring strength was assumed. The flexoelectric properties of the nematic material as well as the ionic space charge were taken into account. Perfectly blocking electrodes were adopted. The director orientation, the electric potential distribution and the space charge density were calculated. The optical transmission of the layer placed between crossed polarizers was also determined. The deformations had nearly threshold character due to the low value of the surface tilt. It was found that the threshold voltage strongly depended on the parameters of the system. When the nematic was not flexoelectric, the value of the threshold voltage was independent of the ion concentration and was equal to about 1 volt. In the case of a flexoelectric nematic, the threshold as low as a few tenths of a volt occurred when the ion concentration was sufficiently high, and given sufficiently large magnitudes of the flexoelectric coefficients. These results can be explained as the effect of the inhomogeneous electric field arising in vicinity of the surfaces created by the ionic space charge redistributed by the external voltage.

  4. Deep-seated gravitational slope deformations near the Trans-Alaska Pipeline, east-central Alaska Range, Alaska, USA

    Science.gov (United States)

    Newman, S. D.; Clague, J. J.; Rabus, B.; Stead, D.

    2013-12-01

    Multiple, active, deep-seated gravitational slope deformations (DSGSD) are present near the Trans-Alaska Pipeline and Richardson Highway in the east-central Alaska Range, Alaska, USA. We documented spatial and temporal variations in rates of surface movement of the DSGSDs between 2003 and 2011 using RADARSAT-1 and RADARSAT-2 D-InSAR images. Deformation rates exceed 10 cm/month over very large areas (>1 km2) of many rock slopes. Recent climatic change and strong seismic shaking, especially during the 2002 M 7.9 Denali Fault earthquake, appear to have exacerbated slope deformation. We also mapped DSGSD geological and morphological characteristics using field- and GIS-based methods, and constructed a conceptual 2D distinct-element numerical model of one of the DSGSDs. Preliminary results indicate that large-scale buckling or kink-band slumping may be occurring. The DSGSDs are capable of generating long-runout landslides that might impact the Trans-Alaska Pipeline and Richardson Highway. They could also block tributary valleys, thereby impounding lakes that might drain suddenly. Wrapped 24-day RADARSAT-2 descending spotlight interferogram showing deformation north of Fels Glacier. The interferogram is partially transparent and is overlaid on a 2009 WorldView-1 panchromatic image. Acquisition interval: August 2 - August 26, 2011. UTM Zone 6N.

  5. Effect of plastic deformation on Corrosion of cadmium in 0.1 m sodium Sulphate solution

    OpenAIRE

    Kandeil, A. Y. [عبد الرزاق يوسف قنديل; El-Gaber, A. S.; Mourad, M. Y.

    1993-01-01

    The present investigation was carried out to study the influence of prior plastic deformation and surface finish on the corrosion behaviour of pure cadmium in 0.1 M Na2SC>4 solution at 25° C. Cylindrical specimens were deformed by compression to different levels of deformation up to 90% reduction in height (RH). Three surface finishes were examined, namely, 120, 320 and 600 grits. The results obtained indicate that the cathodic corrosion rate decreases with deformation up to 30-60% RH, depend...

  6. Nuclear deformation at finite temperature.

    Science.gov (United States)

    Alhassid, Y; Gilbreth, C N; Bertsch, G F

    2014-12-31

    Deformation, a key concept in our understanding of heavy nuclei, is based on a mean-field description that breaks the rotational invariance of the nuclear many-body Hamiltonian. We present a method to analyze nuclear deformations at finite temperature in a framework that preserves rotational invariance. The auxiliary-field Monte Carlo method is used to generate a statistical ensemble and calculate the probability distribution associated with the quadrupole operator. Applying the technique to nuclei in the rare-earth region, we identify model-independent signatures of deformation and find that deformation effects persist to temperatures higher than the spherical-to-deformed shape phase-transition temperature of mean-field theory.

  7. Nuclear Deformation at Finite Temperature

    Science.gov (United States)

    Alhassid, Y.; Gilbreth, C. N.; Bertsch, G. F.

    2014-12-01

    Deformation, a key concept in our understanding of heavy nuclei, is based on a mean-field description that breaks the rotational invariance of the nuclear many-body Hamiltonian. We present a method to analyze nuclear deformations at finite temperature in a framework that preserves rotational invariance. The auxiliary-field Monte Carlo method is used to generate a statistical ensemble and calculate the probability distribution associated with the quadrupole operator. Applying the technique to nuclei in the rare-earth region, we identify model-independent signatures of deformation and find that deformation effects persist to temperatures higher than the spherical-to-deformed shape phase-transition temperature of mean-field theory.

  8. Deformation of Man Made Objects

    KAUST Repository

    Ibrahim, Mohamed

    2012-07-01

    We introduce a framework for 3D object deformation with primary focus on man-made objects. Our framework enables a user to deform a model while preserving its defining characteristics. Moreover, our framework enables a user to set constraints on a model to keep its most significant features intact after the deformation process. Our framework supports a semi-automatic constraint setting environment, where some constraints could be automatically set by the framework while others are left for the user to specify. Our framework has several advantages over some state of the art deformation techniques in that it enables a user to add new features to the deformed model while keeping its general look similar to the input model. In addition, our framework enables the rotation and extrusion of different parts of a model.

  9. Ground and Structure Deformation 3d Modelling with a Tin Based Property Model

    Science.gov (United States)

    TIAN, T.; Zhang, J.; Jiang, W.

    2013-12-01

    With the development of 3D( three-dimensional) modeling and visualization, more and more 3D tectonics are used to assist the daily work in Engineering Survey, in which the prediction of deformation field in strata and structure induced by underground construction is an essential part. In this research we developed a TIN (Triangulated Irregular Network) based property model for the 3D (three dimensional) visualization of ground deformation filed. By record deformation vector for each nodes, the new model can express the deformation with geometric-deformation-style by drawing each node in its new position and deformation-attribute-distribution-style by drawing each node in the color correspond with its deformation attribute at the same time. Comparing with the volume model based property model, this new property model can provide a more precise geometrical shape for structure objects. Furthermore, by recording only the deformation data of the user-interested 3d surface- such as the ground surface or the underground digging surface, the new property model can save a lot of space, which makes it possible to build the deformation filed model of a much more large scale. To construct the models of deformation filed based on TIN model, the refinement of the network is needed to increase the nodes number, which is necessary to express the deformation filed with a certain resolution. The TIN model refinement is a process of sampling the 3D deformation field values on points on the TIN surface, for which we developed a self-adapting TIN refinement method. By set the parameter of the attribute resolution, this self-adapting method refines the input geometric-expressing TIN model by adding more vertexes and triangles where the 3D deformation filed changing faster. Comparing with the even refinement method, the self-adapting method can generate a refined TIN model with nodes counted less by two thirds. Efficiency Comparison between Self-adapting Refinement Method and Even

  10. Deformation of volcanic materials by pore pressurization: analog experiments with simplified geometry

    Science.gov (United States)

    Hyman, David; Bursik, Marcus

    2018-03-01

    The pressurization of pore fluids plays a significant role in deforming volcanic materials; however, understanding of this process remains incomplete, especially scenarios accompanying phreatic eruptions. Analog experiments presented here use a simple geometry to study the mechanics of this type of deformation. Syrup was injected into the base of a sand medium, simulating the permeable flow of fluids through shallow volcanic systems. The experiments examined surface deformation over many source depths and pressures. Surface deformation was recorded using a Microsoft® Kinect™ sensor, generating high-spatiotemporal resolution lab-scale digital elevation models (DEMs). The behavior of the system is controlled by the ratio of pore pressure to lithostatic loading (λ =p/ρ g D). For λ feedback between deformation and pressurization wherein higher pressure ratios yielded larger deformations. For λ >10, fluid expulsion from the layer was much faster, vertically fracturing to the surface with larger pressure ratios yielding less deformation. The temporal behavior of deformation followed a characteristic evolution that produced an approximately exponential increase in deformation with time until complete layer penetration. This process is distinguished from magmatic sources in continuous geodetic data by its rapidity and characteristic time evolution. The time evolution of the experiments compares well with tilt records from Mt. Ontake, Japan, in the lead-up to the deadly 2014 phreatic eruption. Improved understanding of this process may guide the evolution of magmatic intrusions such as dikes, cone sheets, and cryptodomes and contribute to caldera resurgence or deformation that destabilizes volcanic flanks.

  11. The Role of Deformation and Microchemistry in the Corrosion Processes of Type 304 Stainless Steel in Simulated Pressurized Water Reactor Environments

    Science.gov (United States)

    Fisher, Kevin B.

    Degradation of structural components in nuclear environments is a limiting factor in the lifetime of nuclear power plants. Despite decades of research on the topic, there are still aspects of the degradation phenomena that are not well understood, leading to premature failure of components that can be both expensive to repair and potentially dangerous. The current work addresses the role of material deformation on the corrosion phenomena of 304 SS in a simulated nuclear reactor environment by studying the relationship of the material microstructure and microchemistry with the resulting corrosion products using a multiscale analysis approach. The general corrosion phenomenon was studied in relation to the surface deformation of the material, and it was determined that surface deformation not only increases the rate of oxidation, but also has a pronounced impact on the microchemical structure of the oxide film when compared to undeformed material. These findings were applied to understanding the role of deformation in the more complex corrosion phenomena of stress corrosion cracking (SCC) and corrosion fatigue cracking (CFC). In SCC experiments, material deformation in the form of cold work played a synergistic role with unique microchemical features of the materials studied to promote the cracking process under certain environmental and material heat treatment conditions. Despite the fact that the materials studied were low carbon heats of 304L SS thought to be immune to the sensitization and therefore resistant to SCC, elevated boron and delta ferrites in the material were implicated in the SCC susceptibility after heat treatment. On the other hand, low levels of residual deformation played only a minor role in the corrosion processes occurring during CFC experiments over a wide range of rise times. Instead, deformation was suspected to play a larger role in the mechanical cracking response of the material. By studying multiple corrosion processes of 304 SS a

  12. InSAR Observations and Finite Element Modeling of Crustal Deformation Around a Surging Glacier, Iceland

    Science.gov (United States)

    Spaans, K.; Auriac, A.; Sigmundsson, F.; Hooper, A. J.; Bjornsson, H.; Pálsson, F.; Pinel, V.; Feigl, K. L.

    2014-12-01

    Icelandic ice caps, covering ~11% of the country, are known to be surging glaciers. Such process implies an important local crustal subsidence due to the large ice mass being transported to the ice edge during the surge in a few months only. In 1993-1995, a glacial surge occurred at four neighboring outlet glaciers in the southwestern part of Vatnajökull ice cap, the largest ice cap in Iceland. We estimated that ~16±1 km3 of ice have been moved during this event while the fronts of some of the outlet glaciers advanced by ~1 km.Surface deformation associated with this surge has been surveyed using Interferometric Synthetic Aperture Radar (InSAR) acquisitions from 1992-2002, providing high resolution ground observations of the study area. The data show about 75 mm subsidence at the ice edge of the outlet glaciers following the transport of the large volume of ice during the surge (Fig. 1). The long time span covered by the InSAR images enabled us to remove ~12 mm/yr of uplift occurring in this area due to glacial isostatic adjustment from the retreat of Vatnajökull ice cap since the end of the Little Ice Age in Iceland. We then used finite element modeling to investigate the elastic Earth response to the surge, as well as confirm that no significant viscoelastic deformation occurred as a consequence of the surge. A statistical approach based on Bayes' rule was used to compare the models to the observations and obtain an estimate of the Young's modulus (E) and Poisson's ratio (v) in Iceland. The best-fitting models are those using a one-kilometer thick top layer with v=0.17 and E between 12.9-15.3 GPa underlain by a layer with v=0.25 and E from 67.3 to 81.9 GPa. Results demonstrate that InSAR data and finite element models can be used successfully to reproduce crustal deformation induced by ice mass variations at Icelandic ice caps.Fig. 1: Interferograms spanning 1993 July 31 to 1995 June 19, showing the surge at Tungnaárjökull (Tu.), Skaftárjökull (Sk.) and S

  13. DEFORMATION MONITORING OF MOTORWAY UNDERPASSES USING LASER SCANNING DATA

    Directory of Open Access Journals (Sweden)

    I. Puente

    2012-07-01

    deformation monitoring is a Optech Lynx mobile LiDAR. This laser scanner is based on time of flight technology and presents an accuracy of 6 mm in the determination of the geometrical coordinates. This accuracy can be improved to around 1 mm using fitting post-processing techniques and makes this technology very useful for studies related with deformation monitoring. The laser scanner, in comparison with other geodetic techniques as total stations, allows the control of all the structure, including unexpected deformations. Reflective targets are permanently positioned over the small walls of the structure to allow the 3D orientation of the different scans. Two main scans are made for this study, before and after the backfilling process. Backfilling takes about 10 days for the construction companies. The scans need a time of approximately 12 minutes. Construction works do not need to be interrupted during the scans. Point clouds are then post-processed using QT Modeler Software. First, the point cloud is cleaned to use only the data directly related with the structure under study. Then, using the target coordinates, both point clouds are moved to the same coordinate system. Finally, the deformation of the underpass is studied using two algorithms specifically developed using Matlab software. First algorithm fits a geometrical surface to the point cloud of the first scan and evaluates the residuals of both scans for this fitting surface. Differences in the residuals give the deformation map of the structure. Second algorithm takes a portion of the point cloud from the top of the structure, where it is located the joining point between the voussoirs. The joining between two voussoirs shows a height step that in an ideal case must tend to zero. Deformations produced by the loading of the structure are measured as a comparison between the steps before and after the backfilling process. The analysis of the results show as some deformation occurs in the structure in the joining

  14. Deformations of soap bubbles in a uniform electric field

    Science.gov (United States)

    Mawet, Sebastien; Caps, Herve; Dorbolo, Stephane

    The study of the deformations undergone by a soap bubble submitted to an electrical force began with Taylor and Wilson and the observation of so-called Taylor's cones. Beyond this particular structure, few studies analyzed the bubble deformations. For example, what is the link between the deformations and the electrical force or how do charges move in the thin soap film formed by the bubble ? To answer those questions, we characterize the shape variations of the surface of the bubble immersed in the uniform electric field of a plan capacitor. In particular, our study focuses on hemispherical bubbles lying on the bottom electrode of a plane capacitor. This study allows us to observe some interesting phenomena like the appearance of a hysteresis cycle in the deformation amplitude.

  15. Knowledge representation of rock plastic deformation

    Science.gov (United States)

    Davarpanah, Armita; Babaie, Hassan

    2017-04-01

    The first iteration of the Rock Plastic Deformation (RPD) ontology models the semantics of the dynamic physical and chemical processes and mechanisms that occur during the deformation of the generally inhomogeneous polycrystalline rocks. The ontology represents the knowledge about the production, reconfiguration, displacement, and consumption of the structural components that participate in these processes. It also formalizes the properties that are known by the structural geology and metamorphic petrology communities to hold between the instances of the spatial components and the dynamic processes, the state and system variables, the empirical flow laws that relate the variables, and the laboratory testing conditions and procedures. The modeling of some of the complex physio-chemical, mathematical, and informational concepts and relations of the RPD ontology is based on the class and property structure of some well-established top-level ontologies. The flexible and extensible design of the initial version of the RPD ontology allows it to develop into a model that more fully represents the knowledge of plastic deformation of rocks under different spatial and temporal scales in the laboratory and in solid Earth. The ontology will be used to annotate the datasets related to the microstructures and physical-chemical processes that involve them. This will help the autonomous and globally distributed communities of experimental structural geologists and metamorphic petrologists to coherently and uniformly distribute, discover, access, share, and use their data through automated reasoning and enhanced data integration and software interoperability.

  16. Supersymmetric q-deformed quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Traikia, M. H.; Mebarki, N. [Laboratoire de Physique Mathematique et Subatomique, Mentouri University, Constantine (Algeria)

    2012-06-27

    A supersymmetric q-deformed quantum mechanics is studied in the weak deformation approximation of the Weyl-Heisenberg algebra. The corresponding supersymmetric q-deformed hamiltonians and charges are constructed explicitly.

  17. Evidence for cross rift structural controls on deformation and seismicity at a continental rift caldera

    Science.gov (United States)

    Lloyd, Ryan; Biggs, Juliet; Wilks, Matthew; Nowacki, Andy; Kendall, J.-Michael; Ayele, Atalay; Lewi, Elias; Eysteinsson, Hjálmar

    2018-04-01

    In continental rifts structural heterogeneities, such as pre-existing faults and foliations, are thought to influence shallow crustal processes, particularly the formation of rift faults, magma reservoirs and surface volcanism. We focus on the Corbetti caldera, in the southern central Main Ethiopian Rift. We measure the surface deformation between 22nd June 2007 and 25th March 2009 using ALOS and ENVISAT SAR interferograms and observe a semi-circular pattern of deformation bounded by a sharp linear feature cross-cutting the caldera, coincident with the caldera long axis. The signal reverses in sign but is not seasonal: from June to December 2007 the region south of this structure moves upwards 3 cm relative to the north, while from December 2007 until November 2008 it subsides by 2 cm. Comparison of data taken from two different satellite look directions show that the displacement is primarily vertical. We discuss potential mechanisms and conclude that this deformation is associated with pressure changes within a shallow (Analysis of the distribution of post-caldera vents and cones inside the caldera shows their locations are statistically consistent with this fault structure, indicating that the fault has also controlled the migration of magma from a reservoir to the surface over tens of thousands of years. Spatial patterns of seismicity are consistent with a cross-rift structure that extents outside the caldera and to a depth of ∼30 km, and patterns of seismic anisotropy suggests stress partitioning occurs across the structure. We discuss the possible nature of this structure, and conclude that it is most likely associated with the Goba-Bonga lineament, which cross-cuts and pre-dates the current rift. Our observations show that pre-rift structures play an important role in magma transport and shallow hydrothermal processes, and therefore they should not be neglected when discussing these processes.

  18. Simulations of surface stress effects in nanoscale single crystals

    Science.gov (United States)

    Zadin, V.; Veske, M.; Vigonski, S.; Jansson, V.; Muszinsky, J.; Parviainen, S.; Aabloo, A.; Djurabekova, F.

    2018-04-01

    Onset of vacuum arcing near a metal surface is often associated with nanoscale asperities, which may dynamically appear due to different processes ongoing in the surface and subsurface layers in the presence of high electric fields. Thermally activated processes, as well as plastic deformation caused by tensile stress due to an applied electric field, are usually not accessible by atomistic simulations because of the long time needed for these processes to occur. On the other hand, finite element methods, able to describe the process of plastic deformations in materials at realistic stresses, do not include surface properties. The latter are particularly important for the problems where the surface plays crucial role in the studied process, as for instance, in the case of plastic deformations at a nanovoid. In the current study by means of molecular dynamics (MD) and finite element simulations we analyse the stress distribution in single crystal copper containing a nanovoid buried deep under the surface. We have developed a methodology to incorporate the surface effects into the solid mechanics framework by utilizing elastic properties of crystals, pre-calculated using MD simulations. The method leads to computationally efficient stress calculations and can be easily implemented in commercially available finite element software, making it an attractive analysis tool.

  19. Spacetimes for λ-deformations

    Energy Technology Data Exchange (ETDEWEB)

    Sfetsos, Konstadinos [Department of Nuclear and Particle Physics, Faculty of Physics, University of Athens,Athens 15784 (Greece); Thompson, Daniel C. [Theoretische Natuurkunde, Vrije Universiteit Brussel andThe International Solvay Institutes,Pleinlaan 2, B-1050, Brussels (Belgium)

    2014-12-29

    We examine a recently proposed class of integrable deformations to two-dimensional conformal field theories. These λ-deformations interpolate between a WZW model and the non-Abelian T-dual of a Principal Chiral Model on a group G or, between a G/H gauged WZW model and the non-Abelian T-dual of the geometric coset G/H. λ-deformations have been conjectured to represent quantum group q-deformations for the case where the deformation parameter is a root of unity. In this work we show how such deformations can be given an embedding as full string backgrounds whose target spaces satisfy the equations of type-II supergravity. One illustrative example is a deformation of the Sl(2,ℝ)/U(1) black-hole CFT. A further example interpolates between the ((SU(2)×SU(2))/(SU(2)))×((SL(2,ℝ)×SL(2,ℝ))/(SL(2,ℝ)))×U(1){sup 4} gauged WZW model and the non-Abelian T-dual of AdS{sub 3}×S{sup 3}×T{sup 4} supported with Ramond flux.

  20. Deformable bag model of hadrons, 1

    Energy Technology Data Exchange (ETDEWEB)

    Ui, Haruo; Saito, Koich

    1983-05-01

    As a generalization of the MIT spherical bag model, we construct the spheroidal bag model of hadron with an arbitrary eccentricity. This generalization is made by slightly modifying the MIT linear boundary condition: The linear boundary condition is examined in detail. Our model always satisfies two necessary requirements of the MIT bag model - i.e., n.j = 0, no quark colour flux leaves the bag, and q-barq = 0, the scalar density of quark should vanish on the bag surface- and it reduces to the MIT spherical bag model in the limit of zero-eccentricity. Lagrangian formalism of our model is briefly described. The eigenfrequencies of a single massless quark confined in this spheroidal bag are numerically calculated. We obtain the level-splitting of the excited quark orbits, which is just analogous to the well-known Nilsson's splitting of single particle orbits in deformed nuclei. By using the numerical results of the lowest orbit, the effect of the bag-deformation on the mass of low-lying hadrons is estimated. It is found that, although the spherical bag is stable, the quark bag is extremely soft against the quadrupole deformation. Brief discussions are added on the mechanisms which make the spherical bag more stable.

  1. Deformable segmentation via sparse shape representation.

    Science.gov (United States)

    Zhang, Shaoting; Zhan, Yiqiang; Dewan, Maneesh; Huang, Junzhou; Metaxas, Dimitris N; Zhou, Xiang Sean

    2011-01-01

    Appearance and shape are two key elements exploited in medical image segmentation. However, in some medical image analysis tasks, appearance cues are weak/misleading due to disease/artifacts and often lead to erroneous segmentation. In this paper, a novel deformable model is proposed for robust segmentation in the presence of weak/misleading appearance cues. Owing to the less trustable appearance information, this method focuses on the effective shape modeling with two contributions. First, a shape composition method is designed to incorporate shape prior on-the-fly. Based on two sparsity observations, this method is robust to false appearance information and adaptive to statistically insignificant shape modes. Second, shape priors are modeled and used in a hierarchical fashion. More specifically, by using affinity propagation method, our deformable surface is divided into multiple partitions, on which local shape models are built independently. This scheme facilitates a more compact shape prior modeling and hence a more robust and efficient segmentation. Our deformable model is applied on two very diverse segmentation problems, liver segmentation in PET-CT images and rodent brain segmentation in MR images. Compared to state-of-art methods, our method achieves better performance in both studies.

  2. A deformable bag model of hadrons, 1

    International Nuclear Information System (INIS)

    Ui, Haruo; Saito, Koich

    1983-01-01

    As a generalization of the MIT spherical bag model, we construct the spheroidal bag model of hadron with an arbitrary eccentricity. This generalization is made by slightly modifying the MIT linear boundary condition: The linear boundary condition is examined in detail. Our model always satisfies two necessary requirements of the MIT bag model - i.e., n.j = 0, no quark colour flux leaves the bag, and q-barq = 0, the scalar density of quark should vanish on the bag surface- and it reduces to the MIT spherical bag model in the limit of zero-eccentricity. Lagrangian formalism of our model is briefly described. The eigenfrequencies of a single massless quark confined in this spheroidal bag are numerically calculated. We obtain the level-splitting of the excited quark orbits, which is just analogous to the well-known Nilsson's splitting of single particle orbits in deformed nuclei. By using the numerical results of the lowest orbit, the effect of the bag-deformation on the mass of low-lying hadrons is estimated. It is found that, although the spherical bag is stable, the quark bag is extremely soft against the quadrupole deformation. Brief discussions are added on the mechanisms which make the spherical bag more stable. (author)

  3. Heterogeneous structure and surface tension effects on mechanical response in pulmonary acinus: A finite element analysis.

    Science.gov (United States)

    Koshiyama, Kenichiro; Nishimoto, Keisuke; Ii, Satoshi; Sera, Toshihiro; Wada, Shigeo

    2018-01-20

    The pulmonary acinus is a dead-end microstructure that consists of ducts and alveoli. High-resolution micro-CT imaging has recently provided detailed anatomical information of a complete in vivo acinus, but relating its mechanical response with its detailed acinar structure remains challenging. This study aimed to investigate the mechanical response of acinar tissue in a whole acinus for static inflation using computational approaches. We performed finite element analysis of a whole acinus for static inflation. The acinar structure model was generated based on micro-CT images of an intact acinus. A continuum mechanics model of the lung parenchyma was used for acinar tissue material model, and surface tension effects were explicitly included. An anisotropic mechanical field analysis based on a stretch tensor was combined with a curvature-based local structure analysis. The airspace of the acinus exhibited nonspherical deformation as a result of the anisotropic deformation of acinar tissue. A strain hotspot occurred at the ridge-shaped region caused by a rod-like deformation of acinar tissue on the ridge. The local structure becomes bowl-shaped for inflation and, without surface tension effects, the surface of the bowl-shaped region primarily experiences isotropic deformation. Surface tension effects suppressed the increase in airspace volume and inner surface area, while facilitating anisotropic deformation on the alveolar surface. In the lungs, the heterogeneous acinar structure and surface tension induce anisotropic deformation at the acinar and alveolar scales. Further research is needed on structural variation of acini, inter-acini connectivity, or dynamic behavior to understand multiscale lung mechanics. Copyright © 2018 Elsevier Ltd. All rights reserved.

  4. Deforming tachyon kinks and tachyon potentials

    International Nuclear Information System (INIS)

    Afonso, Victor I.; Bazeia, Dionisio; Brito, Francisco A.

    2006-01-01

    In this paper we investigate deformation of tachyon potentials and tachyon kink solutions. We consider the deformation of a DBI type action with gauge and tachyon fields living on D1-brane and D3-brane world-volume. We deform tachyon potentials to get other consistent tachyon potentials by using properly a deformation function depending on the gauge field components. Resolutions of singular tachyon kinks via deformation and applications of deformed tachyon potentials to scalar cosmology scenario are discussed

  5. Persistent and late occurring lesions in irradiated feet of rats: their clinical relevance

    International Nuclear Information System (INIS)

    Hopewell, J.W.

    1982-01-01

    Radiation-induced deformity, as characterized by tissue loss, has been investigated in rat feet. The acute epithelial response and the loss of deeper tissues occur concomitantly after irradiation. The greatest loss of tissue (severe deformity) was produced in feet where the healing of the epithelial reaction was greatly delayed. While deformity will clearly continue to ''persist'' after the acute reaction has healed it is misleading to refer to this lesion as ''late'' damage. A late-occurring lesion, not previously described in the literature, can be produced in the rat foot by high doses of radiation delivered in such a way that moist desquamation is avoided, i.e. by extending the total treatment time. Parallels are drawn between reactions in rodents and those in the skin of pig and man. (author)

  6. On the absence of InSAR-detected volcano deformation spanning the 1995 1996 and 1999 eruptions of Shishaldin Volcano, Alaska

    Science.gov (United States)

    Moran, S. C.; Kwoun, O.; Masterlark, T.; Lu, Z.

    2006-02-01

    Shishaldin Volcano, a large, frequently active basaltic-andesite volcano located on Unimak Island in the Aleutian Arc of Alaska, had a minor eruption in 1995-1996 and a VEI 3 sub-Plinian basaltic eruption in 1999. We used 21 synthetic aperture radar images acquired by ERS-1, ERS-2, JERS-1, and RADARSAT-1 satellites to construct 12 coherent interferograms that span most of the 1993-2003 time interval. All interferograms lack coherence within ˜5 km of the summit, primarily due to persistent snow and ice cover on the edifice. Remarkably, in the 5-15 km distance range where interferograms are coherent, the InSAR images show no intrusion- or withdrawal-related deformation at Shishaldin during this entire time period. However, several InSAR images do show deformation associated with a shallow M L 5.2 earthquake located ˜14 km west of Shishaldin that occurred 6 weeks before the 1999 eruption. We use a theoretical model to predict deformation magnitudes due to a volumetric expansion source having a volume equivalent to the 1999 erupted volume, and find that deformation magnitudes for sources shallower than 10 km are within the expected detection capabilities for interferograms generated from C-band ERS 1/2 and RADARSAT-1 synthetic aperture radar images. We also find that InSAR images cannot resolve relatively shallow deformation sources (1-2 km below sea level) due to spatial gaps in the InSAR images caused by lost coherence. The lack of any deformation, particularly for the 1999 eruption, leads us to speculate that magma feeding eruptions at the summit moves rapidly (at least 80m/day) from > 10 km depth, and that the intrusion-eruption cycle at Shishaldin does not produce significant permanent deformation at the surface.

  7. On the absence of InSAR-detected volcano deformation spanning the 1995-1996 and 1999 eruptions of Shishaldin Volcano, Alaska

    Science.gov (United States)

    Moran, S.C.; Kwoun, O.; Masterlark, Timothy; Lu, Z.

    2006-01-01

    Shishaldin Volcano, a large, frequently active basaltic-andesite volcano located on Unimak Island in the Aleutian Arc of Alaska, had a minor eruption in 1995–1996 and a VEI 3 sub-Plinian basaltic eruption in 1999. We used 21 synthetic aperture radar images acquired by ERS-1, ERS-2, JERS-1, and RADARSAT-1 satellites to construct 12 coherent interferograms that span most of the 1993–2003 time interval. All interferograms lack coherence within ∼5 km of the summit, primarily due to persistent snow and ice cover on the edifice. Remarkably, in the 5–15 km distance range where interferograms are coherent, the InSAR images show no intrusion- or withdrawal-related deformation at Shishaldin during this entire time period. However, several InSAR images do show deformation associated with a shallow ML 5.2 earthquake located ∼14 km west of Shishaldin that occurred 6 weeks before the 1999 eruption. We use a theoretical model to predict deformation magnitudes due to a volumetric expansion source having a volume equivalent to the 1999 erupted volume, and find that deformation magnitudes for sources shallower than 10 km are within the expected detection capabilities for interferograms generated from C-band ERS 1/2 and RADARSAT-1 synthetic aperture radar images. We also find that InSAR images cannot resolve relatively shallow deformation sources (1–2 km below sea level) due to spatial gaps in the InSAR images caused by lost coherence. The lack of any deformation, particularly for the 1999 eruption, leads us to speculate that magma feeding eruptions at the summit moves rapidly (at least 80m/day) from > 10 km depth, and that the intrusion–eruption cycle at Shishaldin does not produce significant permanent deformation at the surface.

  8. Frictional Compliant Haptic Contact and Deformation of Soft Objects

    Directory of Open Access Journals (Sweden)

    Naci Zafer

    2016-05-01

    Full Text Available This paper is concerned with compliant haptic contact and deformation of soft objects. A human soft fingertip model is considered to act as the haptic interface and is brought into contact with and deforms a discrete surface. A nonlinear constitutive law is developed in predicting normal forces and, for the haptic display of surface texture, motions along the surface are also resisted at various rates by accounting for dynamic Lund-Grenoble (LuGre frictional forces. For the soft fingertip to apply forces over an area larger than a point, normal and frictional forces are distributed around the soft fingertip contact location on the deforming surface. The distribution is realized based on a kernel smoothing function and by a nonlinear spring-damper net around the contact point. Experiments conducted demonstrate the accuracy and effectiveness of our approach in real-time haptic rendering of a kidney surface. The resistive (interaction forces are applied at the user fingertip bone edge. A 3-DoF parallel robotic manipulator equipped with a constraint based controller is used for the implementation. By rendering forces both in lateral and normal directions, the designed haptic interface system allows the user to realistically feel both the geometrical and mechanical (nonlinear properties of the deforming kidney.

  9. Ligand-mediated adhesive mechanics of two static, deformed spheres.

    Science.gov (United States)

    Sircar, Sarthok; Nguyen, Giang; Kotousov, Andrei; Roberts, Anthony J

    2016-10-01

    A self-consistent model is developed to investigate attachment/detachment kinetics of two static, deformable microspheres with irregular surface and coated with flexible binding ligands. The model highlights how the microscale binding kinetics of these ligands as well as the attractive/repulsive potential of the charged surface affects the macroscale static deformed configuration of the spheres. It is shown that in the limit of smooth, neutrally charged surface (i.e., the dimensionless inverse Debye length, [Formula: see text]), interacting via elastic binders (i.e., the dimensionless stiffness coefficient, [Formula: see text]) the adhesion mechanics approaches the regime of application of the JKR theory, and in this particular limit, the contact radius, R c , scales with the particle radius, R, according to the scaling law, [Formula: see text]. We show that static, deformed, highly charged, ligand-coated surface of micro-spheres exhibit strong adhesion. Normal stress distribution within the contact area adjusts with the binder stiffness coefficient, from a maximum at the center to a maximum at the periphery of the region. Although reported in some in vitro experiments involving particle adhesion, until now a physical interpretation for this variation of the stress distribution for deformable, charged, ligand-coated microspheres is missing. Surface roughness results in a diminished adhesion with a distinct reduction in the pull-off force, larger separation gap, weaker normal stress and limited area of adhesion. These results are in agreement with the published experimental findings.

  10. An experimental study on the deformation and fracture modes of steel projectiles during impact

    International Nuclear Information System (INIS)

    Rakvåg, K.G.; Børvik, T.; Westermann, I.; Hopperstad, O.S.

    2013-01-01

    Highlights: • The fracture process is ductile for the unhardened projectiles. • A combined ductile–brittle fracture process is obtained for the HRC 40 projectiles. • The fragmentation of HRC 52 projectiles has cleavage as the main mechanism. • The fracture modes were confirmed in a metallurgical study. • The hardened materials have a stochastic variation of the mechanical properties. - Abstract: Previous investigations of the penetration and perforation of high-strength steel plates struck by hardened steel projectiles have shown that under certain test conditions the projectile may fracture or even fragment upon impact. Simulations without an accurate failure description for the projectile material will then predict perforation of the target instead of fragmentation of the projectile, and thus underestimate the ballistic limit velocity of the target plate. This paper presents an experimental investigation of the various deformation and fracture modes that may occur in steel projectiles during impact. This is studied by conducting Taylor bar impact tests using 20 mm diameter, 80 mm long, tool steel projectiles with three different hardness values (HRC 19, 40 and 52). A gas gun was used to fire the projectiles into a rigid wall at impact velocities ranging from 100 to 350 m/s, and the deformation and fracture processes were captured by a high-speed video camera. From the tests, several different deformation and fracture modes were registered for each hardness value. To investigate the influence of material on the deformation and fracture modes, several series of tensile tests on smooth axisymmetric specimens were carried out to characterise the mechanical properties of the three materials. To gain a deeper understanding of the various processes causing fracture and fragmentation during impact, a metallurgical investigation was conducted. The fracture surfaces of the failed projectiles of different hardness were investigated, and the microstructure was

  11. Effect of elastic deformation and the magnetic field on the electrical conductivity of p-Si crystals

    Science.gov (United States)

    Lys, R.; Pavlyk, B.; Didyk, R.; Shykorjak, J.; Karbovnyk, I.

    2018-03-01

    It is shown that at a deformation rate of 0.41 kg/min, the characteristic feature of the dependence of the surface resistance of the p-Si sample on the magnitude of its elastic deformation (R(σ)) is the reduction of the resistance during compression and unclamping. With the increase in the number of "compression-unclamping" cycles, the difference between the positions of the compression and unclamping curves decreases. The transformation of two types of magnetically sensitive defects occurs under the impact of a magnetic field on p-Si crystals. The defects are interrelated with two factors that cause the mutually opposite influence on the conductivity of the crystal. The first factor is that the action of the magnetic field decreases the activation energy of the dislocation holders, which leads to an increase in the electrical conductivity of the sample. The second factor is that due to the decay of molecules of oxygen-containing impurities in the magnetic field, the stable chemisorption bonds appear in the crystal that leads to a decrease in its conductivity. If the sample stays in the magnetic field for a long time, the one or the other mechanism predominates, causing a slow growth or decrease in resistance around a certain (averaged) value. Moreover, the frequency of such changes is greater in the deformed sample. The value of the surface resistance of p-Si samples does not change for a long time without the influence of the magnetic field.

  12. Lava delta deformation as a proxy for submarine slope instability

    Science.gov (United States)

    Di Traglia, Federico; Nolesini, Teresa; Solari, Lorenzo; Ciampalini, Andrea; Frodella, William; Steri, Damiano; Allotta, Benedetto; Rindi, Andrea; Marini, Lorenzo; Monni, Niccolò; Galardi, Emanuele; Casagli, Nicola

    2018-04-01

    The instability of lava deltas is a recurrent phenomenon affecting volcanic islands, which can potentially cause secondary events such as littoral explosions (due to interactions between hot lava and seawater) and tsunamis. It has been shown that Interferometric Synthetic Aperture Radar (InSAR) is a powerful technique to forecast the collapse of newly emplaced lava deltas. This work goes further, demonstrating that the monitoring of lava deltas is a successful strategy by which to observe the long-term deformation of subaerial-submarine landslide systems on unstable volcanic flanks. In this paper, displacement measurements derived from Synthetic Aperture Radar (SAR) imagery were used to detect lava delta instability at Stromboli volcano (Italy). Recent flank eruptions (2002-2003, 2007 and 2014) affected the Sciara del Fuoco (SdF) depression, created a "stacked" lava delta, which overlies a pre-existing scar produced by a submarine-subaerial tsunamigenic landslide that occurred on 30 December 2002. Space-borne X-band COSMO-SkyMED (CSK) and C-band SENTINEL-1A (SNT) SAR data collected between February 2010 and October 2016 were processed using the SqueeSAR algorithm. The obtained ground displacement maps revealed the differential ground motion of the lava delta in both CSK and SNT datasets, identifying a stable area (characterized by less than 2 mm/y in both datasets) within the northern sector of the SdF and an unstable area (characterized by velocity fields on the order of 30 mm/y and 160 mm/y in the CSK and SNT datasets, respectively) in the central sector of the SdF. The slope stability of the offshore part of the SdF, as reconstructed based on a recently performed multibeam bathymetric survey, was evaluated using a 3D Limit Equilibrium Method (LEM). In all the simulations, Factor of Safety (F) values between 0.9 and 1.1 always characterized the submarine slope between the coastline and -250 m a.s.l. The critical surfaces for all the search volumes corresponded to

  13. Non-linear elastic deformations

    CERN Document Server

    Ogden, R W

    1997-01-01

    Classic in the field covers application of theory of finite elasticity to solution of boundary-value problems, analysis of mechanical properties of solid materials capable of large elastic deformations. Problems. References.

  14. Axisymmetric finite deformation membrane problems

    Energy Technology Data Exchange (ETDEWEB)

    Feng, W.W.

    1980-12-12

    Many biomechanic problems involve the analysis of finite deformation axisymmetric membranes. This paper presents the general formulation for solving a class of axisymmetric membrane problems. The material nonlinearity, as well as the geometric nonlinearity, is considered. Two methods are presented to solve these problems. The first method is solving a set of differential equilibrium equations. The governing equations are reduced to three first-order ordinary-differential equations with explicit derivatives. The second method is the Ritz method where a general potential energy functional valid for all axisymmetric deformed positions is presented. The geometric admissible functions that govern the deformed configuration are written in terms of a series with unknown coefficients. These unknown coefficients are determined by the minimum potential energy principle that of all geometric admissible deformed configurations, the equilibrium configuration minimizes the potential energy. Some examples are presented. A comparison between these two methods is mentioned.

  15. Deterritorializing Drawing - transformation/deformation

    DEFF Research Database (Denmark)

    Brabrand, Helle

    2012-01-01

    and deformation as two very different categories. Moves of transformation produce new places or singularities in a series, making a Figure emerge that switches between force and form and between transformation and deformation. Deformation is acted out by sensation, passing from one ‘order’ to another. Bacon...... deformation, about painting the sensation, which is essentially rhythm, making Figure-rhythm relations appear as vibrations that flow through the body - making resonance. Deleuze, with Bergson, argues that art extracts ’a little time in a pure state’ from the everyday repetitions, and thereby opens...... the capacity of the body to be affected by change. The everyday and the ceremonial body, the ordinary and the aberrant movement – these poles generate a passage rather than a difference from the one to the other: from attitude or position to gesture or kinaesthetic twist. Known from without through perception...

  16. Shape Deformations in Atomic Nuclei

    OpenAIRE

    Hamamoto, Ikuko; Mottelson, Ben R.

    2011-01-01

    The ground states of some nuclei are described by densities and mean fields that are spherical, while others are deformed. The existence of non-spherical shape in nuclei represents a spontaneous symmetry breaking.

  17. Nonlinear Deformable-body Dynamics

    CERN Document Server

    Luo, Albert C J

    2010-01-01

    "Nonlinear Deformable-body Dynamics" mainly consists in a mathematical treatise of approximate theories for thin deformable bodies, including cables, beams, rods, webs, membranes, plates, and shells. The intent of the book is to stimulate more research in the area of nonlinear deformable-body dynamics not only because of the unsolved theoretical puzzles it presents but also because of its wide spectrum of applications. For instance, the theories for soft webs and rod-reinforced soft structures can be applied to biomechanics for DNA and living tissues, and the nonlinear theory of deformable bodies, based on the Kirchhoff assumptions, is a special case discussed. This book can serve as a reference work for researchers and a textbook for senior and postgraduate students in physics, mathematics, engineering and biophysics. Dr. Albert C.J. Luo is a Professor of Mechanical Engineering at Southern Illinois University, Edwardsville, IL, USA. Professor Luo is an internationally recognized scientist in the field of non...

  18. M theory on deformed superspace

    Science.gov (United States)

    Faizal, Mir

    2011-11-01

    In this paper we will analyze a noncommutative deformation of the Aharony-Bergman-Jafferis-Maldacena (ABJM) theory in N=1 superspace formalism. We will then analyze the Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetries for this deformed ABJM theory, and its linear as well as nonlinear gauges. We will show that the sum of the gauge fixing term and the ghost term for this deformed ABJM theory can be expressed as a combination of the total BRST and the total anti-BRST variation, in Landau and nonlinear gauges. We will show that in Landau and Curci-Ferrari gauges deformed ABJM theory is invariant under an additional set of symmetry transformations. We will also discuss the effect that the addition of a bare mass term has on this theory.

  19. Discrete kinematic modeling of the 3-D deformation of sedimentary basins; Modelisation cinematique discrete de la deformation 3D des bassins sedimentaires

    Energy Technology Data Exchange (ETDEWEB)

    Cornu, T.

    2001-01-01

    The present work deals with three-dimensional deformation of sedimentary basins. The main goal of the work was to propose new ways to study tectonic deformation and to insert it into basin-modeling environment for hydrocarbon migration applications. To handle the complexity of the deformation, the model uses kinematic laws, a discrete approach, and the construction of a code that allows the greatest diversity in the deformation mechanisms we can take into account. The 3-D-volume deformation is obtained through the calculation of the behavior of the neutral surface of each basin layer. The main idea is to deform the neutral surface of each layer with the help of geometrical laws and to use the result to rebuild the volume deformation of the basin. The constitutive algorithm includes three characteristic features. The first one deals with the mathematical operator we use to describe the flexural-slip mechanism which is a combination of the translation of the neutral surface nodes and the rotation of the vertical edges attached to these nodes. This performs the reversibility that was required for the basin modeling. The second one is about. the use of a discrete approach, which gives a better description of the global deformation and offers to locally control volume evolutions. The knowledge of volume variations can become a powerful tool in structural geology analysis and the perfect complement for a field study. The last one concerns the modularity of the developed code. Indeed, the proposed model uses three main mechanisms of deformation. But the architecture of the code allows the insertion of new mechanisms or a better interaction between them. The model has been validated first with 2-D cases, then with 3-D natural cases. They give good results from a qualitative point of view. They also show the capacity of the model to provide a deformation path that is geologically acceptable, and its ability to control the volume variations of the basin through the

  20. Flexure of thick orthotropic plates by exponential shear deformation theory

    Directory of Open Access Journals (Sweden)

    A. S. Sayyad

    Full Text Available In the present paper, a variationally consistent exponential shear deformation theory taking into account transverse shear deformation effect is presented for the flexural analysis of thick orthotropic plates. The inplane displacement field uses exponential function in terms of thickness coordinate to include the shear deformation effect. The transverse shear stress can be obtained directly from the constitutive relations satisfying the shear stress free surface conditions on the top and bottom surfaces of the plate, hence the theory does not require shear correction factor. Governing equations and boundary conditions of the theory are obtained using the principle of virtual work. Results obtained for static flexure of simply supported orthotropic plates are compared with those of other refined theories and elasticity solution wherever applicable. The results obtained by present theory are in excellent agreement with those of exact results and other higher order theories. Thus the efficacy of the present refined theory is established.

  1. Interaction and deformation of viscoelastic particles: Nonadhesive particles

    International Nuclear Information System (INIS)

    Attard, Phil

    2001-01-01

    A viscoelastic theory is formulated for the deformation of particles that interact with finite-ranged surface forces. The theory generalizes the static approach based upon classic continuum elasticity theory to account for time-dependent effects, and goes beyond contact theories such as Hertz and that given by Johnson, Kendall, and Roberts by including realistic surface interactions. Common devices used to measure load and deformation are modeled and the theory takes into account the driving velocity of the apparatus and the relaxation time of the material. Nonadhesive particles are modeled by an electric double layer repulsion. Triangular, step, and sinusoidal trajectories are analyzed in a unified treatment of loading and unloading. The load-deformation and the load-contact area curves are shown to be velocity dependent and hysteretic

  2. Deformation Monitoring of Motorway Underpasses Using Laser Scanning Data

    Science.gov (United States)

    Puente, I.; González-Jorge, H.; Riveiro, B.; Arias, P.

    2012-07-01

    is a Optech Lynx mobile LiDAR. This laser scanner is based on time of flight technology and presents an accuracy of 6 mm in the determination of the geometrical coordinates. This accuracy can be improved to around 1 mm using fitting post-processing techniques and makes this technology very useful for studies related with deformation monitoring. The laser scanner, in comparison with other geodetic techniques as total stations, allows the control of all the structure, including unexpected deformations. Reflective targets are permanently positioned over the small walls of the structure to allow the 3D orientation of the different scans. Two main scans are made for this study, before and after the backfilling process. Backfilling takes about 10 days for the construction companies. The scans need a time of approximately 12 minutes. Construction works do not need to be interrupted during the scans. Point clouds are then post-processed using QT Modeler Software. First, the point cloud is cleaned to use only the data directly related with the structure under study. Then, using the target coordinates, both point clouds are moved to the same coordinate system. Finally, the deformation of the underpass is studied using two algorithms specifically developed using Matlab software. First algorithm fits a geometrical surface to the point cloud of the first scan and evaluates the residuals of both scans for this fitting surface. Differences in the residuals give the deformation map of the structure. Second algorithm takes a portion of the point cloud from the top of the structure, where it is located the joining point between the voussoirs. The joining between two voussoirs shows a height step that in an ideal case must tend to zero. Deformations produced by the loading of the structure are measured as a comparison between the steps before and after the backfilling process. The analysis of the results show as some deformation occurs in the structure in the joining point of the

  3. A Model for Deformation and Fragmentation in Crushable Brittle Solids

    Science.gov (United States)

    2008-03-01

    such as aggregate–mortar interfaces, but may also occur alongside mortar fissures and aggregate cracking at large deformations [4,19]. Let o represent...131–9. [6] Hanchak SJ, Forrestal MJ, Young ER, Ehrgott JQ. Perforation of concrete slabs with 48MPa (7 ksi) and 140MPa (20 ksi) unconfined compressive

  4. Redistribution of Core-forming Melt During Shear Deformation of Partially Molten Peridotite

    Science.gov (United States)

    Hustoft, J. W.; Kohlstedt, D. L.

    2002-01-01

    To investigate the role of deformation on the distribution of core-forming melt in a partially molten peridotite, samples of olivine-basalt-iron sulfide were sheared to large strains. Dramatic redistribution of sulfide and silicate melts occur during deformation. Additional information is contained in the original extended abstract.

  5. Deformation of high performance concrete plate under humid tropical weather

    Science.gov (United States)

    Niken, C.; Elly, T.; Supartono, FX; Laksmi, I.

    2018-03-01

    This paper presents the relationship between surrounding relative humidity and temperature on deformation behavior of one sample concrete plate with compressive strength of 60MPa. This research was done in Indonesia that is in humid tropical weather. A specimens measuring 3000 mm × 1600 mm × 150 mm were used. The behavior was obtained by using four embedded vibrating wire strain gauges (VWESG). As a result there is a very strong relationship between humidity and deformation at the age range of 7 until 21 days. The largest deformation occurs in the corner and the fluctuation of deformation in side position is larger than in the corner and in the middle. The peaks of surrounding relative humidity were fully followed by the deepest valley of deformation on time in the corner, while in another position the range delay time was 8 - 11 hours. There is a strong relationship between surrounding temperature and deformation at the range of 7 until 14 days. The influenced of surrounding relative humidity to concrete behavior is faster and longer than surrounding temperature. The influence of surrounding temperature in humid tropical weather was shorter than in non-humid tropical weather.

  6. Polygonal deformation bands in sandstone

    Science.gov (United States)

    Antonellini, Marco; Nella Mollema, Pauline

    2017-04-01

    We report for the first time the occurrence of polygonal faults in sandstone, which is compelling given that layer-bound polygonal fault systems have been observed so far only in fine-grained sediments such as clay and chalk. The polygonal faults are dm-wide zones of shear deformation bands that developed under shallow burial conditions in the lower portion of the Jurassic Entrada Fm (Utah, USA). The edges of the polygons are 1 to 5 meters long. The shear deformation bands are organized as conjugate faults along each edge of the polygon and form characteristic horst-like structures. The individual deformation bands have slip magnitudes ranging from a few mm to 1.5 cm; the cumulative average slip magnitude in a zone is up to 10 cm. The deformation bands heaves, in aggregate form, accommodate a small isotropic horizontal extension (strain Crosscutting relationships are rare. The interactions of the deformation bands are similar to those of mode I opening fractures. Density inversion, that takes place where under-compacted and over-pressurized layers (Carmel Fm) lay below normally compacted sediments (Entrada Sandstone), may be an important process for polygonal deformation bands formation. The gravitational sliding and soft sediment structures typically observed within the Carmel Fm support this hypothesis. Soft sediment deformation may induce polygonal faulting in the section of the Entrada Sandstone just above the Carmel Fm. The permeability of the polygonal deformation bands is approximately 10-14 to 10-13 m2, which is less than the permeability of the host, Entrada Sandstone (range 10-12 to 10-11 m2). The documented fault networks have important implications for evaluating the geometry of km-scale polygonal fault systems in the subsurface, top seal integrity, as well as constraining paleo-tectonic stress regimes.

  7. Unitary deformations of counterdiabatic driving

    Science.gov (United States)

    Takahashi, Kazutaka

    2015-04-01

    We study a deformation of the counterdiabatic-driving Hamiltonian as a systematic strategy for an adiabatic control of quantum states. Using a unitary transformation, we design a convenient form of the driver Hamiltonian. We apply the method to a particle in a confining potential and discrete systems to find explicit forms of the Hamiltonian and discuss the general properties. The method is derived by using the quantum brachistochrone equation, which shows the existence of a nontrivial dynamical invariant in the deformed system.

  8. Viscoelastic crustal deformation by magmatic intrusion: A case study in the Kutcharo caldera, eastern Hokkaido, Japan

    Science.gov (United States)

    Yamasaki, Tadashi; Kobayashi, Tomokazu; Wright, Tim J.; Fukahata, Yukitoshi

    2018-01-01

    Geodetic signals observed at volcanoes, particularly their temporal patterns, have required us to make the correlation between the surface displacement and magmatic process at depth in terms of viscoelastic crustal rheology. Here we use a parallelized 3-D finite element model to examine the response of the linear Maxwell viscoelastic crust and mantle to the inflation of a sill in order to show the characteristics of a long-term volcano deformation. In the model, an oblate-spheroidal sill is instantaneously or gradually inflated in a two-layered medium that consists of an elastic layer underlain by a viscoelastic layer. Our numerical experiments show that syn-inflation surface uplift is followed by post-inflation surface subsidence as the viscoelastic substrate relaxes. For gradual inflation events, the magnitude of inflation-induced uplift is reduced by the relaxation, through which the volume of a magma inferred by matching the prediction of an elastic model with observed surface uplift could be underestimated. For a given crustal viscosity, sill depth is the principal factor controlling subsidence caused by viscoelastic relaxation. The subsidence rate is highest when the inflation occurs at the boundary between the elastic and the viscoelastic layers. The mantle viscosity has an insignificant impact unless the depth of the inflation is greater than a half the crustal thickness. We apply the viscoelastic model to the interferometric synthetic aperture radar (InSAR) data in the Kutcharo caldera, eastern Hokkaido, Japan, where the surface has slowly subsided over a period of approximately three years following about a two-year period of inflation. The emplacement of a magmatic sill is constrained to occur at a depth of 4.5 km, which is significantly shallower than the geophysically imaged large-scale magma chamber. The geodetically detected deformation in the caldera reflects the small-scale emplacement of a magma that ascended from the deeper chamber, but not the

  9. Fabrication Methods for Adaptive Deformable Mirrors

    Science.gov (United States)

    Toda, Risaku; White, Victor E.; Manohara, Harish; Patterson, Keith D.; Yamamoto, Namiko; Gdoutos, Eleftherios; Steeves, John B.; Daraio, Chiara; Pellegrino, Sergio

    2013-01-01

    Previously, it was difficult to fabricate deformable mirrors made by piezoelectric actuators. This is because numerous actuators need to be precisely assembled to control the surface shape of the mirror. Two approaches have been developed. Both approaches begin by depositing a stack of piezoelectric films and electrodes over a silicon wafer substrate. In the first approach, the silicon wafer is removed initially by plasmabased reactive ion etching (RIE), and non-plasma dry etching with xenon difluoride (XeF2). In the second approach, the actuator film stack is immersed in a liquid such as deionized water. The adhesion between the actuator film stack and the substrate is relatively weak. Simply by seeping liquid between the film and the substrate, the actuator film stack is gently released from the substrate. The deformable mirror contains multiple piezoelectric membrane layers as well as multiple electrode layers (some are patterned and some are unpatterned). At the piezolectric layer, polyvinylidene fluoride (PVDF), or its co-polymer, poly(vinylidene fluoride trifluoroethylene P(VDF-TrFE) is used. The surface of the mirror is coated with a reflective coating. The actuator film stack is fabricated on silicon, or silicon on insulator (SOI) substrate, by repeatedly spin-coating the PVDF or P(VDFTrFE) solution and patterned metal (electrode) deposition. In the first approach, the actuator film stack is prepared on SOI substrate. Then, the thick silicon (typically 500-micron thick and called handle silicon) of the SOI wafer is etched by a deep reactive ion etching process tool (SF6-based plasma etching). This deep RIE stops at the middle SiO2 layer. The middle SiO2 layer is etched by either HF-based wet etching or dry plasma etch. The thin silicon layer (generally called a device layer) of SOI is removed by XeF2 dry etch. This XeF2 etch is very gentle and extremely selective, so the released mirror membrane is not damaged. It is possible to replace SOI with silicon

  10. Aspects of collision tectonics and intraplate deformation

    Energy Technology Data Exchange (ETDEWEB)

    Coward, M.P.

    1988-08-01

    Alpine collisional tectonics occurred episodically over the past 100 m.y., closing various small Tethyan basins and causing ripples of basin contraction and tectonic inversion across western Europe. Both at the Tethyan margin and in the smaller basins, deformation styles were controlled by existing fault geometries, in particular, (1) the position, dip, and detachment levels of the important bounding normal faults, (2) the locations of northwest-southwest trending lateral ramps/tear faults, which compartmentalize and tram-line the deformation, and (3) the distribution and thickness of Mesozoic postrift sediments. Collision began in the middle Cretaceous, with the closure of Ligurian and Valais basins and the associated reactivation of northwest-southeast strike-slip faults and small basins as far away as the Atlantic margin. This movement was associated with the earliest orogenic flysch deposits, the subduction of Tethyan ophiolites, and local A-type subduction and high-pressure metamorphism close to the Tethyan continental margins. Major crustal shortening occurred in southern Europe (Spain and southern France) in the Late Cretaceous-Paleogene associated with closure of Pyrenean basins, but in the Alps, the major shortening continued throughout the Neogene. Section restorations based on regional studies, linked to commercial and deep seismic data, indicate well over 100 km of crustal shortening in the western and central Alps, with subduction of lower European crust and lithospheric mantle beneath the southern Alps and the Po plain.

  11. TENORM (Technologically Enhanced Naturally Occurring Radioactive Materials)

    Science.gov (United States)

    ... the beginning of time, naturally occurring. radionuclides or radioactive elements as they occur in nature, such as radium , uranium , thorium , potassium, and their radioactive decay products decay products The atoms formed and ...

  12. Transient deformation from daily GPS displacement time series: postseismic deformation, ETS and evolving strain rates

    Science.gov (United States)

    Bock, Y.; Fang, P.; Moore, A. W.; Kedar, S.; Liu, Z.; Owen, S. E.; Glasscoe, M. T.

    2016-12-01

    Detection of time-dependent crustal deformation relies on the availability of accurate surface displacements, proper time series analysis to correct for secular motion, coseismic and non-tectonic instrument offsets, periodic signatures at different frequencies, and a realistic estimate of uncertainties for the parameters of interest. As part of the NASA Solid Earth Science ESDR System (SESES) project, daily displacement time series are estimated for about 2500 stations, focused on tectonic plate boundaries and having a global distribution for accessing the terrestrial reference frame. The "combined" time series are optimally estimated from independent JPL GIPSY and SIO GAMIT solutions, using a consistent set of input epoch-date coordinates and metadata. The longest time series began in 1992; more than 30% of the stations have experienced one or more of 35 major earthquakes with significant postseismic deformation. Here we present three examples of time-dependent deformation that have been detected in the SESES displacement time series. (1) Postseismic deformation is a fundamental time-dependent signal that indicates a viscoelastic response of the crust/mantle lithosphere, afterslip, or poroelastic effects at different spatial and temporal scales. It is critical to identify and estimate the extent of postseismic deformation in both space and time not only for insight into the crustal deformation and earthquake cycles and their underly