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1

Visual field deficit due to downward displacement of optic chiasm.  

PubMed

Visual disturbance in hydrocephalus is typically due to raised intracranial pressure. We describe a patient who presented with marked loss of peripheral visual fields, but without features suggestive of raised intracranial pressure. MR scan showed an enlarged third ventricle and a downward displacement of the optic chiasm, Chiari II malformation. These radiological changes and the visual field deficits reversed after endoscopic third ventriculostomy and foramen magnum decompression. These observations support the view that the treatment of the hydrocephalus in such patients can help to reverse the change in the position of the optic chiasm and the visual field deficits. PMID:19377847

Holsgrove, Daniel; Leach, Paul; Herwadkar, Amit; Gnanalingham, Kanna K

2009-08-01

2

Role of plasma response in displacements of the tokamak edge due to applied non-axisymmetric fields  

SciTech Connect

Linear, two-fluid, resistive modelling of the plasma response to applied non-axisymmetric fields shows significant displacement of edge temperature and density profiles. The calculated displacements, often of 2 cm or more in H-mode pedestals with parameters appropriate to DIII-D, are due to the helical distortions resulting from stable edge modes being driven to finite amplitude by the applied fields. In many cases, these displacements are greater in magnitude, and different in phase, than the distortions of the separatrix manifolds predicted from vacuum modelling. Comparison of these results with experimental measurements from Thomson scattering and soft x-ray imaging finds good quantitative agreement. In these experiments, the phase of the applied non-axisymmetric magnetic field was flipped or rotated in order to probe the non-axisymmetric features of the response. The poloidal structures measured by x-ray imaging show clear indications of a helical response, as opposed to simply a change in the axisymmetric transport. Inclusion of two-fluid effects and rotation are found to be important in obtaining quantitative agreement with Thomson scattering data. Modelling shows screening of islands in the H-mode pedestal, but island penetration near the top of the pedestal where the electron rotation vanishes in plasmas with co-current rotation. Enhanced transport due to these islands may provide a mechanism for maintaining the pedestal width below the stability threshold of edge-localized modes. For typical DIII-D parameters, it is shown that the linear approximation is often near or beyond the limit of validity in the H-mode edge; however, the general agreement with experimental measurements indicates that these linear results nevertheless maintain good predictive value for profile displacements.

Evans, T. E. [General Atomics, San Diego; Ferraro, N. M. [General Atomics, San Diego; Orlov, D. M. [University of California, San Diego & La Jolla; Wade, M. [General Atomics, San Diego; Lao, L. L. [General Atomics, San Diego; Moyer, R. A. [University of California, San Diego; Wingen, A. [University of Dusseldorf, Germany; Nazikian, R. [Princeton Plasma Physics Laboratory (PPPL); Unterberg, Ezekial A [ORNL; Shafer, Morgan W [ORNL

2013-01-01

3

Magnetic Field Due to a Finite Length Current-Carrying Wire Using the Concept of Displacement Current  

NASA Astrophysics Data System (ADS)

In undergraduate E&M courses the magnetic field due to a finite length, current-carrying wire can be calculated using the Biot-Savart law.1 However, to the author's knowledge, no textbook presents the calculation of this field using the Ampere-Maxwell law: ?B .dl=?0[I +?0d?/dt

Buschauer, Robert

2014-10-01

4

Magnetic Field Due to a Finite Length Current-Carrying Wire Using the Concept of Displacement Current  

ERIC Educational Resources Information Center

In undergraduate E&M courses the magnetic field due to a finite length, current-carrying wire can be calculated using the Biot-Savart law. However, to the author's knowledge, no textbook presents the calculation of this field using the Ampere-Maxwell law: ?B [multiplied by] dl = µ[subscript 0] (I + e[subscript 0] dF/dt) [multiplied by] 1

Buschauer, Robert

2014-01-01

5

Crustal Displacements Due to Continental Water Loading  

NASA Technical Reports Server (NTRS)

The effects of long-wavelength (> 100 km), seasonal variability in continental water storage on vertical crustal motions are assessed. The modeled vertical displacements (delta-r(sub M)) have root-mean-square (RMS) values for 1994-1998 as large as 8 mm with ranges up to 30 mm, and are predominantly annual in character. Regional strains are on the order of 20 nanostrain for tilt and 5 nanostrain for horizontal deformation. We compare delta-r(sub M) with observed Global Positioning System (GPS) heights (delta-r(sub O)) (which include adjustments to remove estimated effects of atmospheric pressure and annual tidal and non-tidal ocean loading) for 147 globally distributed sites. When the delta-r(sub O) time series are adjusted by delta-r(sub M), their variances are reduced, on average, by an amount equal to the variance of the delta-r(sub M). Of the delta-r(sub O) time series exhibiting a strong annual signal, more than half are found to have an annual harmonic that is in phase and of comparable amplitude with the annual harmonic in the delta-r(sub M). The delta-r(sub M) time series exhibit long-period variations that could be mistaken for secular tectonic trends or post-glacial rebound when observed over a time span of a few years.

vanDam, T.; Wahr, J.; Milly, P. C. D.; Shmakin, A. B.; Blewitt, G.; Lavallee, D.; Larson, K. M.

2001-01-01

6

Crustal displacements due to continental water loading  

USGS Publications Warehouse

The effects of long-wavelength (> 100 km), seasonal variability in continental water storage on vertical crustal motions are assessed. The modeled vertical displacements (??rM) have root-mean-square (RMS) values for 1994-1998 as large as 8 mm, with ranges up to 30 mm, and are predominantly annual in character. Regional strains are on the order of 20 nanostrain for tilt and 5 nanostrain for horizontal deformation. We compare ??rM with observed Global Positioning System (GPS) heights (??rO) (which include adjustments to remove estimated effects of atmospheric pressure and annual tidal and non-tidal ocean loading) for 147 globally distributed sites. When the ??rO time series are adjusted by ??rM, their variances are reduced, on average, by an amount equal to the variance of the ??rM. Of the ??rO time series exhibiting a strong annual signal, more than half are found to have an annual harmonic that is in phase and of comparable amplitude with the annual harmonic in the ??rM. The ??rM time series exhibit long-period variations that could be mistaken for secular tectonic trends or post-glacial rebound when observed over a time span of a few years.

Van Dam, T.; Wahr, J.; Milly, P.C.D.; Shmakin, A.B.; Blewitt, G.; Lavallee, D.; Larson, K.M.

2001-01-01

7

BLOCK DISPLACEMENT METHOD FIELD DEMONSTRATION AND SPECIFICATIONS  

EPA Science Inventory

The Block Displacement technique has been developed as a remedial action method for isolating large tracks of ground contaminated by hazardous waste. The technique places a low permeability barrier around and under a large block of contaminated earth. The Block Displacement proce...

8

INSPECTION OF SURFACE STRAIN IN MATERIALS USING DENSE DISPLACEMENT FIELDS  

E-print Network

INSPECTION OF SURFACE STRAIN IN MATERIALS USING DENSE DISPLACEMENT FIELDS William F. Clocksin for this task, as image sequences are characterised by both short- and long-range displacements, non differences that need to be calculated. We give results from three studies: mild steel under axial tension

Torr, Philip H. S.

9

A regularized finite-element digital image correlation for irregular displacement field  

NASA Astrophysics Data System (ADS)

A nonlinear Tikhonov regularization scheme is developed to tackle the ill-posed finite-element digital image correlation, which aims to measure the displacement field from consequent digital images before and after deformation. The goal of this algorithm is to resolve the displacement field with fine and irregular structure without deteriorated by the measuring errors due to its ill-posedness. A Newton-type method is employed to linearize the nonlinear problem iteratively, then the Tikhonov regularization is applied to the linearized problem, with the regularization parameter adaptively chosen by the L-curve method. The proposed algorithm is verified by computer simulated input images with a priori displacement field. The result shows that it is capable of resolving displacement field with very fine structure in a reasonable accuracy.

Yang, Reng-cai

2014-05-01

10

Displacement and stress fields around rock fractures opened by irregular overpressure variations  

NASA Astrophysics Data System (ADS)

Many rock fractures are entirely driven open by fluids such as ground water, geothermal water, gas, oil, and magma. These are a subset of extension fractures (mode I cracks; e.g., dikes, mineral veins and joints) referred to as hydrofractures. Field measurements show that many hydrofractures have great variations in aperture. However, most analytical solutions for fracture displacement and stress fields assume the loading to be either constant or with a linear variation. While these solutions have been widely used, it is clear that a fracture hosted by heterogeneous and anisotropic rock is normally subject to loading that is neither constant nor with a linear variation. Here we present new general solutions for the displacement and stress fields around hydrofractures, modelled as two-dimensional elastic cracks, opened by irregular overpressure variations given by the Fourier cosine series. Each solution has two terms. The first term gives the displacement and stress fields due to the average overpressure acting inside the crack; it is given by the initial term of the Fourier coefficients expressing the overpressure variation. The second term gives the displacement and stress fields caused by the overpressure variation; it is given by general terms of the Fourier coefficients and solved through numerical integration. Our numerical examples show that the crack aperture variation closely reflects the overpressure variation. Also, that the general displacement and stress fields close to the crack follow the overpressure variation but tend to be more uniform far from the crack. The present solutions can be used to estimate the displacement and stress fields around any fluid-driven crack, that is, any hydrofracture, as well as its aperture, provided the variation in overpressure can be described by Fourier series. The solutions add to our understanding of local stresses, displacements, and fluid transport associated with hydrofractures in the crust.

Kusumoto, Shigekazu; Gudmundsson, Agust

2014-05-01

11

Tsunami generation by dynamic displacement of sea bed due to dip-slip faulting  

E-print Network

Tsunami generation by dynamic displacement of sea bed due to dip-slip faulting Denys Dutykh, Fr In classical tsunami-generation techniques, one neglects the dynamic sea bed dis- placement resulting from and the NSWE by a finite-volume scheme. A comparison be- tween static and dynamic tsunami-generation approaches

Paris-Sud XI, Université de

12

PREDICTION OF SURFACE SETTLEMENT DUE TO THE DISPLACEMENT OF SOFT ZONES  

SciTech Connect

In areas composed of coastal plain sediments, soft zones subjected to partial overburden may be present in the subsurface. During or after a seismic event, these soft zones may be compressed. The resulting displacement due to the deformation of the soft zones will propagate to the ground surface and cause the surface to settle. This paper presents a method to predict the settlement at the surface due to the propagation of the displacement from the soft zones. This method is performed by discretizing the soft zones into multiple clusters of finite sub-areas or subspaces. Settlement profile at the ground surface due to the displacement of each sub-area or subspace is computed assuming the shape is a normal distribution function. Settlement due to the displacement of the soft zones can then be approximated by adding the settlements computed for all the sub-areas or subspaces. This method provides a simple and useful tool for the prediction of the settlement profile and the results are consistent with those obtained from the finite difference analysis.

Li, W

2008-03-03

13

Optimization of legacy lidar data sets for measuring near-field earthquake displacements  

NASA Astrophysics Data System (ADS)

lidar (light detection and ranging) topography, acquired before and after an earthquake, can provide an estimate of the coseismic surface displacement field by differencing the preevent and postevent lidar point clouds. However, estimated displacements can be contaminated by the presence of large systematic errors in either of the point clouds. We present three-dimensional displacements obtained by differencing airborne lidar point clouds collected before and after the El Mayor-Cucapah earthquake, a Mw 7.2 earthquake that occurred in 2010. The original surface displacement estimates contained large, periodic artifacts caused by systematic errors in the preevent lidar data. Reprocessing the preevent data, detailed herein, removed a majority of these systematic errors that were largely due to misalignment between the scanning mirror and the outgoing laser beam. The methodology presented can be applied to other legacy airborne laser scanning data sets in order to improve change estimates from temporally spaced lidar acquisitions.

Glennie, Craig L.; Hinojosa-Corona, Alejandro; Nissen, Edwin; Kusari, Arpan; Oskin, Michael E.; Arrowsmith, J. Ramon; Borsa, Adrian

2014-05-01

14

Three-dimensional fault displacement validation in Teak Field, Trinidad and Tobago  

SciTech Connect

Fault plane mapping is important to the structural interpretation process, particularly when wells are the primary data source. Two major considerations in fault plane validation are: (1) fault surfaces are relatively smooth and continuous with geologically reasonable dips; and (2) displacement patterns along fault planes balance in map and cross section. Significant decreases in displacement along fault planes must be accommodated by similar increases on other faults. Three-dimensional computer techniques for visualizing and analyzing fault displacement data have been developed and used in Teak Field, Trinidad and Tobago. This is a faulted anticline, dominated by a down-to-the-basin fault with a series of synthetic, antithetic, and counter-regional normal faults. Due to the intense faulting, both fault correlation and determining fault relationships are difficult. Most faults lack significant drag; therefore, the well data usually yields only the subsea location of a fault cut and amount of missing vertical section. when three-dimensional techniques are used, relationships between fault cuts are more apparent, and fault plane validation is enhanced. The model incorporates vertical displacement data that are displayed as displacement contours on a three-dimensional fault plane model. The techniques used increased confidence that the fault correlations are indeed a valid possibility. Display of displacement contours on the three-dimensional fault plane model demonstrated that changes in displacement were accommodated by interactions between faults, ultimately providing a more rigorous structural interpretation.

Hoffman, K.S.; Stewart, J.W.

1995-12-31

15

Tsunami simulation using submarine displacement calculated from simulation of ground motion due to seismic source model  

NASA Astrophysics Data System (ADS)

Since fault fracturing due to an earthquake can simultaneously cause ground motion and tsunami, it is appropriate to evaluate the ground motion and the tsunami by single fault model. However, several source models are used independently in the ground motion simulation or the tsunami simulation, because of difficulty in evaluating both phenomena simultaneously. Many source models for the 2011 off the Pacific coast of Tohoku Earthquake are proposed from the inversion analyses of seismic observations or from those of tsunami observations. Most of these models show the similar features, which large amount of slip is located at the shallower part of fault area near the Japan Trench. This indicates that the ground motion and the tsunami can be evaluated by the single source model. Therefore, we examine the possibility of the tsunami prediction, using the fault model estimated from seismic observation records. In this study, we try to carry out the tsunami simulation using the displacement field of oceanic crustal movements, which is calculated from the ground motion simulation of the 2011 off the Pacific coast of Tohoku Earthquake. We use two fault models by Yoshida et al. (2011), which are based on both the teleseismic body wave and on the strong ground motion records. Although there is the common feature in those fault models, the amount of slip near the Japan trench is lager in the fault model from the strong ground motion records than in that from the teleseismic body wave. First, the large-scale ground motion simulations applying those fault models used by the voxel type finite element method are performed for the whole eastern Japan. The synthetic waveforms computed from the simulations are generally consistent with the observation records of K-NET (Kinoshita (1998)) and KiK-net stations (Aoi et al. (2000)), deployed by the National Research Institute for Earth Science and Disaster Prevention (NIED). Next, the tsunami simulations are performed by the finite difference calculation based on the shallow water theory. The initial wave height for tsunami generation is estimated from the vertical displacement of ocean bottom due to the crustal movements, which is obtained from the ground motion simulation mentioned above. The results of tsunami simulations are compared with the observations of the GPS wave gauges to evaluate the validity for the tsunami prediction using the fault model based on the seismic observation records.

Akiyama, S.; Kawaji, K.; Fujihara, S.

2013-12-01

16

Incremental model for fatigue crack growth based on a displacement partitioning hypothesis of mode I elasticplastic displacement fields.  

E-print Network

- 1 - Incremental model for fatigue crack growth based on a displacement partitioning hypothesis April 2006) Abstract ­ The mode I displacement field in the near crack tip region is assumed. This enables one to establish a yield criterion and a plastic flow rule for the crack tip region

17

Apparent spatial blurring and displacement of a point optical source due to cloud scattering  

SciTech Connect

A Monte Carlo algorithm is used to determine the apparent spatial blurring of a terrestrial 1.07 micron optical point source due to cloud scattering as seen from space. The virtual image of a point source over a virtual source plane area 22.4 x 22.4 square kilometers arising from cloud scattering was determined for stratus clouds (NASA cloud number 5) and altostratus clouds optical source arises from photon scattering by cloud water droplets. Displacement of the virtual source is due to the apparent illumination of the cloud top region directly about the actual source which when viewed at a nonzero look angle gives a projected displacement of the apparent source relative to the actual source. These features are quantified by an analysis of the Monte Carlo computational results.

Brower, K.L.

1997-09-01

18

Analysis of Displacement Fields Near Dislocation Cores in Ordered Polymers  

NASA Astrophysics Data System (ADS)

We have significantly improved a method to characterize the displacement fields near edge dislocations in ordered polymers. Our extended analysis now makes it possible to predict and explain the variation in tilt of different lattice planes in the vicinity of dislocations in isotropic solids, anisotropic crystals and liquid crystals in terms of their elasticity constants. Direct images of the dislocation cores were obtained in three different polymer systems using bright field transmission electron microscopy (TEM) and high resolution electron microscopy (HREM). A b[010]=63 nm edge dislocation was imaged in the ABC triblock copolymer polystyrene-block-poly(ethylene-co-butylene)-block- poly(methylmethacrylate) (SEBM). Fitting the theoretical isotropic displacement fields to the displacements measured from the image, an estimate of the elastic constant anisotropy was obtained. For this material the ratio of the bulk modulus to the shear modulus, K/G, was equal to 0.8 +/- 0.2. A similar analysis using anisotropic dislocation theory was applied to a 3 chain-end, b[200]=2.4 nm edge dislocation in the crystalline polymer [1,6-di(N-carbazolyl)-2,4-hexadiyne] (DCHD). Information about the anisotropy of DCHDs stiffness matrix, C_ij, was obtained. An anisotropy parameter W_2, defined as (C_11+C_33)/(2C_55), was found to be 3.0 +/- 0.1. A b=2.6 nm dislocation in a smectic polymalonate was analyzed using liquid crystalline dislocation theory, and an estimate of ?, the material's characteristic deformation length, was determined to be 1.0 +/- 0.1 nm.

Martin, David; Drummy, Lawrence; Voigt-Martin, Ingrid

2001-03-01

19

An electric field meter based upon a new principle: A dummy displacement electrode. Application to aerospace vehicles  

NASA Astrophysics Data System (ADS)

An electrical field measuring instrument which significantly improves the rejection of noise due to collected electric charges (ionized particles) is presented. Using the principle (dummy displacement electrode), a complete field meter was manufactured. The test results show accurate field measurements in points submitted to a very significant charged particle flux. Instrument data processing and data transmission are also described.

Andre, P.; Boulanger, G.

20

Pneumatic displacement with intravitreal bevacizumab for massive submacular hemorrhage due to polypoidal choroidal vasculopathy  

PubMed Central

Background The purpose of this study was to compare the effectiveness of pneumatic displacement combined with intravitreal bevacizumab (IVB) with that of pneumatic displacement (PD) alone to treat massive submacular hemorrhage (SMH) secondary to polypoidal choroidal vasculopathy (PCV). Methods Thirty-two eyes of 32 patients with massive SMH secondary to PCV were studied. Twenty-two eyes were treated with a combination of PD and 1.25 mg of intravitreal bevacizumab (PD + IVB group), and ten eyes with pneumatic displacement alone (PD group). Results Pretreatment, the differences in best-corrected visual acuity and size of the SMH between the two groups were not significant (P=0.59 and P=0.72, respectively). Complete displacement of the hemorrhage from under the fovea was achieved in 19 of 22 eyes (86.4%) in the PD + IVB group and in five of ten eyes (50%) in the PD group. The best-corrected visual acuity in the PD + IVB group was significantly better than that in the PD group at one, 3, and 6 months after treatment (P<0.001, P<0.001, and P<0.001, respectively). Improvement in best-corrected visual acuity by >0.3 logMAR units was obtained in 18 eyes (81.8%) in the PD + IVB group and two eyes (20%) in the PD group (P<0.001). The number of eyes that required additional treatments was significantly fewer in the PD + IVB group than in the PD group (P=0.0001). Conclusion The combination of PD and IVB may be a better therapeutic procedure for eyes with massive SMH due to PCV in the short term because of the better visual outcome and less need for additional treatments. PMID:24623972

Kitahashi, Masayasu; Baba, Takayuki; Sakurai, Madoka; Yokouchi, Hirotaka; Kubota-Taniai, Mariko; Mitamura, Yoshinori; Yamamoto, Shuichi

2014-01-01

21

Cooperative effects due to interpore surface tension in unstable displacement in porous media  

Microsoft Academic Search

We model fluid-fluid displacement in d = 2 by a diffusion limited aggregation (DLA) algorithm which takes interpore surface tension and capillary forces into account. The invading fluid is non-viscous. Cooperative effects are important when the ratio between capillary forces and tension forces q is ? 1. In that case we introduce a simple rule that considers the wetting displacement

Rafael Rangel

1995-01-01

22

Retrieving three-dimensional displacement fields of mining areas from a single InSAR pair  

NASA Astrophysics Data System (ADS)

This paper presents a novel method for retrieving three-dimensional (3-D) displacement fields of mining areas from a single interferometric synthetic aperture radar (InSAR) pair. This method fully exploits the mechanism of mining subsidence, specifically the proportional relationship between the horizontal displacement and horizontal gradient of vertical displacements caused by underground mining. This method overcomes the limitations of conventional InSAR techniques that can only measure one-dimensional (1-D) deformation of mining area along the radar line-of-sight direction. The proposed method is first validated with simulated 3-D displacement fields, which are obtained by the FLAC software. The root mean square errors of the 3-D displacements retrieved by the proposed method are 13.7, 27.6 and 3.6 mm for the West-East, North-South, and Up-Down components, respectively. We then apply the proposed method to estimate the 3-D displacements of the Qianyingzi and the Xuzhou coal mines in China, respectively, each along with two Advanced Land Observing Satellite (ALOS) Phased Array Type L-band Synthetic Aperture Radar images. Results show that the estimated 3-D displacement is highly consistent with that of the field surveying. This demonstrates that the proposed method is an effective approach for retrieving 3-D mining displacement fields and will play an important role in mining-related hazard prevention and environment assessment under limited InSAR acquisitions.

Li, Zhi Wei; Yang, Ze Fa; Zhu, Jian Jun; Hu, Jun; Wang, Yun Jia; Li, Pei Xian; Chen, Guo Liang

2015-01-01

23

A study of the use of artificial neural networks to estimate dynamic displacements due to dynamic loads in bridges  

NASA Astrophysics Data System (ADS)

Measurement of dynamic displacement is one of the most essential aspects of a structural behavior because it portrays history of the global behavior of structure. In general, structural engineers are accepted these response as reliable physical quantities to evaluate the conditions of a structure. The reason is that these physical quantities can easily generate strain as well as stress, velocity and acceleration at the measuring points. However, it is difficult to directly measure the displacement of the bridge due to problems such as test conditions and the limitations of equipment. Therefore, in this study, an artificial neural network (ANN) demonstrates how it could overcome such limitations and utilize the random dynamic load to obtain the reliable estimations. Numerical analysis is conducted to obtain learning data about the axial strain as well as vertical displacement with time frame at multi-points and then applied to the ANN. The scenario centered on a variety of dynamic loads from the analysis of an urban bridge that was selected based on its general volume of traffic. The analysis was performed to estimate its displacement, which corresponds to the strain on the bridge caused by arbitrary loads of leaning results from the ANN. Then, it is confirmed that the estimated displacements of ANN show well agreements with that of an independent set of traffic scenario.

Ok, S.; Son, W.; Lim, Y. M.

2012-08-01

24

The displacement field characterization of two interacting parallel edge cracks in a finite body  

E-print Network

The goals of this research were to: (1) develop a model to represent the displacement field surrounding two interacting, parallel edge cracks; and (2) use this model to investigate the influence of crack separation and relative crack length...

Keener, Todd Whitney

1996-01-01

25

Field methods to measure surface displacement and strain with the Video Image Correlation method  

NASA Technical Reports Server (NTRS)

The objective of this project was to develop methods and application procedures to measure displacement and strain fields during the structural testing of aerospace components using paint speckle in conjunction with the Video Image Correlation (VIC) system.

Maddux, Gary A.; Horton, Charles M.; Mcneill, Stephen R.; Lansing, Matthew D.

1994-01-01

26

The Displacement Rate Across the Pacific Plate due to Horizontal Thermal Contraction  

NASA Astrophysics Data System (ADS)

Horizontal thermal contraction of oceanic lithosphere is expected to impart a relative velocity between various points on the same tectonic plate [Kumar and Gordon, 2009]. The ridge-parallel component of thermal contraction is especially high in young oceanic lithosphere as the contraction rate is inversely proportional to the age of the lithosphere. Here we present a simple kinematic model for the horizontal velocity field due to thermal contraction of a rectangular portion of lithosphere between two fracture zones. We build on this model to make a flat-earth approximation of the relative velocity of different points on the Pacific plate between Baja California and the Heezen fracture zone. Unlike the model of Kumar and Gordon [1999], our model includes the effects of age offsets across fracture zones. Lithosphere near Baja California is found to approach lithosphere near the Heezen fracture zone at a rate of about 3 mm/yr, which is similar in magnitude to the non-closure in the Pacific-North America global plate motion circuit found by DeMets, Gordon, and Argus [2009]. Implications for global plate motion circuits will be discussed.

Gordon, R. G.; Mishra, J. K.

2009-12-01

27

Tooth displacement due to occlusal contacts: a three-dimensional finite element study.  

PubMed

The use of the Finite Element Method (FE) is an appropriate way to study occlusal forces and tooth movement. The purpose of this study was to evaluate the effects of different occlusal contact patterns on tooth displacement in an adult dentition using a three-dimensional FE model of a human maxilla and mandible. Initially, images of a computerized tomography scan were redrawn in a computer program (CATIA) followed by the FE mesh construction. The MSC/Patran software was used to develop the FE mesh comprising 520,445 elements and 106,633 nodes. The MSC/Nastran program was utilized as pre and post-processor for all mathematical calculations necessary to evaluate dental and mandibular biomechanics. Four occlusal patterns were tested: FEM 1 - standard occlusal contacts; FEM 2 - removal of mesial marginal and mesial tripoidism contacts; FEM 3 - removal of distal marginal and distal tripoidism contacts; FEM 4 - similar to FEM 3 with added contacts between upper and lower incisors. Small changes in the standard distribution of occlusal contacts resulted in an imbalance of occlusal forces and changes in dental positioning. All simulations tested showed mesial displacement of posterior teeth. The most significant changes were registered in the model presenting unstable occlusal contacts when the anterior teeth were in occlusion (FEM 4). These findings may explain mandibular incisors crowding and maxillary incisors flaring as a result of small variations in dental contacts. PMID:17168929

Gomes de Oliveira, S; Seraidarian, P I; Landre, J; Oliveira, D D; Cavalcanti, B N

2006-12-01

28

Displacements of the earth's surface due to atmospheric loading - Effects of gravity and baseline measurements  

NASA Technical Reports Server (NTRS)

Atmospheric mass loads and deforms the earth's crust. By performing a convolution sum between daily, global barometric pressure data and mass loading Green's functions, the time dependent effects of atmospheric loading, including those associated with short-term synoptic storms, on surface point positioning measurements and surface gravity observations are estimated. The response for both an oceanless earth and an earth with an inverted barometer ocean is calculated. Load responses for near-coastal stations are significantly affected by the inclusion of an inverted barometer ocean. Peak-to-peak vertical displacements are frequently 15-20 mm with accompanying gravity perturbations of 3-6 micro Gal. Baseline changes can be as large as 20 mm or more. The perturbations are largest at higher latitudes and during winter months. These amplitudes are consistent with the results of Rabbel and Zschau (1985), who modeled synoptic pressure disturbances as Gaussian functions of radius around a central point. Deformation can be adequately computed using real pressure data from points within about 1000 km of the station. Knowledge of local pressure, alone, is not sufficient. Rabbel and Zschau's hypothesized corrections for these displacements, which use local pressure and the regionally averaged pressure, prove accurate at points well inland but are, in general, inadequate within a few hundred kilometers of the coast.

Van Dam, T. M.; Wahr, J. M.

1987-01-01

29

On the derivation of coseismic displacement fields using differential radar interferometry: the Landers earthquake  

Microsoft Academic Search

We present a map of the coseismic displacement field resulting from the Landers, CA, June 28, 1992 earthquake derived using data acquired from an orbiting high resolution radar system. We achieve results more accurate than previous space studies and similar in accuracy to those obtained by conventional field survey techniques. Data from the ERS-1 synthetic aperture radar instrument acquired in

A. ZEBKER; PAUL ROsEN

1961-01-01

30

Application of dynamic displacement current for diagnostics of subnanosecond breakdowns in an inhomogeneous electric field  

SciTech Connect

The breakdown of different air gaps at high overvoltages in an inhomogeneous electric field was investigated with a time resolution of up to 100 ps. Dynamic displacement current was used for diagnostics of ionization processes between the ionization wave front and a plane anode. It is demonstrated that during the generation of a supershort avalanche electron beam (SAEB) with amplitudes of {approx}10 A and more, conductivity in the air gaps at the breakdown stage is ensured by the ionization wave, whose front propagates from the electrode of small curvature radius, and by the dynamic displacement current between the ionization wave front and the plane electrode. The amplitude of the dynamic displacement current measured by a current shunt is 100 times greater than the SAEB. It is shown that with small gaps and with a large cathode diameter, the amplitude of the dynamic displacement current during a subnanosecond rise time of applied pulse voltage can be higher than 4 kA.

Shao Tao; Zhang Cheng; Yan Ping [Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Power Electronics and Electric Drive, Chinese Academy of Sciences, Beijing 100190 (China); Tarasenko, Victor F.; Burachenko, Alexandr G.; Rybka, Dmitry V.; Kostyrya, Igor' D.; Lomaev, Mikhail I.; Baksht, Evgeni Kh. [Institute of High Current Electronics, Russian Academy of Sciences, Tomsk 634055 (Russian Federation)

2013-05-15

31

Displacement field analysis based on the combination digital speckle correlation method with radial basis function interpolation.  

PubMed

The digital speckle correlation method (DSCM) has been widely used to resolve displacement and deformation gradient fields. The computational time and the computational accuracy are still two challenging problems faced in this area. In this paper, we introduce the radial basis function (RBF) interpolation method to DSCM and propose a method for displacement field analysis based on the combination of DSCM with RBF interpolation. We test the proposed method on two computer-simulated and two experimentally obtained deformation measurements and compare it with the widely used Newton-Raphson iteration (NR method). The experimental results demonstrate that our method performs better than the NR method in terms of both quantitative evaluation and visual quality. In addition, the total computational time of our method is considerably shorter than that of the NR method. Our method is particularly suitable for displacement field analysis of large regions. PMID:20733625

Tang, Chen; Wang, Linlin; Yan, Si; Wu, Jian; Cheng, Liyan; Li, Cancan

2010-08-20

32

Displacement sensor containing magnetic field sensing element between a pair of biased magnets movable as a unit  

NASA Technical Reports Server (NTRS)

A displacement sensor for providing an indication of the position of a first body relative to a second body, the first body being displaceable relative to the second body in a displacement direction. The sensor is composed of: two magnets that are spaced from one another in the displacement direction to define therebetween a region containing a magnetic field; a magnetic field sensing element mounted in the region; and components for coupling at least one of the magnets to one of the bodies and the magnetic field sensing element to the other of the bodies to produce a relative displacement between the at least one magnet and the magnetic field sensing element in the displacement direction in response to displacement of the first body relative to the second body.

Bahr, Joseph K. (Inventor); Johnson, Mont A. (Inventor)

2003-01-01

33

Field performance of the Walker Branch throughfall displacement experiment  

SciTech Connect

The authors are conducting a large-scale manipulative field experiments in an upland oak forest on the Walker Branch Watershed in eastern Tennessee USA to identify important ecosystem responses that might result from future precipitation changes. The manipulation of soil moisture is being implemented by a gravity-driven transfer of throughfall precipitation from one treatment plot to another. Throughfall is intercepted in {approx} 2,000 subcanopy troughs (0.3 x 5 m) suspended above the forest floor of the dry plots ({approx} 33% of the ground area is covered) and transferred by gravity flow across an ambient plot for subsequent distribution onto the wet treatment plot. Percent soil water is being monitored with time domain reflectometers at 310 sampling locations across the site. The experimental system is able to produce statistically significant differences in soil water content in years having both extremely dry and extremely wet conditions. Furthermore, comparisons of pre- and post-installation soil temperature measurements have documented the ability of the experimental design to produce these changes without changing the microclimate of the forest understory.

Hanson, P.J.; Todd, D.E.; Edwards, N.T.; Huston, M.A. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.

1994-10-06

34

FIELD TRIALS OF NEWLY DEVELOPED POSITIVE DISPLACEMENT SUBMERSIBLE PUMP  

SciTech Connect

The purpose of this grant was to evaluate under real world conditions the performance of a new type of downhole pump, the hydraulically driven submersible diaphragm pump. This pump is supplied by Pumping Solutions Incorporated, Albuquerque NM. The original scope of the project was to install 10 submersible pumps, and compare that to 10 similar installations of rod pumps. As an operator, the system as tested was not ready for prime time, but has shown the ability to reduce costs, and increase production, if run times can be improved. The PSI group did improve the product and offered excellent service. The latest design appears to be much better, but more test data is needed to show short run life is not a problem. PSI and Beard Oil intend to continue testing the pump with non-government funding. The testing to date did not uncover any fundamental problems that would preclude the widespread use of this pump, and as an operator, I believe that with further improvement and testing, the pump can have a significant impact on stripper well costs. On the positive side, the pump was easy to run, was more power efficient then a rod pump, and is the only submersible that could handle the large quantities of solids typical of the production environment found at the Weber field and in CMB production. The product shows much promise for the future, and with continued design and testing, this type of submersible pump has the potential to become the standard of the industry.

Rob Beard

2003-10-01

35

Bayesian Identification of Elastic Constants in Multi-Directional Laminate from Moir Interferometry Displacement Fields.  

E-print Network

was applied to a proper orthogonal decomposition (POD) of the displacement fields. The analysis showed for classical lamination theory analysis of multi-directional laminates may differ from those obtained from it can readily model all the uncertainties in the analysis and measurements, and because it provides

Boyer, Edmond

36

Detection of in-plane displacements of acoustic wave fields using extrinsic Fizeau fiber interferometric sensors  

NASA Technical Reports Server (NTRS)

Quantitative measurements of the in-plane particle displacement components of ultrasonic surface acoustic wave fields using extrinsic Fizeau fiber interferometric (EFFI) sensors are reported. Wave propagation in materials and the fiber sensor elements are briefly discussed. Calibrated experimental results obtained for simulated acoustic emission events on homogeneous metal test specimens are reported and compared to previous results obtained using piezoelectric transducers.

Dhawan, R.; Gunther, M. F.; Claus, R. O.

1991-01-01

37

Displacement field for an edge dislocation in a layered half-space  

USGS Publications Warehouse

The displacement field for an edge dislocation in an Earth model consisting of a layer welded to a half-space of different material is found in the form of a Fourier integral following the method given by Weeks et al. [1968]. There are four elementary solutions to be considered: the dislocation is either in the half-space or the layer and the Burgers vector is either parallel or perpendicular to the layer. A general two-dimensional solution for a dip-slip faulting or dike injection (arbitrary dip) can be constructed from a superposition of these elementary solutions. Surface deformations have been calculated for an edge dislocation located at the interface with Burgers vector inclined 0??, 30??, 60??, and 90?? to the interface for the case where the rigidity of the layer is half of that of the half-space and the Poisson ratios are the same. Those displacement fields have been compared to the displacement fields generated by similarly situated edge dislocations in a uniform half-space. The surface displacement field produced by the edge dislocation in the layered half-space is very similar to that produced by an edge dislocation at a different depth in a uniform half-space. In general, a low-modulus (high-modulus) layer causes the half-space equivalent dislocation to appear shallower (deeper) than the actual dislocation in the layered half-space.

Savage, J.C.

1998-01-01

38

Construction of a high-resolution moiré interferometer for investigating microstructural displacement fields in materials.  

PubMed

A high-magnification moiré interferometer has been constructed with a spatial resolution of the order of 1 microm to measure the local in-plane displacement field associated with a material's microstructure. Laser illumination passes through phase-stepping optics and is delivered to the microscope head by polarization-preserving single-mode optical fibres. The head itself is a compact unit consisting of collimating optics, an objective lens and a charge coupled device (CCD) camera. Thin-phase gratings are cast onto the sample surface with a compliant epoxy resin and coated with ca. 5 nm of gold to enhance the fringe contrast and reduce speckle noise. By switching between the laser illumination and white-light illumination, the underlying microstructure is viewed in exact registration with the measured displacement fields. The application of the instrument is illustrated here by visualization of displacement fields in polymer-bonded explosives (PBXs) during deformation to failure. PBXs are highly filled polymers consisting of up to 95% by weight crystalline explosive bound in a variety of polymeric binders. The mechanical properties of PBXs are highly dependent on the microstructure, and moiré interferometry is an ideal tool for investigating the relationship between the 1-100 microm sized crystals and the displacement fields. Methods such as this are required if computer models of inhomogeneous materials are to be accurately validated. PMID:12804287

Goldrein, H T; Rae, P J; Palmer, S J P; Field, J E

2002-05-15

39

Mars: a magnetic field due to thermoremanence?  

Microsoft Academic Search

Presently available magnetic field data suggest a dipole moment of Mars of less than 10?4 times the Earth's dipole moment. Presumably, Mars does not have an active dynamo at present which could give rise to a significant magnetic field. Nevertheless, the presently available data do not rule out a minor intrinsic field which may originate from a magnetized lithosphere. The

Martin Leweling; Tilman Spohn

1997-01-01

40

Possibility of unlimited shear displacement due to sliding-surface-liquefaction of MH gasification and long runout submarine landslides  

NASA Astrophysics Data System (ADS)

Recent studies on the mechanism of occurrence of large scale submarine landslides focuses mostly on the generation of excess pore pressure due to rapid sedimentation rate in certain environment, rather than gasification of methane hydrates (MH), although MH gasification could contribute to the landslides in the transgresssion period. However, at the 1896 Meiji Sanriku-oki Earthquake which caused serious tsunami disaster in the Tohoku region of Japan, there are witnesses of large-scale flame which were of possibly ejected dissolved methane hydrates (MH) from sea floor. We employed the stress-controlled undrained ring shear apparatuses have been developed at Disaster Prevention Research Institute, Kyoto University to reproduce shear behavior of the dry sand-dry ice mixture under constant normal stress and shear speed control tests using the latest ring shear apparatus. Tested sample was mixture of silica sands and dry-ice pellets (frozen carbon-dioxide). Those mixtures are often used for studying the mechanism of the methane hydrates in laboratories because no explosion protection facility is required. Through three series of tests, we obtained following results. (1) Rate Effect: The samples were tested under stepped shear speed ranging from 0.02 cm/s to 10 cm/s. The obtained excess pore-pressure ratio relationship, which is defined as the ratio of excess pore air pressure to initial effective stress, These results clearly shows positive speed dependency, especially for 1 cm/s and 10 cm/s. This phenomenon could be explained by the "sliding surface liquefaction." (2) Difference between internal and external friction: Based on the published observation of the sliding surface and the BSR, the sliding surface can be generated in the boundary of the MH layer. Tests to compare the internal friction and external friction between sand layers reveals that the behaviour of the both conditions have no significant difference. (3) Shear behaviour under cyclic loading condition: Above-mentioned sliding-surface-liquefaction in the sand - dry ice mixture supports the possibility of similar accelerating and unlimited displacement in the sand-MH mixture or boundaries between MH and sand layer induced by certain strong ground motion under sea floor. To simulate the earthquake-induced submarine landslides due to gasification of MH, authors applied the simple sine-curve cyclic loading to the sand-dry ice sample. After certain number of cyclic loading, sliding surface liquefaction appeared. When the mobilized shear resistance reduced by such excess pore pressure becomes smaller than the shear stress, accelerating behavior and unlimited shear displacement could be expected. Thus, MH still has high possibility to cause gigantic submarine landslides under certain strong earthquake condition.

Tsukui, A.; Fukuoka, H.; Yamasaki, S.

2012-04-01

41

The displacement field in the vibration analysis of laminated thick plates  

SciTech Connect

The present paper discusses the assumption of displacement fields used in the vibration analysis of FRP laminated thick plates. For this purpose, the strain and kinetic energies of a FRP cross-ply laminated plate are evaluated analytically based on the three-dimensional theory of elasticity, and the displacements of the rectangular plate, which are simply-supported at all edges, are expanded into the polynomial forms with respect to thickness coordinate. A frequency equation is formulated by using the energy method minimizing the Lagrange function. In the numerical calculations, natural frequencies are obtained for the plates with various stacking sequence and the thickness ratios, and the validity of the assumption of displacement fields and the range of applicability of the various plate theories (e.g. the Classical Plate Theory (CPT), the First-Order Shear Deformation Theory (FSDT) and the Higher-Order Shear Deformation Theory (HSDT)), which are widely used in the vibration analysis of FRP laminated plates, to the laminated thick plates are discussed by comparing the present results with the CPT and the FSDT solutions.

Ohta, Yoshiki; Narita, Yoshihiro [Hokkaido Inst. of Tech., Hokkaido (Japan). Dept. of Mechanical Engineering

1995-11-01

42

Southward displacement of the upper atmosphere zonal jet in the eastern north Pacific due to global warming  

NASA Astrophysics Data System (ADS)

jet stream over the eastern North Pacific (ENPJ) as a core of the atmospheric flow is known to strongly fluctuate meridionally, and its meridional displacement directly influences adjacent regional climate. Here, we investigate how this jet will be changed due to global warming. By analyzing the future scenario experiments of Climate Model Intercomparion Project Phase III (CMIP3) and Phase V (5), it was found that both ENPJ and the eastern tropical Pacific intertropical convergence zone (ITCZ) tend to move southward, which are closely related to the tropical eastern Pacific warming trend. Tropical eastern Pacific warming leads to not only the southward migration of ITCZ by southward-shifting the off-equatorial eastern Pacific warm pool, but also the southward shift of ENPJ by increasing baroclinic instability of the atmosphere in subtropical region through intensifying the meridional sea surface temperature (SST) gradient. Not primary but yet secondly the southward shift of ITCZ contributes to the southward shift of ENPJ through a kinematic connection bridged by local Hadley circulation.

Park, Jae-Heung; An, Soon-Il

2014-11-01

43

Determining crack-tip stress-field parameters from mixed-mode displacement fields  

E-print Network

SOLUTION ALGORITHM FORTRAN LISTING . . 57 59 61 APPENDIX B ISOCHROMATIC FRINGE FORTRAN SUBROUTINE . . 91 APPENDIX C MOIRE FRINGE FORTRAN SUBROUTINES . . 97 VITA 105 LIST OF TABLES TABLE Page I Input load sets used to calculate theoretical... coefficients, (C) =([F] [F]) [F] (-~) (22) This least-squares algorithm can easily be implemented using a computer. A FORTRAN code of the solution scheme is located in the Appendix A. As mentioned earlier, when obtaining experimental displacement fringe...

Matsumoto, Kay Yuri

2012-06-07

44

A Variational Principle for the Calculation of Core Modes Directly in the Displacement Field  

NASA Astrophysics Data System (ADS)

We present a new functional for the variational calculation of core modes expressed directly in the vector displacement field. The Earth's outer core is a rotating, compressible, self-gravitating, stratified fluid, contained within the elastic spherical boundaries of the shell and inner core. The calculation of its long period modes of oscillation is a challenging problem first solved by Smylie et al (1992) using a variational principle based on the scalar generalized potential. While the accurate computations this formulation affords led to the detection of the three translational modes of oscillation of the inner core in the spectra of superconducting gravimeter observations (Smylie, Francis and Merriam, 2001), it is a complicated formulation and leads to a lambda matrix problem of degree eight, even in the case of small non-neutral stratification. The functional presented here gives the displacement field directly and leads to only a quadratic eigenvalue problem for arbitrary non-neutral stratification. It is easily converted to a linear problem of twice the dimension opening the possibility of computing all eigenvalues and eigenvectors below a given degree of spatial complexity, and the construction of a catalogue of core modes.

Ma, H.; Smylie, D. E.; de Viron, O.

2001-12-01

45

Extracting Tractosemas from a Displacement Probability Field for Tractography in DW-MRI?  

PubMed Central

In this paper we present a novel method for estimating a field of asymmetric spherical functions, dubbed tractosemas, given the intra-voxel displacement probability information. The peaks of tractosemas correspond to directions of distinct fibers, which can have either symmetric or asymmetric local fiber structure. This is in contrast to the existing methods that estimate fiber orientation distributions which are naturally symmetric and therefore cannot model asymmetries such as splaying fibers. We propose a method for extracting tractosemas from a given field of displacement probability iso-surfaces via a diffusion process. The diffusion is performed by minimizing a kernel convolution integral, which leads to an update formula expressed in the convenient form of a discrete kernel convolution. The kernel expresses the probability of diffusion between two neighboring spherical functions and we model it by the product of Gaussian and von Mises distributions. The model is validated via experiments on synthetic and real diffusion-weighted magnetic resonance (DW-MRI) datasets from a rat hippocampus and spinal cord. PMID:18979726

Barmpoutis, Angelos; Howland, Dena; Forder, John R.

2009-01-01

46

Coupling loss with long time constants due to large displacement of strands in a large CIC conductor  

Microsoft Academic Search

ac losses consist of both regular losses that are proportional to squared cable twisting pitch and irregular losses that could not be estimated from short conductor sample test results. It was explained from our previous works that irregular loops in the conductor, which are caused by strand displacement as a result of low void fraction of the CIC conductor, produce

T. Yagai; H. Sato; M. Tsuda; T. Hamajima; Y. Nunoya; Y. Takahashi; K. Okuno

2006-01-01

47

Landslide sub-surface characteristics inferred from Terrestrial Laser Scanning surface displacement fields  

NASA Astrophysics Data System (ADS)

Increasingly available Terrestrial Laser Scanner (TLS) data permit the construction of complete ground-surface displacement fields for slow-moving landslides, particularly with the adoption of techniques such as particle-imaging velocimetry (PIV). An important next step, following well-developed analytical methodologies from the earthquake geodesy field, is to use the high-resolution surficial data to infer sub-surface characteristics such as slip-surface orientation and slip magnitude. Here, we first extend the PIV method to estimate a fully three-dimensional surface displacement field. Then, we test the efficacy of using two different sub-surface inference techniques and compare with in situ measurements from the episodically active part of the Cleveland Corral landslide in northern California. A 2-d balanced cross-section (area-balancing) method assuming incompressible material behavior uniquely constrains slip magnitude and depth whereas an elastic dislocation model requires solving a multidimensional non-linear inverse problem. We address this by placing strong prior constraints (e.g. length of the slip patch is about the length of the landslide) on orientation parameters that render the elastic dislocation problem computationally tractable via a direct search of parameter space. This reduction of free parameters is likely to be applicable to most surveyed landslides. The estimated landslide slip depth using both methods is consistent with previous seismic refraction surveys and contemporaneously installed shear rods. Importantly, slip magnitude determined by the balanced cross-section method is nearly twice that estimated using the elastic dislocation model (~ 1m). This two-fold difference is not surprising given the end-member model material properties but it highlights the need for further development of discriminatory criteria. Finally, our demonstration of this general sub-surface inference methodology should stimulate the development and application of more computationally efficient, though rheologically realistic, landslide models for use with inverse methods.

Aryal, A.; Brooks, B. A.; Reid, M. E.

2012-12-01

48

Applying a Bayesian Approach to Identification of Orthotropic Elastic Constants from Full Field Displacement Measurements  

NASA Astrophysics Data System (ADS)

A major challenge in the identification of material properties is handling different sources of uncertainty in the experiment and the modelling of the experiment for estimating the resulting uncertainty in the identified properties. Numerous improvements in identification methods have provided increasingly accurate estimates of various material properties. However, characterizing the uncertainty in the identified properties is still relatively crude. Different material properties obtained from a single test are not obtained with the same confidence. Typically the highest uncertainty is associated with respect to properties to which the experiment is the most insensitive. In addition, the uncertainty in different properties can be strongly correlated, so that obtaining only variance estimates may be misleading. A possible approach for handling the different sources of uncertainty and estimating the uncertainty in the identified properties is the Bayesian method. This method was introduced in the late 1970s in the context of identification [1] and has been applied since to different problems, notably identification of elastic constants from plate vibration experiments [2]-[4]. The applications of the method to these classical pointwise tests involved only a small number of measurements (typically ten natural frequencies in the previously cited vibration test) which facilitated the application of the Bayesian approach. For identifying elastic constants, full field strain or displacement measurements provide a high number of measured quantities (one measurement per image pixel) and hence a promise of smaller uncertainties in the properties. However, the high number of measurements represents also a major computational challenge in applying the Bayesian approach to full field measurements. To address this challenge we propose an approach based on the proper orthogonal decomposition (POD) of the full fields in order to drastically reduce their dimensionality. POD is based on projecting the full field images on a modal basis, constructed from sample simulations, and which can account for the variations of the full field as the elastic constants and other parameters of interest are varied. The fidelity of the decomposition depends on the number of basis vectors used. Typically even complex fields can be accurately represented with no more than a few dozen modes and for our problem we showed that only four or five modes are sufficient [5]. To further reduce the computational cost of the Bayesian approach we use response surface approximations of the POD coefficients of the fields. We show that 3rd degree polynomial response surface approximations provide a satisfying accuracy. The combination of POD decomposition and response surface methodology allows to bring down the computational time of the Bayesian identification to a few days. The proposed approach is applied to Moiré interferometry full field displacement measurements from a traction experiment on a plate with a hole. The laminate with a layup of [45,- 45,0]s is made out of a Toray® T800/3631 graphite/epoxy prepreg. The measured displacement maps are provided in Figure 1. The mean values of the identified properties joint probability density function are in agreement with previous identifications carried out on the same material. Furthermore the probability density function also provides the coefficient of variation with which the properties are identified as well as the correlations between the various properties. We find that while the longitudinal Young’s modulus is identified with good accuracy (low standard deviation), the Poisson’s ration is identified with much higher uncertainty. Several of the properties are also found to be correlated. The identified uncertainty structure of the elastic constants (i.e. variance co-variance matrix) has potential benefits to reliability analyses, by allowing a more accurate description of the input uncertainty. An additional advantage of the Bayesian approach is that it provides a natural way (in the form of the prior probab

Gogu, C.; Yin, W.; Haftka, R.; Ifju, P.; Molimard, J.; Le Riche, R.; Vautrin, A.

2010-06-01

49

Software Detection of Hardware Plateform Failures due to Electromagnetic Fields  

E-print Network

Software Detection of Hardware Plateform Failures due to Electromagnetic Fields MOTET Gilles1 of embedded electronic systems susceptibility to electromagnetic fields is often obtained by hardware devices the system safety as this technology is sensitive to the stresses of the environment and, in particular

Paris-Sud XI, Université de

50

Habitat partitioning and competitive displacement in cattails (Typha): experimental field studies  

Microsoft Academic Search

A conspicuous feature of many plant communities that is often considered evidence of competitive displacement is the segregation of species along a habitat gradient. The extent of competitive displacement is examined in a recently established association of cattails (Typha latifolia L. and T. angustifolia L.). To accomplish this, potential and realized distributions of these two species were compared along a

James B. Grace; Robert G. Wetzel

1981-01-01

51

Cosmological electromagnetic fields due to gravitational wave perturbations Mattias Marklund*  

E-print Network

Cosmological electromagnetic fields due to gravitational wave perturbations Mattias Marklund and Applied Mathematics, University of Cape Town, Rondebosch 7701, Cape Town, South Africa; and Department of Electromagnetics, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden Peter K. S. Dunsby Department

Dunsby, Peter

52

Full-field displacement and strain measurement of small complex bony structures with digital speckle pattern interferometry and shearography  

Microsoft Academic Search

We have developed a simple digital speckle pattern interferometry (DSPI) and shearography setup to measure the displacement and the corresponding strains of small complex bony structures. We choose both optical techniques because we want to obtain very small deformations (+\\/- 20 mum) of small objects (+\\/- 1cm). Furthermore full field and in situ measurements are preferred. We first use a

Joris Soons; Joris J. J. Dirckx

2010-01-01

53

Stress and displacement fields in the outer wedge induced by megathrust earthquakes  

NASA Astrophysics Data System (ADS)

model plate boundary slip at the outer (oceanward) segment of the megathrust wedge as slip at the base of a two-dimensional elastic wedge, subject to gravity force, with a sloping seafloor at the top, and drag at the bottom from a rigid plate in frictional contact. The stress and displacement fields in the wedge are given analytically as functions of basal frictional coefficient ?e. Unlike either conventional dislocation models (constant slip) or crack models (constant stress drop), our wedge model (constant ?e drop) does not show a stress singularity at the updip toe of the plate boundary. The slip increases, but the stress drop decreases updip along the fault toward the trench axis. There is a minimum stress difference state in the wedge when ?e is varied. By referring to this state (?e = ?ec), the stress state is separated into a horizontally tensile regime (?e < ?ec) and a horizontally compressional regime (?e > ?ec). Slip associated with a ?e drop in the range ?e ? ?ec occurs toward increasing horizontal tension and shear energy. Such earthquakes include tsunami earthquakes occurring in the outer segment and the 2011 great Tohoku-Oki earthquake, which involved both the outer and inner segments, with much larger slip in the outer segment. These earthquakes are characterized by an almost complete drop of basal stress, which brings the wedge into the maximum tensile state, leading to the rare occurrence of thrust aftershocks at the base of the wedge and frequent occurrence of normal fault aftershocks within the wedge.

Fukao, Yoshio; Hori, Takane; Kodaira, Shuichi

2014-05-01

54

Analysis of the lateral displacement and optical path difference in wide-field-of-view polarization interference imaging spectrometer  

Microsoft Academic Search

The mechanism of beam splitting and principle of wide-field-of-view compensation of modified Savart polariscope in the wide-field-of-view polarization interference imaging spectrometer (WPIIS) are analyzed and discussed. Formulas for the lateral displacement and optical path difference (OPD) produced by the modified Savart polariscope are derived by ray-tracing method. The theoretical and practical guidance is thereby provided for the study, design, modulation,

Lei Wu; Chunmin Zhang; Baochang Zhao

2007-01-01

55

Flow damping due to stochastization of the magnetic field  

NASA Astrophysics Data System (ADS)

The driving and damping mechanism of plasma flow is an important issue because flow shear has a significant impact on turbulence in a plasma, which determines the transport in the magnetized plasma. Here we report clear evidence of the flow damping due to stochastization of the magnetic field. Abrupt damping of the toroidal flow associated with a transition from a nested magnetic flux surface to a stochastic magnetic field is observed when the magnetic shear at the rational surface decreases to 0.5 in the large helical device. This flow damping and resulting profile flattening are much stronger than expected from the Rechester–Rosenbluth model. The toroidal flow shear shows a linear decay, while the ion temperature gradient shows an exponential decay. This observation suggests that the flow damping is due to the change in the non-diffusive term of momentum transport.

2015-01-01

56

Flow damping due to stochastization of the magnetic field  

PubMed Central

The driving and damping mechanism of plasma flow is an important issue because flow shear has a significant impact on turbulence in a plasma, which determines the transport in the magnetized plasma. Here we report clear evidence of the flow damping due to stochastization of the magnetic field. Abrupt damping of the toroidal flow associated with a transition from a nested magnetic flux surface to a stochastic magnetic field is observed when the magnetic shear at the rational surface decreases to 0.5 in the large helical device. This flow damping and resulting profile flattening are much stronger than expected from the Rechester–Rosenbluth model. The toroidal flow shear shows a linear decay, while the ion temperature gradient shows an exponential decay. This observation suggests that the flow damping is due to the change in the non-diffusive term of momentum transport. PMID:25569268

Ida, K.; Yoshinuma, M.; Tsuchiya, H.; Kobayashi, T.; Suzuki, C.; Yokoyama, M.; Shimizu, A.; Nagaoka, K.; Inagaki, S.; Itoh, K.; Akiyama, T.; Emoto, M.; Evans, T.; Dinklage, A.; Du, X.; Fujii, K.; Goto, M.; Goto, T.; Hasuo, M.; Hidalgo, C.; Ichiguchi, K.; Ishizawa, A.; Jakubowski, M.; Kamiya, K.; Kasahara, H.; Kawamura, G.; Kato, D.; Kobayashi, M.; Morita, S.; Mukai, K.; Murakami, I.; Murakami, S.; Narushima, Y.; Nunami, M.; Ohdach, S.; Ohno, N.; Osakabe, M.; Pablant, N.; Sakakibara, S.; Seki, T.; Shimozuma, T.; Shoji, M.; Sudo, S.; Tanaka, K.; Tokuzawa, T.; Todo, Y.; Wang, H.; Yamada, H.; Takeiri, Y.; Mutoh, T.; Imagawa, S.; Mito, T.; Nagayama, Y.; Watanabe, K. Y.; Ashikawa, N.; Chikaraishi, H.; Ejiri, A.; Furukawa, M.; Fujita, T.; Hamaguchi, S.; Igami, H.; Isobe, M.; Masuzaki, S.; Morisaki, T.; Motojima, G.; Nagasaki, K.; Nakano, H.; Oya, Y.; Suzuki, Y.; Sakamoto, R.; Sakamoto, M.; Sanpei, A.; Takahashi, H.; Tokitani, M.; Ueda, Y.; Yoshimura, Y.; Yamamoto, S.; Nishimura, K.; Sugama, H.; Yamamoto, T.; Idei, H.; Isayama, A.; Kitajima, S.; Masamune, S.; Shinohara, K.; Bawankar, P. S.; Bernard, E.; von Berkel, M.; Funaba, H.; Huang, X. L.; Ii, T.; Ido, T.; Ikeda, K.; Kamio, S.; Kumazawa, R.; Moon, C.; Muto, S.; Miyazawa, J.; Ming, T.; Nakamura, Y.; Nishimura, S.; Ogawa, K.; Ozaki, T.; Oishi, T.; Ohno, M.; Pandya, S.; Seki, R.; Sano, R.; Saito, K.; Sakaue, H.; Takemura, Y.; Tsumori, K.; Tamura, N.; Tanaka, H.; Toi, K.; Wieland, B.; Yamada, I.; Yasuhara, R.; Zhang, H.; Kaneko, O.; Komori, A.

2015-01-01

57

Flow damping due to stochastization of the magnetic field.  

PubMed

The driving and damping mechanism of plasma flow is an important issue because flow shear has a significant impact on turbulence in a plasma, which determines the transport in the magnetized plasma. Here we report clear evidence of the flow damping due to stochastization of the magnetic field. Abrupt damping of the toroidal flow associated with a transition from a nested magnetic flux surface to a stochastic magnetic field is observed when the magnetic shear at the rational surface decreases to 0.5 in the large helical device. This flow damping and resulting profile flattening are much stronger than expected from the Rechester-Rosenbluth model. The toroidal flow shear shows a linear decay, while the ion temperature gradient shows an exponential decay. This observation suggests that the flow damping is due to the change in the non-diffusive term of momentum transport. PMID:25569268

Ida, K; Yoshinuma, M; Tsuchiya, H; Kobayashi, T; Suzuki, C; Yokoyama, M; Shimizu, A; Nagaoka, K; Inagaki, S; Itoh, K

2015-01-01

58

Tune Variations due to Septum Stray Field F. Pederson &  

SciTech Connect

Two types of antiproton instabilities due to trapped ions are harmful in the AA. One is a coherent instability occurring when an ion pocket resonates with a 3-Q mode (hiccups), the other is excitation of 11th and 15th order non-linear resonances due to the non-linear focusing fields from localized ion clouds trapped in uncleared potential well pockets. Accumulation with a good injection yield of antiprotons forces us to locate the tune of the dense core in the general area of the array of 15th order resonances. To avoid harmful blow-up of the dense core the tune is located between the resonances 11Q{sub H} + 4Q{sub V} = 34, 10Q{sub H} + 5Q{sub V} = 34, and 11Q{sub H} = 25, requiring a tune of Q{sub H} = 2.2722 to be maintained with a precision of a few 10{sup -4} (Fig. 4). Different angles of the injection and ejection trajectories require the septum current to be changed from 3860 A during accumulation to 3920 A, during ejection mode. Variations in the septum stray field due to these changes in current cause tune changes in the order of 10{sup -3}. In addition, at a given septum current, a pronounced hysteresis of the stray field causes tune variations of about the same order of magnitude, so also the past history of the septum excitation must be carefully controlled to obtain a reproducible tune.

Rinolfi, L.

1986-10-12

59

Near field 3D displacement of El Mayor-Cupapah Earthquake: A hybrid approach. (Invited)  

NASA Astrophysics Data System (ADS)

The surface rupture produced on April 4th of 2010 by the M 7.2 El Mayor-Cucapah Earthquake is an ideal target to be analyzed by remote sensing techniques. It produced over 100 km of scarps, with vertical and horizontal slip on the order of 2 to 3 m in scarcely vegetated, rugged terrain underlain by mostly igneous rocks. A 3D displacement field (DF) was calculated by matching pre- to post-event airborne LiDAR point clouds through the Iterative Closest Point (ICP) algorithm, which first segments the point clouds into discrete windows, and for each, iteratively converges on a rigid body transformation comprising a translation and a rotation that best aligns the pre- to post-event point clouds. After testing different window sizes, we used a square window 100m a side. The El Mayor-Cucapah LiDAR data sets present special challenges for the ICP technique. The point clouds differ considerably in point density, by ~1:700. This, and the lower precision of the pre-earthquake data, limit the accuracy of the DF results. Despite these issues, the vertical and East-West (E-W) components of the DF from ICP very clearly delineate the trace of the surface rupture, showing east-side down dextral-normal motion in agreement with field measurements and the focal mechanism reported for this event. A systematic error in the LiDAR instrument used for the pre-event survey caused severe distortion of the North-South (N-S) component of the LiDAR returns. After reprocessing the source pre-event point cloud in various ways to correct for the systematic error, a more plausible pattern for the N-S component was obtained for the DF. To have another perspective for the horizontal DF, a subpixel correlation analysis of optical satellite images (SPOT 2.5 m panchromatic images) before and after the earthquake, was performed using the COSI-Corr software. We combined the N-S component from this analysis with the E-W and vertical components of the ICP results, and present the analysis of the resulting DF. We also compare the results from ICP and COSI-Corr individually for each of the horizontal components. Both methods delineate very clearly the rupture, and agree in direction with small discrepancies in magnitude for the horizontal DF. Results from far field deformation measurements obtained from different remote sensing techniques, such as GPS and InSAR, could be fused with the near-field LiDAR and COSI-Corr results to provide a synoptic view of the strain induced by earthquakes such as the El Mayor-Cucapah event.

Hinojosa-Corona, A.; Limon, F. J.; Nissen, E.; Glennie, C. L.; Krishnan, A.; Oskin, M. E.; Arrowsmith, R.; Leprince, S.; Saripalli, S.; Arregui, S. M.; Borsa, A. A.; Kreylos, O.; Banesh, D.; Fletcher, J. M.

2013-12-01

60

Interplate coupling beneath NE Japan inferred from three-dimensional displacement field  

Microsoft Academic Search

The northeastern Japan arc is located in a typical subduction zone and is a seismically active region where large interplate earthquakes have occurred repeatedly. The nationwide GPS network has made it possible to investigate the crustal deformation in unprecedented detail; however, vertical displacements are less accurate than the horizontal ones and have not been used to constrain interplate coupling models.

Yoko Suwa; Satoshi Miura; Akira Hasegawa; Toshiya Sato; Kenji Tachibana

2006-01-01

61

Active displacement field in the Suez–Sinai area: the role of postseismic deformation  

Microsoft Academic Search

By means of a spherical viscoelastic model of co- and postseismic deformation we compute the postseismic displacement associated with the November, 1995, Mw=7.2, Aqaba (Jordan) earthquake. We compare our results with the observational data obtained by a GPS campaign performed in a wide portion of Sinai between November 1997 and May 1998. Though the original purpose of the campaign was

A. Piersanti; C. Nostro; F. Riguzzi

2001-01-01

62

Optics for five-dimensional measurement for correction of vertical displacement error due to attitude of floating body in superconducting magnetic levitation system  

SciTech Connect

An improved optical system for five-dimensional measurement has been developed for the correction of vertical displacement error due to the attitude change of a superconducting floating body that shows five degrees of freedom besides a vertical displacement of 10 mm. The available solid angle for the optical measurement is extremely limited because of the cryogenic laser interferometer sharing the optical window of a vacuum chamber in addition to the basic structure of the cryogenic vessel for liquid helium. The aim of the design was to develop a more practical as well as better optical system compared with the prototype system. Various artifices were built into this optical system and the result shows a satisfactory performance and easy operation overcoming the extremely severe spatial difficulty in the levitation system. Although the system described here is specifically designed for our magnetic levitation system, the concept and each artifice will be applicable to the optical measurement system for an object in a high-vacuum chamber and/or cryogenic vessel where the available solid angle for an optical path is extremely limited.

Shiota, Fuyuhiko; Morokuma, Tadashi [National Metrology Institute of Japan (NMIJ), AIST, Tsukuba Central 3, 1-1-1 Umezono, Ibaraki 305-8563 (Japan); Tokyo Denki University, 2-2 Kanda-Nishiki-cho, Chiyoda-ku, Tokyo 101-8457 (Japan)

2006-09-15

63

Predicting ground electric field due to geomagnetic disturbances  

NASA Astrophysics Data System (ADS)

Electric field induced in the ground by geomagnetic disturbances drives currents in the power transmission grids, telecommunication lines or buried pipelines. These currents, known as Geomagnetically Induced Currents (GIC) are known to cause service disruptions. This effect is maximal at high latitudes due to the presence of strong polar electrojet currents. However both observations and models show that GIC caused by ring current intensifications also pose a risk at low- and mid-latitude locations, where majority of systems vulnerable to GIC are installed. A technique to model geoelectric field induced by the magnetospheric currents in a 3D conductivity model of the Earth is presented by Püthe & Kuvshinov (2013). We extend this work by predicting the induced geoelectric field solely based on Disturbance storm time index (Dst), a measure of ring current activity. Two major components of this effort are 1) Pre-computed 3D electromagnetic response of the ground to a unit magnetopsheric (P01) source and 2) Forecasted Dst data (Temerin & Li, 2002; 2006) from Advanced Composition Explorer (ACE) satellite at the L1 Lagrange point. Depending on the solar wind speed, the Dst forecasts are available approximately 1 hour in advance. The pre-computed response function for a site is multiplied by the Dst data in frequency domain to obtain predicted electric field for that location. Validating our approach, the predicted geoelectric field compares favorably with observed data from an ocean bottom electromagnetic array in the Pacific Ocean during the geomagnetic storm of April 2000. We also compare data from USArray magnetotelluric stations operational during the geomagnetic storm of October 2011. In this case, the results are site specific, with varying degrees of model fit. This indicates the influence of local surface conductivity inhomogeneities on the observed geoelectric data. Averaging data from adjacent stations seems to improve the fit with the prediction.

Nair, M. C.; Püthe, C.; Kuvshinov, A. V.

2013-12-01

64

Evaluation of the Compressive Response of Notched Composite Panels using a Full-Field Displacement Measurement System  

NASA Technical Reports Server (NTRS)

An experimental and analytical evaluation of the compressive response of two composite, notched stiffened panels representative of primary composite wing structure is presented. A three-dimensional full-field image correlation technique is used to measure all three displacement components over global and local areas of the test panels. Point-wise and full-field results obtained using the image correlation technique are presented and compared to experimental results and analytical results obtained using nonlinear finite element analysis. Both global and global-local image correlation results are presented and discussed. Results of a simple calibration test of this image correlation technique are also presented.

McGowan, David M.; Ambur, Damodar R.; Hanna, T. Glen; McNeill, Stephen R.

1999-01-01

65

Full-field displacement and strain measurement of small complex bony structures with digital speckle pattern interferometry and shearography  

NASA Astrophysics Data System (ADS)

We have developed a simple digital speckle pattern interferometry (DSPI) and shearography setup to measure the displacement and the corresponding strains of small complex bony structures. We choose both optical techniques because we want to obtain very small deformations (+/- 20 ?m) of small objects (+/- 1cm). Furthermore full field and in situ measurements are preferred. We first use a Michelson DSPI arrangement with phase shifting. In this way we can obtain the out-of-plane displacements precisely. Second, shearography is introduced to measure the derivative of the out-ofplane displacement. In this way some intrinsic disadvantages of DSPI can be overcome. We have developed these setups to measure the out-of-plane deformations of (small) bird beaks when realistic external forces are applied. In this way, we have a full field validation measurement to which we can compare the outcome of realistic finite element models. The aim is to determine whether the shape, and not only the size, of the bird beaks are optimized to deal with the biting forces that a species encounters. This quantitative analysis will help biologists to investigate if beak morphology is adapted to feeding habits. Applying the method to the famous evolution model of the Darwin's finches will provide scientific proof of functional evolution. In this paper we will present both the DSPI and shearography setup, a comparison of the performance of both techniques on a simple deflection of a cantilever beam and the first results obtained on loaded bird beaks.

Soons, Joris; Dirckx, Joris J. J.

2010-09-01

66

Improved Newton-Raphson digital image correlation method for full-field displacement and strain calculation.  

PubMed

The two-dimensional in-plane displacement and strain calculation problem through digital image processing methods has been studied extensively in the past three decades. Out of the various algorithms developed, the Newton-Raphson partial differential correction method performs the best quality wise and is the most widely used in practical applications despite its higher computational cost. The work presented in this paper improves the original algorithm by including adaptive spatial regularization in the minimization process used to obtain the motion data. Results indicate improvements in the strain accuracy for both small and large strains. The improvements become even more significant when employing small displacement and strain window sizes, making the new method highly suitable for situations where the underlying strain data presents both slow and fast spatial variations or contains highly localized discontinuities. PMID:21102673

Cofaru, Corneliu; Philips, Wilfried; Van Paepegem, Wim

2010-11-20

67

Fields of atomic displacements in crystals of disordered alloys KhN35VT and KhN35VTYu  

NASA Astrophysics Data System (ADS)

As a result of an asymmetrical local environment of each of the atoms in the crystal of a disordered alloy, its equilibrium state is accompanied by atomic displacements from the positions in the sites of the ideal lattice. With the use of original interatomic potentials, we constructed fields of atomic displacements in model alloys (of approximate composition Fe-35% Ni-15% Cr-3% W-2% Ti) that are close to the KhN35VT and KhN35VTYu alloys. It is shown that, depending on the composition of the alloy, it is possible to predict the degree of distortion of the lattice of its disordered phase and, therefore, to prognose its mechanical properties.

Baranov, M. A.; Dubov, E. A.

2007-09-01

68

Field data do not support a textbook example of convergent character displacement.  

PubMed Central

Experimental evidence supporting convergent character displacement is rare; only one example exists and it is in the form of orientation and territory competition experiments performed in the laboratory. However, outcomes of laboratory experiments involving behaviour or competition can be artefacts of unnatural conditions and, therefore, the results of the previous experiments supporting convergent character displacement are equivocal. In this study, we re-examine the evolution of melanic nuptial coloration in male three-spined stickleback (Gasterosteus aculeatus) inhabiting the Chehalis River drainage in Washington State. This novel nuptial coloration has been thought to have evolved in response to competition for nesting territories with the co-distributed Olympic mudminnow (Norzumbra hubbsi), which is also melanic and breeds at the same time. I found that melanic stickleback males did not have an advantage over their red counterparts from typical populations when competing for nesting territories with Olympic mudminnows. Additionally competitive interactions between sticklebacks and mudminnows were rare in both cage experiments and naturally breeding sticklebacks. Finally, melanic coloration in the Chehalis populations did not develop until males were parental, well after the hypothesized territory establishment period. These results refute the only experimental support for convergent character displacement and emphasize the importance of conducting behavioural experiments and observations under natural conditions. PMID:10787166

Scott, R J; Foster, S A

2000-01-01

69

Numerical Simulation of a Displacement Ventilation System with Multi-heat Sources and Analysis of Influential Factors  

E-print Network

Displacement ventilation (DV) is a promising ventilation concept due to its high ventilation efficiency. In this paper, the application of the CFD method, the velocity and temperature fields of three-dimensional displacement ventilation systems...

Wu, X.; Gao, J.; Wu, W.

2006-01-01

70

Faraday Rotation Measure due to the Intergalactic Magnetic Field  

E-print Network

Studying the nature and origin of the intergalactic magnetic field (IGMF) is an outstanding problem of cosmology. Measuring Faraday rotation would be a promising method to explore the IGMF in the large-scale structure (LSS) of the universe. We investigated the Faraday rotation measure (RM) due to the IGMF in filaments of galaxies using simulations for cosmological structure formation. We employed a model IGMF based on turbulence dynamo in the LSS of the universe; it has an average strength of $ \\sim 10$ nG and a coherence length of several $\\times\\ 100\\ h^{-1}$ kpc in filaments. With the coherence length smaller than path length, the inducement of RM would be a random walk process, and we found that the resultant RM is dominantly contributed by the density peak along line of sight. The rms of RM through filaments at the present universe was predicted to be $\\sim 1\\ {\\rm rad\\ m^{-2}}$. In addition, we predicted that the probability distribution function of $|{\\rm RM}|$ through filaments follows the log-normal ...

Akahori, Takuya

2010-01-01

71

Small displacement normal faults as barriers to fluid flow in the complexly faulted anticline of the Wilmington Field  

SciTech Connect

Fault controlled barriers can significantly affect basin flow dynamics. Fault barriers cause compartmentalization of fluid systems, isolating areas of differing fluid pressure, diagenetic processes, and fluid characteristics. Understanding the effects of relatively difficult to detect, small displacement faults on fluid flow is essential when analyzing basin hydrodynamics. The Wilmington structure is a SE plunging asymmetric anticline cut by a series of N-S oriented normal faults in the west and NW-SE oriented normal faults in the east. Fault displacement varies within the field from no displacement at fault tips, to the maxima for each fault, which varies from 10m to 135m. Faults are truncated at a mid Pliocene unconformity above which sediments are neither folded nor faulted. Over 2000 deviated wells penetrate the structure in a sixteen square mile area, often crossing the high angle normal faults. We are first performing a detailed analysis of fault geometry and degree of offset from well logs and a 3D seismic survey. A core recovered through the Temple Avenue fault shows slip over a ten meter zone without a dominant slip plane. Well logs also indicate a zone of deformation associated with the fault. A barrier was present, prior to development, across the fault where offset is less than the thickness of the offset reservoir unit, indicating fault zone properties are responsible for formation of the barrier. Fault barriers are established from offset oil-water contacts, pressure, and production surveys. Preliminary analysis of pressure data shows variability across the field and a lack of fluid communication over short distances.

Teas, P.A.; Thornburg, J. (Univ. of Southern California, Santa Cruz, CA (United States))

1996-01-01

72

Small displacement normal faults as barriers to fluid flow in the complexly faulted anticline of the Wilmington Field  

SciTech Connect

Fault controlled barriers can significantly affect basin flow dynamics. Fault barriers cause compartmentalization of fluid systems, isolating areas of differing fluid pressure, diagenetic processes, and fluid characteristics. Understanding the effects of relatively difficult to detect, small displacement faults on fluid flow is essential when analyzing basin hydrodynamics. The Wilmington structure is a SE plunging asymmetric anticline cut by a series of N-S oriented normal faults in the west and NW-SE oriented normal faults in the east. Fault displacement varies within the field from no displacement at fault tips, to the maxima for each fault, which varies from 10m to 135m. Faults are truncated at a mid Pliocene unconformity above which sediments are neither folded nor faulted. Over 2000 deviated wells penetrate the structure in a sixteen square mile area, often crossing the high angle normal faults. We are first performing a detailed analysis of fault geometry and degree of offset from well logs and a 3D seismic survey. A core recovered through the Temple Avenue fault shows slip over a ten meter zone without a dominant slip plane. Well logs also indicate a zone of deformation associated with the fault. A barrier was present, prior to development, across the fault where offset is less than the thickness of the offset reservoir unit, indicating fault zone properties are responsible for formation of the barrier. Fault barriers are established from offset oil-water contacts, pressure, and production surveys. Preliminary analysis of pressure data shows variability across the field and a lack of fluid communication over short distances.

Teas, P.A.; Thornburg, J. [Univ. of Southern California, Santa Cruz, CA (United States)

1996-12-31

73

International Journal of Rock Mechanics & Mining Sciences 40 (2003) 667685 Displacements and stresses due to a vertical point load in an  

E-print Network

International Journal of Rock Mechanics & Mining Sciences 40 (2003) 667­685 Displacements the effect of inhomogeneity, and the type and degree of rock anisotropy on the vertical surface displacement and vertical normal stress in the inhomogeneous isotropic/ transversely isotropic rocks subjected to a vertical

Pan, Ernie

74

Review of MFTF yin-yang magnet displacement and magnetic field measurements and calculations  

SciTech Connect

During the recent testing of the MFTF yin-yang magnet, measurements of coil position, structural case strain, and magnetic field were made to verify calculated values. Measurements to detect magnet movement were taken throughout cooldown and during the operation of the magnet. The magnetic field at the mirror points was measured by Hall-effect probes. The magnet position, structural case strain, and magnetic field measurements indicated a reasonably close correlation with calculated values. Information obtained from the yin-yang test has been very useful in setting realistic mechanical alignment values for the new MFTF-B magnet system.

Hanson, C.L.; Myall, J.O.; Wohlwend, J.W.

1983-11-21

75

Modeling surface deformation due to CO2 injection at an enhanced oil recovery field in Texas  

NASA Astrophysics Data System (ADS)

The Geodesy Laboratory at the University of South Florida has operated 3 C-GPS stations at an enhanced oil recovery field in Texas since October 2011. Our GPS sites recorded vertical uplift during the injection phase when the reservoir was initially pressurized, and localized subsidence in phase with reservoir pressure after oil extraction started. In this study, we use analytical and numerical models to better understand the small-scale surface deformation observed by GPS due to CO2 injection. First, we use an analytical model of a pressurized horizontal circular crack in an elastic half-space to fit the surface deformation data. Then, constrained by the analytical modeling results, we develop a poroelastic Finite Element Model (FEM) to investigate the influence of reservoir geometry and overlying stratigraphy on surface displacement. A sensitivity study is carried out to understand the effects of realistic geometry and material properties on surface deformation. Our preliminary results show that a poroelastic FEM can explain the location-dependant time delay between the injection and surface response.

Yang, Q.; Abdollahzadeh, M.; Dixon, T. H.; Malservisi, R.; Hosseini, S.

2013-12-01

76

Measuring Oscillatory Velocity Fields Due to Swimming Algae  

E-print Network

In this fluid dynamics video, we present the first time-resolved measurements of the oscillatory velocity field induced by swimming unicellular microorganisms. Confinement of the green alga C. reinhardtii in stabilized thin liquid films allows simultaneous tracking of cells and tracer particles. The measured velocity field reveals complex time-dependent flow structures, and scales inversely with distance. The instantaneous mechanical power generated by the cells is measured from the velocity fields and peaks at 15 fW. The dissipation per cycle is more than four times what steady swimming would require.

Guasto, Jeffrey S; Gollub, J P

2010-01-01

77

Neutron star deformation due to multipolar magnetic fields  

NASA Astrophysics Data System (ADS)

Certain multiwavelength observations of neutron stars, such as intermittent radio emissions from rotation-powered pulsars beyond the pair-cascade death line, the pulse profile of the magnetar SGR 1900+14 after its 1998 August 27 giant flare and X-ray spectral features of PSR J0821-4300 and SGR 0418+5729, suggest that the magnetic fields of non-accreting neutron stars are not purely dipolar and may contain higher order multipoles. Here, we calculate the ellipticity of a non-barotropic neutron star with (i) a quadrupole poloidal-toroidal field, and (ii) a purely poloidal field containing arbitrary multipoles, deriving the relation between the ellipticity and the multipole amplitudes. We present, as a worked example, a purely poloidal field comprising dipole, quadrupole and octupole components. We show the correlation between field energy and ellipticity for each multipole, that the l = 4 multipole has the lowest energy, and that l = 5 has the lowest ellipticity. We show how a mixed multipolar field creates an observationally testable mismatch between the principal axes of inertia (to be inferred from gravitational wave data) and the magnetic inclination angle. Strong quadrupole and octupole components (with amplitudes ˜102 times higher than the dipole) in SGR 0418+5729 still yield ellipticity ˜10-8, consistent with current gravitational wave upper limits. The existence of higher multipoles in fast-rotating objects (e.g. newborn magnetars) has interesting implications for the braking law and hence phase tracking during coherent gravitational wave searches.

Mastrano, A.; Lasky, P. D.; Melatos, A.

2013-09-01

78

Highly localized strain fields due to planar defects in epitaxial SrBi2Nb2O9 thin films  

NASA Astrophysics Data System (ADS)

Thin films of (00l) oriented SrBi2Nb2O9 epitaxially grown on SrTiO3 by sol-gel spin coating have been studied by means of high-resolution x-ray diffraction reciprocal space mapping. It is shown that these materials contain highly localized heterogeneous strain fields due to imperfect stacking faults (i.e., faults that do not propagate throughout the crystallites building up the film). In the film plane, the strain fields are confined to 11 nm wide regions and characterized by a vertical displacement of 0.18c (where c is the cell parameter) showing that the stacking faults are mainly composed of one additional (or missing) perovskite layer. Prolonged thermal annealing at 700 °C strongly reduces the density of stacking faults and yields a more uniform strain distribution within the film volume without inducing significant grain growth.

Boulle, A.; Guinebretière, R.; Dauger, A.

2005-04-01

79

Transport infrastructure monitoring: A ground based optical displacement monitoring system, field tests on a bridge, the Musmeci's bridge in Potenza, Italy.  

NASA Astrophysics Data System (ADS)

A gound based optical displacement monitoring system, "NIODIM", is being developed by Norsk Elektro Optikk in the framework of the activities of the European project "Integrated System for Transport Infrastructure surveillance and Monitoring by Electromagnetic Sensing" (ISTIMES), funded in the 7th Framework Programme (FP7/2007-2013). The optical displacement monitoring system has now participated in two real life field campaigns one in Switzerland and one in Italy. The latter, the tests in Potenza, Italy, will be presented in the following. The NIODIM system has undergone some development during the last year to adopt it for use in a somewhat higher frequency domain by changing the camera sensor part. This to make it more useful for monitoring of structures with oscillation frequencies tens of Hz. The original system was intended to a large extent to monitor land slides, quick clay and rock slides and similar phenomena typically having a relatively slow time response. The system has been significantly speeded up from the original 12 Hz. Current tests have been performed at a frame rate of 64 Hz i.e., the camera part and data processing unit have been running on 64Hz. In connection with the tests in Italy the data processing has been upgraded to include sub-pixel resolution i.e., the measurement results are no longer limited by pixel borders or single pixels. The main part of the NIODIM system is a camera capable of operating at a sufficiently high frame rate. This camera will typically be mounted on firm ground and will depict and monitor a reference point, typically a light emitting diode, LED, which will be mounted on the object susceptible to move. A processing unit will acquire the images from the camera part and find the position of the LED in the image and compare that to threshold values and if required raise a warning or an alarm. The NIODIM system can either be a standalone system or be an integrated part of the overall ISTIMES system, the ISTIMES system being a decision support system. Field trials as part of the ISTIMES project took place in Potenza, Italy, for a week in July 2011. The test target was Musmeci's bridge, a bridge with a design where aesthetic values have been just as important as traditional civil engineering aspects. Several technologies and techniques were tested at the same part of the bridge to allow for data correlation between different sensors. The camera and processing parts of the optical displacement monitoring system were mounted on a concrete wall at the one end of the bridge while the LED reference points were mounted on the bridge approximately 40 metres away. The tests at the Musmeci's bridge are successful and verifying some of the findings from the tests in Switzerland. However, we learned a lesson with regards to temporary mounting of the reference points using glossy stainless steel parts. A short period early in the morning, when illuminated by the sun, these stainless steel parts were just as bright as the LED reference point leading to potential noise in the measurements. Due to availability of the raw data this could be fixed later doing post processing on the stored data. One of the findings was that we have relatively large time of day variation that appear to be periodic with a cycle time of about 24 hours, at least with similar weather conditions. These displacements appear to be in the order of 10 mm and is probably due to thermal effects. Several shorter displacements have also been registered with amplitudes of a couple of mm and duration around 10 seconds. These shorter displacement peaks appear to be caused by heavy vehicles passing by on the bridge. The introduction of the processing using sub-pixel resolution looks very promising and appears to give a significant improvement of the actual resolution of the system. Even thought the measurements in the field are successfully completed we have noted larger slowly moving displacements than originally expected. This combined with shorter lasting peaks could lead to measurements above pre-set thres

Hagene, J. K.

2012-04-01

80

Hot Electromagnetic Outflows. III. Displaced Fireball in a Strong Magnetic Field  

E-print Network

The evolution of a dilute electron-positron fireball is calculated in the regime of strong magnetization and very high compactness (l ~10^3-10^8). Heating is applied at a low effective temperature (fireball is allowed to expand, so that the formation of a black-body spectral distribution is inhibited by pair annihilation. The diffusion equation for Compton scattering is coupled to a single-temperature pair gas and an exact (trans-relativistic) cyclo-synchrotron photon source. We find that the photon spectrum develops a quasi-thermal peak, with a power-law slope below it that is characteristic of gamma-ray bursts. The formation of a thermal high-frequency spectrum is checked using the full kinetic equations at l ~ 10^3. These results have several implications for the central engine of GRBs, and the mechanism of energy transport. 1. Baryon rest mass carries less than ~ 10^{-5} of the energy flux at jet breakout inside ~ 10^{12} cm from the engine, with most carried by the magnetic field. 2...

Thompson, Christopher

2013-01-01

81

Description and field performance of the Walker Branch throughfall displacement experiment: 1993--1996  

SciTech Connect

The authors are conducting a large-scale manipulative field experiment in an upland oak forest on the Walker Branch Watershed in eastern Tennessee to identify important ecosystem responses that might result from future precipitation changes. The manipulation of soil water content is being implemented by a gravity-driven transfer of throughfall from one 6400-m{sup 2} treatment plot to another. Throughfall is intercepted in {approx}1850 subcanopy troughs suspended above the forest floor of the dry plot and transferred by gravity flow across an ambient plot for subsequent distribution onto the wet treatment plot. Soil water content is being monitored at two depths with time domain reflectometers at 310 sampling locations across the site. The experimental system is able to produce statistically significant differences in soil water content in years having both dry and wet conditions. Maximum soil water content differentials between wet and dry plots in the 0- to 0.35-m horizon were 8 to 10% during summers with abundant precipitation and 3 to 5% during drought periods. Treatment impacts on soil water potential were restricted to the surface soil layer. Comparisons of pre- and post-installation soil and litter temperature measurements showed the ability of the experimental design to produce changes in soil water content and water potential without creating large artifacts in the forest understory environment.

Hanson, P.J.; Todd, D.E.; Huston, M.A. [Oak Ridge National lab., TN (United States). Environmental Sciences Div.; Joslin, J.D. [Tennessee Valley Authority, Norris, TN (United States); Croker, J.L.; Auge, R.M. [Univ. of Tennessee, Knoxville, TN (United States). Inst. of Agriculture

1998-04-01

82

Suppression of side lobes in a spectrum of fibre Bragg gratings due to the transverse displacement of phase mask with respect to the optical fibre  

SciTech Connect

The possibility of apodisation of fibre Bragg gratings (FBGs) recorded in the interference region of two Gaussian beams in the phase-mask scheme is considered. The FBG reflection spectra are numerically simulated for different values of recordingbeam parameters and the distance between the axes of interfering beams diffracted into different orders, which is varied by transverse displacement of the phase mask with respect to the optical fibre. Suppression of side lobes and smoothing out of the FBG spectrum with an increase in the transverse displacement of the phase mask is experimentally demonstrated. It is shown that this effect is caused by the equalisation of the mean induced refractive index in the FBG region. (optical fibres, lasers and amplifiers. properties and applications)

Abdullina, S R; Nemov, I N; Babin, Sergei A [Institute of Automation and Electrometry, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

2012-09-30

83

Internal Displacement Monitoring Centre  

NSDL National Science Digital Library

The Internal Displacement Monitoring Centre (IDMC) was established twelve years ago in the hope that they would "raise awareness of the plight of internally displaced people (IDP), point to gaps in national and international responses and promote solutions reflecting international standards and best practices." The Centre also keeps a database of 50 countries in which people have been displaced within their own country due to conflicts or human rights violations. To get a sense of where displaced persons are and how many countries have IDPs, visitors can click on the small world map on the far right hand side of the homepage. Scrolling over the map will reveal the number of displaced people by continent. Visitors interested in learning about an individual country can click on the continent, then click on one of the countries for an "Internal Displacement Profile", "Country Statistics", and an "Overview". The Resources tab, at the top of any page, includes "IDMC Publications", "Picture Galleries" of internally displaced people in India, Cyprus, and the West Bank, to name a few, and "IDP Maps" which has dozens of maps of from 2001 to 2009.

84

Displacement measurements of highway bridges using digital image correlation methods  

NASA Astrophysics Data System (ADS)

Digital image correlation methods (DICMs) are important tools in experimental solid mechanics. DICM is becoming very versatile and cost effective due to the dramatic improvement over the digital cameras. Current study applies DICMs to displacement measurements of full-scale concrete beams. Computer programs are implemented and tested against the contact measurements using a linear variable differential transformer (LVDT). The calculated displacements agree with the LVDT measurements that the difference is mostly within 3%. The DICM programs produce similar displacement fields to those obtained using two computer codes written by other researchers. The DICM programs compute a singlepoint in merely seconds while completing the displacement calculation for a whole-field region of one mega pixels in one hour. Additional tests on the vertical displacement of a highway bridge also achieve a reasonable result which can be extended to health monitoring of bridges.

Chiang, Chih-Hung; Shih, Ming-Hsiang; Chen, Welltin; Yu, Chih-Peng

2011-12-01

85

Collective trauma in the Vanni- a qualitative inquiry into the mental health of the internally displaced due to the civil war in Sri Lanka  

PubMed Central

Background From January to May, 2009, a population of 300,000 in the Vanni, northern Sri Lanka underwent multiple displacements, deaths, injuries, deprivation of water, food, medical care and other basic needs caught between the shelling and bombings of the state forces and the LTTE which forcefully recruited men, women and children to fight on the frontlines and held the rest hostage. This study explores the long term psychosocial and mental health consequences of exposure to massive, existential trauma. Methods This paper is a qualitative inquiry into the psychosocial situation of the Vanni displaced and their ethnography using narratives and observations obtained through participant observation; in depth interviews; key informant, family and extended family interviews; and focus groups using a prescribed, semi structured open ended questionnaire. Results The narratives, drawings, letters and poems as well as data from observations, key informant interviews, extended family and focus group discussions show considerable impact at the family and community. The family and community relationships, networks, processes and structures are destroyed. There develops collective symptoms of despair, passivity, silence, loss of values and ethical mores, amotivation, dependency on external assistance, but also resilience and post-traumatic growth. Conclusions Considering the severity of family and community level adverse effects and implication for resettlement, rehabilitation, and development programmes; interventions for healing of memories, psychosocial regeneration of the family and community structures and processes are essential. PMID:20667090

2010-01-01

86

Aerodynamic sound generation due to vortex-aerofoil interaction. Part 2: Analysis of the acoustic field  

NASA Technical Reports Server (NTRS)

The Lighthill method was the basic procedure used to analyze the sound field associated with a vortex of modified strength interacting with an airfoil. A free vortex interacting with an airfoil in uniform motion was modeled in order to determine the sound field due to all the acoustic sources, not only on the airfoil surfaces (dipoles), but also the ones distributed on the perturbed flow field (quadrupoles) due to the vortex-airfoil interaction. Because inviscid flow is assumed in the study of the interaction, the quadrupoles considered in the perturbed flow field are entirely due to an unsteady flow field. The effects of airfoil thickness on the second radiation are examined by using a symmetric Joukowski airfoil for the vortex-airfoil interaction. Sound radiation in a plane, far field simplification, and computation of the sound field are discussed.

Parasarathy, R.; Karamcheti, K.

1972-01-01

87

To replace or not to replace? - Partial coning and a sixth nerve palsy secondary due to displacement of a tunnelled intrathecal catheter for pain control.  

PubMed

We report the displacement of a tunnelled intrathecal catheter causing significant cerebrospinal fluid (CSF) leak, resulting in partial coning and a sixth nerve palsy. The patient had advanced malignant mesothelioma and all other methods of pain control had been unsuccessful. As far as we are aware, there are no published reports of early replacement of an intrathecal catheter in patients with neurological sequelae. Surgical re-siting of the intrathecal catheter produced good pain relief for many months. Doctors involved in the use of indwelling intrathecal catheters for pain control must be aware of the risk of significant neurological sequelae but should not dismiss re-establishment of intrathecal therapy in the presence of significant neurological complications. PMID:18612034

Gibbins, J; Steeds, C; Greenslade, G L; Tunstall, S R; Patel, N K; Stannard, C F

2008-07-01

88

New numerical method for investigating the displacement and stress fields inside contact bodies of a wire race ball bearing  

Microsoft Academic Search

This paper develops a new numerical integral method in MATLAB® based on the non-conformal contact theory, the superposition principle and Licht's work, for obtaining the displacement and stress of arbitrary points inside contact bodies of a wire race ball bearing used in a missile simulating rotary table. The integral model is assigned to the elliptical integral domain which is greatly

Xiaobiao Shan; Jiangbo Yuan; Tao Xie; Weishan Chen; Haiqun Qi

2009-01-01

89

The dissociation-induced displacement of chemisorbed O2 by mobile O atoms and the autocatalytic recombination of O due to chain fragmentation on Ag(110)  

NASA Astrophysics Data System (ADS)

The interplay between thermal desorption of chemisorbed dioxygen and its dissociation was studied with temperature programmed methods. Analysis of the kinetics of molecular desorption and the fraction of adsorbed molecules which dissociate is consistent with a model in which oxygen atoms released by the dissociation event induce desorption of the molecular species. These unequilibrated atoms exhibit a mean free path relative to the chemisorbed dioxygen of 1.8 nm prior to thermalization with the surface, displacing chemisorbed dioxygen within their reach. Each dissociation event leads to desorption of two oxygen molecules if the space between chemisorbed molecules approaches the minimum of 0.58 nm. This condition can be achieved experimentally by saturating the population of chemisorbed dioxygen (0.33 ML O2) at 90-100 K. Oxygen adatoms recombine near 580 K from the reconstructed (n × 1)-O adlayer with kinetics dictated by progressive fragmentation of the O(AgO)m rows. This behavior gives rise to autocatalytic recombination kinetics of oxygen adatoms which produces both an acceleration of rate at constant temperature and unusual recombination kinetics in temperature programmed desorption.

Eric Klobas, J.; Schmid, Martin; Friend, Cynthia M.; Madix, Robert J.

2014-12-01

90

Model based estimation of image depth and displacement  

NASA Technical Reports Server (NTRS)

Passive depth and displacement map determinations have become an important part of computer vision processing. Applications that make use of this type of information include autonomous navigation, robotic assembly, image sequence compression, structure identification, and 3-D motion estimation. With the reliance of such systems on visual image characteristics, a need to overcome image degradations, such as random image-capture noise, motion, and quantization effects, is clearly necessary. Many depth and displacement estimation algorithms also introduce additional distortions due to the gradient operations performed on the noisy intensity images. These degradations can limit the accuracy and reliability of the displacement or depth information extracted from such sequences. Recognizing the previously stated conditions, a new method to model and estimate a restored depth or displacement field is presented. Once a model has been established, the field can be filtered using currently established multidimensional algorithms. In particular, the reduced order model Kalman filter (ROMKF), which has been shown to be an effective tool in the reduction of image intensity distortions, was applied to the computed displacement fields. Results of the application of this model show significant improvements on the restored field. Previous attempts at restoring the depth or displacement fields assumed homogeneous characteristics which resulted in the smoothing of discontinuities. In these situations, edges were lost. An adaptive model parameter selection method is provided that maintains sharp edge boundaries in the restored field. This has been successfully applied to images representative of robotic scenarios. In order to accommodate image sequences, the standard 2-D ROMKF model is extended into 3-D by the incorporation of a deterministic component based on previously restored fields. The inclusion of past depth and displacement fields allows a means of incorporating the temporal information into the restoration process. A summary on the conditions that indicate which type of filtering should be applied to a field is provided.

Damour, Kevin T.

1992-01-01

91

Novel Theoretical and Numerical Methods for the Computation of Electromagnetic Fields due to Current Sources  

NASA Astrophysics Data System (ADS)

In this dissertation, series expansions are developed for the Incomplete Lipschitz-Hankel integrals (ILHIs) Je_0(a,z) and Ye_0(a,z). These expansions are obtained using the Laplace transform technique together with the theory of contour integration. These special functions are encountered in the solutions for numerous problems in electromagnetics. For example, ILHIs are used in this dissertation to obtain exact, closed-form field expressions for a semi-infinite traveling wave current filament in homogeneous space. They are also used together with the steepest descent technique to obtain expressions for the electromagnetic fields due to a semi-infinite traveling wave current filament above a half space. Superposition of these fields are used to obtain the fields due to a finite length wire carrying a traveling wave current. In addition, the ILHIs are also encountered when Prony's method is used to obtain field expressions for a vertical electric dipole source over earth.

Mechaik, Mehdi Mohamad

92

The 1999 Hector Mine Earthquake, Southern California: Vector Near-Field Displacements from ERS InSAR  

NASA Technical Reports Server (NTRS)

Two components of fault slip are uniquely determined from two line-of-sight (LOS) radar interferograms by assuming that the fault-normal component of displacement is zero. We use this approach with ascending and descending interferograms from the ERS satellites to estimate surface slip along the Hector Mine earthquake rupture. The LOS displacement is determined by visually counting fringes to within 1 km of the outboard ruptures. These LOS estimates and uncertainties are then transformed into strike- and dip-slip estimates and uncertainties; the transformation is singular for a N-S oriented fault and optimal for an E-W oriented fault. In contrast to our previous strike-slip estimates, which were based only on a descending interferogram, we now find good agreement with the geological measurements, except at the ends of the rupture. The ascending interferogram reveals significant west-sidedown dip-slip (approximately 1.0 m) which reduces the strike-slip estimates by 1 to 2 m, especially along the northern half of the rupture. A spike in the strike-slip displacement of 6 m is observed in central part of the rupture. This large offset is confirmed by subpixel cross correlation of features in the before and after amplitude images. In addition to strike slip and dip slip, we identify uplift and subsidence along the fault, related to the restraining and releasing bends in the fault trace, respectively. Our main conclusion is that at least two look directions are required for accurate estimates of surface slip even along a pure strike-slip fault. Models and results based only on a single look direction could have major errors. Our new estimates of strike slip and dip slip along the rupture provide a boundary condition for dislocation modeling. A simple model, which has uniform slip to a depth of 12 km, shows good agreement with the observed ascending and descending interferograms.

Sandwell, David T.; Sichoix, Lydie; Smith, Bridget

2002-01-01

93

PARTICLE DISPLACEMENTS ON THE WALL OF A BOREHOLE FROM INCIDENT PLANE WAVES.  

USGS Publications Warehouse

Particle displacements from incident plane waves at the wall of a fluid-filled borehole are formulated by applying the seismic reciprocity theorem to far-field displacement fields. Such displacement fields are due to point forces acting on a fluid-filled borehole under the assumption of long wavelengths. The displacement fields are analyzed to examine the effect of the borehole on seismic wave propagation, particularly for vertical seismic profiling (VSP) measurements. When the shortest wavelength of interest is approximately 25 times longer than the borehole's diameter, the scattered displacements are proportional to the first power of incident frequency and borehole diameter. When the shortest wavelength of interest is about 40 times longer than the borehole's diameter, borehole effects on VSP measurements using a wall-locking geophone are negligible.

Lee, M.W.

1987-01-01

94

Young’s Modulus Reconstruction for Radio-frequency Ablation Electrode-induced Displacement Fields: A Feasibility Study  

PubMed Central

Radiofrequency (RF) ablation is a minimally invasive treatment for tumors in various abdominal organs. It is effective if good tumor localization and intra-procedural monitoring can be done. In this paper, we investigate the feasibility of using an ultrasound-based Young’s modulus reconstruction algorithm to image an ablated region whose stiffness is elevated due to tissue coagulation. To obtain controllable tissue deformations for abdominal organs during and/or intermediately after the RF ablation, the proposed modulus imaging method is specifically designed for using tissue deformation fields induced by the RF electrode. We have developed a new scheme under which the reconstruction problem is simplified to a two-dimensional problem. Based on this scheme, an iterative Young’s modulus reconstruction technique with edge-preserving regularization was developed to estimate the Young’s modulus distribution. The method was tested in experiments using a tissue-mimicking phantom and on ex vivo bovine liver tissues. Our preliminary results suggest that high contrast modulus images can be successfully reconstructed. In both experiments, the geometries of the reconstructed modulus images of thermal ablation zones match well with the phantom design and the gross pathology image, respectively. PMID:19258195

Jiang, Jingfeng; Varghese, Tomy; Brace, Chris L.; Madsen, Ernest L.; Hall, Timothy J.; Bharat, Shyam; Hobson, Maritza A.; Zagzebski, James A.; Lee, Fred T.

2009-01-01

95

Field ion microscopy of cascades of atomic displacements in metals and alloys after various types of irradiation  

NASA Astrophysics Data System (ADS)

Experimental results on atomic-spatial investigation of radiative defect formation in surface layers of materials, initiated by neutron bombardment (of Pt, E > 0.1 MeV) and ion implantation (in Cu3Au: E = 40 keV, F = 1016 ion/m2, j = 10-3 A/cm2), are considered. Quantitative estimates are obtained for the size, shape, and volume fraction of cascades of atomic displacements formed under various types of irradiation in the surface layers of the materials. It is shown that the average size of radiation clusters after irradiation of platinum to a fast neutron fluence of 6.7 × 1022 m-2 ( E > 0.1 MeV) is about 3.8 nm. The experimentally established average size of a radiation cluster (disordered zone) in the alloy after ion bombardment is 4 × 4 × 1.5 nm.

Ivchenko, V. A.

2014-09-01

96

Electrokinetic particle aggregation patterns in microvortices due to particle-field interaction  

E-print Network

Electrokinetic particle aggregation patterns in microvortices due to particle-field interaction effects. The focusing of the particles into bands is shown to obey negative diffusion dynamics of a long and aggregation dynamics at microflow condi- tions with negligible particle and fluid inertia. These excep- tions

Chang, Hsueh-Chia

97

Deformation of a nearly hemispherical conducting drop due to an electric field: Theory and experiment  

NASA Astrophysics Data System (ADS)

We consider, both theoretically and experimentally, the deformation due to an electric field of a pinned nearly hemispherical static sessile drop of an ionic fluid with a high conductivity resting on the lower substrate of a parallel-plate capacitor. Using both numerical and asymptotic approaches, we find solutions to the coupled electrostatic and augmented Young-Laplace equations which agree very well with the experimental results. Our asymptotic solution for the drop interface extends previous work in two ways, namely, to drops that have zero-field contact angles that are not exactly ?/2 and to higher order in the applied electric field, and provides useful predictive equations for the changes in the height, contact angle, and pressure as functions of the zero-field contact angle, drop radius, surface tension, and applied electric field. The asymptotic solution requires some numerical computations, and so a surprisingly accurate approximate analytical asymptotic solution is also obtained.

Corson, L. T.; Tsakonas, C.; Duffy, B. R.; Mottram, N. J.; Sage, I. C.; Brown, C. V.; Wilson, S. K.

2014-12-01

98

ANALYSIS OF HIGH FIELD NON-LINEAR LOSSES ON SRF SURFACES DUE TO SPECIFIC TOPOGRAPHIC ROUGHNESS  

SciTech Connect

The high-field performance of SRF cavities will eventually be limited by the realization of fundamental material limits, whether it is Hc1 or Hsh, or some derivative thereof, at which the superconductivity is lost. Before reaching this fundamental field limit at the macro level, it must be encountered at localized, perhaps microscopic, sites of field enhancement due to local topography. If such sites are small enough, they may produce thermally stabilized normal-conducting regions which contribute non-linear losses when viewed from the macro resonant field perspective, and thus produce degradation in Q0. We have undertaken a calculation of local surface magnetic field enhancement from specific fine topographic structure by conformal mapping method and numerically. A solution of the resulting normal conducting volume has been derived and the corresponding RF Ohmic loss simulated.

Chen Xu,Charles Reece,Michael Kelley

2012-07-01

99

Surface potential at a ferroelectric grain due to asymmetric screening of depolarization fields  

SciTech Connect

Nonlinear screening of electric depolarization fields, generated by a stripe domain structure in a ferroelectric grain of a polycrystalline material, is studied within a semiconductor model of ferroelectrics. It is shown that the maximum strength of local depolarization fields is rather determined by the electronic band gap than by the spontaneous polarization magnitude. Furthermore, field screening due to electronic band bending and due to presence of intrinsic defects leads to asymmetric space charge regions near the grain boundary, which produce an effective dipole layer at the surface of the grain. This results in the formation of a potential difference between the grain surface and its interior of the order of 1?V, which can be of either sign depending on defect transition levels and concentrations. Exemplary acceptor doping of BaTiO{sub 3} is shown to allow tuning of the said surface potential in the region between 0.1 and 1.3?V.

Genenko, Yuri A., E-mail: genenko@mm.tu-darmstadt.de; Hirsch, Ofer [Technische Universität Darmstadt, Darmstadt (Germany); Erhart, Paul [Chalmers University of Technology, Gothenburg (Sweden)

2014-03-14

100

Melt Motion Due to Peltier Marking During Bridgman Crystal Growth with an Axial Magnetic Field  

NASA Technical Reports Server (NTRS)

This paper treats a liquid-metal flow inside an electrically insulating cylinder with electrically conducting solids above and below the liquid region. There is a uniform axial magnetic field, and there is an electric current through the liquid and both solids. Since the lower liquid-solid interface is concave into the solid and since the liquid is a better electrical conductor than the adjacent solid, the electric current is locally concentrated near the centerline. The return to a uniform current distribution involves a radial electric current which interacts with the axial magnetic field to drive an azimuthal flow. The axial variation of the centrifugal force due to the azimuthal velocity drives a meridional circulation with radial and axial velocities. This problem models the effects of Peltier marking during the vertical Bridgman growth of semiconductor crystals with an externally applied magnetic field, where the meridional circulation due to the Peltier Current may produce important mixing in the molten semiconductor.

Sellers, C. C.; Walker, John S.; Szofran, Frank R.; Motakef, Shariar

2000-01-01

101

Lateral displacement and rotational displacement sensor  

DOEpatents

A position measuring sensor formed from opposing sets of capacitor plates measures both rotational displacement and lateral displacement from the changes in capacitances as overlapping areas of capacitors change. Capacitances are measured by a measuring circuit. The measured capacitances are provided to a calculating circuit that performs calculations to obtain angular and lateral displacement from the capacitances measured by the measuring circuit.

Duden, Thomas

2014-04-22

102

Magma displacements under insular volcanic fields, applications to eruption forecasting: El Hierro, Canary Islands, 2011-2013  

NASA Astrophysics Data System (ADS)

Significant deformations, followed by increased seismicity detected since 2011 July at El Hierro, Canary Islands, Spain, prompted the deployment of additional monitoring equipment. The climax of this unrest was a submarine eruption first detected on 2011 October 10, and located at about 2 km SW of La Restinga, southernmost village of El Hierro Island. The eruption ceased on 2012 March 5, after the volcanic tremor signals persistently weakened through 2012 February. However, the seismic activity did not end with the eruption, as several other seismic crises followed. The seismic episodes presented a characteristic pattern: over a few days the number and magnitude of seismic event increased persistently, culminating in seismic events severe enough to be felt all over the island. Those crises occurred in 2011 November, 2012 June and September, 2012 December to 2013 January and in 2013 March-April. In all cases the seismic unrest was preceded by significant deformations measured on the island's surface that continued during the whole episode. Analysis of the available GPS and seismic data suggests that several magma displacement processes occurred at depth from the beginning of the unrest. The first main magma movement or `injection' culminated with the 2011 October submarine eruption. A model combining the geometry of the magma injection process and the variations in seismic energy release has allowed successful forecasting of the new-vent opening.

García, A.; Fernández-Ros, A.; Berrocoso, M.; Marrero, J. M.; Prates, G.; De la Cruz-Reyna, S.; Ortiz, R.

2014-04-01

103

The Surface Displacement Field of the November 8, 1997, Mw7.6 Manyi (Tibet) Earthquake Observed with ERS InSAR Data  

NASA Technical Reports Server (NTRS)

ERS2 radar data acquired before and after the Mw7.6, Manyi (Tibet) earthquake of November 8, 1997, provide geodetic information about the surface displacement produced by the earthquake in two ways. (1) The sub-pixel geometric adjustment of the before and after images provides a two dimensional offset field with a resolution of approx, 1m in both the range (radar line of sight) and azimuth (satellite track) directions. Comparison of offsets in azimuth and range indicates that the displacement along the fault is essentially strike-slip and in a left-lateral sense. The offset map reveals a relatively smooth and straight, N78E surface rupture that exceeds 150 km in length, consistent with the EW plane of the Harvard CMT solution. The rupture follows the trace of a quaternary fault visible on satellite imagery (Tapponnier and Molnar, 1978; Wan Der Woerd, pers. comm.). (2) Interferometric processing of the SAR data provides a range displacement map with a precision of a few millimeters. The slip distribution along the rupture reconstructed from the range change map is a bell-shaped curve in the 100-km long central section of the fault with smaller, local maxima near both ends. The curve shows that the fault slip exceeds 2.2 m in range, or 6.2 in strike-slip, along a 30-km long section of the fault and remains above 1 m in range, approx. 3 m strike-slip, along most of its length. Preliminary forward modeling of the central section of the rupture, assuming a uniform slip distribution with depth, indicates that the slip occur-red essentially between 0 and the depth of 10 km, consistent with a relatively shallow event (Velasco et al., 1998).

Peltzer, G.; Crampe, F.

1998-01-01

104

Late Cenozoic fault patterns and stress fields in the Great Basin and westward displacement of the Sierra Nevada block  

Microsoft Academic Search

The patterns of late Cenozoic faulting in the Great Basin apparently delimit two deformational fields, each extensional but contrasting in magnitude and style of extension. The field of smaller magnitude, which shows about 10 percent extension, occupies the northern and most of the central part of the Great Basin. It is characterized by steeply dipping normal faults and gently tilted

Lauren Wright

1976-01-01

105

New Optical Scanning Tomography using a rotating slicing for time-resolved measurements of 3D full field displacements in structures  

NASA Astrophysics Data System (ADS)

In this paper, a new optical tomography process is presented. It has been developed for time-resolved measurement of kinematic fields in the whole volume of structure. This new process is based on the scan of the specimen by a plane laser beam submitted to a motion of rotation. Calibration and reconstruction steps have been established and are described in this document. Acquisition is achieved by illuminating successive slices in the specimen using a rotating plane laser beam and data are recorded with a single CCD camera. The recorded volumes are analyzed by Digital Volume Correlation to measure the three displacement components in the bulk. This new acquisition process is assessed by performing sub-voxel rigid body translations along the three axes. We discuss the quality of a reconstructed volume and also the measurement accuracy in terms of mean error and standard deviation through rigid body displacement tests. Results are compared with those obtained using classical Optical Scanning Tomography (OST) and using X-ray Tomography.

Morandi, P.; Brémand, F.; Doumalin, P.; Germaneau, A.; Dupré, J. C.

2014-07-01

106

Soil processes and chemical transport. Heavy metal displacement in a sandy soil at the field scale: 1. Measurements and parameterization of sorption  

SciTech Connect

Downward displacement of cadmium (Cd) and zinc (Zn) at the field scale was investigated in a sandy soil irrigated under controlled conditions for 29 yr with a total of 12.8 m{sup 3} m{sup -2} of municipal wastewater. On a 0.86 ha grid a total of 720 samples was taken from 0 to 1.2 m depth. Cadmium and Zn contents were determined in all samples by extraction with 0.025 M ethylene-diamine-tetra-acetic acid (EDTA) on the assumption that this fraction represents the solution and sorbed phases in soil. Solution phase concentrations of 480 samples were estimated by equilibrating the samples with 0.0025 M CaCl{sub 2}. Heavy metal downward displacement is spatially highly variable. Five percent of EDTA-extractable Cd and Zn were found below 0.7 and 0.9 m depth, respectively. Spatial variability of heavy metal load as measured by recovered mass per unit area reflects the geometry of irrigation systems employed. Measured sorption equilibria could be well described as a function of organic C content and pH by extending the Freundlich equation. 36 refs., 8 figs., 2 tabs.

Streck, T.; Richter, J. [Technical Univ., Carolo-Wilhelmina, Braunschweig (Germany)

1997-01-01

107

CMB distortion anisotropies due to the decay of primordial magnetic fields  

NASA Astrophysics Data System (ADS)

We investigate the power spectrum of the distortion of the cosmic microwave background (CMB) due to the decay of the primordial magnetic fields. It is known that there are two types of the CMB distortions, so-called ? and y types, and we find that the signal of the y-type distortion becomes larger than that of the ?-type one. We also discuss cross power spectra between the CMB distortions and the CMB temperature anisotropy, which are naturally generated due to the existence of the primordial magnetic fields. We find that such cross power spectra have small amplitudes compared with the autopower spectra of the CMB distortions because of the Silk damping effect of the temperature anisotropy. We also investigate the possibility of detecting such a signal in the future CMB experiments, including not only absolutely calibrated experiments such as PIXIE but also relatively calibrated experiments such as LiteBIRD and CMBpol.

Miyamoto, Koichi; Sekiguchi, Toyokazu; Tashiro, Hiroyuki; Yokoyama, Shuichiro

2014-03-01

108

Figure 7. Comparison of experimental Uy (in pixel) displacement field (a), (b), (c) and computed Uy (in pixel) displacement field (d), (e), (f) when 1 pixel = 0.33 m and Ejoint = 150 GPa and  

E-print Network

of discontinuous fibers are studied herein (Fig. 8). This type of composite material is especially designed, a practical situation is considered again. A shear experiment on a composite plate, in which the strain field.4. The correlation parameters are l = 32 pixels and = 32 pixels. DAMAGE SCENARIO IN A SHEAR EXPERIMENT A biaxial

109

Analysis of applied magnetic field and electrical current due to electrical efficiency of MHD accelerator  

Microsoft Academic Search

Analysis of applied magnetic field and electrical current in Magnetohydrodynamic (MHD) accelerator due to electrical efficiency has been numerically investigated. Studies were carried out using air plasma as a working gas in equilibrium condition. Composition of simulated air-plasma consists of two species, N{2}, and O{2}, with concentration of 1 mol and 0.284 mol, respectively. The working gas is seeded with

Sukarsan; M. Anwari

2009-01-01

110

Normal-fault stress and displacement through finite-element analysis  

E-print Network

We compute displacement and stress due to a normal fault by means of two-dimensional plane-strain finite-element analysis. To do so, we apply a system of forces to the fault nodes and develop an iterative algorithm serving to determine the force magnitudes for any slip distribution. As a sample case, we compute the force magnitudes assuming uniform slip on a 10-km two-dimensional normal fault. The numerical model generates displacement and stress fields that compare well to the analytical solution. In fact, we find little difference in displacements (<5%), displacement orientation (<15 DEG), and stress components (<35%, half of which due to slip tolerance). We analyze such misfit, and discuss how the error propagates from displacement to stress. Our scheme provides a convenient way to use the finite-elements direct method in a trial-and-error procedure to reproduce any smooth slip distribution.

Megna, A; Santini, S; Barba, Salvatore; Megna, Antonietta; Santini, Stefano

2005-01-01

111

Temperature fields in a liquid due to the thermocapillary motion of bubbles and drops  

NASA Astrophysics Data System (ADS)

Experiments were performed on the motion of isolated air bubbles and drops of Fluorinert FC-75 moving in a Dow-Corning silicone oil under the action of an applied temperature gradient in a reduced gravity environment aboard the Space Shuttle in orbit. The disturbance of the imposed temperature field due to the motion of the objects was studied optically using a shearing interferometer with a Wollaston prism and the results of a typical bubble run were compared with theoretical predictions. Also, the liquid velocity field surrounding the bubbles and drops has been qualitatively investigated in a few runs by the observation of tracer particles dispersed in the continuous phase fluid. The measurement techniques are described, and the results for the temperature and flow fields are presented and discussed.

Wozniak, G.; Balasubramaniam, R.; Hadland, P. H.; Subramanian, R. S.

112

Enhancement of the thermoelectric figure of merit in a quantum dot due to external ac field  

NASA Astrophysics Data System (ADS)

We investigate the figure of merit of a quantum dot (QD) system irradiated with an external microwave filed by nonequilibrium Green's function (NGF) technique. Results show that the frequency of microwave field influence the figure of merit ZT significantly. At low temperature, a sharp peak can be observed in the figure of merit ZT as the frequency of ac field increases. As the frequency varies, several zero points and resonant peaks emerge in the figure of merit ZT. By adjusting the frequency of the microwave field, we can obtain high ZT. The figure of merit ZT increases with the decreasing of linewidth function ?. In addition, Wiedemann-Franz law does not hold, particularly in the low frequency region due to multi-photon emission and absorption. Some novel thermoelectric properties are also found in two-level QD system.

Chen, Qiao; Wang, Zhi-yong; Xie, Zhong-Xiang

2013-08-01

113

Neural control of visual search by frontal eye field: effects of unexpected target displacement on visual selection and saccade preparation.  

PubMed

The dynamics of visual selection and saccade preparation by the frontal eye field was investigated in macaque monkeys performing a search-step task combining the classic double-step saccade task with visual search. Reward was earned for producing a saccade to a color singleton. On random trials the target and one distractor swapped locations before the saccade and monkeys were rewarded for shifting gaze to the new singleton location. A race model accounts for the probabilities and latencies of saccades to the initial and final singleton locations and provides a measure of the duration of a covert compensation process-target-step reaction time. When the target stepped out of a movement field, noncompensated saccades to the original location were produced when movement-related activity grew rapidly to a threshold. Compensated saccades to the final location were produced when the growth of the original movement-related activity was interrupted within target-step reaction time and was replaced by activation of other neurons producing the compensated saccade. When the target stepped into a receptive field, visual neurons selected the new target location regardless of the monkeys' response. When the target stepped out of a receptive field most visual neurons maintained the representation of the original target location, but a minority of visual neurons showed reduced activity. Chronometric analyses of the neural responses to the target step revealed that the modulation of visually responsive neurons and movement-related neurons occurred early enough to shift attention and saccade preparation from the old to the new target location. These findings indicate that visual activity in the frontal eye field signals the location of targets for orienting, whereas movement-related activity instantiates saccade preparation. PMID:19261711

Murthy, Aditya; Ray, Supriya; Shorter, Stephanie M; Schall, Jeffrey D; Thompson, Kirk G

2009-05-01

114

Experimental verification of a non-axisymmetric displacement field predicted by finite element analysis of a composite disk subjected to an axisymmetric loading  

NASA Astrophysics Data System (ADS)

A finite element analysis of a circular quasi-isotropic composite disk that was clamped around its boundary and subjected to a uniform pressure was developed by the author prior to initiating this work. The analysis was performed as part of a program being developed to measure the permeability of materials. While investigating the results of the proposed configuration, it was determined that the allowable stress for the material to be tested would be exceeded close to the boundary. However, it was suggested that a pre-stress could be incorporated by tapering the clamped boundary so that, after the pressure was applied, the combined stress would fall within the material's allowable limit. Interestingly, the finite element analysis of the pre-stressed disk predicted an unexpected out-of-plane displacement that did not follow the principal material directions despite the fact that the disk was quasi-isotropic and loaded uniformly around the boundary. Further investigation revealed that this was due to variations in the terms contained in the bending stiffness matrix as a function of the angle measured relative to the principal material directions. The permeability test was subsequently adopted as part of the proposed test program and no failures have occurred to date near the boundary. However, since the initial finite element model developed for the pre-stressed condition does not accurately reflect the clamped condition currently found in practice, a more sophisticated model is needed. This dissertation focuses on the actual pre-stressed condition. After a thorough investigation is made of the bending stiffness matrix, two improved finite element models are developed using different analysis codes. The first model was developed in Nastran, mainly because the author used this package in his initial work. But the procedure to develop a nonlinear contact model for Nastran in Patran was found to be cumbersome. So, Abaqus was used because the associated pre-processor provides a simple process for establishing contact regions. Finally, a test is conducted to experimentally measure the displacement profile of a disk subjected to the pre-stressed condition using speckle metrology and digital image correlation. A comparison between the experimental and analytical results shows a good agreement, thereby validating the finite element models and confirming the original observation made regarding the non-axisymmetric out-of-plane displacement.

Oliver, Stanley T.

115

Temperature fields due to jet induced mixing in a typical OTV tank  

NASA Technical Reports Server (NTRS)

The Eclipse Code is being developed as a general tool for analysis of cryogenic propellant behavior in spacecraft tankage. The focus of the work being reported is on prediction of temperature fields due to introduction of a cold jet along the centerline of a typical Orbit Transfer Vehicle tank. A brief description of the formulations used for modeling heat transfer and turbulent flow is presented. Code performance is verified through comparison to experimental data for mixing in small scale tanks. An unexpected difficulty in computing long duration flows is reviewed. Preliminary results for a partially filled full scale tank are obtained by approximating the free surface by a spherical solid boundary.

Hochstein, J. I.; Ji, Hyun-Chul; Aydelott, J. C.

1987-01-01

116

Laser front distortions due to flow field around a helicopter configuration on hover and forward motion  

NASA Astrophysics Data System (ADS)

Laser beam front distortions characterizing near field losses of energy from a turret mounted on a generic helicopter have been computed to support the modeling and simulation effort of a directed energy testing. The flow field has been computed using an unstructured computational fluid dynamics method with (a) Reynolds averaged Navier-Stokes method with Spalart-Almaras (SA) turbulence model and (b) time accurate Detached Eddy Simulation with SA turbulence model. The beam distortions have been computed using an aero-optics model developed at the University of Notre Dame. For study (a), the rotor surface is modeled by an actuator disk with a jump in the pressure at the disk plane with the laser passing through the flow field due to the fuselage and the rotor. In the case of study (b), the laser is passing through a time accurate flow field of an isolated rotor blade. The laser front distortions, computed through optical path differences for several azimuth and elevation angles for hover and forward flight conditions, are presented in this study.

Dodbele, Simha

2009-11-01

117

A Investigation of Molecular Alignment and Material Flow due to Electric Fields in Nematic Liquid Crystals.  

NASA Astrophysics Data System (ADS)

This investigation encompassed a study of molecular alignment and material flow due to electric fields in nematic liquid crystals. The electric field was varied from approximately 100 V/cm to 12,000 V/cm and sample holders were constructed with electrode separations varying from 13 microns to 1.2 cm. The electrodes were made of conductively coated glass so that optical observations could be made at both the free surface and the electrode-to-liquid crystal interface. The optical techniques involved the observation of the movement of foreign particles in the fluid and defects in the structure. The observations frequently included the creation of defects, and a study of their deformation which provided information about material flow. The aligning mechanisms are associated with the dielectric and conductivity anisotropies. Using high frequency (10 kHz) fields the dielectric mechanism was investigated and with very low frequency and DC fields the conduction mechanism was studied. The results presented show that the realignment of the molecules by the dielectric mechanism and by magnetic fields are very similar in both the mechanism involved and the defects that are formed. A model (Carr, 1978) for molecular alignment and material flow was proposed from results using low intensity electric fields that were applied for only short periods to initially well-aligned samples. The work discussed here deals primarily with high electric fields applied continuously. Nevertheless, the results are best explained when this model is used. These results provide excellent support for this model in bulk samples and have also given good evidence in support of the model for thin samples. It is believed that insight into the dynamic scattering mode can be provided by consideration of this model. The work discussed here is consistant with other work using NMR techniques (Tarr and Carr, 1980), which involved high electric fields in bulk samples. Attempts were made to determine if walls (defects) could be detected in liquid crystal samples using ultrasonic methods, but it was established that the effects were too small to be observed.

Kozlowski, Richard William Hugh

118

hal-00252040,version1-12Feb2008 Near-field induction heating of metallic nanoparticles due to infrared magnetic  

E-print Network

hal-00252040,version1-12Feb2008 Near-field induction heating of metallic nanoparticles due mechanism is near-field induction heating, due to Joule dissipation of eddy currents in the particle.ecp.fr We revisit the electromagnetic heat transfer between a metallic nanoparticle and a metallic semi

Paris-Sud XI, Université de

119

Analysis of the Effect of Fiber Orientation on the Elastic Field in a Stiffened Orthotropic Panel under Uniform Tension using Displacement Potential Approach  

Microsoft Academic Search

The effect of fiber orientation on the stresses and displacements at different sections of a stiffened panel of orthotropic composite material under a uniform tension is analyzed. The supporting edge of the panel is rigidly fixed and two opposing edges are stiffened. The mixed boundary value plane stress elasticity problem is formulated in terms of a single displacement potential function

S. K. D. Nath; A. M. Afsar

2009-01-01

120

Modelling the electric and magnetic fields at the Earths surface due to an auroral electrojet  

NASA Astrophysics Data System (ADS)

A calculation of the electric and magnetic fields at the Earths surface due to an ionospheric electrojet system is required for the estimation of geomagnetically induced currents (GIC) in a technological network, which are a manifestation of space weather effects on the ground. Two models of the auroral electrojet for calculating the geoelectromagnetic field are compared in this paper: an infinitely long line current and a more realistic system consisting of an electrojet of a finite length and of vertical (field-aligned) currents at its ends. The Earth is described by a two-layer half-space, and a small and a large period of oscillation in time are considered. In the case of an infinite line current the field at the Earths surface is independent of the space coordinate parallel to the electrojet, and in the case of the finite electrojet two profiles perpendicular to the electrojet and located at the centre of the electrojet and near the edge of the electrojet are considered. The most significant shortcoming of the infinite model is the neglect of the horizontal electric component perpendicular to the electrojet as well as the horizontal magnetic component parallel to the electrojet. It is shown in this paper that these components may in reality get values in the order of 0.1-1 Vkm and 100-200 nT, respectively. The parallel electric component and the perpendicular horizontal magnetic component are overestimated by the infinite model by about 10-50% at their maxima achieved beneath the electrojet. At large distances the infinite model leads to an incorrect sign of these components. The vertical magnetic component is accurately obtained by the infinite model.

Pirjola, R. J.

1998-07-01

121

Pineal melatonin level disruption in humans due to electromagnetic fields and ICNIRP limits.  

PubMed

The International Agency for Research on Cancer (IARC) classifies electromagnetic fields (EMFs) as 'possibly carcinogenic' to humans that might transform normal cells into cancer cells. Owing to high utilisation of electricity in day-to-day life, exposure to power-frequency (50 or 60 Hz) EMFs is unavoidable. Melatonin is a natural hormone produced by pineal gland activity in the brain that regulates the body's sleep-wake cycle. How man-made EMFs may influence the pineal gland is still unsolved. The pineal gland is likely to sense EMFs as light but, as a consequence, may decrease the melatonin production. In this study, more than one hundred experimental data of human and animal studies of changes in melatonin levels due to power-frequency electric and magnetic fields exposure were analysed. Then, the results of this study were compared with the International Committee of Non-Ionizing Radiation Protection (ICNIRP) limit and also with the existing experimental results in the literature for the biological effect of magnetic fields, in order to quantify the effects. The results show that this comparison does not seem to be consistent despite the fact that it offers an advantage of drawing attention to the importance of the exposure limits to weak EMFs. In addition to those inconsistent results, the following were also observedfrom this work: (i) the ICNIRP recommendations are meant for the well-known acute effects, because effects of the exposure duration cannot be considered and (ii) the significance of not replicating the existing experimental studies is another limitation in the power-frequency EMFs. Regardless of these issues, the above observation agrees with our earlier study in which it was confirmed that it is not a reliable method to characterise biological effects by observing only the ratio of AC magnetic field strength to frequency. This is because exposure duration does not include the ICNIRP limit. Furthermore, the results show the significance of disruption of melatonin due to exposure to weak EMFs, which may possibly lead to long-term health effects in humans. PMID:23051584

Halgamuge, Malka N

2013-05-01

122

The use of a displacement device negatively affects the performance of dogs (Canis familiaris) in visible object displacement tasks  

PubMed Central

Visible and invisible displacement tasks have been used widely for comparative studies of animals’ understanding of object permanence, with evidence accumulating that some species can solve invisible displacement tasks and thus reach Piagetian stage 6 of object permanence. In contrast, dogs appear to rely on associative cues, such as the location of the displacement device, during invisible displacement tasks. It remains unclear, however, whether dogs, and other species that failed in invisible displacement tasks, do so due to their inability to form a mental representation of the target object, or simply due to the involvement of a more salient but potentially misleading associative cue, the displacement device. Here we show that the use of a displacement device impairs the performance of dogs also in visible displacement tasks: their search accuracy was significantly lower when a visible displacement was performed with a displacement device, and only two of initially 42 dogs passed the sham-baiting control conditions. The negative influence of the displacement device in visible displacement tasks may be explained by strong associative cues overriding explicit information about the target object’s location, reminiscent of an overshadowing effect, and/or object individuation errors as the target object is placed within the displacement device and moves along a spatiotemporally identical trajectory. Our data suggest that a comprehensive appraisal of a species’ performance in object permanence tasks should include visible displacement tasks with the same displacement device used in invisible displacements, which typically has not been done in the past. PMID:24611641

Müller, Corsin A.; Riemer, Stefanie; Range, Friederike; Huber, Ludwig

2014-01-01

123

Displaced rotations of coherent states  

E-print Network

We propose an approach that enables to use it for construction of rotations of coherent states, in particular, it gives a possibility to construct Hadamard gate for the coherent states. Our approach is based on representation of arbitrary one-mode pure state in free-travelling fields, in particular superposition of coherent states (SCSs), in terms of displaced number states with arbitrary amplitude of displacement. Studied optical scheme is based on alternation of photon additions and displacement operators (in general case, photon additions and displacements are required) with seed coherent state to generate both even and odd displaced squeezed SCSs (DSSCSs) regardless of number of used photon additions. It is shown the studied optical scheme is sensitive to seed coherent state provided that other parameters are invariable. Output states approximate with high fidelity either even squeezed SCS or odd SCS shifted relative each other by some value. It enables to construct local rotation operator for coherent states, in particular, Hadamard gate being mainframe element for quantum computation with coherent states. The effects deteriorating quality of output states are considered.

Sergey A. Podoshvedov

2011-08-06

124

Field location & marking of no-passing zones due to vertical alignments using the global positioning system  

E-print Network

FIELD LOCATION & MARKING OF NO-PASSING ZONES DUE TO VERTICAL ALIGNMENTS USING THE GLOBAL POSITIONING SYSTEM A Thesis by CAMERON LEE WILLIAMS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE May 2008 Major Subject: Civil Engineering FIELD LOCATION & MARKING OF NO-PASSING ZONES DUE TO VERTICAL ALIGNMENTS USING THE GLOBAL POSITIONING SYSTEM A Thesis by CAMERON LEE WILLIAMS...

Williams, Cameron Lee

2008-10-10

125

Faraday Rotation Measure due to the Intergalactic Magnetic Field II: the Cosmological Contribution  

E-print Network

We investigate the Faraday rotation measure (RM) due to the intergalactic magnetic field (IGMF) through the cosmic web up to cosmological distances, using a model IGMF based on turbulence dynamo in the large-scale structure of the universe. By stacking the IGMF and gas density data up to redshift $z=5$ and taking account of the redshift distribution of polarized background radio sources against which the RM is measured, we simulate the sky map of the RM. The contribution from galaxy clusters is subtracted from the map, based on several different criteria of X-ray brightness and temperature. Our findings are as follows. The distribution of RM for radio sources of different redshifts shows that the root-mean-square (rms) value increases with redshift and saturates for $z \\ga 1$. The saturated value is RM$_{\\rm rms} \\approx$ several ${\\rm rad m^{-2}}$. The probability distribution function of $|{\\rm RM}|$ follows the lognormal distribution. The power spectrum has a broad plateau over the angular scale of $\\sim 1...

Akahori, Takuya

2011-01-01

126

Precision displacement reference system  

DOEpatents

A precision displacement reference system is described, which enables real time accountability over the applied displacement feedback system to precision machine tools, positioning mechanisms, motion devices, and related operations. As independent measurements of tool location is taken by a displacement feedback system, a rotating reference disk compares feedback counts with performed motion. These measurements are compared to characterize and analyze real time mechanical and control performance during operation.

Bieg, Lothar F. (Albuquerque, NM); Dubois, Robert R. (Albuquerque, NM); Strother, Jerry D. (Edgewood, NM)

2000-02-22

127

A Methodology to Validate the InSAR Derived Displacement Field of the September 7th, 1999 Athens Earthquake Using Terrestrial Surveying. Improvement of the Assessed Deformation Field by Interferometric Stacking  

PubMed Central

The primary objective of this paper is the evaluation of the InSAR derived displacement field caused by the 07/09/1999 Athens earthquake, using as reference an external data source provided by terrestrial surveying along the Mornos river open aqueduct. To accomplish this, a processing chain to render comparable the leveling measurements and the interferometric derived measurements has been developed. The distinct steps proposed include a solution for reducing the orbital and atmospheric interferometric fringes and an innovative method to compute the actual InSAR estimated vertical ground subsidence, for direct comparison with the leveling data. Results indicate that the modeled deformation derived from a series of stacked interferograms, falls entirely within the confidence interval assessed for the terrestrial surveying data.

Kotsis, Ioannis; Kontoes, Charalabos; Paradissis, Dimitrios; Karamitsos, Spyros; Elias, Panagiotis; Papoutsis, Ioannis

2008-01-01

128

Heating in the MRI environment due to superparamagnetic fluid suspensions in a rotating magnetic field  

E-print Network

In the presence of alternating-sinusoidal or rotating magnetic fields, magnetic nanoparticles will act to realign their magnetic moment with the applied magnetic field. The realignment is characterized by the nanoparticle's ...

Cantillon-Murphy, Padraig

129

Tsunami generation by horizontal displacement of ocean bottom  

Microsoft Academic Search

Tsunami generation by an earthquake is generally modeled by water surface displacement identical to the vertical deformation of ocean bottom due to faulting. The effect of horizontal deformation is usually neglected. However, when the tsunami source is on a steep slope and the horizontal displacement is large relative to the vertical displacement, the effect becomes significant. We show this for

Yuichiro Tanioka; Kenji Satake

1996-01-01

130

Sound propagation through a real jet flow field with scattering due to interaction with turbulence  

NASA Technical Reports Server (NTRS)

The sound propagation through a nonuniform turbulent jet flow field is studied by means of a system of linearized equations governing the acoustic variables. These equations depend on the fluctuating flow-field variables which are prescribed by experimental results. It is shown that the redistribution of the acoustic energy in the far field depends on space-time correlation of the turbulent velocities and on the mean flow variables and their gradients.

Maestrello, L.; Liu, C. H.; Ting, L.; Gunzburger, M.

1974-01-01

131

Primary beam steering due to field leakage from superconducting SHMS magnets  

DOE PAGESBeta

Simulations of the magnetic fields from the Super High Momentum Spectrometer in Hall C at Thomas Jefferson National Accelerator Facility show significant field leakage into the region of the primary beam line between the target and the beam dump. Without mitigation, these remnant fields will steer the unscattered beam enough to limit beam operations at small scattering angles. Presented here are magnetic field simulations of the spectrometer magnets and a solution using optimal placement of a minimal amount of shielding iron around the beam line.

Moore, M.H.; Waidyawansa, B.P.; Covrig, S.; Carlini, R.; Benesch, J.

2014-11-01

132

Electric field enhancement due to a saw-tooth asperity in a channel and implications on microscale gas breakdown  

NASA Astrophysics Data System (ADS)

The electric field enhancement due to an isolated saw-tooth asperity in an infinite channel is considered with the goal of providing some inputs to the choice of field enhancement factors used to describe microscale gas breakdown. The Schwarz–Christoffel transformation is used to map the interior of the channel to the upper half of the transformed plane. The expression for the electric field in the transformed plane is then used to determine the electric field distribution in the channel as well as field enhancement near the asperity. The effective field enhancement factor is determined and its dependence on operating and geometrical parameters is studied. While the effective field enhancement factor depends only weakly on the height of the asperity in comparison to the channel, it is influenced significantly by the base angles of the asperity. Due to the strong dependence of field emission current density on electric field, the effective field enhancement factor (?eff) is shown to vary rapidly with the applied electric field irrespective of the geometrical parameters. This variation is included in the analysis of microscale gas breakdown and compared with results obtained using a constant ?eff as is done traditionally. Even though results for a varying ?eff may be approximately reproduced using an equivalent constant ?eff independent of E-field, it might be important for a range of operating conditions. This is confirmed by extracting ?eff from experimental data for breakdown in argon microgaps with plane-parallel cathodes and comparing its dependence on the E-field. While the use of two-dimensional asperities is shown to be a minor disadvantage of the proposed approach in its current form, it can potentially help in developing predictive capabilities as opposed to treating ?eff as a curve-fitting parameter.

Venkattraman, Ayyaswamy

2014-10-01

133

Distortion of magnetic field and magnetic force of a brushless dc motor due to deformed rubber magnet  

NASA Astrophysics Data System (ADS)

This paper investigates the distortion of magnetic field of a brushless dc (BLDC) motor due to deformed rubber magnet. Global or local deformation of rubber magnet in the BLDC motor is mathematically modeled by using the Fourier series. Distorted magnetic field is calculated by using the finite element method, and unbalanced magnetic force is calculated by using the Maxwell stress tensor. When the rubber magnet is globally or locally deformed, the unbalanced magnetic force has the frequencies with the first harmonic and the harmonics of slot number ±1. However, the harmonic deformation with multiple of common divisor of pole and slot does not generate unbalanced magnetic force due to the rotational symmetry.

Lee, C. J.; Jang, G. H.

2008-04-01

134

Stability of Miscible Displacements Across Stratified Porous Media  

SciTech Connect

This report studied macro-scale heterogeneity effects. Reflecting on their importance, current simulation practices of flow and displacement in porous media were invariably based on heterogeneous permeability fields. Here, it was focused on a specific aspect of such problems, namely the stability of miscible displacements in stratified porous media, where the displacement is perpendicular to the direction of stratification.

Shariati, Maryam; Yortsos, Yanis C.

2000-09-11

135

Probing the mechanical properties of seismically active crust with space geodesy: Study of the coseismic deformation due to the 1992 Mw7.3 Landers (southern California) earthquake  

Microsoft Academic Search

The coseismic deformation due to the 1992 Mw7.3 Landers earthquake, southern California, is investigated using synthetic aperture radar (SAR) and Global Positioning System (GPS) measurements. The ERS-1 satellite data from the ascending and descending orbits are used to generate contiguous maps of three orthogonal components (east, north, up) of the coseismic surface displacement field. The coseismic displacement field exhibits symmetries

Yuri Fialko

2004-01-01

136

Sliding Capacitive Displacement Transducer  

NASA Technical Reports Server (NTRS)

Simple circuit replaces bridge circuit. Sliding capacitive displacement transducer, capacitance varies linearly with displacement, enables use of simple circuit based on operational amplifier instead of complicated capacitance bridge. With new circuit, transducers as small as 0.05 in. (1.3 mm) square and 0.004 in. (0.1 mm) thick have produced output-voltage changes of about 200 mV per 0.005 in. (0.13 mm) of displacement. Piston-type transducer made quite small for installation in confined spaces.

Bryner, B. D.; Godfrey, A. L.

1987-01-01

137

Non-Trivial Excited State Coherence Due to Two Uncorrelated Partially Coherent Fields  

E-print Network

We analyze a model where a $V$ system is excited by two uncorrelated partially coherent fields. We use a collisionally broadened CW laser, which is a good model for a experimentally realizable partially coherent field, and show that it is possible to generate excited state coherences even if the two fields are uncorrelated. This transient coherence can be increased if splitting between the excited states is reduced relative to the radiation coherence time, $\\tau_{d}$. For small excited state splitting, one can use this scheme to generate a long lived coherent response in the system.

Z. S. Sadeq

2014-11-24

138

Phase shifts in precision atom interferometry due to the localization of atoms and optical fields  

SciTech Connect

We discuss details of momentum transfer in the interaction between localized atoms and localized optical fields which are relevant to precision atom interferometry. Specifically, we consider a {lambda}-type atom coherently driven between its ground states by a bichromatic optical field. We assume that the excited state can be eliminated adiabatically from the time evolution. It is shown that the average recoil momentum is given by the phase gradient of the two-photon field at the 'position' of the atom, provided that the optical field can be described by a function which is separable in position and time and that the atomic wave function is symmetric and well localized within the optical field envelope. The result does not require the optical fields to have a Gaussian spatial dependence. Our discussion provides the basis for the analysis of systematic errors in precision atom interferometry arising from optical wave-front curvature, wave-front distortion, and the Gouy phase shift of Gaussian beams. We apply our result to the atom interferometer experiment of Chu and co-workers which measures the fine-structure constant.

Wicht, A.; Sarajlic, E.; Hensley, J.M.; Chu, S. [Institute for Experimental Physics, Heinrich-Heine-Universitaet Duesseldorf, Universitaetsstr. 1, D-40225 Duesseldorf (Germany); Physics Department, Stanford University, Stanford, California 94305 (United States)

2005-08-15

139

A study on the flow field and local heat transfer performance due to geometric scaling of centrifugal fans  

Microsoft Academic Search

Scaled versions of fan designs are often chosen to address thermal management issues in space constrained applications. Using velocity field and local heat transfer measurement techniques, the thermal performance characteristics of a range of geometrically scaled centrifugal fan designs have been investigated. Complex fluid flow structures and surface heat transfer trends due to centrifugal fans were found to be common

Jason Stafford; Ed Walsh; Vanessa Egan

140

Computation of eddy currents in human body due to pulsed magnetic field  

Microsoft Academic Search

The evaluation of eddy currents induced inside the human body by pulsed electromagnetic sources involves the characterization of tissues conductivity and permittivity values at different frequencies. The transient problem requires the transformation of the dispersion relation into a time domain relation by a convolution integral. Comparisons of results using different material properties for a pulsed excitation due to a resistance

F. Freschi; A. Guerrisi; M. Repetto

2010-01-01

141

Field monitoring and modeling of pavement response and service life consumption due to overweight truck traffic  

E-print Network

performance with respect to both rutting and fatigue cracking. Charts to evaluate the service life of the existing pavement subjected to OTTs are established in terms of the unit service life consumed due to the rutting and fatigue cracking with the various...

Oh, Jeong-Ho

2004-11-15

142

Regional tree growth reductions due to ambient ozone: evidence from field experiments. [Populus deltoides; Robinia pseudoacacia  

SciTech Connect

Observations from extensive regions in Europe and North America suggest that many forests may be in early stages of ecosystem decline. The authors present experimental evidence from open-top chamber field studies indicating that ambient ozone at levels below the ambient air quality standard (235 ..mu..g m/sup -3/) causes significant reductions (19%) in the growth of sapling poplars (hybrid Populus). While ozone-induced reductions in growth have been observed under laboratory and greenhouse conditions, demonstration of this effect under field conditions is critical to the establishment of ozone standards. Growth reductions for Populus deltoides and Robinia pseudoacacia were not significant. Reductions in productivity and height growth occurred without visible symptoms of foliar injury and at ozone concentrations below current standards. If this invisible injury is typical in other tree species, the extent of ozone-induced forest damage may presently be greatly underestimated. Additional field studies on a regional basis are needed.

Wang, D.; Bormann, F.H.; Karnosky, D.F.

1986-11-01

143

Neoclassical Drift of Circulating Orbits Due toToroidal Electric Field in Tokamaks  

SciTech Connect

In tokamaks, Ware pinch is a well known neoclassical effect for trapped particles in response to a toroidal electric field. It is generally believed that there exists no similar neoclassical effect for circulating particles without collisions. However, this belief is erroneous, and misses an important effect. We show both analytically and numerically that under the influence of a toroidal electric field parallel to the current, the circulating orbits drift outward toward the outer wall with a characteristic velocity O ({var_epsilon}{sup -1}) larger than the E x B velocity, where {var_epsilon} is the inverse aspect-ratio of a tokamak. During a RF overdrive, the toroidal electric field is anti-parallel to the current. As a consequence, all charged particles, including backward runaway electrons, will drift inward towards the inner wall.

Hong, Qin, Xiaoyin Guan and Nathaniel J. Fisch

2011-07-19

144

Transient particle acceleration in strongly magnetized neutron stars. II - Effects due to a dipole field geometry  

NASA Technical Reports Server (NTRS)

Sheared Alfven waves generated by nonradial crustal disturbances above the polar cap of a strongly magnetized neutron star induce an electric field component parallel to B. An attempt is made to determine the manner in which the strong radial dependence of B affects the propagation of these sheared Alfven waves, and whether this MHD process is still an effective particle accelerator. It is found that although the general field equation is quite complicated, a simple wavelike solution can still be obtained under the conditions of interest for which the Alfven phase velocity decouples from the wave equation. The results may be applicable to gamma-ray burst sources.

Fatuzzo, Marco; Melia, Fulvio

1991-01-01

145

Is the Cosmic "Axis of Evil" due to a Large-Scale Magnetic Field  

E-print Network

I propose a mechanism that would explain the near alignment of the low order multipoles of the cosmic microwave background (CMB). This mechanism supposes a large-scale cosmic magnetic field that tends to align the cyclotron orbit axes of electrons in hot plasmas along the same direction. Inverse Compton scattering of the CMB photons then imprints this pattern on the CMB, thus causing the low- multipoles to be generally aligned. The spins of the majority of spiral galaxies and that of our own Galaxy appear to be aligned along the cosmic magnetic field.

Michael J. Longo

2007-03-29

146

Observation of Megagauss-Field Topology Changes due to Magnetic Reconnection in Laser-Produced Plasmas  

E-print Network

Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA R. P. J. Town and O. L reconnection physics in all regimes. In addition, the methodology is quite general and is appli- cable,18]. It follows that the ratio of thermal pressure to field pressure was #12; 1, indicating that plasma motion

147

The nature and origin of off-fault damage surrounding strike-slip fault zones with a wide range of displacements: A field study from the Atacama fault system, northern Chile  

NASA Astrophysics Data System (ADS)

Damage surrounding the core of faults is represented by deformation on a range of scales from microfracturing of the rock matrix to macroscopic fracture networks. The spatial distribution and geometric characterization of damage at various scales can help to predict fault growth processes, subsequent mechanics, bulk hydraulic and seismological properties of a fault zone. Within the excellently exposed Atacama fault system, northern Chile, micro- and macroscale fracture densities and orientation surrounding strike-slip faults with well-constrained displacements ranging over nearly 5 orders of magnitude (˜0.12 m-5000 m) have been analyzed. Faults have been studied that cut granodiorite and have been passively exhumed from 6 to 10 km depth. This allows direct comparison of the damage surrounding faults of different displacements. The faults consist of a fault core and associated damage zone. Macrofractures in the damage zone are predominantly shear fractures orientated at high angles to the faults studied. They have a reasonably well-defined exponential decrease with distance from the fault core. Microfractures are a combination of open, healed, partially healed and fluid inclusion planes (FIPs). FIPs are the earliest set of fractures and show an exponential decrease in fracture density with perpendicular distance from the fault core. Later microfractures do not show a clear relationship of microfracture density with perpendicular distance from the fault core. Damage zone widths defined by the density of FIPs scale with fault displacement but appear to reach a maximum at a few km displacement. One fault, where damage was characterized on both sides of the fault core shows no damage asymmetry. All faults appear to have a critical microfracture density at the fault core/damage zone boundary that is independent of displacement. An empirical relationship for microfracture density distribution with displacement is presented. Preferred FIP orientations have a high angle to the fault close to the fault core and become more diffuse with distance. Models that predict off-fault damage such as a migrating process zone during fault formation, wear from geometrical irregularities and dynamic rupture are all consistent with our data. We conclude it is very difficult to distinguish between them on the basis of field data alone, at least within the limits of this study.

Mitchell, T. M.; Faulkner, D. R.

2009-08-01

148

Ultrasonic propagation velocity in magnetic and magnetorheological fluids due to an external magnetic field.  

PubMed

Ultrasonic propagation velocity in a magnetic fluid (MF) and magnetorheological fluid (MRF) changes with the application of an external magnetic field. The formation of clustering structures inside the MF and MRF clearly has an influence on the ultrasonic propagation velocity. Therefore, we propose a qualitative analysis of these structures by measuring properties of ultrasonic propagation. Since MF and MRF are opaque, non-contact inspection using the ultrasonic technique can be very useful for analyzing the inner structures of MF and MRF. In this study, we measured ultrasonic propagation velocity in a hydrocarbon-based MF and MRF precisely. Based on these results, the clustering structures of these fluids are analyzed experimentally in terms of elapsed time dependence and the effect of external magnetic field strength. The results reveal hysteresis and anisotropy in the ultrasonic propagation velocity. We also discuss differences of ultrasonic propagation velocity between MF and MRF. PMID:21386478

Bramantya, M A; Motozawa, M; Sawada, T

2010-08-18

149

Spinmotive force due to motion of magnetic bubble arrays driven by magnetic field gradient.  

PubMed

Interaction between local magnetization and conduction electrons is responsible for a variety of phenomena in magnetic materials. It has been recently shown that spin current and associated electric voltage can be induced by magnetization that depends on both time and space. This effect, called spinmotive force, provides for a powerful tool for exploring the dynamics and the nature of magnetic textures, as well as a new source for electromotive force. Here we theoretically demonstrate the generation of electric voltages in magnetic bubble array systems subjected to a magnetic field gradient. It is shown by deriving expressions for the electric voltages that the present system offers a direct measure of phenomenological parameter ? that describes non-adiabaticity in the current induced magnetization dynamics. This spinmotive force opens a door for new types of spintronic devices that exploit the field-gradient. PMID:25365971

Yamane, Yuta; Hemmatiyan, Shayan; Ieda, Jun'ichi; Maekawa, Sadamichi; Sinova, Jairo

2014-01-01

150

Spinmotive force due to motion of magnetic bubble arrays driven by magnetic field gradient  

PubMed Central

Interaction between local magnetization and conduction electrons is responsible for a variety of phenomena in magnetic materials. It has been recently shown that spin current and associated electric voltage can be induced by magnetization that depends on both time and space. This effect, called spinmotive force, provides for a powerful tool for exploring the dynamics and the nature of magnetic textures, as well as a new source for electromotive force. Here we theoretically demonstrate the generation of electric voltages in magnetic bubble array systems subjected to a magnetic field gradient. It is shown by deriving expressions for the electric voltages that the present system offers a direct measure of phenomenological parameter ? that describes non-adiabaticity in the current induced magnetization dynamics. This spinmotive force opens a door for new types of spintronic devices that exploit the field-gradient. PMID:25365971

Yamane, Yuta; Hemmatiyan, Shayan; Ieda, Jun'ichi; Maekawa, Sadamichi; Sinova, Jairo

2014-01-01

151

Spatial distortion due to field inhomogeneity in 3.0 tesla intraoperative MRI.  

PubMed

We describe a 14-year-old boy with a pilocytic astrocytoma of the left caudate head. Preoperative localization MR imaging (MRI) was performed in the operating room, and spatial distortion was noted felt to be related to head positioning relative to the isocenter of the magnetic field. The distortion artifact was subtle enough to be difficult to detect, but large enough to change the location of the lesion potentially leading to a non-diagnostic stereotactic biopsy. Repeat imaging after changing the head position to allow scanning closer to the isocenter of the magnetic field showed decreased distortion, an improvement greater than that using the manufacturer's distortion correction algorithm on the initial images. Intraoperative MRI, and its requisite limitations in positioning, requires vigilance to detect possible distortion that could alter surgical outcomes if not identified and corrected prospectively. PMID:25196608

Choudhri, Asim F; Chin, Eric M; Klimo, Paul; Boop, Frederick A

2014-09-01

152

The distortion of a uniform flow field due to a finite flat plate  

E-print Network

-steady incompressible viscous flow problems. Fromm has presented a discussion of the initial and 5 boundary conditions appropriate to numerical solutions of non- steady, incompressible fluid flow problems, and has compared the numerical solutions obtained for flows... based on assumptions about the flow, and are restricted to special flow conditions, or regions of the flow field. The use of numerical methods allows the complete non-linear equations of fluid motion to be applied in the study of flow problems, since...

Zull, Lawrence Michael

1970-01-01

153

Quadrupolar spin relaxation due to electric field gradients induced by vibrations and collisions  

Microsoft Academic Search

The spin relaxation of quadrupolar nuclei in highly symmetric electronic environments via vibrationally-induced electric field gradients is considered. A model is presented for tetrahedral molecules which yields a nuclear quadrupole coupling constant for 189Os in an excited vibrational state of OsO4 which is in reasonable agreement with experimentally observed values. The nuclear quadrupole coupling constants for the central nucleus in

H. Jörg Osten; Cynthia J. Jameson

1986-01-01

154

Quadrupolar spin relaxation due to electric field gradients induced by vibrations and collisions  

Microsoft Academic Search

The spin relaxation of quadrupolar nuclei in highly symmetric electronic environments via vibrationally-induced electric field gradients is considered. A model is presented for tetrahedral molecules which yields a nuclear quadrupole coupling constant for Os in an excited vibrational state of OsO4 which is in reasonable agreement with experimentally observed values. The nuclear quadrupole coupling constants for the central nucleus in

H. Jörg Osten; Cynthia J. Jameson

1986-01-01

155

Novel Theoretical and Numerical Methods for the Computation of Electromagnetic Fields due to Current Sources  

Microsoft Academic Search

In this dissertation, series expansions are developed for the Incomplete Lipschitz-Hankel integrals (ILHIs) Je_0(a,z) and Ye_0(a,z). These expansions are obtained using the Laplace transform technique together with the theory of contour integration. These special functions are encountered in the solutions for numerous problems in electromagnetics. For example, ILHIs are used in this dissertation to obtain exact, closed-form field expressions for

Mehdi Mohamad Mechaik

1994-01-01

156

VISCOUS EVOLUTION AND PHOTOEVAPORATION OF CIRCUMSTELLAR DISKS DUE TO EXTERNAL FAR ULTRAVIOLET RADIATION FIELDS  

SciTech Connect

This paper explores the effects of FUV radiation fields from external stars on circumstellar disk evolution. Disks residing in young clusters can be exposed to extreme levels of FUV flux from nearby OB stars, and observations show that disks in such environments are being actively photoevaporated. Typical FUV flux levels can be factors of {approx}10{sup 2}-10{sup 4} higher than the interstellar value. These fields are effective in driving mass loss from circumstellar disks because they act at large radial distance from the host star, i.e., where most of the disk mass is located, and where the gravitational potential well is shallow. We combine viscous evolution (an {alpha}-disk model) with an existing FUV photoevaporation model to derive constraints on disk lifetimes, and to determine disk properties as functions of time, including mass-loss rates, disk masses, and radii. We also consider the effects of X-ray photoevaporation from the host star using an existing model, and show that for disks around solar-mass stars, externally generated FUV fields are often the dominant mechanism in depleting disk material. For sufficiently large viscosities, FUV fields can efficiently photoevaporate disks over the entire range of parameter space. Disks with viscosity parameter {alpha} = 10{sup -3} are effectively dispersed within 1-3 Myr; for higher viscosities ({alpha} = 10{sup -2}) disks are dispersed within {approx}0.25-0.5 Myr. Furthermore, disk radii are truncated to less than {approx}100 AU, which can possibly affect the formation of planets. Our model predictions are consistent with the range of observed masses and radii of proplyds in the Orion Nebula Cluster.

Anderson, Kassandra R.; Adams, Fred C. [Physics Department, University of Michigan, Ann Arbor, MI 48109 (United States); Calvet, Nuria [Astronomy Department, University of Michigan, Ann Arbor, MI 48109 (United States)

2013-09-01

157

Quantization as an emergent phenomenon due to matter-zeropoint field interaction  

NASA Astrophysics Data System (ADS)

Quantization is derived as an emergent phenomenon, resulting from the permanent interaction between matter and radiation field. The starting point for the derivation is the existence of the (continuous) random zero-point electromagnetic radiation field (zpf) of mean energy hslash?/2 per normal mode. A thermodynamic and statistical analysis leads unequivocally (and without quantum assumptions) to the Planck distribution law for the complete field in equilibrium. The problem of the quantization of matter is then approached from the same perspective: A detailed study of the dynamics of a particle embedded in the zpf shows that when the entire system eventually reaches a situation of energy balance thanks to the combined effect of diffusion and dissipation, the particle has acquired its characteristic quantum properties. To obtain the quantum-mechanical description it has been necessary to do a partial averaging and take the radiationless approximation. Consideration of the neglected radiative terms allows to establish contact with nonrelativistic quantum electrodynamics and derive the correct formulas for the first-order radiative corrections. Quantum mechanics emerges therefore as a partial, approximate and time-asymptotic description of a phenomenon that in its original (pre-quantum) description is entirely local and causal.

Cetto, A. M.; de la Peña, L.; Valdés-Hernández, A.

2012-05-01

158

Ultra-Sensitive Magnetoresistive Displacement Sensing Device  

NASA Technical Reports Server (NTRS)

An ultrasensitive displacement sensing device for use in accelerometers, pressure gauges, temperature transducers, and the like, comprises a sputter deposited, multilayer, magnetoresistive field sensor with a variable electrical resistance based on an imposed magnetic field. The device detects displacement by sensing changes in the local magnetic field about the magnetoresistive field sensor caused by the displacement of a hard magnetic film on a movable microstructure. The microstructure, which may be a cantilever, membrane, bridge, or other microelement, moves under the influence of an acceleration a known displacement predicted by the configuration and materials selected, and the resulting change in the electrical resistance of the MR sensor can be used to calculate the displacement. Using a micromachining approach, very thin silicon and silicon nitride membranes are fabricated in one preferred embodiment by means of anisotropic etching of silicon wafers. Other approaches include reactive ion etching of silicon on insulator (SOI), or Low Pressure Chemical Vapor Deposition of silicon nitride films over silicon substrates. The device is found to be improved with the use of giant magnetoresistive elements to detect changes in the local magnetic field.

Olivas, John D. (Inventor); Lairson, Bruce M. (Inventor); Ramesham, Rajeshuni (Inventor)

2003-01-01

159

Vibroacoustic Response of Residential Housing due to Sonic Boom Exposure: A Summary of two Field Tests  

NASA Technical Reports Server (NTRS)

Two experiments have been performed to measure the vibroacoustic response of houses exposed to sonic booms. In 2006, an old home in the base housing area of Edwards Air Force Base, built around 1960 and demolished in 2007, was instrumented with 288 transducers. During a 2007 follow-on test, a newer home in the base housing area, built in 1997, was instrumented with 112 transducers. For each experiment, accelerometers were placed on walls, windows and ceilings in bedrooms of the house to measure the vibration response of the structure. Microphones were placed outside and inside the house to measure the excitation field and resulting interior sound field. The vibroacoustic response of each house was measured for sonic boom amplitudes spanning from 2.4 to 96 Pa (0.05 to 2 lbf/sq ft). The boom amplitudes were systematically varied using a unique dive maneuver of an F/A-18 airplane. In total, the database for both houses contains vibroacoustic response data for 154 sonic booms. In addition, several tests were performed with mechanical shaker excitation of the structure to characterize the forced response of the houses. The purpose of this paper is to summarize all the data from these experiments that are available to the research community, and to compare and contrast the vibroacoustic behavior of these two dissimilar houses.

Klos, Jacob; Buehrle, Ralph; Sullivan, Brenda; Gavin, Joseph; Salamone, Joseph; Haering, Edward A., jr.; Miller, Denise M.

2008-01-01

160

Global Simulation of Proton Precipitation Due to Field Line Curvature During Substorms  

NASA Technical Reports Server (NTRS)

The low latitude boundary of the proton aurora (known as the Isotropy Boundary or IB) marks an important boundary between empty and full downgoing loss cones. There is significant evidence that the IB maps to a region in the magnetosphere where the ion gyroradius becomes comparable to the local field line curvature. However, the location of the IB in the magnetosphere remains in question. In this paper, we show simulated proton precipitation derived from the Field Line Curvature (FLC) model of proton scattering and a global magnetohydrodynamic simulation during two substorms. The simulated proton precipitation drifts equatorward during the growth phase, intensifies at onset and reproduces the azimuthal splitting published in previous studies. In the simulation, the pre-onset IB maps to 7-8 RE for the substorms presented and the azimuthal splitting is caused by the development of the substorm current wedge. The simulation also demonstrates that the central plasma sheet temperature can significantly influence when and where the azimuthal splitting takes place.

Gilson, M. L.; Raeder, J.; Donovan, E.; Ge, Y. S.; Kepko, L.

2012-01-01

161

Water displacement mercury pump  

DOEpatents

A water displacement mercury pump has a fluid inlet conduit and diffuser, a valve, a pressure cannister, and a fluid outlet conduit. The valve has a valve head which seats in an opening in the cannister. The entire assembly is readily insertable into a process vessel which produces mercury as a product. As the mercury settles, it flows into the opening in the cannister displacing lighter material. When the valve is in a closed position, the pressure cannister is sealed except for the fluid inlet conduit and the fluid outlet conduit. Introduction of a lighter fluid into the cannister will act to displace a heavier fluid from the cannister via the fluid outlet conduit. The entire pump assembly penetrates only a top wall of the process vessel, and not the sides or the bottom wall of the process vessel. This insures a leak-proof environment and is especially suitable for processing of hazardous materials.

Nielsen, Marshall G. (Woodside, CA)

1985-01-01

162

Water displacement mercury pump  

DOEpatents

A water displacement mercury pump has a fluid inlet conduit and diffuser, a valve, a pressure cannister, and a fluid outlet conduit. The valve has a valve head which seats in an opening in the cannister. The entire assembly is readily insertable into a process vessel which produces mercury as a product. As the mercury settles, it flows into the opening in the cannister displacing lighter material. When the valve is in a closed position, the pressure cannister is sealed except for the fluid inlet conduit and the fluid outlet conduit. Introduction of a lighter fluid into the cannister will act to displace a heavier fluid from the cannister via the fluid outlet conduit. The entire pump assembly penetrates only a top wall of the process vessel, and not the sides or the bottom wall of the process vessel. This insures a leak-proof environment and is especially suitable for processing of hazardous materials.

Nielsen, M.G.

1984-04-20

163

Optical displacement sensor  

DOEpatents

An optical displacement sensor is disclosed which uses a vertical-cavity surface-emitting laser (VCSEL) coupled to an optical cavity formed by a moveable membrane and an output mirror of the VCSEL. This arrangement renders the lasing characteristics of the VCSEL sensitive to any movement of the membrane produced by sound, vibrations, pressure changes, acceleration, etc. Some embodiments of the optical displacement sensor can further include a light-reflective diffractive lens located on the membrane or adjacent to the VCSEL to control the amount of lasing light coupled back into the VCSEL. A photodetector detects a portion of the lasing light from the VCSEL to provide an electrical output signal for the optical displacement sensor which varies with the movement of the membrane.

Carr, Dustin W. (Albuquerque, NM)

2008-04-08

164

Oscillation of electron mobility in parabolic double quantum well structure due to applied electric field  

NASA Astrophysics Data System (ADS)

We show that oscillation of low temperature electron mobility ? can be obtained by applying an electric field F along the growth direction of the asymmetrically barrier delta doped AlxGa1-xAs parabolic double quantum well structure. The drastic changes in the subband Fermi energies and distributions of subband wave functions as a function of F yield nonmonotonic intra- and intersubband scattering rate matrix elements mediated by intersubband effects. The oscillatory enhancement of ?, which is attributed to the subband mobilities governed by the ionized impurity scattering, magnifies with increase in well width and decrease in height of the parabolic structure potential. The results can be utilized for nanoscale low temperature device applications.

Sahoo, Narayan; Sahu, Trinath

2014-12-01

165

Field-induced relaxation of bulk composition due to internal boundaries  

NASA Astrophysics Data System (ADS)

The establishment of compositional variations in solids caused by an external electric field usually requires electrodes that block either electronic or ionic charge carriers. Here we present unambiguous experimental and theoretical evidence that the compositional variations can occur even in the case of completely nonblocking electrodes if grain boundaries are present. In addition to the proper grain boundary impedance arc characterized by the dielectric relaxation time, ?, a second arc occurs at much lower frequencies (??). It is shown that this low-frequency response refers to a chemical relaxation (Warburg diffusion) induced by the selectively blocking grain boundary. The effect is the analogue to the chemical relaxation induced by selectively blocking electrodes (cf. Wagner-Hebb polarization).

Jamnik, J.; Guo, X.; Maier, J.

2003-04-01

166

Electromagnetic wake-field due to surface roughness in an optical structure  

NASA Astrophysics Data System (ADS)

In this study we investigate the properties of the electromagnetic wake-field generated by an electron bunch moving in the vicinity of an optical structure of finite roughness. The model employed consists of a metallic cylindrical waveguide to which grooves of random width, height, and location are attached. Based on this model analytic expressions have been developed for the average energy emitted per groove and for its standard deviation. As expected, both quantities are virtually independent of the momentum in a highly relativistic regime and the average energy emitted per groove is proportional to the roughness parameter. Moreover, it has been found that the standard deviation of the energy emitted per groove is proportional to the standard deviation of the roughness parameter to the power of 1/4. The cumulative effect of surface roughness was studied resorting to both periodic and quasiperiodic structures—significant differences in the spectrum have been observed only for low frequencies.

Banna, S.; Schieber, D.; Schächter, L.

2004-04-01

167

Missile generation due to electrical arcing in high field fusion magnets  

SciTech Connect

Large amounts of energy (10 /sup 10/-10/sup 11/ J) are stored in the magnetic field of superconducting magnet systems used in conceptual fusion-reactor designs. If only part of this energy is released accidentally, damage to the magnet and to other rector subsystems may result. In fusion-reactor environments it may lead to the evaporation of activated material and to the generation of energetic missiles, involving interference with sources of radioaactive material in the plant. Results from a Runge-Kutta routine have been obtained for FINTOR, a minimum size Tokamak DT experimental reactor, indicating that missiles of about 20 kg weight may reach velocities in the order of 100 m/s.

Schneider, H.; Caretta, A.

1981-01-01

168

Micrograting Displacement Sensor with Integrated Electrostatic Actuation  

NASA Astrophysics Data System (ADS)

A high-resolution micro-grating displacement sensor with diffraction-based and integrated electrostatic actuation is proposed and experimentally demonstrated. The Al reflecting membrane is fabricated at the bottom of a silicon moving part and the Au micro-gratings are patterned on a transparent substrate. This structure forms a phase sensitive diffraction grating, providing the displacement sensitivity of the micro-grating interferometer. It shows sensitivity adjustment and self-calibration capabilities with electrostatic actuation. Additional system components include a coherent light source, photodiodes, and required electronics. Experimental results show that the displacement sensor has a sensitivity of about 1.8 mV/nm and a resolution of less than 1 nm in the linear region. This displacement sensor is very promising in the fields requiring high sensitivity, broad dynamic range, and immunity to electromagnetic interference.

Yao, Bao-Yin; Feng, Li-Shuang; Wang, Xiao; Liu, Wei-Fang; Liu, Mei-Hua

2014-07-01

169

Fragmentation and Isomerization Due to Field Heating in Traveling Wave Ion Mobility Spectrometry  

NASA Astrophysics Data System (ADS)

During their travel inside a traveling wave ion mobility cell (TW IMS), ions are susceptible to heating because of the presence of high intensity electric fields. Here, we report effective temperatures T eff,vib obtained at the injection and inside the mobility cell of a SYNAPT G2 HDMS spectrometer for different probe ions: benzylpyridinium ions and leucine enkephalin. Using standard parameter sets, we obtained a temperature of ~800 K at injection and 728 ± 2 K into the IMS cell for p-methoxybenzylpyridinium. We found that T eff,vib inside the cell was dependent on the separation parameters and on the nature of the analyte. While the mean energy of the Boltzmann distributions increases with ion size, the corresponding temperature decreases because of increasing numbers of vibrational normal modes. We also investigated conformational rearrangements of 7+ ions of cytochrome c and reveal isomerization of the most compact structure, therefore highlighting the effects of weak heating on the gas-phase structure of biologically relevant ions.

Morsa, Denis; Gabelica, Valérie; De Pauw, Edwin

2014-08-01

170

Nanofluid flow and heat transfer due to a stretching cylinder in the presence of magnetic field  

NASA Astrophysics Data System (ADS)

In this paper, flow and heat transfer of a nanofluid over a stretching cylinder in the presence of magnetic field has been investigated. The governing partial differential equations with the corresponding boundary conditions are reduced to a set of ordinary differential equations with the appropriate boundary conditions using similarity transformation, which is then solved numerically by the fourth order Runge-Kutta integration scheme featuring a shooting technique. Different types of nanoparticles as copper (Cu), silver (Ag), alumina (Al2O3) and titanium oxide (TiO2) with water as their base fluid has been considered. The influence of significant parameters such as nanoparticle volume fraction, nanofluids type, magnetic parameter and Reynolds number on the flow and heat transfer characteristics is discussed. It was found that the Nusselt number increases as each of Reynolds number or nanoparticles volume fraction increase, but it decreases as magnetic parameter increase. Also it can be found that choosing copper (for small of magnetic parameter) and alumina (for large values of magnetic parameter) leads to the highest cooling performance for this problem.

Ashorynejad, H. R.; Sheikholeslami, M.; Pop, I.; Ganji, D. D.

2013-03-01

171

Near-Field Scattering due to Topography and Lateral Velocity Heterogeneity  

NASA Astrophysics Data System (ADS)

The scattering of seismic waves traveling in the Earth is not only caused by velocity heterogeneity, but also by rough surface topography. Both factors are known to play an important role on ground motion complexity even at short distances from the source. In this study, we simulate ground motion with a 3D finite-difference wave propagation solver in the frequency band 0-5 Hz using different rough topography models and realistic heterogeneous media characterized by Von Karman correlation functions. We analyze the characteristics of the scattered wave-field, focusing in particular on coda waves. Our study shows that topography and velocity heterogeneity scattering generate coda waves with different characteristics. We notice that, while coda waves originated by velocity heterogeneity have a more diffusive nature presenting envelope broadening as a result of forward scattering, coda waves caused by topography scattering are composed of more coherent body and surface waves reflected and diffracted by irregular topography surface. Results indicate that, for shallow sources, topography scattering can generate more intense early-coda waves at short and intermediate distances from the source. As distance increases, velocity heterogeneity scattering starts to dominate. However results show a rather high degree of variability as topography scattering is very sensitive to source position and features of the topography model. On the other hand, velocity perturbations generate more intense late-coda waves We conclude that topography scattering cannot be used as a proxy for velocity heterogeneity scattering.

Imperatori, Walter; Mai, Martin

2014-05-01

172

Microstructural changes in a cementitious membrane due to the application of a DC electric field.  

PubMed

The use of electromigration techniques to accelerate chloride ions motion is commonly employed to characterise the permeability of cementitious samples to chlorides, a relevant parameter in reinforced concrete corrosion. This paper is devoted to the study of microstructure's changes occurring in mortar samples when submitted to natural diffusion and migration experiments. The application of an electric field reduces testing time in about one order of magnitude with respect to natural diffusion experiments. Nevertheless, the final sample's microstructure differs in both tests. Impedance Spectroscopy is employed for real time monitoring of microstructural changes. During migration experiments the global impedance undergoes important increase in shorter period of time compared to natural diffusion tests. So, the forced motion of ions through the concrete membrane induces significant variations in the porous structure, as confirmed by Mercury Intrusion Porosimetry. After migration experiments, an important increase in the capillary pore size (10-100 nm) was detected. Conversely, no relevant variations are found after natural diffusion tests. Results presented in this work cast doubt on the significance of diffusion coefficient values obtained under accelerated conditions. PMID:18569312

Covelo, Alba; Diaz, Belen; Freire, Lorena; Novoa, X Ramon; Perez, M Consuelo

2008-07-01

173

Scavenging of rodent carcasses following simulated mortality due to field applications of anticoagulant rodenticide.  

PubMed

Worldwide, agricultural uses of anticoagulant rodenticides (ARs) cause poisonings of non-target wildlife as observed in France where bromadiolone is used to control water vole outbreaks. Following bromadiolone field application, a part of the vole population may die aboveground of the treated plots and thus, can represent an important risk of secondary poisoning for scavengers. In this study, water voles were trapped in a non-treated area and their carcasses were placed aboveground in plots located in an area where a vole outbreak occurred. Then, the environmental persistence, the diurnal and nocturnal scavenging rates of water vole carcasses were assessed in autumn 2011 and in spring 2012. The diurnal scavenger species were also identified. The environmental persistence of the carcasses to reach at least a scavenging rate of 87.5 % was 0.5-1.5 day. The average rates of diurnal and nocturnal scavenging ranged from 67 to 100 % and 5 to 100 %, respectively. They depended on the composition of the scavenger community present near the monitored plots; diurnal scavenging rates being higher with corvids than with raptors. In autumn, the red kite and the common buzzard were the main scavengers in one of the plots, what suggests a high risk of poisoning for these raptors during post-nuptial migration. So, the collection of vole carcasses after treatments and the limitations of bromadiolone applications when high densities of predators/scavengers are observed could be implemented to mitigate the risks of secondary poisoning. PMID:25147048

Montaz, Julie; Jacquot, Marion; Coeurdassier, Michaël

2014-11-01

174

An Alternative to Dirac's Model, Confining Change due to the Bound Electron, not in the Field, but Within the Electron Itself  

NASA Astrophysics Data System (ADS)

Yarman et al. proposed a new Dirac-like equation confining the change due to the bound electron, not in the field, but within the electron itself, as an alternative to the standard field approach. Solving this equation, they showed that for the ground state of the Hydrogen atom, the two approaches produce the same result, which supports previous efforts towards the description of the micro and macro worlds, based on the same philosophy, thus providing a unique fusion of these worlds. In this work we study the energies of the excited states of the Hydrogen atom at possible total angular momenta, j's. And for the transition between any pair of j's, we find practically the same energy difference as that predicted by the standard Dirac equation, but surprisingly with the opposite sign. Since not the energy levels alone, but the energy differences between levels are measured, we come to the amazing bifurcation point of choosing between the change-in-the-field-concept versus the change-in-the-particle-concept. It is further interesting to note that the levels such as 2S(1/2) and 2P(1/2), which are identical in the standard approach, turn also to be identical in our approach. We happen accordingly to predict the same Lamb shift as the difference of the magnitudes of the lines 2P(3/2)-2S(1/2) and 2P(3/2)-2P(1/2), assuming yet that the 2S(1/2) level (Lamb-shift-wise) is displaced downward (and not upward), in contrast with what the common approach, rather deliberately, supposes. While the standard approach, neither in the celestial world nor in the atomic world, allows any unification of these two worlds, our approach, on the contrary, provides an easy fusion of them through simple means, and the same change of metric, allowing further an immediate quantization of the celestial world. The main problem in the atomic world, according to our approach, arises to be, the choice between the following two statements:1) The greater j, the higher is the energy level (common approach). 2) The greater j, the lower is the energy level (our approach). A heuristic assessment favors our approach against the common approach.

Yarman, Tolga; Arik, Metin; Ozaydin, Fatih; Altintas, Azmi Ali; Susam, Lidya Amon

2013-09-01

175

Study on optical fiber based displacement sensor  

NASA Astrophysics Data System (ADS)

Fiber optic sensor is commonly used in control and monitoring system for material deformation, strain, temperature, pressure and other industrial process parameters. Fiber optic displacement sensor based on intensity modulation can be designed by using the transmission technique where the intensity gradually changes due to change of detected laser intensity. Previous optical fiber based displacement sensors are constructed using two fibers along with a mirror arrangement or a single optical fiber acting as both transmitter and receiver such as 2X1 fiber couplers. The reported resolution of the system was in the range of 5 ?m-10 ?m. In our present study the displacement sensor composed of a laser source, optical fiber cable, microscope objective and power meter is designed. As in source-fiber coupling geometry, the microscope objective focuses the laser light onto a multimode glass fiber. The other end of the fiber is coupled to a power meter. As the fiber is displaced towards the focused spot, the detected power changes. The displacement resolution of 5 ?m is obtained with this simple setup. In the present paper, the results of theoretical analysis and experimental study of such a simple optical fiber based displacement sensor are presented.

Chakraborty, B.; Sinha, B. K.

2011-10-01

176

Shock formation processes due to interactions of two plasmas in a magnetic field and modified two-stream instabilities  

SciTech Connect

The study of interactions of exploding and surrounding plasmas in an external magnetic field [K. Yamauchi and Y. Ohsawa, Phys. Plasmas 14, 053110 (2007)] is verified with two-dimensional (2D) electromagnetic particle simulations, for a case in which the initial velocity of the exploding plasma is perpendicular to the external magnetic field. The 2D simulations show essentially the same shock-formation processes as those in the previous one-dimensional simulation, including penetration of exploding ions into surrounding plasma, formation of a strong magnetic-field pulse due to deceleration of the exploding ions, ion reflection by the pulse, and subsequent splitting of the pulse into two magnetosonic pulses which then develop into forward and reverse shock waves. Furthermore, the 2D structure of electromagnetic fields in the region, where the exploding and surrounding ions overlap, is investigated with particular attention to the linear and nonlinear evolution of modified two-stream instabilities in the magnetic field that is being gradually compressed. The effects of these instabilities on ion reflection and on 2D magnetic fluctuations in the two generated pulses are also discussed.

Toida, Mieko; Uragami, Tatsunori [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)] [Department of Physics, Nagoya University, Nagoya 464-8602 (Japan)

2013-11-15

177

Diplopia due to Dacryops  

PubMed Central

Dacryops is a lacrimal ductal cyst. It is known that it can cause globe displacement, motility restriction, and proptosis because of the mass effect. Diplopia due to dacryops has not been reported previously. Here, we present a 57-year-old man with binocular horizontal diplopia that occurred during left direction gaze due to dacryops. PMID:24368956

Duman, Re?at; Balc?, Mehmet

2013-01-01

178

Using time-lapse seismic amplitude data to detect variations of pore pressure and fluid saturation due to oil displacement by water: a numerical study based on one-dimensional prestack inversion  

Microsoft Academic Search

We describe a numerical study performed to appraise the ability of seismic amplitude data to infer the time evolution of pore pressure and fluid saturation due to hydrocarbon production. To this end, we construct a synthetic, spatially heterogeneous hydrocarbon reservoir model that is subject to numerical simulation of multiphase fluid flow. Hydrocarbon production is assumed in the form of one

Omar J Varela; Carlos Torres-Verdín; Mrinal K Sen; Indrajit G Roy

2006-01-01

179

Experimental investigation of local displacement speeds of wrinkled unsteady flames  

NASA Astrophysics Data System (ADS)

Local flame displacement speeds were measured along the flame front of laminar unsteady premixed flames wrinkled by laminar toroidal vortices. The displacement speed is argued to be the most important and sensitive parameter that must be simulated correctly in numerical simulation of turbulent flames. An axisymetric flame wrinkle is created in order to measure all components of the normal velocity vector and stretch; particle image velocimetry (PIV) and high-speed shadowgraph cinematography yield the difference between the interface velocity and the reactant gas velocity---the displacement speed. This repeatable flame-vortex interaction problem provides a useful test data to assess direct numerical simulation models and flame stretch theory. Lean and rich methane-air, and lean propane-air flames were investigated to assess stable and unstable preferential diffusion effects on local displacement speeds. The strength of the laminar toroidal vortices was varied from 1.4 to 10 times the unstretched laminar flame burning velocities, S L. Results showed that the local displacement speeds follow the trends predicted by the laminar steady-state theory, but not the magnitudes. Large variations in local displacement speed measurements were found, ranging from --6 to 10 times SL. The negative values occur at the two locations that the steady-state theory predicts low values. Planar laser induced fluorescence of the OH radical was used successfully to locate the flame front boundary in the velocity fields obtained from the PIV images. Microgravity studies at NASA Lewis 2.2 second drop tower showed that when the stabilizing influence of buoyancy is removed, the wrinkling amplitude of the premixed flames caused by toroidal vortices increases by as much as a factor of three. The degree of wrinkling for preferential diffusion unstable flames is larger than those showed by stable ones. Vorticity fields obtained from the PIV images (at one-g) indicate that baroclinic torques due to buoyancy create "flame-generated vorticity" which induces a velocity that suppresses flame wrinkles. Scaling concepts indicate that the ratio of Baroclinic torques to the Rayleigh-Taylor stabilizing force scales inversely with Froude number. In the present experiment, the velocity induced by Baroclinic torques is equal to that induced by the Rayleigh-Taylor forces. Thus, baroclinic torques in this experiment are important but not dominant.

Sinibaldi, Jose Oscar

180

Estimating present-day displacement fields and tectonic deformation in active mountain belts: an example from the Chartreuse Massif and the southern Jura Mountains, western Alps  

NASA Astrophysics Data System (ADS)

Determination of relative movements between the alpine foreland and the External Crystalline Massif is a key-point for the understanding of the present-day tectonics of the western Alps. In this study we try to test the continuity of the present-day tectonics with the Mio-Pliocene deformation. In particular, we will test if the present-day displacements are localized along the thrusts of the Jura Mountains, or along a blind thrust in the Bas Dauphiné Molasse Basin. Definition of relative movements is achieved by several methods, including a comparison of two high precision leveling networks to estimate vertical displacements, horizontal deformation measurements performed by triangulation/triangulation and triangulation/GPS comparison, in situ stress measurements performed in the different tectonic units and geomorphologic observations that constrain the location and the magnitude of the Quaternary deformation. Comparison of leveling data demonstrates: (1) an uplift of the southern Bas Dauphiné Molasse Basin relative to its northern part (0.8 mm/year), also revealed by geomorphologic analysis, (2) a significant uplift of the most external jurassian anticlines (0.8 to 2 mm/year), also recorded by the deformation of a paleo-river bed, and (3) an important uplift (up to 2 mm/year) of the Subalpine Massifs. The horizontal strain estimated from comparison of horizontal geodetic data (triangulation, GPS) shows (1) a NW-SE directed shortening between the eastern Chartreuse Massif and the Bas Dauphiné Molasses Basin (approximately 3 mm/year), (2) an E-W-directed shortening in the Jura Mountains (approximately 4-3 mm/year) and (3) a dextral strike-slip motion consistent with focal mechanisms along a NNE-SSW direction between the eastern Chartreuse Massif and the eastern Belledonne Massif. These data reveal a present-day strain partitioning between the Belledonne External Crystalline Massif and the Bas Dauphiné Molasses Basin. The westward motion of the Subalpine Massifs is partitioned along two southern jurassian thrust-folds, and a dextral NNE-SSW strike-slip shear zone between the Chartreuse Massif and the Belledonne Massif. This strain partitioning is also accompanied by a stress partitioning between the alpine foreland and the External Crystalline Massifs.

Jouanne, François; Genaudeau, Nicolas; Ménard, Gilles; Darmendrail, Xavier

1998-11-01

181

Quenching of the transient miniband photoconductivity in semiconductor superlattices due to a cancellation of field acceleration by Bragg reflection  

NASA Astrophysics Data System (ADS)

We have investigated transient conductivity of photoexcited electrons in the miniband of a semiconductor superlattice (SL) by using time-domain terahertz (THz) spectroscopy. When the pump photon energy of the femtosecond laser pulses lies in the SL miniband energy range, clear Bloch emission is observed. However, when the pump photon energy is set much above the miniband, the Bloch emission disappears and, instead, THz emission due to the optical rectification effect shows up. This fact can be interpreted as the quenching of transient miniband transport due to the cancellation of field acceleration by the Bragg reflection when the miniband is uniformly populated in k space by electrons photoexcited by the above-miniband femtosecond laser pulses.

Ihara, T.; Cardenas, J. R.; Sakasegawa, Y.; Ferreira, R.; Bastard, G.; Hirakawa, K.

2012-10-01

182

Displacement and Velocity Ratios  

NSDL National Science Digital Library

This interactive presentation, created by James Bourassa and John Rosz for the Electromechanical Digital Library, discusses displacement and velocity ratios. Bourassa and Rosz begin by providing detailed definitions of both topics and then provide mathematical examples of each. Once this basic explanation is complete, the authors allow students to practice these theories in a set of self-correcting quiz questions. Bourassa and Rosz explain each using helpful interactive flash animations. These are not only useful in explanation, but they allow the student to more fully engage with the topic. Overall, this is a nice introduction to the physical and mathematical concepts of displacement and velocity ratios. This could be a valuable learning resource in everything from a physics to a technical education classroom.

Bourassa, James; Rosz, John

2011-04-05

183

Exploration of Quench Initiation Due to Intentional Geometrical Defects in a High Magnetic Field Region of an SRF Cavity  

SciTech Connect

A computer program which was used to simulate and analyze the thermal behaviors of SRF cavities has been developed at Jefferson Lab using C++ code. This code was also used to verify the quench initiation due to geometrical defects in high magnetic field region of SRF cavities. We built a CEBAF single cell cavity with 4 artificial defects near equator, and this cavity has been tested with T-mapping. The preheating behavior and quench initiation analysis of this cavity will be presented here using the computer program.

J. Dai, K. Zhao, G.V. Eremeev, R.L. Geng, A.D. Palczewski; Dai, J. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Palczewski, A. D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Eremeev, G. V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Geng, R. L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Zhao, K. [Institute of Heavy Ion Physics, Peking University, Beijing (China)

2011-07-01

184

Spatiotemporal Splitting of Global Eigenmodes due to Cross-Field Coupling via Vortex Dynamics in Drift Wave Turbulence  

NASA Astrophysics Data System (ADS)

Spatiotemporal splitting events of drift wave (DW) eigenmodes due to nonlinear coupling are investigated in a cylindrical helicon plasma device. DW eigenmodes in the radial-azimuthal cross section have been experimentally observed to split at radial locations and recombine into the global eigenmode with a time shorter than the typical DW period (t ?fDW-1 ). The number of splits correlates with the increase of turbulence. The observed dynamics can be theoretically reproduced by a Kuramoto-type model of a network of radially coupled azimuthal eigenmodes. Coupling by E ×B —vortex convection cell dynamics and ion gyro radii motion leads to cross-field synchronization and occasional mode splitting events.

Brandt, C.; Thakur, S. C.; Light, A. D.; Negrete, J.; Tynan, G. R.

2014-12-01

185

Above Water: Buoyancy & Displacement  

NSDL National Science Digital Library

In an investigation called "Shape It!" learners craft tiny boats out of clay, set them afloat on water and then add weight loads to them, in order to explore: how objects stay afloat in water; what the relationship is among surface tension, buoyancy, density and displacement; and how shape, size, and type of material affect an object's ability to remain buoyant. The introductory text discusses how heavy steel ships can float on bodies of water like rivers, bays and oceans.

2013-12-18

186

The Displaced Aggression Questionnaire  

Microsoft Academic Search

Previous measures of aggressive personality have focused on direct aggression (i.e., retaliation toward the provoking agent). An original self-report measure of trait displaced aggression is presented. Exploratory and confirmatory factor analyses provided support for a 3-factor conceptualization of the construct. These analyses identified an affective dimension (angry rumination), a cognitive dimension (revenge planning), and a behavioral dimension (general tendency to

Thomas F. Denson; William C. Pedersen; Norman Miller

2006-01-01

187

Optimization of displacement efficiency of oil recovery in porous media using optimal control theory  

NASA Astrophysics Data System (ADS)

An important issue in reservoir management is the optimization of displacement efficiency in processes where a displacing agent is injected at various wells to displace oil in place. Given a well configuration, the optimization of displacement efficiency should be done by controlling the injection rates. At present, this problem has not been systematically addressed. The objective of this thesis is to investigate the optimization of displacement efficiency by controlling injection rates in a system with a non-symmetric well configuration, due to geometry and/or heterogeneity. An optimal control methodology is developed for optimizing the displacement efficiency at breakthrough in displacements involving incompressible fluids in 2-D, areal reservoirs with multiple injectors and one producer, where effects of gravity, dispersion and capillarity are neglected. It is found that the optimal injection policy is of the bang-bang type, in which the injection rate takes either a maximum or a minimum value. Numerical and experimental results show that this policy gives better efficiency at breakthrough than a constant-rate injection policy, confirming the theoretical predictions. The results also show that the efficiency improvement depends on the well configuration (it increases as the well configuration becomes more asymmetric), the reservoir heterogeneity (it varies significantly from one realization of permeability field to another), and the mobility ratio (it increases with mobility ratio). We also studied the related "targeted delivery" problem, in which a fluid parcel is steered along a specified trajectory in a porous medium by controlling the flow rates at various wells. An algorithm for specifying flow rates to steer a fluid parcel along a specified trajectory was devised. Numerical results show, however, that the non-uniform flow field, caused by the limited number of wells and/or the reservoir heterogeneity, deforms the shape of the fluid parcel significantly. The reservoir variability leads to a deviation of the actual trajectory from the specified one, which grows with time according to a power-law.

Sudaryanto, Bagus

188

The field-dependent shock profiles of a magnetorhelogical damper due to high impact: an experimental investigation  

NASA Astrophysics Data System (ADS)

This work proposes a new damper featuring magnetorheological fluid (MR damper) and presents its field-dependent damping forces due to high impact. To achieve this goal, a large MR damper, which can produce a damping force of 100 kN at 6 A, is designed and manufactured based on the analysis of the magnetic flux intensity of the damper. After identifying the field-dependent damping force levels of the manufactured MR damper, a hydraulic horizontal shock tester is established. This shock testing system consists of a velocity generator, impact mass, shock programmer, and test mass. The MR damper is installed at the end of the wall in the shock tester and tested under four different experimental conditions. The shock profile characteristics of the MR damper due to different impact velocities are investigated at various input current levels. In addition, the inner pressure of the MR damper during impact, which depends on the input’s current level, is evaluated at two positions that can represent the pressure drop that generates the damping force of the MR damper. It is demonstrated from this impact testing that the shock profiles can be changed by the magnitude of the input current applied to the MR damper. It directly indicates that a desired shock profile can be achieved by installing the MR damper associated with appropriate control logics to adjust the magnitude of the input current.

Kim, Hwan-Choong; Oh, Jong-Seok; Choi, Seung-Bok

2015-02-01

189

A displacement-doubling prism  

NASA Astrophysics Data System (ADS)

A novel prism has been devised which can be used in place of the ‘flag' in an optical shadow-sensing type of displacement sensor, for example. In this way, theoretically the displacement sensitivity of the sensor can be doubled. Such a prism has been manufactured, and its displacement-doubling property has been verified.

Lockerbie, Nicholas A.

2014-03-01

190

Polyimidazoles via aromatic nucleophilic displacement  

NASA Technical Reports Server (NTRS)

Polyimidazoles (PI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl) imidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The reactions are carried out in polar aprotic solvents such as N,N-dimethyl acetamide, sulfolane, N-methylpyrrolidinone, dimethylsulfoxide, or diphenylsulfone using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. The di(hydroxyphenyl) imidazole monomers are prepared by reacting an aromatic aldehyde with a dimethoxybenzil or by reacting an aromatic dialdehyde with a methoxybenzil in the presence of ammonium acetate. The di(methoxyphenyl) imidazole is subsequently treated with aqueous hydrobromic acid to give the di(hydroxphenyl) imidazole monomer. This synthetic route has provided high molecular weight PI of new chemical structure, is economically and synthetically more favorable than other routes, and allows for facile chemical structure variation due to the availability of a large variety of activated aromatic dihalides and dinitro compounds.

Connell, John W. (inventor); Hergenrother, Paul M. (inventor)

1992-01-01

191

Transmitted sound field due to an impulsive line acoustic source bounded by a plate followed by a vortex sheet  

NASA Technical Reports Server (NTRS)

The propagation of sound due to a line acoustic source in the moving stream across a semiinfinite vortex sheet which trails from a rigid plate is examined in a linear theory for the subsonic case. A solution for the transmitted sound field is obtained with the aid of multiple integral transforms and the Wiener-Hopf technique for both the steady state (time harmonic) and initial value (impulsive source) situations. The contour of inverse transform and hence the decomposition of the functions are determined through causality and radiation conditions. The solution obtained satisfies causality and the full Kutta conditions. The transmitted sound field is composed of two waves in both the stady state and initial value problems. One is the wave scattered from the edge of the plate which is associated with the bow wave and the instability wave. These waves exist in the downstream sectors. The other is the wave transmitted through the vortex sheet which is also associated with the instability wave. Regional divisions of the transmitted sound field are identified.

Miura, T.; Chao, C. C.

1980-01-01

192

Helium vs. Proton Induced Displacement Damage in Electronic Materials  

NASA Technical Reports Server (NTRS)

In this project, the specific effects of displacement damage due to the passage of protons and helium nuclei on some typical electronic materials will be evaluated and contrasted. As the electronic material absorbs the energetic proton and helium momentum, degradation of performance occurs, eventually leading to overall failure. Helium nuclei traveling at the same speed as protons are expected to impart more to the material displacement damage; due to the larger mass, and thus momentum, of helium nuclei compared to protons. Damage due to displacement of atoms in their crystalline structure can change the physical properties and hence performance of the electronic materials.

Ringo, Sawnese; Barghouty, A. F.

2010-01-01

193

HELIUM EFFECTS ON DISPLACEMENT CASCADE IN TUNGSTEN  

SciTech Connect

Molecular dynamics (MD) simulations were performed to investigate He effects on displacement cascades in W. Helium content, proportion of interstitial and substitutional He and temperature were varied to reveal the various effects. The effect of interstitial He on the number of self-interstitial atoms (SIAs) produced during cascade damage appears to be insignificant. However, interstitial He tends to fill a vacancy (V). Nevertheless, this process is less favorable than SIA-V recombination particularly when excess SIAs are present before a cascade. The efficiency of He filling and SIA-V recombination increases as temperature increases due to increased point defect mobility. Likewise, substitutional He is more susceptible to displacement during a collision cascade than W. This susceptibility increases towards higher temperatures. Consequently, the number of surviving V is governed by the interplay between displaced substitutional He and SIA-V recombination. The temperature dependence of these processes results in a minimum number of V reached at an intermediate temperature.

Setyawan, Wahyu; Nandipati, Giridhar; Roche, Kenneth J.; Heinisch, Howard L.; Kurtz, Richard J.; Wirth, Brian D.

2013-09-30

194

Selective displacement chromatography of proteins.  

PubMed

In contrast to high molecular weight polyelectrolyte displacers, the efficacy of low molecular weight displacers are dependent on both mobile phase salt and displacer concentration. This sensitivity to the operating conditions opens up the possibility of carrying out selective displacement where the product(s) of interest can be selectively displaced while the low affinity impurities can be desorbed in the induced salt gradient ahead of the displacement train, and the high affinity impurities either retained or desorbed in the displacer zone. This type of displacement combines the operational advantages of step gradient and the high resolution inherent in a true displacement process, in a single operation. Theoretical expressions are presented for establishing selective displacement operating conditions (initial salt concentration, displacer concentration) based on the Steric Mass Action parameters of the displacer and the linear Steric Mass Action parameters of the feed proteins. Experimental results are presented to elucidate the concept of selective displacement in both cation and anion exchange systems. A mixture of alpha-lactalbumin and beta-lactoglobulin A and B has been used for anion-exchange systems; a four-protein mixture consisting of ribonuclease B, bovine and horse heart cytochrome c, and lysozyme has been employed in cation exchange systems. This article also demonstrates that on-line monitoring can be readily employed for the selective displacement process, thus facilitating the scale-up and control of the process. This work sets the stage for the development of robust large scale high resolution separations using selective displacement chromatography. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 119-129, 1997. PMID:18636617

Kundu, A; Barnthouse, K A; Cramer, S M

1997-10-20

195

Displacement Data Assimilation  

NASA Astrophysics Data System (ADS)

Geometric corrections are blended with nonlinear/non-Gaussian estimation methods to produced improved data assimilation outcomes on problems where features are critical. Problems of this sort are the estimation of hurricane tracks, tracking jet meandering, front propagation, among many others. The geometric correction is made possible by a data preserving map. It makes corrections on phase, primarily, as well as in the amplitude. The displacement assimilation is embedded in the analysis stage of a nonlinear/non-Gaussian Bayesian data assimilation scheme, such as the path integral method. In addition to showing how the method improves upon the results, as compared to more standard methodologies.

Restrepo, J. M.; Rosenthal, S.; Venkataramani, S.

2013-05-01

196

Gas miscible displacement enhanced oil recovery: Technology status report  

SciTech Connect

Gas miscible displacement enhanced oil recovery research is conducted by the US Department of Energy's Morgantown Energy Technology Center to advance the application of miscible carbon dioxide flooding. This research is an integral part of a multidisciplinary effort to improve the technology for producing additional oil from US resources. This report summarizes the problems of the technology and the 1986 results of the ongoing research that was conducted to solve those problems. Poor reservoir volumetric sweep efficiency is the major problem associated with gas flooding and all miscible displacements. This problem results from the channeling and viscous fingering that occur due to the large differences between viscosity or density of the displacing and displaced fluids (i.e., carbon dioxide and oil, respectively). Simple modeling and core flooding studies indicate that, because of differences in fluid viscosities, breakthrough can occur after only 30% of the total pore volume (PV) of the rock has been injected with gas, while field tests have shown breakthrough occurring much earlier. The differences in fluid densities lead to gravity segregation. The lower density carbon dioxide tends to override the residual fluids in the reservoir. This process would be considerably more efficient if a larger area of the reservoir could be contacted by the gas. Current research has focused on the mobility control, computer simulation, and reservoir heterogeneity studies. Three mobility control methods have been investigated: (1) the use of polymers for direct thickening of high-density carbon dioxide, (2) mobile ''foam-like dispersions'' of carbon dioxide and an aqueous surfactant, and (3) in situ deposition of chemical precipitates. 22 refs., 14 figs., 6 tabs.

Not Available

1986-10-01

197

Wavelet denoising of displacement estimates in elastography.  

PubMed

Wavelet shrinkage denoising of the displacement estimates to reduce noise artefacts, especially at high overlaps in elastography, is presented in this paper. Correlated errors in the displacement estimates increase dramatically with an increase in the overlap between the data segments. These increased correlated errors (due to the increased correlation or similarity between consecutive displacement estimates) generate the so-called "worm" artefact in elastography. However, increases in overlap on the order of 90% or higher are essential to improve axial resolution in elastography. The use of wavelet denoising significantly reduces errors in the displacement estimates, thereby reducing the worm artefacts, without compromising on edge (high-frequency or detail) information in the elastogram. Wavelet denoising is a term used to characterize noise rejection by thresholding the wavelet coefficients. Worm artefacts can also be reduced using a low-pass filter; however, low-pass filtering of the displacement estimates does not preserve local information such as abrupt change in slopes, causing the smoothing of edges in the elastograms. Simulation results using the analytic 2-D model of a single inclusion phantom illustrate that wavelet denoising produces elastograms with the closest correspondence to the ideal mechanical strain image. Wavelet denoising applied to experimental data obtained from an in vitro thermal lesion phantom generated using radiofrequency (RF) ablation also illustrates the improvement in the elastogram noise characteristics. PMID:15121250

Techavipoo, Udomchai; Varghese, Tomy

2004-04-01

198

Adapting to variable prismatic displacement  

NASA Technical Reports Server (NTRS)

In each of two studies, subjects were exposed to a continuously changing prismatic displacement with a mean value of 19 prism diopters (variable displacement) and to a fixed 19-diopter displacement (fixed displacement). In Experiment 1, significant adaptation (post-pre shifts in hand-eye coordination) was found for fixed, but not for variable, displacement. Experiment 2 demonstrated that adaptation was obtained for variable displacement, but it was very fragile and is lost if the measures of adaptation are preceded by even a very brief exposure of the hand to normal or near-normal vision. Contrary to the results of some previous studies, an increase in within-S dispersion was not found of target pointing responses as a result of exposure to variable displacement.

Welch, Robert B.; Cohen, Malcolm M.

1989-01-01

199

Joint estimation of real squeezing and displacement  

E-print Network

We study the problem of joint estimation of real squeezing and amplitude of the radiation field, deriving the measurement that maximizes the probability density of detecting the true value of the unknown parameters. More generally, we provide a solution for the problem of estimating the unknown unitary action of a nonunimodular group in the maximum likelihood approach. Remarkably, in this case the optimal measurements do not coincide with the so called square-root measurements. In the case of squeezing and displacement we analyze in detail the sensitivity of estimation for coherent states and displaced squeezed states, deriving the asymptotic relation between the uncertainties in the joint estimation and the corresponding uncertainties in the optimal separate measurements of squeezing and displacement. A two-mode setup is also analyzed, showing how entanglement between optical modes can be used to approximate perfect estimation.

G. Chiribella; G. M. D'Ariano; M. F. Sacchi

2005-11-21

200

Investigating the relation between geothermal reservoir compaction, geometry and production rates from a ten-year InSAR ground displacement history at the Bradys and Desert Peak fields: Assessing the potential of retrospective InSAR monitoring to assist reservoir management and expansion over fields without previously documented subsidence  

Microsoft Academic Search

Knowledge of a geothermal reservoir's hydro-thermal-mechanical response to production is critical to sustaining and\\/or expanding its production capacity. We propose investigating the relation between geothermal reservoir compaction (or bulk porosity loss), geometry and production rates by recovering a ten-year InSAR ground displacement history at the Bradys and Desert Peak fields, in west central Nevada. Our objectives are to 1) Demonstrate

Gary Oppliger

201

Fuel Efficient Stoves for Darfur Camps of Internally DisplacedPersons - Report of Field Trip to North and South Darfur, Nov. 16 -Dec.17, 2005  

SciTech Connect

Approximately 2.2 million internally displaced persons (''IDPs'') in Darfur are living in dense camps scattered in arid areas with low fuelwood productivity. Unsustainable harvesting of fuelwood by the IDPs has created ever increasing zones of denudation, that now (in November 2005) have reached several kilometers from the camp boundaries. Leaving the safety of the camps to fetch fuelwood from farther and farther away imposes great risk and hardship on the IDP women. Three different metal fuel efficient stove (''FES'') designs were tested in Darfur IDP camps for their suitability to substantially reduce the fuelwood needs of IDPs. The mud-and-dung ''ITDG'' stoves being promoted under the current FES program were also examined and tested. A modified design of the ITDG mud-and-dung stove, ''Avi'', was developed, built and tested. Systematic informal surveys of IDP households were undertaken in North and South Darfur to understand the household parameters related to family size, food, fuel, cooking habits, cooking pots, expenditure on fuel, and preferences related to alternative ways to spend time/money if fuel could be saved. Surveys found that a significant fraction of families are missing meals for lack of fuel (50% in South Darfur, and 90% in the North Darfur camps visited by the mission). About 60% of women in South Darfur, and about 90% of women in North Darfur camps purchase fuelwood. Selling some of the food rations to purchase fuel to cook meals was significant (40%) in South Darfur and has become common (80%) in North Darfur. The LBNL mission found that two of the metal stoves and the mud-and-dung Avi can significantly reduce fuelwood consumption using the same fuel, pot, cooking methods, and food ingredients used by Darfur IDPs. The most suitable design for Darfur conditions would be a modified ''Tara'' stove. With training of the cooks in tending the fire, this stove can save 50% fuel for the IDPs. The stove costs less than $10 (US) to produce in Darfur, and saves fuelwood worth $160 annually at local market prices. For programmatic and administrative reasons, the LBNL mission do not recommend a mud-and-dung stove, for which control of quality and dimensional accuracy is expensive and cumbersome to administer, particularly in a rapid large rollout effort. A light metal stove, on the other hand, can be rapidly produced in large numbers locally in Darfur, with good quality control exercised on the material and dimensions of the stoves right at the workshop where it is produced. LBNL mission also recommends immediate trials of 50 Tara stoves in a pilot technical rollout, 500 Tara stoves in a pilot social rollout, in parallel with a technical effort to modify the Tara design to make it better suited for Darfur camp conditions. The mission also recommends a program for manufacturing, disseminating the metal stoves, and educating the IDPs in fuel-efficient cooking practices. Monitoring of the stove quality, dissemination effort and training should be an integral part of the program, with systematic summaries planned with 10,000, 50,000 and 100,000 stoves have been disseminated. In the above pilot rollouts as well as in the final implementation, it is important to continue to pay attention to training of the cooks in tending the cooking fire in the stoves, and offer continued social reinforcement to this training (e.g., through periodic competitions to cook normal meals with the least fuelwood use.)

Galitsky, Christina; Gadgil, Ashok; Jacobs, Mark; Lee, Yoo-Mi

2006-02-01

202

Electrostatic Fields Near the Active Site of Human Aldose Reductase: 2. New Inhibitors and Complications due to Hydrogen Bonds†  

PubMed Central

Vibrational Stark effect spectroscopy was used to measure electrostatic fields in the hydrophobic region of the active site of human aldose reductase (hALR2). A new nitrile-containing inhibitor was designed and synthesized, and the x-ray structure of its complex, along with cofactor NADP+, with wild-type hALR2 was determined at 1.3 Å resolution. The nitrile is found to be in close proximity to T113, consistent with a hydrogen bond interaction. Two vibrational absorption peaks were observed at room temperature in the nitrile region when the inhibitor binds to wild-type hALR2, indicating that the nitrile probe experiences two different microenvironments, and these could be empirically separated into a hydrogen bonded and non-hydrogen bonded population by comparison with the mutant T113A, where a hydrogen bond to the nitrile is not present. Classical molecular dynamics simulations based on the structure predict a double-peaked distribution in protein electric fields projected along the nitrile probe. The interpretation of these two peaks as a hydrogen bond formation-dissociation process between the probe nitrile group and a nearby amino acid side chain is used to explain the observation of two IR bands, and the simulations were used to investigate the molecular details of this conformational change. Hydrogen bonding complicates the simplest analysis of vibrational frequency shifts as being due solely to electrostatic interactions through the vibrational Stark effect, and the consequences of this complication are discussed. PMID:21859105

Xu, Lin; Cohen, Aina E.; Boxer, Steven G.

2011-01-01

203

Variable displacement blower  

DOEpatents

A blower having a stationary casing for rotatably supporting a rotor assembly having a series of open ended chambers arranged to close against the surrounding walls of the casing. Pistons are slidably mounted within each chamber with the center of rotation of the pistons being offset in regard to the center of rotation of the rotor assembly whereby the pistons reciprocate in the chambers as the rotor assembly turns. As inlet port communicates with the rotor assembly to deliver a working substance into the chamber as the pistons approach a top dead center position in the chamber while an outlet port also communicates with the rotor to exhaust the working substance as the pistons approach a bottom dead center position. The displacement of the blower is varied by adjusting the amount of eccentricity between the center of rotation of the pistons and the center of rotation of the rotor assembly.

Bookout, Charles C. (Niskayuna, NY); Stotts, Robert E. (Clifton Park, NY); Waring, Douglass R. (Ballston Spa, NY); Folsom, Lawrence R. (Ohain, BE)

1986-01-01

204

Displacement parameter inversion for a novel electromagnetic underground displacement sensor.  

PubMed

Underground displacement monitoring is an effective method to explore deep into rock and soil masses for execution of subsurface displacement measurements. It is not only an important means of geological hazards prediction and forecasting, but also a forefront, hot and sophisticated subject in current geological disaster monitoring. In previous research, the authors had designed a novel electromagnetic underground horizontal displacement sensor (called the H-type sensor) by combining basic electromagnetic induction principles with modern sensing techniques and established a mutual voltage measurement theoretical model called the Equation-based Equivalent Loop Approach (EELA). Based on that work, this paper presents an underground displacement inversion approach named "EELA forward modeling-approximate inversion method". Combining the EELA forward simulation approach with the approximate optimization inversion theory, it can deduce the underground horizontal displacement through parameter inversion of the H-type sensor. Comprehensive and comparative studies have been conducted between the experimentally measured and theoretically inversed values of horizontal displacement under counterpart conditions. The results show when the measured horizontal displacements are in the 0-100 mm range, the horizontal displacement inversion discrepancy is generally tested to be less than 3 mm under varied tilt angles and initial axial distances conditions, which indicates that our proposed parameter inversion method can predict underground horizontal displacement measurements effectively and robustly for the H-type sensor and the technique is applicable for practical geo-engineering applications. PMID:24858960

Shentu, Nanying; Li, Qing; Li, Xiong; Tong, Renyuan; Shentu, Nankai; Jiang, Guoqing; Qiu, Guohua

2014-01-01

205

Influence of Combined Alternating and Static Electromagnetic Fields on Cell Plasma Membrane  

E-print Network

The force due to alternating electric field and static magnetic field considering non linear model is givenDisplacment/Log 0 (radians/sec) (c) Alternating E Field and Alternating and Static B Field Figure 1: Non-Linear initial conditions as x = 1, y = 1, z = 1. (b) Alternating Magnetic Field and Static Magnetic Field Non-linear

Halgamuge, Malka N.

206

Displacement of conjugate points during a substorm in a global magnetohydrodynamic simulation  

Microsoft Academic Search

We reproduced substorm-related changes in the magnetic fieldWe identify major factors controlling the displacement of conjugate pointsWe identify the factors that cause displacements of conjugate auroras

S. Saita; A. Kadokura; N. Sato; S. Fujita; T. Tanaka; Y. Ebihara; S. Ohtani; G. Ueno; K. Murata; D. Matsuoka; A. Kitamoto; T. Higuchi

2011-01-01

207

Effects of Notch Misalignment and Tip Radius on Displacement Field in V-Notch Rail Shear Test as Determined by Photogrammetry  

NASA Technical Reports Server (NTRS)

Evolution of the 3D strain field during ASTM-D-7078 v-notch rail shear tests on 8-ply quasi-isotropic carbon fiber/epoxy laminates was determined by optical photogrammetry using an ARAMIS system. Specimens having non-optimal geometry and minor discrepancies in dimensional tolerances were shown to display non-symmetry and/or stress concentration in the vicinity of the notch relative to a specimen meeting the requirements of the standard, but resulting shear strength and modulus values remained within acceptable bounds of standard deviation. Based on these results, and reported difficulty machining specimens to the required tolerances using available methods, it is suggested that a parametric study combining analytical methods and experiment may provide rationale to increase the tolerances on some specimen dimensions, reducing machining costs, increasing the proportion of acceptable results, and enabling a wider adoption of the test method.

Hill, Charles S.; Oliveras, Ovidio M.

2011-01-01

208

Unsteady flow simulations in a three-lobe positive displacement blower  

NASA Astrophysics Data System (ADS)

To improve the performance of the positive displacement blower, it is imperative to understand the detailed internal flow characteristics or enable a visualization of flow status. However, the existing two-dimensional unsteady, three-dimensional steady or quasi-unsteady numerical simulation and theoretical analysis cannot provide the detailed flow information, which is unfavorable to improve the performance of positive displacement blower. Therefore, the unsteady flow characteristics in a three-lobe positive displacement blower are numerically investigated by solving the three-dimensional, unsteady, compressible Navier-Stokes equations coupled with RNG k- ? turbulent model. In the numerical simulation, the dynamic mesh technique and overset mesh updating method are adopted. Due to the air being compressed in the process of the rotors rotating, the variation of the temperature field in the positive displacement blower is considered. By comparing the experimental measurements and the numerical results on the variation of flow rate with the outlet pressure, the maximum relative error of the flow rate is less than 2.15% even at the maximum outlet pressure condition, which means that the calculation model and numerical computational method used are effective. The numerical results show that in the intake region, the fluctuations of the inlet flow are greatly affected by the direction of the velocity vectors. In the exhaust region, the temperature changes significantly, which leads to the increase of the airflow pulsation. Through analysis on the velocity, pressure and temperature fields obtained from the numerical simulations, three-dimensional unsteady flow characteristics in the positive displacement blower are revealed. The studied results will provide useful reference for improving the performance and empirical correction in the design of the positive displacement blower.

Liu, Xiaomin; Lu, Jun

2014-05-01

209

Timing of Landform Displacements along the Mojave Section of the San Andreas Fault: A Comparison of Field-based and Remote Reconstructions at Two Sites  

NASA Astrophysics Data System (ADS)

Determining the Holocene slip rate of the Mojave section of the San Andreas Fault (MSAF) is key for assessing the earthquake hazard that this ~150-km-long section of fault poses to the Los Angeles metropolitan area, which is located ~45 km to the southwest. Possible temporal variations in slip rate along the MSAF are suggested by an apparent discrepancy between geologically and geodetically determined slip rates, with rates from geologic observations reported to be up to twice as fast as those reported from geodetic data. This apparent variability could be the result of changes in slip rate over time, which is known as secular variation in slip. To test the hypothesis that the MSAF exhibits variability in slip rate over time requires establishing not just a Holocene-average slip rate, but a Holocene slip history. Previous work along the MSAF using remote, virtual-reality based analysis of B4 LiDAR topographic data and pilot field observations identified ~60 potential slip-rate sites with landform offsets between 30 and 300 m, 10 of which are particularly promising. We are currently conducting detailed, field-based studies at two of these 10 sites (Oakdale and Shoemaker Canyon), with an emphasis on collecting age and offset data to determine both Holocene-average slip rates and constrain slip-history analysis. Initial offset estimates were made by remote analysis using 3D visualization software with 1-meter resolution LiDAR (Light Detection and Ranging) data. We plan to excavate exploratory, fault-parallel trenches both northwest and southeast of the fault to constrain the ages of offset landforms, correlate depositional events across the fault, and test the offset estimates that were determined remotely. Upon establishing the stratigraphic relationships of lithologic units within the trenches and correlating this stratigraphy across the fault, we plan to employ geochronologic techniques to quantify the age of depositional events. The nature of the deposits will determine the type of geochronology that we will utilize. Both locations are moderately vegetated and likely to yield organic-rich deposits ideal for radiocarbon dating. If sand units are present, we may also use optically stimulated luminescence (OSL) dating, because of the potential for multiple dating techniques to strengthen the age determinations.

Barr, M. A.; Cowgill, E.

2013-12-01

210

FDTD analysis of temperature elevation in the lens of human and rabbit models due to near-field and far-field exposures at 2.45 GHz.  

PubMed

The eye is said to be one of the most sensitive organs to microwave heating. According to previous studies, the possibility of microwave-induced cataract formation has been experimentally investigated in rabbit and monkey eyes, but not for the human eye due to ethical reasons. In the present study, the temperature elevation in the lens, the skin around the eye and the core temperature of numerical human and rabbit models for far-field and near-field exposures at 2.45 GHz are investigated. The temperature elevations in the human and rabbit models were compared with the threshold temperatures for inducing cataracts, thermal pain in the skin and reversible health effects such as heat exhaustion or heat stroke. For plane-wave exposure, the core temperature elevation is shown to be essential both in the human and in the rabbit models as suggested in the international guidelines and standards. For localised exposure of the human eye, the temperature elevation of the skin was essential, and the lens temperature did not reach its threshold for thermal pain. On the other hand, the lens temperature elevation was found to be dominant for the rabbit eye. PMID:23390146

Oizumi, Takuya; Laakso, Ilkka; Hirata, Akimasa; Fujiwara, Osamu; Watanabe, Soichi; Taki, Masao; Kojima, Masami; Sasaki, Hiroshi; Sasaki, Kazuyuki

2013-07-01

211

Calculation of Crystallographic Texture due to Displacive Transformations  

E-print Network

­controlled weld metals, as a means for counteracting the development of residual stresses in welds. Welding is deformed into that of the product without the need for any diffusion. Since the co-ordinated movements

Cambridge, University of

212

Monitoring pipe line stress due to ground displacement  

SciTech Connect

Northwest Pipeline Corp. has a large-diameter natural gas pipe line system from Ignacio, Colo., to Sumas, Wash. At Douglas Pass in Colorado, large landslides required several sections of the line to be relocated outside the slide areas: 4,400 ft of new line in April 1962 and 3,200 ft in March 1963. No serious disruptions occurred for the next 16 years. Then in July 1979, some 1,200 ft had to be relocated. From 1980 to date, many landslides in the Douglas Pass area have caused new deformations, with the springs of 1983 and 1984 being the worst years. In 1980, Northwest Pipeline began engineering and geotechnical studies of the landslide problems. These led to instrumentation and pipe monitoring which indicated that pipe failure can be predicted and prevented if important slope deformations or increases in pipe stresses are detected early enough to implement some mitigating measures. Excavation of the pipe to relieve the stresses was used in most cases. The method was so successful that no pipe failure occurred in 1984 within instrumented sections, in spite of the exceptionally bad climatic conditions experienced.

Greenwood, J.H. Jr.

1986-04-01

213

Regenerative rotary displacer Stirling engine  

Microsoft Academic Search

A few rotary displacer Stirling engines whose displacers have one gas pocket space at one side, and rotate in a main enclosed cylinder, which is heated from one side and cooled from the opposite side without any regenerator have been tried and studied for a considerable time by the authors. They then tried to improve this engine by equipping them

Naotsugu Isshiki; Luca Raggi; S. Isshiki; K. Hirata; H. Watanabe

1996-01-01

214

Earnings Losses of Displaced Workers  

Microsoft Academic Search

The authors exploit administrative data combining workers' earnings histories with information about their firms to estimate the magnitude and temporal pattern of displaced workers' earnings losses. They find that high-tenure workers separating from distressed firms suffer long-term losses averaging 25 percent per year. In addition, the authors find that displaced workers' losses (1) begin mounting before their separations; (2) depend

Louis S. JACOBSON; ROBERT J. LALONDE; DANIEL G. SULLIVAN

1993-01-01

215

The Displaced vs. the Disadvantaged: A Necessary Dichotomy? Occasional Paper 1994-2.  

ERIC Educational Resources Information Center

The current displaced worker initiative towers over the 30-year effort to bring the economically disadvantaged into the mainstream of the labor market. The Congressional Budget Office defines displacement as all workers 18 years of age and older who lose full-time employment due to slack work, job abolition, or plant closure. Major displaced

Levitan, Sar A.; Mangum, Stephen L.

216

Comparing psychological responses of internally displaced and non-displaced Turkish Cypriots.  

PubMed

During the 1963-1964 ethnic conflict and 1974 war in Cyprus, many Turkish Cypriots were displaced by Greek Cypriot forces. The psychological condition of Turkish Cypriots after these conflicts has not been studied to the present day. At the time of the Annan Plan Referendum on April 24th 2004, when people on both sides were to decide whether to reunite or not, and when old traumatic events where being discussed in vivid detail, the psychological responses of the internally displaced and non-displaced Turkish Cypriots were investigated. The sample of the study derived from a sample of a larger household survey study conducted on 408 adult people taken randomly from three different districts. People who settled down in Cyprus after 1974 or who had never experienced a war in Cyprus were not included in the study. 129 Turkish Cypriots who experienced either 1963-64 conflict or the 1974 war were included in the present study. 86 of these had been displaced. The first part of the questionnaire that was administered to the subjects included demographic characteristics, war-related traumatic experiences, the level of seriousness, and traumatic incidents resulting from other circumstances. In the second part of the questionnaire, the Traumatic Stress Symptom Checklist (TSSC) and Brief Symptom Inventory (BSI) were used to investigate the symptoms of the post-traumatic process. The outcomes indicates that the internally displaced persons (IDPs) where subjected to traumatic incidents at a higher degree due to killing, displacement, captivity, or killing of family members and relatives. The rate of posttraumatic stress disorder (PTSD) of IDPs is 20%, and is significantly higher than for non-displaced persons. The comparison of BSI subscales show that IDPs had a higher level of depression scores than the non-displaced persons. The somatization subscale scores are higher in non-displaced persons. The study reveals a higher frequency of war-related traumatic events in IDPs than in non-displaced people, greater suffering from posttraumatic stress and more negative beliefs about future reunion. PMID:19289879

Ergun, Deniz; Cakici, Mehmet; Cakici, Ebru

2008-01-01

217

Pitot-probe displacement in a supersonic turbulent boundary layer  

NASA Technical Reports Server (NTRS)

Eight circular pitot probes ranging in size from 2 to 70 percent of the boundary-layer thickness were tested to provide experimental probe displacement results in a two-dimensional turbulent boundary layer at a nominal free-stream Mach number of 2 and unit Reynolds number of 8 million per meter. The displacement obtained in the study was larger than that reported by previous investigators in either an incompressible turbulent boundary layer or a supersonic laminar boundary layer. The large probes indicated distorted Mach number profiles, probably due to separation. When the probes were small enough to cause no appreciable distortion, the displacement was constant over most of the boundary layer. The displacement in the near-wall region decreased to negative displacement in some cases. This near-wall region was found to extend to about one probe diameter from the test surface.

Allen, J. M.

1972-01-01

218

Development and Displacement in India: Reforming the Economy towards Sustainability  

NASA Astrophysics Data System (ADS)

Displacement of human populations from the natural habitats results in a host of socio-economic impacts. This study will focus on mainly farmers and tribal communities in India and how the modernisation process has affected these communities especially since the adoption of neoliberal economic reforms. For the rural people the displacement is a traumatic both in terms livelihoods and cultural point of view. The paper will analyse the issues of displacement of the villages that have been relatively isolated from the outside world. The development induced displacement becomes important due to its impact on the rural communities through land alienation in the form of protests by the affected communities. I find that not even a single study shows the socio-economic and environmental effects of these policies on the rural poor. Analysis of the reasons for these changes point in many directions. Displacement, the loss of traditional livelihoods of the rural communities and environmental destruction are the most prominent among them.

Siddiqui, Kalim

2012-05-01

219

JOURNAL DE PHYSIQUE ColloqueCl,supplkment au nO 1, Tome41,janvier 1980,page C1-355 M~~SSBAUER ELECTRIC FIELD GRADIENT AM) MEN SQUARE DISPLACEMENT IN NATURALLY OCCURING FeS2 (PYRITE)  

E-print Network

~~SSBAUER ELECTRIC FIELD GRADIENT AM) MEN SQUARE DISPLACEMENT IN NATURALLY OCCURING FeS2 (PYRITE) SINGLE CRYSTALS R Espirito Santo, 29.000 Victoria, E.S., Brazi 2. Pyrite, cubic mineral of FeS2, has four molecules per unit = 0.386, forming four equivalent but differently oriented sites. M8ssbauer spectra of pyrite, fig. 1

Paris-Sud XI, Université de

220

3D ELLIPTICAL CRACK DEPTH ESTIMATION FROM 2D SURFACE DISPLACEMENT OBSERVATION  

E-print Network

.3. Mechanical loading of tension in x direction is applied with displacements ux = ±0.2 on lateral sides3D ELLIPTICAL CRACK DEPTH ESTIMATION FROM 2D SURFACE DISPLACEMENT OBSERVATION Pierre Pineau1 on surface displacement fields. An iterative numerical procedure with least- squares error minimisation

Boyer, Edmond

221

Application of PCR-denaturing-gradient gel electrophoresis (DGGE) method to examine microbial community structure in asparagus fields with growth inhibition due to continuous cropping.  

PubMed

Growth inhibition due to continuous cropping of asparagus is a major problem; the yield of asparagus in replanted fields is low compared to that in new fields, and missing plants occur among young seedlings. Although soil-borne disease and allelochemicals are considered to be involved in this effect, this is still controversial. We aimed to develop a technique for the biological field diagnosis of growth inhibition due to continuous cropping. Therefore, in this study, fungal community structure and Fusarium community structure in continuously cropped fields of asparagus were analyzed by polymerase chain reaction/denaturing-gradient gel electrophoresis (PCR-DGGE). Soil samples were collected from the Aizu region of Fukushima Prefecture, Japan. Soil samples were taken from both continuously cropped fields of asparagus with growth inhibition and healthy neighboring fields of asparagus. The soil samples were collected from the fields of 5 sets in 2008 and 4 sets in 2009. We were able to distinguish between pathogenic and non-pathogenic Fusarium by using Alfie1 and Alfie2GC as the second PCR primers and PCR-DGGE. Fungal community structure was not greatly involved in the growth inhibition of asparagus due to continuous cropping. By contrast, the band ratios of Fusarium oxysporum f. sp. asparagi in growth-inhibited fields were higher than those in neighboring healthy fields. In addition, there was a positive correlation between the band ratios of Fusarium oxysporum f. sp. asparagi and the ratios of missing asparagus plants. We showed the potential of biological field diagnosis of growth inhibition due to continuous cropping of asparagus using PCR-DGGE. PMID:22200640

Urashima, Yasufumi; Sonoda, Takahiro; Fujita, Yuko; Uragami, Atsuko

2012-01-01

222

Application of PCR-Denaturing-Gradient Gel Electrophoresis (DGGE) Method to Examine Microbial Community Structure in Asparagus Fields with Growth Inhibition due to Continuous Cropping  

PubMed Central

Growth inhibition due to continuous cropping of asparagus is a major problem; the yield of asparagus in replanted fields is low compared to that in new fields, and missing plants occur among young seedlings. Although soil-borne disease and allelochemicals are considered to be involved in this effect, this is still controversial. We aimed to develop a technique for the biological field diagnosis of growth inhibition due to continuous cropping. Therefore, in this study, fungal community structure and Fusarium community structure in continuously cropped fields of asparagus were analyzed by polymerase chain reaction/denaturing-gradient gel electrophoresis (PCR-DGGE). Soil samples were collected from the Aizu region of Fukushima Prefecture, Japan. Soil samples were taken from both continuously cropped fields of asparagus with growth inhibition and healthy neighboring fields of asparagus. The soil samples were collected from the fields of 5 sets in 2008 and 4 sets in 2009. We were able to distinguish between pathogenic and non-pathogenic Fusarium by using Alfie1 and Alfie2GC as the second PCR primers and PCR-DGGE. Fungal community structure was not greatly involved in the growth inhibition of asparagus due to continuous cropping. By contrast, the band ratios of Fusarium oxysporum f. sp. asparagi in growth-inhibited fields were higher than those in neighboring healthy fields. In addition, there was a positive correlation between the band ratios of Fusarium oxysporum f. sp. asparagi and the ratios of missing asparagus plants. We showed the potential of biological field diagnosis of growth inhibition due to continuous cropping of asparagus using PCR-DGGE. PMID:22200640

Urashima, Yasufumi; Sonoda, Takahiro; Fujita, Yuko; Uragami, Atsuko

2012-01-01

223

Anisotropic Transport in Energetic Displacement Cascades  

NASA Astrophysics Data System (ADS)

Theoretical concepts and experimental investigations of the effect of target species atomic mass, system geometry, and thermodynamic effects on the anisotropic transport in the ion mixing of metallic systems are reported. Atomic transport mechanisms are discussed in terms of ballistic (collision cascades) and thermal spike transport theory. In the collision cascade case the largely isotropic low energy displacements have a small anisotropic component due to preferential inward momentum distributions. This anisotropic component depends on projectile mass, target mass, and energy transfer to the target atom. Lighter mass species are thought to preferentially displace inward, in a bilayer interface mixing case, due to their greater associated range. Furthermore, the preferential transport is thought to compound with increasing irradiation dose. In the thermal spike case atomic transport is described as an isotropic process when both species in a bilayer system have approximately equal cohesive energies, however, thermal spike induced transport becomes anisotropic when the cohesive energy of the bilayer species differ. Under conditions of different cohesive energies on each side of a bilayer interface, it is thought that the cohesive energy material displaces preferentially into the low cohesive energy layer. Experimental systems of bilayer samples with zero heats of mixing and similar cohesive energies, but different atomic masses, such as Ta on top of Nb (Ta/Nb), Nb on top of Ta (Nb/Ta), Hf on top of Zr (Hf/Zr), and Zr on top of Hf (Zr/Hf) were irradiated by 300 keV Kr^ {++} at a dose of 2 times 10^{16}Kr ^{++}/cm^2 at 77 K. The samples were investigated using embedded markers and Rutherford backscattering spectrometry. The experimental results indicate that the anisotropic transport is dominated by a preferential displacement of the top layer species into the bottom layer. In addition, there is a small enhancement of the inward displacement when the lighter species is on top, indicating a small preferential recoil displacement of the lighter species over the heavier one. The effect of a gradient in cohesive energy across a bilayer interface was investigated by ion mixing experiments of W/Pd, Pd/W, Nb/Cu, Cu/Nb, Ag/V, and V/Ag. The results indicate a preferential transport of higher cohesive energy material (W, Nb, and V) into the low cohesive energy material (Pd, Cu, and Ag). This phenomenon is explained in terms of activation energies and energy deposition gradients. The experimental results suggest that the mechanisms responsible for interface mixing during ion irradiation scale with species cohesive energy. High cohesive energy systems are governed largely by collision cascade transport while low cohesive energy systems are governed by thermal spike transport.

Auner, Gregory William

224

Displacement of large-scale open solar magnetic fields from the zone of active longitudes and the heliospheric storm of November 3-10, 2004: 2. "Explosion" of singularity and dynamics of sunspot formation and energy release  

NASA Astrophysics Data System (ADS)

A more detailed scenario of one stage (August-November 2004) of the quasibiennial MHD process "Origination ... and dissipation of the four-sector structure of the solar magnetic field" during the decline phase of cycle 23 has been constructed. It has been indicated that the following working hypothesis on the propagation of an MHD disturbance westward (in the direction of solar rotation) and eastward (toward the zone of active longitudes) with the displacement of the large-scale open solar magnetic field (LOSMF) from this zone can be constructed based on LOSMF model representations and data on sunspot formation, flares, active filaments, and coronal ejections as well as on the estimated contribution of sporadic energy release to the flare luminosity and kinetic energy of ejections: (1) The "explosion" of the LOSMF singularity and the formation in the explosion zone of an anemone active region (AR), which produced the satellite sunspot formation that continued west and east of the "anemone," represented a powerful and energy-intensive source of MHD processes at this stage. (2) This resulted in the origination of two "governing" large-scale MHD processes, which regulated various usual manifestations of solar activity: the fast LOSMF along the neutral line in the solar atmosphere, strongly affecting the zone of active longitudes, and the slow LOSMF in the outer layers of the convection zone. The fronts of these processes were identified by powerful (about 1031 erg) coronal ejections. (3) The collision of a wave reflected from the zone of active longitudes with the eastern front of the hydromagnetic impulse of the convection zone resulted in an increase in LOSMF magnetic fluxes, origination of an active sector boundary in the zone of active longitudes, shear-convergent motions, and generation and destabilization of the flare-productive AR 10696 responsible for the heliospheric storm of November 3-10, 2004.

Ivanov, K. G.

2010-12-01

225

Wirelessly Interrogated Position or Displacement Sensors  

NASA Technical Reports Server (NTRS)

Two simple position or displacement sensors based on inductance-capacitance resonant circuits have been conceived. These sensors are both powered and interrogated without use of wires and without making contact with other objects. Instead, excitation and interrogation are accomplished by means of a magnetic-field-response recorder. Both of the present position or displacement sensors consist essentially of variable rectangular parallel-plate capacitors electrically connected in series with fixed inductors. Simple inductance-capacitance circuits of the type used in these sensors are inherently robust; their basic mode of operation does not depend on maintenance of specific environmental conditions. Hence, these sensors can be used under such harsh conditions as cryogenic temperatures, high pressures, and radioactivity.

Woodard, Stanley E.; Taylor, Bryant D.

2007-01-01

226

Literature Review of Displacement Ventilation  

E-print Network

Performance Evaluation and Design Guidelines for Displacement Ventilation” by Chen and Clicksman (2003), were used to begin the literature search. Their references include papers, articles, and web sites presenting major contributions to the understanding...

Cho, S.; Im, P.; Haberl, J. S.

227

Rapid Sunspot Displacement Associated with Solar Eruptions  

NASA Astrophysics Data System (ADS)

Many observational and modeling studies of solar eruptions merely treat photosphere as the lower boundary and assume no significant changes of magnetic fields anchoring there to occur during flares/CMEs. With increasing evidence of photospheric magnetic fields variations resulting from energy release in the upper atmosphere, Hudson, Fisher and Welsch (2008, ASP, 383, 221) proposed that the photosphere and even solar interior would respond in a back-reaction process to the coronal magnetic field restructuring. Inspired by this concept, we analyzed white-light images obtained with TRACE and report here rapid and permanent perturbation in the position of delta spot umbrae associated with five X-class flares. Our main results are the following: (1) The centroids of umbrae with opposite magnetic polarities undergo relative as well as overall displacement on the order of 1E3 km after flares/CMEs. (2) The estimated total kinetic energy associated with these motions (Ek) is on the order of 1E29 ergs and appears to correlate with the 6 mHZ seismic energy (Es) derived by the Monash group. (3) There appears correlation between both the Ek and Es corresponding to the velocity of CMEs. We suggest that: (1) sunspot displacement provides a direct observational evidence of the photospheric back-reaction and could potentially serve as an alternative excitation mechanism of seismic waves; (2) These could provide rational support to the back-reaction mechanism in the sense that its magnitude might be related to how violent the coronal magnetic field is disrupted. For selected events with good multiwavelength coverage, we also analyze in detail spatial as well as temporal relationship among the sunspot displacement, magnetic field changes, seismic sources, hard X-ray emissions, and overall flaring condition. This work is supported by NSF grants ATM 08-19662 and ATM 07-45744, and NASA grants NNX 08AQ90G, NNX 07AH78G, and NNX 08AQ32G.

Liu, Chang; Deng, N.; Wang, H.

2010-05-01

228

A novel linear displacement sensor  

NASA Astrophysics Data System (ADS)

With development of time grating technology in the past 10 years, the theory of using time to measure spatial displacement has been completed greatly. In the study of time grating, one novel linear displacement sensor is proposed based on the measurement principles of time grating. The measurement principles of linear displacement are similar to that of angular displacement. Both of them need one endless coordinate with uniform velocity. The theory of linear AC motor is used, and the three-phase winding with equal division space of 120° and three-phase exciting signal with uniform time are utilized to generate the endless moving coordinate with uniform velocity. The magnetic traveling wave arises from the left endpoint and disappears in the right endpoint, and it travels pole pitch distance of W during the periodic time of T with the uniform velocity. When magnetic traveling wave passes by the static probe and the moving probe, the electric signals will be induced on the winding, respectively. Therefore, the linear displacement can be achieved by comparing the phase between the two output induced signals from he static probe and the moving probe. Furthermore, in order to improve the machining technique, four kinds of winding framework are designed to employ. The experimental results show that advantages and disadvantages both exist in the design methods and the precision of experiment results reaches +/-2µm. The next study plan is to choose the most excellent design method through further experiments and improve the precision of displacement sensor greatly.

Yang, Ji-sen; Zhang, Jing; Chen, Xi-hou; Zhang, Tian-heng

2011-12-01

229

40 CFR 205.153 - Engine displacement.  

Code of Federal Regulations, 2014 CFR

...Engine displacement. (a) Engine displacement must be calculated using nominal engine values and rounded to the...American Society for Testing Materials (ASTM) E 29-67. (b) For rotary engines, displacement means...

2014-07-01

230

40 CFR 205.153 - Engine displacement.  

Code of Federal Regulations, 2011 CFR

...Engine displacement. (a) Engine displacement must be calculated using nominal engine values and rounded to the...American Society for Testing Materials (ASTM) E 29-67. (b) For rotary engines, displacement means...

2011-07-01

231

40 CFR 205.153 - Engine displacement.  

Code of Federal Regulations, 2010 CFR

...Engine displacement. (a) Engine displacement must be calculated using nominal engine values and rounded to the...American Society for Testing Materials (ASTM) E 29-67. (b) For rotary engines, displacement means...

2010-07-01

232

40 CFR 205.153 - Engine displacement.  

Code of Federal Regulations, 2013 CFR

...Engine displacement. (a) Engine displacement must be calculated using nominal engine values and rounded to the...American Society for Testing Materials (ASTM) E 29-67. (b) For rotary engines, displacement means...

2013-07-01

233

40 CFR 205.153 - Engine displacement.  

Code of Federal Regulations, 2012 CFR

...Engine displacement. (a) Engine displacement must be calculated using nominal engine values and rounded to the...American Society for Testing Materials (ASTM) E 29-67. (b) For rotary engines, displacement means...

2012-07-01

234

Comparing Teaching Approaches About Maxwell's Displacement Current  

NASA Astrophysics Data System (ADS)

Due to its fundamental role for the consolidation of Maxwell's equations, the displacement current is one of the most important topics of any introductory course on electromagnetism. Moreover, this episode is widely used by historians and philosophers of science as a case study to investigate several issues (e.g. the theory-experiment relationship). Despite the consensus among physics educators concerning the relevance of the topic, there are many possible ways to interpret and justify the need for the displacement current term. With the goal of understanding the didactical transposition of this topic more deeply, we investigate three of its domains: (1) The historical development of Maxwell's reasoning; (2) Different approaches to justify the term insertion in physics textbooks; and (3) Four lectures devoted to introduce the topic in undergraduate level given by four different professors. By reflecting on the differences between these three domains, significant evidence for the knowledge transformation caused by the didactization of this episode is provided. The main purpose of this comparative analysis is to assist physics educators in developing an epistemological surveillance regarding the teaching and learning of the displacement current.

Karam, Ricardo; Coimbra, Debora; Pietrocola, Maurício

2014-08-01

235

Measuring frequency changes due to microwave power variations as a function of C-field setting in a rubidium frequency standard  

NASA Technical Reports Server (NTRS)

It has been shown in previous studies that in some cesium frequency standards there exist certain C-field settings that minimize frequency changes that are due to variations in the microwave power. In order to determine whether similar results could be obtained with rubidium (Rb) frequency standards (clocks), we performed a similar study, using a completely automated measurement system, on a commercial Rb standard. From our measurements we found that changing the microwave power to the filter cell resulted in significant changes in frequency, and that the magnitude of these frequency changes at low C-field levels went to zero and decreased as the C-field was increased.

Sarosy, E. B.; Johnson, Walter A.; Karuza, Sarunas K.; Voit, Frank J.

1992-01-01

236

Development of a Wireless Displacement Measurement System Using Acceleration Responses  

PubMed Central

Displacement measurements are useful information for various engineering applications such as structural health monitoring (SHM), earthquake engineering and system identification. Most existing displacement measurement methods are costly, labor-intensive, and have difficulties particularly when applying to full-scale civil structures because the methods require stationary reference points. Indirect estimation methods converting acceleration to displacement can be a good alternative as acceleration transducers are generally cost-effective, easy to install, and have low noise. However, the application of acceleration-based methods to full-scale civil structures such as long span bridges is challenging due to the need to install cables to connect the sensors to a base station. This article proposes a low-cost wireless displacement measurement system using acceleration. Developed with smart sensors that are low-cost, wireless, and capable of on-board computation, the wireless displacement measurement system has significant potential to impact many applications that need displacement information at multiple locations of a structure. The system implements an FIR-filter type displacement estimation algorithm that can remove low frequency drifts typically caused by numerical integration of discrete acceleration signals. To verify the accuracy and feasibility of the proposed system, laboratory tests are carried out using a shaking table and on a three storey shear building model, experimentally confirming the effectiveness of the proposed system. PMID:23881123

Park, Jong-Woong; Sim, Sung-Han; Jung, Hyung-Jo; Spencer, Billie F.

2013-01-01

237

Contactless sub-millimeter displacement measurements  

NASA Astrophysics Data System (ADS)

Weather effects on foldable domes, as used at the DOT and GREGOR, are investigated, in particular the correlation between the wind field and the stresses caused to both metal framework and tent clothing. Camera systems measure contactless the displacement of several dome points. The stresses follow from the measured deformation pattern. The cameras placed near the dome floor do not disturb telescope operations. In the set-ups of DOT and GREGOR, these cameras are up to 8 meters away from the measured points and must be able to detect displacements of less than 0.1 mm. The cameras have a FireWire (IEEE1394) interface to eliminate the need for frame grabbers. Each camera captures 15 images of 640 × 480 pixels per second. All data is processed on-site in real-time. In order to get the best estimate for the displacement within the constraints of available processing power, all image processing is done in Fourier-space, with all convolution operations being pre-computed once. A sub-pixel estimate of the peak of the correlation function is made. This enables to process the images of four cameras using only one commodity PC with a dual-core processor, and achieve an effective sensitivity of up to 0.01 mm. The deformation measurements are well correlated to the simultaneous wind measurements. The results are of high interest to upscaling the dome design (ELTs and solar telescopes).

Sliepen, Guus; Jägers, Aswin P. L.; Bettonvil, Felix C. M.; Hammerschlag, Robert H.

2008-07-01

238

Aggregation of gold nanoframes reduces, rather than enhances, SERS efficiency due to the trade-off of the inter- and intraparticle plasmonic fields.  

PubMed

It is usually observed and understood that aggregation of silver and gold solid nanoparticles gives rise to enhanced SERS spectra due to the increased plasmon field between the particles. In the present work, we observed that the increase of aggregation of Langmuir-Blodgett assembled 80 nm gold nanoframe particles reduces the efficiency of the surface-enhanced Raman spectra of adsorbed thiophenol molecules. Using discrete dipole approximation simulation of the plasmonic fields of a pair of nanoframes as a function of their interparticle separation, it is found that at large separation the fields inside the cavities are stronger than those outside. As the interpair separation decreases, the gain in the interparticle field does not make up for the loss in the field within the cavities, supporting the observation of the decrease in the SERS intensity with aggregation. PMID:19585987

Mahmoud, M A; El-Sayed, M A

2009-08-01

239

Change of ionospheric plasma parameters under the influence of electric field which has lithospheric origin and due to radon emanation  

NASA Astrophysics Data System (ADS)

A mechanism of electric-photochemistry channel of seismo-ionospheric coupling is investigated. In particular, the penetration of electric field from the lithospheric source into the ionosphere and effect of this field on the photochemistry coefficient and ionospheric parameters in the altitude range in the lower D region are modeled numerically. It is shown that observable effects can be expected when lithospheric electric source strength is of the order of 1.5 kV/m. In this case, variations of electron temperature and electron concentration will be of the order of (40-60)% and (25-40)% respectively at the range of altitudes 60-70 km. An increase of near-ground conductivity (caused by increasing humidity and/or radon emanation) by ?2.3 times can cause increase of electric field intensity by ?2 times in altitude ranges of 60-70 km. Corresponding relative change of Te increases up to ?50%, as compared with the case of lower near-ground temperature. Spatial shapes of relative distribution of electron temperature and the ratio of negative ion-electron concentration map the spatial shape of the lithospheric electric field distribution. Spatial shapes of electron concentration distribution and electric field strength distribution of the lithospheric source are “opposite” to each other.

Rapoport, Y.; Grimalsky, V.; Hayakawa, M.; Ivchenko, V.; Juarez-R, D.; Koshevaya, S.; Gotynyan, O.

240

Neutron star deformation due to poloidal-toroidal magnetic fields of arbitrary multipole order: a new analytic approach  

E-print Network

A recipe is presented to construct an analytic, self-consistent model of a non-barotropic neutron star with a poloidal-toroidal field of arbitrary multipole order, whose toroidal component is confined in a torus around the neutral curve inside the star, as in numerical simulations of twisted tori. The recipe takes advantage of magnetic-field-aligned coordinates to ensure continuity of the mass density at the surface of the torus. The density perturbation and ellipticity of such a star are calculated in general and for the special case of a mixed dipole-quadrupole field as a worked example. The calculation generalises previous work restricted to dipolar, poloidal-toroidal and multipolar, poloidal-only configurations. The results are applied, as an example, to magnetars whose observations (e.g., spectral features and pulse modulation) indicate that the internal magnetic fields may be at least one order of magnitude stronger than the external fields, as inferred from their spin downs, and are not purely dipolar.

Mastrano, Alpha; Melatos, Andrew

2015-01-01

241

Forest transition in Vietnam and displacement of deforestation abroad  

PubMed Central

In some countries across the globe, tropical forest cover is increasing. The national-scale reforestation of Vietnam since 1992 is assumed to contribute to this recovery. It is achieved, however, by the displacement of forest extraction to other countries on the order of 49 (34–70) M m3, or ?39% of the regrowth of Vietnam's forests from 1987 to 2006. Approximately half of wood imports to Vietnam during this period were illegal. Leakage due to policies restricting forest exploitation and displacement due to growing domestic consumption and exports contributed respectively to an estimated 58% and 42% of total displacement. Exports of wood products from Vietnam also grew rapidly, amounting to 84% of the displacement, which is a remarkable feature of the forest transition in Vietnam. Attribution of the displacement and corresponding forest extraction to Vietnam, the source countries or the final consumers is thus debatable. Sixty-one percent of the regrowth in Vietnam was, thus, not associated with displacement abroad. Policies allocating credits to countries for reducing deforestation and forest degradation should monitor illegal timber trade and take into account the policy-induced leakage of wood extraction to other countries. PMID:19805270

Meyfroidt, Patrick; Lambin, Eric F.

2009-01-01

242

Generation of displaced squeezed superpositions of coherent states  

SciTech Connect

We study the method of generation of states that approximate superpositions of large-amplitude coherent states (SCSs) with high fidelity in free-traveling fields. Our approach is based on the representation of an arbitrary single-mode pure state, and SCSs in particular, in terms of displaced number states with an arbitrary displacement amplitude. The proposed optical scheme is based on alternation of photon additions and displacement operators (in the general case, N photon additions and N - 1 displacements are required) with a seed coherent state to generate both even and odd displaced squeezed SCSs regardless of the parity of the used photon additions. It is shown that the optical scheme studied is sensitive to the seed coherent state if the other parameters are unchanged. Output states can approximate either even squeezed SCS or odd SCS shifted relative to each other by some value. This allows constructing a local rotation operator, in particular, the Hadamard gate, which is a mainframe element for quantum computation with coherent states. We also show that three-photon additions with two intermediate displacement operators are sufficient to generate even displaced squeezed SCS with the amplitude 1.7 and fidelity more than 0.99. The effects deteriorating the quality of output states are considered.

Podoshvedov, S. A., E-mail: sapo66@mail.ru [South Ural State University, Department of General and Theoretical Physics (Russian Federation)

2012-03-15

243

Charge Induction and Polarization on the Surface of a Topological Insulator Due to an Emergent Gauge Field  

NASA Astrophysics Data System (ADS)

Exchange interaction with surface magnetization exerts a local U(1) gauge field on Dirac fermions that exist on the surface of a topological insulator (TI). We show that the emergent gauge field gives rise to charge induction and polarization on the TI surface via the quantum anomalous Hall (QAH) effect. These phenomena correspond to an implementation of the Laughlin’s thought experiment [R. B. Laughlin, Phys. Rev. B 23, 5632 (1981)] without inserting a magnetic flux, and enable a local evaluation of the QAH transport on a specific TI surface.

Hattori, Kiminori

2014-03-01

244

The Effects of an Induced Electric Dipole Moment due to Earth's Electric Field on the Artificial Satellites Orbit  

NASA Astrophysics Data System (ADS)

The orbits of artificial satellites are very sensitive to a large number of disturbances, whose effects add to the main force exerted by Earth's gravitational field. The most important perturbations, caused by solar radiation pressure, the Moon and the Sun gravitational fields, have been extensively discussed in the literature, and must be taken into account in order to correct the orbital motion, to prevent collisions between satellites in close orbits. In this paper we consider an additional source of acceleration arising from an electric dipole moment induced by the high altitude Earth electric field in a metallic satellite of spherical shape. The order of magnitude of such effect is estimated to be in the range of 10 - 23m/s2. It is emphasized that the electric dipole moment effect(EDME) is dependent on the satellite shape and geometry and proportional to E_0 v/r^4. The Earth electric field E 0 is largely influenced by atmospheric electromagnetic phenomena, such as whistler waves and thunderstorms.

Heilmann, Armando; Ferreira, Luiz Danilo Damasceno; Dartora, Cesar Augusto

2012-04-01

245

FIELD ACTIVITIES PLAN This template is designed to help you ensure you are meeting your due diligence  

E-print Network

; Approx. 6 min. via helicopter or 6 hours on foot 2. Field Research Participants Name: Position: Emergency Helicopters Local Emergency Response Number: 907-789-5600 Juneau Police: 907-586-0600 Other: 911 (available likely to stem from (1) exposure; (2) glacier travel; (3) working adjacent to an ice-marginal lake

Machel, Hans

246

Perceived displacement explains wolfpack effect  

PubMed Central

We investigate the influence of perceived displacement of moving agent-like stimuli on the performance in dynamic interactive tasks. In order to reliably measure perceived displacement we utilize multiple tasks with different task demands. The perceived center of an agent's body is displaced in the direction in which the agent is facing and this perceived displacement is larger than the theoretical position of the center of mass would predict. Furthermore, the displacement in the explicit judgment is dissociated from the displacement obtained by the implicit measures. By manipulating the location of the pivot point, we show that it is not necessary to postulate orientation as an additional cue utilized by perception, as has been suggested by earlier studies. These studies showed that the agent's orientation influences the detection of chasing motion and the detection-related performance in interactive tasks. This influence has been labeled wolfpack effect. In one of the demonstrations of the wolfpack effect participants control a green circle on a display with a computer mouse. It has been shown that participants avoid display areas with agents pointing toward the green circle. Participants do so in favor of areas where the agents point in the direction perpendicular to the circle. We show that this avoidance behavior arises because the agent's pivot point selected by the earlier studies is different from where people locate the center of agent's body. As a consequence, the nominal rotation confounds rotation and translation. We show that the avoidance behavior disappears once the pivot point is set to the center of agent's body. PMID:25566114

Šimkovic, Matúš; Träuble, Birgit

2014-01-01

247

A Wireless Laser Displacement Sensor Node for Structural Health Monitoring  

PubMed Central

This study describes a wireless laser displacement sensor node that measures displacement as a representative damage index for structural health monitoring (SHM). The proposed measurement system consists of a laser displacement sensor (LDS) and a customized wireless sensor node. Wireless communication is enabled by a sensor node that consists of a sensor module, a code division multiple access (CDMA) communication module, a processor, and a power module. An LDS with a long measurement distance is chosen to increase field applicability. For a wireless sensor node driven by a battery, we use a power control module with a low-power processor, which facilitates switching between the sleep and active modes, thus maximizing the power consumption efficiency during non-measurement and non-transfer periods. The CDMA mode is also used to overcome the limitation of communication distance, which is a challenge for wireless sensor networks and wireless communication. To evaluate the reliability and field applicability of the proposed wireless displacement measurement system, the system is tested onsite to obtain the required vertical displacement measurements during the construction of mega-trusses and an edge truss, which are the primary structural members in a large-scale irregular building currently under construction. The measurement values confirm the validity of the proposed wireless displacement measurement system and its potential for use in safety evaluations of structural elements. PMID:24084114

Park, Hyo Seon; Kim, Jong Moon; Choi, Se Woon; Kim, Yousok

2013-01-01

248

Force field and potential due to the Fermi-Coulomb hole charge for nonspherical-density atoms  

Microsoft Academic Search

In the work formalism for the determination of electronic structure, the exchange-correlation energy and (local) potential of the electrons both arise via Coulomb's law from the same source, viz., the quantum-mechanical Fermi-Coulomb hole charge. The potential is the work Wxc(r) done to move an electron in the field of its Fermi-Coulomb hole and the energy is the interaction energy between

Marlina Slamet; Viraht Sahni; Manoj K. Harbola

1994-01-01

249

Land subsidence due to groundwater withdrawal detected by InSAR time-series in Tazerbo well field, Libya  

NASA Astrophysics Data System (ADS)

The Tazerbo well field is one of the well fields designed within the Great Man-Made River Project (GMMRP), which aims to deliver water to the eastern coast of Libya through an underground pipe network. It consists of 108 wells in three rows, where the wells are separated 1.3 km in longitude and 10 km in latitude. The planned total groundwater withdrawal from all wells is 1 million m3/day. The water is pumped from the deep sandstone aquifer (Nubian sandstone), which is overlaid by a thick mudstone-siltstone aquitard. Being heavily pumped, the aquifer and fine-grained sediments of the aquitard are expected to compact in time resulting in land subsidence. In order to investigate the surface deformation caused by groundwater pumping in the Tazerbo well field, Interferometric Synthetic Aperture Radar (InSAR) technique was utilized. InSAR is widely used for monitoring land subsidence and can provide sub-cm scale deformation information over large areas. Using the Persistent Scatterer method, SAR time series of 20 Envisat images, spanning from 2004 to 2010, are employed to analyze spatial and temporal distribution of land subsidence induced by groundwater withdrawal. The results are in a good agreement with simulated subsidence. In addition, the spatial distribution of InSAR observations seems to be promising in terms of detecting spatial heterogeneity of aquifer material.

Tufekci, Nesrin; Schoups, Gerrit; Mahapatra, Pooja; van de Giesen, Nick; Hanssen, Ramon F.

2014-05-01

250

DISPLACEMENT BASED SEISMIC DESIGN METHODS.  

SciTech Connect

A research effort was undertaken to determine the need for any changes to USNRC's seismic regulatory practice to reflect the move, in the earthquake engineering community, toward using expected displacement rather than force (or stress) as the basis for assessing design adequacy. The research explored the extent to which displacement based seismic design methods, such as given in FEMA 273, could be useful for reviewing nuclear power stations. Two structures common to nuclear power plants were chosen to compare the results of the analysis models used. The first structure is a four-story frame structure with shear walls providing the primary lateral load system, referred herein as the shear wall model. The second structure is the turbine building of the Diablo Canyon nuclear power plant. The models were analyzed using both displacement based (pushover) analysis and nonlinear dynamic analysis. In addition, for the shear wall model an elastic analysis with ductility factors applied was also performed. The objectives of the work were to compare the results between the analyses, and to develop insights regarding the work that would be needed before the displacement based analysis methodology could be considered applicable to facilities licensed by the NRC. A summary of the research results, which were published in NUREGICR-6719 in July 2001, is presented in this paper.

HOFMAYER,C.MILLER,C.WANG,Y.COSTELLO,J.

2003-07-15

251

Retraining Displaced Workers. Policy Brief  

ERIC Educational Resources Information Center

Robert LaLonde of the University of Chicago and Daniel Sullivan of the Federal Reserve Bank of Chicago suggest that retraining through our nation's community colleges is a way to reduce the skills gaps of at least some of these displaced workers and increase their reemployment earnings. Although workers may still experience significant earnings…

LaLonde, Robert; Sullivan, Daniel

2010-01-01

252

DISPLACEMENTS OF THE DESIRING MACHINE  

Microsoft Academic Search

The ‘cinematic gaze’ can be conceived today as a kind of metaphorical practice, particularly in relation to viewing Patty Chang's video artwork In Love (2001). Chang's artistic expression theatricalizes familial love and reveals how bodily inscriptions of sexuality and ‘race’ are still predetermined by an affected gaze. The original site of the ‘cinema of displacement’ was in the substitute of

Jane Chin Davidson

2012-01-01

253

Electromagnetic Fields Due to a Loop Current in a CasedBorehole Surrounded by Uniform Whole Space  

SciTech Connect

Precise evaluation of electromagnetic (EM) response in steel-cased borehole is an essential first step towards developing techniques for casing parameter evaluation, which would ultimately help evaluating the formation response. In this report we demonstrate a numerical scheme for accurately computing EM responses in cased borehole environment. For improved numerical accuracy we use explicit representations of the electromagnetic spectra inside the borehole, in the casing, and in the formation. Instead of conventional Hankel transform, FFT is used to improve the numerical accuracy. The FFT approach allows us to compute fields at positions very close to the source loop, including the center of the transmitter loop.

Lee, K.H.; Song, Y.

1998-01-01

254

Linearly polarized radiation from astrophysical masers due to magnetic fields when the rate for stimulated emission exceeds the Zeeman frequency  

NASA Technical Reports Server (NTRS)

The results are presented of reformulating the treatment of polarized maser radiation in the presence of magnetic fields in a way that seems somewhat more convenient for calculations with masing states having angular momenta greater than J = 1 and 0. Calculations are then performed for the case of small Zeeman splitting using idealizations which are equivalant to those made previously in calculations for a J = 1-0 transition. The results provide a complete, general description of the polarization characteristics of astrophysical maser radiation involving states of higher angular momentum of closed-shell molecules.

Deguchi, Shuji; Watson, William D.

1990-01-01

255

Internal electric fields due to piezoelectric and spontaneous polarizations in CdZnO/MgZnO quantum well  

NASA Astrophysics Data System (ADS)

We have investigated optical properties as a function of internal and external fields in the quantum well (QW). Optical properties of CdZnO/MgZnO QW structures are investigated by using many-body effects. The CdZnO/MgZnO QW structure with high Cd composition is found to have smaller optical gain because the strain-induced piezoelectric polarization and the spontaneous polarization in the well increase with the inclusion of Cd. These results demonstrate that high performance laser diode operation can be realized in CdZnO/MgZnO QW structures by reducing those polarizations adopting dipole reverse method.

Jeon, H. C.; Lee, S. J.; Kang, T. W.; Park, S. H.; Yeo, Yung Kee; George, T. F.

2011-12-01

256

Is the Long-Term Persistency of Circular Polarisation due to the Constant Helicity of the Magnetic Fields in Rotating Quasar Engines?  

Microsoft Academic Search

Many compact radio sources like quasars, blazars, radio galaxies, and\\u000amicro-quasars emit circular polarisation (CP) with surprising temporal\\u000apersistent handedness. We propose that the CP is caused by Faraday conversion\\u000aof linear polarisation synchrotron light which propagates along a line-of-sight\\u000athrough helical magnetic fields. Jet outflows from radio galaxies should have\\u000athe required magnetic helicity in the emission region due

Torsten A. Ensslin

2003-01-01

257

An effective 3-D finite element scheme for computing electromagnetic field distortions due to defects in eddy-current nondestructive evaluation  

Microsoft Academic Search

A new three-dimensional (3-D) finite element scheme for eddy-current nondestructive evaluation (NDE) problems is described that calculates directly the perturbation of the electromagnetic field due to defects in metallic specimens. The computational costs of such problems are usually very high using available finite element schemes, and the new scheme is supposed to lower these costs. The basic concept, the direct

Zsolt Badics; Yoshihiro Matsumoto; Kazuhiko Aoki; Fumio Nakayasu; Mitsuru Uesaka; Kenzo Miya

1997-01-01

258

Transient Phenomena of Current and Field Distortion due to Dynamics of Packet-Like Charges in LDPE Films  

NASA Astrophysics Data System (ADS)

Simultaneous measurements for space charge and external current were carried out using a PEA measurement system with an electrometer on the back of a grounding electrode in order to clarify physical situation of a huge packet of positive space charges in LDPE films. A large number of positive charges from semi-conduction anode were accumulated at the interface between LDPE and Al-cathode under 1.5MV/cm of mean applied field and then they finally disappeared. Results of the simultaneous measurements showed that the external current kept a relatively high value during the charge accumulation and it further increased when the charges disappeared. Both the charge dynamics and the external current were restricted by addition of a low-molecular-weight paraffin wax, indicating that the carrier transport was influenced by micro structure of the polymer. Dynamics of residual charges after short-circuiting is also discussed.

Yoshioka, Hirokazu; Kadowaki, Kazunori; Kitani, Isamu

259

ULF magnetic signatures at the earth surface due to ground water flow - A possible precursor to earthquakes  

NASA Technical Reports Server (NTRS)

Magnetic field fluctuations at the earth's surface at less than 1 Hz are shown to result from motion with a peak velocity of about 4 cm/s of ground water (about 4 S/m) at about 5 km depth. Surface field changes can occur due to either divergence free fluid motion with transverse spatial wavelengths of a few tens of km, and/or homogeneous flow which displaces local inhomogeneities in the earth magnetic field.

Draganov, A. B.; Inan, U. S.; Taranenko, Iu. N.

1991-01-01

260

Size effects on electromechanical coupling fields of a bending piezoelectric nanoplate due to surface effects and flexoelectricity  

NASA Astrophysics Data System (ADS)

Due to large surface to volume ratio and manifest strain gradients typically present in nanostructures, it is essential to incorporate both surface effects and flexoelectricity in studying the size-dependent electromechanical coupling behaviors of piezoelectric materials at the nano-scale. In the current work, a modified Kirchhoff plate model with the consideration of residual surface stress, surface elasticity, surface piezoelectricity, and flexoelectricity is developed to investigate the electroelastic responses and vibrational behaviors of a bending piezoelectric nanoplate (PNP). The governing equations and the corresponding boundary conditions accounting for both the surface effects and the flexoelectricity are derived by the variational principle. Ritz approximate solutions of the static bending and the free vibration indicate that these nano-scale features are more prominent for thinner plates with smaller thickness. The simulation results also reveal that the influence of the flexoelectricity and the surface effects upon the bending behaviors of the PNP depends on the applied electrical loading and the plate dimensions. Moreover, it is also observed that the frequency tuning of PNP-based nanoresonators by adjusting applied electrical load can be modified by both the flexoelectricity and the surface effects. The current work is expected to provide increased understanding on the theoretical basis for the design and applications of PNP-based nanodevices.

Zhang, Zhengrong; Jiang, Liying

2014-10-01

261

Ultrasonic Tracking of Acoustic Radiation Force-Induced Displacements in Homogeneous Media  

PubMed Central

The use of ultrasonic methods to track the tissue deformation generated by acoustic radiation force is subject to jitter and displacement underestimation errors, with displacement underestimation being primarily caused by lateral and elevation shearing within the point spread function (PSF) of the ultrasonic beam. Models have been developed using finite element methods and Field II, a linear acoustic field simulation package, to study the impact of focal configuration, tracking frequency, and material properties on the accuracy of ultrasonically tracking the tissue deformation generated by acoustic radiation force excitations. These models demonstrate that lateral and elevation shearing underneath the PSF of the tracking beam leads to displacement underestimation in the focal zone. Displacement underestimation can be reduced by using tracking beams that are narrower than the spatial extent of the displacement fields. Displacement underestimation and jitter decrease with time after excitation as shear wave propagation away from the region of excitation reduces shearing in the lateral and elevation dimensions. The use of higher tracking frequencies in broadband transducers, along with 2D focusing in the elevation dimension, will reduce jitter and improve displacement tracking accuracy. Relative displacement underestimation remains constant as a function of applied force, while jitter increases with applied force. Underdeveloped speckle (SNR <1.91) leads to greater levels of jitter and peak displacement underestimation. Axial shearing is minimal over the tracking kernel lengths used in Acoustic Radiation Force Impulse (ARFI) imaging and thus does not impact displacement tracking. PMID:16889337

Palmeri, Mark L.; McAleavey, Stephen A.; Trahey, Gregg E.; Nightingale, Kathryn R.

2007-01-01

262

Nonmalignant pleural lesions due to environmental exposure to asbestos: a field-based, cross-sectional study.  

PubMed

The aim of the present study was to investigate the frequencies of asbestos-related benign pleural diseases in villagers environmentally exposed to asbestos and the factors affecting these frequencies. A field-based, cross-sectional study was designed. In total, 991 villagers from 10 villages, randomly chosen from 67 villages with known use of asbestos-containing white soil in central Anatolia (Turkey), were investigated. The type of asbestos in the white soil was determined for each village, as well as air-borne fibre concentrations. The villagers were investigated with small-size chest roentgenograms and epidemiological features were recorded. The air-borne fibre levels were generally low. Despite this, pleural plaques were found in 14.4% of the villagers, 10.4% had diffuse pleural fibrosis and 0.4% asbestosis. The significant variables for plaques were age, sex, type of asbestos fibre, e.g. actinolite and tremolite, and exposure duration, while there was a negative relationship with cumulative exposure. The variables affecting diffuse pleural fibrosis were age, exposure duration and cumulative exposure. In conclusion, villagers exposed to environmental asbestos have high frequencies of pleural plaques and diffuse pleural fibrosis, similar to occupationally exposed asbestos cohorts. Different types of asbestos appear to result in different frequencies of pleural lesions. PMID:16264049

Metintas, M; Metintas, S; Hillerdal, G; Ucgun, I; Erginel, S; Alatas, F; Yildirim, H

2005-11-01

263

Annoyance and self-reported sleep disturbance due to night-time railway noise examined in the field.  

PubMed

Railway noise interferes with daytime activities and disturbs sleep leading to annoyance of exposed residents. The main objective of this paper was to establish exposure-response relationships between nocturnal railway noise exposure and annoyance and to examine self-reported sleep disturbances as short-term reactions to noise. In a field study 33 residents living close to railway tracks in the Cologne/Bonn area (Germany) were investigated. Railway noise was measured indoors during nine consecutive nights at each site. Questionnaires referring to annoyance and non-acoustical factors were performed. Annoyance ratings increased significantly with the total number of trains and freight trains per night, and non-significantly with rising number of passenger trains and energy equivalent sound pressure level (L(Aeq)), when adjusting the model for non-acoustical variables. The total number of trains and the number of freight trains also significantly affected self-reported awakening frequency, but no other aspects of subjective sleep disturbances. The responses of this subject sample referring to railway noise in the previous night point to rather low impairments of exposed residents. PMID:23145596

Pennig, Sibylle; Quehl, Julia; Mueller, Uwe; Rolny, Vinzent; Maass, Hartmut; Basner, Mathias; Elmenhorst, Eva-Maria

2012-11-01

264

An evaluation of the sensitivity of the Standardised Field Sobriety Tests (SFSTs) to detect impairment due to marijuana intoxication.  

PubMed

The Standardised Field Sobriety Tests (SFST) were developed to test for alcohol intoxication but are currently being used by the State Police of Victoria (Australia) to test for driving impairment associated with drugs other than alcohol. The aim of the present study was to assess whether the SFSTs provide a sensitive measure of impairment following the consumption of a drug other than alcohol: delta-9-tetrahydrocannabinol (THC or cannabis). In a repeated-measures design, 40 participants consumed cigarettes that contained either 0% THC (placebo), 1.74% THC (low dose) or 2.93% THC (high dose). For each condition, after smoking a cigarette, participants performed the SFSTs on three occasions: 5 min (Time 1), 55 min (Time 2) and 105 min (Time 3) after the smoking procedure had been completed. The results revealed that there was a positive relationship between the dose of THC administered and the number of participants classified as impaired based on the SFSTs. Results also revealed that the percentage of participants classified as impaired decreased from Time 1 to Time 3 and that the addition of a new sign, head movements or jerks (HMJ), increased the percentage of participants classified as impaired in both the low and high THC conditions. These findings suggest that impaired performance on the SFSTs is positively related to the dose of THC administered and that the inclusion of HMJ as a scored sign in the SFSTs improves their predictive validity when testing for THC intoxication. PMID:15619106

Papafotiou, K; Carter, J D; Stough, C

2005-06-01

265

Control of clinical coccidiosis of calves due to Eimeria bovis and Eimeria zuernii with toltrazuril under field conditions.  

PubMed

The efficacy of metaphylactic treatment with toltrazuril (Baycox 5% suspension) against natural infections with Eimeria bovis and/or Eimeria zuernii in calves was investigated. The study was conducted with 208 calves on five calf-rearing farms in Germany and the Czech Republic. All participating farms had a notable incidence of coccidiosis. Animals were treated 14 days after stabling in the respective facility. One group was treated with 15 mg toltrazuril/kg body weight, and a second group served as the sham-treated control. Assessment of efficacy was based on faecal consistency and oocyst excretion of E. bovis and E. zuernii, both investigated throughout the study. Duration and rate of oocyst excretion as well as number of scour days with E. bovis or E. zuernii oocyst shedding and the severity of diarrhoea were significantly lower in the toltrazuril-treated groups. It is concluded that a single metaphylactic treatment with toltrazuril controls coccidiosis of housed calves under various field conditions. PMID:16228270

Mundt, H-C; Bangoura, B; Mengel, H; Keidel, J; Daugschies, A

2005-10-01

266

Characterization of carbonate reservoir property changes due to dissolution for far-field conditions of CO2 storage  

NASA Astrophysics Data System (ADS)

Geological storage of CO2 in reservoir pore fluid (e.g. deep saline aquifers), is one of the diverse technologies being explored for deacreasing atmospheric CO2 concentration. After injecting the CO2 as a supercritical fluid at depth, it will slowly dissolve into the pore water producing low pH fluids with a high capacity for dissolving carbonates and consequently changing irreversibly the hydrodynamical properties of the reservoir. Characterizing these changes is essential for modelling flow and CO2 transport during and after the CO2 injection. Here we report experimental results from the injection of the CO2-saturated brine into two distinct limestone cores (a bioclastic carbonate and an oolitic carbonate) of 9 mm diameter, 18 mm length. 3D high-resolution X-ray microtomography (XRMT) of the rock sample have been performed before and after the experiments. The experiments were performed using in-situ sequestration conditions (P = 12MPa and T = 100°C), and notably, under chemical conditions given at the position far away from the well injection site (i.e area where the volume of dissolved CO2 into the brine is low, due to CO2 consumption by the dissolution processes occured during its transport from the well injection site). Permeability k is calculated from the pressure drop across the sample and porosity ? is deduced from chemical concentration of the outlet fluid. The change of the pore structure is analysed in terms of connectivity, tortuosity and fluid-rock interface from processing the XRMT images. These experiments show that far from the well injection site, dissolution processes are characterized by slow mass tranfer including, in the case of carbonate rock, transport of fine particles, which locally clog the porous space. Then, that leads to the damage of the carbonate reservoir both in terms of connectivity of the porous space and CO2 hydrodynamical storage capacity. In fact, the results of the two experiments show that the porosity decreased locally into the carbonate rock sample, particularly at the bottom of the sample, caused by the deposit of fine particles into the pore spaces. On the other hand, the volume ratio of voids on the top of the samples (e.g. area where the CO2 enriched fluid is more reactive) increased by dissolution of the solid and microporous phase. Indeed, the pronounced dissolution processes at the top of the samples were associated with the extraction of fine solid particles from the solid phase and especially from the microporous phase. The particles were transported in the flow direction suspended in the CO2 rich fluid away from the extraction site and were deposited somewhere else. Subsequently they formed particle aggregates through the porous space. The compartmentalization of the porous network (eg. decrease of the pore connectivity) led, for the two experiments, to the decrease of the permeability due the dissolution processes occuring during CO2 enriched fluid percolation.

Mangane, P. O.; Gouze, P.; Luquot, L.

2012-12-01

267

Compositional Simulation of Subsurface Remediation via Density Modified Displacement  

Microsoft Academic Search

Reduced interfacial tension displacement of nonaqueous phase liquids (NAPLs) in the subsurface can be an efficient means of remediating contaminant source zones. Application of technologies based upon this principle, however, is problematic for NAPLs that are denser than water (DNAPLs) due to their tendency to sink further into the subsurface when mobilized. Pre-mobilization density conversion via alcohol partitioning has been

T. J. Phelan; C. A. Ramsburg; L. M. Abriola

2004-01-01

268

Comparing Teaching Approaches about Maxwell's Displacement Current  

ERIC Educational Resources Information Center

Due to its fundamental role for the consolidation of Maxwell's equations, the displacement current is one of the most important topics of any introductory course on electromagnetism. Moreover, this episode is widely used by historians and philosophers of science as a case study to investigate several issues (e.g. the theory-experiment…

Karam, Ricardo; Coimbra, Debora; Pietrocola, Maurício

2014-01-01

269

The effect of elbow joint centre displacement on force generation and neural excitation  

Microsoft Academic Search

Joint centre displacement may occur following total elbow replacement due to aseptic loosening or surgical misalignment, and\\u000a has been linked to implant failure. In this study, the effects of joint centre displacement were examined using a neuromusculoskeletal\\u000a model of the elbow joint. Isometric contractions were simulated at a range of joint angles during elbow flexion and extension.\\u000a Displacement of the

Emer P. Doheny; Madeleine M. Lowery; Mark J. O’Malley; David P. FitzPatrick

2009-01-01

270

Knowledge integration and displaced volume  

NSDL National Science Digital Library

This study contrasted spontaneous and reflective knowledge integration instruction delivered using a computer learning environment to enhance understanding of displaced volume. Both forms of instruction provided animated experiments and required students to predict outcomes, observe results, and explain their ideas. In addition, the reflective instruction diagnosed specific inconsistencies in student reasoning and encouraged students to reflect on these dilemmas as well as to construct general principles. We distinguished the impact of instruction on students who believed scientific phenomena are governed by principles (cohesive beliefs) versus students who believed that science is a collection of unrelated ldquofactsrdquo (dissociated beliefs). Students typically held multiple models of displacement, using different explanations depending on the form of assessment. For example, we found that 17% of these middle school students made accurate predictions about displacement experiments prior to instruction and 25% could construct an accurate general principle. However, only 12% consistently used the same explanation across assessments. After instruction, students were more accurate and more consistent: over 50% accurately predicted experimental outcomes, 79% gave an accurate general principle, and about 40% gave consistent responses. We found no advantages for enhanced animations over straightforward animated experiments. The reflective integration instruction led to more substantial long-term changes in student understanding than did spontaneous integration instruction. Furthermore, on a delayed posttest we found that students with cohesive beliefs not only sustained their understanding of displaced volume, but, when exposed to reflective integration instruction, actually continued to construct more predictive views following instruction. In contrast, students with dissociated beliefs made no long-term progress independent of the form of instruction.

Linn, Marcia; Eylon, Bat-Sheva

2006-12-07

271

Are microseismic ground displacements a significant geomorphic agent?  

NASA Astrophysics Data System (ADS)

This paper considers the role that microseismic ground displacements may play in fracturing rock via cyclic loading and subcritical crack growth. Using a coastal rock cliff as a case study, we firstly undertake a literature review to define the spatial locations that may be prone to microseismic damage. It is suggested that microseismic weakening of rock can only occur in ‘damage accumulation zones’ of limited spatial extent. Stress concentrations resulting from cliff height, slope angle and surface morphology may nucleate and propagate a sufficiently dense population of microcracks that can then be exploited by microseismic cyclic loading. We subsequently examine a 32-day microseismic dataset obtained from a coastal cliff-top location at Staithes, UK. The dataset demonstrates that microseismic ground displacements display low peak amplitudes that are punctuated by periods of greater displacement during storm conditions. Microseismic displacements generally display limited preferential directivity, though we observe rarely occurring sustained ground motions with a cliff-normal component during storm events. High magnitude displacements and infrequently experienced ground motion directions may be more damaging than the more frequently occurring, reduced magnitude displacements characteristic of periods of relative quiescence. As high magnitude, low frequency events exceed and then increase the damage threshold, these extremes may also render intervening, reduced magnitude microseismic displacements ineffective in terms of damage accumulation as a result of crack tip blunting and the generation of residual compressive stresses that close microcracks. We contend that damage resulting from microseismic ground motion may be episodic, rather than being continuous and in (quasi-)proportional and cumulative response to environmental forcing. A conceptual model is proposed that describes when and where microseismic ground motions can operate effectively. We hypothesise that there are significant spatial and temporal limitations on effective microseismic damage accumulation, such that the net efficacy of microseismic ground motions in preparing rock for fracture, and hence in enhancing erosion, may be considerably lower than previously suggested in locations where high magnitude displacements punctuate ‘standard’ displacement conditions. Determining and measuring the exact effects of microseismic ground displacement on damage accumulation and as a trigger to macro-scale fracture in the field is not currently possible, though our model remains consistent with field observations and conceptual models of controls on rockfall activity.

Brain, Matthew J.; Rosser, Nicholas J.; Norman, Emma C.; Petley, David N.

2014-02-01

272

Analog-to-digital conversion as a source of drifts in displacements derived from digital recordings of ground acceleration  

USGS Publications Warehouse

Displacements obtained from double integration of digitally recorded ground accelerations often show drifts much larger than those expected for the true ground displacements. These drifts might be due to many things, including dynamic elastic ground tilt, inelastic ground deformation, hysteresis in the instruments, and cross feed due to misalignment of nominally orthogonal sensors. This article shows that even if those effects were not present, the analog-to-digital conversion (ADC) process can produce apparent "pulses" and offsets in the acceleration baseline if the ground motion is slowly varying compared with the quantization level of the digitization. Such slowly varying signals can be produced by constant offsets that do not coincide with a quantization level and by near- and intermediate-field terms in the wave field radiated from earthquakes. Double integration of these apparent pulses and offsets leads to drifts in the displacements similar to those found in processing real recordings. These effects decrease in importance as the resolution of the ADC process increases.

Boore, D.M.

2003-01-01

273

All-optical control in metal nanocomposites due to a reversible transition between local field enhancement and local field depression upon irradiation by ultrashort control-pulses of light  

NASA Astrophysics Data System (ADS)

We theoretically study the non-perturbative effective nonlinear responses of metal nanocomposites based on the intrinsic third-order nonlinear response of metal nanoparticles. The large intrinsic third-order nonlinear susceptibility of metal nanoparticles and irradiation by an ultrashort control pulse of light with a sufficiently high peak intensity and moderate fluence can induce a local field depression and saturated plasmon bleaching in the metal nanoparticles. If the control pulse is on, the metal nanocomposites behave like a dielectric due to the local field depression, while if the control pulse is off, they behave like a metal, showing a high absorption due to the local field enhancement at the plasmon resonance. This phenomenon can be applied to the ultrafast and remote control of light in metal nanocomposites.

Im, Song-Jin; Ho, Gum-Song

2014-04-01

274

Immiscible displacements in rough-walled fractures: competition between roughening by random aperture variations and smoothing by in-plane curvature.  

PubMed

Phase structure during capillary displacement of fluid phases within rough-walled fractures is controlled by the competition between random aperture variability which tends to roughen the interface and in-plane curvature which tends to smooth it. We show that the phase structure and corresponding areal saturation at the end of displacement depend primarily on the ratio of two dimensionless parameters: one that controls roughening (the coefficient of variation of the aperture field, delta) and another that controls smoothing (the curvature number C, which weighs the mean influences of aperture induced and in-plane curvature). Interestingly, for C/delta above approximately 0.5, areal saturation for wetting and nonwetting invasion first diverges and then converges to create an envelope, whose width increases with delta. This nonunique behavior with respect to wettability is fundamental to capillary displacements in rough-walled fractures and is due to an asymmetry in capillary competition in wetting versus nonwetting invasions. PMID:14754183

Glass, Robert J; Rajaram, Harihar; Detwiler, Russell L

2003-12-01

275

Engineering of Schroedinger cat states by a sequence of displacements and photon additions or subtractions  

SciTech Connect

A method to generate Schroedinger cat states in free propagating optical fields based on the use of displaced states (or displacement operators) is developed. Some optical schemes with photon-added coherent states are studied. The schemes are modifications of the general method based on a sequence of displacements and photon additions or subtractions adjusted to generate Schroedinger cat states of a larger size. The effects of detection inefficiency are taken into account.

Podoshvedov, S. A., E-mail: podoshvedov@mail.ru [Seoul National University, Center for Subwavelength Optics and Department of Physics and Astronomy (Korea, Republic of)

2011-04-15

276

Theoretical Analysis of Photoacoustic Displacement for Inhomogeneous Materials  

Microsoft Academic Search

A method for theoretically analyzing photoacoustic displacement (PAD) induced by a pump beam in a three-dimensional model is presented. The analysis is based on rigorous methods in terms of temperature fields expanded by eigenmodes for an imaginary bounded system, and it is formulated in matrix form so that calculations for inhomogeneous materials can be performed systematically. It is shown that

Hiroyuki Takamatsu; Shingo Sumie; Tsutomu Morimoto; Yutaka Kawata; Yoshiro Nishimoto; Takefumi Horiuchi; Hiroshi Nakayama; Takashi Kita; Taneo Nishino

1994-01-01

277

Water Mist Suppression in Conjunction with Displacement  

E-print Network

Water Mist Suppression in Conjunction with Displacement Ventilation By Benjamin Piers Hume-2758 #12;#12;Displacement Water Mist System Masters of Fire Engineering Thesis 2003 i A man of genius makes Water Mist System Masters of Fire Engineering Thesis 2003 ii #12;Displacement Water Mist System Masters

Hickman, Mark

278

The case for character displacement in plants  

PubMed Central

The evidence for character displacement as a widespread response to competition is now building. This progress is largely the result of the establishment of rigorous criteria for demonstrating character displacement in the animal literature. There are, however, relatively few well-supported examples of character displacement in plants. This review explores the potential for character displacement in plants by addressing the following questions: (1) Why aren't examples of character displacement in plants more common? (2) What are the requirements for character displacement to occur and how do plant populations meet those requirements? (3) What are the criteria for testing the pattern and process of character displacement and what methods can and have been used to address these criteria in the plant literature? (4) What are some additional approaches for studying character displacement in plants? While more research is needed, the few plant systems in which character displacement hypotheses have been rigorously tested suggest that character displacement may play a role in shaping plant communities. Plants are especially amenable to character displacement studies because of the experimental ease with which they can be used in common gardens, selection analyses, and breeding designs. A deeper investigation of character displacement in plants is critical for a more complete understanding of the ecological and evolutionary processes that permit the coexistence of plant species. PMID:24683467

Beans, Carolyn M

2014-01-01

279

Three-input majority logic gate and multiple input logic circuit based on DNA strand displacement.  

PubMed

In biomolecular programming, the properties of biomolecules such as proteins and nucleic acids are harnessed for computational purposes. The field has gained considerable attention due to the possibility of exploiting the massive parallelism that is inherent in natural systems to solve computational problems. DNA has already been used to build complex molecular circuits, where the basic building blocks are logic gates that produce single outputs from one or more logical inputs. We designed and experimentally realized a three-input majority gate based on DNA strand displacement. One of the key features of a three-input majority gate is that the three inputs have equal priority, and the output will be true if any of the two inputs are true. Our design consists of a central, circular DNA strand with three unique domains between which are identical joint sequences. Before inputs are introduced to the system, each domain and half of each joint is protected by one complementary ssDNA that displays a toehold for subsequent displacement by the corresponding input. With this design the relationship between any two domains is analogous to the relationship between inputs in a majority gate. Displacing two or more of the protection strands will expose at least one complete joint and return a true output; displacing none or only one of the protection strands will not expose a complete joint and will return a false output. Further, we designed and realized a complex five-input logic gate based on the majority gate described here. By controlling two of the five inputs the complex gate can realize every combination of OR and AND gates of the other three inputs. PMID:23710909

Li, Wei; Yang, Yang; Yan, Hao; Liu, Yan

2013-06-12

280

Current Density and Plasma Displacement Near Perturbed Rational Surface  

SciTech Connect

The current density in the vicinity of a rational surface of a force-free magnetic field subjected to an ideal perturbation is shown to be the sum of both a smooth and a delta-function distribution, which give comparable currents. The maximum perturbation to the smooth current density is comparable to a typical equilibrium current density and the width of the layer in which the current flows is shown to be proportional to the perturbation amplitude. In the standard linearized theory, the plasma displacement has an unphysical jump across the rational surface, but the full theory gives a continuous displacement.

A.H. Boozer and N. Pomphrey

2010-10-10

281

Proposal Due: _________________________ Senior Project Due: _________________________  

E-print Network

Proposal Due: _________________________ HURCA & Senior Project Due: _________________________ Priorities: Senior Project Guide #12;2 The Honors College Senior Project Guide Why Research? Research the communication and critical thinking skills necessary for graduate school and professional employment. Honors

Huang, Haiying

282

An Alternative to Maxwell's Displacement Current  

E-print Network

Though sufficient for local conservation of charge, we show that Maxwells displacement current is not necessary. An alternative to the Ampere Maxwell equation is exhibited and the alternative s electric and magnetic fields and scalar and vector potentials are expressed in terms of the charge and current densities. The alternative describes a theory in which action is instantaneous and so may provide a good approximation to Maxwells equations where and when the finite speed of light can be neglected. The result is reminiscent of the Darwin approximation which arose from the study classical charged point particles to order (v/c)2 in the Lagrangian. Unlike Darwin, this approach does not depend on the constitution of the electric current. Instead, this approach grows from a straightforward revision of the Ampere Equation which revision enforces the local conservation of charge.

Wolsky, Alan M

2014-01-01

283

Interferometric fiber optic displacement sensor  

DOEpatents

A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically.

Farah, John (M.I.T. P.O. Box 397301, Cambridge, MA 02139)

1999-01-01

284

Interferometric fiber optic displacement sensor  

DOEpatents

A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically. 23 figs.

Farah, J.

1999-04-06

285

Interferometric fiber optic displacement sensor  

DOEpatents

A method is presented to produce a change in the optical path length in the gap between two single mode optical fibers proportional to the lateral displacement of either fiber end normal to its axis. This is done with the use of refraction or diffraction at the interface between a guiding and non-guiding media to change the direction of propagation of the light in the gap. A method is also presented for laying a waveguide on a cantilever so that the displacement of the tip of the cantilever produces a proportional path length change in the gap by distancing the waveguide from the neutral axis of the cantilever. The fiber is supported as a cantilever or a waveguide is deposited on a micromachined cantilever and incorporated in an interferometer which is made totally on a silicon substrate with the use of integrated-optic technology. A resonant element in the form of a micro-bridge is incorporated in the ridge waveguide and produces a frequency output which is readily digitizeable and immune to laser frequency noise. Finally, monolithic mechanical means for phase modulation are provided on the same sensor substrate. This is done by vibrating the cantilever or micro-bridge either electrically or optically. 29 figs.

Farah, J.

1995-05-30

286

Current density and plasma displacement near perturbed rational surfaces  

SciTech Connect

The current density in the vicinity of a rational surface of a force-free magnetic field subjected to an ideal perturbation is shown to be the sum of both a smooth and a delta-function distribution, which give comparable currents. The maximum perturbation to the smooth current density is comparable to a typical equilibrium current density and the width of the layer in which the current flows is shown to be proportional to the perturbation amplitude. In the standard linearized theory, the plasma displacement has an unphysical jump across the rational surface, but the full theory gives a continuous displacement. A resolution of the paradox of a jump in the displacement is required for interpreting perturbed tokamak equilibria.

Boozer, Allen H. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States); Pomphrey, Neil [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

2010-11-15

287

A Theoretical Model to Predict Both Horizontal Displacement and Vertical Displacement for Electromagnetic Induction-Based Deep Displacement Sensors  

PubMed Central

Deep displacement observation is one basic means of landslide dynamic study and early warning monitoring and a key part of engineering geological investigation. In our previous work, we proposed a novel electromagnetic induction-based deep displacement sensor (I-type) to predict deep horizontal displacement and a theoretical model called equation-based equivalent loop approach (EELA) to describe its sensing characters. However in many landslide and related geological engineering cases, both horizontal displacement and vertical displacement vary apparently and dynamically so both may require monitoring. In this study, a II-type deep displacement sensor is designed by revising our I-type sensor to simultaneously monitor the deep horizontal displacement and vertical displacement variations at different depths within a sliding mass. Meanwhile, a new theoretical modeling called the numerical integration-based equivalent loop approach (NIELA) has been proposed to quantitatively depict II-type sensors’ mutual inductance properties with respect to predicted horizontal displacements and vertical displacements. After detailed examinations and comparative studies between measured mutual inductance voltage, NIELA-based mutual inductance and EELA-based mutual inductance, NIELA has verified to be an effective and quite accurate analytic model for characterization of II-type sensors. The NIELA model is widely applicable for II-type sensors’ monitoring on all kinds of landslides and other related geohazards with satisfactory estimation accuracy and calculation efficiency. PMID:22368467

Shentu, Nanying; Zhang, Hongjian; Li, Qing; Zhou, Hongliang; Tong, Renyuan; Li, Xiong

2012-01-01

288

A theoretical model to predict both horizontal displacement and vertical displacement for electromagnetic induction-based deep displacement sensors.  

PubMed

Deep displacement observation is one basic means of landslide dynamic study and early warning monitoring and a key part of engineering geological investigation. In our previous work, we proposed a novel electromagnetic induction-based deep displacement sensor (I-type) to predict deep horizontal displacement and a theoretical model called equation-based equivalent loop approach (EELA) to describe its sensing characters. However in many landslide and related geological engineering cases, both horizontal displacement and vertical displacement vary apparently and dynamically so both may require monitoring. In this study, a II-type deep displacement sensor is designed by revising our I-type sensor to simultaneously monitor the deep horizontal displacement and vertical displacement variations at different depths within a sliding mass. Meanwhile, a new theoretical modeling called the numerical integration-based equivalent loop approach (NIELA) has been proposed to quantitatively depict II-type sensors' mutual inductance properties with respect to predicted horizontal displacements and vertical displacements. After detailed examinations and comparative studies between measured mutual inductance voltage, NIELA-based mutual inductance and EELA-based mutual inductance, NIELA has verified to be an effective and quite accurate analytic model for characterization of II-type sensors. The NIELA model is widely applicable for II-type sensors' monitoring on all kinds of landslides and other related geohazards with satisfactory estimation accuracy and calculation efficiency. PMID:22368467

Shentu, Nanying; Zhang, Hongjian; Li, Qing; Zhou, Hongliang; Tong, Renyuan; Li, Xiong

2012-01-01

289

Monte Carlo simulations of patient dose perturbations in rotational-type radiotherapy due to a transverse magnetic field: A tomotherapy investigation  

PubMed Central

Purpose: Several groups are exploring the integration of magnetic resonance (MR) image guidance with radiotherapy to reduce tumor position uncertainty during photon radiotherapy. The therapeutic gain from reducing tumor position uncertainty using intrafraction MR imaging during radiotherapy could be partially offset if the negative effects of magnetic field-induced dose perturbations are not appreciated or accounted for. The authors hypothesize that a more rotationally symmetric modality such as helical tomotherapy will permit a systematic mediation of these dose perturbations. This investigation offers a unique look at the dose perturbations due to homogeneous transverse magnetic field during the delivery of Tomotherapy® Treatment System plans under varying degrees of rotational beamlet symmetry. Methods: The authors accurately reproduced treatment plan beamlet and patient configurations using the Monte Carlo code geant4. This code has a thoroughly benchmarked electromagnetic particle transport physics package well-suited for the radiotherapy energy regime. The three approved clinical treatment plans for this study were for a prostate, head and neck, and lung treatment. The dose heterogeneity index metric was used to quantify the effect of the dose perturbations to the target volumes. Results: The authors demonstrate the ability to reproduce the clinical dose–volume histograms (DVH) to within 4% dose agreement at each DVH point for the target volumes and most planning structures, and therefore, are able to confidently examine the effects of transverse magnetic fields on the plans. The authors investigated field strengths of 0.35, 0.7, 1, 1.5, and 3 T. Changes to the dose heterogeneity index of 0.1% were seen in the prostate and head and neck case, reflecting negligible dose perturbations to the target volumes, a change from 5.5% to 20.1% was observed with the lung case. Conclusions: This study demonstrated that the effect of external magnetic fields can be mitigated by exploiting a more rotationally symmetric treatment modality.

Yang, Y. M.; Geurts, M.; Smilowitz, J. B.; Sterpin, E.; Bednarz, B. P.

2015-01-01

290

Signal processing for order 10 pm accuracy displacement metrology in real-world scientific applications  

NASA Technical Reports Server (NTRS)

This paper describes heterodyne displacement metrology gauge signal processing methods that achieve satisfactory robustness against low signal strength and spurious signals, and good long-term stability. We have a proven displacement-measuring approach that is useful not only to space-optical projects at JPL, but also to the wider field of distance measurements.

Halverson, Peter G.; Loya, Frank M.

2004-01-01

291

Reciprocating magnetic refrigerator employing tandem porous matrices within a reciprocating displacer  

NASA Technical Reports Server (NTRS)

Disclosed is a method and apparatus for a magnetic refrigeration system. A continuously reciprocating displacer houses at least a pair of paramagnetic substances each of which is alternately driven into and out of a magnetic field. Two separate bidirectional pumping systems flow helium gas through the displacer and through both paramagnetic substances to create heat exchange conditions at two separate temperature extremes.

Johnson, D. L. (inventor)

1985-01-01

292

Displacement Based Seismic Design Criteria  

SciTech Connect

The USNRC has initiated a project to determine if any of the likely revisions to traditional earthquake engineering practice are relevant to seismic design of the specialized structures, systems and components of nuclear power plants and of such significance to suggest that a change in design practice might be warranted. As part of the initial phase of this study, a literature survey was conducted on the recent changes in seismic design codes/standards, on-going activities of code-writing organizations/communities, and published documents on displacement-based design methods. This paper provides a summary of recent changes in building codes and on-going activities for future codes. It also discusses some technical issues for further consideration.

Costello, J.F.; Hofmayer, C.; Park, Y.J.

1999-03-29

293

Polybenzimidazoles via aromatic nucleophilic displacement  

NASA Technical Reports Server (NTRS)

Novel molecular weight controlled and endcapped polybenzimidazoles (PBI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenyl benzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The PBI are endcapped with mono(hydroxyphenyl) benzimidazoles. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. Mono(hydroxyphenyl) benzimidazoles are synthesizedby reacting phenyl-4-hydroxybenzoate with aromatic (o-diamine)s in diphenylsulfone. Molecular weight controlled and endcapped PBI of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.

Connell, John W. (inventor); Hergenrother, Paul M. (inventor); Smith, Joseph G., Jr. (inventor)

1995-01-01

294

Polybenzimidazoles Via Aromatic Nucleophilic Displacement  

NASA Technical Reports Server (NTRS)

Novel molecular weight controlled and endcapped polybenzimidazoles (PBI) are prepared by the aromatic nucleophilic displacement reaction of di(hydroxyphenylbenzimidazole) monomers with activated aromatic dihalides or activated aromatic dinitro compounds. The PBI are endcapped with mono(hydroxyphenyl)benzimidazoles. The polymerizations are carried out in polar aprotic solvents such as N-methyl-2-pyrrolidinone or N,N-dimethylacetamide using alkali metal bases such as potassium carbonate at elevated temperatures under nitrogen. Mono(hydroxyphenyl)benzimidazoles are synthesized by reacting phenyl-4-hydroxybenzoate with aromatic (o-diamine)s in diphenylsulfone. Molecular weight controlled and endcapped PBI of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.

Connell, John W. (Inventor); Hergerrother, Paul M. (Inventor); Smith, Joseph G., Jr. (Inventor)

1997-01-01

295

DISPLACEMENT BASED SEISMIC DESIGN CRITERIA  

SciTech Connect

The USNRC has initiated a project to determine if any of the likely revisions to traditional earthquake engineering practice are relevant to seismic design of the specialized structures, systems and components of nuclear power plants and of such significance to suggest that a change in design practice might be warranted. As part of the initial phase of this study, a literature survey was conducted on the recent changes in seismic design codes/standards, on-going activities of code-writing organizations/communities, and published documents on displacement-based design methods. This paper provides a summary of recent changes in building codes and on-going activities for future codes. It also discusses some technical issues for further consideration.

HOFMAYER,C.H.

1999-03-29

296

Variable delivery, fixed displacement pump  

DOEpatents

A variable delivery, fixed displacement pump comprises a plurality of pistons reciprocated within corresponding cylinders in a cylinder block. The pistons are reciprocated by rotation of a fixed angle swash plate connected to the pistons. The pistons and cylinders cooperate to define a plurality of fluid compression chambers each have a delivery outlet. A vent port is provided from each fluid compression chamber to vent fluid therefrom during at least a portion of the reciprocal stroke of the piston. Each piston and cylinder combination cooperates to close the associated vent port during another portion of the reciprocal stroke so that fluid is then pumped through the associated delivery outlet. The delivery rate of the pump is varied by adjusting the axial position of the swash plate relative to the cylinder block, which varies the duration of the piston stroke during which the vent port is closed.

Sommars, Mark F. (Sparland, IL)

2001-01-01

297

Displaceable Gear Torque Controlled Driver  

NASA Technical Reports Server (NTRS)

Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

Cook, Joseph S., Jr. (Inventor)

1997-01-01

298

Length-displacement scaling relations and the development of faults  

NASA Astrophysics Data System (ADS)

Faults are complex systems whose growth and general evolution are still not well understood. Such an understanding, however, is important for several reasons: one is that seismogenic faults generate earthquakes and another is that faults are major conduits for fluids (groundwater, geothermal water, gas, oil, magma). It is widely accepted that faults normally initiate from 'flaws' or weaknesses in the rocks, but their subsequent development and growth and their seismogenic activity are less well understood. Here we present results on the slip/displacement-length scaling relations, both for faults and co-seismic ruptures, from a single comparatively small area, namely the eastern flank of the volcano Etna, Italy (Sicily). Using these data, together with data from the literature and analytical and numerical models, we provide a general growth model for faults. Following an earthquake in a fault zone, the co-seismic rupture length and the slip are commonly measured. Similarly, in a structural analysis of major faults, the total fault length and displacement are measured when possible. It is well known that typical rupture length - slip ratios are generally orders of magnitude larger than typical fault length-displacement ratios. So far, however, most of the measured co-seismic ruptures and faults have been from different areas and commonly hosted by rocks of widely different mechanical properties (which have strong effects on these ratios). The data presented here is composed of length-displacement ratios from 7 fault zones in Holocene lava flows on the flanks of the volcano Etna and 19 co-seismic rupture lengths-slips mostly from the same fault zones and thus hosted by rocks with largely the same mechanical properties. For the co-seismic ruptures, the average length is 3,657 m, the average slip 0.31 m, and the average length-slip ratio 19,595. For the faults, the average length is 6,341 m, the average displacement 73 m, and the average length-displacement ratio 130. Thus, the average rupture-slip ratio is about 150-times larger than the length-displacement ratio. We propose that the differences between the length-slip and the length-displacement ratios can be partly explained by dynamic Young's modulus of fault zone being 101-2-times greater than its static modulus. In this model, the dynamic modulus controls the length-slip ratios whereas the static modulus controls the length-displacement ratio. We suggest that the common aseismic slip in fault zones is partly due to adjustment of the short-term seismogenic length-slip ratios to the long-term length-displacement ratios. Fault displacement is here regarded as analogous to plastic flow, in which case the long-term displacement can be very large so long as sufficient shear stress concentrates in the fault. In conclusion, this model explains, partly at least, the difference in the slip/displacement-length scaling relations between co-seismic ruptures and faults and also explains slow earthquakes and aseismic slip, features that are now known to be very common in active fault zones.

Gudmundsson, Agust; De Guidi, Giorgio; Scudero, Salvatore

2013-04-01

299

Incorporation of the effect of the composite electric fields of molecular ions as a simulation tool for biological damage due to heavy ion irradiation II  

NASA Astrophysics Data System (ADS)

This paper presents a theoretical study of the DNA damage due to the effect of the composite electric fields of H2O+ ions produced from the irradiation of a heavy ion onto a cell. It is found that a much larger number of electrons, which are produced from electron impact ionization, is trapped near the track of an incident ion in the case of C6+ ion irradiation with the energy of 3 MeV/u than that of proton irradiation. Therefore, the irradiation of carbon ions may produce a larger number of cluster DNA damage than that in the irradiation of protons. This may lead to the understanding of relative biological effectiveness (RBE).

Moribayashi, Kengo

2012-07-01

300

Testing fault displacement-length scaling relations through analogue modeling in an extensional setting  

NASA Astrophysics Data System (ADS)

The scaling relation between displacement and length of faults plays a crucial role in understanding the growth history of individual faults and their possible linkage and reactivation in future ruptures. Displacement-length relations are commonly based on empirical data. The measurement of fault geometric properties, however, is generally affected by large scattering due not only to intrinsic difficulties of making observations in natural cases (outcrop availability, seismic profiles), but also to the variety of geological factors that may affect the rupture patterns. These can be the interaction between the present-day tectonic regime and an inherited structural fabric, or that between a master fault at depth and shallow structural features. As an alternative to field observations, analogue modeling provides an opportunity to investigate the faulting processes in a controlled environment. During the last decade, the ability of scaled models to properly reproduce such geological processes has greatly improved thanks to the introduction of new materials (e.g. wet kaolin) suitable for reproducing brittle deformation in the upper crust and hi-tech monitoring systems (e.g. laser scanner, particle image velocimetry) with the ability of capturing structural details and performing accurate measurements. We use a dedicated apparatus with such properties to gain insights on the evolution of extensional faults through a suite of experiments which includes (a) setups in homogeneous material to test our ability in meeting general criteria related with fault displacement-length parameters; and (b) increasing complexities attained by inserting various pre-existing fault patterns to analyze how shallow mechanical discontinuities affect our ability to characterize a major fault at depth. Our results show that pre-existing faults can either halt or favor fault development and growth depending on their location/orientation with respect to the applied stress field and suggest the reappraisal of natural case studies under a different perspective.

Bonini, L.; Basili, R.; Burrato, P.; Kastelic, V.; Toscani, G.; Seno, S.; Valensise, G.

2013-12-01

301

An improved displacement damage monitor LED  

Microsoft Academic Search

A frequency-domain technique for measuring carrier lifetime in GaAs light-emitting-diode (LED) displacement damage monitors capable of high sensitivity and repeatability is developed. Applications of this technique that take advantage of the high sensitivity of this method, including the measurement of the threshold energy for lattice displacement in GaAs, are described. The measured minimum electron energy for displacement damage was 270±15

A. L. Barry; R. Maxseiner; R. Wojcik; M. A. Briere; D. Braeunig

1990-01-01

302

Displacement of crude oil by carbon dioxide  

E-print Network

that passed through the core. Seeson and Ortloff conducted a laboratory study in which they investigated the oil recovery from displacing some high and low viscosity crudes from linear sandstone models. A 400 cp Ada crude oil was displaced from linear... Topedo sandstone and a 6 cp Loudon crude oil was displaced from linear models of Weiler sand- stone at 70 F and at about 1000 psi by water propelled carbon dioxide slugs. They found that the displacement technique was more efficient than waterflooding...

Omole, Olusegun

2012-06-07

303

Integrating a MRI scanner with a 6 MV radiotherapy accelerator: dose increase at tissue-air interfaces in a lateral magnetic field due to returning electrons.  

PubMed

In the framework of the development of the integration of a MRI-scanner with a linear accelerator, the influence of a lateral, magnetic field on the dose distribution has to be determined. Dose increase is expected at tissue-air boundaries, due to the electron return effect (ERE): electrons entering air will describe a circular path and return into the phantom causing extra dose deposition. Using IMRT with many beam directions, this exit dose will not constitute a problem. Dose levels behind air cavities will decrease because of the absence of electrons crossing the cavity. The ERE has been demonstrated both by simulation and experiment. Monte Carlo simulations are performed with GEANT4, irradiating a water-air-water phantom in a lateral magnetic field. Also an air tube in water has been simulated, resulting in slightly twisted regions of dose increase and decrease. Experimental demonstration is achieved by film measurement in a perspex-air-perspex phantom in an electromagnet. Although the ERE causes dose increase before air cavities, relatively flat dose profiles can be obtained for the investigated cases using opposite beam configurations. More research will be necessary whether this holds for more realistic geometries with the use of IMRT and whether the ERE can be turned to our advantage when treating small tumour sites at air cavities. PMID:15798329

Raaijmakers, A J E; Raaymakers, B W; Lagendijk, J J W

2005-04-01

304

Investigation of wing upper surface flow-field disturbance due to NASA DC-8-72 in-flight inboard thrust-reverser deployment  

NASA Technical Reports Server (NTRS)

An investigation of the wing upper surface flow-field disturbance due to in-flight inboard thrust reverser deployment on the NASA DC-8-72, which was conducted cooperatively by NASA Ames, the Federal Aviation Administration (FAA), McDonnell Douglas, and the Aerospace Industry Association (AIA), is outlined and discussed in detail. The purpose of this flight test was to obtain tufted flow visualization data which demonstrates the effect of thrust reverser deployment on the wing upper surface flow field to determine if the disturbed flow regions could be modeled by computational methods. A total of six symmetric thrust reversals of the two inboard engines were performed to monitor tuft and flow cone patterns as well as the character of their movement at the nominal Mach numbers of 0.55, 0.70, and 0.85. The tufts and flow cones were photographed and video-taped to determine the type of flow field that occurs with and without the thrust reversers deployed. In addition, the normal NASA DC-8 onboard Data Acquisition Distribution System (DADS) was used to synchronize the cameras. Results of this flight test will be presented in two parts. First, three distinct flow patterns associated with the above Mach numbers were sketched from the motion videos and discussed in detail. Second, other relevant aircraft parameters, such as aircraft's angular orientation, altitude, Mach number, and vertical descent, are discussed. The flight test participants' comments were recorded on the videos and the interested reader is referred to the video supplement section of this report for that information.

Hamid, Hedayat U.; Margason, Richard J.; Hardy, Gordon

1995-01-01

305

Your Dues  

NASA Astrophysics Data System (ADS)

Your AGU dues, at $20, are truly a bargain and have been so for 40 years. It would be difficult to point to the primary driver for the extraordinary growth in AGU membership during the past 40 years, but surely the low and stable dues have been a major contributor. The low entry fee brings a diverse, worldwide community of scientists into our network. It is also consistent with AGU's commitment to the public good, which is the basis for the tax-exempt status the Union enjoys in the United States.

Spilhaus, Fred

2009-01-01

306

The affine equivalence of local stress and displacement distributions in damaged composites and Batdorf's electric analog  

NASA Technical Reports Server (NTRS)

The composite solid/analog device affine equations are shown to be elastically and electrically material independent. Analog experimental solutions yield the stress and displacement fields of the composite solid for a wide range of physical variables.

Brunelle, E. J.

1984-01-01

307

Three-dimensional coseismic displacements from point-like target tracking of high-resolution SAR images: Application to the 2011 Van (Turkey) earthquake  

NASA Astrophysics Data System (ADS)

The complete three-dimensional (3D) coseismic displacement field of earthquakes is important for constraining fault slip models. However, Interferometric Synthetic Aperture Radar (InSAR) only provides accurate measurements along the single Line-Of-Sight (LOS) direction, meaning that multiple observations need to be combined to derive the 3D displacement field. This is often achieved by including SAR Pixel-offset (PO) tracking, although less accurate, which can provide unambiguous displacement measurements of both the LOS and along-track (azimuth) directions. Today, X-band data from the COSMO-SkyMed (CSK) and TerraSAR-X (TSX) satellites are the main sources of InSAR data for geoscientific applications. X-band signals do however often decorrelate in a relatively short period because their limited penetration capability and short wavelength. Therefore, the formed interferograms are often unusable due to low coherence and/or aliasing fringes. The accuracy of PO tracking on the other hand has significantly improved because of meter-level pixel spacing of these X-band data. It is therefore useful to reconsider the role of PO tracking in measuring coseismic displacements in the context of high-resolution SAR images. Here, we show that by estimating pixel offsets we can obtain accurate 3D-displacement maps even if the corresponding interferograms are totally decorrelated. Using both ascending TerraSAR-X and descending COSMO-SkyMed images of the 2011 Van (Turkey) earthquake we first coregister the images. We then search for point-like targets and focus our azimuth and range offset estimation on sub-images containing identified targets. The offset measurements are spatially median-filtered before the range and azimuth offsets are combined to estimate the 3D displacement field. The results show strong uplift of the hanging wall with diverging horizontal displacements, as expected from this thrust-faulting earthquake. Our results indicate that point-like offset tracking of high-resolution SAR images can be used to measure coseismic displacement with the accuracy of several centimeters.

Wang, T.; Jonsson, S.

2013-12-01

308

Polybenzoxazole via aromatic nucleophilic displacement  

NASA Technical Reports Server (NTRS)

Polybenzoxazoles (PBO) are heterocyclic macromolecules which were first synthesized in a two-step process by the initial formation of aromatic diacid chlorides with bis(o-aminophenol)s through solution condensation of aromatic diacid chlorides with bis(o-aminophenol)s followed by thermal cyclodehydration. Since then several methods were utilized in their synthesis. The most common synthetic method for PBO involves a polycondensation of bis(o-aminophenol)s with aromatic diacid diphenyl esters. Another preparative route involves the solution polycondensation of the hydrochloride salts of bis(o-amino phenol)s with aromatic diacids in polyphosphoric acid. Another synthetic method involves the initial formation of poly(o-hydroxy amide)s from silylated bis(o-aminophenol)s with aromatic diacid chlorides followed by thermal cyclodehydration to PBO. A recent preparative route involves the reaction of aromatic bisphenols with bis(fluorophenyl) benzoxazoles by the displacement reaction to form PBO. The novelty of the present invention is that high molecular weight PBO of new chemical structures are prepared that exhibit a favorable combination of physical and mechanical properties.

Hergenrother, Paul M. (inventor); Connell, John W. (inventor); Smith, Joseph G., Jr. (inventor)

1993-01-01

309

Refined beam elements with only displacement variables and plate\\/shell capabilities  

Microsoft Academic Search

This paper proposes a refined beam formulation with displacement variables only. Lagrange-type polynomials, in fact, are used\\u000a to interpolate the displacement field over the beam cross-section. Three- (L3), four- (L4), and nine-point (L9) polynomials\\u000a are considered which lead to linear, quasi-linear (bilinear), and quadratic displacement field approximations over the beam\\u000a cross-section. Finite elements are obtained by employing the principle of

Erasmo Carrera; Marco Petrolo

310

Motion of the Esophagus Due to Cardiac Motion  

PubMed Central

When imaging studies (e.g. CT) are used to quantify morphological changes in an anatomical structure, it is necessary to understand the extent and source of motion which can give imaging artifacts (e.g. blurring or local distortion). The objective of this study was to assess the magnitude of esophageal motion due to cardiac motion. We used retrospective electrocardiogram-gated contrast-enhanced computed tomography angiography images for this study. The anatomic region from the carina to the bottom of the heart was taken at deep-inspiration breath hold with the patients' arms raised above their shoulders, in a position similar to that used for radiation therapy. The esophagus was delineated on the diastolic phase of cardiac motion, and deformable registration was used to sequentially deform the images in nearest-neighbor phases among the 10 cardiac phases, starting from the diastolic phase. Using the 10 deformation fields generated from the deformable registration, the magnitude of the extreme displacements was then calculated for each voxel, and the mean and maximum displacement was calculated for each computed tomography slice for each patient. The average maximum esophageal displacement due to cardiac motion for all patients was 5.8 mm (standard deviation: 1.6 mm, maximum: 10.0 mm) in the transverse direction. For 21 of 26 patients, the largest esophageal motion was found in the inferior region of the heart; for the other patients, esophageal motion was approximately independent of superior-inferior position. The esophagus motion was larger at cardiac phases where the electrocardiogram R-wave occurs. In conclusion, the magnitude of esophageal motion near the heart due to cardiac motion is similar to that due to other sources of motion, including respiratory motion and intra-fraction motion. A larger cardiac motion will result into larger esophagus motion in a cardiac cycle. PMID:24586540

Palmer, Jacob; Yang, Jinzhong; Pan, Tinsu; Court, Laurence E.

2014-01-01

311

Fiber-optic displacement sensors on the Hunters Trophy UGT impulse gauge experiments  

SciTech Connect

As part of a program to develop gauges for measurement of various mechanical properties in hostile environments, the authors fielded purely optical displacement sensors at the ends of long fiber-optic cables as supplements to the regular displacement sensors of four impulse gauges fielded as part of a materials study on the Hunters Trophy underground effects test at the Nevada Test Site. These fiber-optic sensor systems and their performance on the Hunters Trophy test are described in this report.

Green, R.E.L.; Poutiatine, A.I.

1995-03-01

312

Displaced Homemakers: Vo-Tech Workshop Guide.  

ERIC Educational Resources Information Center

Written for displaced homemaker programs in vocational-technical schools, this curriculum contains material designed so that instructors can prepare student manuals appropriate to almost any educational support situation for displaced homemakers. An overview provides information on special needs groups, curriculum use, and resources and sample…

Peltier, Wanda Jo

313

High displacement ceramic metal composite actuators (moonies)  

Microsoft Academic Search

The two most common type of piezoelectric actuators are the multilayer actuator with internal electrodes and the cantilevered bimorph actuator. A new type of composite ceramic actuator is the multilayered multistacked moonie (multi-multi moonie). Normal multilayer actuators produce a large generative force, but only a small displacement. Conversely, bimorphs produce large displacements but the forces are very small. The moonie

Aydin Dogan; Qichang Xu; Katsuhiko Onitsuka; Shoko Yoshikawa; Kenji Uchino; Robert E. Newnham

1994-01-01

314

Video Games, Adolescents, and the Displacement Effect  

ERIC Educational Resources Information Center

The displacement effect (the idea that time spent in one activity displaces time spent in other activities) was examined within the lens of adolescents' video game use and their time spent reading, doing homework, in physically active sports and activities, in creative play, and with parents and friends. Data were drawn from the Panel Study…

Fisher, Carla Christine

2012-01-01

315

Stress-free displacement control of structures  

Microsoft Academic Search

Summary. The theorem on the unique decomposition of eigenstrain provides the tool to construct prescribed displacements inside and (or) at the surface of a linear elastic body in two novel ways (e.g., in connection with shape control). The first approach applies Maysel’s formula and renders the linear relationship between nodal displacements and impotent eigenstrain in discrete or discretized systems. The

Y. Nyashin; V. Lokhov; F. Ziegler

2005-01-01

316

Management of an Extremely Displaced Maxillary Canine  

Microsoft Academic Search

Case Report: Aligning a displaced maxillary canine into the den- tal arch is one of the most complicated problems in orthodontics. In cases of extremely high displacement, the tooth is frequently removed surgically. Because of the upper canines' significance to dental esthetics and functional occlusion, such a decision is a very serious one. This case report illustrates the treatment of

Torsten Grande; Annemarie Stolze; Heiko Goldbecher

2005-01-01

317

Study of microdosimetric energy deposition patterns in tissue-equivalent medium due to low-energy neutron fields using a graphite-walled proportional counter.  

PubMed

To improve radiation protection dosimetry for low-energy neutron fields encountered in nuclear power reactor environments, there is increasing interest in modeling neutron energy deposition in metrological instruments such as tissue-equivalent proportional counters (TEPCs). Along with these computational developments, there is also a need for experimental data with which to benchmark and test the results obtained from the modeling methods developed. The experimental work described in this paper is a study of the energy deposition in tissue-equivalent (TE) medium using an in-house built graphite-walled proportional counter (GPC) filled with TE gas. The GPC is a simple model of a standard TEPC because the response of the counter at these energies is almost entirely due to the neutron interactions in the sensitive volume of the counter. Energy deposition in tissue spheres of diameter 1, 2, 4 and 8 µm was measured in low-energy neutron fields below 500 keV. We have observed a continuously increasing trend in microdosimetric averages with an increase in neutron energy. The values of these averages decrease as we increase the simulated diameter at a given neutron energy. A similar trend for these microdosimetric averages has been observed for standard TEPCs and the Rossi-type, TE, spherical wall-less counter filled with propane-based TE gas in the same energy range. This implies that at the microdosimetric level, in the neutron energy range we employed in this study, the pattern of average energy deposited by starter and insider proton recoil events in the gas is similar to those generated cumulatively by crosser and stopper events originating from the counter wall plus starter and insider recoil events originating in the sensitive volume of a TEPC. PMID:21476858

Waker, A J; Aslam

2011-06-01

318

Lattice Boltzmann Simulations of Supercritical CO2-Water Drainage Displacement in Porous Media: CO2 Saturation and Displacement Mechanism.  

PubMed

CO2 geosequestration in deep aquifers requires the displacement of water (wetting phase) from the porous media by supercritical CO2 (nonwetting phase). However, the interfacial instabilities, such as viscous and capillary fingerings, develop during the drainage displacement. Moreover, the burstlike Haines jump often occurs under conditions of low capillary number. To study these interfacial instabilities, we performed lattice Boltzmann simulations of CO2-water drainage displacement in a 3D synthetic granular rock model at a fixed viscosity ratio and at various capillary numbers. The capillary numbers are varied by changing injection pressure, which induces changes in flow velocity. It was observed that the viscous fingering was dominant at high injection pressures, whereas the crossover of viscous and capillary fingerings was observed, accompanied by Haines jumps, at low injection pressures. The Haines jumps flowing forward caused a significant drop of CO2 saturation, whereas Haines jumps flowing backward caused an increase of CO2 saturation (per injection depth). We demonstrated that the pore-scale Haines jumps remarkably influenced the flow path and therefore equilibrium CO2 saturation in crossover domain, which is in turn related to the storage efficiency in the field-scale geosequestration. The results can improve our understandings of the storage efficiency by the effects of pore-scale displacement phenomena. PMID:25427299

Yamabe, Hirotatsu; Tsuji, Takeshi; Liang, Yunfeng; Matsuoka, Toshifumi

2015-01-01

319

Design of Nafion actuator with enhanced displacement  

NASA Astrophysics Data System (ADS)

A new actuator system has been developed. This actuator uses Nafion, a solid electrolyte, in combination with Platinum Copper (Pt-Cu) electrodes and mobile ions of Cu2+ to create much larger actuation displacement at smaller levels of applied voltage (1V or less). This actuator provides bending deformation. Large deformation is provided by electrode reaction of copper. Since this reaction is reversible, Cu electrode is not consumed by using polarity change of applied voltage. This actuation mechanism is different from others. Because the induction of the large deflection of Nafion, the large number of the mobile cations is essential. Although it is possible to induce a large deflection by applying a higher electric field as alternative way, this would introduce the electrolysis of water that is not desired unless the device is always submerged in water. To convert bending deformation to liner actuation, we designed a device using a pair of Nafion actuator, which is termed as loop actuator. This loop actuator can be designed into the device with large force by making parallel array. Solid polymer electrolyte-metal composite actuator contains water inside. Therefore coating that prevents water from evaporation is needed for its use in dry condition.

Uchida, Mikio; Xu, Chunye; Le Guilly, Marie; Taya, Minoru

2002-07-01

320

Topographic amplification of tectonic displacement: Implications for geodetic measurement of strain changes  

NASA Astrophysics Data System (ADS)

Correlations of level changes with topography demand an assessment of the effect of an irregular free boundary on surface deformation. This is examined through a plane strain elastic model with topography of small slope, subjected to a change in the far-field horizontal stress. To leading order, vertical surface displacements due to the topographic perturbation are proportional to the local relief. Elevation-dependent uplift results from a compressional change, and downdrop results from a tensional change. The model further predicts that the ratio of elevation change to elevation is proportional to and of the same order of magnitude as the regional strain. Horizontal strains are locally perturbed by topography as well, with the magnitude scaling with the local slope. The predicted localization of level changes is very small in aseismic regions and cannot contribute significantly to measured correlations. A test case in southern California bears this out, with strains of order 10-6 accompanied by elevation change to elevation ratios of order 10-4. Releveling following the Nankaido-Tonankai earthquakes, which induced large coseismic and postseismic strains, reveals scattered examples of elevation-dependent level changes. However, when compared to modeled strains, the correlations are again at least an order of magnitude larger than the localization effect predicted by the elastic model. Although the topographic perturbation of vertical displacements appears to be unmeasurably small, local variations in horizontal strain or borehole dilatation across steep relief may be discernible with current technology.

McTigue, David F.; Stein, Ross S.

1984-02-01

321

Development and Evolution of Character Displacement  

PubMed Central

Character displacement occurs when competition for either resources or successful reproduction imposes divergent selection on interacting species, causing divergence in traits associated with resource use or reproduction. Here, we describe how character displacement can be mediated either by genetically canalized changes (i.e., changes that reflect allelic or genotype frequency changes) or by phenotypic plasticity. We also discuss how these two mechanisms influence the tempo of character displacement. Specifically, we suggest that, under some conditions, character displacement mediated by phenotypic plasticity might occur more rapidly than that mediated by genetically canalized changes. Finally, we describe how these two mechanisms may act together and determine character displacement’s mode, such that it proceeds through an initial phase in which trait divergence is environmentally induced to a later phase in which divergence becomes genetically canalized. This plasticity-first hypothesis predicts that character displacement should be generally mediated by ancestral plasticity and that it will arise similarly in multiple, independently evolving populations. We conclude by highlighting future directions for research that would test these predictions. PMID:22257002

Pfennig, David W.; Pfennig, Karin S.

2012-01-01

322

Total displacement functions for SiC  

NASA Astrophysics Data System (ADS)

Numerical solutions for the displacement functions in SiC are determined from the coupled integro-differential equations governing the total number of type- j atoms displaced in the collision cascade initiated by a primary knock-on atom (PKA) of type- i and energy E. Atomic scattering cross sections based on either the inverse power law screening potentials or the Ziegler, Biersack, and Littmark (ZBL) universal screening potential are used in the calculation of the displacement functions. The electronic stopping powers used in the calculations are either derived from the LSS and Bethe-Bloch theories or generated from the SRIM-96 electronic stopping power data base. The displacement functions determined using LSS/Bethe-Bloch electronic stopping powers are 25 to 100% larger than the displacement functions determined using the electronic stopping powers generated by SRIM-96. The total number of displaced atoms determined numerically for each PKA type, based on ZBL scattering cross sections and SRIM-96 electronic stopping powers, is in excellent agreement, over the entire range of PKA energies (10 eV to 10 MeV), with the total number of displacements determined by full cascade Monte Carlo simulations using the TRIM code in SRIM-96.

Weber, W. J.; Williford, R. E.; Sickafus, K. E.

1997-04-01

323

Computational Studies of Vertical Displacement Events in Tokamaks  

NASA Astrophysics Data System (ADS)

Loss of toroidal equilibrium initiated by the thermal-quench phase of a disruption in elongated plasmas is generally followed by a large-scale vertical displacement event (VDE) that brings the plasma column in contact with the surrounding structures. First observed in a JET discharge(P. R. Thomas, J. A. Wesson, F. Alladio, et al.), Plasma Phys. and Controlled Nucl. Fusion Research, IAEA, Vienna, Vol I, 353 (1985)., VDE's have been subsequently studied in all major tokamaks with a shaped cross-section.(See for example, R. S. Granetz, et al.), Nucl. Fusion, 36 545 (1996). Here, these highly nonlinear and possibly dangerous events, during which a large fraction of the plasma current is transferred to the vacuum vessel, are studied numerically using CTD, our 3D MHD code that can efficiently and self-consistently treat a halo and vacuum region around the plasma, as well as a resistive wall. In our numerical experiments, simple axisymmetric VDE's, as well as the interaction of a VDE with a nonlinear external kink (usually an n=1 mode), and the generated halo currents, poloidal and toroidal currents in the vacuum vessel, and the resulting electromechanical forces, are examined. It is well understood that the nonuniform nature of these vessel currents and the associated forces exacerbates their potential danger. Observed poloidal nonuniformity in the toroidal currents is due to the opposing effects of the electric fields induced by the rapid plasma motion and the decaying plasma current. On the other hand, poloidal currents are, by their nature, poloidally localized in the vessel, and their toroidal nonuniformity is due to the interaction of the VDE with an external kink. Sometimes, VDE's are the cause, and not the result of a disruption. Role of ``killer'' pellets in mitigating the effects of those VDE's that occur spontaneously and are not proceeded by a thermal quench are also being investigated. An additional by-product of these studies is the characterization of wall eddy-currents due to nonlinear external kinks (with or without a VDE) that can be used in feedback stabilization of these modes.

Aydemir, Ahmet Y.

1999-11-01

324

Dynamically Induced Displacements of a Persistent Cold-Air Pool  

NASA Astrophysics Data System (ADS)

We examine the influence of a passing weather system on a persistent cold-air pool (CAP) during the Persistent Cold-Air Pool Study in the Salt Lake Valley, Utah, USA. The CAP experiences a sequence of along-valley displacements that temporarily and partially remove the cold air in response to increasing along-valley winds aloft. The displacements are due to the formation of a mountain wave over the upstream topography as well as adjustments to the regional horizontal pressure gradient and wind-stress divergence acting on the CAP. These processes appear to help establish a balance wherein the depth of the CAP increases to the north. When that balance is disrupted, the CAP tilt collapses, which sends a gravity current of cold air travelling upstream and thereby restores CAP conditions throughout the valley. Intra-valley mixing of momentum, heat, and pollution within the CAP by Kelvin-Helmholtz waves and seiching is also examined.

Lareau, Neil P.; Horel, John D.

2015-02-01

325

Wireless displacement sensing system for bridges using multi-sensor fusion  

NASA Astrophysics Data System (ADS)

Accurate displacement sensing or estimation is an important task for reliably assessing the condition of civil infrastructure such as bridges and buildings, because the structural displacement describes the behavior of a structure and indicates structural safety according to the design limit. However, it is difficult to directly measure the displacement of a bridge structure due to the inaccessibility of a reference point especially when bridges are built over a highway, a river or the sea. As an alternative, an indirect displacement estimation using two different types of measurements such as strain and acceleration (i.e., multimetric data) has been developed. While the approach has been seen as promising, the combination of the traditional sensing system based on wired sensors and the multimetric data-based algorithm is inappropriate or impractical in real-world applications of the approach. This paper proposes a new displacement sensing system by incorporating wireless sensor technology with the multimetric data-based algorithm, which can address the difficulties and issues found in the traditional sensing system to realize a practical means of measuring displacement in full-scale bridges. The proposed wireless displacement sensing system enables (a) time-synchronized acceleration and strain measurement, (b) high-precision strain sensing and (c) improved applicability due to the wireless communication as well as the previous two features. The effectiveness of the proposed system is experimentally verified in laboratory and full-scale experiments.

Park, Jong-Woong; Sim, Sung-Han; Jung, Hyung-Jo

2014-04-01

326

Length-displacement scaling and fault growth  

NASA Astrophysics Data System (ADS)

Following an earthquake in a fault zone, commonly the co-seismic rupture length and the slip are measured. Similarly, in a structural analysis of major faults, the total fault length and displacement are measured when possible. It is well known that typical rupture length-slip ratios are generally orders of magnitude larger than typical fault length-displacement ratios. So far, however, most of the measured co-seismic ruptures and faults have been from different areas and commonly hosted by rocks of widely different mechanical properties (which have strong effects on these ratios). Here we present new results on length-displacement ratios from 7 fault zones in Holocene lava flows on the flanks of the volcano Etna (Italy), as well as 10 co-seismic rupture length-slips, and compare them with fault data from Iceland. The displacement and slip data from Etna are mostly from the same fault zones and hosted by rocks with largely the same mechanical properties. For the co-seismic ruptures, the average length is 3657 m, the average slip 0.31 m, and the average length-slip ratio 19,595. For the faults, the average length is 6341 m, the average displacement 73 m, and the average length-displacement ratio 130. Thus, the average rupture-slip ratio is about 150-times larger than the average length-displacement ratio. We propose a model where the differences between the length-slip and the length-displacement ratios can be partly explained by the dynamic Young's modulus of a fault zone being 101-2-times greater than its static modulus. In this model, the dynamic modulus controls the length-slip ratios whereas the static modulus controls the length-displacement ratio. We suggest that the common aseismic slip in fault zones is partly related to adjustment of the short-term seismogenic length-slip ratios to the long-term length-displacement ratios. Fault displacement is here regarded as analogous to plastic flow, in which case the long-term displacement can be very large so long as sufficient shear stress concentrates in the fault.

Gudmundsson, Agust; De Guidi, Giorgio; Scudero, Salvatore

2013-11-01

327

Attenuation of surface-enhanced Raman scattering of magnetic-plasmonic FePt@Ag core-shell nanoparticles due to an external magnetic field  

NASA Astrophysics Data System (ADS)

The surface-enhanced Raman scattering (SERS) activities of Ag and FePt@Ag nanoparticle probes were examined using thiophenol as a Raman reporter molecule in the absence and presence of a magnetic field. Under external magnetic fields of different field strength, the SERS activities of both types of nanoparticles (NPs) were weakened as a function of magnetic field strength. The attenuation degree of SERS activity by the magnetic field in the case of FePt@Ag NPs is found to be two times higher than for Ag NPs, because the superparamagnetic FePt cores enhance the local magnetic field at the area of the Ag shells.

Trang, Nguyen T. T.; Thuy, Trinh T.; Mott, Derrick M.; Koyano, Mikio; Maenosono, Shinya

2013-06-01

328

REVERSE DISPLACEMENT ANALYSIS FOR TENSEGRITY STRUCTURES  

E-print Network

REVERSE DISPLACEMENT ANALYSIS FOR TENSEGRITY STRUCTURES By TUNG MINH TRAN A THESIS PRESENTED INTRODUCTION.........................................................................1 2 THREE-THREE TENSEGRITY-THREE TENSEGRITY PLATFORMS WITH AN APPLIED EXTERNAL WRENCH....................................... 28 Plücker

Florida, University of

329

Scale model studies of displacement ventilation  

E-print Network

Displacement ventilation is an air conditioning method that provides conditioned air to indoor environments with the goal to improve air quality while reducing energy consumption. This study investigates the performance ...

Okutan, Galip Mehmet

1995-01-01

330

Effect of Interfacial Tension on Displacement Efficiency  

Microsoft Academic Search

Immiscible displacement tests were performed in a consolidated sandstone core over the interfacial tension range from less than 0.01 dynes\\/cm to 5 dynes\\/cm to better define how interfacial tension (IFT) reduction can lead to increased oil recovery. The data obtained were displacement efficiency at breakthrough vs. IFT for both drainage and imbibition conditions. These tests simulate waterflooding under oil-wet conditions

O. R. Wagner; R. O. Leach

1966-01-01

331

Mechanically amplified large displacement piezoelectric actuators  

Microsoft Academic Search

This paper deals with large displacement actuators based on mechanically amplified movements of pre-stressed piezoelectric disks. The bridge-type amplifier structures were made of laser cut polymer laminates fold to certain geometries to accomplish enhanced displacement of the input translation. Optimization of the lever lengths and their positions were carried out using computer-assisted design (by AutoCAD) and mathematical calculations (by MATLAB).

J. Juuti; K. Kordás; R. Lonnakko; V.-P. Moilanen; S. Leppävuori

2005-01-01

332

Tsunami mortality and displacement in Aceh province, Indonesia  

E-print Network

Tsunami mortality and displacement in Aceh province, Indonesia Abdur Rofi, MA Mercy Corps Indonesia, Indonesia, Shannon Doocy, PhD Research Associate, Johns Hopkins Bloomberg School of Public Health, US. Keywords: displacement, internally displaced persons (IDPs), Indonesia, mortality, tsunami Introduction

Scharfstein, Daniel

333

A self-adaptive sampling digital image correlation algorithm for accurate displacement measurement  

NASA Astrophysics Data System (ADS)

Digital image correlation (DIC) is nowadays widely applied to many engineering areas as an effective optical displacement measurement technique. To minimize the potential effect of spatial sampling locations on full-field displacement measurement, this paper develops a self-adaptive sampling DIC algorithm for accurate and reliable displacement computation over entire specimen surfaces. Depending on local deformation states, the algorithm can automatically optimize spatial distribution of sampling points over specimen surfaces in a self-adaptive manner in combination with the well-developed DIC algorithm with Gaussian windows. Both a series of well-designed computer-simulated speckle images and actual cell-substrate deformation ones are employed to verify the feasibility and effectiveness of the proposed algorithm, which demonstrates that the set of self-adaptive sampling algorithm is capable of recovering more accurate and precise full-field displacements compared to the conventional DIC algorithm with equidistant sampling.

Yuan, Yuan; Huang, Jianyong; Fang, Jing; Yuan, Fan; Xiong, Chunyang

2015-02-01

334

Viral fitness does not correlate with three genotype displacement events involving infectious hematopoietic necrosis virus  

USGS Publications Warehouse

Viral genotype displacement events are characterized by the replacement of a previously dominant virus genotype by a novel genotype of the same virus species in a given geographic region. We examine here the fitness of three pairs of infectious hematopoietic necrosis virus (IHNV) genotypes involved in three major genotype displacement events in Washington state over the last 30 years to determine whether increased virus fitness correlates with displacement. Fitness was assessed using in vivo assays to measure viral replication in single infection, simultaneous co-infection, and sequential superinfection in the natural host, steelhead trout. In addition, virion stability of each genotype was measured in freshwater and seawater environments at various temperatures. By these methods, we found no correlation between increased viral fitness and displacement in the field. These results suggest that other pressures likely exist in the field with important consequences for IHNV evolution.

Kell, Alison M.; Wargo, Andrew R.; Kurath, Gael

2014-01-01

335

Coupled diffusional/displacive transformations  

E-print Network

), the simultaneous solution of the interface mobility and the diffusion-field velocity functions for a specified temperature led to the curves of velocity versus supersaturation for Fe-O.4C wt.% alloy. Superimposed on these curves, are the data obtained using... 4 Addition of Substitutional Alloying Elements 42 4.1 Introduction 42 4.2 Results and Discussion 43 4.2.1 Martensite-start Temperature 43 4.2.2 Bainite-start Temperature 44 4.4 Conclusion 45 Chapter 5 Partitioning of Carbon from Supersaturated...

Mujahid, Shafiq Ahmad

336

Simulation of foam displacement in porous media  

SciTech Connect

Foam is an excellent fluid for achieving mobility control of gas in porous media. Practical application of foams for EOR processes, however requires a predictive model of foam displacement. Further, quantitative information on foam-flow behavior at reservoir flow rates and pressures is required as input to any field-scale modeling. An experimental and mechanistic-modeling study is reported for the transient flow of foam through 1.3 {mu}m{sup 2} (1.3 D) Boise sandstone at backpressures in excess of 5 MPa (700 psi) over a quality range from 0.80 to 0.99. Total superficial velocities range from as little as 0.42 to 2.20 m/day (1.4 ft/day to 7 ft/day). Sequential pressure taps and gamma-ray densitometry measure flow resistance and in-situ liquid saturations, respectively. We garner experimental pressure and saturation profiles in both the transient and steady states. Adoption of a mean-size foam-bubble conservation equation along with the traditional reservoir simulation equations allows mechanistic foam simulation. Since foam mobility depends heavily upon its texture, the bubble population balance is both useful and necessary as the role of foam texture must be incorporated into any model which seeks accurate prediction of flow properties. Our model employs capillary-pressure-dependent kinetic expressions for lamellae generation and coalescence and also a term for trapping of lamellae. Additionally, the effects of surfactant chemical transport are included. We find quantitative agreement between experimental and theoretical saturation and pressure profiles in both the transient and steady states.

Kovscek, A.R.; Patzek, T.W.; Radke, C.J.

1993-08-01

337

Method for the estimation of the total displacement of ferroelectric actuators under mixed thermal and electrical loading  

Microsoft Academic Search

The temperature behavior of the displacement of ferroelectric actuators, when operating at varying temperature, is affected by several factors. First of all, there are changes in field induced strain with temperature. However, the total displacement of an actuator depends also on the poling strain and strain from thermal expansion. These two effects are coupled, because thermal expansion is anisotropic and

Hans Kungl; Michael J. Hoffmann

2008-01-01

338

Resistance to the Bacillus thuringiensis Bioinsecticide in a Field Population of Plutella xylostella is Due to a Change in a Midgut Membrane Receptor  

Microsoft Academic Search

The biochemical mechanism for resistance to Bacillus thuringiensis crystal proteins was studied in a field population of diamondback moths (Plutella xylostella) with a reduced susceptibility to the bioinsecticidal spray. The toxicity and binding characteristics of three crystal proteins [CryIA(b), CryIB, and CryIC] were compared between the field population and a laboratory strain. The field population proved resistant (>200-fold compared with

Juan Ferre; Maria Dolores Real; Jeroen van Rie; Stefan Jansens; Marnix Peferoen

1991-01-01

339

Estimation of structural static displacements based on vibration data using known mass perturbation  

NASA Astrophysics Data System (ADS)

This note presents a new method for conveniently estimating static displacements of a structure based on its vibration data. In the proposed method, structural static displacements can be estimated using a normalized modal flexibility matrix assisted by a known mass perturbation method in order to overcome several shortcomings of existing displacement sensors (e.g., linear variable differential transformers, laser Doppler vibrometer, etc) such as limitations on installation due to surrounding environments and inconvenience to the public during static loading tests. For validating the feasibility of the proposed method, experimental validation was carried out on a simply-supported beam model. In the experimental tests, the vibration data under excitation by wind loads was first measured with eight accelerometers. Then the known masses were added on a specific location on the beam and the measurements were carried out under the same settings as the first experiment. The determination of the changes in modal parameters allows estimation of the scaling constants to obtain mass-normalized mode shapes. Finally, the normalized modal flexibility matrix was calculated by using the mass-normalized mode shapes based on the scaling constants and the displacements were estimated by the normalized modal flexibility matrix. These results were compared with real static displacements estimated from the laser-type displacement sensor. It was found that they matched each other well. Therefore, the proposed method can be an effective alternative to conventional static displacement estimation.

Sung, S. H.; Park, J. W.; Moon, Y. J.; Jung, H. J.

2014-03-01

340

Criteria for displacement by gas versus water in oil reservoirs  

E-print Network

of Model for Base Case Gas Injection Runs. . Capillary Pressure Functions 3 Oil -Water Relative Permeability . 10 Gas-Oil Relative Permeability, Correlation of Oil Recovery with Dimensionless Rate and Time. 17 Comparison of Oil Recovery from Base... the Buckley-Leverett and Dietz displacement theories and found that the former more accu- rately described their thin tube exper1ments due to capillary ef- fects, a f1nd1ng which corfirmed conclusions reached by DietzT con- cerning his sharp interface...

Piper, Larry Dean

2012-06-07

341

Atomic displacements during structural relaxation in a metallic glass  

NASA Astrophysics Data System (ADS)

Structural relaxation in the metallic glass Pd40Ni40P20 has been studied by x-ray diffraction. For the first time the structural changes occurring in reversible relaxation have been directly observed. The data have been analyzed by a method that distinguishes effects due to processes where the density changes from those where it is conserved. The results show a clear contrast between reversible and irreversible relaxation and also that the nature of atomic displacements in reversible relaxation changes as the temperature is lowered.

Brüning, Ralf; Ström-Olsen, J. O.

1990-02-01

342

Modeling Propagating Discontinuities in Finite Elements with Linear Displacement Jumps  

NASA Astrophysics Data System (ADS)

Finite elements with embedded discontinuities have been developed over the course of a more than a decade. Upon detection of a failure condition, a surface can be added in these elements at an orientation consistent with the critical angle of the failure condition, and at a location consistent with the propagating fracture. Displacements may then occur along this surface according to a post-localization constitutive law. Hence, the element may be used to track propagating deformation bands and fractures through a body. Until recently, however, the embedded displacement jump in the element was limited in that it had to be constant in that element, disallowing a jump in the strain and stress fields on opposite sides of the discontinuity. In many fault systems, however, there is relative tension on one side of the fault in the direction parallel to the fault. This is especially true at the ends of the fault, where the behavior can significantly affect the propagation, and lead to secondary cracking and other structures. We enhance the kinematics of the element to account for linear displacement jumps, thus allowing for stress and strain jump across the element, while maintaining traction continuity. This enhancement allows for more realistic capturing of the stresses along a fault, and hence more realistic propagation. It is also a preliminary step in modeling secondary cracking (e.g. splay cracks) in the system. We apply this element to some example problems from the literature.

Foster, C. D.

2007-12-01

343

SIFT flow for large-displacement object tracking.  

PubMed

Traditional tracking methods place an emphasis on how to cope with the variations in target appearance effectively. However, when the motion displacement of the target between image frames becomes larger, these methods may be unstable. This paper presents a novel (to our knowledge) visual object tracking method. In this method, we first introduce scale-invariant feature transform (SIFT) flow into the tracking problem and develop a real-time motion prediction method to capture large displacement between consecutive image frames. Then we use belief propagation (BP) to convert the problem of finding maximum a posteriori probability (MAP) to globally minimizing an energy function to get the best matching pairs of points for producing good candidate regions of the target. And last, the refined point trajectories are obtained according to the bidirectional flow field consistency estimation and covariance region descriptor matching, which can update model states efficiently so as to achieve enhanced robustness for visual tracking. Compared with the state-of-art tracking methods, the experimental results demonstrate that the proposed algorithm shows favorable performance when the object undergoes large motion displacement between image frames. PMID:25322097

Zhang, Huanlong; Hu, Shiqiang; Zhang, Xiaoyu

2014-09-20

344

Conflict induced internal displacement in Nepal.  

PubMed

Nepal has witnessed a humanitarian crisis since the Maoist conflict began ten years ago. The plight of internally displaced persons (IDPs) in Nepal has received little international attention despite being rated one of the worst displacement scenarios in the world. An estimated 200,000 people have been displaced as a result of the conflict, with the far-western districts of Nepal being the worst affected. Internal displacement has stretched the carrying capacity of several cities with adverse physical and mental health consequences for the displaced. Vulnerable women and children have been the worst affected. The government has adopted a discriminatory approach and failed to fulfil its obligations towards IDPs. Non-governmental organisations and international agencies have provided inadequate services to IDPs in their programmes. Tackling the issues of IDPs requires co-operation between government and development agencies: acknowledging the burden of the problem of IDPs, adequate registration and needs assessment, along with health and nutritional surveys, and development of short-term emergency relief packages and long-term programmes for their assistance. PMID:17542185

Singh, Sonal; Sharma, Sharan Prakash; Mills, Edward; Poudel, Krishna C; Jimba, Masamine

2007-01-01

345

Frictional behavior of large displacement experimental faults  

USGS Publications Warehouse

The coefficient of friction and velocity dependence of friction of initially bare surfaces and 1-mm-thick simulated fault gouges (400 mm at 25??C and 25 MPa normal stress. Steady state negative friction velocity dependence and a steady state fault zone microstructure are achieved after ???18 mm displacement, and an approximately constant strength is reached after a few tens of millimeters of sliding on initially bare surfaces. Simulated fault gouges show a large but systematic variation of friction, velocity dependence of friction, dilatancy, and degree of localization with displacement. At short displacement (<10 mm), simulated gouge is strong, velocity strengthening and changes in sliding velocity are accompanied by relatively large changes in dilatancy rate. With continued displacement, simulated gouges become progressively weaker and less velocity strengthening, the velocity dependence of dilatancy rate decreases, and deformation becomes localized into a narrow basal shear which at its most localized is observed to be velocity weakening. With subsequent displacement, the fault restrengthens, returns to velocity strengthening, or to velocity neutral, the velocity dependence of dilatancy rate becomes larger, and deformation becomes distributed. Correlation of friction, velocity dependence of friction and of dilatancy rate, and degree of localization at all displacements in simulated gouge suggest that all quantities are interrelated. The observations do not distinguish the independent variables but suggest that the degree of localization is controlled by the fault strength, not by the friction velocity dependence. The friction velocity dependence and velocity dependence of dilatancy rate can be used as qualitative measures of the degree of localization in simulated gouge, in agreement with previous studies. Theory equating the friction velocity dependence of simulated gouge to the sum of the friction velocity dependence of bare surfaces and the velocity dependence of dilatancy rate of simulated gouge fails to quantitatively account for the experimental observations.

Beeler, N.M.; Tullis, T.E.; Blanpied, M.L.; Weeks, J.D.

1996-01-01

346

Rhetorics of Displacement: Constructing Identities in Forced Relocations  

ERIC Educational Resources Information Center

Forced displacement has often involved the use of rhetoric, both by government institutions and by people who struggle not only to survive displacement, but also to resist it. In this article, the author offers first a theoretical framework that informs her thinking about displacement narratives. She briefly examines two published displacement

Powell, Katrina M.

2012-01-01

347

Enhancement of coherent longitudinal optical phonon oscillations in a GaAs\\/AlAs multiple quantum well due to intersubband energy tuning under an electric field  

Microsoft Academic Search

We have demonstrated the generation of intense coherent longitudinal optical (LO) phonon oscillations with use of intersubband energy tuning by application of electric field. The coherent LO phonon in a GaAs\\/AlAs multiple quantum well was investigated in detail as a function of electric field by using a reflection-type pump-probe technique. In the case that the intersubband energy is tuned to

O. Kojima; K. Mizoguchi; M. Nakayama

2004-01-01

348

Development of A Continuous Process for Displacement Dewatering  

SciTech Connect

The subject of this contract was to investigate the viability of a new process for dewatering paper called displacement pressing. The term “displacement pressing” was coined in the 1980s by researchers to describe a paper dewatering process where air is blown through a sheet of paper while it is being pressed. It was shown at that time that the combination of air and low pressing force could dramatically increase both sheet bulk and sheet solids which in theory would translate into huge savings in energy and fiber consumption. But there was a catch. Although the research results were dramatic, no one could figure out a commercially viable process to carry out displacement pressing. All research work had been done with batch processes, and there was no obvious way to convert these processes into a continuous process. By the end of the early1990’s no one was researching in this area because no continuous process existed. Recently we proposed a new method to carry out displacement pressing. Our process uses special pressing fabrics and a special 4 roll press that we call a “Beck Cluster Press” or BCP. The BCP provides a pressurized atmosphere that acts on a moving web of paper and fabrics. The special fabrics designed for this process use this atmosphere to press the sheet and at the same time, these special fabrics force air through the sheet to carry out displacement pressing. 1 Because of the complexity and cost of building the first functioning BCP, a simple simulator was built to confirm and study the process. Although results from this simulator were extremely favorable, financial times were hard in the paper industry. We are grateful for the DOE contract that allowed us to continue research that showed the tremendous benefits of displacement pressing. Specifically, accomplishments from the DOE contract are as follows: 1. A narrow (5” wide sheet) lab Beck Cluster Press (BCP) was started up, and made operational. This press accepts hand sheets and displacement presses them at conditions that duplicate commercial conditions for dwell time, and pressure. 2. The lab BCP machine was used to verify simulator results. Results showed the lab BCP gave paper dryness that exceeded simulator results for dryness. 3. Sheet samples were obtained for several paper grades. These samples were pressed conventionally (shoe and roll presses) and with the lab BCP. Results showed significant gains in bulk (5-48%) compared to commercially pressed sheets while producing similar or higher dryness. These results verified the predictions of the earlier research papers. 4. Sheet bulk exceeded the Agenda 2020 goal a 7% increase. This increase in bulk was reported by Agenda 2020 as being worth about 3 billion dollars per year in fiber savings. Potential energy savings due to dryness savings could be worth $1 billion per year. However energy savings and fiber savings are inter-related so while savings are likely in both energy and fiber at the same time, increasing one will cause the other to decrease. 5. Based on the significant results of small-scale BCP trials, a 1m pilot BCP press stand was built to determine scalability of the process. 6. 1m pilot press stand was started up. This machine was shown to hold design pressure. Drive issues however prevented operation at operating speed and pressure during the contact period. Improvements to the drive system since the end of the DOE contract have allowed us to reach operating pressure and speed. 7. The last DOE objective of passing paper through the 1m BCP was not reached due to drive issues and the desire to study and qualify sealing systems. All other original objectives and the added objective (by contract revision) of this ambitious project have been met. 8. Several paper companies have showed interest in helping us commercialize this process. Interest is so high that these companies appear willing to invest in further development.

Dave Beck

2006-10-30

349

Crack opening displacement determination in damaged cross-ply laminate using electronic speckle pattern interferometry (ESPI)  

NASA Astrophysics Data System (ADS)

Composite laminates during service undergo complex combinations of thermal and mechanical loading leading to microdamage accumulation in the plies. The most common damage mode and the one examined in this work is intralaminar cracking in layers. The crack opening displacement (COD) and the crack sliding displacement (CSD) during loading reduce the average stress in the damaged layer, thus reducing the laminate stiffness. These parameters depend on material properties of the damaged layer and surrounding layers, on layer orientation and thickness. Previously these parameters have been calculated using finite element method (FEM) assuming linear elastic material with idealized geometry of cracks. To validate these assumptions experimentally the displacement field on the surface of a [90/0/90] carbon fiber/epoxy laminate specimens with multiple intralaminar cracks in the surface layer is studied and the COD dependence on the applied mechanical load is measured. The specimen full-field displacement measurement is carried out using ESPI (Electronic Speckle Pattern Interferometry). The displacement jumps corresponding to cracks are clearly visible and can be used to determine the opening displacement along the cracks. The effect of crack interaction on the COD at high crack density is also investigated.

Zrida, H.; Loukil, M. S.; Varna, J.; Ayadi, Z.

2012-02-01

350

A relativistic self-consistent model for studying enhancement of space charge limited field emission due to counter-streaming ions  

SciTech Connect

Recently, field emission has attracted increasing attention despite the practical limitation that field emitters operate below the Child-Langmuir space charge limit. By introducing counter-streaming ion flow to neutralize the electron charge density, the space charge limited field emission (SCLFE) current can be dramatically enhanced. In this work, we have developed a relativistic self-consistent model for studying the enhancement of SCLFE by a counter-streaming ion current. The maximum enhancement is found when the ion effect is saturated, as shown analytically. The solutions in non-relativistic, intermediate, and ultra-relativistic regimes are obtained and verified with 1-D particle-in-cell simulations. This self-consistent model is general and can also serve as a benchmark or comparison for verification of simulation codes, as well as extension to higher dimensions.

Lin, M. C., E-mail: mingchiehlin@gmail.com; Lu, P. S. [NanoScience Simulation Laboratory, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China) [NanoScience Simulation Laboratory, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China); Plasma Theory and Simulation Group, Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States); Chang, P. C. [NanoScience Simulation Laboratory, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China) [NanoScience Simulation Laboratory, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China); Plasma Theory and Simulation Group, Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States); Department of Physics, National Taiwan University, Taipei 106, Taiwan (China); Ragan-Kelley, B. [Plasma Theory and Simulation Group, Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States) [Plasma Theory and Simulation Group, Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States); Applied Science and Technology, University of California, Berkeley, California 94720 (United States); Verboncoeur, J. P. [Plasma Theory and Simulation Group, Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States) [Plasma Theory and Simulation Group, Department of Nuclear Engineering, University of California, Berkeley, California 94720 (United States); Department of Electrical and Computer Engineering, Michigan State University, East Lansing, Michigan 48824 (United States)

2014-02-15

351

Vortex chains due to nonpairwise interactions and field-induced phase transitions between states with different broken symmetry in superconductors with competing order parameters  

NASA Astrophysics Data System (ADS)

We study superconductors with two order components and phase separation driven by intercomponent density-density interaction, focusing on the phase where only one condensate has nonzero ground-state density and a competing order parameter exists only in vortex cores. We demonstrate there that multibody intervortex interactions can be strongly nonpairwise, leading to some unusual vortex patterns in an external field, such as vortex pairs and vortex chains. We demonstrate that in an external magnetic field such a system undergoes a field-driven phase transition from (broken) U (1 ) to (broken) U (1 )×U (1 ) symmetries when a subdominant order parameter in the vortex cores acquires global coherence. Observation of these characteristic ordering patterns in surface probes may signal the presence of a subdominant condensate in the vortex core.

Garaud, Julien; Babaev, Egor

2015-01-01

352

Borehole tool outrigger arm displacement control mechanism  

Microsoft Academic Search

As the outrigger arms of a borehole logging tool are flexed inwardly and outwardly according to the diameter of the borehole opening through which they pass, the corresponding axial displacements of the ends of the arms are controlled to determine the axial positions of the arms relative to the tool. Specifically, as the arm ends move, they are caused to

1985-01-01

353

REVERSE DISPLACEMENT ANALYSIS FOR TENSEGRITY STRUCTURES  

Microsoft Academic Search

Abstract of Thesis Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Master of Science REVERSE DISPLACEMENT ANALYSIS FOR TENSEGRITY STRUCTURES By Tung Minh Tran May 2002 Chairman: Dr Carl D Crane III Major Department: Mechanical Engineering A new type of parallel mechanism is introduced that is based on

TUNG MINH TRAN

354

Displacement Damage in Bipolar Linear Integrated Circuits  

NASA Technical Reports Server (NTRS)

Although many different processes can be used to manufacture linear integrated circuits, the process that is used for most circuits is optimized for high voltage -- a total power supply voltage of about 40 V -- and low cost. This process, which has changed little during the last twenty years, uses lateral and substrate p-n-p transistors. These p-n-p transistors have very wide base regions, increasing their sensitivity to displacement damage from electrons and protons. Although displacement damage effects can be easily treated for individual transistors, the net effect on linear circuits can be far more complex because circuit operation often depends on the interaction of several internal transistors. Note also that some circuits are made with more advanced processes with much narrower base widths. Devices fabricated with these newer processes are not expected to be significantly affected by displacement damage for proton fluences below 1 x 10(exp 12) p/sq cm. This paper discusses displacement damage in linear integrated circuits with more complex failure modes than those exhibited by simpler devices, such as the LM111 comparator, where the dominant response mode is gain degradation of the input transistor. Some circuits fail catastrophically at much lower equivalent total dose levels compared to tests with gamma rays. The device works satisfactorily up to nearly 1 Mrad(Si) when it is irradiated with gamma rays, but fails catastrophically between 50 and 70 krad(Si) when it is irradiated with protons.

Rax, B. G.; Johnston, A. H.; Miyahira, T.

2000-01-01

355

Ground Displacement by Strike-Slip Motion  

NSDL National Science Digital Library

This photograph illustrates strike-slip motion along a fault trace. The section of fence in the foreground has been offset 8.5 feet to the left relative to the segment in the background. The displacement occured in a rural area near Woodville, California, as a result of the San Francisco Earthquake on April 18, 1906.

356

Job Displacement and the Rural Worker.  

ERIC Educational Resources Information Center

High rates of unemployment in rural areas poses questions as what education can do with the problem. This report examines the effects of rural American economies as they grow away from agriculture and toward dependence on manufacturing and service industries. Using data from the federal Bureau of Labor Statistics' Displaced Worker Survey, the…

Podgursky, Michael

357

Ko Displacement Theory for Structural Shape Predictions  

NASA Technical Reports Server (NTRS)

The development of the Ko displacement theory for predictions of structure deformed shapes was motivated in 2003 by the Helios flying wing, which had a 247-ft (75-m) wing span with wingtip deflections reaching 40 ft (12 m). The Helios flying wing failed in midair in June 2003, creating the need to develop new technology to predict in-flight deformed shapes of unmanned aircraft wings for visual display before the ground-based pilots. Any types of strain sensors installed on a structure can only sense the surface strains, but are incapable to sense the overall deformed shapes of structures. After the invention of the Ko displacement theory, predictions of structure deformed shapes could be achieved by feeding the measured surface strains into the Ko displacement transfer functions for the calculations of out-of-plane deflections and cross sectional rotations at multiple locations for mapping out overall deformed shapes of the structures. The new Ko displacement theory combined with a strain-sensing system thus created a revolutionary new structure- shape-sensing technology.

Ko, William L.

2010-01-01

358

Interactive Solid Animation Using Linearized Displacement Constraints  

E-print Network

Interactive Solid Animation Using Linearized Displacement Constraints Franc¸ois Faure Institut f¨ur Computergrafik Technische Universit¨at, Wien Abstract. We present a new approach for interactive solid animation animation. However, interactive articulated solid animation has yet been restricted to small structures

Paris-Sud XI, Université de

359

Retraining Displaced Workers--Barriers and Facilitators.  

ERIC Educational Resources Information Center

Although plant closings and layoffs have been happening for a long time, today's recessions, major changes in the structure of the economy, and a tight job market have combined to make plant closings a more serious problem. Workers are faced with unemployment from both traditional labor-displacing changes, such as the increasing use of robotics;…

Wolansky, William D.

360

Nanoliter Reactors Improve Multiple Displacement Amplification  

E-print Network

Nanoliter Reactors Improve Multiple Displacement Amplification of Genomes from Single Cells Yann was greatly reduced in nanoliter volumes, thereby providing a more even representation of all sequences. Single-cell amplicons from both microliter and nanoliter volumes provided high-quality sequence data

Quake, Stephen R.

361

Comb-drive actuators for large displacements  

Microsoft Academic Search

The design, fabrication and experimental results of lateral-comb-drive actuators for large displacements at low driving voltages is presented. A comparison of several suspension designs is given, and the lateral large deflection behaviour of clamped - clamped beams and a folded flexure design is modelled. An expression for the axial spring constant of folded flexure designs including bending effects from lateral

Rob Legtenberg; A. W. Groeneveld; M. Elwenspoek

1996-01-01

362

Extracting gravity line displacement from stabilographic recordings  

Microsoft Academic Search

Three algorithms for determining gravity line (GL) location from center of pressure (COP) and horizontal force (Fx) recordings are suggested. The algorithms are designed to study upright standing posture and are based on the following premises: (a) the foot(feet) is a solid body and does not move, (b) the axis of rotation of the ankle joint does not displace, and

Deborah L. King; Vladimir M. Zatsiorsky

1997-01-01

363

Variable-Displacement Hydraulic Drive Unit  

NASA Technical Reports Server (NTRS)

Hydraulic power controlled through multiple feedback loops. In hydraulic drive unit, power closely matched to demand, thereby saving energy. Hydraulic flow to and from motor adjusted by motor-control valve connected to wobbler. Wobbler angle determines motor-control-valve position, which in turn determines motor displacement. Concept applicable to machine tools, aircraft controls, and marine controls.

Lang, D. J.; Linton, D. J.; Markunas, A.

1986-01-01

364

Impact of plasma response on plasma displacements in DIII-D during application of external 3D perturbations  

NASA Astrophysics Data System (ADS)

The effects of applied 3D resonant magnetic perturbations are modelled with and without self-consistent plasma response. The plasma response is calculated using a linear two-fluid model. A synthetic diagnostic is used to simulate soft x-ray (SXR) emission within the steep gradient region of the pedestal, 0.98 > ? > 0.94. Two methods for simulating the SXR emission given the perturbed fields are considered. In the first method, the emission is assumed to be constant on magnetic field lines, with the emission on each line determined by the penetration depth into the plasma. In the second method, the emission is taken to be a function of the perturbed electron temperature and density calculated by the two-fluid model. It is shown that the latter method is more accurate within the plasma, but is inadequate in the scrape-off layer due to the breakdown of the linearized temperature equation in the two-fluid model. The resulting synthetic emission is compared to measured SXR data, which show helical m = 11 ± 1 displacements around the 11/3 rational surface of sizes up to 5 cm, depending on the poloidal angle. The helical displacements around the 11/3 surface are identified to be directly related to the kink response, caused by amplification of non-resonant components of the magnetic field due to plasma response. The role of different plasma parameters is investigated, but it appears that the electron rotation plays a key role in the formation of screening and resonant amplification, while the kinking appears to be sensitive to the edge current density. It is also hypothesized that the plasma response affects the edge-localized-mode (ELM) stability, i.e. the discharge's operational point relative to the peeling-ballooning stability boundary.

Wingen, A.; Ferraro, N. M.; Shafer, M. W.; Unterberg, E. A.; Evans, T. E.; Hillis, D. L.; Snyder, P. B.

2014-06-01

365

Paddy-field contamination with 134Cs and 137Cs due to Fukushima Dai-ichi Nuclear Power Plant accident and soil-to-rice transfer coefficients.  

PubMed

The transfer coefficient (TF) from soil to rice plants of (134)Cs and (137)Cs in the form of radioactive deposition from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in March 2011 was investigated in three rice paddy fields in Minami-Soma City. Rice crops were planted in the following May and harvested at the end of September. Soil cores of 30-cm depth were sampled from rice-planted paddy fields to measure (134)Cs and (137)Cs radioactivity at 5-cm intervals. (134)Cs and (137)Cs radioactivity was also measured in rice ears (rice with chaff), straws and roots. The rice ears were subdivided into chaff, brown rice, polished rice and rice bran, and the (134)Cs and (137)Cs radioactivity concentration of each plant part was measured to calculate the respective TF from the soil. The TF of roots was highest at 0.48 ± 0.10 in the field where the (40)K concentration in the soil core was relatively low, in comparison with TF values of 0.31 and 0.38 in other fields. Similar trends could be found for the TF of whole rice plants, excluding roots. The TF of rice ears was relatively low at 0.019-0.026. The TF of chaff, rice bran, brown rice and polished rice was estimated to be 0.049, 0.10-0.16, 0.013-0.017 and 0.005-0.013, respectively. PMID:23103577

Endo, Satoru; Kajimoto, Tsuyoshi; Shizuma, Kiyoshi

2013-02-01

366

Electro-optical processor for measuring displacement employing the Talbot and the nonsteady-state photo-electromotive force effects.  

PubMed

We present a device for measuring displacement based on the Talbot and the nonsteady photo-electromotive force effects. The proposed device does not require any numerical signal processing since its output signal is, in appropriate regions, linearly related to the measured displacement. The proposed system requires an illuminating field with a sinusoidal amplitude distribution and low fringe visibility. The dynamic range can be adjusted according to the illuminating field spatial period or wavelength. Displacements with an estimated resolution better than 10 ?m in a dynamic range of 1.5 mm were detected using a sinusoidal amplitude grating with a period d=100 ?m. PMID:24365833

Rodriguez-Montero, P; Sánchez-de-la-Llave, D; Mansurova, S

2014-01-01

367

3D displacement time series in the Afar rift zone computed from SAR phase and amplitude information  

NASA Astrophysics Data System (ADS)

Large and rapid deformations, such as those caused by earthquakes, eruptions, and landslides cannot be fully measured by using standard DInSAR applications. Indeed, the phase information often degrades and some areas of the interferograms are affected by high fringe rates, leading to difficulties in the phase unwrapping, and/or to complete loss of coherence due to significant misregistration errors. This limitation can be overcome by exploiting the SAR image amplitude information instead of the phase, and by calculating the Pixel-Offset (PO) field SAR image pairs, for both range and azimuth directions. Moreover, it is possible to combine the PO results by following the same rationale of the SBAS technique, to finally retrieve the offset-based deformation time series. Such technique, named PO-SBAS, permits to retrieve the deformation field in areas affected by very large displacements at an accuracy that, for ENVISAT data, correspond to 30 cm and 15 cm for the range and azimuth, respectively [1]. Moreover, the combination of SBAS and PO-SBAS time series can help to better study and model deformation phenomena characterized by spatial and temporal heterogeneities [2]. The Dabbahu rift segment of the Afar depression has been active since 2005 when a 2.5 km3 dyke intrusion and hundreds of earthquakes marked the onset a rifting episode which continues to date. The ENVISAT satellite has repeatedly imaged the Afar depression since 2003, generating a large SAR archive. In this work, we study the Afar rift region deformations by using both the phase and amplitude information of several sets of SAR images acquired from ascending and descending ENVISAT tracks. We combined sets of small baseline interferograms through the SBAS algorithm, and we generate both ground deformation maps and time series along the satellite Line-Of-Sight (LOS). In areas where the deformation gradient causes loss of coherence, we retrieve the displacement field through the amplitude information. Furthermore, we could also retrieve the full 3D deformation field, by considering the North-South displacement component obtained from the azimuth PO information. The combination of SBAS and PO-SBAS information permits to better retrieve and constrain the full deformation field due to repeated intrusions, fault movements, as well as the magma movements from individual magma chambers. [1] Casu, F., A. Manconi, A. Pepe and R. Lanari, 2011. Deformation time-series generation in areas characterized by large displacement dynamics: the SAR amplitude Pixel-Offset SBAS technique, IEEE Transaction on Geosciences and Remote Sensing. [2] Manconi, A. and F. Casu, 2012. Joint analysis of displacement time series retrieved from SAR phase and amplitude: impact on the estimation of volcanic source parameters, Geophysical Research Letters, doi:10.1029/2012GL052202.

Casu, Francesco; Manconi, Andrea

2013-04-01

368

Displacement and interaction of normal fault segments branched at depth: Implications for fault growth and potential earthquake rupture size  

Microsoft Academic Search

We present field data from segmented normal faults having particular displacement and overlapping geometries that may be related to down-dip branching of the fault segments. Based on a 3-D numerical modeling study of computed displacement and stress fields around different geometries of down-dip branched normal fault segments, we show that the bends of fault surfaces that coalesce at depth exert

R. Soliva; A. Benedicto; R. A. Schultz; L. Maerten; L. Micarelli

2008-01-01

369

Three-dimensional elastic stress and displacement analysis of finite geometry solids containing cracks  

NASA Technical Reports Server (NTRS)

The line method of analysis is applied to the Navier-Cauchy equations of elastic equilibrium to calculate the displacement fields in finite geometry bars containing central, surface, and double-edge cracks under extensionally applied uniform loading. The application of this method to these equations leads to coupled sets of simultaneous ordinary differential equations whose solutions are obtained along sets of lines in a discretized region. Normal stresses and the stress intensity factor variation along the crack periphery are calculated using the obtained displacement field. The reported results demonstrate the usefulness of this method in calculating stress intensity factors for commonly encountered crack geometries in finite solids.

Kring, J.; Gyekenyesi, J.; Mendelson, A.

1977-01-01

370

Particle separation using virtual deterministic lateral displacement (vDLD).  

PubMed

We present a method for sensitive and tunable particle sorting that we term virtual deterministic lateral displacement (vDLD). The vDLD system is composed of a set of interdigital transducers (IDTs) within a microfluidic chamber that produce a force field at an angle to the flow direction. Particles above a critical diameter, a function of the force induced by viscous drag and the force field, are displaced laterally along the minimum force potential lines, while smaller particles continue in the direction of the fluid flow without substantial perturbations. We demonstrate the effective separation of particles in a continuous-flow system with size sensitivity comparable or better than other previously reported microfluidic separation techniques. Separation of 5.0 ?m from 6.6 ?m, 6.6 ?m from 7.0 ?m and 300 nm from 500 nm particles are all achieved using the same device architecture. With the high sensitivity and flexibility vDLD affords we expect to find application in a wide variety of microfluidic platforms. PMID:24638896

Collins, David J; Alan, Tuncay; Neild, Adrian

2014-05-01

371

Fabrication of DNA-templated Te and Bi2Te3 nanowires by galvanic displacement.  

PubMed

This paper demonstrates the use of galvanic displacement to form continuous tellurium-based nanowires on DNA templates, enabling the conversion of metals, which can be deposited site-specifically, into other materials needed for device fabrication. Specifically, galvanic displacement reaction of copper and nickel nanowires is used to fabricate tellurium and bismuth telluride nanowires on ?-DNA templates. The method is simple, rapid, highly selective, and applicable to a number of different materials. In this study, continuous Ni and Cu nanowires are formed on DNA templates by seeding with Ag followed by electroless plating of the desired metal. These wires are then displaced by a galvanic displacement reaction where either Te or Bi2Te3 is deposited from an acidic solution containing HTeO2(+) ions or a combination of HTeO2(+) and Bi(3+) ions, and the metal wire is simultaneously dissolved due to oxidation. Both tellurium and bismuth telluride wires can be formed from nickel templates. In contrast, copper templates only form tellurium nanowires under the conditions considered. Therefore, the composition of the metal being displaced can be used to influence the chemistry of the resulting nanowire. Galvanic displacement of metals deposited on DNA templates has the potential to enable site-specific fabrication of a variety of materials and, thereby, make an important contribution to the advancement of useful devices via self-assembled nanotemplates. PMID:23901791

Liu, Jianfei; Uprety, Bibek; Gyawali, Shailendra; Woolley, Adam T; Myung, Nosang V; Harb, John N

2013-09-01

372

On the biophysics and kinetics of toehold-mediated DNA strand displacement  

PubMed Central

Dynamic DNA nanotechnology often uses toehold-mediated strand displacement for controlling reaction kinetics. Although the dependence of strand displacement kinetics on toehold length has been experimentally characterized and phenomenologically modeled, detailed biophysical understanding has remained elusive. Here, we study strand displacement at multiple levels of detail, using an intuitive model of a random walk on a 1D energy landscape, a secondary structure kinetics model with single base-pair steps and a coarse-grained molecular model that incorporates 3D geometric and steric effects. Further, we experimentally investigate the thermodynamics of three-way branch migration. Two factors explain the dependence of strand displacement kinetics on toehold length: (i) the physical process by which a single step of branch migration occurs is significantly slower than the fraying of a single base pair and (ii) initiating branch migration incurs a thermodynamic penalty, not captured by state-of-the-art nearest neighbor models of DNA, due to the additional overhang it engenders at the junction. Our findings are consistent with previously measured or inferred rates for hybridization, fraying and branch migration, and they provide a biophysical explanation of strand displacement kinetics. Our work paves the way for accurate modeling of strand displacement cascades, which would facilitate the simulation and construction of more complex molecular systems. PMID:24019238

Srinivas, Niranjan; Ouldridge, Thomas E.; Šulc, Petr; Schaeffer, Joseph M.; Yurke, Bernard; Louis, Ard A.; Doye, Jonathan P. K.; Winfree, Erik

2013-01-01

373

Does juvenile competition explain displacement of a native crayfish by an introduced crayfish?  

USGS Publications Warehouse

The coldwater crayfish Orconectes eupunctus is endemic to the Spring and Eleven Point Rivers of Arkansas and Missouri, and appears to have been displaced from a portion of its range by the recently introduced ringed crayfish Orconectes neglectus. We examined competition among juveniles as a potential mechanism for this crayfish species displacement through laboratory and field experiments. Orconectes eupunctus juveniles survived and grew in stream cages in their former range, implicating biotic interactions rather than habitat degradation in the displacement. Laboratory experiments revealed O. neglectus juveniles were dominant in the presence of limited food, whereas size rather than species determined occupancy of limited shelter. In a field competition experiment using stream cages, O. neglectus juveniles did not inhibit growth or reduce survival of O. eupunctus juveniles. Consequently, laboratory evidence of O. neglectus dominance did not correspond with competition under field conditions. Combined with previous studies examining the effects of O. neglectus on O. eupunctus, these results suggest that competition may not be a factor in this crayfish species displacement. Alternate mechanisms for the apparent displacement of O. eupunctus by O. neglectus, such as differential predation or reproductive interference, should be investigated. ?? 2008 Springer Science+Business Media B.V.

Larson, E.R.; Magoulick, D.D.

2009-01-01

374

FIELD TRIALS OF NEWLY DEVELOPED POSITIVE DISPLACEMENT SUBMERSIBLE PUMP  

SciTech Connect

The purpose of this grant was to evaluate under real world conditions the performance of a new type of downhole pump, the hydraulically driven submersible diaphragm pump. This pump is supplied by Pumping Solutions Incorporated, Albuquerque NM. The original scope of the project was to install 10 submersible pumps, and compare that to 10 similar installations of rod pumps. As an operator, the system as tested was not ready for prime time. The PSI group did improve the product and offered excellent service. The latest design appears to be much better, but more test data is needed to show short run life is not a problem. This product should continue to be developed; the testing did not uncover any fundamental problems that would preclude it's widespread use. On the positive side, the pump was easy to run, was more power efficient then a rod pump, and is the only submersible that could handle the large quantities of solids typical of CBM production. The product shows much promise for the future, and with continued design and testing, this type of submersible pump has the potential to become the standard of the industry.

Rob Beard; Leland Traylor

2002-12-01

375

Grain boundary barrier modification due to coupling effect of crystal polar field and water molecular dipole in ZnO-based structures  

SciTech Connect

Surface water molecules induced grain boundaries (GBs) barrier modification was investigated in ZnO and ZnMgO/ZnO films. Tunable electronic transport properties of the samples by water were characterized via a field effect transistor (FET) device structure. The FETs fabricated from polar C-plane ZnO and ZnMgO/ZnO films that have lots of GBs exhibited obvious double Schottky-like current-voltage property, whereas that fabricated from nonpolar M-plane samples with GBs and ZnO bulk single-crystal had no obvious conduction modulation effects. Physically, these hallmark properties are supposed to be caused by the electrostatical coupling effect of crystal polar field and molecular dipole on GBs barrier.

Ji, Xu; Zhu, Yuan, E-mail: zhuy9@mail.sysu.edu, E-mail: phzktang@ust.hk; Chen, Mingming; Su, Longxing; Chen, Anqi; Zhao, Chengchun; Gui, Xuchun; Xiang, Rong; Huang, Feng [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Tang, Zikang, E-mail: zhuy9@mail.sysu.edu, E-mail: phzktang@ust.hk [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China); Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

2014-06-16

376

Theoretical limits on the threshold for the response of long cells to weak extremely low frequency electric fields due to ionic and molecular flux rectification.  

PubMed Central

Understanding exposure thresholds for the response of biological systems to extremely low frequency (ELF) electric and magnetic fields is a fundamental problem of long-standing interest. We consider a two-state model for voltage-gated channels in the membrane of an isolated elongated cell (Lcell = 1 mm; rcell = 25 micron) and use a previously described process of ionic and molecular flux rectification to set lower bounds for a threshold exposure. A key assumption is that it is the ability of weak physical fields to alter biochemistry that is limiting, not the ability of a small number of molecules to alter biological systems. Moreover, molecular shot noise, not thermal voltage noise, is the basis of threshold estimates. Models with and without stochastic resonance are used, with a long exposure time, texp = 10(4) s. We also determined the dependence of the threshold on the basal transport rate. By considering both spherical and elongated cells, we find that the lowest bound for the threshold is Emin approximately 9 x 10(-3) V m-1 (9 x 10(-5) V cm-1). Using a conservative value for the loop radius rloop = 0.3 m for induced current, the corresponding lower bound in the human body for a magnetic field exposure is Bmin approximately 6 x 10(-4) T (6 G). Unless large, organized, and electrically amplifying multicellular systems such as the ampullae of Lorenzini of elasmobranch fish are involved, these results strongly suggest that the biophysical mechanism of voltage-gated macromolecules in the membranes of cells can be ruled out as a basis of possible effects of weak ELF electric and magnetic fields in humans. PMID:9788920

Weaver, J C; Vaughan, T E; Adair, R K; Astumian, R D

1998-01-01

377

Is the Long-Term Persistency of Circular Polarisation due to the Constant Helicity of the Magnetic Fields in Rotating Quasar Engines?  

Microsoft Academic Search

Many compact radio sources like quasars, blazars, radio galaxies, and micro-quasars emit circular polarisation (CP) with surprising temporal persistent handedness. We propose that the CP is caused by Faraday conversion (FC) of linear polarisation (LP) synchrotron light which propagates along a line-of-sight (LOS) through helical magnetic fields. Jet outflows from radio galaxies should have the required magnetic helicity in the

Torsten A. Enßlin

378

Control of Coccidiosis due to Eimeria bovis and Eimeria zuernii in Calves with Toltrazuril under Field Conditions in Comparison with Diclazuril and Untreated Controls  

Microsoft Academic Search

The efficacy of preventive treatment with toltrazuril against natural infections with Eimeria bovis and\\/or Eimeria zuernii in calves was investigated in comparison with diclazuril and untreated controls. The study was conducted as a multi-centred,\\u000a blinded, controlled and randomised field study, with 164 calves at four centres (farms) in northern, eastern and southern\\u000a Germany. All participating farms had a known history

H.-C. Mundt; F. Rödder; H. Mengel; B. Bangoura; M. Ocak; A. Daugschies

2007-01-01

379

Conflict, displacement and health in the Middle East.  

PubMed

Displacement is a hallmark of modern humanitarian emergencies. Displacement itself is a traumatic event that can result in illness or death. Survivors face challenges including lack of adequate shelter, decreased access to health services, food insecurity, loss of livelihoods, social marginalisation as well as economic and sexual exploitation. Displacement takes many forms in the Middle East and the Arab World. Historical conflicts have resulted in long-term displacement of Palestinians. Internal conflicts have driven millions of Somalis and Sudanese from their homes. Iraqis have been displaced throughout the region by invasion and civil strife. In addition, large numbers of migrants transit Middle Eastern countries or live there illegally and suffer similar conditions as forcibly displaced people. Displacement in the Middle East is an urban phenomenon. Many displaced people live hidden among host country populations in poor urban neighbourhoods - often without legal status. This represents a challenge for groups attempting to access displaced populations. Furthermore, health information systems in host countries often do not collect data on displaced people, making it difficult to gather data needed to target interventions towards these vulnerable populations. The following is a discussion of the health impacts of conflict and displacement in the Middle East. A review was conducted of published literature on migration and displacement in the region. Different cases are discussed with an emphasis on the recent, large-scale and urban displacement of Iraqis to illustrate aspects of displacement in this region. PMID:21590557

Mowafi, Hani

2011-01-01

380

Global surface displacement data for assessing variability of displacement at a point on a fault  

USGS Publications Warehouse

This report presents a global dataset of site-specific surface-displacement data on faults. We have compiled estimates of successive displacements attributed to individual earthquakes, mainly paleoearthquakes, at sites where two or more events have been documented, as a basis for analyzing inter-event variability in surface displacement on continental faults. An earlier version of this composite dataset was used in a recent study relating the variability of surface displacement at a point to the magnitude-frequency distribution of earthquakes on faults, and to hazard from fault rupture (Hecker and others, 2013). The purpose of this follow-on report is to provide potential data users with an updated comprehensive dataset, largely complete through 2010 for studies in English-language publications, as well as in some unpublished reports and abstract volumes.

Hecker, Suzanne; Sickler, Robert; Feigelson, Leah; Abrahamson, Norman; Hassett, Will; Rosa, Carla; Sanquini, Ann

2014-01-01

381

Prolonged Internal Displacement and Common Mental Disorders in Sri Lanka: The COMRAID Study  

PubMed Central

Background Evidence is lacking on the mental health issues of internally displaced persons, particularly where displacement is prolonged. The COMRAID study was carried out in year 2011 as a comprehensive evaluation of Muslims in North-Western Sri Lanka who had been displaced since 1990 due to conflict, to investigate the prevalence and correlates of common mental disorders. Methods A cross-sectional survey was carried out among a randomly selected sample of internally displaced people who had migrated within last 20 years or were born in displacement. The total sample consisted of 450 adults aged 18–65 years selected from 141 settlements. Common mental disorders (CMDs) and post-traumatic stress disorder (PTSD) prevalences were measured using the Patient Health Questionnaire and CIDI sub-scale respectively. Results The prevalence of any CMD was 18.8%, and prevalence for subtypes was as follows: somatoform disorder 14.0%, anxiety disorder 1.3%, major depression 5.1%, other depressive syndromes 7.3%. PTSD prevalence was 2.4%. The following factors were significantly associated with CMDs: unemployment (odds ratio 2.8, 95% confidence interval 1.6–4.9), widowed or divorced status (4.9, 2.3–10.1) and food insecurity (1.7, 1.0–2.9). Conclusions This is the first study investigating the mental health impact of prolonged forced displacement in post-conflict Sri Lanka. Findings add new insight in to mental health issues faced by internally displaced persons in Sri Lanka and globally, highlighting the need to explore broader mental health issues of vulnerable populations affected by forced displacement. PMID:23717656

Siriwardhana, Chesmal; Adikari, Anushka; Pannala, Gayani; Siribaddana, Sisira; Abas, Melanie; Sumathipala, Athula; Stewart, Robert

2013-01-01

382

Competitive displacement between two invasive whiteflies: insecticide application and host plant effects.  

PubMed

The cryptic species Middle East-Asia Minor 1 (MEAM1), formerly referred to as 'B biotype', of the whitefly Bemisia tabaci complex entered China in the mid 1990s, and the Mediterranean (MED) cryptic species, formerly referred to as 'Q biotype', of the same whitefly complex entered China around 2003. Field surveys in China after 2003 indicate that in many regions MED has been replacing the earlier invader MEAM1. The factors underlying this displacement are unclear. We conducted laboratory experiments and field sampling to examine the effects of insecticide application on the competitive interactions between MEAM1 and MED. In the laboratory, on cotton, a plant showing similar levels of suitability to both whitefly species, MEAM1 displaced MED in five generations when initial populations of the two species were equal and no insecticide was applied. In contrast, MED displaced MEAM1 in seven and two generations, respectively, when 12.5 and 50.0 mg l?¹ imidacloprid was applied to the plants via soil drench. Field sampling indicated that in a single season MED displaced MEAM1 on crops heavily sprayed with neonicotinoid insecticides but the relative abundance of the two species changed little on crops without insecticide spray. We also examined the effects of host plants on the competitive interactions between the two species in the laboratory. When cohorts with equal abundance of MEAM1 and MED were set up on different host plants, MEAM1 displaced MED on cabbage and tomato in five and seven generations, respectively, but MED displaced MEAM1 on pepper in two generations. As field populations of MED have lower susceptibility than those of MEAM1 to nearly all commonly used insecticides including imidacloprid, insecticide application seems to have played a major role in shifting the species competitive interaction effects in favour of MED in the field across China. Host plants may also shape competition between the two species depending on the relative levels of plant suitability. PMID:23458717

Sun, Di-Bing; Liu, Yin-Quan; Qin, Li; Xu, Jing; Li, Fang-Fang; Liu, Shu-Sheng

2013-06-01

383

MRI imaging of displaced meniscal tears: Report of a case highlighting new potential pitfalls of the MRI signs.  

PubMed

Magnetic resonance imaging (MRI) has been found to be an excellent imaging tool for meniscal injuries. Various MRI signs have been described to detect displaced meniscal injuries, specifically the bucket-handle tears. Although these signs are quite helpful in diagnosing meniscal tears, various pitfalls have also been reported for these signs. Double anterior cruciate ligament (ACL) sign refers to presence of a linear hypointense soft tissue anterior to the ACL, which represented the flipped bucket-handle tear of the meniscus. Disproportional posterior horn and flipped meniscus signs represent asymmetrically thickened horns of the menisci due to overlying displaced meniscal fragments. We report a case wherein MRI of the knee showed tear and displacement of the medial patellofemoral ligament (MPFL) and vastus medialis complex, medial collateral ligament (MCL), and posterior cruciate ligament (PCL) mimicking these signs. To our knowledge, internally displaced MPFL and MCLs have not been described as mimics for displaced meniscal fragments. PMID:25114394

Prasad, Abhishek; Brar, Rahat; Rana, Shaleen

2014-07-01

384

MRI imaging of displaced meniscal tears: Report of a case highlighting new potential pitfalls of the MRI signs  

PubMed Central

Magnetic resonance imaging (MRI) has been found to be an excellent imaging tool for meniscal injuries. Various MRI signs have been described to detect displaced meniscal injuries, specifically the bucket-handle tears. Although these signs are quite helpful in diagnosing meniscal tears, various pitfalls have also been reported for these signs. Double anterior cruciate ligament (ACL) sign refers to presence of a linear hypointense soft tissue anterior to the ACL, which represented the flipped bucket-handle tear of the meniscus. Disproportional posterior horn and flipped meniscus signs represent asymmetrically thickened horns of the menisci due to overlying displaced meniscal fragments. We report a case wherein MRI of the knee showed tear and displacement of the medial patellofemoral ligament (MPFL) and vastus medialis complex, medial collateral ligament (MCL), and posterior cruciate ligament (PCL) mimicking these signs. To our knowledge, internally displaced MPFL and MCLs have not been described as mimics for displaced meniscal fragments. PMID:25114394

Prasad, Abhishek; Brar, Rahat; Rana, Shaleen

2014-01-01

385

Magnetic field effects on the vestibular system: calculation of the pressure on the cupula due to ionic current-induced Lorentz force.  

PubMed

Large static magnetic fields may be employed in magnetic resonance imaging (MRI). At high magnetic field strengths (usually from about 3 T and above) it is possible for humans to perceive a number of effects. One such effect is mild vertigo. Recently, Roberts et al (2011 Current Biology 21 1635-40) proposed a Lorentz-force mechanism resulting from the ionic currents occurring naturally in the endolymph of the vestibular system. In the present work a more detailed calculation of the forces and resulting pressures in the vestibular system is carried out using a numerical model. Firstly, realistic 3D finite element conductivity and fluid maps of the utricle and a single semi-circular canal containing the current sources (dark cells) and sinks (hair cells) of the utricle and ampulla were constructed. Secondly, the electrical current densities in the fluid are calculated. Thirdly, the developed Lorentz force is used directly in the Navier-Stokes equation and the trans-cupular pressure is computed. Since the driving force field is relatively large in comparison with the advective acceleration, we demonstrate that it is possible to perform an approximation in the Navier-Stokes equations that reduces the problem to solving a simpler Poisson equation. This simplification allows rapid and easy calculation for many different directions of applied magnetic field. At 7 T a maximum cupula pressure difference of 1.6 mPa was calculated for the combined ampullar (0.7 µA) and utricular (3.31 µA) distributed current sources, assuming a hair-cell resting current of 100 pA per unit. These pressure values are up to an order of magnitude lower than those proposed by Roberts et al using a simplistic model and calculation, and are in good agreement with the estimated pressure values for nystagmus velocities in caloric experiments. This modeling work supports the hypothesis that the Lorentz force mechanism is a significant contributor to the perception of magnetic field induced vertigo. PMID:22722424

Antunes, A; Glover, P M; Li, Y; Mian, O S; Day, B L

2012-07-21

386

Particle image velocimetry for the Surface Tension Driven Convection Experiment using a particle displacement tracking technique  

NASA Technical Reports Server (NTRS)

The Surface Tension Driven Convection Experiment (STDCE) is a Space Transportation System flight experiment to study both transient and steady thermocapillary fluid flows aboard the USML-1 Spacelab mission planned for 1992. One of the components of data collected during the experiment is a video record of the flow field. This qualitative data is then quantified using an all electronic, two-dimensional particle image velocimetry technique called particle displacement tracking (PDT) which uses a simple space domain particle tracking algorithm. The PDT system is successful in producing velocity vector fields from the raw video data. Application of the PDT technique to a sample data set yielded 1606 vectors in 30 seconds of processing time. A bottom viewing optical arrangement is used to image the illuminated plane, which causes keystone distortion in the final recorded image. A coordinate transformation was incorporated into the system software to correct this viewing angle distortion. PDT processing produced 1.8 percent false identifications, due to random particle locations. A highly successful routine for removing the false identifications was also incorporated, reducing the number of false identifications to 0.2 percent.

Wernet, Mark P.; Pline, Alexander D.

1991-01-01

387

Particle image velocimetry for the surface tension driven convection experiment using a particle displacement tracking technique  

NASA Technical Reports Server (NTRS)

The Surface Tension Driven Convection Experiment (STDCE) is a Space Transportation System flight experiment to study both transient and steady thermocapillary fluid flows aboard the USML-1 Spacelab mission planned for 1992. One of the components of data collected during the experiment is a video record of the flow field. This qualitative data is then quantified using an all electronic, two-dimensional particle image velocimetry technique called particle displacement tracking (PDT) which uses a simple space domain particle tracking algorithm. The PDT system is successful in producing velocity vector fields from the raw video data. Application of the PDT technique to a sample data set yielded 1606 vectors in 30 seconds of processing time. A bottom viewing optical arrangement is used to image the illuminated plane, which causes keystone distortion in the final recorded image. A coordinate transformation was incorporated into the system software to correct this viewing angle distortion. PDT processing produced 1.8 percent false identifications, due to random particle locations. A highly successful routine for removing the false identifications was also incorporated, reducing the number of false identifications to 0.2 percent.

Wernet, Mark P.; Pline, Alexander D.

1991-01-01

388

Adjustment to trauma exposure in refugee, displaced, and non-displaced Bosnian women.  

PubMed

The war in Bosnia resulted in the displacement of millions of civilians, most of them women. Ten years after the civil war, many of them are still living as refugees in their country of origin or abroad. Research on different refugee groups has continuously reported persistent levels of posttraumatic stress disorder (PTSD) and other mental-health problems in this population. The present study compared PTSD and self-concept in Bosnian refugee women (n = 29) with women who were internally displaced (IDP; n = 26) and non-displaced women (n = 32). Data were collected using the Bosnian Trauma Questionnaire and four scales assessing self-esteem, perceived incompetence, externality of control attribution, and persistence. IDPs scored significantly higher on PTSD symptoms, externality of control attribution and perceived incompetence, and lower on self-esteem than both refugee and non-displaced women. The level of education most strongly predicted PTSD symptom severity, followed by the type of displacement, and exposure to violence during the war. Associations of self-concept with displacement and psychopathology were inconsistent, with type of displacement predicting control attributions but not other aspects of self-concept and PTSD symptoms being partly related to perceived incompetence and self-esteem. These results support previous findings stating that, in the long run, refugees show better mental health than IDPs, and that witnessing violence is a traumatic experience strongly linked to the development of PTSD symptoms. Results further indicate that education plays an important role in the development of PTSD symptoms. Associations of control attributions and type of displacement were found; these results have not been previously documented in literature. PMID:18802740

Schmidt, Martina; Kravic, Nera; Ehlert, Ulrike

2008-09-01

389

From individual to collective displacements in heterogeneous environments.  

PubMed

Animal displacement plays a central role in many ecological questions. It can be interpreted as a combination of components that only depend on the animal (for example a random walk) and external influences given by the heterogeneity of the environment. Here we treat the case where animals switch between random walks in a homogeneous 2D environment and its 1D boundary, combined with a tendency for wall-following behaviour (thigmotactism) that is treated as a Markovian process. In the first part we use mesoscopic techniques to derive from these assumptions a set of partial differential equations (PDE) with specific boundary conditions and parameters that are directly given by the individual displacement parameters. All assumptions and approximations made during this derivation are rigorously validated for the case of exploratory behaviour of the ant Messor sanctus. These PDE predict that the stationary density ratio between the 2D (centre) and 1D (border) environment only depends on the thigmotactic component, not on the size of the centre or border areas. In the second part we test this prediction with the same exploratory behaviour of M. sanctus, in particular when many ants move around simultaneously and may interact directly or indirectly. The prediction holds when there is a low degree of heterogeneity (simple square arena with straight borders), the collective behaviour is "simply" the sum of the individual behaviours. But this prediction breaks down when heterogeneity increases (obstacles inside the arena) due to the emergence of pheromone trails. Our approach may be applied to study the effects of animal displacement in any environment where the animals are confronted with an alternation of 2D space and 1D borders as for example in fragmented landscapes. PMID:18037447

Casellas, E; Gautrais, J; Fournier, R; Blanco, S; Combe, M; Fourcassié, V; Theraulaz, G; Jost, C

2008-02-01

390

Coastal foredune displacement and recovery, Barrett Beach-Talisman, Fire Island, New York, USA  

USGS Publications Warehouse

Coastal foredune mobility has been tracked at Fire Island National Seashore since 1976 with annual field surveys and analysis of frequent aerial photography. Sequential mapping of the foredune crestline depicts nearly islandwide displacement during major storm events, such as in 1992, and localized displacement during alongshore passage of inshore circulation cells during other years. An instance of localized landward erosion and curvilinear displacement along approximately 400 m of foredune occurred in 1994, followed by recovery over the next nine years. Data from annual surveys and partially supported by four LIDAR flights establish that volume recovery rates in the foredune ranged from about 1.0 m3/m/yr to nearly 12.0 m 3/m/yr. Analysis of the foredune morphology and location shows nearly complete recovery of foredune shape and dimension during this interval and it also demonstrates that there has been inland displacement of the foredune crestline of up to 40 m. Total volume recovery within the localized foredune erosion site was greatest, between 34 m3/m to 47 m3/m, in areas of greatest displacement and eventually contributed to creation of a foredune of similar dimension along the entire eroded zone. This process of erosion and recovery describes a mechanism for foredune dimension retention during episodic erosion and displacement and may be a model for foredune persistence accompanying barrier island migration. ?? 2005 Gebru??der Borntraeger.

Psuty, N.P.; Pace, J.P.; Allen, J.R.

2005-01-01

391

Coastal foredune displacement and recovery, Barrett Beach-Talisman, Fire Island, New York, USA  

USGS Publications Warehouse

Coastal foredune mobility has been tracked at Fire Island National Seashore since 1976 with annual field surveys and analysis of frequent aerial photography. Sequential mapping of the foredune crestline depicts nearly islandwide displacement during major storm events, such as in 1992, and localized displacement during alongshore passage of inshore circulation cells during other years. An instance of localized landward erosion and curvilinear displacement along approximately 400 m of foredune occurred in 1994, followed by recovery over the next nine years. Data from annual surveys and partially supported by four LIDAR flights establish that volume recovery rates in the foredune ranged from about 1.0 m3/m/yr to nearly 12.0 m3/m/yr. Analysis of the foredune morphology and location shows nearly complete recovery of foredune shape and dimension during this interval and it also demonstrates that there has been inland displacement of the foredune crestline of up to 40 m. Total volume recovery within the localized foredune erosion site was greatest, between 34 m3/m to 47 m3/m, in areas of greatest displacement and eventually contributed to creation of a foredune of similar dimension along the entire eroded zone. This process of erosion and recovery describes a mechanism for foredune dimension retention during episodic erosion and displacement and may be a model for foredune persistence accompanying barrier island migration.

Psuty, N.P.; Pace, J.P.; Allen, J.R.

2005-01-01

392

Minimally displaced clavicle fracture after high-energy injury: Are they likely to displace?  

PubMed Central

Background Nondisplaced or minimally displaced clavicle fractures are often considered to be benign injuries. These fractures in the trauma patient population, however, may deserve closer follow-up than their low-energy counterparts. We sought to determine the initial assessment performed on these patients and the rate of subsequent fracture displacement in patients sustaining high-energy trauma when a supine chest radiograph on initial trauma survey revealed a well-aligned clavicle fracture. Methods We retrospectively reviewed the cases of trauma alert patients who sustained a midshaft clavicle fracture (AO/OTA type 15-B) with less than 100% displacement treated at a single level 1 trauma centre between 2005 and 2010. We compared fracture displacement on initial supine chest radiographs and follow-up radiographs. Orthopedic consultation and the type of imaging studies obtained were also recorded. Results Ninety-five patients with clavicle fractures met the inclusion criteria. On follow-up, 57 (60.0%) had displacement of 100% or more of the shaft width. Most patients (63.2%) in our study had an orthopedic consultation during their hospital admission, and 27.4% had clavicle radiographs taken on the day of admission. Conclusion Clavicle fractures in patients with a high-energy mechanism of injury are prone to fracture displacement, even when initial supine chest radiographs show nondisplacement. We recommend clavicle films as part of the initial evaluation for all patients with clavicle fractures and early follow-up within the first 2 weeks of injury. PMID:24869608

Riehl, John T.; Athans, Bill J.; Munro, Mark W.; Langford, Joshua R.; Kupiszewski, Stanley J.; Haidukewych, George J.; Koval, Kenneth J.

2014-01-01

393

The self-consistent parallel electric field due to electrostatic ion-cyclotron turbulence in downward auroral-current regions of the Earth's magnetosphere. IV  

SciTech Connect

The physical processes that determine the self-consistent electric field (E{sub ||}) parallel to the magnetic field have been an unresolved problem in magnetospheric physics for over 40 years. Recently, a new multimoment fluid theory was developed for inhomogeneous, nonuniformly magnetized plasma in the guiding-center and gyrotropic approximation that includes the effect of electrostatic, turbulent, wave-particle interactions (see Jasperse et al. [Phys. Plasmas 13, 072903 (2006); ibid.13, 112902 (2006)]). In the present paper and its companion paper [Jasperse et al., Phys. Plasmas 17, 062903 (2010)], which are intended as sequels to the earlier work, a fundamental model for downward, magnetic field-aligned (Birkeland) currents for quasisteady conditions is presented. The model includes the production of electrostatic ion-cyclotron turbulence in the long-range potential region by an electron, bump-on-tail-driven ion-cyclotron instability. Anomalous momentum transfer (anomalous resistivity) by itself is found to produce a very small contribution to E{sub ||}; however, the presence of electrostatic, ion-cyclotron turbulence has a very large effect on the altitude dependence of the entire quasisteady solution. Anomalous energy transfer (anomalous heating and cooling) modifies the density, drift, and temperature altitude profiles and hence the generalized parallel-pressure gradients and mirror forces in the electron and ion momentum-balance equations. As a result, |E{sub ||}| is enhanced by nearly a factor of 40 compared to its value when turbulence is absent. The space-averaged potential increase associated with the strong double layer at the bottom of the downward-current sheet is estimated using the FAST satellite data and the multimoment fluid theory.

Jasperse, John R.; Basu, Bamandas [Air Force Research Laboratory, Space Vehicles Directorate, Hanscom AFB, Massachusetts 01731 (United States); Lund, Eric J. [Space Science Center, University of New Hampshire, Durham, New Hampshire 03824 (United States); Grossbard, Neil [Institute for Scientific Research, Boston College, Chestnut Hill, Massachusetts 02467 (United States)

2010-06-15

394

Remember Me: Displaced Children of the Holocaust  

NSDL National Science Digital Library

The United States Holocaust Museum (USHM) has worked on a number of important projects, and this might be one of their most moving. Working with the archives of the World Jewish Congress (WJC), they have digitized approximately 1100 photographs of children who were displaced or orphaned as a result of the persecution carried out by the Nazis and their collaborators. The intent of this project is "to identify these children, piece together information about their wartime and postwar experiences, and facilitate renewed connections among these young survivors, their families, and other individuals who were involved in their care during and after the war." Visitors to the site can browse the photos by name or just by viewing the gallery as they see fit. The site also includes a 1945 BBC radio broadcast seeking relatives of displaced children and a section with updates on the project's progress.

395

Selective spectral displacement projection for multifrequency MRE  

PubMed Central

We introduce a new motion encoding concept for the displacement vector in multifrequency Magnetic Resonance Elastography (MRE). Selective spectral displacement projection (SDP)-MRE can be applied to a vibration spectrum composed of three frequencies and exploits the filter condition of MRE for selecting one frequency each per spatial motion encoding direction. The selected components are simultaneously encoded in the phase of the MR signal. Therefore, the total MR phase is represented by a sum of phase portions, each corresponding to a distinct spatial projection and vibration frequency. The individual components can be decomposed by applying a Fourier-transform to the temporally-resolved phase images. SDP-MRE reduces the number of temporally-resolved MRE experiments for data acquisition by a factor of 3, while providing similar wave images as found using conventional monofrequency MRE. PMID:23912182

Yasar, Temel K.; Klatt, Dieter; Magin, Richard L.; Royston, Thomas J.

2013-01-01

396

Character displacement of Cercopithecini primate visual signals  

PubMed Central

Animal visual signals have the potential to act as an isolating barrier to prevent interbreeding of populations through a role in species recognition. Within communities of competing species, species recognition signals are predicted to undergo character displacement, becoming more visually distinctive from each other, however this pattern has rarely been identified. Using computational face recognition algorithms to model primate face processing, we demonstrate that the face patterns of guenons (tribe: Cercopithecini) have evolved under selection to become more visually distinctive from those of other guenon species with whom they are sympatric. The relationship between the appearances of sympatric species suggests that distinguishing conspecifics from other guenon species has been a major driver of diversification in guenon face appearance. Visual signals that have undergone character displacement may have had an important role in the tribe’s radiation, keeping populations that became geographically separated reproductively isolated on secondary contact. PMID:24967517

Allen, William L.; Stevens, Martin; Higham, James P.

2014-01-01

397

Thermocapillary mechanism of melt displacement during keyhole formation by the laser beam  

Microsoft Academic Search

A thermocapillary model of keyhole formation in laser welding is presented. According to the thermocapillary hypothesis, a cavity forms as the result of surface tension-induced melt displacement on a non-uniformly heated surface. In this case the transition of welding into a keyhole mode is due to the change in the structure of the thermocapillary divergent flow on the attainment of

R. D. Seidgazov

2009-01-01

398

Evaluation of genome coverage and fidelity of multiple displacement amplification from single cells by SNP array  

Microsoft Academic Search

The scarce amount of DNA contained in a singe cell is a limiting factor for clinical application of preimplantation genetic diagnosis mainly due to the risk of misdiagnosis caused by allele dropout and the difficulty in obtaining copy number variations in all 23 pairs of chromosomes. Multiple displacement amplification (MDA) has been reported to generate large quantity of products from

Jiawei Ling; Guanglun Zhuang; Barbara Tazon-Vega; Chenhui Zhang; Baoqiang Cao; Zev Rosenwaks; Kangpu Xu

2009-01-01

399

Displaced Worker Transition Programs: Leading the Workforce Back to Community Colleges.  

ERIC Educational Resources Information Center

In response to the increasing numbers of displaced workers due to corporate downsizing, Pellissippi State Technical Community College, in Tennessee, has initiated the Workplace Innovation (WIN) Project to help adults gain prerequisite academic and personal skills to re-enter the workforce or enter college for eventual placement in higher-paying…

Walters, Greg; And Others

400

Ultra-High-Frequency Capacitive Displacement Sensor  

NASA Technical Reports Server (NTRS)

Improved class of compact, high-resolution capacitive displacement sensors operates at excitation frequency of 915 MHz and measures about 7.5 by 4 by 2 centimeters. Contains commercially available 915-MHz oscillator and transmission-line resonator. Resonator contains stripline inductor in addition to variable capacitor. Ultrahigh excitation frequency offers advantages of resolution and frequency response. Not deleteriously affected by mechanical overdriving, or contact between electrodes.

Vanzandt, Thomas R.; Kenny, Thomas W.; Kaiser, William J.

1994-01-01

401

Displaced-Phase-Center Antenna Technique  

Microsoft Academic Search

This article describes Lincoln Laboratory contributions to the development of the displaced-phase-center antenna (DPCA) technique, which was used to improve the detection performance of airborne or space-borne MTI radars that are subject to clutter. In the 1950s the DPCA technique was applied to airborne early warning (AEW) radars for defense of North America against long-range bombers carrying nuclear weapons. Lincoln

Charles Edward Muehe; Melvin Labitt

2000-01-01

402

THREE-DIMENSIONAL FEATURES OF THE OUTER HELIOSPHERE DUE TO COUPLING BETWEEN THE INTERSTELLAR AND INTERPLANETARY MAGNETIC FIELDS. III. THE EFFECTS OF SOLAR ROTATION AND ACTIVITY CYCLE  

SciTech Connect

We investigate the effects of the 11 year solar cycle and 25 day rotation period of the Sun on the interaction of the solar wind (SW) with the local interstellar medium (LISM). Our models take into account the partially ionized character of the LISM and include momentum and energy transfer between the ionized and neutral components. We assume that the interstellar magnetic field vector belongs to the hydrogen deflection plane as discovered in the SOHO SWAN experiment. This plane is inclined at an angle of about 60 deg. toward the ecliptic plane of the Sun, as suggested in recent publications relating the local interstellar cloud properties to the radio emission observed by Voyager 1. It is assumed that the latitudinal extent of the boundary between the slow and fast SW regions, as well as the angle between the Sun's rotation and magnetic-dipole axes, are periodic functions of time, while the polarity of the interstellar magnetic field changes sign every 11 years at the solar maximum. The global variation of the SW-LISM interaction pattern, the excursions of the termination shock and the heliopause, and parameter distributions in certain directions are investigated. The analysis of the behavior of the wavy heliospheric current sheet in the supersonic SW region shows the importance of neutral atoms on its dynamics.

Pogorelov, Nikolai V.; Borovikov, Sergey N.; Zank, Gary P. [Physics Department and Center for Space Plasma and Aeronomic Research, University of Alabama in Huntsville, 320 Sparkman Dr., Huntsville, AL 35805 (United States); Ogino, Tatsuki [Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8601 (Japan)], E-mail: Nikolai.Pogorelov@uah.edu, E-mail: snb0003@uah.edu, E-mail: zank@cspar.uah.edu, E-mail: ogino@stelab.nagoya-u.ac.jp

2009-05-10

403

Concurrent adaptation to opposing visual displacements during an alternating movement  

PubMed Central

It has been suggested that, during tasks in which subjects are exposed to a visual rotation of cursor feedback, alternating bimanual adaptation to opposing rotations is as rapid as unimanual adaptation to a single rotation (Bock et al. in Exp Brain Res 162:513–519, 2005). However, that experiment did not test strict alternation of the limbs but short alternate blocks of trials. We have therefore tested adaptation under alternate left/right hand movement with opposing rotations. It was clear that the left and right hand, within the alternating conditions, learnt to adapt to the opposing displacements at a similar rate suggesting that two adaptive states were formed concurrently. We suggest that the separate limbs are used as contextual cues to switch between the relevant adaptive states. However, we found that during online correction the alternating conditions had a significantly slower rate of adaptation in comparison to the unimanual conditions. Control conditions indicate that the results are not directly due the alternation between limbs or to the constant switching of vision between the two eyes. The negative interference may originate from the requirement to dissociate the visual information of these two alternating displacements to allow online control of the two arms. PMID:16835793

Miall, R. C.

2006-01-01

404

Experimental results of field windings and concepts of rotor component development of superconducting generator  

NASA Astrophysics Data System (ADS)

Field windings of superconducting generators are wound in slots which are cut on the outer surface of a support tube, and they are supported by wedges against centrifugal and electromagnetic forces. To improve reliability of field windings, ac losses due to flux change, and ohmic losses due to the winding, connections must be small and field windings must be tightly compressed by wedges. This paper presents experimental results of ac losses, ohmic losses, compression-displacement measurements of field windings, and design concepts of the present rotor-component development project.

Ueda, A.; Hirao, T.; Hatanaka, H.; Morita, M.

1987-09-01

405

A reverse updated Lagrangian finite element formulation for determining material properties from measured force and displacement data  

NASA Astrophysics Data System (ADS)

The mechanical response of solids exhibiting complex material behavior has traditionally been determined by fitting constitutive models of specified functional form to experimentally derived force-displacement (stress-strain) data. However, characterizing the nonlinear mechanical behavior of complex materials requires a method of quantifying material behavior that is not restricted by a specific constitutive relation. To this end, a new method, termed the reverse updated Lagrangian finite element method (RULFEM), which is based on the three-dimensional displacement field of the deformed solid and the finite element method, is developed for incrementally linear materials. Using the RULEFM, the body is discretized by finite elements and its material properties are determined element-wise, i.e., the properties are assumed to be uniform at the element level and may vary from one element to another. The validity of RULFEM is demonstrated by three noise-free numerical examples and three numerical examples with various input noise levels. Two methods to assess the global and local errors of the results due to error in the measured input data (noisy data) are also discussed.

Tartibi, M.; Steigmann, D. J.; Komvopoulos, K.

2014-12-01

406

Direct and precise measurement of displacement and velocity of flexible web in roll-to-roll manufacturing systems.  

PubMed

Interest in the production of printed electronics using a roll-to-roll system has gradually increased due to its low mass-production costs and compatibility with flexible substrate. To improve the accuracy of roll-to-roll manufacturing systems, the movement of the web needs to be measured precisely in advance. In this paper, a novel measurement method is developed to measure the displacement and velocity of the web precisely and directly. The proposed algorithm is based on the traditional single field encoder principle, and the scale grating has been replaced with a printed grating on the web. Because a printed grating cannot be as accurate as a scale grating in a traditional encoder, there will inevitably be variations in pitch and line-width, and the motion of the web should be measured even though there are variations in pitch and line-width in the printed grating patterns. For this reason, the developed algorithm includes a precise method of estimating the variations in pitch. In addtion, a method of correcting the Lissajous curve is presented for precision phase interpolation to improve measurement accuracy by correcting Lissajous circle to unit circle. The performance of the developed method is evaluated by simulation and experiment. In the experiment, the displacement error was less than 2.5 ?m and the velocity error of 1? was about 0.25%, while the grating scale moved 30 mm. PMID:24387460

Kang, Dongwoo; Kim, Young duk; Lee, Eonseok; Choi, Young-Man; Lee, Taik-Min; Kim, Dongmin

2013-12-01

407

Direct and precise measurement of displacement and velocity of flexible web in roll-to-roll manufacturing systems  

NASA Astrophysics Data System (ADS)

Interest in the production of printed electronics using a roll-to-roll system has gradually increased due to its low mass-production costs and compatibility with flexible substrate. To improve the accuracy of roll-to-roll manufacturing systems, the movement of the web needs to be measured precisely in advance. In this paper, a novel measurement method is developed to measure the displacement and velocity of the web precisely and directly. The proposed algorithm is based on the traditional single field encoder principle, and the scale grating has been replaced with a printed grating on the web. Because a printed grating cannot be as accurate as a scale grating in a traditional encoder, there will inevitably be variations in pitch and line-width, and the motion of the web should be measured even though there are variations in pitch and line-width in the printed grating patterns. For this reason, the developed algorithm includes a precise method of estimating the variations in pitch. In addtion, a method of correcting the Lissajous curve is presented for precision phase interpolation to improve measurement accuracy by correcting Lissajous circle to unit circle. The performance of the developed method is evaluated by simulation and experiment. In the experiment, the displacement error was less than 2.5 ?m and the velocity error of 1? was about 0.25%, while the grating scale moved 30 mm.

Kang, Dongwoo; duk Kim, Young; Lee, Eonseok; Choi, Young-Man; Lee, Taik-Min; Kim, Dongmin

2013-12-01

408

Modeling of the saturation current of a fission chamber taking into account the distorsion of electric field due to space charge effects  

E-print Network

Fission chambers were first made fifty years ago for neutron detection. At the moment, the French Atomic Energy Commission \\textsf{(CEA-Cadarache)} is developing a sub-miniature fission chamber technology with a diameter of 1.5 mm working in the current mode (Bign). To be able to measure intense fluxes, it is necessary to adjust the chamber geometry and the gas pressure before testing it under real neutron flux. In the present paper, we describe a theoretical method to foresee the current-voltage characteristics (sensitivity and saturation plateau) of a fission chamber whose geometrical features are given, taking into account the neutron flux to be measured (spectrum and intensity). The proposed theoretical model describes electric field distortion resulting from charge collection effect. A computer code has been developed on this model basis. Its application to 3 kinds of fission chambers indicates excellent agreement between theoretical model and measured characteristics.

Olivier Poujade; Alain Lebrun

2002-02-08

409

FPGA implementation of 3D-displacement measurement based on 2D-DIC and FPP  

NASA Astrophysics Data System (ADS)

Nondestructive optical techniques have been widely used to satisfy engineering applicat ion. 2D digital image correlation (DIC) method has superiority of convenient manipulation and high accuracy in measuring planar displacement. Moreover, fringe pattern profilometry (FPP) method has become a highly developed technique to measure surface profile. Combined with 2D-DIC method, FPP method can be applied to measure three-dimensional displacements conveniently. As a semi-custom integrated circuit, Field-Programmable Gate Array (FPGA) has been popular for its powerful programming performance on controlling experimental instrument. Furthermore, Labview, an efficient graphical programming language which excels in instrument communication, can be used to program FPGA. In this paper, a corrected dynamic FPP method combined with 2D-DIC method has been presented and achieved by Labview programming to measure dynamic deformation. An experimental system including a projector and a camera is used to project fringe patterns and acquire images alternately at a high speed. By the referred method a series of spatial-discrete displacement data in equal intervals of time are obtained. Then a four-dimensional interpolation is adopted to get full-field and continuous-time displacement data. Thus, the planar and out-plane displacements can be simultaneously measured. Experiments were performed and verified the feasibility of proposed method.

Lei, Zhenkun; Zhang, Fangxu; Li, Xuan

2014-07-01

410

40 CFR 86.419-2006 - Engine displacement, motorcycle classes.  

Code of Federal Regulations, 2010 CFR

...Engine displacement, motorcycle classes. 86.419-2006 Section 86.419-2006 Protection of Environment ENVIRONMENTAL PROTECTION...New Motorcycles, General Provisions § 86.419-2006 Engine displacement, motorcycle classes....

2010-07-01

411

Indicator displacement assays that detect bilayer membranes enriched in phosphatidylserine  

E-print Network

Indicator displacement assays that detect bilayer membranes enriched in phosphatidylserine Roger G: 10.1039/b500522a Three indicator displacement assays are described for the detection selectively to the phosphatidylserine and act as a colorimetric chemosensing ensemble when combined

Smith, Bradley D.

412

Worker Displacement Still Common in the Late 1980s.  

ERIC Educational Resources Information Center

Even during a period of rapid employment growth, over four million people were displaced from their jobs in the 1980s. Workers displaced during the latter half of the decade had a much easier time finding new jobs. (Author)

Herz, Diane E.

1991-01-01

413

Increased upconversion quantum yield in photonic structures due to local field enhancement and modification of the local density of states--a simulation-based analysis.  

PubMed

In upconversion processes, two or more low-energy photons are converted into one higher-energy photon. Besides other applications, upconversion has the potential to decrease sub-band-gap losses in silicon solar cells. Unfortunately, upconverting materials known today show quantum yields, which are too low for this application. In order to improve the upconversion quantum yield, two parameters can be tuned using photonic structures: first, the irradiance can be increased within the structure. This is beneficial, as upconversion is a non-linear process. Second, the rates of the radiative transitions between ionic states within the upconverter material can be altered due to a varied local density of photonic states. In this paper, we present a theoretical model of the impact of a photonic structure on upconversion and test this model in a simulation based analysis of the upconverter material ? -NaYF(4):20% Er(3+) within a dielectric waveguide structure. The simulation combines a finite-difference time-domain simulation model that describes the variations of the irradiance and the change of the local density of photonic states within a photonic structure, with a rate equation model of the upconversion processes. We find that averaged over the investigated structure the upconversion luminescence is increased by a factor of 3.3, and the upconversion quantum yield can be improved in average by a factor of 1.8 compared to the case without the structure for an initial irradiance of 200 Wm(-2). PMID:24104583

Herter, Barbara; Wolf, Sebastian; Fischer, Stefan; Gutmann, Johannes; Bläsi, Benedikt; Goldschmidt, Jan Christoph

2013-09-01

414

Three-dimensional image correlation for surface-displacement measurement  

NASA Astrophysics Data System (ADS)

This paper describes a 3D surface profile and displacement measurement system capable of micron level accuracy using moderately priced off-the-shelf equipment. A non-linear optimization based calibration system is presented. The calibration system determines the position and operating characteristics of the cameras as well as correcting for lens distortion. Also presented is a surface profile and displacement measurement system base on projections into space of subsets of the recorded images. This method provides information about both the location and orientation in space of the subset. The accuracy of the system is established through a series of experiments. The calibration is assessed and the results are expressed using several different error measurements including a new error measurement proposed by the authors. The baseline accuracy of the measurement system was determined through a series of profile and translation tests. The system is capable of measurements to an accuracy of 0.003 mm over a 14 mm X 18 mm field from a distance of 416 mm using a 512 X 480 CCD camera and a magnification factor of 27 pixels/mm. The system was also used to measure the bending of a circular plate under pressure loading. The experimental results are analyzed and compared with theoretical prediction.

Helm, Jeffrey D.; Sutton, Michael A.; McNeill, Stephen R.

1994-10-01

415

High precision micro-displacement fiber sensor through a suspended-core Sagnac interferometer.  

PubMed

A sensing system for micro-displacement measurement based in a suspended-core fiber Sagnac interferometer is presented. The suspended-core fiber characterization was made through the use of an optical backscatter reflectometer, screening its multimodal and birefringent behavior. Its sensitivity to displacement measurements is shown to be due only to birefringence, being that core-cladding mode coupling is negligible. High precision (~0.45 ?m) was obtained using three different measurement instruments, showing an extremely high stability and high insensitivity to temperature, demonstrating that the sensing system has the ability for low cost applications. PMID:22854467

Bravo, M; Pinto, A M R; Lopez-Amo, M; Kobelke, J; Schuster, K

2012-01-15

416

Optical knife-edge technique for nanomechanical displacement detection  

SciTech Connect

We describe an optical knife-edge technique for nanomechanical displacement detection. Here, one carefully focuses a laser spot on a moving edge and monitors the reflected power as the edge is displaced sideways. To demonstrate nanomechanical displacement detection using the knife-edge technique, we have measured in-plane resonances of nanometer scale doubly clamped beams. The obtained displacement sensitivity is in the {approx}1 pm/{radical}(Hz) range--in close agreement with a simple analytical model.

Karabacak, D.; Kouh, T.; Huang, C.C.; Ekinci, K.L. [Department of Aerospace and Mechanical Engineering, Boston University, Boston, Massachusetts 02215 (United States); Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215 (United States); Department of Aerospace and Mechanical Engineering, Boston University, Boston, Massachusetts 02215 (United States)

2006-05-08

417

Use of pulsed-field gel electrophoresis typing to study an outbreak of infection due to Serratia marcescens in a neonatal intensive care unit.  

PubMed Central

Serratia marcescens is a well-known cause of nosocomial infections and outbreaks, particularly in critically ill neonates and immunocompromised patients. Numerous methods have been proposed for typing. We used pulsed-field gel electrophoresis (PFGE) typing to analyze an outbreak in a neonatal intensive care unit (NICU). We included 23 patient isolates from an outbreak (March to July 1995), and 10 patient isolates from different wards during the same time period. PFGE of whole-cell DNA digested by SpeI was used as a marker of strain identity. The most common presentation of the infection was sepsis in 18 of 23 (78%) neonates. Only four different biotypes were identified; biotype A8d accounted for 84% of the strains. PFGE typing revealed two clones responsible for two different clonal strain dissemination outbreaks from March to July, with 24 patient isolates being pattern A and 4 patient isolates being pattern E. PFGE typing suggests cross transmission between patients in the NICU and other wards. The isolates from 5 other patients showed distinct PFGE patterns. Extensive investigation and cultures failed to identify any environmental or staff reservoir of S. marcescens. This is one of the first reports applying PFGE to the study of S. marcescens, and this method was a useful marker of strain identity. PFGE typing distinguished strains which appeared to be the same by biotyping. PMID:8940460

Miranda, G; Kelly, C; Solorzano, F; Leanos, B; Coria, R; Patterson, J E

1996-01-01

418

Collateral damage: Evolution with displacement of fracture distribution and secondary fault strands in fault  

E-print Network

Collateral damage: Evolution with displacement of fracture distribution and secondary fault strands in fault damage zones Heather M. Savage1,2 and Emily E. Brodsky1 Received 22 April 2010; revised 10 faults is governed by the same process. Based on our own field work combined with data from

Savage, Heather M.

419

Miscible displacement of viscous, non-Newtonian fluids in different geometries. An analytical approach  

Microsoft Academic Search

Solutions are given for the displacement occurring between parallel plates and in tubes under conditions of constant flow rate. For tubes, a solution is also given for the case when a constant pressure drop is imposed across the flow field. The analytical approach used relied on principles from the hydrodynamic theory of lubrication. The results showed that the process was

R. M. Beirute

1977-01-01

420

Digital PIV Measurements of Acoustic Particle Displacements in a Normal Incidence Impedance Tube  

NASA Technical Reports Server (NTRS)

Acoustic particle displacements and velocities inside a normal incidence impedance tube have been successfully measured for a variety of pure tone sound fields using Digital Particle Image Velocimetry (DPIV). The DPIV system utilized two 600-mj Nd:YAG lasers to generate a double-pulsed light sheet synchronized with the sound field and used to illuminate a portion of the oscillatory flow inside the tube. A high resolution (1320 x 1035 pixel), 8-bit camera was used to capture double-exposed images of 2.7-micron hollow silicon dioxide tracer particles inside the tube. Classical spatial autocorrelation analysis techniques were used to ascertain the acoustic particle displacements and associated velocities for various sound field intensities and frequencies. The results show that particle displacements spanning a range of 1-60 microns can be measured for incident sound pressure levels of 100-130 dB and for frequencies spanning 500-1000 Hz. The ability to resolve 1 micron particle displacements at sound pressure levels in the 100 dB range allows the use of DPIV systems for measurement of sound fields at much lower sound pressure levels than had been previously possible. Representative impedance tube data as well as an uncertainty analysis for the measurements are presented.

Humphreys, William M., Jr.; Bartram, Scott M.; Parrott, Tony L.; Jones, Michael G.

1998-01-01

421

Calculation of the Displacement Current Using the Integral Form of Ampere's Law.  

ERIC Educational Resources Information Center

Derives the magnetic field as a function of position between two capacitor plates during discharge with the use of the integral form of Ampere's law and real currents only. The displacement current must be included to obtain the same result for arbitrary choices of contours. (Author/GA)

Dahm, A. J.

1978-01-01

422

The displacement estimation error back-propagation (DEEP) method for a multiple structural displacement monitoring system  

NASA Astrophysics Data System (ADS)

Visually servoed paired structured light system (ViSP) has been found to be useful in estimating 6-DOF relative displacement. The system is composed of two screens facing each other, each with one or two lasers, a 2-DOF manipulator and a camera. The displacement between two sides is estimated by observing positions of the projected laser beams and rotation angles of the manipulators. To apply the system to massive structures, the whole area should be partitioned and each ViSP module is placed in each partition in a cascaded manner. The estimated displacement between adjoining ViSPs is combined with the next partition so that the entire movement of the structure can be estimated. The multiple ViSPs, however, have a major problem that the error is propagated through the partitions. Therefore, a displacement estimation error back-propagation (DEEP) method which uses Newton-Raphson or gradient descent formulation inspired by the error back-propagation algorithm is proposed. In this method, the estimated displacement from the ViSP is updated using the error back-propagated from a fixed position. To validate the performance of the proposed method, various simulations and experiments have been performed. The results show that the proposed method significantly reduces the propagation error throughout the multiple modules.

Jeon, H.; Shin, J. U.; Myung, H.

2013-04-01

423

Industry-Specific Human Capital: Evidence from Displaced Workers  

Microsoft Academic Search

Results from the Displaced Worker Surveys show that the wage cost of switching industries following displacement is strongly correlated with predisplacement measures of both work experience and tenure. Workers apparently receive compensation for some skills that are neither completely general nor firm-specific but rather specific to their industry or line of work. Further, among displaced workers who find new jobs

Derek Neal

1995-01-01

424

Nanoscale Displacement and Strain Measurement , Francois Barthelat1)  

E-print Network

Nanoscale Displacement and Strain Measurement Yong Zhu1) , Francois Barthelat1) , Paul E) requires precise measurements of displacement and strain in the nanometer scale. Integrated testing devices generation and measurement, as well as displacement and strain measurement are the generic challenges

Espinosa, Horacio D.

425

Direct Reconstruction of a Displaced Subdivision Surface from Unorganized Points  

Microsoft Academic Search

In this paper we describe the generation of a displaced subdivision surface directly from a set of unorganized points. The displaced subdivision surface is an efficient mesh representation that defines a detailed mesh with a displacement map over a smooth domain surface and has many benefits including compression, rendering, and animation, which overcome limitations of an irregular mesh produced by

Won-ki Jeong; Chang-hun Kim