14 CFR 25.471 - General.

Code of Federal Regulations, 2012 CFR

2012-01-01

.... Lateral displacements of the c.g. from the airplane centerline which would result in main gear loads not... without considering the effects of these lateral c.g. displacements on the loading of the main gear elements, or on the airplane structure provided— (1) The lateral displacement of the c.g. results from...

14 CFR 25.471 - General.

Code of Federal Regulations, 2013 CFR

2013-01-01

.... Lateral displacements of the c.g. from the airplane centerline which would result in main gear loads not... without considering the effects of these lateral c.g. displacements on the loading of the main gear elements, or on the airplane structure provided— (1) The lateral displacement of the c.g. results from...

14 CFR 25.471 - General.

Code of Federal Regulations, 2014 CFR

2014-01-01

.... Lateral displacements of the c.g. from the airplane centerline which would result in main gear loads not... without considering the effects of these lateral c.g. displacements on the loading of the main gear elements, or on the airplane structure provided— (1) The lateral displacement of the c.g. results from...

14 CFR 25.471 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

.... Lateral displacements of the c.g. from the airplane centerline which would result in main gear loads not... without considering the effects of these lateral c.g. displacements on the loading of the main gear elements, or on the airplane structure provided— (1) The lateral displacement of the c.g. results from...

Evaluation of Stiffness Changes in a High-Rise Building by Measurements of Lateral Displacements Using GPS Technology

PubMed Central

Choi, Se Woon; Kim, Ill Soo; Park, Jae Hwan; Kim, Yousok; Sohn, Hong Gyoo; Park, Hyo Seon

2013-01-01

The outrigger truss system is one of the most frequently used lateral load resisting structural systems. However, little research has been reported on the effect of installation of outrigger trusses on improvement of lateral stiffness of a high-rise building through full-scale measurements. In this paper, stiffness changes of a high-rise building due to installation of outrigger trusses have been evaluated by measuring lateral displacements using a global positioning system (GPS). To confirm the error range of the GPS measurement system used in the full-scale measurement tests, the GPS displacement monitoring system is investigated through a free vibration test of the experimental model. Then, for the evaluation of lateral stiffness of a high-rise building under construction, the GPS displacement monitoring system is applied to measurements of lateral displacements of a 66-story high-rise building before and after installation of outrigger truss. The stiffness improvement of the building before and after the installation is confirmed through the changes of the natural frequencies and the ratios of the base shear forces to the roof displacements. PMID:24233025

Progesterone's 5 alpha-reduced metabolite, 3 alpha,5 alpha-THP, mediates lateral displacement of hamsters.

PubMed

Frye, Cheryl A; Rhodes, Madeline E

2005-03-15

5 alpha-Pregnan-3 alpha-ol-20-one (3 alpha,5 alpha-THP), progesterone (P4)'s 5 alpha-reduced, 3 alpha-hydroxysteroid oxidoreduced product, facilitates lordosis of rodents in part via agonist-like actions at GABA(A)/benzodiazepine receptor complexes in the ventral tegmental area (VTA). Whether 3 alpha,5 alpha-THP influences another reproductively-relevant behavior, lateral displacement, of hamsters was investigated. Lateral displacement is the movement that female hamsters make with their perineum towards male-like tactile stimulation. This behavior facilitates, and is essential for, successful mating. Hamsters in behavioral estrus had greater lateral displacement responses when endogenous progestin levels were elevated compared to when progestin levels were lower. Administration of P4, a prohormone for 3 alpha,5 alpha-THP, dose-dependently (500 > 200 > 100, 50, or 0 microg) enhanced lateral displacement of ovariectomized hamsters that had been primed with SC estradiol benzoate (5 or 10 microg). Inhibiting P4's metabolism to 3 alpha,5 alpha-THP by co-administering finasteride, a 5 alpha-reductase inhibitor, or indomethacin, a 3 alpha-hydroxysteroid oxidoreductase inhibitor, either systemically or to the VTA, significantly decreased lateral displacement and midbrain progestin levels of naturally receptive or hormone-primed hamsters compared to controls. These data suggest that lateral displacement is progestin-sensitive and requires the formation of 3 alpha,5 alpha-THP in the midbrain VTA.

Rate of displacement for Jakob Type 1 lateral condyle fractures treated with a cast.

PubMed

Zale, C; Winthrop, Z A; Hennrikus, W

2018-04-01

The aim of this retrospective study is to report the rate of displacement of Jakob Type 1 lateral condyle fractures that were initially treated in a cast. We performed a retrospective review of all patients that were treated for a non-displaced (Jakob Type 1 < 2 mm) lateral condyle fracture of the humerus at our institution between 2002 and 2015. A total of 59 patients were initially treated with casting. Five fractures displaced and were converted to a closed pinning treatment plan with a conversion rate of 8.5%. There was a mean of 13.2 days (4 to 21) between treatment by initial casting and closed pinning. This study demonstrates an 8.5% displacement and conversion rate from cast treatment to closed pinning for initially non-displaced Jakob Type 1 lateral condyle fractures of the humerus. The internal oblique radiograph is most accurate to determine displacement. We recommend obtaining an internal oblique view at initial evaluation and at follow-up in the cast for lateral condyle fractures. To minimize movement at the fracture site, we recommend treating Jakob Type 1 lateral condyle fractures with a long arm cast with the elbow at 90° and the forearm in the supine position with a sling-loop design. IV - retrospective therapeutic study.

Competing edge networks

NASA Astrophysics Data System (ADS)

Parsons, Mark; Grindrod, Peter

2012-06-01

We introduce a model for a pair of nonlinear evolving networks, defined over a common set of vertices, subject to edgewise competition. Each network may grow new edges spontaneously or through triad closure. Both networks inhibit the other's growth and encourage the other's demise. These nonlinear stochastic competition equations yield to a mean field analysis resulting in a nonlinear deterministic system. There may be multiple equilibria; and bifurcations of different types are shown to occur within a reduced parameter space. This situation models competitive communication networks such as BlackBerry Messenger displacing SMS; or instant messaging displacing emails.

Increasing Accuracy of Tissue Shear Modulus Reconstruction Using Ultrasonic Strain Tensor Measurement

NASA Astrophysics Data System (ADS)

Sumi, C.

Previously, we developed three displacement vector measurement methods, i.e., the multidimensional cross-spectrum phase gradient method (MCSPGM), the multidimensional autocorrelation method (MAM), and the multidimensional Doppler method (MDM). To increase the accuracies and stabilities of lateral and elevational displacement measurements, we also developed spatially variant, displacement component-dependent regularization. In particular, the regularization of only the lateral/elevational displacements is advantageous for the lateral unmodulated case. The demonstrated measurements of the displacement vector distributions in experiments using an inhomogeneous shear modulus agar phantom confirm that displacement-component-dependent regularization enables more stable shear modulus reconstruction. In this report, we also review our developed lateral modulation methods that use Parabolic functions, Hanning windows, and Gaussian functions in the apodization function and the optimized apodization function that realizes the designed point spread function (PSF). The modulations significantly increase the accuracy of the strain tensor measurement and shear modulus reconstruction (demonstrated using an agar phantom).

Microfluidic, marker-free isolation of circulating tumor cells from blood samples

PubMed Central

Karabacak, Nezihi Murat; Spuhler, Philipp S; Fachin, Fabio; Lim, Eugene J; Pai, Vincent; Ozkumur, Emre; Martel, Joseph M; Kojic, Nikola; Smith, Kyle; Chen, Pin-i; Yang, Jennifer; Hwang, Henry; Morgan, Bailey; Trautwein, Julie; Barber, Thomas A; Stott, Shannon L; Maheswaran, Shyamala; Kapur, Ravi; Haber, Daniel A; Toner, Mehmet

2014-01-01

The ability to isolate and analyze rare circulating tumor cells (CTCs) has the potential to further our understanding of cancer metastasis and enhance the care of cancer patients. In this protocol, we describe the procedure for isolating rare CTCs from blood samples by using tumor antigen–independent microfluidic CTC-iChip technology. The CTC-iChip uses deterministic lateral displacement, inertial focusing and magnetophoresis to sort up to 107 cells/s. By using two-stage magnetophoresis and depletion antibodies against leukocytes, we achieve 3.8-log depletion of white blood cells and a 97% yield of rare cells with a sample processing rate of 8 ml of whole blood/h. The CTC-iChip is compatible with standard cytopathological and RNA-based characterization methods. This protocol describes device production, assembly, blood sample preparation, system setup and the CTC isolation process. Sorting 8 ml of blood sample requires 2 h including setup time, and chip production requires 2–5 d. PMID:24577360

Radiography versus computed tomography for displacement assessment in calcaneal fractures.

PubMed

Ogawa, Brent K; Charlton, Timothy P; Thordarson, David B

2009-10-01

Coronal computed tomography (CT) scans are commonly used in fracture classification systems for calcaneus fractures. However, they may not accurately reflect the amount of fracture displacement. The purpose of this paper was to determine whether lateral radiographs provide superior assessment of the displacement of the posterior facet compared to coronal CT scans. Lateral radiographs of calcaneus fractures were compared with CT coronal images of the posterior facet in 30 displaced intra-articular calcaneus fractures. The average patient age was 39 years old. Using a Picture Archiving and Communication System (PACS), measurements were obtained to quantify the amount of displacement on the lateral radiograph and compared with the amount of depression on corresponding coronal CT scans. On lateral radiographs, the angle of the depressed portion of the posterior facet relative to the undersurface of the calcaneus averaged 28.2 degrees; Bohler's angle averaged 12.7 degrees. These numbers were poorly correlated (r = 0.25). In corresponding CT images from posterior to anterior, the difference in the amount of displacement of the lateral portion of the displaced articular facet versus the nondisplaced medial, constant fragment, was minimal and consistently underestimated the amount of displacement. Underestimation of the amount of depression and rotation of the posterior facet fragment was seen on the coronal CT scan. We attribute this finding to the combined rotation and depression of the posterior facet which may not be measured accurately with the typical semicoronal CT orientation. While sagittal reconstructed images would show this depression better, if they are unavailable we recommend using lateral radiographs to better gauge the amount of fracture displacement.

Levitation and lateral forces between a point magnetic dipole and a superconducting sphere

NASA Astrophysics Data System (ADS)

H, M. Al-Khateeb; M, K. Alqadi; F, Y. Alzoubi; B, Albiss; M, K. Hasan (Qaseer; N, Y. Ayoub

2016-05-01

The dipole-dipole interaction model is employed to investigate the angular dependence of the levitation and lateral forces acting on a small magnet in an anti-symmetric magnet/superconducting sphere system. Breaking the symmetry of the system enables us to study the lateral force which is important in the stability of the magnet above a superconducting sphere in the Meissner state. Under the assumption that the lateral displacement of the magnet is small compared to the physical dimensions of our proposed system, analytical expressions are obtained for the levitation and lateral forces as a function of the geometrical parameters of the superconductor as well as the height, the lateral displacement, and the orientation of the magnetic moment of the magnet. The dependence of the levitation force on the height of the levitating magnet is similar to that in the symmetric magnet/superconducting sphere system within the range of proposed lateral displacements. It is found that the levitation force is linearly dependent on the lateral displacement whereas the lateral force is independent of this displacement. A sinusoidal variation of both forces as a function of the polar and azimuthal angles specifying the orientation of the magnetic moment is observed. The relationship between the stability and the orientation of the magnetic moment is discussed for different orientations.

Borehole optical lateral displacement sensor

DOEpatents

Lewis, R.E.

1998-10-20

There is provided by this invention an optical displacement sensor that utilizes a reflective target connected to a surface to be monitored to reflect light from a light source such that the reflected light is received by a photoelectric transducer. The electric signal from the photoelectric transducer is then imputed into electronic circuitry to generate an electronic image of the target. The target`s image is monitored to determine the quantity and direction of any lateral displacement in the target`s image which represents lateral displacement in the surface being monitored. 4 figs.

Accuracy of radiographs in assessment of displacement in lateral humeral condyle fractures.

PubMed

Knutsen, Ashleen; Avoian, Tigran; Borkowski, Sean L; Ebramzadeh, Edward; Zionts, Lewis E; Sangiorgio, Sophia N

2014-02-01

Determining the magnitude of displacement in pediatric lateral humeral condyle fractures can be difficult. The purpose of this study was to (1) assess the effect of forearm rotation on true fracture displacement using a cadaver model and to (2) determine the accuracy of radiographic measurements of the fracture gap. A non-displaced fracture was created in three human cadaveric arms. The specimens were mounted on a custom apparatus allowing forearm rotation with the humerus fixed. First, the effect of pure rotation on fracture displacement was simulated by rotating the forearm from supination to pronation about the central axis of the forearm, to isolate the effects of muscle pull. Then, the clinical condition of obtaining a lateral oblique radiograph was simulated by rotating the forearm about the medial aspect of the forearm. Fracture displacements were measured using a motion-capture system (true-displacement) and clinical radiographs (apparent-displacement). During pure rotation of the forearm, there were no significant differences in fracture displacement between supination and pronation, with changes in displacement of <1.0 mm. During rotation about the medial aspect of the forearm, there was a significant difference in true displacements between supination and pronation at the posterior edge (p < 0.05). Overall, true fracture displacement measurements were larger than apparent radiographic displacement measurements, with differences from 1.6 to 6.0 mm, suggesting that the current clinical methods may not be sensitive enough to detect a displacement of 2.0 mm, especially when positioning the upper extremity for an internal oblique lateral radiograph.

Paediatric lateral humeral condyle fractures: internal oblique radiographs alter the course of conservative treatment.

PubMed

Kurtulmuş, Tuhan; Sağlam, Necdet; Saka, Gursel; Avcı, Cem Coşkun; Uğurlar, Meriç; Türker, Mehmet

2014-10-01

At first presentation of paediatric humeral lateral condyle fractures, radiological methods such as computerised tomography, ultrasonography, magnetic resonance imaging, arthrography, and internal oblique radiography are used to determine stability. Very few studies show which radiological method should be used to evaluate displacement at follow-up for conservatively treated patients. This study aimed to show that internal oblique radiography is a simple, effective method to determine the subsequent development of fracture displacement in patients with an initially non-displaced or minimally displaced fracture. In this retrospective study, 27 paediatric patients with non-displaced or minimally displaced (<2 mm) humerus lateral condyle fracture were evaluated by elbow anteroposterior radiograph. The degree of fracture displacement was evaluated by anteroposterior then by internal oblique radiographs. The first follow-up was made between the 5th and 8th day and thereafter at intervals of 7-10 days. Of the 27 patients identified with non-displaced or minimally displaced (<2 mm) fracture from the initial anteroposterior radiograph, 16 were accepted as displacement >2 mm as a result of the evaluation of the internal oblique radiography and underwent surgery. At follow-up, 2 of 11 patients were defined with displacement from anteroposterior and internal oblique radiographs and 4 from the internal oblique radiographs and underwent surgery. Conservative treatment was applied to 5 patients. Internal oblique radiography is the best imaging showing subsequent fracture displacement in initially non-displaced or minimally displaced humerus lateral condyle fractures. At the first week follow-up, anteroposterior and particularly internal oblique radiographs should be taken of conservatively treated patients.

Comparing mode-crosstalk and mode-dependent loss of laterally displaced orbital angular momentum and Hermite-Gaussian modes for free-space optical communication.

PubMed

Ndagano, Bienvenu; Mphuthi, Nokwazi; Milione, Giovanni; Forbes, Andrew

2017-10-15

There is interest in using orbital angular momentum (OAM) modes to increase the data speed of free-space optical communication. A prevalent challenge is the mitigation of mode-crosstalk and mode-dependent loss that is caused by the modes' lateral displacement at the data receiver. Here, the mode-crosstalk and mode-dependent loss of laterally displaced OAM modes (LG 0,+1 , LG 0,-1 ) are experimentally compared to that of a Hermite-Gaussian (HG) mode subset (HG 0,1 , HG 1,0 ). It is shown, for an aperture larger than the modes' waist sizes, some of the HG modes can experience less mode-crosstalk and mode-dependent loss when laterally displaced along a symmetry axis. It is also shown, over a normal distribution of lateral displacements whose standard deviation is 2× the modes' waist sizes, on average, the HG modes experience 66% less mode-crosstalk and 17% less mode-dependent loss.

How much articular displacement can be detected using fluoroscopy for tibial plateau fractures?

PubMed

Haller, Justin M; O'Toole, Robert; Graves, Matthew; Barei, David; Gardner, Michael; Kubiak, Erik; Nascone, Jason; Nork, Sean; Presson, Angela P; Higgins, Thomas F

2015-11-01

While there is conflicting evidence regarding the importance of anatomic reduction for tibial plateau fractures, there are currently no studies that analyse our ability to grade reduction based on fluoroscopic imaging. The purpose of this study was to determine the accuracy of fluoroscopy in judging tibial plateau articular reduction. Ten embalmed human cadavers were selected. The lateral plateau was sagitally sectioned, and the joint was reduced under direct visualization. Lateral, anterior-posterior (AP), and joint line fluoroscopic views were obtained. The same fluoroscopic views were obtained with 2mm displacement and 5mm displacement. The images were randomised, and eight orthopaedic traumatologists were asked whether the plateau was reduced. Within each pair of conditions (view and displacement from 0mm to 5mm) sensitivity, specificity, and intraclass correlations (ICC) were evaluated. The AP-lateral view with 5mm displacement yielded the highest accuracy for detecting reduction at 90% (95% CI: 83-94%). For the other conditions, accuracy ranged from (37-83%). Sensitivity was highest for the reduced lateral view (79%, 95% CI: 57-91%). Specificity was highest in the AP-lateral view 98% (95% CI: 93-99%) for 5mm step-off. ICC was perfect for the AP-lateral view with 5mm displacement, but otherwise agreement ranged from poor to moderate at ICC=0.09-0.46. Finally, there was no additional benefit to including the joint-line view with the AP and lateral views. Using both AP and lateral views for 5mm displacement had the highest accuracy, specificity, and ICC. Outside of this scenario, agreement was poor to moderate and accuracy was low. Applying this clinically, direct visualization of the articular surface may be necessary to ensure malreduction less than 5mm. Copyright © 2015 Elsevier Ltd. All rights reserved.

Robot-aided in vitro measurement of patellar stability with consideration to the influence of muscle loading.

PubMed

Lorenz, Andrea; Bobrowitsch, Evgenij; Wünschel, Markus; Walter, Christian; Wülker, Nikolaus; Leichtle, Ulf G

2015-07-23

Anterior knee pain is often associated with patellar maltracking and instability. However, objective measurement of patellar stability under clinical and experimental conditions is difficult, and muscular activity influences the results. In the present study, a new experimental setting for in vitro measurement of patellar stability was developed and the mediolateral force-displacement behavior of the native knee analyzed with special emphasis on patellar tilt and muscle loading. In the new experimental setup, two established testing methods were combined: an upright knee simulator for positioning and loading of the knee specimens, and an industry robot for mediolateral patellar displacement. A minimally invasive coupling and force control mechanism enabled unconstrained motion of the patella as well as measurement of patellar motion in all six degrees of freedom via an external ultrasonic motion-tracking system. Lateral and medial patellar displacement were measured on seven fresh-frozen human knee specimens in six flexion angles with varying muscle force levels, muscle force distributions, and displacement forces. Substantial repeatability was achieved for patellar shift (ICC(3,1) = 0.67) and tilt (ICC(3,1) = 0.75). Patellar lateral and medial shift decreased slightly with increasing flexion angle. Additional measurement of patellar tilt provided interesting insights into the different displacement mechanisms in lateral and medial directions. For lateral displacement, the patella tilted in the same (lateral) direction, and tilted in the opposite direction (again laterally) for medial displacement. With regard to asymmetric muscle loading, a significant influence (p < 0.03, up to 5 mm shift and 8° tilt) was found for lateral displacement and a reasonable relationship between muscle and patellar force, whereas no effect was visible in the medial direction. The developed experimental setup delivered reproducible results and was found to be an excellent testing method for the in vitro analysis of patellar stability and future investigation of surgical techniques for patellar stabilization and total knee arthroplasty. We demonstrated a significant influence of asymmetric quadriceps loading on patellar stability. In particular, increased force application on the vastus lateralis muscle led to a clear increase of lateral patellar displacement.

Effect of Uncertainty on Deterministic Runway Scheduling

NASA Technical Reports Server (NTRS)

Gupta, Gautam; Malik, Waqar; Jung, Yoon C.

2012-01-01

Active runway scheduling involves scheduling departures for takeoffs and arrivals for runway crossing subject to numerous constraints. This paper evaluates the effect of uncertainty on a deterministic runway scheduler. The evaluation is done against a first-come- first-serve scheme. In particular, the sequence from a deterministic scheduler is frozen and the times adjusted to satisfy all separation criteria; this approach is tested against FCFS. The comparison is done for both system performance (throughput and system delay) and predictability, and varying levels of congestion are considered. The modeling of uncertainty is done in two ways: as equal uncertainty in availability at the runway as for all aircraft, and as increasing uncertainty for later aircraft. Results indicate that the deterministic approach consistently performs better than first-come-first-serve in both system performance and predictability.

Insights on surface spalling of rock

NASA Astrophysics Data System (ADS)

Tarokh, Ali; Kao, Chu-Shu; Fakhimi, Ali; Labuz, Joseph F.

2016-07-01

Surface spalling is a complex failure phenomenon that features crack propagation and detachment of thin pieces of rock near free surfaces, particularly in brittle rock around underground excavations when large in situ stresses are involved. A surface instability apparatus was used to study failure of rock close to a free surface, and damage evolution was monitored by digital image correlation (DIC). Lateral displacement at the free face was used as the feedback signal to control the post-peak response of the specimen. DIC was implemented in order to obtain the incremental displacement fields during the spalling process. Displacement fields were computed in the early stage of loading as well as close to the peak stress. Fracture from the spalling phenomenon was revealed by incremental lateral displacement contours. The axial and lateral displacements suggested that the displacement gradient was uniform in both directions at early loading stages and as the load increased, the free-face effect started to influence the displacements, especially the lateral displacement field. A numerical approach, based on the discrete element method, was developed and validated from element testing. Damage evolution and localization observed in numerical simulations were similar to those observed in experiments. By performing simulations in two- and three-dimensions, it was revealed that the intermediate principal stress and platen-rock interfaces have important effects on simulation of surface spalling.

Effect of posterior cruciate ligament rupture on the radial displacement of lateral meniscus.

PubMed

Lei, Pengfei; Sun, Rongxin; Hu, Yihe; Li, Kanghua; Liao, Zhan

2015-06-01

The relationship between lateral meniscus tear and posterior cruciate ligament injury is not well understood. The present study aims to investigate and assess the effect of posterior cruciate ligament rupture on lateral meniscus radial displacement at different flexion angles under static loading conditions. Twelve fresh human cadaveric knee specimens were divided into four groups such as posterior cruciate ligament intact, anterolateral band rupture, posteromedial band rupture and posterior cruciate ligament complete rupture groups, according to the purpose and order of testing. Radial displacement of lateral meniscus was measured under different loads (200-1000N) at 0°, 30°, 60°, and 90° of knee flexion. Compared with posterior cruciate ligament intact group, the displacement values of lateral meniscus in anterolateral band rupture group increased at 0° flexion with 600N, 800N, and 1000N and at 30°, 60° and 90° flexion under all loading conditions. Posteromedial band rupture group exhibited higher displacement at 0° flexion under all loading conditions, at 30° and 60° flexion with 600, 800N and 1000N, and at 90° flexion with 400N, 600N, 800N, and 1000N than the posterior cruciate ligament intact group. The posterior cruciate ligament complete rupture group had a higher displacement value of lateral medial meniscus at 0°, 30°, 60° and 90° flexion under all loading conditions, as compared to the posterior cruciate ligament intact group. The study concludes that partial and complete rupture of the posterior cruciate ligament can trigger the increase of radial displacement on lateral meniscus. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nonclassical point of view of the Brownian motion generation via fractional deterministic model

NASA Astrophysics Data System (ADS)

Gilardi-Velázquez, H. E.; Campos-Cantón, E.

In this paper, we present a dynamical system based on the Langevin equation without stochastic term and using fractional derivatives that exhibit properties of Brownian motion, i.e. a deterministic model to generate Brownian motion is proposed. The stochastic process is replaced by considering an additional degree of freedom in the second-order Langevin equation. Thus, it is transformed into a system of three first-order linear differential equations, additionally α-fractional derivative are considered which allow us to obtain better statistical properties. Switching surfaces are established as a part of fluctuating acceleration. The final system of three α-order linear differential equations does not contain a stochastic term, so the system generates motion in a deterministic way. Nevertheless, from the time series analysis, we found that the behavior of the system exhibits statistics properties of Brownian motion, such as, a linear growth in time of mean square displacement, a Gaussian distribution. Furthermore, we use the detrended fluctuation analysis to prove the Brownian character of this motion.

Experimental Validation of Displacement Underestimation in ARFI Ultrasound

PubMed Central

Czernuszewicz, Tomasz J.; Streeter, Jason E.; Dayton, Paul A.; Gallippi, Caterina M.

2014-01-01

Acoustic radiation force impulse (ARFI) imaging is an elastography technique that uses ultrasonic pulses to both displace and track tissue motion. Previous modeling studies have shown that ARFI displacements are susceptible to underestimation due to lateral and elevational shearing that occurs within the tracking resolution cell. In this study, optical tracking was utilized to experimentally measure the displacement underestimation achieved by acoustic tracking using a clinical ultrasound system. Three optically translucent phantoms of varying stiffness were created, embedded with sub-wavelength diameter microspheres, and ARFI excitation pulses with F/1.5 or F/3 lateral focal configurations were transmitted from a standard linear array to induce phantom motion. Displacements were tracked using confocal optical and acoustic methods. As predicted by earlier FEM studies, significant acoustic displacement underestimation was observed for both excitation focal configurations; the maximum underestimation error was 35% of the optically measured displacement for the F/1.5 excitation pulse in the softest phantom. Using higher F/#, less tightly focused beams in the lateral dimension improved accuracy of displacements by approximately 10 percentage points. This work experimentally demonstrates limitations of ARFI implemented on a clinical scanner using a standard linear array and sets up a framework for future displacement tracking validation studies. PMID:23858054

The effect of complete radial lateral meniscus posterior root tear on the knee contact mechanics: a finite element analysis.

PubMed

Bao, H R C; Zhu, D; Gong, H; Gu, G S

2013-03-01

In recent years, with technological advances in arthroscopy and magnetic resonance imaging and improved biomechanical studies of the meniscus, there has been some progress in the diagnosis and treatment of injuries to the roots of the meniscus. However, the biomechanical effect of posterior lateral meniscus root tears on the knee has not yet become clear. The purpose of this study was to determine the effect of a complete radial posterior lateral meniscus root tear on the knee contact mechanics and the function of the posterior meniscofemoral ligament on the knee with tear in the posterior root of lateral meniscus. A finite element model of the knee was developed to simulate different cases for intact knee, a complete radial posterior lateral meniscus root tear, a complete radial posterior lateral meniscus root tear with posterior meniscofemoral ligament deficiency, and total meniscectomy of the lateral meniscus. A compressive load of 1000 N was applied in all cases to calculate contact areas, contact pressure, and meniscal displacements. The complete radial posterior lateral meniscus root tear decreased the contact area and increased the contact pressure on the lateral compartment under compressive load. We also found a decreased contact area and increased contact pressure in the medial compartment, but it was not obvious compared to the lateral compartment. The lateral meniscus was radially displaced by compressive load after a complete radial posterior lateral meniscus root tear, and the displacement took place mainly in the body and posterior horn of lateral meniscus. There were further decrease in contact area and increases in contact pressure and raidial displacement of the lateral meniscus in the case of the complete posterior lateral meniscus root tear in combination with posterior meniscofemoral ligament deficiency. Complete radial posterior lateral meniscus root tear is not functionally equivalent to total meniscectomy. The posterior root torn lateral meniscus continues to provide some load transmission and distribution functions across the joint. The posterior meniscofemoral ligament prevents excessive radial displacement of the posterior root torn lateral meniscus and assists the torn lateral meniscus in transmitting a certain amount of stress in the lateral compartment.

A novel Sagnac imaging polarization spectrometer

NASA Astrophysics Data System (ADS)

Gao, Peng; Ai, Jingjing; Wang, Xia; Zhang, Chunmin

2017-06-01

A novel Sagnac imaging polarization spectrometer based on a modified Sagnac interferometer (MSI) with a moving wedge prism is proposed in this paper, and it is a framing instrument with the advantages of miniaturization, variable optical path difference (OPD) and large field of view. The construction and split-beam principle of the system are described detailedly, and the exact expressions of the OPD and lateral displacement changing with different parameters are obtained. The variations of the OPD and lateral displacement as a function of the wedge angle and moving displacement are simulated, and the influences of the wedge angle on the OPD and lateral displacement are very small, while most effects come from the moving displacement. In order to obtain a larger OPD and lateral displacement, the wedge angle is controlled in a range of [ 45 ° , 50 ° ] . In addition, the influences of the dispersion effect of the glass plate on the OPD and lateral displacement are analyzed and discussed, and the suitable material choice for the MSI can reduce the influence of the dispersion effect on the OPD, which also allows the system construction spanning the spectral range of [480 nm, 960 nm]. In comparison with the conventional Sagnac interferometer with a large optical path difference (LOPDSI), the spectral resolution of the MSI can be made much higher if choosing suitable parameters. This study provides a theoretical and practical guidance for the design and engineering of the Sagnac imaging polarization spectrometer.

Remagnetization effects due to lateral displacement above a PMG on bulk HTS magnet

NASA Astrophysics Data System (ADS)

Liu, W.; Wang, J. S.; Ma, G. T.; Zheng, J.; Ren, J. F.; Li, L. L.; Yang, X. F.; Ye, C. Q.; Wang, S. Y.

2012-12-01

For a high-Tc superconducting (HTS) maglev system with large force requirements, the use of magnetized bulk high-Tc superconductor magnets (MBSCMs) is a good candidate because of its strong flux pinning ability and corresponding high trapped flux. Different from the rare-earth permanent magnet (PM), the trapped flux of a MBSCM is sustained by the supercurrent produced by a magnetizing process, so the trapped flux is sensitive to variations of the supercurrent. The lateral displacement of a MBSCM above a PM guideway (PMG) will provide disturbance of the applied field and then alter the supercurrent as a process of remagnetization. Different magnetization histories will bring different remagnetization characteristics and consequently diverse levitation performances for a MBSCM during the lateral displacements. When the MBSCMs are applied into the HTS maglev system, the influence of lateral displacements on levitation performance should be taken into consideration. This article investigates the remagnetization characteristics of a MBSCM when it is subject to the lateral displacements above a PMG with different trapped magnetic flux and opposite magnetization polarities. Relevant analyses about the internal supercurrent configuration based on the critical state model are also included to better understand the remagnetization characteristic of a MBSCM.

Fractionation of Exosomes and DNA using Size-Based Separation at the Nanoscale

NASA Astrophysics Data System (ADS)

Wunsch, Benjamin; Smith, Joshua; Wang, Chao; Gifford, Stacey; Brink, Markus; Bruce, Robert; Solovitzky, Gustavo; Austin, Robert; Astier, Yann

Exosomes, a key target of ``liquid biopsies'', are nano-vesicles found in nearly all biological fluids. Exosomes are secreted by eukaryotic and prokaryotic cells alike, and contain information about their originating cells, including surface proteins, cytoplasmic proteins, and nucleic acids. One challenge in studying exosome morphology is the difficulty of sorting exosomes by size and surface markers. Common separation techniques for exosomes include ultracentrifugation and ultrafiltration, for preparation of large volume samples, but these techniques often show contamination and significant heterogeneity between preparations. To date, deterministic lateral displacement (DLD) pillar arrays in silicon have proven an efficient technology to sort, separate, and enrich micron-scale particles including human parasites, eukaryotic cells, blood cells, and circulating tumor cells in blood; however, the DLD technology has never been translated to the true nanoscale, where it could function on bio-colloids such as exosomes. We have fabricated nanoscale DLD (nanoDLD) arrays capable of rapidly sorting colloids down to 20 nm in continuous flow, and demonstrated size sorting of individual exosome vesicles and dsDNA polymers, opening the potential for on-chip biomolecule separation and diagnosti

Does C₁ fracture displacement correlate with transverse ligament integrity?

PubMed

Radcliff, Kristen E; Sonagli, Marcos A; Rodrigues, Luciano M; Sidhu, Gursukhman S; Albert, Todd J; Vaccaro, Alexander R

2013-05-01

The Rule of Spence states that displacement of the C₁ lateral masses by >6.9-8.1 mm suggests loss of transverse ligament integrity. The purpose of this study was to establish the thresholds of C₁ displacement on CT scans that correspond to transverse ligament disruption. Over four years, consecutive patients with acute C₁ fractures with at least three fracture lines were analyzed. CT measurements and MRI were assessed by blinded observers for bony displacement in the axial (internal and external lateral mass separation), coronal and sagittal planes and transverse ligament integrity. Eighteen patients were studied. Mean CT bony measurements were as follows: internal border lateral mass separation (ILM) 23.3 ± 3.4 mm, external border lateral mass separation (ELM) 50.3 ± 4.3 mm, total C₁ lateral mass overhang over the C₂ superior process (LMO) 5.4 ± 1.3 mm. Twelve patients were identified as having intact transverse ligament and six had transverse ligament disruption. There was no difference in mean normalized ILM, ELM, or LMO between patients with or without transverse ligament integrity (P > 0.05). There was no correlation between bony displacement and transverse ligament integrity. CT scans post-injury may not show the position of maximal displacement. If there is clinical concern about a possible transverse ligament injury, MRI should be performed. © 2013 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd.

On- and off-fault deformation associated with the September 2013 Mw7.7 Balochistan earthquake: implications for geologic slip rate measurements

USGS Publications Warehouse

Gold, Ryan D.; Reitman, Nadine G.; Briggs, Richard; Barnhart, William; Hayes, Gavin; Wilson, Earl M.

2015-01-01

The 24 September 2013 Mw7.7 Balochistan, Pakistan earthquake ruptured a ~ 200 km-long stretch of the Hoshab fault in southern Pakistan and produced the second-largest lateral surface displacement observed for a continental strike-slip earthquake. We remotely measured surface deformation associated with this event using high-resolution (0.5 m) pre- and post-event satellite optical imagery. We document left lateral, near-field, on-fault offsets (10 m from fault) using 309 laterally offset piercing points, such as streams, terrace risers, and roads. Peak near-field displacement is 13.6 + 2.5/− 3.4 m. We characterize off-fault deformation by measuring medium- (< 350 m from fault) and far-field (> 350 m from fault) displacement using manual (259 measurements) and automated image cross-correlation methods, respectively. Off-fault peak lateral displacement values are ~ 15 m and exceed on-fault displacement magnitudes for ~ 85% of the rupture length. Our observations suggest that for this rupture, coseismic surface displacement typically increases with distance away from the surface trace of the fault; however, nearly 100% of total surface displacement occurs within a few hundred meters of the primary fault trace. Furthermore, off-fault displacement accounts for, on average, 28% of the total displacement but exhibits a highly heterogeneous along-strike pattern. The best agreement between near-field and far-field displacements generally corresponds to the narrowest fault zone widths. Our analysis demonstrates significant and heterogeneous mismatches between on- and off-fault coseismic deformation, and we conclude that this phenomenon should be considered in hazard models based on geologically determined on-fault slip rates.

On- and off-fault deformation associated with the September 2013 Mw 7.7 Balochistan earthquake: Implications for geologic slip rate measurements

NASA Astrophysics Data System (ADS)

Gold, Ryan D.; Reitman, Nadine G.; Briggs, Richard W.; Barnhart, William D.; Hayes, Gavin P.; Wilson, Earl

2015-10-01

The 24 September 2013 Mw7.7 Balochistan, Pakistan earthquake ruptured a ~ 200 km-long stretch of the Hoshab fault in southern Pakistan and produced the second-largest lateral surface displacement observed for a continental strike-slip earthquake. We remotely measured surface deformation associated with this event using high-resolution (0.5 m) pre- and post-event satellite optical imagery. We document left lateral, near-field, on-fault offsets (10 m from fault) using 309 laterally offset piercing points, such as streams, terrace risers, and roads. Peak near-field displacement is 13.6 + 2.5/- 3.4 m. We characterize off-fault deformation by measuring medium- (< 350 m from fault) and far-field (> 350 m from fault) displacement using manual (259 measurements) and automated image cross-correlation methods, respectively. Off-fault peak lateral displacement values are ~ 15 m and exceed on-fault displacement magnitudes for ~ 85% of the rupture length. Our observations suggest that for this rupture, coseismic surface displacement typically increases with distance away from the surface trace of the fault; however, nearly 100% of total surface displacement occurs within a few hundred meters of the primary fault trace. Furthermore, off-fault displacement accounts for, on average, 28% of the total displacement but exhibits a highly heterogeneous along-strike pattern. The best agreement between near-field and far-field displacements generally corresponds to the narrowest fault zone widths. Our analysis demonstrates significant and heterogeneous mismatches between on- and off-fault coseismic deformation, and we conclude that this phenomenon should be considered in hazard models based on geologically determined on-fault slip rates.

Biomechanical mechanism of lateral trunk lean gait for knee osteoarthritis patients.

PubMed

Tokuda, Kazuki; Anan, Masaya; Takahashi, Makoto; Sawada, Tomonori; Tanimoto, Kenji; Kito, Nobuhiro; Shinkoda, Koichi

2018-01-03

The biomechanical mechanism of lateral trunk lean gait employed to reduce external knee adduction moment (KAM) for knee osteoarthritis (OA) patients is not well known. This mechanism may relate to the center of mass (COM) motion. Moreover, lateral trunk lean gait may affect motor control of the COM displacement. Uncontrolled manifold (UCM) analysis is an evaluation index used to understand motor control and variability of the motor task. Here we aimed to clarify the biomechanical mechanism to reduce KAM during lateral trunk lean gait and how motor variability controls the COM displacement. Twenty knee OA patients walked under two conditions: normal and lateral trunk lean gait conditions. UCM analysis was performed with respect to the COM displacement in the frontal plane. We also determined how the variability is structured with regards to the COM displacement as a performance variable. The peak KAM under lateral trunk lean gait was lower than that under normal gait. The reduced peak KAM observed was accompanied by medially shifted knee joint center, shortened distance of the center of pressure to knee joint center, and shortened distance of the knee-ground reaction force lever arm during the stance phase. Knee OA patients with lateral trunk lean gait could maintain kinematic synergy by utilizing greater segmental configuration variance to the performance variable. However, the COM displacement variability of lateral trunk lean gait was larger than that of normal gait. Our findings may provide clinical insights to effectively evaluate and prescribe gait modification training for knee OA patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Is fibular fracture displacement consistent with tibiotalar displacement?

PubMed

van den Bekerom, Michel P J; van Dijk, C Niek

2010-04-01

We believed open reduction with internal fixation is required for supination-external rotation ankle fractures located at the level of the distal tibiofibular syndesmosis (Lauge-Hanssen SER II and Weber B) with 2 mm or more fibular fracture displacement. The rationale for surgery for these ankle fractures is based on the notion of elevated intraarticular contact pressures with lateral displacement. To diagnose these injuries, we presumed that in patients with a fibular fracture with at least 2 mm fracture displacement, the lateral malleolus and talus have moved at least 2 mm in a lateral direction without medial displacement of the proximal fibula. We reviewed 55 adult patients treated operatively for a supination-external rotation II ankle fracture (2 mm or more fibular fracture displacement) between 1990 and 1998. On standard radiographs, distance from the tibia to the proximal fibula, distance from the tibia to the distal fibula, and displacement at the level of the fibular fracture were measured. These distances were compared preoperatively and postoperatively. We concluded tibiotalar displacement cannot be reliably assessed at the level of the fracture. Based on this and other studies, we believe there is little evidence to perform open reduction and internal fixation of supination-external rotation II ankle fractures. Level IV, case series. See Guidelines for Authors for a complete description of levels of evidence.

({The) Solar System Large Planets influence on a new Maunder Miniμm}

NASA Astrophysics Data System (ADS)

Yndestad, Harald; Solheim, Jan-Erik

2016-04-01

In 1890´s G. Spörer and E. W. Maunder (1890) reported that the solar activity stopped in a period of 70 years from 1645 to 1715. Later a reconstruction of the solar activity confirms the grand minima Maunder (1640-1720), Spörer (1390-1550), Wolf (1270-1340), and the minima Oort (1010-1070) and Dalton (1785-1810) since the year 1000 A.D. (Usoskin et al. 2007). These minimum periods have been associated with less irradiation from the Sun and cold climate periods on Earth. An identification of a three grand Maunder type periods and two Dalton type periods in a period thousand years, indicates that sooner or later there will be a colder climate on Earth from a new Maunder- or Dalton- type period. The cause of these minimum periods, are not well understood. An expected new Maunder-type period is based on the properties of solar variability. If the solar variability has a deterministic element, we can estimate better a new Maunder grand minimum. A random solar variability can only explain the past. This investigation is based on the simple idea that if the solar variability has a deterministic property, it must have a deterministic source, as a first cause. If this deterministic source is known, we can compute better estimates the next expected Maunder grand minimum period. The study is based on a TSI ACRIM data series from 1700, a TSI ACRIM data series from 1000 A.D., sunspot data series from 1611 and a Solar Barycenter orbit data series from 1000. The analysis method is based on a wavelet spectrum analysis, to identify stationary periods, coincidence periods and their phase relations. The result shows that the TSI variability and the sunspots variability have deterministic oscillations, controlled by the large planets Jupiter, Uranus and Neptune, as the first cause. A deterministic model of TSI variability and sunspot variability confirms the known minimum and grand minimum periods since 1000. From this deterministic model we may expect a new Maunder type sunspot minimum period from about 2018 to 2055. The deterministic model of a TSI ACRIM data series from 1700 computes a new Maunder type grand minimum period from 2015 to 2071. A model of the longer TSI ACRIM data series from 1000 computes a new Dalton to Maunder type minimum irradiation period from 2047 to 2068.

Inverse kinematic problem for a random gradient medium in geometric optics approximation

NASA Astrophysics Data System (ADS)

Petersen, N. V.

1990-03-01

Scattering at random inhomogeneities in a gradient medium results in systematic deviations of the rays and travel times of refracted body waves from those corresponding to the deterministic velocity component. The character of the difference depends on the parameters of the deterministic and random velocity component. However, at great distances to the source, independently of the velocity parameters (weakly or strongly inhomogeneous medium), the most probable depth of the ray turning point is smaller than that corresponding to the deterministic velocity component, the most probable travel times also being lower. The relative uncertainty in the deterministic velocity component, derived from the mean travel times using methods developed for laterally homogeneous media (for instance, the Herglotz-Wiechert method), is systematic in character, but does not exceed the contrast of velocity inhomogeneities by magnitude. The gradient of the deterministic velocity component has a significant effect on the travel-time fluctuations. The variance at great distances to the source is mainly controlled by shallow inhomogeneities. The travel-time flucutations are studied only for weakly inhomogeneous media.

Analysis of stochastic model for non-linear volcanic dynamics

NASA Astrophysics Data System (ADS)

Alexandrov, D.; Bashkirtseva, I.; Ryashko, L.

2014-12-01

Motivated by important geophysical applications we consider a dynamic model of the magma-plug system previously derived by Iverson et al. (2006) under the influence of stochastic forcing. Due to strong nonlinearity of the friction force for solid plug along its margins, the initial deterministic system exhibits impulsive oscillations. Two types of dynamic behavior of the system under the influence of the parametric stochastic forcing have been found: random trajectories are scattered on both sides of the deterministic cycle or grouped on its internal side only. It is shown that dispersions are highly inhomogeneous along cycles in the presence of noises. The effects of noise-induced shifts, pressure stabilization and localization of random trajectories have been revealed with increasing the noise intensity. The plug velocity, pressure and displacement are highly dependent of noise intensity as well. These new stochastic phenomena are related with the nonlinear peculiarities of the deterministic phase portrait. It is demonstrated that the repetitive stick-slip motions of the magma-plug system in the case of stochastic forcing can be connected with drumbeat earthquakes.

Newly designed anterolateral and posterolateral locking anatomic plates for lateral tibial plateau fractures: a finite element study.

PubMed

Chen, Pengbo; Lu, Hua; Shen, Hao; Wang, Wei; Ni, Binbin; Chen, Jishizhan

2017-02-23

Lateral column tibial plateau fracture fixation with a locking screw plate has higher mechanical stability than other fixation methods. The objectives of the present study were to introduce two newly designed locking anatomic plates for lateral tibial plateau fracture and to demonstrate their characteristics of the fixation complexes under the axial loads. Three different 3D finite element models of the lateral tibial plateau fracture with the bone plates were created. Various axial forces (100, 500, 1000, and 1500 N) were applied to simulate the axial compressive load on an adult knee during daily life. The equivalent maps of displacement and stress were output, and relative displacement was calculated along the fracture lines. The displacement and stresses in the fixation complexes increased with the axial force. The equivalent displacement or stress map of each fixation under different axial forces showed similar distributing characteristics. The motion characteristics of the three models differed, and the max-shear stress of trabecula increased with the axial load. These two novel plates could fix lateral tibial plateau fractures involving anterolateral and posterolateral fragments. Motions after open reduction and stable internal fixation should be advised to decrease the risk of trabecular microfracture. The relative displacement of the posterolateral fragments is different when using anterolateral plate and posterolateral plate, which should be considered in choosing the implants for different posterolateral plateau fractures.

Examination of center of pressure displacement and muscle activity of the hip girdle muscles on lateral movement in the sitting position, focusing on kinematic features before and after the start of exercise.

PubMed

Ikeda, Kouji; Suehiro, Kenji; Kizu, Akito; Kunieda, Hideki; Takasaki, Hirokazu; Suzuki, Toshiaki

2017-03-01

[Purpose] This study aimed to evaluate the kinematic characteristics at the start of lateral movement in the sitting position, for application in physical therapy. [Subjects and Methods] Eleven healthy male subjects (mean age, 24.8 ± 3.7 years) were included in the study after they provided informed consent. The electromyographic activities of the tensor fascia lata, gluteus medius, and rectus femoris, and the center of pressure (COP) displacement during lateral reach in the sitting position were measured. The task was recorded on video for analysis. [Results] In almost all subjects, before the beginning of the task, the electromyographic activity in the opposite side of each studied muscle was recorded, and the opposite and anterior displacement of the COP was observed. The video analysis revealed that all subjects showed lateral displacement of the thoracic part of the trunk after the start of the task. However, the lumbar region and pelvis maintained their starting positions. [Conclusion] COP displacement occurred in the reverse reaction before the task, and this involved the hip girdle muscles of the opposite side. A reverse reaction displaced the pelvis to the opposite side to ensure instability of posture through side tilting of the trunk at the beginning of the task.

The relationship between resonance frequency analysis (RFA) and lateral displacement of dental implants: an in vitro study.

PubMed

Pagliani, L; Sennerby, L; Petersson, A; Verrocchi, D; Volpe, S; Andersson, P

2013-03-01

This in vitro investigation was conducted to study the relationship between resonance frequency analysis (RFA) and lateral displacement measurements of dental implants. A total of 30 implant sites were prepared in nine fresh bovine bone specimens. The bone density around each preparation was determined by using cone beam computerized tomography (CBCT) and imaging software. Dental implants were then inserted during continuous registration of insertion torque. RFA measurements were performed in perpendicular and parallel to the long axis of the specimens. The bone blocks were embedded in plaster and fixated in a specially designed rig for displacement measurements. A lateral force of 25 N was applied via an abutment perpendicular and parallel to each implant and the displacement measured in μm. In addition, a flex constant (μm N(-1) ) was calculated for each measurement. There was a significant inverse correlation between RFA and lateral implant displacement (μm) measurements and between RFA measurements and the flex constant in both perpendicular and parallel directions in bone (P ≤ 0·001). Moreover, both RFA and displacement measurements correlated with bone density (P ≤ 0·001). It is concluded that RFA measurements reflect the micromobility of dental implants, which in turn is determined by the bone density at the implant site. © 2012 Blackwell Publishing Ltd.

Examination of center of pressure displacement and muscle activity of the hip girdle muscles on lateral movement in the sitting position, focusing on kinematic features before and after the start of exercise

PubMed Central

Ikeda, Kouji; Suehiro, Kenji; Kizu, Akito; Kunieda, Hideki; Takasaki, Hirokazu; Suzuki, Toshiaki

2017-01-01

[Purpose] This study aimed to evaluate the kinematic characteristics at the start of lateral movement in the sitting position, for application in physical therapy. [Subjects and Methods] Eleven healthy male subjects (mean age, 24.8 ± 3.7 years) were included in the study after they provided informed consent. The electromyographic activities of the tensor fascia lata, gluteus medius, and rectus femoris, and the center of pressure (COP) displacement during lateral reach in the sitting position were measured. The task was recorded on video for analysis. [Results] In almost all subjects, before the beginning of the task, the electromyographic activity in the opposite side of each studied muscle was recorded, and the opposite and anterior displacement of the COP was observed. The video analysis revealed that all subjects showed lateral displacement of the thoracic part of the trunk after the start of the task. However, the lumbar region and pelvis maintained their starting positions. [Conclusion] COP displacement occurred in the reverse reaction before the task, and this involved the hip girdle muscles of the opposite side. A reverse reaction displaced the pelvis to the opposite side to ensure instability of posture through side tilting of the trunk at the beginning of the task. PMID:28356627

Influence of lateral displacement on the levitation performance of a magnetized bulk high-Tc superconductor magnet

NASA Astrophysics Data System (ADS)

Liu, W.; Wang, J. S.; Ma, G. T.; Zheng, J.; Tuo, X. G.; Li, L. L.; Ye, C. Q.; Liao, X. L.; Wang, S. Y.

2012-03-01

Compared with the permanent magnet, the magnetized bulk high-Tc superconductor magnet (MBSCM) can trap higher magnetic field due to its strong flux pinning ability, so it is a good candidate to improve the levitation performance of high-Tc superconductive (HTS) maglev system. The trapped magnetic flux of a MBSCM is sustained by the inductive superconducting current produced by the magnetizing process and is susceptible to the current intensity as well as configuration. In the HTS maglev system, the lateral displacement is an important process to change the superconducting current within a MBSCM and then affects its levitation performance, which is essential for the traffic ability in curve-way, the loading capacity of lateral impact and so on. The research about influence of lateral displacement on the levitation performance of MBSCM is necessary when MBSCM is applied on the HTS maglev vehicle. The experimental investigations about the influence of lateral displacement on the levitation performance of a MBSCM with different trapped fluxes and applied fields are processed in this article. The analyses and conclusions of this article are useful for the practical application of MBSCM in HTS maglev system.

Goos-Hänchen-like shift in biased silicene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Bang-Shan; Wang, Yu, E-mail: ywang@semi.ac.cn; Lou, Yi-Yi

2016-04-28

We have theoretically studied the Goos-Hänchen-like shift of spinor-unpolarized beams tunneling through various gate-biased silicene nanostructures. Following the stationary-phase method, lateral displacement in single-, dual-, and multiple-gated silicene systems has been systematically demonstrated. It is shown for simple single-gated silicene that lateral displacement can be generally enhanced by Fabry-Perot interference, and near the transition point turning on the evanescent mode a very large lateral shift could be observed. For the dual-gated structure, we have also shown the crucial role of localized modes like quantum well states in enhancing the beam lateral displacement, while for the multiple gate-biased systems the resultingmore » superlattice subbands are also favorable for lateral displacement enhancement. Importantly, including the degeneracy-broken mechanisms such as gate-field and magnetic modulations, a fully spinor-resolved beam can be distinguished from the rest counterparts by aligning the incident beam with a proper spinor-resolved transition point, localized state, and subband, all of which can be flexibly modulated via electric means, offering the very desirable strategies to achieve the fully spinor-polarized beam for functional electronic applications.« less

Elasto-limited plastic analysis of structures for probabilistic conditions

NASA Astrophysics Data System (ADS)

Movahedi Rad, M.

2018-06-01

With applying plastic analysis and design methods, significant saving in material can be obtained. However, as a result of this benefit excessive plastic deformations and large residual displacements might develop, which in turn might lead to unserviceability and collapse of the structure. In this study, for deterministic problem the residual deformation of structures is limited by considering a constraint on the complementary strain energy of the residual forces. For probabilistic problem the constraint for the complementary strain energy of the residual forces is given randomly and critical stresses updated during the iteration. Limit curves are presented for the plastic limit load factors. The results show that these constraints have significant effects on the load factors. The formulations of the deterministic and probabilistic problems lead to mathematical programming which are solved by the use of nonlinear algorithm.

Displacement of dental implants in trabecular bone under a static lateral load in fresh bovine bone.

PubMed

Engelke, Wilfried; Müller, Alois; Decco, Oscar A; Rau, María J; Cura, Andrea C; Ruscio, Mara L; Knösel, Michael

2013-04-01

The study aims to provide objective data for the displacement of titanium screw implants in trabecular bone specimens. One hundred Semados implants (Bego, Bremen, Germany) were inserted in bovine type IV bone specimens. All implants had a diameter of 3.75 mm; 50 implants had a length of 8.5 mm and 50 implants had a length of 15 mm. Insertion torque was determined at intervals of 10, 20, and 30 Ncm. Implants were loaded horizontally with 10, 20, and 30 N for 2 seconds. An indicator strip was attached to the implant abutment to allow direct observation of implant movement relative to the bone surface. Horizontal displacement was assessed with an accuracy of measurement of 10 µm. Seven implants got lost by visible loosening. Degree of displacement was subject to evaluation with all others. Those implants showed a mean displacement of 59 µm for 10 N (n = 100), 173 µm for 20 N (n = 99), and 211 µm for 30 N (n = 93). The mean displacement of 15-mm implants (16, 37, 51 µm) was significantly lower compared with 8.5-mm implants (103, 311, 396 µm) corresponding to 10, 20, and 30 N as lateral loads. Displacement of screw implants in trabecular bone can be detected and visualized using commercially available endoscopes with a high magnification. A lateral load of 20 N indicates a mean displacement of over 100 µm and therefore results in a critical displacement. © 2011 Wiley Periodicals, Inc.

Lateral-Torsional Buckling Instability Caused by Individuals Walking on Wood Composite I-Joists

NASA Astrophysics Data System (ADS)

Villasenor Aguilar, Jose Maria

Recent research has shown that a significant number of the falls from elevation occur when laborers are working on unfinished structures. Workers walking on wood I-joists on roofs and floors are prone to fall hazards. Wood I-joists have been replacing dimension lumber for many floor systems and a substantial number of roof systems in light-frame construction. Wood I-joists are designed to resist axial stresses on the flanges and shear stresses on the web while minimizing material used. However, wood I-joists have poor resistance to applied lateral and torsional loads and are susceptible to lateral-torsional buckling instability. Workers walking on unbraced or partially braced wood I-joists can induce axial and lateral forces as well as twist. Experimental testing demonstrated that workers cause lateral-torsional buckling instability in wood I-joists. However, no research was found related to the lateral-torsional buckling instability induced by individuals walking on the wood I-joists. Furthermore, no research was found considering the effects of the supported end conditions and partial bracing in the lateral-torsional buckling instability of wood I-joists. The goal of this research was to derive mathematical models to predict the dynamic lateral-torsional buckling instability of wood composite I-joists loaded by individuals walking considering different supported end conditions and bracing system configurations. The dynamic lateral-torsional buckling instability was analyzed by linearly combining the static lateral-torsional buckling instability with the lateral bending motion of the wood Ijoists. Mathematical models were derived to calculate the static critical loads for the simply supported end condition and four wood I-joist hanger supported end conditions. Additionally, mathematical models were derived to calculate the dynamic maximum lateral displacements and positions of the individual walking on the wood Ijoists for the same five different supported end conditions. Three different lean-on bracing systems were investigated, non-bracing, one-bracing, and two-bracing systems. Mathematical models were derived to calculate the amount of constraint due to the lean-on bracing system. The derived mathematical models were validated by comparison to data from testing for all supported end conditions and bracing systems. The predicted critical loads using the static buckling theoretical models for the non-bracing system and the static buckling theoretical models combined with the bracing theoretical models for the simply and hanger supported end conditions agreed well with the critical loads obtained from testing for the two wood I-joist sizes investigated. The predicted maximum lateral displacements and individual positions using the bending motion theoretical models for the simply and hanger supported end conditions agreed well with the corresponding maximum lateral displacements and individual positions obtained from testing for both wood I-joist sizes. Results showed that; a) the supported end condition influenced the critical loads, maximum lateral displacements and individual positions, b) the bracing system increased the critical loads and reduced the maximum lateral displacements, c) the critical load increased as the load position displaced away from the wood I-joist mid-span, d) the critical load reduced as the initial lateral displacement of the wood I-joist increased and e) the wood I-joist mid-span was the critical point in the dynamic lateral-torsional buckling instability.

Earthquake mechanism and seafloor deformation for tsunami generation

USGS Publications Warehouse

Geist, Eric L.; Oglesby, David D.; Beer, Michael; Kougioumtzoglou, Ioannis A.; Patelli, Edoardo; Siu-Kui Au, Ivan

2014-01-01

Tsunamis are generated in the ocean by rapidly displacing the entire water column over a significant area. The potential energy resulting from this disturbance is balanced with the kinetic energy of the waves during propagation. Only a handful of submarine geologic phenomena can generate tsunamis: large-magnitude earthquakes, large landslides, and volcanic processes. Asteroid and subaerial landslide impacts can generate tsunami waves from above the water. Earthquakes are by far the most common generator of tsunamis. Generally, earthquakes greater than magnitude (M) 6.5–7 can generate tsunamis if they occur beneath an ocean and if they result in predominantly vertical displacement. One of the greatest uncertainties in both deterministic and probabilistic hazard assessments of tsunamis is computing seafloor deformation for earthquakes of a given magnitude.

Comminuted supracondylar femoral fractures: a biomechanical analysis comparing the stability of medial versus lateral plating in axial loading.

PubMed

Briffa, Nikolai; Karthickeyan, Raju; Jacob, Joshua; Khaleel, Arshad

2016-11-01

The aim of this study was to compare the biomechanical properties of medial and lateral plating of a medially comminuted supracondylar femoral fracture. A supracondylar femoral fracture model comparing two fixation methods was tested cyclically in axial loading. One-centimetre supracondylar gap osteotomies were created in six synthetic femurs approximately 6 cm proximal to the knee joint. There were two constructs investigated: group 1 and group 2 were stabilized with an 8-hole LC-DCP, medially and laterally, respectively. Both construct groups were axially loaded. Global displacement (total length), wedge displacement, bending moment and strain were measured. Medial plating showed a significantly decreased displacement, bending moment and strain at the fracture site in axial loading. Medial plating of a comminuted supracondylar femur fracture is more stable than lateral plating.

A semi-empirical model for the estimation of maximum horizontal displacement due to liquefaction-induced lateral spreading

USGS Publications Warehouse

Faris, Allison T.; Seed, Raymond B.; Kayen, Robert E.; Wu, Jiaer

2006-01-01

During the 1906 San Francisco Earthquake, liquefaction-induced lateral spreading and resultant ground displacements damaged bridges, buried utilities, and lifelines, conventional structures, and other developed works. This paper presents an improved engineering tool for the prediction of maximum displacement due to liquefaction-induced lateral spreading. A semi-empirical approach is employed, combining mechanistic understanding and data from laboratory testing with data and lessons from full-scale earthquake field case histories. The principle of strain potential index, based primary on correlation of cyclic simple shear laboratory testing results with in-situ Standard Penetration Test (SPT) results, is used as an index to characterized the deformation potential of soils after they liquefy. A Bayesian probabilistic approach is adopted for development of the final predictive model, in order to take fullest advantage of the data available and to deal with the inherent uncertainties intrinstiic to the back-analyses of field case histories. A case history from the 1906 San Francisco Earthquake is utilized to demonstrate the ability of the resultant semi-empirical model to estimate maximum horizontal displacement due to liquefaction-induced lateral spreading.

Shaft-Condylar Angle for surgical correction in neglected and displaced lateral humeral condyle fracture in children.

PubMed

Mulpruek, Pornchai; Angsanuntsukh, Chanika; Woratanarat, Patarawan; Sa-Ngasoongsong, Paphon; Tawonsawatruk, Tulyapruek; Chanplakorn, Pongsthorn

2015-09-01

To assess the outcome after using the Shaft-Condylar angle (SCA) as intraoperative reference for sagittal plane correction in displaced lateral humeral condyle fractures in children presented 3-weeks after injury. Ten children, with delayed presentation of a displaced lateral humeral condyle fracture and undergoing surgery during 1999-2011, were reviewed. The goal was to obtain a smooth articular surface with an intraoperative SCA of nearly 40° and nearest-anatomical carrying angle. They were allocated into two groups according to the postoperative SCA [Good-reduction group (SCA=30-50°), and Bad-reduction group (SCA<30°, >50°)] and the final outcomes were then compared. All fractures united without avascular necrosis. The Good-reduction group (n=7) showed a significant improvement in final range of motion and functional outcome compared to the Bad-reduction group (n=3) (p=0.02). However, there was no significant difference in pain, carrying angle and overall outcome between both groups. SCA is a possible intraoperative reference for sagittal alignment correction in late presented displaced lateral humeral condyle fractures.

Return to sport following clavicle fractures: a systematic review.

PubMed

Robertson, G A J; Wood, A M

2016-09-01

This review aims to provide information on the return rates and return times to sport following clavicle fractures. A systematic search of Medline, EMBASE, CINAHAL, Cochrane, Web of Science, PEDro, SPORTDiscus, Scopus and Google Scholar was performed using the keywords 'clavicle', 'clavicular', 'fractures', 'athletes', 'sports', 'non-operative', 'conservative', 'operative', 'return to sport'. Twenty-three studies were included: 10 reported on mid-shaft fractures, 14 on lateral fractures. The management principles for athletic patients were to attempt non-operative management for undisplaced fractures to undertake operative intervention for displaced lateral fractures and to recommend operative intervention for displaced mid-shaft fractures. The optimal surgical modality for mid-shaft and lateral clavicle fractures. Operative management of displaced mid-shaft fractures offers improved return rates and times to sport compared to non-operative management. Suture fixation and non-acromio-clavicular joint (ACJ)-spanning plate fixation of displaced lateral fractures show promising results. Future prospective studies should aim to establish the optimal treatment modalities for clavicle fractures. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

40 CFR 86.419-78 - Engine displacement, motorcycle classes.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 19 2014-07-01 2014-07-01 false Engine displacement, motorcycle... Emission Regulations for 1978 and Later New Motorcycles, General Provisions § 86.419-78 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using nominal engine values and rounded to...

40 CFR 86.419-78 - Engine displacement, motorcycle classes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Engine displacement, motorcycle... Emission Regulations for 1978 and Later New Motorcycles, General Provisions § 86.419-78 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using nominal engine values and rounded to...

40 CFR 86.419-78 - Engine displacement, motorcycle classes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Engine displacement, motorcycle... Emission Regulations for 1978 and Later New Motorcycles, General Provisions § 86.419-78 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using nominal engine values and rounded to...

40 CFR 86.419-78 - Engine displacement, motorcycle classes.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 19 2013-07-01 2013-07-01 false Engine displacement, motorcycle... Emission Regulations for 1978 and Later New Motorcycles, General Provisions § 86.419-78 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using nominal engine values and rounded to...

40 CFR 86.419-78 - Engine displacement, motorcycle classes.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 19 2012-07-01 2012-07-01 false Engine displacement, motorcycle... Emission Regulations for 1978 and Later New Motorcycles, General Provisions § 86.419-78 Engine displacement, motorcycle classes. (a)(1) Engine displacement shall be calculated using nominal engine values and rounded to...

Drift Reliability Assessment of a Four Storey Frame Residential Building Under Seismic Loading Considering Multiple Factors

NASA Astrophysics Data System (ADS)

Sil, Arjun; Longmailai, Thaihamdau

2017-09-01

The lateral displacement of Reinforced Concrete (RC) frame building during an earthquake has an important impact on the structural stability and integrity. However, seismic analysis and design of RC building needs more concern due to its complex behavior as the performance of the structure links to the features of the system having many influencing parameters and other inherent uncertainties. The reliability approach takes into account the factors and uncertainty in design influencing the performance or response of the structure in which the safety level or the probability of failure could be ascertained. This present study, aims to assess the reliability of seismic performance of a four storey residential RC building seismically located in Zone-V as per the code provisions given in the Indian Standards IS: 1893-2002. The reliability assessment performed by deriving an explicit expression for maximum roof-lateral displacement as a failure function by regression method. A total of 319, four storey RC buildings were analyzed by linear static method using SAP2000. However, the change in the lateral-roof displacement with the variation of the parameters (column dimension, beam dimension, grade of concrete, floor height and total weight of the structure) was observed. A generalized relation established by regression method which could be used to estimate the expected lateral displacement owing to those selected parameters. A comparison made between the displacements obtained from analysis with that of the equation so formed. However, it shows that the proposed relation could be used directly to determine the expected maximum lateral displacement. The data obtained from the statistical computations was then used to obtain the probability of failure and the reliability.

Abdominal Hollowing Reduces Lateral Trunk Displacement During Single-Leg Squats in Healthy Females But Does Not Affect Peak Hip Abduction Angle or Knee Abductio Angle/Moment.

PubMed

Linde, Lukas D; Archibald, Jessica; Lampert, Eve C; Srbely, John Z

2017-07-17

Females suffer 4-6 times more non-contact anterior cruciate ligament (ACL) injuries than males due to neuromuscular control deficits of the hip musculature leading to increases in hip adduction angle, knee abduction angle, and knee abduction moment during dynamic tasks such as single-leg squats. Lateral trunk displacement has been further related to ACL injury risk in females, leading to the incorporation of core strength/stability exercises in ACL preventative training programs. However, the direct mechanism relating lateral trunk displacement and lower limb ACL risk factors is not well established. To assess the relationship between lateral trunk displacement and lower limb measures of ACL injury risk by altering trunk control through abdominal activation techniques during single-leg squats in healthy females. Interventional Study Setting: Movement and Posture Laboratory Participants: 13 healthy females (21.3±0.88y, 1.68±0.07m, 58.27±5.46kg) Intervention: Trunk position and lower limb kinematics were recorded using an optoelectric motion capture system during single-leg squats under differing conditions of abdominal muscle activation (abdominal hollowing, abdominal bracing, control), confirmed via surface electromyography. Lateral trunk displacement, peak hip adduction angle, peak knee abduction angle/moment, and average muscle activity from bilateral internal oblique, external oblique, and erector spinae muscles. No differences were observed for peak lateral trunk displacement, peak hip adduction angle or peak knee abduction angle/moment. Abdominal hollowing and bracing elicited greater muscle activation than the control condition, and bracing was greater than hollowing in four of six muscles recorded. The lack of reduction in trunk, hip, and knee measures of ACL injury risk during abdominal hollowing and bracing suggests that these techniques alone may provide minimal benefit in ACL injury prevention training.

Lateral Displacement and Shear Lag Effect of Combination of Diagrid-Frame

NASA Astrophysics Data System (ADS)

Abd. Samat, Roslida; Chua, Fong Teng; Mustakim, Nur Akmal Hayati Mohd; Saad, Sariffuddin; Abu Bakar, Suhaimi

2018-03-01

Diagrid system, which is the portmanteau of diagonal grid member, is an exterior lateral load resisting system for tall building that has gained a wide acceptance in the design of tall buildings. There is abundance of researches that studied the efficiency of diagrid systems, which are constructed from the ground level to the top of the buildings in resisting the lateral load. Nevertheless, no study had been performed on the effectiveness of the diagrid that is constructed above other tall building systems despite the existence of a few buildings in the world that employ such system. The objective of this research is to understand the behavior of the lateral displacement and shear lag effect due to wind load when the diagrid structure is constructed above a frame. Models of 60-story buildings with a footprint of 36m x 36m were analyzed by using Staad.Pro software. The level where the diagrid members started was altered. The lateral displacement was reduced to 60.6 percent and 41 percent of the lateral displacement of a building with full frame system when the combination of frame-diagrid that had the diagrid started at Level 1 and Level 45, respectively were employed. Furthermore, the shear lag ratio was reduced from 1.7 to 1.3 when the level where the diagrid started was increased from Level 1 to Level 45.

Displacement Vector Measurement Using 2D Modulation by Virtual Hyperbolic Beam Forming

NASA Astrophysics Data System (ADS)

Kondo, Kengo; Yamakawa, Makoto; Shiina, Tsuyoshi

For the purpose of diagnosing ischemic heart disease by detection of malfunction area and cancer tumor by detection of hard area, 3-D tissue motion must be correctly evaluated. So far various methods of measuring multidimensional displacement have been developed. Most of present techniques are restricted to one-dimensional measurement of tissue displacement such as myocardial stain-rate imaging. Although lateral modulation method enables us to attain high-accuracy measurement of lateral displacement as well as axial direction by generating lateral oscillating RF signals, the method causes distorted RF far from center of aperture. As a result, the method is not suited to sector scan which is used for myocardial examination. We propose a method to solve the problem by using 2-D modulation with the virtual hyperbolic beam forming and detection of 2-D displacement vector. The feasibilities of the proposed method were evaluated by numerically simulating the left ventricle short-axis imaging of cylindrical myocardial model. The volume strain image obtained by the proposed method clearly depicted the hard infarction area where conventional multi-beam Doppler imaging could not.

Deterministic Methods of Seismic Source Identification

DTIC Science & Technology

1983-09-30

activity is implied by Figure 7 , compared to that inferred from Fig- ure 6 . We expect that the residual scatter, about the one to one slope line...side of the boundary, and in this case the general forms of the conservation laws expressed by (3). (4) and ( 6 ), or ( 6 ) and ( 7 ). are the appropriate...such as given in (8) and ( 7 ). to obtain an integral equation for the unknown alastodynamic displacement field in an elastic (or anelastic) medium. Such

Influence of body position on the displacement of nasal prongs in preterm newborns receiving continuous positive airway pressure

PubMed Central

Brunherotti, Marisa Afonso Andrade; Martinez, Francisco Eulógio

2015-01-01

Abstract Objective: To evaluate the influence of body position on the displacement of nasal prongs in preterm infants. Methods: This prospective, randomized, crossover study enrolled infants born at a mean gestational age of 29.7±2 weeks, birth weight of 1353±280g and 2.9±2.2 days of life, submitted to continuous positive airway pressure by nasal prongs. The main outcome was the number of times that the nasal prongs were displaced following infant positioning in the following body positions: prone, right lateral, left lateral, and supine, according to a pre-established random order. Moreover, cardiorespiratory variables (respiratory rate, heart rate, and oxygen saturation) were evaluated for each body position. Data for each position were collected every 10 min, over a period of 60 min. An occurrence was defined when the nasal prongs were displaced from the nostrils after 3 min in the desired position, requiring intervention of the examiner. Results: Among the 16 studied infants, the occurrence of nasal prong displacement was only observed in the prone position (9 infants - 56.2%) and in the left lateral position (2 infants - 12.5%). The number of times that the prongs were displaced was 11 in the prone position (7 within the first 10min) and 2 in the left lateral position (1 within the first 10min). No clinically significant changes were observed in the cardiorespiratory variables. Conclusions: Maintenance of the nasal prongs to provide adequate noninvasive respiratory support was harder in the prone position. PMID:26116326

Universal quantum computation using all-optical hybrid encoding

NASA Astrophysics Data System (ADS)

Guo, Qi; Cheng, Liu-Yong; Wang, Hong-Fu; Zhang, Shou

2015-04-01

By employing displacement operations, single-photon subtractions, and weak cross-Kerr nonlinearity, we propose an alternative way of implementing several universal quantum logical gates for all-optical hybrid qubits encoded in both single-photon polarization state and coherent state. Since these schemes can be straightforwardly implemented only using local operations without teleportation procedure, therefore, less physical resources and simpler operations are required than the existing schemes. With the help of displacement operations, a large phase shift of the coherent state can be obtained via currently available tiny cross-Kerr nonlinearity. Thus, all of these schemes are nearly deterministic and feasible under current technology conditions, which makes them suitable for large-scale quantum computing. Project supported by the National Natural Science Foundation of China (Grant Nos. 61465013, 11465020, and 11264042).

A lateral flow biosensor for detection of single nucleotide polymorphism by circular strand displacement reaction.

PubMed

Xiao, Zhuo; Lie, Puchang; Fang, Zhiyuan; Yu, Luxin; Chen, Junhua; Liu, Jie; Ge, Chenchen; Zhou, Xuemeng; Zeng, Lingwen

2012-09-04

A lateral flow biosensor for detection of single nucleotide polymorphism based on circular strand displacement reaction (CSDPR) has been developed. Taking advantage of high fidelity of T4 DNA ligase, signal amplification by CSDPR, and the optical properties of gold nanoparticles, this assay has reached a detection limit of 0.01 fM.

Biomechanical in vitro - stability testing on human specimens of a locking plate system against conventional screw fixation of a proximal first metatarsal lateral displacement osteotomy.

PubMed

Arnold, Heino; Stukenborg-Colsman, Christina; Hurschler, Christof; Seehaus, Frank; Bobrowitsch, Evgenij; Waizy, Hazibullah

2012-01-01

The aim of this study was to examine resistance to angulation and displacement of the internal fixation of a proximal first metatarsal lateral displacement osteotomy, using a locking plate system compared with a conventional crossed screw fixation. Seven anatomical human specimens were tested. Each specimen was tested with a locking screw plate as well as a crossed cancellous srew fixation. The statistical analysis was performed by the Friedman test. The level of significance was p = 0.05. We found larger stability about all three axes of movement analyzed for the PLATE than the crossed screws osteosynthesis (CSO). The Friedman test showed statistical significance at a level of p = 0.05 for all groups and both translational and rotational movements. The results of our study confirm that the fixation of the lateral proximal first metatarsal displacement osteotomy with a locking plate fixation is a technically simple procedure of superior stability.

Biomechanical In Vitro - Stability Testing on Human Specimens of a Locking Plate System Against Conventional Screw Fixation of a Proximal First Metatarsal Lateral Displacement Osteotomy

PubMed Central

Arnold, Heino; Stukenborg-Colsman, Christina; Hurschler, Christof; Seehaus, Frank; Bobrowitsch, Evgenij; Waizy, Hazibullah

2012-01-01

Introduction: The aim of this study was to examine resistance to angulation and displacement of the internal fixation of a proximal first metatarsal lateral displacement osteotomy, using a locking plate system compared with a conventional crossed screw fixation. Materials and Methodology: Seven anatomical human specimens were tested. Each specimen was tested with a locking screw plate as well as a crossed cancellous srew fixation. The statistical analysis was performed by the Friedman test. The level of significance was p = 0.05. Results: We found larger stability about all three axes of movement analyzed for the PLATE than the crossed screws osteosynthesis (CSO). The Friedman test showed statistical significance at a level of p = 0.05 for all groups and both translational and rotational movements. Conclusion: The results of our study confirm that the fixation of the lateral proximal first metatarsal displacement osteotomy with a locking plate fixation is a technically simple procedure of superior stability. PMID:22675409

Detection of radial motion depends on spatial displacement.

PubMed

de la Malla, Cristina; López-Moliner, Joan

2010-06-01

Nakayama and Tyler (1981) disentangled the use of pure motion (speed) information from spatial displacement information for the detection of lateral motion. They showed that when positional cues were removed the contribution of motion or spatial information was dependent on the temporal frequency: for temporal frequencies lower than 1Hz the mechanism used to detect motion relied on speed information while for higher temporal frequencies a mechanism based on displacement information was used. Here we test whether the same dependency is also revealed in radial motion. In order to do so, we adapted the paradigm previously used by Nakayama and Tyler to obtain detection thresholds for lateral and radial motion by using a 2-IFC procedure. Subjects had to report which of the intervals contained the signal stimulus (33% coherent motion). We replicated the temporal frequency dependency for lateral motion but results indicate, however, that the detection of radial is always consistent with detecting a spatial displacement amplitude. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Patient satisfaction after open reduction and internal fixation through lateral extensile approach in displaced intraarticular calcaneal fractures (Sander's type II and III).

PubMed

Kavin, Khatri; Vijay, Sharma; Devendra, Lakhotia; Kamran, Farooque

2016-01-01

To determine patient satisfaction in the patients of displaced intraarticular calcaneal fractures treated with standard lateral approach. The patients of displaced calcaneal fractures (Sander's type II and III) treated between March 2009 and March 2012 were included in the retrospective review and functional outcome was evaluated using American Orthopaedic Foot and Ankle Society (AOFAS) hind foot score, Creighton Nebraska Health Foundation Assessment (CNHFA) scale and foot function index (FFI). The cohort included 26 patients (19 males: seven were females) with a mean age of 38.16 ± 13.53 years (range 18-64 years). The mean period of follow-up was 24.42 ± 6.68 months. The patients achieved good functional scores after anatomical reduction of the fracture. The complication rate was low following strict inclusion criteria. Careful patient selection in displaced intraarticular calcaneal fractures treated through lateral extensile approach achieves good patient satisfaction.

Experimental modeling of the effect of hurricane wind forces on driving behavior and vehicle performance.

PubMed

Rodriguez, Jose M; Codjoe, Julius; Osman, Osama; Ishak, Sherif; Wolshon, Brian

2015-01-01

While traffic planning is important for developing a hurricane evacuation plan, vehicle performance on the roads during extreme weather conditions is critical to the success of the planning process. This novel study investigates the effect of gusty hurricane wind forces on the driving behavior and vehicle performance. The study explores how the parameters of a driving simulator could be modified to reproduce wind loadings experienced by three vehicle types (passenger car, ambulance, and bus) during gusty hurricane winds, through manipulation of appropriate software. Thirty participants were then tested on the modified driving simulator under five wind conditions (ranging from normal to hurricane category 4). The driving performance measures used were heading error and lateral displacement. The results showed that higher wind forces resulted in more varied and greater heading error and lateral displacement. The ambulance had the greatest heading errors and lateral displacements, which were attributed to its large lateral surface area and light weight. Two mathematical models were developed to estimate the heading error and lateral displacements for each of the vehicle types for a given change in lateral wind force. Through a questionnaire, participants felt the different characteristics while driving each vehicle type. The findings of this study demonstrate the valuable use of a driving simulator to model the behavior of different vehicle types and to develop mathematical models to estimate and quantify driving behavior and vehicle performance under hurricane wind conditions.

Early Weightbearing After Operatively Treated Ankle Fractures: A Biomechanical Analysis.

PubMed

Tan, Eric W; Sirisreetreerux, Norachart; Paez, Adrian G; Parks, Brent G; Schon, Lew C; Hasenboehler, Erik A

2016-06-01

No consensus exists regarding the timing of weightbearing after surgical fixation of unstable traumatic ankle fractures. We evaluated fracture displacement and timing of displacement with simulated early weightbearing in a cadaveric model. Twenty-four fresh-frozen lower extremities were assigned to Group 1, bimalleolar ankle fracture (n=6); Group 2, trimalleolar ankle fracture with unfixed small posterior malleolar fracture (n=9); or Group 3, trimalleolar ankle fracture with fixed large posterior malleolar fracture (n=9) and tested with axial compressive load at 3 Hz from 0 to 1000 N for 250 000 cycles to simulate 5 weeks of full weightbearing. Displacement was measured by differential variable reluctance transducer. The average motion at all fracture sites in all groups was significantly less than 1 mm (P < .05). Group 1 displacement of the lateral and medial malleolus fracture was 0.1±0.1 mm and 0.4±0.4 mm, respectively. Group 2 displacement of the lateral, medial, and posterior malleolar fracture was 0.6±0.4 mm, 0.5±0.4 mm, and 0.5±0.6 mm, respectively. Group 3 displacement of the lateral, medial, and posterior malleolar fracture was 0.1±0.1 mm, 0.5±0.7 mm, and 0.5±0.4 mm, respectively. The majority of displacement (64.0% to 92.3%) occurred in the first 50 000 cycles. There was no correlation between fracture displacement and bone mineral density. No significant fracture displacement, no hardware failure, and no new fractures occurred in a cadaveric model of early weightbearing in unstable ankle fracture after open reduction and internal fixation. This study supports further investigation of early weightbearing postoperative protocols after fixation of unstable ankle fractures. © The Author(s) 2016.

Behavior of braced excavation in sand under a seismic condition: experimental and numerical studies

NASA Astrophysics Data System (ADS)

Konai, Sanku; Sengupta, Aniruddha; Deb, Kousik

2018-04-01

The behavior of braced excavation in dry sand under a seismic condition is investigated in this paper. A series of shake table tests on a reduced scale model of a retaining wall with one level of bracing were conducted to study the effect of different design parameters such as excavation depth, acceleration amplitude and wall stiffness. Numerical analyses using FLAC 2D were also performed considering one level of bracing. The strut forces, lateral displacements and bending moments in the wall at the end of earthquake motion were compared with experimental results. The study showed that in a post-seismic condition, when other factors were constant, lateral displacement, bending moment, strut forces and maximum ground surface displacement increased with excavation depth and the amplitude of base acceleration. The study also showed that as wall stiffness decreased, the lateral displacement of the wall and ground surface displacement increased, but the bending moment of the wall and strut forces decreased. The net earth pressure behind the walls was influenced by excavation depth and the peak acceleration amplitude, but did not change significantly with wall stiffness. Strut force was the least affected parameter when compared with others under a seismic condition.

Horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications.

PubMed

Ma, Hongcai; Wu, Lin

2015-07-10

We present the design of a horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications. This solar concentrator consists of an array of telecentric primary concentrators, a horizontally staggered lightguide layer, and a vertically tapered lightguide layer. The primary concentrator is realized by two plano-aspheric lenses with lateral movement and maintains a high F-number over an angle range of ±23.5°. The results of the simulations show that the solar concentrator achieves a high concentration ratio of 500× with ±0.5° of acceptance angle by a single-axis tracker and dual lateral translation stages.

Three-dimensional analysis of postoperative returning movement of perioperative condylar displacement after bilateral sagittal split ramus osteotomy for mandibular setback with different fixation methods.

PubMed

Han, Jeong Joon; Hwang, Soon Jung

2015-11-01

This study aimed to evaluate postoperative returning movement of perioperative condylar displacement after bilateral sagittal split ramus osteotomy (BSSRO) depending on a fixation method using three-dimensional (3D) analysis of computed tomography (CT). Twenty-five mandibular prognathic patients (50 condyles) who underwent orthognathic surgery with BSSRO were divided into three groups depending on the fixation method, which consisted of miniplate only (Group A), combined with single bicortical screw (Group B), or with more than one bicortical screw (Group C). CT data taken before, immediately after, and 3 to 6 months after surgery were analyzed. The condyle exhibited mainly lateral bodily displacement and inward and inferior rotation immediately after surgery. The amount of perioperative lateral displacement of the condyle increased according to the increasing number of fixation screws, but the mean displacements were not significantly different among the three groups. During the postoperative follow-up period, the amount of medial returning of the condyle was 102.2% of the intraoperative lateral displacement in Group A. In contrast, Group B and C exhibited partial returning movement by 71.3% and 38.9% of cases, respectively. In conclusion, stronger rigid internal fixation in orthognathic surgery using BSSRO is associated with reduced flexibility of postoperative functional adjustment of displaced condyle to the preoperative condylar position. Copyright © 2015 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

[Exploring a new method for superimposition of pre-treatment and post-treatment mandibular digital dental casts in adults].

PubMed

Dai, F F; Liu, Y; Xu, T M; Chen, G

2018-04-18

To explore a cone beam computed tomography (CBCT)-independent method for mandibular digital dental cast superimposition to evaluate three-dimensional (3D) mandibular tooth movement after orthodontic treatment in adults, and to evaluate the accuracy of this method. Fifteen post-extraction orthodontic treatment adults from the Department of Orthodontics, Peking University School and Hospital of Stomatology were included. All the patients had four first premolars extracted, and were treated with straight wire appliance. The pre- and post-treatment plaster dental casts and craniofacial CBCT scans were obtained. The plaster dental casts were transferred to digital dental casts by 3D laser scanning, and lateral cephalograms were created from the craniofacial CBCT scans by orthogonal projection. The lateral cephalogram-based mandibular digital dental cast superimposition was achieved by sequential maxillary dental cast superimposition registered on the palatal stable region, occlusal transfer, and adjustment of mandibular rotation and translation obtained from lateral cephalogram superimposition. The accuracy of the lateral cephalogram-based mandibular digital dental cast superimposition method was evaluated with the CBCT-based mandibular digital dental cast superimposition method as the standard reference. After mandibular digital dental cast superimposition using both methods, 3D coordinate system was established, and 3D displacements of the lower bilateral first molars, canines and central incisors were measured. Differences between the two superimposition methods in tooth displacement measurements were assessed using the paired t-test with the level of statistical significance set at P<0.05. No significant differences were found between the lateral cephalogram-based and CBCT-based mandibular digital dental cast superimposition methods in 3D displacements of the lower first molars, and sagittal and vertical displacements of the canines and central incisors; transverse displacements of the canines and central incisors differed by (0.3±0.5) mm with statistical significance. The lateral cephalogram-based mandibular digital dental cast superimposition method has the similar accuracy as the CBCT-based mandibular digital dental cast superimposition method in 3D evaluation of mandibular orthodontic tooth displacement, except for minor differences for the transverse displacements of anterior teeth. This method is applicable to adult patients with conventional orthodontic treatment records, especially the previous precious orthodontic data in the absence of CBCT scans.

Experimental Analysis of Proton-Induced Displacement and Ionization Damage Using Gate-Controlled Lateral PNP Bipolar Transistors

NASA Technical Reports Server (NTRS)

Ball, D. R.; Schrimpf, R. D.; Barnaby, H. J.

2006-01-01

The electrical characteristics of proton-irradiated bipolar transistors are affected by ionization damage to the insulating oxide and displacement damage to the semiconductor bulk. While both types of damage degrade the transistor, it is important to understand the mechanisms individually and to be able to analyze them separately. In this paper, a method for analyzing the effects of ionization and displacement damage using gate-controlled lateral PNP bipolar junction transistors is described. This technique allows the effects of oxide charge, surface recombination velocity, and bulk traps to be measured independently.

A prospective study on the effectiveness of cotton versus waterproof cast padding in maintaining the reduction of pediatric distal forearm fractures.

PubMed

Robert, Christopher E; Jiang, Jimmy J; Khoury, Joseph G

2011-03-01

Distal forearm fractures, one of the most common fractures seen in the pediatric population, are regularly treated by closed reduction and casting. Our study investigates the effectiveness of Gore-Tex-lined casting in maintaining the reduction of 100% displaced distal forearm fractures compared with traditional cotton-lined casts. We screened all patients from February 2007 to July 2009 who presented to Children's Hospital in Birmingham, AL with a distal radius fracture. Only patients with 100% displaced distal radius fractures were eligible to be assigned to either the cotton-lined or Gore-Tex-lined cast groups. Power analysis was performed to identify an adequate patient sample size. The mean maximum change between initial post-reduction x-rays and follow-up x-rays for anterior-posterior (AP) angulation, AP displacement, lateral angulation, and lateral displacement of the radius were calculated for both cotton and Gore-Tex groups. The rate of subsequent intervention and/or unacceptable results for each group was also analyzed. Seven hundred and twenty-two patients were treated with distal radius fractures at our hospital with 59 patients eligible for inclusion in our study. Thirty-six of our patients were treated with cotton-lined casts, and 23 patients were treated with Gore-Tex-lined cast. The mean maximum change in AP angulation, AP displacement, lateral angulation, and lateral displacement of the radius after initial reduction was 9.2 degrees, 6.9%, 13.9 degrees, and 13.6%, respectively, for the cotton-lined cast group and 7.7 degrees, 6.1%, 14.6 degrees, and 9.6%, respectively, for the Gore-Tex-lined cast group. There were no statistical differences between the means of the 4 measurements (P=0.33, 0.69, 0.73, and 0.10, respectively). There were also no significant differences between groups for final AP and lateral angulation and displacement. Subgroup analysis showed no significant differences in all measurements between cotton and Gore-Tex groups. Gore-Tex and cotton-lined casts are equally effective in their ability to maintain the reduction of 100% displaced distal forearm fractures. Thus, Gore-Tex-lined casts can be offered to pediatric patients immediately after closed reduction of distal radius fractures of any severity. Therapeutic level II.

Out-of-Field Dose Equivalents Delivered by Passively Scattered Therapeutic Proton Beams for Clinically Relevant Field Configurations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wroe, Andrew; Centre for Medical Radiation Physics, University of Wollongong, Wollongong; Clasie, Ben

2009-01-01

Purpose: Microdosimetric measurements were performed at Massachusetts General Hospital, Boston, MA, to assess the dose equivalent external to passively delivered proton fields for various clinical treatment scenarios. Methods and Materials: Treatment fields evaluated included a prostate cancer field, cranial and spinal medulloblastoma fields, ocular melanoma field, and a field for an intracranial stereotactic treatment. Measurements were completed with patient-specific configurations of clinically relevant treatment settings using a silicon-on-insulator microdosimeter placed on the surface of and at various depths within a homogeneous Lucite phantom. The dose equivalent and average quality factor were assessed as a function of both lateral displacement frommore » the treatment field edge and distance downstream of the beam's distal edge. Results: Dose-equivalent value range was 8.3-0.3 mSv/Gy (2.5-60-cm lateral displacement) for a typical prostate cancer field, 10.8-0.58 mSv/Gy (2.5-40-cm lateral displacement) for the cranial medulloblastoma field, 2.5-0.58 mSv/Gy (5-20-cm lateral displacement) for the spinal medulloblastoma field, and 0.5-0.08 mSv/Gy (2.5-10-cm lateral displacement) for the ocular melanoma field. Measurements of external field dose equivalent for the stereotactic field case showed differences as high as 50% depending on the modality of beam collimation. Average quality factors derived from this work ranged from 2-7, with the value dependent on the position within the phantom in relation to the primary beam. Conclusions: This work provides a valuable and clinically relevant comparison of the external field dose equivalents for various passively scattered proton treatment fields.« less

Pre- and postoperative magnetic resonance imaging appearance of the normal residual pituitary gland following macroadenoma resection: Clinical implications

PubMed Central

Maio, Salvatore Di; Biswas, Arundhati; Vézina, Jean Lorrain; Hardy, Jules; Mohr, Gérard

2012-01-01

Background: To assess the relationship between the preoperative magnetic resonance imaging (MRI) appearance of the normal residual pituitary gland (NRPG) and pituitary functional outcome following transsphenoidal resection of pituitary macroadenomas. Methods: We retrospectively reviewed the medical records of 100 consecutive patients with a pituitary macroadenoma, who underwent transsphenoidal resection. The preoperative configuration of the displaced NRPG was stratified as superior, superolateral or lateral. The extent of postoperative restitution of the NRPG was divided into four groups: Group 1 — normal residual gland or almost normal; Group 2 — more than 50% restitution; Group 3 — less than 50% of the normal residual gland; and Group 4 — barely visible or absent residual gland. The pre- and postoperative NRPG appearance was correlated with pituitary functional status. Results: Preoperatively, the NRPG was identifiable in 79 patients, with extrasellar displacement in 53%. The displacement pattern was superior in 8%, superolateral in 32%, and lateral in 58% of the patients. If the NRPG was displaced laterally, the ipsilateral cavernous sinus was not invaded by the pituitary macroadenoma. Partial or complete pituitary function was lost in 6 / 23 (26.1%) patients with superior or superolateral displacement of the NRPG, compared to only 1 / 36 (2.8%) patients without superior displacement of the NRPG (P = 0.025). Progressive postoperative reconstitution of the NRPG was related to the preservation of the pituitary hormonal axis (Pearson Chi-Square P < 0.001). Conclusions: Progressive displacement of the NRPG preoperatively, and lack of restitution of the NRPG on postoperative MRI appeared to correlate with the postoperative pituitary functional loss. PMID:22754732

Analysis of the Postoperative Displacement of Trochanteric Fractures on Lateral View Radiographs.

PubMed

Furui, Atsuo; Terada, Nobuki

2017-08-01

Achieving sufficient support of the anterior cortex of the femoral neck is a fundamental goal of the reduction of trochanteric fractures. However, anterior-cortex support is often lost after the fracture reduction. Our aim was to analyze factors contributing to the postoperative displacement of an acceptably reduced trochanteric fracture. The cases of 40 patients with a post-reduction Ikuta subtype N fracture alignment were reviewed. All fractures were fixed with 135° free-sliding plates. On postoperative day 14, patients were classified into two groups: those with retention of the Ikuta subtype N alignment, and those with progression to Ikuta subtype P alignment. The clinical and radiological factors were evaluated between the groups. In addition, to define one of the factors, i.e., the postoperative rotational displacement between the proximal and distal fragments, the relationship between radiographic findings and computed tomography image measurements was assessed in 15 of the 40 patients. Angulation at the fracture site on lateral view radiographs was defined as postoperative rotational displacement, and unstable trochanteric fractures and postoperative rotational displacement were identified as significant risk factors for the postoperative displacement. Therefore, cautious and careful follow-up is warranted for patients with unstable trochanteric fractures or fractures having rotational displacement.

Electrostatic stabilizer for a passive magnetic bearing system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Post, Richard F

2016-10-11

Electrostatic stabilizers are provided for passive bearing systems composed of annular magnets having a net positive stiffness against radial displacements and that have a negative stiffness for vertical displacements, resulting in a vertical instability. Further embodiments are shown of a radial electrostatic stabilizer geometry (using circuitry similar to that employed in the vertical stabilizer). This version is suitable for stabilizing radial (lateral) displacements of a rotor that is levitated by annular permanent magnets that are stable against vertical displacements but are unstable against radial displacements.

Electrostatic stabilizer for a passive magnetic bearing system

DOEpatents

Post, Richard F.

2015-11-24

Electrostatic stabilizers are provided for passive bearing systems composed of annular magnets having a net positive stiffness against radial displacements and that have a negative stiffness for vertical displacements, resulting in a vertical instability. Further embodiments are shown of a radial electrostatic stabilizer geometry (using circuitry similar to that employed in the vertical stabilizer). This version is suitable for stabilizing radial (lateral) displacements of a rotor that is levitated by annular permanent magnets that are stable against vertical displacements but are unstable against radial displacements.

49 CFR 24.402 - Replacement housing payment for 90-day occupants.

Code of Federal Regulations, 2012 CFR

2012-10-01

... occupied the displacement dwelling for at least 90 days immediately prior to the initiation of negotiations... or she moves from the displacement dwelling; or (ii) For an owner-occupant, the later of: (A) The date he or she receives final payment for the displacement dwelling, or in the case of condemnation...

49 CFR 24.402 - Replacement housing payment for 90-day occupants.

Code of Federal Regulations, 2010 CFR

2010-10-01

... occupied the displacement dwelling for at least 90 days immediately prior to the initiation of negotiations... or she moves from the displacement dwelling; or (ii) For an owner-occupant, the later of: (A) The date he or she receives final payment for the displacement dwelling, or in the case of condemnation...

49 CFR 24.402 - Replacement housing payment for 90-day occupants.

Code of Federal Regulations, 2014 CFR

2014-10-01

... occupied the displacement dwelling for at least 90 days immediately prior to the initiation of negotiations... or she moves from the displacement dwelling; or (ii) For an owner-occupant, the later of: (A) The date he or she receives final payment for the displacement dwelling, or in the case of condemnation...

49 CFR 24.402 - Replacement housing payment for 90-day occupants.

Code of Federal Regulations, 2013 CFR

2013-10-01

... occupied the displacement dwelling for at least 90 days immediately prior to the initiation of negotiations... or she moves from the displacement dwelling; or (ii) For an owner-occupant, the later of: (A) The date he or she receives final payment for the displacement dwelling, or in the case of condemnation...

49 CFR 24.402 - Replacement housing payment for 90-day occupants.

Code of Federal Regulations, 2011 CFR

2011-10-01

... occupied the displacement dwelling for at least 90 days immediately prior to the initiation of negotiations... or she moves from the displacement dwelling; or (ii) For an owner-occupant, the later of: (A) The date he or she receives final payment for the displacement dwelling, or in the case of condemnation...

Transport of nano-objects in narrow channels: influence of Brownian diffusion, confinement and particle nature

NASA Astrophysics Data System (ADS)

Liot, O.; Socol, M.; Garcia, L.; Thiéry, J.; Figarol, A.; Mingotaud, A. F.; Joseph, P.

2018-06-01

This paper presents experimental results about transport of dilute suspensions of nano-objects in silicon-glass micrometric and sub-micrometric channels. Two kinds of objects are used: solid, rigid latex beads and spherical capsule-shaped, soft polymersomes. They are tracked using fluorescence microscopy. Three aspects are studied: confinement (ratio between particle diameter and channel depth), Brownian diffusion and particle nature. The aim of this work is to understand how these different aspects affect the transport of suspensions in narrow channels and to understand the different mechanisms at play. Concerning the solid beads we observe the appearance of two regimes, one where the experimental mean velocity is close to the expected one and another where this velocity is lower. This is directly related to a competition between confinement, Brownian diffusion and advection. These two regimes are shown to be linked to the inhomogeneity of particles distribution in the channel depth, which we experimentally deduce from velocity distributions. This inhomogeneity appears during the entrance process into the sub-micrometric channels, as for hydrodynamic separation or deterministic lateral displacement. Concerning the nature of the particles we observed a shift of transition towards the second regime likely due to the relationships between shear stress and polymersomes mechanical properties which could reduce the inhomogeneity imposed by the geometry of our device.

Transport of nano-objects in narrow channels: influence of Brownian diffusion, confinement and particle nature.

PubMed

Liot, O; Socol, M; Garcia, L; Thiéry, J; Figarol, A; Mingotaud, A F; Joseph, P

2018-06-13

This paper presents experimental results about transport of dilute suspensions of nano-objects in silicon-glass micrometric and sub-micrometric channels. Two kinds of objects are used: solid, rigid latex beads and spherical capsule-shaped, soft polymersomes. They are tracked using fluorescence microscopy. Three aspects are studied: confinement (ratio between particle diameter and channel depth), Brownian diffusion and particle nature. The aim of this work is to understand how these different aspects affect the transport of suspensions in narrow channels and to understand the different mechanisms at play. Concerning the solid beads we observe the appearance of two regimes, one where the experimental mean velocity is close to the expected one and another where this velocity is lower. This is directly related to a competition between confinement, Brownian diffusion and advection. These two regimes are shown to be linked to the inhomogeneity of particles distribution in the channel depth, which we experimentally deduce from velocity distributions. This inhomogeneity appears during the entrance process into the sub-micrometric channels, as for hydrodynamic separation or deterministic lateral displacement. Concerning the nature of the particles we observed a shift of transition towards the second regime likely due to the relationships between shear stress and polymersomes mechanical properties which could reduce the inhomogeneity imposed by the geometry of our device.

Surface deformation associated with the 2013 Mw7.7 Balochistan earthquake: Geologic slip rates may significantly underestimate strain release

NASA Astrophysics Data System (ADS)

Gold, Ryan; Reitman, Nadine; Briggs, Richard; Barnhart, William; Hayes, Gavin

2015-04-01

The 24 September 2013 Mw7.7 Balochistan, Pakistan earthquake ruptured a ~200 km-long stretch of the 60° ± 15° northwest-dipping Hoshab fault in southern Pakistan. The earthquake is notable because it produced the second-largest lateral surface displacement observed for a continental strike-slip earthquake. Surface displacements and geodetic and teleseismic inversions indicate that peak slip occurred within the upper 0-3 km of the crust. To explore along-strike and fault-perpendicular surface deformation patterns, we remotely mapped the surface trace of the rupture and measured its surface deformation using high-resolution (0.5 m) pre- and post-event satellite imagery. Post-event images were collected 7-114 days following the earthquake, so our analysis captures the sum of both the coseismic and post-seismic (e.g., after slip) deformation. We document peak left-lateral offset of ~15 m using 289 near-field (±10 m from fault) laterally offset piercing points, such as streams, terrace risers, and roads. We characterize off-fault deformation by measuring the medium- (±200 m from fault) and far-field (±10 km from fault) displacement using manual (242 measurements) and automated image cross-correlation methods. Off-fault peak lateral displacement values (medium- and far-field) are ~16 m and commonly exceed the on-fault displacement magnitudes. Our observations suggest that coseismic surface displacement typically increases with distance away from the surface trace of the fault; however, the majority of surface displacement is within 100 m of the primary fault trace and is most localized on sections of the rupture exhibiting narrow (<5 m) zones of observable surface deformation. Furthermore, the near-field displacement measurements account for, on average, only 73% of the total coseismic displacement field and the pattern is highly heterogeneous. This analysis highlights the importance of identifying paleoseismic field study sites (e.g. trenches) that span fault sections with narrow deformation zones in order to capture the full deformation field. Our results imply that hazard analyses based on geologically-determined fault slip rates (e.g., near-field) should consider the significant and heterogeneous mismatch we document between on- and off-fault coseismic deformation.

Comparing Newmark

NASA Astrophysics Data System (ADS)

Rodríguez-Peces, M. J.; García-Mayordomo, J.; Azañón-Hernández, J. M.; Jabaloy-Sánchez, A.

2009-04-01

The Lorca Basin (Eastern Betic Cordillera, SE Spain) is one of the most seismically active regions of Spain. In this area there are well known cases of earthquake-induced slope instabilities associated to specific earthquakes (e.g., Bullas 2002, La Paca 2005). Furthermore, this area is characterized by moderate magnitude seismicity which mainly produces rock-falls and avalanches. In this work we present the results of our research at regional and site scales. For the regional scale, we have used a geographic information system (GIS) to develop an implementation of the Newmark's sliding rigid block method. We have particularly proposed a new variation of Newmark's method to consider soil and topographic amplification effects. Subsequently, we produced "Newmark displacement" maps for both probabilistic and deterministic seismic scenarios in the Lorca Basin. Probabilistic seismic scenarios consider three hazard maps in terms of peak ground acceleration (PGA) on rock corresponding to the 475-, 975- and 2475-year return periods (exceedance probability of 10, 5 and 2% in 50 years, respectively) in the Murcia Region. Deterministic seismic scenarios consider the occurrence of the most probable earthquake for a 475-year return period (Mw=5.0) at every location, or either a complete rupture of Lorca-Totana (Mw=6.7) or Puerto Lumbreras-Lorca (Mw=6.8) segments of Alhama de Murcia Fault. The Newmark displacement maps allowed us to identify areas with the highest potential seismic hazard, and also locate areas for future particular studies. We have found that rock-falls produced during the last earthquakes in Lorca Basin (e.g., Bullas 2002, La Paca 2005) match very well with areas with values of Newmark displacement lower than 2 cm in all the seismic scenarios considered. Therefore, it seems that low values of Newmark displacements are very likely associated with rock-falls. To support this hypothesis we have applied the Newmark method at a site scale. To do this, we have selected La Paca rock-fall which was generated during La Paca 2005 earthquake (mbLg=4.7, IEMS=VI-VII). We have used a terrestrial laser scanner in order to obtain a high resolution digital elevation model of La Paca rock-fall area. Moreover, we have performed a back-analysis based on field data to estimate the static safety factor previous to the earthquake and the critical acceleration. Furthermore, we have selected a representative strong ground motion record for La Paca earthquake from international databases. The critical acceleration and the peak ground acceleration values obtained from the strong ground motion record allowed us to estimate the actual soil and topographic amplification effects. Finally, we have calculated analytically the real Newmark displacement at La Paca rock-fall and we have compared this displacement with our GIS estimation in order to improve the calibration of Newmark's method at the regional scale.

Finger displacement in Parkinson disease: up? down? sideways?

PubMed

Lieberman, Abraham; Dhall, Rohit; Salins, Naomi; Sadreddin, Arshia; Moguel-Cobos, Guillermo; Karis, John; Krishnamurthi, Narayanan

2014-05-01

We previously reported that patients with tremor preponderant Parkinson disease (PD) displayed upward or lateral displacement of their more tremulous finger when they pointed both their index fingers at a target and closed their eyes for 15 seconds. In this study, we examined the phenomenon in 104 PD patients: 72 patients without tremor and 32 with minimal tremor to see if the displacement is related to the disease or the tremor. Sixty-eight of the 72 patients without tremor, 94%, exhibited finger displacement suggesting the phenomenon is related to the disease. None of the 104 patients were demented: mini-mental status examination (MMSE) score 29.0 ± 0. 75. Ninety patients displayed upward displacement (56 patients) or lateral or medial displacement (34 patients). MMSE score of the 90 patients: 29.2 ± 0.74 with no score < 28. Eight patients (6 without tremor) displayed downward displacement. MMSE score of the 8 patients: 27.5 ± 0.35 with 5 having MMSE score of 27. Although not significant the results suggest that patients with downward displacement and lower MMSE score may be evolving a dementia. Upward displacement with eyes closed for 15 seconds requires an ability to "remember" the position of the finger in space and to alter tone to overcome gravity. Downward displacement implies an inability to "remember" the position of the finger in space an inability to overcome the effects of gravity. This may be more likely in patients who are evolving a dementia. Two patients, with PD-like symptoms, and specific anatomical abnormalities are also presented as they illustrate the anatomy of finger displacement.

Hemodynamic Deterioration in Lateral Compression Pelvic Fracture After Prehospital Pelvic Circumferential Compression Device Application.

PubMed

Garner, Alan A; Hsu, Jeremy; McShane, Anne; Sroor, Adam

Increased fracture displacement has previously been described with the application of pelvic circumferential compression devices (PCCDs) in patients with lateral compression-type pelvic fracture. We describe the first reported case of hemodynamic deterioration temporally associated with the prehospital application of a PCCD in a patient with a complex acetabular fracture with medial displacement of the femoral head. Active hemorrhage from a site adjacent to the acetabular fracture was subsequently demonstrated on angiography. Caution in the application of PCCDs to patients with lateral compression-type fractures is warranted. Copyright © 2017 Air Medical Journal Associates. All rights reserved.

Changing contributions of stochastic and deterministic processes in community assembly over a successional gradient.

PubMed

Måren, Inger Elisabeth; Kapfer, Jutta; Aarrestad, Per Arild; Grytnes, John-Arvid; Vandvik, Vigdis

2018-01-01

Successional dynamics in plant community assembly may result from both deterministic and stochastic ecological processes. The relative importance of different ecological processes is expected to vary over the successional sequence, between different plant functional groups, and with the disturbance levels and land-use management regimes of the successional systems. We evaluate the relative importance of stochastic and deterministic processes in bryophyte and vascular plant community assembly after fire in grazed and ungrazed anthropogenic coastal heathlands in Northern Europe. A replicated series of post-fire successions (n = 12) were initiated under grazed and ungrazed conditions, and vegetation data were recorded in permanent plots over 13 years. We used redundancy analysis (RDA) to test for deterministic successional patterns in species composition repeated across the replicate successional series and analyses of co-occurrence to evaluate to what extent species respond synchronously along the successional gradient. Change in species co-occurrences over succession indicates stochastic successional dynamics at the species level (i.e., species equivalence), whereas constancy in co-occurrence indicates deterministic dynamics (successional niche differentiation). The RDA shows high and deterministic vascular plant community compositional change, especially early in succession. Co-occurrence analyses indicate stochastic species-level dynamics the first two years, which then give way to more deterministic replacements. Grazed and ungrazed successions are similar, but the early stage stochasticity is higher in ungrazed areas. Bryophyte communities in ungrazed successions resemble vascular plant communities. In contrast, bryophytes in grazed successions showed consistently high stochasticity and low determinism in both community composition and species co-occurrence. In conclusion, stochastic and individualistic species responses early in succession give way to more niche-driven dynamics in later successional stages. Grazing reduces predictability in both successional trends and species-level dynamics, especially in plant functional groups that are not well adapted to disturbance. © 2017 The Authors. Ecology, published by Wiley Periodicals, Inc., on behalf of the Ecological Society of America.

Optical tracking of acoustic radiation force impulse-induced dynamics in a tissue-mimicking phantom

PubMed Central

Bouchard, Richard R.; Palmeri, Mark L.; Pinton, Gianmarco F.; Trahey, Gregg E.; Streeter, Jason E.; Dayton, Paul A.

2009-01-01

Optical tracking was utilized to investigate the acoustic radiation force impulse (ARFI)-induced response, generated by a 5-MHz piston transducer, in a translucent tissue-mimicking phantom. Suspended 10-μm microspheres were tracked axially and laterally at multiple locations throughout the field of view of an optical microscope with 0.5-μm displacement resolution, in both dimensions, and at frame rates of up to 36 kHz. Induced dynamics were successfully captured before, during, and after the ARFI excitation at depths of up to 4.8 mm from the phantom’s proximal boundary. Results are presented for tracked axial and lateral displacements resulting from on-axis and off-axis (i.e., shear wave) acquisitions; these results are compared to matched finite element method modeling and independent ultrasonically based empirical results and yielded reasonable agreement in most cases. A shear wave reflection, generated by the proximal boundary, consistently produced an artifact in tracked displacement data later in time (i.e., after the initial ARFI-induced displacement peak). This tracking method provides high-frame-rate, two-dimensional tracking data and thus could prove useful in the investigation of complex ARFI-induced dynamics in controlled experimental settings. PMID:19894849

A comparison of lateral ankle ligament suture anchor strength.

PubMed

Barber, F Alan; Herbert, Morley A; Crates, John M

2013-06-01

Lateral ankle ligament repairs increasingly use suture anchors instead of bone tunnels. Our purpose was to compare the biomechanical properties of a knotted and knotless suture anchor appropriate for a lateral ankle ligament reconstruction. In porcine distal fibulae, 10 samples of 2 different PEEK anchors were inserted. The attached sutures were cyclically loaded between 10N and 60N for 200 cycles. A destructive pull was performed and failure loads, cyclic displacement, stiffness, and failure mode recorded. PushLock 2.5 anchors failed before 200 cycles. PushLock 100 cycle displacement was less than Morphix 2.5 displacement (p<0.001). Ultimate failure load for anchors completing 200 cycles was 86.5N (PushLock) and 252.1N (Morphix) (p<0.05). The failure mode was suture breaking for all PushLocks while the Morphix failed equally by anchor breaking and suture breakage. The knotted Morphix demonstrated more displacement and greater failure strength than the knotless PushLock. The PushLock failed consistently with suture breaking. The Morphix anchor failed both by anchor breaking and by suture breaking. Copyright © 2012 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Center of Pressure Displacement of Standing Posture during Rapid Movements Is Reorganised Due to Experimental Lower Extremity Muscle Pain.

PubMed

Shiozawa, Shinichiro; Hirata, Rogerio Pessoto; Graven-Nielsen, Thomas

2015-01-01

Postural control during rapid movements may be impaired due to musculoskeletal pain. The purpose of this study was to investigate the effect of experimental knee-related muscle pain on the center of pressure (CoP) displacement in a reaction time task condition. Nine healthy males performed two reaction time tasks (dominant side shoulder flexion and bilateral heel lift) before, during, and after experimental pain induced in the dominant side vastus medialis or the tibialis anterior muscles by hypertonic saline injections. The CoP displacement was extracted from the ipsilateral and contralateral side by two force plates and the net CoP displacement was calculated. Compared with non-painful sessions, tibialis anterior muscle pain during the peak and peak-to-peak displacement for the CoP during anticipatory postural adjustments (APAs) of the shoulder task reduced the peak-to-peak displacement of the net CoP in the medial-lateral direction (P<0.05). Tibialis anterior and vastus medialis muscle pain during shoulder flexion task reduced the anterior-posterior peak-to-peak displacement in the ipsilateral side (P<0.05). The central nervous system in healthy individuals was sufficiently robust in maintaining the APA characteristics during pain, although the displacement of net and ipsilateral CoP in the medial-lateral and anterior-posterior directions during unilateral fast shoulder movement was altered.

Surface Rupture and Slip Distribution Resulting from the 2013 M7.7 Balochistan, Pakistan Earthquake

NASA Astrophysics Data System (ADS)

Reitman, N. G.; Gold, R. D.; Briggs, R. W.; Barnhart, W. D.; Hayes, G. P.

2014-12-01

The 24 September 2013 M7.7 earthquake in Balochistan, Pakistan, produced a ~200 km long left-lateral strike-slip surface rupture along a portion of the Hoshab fault, a moderately dipping (45-75º) structure in the Makran accretionary prism. The rupture is remarkably continuous and crosses only two (0.7 and 1.5 km wide) step-overs along its arcuate path through southern Pakistan. Displacements are dominantly strike-slip, with a minor component of reverse motion. We remotely mapped the surface rupture at 1:5,000 scale and measured displacements using high resolution (0.5 m) pre- and post-event satellite imagery. We mapped 295 laterally faulted stream channels, terrace margins, and roads to quantify near-field displacement proximal (±10 m) to the rupture trace. The maximum near-field left-lateral offset is 15±2 m (average of ~7 m). Additionally, we used pre-event imagery to digitize 254 unique landforms in the "medium-field" (~100-200 m from the rupture) and then measured their displacements compared to the post-event imagery. At this scale, maximum left-lateral offset approaches 17 m (average of ~8.5 m). The width (extent of observed surface faulting) of the rupture zone varies from ~1 m to 3.7 km. Near- and medium-field offsets show similar slip distributions that are inversely correlated with the width of the fault zone at the surface (larger offsets correspond to narrow fault zones). The medium-field offset is usually greater than the near-field offset. The along-strike surface slip distribution is highly variable, similar to the slip distributions documented for the 2002 Denali M7.9 earthquake and 2001 Kunlun M7.8 earthquake, although the Pakistan offsets are larger in magnitude. The 2013 Pakistan earthquake ranks among the largest documented continental strike-slip displacements, possibly second only to the 18+ m surface displacements attributed to the 1855 Wairarapa M~8.1 earthquake.

Probabilistic Evaluation of Advanced Ceramic Matrix Composite Structures

NASA Technical Reports Server (NTRS)

Abumeri, Galib H.; Chamis, Christos C.

2003-01-01

The objective of this report is to summarize the deterministic and probabilistic structural evaluation results of two structures made with advanced ceramic composites (CMC): internally pressurized tube and uniformly loaded flange. The deterministic structural evaluation includes stress, displacement, and buckling analyses. It is carried out using the finite element code MHOST, developed for the 3-D inelastic analysis of structures that are made with advanced materials. The probabilistic evaluation is performed using the integrated probabilistic assessment of composite structures computer code IPACS. The affects of uncertainties in primitive variables related to the material, fabrication process, and loadings on the material property and structural response behavior are quantified. The primitive variables considered are: thermo-mechanical properties of fiber and matrix, fiber and void volume ratios, use temperature, and pressure. The probabilistic structural analysis and probabilistic strength results are used by IPACS to perform reliability and risk evaluation of the two structures. The results will show that the sensitivity information obtained for the two composite structures from the computational simulation can be used to alter the design process to meet desired service requirements. In addition to detailed probabilistic analysis of the two structures, the following were performed specifically on the CMC tube: (1) predicted the failure load and the buckling load, (2) performed coupled non-deterministic multi-disciplinary structural analysis, and (3) demonstrated that probabilistic sensitivities can be used to select a reduced set of design variables for optimization.

Simulating interfering fringe displacements by lateral shifts of a camera for educational purposes

NASA Astrophysics Data System (ADS)

Rivera-Ortega, Uriel

2018-07-01

In this manuscript we propose a simple method to emulate fringe displacements in a fringe pattern, due to the interference of two plane waves, by using lateral shifts of a CMOS detector under the scheme of a Twyman–Green interferometric setup, avoiding unwanted vibrations and the need for specific and expensive devices in order to accomplish the task. The simplicity of the proposed experimental setup allows it to be easily replicated and used for teaching or demonstrative purposes, essentially for undergraduate students.

Concomitant intra-articular glenohumeral injuries in displaced fractures of the lateral clavicle.

PubMed

Beirer, Marc; Zyskowski, Michael; Crönlein, Moritz; Pförringer, Dominik; Schmitt-Sody, Marcus; Sandmann, Gunther; Huber-Wagner, Stefan; Biberthaler, Peter; Kirchhoff, Chlodwig

2017-10-01

To detect concomitant intra-articular glenohumeral injuries, in acute displaced fractures of the lateral clavicle, initially missed due to unfeasible clinical evaluation of the acutely injured shoulder. All patients suffering from an acute displaced lateral clavicle fracture with indication to surgical treatment underwent diagnostic shoulder arthroscopy prior to open reduction and internal fixation. In case of therapy-relevant intra-articular glenohumeral injuries, subsequent surgical treatment was performed. Intra-articular injuries were found in 13 of 28 patients (46.4 %) with initially suspected isolated lateral clavicle fracture. Additional surgical treatment was performed in 8 of 28 cases (28.6 %). Superior labral anterior-posterior (SLAP) lesions were observed in 4 of 28 patients (14.3 %; SLAP II a: 1; II b: 1; III: 1; and IV: 1). Lesions of the pulley system were found in 3 of 28 patients (10.7 %; Habermeyer III°). One partial articular supraspinatus tendon avulsion lesion (3.6 %) and one lesion of the subscapularis tendon (3.6 %; Fox and Romeo II°) were observed. Traumatic concomitant glenohumeral injuries in lateral clavicle fractures seem to be more frequent than expected in general. Subsequent surgical treatment of these formerly missed but therapy-relevant injuries may increase functional outcome and reduce complication rate. IV.

Comparison of a tube-holder (Rescuefix) versus tape-tying for minimizing double-lumen tube displacement during lateral positioning in thoracic surgery

PubMed Central

Byun, Sung Hye; Kang, Su Hwang; Kim, Jong Hae; Ryu, Taeha; Kim, Baek Jin; Jung, Jin Yong

2016-01-01

Abstract Background: Double-lumen endotracheal tubes (DLTs) are often displaced during change from the supine to the lateral decubitus position. The aim of this study was to determine whether Rescuefix, a recently developed tube-holder device, is more effective than the traditional tape-tying method for tube security during lateral positioning. Methods: Patients were randomly assigned to a Rescuefix (R) group (n = 22) or a tape (T) group (n = 22). After intubation with a left-sided DLT and adjustment of the appropriate DLT position using a fiberoptic bronchoscope, the DLT was fixed firmly at the side of the mouth by either Rescuefix or Durapore tape. “Tracheal depth” (from the tracheal carina to the elbow connector of the DLT) and “bronchial depth” (from the left bronchial carina to the elbow connector of the DLT) were measured in the supine position using the fiberoptic bronchoscope. After positional change, tracheal and bronchial depths were measured as described above. As the primary endpoint, displacement of the DLT during positional change was evaluated by obtaining the difference in depths measured when the patient was in the supine and lateral decubitus positions. In addition, after lateral positioning of the patient, any requirement for repositioning the DLT was recorded. Results: After lateral positioning, there were no significant differences in changes in tracheal and bronchial depths between the groups (tracheal depth 6.1 ± 4.4 mm [R group] and 9.1 ± 5.6 mm [T group], P = 0.058; bronchial depth 6.5 ± 4.4 mm [R group], and 8.5 ± 4.6 mm [T group], P = 0.132). Although the amount of change in tracheal and bronchial depths was not different between the groups, the need to reposition the DLT was significantly lower in the R group than in the T group (32% vs 68%, P = 0.016). Conclusion: This study demonstrated that use of Rescuefix did not reduce the amount of DLT displacement, but it did significantly lower the incidence of DLT repositioning compared with the tape-tying method. Therefore, Rescuefix appears to be an effective alternative to minimizing DLT displacement during lateral positioning in thoracic surgery. Trial registration: http://cris.nih.go.kr identifier: KCT0001949. PMID:27495093

Micromanipulation of statoliths in gravity-sensing Chara rhizoids by optical tweezers.

PubMed

Leitz, G; Schnepf, E; Greulich, K O

1995-09-01

Infrared laser traps (optical tweezers) were used to micromanipulate statoliths in gravity-sensing rhizoids of the green alga Chara vulgaris Vail. We were able to hold and move statoliths with high accuracy and to observe directly the effects of statolith position on cell growth in horizontally positioned rhizoids. The first step in gravitropism, namely the physical action of gravity on statoliths, can be simulated by optical tweezers. The direct laser microirradiation of the rhizoid apex did not cause any visible damage to the cells. Through lateral positioning of statoliths a differential growth of the opposite flank of the cell wall could be induced, corresponding to bending growth in gravitropism. The acropetal displacement of the statolith complex into the extreme apex of the rhizoid caused a temporary decrease in cell growth rate. The rhizoids regained normal growth after remigration of the statoliths to their initial position 10-30 micrometers basal to the rhizoid apex. During basipetal displacement of statoliths, cell growth continued and the statoliths remigrated towards the rhizoid tip after release from the optical trap. The resistance to statolith displacement increased towards the nucleus. The basipetal displacement of the whole complex of statoliths for a long distance (>100 micrometers) caused an increase in cell diameter and a subsequent regaining of normal growth after the statoliths reappeared in the rhizoid apex. We conclude that the statolith displacement interferes with the mechanism of tip growth, i.e. with the transport of Golgi vesicles, either directly by mechanically blocking their flow and/or, indirectly, by disturbing the actomyosin system. In the presence of the actin inhibitor cytochalasin B the optical forces required for acropetal and basipetal displacement of statoliths were significantly reduced to a similar level. The lateral displacement of statoliths was not changed by cytochalasin B. The results indicate: (i) the viscous resistance to optical displacement of statoliths depend mainly on actin, (ii) the lateral displacement of statoliths is not impeded by actin filaments, (iii) the axially directed actin-mediated forces against optical displacement of statoliths (for a distance of 10 micrometers) are stronger in the basipetal than in the acropetal direction, (iv) the forces acting on single statoliths by axially oriented actin filaments are estimated to be in the range of 11-110 pN for acropetal and of 18-180 pN for basipetal statolith displacements.

Comparison of microtweezers based on three lateral thermal actuator configurations

NASA Astrophysics Data System (ADS)

Luo, J. K.; Flewitt, A. J.; Spearing, S. M.; Fleck, N. A.; Milne, W. I.

2005-06-01

Thermal actuator-based microtweezers with three different driving configurations have been designed, fabricated and characterized. Finite element analysis has been used to model the device performance. It was found that one configuration of microtweezer, based on two lateral bimorph thermal actuators, has a small displacement (tip opening of the tweezers) and a very limited operating power range. An alternative configuration consisting of two horizontal hot bars with separated beams as the arms can deliver a larger displacement with a much-extended operating power range. This structure can withstand a higher temperature due to the wider beams used, and has flexible arms for increased displacement. Microtweezers driven by a number of chevron structures in parallel have similar maximum displacements but at a cost of higher power consumption. The measured temperature of the devices confirms that the device with the chevron structure can deliver the largest displacement for a given working temperature, while the bimorph thermal actuator design has the highest operating temperature at the same power due to its thin hot arm, and is prone to structural failure.

Neutral heel lateral push test: The first clinical examination of spring ligament integrity.

PubMed

Pasapula, Chandra; Devany, Adam; Magan, Ahmed; Memarzadeh, A; Pasters, V; Shariff, S

2015-06-01

The spring (calcaneonavicular) ligament is an intricate multiligament complex whose primary role is to stabilise the medial longitudinal arch and head of talus. Clinical suspicion of a spring ligament injury in isolation is roused when persistent medial midfoot pain is present with associated pes planus following trauma. We undertook a cadaveric study on 21 specimens to assess the use of a neutral heel lateral push test to examine the spring ligament in a standardised procedure, measuring lateral translation with graduated antegrade and retrograde defunctioning of surrounding structures and the spring ligament. In all specimens, a significant displacement occurred on incision of the spring ligament regardless of order of dissection. The degree of displacement increased by an insignificant amount as surrounding structures were incised at each incremental force applied. The neutral heel push test is the first clinical examination to be described to determine integrity of the spring ligament complex. Our study objectively demonstrates that lateral displacement in relation to the mid and hind-foot is influenced most significantly by the integrity of the spring ligament and to a lesser extent by tibialis posterior and flexor digitorum longus. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Relationship of Static Tibial Tubercle-Trochlear Groove Measurement and Dynamic Patellar Tracking.

PubMed

Carlson, Victor R; Sheehan, Frances T; Shen, Aricia; Yao, Lawrence; Jackson, Jennifer N; Boden, Barry P

2017-07-01

The tibial tubercle to trochlear groove (TT-TG) distance is used for screening patients with a variety of patellofemoral joint disorders to determine who may benefit from patellar medialization using a tibial tubercle osteotomy. Clinically, the TT-TG distance is predominately based on static imaging with the knee in full extension; however, the predictive ability of this measure for dynamic patellar tracking patterns is unknown. To determine whether the static TT-TG distance can predict dynamic lateral displacement of the patella. Cohort study (Diagnosis); Level of evidence, 2. The static TT-TG distance was measured at full extension for 70 skeletally mature subjects with (n = 32) and without (n = 38) patellofemoral pain. The dynamic patellar tracking patterns were assessed from approximately 45° to 0° of knee flexion by use of dynamic cine-phase contrast magnetic resonance imaging. For each subject, the value of dynamic lateral tracking corresponding to the exact knee angle measured in the static images for that subject was identified. Linear regression analysis determined the predictive ability of static TT-TG distance for dynamic patellar lateral displacement for each cohort. The static TT-TG distance measured with the knee in full extension cannot accurately predict dynamic lateral displacement of the patella. There was weak predictive ability among subjects with patellofemoral pain ( r 2 = 0.18, P = .02) and no predictive capability among controls. Among subjects with patellofemoral pain and static TT-TG distances 15 mm or more, 8 of 13 subjects (62%) demonstrated neutral or medial patellar tracking patterns. The static TT-TG distance cannot accurately predict dynamic lateral displacement of the patella. A large percentage of patients with patellofemoral pain and pathologically large TT-TG distances may have neutral to medial maltracking patterns.

Model based estimation of image depth and displacement

NASA Technical Reports Server (NTRS)

Damour, Kevin T.

1992-01-01

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.

Do macroeconomic contractions induce or 'harvest' suicides? A test of competing hypotheses.

PubMed

Gemmill, Alison; Falconi, April; Karasek, Deborah; Hartig, Terry; Anderson, Elizabeth; Catalano, Ralph

2015-11-01

Researchers often invoke a mortality displacement or 'harvesting' mechanism to explain mortality patterns, such that those with underlying health vulnerabilities die sooner than expected in response to environmental phenomena, such as heat waves, cold spells and air pollution. It is unclear if this displacement mechanism might also explain observed increases in suicide following economic contraction, or if suicides are induced in persons otherwise unlikely to engage in self-destructive behaviour. Here, we test two competing hypotheses explaining an observed increase in suicides following unemployment-induction or displacement. We apply time series methods to monthly suicide and unemployment data from Sweden for the years 2000-2011. Tests are conducted separately for working age (20-64 years old) men and women as well as older (aged 65 years and older) men and women. Displacement appeared among older men and women; an unexpected rise in unemployment predicted an increase in suicides 6 months later, followed by a significant decrease 8 months later. Induction appeared among working age men, but not among working age women; an unexpected rise in unemployment predicted an increase in suicides 4-6 months later. Displacement and induction both appear to have operated following unexpected labour market contractions in Sweden, though with different population segments. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Effect of magnetic attachment with stress breaker on lateral stress to abutment tooth under overdenture.

PubMed

Gonda, T; Ikebe, K; Ono, T; Nokubi, T

2004-10-01

Recently, a newly developed magnetic attachment with stress breaker was used in retentive components in overdentures. Excessive lateral stress has a more harmful effect on natural teeth than axial stress, and the magnetic attachment with stress breaker is expected to reduce lateral forces on abutment teeth and protect it teeth from excessive stress. However, the properties of this retainer have not yet been determined experimentally. This study compares the lateral forces on abutment teeth for three retainers under loading on the denture base in a model study. A mandibular simulation model is constructed to measure lateral stress. Three types of retentive devices are attached to the canine root. These devices include the conventional root coping, the conventional magnetic attachment and the new magnetic attachment with stress breaker. For each retentive device, load is generated on the occlusal table of the model overdenture, and the lateral stress on the canine root and the displacement of the overdenture measured. The magnetic attachment with stress breaker does not displace the denture and exhibits lower lateral stress in the canine root than conventional root coping and magnetic attachments.

Force and displacement measurements of the distal fibula during simulated ankle loading tests for high ankle sprains.

PubMed

Markolf, Keith L; Jackson, Steven; McAllister, David R

2012-09-01

Syndesmosis (high ankle) sprains produce disruption of the distal tibiofibular ligaments. Forces on the distal fibula that produce these injuries are unknown. Twenty-seven fresh-frozen lower extremities were used for this study. A load cell recorded forces acting on the distal fibula from forced ankle dorsiflexion and applied external foot torque; medial-lateral and anterior-posterior displacements of the distal fibula were recorded. Fibular forces and axial displacements were also recorded with applied axial force. During forced ankle dorsiflexion and external foot torque tests, the distal fibula always displaced posteriorly with respect to the tibia with no measurable medial-lateral displacement. With 10 Nm dorsiflexion moment, cutting the tibiofibular ligaments approximately doubled fibular force and displacement values. Cutting the tibiofibular ligaments significantly increased fibular displacement from applied external foot torque. Fibular forces and axial displacements from applied axial weight-bearing force were highest with the foot dorsiflexed. The highest mean fibular force in the study (271.9 N) occurred with 10 Nm external foot torque applied to a dorsiflexed foot under 1000 N axial force. Two important modes of loading that could produce high ankle sprains were identified: forced ankle dorsiflexion and external foot torque applied to a dorsiflexed ankle loaded with axial force. The distal tibiofibular ligaments restrained fibular displacement during these tests. Residual mortise widening observed at surgery may be the result of tibiofibular ligament injuries caused by posterior displacement of the fibula. Therefore, a syndesmosis screw used to fix the fibula would be subjected to posterior bending forces from these loading modes. Ankle bracing to prevent extreme ankle dorsiflexion during rehabilitation may be advisable to prevent excessive fibular motions that could affect syndesmosis healing.

Taking a gamble or playing by the rules: Dissociable prefrontal systems implicated in probabilistic versus deterministic rule-based decisions

PubMed Central

Bhanji, Jamil P.; Beer, Jennifer S.; Bunge, Silvia A.

2014-01-01

A decision may be difficult because complex information processing is required to evaluate choices according to deterministic decision rules and/or because it is not certain which choice will lead to the best outcome in a probabilistic context. Factors that tax decision making such as decision rule complexity and low decision certainty should be disambiguated for a more complete understanding of the decision making process. Previous studies have examined the brain regions that are modulated by decision rule complexity or by decision certainty but have not examined these factors together in the context of a single task or study. In the present functional magnetic resonance imaging study, both decision rule complexity and decision certainty were varied in comparable decision tasks. Further, the level of certainty about which choice to make (choice certainty) was varied separately from certainty about the final outcome resulting from a choice (outcome certainty). Lateral prefrontal cortex, dorsal anterior cingulate cortex, and bilateral anterior insula were modulated by decision rule complexity. Anterior insula was engaged more strongly by low than high choice certainty decisions, whereas ventromedial prefrontal cortex showed the opposite pattern. These regions showed no effect of the independent manipulation of outcome certainty. The results disambiguate the influence of decision rule complexity, choice certainty, and outcome certainty on activity in diverse brain regions that have been implicated in decision making. Lateral prefrontal cortex plays a key role in implementing deterministic decision rules, ventromedial prefrontal cortex in probabilistic rules, and anterior insula in both. PMID:19781652

40 CFR 60.4204 - What emission standards must I meet for non-emergency engines if I am an owner or operator of a...

Code of Federal Regulations, 2010 CFR

2010-07-01

... with a displacement of less than 10 liters per cylinder must comply with the emission standards in... with a displacement of greater than or equal to 10 liters per cylinder and less than 30 liters per... model year and later non-emergency stationary CI ICE with a displacement of less than 30 liters per...

The effect of shear wall location in resisting earthquake

NASA Astrophysics Data System (ADS)

Tarigan, J.; Manggala, J.; Sitorus, T.

2018-02-01

Shear wall is one of lateral resisting structure which is used commonly. Shear wall gives high stiffness to the structure so as the structure will be stable. Applying shear wall can effectively reduce the displacement and story-drift of the structure. This will reduce the destruction comes from lateral loads such as an earthquake. Earlier studies showed that shear wall gives different performance based on its position in structures. In this paper, seismic analysis has been performed using response spectrum method for different Model of structures; they are the open frame, the shear wall at core symmetrically, the shear wall at periphery symmetrically, and the shear wall at periphery asymmetrically. The results are observed by comparing the displacement and story-drift. Based on the analysis, the placement of shear wall at the core of structure symmetrically gives the best performance to reduce the displacement and story-drift. It can reduce the displacement up to 61.16% (X-dir) and 70.60% (Y-dir). The placement of shear wall at periphery symmetrically will reduce the displacement up to 53.85% (X-dir) and 47.87% (Y-dir) while the placement of shear wall at periphery asymmetrically reducing the displacement up to 59.42% (X-dir) and 66.99% (Y-dir).

Identification of Lembang fault, West-Java Indonesia by using controlled source audio-magnetotelluric (CSAMT)

NASA Astrophysics Data System (ADS)

Sanny, Teuku A.

2017-07-01

The objective of this study is to determine boundary and how to know surrounding area between Lembang Fault and Cimandiri fault. For the detailed study we used three methodologies: (1). Surface deformation modeling by using Boundary Element method and (2) Controlled Source Audiomagneto Telluric (CSAMT). Based on the study by using surface deformation by using Boundary Element Methods (BEM), the direction Lembang fault has a dominant displacement in east direction. The eastward displacement at the nothern fault block is smaller than the eastward displacement at the southern fault block which indicates that each fault block move in left direction relative to each other. From this study we know that Lembang fault in this area has left lateral strike slip component. The western part of the Lembang fault move in west direction different from the eastern part that moves in east direction. Stress distribution map of Lembang fault shows difference between the eastern and western segments of Lembang fault. Displacement distribution map along x-direction and y-direction of Lembang fault shows a linement oriented in northeast-southwest direction right on Tangkuban Perahu Mountain. Displacement pattern of Cimandiri fault indicates that the Cimandiri fault is devided into two segment. Eastern segment has left lateral strike slip component while the western segment has right lateral strike slip component. Based on the displacement distribution map along y-direction, a linement oriented in northwest-southeast direction is observed at the western segment of the Cimandiri fault. The displacement along x-direction and y-direction between the Lembang and Cimandiri fault is nearly equal to zero indicating that the Lembang fault and Cimandiri Fault are not connected to each others. Based on refraction seismic tomography that we know the characteristic of Cimandiri fault as normal fault. Based on CSAMT method th e lembang fault is normal fault that different of dip which formed as graben structure.

Computational analysis of the roles of biochemical reactions in anomalous diffusion dynamics

NASA Astrophysics Data System (ADS)

Naruemon, Rueangkham; Charin, Modchang

2016-04-01

Most biochemical processes in cells are usually modeled by reaction-diffusion (RD) equations. In these RD models, the diffusive process is assumed to be Gaussian. However, a growing number of studies have noted that intracellular diffusion is anomalous at some or all times, which may result from a crowded environment and chemical kinetics. This work aims to computationally study the effects of chemical reactions on the diffusive dynamics of RD systems by using both stochastic and deterministic algorithms. Numerical method to estimate the mean-square displacement (MSD) from a deterministic algorithm is also investigated. Our computational results show that anomalous diffusion can be solely due to chemical reactions. The chemical reactions alone can cause anomalous sub-diffusion in the RD system at some or all times. The time-dependent anomalous diffusion exponent is found to depend on many parameters, including chemical reaction rates, reaction orders, and chemical concentrations. Project supported by the Thailand Research Fund and Mahidol University (Grant No. TRG5880157), the Thailand Center of Excellence in Physics (ThEP), CHE, Thailand, and the Development Promotion of Science and Technology.

Real-time modulated nanoparticle separation with an ultra-large dynamic range.

PubMed

Zeming, Kerwin Kwek; Thakor, Nitish V; Zhang, Yong; Chen, Chia-Hung

2016-01-07

Nanoparticles exhibit size-dependent properties which make size-selective purification of proteins, DNA or synthetic nanoparticles essential for bio-analytics, clinical medicine, nano-plasmonics and nano-material sciences. Current purification methods of centrifugation, column chromatography and continuous-flow techniques suffer from particle aggregation, multi-stage process, complex setups and necessary nanofabrication. These increase process costs and time, reduce efficiency and limit dynamic range. Here, we achieve an unprecedented real-time nanoparticle separation (51-1500 nm) using a large-pore (2 μm) deterministic lateral displacement (DLD) device. No external force fields or nanofabrication are required. Instead, we investigated innate long-range electrostatic influences on nanoparticles within a fluid medium at different NaCl ionic concentrations. In this study we account for the electrostatic forces beyond Debye length and showed that they cannot be assumed as negligible especially for precise nanoparticle separation methods such as DLD. Our findings have enabled us to develop a model to simultaneously quantify and modulate the electrostatic force interactions between nanoparticle and micropore. By simply controlling buffer solutions, we achieve dynamic nanoparticle size separation on a single device with a rapid response time (<20 s) and an enlarged dynamic range (>1200%), outperforming standard benchtop centrifuge systems. This novel method and model combines device simplicity, isolation precision and dynamic flexibility, opening opportunities for high-throughput applications in nano-separation for industrial and biological applications.

Lateral Attitude Change.

PubMed

Glaser, Tina; Dickel, Nina; Liersch, Benjamin; Rees, Jonas; Süssenbach, Philipp; Bohner, Gerd

2015-08-01

The authors propose a framework distinguishing two types of lateral attitude change (LAC): (a) generalization effects, where attitude change toward a focal object transfers to related objects, and (b) displacement effects, where only related attitudes change but the focal attitude does not change. They bring together examples of LAC from various domains of research, outline the conditions and underlying processes of each type of LAC, and develop a theoretical framework that enables researchers to study LAC more systematically in the future. Compared with established theories of attitude change, the LAC framework focuses on lateral instead of focal attitude change and encompasses both generalization and displacement. Novel predictions and designs for studying LAC are presented. © 2014 by the Society for Personality and Social Psychology, Inc.

Rotation elastogram: a novel method to visualize local rigid body rotation under quasi-static compression

NASA Astrophysics Data System (ADS)

Sowmiya, C.; Kothawala, Ali Arshad; Thittai, Arun K.

2016-04-01

During manual palpation of breast masses, the perception of its stiffness and slipperiness are the two commonly used information by the physician. In order to reliably and quantitatively obtain this information several non-invasive elastography techniques have been developed that seek to provide an image of the underlying mechanical properties, mostly stiffness-related. Very few approaches have visualized the "slip" at the lesion-background boundary that only occurs for a loosely-bonded benign lesion. It has been shown that axial-shear strain distribution provides information about underlying slip. One such feature, referred to as "fill-in" was interpreted as a surrogate of the rotation undergone by an asymmetrically-oriented-loosely bonded-benign-lesion under quasi-static compression. However, imaging and direct visualization of the rotation itself has not been addressed yet. In order to accomplish this, the quality of lateral displacement estimation needs to be improved. In this simulation study, we utilize spatial compounding approach and assess the feasibility to obtain good quality rotation elastogram. The angular axial and lateral displacement estimates were obtained at different insonification angles from a phantom containing an elliptical inclusion oriented at 45°, subjected to 1% compression from the top. A multilevel 2D-block matching algorithm was used for displacement tracking and 2D-least square compounding of angular axial and lateral displacement estimates was employed. By varying the maximum steering angle and incremental angle, the improvement in the lateral motion tracking accuracy and its effects on the quality of rotational elastogram were evaluated. Results demonstrate significantly-improved rotation elastogram using this technique.

The evaluation of lateral pterygoid muscle pathologic changes and insertion patterns in temporomandibular joints with or without disc displacement using magnetic resonance imaging.

PubMed

Imanimoghaddam, M; Madani, A S; Hashemi, E M

2013-09-01

Temporomandibular joint (TMJ) disc displacement is a common disorder in patients with internal derangement. Certain anatomic features of TMJ may make the patient prone to this condition, namely lateral pterygoid muscle (LPM) insertion variations. The aim of this study was to investigate LPM attachments and their relationships with disc displacement and subsequent pathologic changes. A total of 26 patients with clinical temporomandibular disorders (TMDs) and a control group of 14 unaffected individuals were studied. Magnetic resonance images (MRIs) were taken to evaluate LPM insertion patterns, superior LPM head pathologic changes, and relative disc to condyle position. Data registration and analysis were done using SPSS v. 16.0. The most common variation (type I) was shown to be the superior head with two bundles, one attached to the disc and another to the condyle. No significant relationship between LPM insertion type and disc displacement or pathologic changes of the muscle was found. However, a link between disc displacement and muscle pathologic changes was established (P=0.001). Copyright © 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Crack Monitoring of Operational Wind Turbine Foundations

PubMed Central

McAlorum, Jack; Fusiek, Grzegorz; Niewczas, Pawel; McKeeman, Iain; Rubert, Tim

2017-01-01

The degradation of onshore, reinforced-concrete wind turbine foundations is usually assessed via above-ground inspections, or through lengthy excavation campaigns that suspend wind power generation. Foundation cracks can and do occur below ground level, and while sustained measurements of crack behaviour could be used to quantify the risk of water ingress and reinforcement corrosion, these cracks have not yet been monitored during turbine operation. Here, we outline the design, fabrication and field installation of subterranean fibre-optic sensors for monitoring the opening and lateral displacements of foundation cracks during wind turbine operation. We detail methods for in situ sensor characterisation, verify sensor responses against theoretical tower strains derived from wind speed data, and then show that measured crack displacements correlate with monitored tower strains. Our results show that foundation crack opening displacements respond linearly to tower strain and do not change by more than ±5 μm. Lateral crack displacements were found to be negligible. We anticipate that the work outlined here will provide a starting point for real-time, long-term and dynamic analyses of crack displacements in future. Our findings could furthermore inform the development of cost-effective monitoring systems for ageing wind turbine foundations. PMID:28825687

Shell Tectonics: A Mechanical Model for Strike-slip Displacement on Europa

NASA Technical Reports Server (NTRS)

Rhoden, Alyssa Rose; Wurman, Gilead; Huff, Eric M.; Manga, Michael; Hurford, Terry A.

2012-01-01

We introduce a new mechanical model for producing tidally-driven strike-slip displacement along preexisting faults on Europa, which we call shell tectonics. This model differs from previous models of strike-slip on icy satellites by incorporating a Coulomb failure criterion, approximating a viscoelastic rheology, determining the slip direction based on the gradient of the tidal shear stress rather than its sign, and quantitatively determining the net offset over many orbits. This model allows us to predict the direction of net displacement along faults and determine relative accumulation rate of displacement. To test the shell tectonics model, we generate global predictions of slip direction and compare them with the observed global pattern of strike-slip displacement on Europa in which left-lateral faults dominate far north of the equator, right-lateral faults dominate in the far south, and near-equatorial regions display a mixture of both types of faults. The shell tectonics model reproduces this global pattern. Incorporating a small obliquity into calculations of tidal stresses, which are used as inputs to the shell tectonics model, can also explain regional differences in strike-slip fault populations. We also discuss implications for fault azimuths, fault depth, and Europa's tectonic history.

Crack Monitoring of Operational Wind Turbine Foundations.

PubMed

Perry, Marcus; McAlorum, Jack; Fusiek, Grzegorz; Niewczas, Pawel; McKeeman, Iain; Rubert, Tim

2017-08-21

The degradation of onshore, reinforced-concrete wind turbine foundations is usually assessed via above-ground inspections, or through lengthy excavation campaigns that suspend wind power generation. Foundation cracks can and do occur below ground level, and while sustained measurements of crack behaviour could be used to quantify the risk of water ingress and reinforcement corrosion, these cracks have not yet been monitored during turbine operation. Here, we outline the design, fabrication and field installation of subterranean fibre-optic sensors for monitoring the opening and lateral displacements of foundation cracks during wind turbine operation. We detail methods for in situ sensor characterisation, verify sensor responses against theoretical tower strains derived from wind speed data, and then show that measured crack displacements correlate with monitored tower strains. Our results show that foundation crack opening displacements respond linearly to tower strain and do not change by more than ±5 μ m. Lateral crack displacements were found to be negligible. We anticipate that the work outlined here will provide a starting point for real-time, long-term and dynamic analyses of crack displacements in future. Our findings could furthermore inform the development of cost-effective monitoring systems for ageing wind turbine foundations.

A Lateral Flow Biosensor for the Detection of Single Nucleotide Polymorphisms.

PubMed

Zeng, Lingwen; Xiao, Zhuo

2017-01-01

A lateral flow biosensor (LFB) is introduced for the detection of single nucleotide polymorphisms (SNPs). The assay is composed of two steps: circular strand displacement reaction and lateral flow biosensor detection. In step 1, the nucleotide at SNP site is recognized by T4 DNA ligase and the signal is amplified by strand displacement DNA polymerase, which can be accomplished at a constant temperature. In step 2, the reaction product of step 1 is detected by a lateral flow biosensor, which is a rapid and cost effective tool for nuclei acid detection. Comparing with conventional methods, it requires no complicated machines. It is suitable for the use of point of care diagnostics. Therefore, this simple, cost effective, robust, and promising LFB detection method of SNP has great potential for the detection of genetic diseases, personalized medicine, cancer related mutations, and drug-resistant mutations of infectious agents.

Deployment Repeatability

DTIC Science & Technology

2016-08-31

photogrammetry to track a set of LEDS in two dimensions, a method that was able to resolve 2.2-mm lateral displacements of a 40-meter boom. This method... displacements . Sub-milliradian repeatability in MOIRE [This is a stand-in section for the MOIRE case study, which Dave Waller is getting through...The structure will most likely be under this stowed state for a long time under displacement paths and put this data into a computationally cheap 1

Failed rib region prediction in a human body model during crash events with precrash braking.

PubMed

Guleyupoglu, B; Koya, B; Barnard, R; Gayzik, F S

2018-02-28

The objective of this study is 2-fold. We used a validated human body finite element model to study the predicted chest injury (focusing on rib fracture as a function of element strain) based on varying levels of simulated precrash braking. Furthermore, we compare deterministic and probabilistic methods of rib injury prediction in the computational model. The Global Human Body Models Consortium (GHBMC) M50-O model was gravity settled in the driver position of a generic interior equipped with an advanced 3-point belt and airbag. Twelve cases were investigated with permutations for failure, precrash braking system, and crash severity. The severities used were median (17 kph), severe (34 kph), and New Car Assessment Program (NCAP; 56.4 kph). Cases with failure enabled removed rib cortical bone elements once 1.8% effective plastic strain was exceeded. Alternatively, a probabilistic framework found in the literature was used to predict rib failure. Both the probabilistic and deterministic methods take into consideration location (anterior, lateral, and posterior). The deterministic method is based on a rubric that defines failed rib regions dependent on a threshold for contiguous failed elements. The probabilistic method depends on age-based strain and failure functions. Kinematics between both methods were similar (peak max deviation: ΔX head = 17 mm; ΔZ head = 4 mm; ΔX thorax = 5 mm; ΔZ thorax = 1 mm). Seat belt forces at the time of probabilistic failed region initiation were lower than those at deterministic failed region initiation. The probabilistic method for rib fracture predicted more failed regions in the rib (an analog for fracture) than the deterministic method in all but 1 case where they were equal. The failed region patterns between models are similar; however, there are differences that arise due to stress reduced from element elimination that cause probabilistic failed regions to continue to rise after no deterministic failed region would be predicted. Both the probabilistic and deterministic methods indicate similar trends with regards to the effect of precrash braking; however, there are tradeoffs. The deterministic failed region method is more spatially sensitive to failure and is more sensitive to belt loads. The probabilistic failed region method allows for increased capability in postprocessing with respect to age. The probabilistic failed region method predicted more failed regions than the deterministic failed region method due to force distribution differences.

On- and off-fault coseismic surface deformation associated with the September 2013 M7.7 Balochistan, Pakistan earthquake measured from mapping and automated pixel correlation

NASA Astrophysics Data System (ADS)

Gold, R. D.; Reitman, N. G.; Briggs, R. W.; Barnhart, W. D.; Hayes, G. P.

2014-12-01

The 24 September 2013 Mw7.7 Balochistan, Pakistan earthquake ruptured a ~200 km-long stretch of the Hoshab fault in southern Pakistan. We remotely measured the coseismic surface deformation field using high-resolution (0.5 m) pre- and post-event satellite imagery. We measured ~300 near-field (0-10 m from fault) laterally offset piercing points (streams, terrace risers, roads, etc.) and find peak left-lateral offsets of ~12-15 m. We characterized the far-field (0-10 km from fault) displacement field using manual (~250 measurements) and automated image cross-correlation methods (e.g., pixel tracking) and find peak displacement values of ~16 m, which commonly exceed the on-fault displacement magnitudes. Our preliminary observations suggest the following: (1) coseismic surface displacement typically increases with distance away from the surface trace of the fault (e.g., highest displacement values in the far field), (2) for certain locations along the fault rupture, as little as 50% of the coseismic displacement field occurred in the near-field; and (3) the magnitudes of individual displacements are inversely correlated to the width of the surface rupture zone (e.g., largest displacements where the fault zone is narrowest). This analysis highlights the importance of identifying field study sites spanning fault sections with narrow deformation zones in order to capture the entire deformation field. For regions of distributed deformation, these results would predict that geologic slip rate studies underestimate a fault's complete slip rate.

Ground-penetrating radar investigations along the North Anatolian fault near Izmit, Turkey: Constraints on the right-lateral movement and slip history

NASA Astrophysics Data System (ADS)

Ferry, Matthieu; Meghraoui, Mustapha; Girard, Jean-François; Rockwell, Thomas K.; Kozaci, Özgur; Akyuz, Serdar; Barka, Aykut

2004-01-01

We analyze ground-penetrating radar (GPR) profiles made across and parallel to the August 1999 earthquake ruptures of the North Anatolian fault in Turkey. The profiles document cumulative right-lateral offset of stream channels and the successive faulting of a medieval (Ottoman) canal. The dominance of fine sand to coarse gravel in the sections imaged allows for reasonably deep penetration, and processed radar signals clearly image visible reflectors within the uppermost 5 m. Near Köseköy, buried fluvial-channel deposits, exposed in some trenches dug to determine paleoseismicity, are also visible on profiles and show a maximum 6.7 7.4 m of lateral displacement. Younger channel units display 4.5 4.9 m of right-lateral displacement at 2 3 m depth and show that the penultimate rupture along the Izmit segment produced a similar amount of displacement as in 1999. At the Ottoman canal site, GPR profiles complement a trench study and provide consistent results showing the occurrence of three faulting events after A.D. 1591, the date of canal construction. This study demonstrates that the use of GPR method in paleoseismology contributes to better identification of cumulative slip along active faults.

The effects of alveolar bone loss and miniscrew position on initial tooth displacement during intrusion of the maxillary anterior teeth: Finite element analysis

PubMed Central

Cho, Sun-Mi; Choi, Sung-Hwan; Sung, Sang-Jin; Yu, Hyung-Seog

2016-01-01

Objective The aim of this study was to determine the optimal loading conditions for pure intrusion of the six maxillary anterior teeth with miniscrews according to alveolar bone loss. Methods A three-dimensional finite element model was created for a segment of the six anterior teeth, and the positions of the miniscrews and hooks were varied after setting the alveolar bone loss to 0, 2, or 4 mm. Under 100 g of intrusive force, initial displacement of the individual teeth in three directions and the degree of labial tilting were measured. Results The degree of labial tilting increased with reduced alveolar bone height under the same load. When a miniscrew was inserted between the two central incisors, the amounts of medial-lateral and anterior-posterior displacement of the central incisor were significantly greater than in the other conditions. When the miniscrews were inserted distally to the canines and an intrusion force was applied distal to the lateral incisors, the degree of labial tilting and the amounts of displacement of the six anterior teeth were the lowest, and the maximum von Mises stress was distributed evenly across all the teeth, regardless of the bone loss. Conclusions Initial tooth displacement similar to pure intrusion of the six maxillary anterior teeth was induced when miniscrews were inserted distal to the maxillary canines and an intrusion force was applied distal to the lateral incisors. In this condition, the maximum von Mises stresses were relatively evenly distributed across all the teeth, regardless of the bone loss. PMID:27668194

Distal radius fracture arthroscopic intraarticular displacement measurement after open reduction and internal fixation from a volar approach.

PubMed

Ono, Hiroshi; Furuta, Kazuhiko; Fujitani, Ryotaro; Katayama, Takeshi; Akahane, Manabu

2010-07-01

The purpose of this study was to assess articular surface reduction arthroscopically after volar locked-plate fixation of distal radius fractures (DRFs) via fluoroscopyguided open reduction/internal fixation. We also aimed to develop preoperative radiographic criteria to help assist in determining which DRFs may need arthroscopic evaluation. A total of 31 consecutive patients with DRF were prospectively enrolled. Posteroanterior (PA) and lateral radiographs as well as axial, coronal, and sagittal CT scans were obtained just after attempted reduction of the DRF. The widest articular displacement at the radiocarpal joint surface of the distal radius (preopD) was then measured using a digital radiography imaging system. The DRF was reduced under fluoroscopy, and a volar locked plate was applied. The degree of residual articular displacement was then measured arthroscopically, and the maximum displacement (postopD) was measured with a calibrated probe. Of the 31 patients, 7 had an arthroscopically assessed maximum postopD of > or = 2 mm after internal fixation. The correlation coefficients between each preopD and postopD of all radiographs and CTs were statistically significant. The cutoff values were 0.5 mm for PA radiographs, 2.10 mm for lateral radiographs, 2.15 mm for axial CT scans, 3.15 mm for coronal CT scans, and 1.20 mm for sagittal CT scans. All cutoff values for PA and lateral radiographs and for axial, coronal, and sagittal CT scans were unsuitable as screening criteria for arthroscopic reduction of DRF because of their low sensitivities and specificities. The cutoff value of the new preopD (the sum of the preopDs determined by lateral radiography and coronal CT scan) was 5.80 mm, and its sensitivity and specificity were 100% and 83.3%, respectively. Because a new preopD cutoff value of 5.80 mm is a good indicator for residual articular displacement after internal fixation of >2 mm, it is also a good indicator for the need for arthroscopic evaluation after internal fixation.

GPS measurements of deformation associated with the 1987 Superstition Hills earthquake: Evidence for conjugate faulting

NASA Technical Reports Server (NTRS)

Larsen, Shawn; Reilinger, Robert; Neugebauer, Helen; Strange, William

1991-01-01

Large station displacements observed from Imperial Valley Global Positioning System (GPS) campaigns are attributed to the November 24, 1987 Superstition Hills earthquake sequence. Thirty sites from a 42 station GPS network established in 1986 were reoccupied during 1988 and/or 1990. Displacements at three sites within 3 kilometers of the surface rupture approach 0.5 m. Eight additional stations within 20 km of the seismic zone are displaced at least 10 cm. This is the first occurrence of a large earthquake (M(sub S) 6.6) within a preexisting GPS network. Best-fitting uniform slip models of rectangular dislocations in an elastic half-space indicate 130 + or - 8 cm right-lateral displacement along the northwest-trending Superstition Hills fault and 30 + or - 10 cm left-lateral displacement along the conjugate northeast-trending Elmore Ranch fault. The geodetic moments are 9.4 x 10(exp 25) dyne-cm and 2.3 x 10(exp 25) dyne-cm for the Superstition Hills and Elmore Ranch faults, respectively, consistent with teleseismic source parameters. The data also suggest the post seismic slip along the Superstition Hills fault is concentrated at shallow depths. Distributed slip solutions using Singular Value Decomposition indicate near uniform displacement along the Elmore Ranch fault and concentrated slip to the northwest and southeast along the Superstition Hills fault. A significant component of non-seismic displacement is observed across the Imperial Valley, which is attributed in part to interseismic plate-boundary deformation.

Lateral restoring force on a magnet levitated above a superconductor

NASA Technical Reports Server (NTRS)

Davis, L. C.

1990-01-01

The lateral restoring force on a magnet levitated above a superconductor is calculated as a function of displacement from its original position at rest using Bean's critical-state model to describe flux pinning. The force is linear for small displacements and saturates at large displacements. In the absence of edge effects the force always attracts the magnet to its original position. Thus it is a restoring force that contributes to the stability of the levitated magnet. In the case of a thick superconductor slab, the origin of the force is a magnetic dipole layer consisting of positive and negative supercurrents induced on the trailing side of the magnet. The qualitative behavior is consistent with experiments reported to date. Effects due to the finite thickness of the superconductor slab and the granular nature of high-Tc materials are also considered.

Lower Lateral Cartilage Cephalic Malposition: An Over-Diagnosed Entity.

PubMed

Hafezi, Farhad; Naghibzadeh, Bijan; Kazemi Ashtiani, Abbas

2018-06-01

Lower lateral cartilage malposition is represented by anterior convexity of the lower lateral cartilage (LLC) dome with posterior pinch, as defined by Sheen and Constantian. This anatomic variation consists of cephalic, or upward and inward, rotation of lateral crura, particularly in bulbous tip patients. In most cases, "bulbous pinch" LLC is positioned toward the medial canthus, not laterally, so it is referred to as cephalic displacement. Accordingly, it is recommended to caudally displace cartilage in the majority of rhinoplasty cases in which variation is seen. The purpose of this paper is to measure the exact angle of lateral crura with fixed reference points on the face. We drew and marked LLC contours and vertical/horizontal lines in 40 consecutive rhinoplasty cases. We then divided them into two groups: (1) bulbous pinch and (2) flat LLCs. The right- and left-sided LLC angles to midline and horizontal lines were measured and compared to assess whether there was any significant difference between the two subgroups. There was no significant difference between the angles of LLC rotation in the bulbous and flat LLCs groups, measured both vertically and horizontally. Based on our findings, although cephalic malposition of LLCs may be present in some patients but in the majority of cases the etiology of nasal lateral wall pinching is not cephalic displacement of lateral crura but most probably is due, rather, to severe convexity of the posterior and lateral crura. According to our findings, cephalic malposition is an uncommon anatomic variation of LLCs that has been reported at high frequency (60-70% of their rhinoplasty cases). This finding may help to correct this deformity into a normal anatomic configuration. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Simulation the Effect of Internal Wave on the Acoustic Propagation

NASA Astrophysics Data System (ADS)

Ko, D. S.

2005-05-01

An acoustic radiation transport model with the Monte Carlo solution has been developed and applied to study the effect of internal wave induced random oceanic fluctuations on the deep ocean acoustic propagation. Refraction in the ocean sound channel is performed by means of bi-cubic spline interpolation of discrete deterministic ray paths in the angle(energy)-range-depth coordinates. Scattering by random internal wave fluctuations is accomplished by sampling a power law scattering kernel applying the rejection method. Results from numerical experiments show that the mean positions of acoustic rays are significantly displaced tending toward the sound channel axis due to the asymmetry of the scattering kernel. The spreading of ray depths and angles about the means depends strongly on frequency. The envelope of the ray displacement spreading is found to be proportional to the square root of range which is different from "3/2 law" found in the non-channel case. Suppression of the spreading is due to the anisotropy of fluctuations and especially due to the presence of sound channel itself.

Pulsed laser manipulation of an optically trapped bead: averaging thermal noise and measuring the pulsed force amplitude.

PubMed

Lindballe, Thue B; Kristensen, Martin V G; Berg-Sørensen, Kirstine; Keiding, Søren R; Stapelfeldt, Henrik

2013-01-28

An experimental strategy for post-eliminating thermal noise on position measurements of optically trapped particles is presented. Using a nanosecond pulsed laser, synchronized to the detection system, to exert a periodic driving force on an optically trapped 10 μm polystyrene bead, the laser pulse-bead interaction is repeated hundreds of times. Traces with the bead position following the prompt displacement from equilibrium, induced by each laser pulse, are averaged and reveal the underlying deterministic motion of the bead, which is not visible in a single trace due to thermal noise. The motion of the bead is analyzed from the direct time-dependent position measurements and from the power spectrum. The results show that the bead is on average displaced 208 nm from the trap center and exposed to a force amplitude of 71 nanoNewton, more than five orders of magnitude larger than the trapping forces. Our experimental method may have implications for microrheology.

Nanoscale probing of image-dipole interactions in a metallic nanostructure

PubMed Central

Ropp, Chad; Cummins, Zachary; Nah, Sanghee; Fourkas, John T.; Shapiro, Benjamin; Waks, Edo

2015-01-01

An emitter near a surface induces an image dipole that can modify the observed emission intensity and radiation pattern. These image-dipole effects are generally not taken into account in single-emitter tracking and super-resolved imaging applications. Here we show that the interference between an emitter and its image dipole induces a strong polarization anisotropy and a large spatial displacement of the observed emission pattern. We demonstrate these effects by tracking the emission of a single quantum dot along two orthogonal polarizations as it is deterministically positioned near a silver nanowire. The two orthogonally polarized diffraction spots can be displaced by up to 50 nm, which arises from a Young’s interference effect between the quantum dot and its induced image dipole. We show that the observed spatially varying interference fringe provides a useful measure for correcting image-dipole-induced distortions. These results provide a pathway towards probing and correcting image-dipole effects in near-field imaging applications. PMID:25790228

Multiplexing curvature sensors using fibre segment interferometry for lateral vibration measurements

NASA Astrophysics Data System (ADS)

Kissinger, Thomas; Chehura, Edmon; James, Stephen W.; Tatam, Ralph P.

2017-04-01

Dynamic fibre-optic curvature sensing is demonstrated by interrogating chains of fibre segments, separated by broadband Bragg grating reflectors, using range-resolved interferometry (RRI). Four fibre strings, containing four fibre segments each of gauge length 20 cm, are attached to the opposing sides of a support structure and the resulting differential strain measurements allow inference of lateral displacements of a cantilever test object. Dynamic tip displacement resolutions in the micrometre range at an interferometric bandwidth of 21 kHz demonstrate the suitability of this approach for highly sensitive and cost-effective fibre-optic directional vibration measurements of smart structures.

Egocentric and nonegocentric coding in memory for spatial layout: Evidence from scene recognition

PubMed Central

2005-01-01

Much contemporary research has suggested that memories for spatial layout are stored with a preferred orientation. The present paper examines whether spatial memories are also stored with a preferred viewpoint position. Participants viewed images of an arrangement of objects taken from a single viewpoint, and were subsequently tested on their ability to recognize the arrangement from novel viewpoints that had been translated in either the lateral or depth dimension. Lateral and forward displacements of the viewpoint resulted in increasing response latencies and errors. Backward displacement showed no such effect, nor did lateral translation that resulted in a centered “canonical” view of the arrangement. These results further constrain the specificity of spatial memory, while also providing some evidence that nonegocentric spatial information is coded in memory. PMID:16933759

The Talas-Fergana Fault, Kirghiz and Kazakh, USSR

USGS Publications Warehouse

Wallace, R.E.

1976-01-01

The great Talas-Fergana fault transects the Soviet republic of Kirghiz in Soviet Central Asia and extends southeastward into China and northwestward into Kazakh SSR (figs. 1 and 2). This great rupture in the Earth's crust rivals the San Andreas fault in California; it is long (approximately 900 kilometers), complex, and possibly has a lateral displacement of hundreds of kilometers similar to that on the San Andreas fault. The Soviet geologist V. S. Burtman suggested that right-lateral offset of 250 kilometers has occurred, citing a shift of Devonian rocks as evidence (fig. 3). By no means do all Soviet geologists agree. Some hold the view that there is no lateral displacement along the Talas-Fergana fault and that the anomalous distribution of Paleozoic rocks is a result of the original position of deposition. 

Combining deterministic and stochastic velocity fields in the analysis of deep crustal seismic data

NASA Astrophysics Data System (ADS)

Larkin, Steven Paul

Standard crustal seismic modeling obtains deterministic velocity models which ignore the effects of wavelength-scale heterogeneity, known to exist within the Earth's crust. Stochastic velocity models are a means to include wavelength-scale heterogeneity in the modeling. These models are defined by statistical parameters obtained from geologic maps of exposed crystalline rock, and are thus tied to actual geologic structures. Combining both deterministic and stochastic velocity models into a single model allows a realistic full wavefield (2-D) to be computed. By comparing these simulations to recorded seismic data, the effects of wavelength-scale heterogeneity can be investigated. Combined deterministic and stochastic velocity models are created for two datasets, the 1992 RISC seismic experiment in southeastern California and the 1986 PASSCAL seismic experiment in northern Nevada. The RISC experiment was located in the transition zone between the Salton Trough and the southern Basin and Range province. A high-velocity body previously identified beneath the Salton Trough is constrained to pinch out beneath the Chocolate Mountains to the northeast. The lateral extent of this body is evidence for the ephemeral nature of rifting loci as a continent is initially rifted. Stochastic modeling of wavelength-scale structures above this body indicate that little more than 5% mafic intrusion into a more felsic continental crust is responsible for the observed reflectivity. Modeling of the wide-angle RISC data indicates that coda waves following PmP are initially dominated by diffusion of energy out of the near-surface basin as the wavefield reverberates within this low-velocity layer. At later times, this coda consists of scattered body waves and P to S conversions. Surface waves do not play a significant role in this coda. Modeling of the PASSCAL dataset indicates that a high-gradient crust-mantle transition zone or a rough Moho interface is necessary to reduce precritical PmP energy. Possibly related, inconsistencies in published velocity models are rectified by hypothesizing the existence of large, elongate, high-velocity bodies at the base of the crust oriented to and of similar scale as the basins and ranges at the surface. This structure would result in an anisotropic lower crust.

Impact of High Temperature Creep on the Buckling of Axially Compressed Steel Members

NASA Astrophysics Data System (ADS)

Włóka, Agata; Pawłowski, Kamil; Świerzko, Robert

2017-10-01

The paper presents results of the laboratory tests of the impact of creep on the buckling of axially compressed steel members at elevated temperatures. Tests were conducted on samples prepared of normal strength steel (S235JR) and high strength steel (S355J2). Samples were made in the form of a prismatic bar of a rectangular cross section 12 x 30 mm and a length of 500 mm. Support type of the specimens during tests was hinged on both ends. The tests were done at 600, 700 and 800°C. Experiments were carried out at static loads corresponding to values 0,8Ncr,T, 0,9Ncr,T, 1,0Ngr,T, where Ncr,T was theoretical value of Euler’s critical load at given temperature. Short-term creep analyses were performed in the universal testing machine Instron/Satec KN 600 equipped with a furnace for high-temperature testing type SF-16 2230, that enables testing at temperatures up to 1200°C. Temperature of the sample placed inside the furnace was verified and recorded with use of the compactRIO cRIO-9076 controller, equipped with a module for the connection of NI 9211 and K-type thermocouples. The system for the measurement and recording of the temperature of the analysed samples operated in the LabVIEW software environment. To measure lateral and longitudinal displacements LVTD Solatron ACR 100 displacement transducer was used. During the tests, the samples were heated to the given temperature (600, 700 or 800°C) and then subjected to a constant compressive load. During each test, for each sample following data was registered: the temperature on the surface of samples, longitudinal and lateral displacements in the middle of the sample. Basing on the conducted tests it was noted, for both analysed steel types, at the temperature of 800°C, growth of lateral displacements due to creep was very rapid, and tested elements were losing bearing capacity over the period of tens to hundreds of seconds, depending on stress level and the grade of the steel. At a temperature of 700°C growth of lateral displacements was much slower and the total loss of the bearing capacity of tested samples has occurred after 2 to 5 hours. At the temperature of 600°C samples did not show significant increments of lateral displacements at the test duration more than 6 hours, while maintaining throughout the test rectilinear form.

Three lateral divergent or parallel pin fixations for the treatment of displaced supracondylar humerus fractures in children.

PubMed

Lee, Young Ho; Lee, Sang Ki; Kim, Byung Sung; Chung, Moon Sang; Baek, Goo Hyun; Gong, Hyun Sik; Lee, Joon Kyu

2008-06-01

To evaluate the efficacy of lateral or parallel pin fixation using 3 smooth Kirschner wires (K-wires) or smooth Steinmann pins for the operative management of displaced supracondylar humeral fracture in a consecutive series of children. Sixty-one consecutive displaced or angled supracondylar humeral fractures (Gartland type II or III) in children (mean age, 5 years 6 months) treated by 2 orthopaedic surgeons between 2001 and 2004 according to the following protocol: close reduction under general anesthesia with fluoroscopic guidance and only lateral percutaneous pinning using 3 divergent or parallel Kirschner wires or Steinmann pins. Minimum 2 years' follow-up was done in all 61 patients (range, 2.0-3.3 years). Clinical assessment was obtained at final follow-up using Flynn criteria, and radiologic assessment was obtained using the Baumann and lateral humerocapitellar angles of both arms. Statistical analysis was performed by means of the Student t test (P < 0.05). The study group consisted of 61 patients, of whom 24 (39%) presented with Gartland type II fractures, and the remaining 37 (61%) presented with a type III fracture. A comparison of perioperative and final radiographs shows no loss of reduction of any fracture. There was also no clinically evident cubitus varus, hyperextension, or loss of motion. Eight patients had preoperative nerve palsy. Five of these nerve injuries resolved immediately after surgery, and the other 3 resolved completely within 12 weeks of surgery. After an average of 28 months postoperation, 56 (91.8%) patients had achieved an excellent clinical result, and 5 (8.2%) achieved a good result. There were no iatrogenic nerve palsies, and no patient required additional surgery. One patient had a minor pin-track infection. Our series demonstrates that only 3 lateral divergent or parallel pin fixations are effective and safe for avoiding iatrogenic ulnar nerve injury and are appropriate treatment options for displaced or angled supracondylar humeral fractures in children. Therapeutic study, level III.

Surface slip during large Owens Valley earthquakes

NASA Astrophysics Data System (ADS)

Haddon, E. K.; Amos, C. B.; Zielke, O.; Jayko, A. S.; Bürgmann, R.

2016-06-01

The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of laterally and vertically displaced landforms for 1872 and prehistoric Owens Valley earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross-correlation of sublinear topographic features and to produce a uniquely shaped probability density function (PDF) for each measurement. Stacking PDFs along strike to form cumulative offset probability distribution plots (COPDs) highlights common values corresponding to single and multiple-event displacements. Lateral offsets for 1872 vary systematically from ˜1.0 to 6.0 m and average 3.3 ± 1.1 m (2σ). Vertical offsets are predominantly east-down between ˜0.1 and 2.4 m, with a mean of 0.8 ± 0.5 m. The average lateral-to-vertical ratio compiled at specific sites is ˜6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7-11 m and net average of 4.4 ± 1.5 m, corresponding to a geologic Mw ˜7.5 for the 1872 event. We attribute progressively higher-offset lateral COPD peaks at 7.1 ± 2.0 m, 12.8 ± 1.5 m, and 16.6 ± 1.4 m to three earlier large surface ruptures. Evaluating cumulative displacements in context with previously dated landforms in Owens Valley suggests relatively modest rates of fault slip, averaging between ˜0.6 and 1.6 mm/yr (1σ) over the late Quaternary.

Effect of Body Mass Index on Intrafraction Prostate Displacement Monitored by Real-Time Electromagnetic Tracking

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butler, Wayne M., E-mail: wbutler@wheelinghospital.org; Wheeling Jesuit University, Wheeling, West Virginia; Morris, Mallory N.

2012-10-01

Purpose: To evaluate, using real-time monitoring of implanted radiofrequency transponders, the intrafraction prostate displacement of patients as a function of body mass index (BMI). Methods and Materials: The motions of Beacon radiofrequency transponders (Calypso Medical Technologies, Seattle, WA) implanted in the prostate glands of 66 men were monitored throughout the course of intensity modulated radiation therapy. Data were acquired at 10 Hz from setup to the end of treatment, but only the 1.7 million data points with a 'beam on' tag were used in the analysis. There were 21 obese patients, with BMI {>=}30 and 45 nonobese patients in themore » study. Results: Mean displacements were least in the left-right lateral direction (0.56 {+-} 0.24 mm) and approximately twice that magnitude in the superior-inferior and anterior-posterior directions. The net vector displacement was larger still, 1.95 {+-} 0.47 mm. Stratified by BMI cohort, the mean displacements per patient in the 3 Cartesian axes as well as the net vector for patients with BMI {>=}30 were slightly less (<0.2 mm) but not significantly different than the corresponding values for patients with lower BMIs. As a surrogate for the magnitude of oscillatory noise, the standard deviation for displacements in all measured planes showed no significant differences in the prostate positional variability between the lower and higher BMI groups. Histograms of prostate displacements showed a lower frequency of large displacements in obese patients, and there were no significant differences in short-term and long-term velocity distributions. Conclusions: After patients were positioned accurately using implanted radiofrequency transponders, the intrafractional displacements in the lateral, superior-inferior, and anterior-posterior directions as well as the net vector displacements were smaller, but not significantly so, for obese men than for those with lower BMI.« less

Differential Extension, Displacement Transfer, and the South to North Decrease in Displacement on the Furnace Creek - Fish Lake Valley Fault System, Western Great Basin.

NASA Astrophysics Data System (ADS)

Katopody, D. T.; Oldow, J. S.

2015-12-01

The northwest-striking Furnace Creek - Fish Lake Valley (FC-FLV) fault system stretches for >250 km from southeastern California to western Nevada, forms the eastern boundary of the northern segment of the Eastern California Shear Zone, and has contemporary displacement. The FC-FLV fault system initiated in the mid-Miocene (10-12 Ma) and shows a south to north decrease in displacement from a maximum of 75-100 km to less than 10 km. Coeval elongation by extension on north-northeast striking faults within the adjoining blocks to the FC-FLV fault both supply and remove cumulative displacement measured at the northern end of the transcurrent fault system. Elongation and displacement transfer in the eastern block, constituting the southern Walker Lane of western Nevada, exceeds that of the western block and results in the net south to north decrease in displacement on the FC-FLV fault system. Elongation in the eastern block is accommodated by late Miocene to Pliocene detachment faulting followed by extension on superposed, east-northeast striking, high-angle structures. Displacement transfer from the FC-FLV fault system to the northwest-trending faults of the central Walker Lane to the north is accomplished by motion on a series of west-northwest striking transcurrent faults, named the Oriental Wash, Sylvania Mountain, and Palmetto Mountain fault systems. The west-northwest striking transcurrent faults cross-cut earlier detachment structures and are kinematically linked to east-northeast high-angle extensional faults. The transcurrent faults are mapped along strike for 60 km to the east, where they merge with north-northwest faults forming the eastern boundary of the southern Walker Lane. The west-northwest trending transcurrent faults have 30-35 km of cumulative left-lateral displacement and are a major contributor to the decrease in right-lateral displacement on the FC-FLV fault system.

A new method to approximate load-displacement relationships of spinal motion segments for patient-specific multi-body models of scoliotic spine.

PubMed

Jalalian, Athena; Tay, Francis E H; Arastehfar, Soheil; Liu, Gabriel

2017-06-01

Load-displacement relationships of spinal motion segments are crucial factors in characterizing the stiffness of scoliotic spine models to mimic the spine responses to loads. Although nonlinear approach to approximation of the relationships can be superior to linear ones, little mention has been made to deriving personalized nonlinear load-displacement relationships in previous studies. A method is developed for nonlinear approximation of load-displacement relationships of spinal motion segments to assist characterizing in vivo the stiffness of spine models. We propose approximation by tangent functions and focus on rotational displacements in lateral direction. The tangent functions are characterized using lateral bending test. A multi-body model was characterized to 18 patients and utilized to simulate four spine positions; right bending, left bending, neutral, and traction. The same was done using linear functions to assess the performance of the proposed tangent function in comparison with the linear function. Root-mean-square error (RMSE) of the displacements estimated by the tangent functions was 44 % smaller than the linear functions. This shows the ability of our tangent function in approximation of the relationships for a range of infinitesimal to large displacements involved in the spine movement to the four positions. In addition, the models based on the tangent functions yielded 67, 55, and 39 % smaller RMSEs of Ferguson angles, locations of vertebrae, and orientations of vertebrae, respectively, implying better estimates of spine responses to loads. Overall, it can be concluded that our method for approximating load-displacement relationships of spinal motion segments can offer good estimates of scoliotic spine stiffness.

Lateral Radiograph of the Hip in Fracture Neck of Femur: Is it a Ritual?

PubMed

Kumar, Dheerendra S; Gubbi, Shivarathre D; Abdul, Bari; Bisalahalli, Muddu

2008-10-01

Historically routine work up of a patient with a fracture neck of femur has always included an antero-posterior (AP) and a lateral view of the hip. The aim of the study was to know whether a lateral view of hip influenced the decision of an Orthopedic Surgeon regarding management at a District General Hospital. A prospective study was conducted from February 2005 to September 2005 at Tameside General Hospital. X-rays of patients admitted with fracture neck of femur were shown to two independent observers in the daily trauma meeting. AP view of the hip was shown initially to observers and their classification and intended treatment was recorded. They were asked if they needed a lateral view to decide on management option and answers were recorded. The observers were then showed a lateral view of same hip and asked to comment on quality of film and also whether it would change their classification or intended management. There were 100 patients over six months. On AP view 56 were classified to have extra-capsular fracture, 37 were classified as displaced subcapital fracture and seven were classified undisplaced subcapital fracture. There was an interobserver variation in one patient between undisplaced or displaced subcapital fracture. The observers felt they would need a lateral X-ray on three occasions and there was a change in classification from undisplaced subcapital to displaced subcapital fracture on first occasion. There was no change in management plan in all the 100 patients after looking at a lateral X-ray. We can conclude that unless required for management a lateral X-ray of hip should be avoided routinely in all patients with fracture neck of femur as it would not only be cost effective but will also reduce radiation exposure to patient and relieve work pressure on radiographers, nursing and portering staff.

The alteration of extraocular muscle arc after hang-back recession in animal experiments.

PubMed

Lee, J; Kim, S

1996-01-01

We did an animal experimental study to investigate the extraocular muscle arc after hang-back recession on horizontal rectus muscles of five dogs. Two tiny sutures using 8-0 nylon were made on the sclera 8-10 mm posterior to the muscle insertion along the upper and lower margins of the right lateral rectus and left medial rectus to compare the altered muscle arc with the original muscle arc. Hang-back recession was performed on the horizontal rectus muscles and three months later we investigated the change in the muscle arc. Four of the 10 muscles operated showed no change, four were displaced upward (mean +/- SD; 1.00 +/- 0.16 mm) and two were displaced downward (1.00 +/- 0.00 mm). The average displacement was 0.60 +/- 0.52 mm. The alteration of muscle arc after hang-back recession thus seems insignificant.

Numerical Simulation and Experimental Verification of Hollow and Foam-Filled Flax-Fabric-Reinforced Epoxy Tubular Energy Absorbers Subjected to Crashing

NASA Astrophysics Data System (ADS)

Sliseris, J.; Yan, L.; Kasal, B.

2017-09-01

Numerical methods for simulating hollow and foam-filled flax-fabric-reinforced epoxy tubular energy absorbers subjected to lateral crashing are presented. The crashing characteristics, such as the progressive failure, load-displacement response, absorbed energy, peak load, and failure modes, of the tubes were simulated and calculated numerically. A 3D nonlinear finite-element model that allows for the plasticity of materials using an isotropic hardening model with strain rate dependence and failure is proposed. An explicit finite-element solver is used to address the lateral crashing of the tubes considering large displacements and strains, plasticity, and damage. The experimental nonlinear crashing load vs. displacement data are successfully described by using the finite-element model proposed. The simulated peak loads and absorbed energy of the tubes are also in good agreement with experimental results.

Displaceable Spur Gear Torque Controlled Driver and Method

NASA Technical Reports Server (NTRS)

Cook, Joseph S., Jr. (Inventor)

1996-01-01

Methods and apparatus are provided for a torque driver including a laterally displaceable gear support member to carry an output spur gear. A biasing assembly biases the output spur gear into engagement with a pinion to which is applied an input torque greater than a desired output torque limit for a threaded fastener such as a nut or screw. A coiled output linkage connects the output spur gear with a 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. A gauged selector mechanism is provided to laterally displace multiple driven members for fasteners arranged in differing configurations. The torque limit is selectably adjustable and may be different for fasteners within the same fastener configuration.

Displaceable spur gear torque controlled driver and method

NASA Technical Reports Server (NTRS)

Cook, Joseph S., Jr. (Inventor)

1994-01-01

Methods and apparatus are provided for a torque driver including a laterally displaceable gear support member to carry an output spur gear. A biasing assembly biases the output spur gear into engagement with a pinion to which is applied an input torque greater than a desired output torque limit for a threaded fastener such as a nut or screw. A coiled output linkage connects the output spur gear with a 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. A gauged selector mechanism is provided to laterally displace multiple driver members for fasteners arranged in differing configurations. The torque limit is selectably adjustable and may be different for fasteners within the same fastener configuration.

State of art of seismic design and seismic hazard analysis for oil and gas pipeline system

NASA Astrophysics Data System (ADS)

Liu, Aiwen; Chen, Kun; Wu, Jian

2010-06-01

The purpose of this paper is to adopt the uniform confidence method in both water pipeline design and oil-gas pipeline design. Based on the importance of pipeline and consequence of its failure, oil and gas pipeline can be classified into three pipe classes, with exceeding probabilities over 50 years of 2%, 5% and 10%, respectively. Performance-based design requires more information about ground motion, which should be obtained by evaluating seismic safety for pipeline engineering site. Different from a city’s water pipeline network, the long-distance oil and gas pipeline system is a spatially linearly distributed system. For the uniform confidence of seismic safety, a long-distance oil and pipeline formed with pump stations and different-class pipe segments should be considered as a whole system when analyzing seismic risk. Considering the uncertainty of earthquake magnitude, the design-basis fault displacements corresponding to the different pipeline classes are proposed to improve deterministic seismic hazard analysis (DSHA). A new empirical relationship between the maximum fault displacement and the surface-wave magnitude is obtained with the supplemented earthquake data in East Asia. The estimation of fault displacement for a refined oil pipeline in Wenchuan M S8.0 earthquake is introduced as an example in this paper.

SU-E-J-184: Stereo Time-Of-Flight System for Patient Positioning in Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wentz, T; Gilles, M; Visvikis, D

2014-06-01

Purpose: The objective of this work is to test the advantage of using the surface acquired by two stereo Time-of-Flight (ToF) cameras in comparison of the use of one camera only for patient positioning in radiotherapy. Methods: A first step consisted on validating the use of a stereo ToFcamera system for positioning management of a phantom mounted on a linear actuator producing very accurate and repeatable displacements. The displacements between two positions were computed from the surface point cloud acquired by either one or two cameras thanks to an iterative closest point algorithm. A second step consisted on determining themore » displacements on patient datasets, with two cameras fixed on the ceiling of the radiotherapy room. Measurements were done first on voluntary subject with fixed translations, then on patients during the normal clinical radiotherapy routine. Results: The phantom tests showed a major improvement in lateral and depth axis for motions above 10 mm when using the stereo-system instead of a unique camera (Fig1). Patient measurements validate these results with a mean real and measured displacement differences in the depth direction of 1.5 mm when using one camera and 0.9 mm when using two cameras (Fig2). In the lateral direction, a mean difference of 1 mm was obtained by the stereo-system instead of 3.2 mm. Along the longitudinal axis mean differences of 5.4 and 3.4 mm with one and two cameras respectively were noticed but these measurements were still inaccurate and globally underestimated in this direction as in the literature. Similar results were also found for patient subjects with a mean difference reduction of 35%, 7%, and 25% for the lateral, depth, and longitudinal displacement with the stereo-system. Conclusion: The addition of a second ToF-camera to determine patient displacement strongly improved patient repositioning results and therefore insures better radiation delivery.« less

DEM Simulated Results And Seismic Interpretation of the Red River Fault Displacements in Vietnam

NASA Astrophysics Data System (ADS)

Bui, H. T.; Yamada, Y.; Matsuoka, T.

2005-12-01

The Song Hong basin is the largest Tertiary sedimentary basin in Viet Nam. Its onset is approximately 32 Ma ago since the left-lateral displacement of the Red River Fault commenced. Many researches on structures, formation and tectonic evolution of the Song Hong basin have been carried out for a long time but there are still remained some problems that needed to put into continuous discussion such as: magnitude of the displacements, magnitude of movement along the faults, the time of tectonic inversion and right lateral displacement. Especially the mechanism of the Song Hong basin formation is still in controversy with many different hypotheses due to the activation of the Red River fault. In this paper PFC2D based on the Distinct Element Method (DEM) was used to simulate the development of the Red River fault system that controlled the development of the Song Hong basin from the onshore to the elongated portion offshore area. The numerical results show the different parts of the stress field such as compress field, non-stress field, pull-apart field of the dynamic mechanism along the Red River fault in the onshore area. This propagation to the offshore area is partitioned into two main branch faults that are corresponding to the Song Chay and Song Lo fault systems and said to restrain the east and west flanks of the Song Hong basin. The simulation of the Red River motion also showed well the left lateral displacement since its onset. Though it is the first time the DEM method was applied to study the deformation and geodynamic evolution of the Song Hong basin, the results showed reliably applied into the structural configuration evaluation of the Song Hong basin.

Subsurface Constraints on Late Cenozoic Basin Geometry in Northern Fish Lake Valley and Displacement Transfer Along the Northern Fish Lake Valley Fault Zone, Western Nevada

NASA Astrophysics Data System (ADS)

Mueller, N.; Kerstetter, S. R.; Katopody, D. T.; Oldow, J. S.

2016-12-01

The NW-striking, right-oblique Fish Lake Valley fault zone (FLVFZ) forms the northern segment of the longest active structure in the western Great Basin; the Death Valley - Furnace Creek - Fish Lake Valley fault system. Since the mid-Miocene, 50 km of right-lateral displacement is documented on the southern FLVFZ and much of that displacement was and is transferred east and north on active WNW left-lateral faults. Prior to the Pliocene, displacement was transferred east and north on a low-angle detachment. Displacement on the northern part of the FLVFZ continues and is transferred to a fanned array of splays striking (west to east) WNW, NNW, ENE and NNE. To determine the displacement budget on these structures, we conducted a gravity survey to determine subsurface basin morphology and its relation to active faults. Over 2450 stations were collected and combined with existing PACES and proprietary data for a total of 3388 stations. The data were terrain corrected and reduced to a 2.67 g/cm3 density to produce a residual complete Bouguer anomaly. The eastern part of northern Fish Lake Valley is underlain by several prominent gravity lows forming several sub-basins with maximum RCBA values ranging from -24 to -28 mGals. The RCBA was inverted for depth using Geosoft Oasis Montaj GM-SYS 3D modeling software. Density values for the inversion were constrained by lithologic and density logs from wells that penetrate the entire Cenozoic section into the Paleozoic basement. Best fitting gravity measurements taken at the wellheads yielded an effective density of 2.4 g/cm3 for the basin fill. Modeled basement depths range between 2.1 to 3 km. The sub-basins form an arc opening to the NW and are bounded by ENE and NNE faults in the south and NS to NNW in the north. At the northern end of the valley, the faults merge with ENE left-lateral strike slip faults of the Mina deflection, which carries displacement to NW dextral strike-slip faults of the central Walker Lane.

Cyclic biomechanical testing of biocomposite lateral row knotless anchors in a human cadaveric model.

PubMed

Barber, F Alan; Bava, Eric D; Spenciner, David B; Piccirillo, Justin

2013-06-01

The purpose of this study was to assess the mechanical performance of biocomposite knotless lateral row anchors based on both anchor design and the direction of pull. Two lateral row greater tuberosity insertion sites (anterior and posterior) were identified in matched pairs of fresh-frozen human cadaveric shoulders DEXA (dual energy X-ray absorptiometry) scanned to verify comparability. The humeri were stripped of all soft tissue and 3 different biocomposite knotless lateral row anchors: HEALIX Knotless BR (DePuy Mitek, Raynham MA), BioComposite PushLock (Arthrex, Naples, FL), and Bio-SwiveLock (Arthrex). Fifty-two anchors were distributed among the insertion locations and tested them with either an anatomic or axial pull. A fixed-gauge loop (15 mm) of 2 high-strength sutures from each anchor was created. After a 10-Nm preload, anchors were cycled from 10 to 45 Nm at 0.5 Hz for 200 cycles and tested to failure at 4.23 mm/second. The load to reach 3 mm and 5 mm displacement, ultimate failure load, displacement at ultimate failure, and failure mode were recorded. Threaded anchors (Bio-SwiveLock, P = .03; HEALIX Knotless, P = .014) showed less displacement with anatomic testing than did the nonthreaded anchor (BioComposite PushLock), and the HEALIX Knotless showed less overall displacement than did the other 2 anchors. The Bio-SwiveLock exhibited greater failure loads than did the other 2 anchors (P < .05). Comparison of axial and anatomic loading showed no maximum load differences for all anchors as a whole (P = .1084). Yet, anatomic pulling produced higher failure loads than did axial pulling for the Bio-SwiveLock but not for the BioComposite PushLock or the HEALIX Knotless. The nonthreaded anchor (BioComposite PushLock) displayed lower failure loads than did both threaded anchors with axial pulling. Threaded biocomposite anchors (HEALIX Knotless BR and Bio-SwiveLock) show less anatomic loading displacement and higher axial failure loads than do the nonthreaded (BioComposite PushLock) anchor. The HEALIX Knotless BR anchor showed less displacement than did the BioComposite PushLock and Bio-SwiveLock anchors. Neither axial nor anatomic loading had an effect on overall anchor displacement. Because of the strength profiles exhibited, this study supports the use of biocomposite anchors, which have definite advantages over polyetheretherketone (PEEK) and metal products. However, the nonthreaded BioComposite PushLock anchor cannot be recommended. Copyright © 2013 Arthroscopy Association of North America. All rights reserved.

High-Definition Fiber Tractography in the Evaluation and Surgical Planning of Lhermitte-Duclos Disease: A Case Report.

PubMed

Fernandes-Cabral, David T; Zenonos, Georgios A; Hamilton, Ronald L; Panesar, Sandip S; Fernandez-Miranda, Juan C

2016-08-01

Preoperative delineation of normal tissue displacement patterns in Lhermitte-Duclos disease has not been feasible with conventional imaging means. Surgical resection of this type of lesion remains challenging, because the boundaries of the lesion are indistinguishable during surgery. The clinical presentation, preoperative and postoperative magnetic resonance imaging (MRI) findings, high-definition fiber tractography (HDFT) and histopathological studies, are presented in a 46-year-old male subject with symptomatic Lhermitte-Duclos disease. HDFT was performed using a quantitative anisotropy-based generalized deterministic tracking algorithm to define fiber tracts. Displacement of the cerebellar and brainstem tracts on the affected side was performed using the unaffected contralateral side as a comparison. The displacement of the normal tissues was not apparent on preoperative MRI but was immediately evident on the preoperative HDFT. Of note, there was a relative paucity of fiber tracts within the lesion. By tailoring our operative boundaries based on the HDFT findings, we were able to spare the displaced fiber tracts when debulking the tumor. Restoration of normal fiber tract anatomy on postoperative HDFT imaging was correlated with clinical resolution of preoperative symptoms. This case report suggests that HDFT may be a powerful surgical planning tool in cases of Lhermitte-Duclos disease, in which the pattern of normal tissue displacement is not evident with conventional imaging, allowing maximal lesion resection without damage to the unaffected tracts. Therefore, this report contributes to solving the greatest challenge when operating on this type of lesion, which has not been resolved in any previous report in our review of the English literature. Copyright © 2016 Elsevier Inc. All rights reserved.

Power hand tool kinetics associated with upper limb injuries in an automobile assembly plant.

PubMed

Ku, Chia-Hua; Radwin, Robert G; Karsh, Ben-Tzion

2007-06-01

This study investigated the relationship between pneumatic nutrunner handle reactions, workstation characteristics, and prevalence of upper limb injuries in an automobile assembly plant. Tool properties (geometry, inertial properties, and motor characteristics), fastener properties, orientation relative to the fastener, and the position of the tool operator (horizontal and vertical distances) were measured for 69 workstations using 15 different pneumatic nutrunners. Handle reaction response was predicted using a deterministic mechanical model of the human operator and tool that was previously developed in our laboratory, specific to the measured tool, workstation, and job factors. Handle force was a function of target torque, tool geometry and inertial properties, motor speed, work orientation, and joint hardness. The study found that tool target torque was not well correlated with predicted handle reaction force (r=0.495) or displacement (r=0.285). The individual tool, tool shape, and threaded fastener joint hardness all affected predicted forces and displacements (p<0.05). The average peak handle force and displacement for right-angle tools were twice as great as pistol grip tools. Soft-threaded fastener joints had the greatest average handle forces and displacements. Upper limb injury cases were identified using plant OSHA 200 log and personnel records. Predicted handle forces for jobs where injuries were reported were significantly greater than those jobs free of injuries (p<0.05), whereas target torque and predicted handle displacement did not show statistically significant differences. The study concluded that quantification of handle reaction force, rather than target torque alone, is necessary for identifying stressful power hand tool operations and for controlling exposure to forces in manufacturing jobs involving power nutrunners. Therefore, a combination of tool, work station, and task requirements should be considered.

Does distal tibiofibular joint mobilization decrease limitation of ankle dorsiflexion?

PubMed

Fujii, Misaki; Suzuki, Daisuke; Uchiyama, Eiichi; Muraki, Takayuki; Teramoto, Atsushi; Aoki, Mitsuhiro; Miyamoto, Shigenori

2010-02-01

Limitation of ankle motion is in many cases treated by joint mobilization (JM), a kind of manual physical therapy technique. Until now, the JM approach has mainly focused on the talocrural joint, with less attention to the distal tibiofibular joint. We applied cyclic loading to the lateral malleolus as in JM in order to clarify the relationship between the dorsiflexion angle and the excursion of the lateral malleolus. Seven normal, fresh-frozen cadaver legs were used. To each specimen, cyclic loading with a 30N force was applied 1000 times to the lateral malleolus at a speed of 15N/s. The displacement of the lateral malleolus was measured with a magnetic tracking system. The maximum dorsiflexion angle was measured before and after cyclic loading. After the first 100 and 1000 times of cyclic loading, the tibia was displaced 0.44+/-0.30mm and 0.75+/-0.36mm, respectively, and the fibula was displaced 0.44+/-0.28mm and 0.92+/-0.39mm, respectively. The average dorsiflexion angle increased from 14.36+/-7.51 degrees to 16.74+/-7.21 degrees after cyclic loading (P<0.05). Movement of the distal tibiofibular joint led to a significant increase in the range of ankle dorsiflexion. These results suggest that tibiofibular JM would be effective for limitation of ankle dorsiflexion.

Lateral spread hazard mapping of the northern Salt Lake Valley, Utah, for a M7.0 scenario earthquake

USGS Publications Warehouse

Olsen, M.J.; Bartlett, S.F.; Solomon, B.J.

2007-01-01

This paper describes the methodology used to develop a lateral spread-displacement hazard map for northern Salt Lake Valley, Utah, using a scenario M7.0 earthquake occurring on the Salt Lake City segment of the Wasatch fault. The mapping effort is supported by a substantial amount of geotechnical, geologic, and topographic data compiled for the Salt Lake Valley, Utah. ArcGIS?? routines created for the mapping project then input this information to perform site-specific lateral spread analyses using methods developed by Bartlett and Youd (1992) and Youd et al. (2002) at individual borehole locations. The distributions of predicted lateral spread displacements from the boreholes located spatially within a geologic unit were subsequently used to map the hazard for that particular unit. The mapped displacement zones consist of low hazard (0-0.1 m), moderate hazard (0.1-0.3 m), high hazard (0.3-1.0 m), and very high hazard (> 1.0 m). As expected, the produced map shows the highest hazard in the alluvial deposits at the center of the valley and in sandy deposits close to the fault. This mapping effort is currently being applied to the southern part of the Salt Lake Valley, Utah, and probabilistic maps are being developed for the entire valley. ?? 2007, Earthquake Engineering Research Institute.

Tunable Stable Levitation Based on Casimir Interaction between Nanostructures

NASA Astrophysics Data System (ADS)

Liu, Xianglei; Zhang, Zhuomin M.

2016-03-01

Quantum levitation enabled by repulsive Casimir force has been desirable due to the potential exciting applications in passive-suspension devices and frictionless bearings. In this paper, dynamically tunable stable levitation is theoretically demonstrated based on the configuration of dissimilar gratings separated by an intervening fluid using exact scattering theory. The levitation position is insensitive to temperature variations and can be actively tuned by adjusting the lateral displacement between the two gratings. This work investigates the possibility of applying quantum Casimir interactions into macroscopic mechanical devices working in a noncontact and low-friction environment for controlling the position or transducing lateral movement into vertical displacement at the nanoscale.

Note: Comparison experimental results of the laser heterodyne interferometer for angle measurement based on the Faraday effect.

PubMed

Zhang, Enzheng; Chen, Benyong; Zheng, Hao; Teng, Xueying; Yan, Liping

2018-04-01

A laser heterodyne interferometer for angle measurement based on the Faraday effect is proposed. A novel optical configuration, designed by using the orthogonal return method for a linearly polarized beam based on the Faraday effect, guarantees that the measurement beam can return effectively even though an angular reflector has a large lateral displacement movement. The optical configuration and measurement principle are presented in detail. Two verification experiments were performed; the experimental results show that the proposed interferometer can achieve a large lateral displacement tolerance of 7.4 mm and also can realize high precision angle measurement with a large measurement range.

Note: Comparison experimental results of the laser heterodyne interferometer for angle measurement based on the Faraday effect

NASA Astrophysics Data System (ADS)

Zhang, Enzheng; Chen, Benyong; Zheng, Hao; Teng, Xueying; Yan, Liping

2018-04-01

A laser heterodyne interferometer for angle measurement based on the Faraday effect is proposed. A novel optical configuration, designed by using the orthogonal return method for a linearly polarized beam based on the Faraday effect, guarantees that the measurement beam can return effectively even though an angular reflector has a large lateral displacement movement. The optical configuration and measurement principle are presented in detail. Two verification experiments were performed; the experimental results show that the proposed interferometer can achieve a large lateral displacement tolerance of 7.4 mm and also can realize high precision angle measurement with a large measurement range.

Near-field acoustic microbead trapping as remote anchor for single particle manipulation

NASA Astrophysics Data System (ADS)

Hwang, Jae Youn; Cheon, Dong Young; Shin, Hyunjune; Kim, Hyun Bin; Lee, Jungwoo

2015-05-01

We recently proposed an analytical model of a two-dimensional acoustic trapping of polystyrene beads in the ray acoustics regime, where a bead diameter is larger than the wavelength used. As its experimental validation, this paper demonstrates the transverse (or lateral) trapping of individual polystyrene beads in the near field of focused ultrasound. A 100 μm bead is immobilized on the central beam axis by a focused sound beam from a 30 MHz single element lithium niobate transducer, after being laterally displaced through hundreds of micrometers. Maximum displacement, a longest lateral distance at which a trapped bead can be directed towards the central axis, is thus measured over a discrete frequency range from 24 MHz to 36 MHz. The displacement data are found to be between 323.7 μm and 470.2 μm, depending on the transducer's driving frequency and input voltage amplitude. The experimental results are compared with their corresponding model values, and their relative errors lie between 0.9% and 3.9%. The results suggest that this remote maneuvering technique may be employed to manipulate individual cells through solid microbeads, provoking certain cellular reactions to localized mechanical disturbance without direct contact.

Inelastic Strain and Damage in Surface Instability Tests

NASA Astrophysics Data System (ADS)

Kao, Chu-Shu; Tarokh, Ali; Biolzi, Luigi; Labuz, Joseph F.

2016-02-01

Spalling near a free surface in laboratory experiments on two sandstones was characterized using acoustic emission and digital image correlation. A surface instability apparatus was used to reproduce a state of plane strain near a free surface in a modeled semi-infinite medium subjected to far-field compressive stress. Comparison between AE locations and crack trajectory mapped after the test showed good consistency. Digital image correlation was used to find the displacements in directions parallel (axial direction) and perpendicular (lateral direction) to the free surface at various stages of loading. At a load ratio, LR = current load/peak load, of approximately 30 %, elastic deformation was measured. At 70-80 % LR, the free-face effect started to appear in the displacement contours, especially for the lateral displacement measurements. As the axial compressive stress increased close to peak, extensional lateral strain started to show concentrations associated with localized damage. Continuum damage mechanics was used to describe damage evolution in the surface instability test, and it was shown that a critical value of extensional inelastic strain, on the order of -10-3 for the virgin sandstones, may provide an indicator for determining the onset of surface spalling.

Biomechanical study of patellofemoral joint instability

NASA Astrophysics Data System (ADS)

Senavongse, Wongwit

2005-04-01

Patellofemoral joint instability is a complex clinical problem. It may be a consequence of pre-existing anatomical abnormality or trauma. The objectives of this study were to use experimental mechanics to measure patellar stability and to quantify the effects of pathological abnormalities on patellar stability in vitro. Eight fresh-frozen cadaver knees were studies. The patellar stability was measured using an Instron material testing machine. A total load of 175N was applied to the quadriceps muscles. Patellar force-displacement was tested at different knee flexion angles as the patella was cyclically displaced 10mm laterally and medially. Three pathological abnormalities were applied; VMO malfunction, flat lateral trochlea, and medial retinacular structure rupturing. For the first time, this study has shown comparative and quantitative influence of pathological abnormalities on patellar stability. It was found that a flat lateral trochlea has greater effect than the medial retinacular rupturing whereas the medial retinacular rupturing has greater effect than VMO malfunction on patellar lateral stability. These results are important for future investigations on the treatment of patellofemoral instability.

Kicking the digital dog: a longitudinal investigation of young adults' victimization and cyber-displaced aggression.

PubMed

Wright, Michelle F; Li, Yan

2012-09-01

Using the general strain theory as a theoretical framework, the present longitudinal study investigated both face-to-face and cyber victimization in relation to cyber-displaced aggression. Longitudinal data were collected from 130 (70 women) young adults who completed measures assessing their victimization (face-to-face and cyber), cyber aggression, and both face-to-face and cyber-displaced aggression. Findings indicated that victimization in both social contexts (face-to-face and cyber) contributed to cyber-displaced aggression 6 months later (Time 2), after controlling for gender, cyber aggression, face-to-face displaced aggression, and cyber-displaced aggression at Time 1. A significant two-way interaction revealed that Time 1 cyber victimization was more strongly related to Time 2 cyber-displaced aggression when young adults had higher levels of face-to-face victimization at Time 1. Implications of these findings are discussed as well as a call for more research investigating displaced aggression in the cyber context.

Tracing the lateral movement of sediments through a shrubland environment using fallout radionuclides, Jornada Basin, Southern New Mexico

USDA-ARS?s Scientific Manuscript database

Semi-arid grassland and savanna communities in many parts of the world have been displaced by woody shrubs. In the Jornada Basin of southern New Mexico, the displacement of perennial grasslands is well documented beginning in 1858. As shrubs invade semi-arid perennial grasslands, the length, number,...

Joint stability characteristics of the ankle complex after lateral ligamentous injury, part I: a laboratory comparison using arthrometric measurement.

PubMed

Kovaleski, John E; Heitman, Robert J; Gurchiek, Larry R; Hollis, J M; Liu, Wei; Pearsall, Albert W

2014-01-01

The mechanical property of stiffness may be important to investigating how lateral ankle ligament injury affects the behavior of the viscoelastic properties of the ankle complex. A better understanding of injury effects on tissue elastic characteristics in relation to joint laxity could be obtained from cadaveric study. To biomechanically determine the laxity and stiffness characteristics of the cadaver ankle complex before and after simulated injury to the anterior talofibular ligament (ATFL) and calcaneofibular ligament (CFL) during anterior drawer and inversion loading. Cross-sectional study. University research laboratory. Seven fresh-frozen cadaver ankle specimens. All ankles underwent loading before and after simulated lateral ankle injury using an ankle arthrometer. The dependent variables were anterior displacement, anterior end-range stiffness, inversion rotation, and inversion end-range stiffness. Isolated ATFL and combined ATFL and CFL sectioning resulted in increased anterior displacement but not end-range stiffness when compared with the intact ankle. With inversion loading, combined ATFL and CFL sectioning resulted in increased range of motion and decreased end-range stiffness when compared with the intact and ATFL-sectioned ankles. The absence of change in anterior end-range stiffness between the intact and ligament-deficient ankles indicated bony and other soft tissues functioned to maintain stiffness after pathologic joint displacement, whereas inversion loading of the CFL-deficient ankle after pathologic joint displacement indicated the ankle complex was less stiff when supported only by the secondary joint structures.

Field Test of Driven Pile Group under Lateral Loading

NASA Astrophysics Data System (ADS)

Gorska, Karolina; Rybak, Jaroslaw; Wyjadlowski, Marek

2017-12-01

All the geotechnical works need to be tested because the diversity of soil parameters is much higher than in other fields of construction. Horizontal load tests are necessary to determine the lateral capacity of driven piles subject to lateral load. Various load tests were carried out altogether on the test field in Kutno (Poland). While selecting the piles for load tests, different load combinations were taken into account. The piles with diverse length were chosen, on the basis of the previous tests of their length and integrity. The subsoil around the piles consisted of mineral soils: clays and medium compacted sands with the density index ID>0.50. The pile heads were free. The points of support of the “base” to which the dial gauges (displacement sensors) were fastened were located at the distance of 0.7 m from the side surface of the pile loaded laterally. In order to assure the independence of measurement, additional control (verifying) geodetic survey of the displacement of the piles subject to the load tests was carried out (by means of the alignment method). The trial load was imposed in stages by means of a hydraulic jack. The oil pressure in the actuator was corrected by means of a manual pump in order to ensure the constant value of the load in the on-going process of the displacement of the pile under test. On the basis of the obtained results it is possible to verify the numerical simulations of the behaviour of piles loaded by a lateral force.

Contralateral Anterior Interhemispheric Transparaterminal Gyrus Approach for Thalamopeduncular Pilocytic Astrocytoma in an Adult: Technical Report.

PubMed

Kumar, Amandeep; Sharma, Raghavendra; Garg, Ajay; Sharma, Bhawani S

2016-03-01

Thalamopeduncular gliomas arise at the junction of the thalamus and cerebral peduncle and constitute a subgroup of thalamic gliomas. These are surgically challenging lesions because of close proximity to important neural structures including corticospinal tracts (CSTs) and the thalamus. These tumors usually displace CSTs anterolaterally or extend to the lateral ventricular surface. Such tumors can be removed by either temporal or transventricular approaches. However, if CSTs cover the entire lateral surface of tumor and tumor does not extend to the ventricular surface, temporal and transventricular approaches cannot be used because the trajectories of both approaches would pass through normal eloquent structures (CSTs and thalamus), and consequently there would be a very high risk of postoperative neurologic deficits developing. A 50-year-old woman presented with contralateral hemiparesis. Radiologic evaluation revealed a right Thalamopeduncular glioma that displaced CSTs laterally and was covered by normal thalamus superiorly. Some CST fibers passed through the tumor. Because both lateral and superior surfaces were covered by eloquent structures, we used an anterior interhemispheric transparaterminal gyrus approach to access the tumor successfully and achieved subtotal excision. The patient had transient neurologic deterioration postoperatively that recovered to preoperative level within 2 weeks. The anterior interhemispheric transparaterminal gyrus approach has not been described previously for accessing brainstem lesions. This approach can be used to access tumors of the cerebral peduncle that displace CSTs laterally and are covered by normal thalamus superiorly. The anterior interhemispheric transparaterminal gyrus approach adds to the armamentarium of neurosurgeons for treatment of cerebral peduncular lesions. Copyright © 2016 Elsevier Inc. All rights reserved.

Fluidic Energy Harvester Optimization in Grid Turbulence

NASA Astrophysics Data System (ADS)

Danesh-Yazdi, Amir; Elvin, Niell; Andreopoulos, Yiannis

2017-11-01

Even though it is omnipresent in nature, there has not been a great deal of research in the literature involving turbulence as an energy source for piezoelectric fluidic harvesters. In the present work, a grid-generated turbulence forcing function model which we derived previously is employed in the single degree-of-freedom electromechanical equations to find the power output and tip displacement of piezoelectric cantilever beams. Additionally, we utilize simplified, deterministic models of the turbulence forcing function to obtain closed-form expressions for the power output. These theoretical models are studied using experiments that involve separately placing a hot-wire anemometer probe and a short PVDF beam in flows where turbulence is generated by means of passive and semi-passive grids. From a parametric study on the deterministic models, we show that the white noise forcing function best mimics the experimental data. Furthermore, our parametric study of the response spectrum of a generic fluidic harvester in grid-generated turbulent flow shows that optimum power output is attained for beams placed closer to the grid with a low natural frequency and damping ratio and a large electromechanical coupling coefficient. NSF Grant No. CBET 1033117.

Patterned arrays of lateral heterojunctions within monolayer two-dimensional semiconductors

DOE PAGES

Mahjouri-Samani, Masoud; Lin, Ming-Wei; Wang, Kai; ...

2015-07-22

The formation of semiconductor heterojunctions and their high density integration are foundations of modern electronics and optoelectronics. To enable two-dimensional (2D) crystalline semiconductors as building blocks in next generation electronics, developing methods to deterministically form lateral heterojunctions is crucial. Here we demonstrate a process strategy for the formation of lithographically-patterned lateral semiconducting heterojunctions within a single 2D crystal. E-beam lithography is used to pattern MoSe 2 monolayer crystals with SiO 2, and the exposed locations are selectively and totally converted to MoS 2 using pulsed laser deposition (PLD) of sulfur in order to form MoSe 2/MoS 2 heterojunctions in predefinedmore » patterns. The junctions and conversion process are characterized by atomically resolved scanning transmission electron microscopy, photoluminescence, and Raman spectroscopy. This demonstration of lateral semiconductor heterojunction arrays within a single 2D crystal is an essential step for the lateral integration of 2D semiconductor building blocks with different electronic and optoelectronic properties for high-density, ultrathin circuitry.« less

Reliability of internal oblique elbow radiographs for measuring displacement of medial epicondyle humerus fractures: a cadaveric study.

PubMed

Gottschalk, Hilton P; Bastrom, Tracey P; Edmonds, Eric W

2013-01-01

Standard elbow radiographs (AP and lateral views) are not accurate enough to measure true displacement of medial epicondyle fractures of the humerus. The amount of perceived displacement has been used to determine treatment options. This study assesses the utility of internal oblique radiographs for measurement of true displacement in these fractures. A medial epicondyle fracture was created in a cadaveric specimen. Displacement of the fragment (mm) was set at 5, 10, and 15 in line with the vector of the flexor pronator mass. The fragment was sutured temporarily in place. Radiographs were obtained at 0 (AP), 15, 30, 45, 60, 75, and 90 degrees (lateral) of internal rotation, with the elbow in set positions of flexion. This was done with and without radio-opaque markers placed on the fragment and fracture bed. The 45 and 60 degrees internal oblique radiographs were then presented to 5 separate reviewers (of different levels of training) to evaluate intraobserver and interobserver agreement. Change in elbow position did not affect the perceived displacement (P=0.82) with excellent intraobserver reliability (intraclass correlation coefficient range, 0.979 to 0.988) and interobserver agreement of 0.953. The intraclass correlation coefficient for intraobserver reliability on 45 degrees internal oblique films for all groups ranged from 0.985 to 0.998, with interobserver agreement of 0.953. For predicting displacement, the observers were 60% accurate in predicting the true displacement on the 45 degrees internal oblique films and only 35% accurate using the 60 degrees internal oblique view. Standardizing to a 45 degrees internal oblique radiograph of the elbow (regardless of elbow flexion) can augment the treating surgeon's ability to determine true displacement. At this degree of rotation, the measured number can be multiplied by 1.4 to better estimate displacement. The addition of a 45 degrees internal oblique radiograph in medial humeral epicondyle fractures has good intraobserver and interobserver reliability to more accurately estimate the true displacement of these fractures. Diagnostic study, Level II (Development of diagnostic study with universally applied reference "gold" standard).

Laterally loaded pile cap connections.

DOT National Transportation Integrated Search

2010-08-01

This study investigated the moment capacity and load-displacement response of the pile-to-cap connection details. Lateral load tests were conducted on four pile caps (3 ft H x 3 ft W x 6.5 ft L) with two 40 foot-long steel pipe piles (12.75 inch OD) ...

Statistical relations among earthquake magnitude, surface rupture length, and surface fault displacement

USGS Publications Warehouse

Bonilla, Manuel G.; Mark, Robert K.; Lienkaemper, James J.

1984-01-01

In order to refine correlations of surface-wave magnitude, fault rupture length at the ground surface, and fault displacement at the surface by including the uncertainties in these variables, the existing data were critically reviewed and a new data base was compiled. Earthquake magnitudes were redetermined as necessary to make them as consistent as possible with the Gutenberg methods and results, which make up much of the data base. Measurement errors were estimated for the three variables for 58 moderate to large shallow-focus earthquakes. Regression analyses were then made utilizing the estimated measurement errors.The regression analysis demonstrates that the relations among the variables magnitude, length, and displacement are stochastic in nature. The stochastic variance, introduced in part by incomplete surface expression of seismogenic faulting, variation in shear modulus, and regional factors, dominates the estimated measurement errors. Thus, it is appropriate to use ordinary least squares for the regression models, rather than regression models based upon an underlying deterministic relation in which the variance results primarily from measurement errors.Significant differences exist in correlations of certain combinations of length, displacement, and magnitude when events are grouped by fault type or by region, including attenuation regions delineated by Evernden and others.Estimates of the magnitude and the standard deviation of the magnitude of a prehistoric or future earthquake associated with a fault can be made by correlating Ms with the logarithms of rupture length, fault displacement, or the product of length and displacement.Fault rupture area could be reliably estimated for about 20 of the events in the data set. Regression of Ms on rupture area did not result in a marked improvement over regressions that did not involve rupture area. Because no subduction-zone earthquakes are included in this study, the reported results do not apply to such zones.

Statistical relations among earthquake magnitude, surface rupture length, and surface fault displacement

USGS Publications Warehouse

Bonilla, M.G.; Mark, R.K.; Lienkaemper, J.J.

1984-01-01

In order to refine correlations of surface-wave magnitude, fault rupture length at the ground surface, and fault displacement at the surface by including the uncertainties in these variables, the existing data were critically reviewed and a new data base was compiled. Earthquake magnitudes were redetermined as necessary to make them as consistent as possible with the Gutenberg methods and results, which necessarily make up much of the data base. Measurement errors were estimated for the three variables for 58 moderate to large shallow-focus earthquakes. Regression analyses were then made utilizing the estimated measurement errors. The regression analysis demonstrates that the relations among the variables magnitude, length, and displacement are stochastic in nature. The stochastic variance, introduced in part by incomplete surface expression of seismogenic faulting, variation in shear modulus, and regional factors, dominates the estimated measurement errors. Thus, it is appropriate to use ordinary least squares for the regression models, rather than regression models based upon an underlying deterministic relation with the variance resulting from measurement errors. Significant differences exist in correlations of certain combinations of length, displacement, and magnitude when events are qrouped by fault type or by region, including attenuation regions delineated by Evernden and others. Subdivision of the data results in too few data for some fault types and regions, and for these only regressions using all of the data as a group are reported. Estimates of the magnitude and the standard deviation of the magnitude of a prehistoric or future earthquake associated with a fault can be made by correlating M with the logarithms of rupture length, fault displacement, or the product of length and displacement. Fault rupture area could be reliably estimated for about 20 of the events in the data set. Regression of MS on rupture area did not result in a marked improvement over regressions that did not involve rupture area. Because no subduction-zone earthquakes are included in this study, the reported results do not apply to such zones.

Large Lateral Photovoltaic Effect in Metal-(Oxide-) Semiconductor Structures

PubMed Central

Yu, Chongqi; Wang, Hui

2010-01-01

The lateral photovoltaic effect (LPE) can be used in position-sensitive detectors to detect very small displacements due to its output of lateral photovoltage changing linearly with light spot position. In this review, we will summarize some of our recent works regarding LPE in metal-semiconductor and metal-oxide-semiconductor structures, and give a theoretical model of LPE in these two structures. PMID:22163463

Specification and Design Criteria for the Construction of Continuous Flight Auger Piles in the Houston Area.

DOT National Transportation Integrated Search

1997-08-01

Five continuous-flight-auger piles were installed in a stiff clay soil following standard practice. Four of these piles were later subjected to lateral load tests to large displacements. The length and diameter of the test piles were varied to invest...

Displacement and Revitalization of the Nahuatl Language in the High Mountains of Veracruz, Mexico

ERIC Educational Resources Information Center

Sandoval Arenas, Carlos O.

2017-01-01

This article focuses on language displacement in the High Mountains of Central Veracruz. It begins by presenting a brief historical account of the Nahuatl presence in the region in order to distinguish this group from other Nahuatl-speaking groups. Later, it describes the situation of language loss that is currently underway and argues that the…

Measuring relative-story displacement and local inclination angle using multiple position-sensitive detectors.

PubMed

Matsuya, Iwao; Katamura, Ryuta; Sato, Maya; Iba, Miroku; Kondo, Hideaki; Kanekawa, Kiyoshi; Takahashi, Motoichi; Hatada, Tomohiko; Nitta, Yoshihiro; Tanii, Takashi; Shoji, Shuichi; Nishitani, Akira; Ohdomari, Iwao

2010-01-01

We propose a novel sensor system for monitoring the structural health of a building. The system optically measures the relative-story displacement during earthquakes for detecting any deformations of building elements. The sensor unit is composed of three position sensitive detectors (PSDs) and lenses capable of measuring the relative-story displacement precisely, even if the PSD unit was inclined in response to the seismic vibration. For verification, laboratory tests were carried out using an Xθ-stage and a shaking table. The static experiment verified that the sensor could measure the local inclination angle as well as the lateral displacement. The dynamic experiment revealed that the accuracy of the sensor was 150 μm in the relative-displacement measurement and 100 μrad in the inclination angle measurement. These results indicate that the proposed sensor system has sufficient accuracy for the measurement of relative-story displacement in response to the seismic vibration.

An approach to unbiased subsample interpolation for motion tracking.

PubMed

McCormick, Matthew M; Varghese, Tomy

2013-04-01

Accurate subsample displacement estimation is necessary for ultrasound elastography because of the small deformations that occur and the subsequent application of a derivative operation on local displacements. Many of the commonly used subsample estimation techniques introduce significant bias errors. This article addresses a reduced bias approach to subsample displacement estimations that consists of a two-dimensional windowed-sinc interpolation with numerical optimization. It is shown that a Welch or Lanczos window with a Nelder-Mead simplex or regular-step gradient-descent optimization is well suited for this purpose. Little improvement results from a sinc window radius greater than four data samples. The strain signal-to-noise ratio (SNR) obtained in a uniformly elastic phantom is compared with other parabolic and cosine interpolation methods; it is found that the strain SNR ratio is improved over parabolic interpolation from 11.0 to 13.6 in the axial direction and 0.7 to 1.1 in the lateral direction for an applied 1% axial deformation. The improvement was most significant for small strains and displacement tracking in the lateral direction. This approach does not rely on special properties of the image or similarity function, which is demonstrated by its effectiveness with the application of a previously described regularization technique.

Synchronization of random bit generators based on coupled chaotic lasers and application to cryptography.

PubMed

Kanter, Ido; Butkovski, Maria; Peleg, Yitzhak; Zigzag, Meital; Aviad, Yaara; Reidler, Igor; Rosenbluh, Michael; Kinzel, Wolfgang

2010-08-16

Random bit generators (RBGs) constitute an important tool in cryptography, stochastic simulations and secure communications. The later in particular has some difficult requirements: high generation rate of unpredictable bit strings and secure key-exchange protocols over public channels. Deterministic algorithms generate pseudo-random number sequences at high rates, however, their unpredictability is limited by the very nature of their deterministic origin. Recently, physical RBGs based on chaotic semiconductor lasers were shown to exceed Gbit/s rates. Whether secure synchronization of two high rate physical RBGs is possible remains an open question. Here we propose a method, whereby two fast RBGs based on mutually coupled chaotic lasers, are synchronized. Using information theoretic analysis we demonstrate security against a powerful computational eavesdropper, capable of noiseless amplification, where all parameters are publicly known. The method is also extended to secure synchronization of a small network of three RBGs.

An Improved Protocol for Controlled Deterministic Secure Quantum Communication Using Five-Qubit Entangled State

NASA Astrophysics Data System (ADS)

Kao, Shih-Hung; Lin, Jason; Tsai, Chia-Wei; Hwang, Tzonelih

2018-03-01

In early 2009, Xiu et al. (Opt. Commun. 282(2) 333-337 2009) presented a controlled deterministic secure quantum communication (CDSQC) protocol via a newly constructed five-qubit entangled quantum state. Later, Qin et al. (Opt. Commun. 282(13), 2656-2658 2009) pointed out two security loopholes in Xiu et al.'s protocol: (1) A correlation-elicitation (CE) attack can reveal the entire secret message; (2) A leakage of partial information for the receiver is noticed. Then, Xiu et al. (Opt. Commun. 283(2), 344-347 2010) presented a revised CDSQC protocol to remedy the CE attack problem. However, the information leakage problem still remains open. This work proposes a new CDSQC protocol using the same five-qubit entangled state which can work without the above mentioned security problems. Moreover, the Trojan Horse attacks can be automatically avoided without using detecting devices in the new CDSQC.

An Improved Protocol for Controlled Deterministic Secure Quantum Communication Using Five-Qubit Entangled State

NASA Astrophysics Data System (ADS)

Kao, Shih-Hung; Lin, Jason; Tsai, Chia-Wei; Hwang, Tzonelih

2018-06-01

In early 2009, Xiu et al. (Opt. Commun. 282(2) 333-337 2009) presented a controlled deterministic secure quantum communication (CDSQC) protocol via a newly constructed five-qubit entangled quantum state. Later, Qin et al. (Opt. Commun. 282(13), 2656-2658 2009) pointed out two security loopholes in Xiu et al.'s protocol: (1) A correlation-elicitation (CE) attack can reveal the entire secret message; (2) A leakage of partial information for the receiver is noticed. Then, Xiu et al. (Opt. Commun. 283(2), 344-347 2010) presented a revised CDSQC protocol to remedy the CE attack problem. However, the information leakage problem still remains open. This work proposes a new CDSQC protocol using the same five-qubit entangled state which can work without the above mentioned security problems. Moreover, the Trojan Horse attacks can be automatically avoided without using detecting devices in the new CDSQC.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Butler, W; Merrick, G; Kurko, B

Purpose: To quantify the effect of metal hip prosthesis on the ability to track and localize electromagnetic transponders. Methods: Three Calypso transponders were implanted into two prostate phantoms. The geometric center of the transponders were identified on computed tomography and set as the isocenter. With the phantom stationary on the treatment table and the tracking array 14-cm above the isocenter, data was acquired by the Calypso system at 10 Hz to establish the uncertainty in measurements. Transponder positional data was acquired with unilateral hip prostheses of different metallic compositions and then with bilateral hips placed at variable separation from themore » phantom. Results: Regardless of hip prosthesis composition, the average vector displacement in the presence of a unilateral prosthesis was < 0.5 mm. The greatest contribution to overall vector displacement occurred in the lateral dimension. With bilateral hip prosthesis, the average vector displacement was 0.3 mm. The displacement in the lateral dimension was markedly reduced compared with a unilateral hip, suggesting that there was a countervailing effect with bilateral hip prosthesis. The greatest average vector displacement was 0.6 mm and occurred when bilateral hip prostheses were placed within 4 cm of the detector array. Conclusion: Unilateral and bilateral hip prostheses did not have any meaningful effect on the ability to accurately track electromagnetic transponders implanted in a prostate phantom. At clinically realistic distances between the hip and detection array, the average tracking error is negligible.« less

Experimental demonstration of beaconless beam displacement tracking for an orbital angular momentum multiplexed free-space optical link.

PubMed

Li, Long; Zhang, Runzhou; Xie, Guodong; Ren, Yongxiong; Zhao, Zhe; Wang, Zhe; Liu, Cong; Song, Haoqian; Pang, Kai; Bock, Robert; Tur, Moshe; Willner, Alan E

2018-05-15

In this Letter, we experimentally demonstrate beaconless beam displacement tracking for free-space optical communication link multiplexing multiple orbital angular momentum (OAM) beams, where the data-carrying OAM beams are used for position detection. 400 Gbit/s data transmission is demonstrated under emulated lateral displacement of up to ±10  mm with power penalties of less than 3 dB for all channels. Channel crosstalk is reduced by the beam tracking system to below -18  dB. Moreover, we investigate using a Gaussian beacon for beam displacement tracking, and achieve similar channel crosstalk and power penalties, compared with using the beaconless beam tracking.

[Management of disk displacement with condylar fracture].

PubMed

Yu, Shi-bin; Li, Zu-bing; Yang, Xue-wen; Zhao, Ji-hong; Dong, Yao-jun

2003-07-01

To investigate clinical features of disk displacement during the course of condylar fracture and to explore the techniques of disk reposition and suturation. 32 patients (10 females and 22 males) who had disk displacements with condylar fractures were followed up. Reduction and reposition of the dislocated disks simultaneously with fixation of fractures were performed. 7 patients underwent intermaxillary fixation with elastic bands for 1 to 2 weeks. The occlusions were satisfactory in all cases but one for the reason of ramus height loss. No TMJ symptom was found when examined 3 months post operation. Anterior disk displacements were most occurred with high condylar process fractures. Surgical reposition and suturation of disk play an important role for the later TMJ-function.

Fracture of the fabella.

PubMed

Woo, C C

1988-10-01

A very rare case of traumatic avulsion fracture of the fabella in a middle-age lady, presented as intermittent posterolateral localized knee pain accentuated by compression against the lateral femoral condyle and by active and passive knee extension, is illustrated. The accumulated chronic microtrauma of the osteoarthritic fabello femoral joint in this lady especially during the whip-kick of daily breaststroke swimming for over 30 yr, may precipitate a fabella stress fracture. Radiographs reveal bilateral fabellae with a left bipartite fabella as a stress fracture traversing it without displacement; this later became a completely displaced bipartite avulsion fracture after accidental knee hyperextension. Conservative treatment consisted of anti-inflammatory/analgesic cream, cryotherapy, TENS, strapping and avoiding knee hyperextension.

Medial joint space widening of the ankle in displaced Tillaux and Triplane fractures in children.

PubMed

Gourineni, Prasad; Gupta, Asheesh

2011-10-01

Tillaux and Triplane fractures occur in children predominantly from external rotation mechanism. We hypothesized that in displaced fractures, the talus would shift laterally along with the distal fibula and the distal tibial epiphyseal fragment increasing the medial joint space. Consecutive cases evaluated retrospectively. Level I and Level II centers. Twenty-two skeletally immature patients with 14 displaced Triplane fractures and eight displaced Tillaux fractures were evaluated for medial joint space widening. Measurement of fracture displacement and medial joint space widening before and after intervention. Thirteen Triplane and six Tillaux fractures (86%) showed medial space widening of 1 to 9 mm and equal to the amount of fracture displacement. Reduction of the fracture reduced the medial space to normal. There were no known complications. Medial space widening of the ankle may be a sign of ankle fracture displacement. Anatomic reduction of the fracture reduces the medial space and may improve the results in Tillaux and Triplane fractures.

Improved characterization of slow-moving landslides by means of adaptive NL-InSAR filtering

NASA Astrophysics Data System (ADS)

Albiol, David; Iglesias, Rubén.; Sánchez, Francisco; Duro, Javier

2014-10-01

Advanced remote sensing techniques based on space-borne Synthetic Aperture Radar (SAR) have been developed during the last decade showing their applicability for the monitoring of surface displacements in landslide areas. This paper presents an advanced Persistent Scatterer Interferometry (PSI) processing based on the Stable Point Network (SPN) technique, developed by the company Altamira-Information, for the monitoring of an active slowmoving landslide in the mountainous environment of El Portalet, Central Spanish Pyrenees. For this purpose, two TerraSAR-X data sets acquired in ascending mode corresponding to the period from April to November 2011, and from August to November 2013, respectively, are employed. The objective of this work is twofold. On the one hand, the benefits of employing Nonlocal Interferomtric SAR (NL-InSAR) adaptive filtering techniques over vegetated scenarios to maximize the chances of detecting natural distributed scatterers, such as bare or rocky areas, and deterministic point-like scatterers, such as man-made structures or poles, is put forward. In this context, the final PSI displacement maps retrieved with the proposed filtering technique are compared in terms of pixels' density and quality with classical PSI, showing a significant improvement. On the other hand, since SAR systems are only sensitive to detect displacements in the line-of-sight (LOS) direction, the importance of projecting the PSI displacement results retrieved along the steepest gradient of the terrain slope is discussed. The improvements presented in this paper are particularly interesting in these type of applications since they clearly allow to better determine the extension and dynamics of complex landslide phenomena.

Estimation of liquefaction-induced lateral spread from numerical modeling and its application

NASA Astrophysics Data System (ADS)

Meng, Xianhong

A noncoupled numerical procedure was developed using a scheme of pore water generation that causes shear modulus degradation and shear strength degradation resulting from earthquake cyclic motion. The designed Fast Lagrangian Analysis of Continua (FLAC) model procedure was tested using the liquefaction-induced lateral spread and ground response for Wildlife and Kobe sites. Sixteen well-documented case histories of lateral spread were reviewed and modeled using the modeling procedure. The dynamic residual strength ratios were back-calculated by matching the predicted displacement with the measured lateral spread, or with the displacement predicted by the Yound et al. model. Statistical analysis on the modeling results and soil properties show that most significant parameters governing the residual strength of the liquefied soil are the SPT blow count, fine content and soil particle size of the lateral spread layer. A regression equation was developed to express the residual strength values with these soil properties. Overall, this research demonstrated that a calibrated numerical model can predict the first order effectiveness of liquefaction-induced lateral spread using relatively simple parameters obtained from routine geotechnical investigation. In addition, the model can be used to plan a soil improvement program for cases where liquefaction remediation is needed. This allows the model to be used for design purposes at bridge approaches structured on liquefiable materials.

Inter and intra-observer reliability in assessment of the position of the lateral sesamoid in determining the severity of hallux valgus.

PubMed

Panchani, Sunil; Reading, Jonathan; Mehta, Jaysheel

2016-06-01

The position of the lateral sesamoid on standard dorso-plantar weight bearing radiographs, with respect to the lateral cortex of the first metatarsal, has been shown to correlate well with the degree of the hallux valgus angle. This study aimed to assess the inter- and intra-observer error of this new classification system. Five orthopaedic consultants and five trainee orthopaedic surgeons were recruited to assess and document the degree of displacement of the lateral sesamoid on 144 weight-bearing dorso-plantar radiographs on two separate occasions. The severity of hallux valgus was defined as normal (0%), mild (≤50%), moderate (51-≤99%) or severe (≥100%) depending on the percentage displacement of the lateral sesamoid body from the lateral cortical border of the first metatarsal. Consultant intra-observer variability showed good agreement between repeated assessment of the radiographs (mean Kappa=0.75). Intra-observer variability for trainee orthopaedic surgeons also showed good agreement with a mean Kappa=0.73. Intraclass correlations for consultants and trainee surgeons was also high. The new classification system of assessing the severity of hallux valgus shows high inter- and intra-observer variability with good agreement and reproducibility between surgeons of consultant and trainee grades. Copyright © 2015 Elsevier Ltd. All rights reserved.

SU-E-T-577: Commissioning of a Deterministic Algorithm for External Photon Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, T; Finlay, J; Mesina, C

Purpose: We report commissioning results for a deterministic algorithm for external photon beam treatment planning. A deterministic algorithm solves the radiation transport equations directly using a finite difference method, thus improve the accuracy of dose calculation, particularly under heterogeneous conditions with results similar to that of Monte Carlo (MC) simulation. Methods: Commissioning data for photon energies 6 – 15 MV includes the percentage depth dose (PDD) measured at SSD = 90 cm and output ratio in water (Spc), both normalized to 10 cm depth, for field sizes between 2 and 40 cm and depths between 0 and 40 cm. Off-axismore » ratio (OAR) for the same set of field sizes was used at 5 depths (dmax, 5, 10, 20, 30 cm). The final model was compared with the commissioning data as well as additional benchmark data. The benchmark data includes dose per MU determined for 17 points for SSD between 80 and 110 cm, depth between 5 and 20 cm, and lateral offset of up to 16.5 cm. Relative comparisons were made in a heterogeneous phantom made of cork and solid water. Results: Compared to the commissioning beam data, the agreement are generally better than 2% with large errors (up to 13%) observed in the buildup regions of the FDD and penumbra regions of the OAR profiles. The overall mean standard deviation is 0.04% when all data are taken into account. Compared to the benchmark data, the agreements are generally better than 2%. Relative comparison in heterogeneous phantom is in general better than 4%. Conclusion: A commercial deterministic algorithm was commissioned for megavoltage photon beams. In a homogeneous medium, the agreement between the algorithm and measurement at the benchmark points is generally better than 2%. The dose accuracy for a deterministic algorithm is better than a convolution algorithm in heterogeneous medium.« less

Analysis of cell mechanics in single vinculin-deficient cells using a magnetic tweezer

NASA Technical Reports Server (NTRS)

Alenghat, F. J.; Fabry, B.; Tsai, K. Y.; Goldmann, W. H.; Ingber, D. E.

2000-01-01

A magnetic tweezer was constructed to apply controlled tensional forces (10 pN to greater than 1 nN) to transmembrane receptors via bound ligand-coated microbeadswhile optically measuring lateral bead displacements within individual cells. Use of this system with wild-type F9 embryonic carcinoma cells and cells from a vinculin knockout mouse F9 Vin (-/-) revealed much larger differences in the stiffness of the transmembrane integrin linkages to the cytoskeleton than previously reported using related techniques that measured average mechanical properties of large cell populations. The mechanical properties measured varied widely among cells, exhibiting an approximately log-normal distribution. The median lateral bead displacement was 2-fold larger in F9 Vin (-/-) cells compared to wild-type cells whereas the arithmetic mean displacement only increased by 37%. We conclude that vinculin serves a greater mechanical role in cells than previously reported and that this magnetic tweezer device may be useful for probing the molecular basis of cell mechanics within single cells. Copyright 2000 Academic Press.

TU-AB-303-11: Predict Parotids Deformation Applying SIS Epidemiological Model in H&N Adaptive RT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maffei, N; Guidi, G; University of Bologna, Bologna, Bologna

2015-06-15

Purpose: The aim is to investigate the use of epidemiological models to predict morphological variations in patients undergoing radiation therapy (RT). The susceptible-infected-susceptible (SIS) deterministic model was applied to simulate warping within a focused region of interest (ROI). Hypothesis is to consider each voxel like a single subject of the whole sample and to treat displacement vector fields like an infection. Methods: Using Raystation hybrid deformation algorithms and automatic re-contouring based on mesh grid, we post-processed 360 MVCT images of 12 H&N patients treated with Tomotherapy. Study focused on parotid glands, identified by literature and previous analysis, as ROI moremore » susceptible to warping in H&N region. Susceptible (S) and infectious (I) cases were identified in voxels with inter-fraction movement respectively under and over a set threshold. IronPython scripting allowed to export positions and displacement data of surface voxels for every fraction. A MATLAB homemade toolbox was developed to model the SIS. Results: SIS model was validated simulating organ motion on QUASAR phantom. Applying model in patients, within a [0–1cm] range, a single voxel movement of 0.4cm was selected as displacement threshold. SIS indexes were evaluated by MATLAB simulations. Dynamic time warping algorithm was used to assess matching between model and parotids behavior days of treatments. The best fit of the model was obtained with contact rate of 7.89±0.94 and recovery rate of 2.36±0.21. Conclusion: SIS model can follow daily structures evolutions, making possible to compare warping conditions and highlighting challenges due to abnormal variation and set-up errors. By epidemiology approach, organ motion could be assessed and predicted not in terms of average of the whole ROI, but in a voxel-by-voxel deterministic trend. Identifying anatomical region subjected to variations, would be possible to focus clinic controls within a cohort of pre-selected patients eligible for adaptive RT. The research is partially co-funded by the Italian Research Grant: Dose warping methods for IGRT and Adaptive RT: dose accumulation based on organ motion and anatomical variations of the patients during radiation therapy treatments,MoH (GR-2010-2318757) and Tecnologie Avanzate S.r.l.(Italy)« less

Determination of torque-limits for human and cat lumbar spine specimens during displacement-controlled physiological motions.

PubMed

Ianuzzi, Allyson; Pickar, Joel G; Khalsa, Partap S

2009-01-01

Quadruped animal models have been validated and used as biomechanical models for the lumbar spine. The biomechanics of the cat lumbar spine has not been well characterized, even though it is a common model used in neuromechanical studies. Compare the physiological ranges of motion and determine torque-limits for cat and human lumbar spine specimens during physiological motions. Biomechanics study. Cat and human lumbar spine specimens. Intervertebral angle (IVA), joint moment, yield point, torque-limit, and correlation coefficients. Cat (L2-sacrum) and human (T12-sacrum) lumbar spine specimens were mechanically tested to failure during displacement-controlled extension (E), lateral bending (LB), and axial rotation (AR). Single trials consisted of 10 cycles (10mm/s or 5 degrees /s) to a target displacement where the magnitude of the target displacement was increased for subsequent trials until failure occurred. Whole-lumbar stiffness, torque at yield point, and joint stiffness were determined. Scaling relationships were established using equations analogous to those that describe the load response of elliptically shaped beams. IVA magnitudes for cat and human lumbar spines were similar during physiological motions. Human whole-lumbar and joint stiffness magnitudes were significantly greater than those for cat spine specimens (p<.05). Torque-limits were also greater for humans compared with cats. Scaling relationships with high correlation (R(2) greater than 0.77) were established during later LB and AR. The current study defined "physiological ranges of movement" for human and cat lumbar spine specimens during displacement-controlled testing, and should be observed in future biomechanical studies conducted under displacement control.

Relationship between patellar mobility and patellofemoral joint cartilage degeneration after anterior cruciate ligament reconstruction.

PubMed

Ota, Susumu; Kurokouchi, Kazutoshi; Takahashi, Shigeo; Yoda, Masaki; Yamamoto, Ryuichiro; Sakai, Tadahiro

2017-11-01

Patellofemoral cartilage degeneration is a potential complication of anterior cruciate ligament reconstruction (ACLR) surgery. Hypomobility of the patella in the coronal plane is often observed after ACLR. Few studies, however, have examined the relationship between cartilage degeneration in the patellofemoral joint and mobility after ACLR. The present study investigated 1) the coronal mobility of the patella after ACLR, 2) the relationship between patellar mobility and cartilage degeneration of the patellofemoral joint, and 3) the relationship between patellar mobility and knee joint function after ACLR. Forty patients who underwent medial hamstring-based ACLR participated in the study. Lateral and medial patellar displacements were assessed with a modified patellofemoral arthrometer, and the absolute values of the displacements were normalized to patient height. The International Cartilage Repair Society (ICRS) cartilage injury classification of the patellar and femoral (trochlear) surfaces, and the Lysholm Knee Scoring Scale were used to evaluate knee function. Lateral and medial patellar displacements were reduced compared with the non-operated knee at the second-look arthroscopy and bone staple extraction operation (second operation; 24.4 ± 7.9 months after ACLR, P<0.01). The ICRS grades of the patellofemoral joint (patella and trochlea) were significantly worse than those pre-ACLR. Neither lateral nor medial patellar mobility, however, were significantly correlated with the ICRS grade or the Lysholm score. Although patellar mobility at approximately 2 years after ACLR was decreased compared to the non-operated knee, small displacement of the patella was not related to cartilage degeneration or knee joint function at the time of the second operation.

More than 60 years later: the mediating role of trauma and posttraumatic stress disorder for the association of forced displacement in world war II with somatization in old age.

PubMed

Kuwert, Philipp; Braehler, Elmar; Freyberger, Harald J; Glaesmer, Heide

2012-10-01

Up to now, it has remained unclear whether displacement itself is the pathogenetic factor for the impairment of mental health in uprooted individuals or whether the effect is mediated by the amount of traumatic events experienced during forced displacement and/or by the development of posttraumatic stress disorder (PTSD). A total of 1657 participants were included in this population-based study, who were then administered with the Patient Health Questionnaire, a modified trauma list of the PTSD module of the Munich Composite International Diagnostic Interview, and the Posttraumatic Diagnostic Scale. Displacement was associated with increased rates of traumatic events. The displaced participants were significantly more affected by somatoform symptoms and PTSD than the nondisplaced population. It was not displacement itself but the amount of trauma experienced during displacement that predicts current somatization in the population-based sample. The results highlight the necessity for prevention and treatment of posttraumatic conditions in displaced individuals and underpin the importance to understand somatization as one condition of the posttraumatic symptoms spectrum in the elderly.

Surgical treatment of high-standing greater trochanter.

PubMed

Takata, K; Maniwa, S; Ochi, M

1999-01-01

Eleven patients with high-standing greater trochanter (13 joints) aged 13-36 years underwent surgery. Distal transfer of the greater trochanter (group T) was performed in 4 patients (5 joints) and lateral displacement osteotomy (group L) in 7 (8 joints). The average follow-up duration was 13.4 years in group T and 5.9 years in group L. Clinical results were evaluated by the hip score according to Merle d'Aubigne. The mean hip score in group T was 13.4 points before operation and 15.4 points after operation, and in group L, 12.8 and 17.4 points, respectively. The postoperative clinical results of group L were significantly better than those of group T (P = 0.0494). In radiological evaluation, although the articulo-trochanteric distance (ATD) increased in both groups in group L it improved remarkably from 9.8 to 24.3, indicating a large descending distance of the greater trochanter. The lever arm ratio (LAR) did not change significantly in group T, but it decreased from 1.97 to 1.60 in group L (P = 0.004). This means that the lever arm of the abductors can certainly be extended by lateral displacement osteotomy. Lateral displacement osteotomy is the most effective procedure for high-standing greater trochanter.

Patients' understanding of and responses to multiplex genetic susceptibility test results.

PubMed

Kaphingst, Kimberly A; McBride, Colleen M; Wade, Christopher; Alford, Sharon Hensley; Reid, Robert; Larson, Eric; Baxevanis, Andreas D; Brody, Lawrence C

2012-07-01

Examination of patients' responses to direct-to-consumer genetic susceptibility tests is needed to inform clinical practice. This study examined patients' recall and interpretation of, and responses to, genetic susceptibility test results provided directly by mail. This observational study had three prospective assessments (before testing, 10 days after receiving results, and 3 months later). Participants were 199 patients aged 25-40 years who received free genetic susceptibility testing for eight common health conditions. More than 80% of the patients correctly recalled their results for the eight health conditions. Patients were unlikely to interpret genetic results as deterministic of health outcomes (mean = 6.0, s.d. = 0.8 on a scale of 1-7, 1 indicating strongly deterministic). In multivariate analysis, patients with the least deterministic interpretations were white (P = 0.0098), more educated (P = 0.0093), and least confused by results (P = 0.001). Only 1% talked about their results with a provider. Findings suggest that most patients will correctly recall their results and will not interpret genetics as the sole cause of diseases. The subset of those confused by results could benefit from consultation with a health-care provider, which could emphasize that health habits currently are the best predictors of risk. Providers could leverage patients' interest in genetic tests to encourage behavior changes to reduce disease risk.

Seismic transmission operator reciprocity - II: impedance-operator symmetry via elastic lateral modes

NASA Astrophysics Data System (ADS)

Thomson, C. J.

2015-08-01

The properties of the overburden transmission response are of particular interest for the analysis of reflectivity illumination or blurring in seismic depth imaging. The first step to showing a transmission-operator reciprocity property is to identify the symmetry of the so-called displacement-to-traction operators. The latter are analogous to Dirichlet-to-Neumann operators and they may also be called impedance operators. Their symmetry is deduced here after development of a formal spectral or modal theory of lateral wavefunctions in a laterally heterogeneous generally anisotropic elastic medium. The elastic lateral modes are displacement-traction 6-vectors and they are built from two auxiliary 3-vector lateral-mode bases. These auxiliary modes arise from Hermitian and anti-Hermitian operators, so they have familiar properties such as orthogonality. There is no assumption of down/up symmetry of the elasticity tensor, but basic assumptions are made about the existence and completeness of the elastic modes. A point-symmetry property appears and plays a central role. The 6-vector elastic modes have a symplectic orthogonality property, which facilitates the development of modal expansions for 6-vector functions of the lateral coordinates when completeness is assumed. While the elastic modal theory is consistent with the laterally homogeneous case, numerical work would provide confidence that it is correct in general. An appendix contains an introductory overview of acoustic lateral modes that were studied by other authors, given from the perspective of this new work. A distinction is drawn between unit normalization of scalar auxiliary modes and a separate energy-flux normalization of 2-vector acoustic modes. Neither is crucial to the form of acoustic pressure-to-velocity or impedance operators. This statement carries over to the elastic case for the 3-vector auxiliary- and 6-vector elastic-mode normalizations. The modal theory is used to construct the kernel of the elastic displacement-to-traction or impedance operator. Symmetry properties of this operator are then deduced, which is the main goal of this paper. The implications of elastic impedance-operator symmetry and the symplectic property for the transmission and reflection responses of finite regions are described in a companion paper.

Radiographic follow-up of 84 operatively treated scapula neck and body fractures.

PubMed

Cole, Peter A; Gauger, Erich M; Herrera, Diego A; Anavian, Jack; Tarkin, Ivan S

2012-03-01

Certain scapula fractures may warrant surgical management to restore shoulder anatomy and promote optimal function. The purpose of this study is to determine the early radiographic follow-up of open reduction internal fixation (ORIF) for displaced, scapular fractures involving the glenoid neck and body. Eighty-four patients with a scapula body or neck fracture (with or without articular involvement) underwent ORIF between 2002 and 2010 at a single level I trauma centre. This study represents a retrospective review of data prospectively collected into a dedicated scapula fracture database. All patients met at least one of the following operative criteria: ≥20 mm medial/lateral (M/L) displacement (lateral border offset), ≥45° of angular deformity on a scapular-Y X-ray, the combination of angulation ≥30° plus M/L displacement ≥15 mm, double disruptions of the superior shoulder suspensory complex both displaced ≥10 mm, glenopolar angle (GPA) ≤22° and open fractures. Eighty-eight percent (74/84) had sufficient follow-up defined as at least 6 months. Measured outcomes included rates of scapula union and malunion, as well as surgical complications and re-operations. All fractures were caused by high-energy trauma with 24 (29%) resulting from motor-vehicle collisions. Associated injuries occurred in 94% of patients, most commonly involving the chest (70%) and ipsilateral shoulder girdle (43%). Forty-eight patients had M/L displacement as an operative indication with a mean displacement of 25.7 mm (range=20-40). Thirty-eight (45%) had ≥2 operative indications. A single surgeon performed ORIF in all patients using a posterior approach. Five patients also required an anterior (deltopectoral) approach. The fixation strategy included lateral and vertebral border stabilisation with dynamic compression and reconstruction plates, respectively. Union was achieved in all cases. There were three cases of malunion based on a GPA difference >10° from the uninjured shoulder. Re-operations included removal of hardware (seven patients) and manipulation under anaesthesia (three patients). There were no infections or wound dehiscence. ORIF for displaced scapula fractures is a relatively safe and effective procedure for restoration of anatomy and promotion of union. Therapeutic study, level IV. Copyright © 2011 Elsevier Ltd. All rights reserved.

Deterministic Execution of Ptides Programs

DTIC Science & Technology

2013-05-15

at a time no later than 30+1+5 = 36. Assume the maximum clock synchronization error is . Therefore, the AddSubtract adder must delay processing the...the synchronization of the platform real- time clock to its peers in other system platforms. The portions of PtidyOS code that implement access to the...interesting opportunities for future research. References [1] Y. Zhao, E. A. Lee, and J. Liu, “A programming model for time - synchronized distributed real

An Alternative Introduction to Maxwell's Displacement Current

ERIC Educational Resources Information Center

Reich, Gary

2013-01-01

In introductory texts Ampere's law is generally introduced in the steady-current form ?B · dl = µ[subscript 0]I, and it is later extended to a more general form involving the so-called displacement current I[subscript d], ?B · dl = µ[subscript 0](I + I[subscript d]) · (1). Here the line integral is to be taken along a closed…

Surface slip during large Owens Valley earthquakes

USGS Publications Warehouse

Haddon, E.K.; Amos, C.B.; Zielke, O.; Jayko, Angela S.; Burgmann, R.

2016-01-01

The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of laterally and vertically displaced landforms for 1872 and prehistoric Owens Valley earthquakes. Our lidar analysis uses a newly developed analytical tool to measure fault slip based on cross-correlation of sublinear topographic features and to produce a uniquely shaped probability density function (PDF) for each measurement. Stacking PDFs along strike to form cumulative offset probability distribution plots (COPDs) highlights common values corresponding to single and multiple-event displacements. Lateral offsets for 1872 vary systematically from ∼1.0 to 6.0 m and average 3.3 ± 1.1 m (2σ). Vertical offsets are predominantly east-down between ∼0.1 and 2.4 m, with a mean of 0.8 ± 0.5 m. The average lateral-to-vertical ratio compiled at specific sites is ∼6:1. Summing displacements across subparallel, overlapping rupture traces implies a maximum of 7–11 m and net average of 4.4 ± 1.5 m, corresponding to a geologic Mw ∼7.5 for the 1872 event. We attribute progressively higher-offset lateral COPD peaks at 7.1 ± 2.0 m, 12.8 ± 1.5 m, and 16.6 ± 1.4 m to three earlier large surface ruptures. Evaluating cumulative displacements in context with previously dated landforms in Owens Valley suggests relatively modest rates of fault slip, averaging between ∼0.6 and 1.6 mm/yr (1σ) over the late Quaternary.

Spring constant measurement using a MEMS force and displacement sensor utilizing paralleled piezoresistive cantilevers

NASA Astrophysics Data System (ADS)

Kohyama, Sumihiro; Takahashi, Hidetoshi; Yoshida, Satoru; Onoe, Hiroaki; Hirayama-Shoji, Kayoko; Tsukagoshi, Takuya; Takahata, Tomoyuki; Shimoyama, Isao

2018-04-01

This paper reports on a method to measure a spring constant on site using a micro electro mechanical systems (MEMS) force and displacement sensor. The proposed sensor consists of a force-sensing cantilever and a displacement-sensing cantilever. Each cantilever is composed of two beams with a piezoresistor on the sidewall for measuring the in-plane lateral directional force and displacement. The force resolution and displacement resolution of the fabricated sensor were less than 0.8 µN and 0.1 µm, respectively. We measured the spring constants of two types of hydrogel microparticles to demonstrate the effectiveness of the proposed sensor, with values of approximately 4.3 N m-1 and 15.1 N m-1 obtained. The results indicated that the proposed sensor is effective for on-site spring constant measurement.

Association between measures of patella height, morphologic features of the trochlea, and patellofemoral joint alignment: the MOST study.

PubMed

Stefanik, Joshua J; Zumwalt, Ann C; Segal, Neil A; Lynch, John A; Powers, Christopher M

2013-08-01

Patellofemoral joint (PFJ) malalignment (lateral patella displacement and tilt) has been proposed as a cause of patellofemoral pain. Patella height and/or the morphologic features of the femoral trochlea may predispose one to patella malalignment. The purposes of our study were to assess the associations among patella height, morphologic features of the trochlea, and measures of PFJ alignment and to determine which measures of patella height and morphologic features of the trochlea were the best predictors of PFJ alignment. Measures of patella height (Insall-Salvati ratio and modified Insall-Salvati ratio), morphologic features of the trochlea (sulcus angle, trochlear angle, lateral trochlear inclination, medial trochlear inclination), and PFJ alignment (bisect offset and patella tilt angle) were assessed in 566 knees from the Multicenter Osteoarthritis Study. Bisect offset was correlated with the Insall-Salvati ratio (r = 0.25) and lateral trochlear inclination (r = -0.38). Patella tilt angle correlated with the trochlear angle (-0.27) and lateral trochlear inclination (-0.32). Linear regression models including the Insall-Salvati ratio and lateral trochlear inclination explained 20% and 11% of the variance in bisect offset and patella tilt angle, respectively. Of the variables measured in the current study, the Insall-Salvati ratio and lateral trochlear inclination were the best predictors of lateral patella displacement and lateral tilt. This knowledge will aid clinicians in the identification of anatomic risk factors for PFJ malalignment and/or PFJ dysfunction.

A Demonstration of Optimal Apodization Determination for Proper Lateral Modulation

NASA Astrophysics Data System (ADS)

Sumi, Chikayoshi; Komiya, Yuichi; Uga, Shinya

2009-07-01

We have realized effective ultrasound (US) beamformings by the steering of plural beams and apodizations for B-mode imaging with a high lateral resolution and accurate measurement of tissue or blood displacement vector and/or strain tensor using the multidimensional cross-spectrum phase gradient method (MCSPGM), or multidimensional autocorrelation or Doppler methods (MAM and MDM) using multidimensional analytic signals. For instance, the coherent superposition of the steered beams performed in the lateral cosine modulation method (LCM) has a higher potential for realizing a more accurate measurement of a displacement vector than the synthesis of the displacement vector using the accurately measured axial displacements obtained by the multidimensional synthetic aperture method (MDSAM), multidirectional transmission method (MTM) or the use of plural US transducers. Originally, the apodization function to be used for realizing a designed point spread function (PSF) was obtained by the Fraunhofer approximation (FA). However, to obtain the best approximated, designed PSF in the least-squares sense, we proposed a linear optimization (LO) method. Furthermore, on the basis of the knowledge about the losts of US energy during the propagation, we have recently developed a nonlinear optimization (NLO) method, in which the feet of the main lobes in apodization function are properly truncated. Thus, NLO also allows the decrease in the number of channels or the confinement of the effective aperture. In this study, to gain insight into the ideal shape of the PSF, the accuracies of the two-dimensional (2D) displacement vector measurements were compared for typical PSFs with distinct lateral envelope shapes, particularly, in terms of full width at half maximum (FWHM) and the length of the feet, i.e., the Gaussian function, Hanning window and parabolic function. It was confirmed that a PSF having a wide FWHM and short feet was ideal. Such a PSF yielded an echo with a high signal-to-noise ratio (SNR), a large bandwidth and a large maximum spectrum of the center frequency. Moreover, for the three PSFs used, by calculating the PSFs using a typical transducer model and the apodization functions obtained by the respective LO and NLO methods and FA, we compare the approximation accuracies of the realized PSFs. NLO was effective for realizing such an ideal PSF. In addition, NLO allowed the significant decrease in the number of channels or the confinement of the effective aperture. Thus, in the comparisons of the three distinct PSFs, we obtain an appropriate apodization function. This study will assist the realization of the best lateral modulation.

A reliable simultaneous representation of seismic hazard and of ground shaking recurrence

NASA Astrophysics Data System (ADS)

Peresan, A.; Panza, G. F.; Magrin, A.; Vaccari, F.

2015-12-01

Different earthquake hazard maps may be appropriate for different purposes - such as emergency management, insurance and engineering design. Accounting for the lower occurrence rate of larger sporadic earthquakes may allow to formulate cost-effective policies in some specific applications, provided that statistically sound recurrence estimates are used, which is not typically the case of PSHA (Probabilistic Seismic Hazard Assessment). We illustrate the procedure to associate the expected ground motions from Neo-deterministic Seismic Hazard Assessment (NDSHA) to an estimate of their recurrence. Neo-deterministic refers to a scenario-based approach, which allows for the construction of a broad range of earthquake scenarios via full waveforms modeling. From the synthetic seismograms the estimates of peak ground acceleration, velocity and displacement, or any other parameter relevant to seismic engineering, can be extracted. NDSHA, in its standard form, defines the hazard computed from a wide set of scenario earthquakes (including the largest deterministically or historically defined credible earthquake, MCE) and it does not supply the frequency of occurrence of the expected ground shaking. A recent enhanced variant of NDSHA that reliably accounts for recurrence has been developed and it is applied to the Italian territory. The characterization of the frequency-magnitude relation can be performed by any statistically sound method supported by data (e.g. multi-scale seismicity model), so that a recurrence estimate is associated to each of the pertinent sources. In this way a standard NDSHA map of ground shaking is obtained simultaneously with the map of the corresponding recurrences. The introduction of recurrence estimates in NDSHA naturally allows for the generation of ground shaking maps at specified return periods. This permits a straightforward comparison between NDSHA and PSHA maps.

Neo-deterministic seismic hazard scenarios for India—a preventive tool for disaster mitigation

NASA Astrophysics Data System (ADS)

Parvez, Imtiyaz A.; Magrin, Andrea; Vaccari, Franco; Ashish; Mir, Ramees R.; Peresan, Antonella; Panza, Giuliano Francesco

2017-11-01

Current computational resources and physical knowledge of the seismic wave generation and propagation processes allow for reliable numerical and analytical models of waveform generation and propagation. From the simulation of ground motion, it is easy to extract the desired earthquake hazard parameters. Accordingly, a scenario-based approach to seismic hazard assessment has been developed, namely the neo-deterministic seismic hazard assessment (NDSHA), which allows for a wide range of possible seismic sources to be used in the definition of reliable scenarios by means of realistic waveforms modelling. Such reliable and comprehensive characterization of expected earthquake ground motion is essential to improve building codes, particularly for the protection of critical infrastructures and for land use planning. Parvez et al. (Geophys J Int 155:489-508, 2003) published the first ever neo-deterministic seismic hazard map of India by computing synthetic seismograms with input data set consisting of structural models, seismogenic zones, focal mechanisms and earthquake catalogues. As described in Panza et al. (Adv Geophys 53:93-165, 2012), the NDSHA methodology evolved with respect to the original formulation used by Parvez et al. (Geophys J Int 155:489-508, 2003): the computer codes were improved to better fit the need of producing realistic ground shaking maps and ground shaking scenarios, at different scale levels, exploiting the most significant pertinent progresses in data acquisition and modelling. Accordingly, the present study supplies a revised NDSHA map for India. The seismic hazard, expressed in terms of maximum displacement (Dmax), maximum velocity (Vmax) and design ground acceleration (DGA), has been extracted from the synthetic signals and mapped on a regular grid over the studied territory.

[Three-dimensional finite element analysis of maxillary incisor retraction with step-shaped vertical closing loop].

PubMed

Zhang, Sheng; Mai, Li-xiang; Liu, Cong-hua; Wang, Da-wei

2011-07-01

To investigate the displacement and stress distribution of upper incisors in three-dimensional (3D) space controlled by step-shaped vertical closing loop. The maxillary teeth and alveolar bone of a volunteer with normal occlusion were scanned with 3D spiral CT. Modeling and calculation were only carried out on right upper central incisor, lateral incisor and their alveolar bone in order to simplify the procedures. A 3D finite element model of archwire-brackets-upper incisors and periodontal tissues was developed using Ansys finite element package. Finally, a 3D finite element model of archwire-brackets-upper incisors and periodontal tissues was established based on mirror symmetry principle. The displacement of maxillary incisors and stress distribution in periodontal tissues were analyzed. When step-shaped vertical closing loop was simply drew back 1 mm, the maximum displacement of upper central incisor in labial and lingual direction were 5.29 × 10(-2) and 0.71 × 10(-2) mm; 10.47 × 10(-3) and 10.20 × 10(-3) mm in gingival and occlusal direction, 10.26 × 10(-3) and 1.63 × 10(-3) mm in medial and distal direction; the maximum displacement of upper lateral incisor in labial and lingual direction were 3.31 × 10(-2) and 0.41 × 10(-2) mm, 10.52 × 10(-3) and 5.10 × 10(-3) mm in gingival and occlusal direction, 6.29 × 10(-3) and 4.64 × 10(-3) mm in medial and distal direction, the displacement trend of them were moving lingually and gingivally similar to bodily movement. The stress peach of upper central incisor, periodontal ligament and alveolar bone were 31.35, 2.52 and 4.64 MPa, the stress peach of upper lateral incisor, periodontal ligament and alveolar bone were 19.59, 1.28 and 4.12 Mpa, the stress distribution of them were similar and the periodontal ligament buffered the stress imposed on the tooth.

Cryogenic cooler apparatus

DOEpatents

Wheatley, J.C.; Paulson, D.N.; Allen, P.C.

1983-01-04

A Malone-type final stage for utilization in a Stirling cycle cryogenic cooler apparatus includes a displacer slidable within a vessel. [sup 4]He, [sup 3]He, or a mixture thereof is made to flow in a pulsating unidirectional manner through a regenerator in the displacer by utilization of check valves in separate fluid channels. Stacked copper screen members extend through the channels and through a second static thermodynamic medium within the displacer to provide efficient lateral heat exchange and enable cooling to temperatures in the range of 3--4 K. Another embodiment utilizes sintered copper particles in the regenerator. Also described is a final stage that has a non-thermally conducting displacer having passages with check valves for directing fluid past a regenerator formed in the surrounding vessel. 10 figs.

Cryogenic cooler apparatus

DOEpatents

Wheatley, John C.; Paulson, Douglas N.; Allen, Paul C.

1983-01-01

A Malone-type final stage for utilization in a Stirling cycle cryogenic cooler apparatus includes a displacer slidable within a vessel. .sup.4 He, .sup.3 He, or a mixture thereof is made to flow in a pulsating unidirectional manner through a regenerator in the displacer by utilization of check valves in separate fluid channels. Stacked copper screen members extend through the channels and through a second static thermodynamic medium within the displacer to provide efficient lateral heat exchange and enable cooling to temperatures in the range of 3-4 K. Another embodiment utilizes sintered copper particles in the regenerator. Also described is a final stage that has a non-thermally conducting displacer having passages with check valves for directing fluid past a regenerator formed in the surrounding vessel.

Patterned arrays of lateral heterojunctions within monolayer two-dimensional semiconductors

PubMed Central

Mahjouri-Samani, Masoud; Lin, Ming-Wei; Wang, Kai; Lupini, Andrew R.; Lee, Jaekwang; Basile, Leonardo; Boulesbaa, Abdelaziz; Rouleau, Christopher M.; Puretzky, Alexander A.; Ivanov, Ilia N.; Xiao, Kai; Yoon, Mina; Geohegan, David B.

2015-01-01

The formation of semiconductor heterojunctions and their high-density integration are foundations of modern electronics and optoelectronics. To enable two-dimensional crystalline semiconductors as building blocks in next-generation electronics, developing methods to deterministically form lateral heterojunctions is crucial. Here we demonstrate an approach for the formation of lithographically patterned arrays of lateral semiconducting heterojunctions within a single two-dimensional crystal. Electron beam lithography is used to pattern MoSe2 monolayer crystals with SiO2, and the exposed locations are selectively and totally converted to MoS2 using pulsed laser vaporization of sulfur to form MoSe2/MoS2 heterojunctions in predefined patterns. The junctions and conversion process are studied by Raman and photoluminescence spectroscopy, atomically resolved scanning transmission electron microscopy and device characterization. This demonstration of lateral heterojunction arrays within a monolayer crystal is an essential step for the integration of two-dimensional semiconductor building blocks with different electronic and optoelectronic properties for high-density, ultrathin devices. PMID:26198727

Structurally controllable spin spatial splitter in a hybrid ferromagnet and semiconductor nanostructure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Mao-Wang, E-mail: maowanglu@126.com; Cao, Xue-Li; Huang, Xin-Hong

2014-05-07

We theoretically investigate modulation of a tunable δ-potential to the lateral displacement of electrons across a magnetically modulated semiconductor nanostructure. Experimentally, this nanostructure can be produced by depositing a nanosized ferromagnetic stripe with in-plane magnetization on top of a semiconductor heterostructure, while the δ-potential can be realized by means of the atomic layer doping technique. Theoretical analysis reveals that this δ-doping can break the intrinsic symmetry in nanostructure and a considerable spin polarization in the lateral displacement will appear. Numerical calculations demonstrate that both magnitude and sign of spin polarization can be manipulated by changing the height and/or position ofmore » the δ-doping, giving rise to a structurally tunable spin spatial splitter.« less

Optimal Post-Operative Immobilisation for Supracondylar Humeral Fractures.

PubMed

Azzolin, Lucas; Angelliaume, Audrey; Harper, Luke; Lalioui, Abdelfettah; Delgove, Anaïs; Lefèvre, Yan

2018-05-25

Supracondylar humeral fractures (SCHFs) are very common in paediatric patients. In France, percutaneous fixation with two lateral-entry pins is widely used after successful closed reduction. Post-operative immobilisation is typically with a long arm cast combined with a tubular-bandage sling that immobilises the shoulder and holds the arm in adduction and internal rotation to prevent external rotation of the shoulder, which might cause secondary displacement. The objective of this study was to compare this standard immobilisation technique to a posterior plaster splint with a simple sling. Secondary displacement is not more common with a posterior plaster splint and sling than with a long arm cast. 100 patients with extension Gartland type III SCHFs managed by closed reduction and percutaneous fixation with two lateral-entry pins between December 2011 and December 2015 were assessed retrospectively. Post-operative immobilisation was with a posterior plaster splint and a simple sling worn for 4 weeks. Radiographs were obtained on days 1, 45, and 90. Secondary displacement occurred in 8% of patients. No patient required revision surgery. The secondary displacement rate was comparable to earlier reports. Of the 8 secondary displacements, 5 were ascribable to technical errors. The remaining 3 were not caused by rotation of the arm and would probably not have been prevented by using the tubular-bandage sling. A posterior plaster splint combined with a simple sling is a simple and effective immobilisation method for SCHFs provided internal fixation is technically optimal. IV, retrospective observational study. Copyright © 2018. Published by Elsevier Masson SAS.

Fault geometry and cumulative offsets in the central Coast Ranges, California: Evidence for northward increasing slip along the San Gregorio-San Simeon-Hosgri fault

USGS Publications Warehouse

Langenheim, V.E.; Jachens, R.C.; Graymer, R.W.; Colgan, J.P.; Wentworth, C.M.; Stanley, R.G.

2012-01-01

Estimates of the dip, depth extent, and amount of cumulative displacement along the major faults in the central California Coast Ranges are controversial. We use detailed aeromagnetic data to estimate these parameters for the San Gregorio–San Simeon–Hosgri and other faults. The recently acquired aeromagnetic data provide an areally consistent data set that crosses the onshore-offshore transition without disruption, which is particularly important for the mostly offshore San Gregorio–San Simeon–Hosgri fault. Our modeling, constrained by exposed geology and in some cases, drill-hole and seismic-reflection data, indicates that the San Gregorio–San Simeon–Hosgri and Reliz-Rinconada faults dip steeply throughout the seismogenic crust. Deviations from steep dips may result from local fault interactions, transfer of slip between faults, or overprinting by transpression since the late Miocene. Given that such faults are consistent with predominantly strike-slip displacement, we correlate geophysical anomalies offset by these faults to estimate cumulative displacements. We find a northward increase in right-lateral displacement along the San Gregorio–San Simeon–Hosgri fault that is mimicked by Quaternary slip rates. Although overall slip rates have decreased over the lifetime of the fault, the pattern of slip has not changed. Northward increase in right-lateral displacement is balanced in part by slip added by faults, such as the Reliz-Rinconada, Oceanic–West Huasna, and (speculatively) Santa Ynez River faults to the east.

The Honey Lake fault zone, northeastern California: Its nature, age, and displacement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wagner, D.L.; Saucedo, G.J.; Grose, T.L.T.

The Honey Lake fault zone of northeastern California is composed of en echelon, northwest trending faults that form the boundary between the Sierra Nevada and the Basin Ranges provinces. As such the Honey Lake fault zone can be considered part of the Sierra Nevada frontal fault system. It is also part of the Walker Lane of Nevada. Faults of the Honey Lake zone are vertical with right-lateral oblique displacements. The cumulative vertical component of displacement along the fault zone is on the order of 800 m and right-lateral displacement is at least 10 km (6 miles) but could be considerablymore » more. Oligocene to Miocene (30 to 22 Ma) age rhyolite tuffs can be correlated across the zone, but mid-Miocene andesites do not appear to be correlative indicating the faulting began in early to mid-Miocene time. Volcanic rocks intruded along faults of the zone, dated at 16 to 8 Ma, further suggest that faulting in the Honey Lake zone was initiated during mid-Miocene time. Late Quaternary to Holocene activity is indicated by offset of the 12,000 year old Lake Lahontan high stand shoreline and the surface rupture associated with the 1950 Fort Sage earthquake.« less

An Approach to Unbiased Subsample Interpolation for Motion Tracking

PubMed Central

McCormick, Matthew M.; Varghese, Tomy

2013-01-01

Accurate subsample displacement estimation is necessary for ultrasound elastography because of the small deformations that occur and the subsequent application of a derivative operation on local displacements. Many of the commonly used subsample estimation techniques introduce significant bias errors. This article addresses a reduced bias approach to subsample displacement estimations that consists of a two-dimensional windowed-sinc interpolation with numerical optimization. It is shown that a Welch or Lanczos window with a Nelder–Mead simplex or regular-step gradient-descent optimization is well suited for this purpose. Little improvement results from a sinc window radius greater than four data samples. The strain signal-to-noise ratio (SNR) obtained in a uniformly elastic phantom is compared with other parabolic and cosine interpolation methods; it is found that the strain SNR ratio is improved over parabolic interpolation from 11.0 to 13.6 in the axial direction and 0.7 to 1.1 in the lateral direction for an applied 1% axial deformation. The improvement was most significant for small strains and displacement tracking in the lateral direction. This approach does not rely on special properties of the image or similarity function, which is demonstrated by its effectiveness with the application of a previously described regularization technique. PMID:23493609

Development and Evolution of Character Displacement

PubMed Central

Pfennig, David W.; Pfennig, Karin S.

2012-01-01

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

The triple PCL sign: bucket handle tears of both medial and lateral menisci in a chronically ACL-deficient knee.

PubMed

Kakel, Rafid; Russell, Robert; VanHeerden, Pieter

2010-10-11

Bucket handle tears of both menisci in the setting of acute or chronic anterior cruciate ligament (ACL) tears of the same knee have rarely been reported in the literature. This article presents a case of a bucket handle tear affecting both the medial and lateral menisci in a patient with chronic ACL rupture. Both bucket handle tears were displaced and locked in the intercondylar notch. A new magnetic resonance image (MRI) sign suggested on sagittal view is called the triple PCL sign, comprising the intact posterior cruciate ligament (PCL) and the 2 displaced fragments in the intercondylar notch from the two bucket handle tears. The precise diagnosis of this condition is of obvious importance for optimal operative planning. While finding the displaced fragment from the medial meniscus is expected to cause the double PCL sign, the torn ACL may have made it easier to visualize the bucket handle tear of the lateral meniscus in the same sagittal plane as the PCL. Only 5 other reports mention bimeniscal bucket handle tears of both the medial and lateral menisci in association with an ACL tear. None have shown the suggested triple PCL sign because of lack of overlap between the 2 bucket handle tears in the coronal plane while lying in the intercondylar notch causing them not to fall in the same sagittal plane. Our patient showed some overlap between the 2 meniscal fragments while lying in the notch to create the triple PCL sign on sagittal MRI. Copyright 2010, SLACK Incorporated.

Stress and displacement patterns in the craniofacial skeleton with rapid maxillary expansion: a finite element method study.

PubMed

Gautam, Pawan; Valiathan, Ashima; Adhikari, Raviraj

2007-07-01

The purpose of this finite element study was to evaluate stress distribution along craniofacial sutures and displacement of various craniofacial structures with rapid maxillary expansion (RME) therapy. The analytic model for this study was developed from sequential computed tomography scan images taken at 2.5-mm intervals of a dry young human skull. Subsequently, a finite element method model was developed from computed tomography images by using AutoCAD software (2004 version, Autodesk, Inc, San Rafael, Calif) and ANSYS software (version 10, Belcan Engineering Group, Downers Grove, Ill). The maxilla moved anteriorly and downward and rotated clockwise in response to RME. The pterygoid plates were displaced laterally. The distant structures of the craniofacial skeleton--zygomatic bone, temporal bone, and frontal bone--were also affected by transverse orthopedic forces. The center of rotation of the maxilla in the X direction was somewhere between the lateral and the medial pterygoid plates. In the frontal plane, the center of rotation of the maxilla was approximately at the superior orbital fissure. The maximum von Mises stresses were found along the frontomaxillary, nasomaxillary, and frontonasal sutures. Both tensile and compressive stresses could be demonstrated along the same suture. RME facilitates expansion of the maxilla in both the molar and the canine regions. It also causes downward and forward displacement of the maxilla and thus can contribute to the correction of mild Class III malocclusion. The downward displacement and backward rotation of the maxilla could be a concern in patients with excessive lower anterior facial height. High stresses along the deep structures and the various sutures of the craniofacial skeleton signify the role of the circummaxillary sutural system in downward and forward displacement of the maxilla after RME.

Detailed ground surface displacement and fault ruptures of the 2016 Kumamoto Earthquake revealed by SAR and GNSS data

NASA Astrophysics Data System (ADS)

Kobayashi, T.; Yarai, H.; Morishita, Y.; Kawamoto, S.; Fujiwara, S.; Nakano, T.

2016-12-01

We report ground displacement associated with the 2016 Kumamoto Earthquake obtained by ALOS-2 SAR and GNSS data. For the SAR analyses, we applied InSAR, MAI, and pixel offset methods, which has successfully provided a 3D displacement field showing the widely- and locally-distributed deformation. The obtained displacement field shows clear displacement boundaries linearly along the Futagawa, the Hinagu, and the Denokuchi faults across which the sign of displacement component turns to be opposite, suggesting that the fault ruptures occurred there. Our fault model for the main shock suggests that the main rupture occurred on the Futagawa fault with a right-lateral motion including a slight normal fault motion. Due to the normal faulting movement, the northern side of the active fault subsides with approximately 2 m. The rupture on the Futagawa fault extends into the Aso caldera with slightly shifting the position northward. Of note, the fault plane oppositely dips toward southeast. It may be a conjugate fault against the main fault. In the western side of the Futagawa fault, the slip on the Hinagu fault, in which the Mj6.5 and Mj6.4 foreshocks occurred with a pure right-lateral motion, is also deeply involved with the main shock. This fault rupture released the amount of approximately 30 percent of the total seismic moment. The hypocenter is determined near the fault and its focal mechanism is consistent with the estimated slip motion of this fault plane, maybe suggesting that the rupture started at this fault and proceeded toward the Futagawa fault eastward. Acknowledgements: ALOS-2 data were provided from the Earthquake Working Group under a cooperative research contract with JAXA (Japan Aerospace Exploration Agency). The ownership of ALOS-2 data belongs to JAXA.

Optimisation of lateral car dynamics taking into account parameter uncertainties

NASA Astrophysics Data System (ADS)

Busch, Jochen; Bestle, Dieter

2014-02-01

Simulation studies on an active all-wheel-steering car show that disturbance of vehicle parameters have high influence on lateral car dynamics. This motivates the need of robust design against such parameter uncertainties. A specific parametrisation is established combining deterministic, velocity-dependent steering control parameters with partly uncertain, velocity-independent vehicle parameters for simultaneous use in a numerical optimisation process. Model-based objectives are formulated and summarised in a multi-objective optimisation problem where especially the lateral steady-state behaviour is improved by an adaption strategy based on measurable uncertainties. The normally distributed uncertainties are generated by optimal Latin hypercube sampling and a response surface based strategy helps to cut down time consuming model evaluations which offers the possibility to use a genetic optimisation algorithm. Optimisation results are discussed in different criterion spaces and the achieved improvements confirm the validity of the proposed procedure.

Post seismic deformation associated with the 1992 Mω=7.3 Landers earthquake, southern California

USGS Publications Warehouse

Savage, J.C.; Svarc, J.L.

1997-01-01

Following the 1992 Mω=7.3 Landers earthquake, a linear array of 10 geodetic monuments at roughly 5-km spacing was established across the Emerson fault segment of the Landers rupture. The array trends perpendicular to the local strike of the fault segment and extends about 30 km on either side of it. The array was surveyed by Global Positioning System 0.034, 0.048, 0.381, 1.27, 1.88, 2.60, and 3.42 years after the Landers earthquake to measure both the spatial and temporal character of the postearthquake relaxation. The temporal behavior is described roughly by a short-term (decay time 84±23 days) exponential relaxation superimposed upon an apparently linear trend. Because the linear trend represents motions much more rapid than the observed preseismic motions, we attribute that trend to a slower (decay time greater than 5 years) postseismic relaxation, the curvature of which cannot be resolved in the short run (3.4 years) of postseismic data. About 100 mm of right-lateral displacement and 50 mm of fault-normal displacement accumulated across the geodetic array in the 3.4-year interval covered by the postseismic surveys. Those displacements are attributed to postseismic, right-lateral slip in the depth interval 10 to 30 km on the downward extension of the rupture trace. The right-lateral slip amounted to about 1 m directly beneath the geodetic array, and the fault-normal displacement is apparently primarily a consequence of the curvature of the rupture. These conclusions are based upon dislocation models fit to the observed deformation. However, no dislocation model was found with rms residuals as small as the expected observational error.

Toddler development

MedlinePlus

Toddlers are children ages 1 to 3. CHILD DEVELOPMENT THEORIES Cognitive (thought) development skills typical for toddlers include: Early use of instruments or tools Following visual (then later, invisible) displacement (moving from ...

Spatial delineation, fluid-lithology characterization, and petrophysical modeling of deepwater Gulf of Mexico reservoirs though joint AVA deterministic and stochastic inversion of three-dimensional partially-stacked seismic amplitude data and well logs

NASA Astrophysics Data System (ADS)

Contreras, Arturo Javier

This dissertation describes a novel Amplitude-versus-Angle (AVA) inversion methodology to quantitatively integrate pre-stack seismic data, well logs, geologic data, and geostatistical information. Deterministic and stochastic inversion algorithms are used to characterize flow units of deepwater reservoirs located in the central Gulf of Mexico. A detailed fluid/lithology sensitivity analysis was conducted to assess the nature of AVA effects in the study area. Standard AVA analysis indicates that the shale/sand interface represented by the top of the hydrocarbon-bearing turbidite deposits generate typical Class III AVA responses. Layer-dependent Biot-Gassmann analysis shows significant sensitivity of the P-wave velocity and density to fluid substitution, indicating that presence of light saturating fluids clearly affects the elastic response of sands. Accordingly, AVA deterministic and stochastic inversions, which combine the advantages of AVA analysis with those of inversion, have provided quantitative information about the lateral continuity of the turbidite reservoirs based on the interpretation of inverted acoustic properties and fluid-sensitive modulus attributes (P-Impedance, S-Impedance, density, and LambdaRho, in the case of deterministic inversion; and P-velocity, S-velocity, density, and lithotype (sand-shale) distributions, in the case of stochastic inversion). The quantitative use of rock/fluid information through AVA seismic data, coupled with the implementation of co-simulation via lithotype-dependent multidimensional joint probability distributions of acoustic/petrophysical properties, provides accurate 3D models of petrophysical properties such as porosity, permeability, and water saturation. Pre-stack stochastic inversion provides more realistic and higher-resolution results than those obtained from analogous deterministic techniques. Furthermore, 3D petrophysical models can be more accurately co-simulated from AVA stochastic inversion results. By combining AVA sensitivity analysis techniques with pre-stack stochastic inversion, geologic data, and awareness of inversion pitfalls, it is possible to substantially reduce the risk in exploration and development of conventional and non-conventional reservoirs. From the final integration of deterministic and stochastic inversion results with depositional models and analogous examples, the M-series reservoirs have been interpreted as stacked terminal turbidite lobes within an overall fan complex (the Miocene MCAVLU Submarine Fan System); this interpretation is consistent with previous core data interpretations and regional stratigraphic/depositional studies.

"Maxillary lateral incisor partial anodontia sequence": a clinical entity with epigenetic origin.

PubMed

Consolaro, Alberto; Cardoso, Maurício Almeida; Consolaro, Renata Bianco

2017-01-01

The relationship between maxillary lateral incisor anodontia and the palatal displacement of unerupted maxillary canines cannot be considered as a multiple tooth abnormality with defined genetic etiology in order to be regarded as a "syndrome". Neither were the involved genes identified and located in the human genome, nor was it presumed on which chromosome the responsible gene would be located. The palatal maxillary canine displacement in cases of partial anodontia of the maxillary lateral incisor is potentially associated with environmental changes caused by its absence in its place of formation and eruption, which would characterize an epigenetic etiology. The lack of the maxillary lateral incisor in the canine region means removing one of the reference guides for the eruptive trajectory of the maxillary canine, which would therefore, not erupt and /or impact on the palate. Consequently, and in sequence, it would lead to malocclusion, maxillary atresia, transposition, prolonged retention of the deciduous canine and resorption in the neighboring teeth. Thus, we can say that we are dealing with a set of anomalies and multiple sequential changes known as sequential development anomalies or, simply, sequence. Once the epigenetics and sequential condition is accepted for this clinical picture, it could be called "Maxillary Lateral Incisor Partial Anodontia Sequence."

“Maxillary lateral incisor partial anodontia sequence”: a clinical entity with epigenetic origin

PubMed Central

Consolaro, Alberto; Cardoso, Maurício Almeida; Consolaro, Renata Bianco

2017-01-01

ABSTRACT The relationship between maxillary lateral incisor anodontia and the palatal displacement of unerupted maxillary canines cannot be considered as a multiple tooth abnormality with defined genetic etiology in order to be regarded as a “syndrome”. Neither were the involved genes identified and located in the human genome, nor was it presumed on which chromosome the responsible gene would be located. The palatal maxillary canine displacement in cases of partial anodontia of the maxillary lateral incisor is potentially associated with environmental changes caused by its absence in its place of formation and eruption, which would characterize an epigenetic etiology. The lack of the maxillary lateral incisor in the canine region means removing one of the reference guides for the eruptive trajectory of the maxillary canine, which would therefore, not erupt and /or impact on the palate. Consequently, and in sequence, it would lead to malocclusion, maxillary atresia, transposition, prolonged retention of the deciduous canine and resorption in the neighboring teeth. Thus, we can say that we are dealing with a set of anomalies and multiple sequential changes known as sequential development anomalies or, simply, sequence. Once the epigenetics and sequential condition is accepted for this clinical picture, it could be called “Maxillary Lateral Incisor Partial Anodontia Sequence.” PMID:29364376

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nour, Ali, E-mail: ali.nour@polymtl.ca; Hydro Quebec, Montreal, Quebec, H2L 4P5; Massicotte, Bruno

This study is aimed at proposing a simple analytical model to investigate the post-cracking behaviour of FRC panels, using an arbitrary tension softening, stress crack opening diagram, as the input. A new relationship that links the crack opening to the panel deflection is proposed. Due to the stochastic nature of material properties, the random fibre distribution, and other uncertainties that are involved in concrete mix, this relationship is developed from the analysis of beams having the same thickness using the Monte Carlo simulation (MCS) technique. The softening diagrams obtained from direct tensile tests are used as the input for themore » calculation, in a deterministic way, of the mean load displacement response of round panels. A good agreement is found between the model predictions and the experimental results.« less

Quantized orbits in weakly coupled Belousov-Zhabotinsky reactors

NASA Astrophysics Data System (ADS)

Weiss, S.; Deegan, R. D.

2015-06-01

Using numerical and experimental tools, we study the motion of two coupled spiral cores in a light-sensitive variant of the Belousov-Zhabotinsky reaction. Each core resides on a separate two-dimensional domain, and is coupled to the other by light. When both spirals have the same sense of rotation, the cores are attracted to a circular trajectory with a diameter quantized in integer units of the spiral wavelength λ. When the spirals have opposite senses of rotation, the cores are attracted towards different but parallel straight trajectories, separated by an integer multiple of λ/2. We present a model that explains this behavior as the result of a spiral wavefront-core interaction that produces a deterministic displacement of the core and a retardation of its phase.

Displacement, distance, and shape measurements of fast-rotating rough objects by two mutually tilted interference fringe systems.

PubMed

Günther, Philipp; Kuschmierz, Robert; Pfister, Thorsten; Czarske, Jürgen W

2013-05-01

The precise distance measurement of fast-moving rough surfaces is important in several applications such as lathe monitoring. A nonincremental interferometer based on two mutually tilted interference fringe systems has been realized for this task. The distance is coded in the phase difference between the generated interference signals corresponding to the fringe systems. Large tilting angles between the interference fringe systems are necessary for a high sensitivity. However, due to the speckle effect at rough surfaces, different envelopes and phase jumps of the interference signals occur. At large tilting angles, these signals become dissimilar, resulting in a small correlation coefficient and a high measurement uncertainty. Based on a matching of illumination and receiving optics, the correlation coefficient and the phase difference estimation have been improved significantly. For axial displacement measurements of recurring rough surfaces, laterally moving with velocities of 5 m/s, an uncertainty of 110 nm has been attained. For nonrecurring surfaces, a distance measurement uncertainty of 830 nm has been achieved. Incorporating the additionally measured lateral velocity and the rotational speed, the two-dimensional shape of rotating objects results. Since the measurement uncertainty of the displacement, distance, and shape is nearly independent of the lateral surface velocity, this technique is predestined for fast-rotating objects, such as crankshafts, camshafts, vacuum pump shafts, or turning parts of lathes.

Magnetic forces in high-Tc superconducting bearings

NASA Technical Reports Server (NTRS)

Moon, F. C.

1991-01-01

In September 1987, researchers at Cornell levitated a small rotor on superconducting bearings at 10,000 rpm. In April 1989, a speed of 120,000 rpm was achieved in a passive bearing with no active control. The bearing material used was YBa2Cu307. There is no evidence that the rotation speed has any significant effect on the lift force. Magnetic force measurements between a permanent rare-earth magnet and high T(sub c) superconducting material versus vertical and lateral displacements were made. A large hysteresis loop results for large displacements, while minor loops result for small displacements. These minor loops seem to give a slope proportional to the magnetic stiffness, and are probably indicative of flux pinning forces. Experiments of rotary speed versus time show a linear decay in a vacuum. Measurements of magnetic dipole over a high-T(sub c) superconducting disc of YBCO show that the lateral vibrations of levitated rotors were measured which indicates that transverse flux motion in the superconductor will create dissipation. As a result of these force measurements, an optimum shape for the superconductor bearing pads which gives good lateral and axial stability was designed. Recent force measurements on melt-quench processed superconductors indicate a substantial increase in levitation force and magnetic stiffness over free sintered materials. As a result, application of high-T(sub c) superconducting bearings are beginning to show great promise at this time.

Coseismic surface displacements from optical and SAR image offset tracking, fault modeling and geomorphological analysis of the Sept. 24th, 2013 M7.7 Balochistan earthquake

NASA Astrophysics Data System (ADS)

Harrington, Jonathan; Wang, Teng; Feng, Guangcai; Akoglu, Ahmet; Jónsson, Sigurjón; Motagh, Mahdi

2014-05-01

The M 7.7 earthquake in the Balochistan province of Pakistan on September 24th, 2013 took place along a subsidiary fault in the transition area between the Makran accretionary prism and the Chaman transform fault. This tectonics of the Indian and Arabian plate collisions with Eurasia produce primarily oblique left-lateral strike slip in this region. In this work, measurements of displacement and mapping of the rupture trace are achieved through image correlation of Landsat 8 images and SAR offset tracking of TerraSAR-X data. Horizontal displacements from both methods and derived vertical displacements are used to constrain a fault rupture model for the earthquake. Preliminary results show a surprisingly uniform slip distribution with maximum displacement near the surface. The total fault rupture length is ~210 km, with up to 9 m of left-lateral strike-slip and 3 m of reverse faulting. Additionally, mapping of the rupture trace is made use of for geomorphological observations relating to slip rates and identification of transpressional and transtensional features. Our results indicate a mostly smooth rupture trace, with the presence of two restraining steps, a releasing bend and a 3 km long sliver where the surface rupture jumped from the foot of the range-front into the alluvial fans at their base. A small block at one of the restraining steps shows intermediate displacement in both data sets. At the southern end of the rupture we observe that displacement from the earthquake cuts across a fold-and-thrust belt of the Makran accretionary prism. Preliminary results show a minimum of 12 km of repeated section of the accretionary wedge, and within the southern repeated section we find an offset of 600 m between two parallel ridges across the rupture trace. We relate these observations to conceptual models of fault segmentation and growth.

40 CFR 1051.107 - What are the exhaust emission standards for all-terrain vehicles (ATVs) and offroad utility...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Phase 1 2006 50 1.5 35 20.0 2007 and later 100 1.5 35 20.0 (2) You may certify ATVs with engines that... life. For ATVs with engines that have total displacement of 100 cc or greater, the minimum useful life... with engines that have total displacement of less than 100 cc, the minimum useful life is 5,000...

40 CFR 1051.107 - What are the exhaust emission standards for all-terrain vehicles (ATVs) and offroad utility...

Code of Federal Regulations, 2011 CFR

2011-07-01

... Phase 1 2006 50 1.5 35 20.0 2007 and later 100 1.5 35 20.0 (2) You may certify ATVs with engines that... life. For ATVs with engines that have total displacement of 100 cc or greater, the minimum useful life... with engines that have total displacement of less than 100 cc, the minimum useful life is 5,000...

Public health implications and risks for children and families resettled after exposure to armed conflict and displacement.

PubMed

Calam, Rachel

2017-05-01

Early adverse experiences can precede long-term negative effects on physical health. Children experiencing armed conflict, flight and displacement, and refugee life may be at enhanced risk. Recent psychobiological models integrating knowledge about perinatal and childhood stress with susceptibility to chronic illnesses in later life make clear the pressing need for protective provision for war-affected children, who experience multiple traumas and continuing stressors. There is increasing recognition of the mechanisms linking physical and mental health with adult diseases seen as developmental disorders with origins early in life. Biological embedding models propose links between early adversity and increased vulnerability to later disease and premature death. Threat is central for children and families whose lives are changed by war and displacement, and may activate biological and behavioural systems that could increase the risk of long-term ill-health. Applying these models to understanding the experiences of refugees and the translation of these into the care provided and ways of monitoring and protecting long-term population health could potentially promote interventions to reduce longer term and secondary harms.

Path-integral theory of an axially confined worm-like chain

NASA Astrophysics Data System (ADS)

Smith, D. A.

2001-06-01

A path-integral formulation is developed for the thermodynamic properties of a worm-like chain moving on a surface and laterally confined by a harmonic potential. The free energy of the chain is calculated as a function of its length and boundary conditions at each end. Distribution functions for chain displacements can be constructed by utilizing the Markov property as a function of displacement φ(s) and its derivative dφ(s)/ds along the path. These quantities are also calculated in the presence of pinning sites which impose fixed positive or negative displacements, foreshadowing their application to a model for the regulation of striated muscle.

Nanoscale displacement sensing using microfabricated variable-inductance planar coils

NASA Astrophysics Data System (ADS)

Coskun, M. Bulut; Thotahewa, Kasun; Ying, York-Sing; Yuce, Mehmet; Neild, Adrian; Alan, Tuncay

2013-09-01

Microfabricated spiral inductors were employed for nanoscale displacement detection, suitable for use in implantable pressure sensor applications. We developed a variable inductor sensor consisting of two coaxially positioned planar coils connected in series to a measurement circuit. The devices were characterized by varying the air gap between the coils hence changing the inductance, while a Colpitts oscillator readout was used to obtain corresponding frequencies. Our approach shows significant advantages over existing methodologies combining a displacement resolution of 17 nm and low hysteresis (0.15%) in a 1 × 1 mm2 device. We show that resolution could be further improved by shrinking the device's lateral dimensions.

An evaluation of string theory for the prediction of dynamic tire properties using scale model aircraft tires

NASA Technical Reports Server (NTRS)

Clark, S. K.; Dodge, R. N.; Nybakken, G. H.

1972-01-01

The string theory was evaluated for predicting lateral tire dynamic properties as obtained from scaled model tests. The experimental data and string theory predictions are in generally good agreement using lateral stiffness and relaxation length values obtained from the static or slowly rolling tire. The results indicate that lateral forces and self-aligning torques are linearly proportional to tire lateral stiffness and to the amplitude of either steer or lateral displacement. In addition, the results show that the ratio of input excitation frequency to road speed is the proper independent variable by which frequency should be measured.

Surface faulting near Livermore, California, associated with the January 1980 earthquakes

USGS Publications Warehouse

Bonilla, Manuel G.; Lienkaemper, James J.; Tinsley, John C.

1980-01-01

The earthquakes of 24 January (Ms 5.8) 1980 north of Livermore, California, and 26 January (Ms 5.2), were accompanied by surface faulting in the Greenville fault zone and apparently in the Las Positas fault zone also. The surface faulting was discontinuous and of small displacement. The main rupture within the Greenville fault zone trended about N.38°W. It was at least 4.2 km long and may have extended southward to Interstate Highway 580, giving a possible length of 6.2 km; both of these lengths included more gaps than observed surface rupture. Maximum displacements measured by us were about 25 mm of right slip (including afterslip through 28 January); vertical components of as much as 50 mm were seen locally, but these included gravity effects of unknown amount. The main break within the Greenville fault zones is very close to a fault strand mapped by Herd (1977, and unpublished data). A subsidiary break within the Greenville fault zone was about 0.5 km. long, had a general trend of N.46°W., and lay 0.12 to 0.25 km east of the main break. It was characterized by extension of as much as 40 mm and right slip of as much as 20 mm. This break was no more than 25 m from a fault mapped by Herd (unpublished data). Another break within the Greenville fault zone lay about 0.3 km southwest of the projection of the main break and trended about N33°W. It was at least 0.3 km long and showed mostly extension, but at several places a right-lateral component (up to 5 mm) was seen. This break was 80 to 100 m from a strand of the Greenville fault mapped by Herd (1977). Extensional fractures within the Greenville fault zone on the frontage roads north and south of Interstate Highway 580 may be related to regional extension or other processes, but do not seem to have resulted from faulting of the usual kind. One exception in this group is a fracture at the east side of Livermore valley which showed progressive increase in right-lateral displacement in February and March, 1980, and is directly on the projection of a fault in the Greenville fault zone mapped by Herd (1977). A group of more than 20 extensional fractures in Laughlin Road 1 km north of Interstate 580 probably are related to small tectonic displacements on faults in the Greenville fault zone. They are adjacent and parallel to two faults mapped by Herd (1977), are diagonal to the road, and most of them developed between 25 and 29 January, a period that included the Ms 5.2 shock of 26 January. Observations at two locations indicate tectonic displacement on the Las Positas fault zone as mapped by Herd (1977). At Vasco Road a prominent break on a strand of the fault showed about 0.5 mm of left-lateral strike slip on 7 February. An alinement array across this and other fractures at the locality indicates about 6 mm of left-lateral displacement occurred between 21 February and 26 March. On Tesla Road several right-stepping fractures, one of which showed 1.5 mm of left-lateral strike slip, lie on or close tp previously mapped strands of the Las Positas fault zone. The evidence at these two localities indicates that tectonic surface displacement occurred along at least 1.1 km of the Las Positas fault zone.

Structural Data for the Columbus Salt Marsh Geothermal Area - GIS Data

DOE Data Explorer

Faulds, James E.

2011-12-31

Shapefiles and spreadsheets of structural data, including attitudes of faults and strata and slip orientations of faults. - Detailed geologic mapping of ~30 km2 was completed in the vicinity of the Columbus Marsh geothermal field to obtain critical structural data that would elucidate the structural controls of this field. - Documenting E‐ to ENE‐striking left lateral faults and N‐ to NNE‐striking normal faults. - Some faults cut Quaternary basalts. - This field appears to occupy a displacement transfer zone near the eastern end of a system of left‐lateral faults. ENE‐striking sinistral faults diffuse into a system of N‐ to NNE‐striking normal faults within the displacement transfer zone. - Columbus Marsh therefore corresponds to an area of enhanced extension and contains a nexus of fault intersections, both conducive for geothermal activity.

Lateral X-ray for proximal femoral fractures - Is it really necessary?

PubMed

Riaz, Osman; Nisar, Sohail; Arshad, Rizwan; Vanker, Raees

2016-10-01

Historically routine work up of a patient with a proximal femoral fracture always included anterior-posterior (AP) and a lateral film of the hip. The aim was to define the role of the lateral X-ray in the assessment and surgical planning of proximal femur fractures. Radiographs of 320 consecutive patients with proximal femoral fractures who were admitted over a 12 months period were divided into lateral and AP views. Two blinded reviewers independently assessed the AP view alone and then the AP plus the lateral view. Fracture classification was noted for each X-ray and then compared with intraoperative diagnosis which was our study's gold standard. A 2 × 2 contingency square table and Pearson's x(2) test were used for statistical analysis. The rate of correct classification by the reviewers enhanced by the assessment of the lateral X-ray in addition to the AP view for intracapsular fractures (p = 0.018) but not for extracapsular fractures (p = 0.29). Operative management did not change for intracapsular fractures which appeared displaced on initial AP view after reviewing the lateral X-ray. The only advantage of obtaining a lateral view in intracapsular fracture was the detection of displacement were the fracture appeared to be undisplaced on initial AP view. This study provides statistical evidence that one view is adequate and safe for majority of proximal femoral fractures. The lateral radiograph should not be performed on a routine basis thus making considerable saving in time and money, and avoiding unnecessary radiation exposure and discomfort to the patient. Copyright © 2015 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Dose limits for astronauts

NASA Technical Reports Server (NTRS)

Sinclair, W. K.

2000-01-01

Radiation exposures to individuals in space can greatly exceed natural radiation exposure on Earth and possibly normal occupational radiation exposures as well. Consequently, procedures limiting exposures would be necessary. Limitations were proposed by the Radiobiological Advisory Panel of the National Academy of Sciences/National Research Council in 1970. This panel recommended short-term limits to avoid deterministic effects and a single career limit (of 4 Sv) based on a doubling of the cancer risk in men aged 35 to 55. Later, when risk estimates for cancer had increased and were recognized to be age and sex dependent, the NCRP, in Report No. 98 in 1989, recommended a range of career limits based on age and sex from 1 to 4 Sv. NCRP is again in the process of revising recommendations for astronaut exposure, partly because risk estimates have increased further and partly to recognize trends in limiting radiation exposure occupationally on the ground. The result of these considerations is likely to be similar short-term limits for deterministic effects but modified career limits.

Evaluation of hypotheses for right-lateral displacement of Neogene strata along the San Andreas Fault between Parkfield and Maricopa, California

USGS Publications Warehouse

Stanley, Richard G.; Barron, John A.; Powell, Charles L.

2017-12-22

We used geological field studies and diatom biostratigraphy to test a published hypothesis that Neogene marine siliceous strata in the Maricopa and Parkfield areas, located on opposite sides of the San Andreas Fault, were formerly contiguous and then were displaced by about 80–130 kilometers (km) of right-lateral slip along the fault. In the Maricopa area on the northeast side of the San Andreas Fault, the upper Miocene Bitterwater Creek Shale consists of hard, siliceous shale with dolomitic concretions and turbidite sandstone interbeds. Diatom assemblages indicate that the Bitterwater Creek Shale was deposited about 8.0–6.7 million years before present (Ma) at the same time as the uppermost part of the Monterey Formation in parts of coastal California. In the Parkfield area on the southwest side of the San Andreas Fault, the upper Miocene Pancho Rico Formation consists of soft to indurated mudstone and siltstone and fossiliferous, bioturbated sandstone. Diatom assemblages from the Pancho Rico indicate deposition about 6.7–5.7 Ma (latest Miocene), younger than the Bitterwater Creek Shale and at about the same time as parts of the Sisquoc Formation and Purisima Formation in coastal California. Our results show that the Bitterwater Creek Shale and Pancho Rico Formation are lithologically unlike and of different ages and therefore do not constitute a cross-fault tie that can be used to estimate rightlateral displacement along the San Andreas Fault.In the Maricopa area northeast of the San Andreas Fault, the Bitterwater Creek Shale overlies conglomeratic fan-delta deposits of the upper Miocene Santa Margarita Formation, which in turn overlie siliceous shale of the Miocene Monterey Formation from which we obtained a diatom assemblage dated at about 10.0–9.3 Ma. Previous investigations noted that the Santa Margarita Formation in the Maricopa area contains granitic and metamorphic clasts derived from sources in the northern Gabilan Range, on the opposite side of the San Andreas Fault, that have moved relatively northwestward by 254 ± 5 km of right-lateral displacement along the fault. Our new diatom ages suggest that Santa Margarita deposition and fault displacement began about 10–8 Ma and imply long-term average slip rates along the San Andreas Fault of about 25–32 millimeters per year (mm/yr), Evaluation of Hypotheses for Right-Lateral Displacement of Neogene Strata Along the San Andreas Fault Between Parkfield and Maricopa, California By Richard G. Stanley, John A. Barron, and Charles L. Powell, II about the same as published estimates of Quaternary average slip rates based on geologic and geodetic studies.

Injury tolerance and moment response of the knee joint to combined valgus bending and shear loading.

PubMed

Bose, Dipan; Bhalla, Kavi S; Untaroiu, Costin D; Ivarsson, B Johan; Crandall, Jeff R; Hurwitz, Shepard

2008-06-01

Valgus bending and shearing of the knee have been identified as primary mechanisms of injuries in a lateral loading environment applicable to pedestrian-car collisions. Previous studies have reported on the structural response of the knee joint to pure valgus bending and lateral shearing, as well as the estimated injury thresholds for the knee bending angle and shear displacement based on experimental tests. However, epidemiological studies indicate that most knee injuries are due to the combined effects of bending and shear loading. Therefore, characterization of knee stiffness for combined loading and the associated injury tolerances is necessary for developing vehicle countermeasures to mitigate pedestrian injuries. Isolated knee joint specimens (n=40) from postmortem human subjects were tested in valgus bending at a loading rate representative of a pedestrian-car impact. The effect of lateral shear force combined with the bending moment on the stiffness response and the injury tolerances of the knee was concurrently evaluated. In addition to the knee moment-angle response, the bending angle and shear displacement corresponding to the first instance of primary ligament failure were determined in each test. The failure displacements were subsequently used to estimate an injury threshold function based on a simplified analytical model of the knee. The validity of the determined injury threshold function was subsequently verified using a finite element model. Post-test necropsy of the knees indicated medial collateral ligament injury consistent with the clinical injuries observed in pedestrian victims. The moment-angle response in valgus bending was determined at quasistatic and dynamic loading rates and compared to previously published test data. The peak bending moment values scaled to an average adult male showed no significant change with variation in the superimposed shear load. An injury threshold function for the knee in terms of bending angle and shear displacement was determined by performing regression analysis on the experimental data. The threshold values of the bending angle (16.2 deg) and shear displacement (25.2 mm) estimated from the injury threshold function were in agreement with previously published knee injury threshold data. The continuous knee injury function expressed in terms of bending angle and shear displacement enabled injury prediction for combined loading conditions such as those observed in pedestrian-car collisions.

Up-dip partitioning of displacement components on the oblique-slip Clarence Fault, New Zealand

NASA Astrophysics Data System (ADS)

Nicol, Andrew; Van Dissen, Russell

2002-09-01

Active strike-slip faults in New Zealand occur within an obliquely-convergent plate boundary zone. Although the traces of these faults commonly delineate the base of mountain ranges, they do not always accommodate significant shortening at the free surface. Along the active trace of Clarence Fault in northeastern South Island, New Zealand, displaced landforms and slickenside striations indicate predominantly horizontal displacements at the ground surface, and a right-lateral slip rate of ca. 3.5-5 mm/year during the Holocene. The Inland Kaikoura mountain range occupies the hanging wall of the fault and rises steeply from the active trace to altitudes of ca. 3 km. The geomorphology of the range indicates active uplift and mountain building, which is interpreted to result, in part, from a vertical component of fault slip at depth. These data are consistent with the fault accommodating oblique-slip at depth aligned parallel to the plate-motion vector and compatible with regional geodetic data and earthquake focal-mechanisms. Oblique-slip on the Clarence Fault at depth is partitioned at the free surface into: (1) right-lateral displacement on the fault, and (2) hanging wall uplift produced by distributed displacement on small-scale faults parallel to the main fault. Decoupling of slip components reflects an up-dip transfer of fault throw to an off-fault zone of distributed uplift. Such zones are common in the hanging walls of thrusts and reverse faults, and support the idea that the dip of the oblique-slip Clarence Fault steepens towards the free surface.

Investigation of Thermal Effects of Photocoagulation on Retinal Tissue Using Fine-Motion-Sensitive Dynamic Optical Coherence Tomography.

PubMed

Kurokawa, Kazuhiro; Makita, Shuichi; Yasuno, Yoshiaki

2016-01-01

To enable an objective evaluation of photocoagulation, we characterize thermal tissue changes induced by laser irradiation with different laser parameters using optical coherence tomography (OCT). Spectral-domain OCT with a newly developed image processing method was used to monitor the thermal changes of ex vivo porcine retina. A sequence of OCT B-scans was obtained at the same retinal position simultaneously with the photocoagulation. Cross-sectional tissue displacement maps with respect to an OCT image taken before laser irradiation were computed for images taken before, during, and after laser irradiation, by using a correlation-based custom algorithm. Cross-sectional correlation maps (OCT correlation maps) were also computed from an OCT image taken before laser irradiation as a base-line to visualize alterations of tissue microstructure induced by laser irradiation. By systematically controlling laser power and exposure times, tissue displacements and structural changes of 200 retinal regions of 10 porcine eyes were characterized. Thermal tissue changes were characterized by B-scan images, OCT correlation maps, and tissue displacement maps. Larger tissue deformation was induced with higher laser power and shorter exposure time, while the same total laser energy (10 mJ) was applied. The measured tissue displacements revealed the complicated dynamics of tissue displacements. Three types of dynamics were observed; lateral expansion, lateral constriction, and a type showing more complicated dynamics. The results demonstrated the ability of this OCT-based method to evaluate retinal changes induced by laser irradiation. This evaluation could lead to further understanding of thermal effects, and increasing reproducibility of photocoagulation therapy.

Estimate Tsunami Flow Conditions and Large-Debris Tracks for the Design of Coastal Infrastructures along Coastlines of the U.S. Pacific Northwest

NASA Astrophysics Data System (ADS)

Wei, Y.; Thomas, S.; Zhou, H.; Arcas, D.; Titov, V. V.

2017-12-01

The increasing potential tsunami hazards pose great challenges for infrastructures along the coastlines of the U.S. Pacific Northwest. Tsunami impact at a coastal site is usually assessed from deterministic scenarios based on 10,000 years of geological records in the Cascadia Subduction Zone (CSZ). Aside from these deterministic methods, the new ASCE 7-16 tsunami provisions provide engineering design criteria of tsunami loads on buildings based on a probabilistic approach. This work develops a site-specific model near Newport, OR using high-resolution grids, and compute tsunami inundation depth and velocities at the study site resulted from credible probabilistic and deterministic earthquake sources in the Cascadia Subduction Zone. Three Cascadia scenarios, two deterministic scenarios, XXL1 and L1, and a 2,500-yr probabilistic scenario compliant with the new ASCE 7-16 standard, are simulated using combination of a depth-averaged shallow water model for offshore propagation and a Boussinesq-type model for onshore inundation. We speculate on the methods and procedure to obtain the 2,500-year probabilistic scenario for Newport that is compliant with the ASCE 7-16 tsunami provisions. We provide details of model results, particularly the inundation depth and flow speed for a new building, which will also be designated as a tsunami vertical evacuation shelter, at Newport, Oregon. We show that the ASCE 7-16 consistent hazards are between those obtained from deterministic L1 and XXL1 scenarios, and the greatest impact on the building may come from later waves. As a further step, we utilize the inundation model results to numerically compute tracks of large vessels in the vicinity of the building site and estimate if these vessels will impact on the building site during the extreme XXL1 and ASCE 7-16 hazard-consistent scenarios. Two-step study is carried out first to study tracks of massless particles and then large vessels with assigned mass considering drag force, inertial force, ship grounding and mooring. The simulation results show that none of the large vessels will impact on the building site in all tested scenarios.

Effect of Soft Tissue Releases on Joint Space Opening in Total Knee Arthroplasty.

PubMed

Burkhart, Timothy A; Perry, Kevin I; Dobbin, Emily; Howard, James; Lanting, Brent

2016-12-01

The purpose of this study was to determine the gap achieved to the medial and lateral compartments following sectioning and release of the relevant soft tissues in preparation for a total knee arthroplasty. A custom-designed knee tensioner allowed the application of forces to the medial and lateral compartments of 12 cadaveric knee specimens. Loads of 100 N and 200 N were applied to each compartment, and the resulting displacement was measured in the following conditions: (1) All soft tissues intact, (2) an arthrotomy, (3) anterior cruciate ligament (ACL) sectioned, (4) posterior cruciate ligament (PCL) sectioned, and (5) release of the anterior aspect of the deep medial collateral ligament (MCL) fibers. Tensions were applied for all conditions from 90° to 0° of knee flexion in 30° increments. No differences were found in medial or lateral displacement after the arthrotomy or releasing the ACL or PCL at either 100 N or 200 N. At the 100 N load application, there was a significant increase in gap width when the anterior portion of the deep MCL was released (7.49 mm) compared to the intact (5.28 mm) and arthrotomy (5.75 mm) conditions. With respect to the 200 N load application, there were statistically significant differences detected between the deep MCL fiber release (11.09 mm) and intact conditions (8.05 mm) and release of the deep MCL and arthrotomy conditions (8.77 mm). The medial parapetellar arthrotomy, ACL and PCL sectioning did not result in medial or lateral displacement changes. The release of the anterior fibers of the deep MCL as part of the surgical exposure increased the medial gap magnitude. Copyright © 2016 Elsevier Inc. All rights reserved.

Coronary perfusion pressure and compression quality in maternal cardiopulmonary resuscitation in supine and left-lateral tilt positions: A prospective, crossover study using mannequins and swine models.

PubMed

Dohi, Satoshi; Ichizuka, Kiyotake; Matsuoka, Ryu; Seo, Kohei; Nagatsuka, Masaaki; Sekizawa, Akihiko

2017-09-01

The risk of maternal and fetal mortality is high if cardiopulmonary arrest occurs during pregnancy. To assess the best position for maternal cardiopulmonary resuscitation (CPR), a prospective randomized crossover study was undertaken, involving basic life support mannequin-based simulation (BLS-MS) and a swine model of pulseless electrical activity (an unstable cardiac state) incorporating a fetal mannequin (PEA-FM). The BLS-MS (performed by certified rescuers) served to evaluate the quality of chest compressions in 30° left lateral tilt (LLT) and supine positions. Based on a 5-point scale, each rescuer subjectively graded their experience. The PEA-FM model was used to compare coronary perfusion pressure readings during CPR in supine, supine with left uterine displacement, 30° LLT, and 30° right lateral tilt positions. Compression rate and correctness of hand position, compression depth, and recoil were measures of compression quality (BLS-MS). Compared with LLT position, supine position enabled correct hand position (rate: 0.99 vs 0.88; p<0.05) and compression depth (rate: 0.76 vs 0.36; p<0.001) significantly more often. Moreover, BLS-MS rescuers found chest compressions significantly easier to perform with the mannequin in supine (vs LLT) position (difficulty score: 1.75 vs 3.95; p<0.001). In the PEA-FM study arm, supine position with left uterine displacement and right lateral tilt positions had the highest and lowest recorded coronary perfusion pressure readings, respectively. Supine position with left uterine displacement is optimal for maternal CPR. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Revisiting the Cramér Rao Lower Bound for Elastography: Predicting the Performance of Axial, Lateral and Polar Strain Elastograms.

PubMed

Verma, Prashant; Doyley, Marvin M

2017-09-01

We derived the Cramér Rao lower bound for 2-D estimators employed in quasi-static elastography. To illustrate the theory, we modeled the 2-D point spread function as a sinc-modulated sine pulse in the axial direction and as a sinc function in the lateral direction. We compared theoretical predictions of the variance incurred in displacements and strains when quasi-static elastography was performed under varying conditions (different scanning methods, different configuration of conventional linear array imaging and different-size kernels) with those measured from simulated or experimentally acquired data. We performed studies to illustrate the application of the derived expressions when performing vascular elastography with plane wave and compounded plane wave imaging. Standard deviations in lateral displacements were an order higher than those in axial. Additionally, the derived expressions predicted that peak performance should occur when 2% strain is applied, the same order of magnitude as observed in simulations (1%) and experiments (1%-2%). We assessed how different configurations of conventional linear array imaging (number of active reception and transmission elements) influenced the quality of axial and lateral strain elastograms. The theoretical expressions predicted that 2-D echo tracking should be performed with wide kernels, but the length of the kernels should be selected using knowledge of the magnitude of the applied strain: specifically, longer kernels for small strains (<5%) and shorter kernels for larger strains. Although the general trends of theoretical predictions and experimental observations were similar, biases incurred during beamforming and subsample displacement estimation produced noticeable differences. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Strike-slip faulting of ridged plains near Valles Marineris, Mars

NASA Astrophysics Data System (ADS)

Schultz, R. A.

1989-10-01

This paper identifies and documents several well-preserved examples of Martian strike-slip faults and examines their relationships to wrinkle-ridges. The strike-slip faulting predates or overlaps periods of wrinkle-ridge growth southeast of Valles Marineris, and some wrinkle ridges may have nucleated and grown as a result of strike-slip displacements along the echelon fault arrays. Lateral displacements of several km inferred along these arrays may be related to tectonism in Tharsis.

Optimization-based controller design for rotorcraft

NASA Technical Reports Server (NTRS)

Tsing, N.-K.; Fan, M. K. H.; Barlow, J.; Tits, A. L.; Tischler, M. B.

1993-01-01

An optimization-based methodology for linear control system design is outlined by considering the design of a controller for a UH-60 rotorcraft in hover. A wide range of design specifications is taken into account: internal stability, decoupling between longitudinal and lateral motions, handling qualities, and rejection of windgusts. These specifications are investigated while taking into account physical limitations in the swashplate displacements and rates of displacement. The methodology crucially relies on user-machine interaction for tradeoff exploration.

A surface wave reflector in Southwestern Japan

NASA Astrophysics Data System (ADS)

Mak, S.; Koketsu, K.; Miyake, H.; Obara, K.; Sekine, S.

2009-12-01

Surface waves at short periods (<35s) are affected severely by heterogeneities in the crust and the uppermost mantle. When the scale of heterogeneity is sufficiently large, its effect can be studied in a deterministic way using conventional concepts of reflection and refraction. A well-known example is surface wave refraction at continental margin. We present a case study to investigate the composition of surface wave coda in a deterministic approach. A long duration of surface wave coda with a predominant period of 20s is observed during various strong earthquakes around Japan. The coda shows an unambiguous propagation direction, implying a deterministic nature. Beamforming and particle motion analysis suggest that the surface wave later arrivals could be explained by Love wave reflections by a point reflector located at offshore southeast to Kyushu. The reflection demonstrates a seemingly incidence-independent favorable azimuth in emitting strength. In additional to beamforming, we use a new regional crustal velocity model to perform a grid-search ray-tracing with the assumption of point reflector to further constrain to location of coda generation. Because strong velocity anomalies exist near the zone of interest, we decide to use a network shortest-path ray-tracing method, instead of analytical methods like shooting and bending, to avoid the problems like convergence, shadow zone, and smooth model assumption. Two geological features are found to be related to the formation of the coda. The primary one is the intersection between the Kyushu-Palau Ridge and the Nankai Trough at offshore southeast to Kyushu (hereafter referred as "KPR-NT"), which may act as a point reflector. There is a strong Love wave phase velocity anomaly at KPR-NT but not other parts of the ridge, implying that topography is irrelevant. Rayleigh wave phase velocity does not experience a strong anomaly there, which is consistent to the absence of Rayleigh wave reflections implied by the observed particle motions. The secondary one is a low phase velocity (<2km/s for T=20s) at the accretionary wedge of the Nankai Trough due to the thick sediment. Such a long and narrow low velocity zone, with its southwest tip at KPR-NT, is a potential wave-guide to channel waves towards KPR-NT. The longer duration of deterministic later arrivals than the direct arrival is partially explained by multi-pathing due to the wave-guide. The surface wave coda is observable for earthquakes whose propagation path does not include the accretionary wedge, implying that the wedge is an enhancer but not indispensable of the formation of the observed coda.

A low cost imaging displacement measurement system for spacecraft thermal vacuum testing

NASA Technical Reports Server (NTRS)

Dempsey, Brian

2006-01-01

A low cost imaging displacement technique suitable for use in thermal vacuum testing was built and tested during thermal vacuum testing of the space infrared telescope facility (SIRTF, later renamed Spitzer infrared telescope facility). The problem was to measure the relative displacement of different portions of the spacecraft due to thermal expansion or contraction. Standard displacement measuring instrumentation could not be used because of the widely varying temperatures on the spacecraft and for fear of invalidating the thermal vacuum testing. The imaging system was conceived, designed, purchased, and installed in approximately 2 months at very low cost. The system performed beyond expectations proving that sub millimeter displacements could be measured from over 2 meters away. Using commercial optics it was possible to make displacement measurements down to 10 (mu)m. An automated image processing tool was used to process the data, which not only speeded up data reduction, but showed that velocities and accelerations could also be measured. Details of the design and capabilities of the system are discussed along with the results of the test on the observatory. Several images from the actual test are presented.

Geology and structure of the North Boqueron Bay-Punta Montalva Fault System

NASA Astrophysics Data System (ADS)

Roig Silva, Coral Marie

The North Boqueron Bay-Punta Montalva Fault Zone is an active fault system that cuts across the Lajas Valley in southwestern Puerto Rico. The fault zone has been recognized and mapped based upon detailed analysis of geophysical data, satellite images and field mapping. The fault zone consists of a series of Cretaceous bedrock faults that reactivated and deformed Miocene limestone and Quaternary alluvial fan sediments. The fault zone is seismically active (ML < 5.0) with numerous locally felt earthquakes. Focal mechanism solutions and structural field data suggest strain partitioning with predominantly east-west left-lateral displacements with small normal faults oriented mostly toward the northeast. Evidence for recent displacement consists of fractures and small normal faults oriented mostly northeast found in intermittent streams that cut through the Quaternary alluvial fan deposits along the southern margin of the Lajas Valley, Areas of preferred erosion, within the alluvial fan, trend toward the west-northwest parallel to the on-land projection of the North Boqueron Bay Fault. Beyond the faulted alluvial fan and southeast of the Lajas Valley, the Northern Boqueron Bay Fault joins with the Punta Montalva Fault. The Punta Montalva Fault is defined by a strong topographic WNW lineament along which stream channels are displaced left laterally 200 meters and Miocene strata are steeply tilted to the south. Along the western end of the fault zone in northern Boqueron Bay, the older strata are only tilted 3° south and are covered by flat lying Holocene sediments. Focal mechanisms solutions along the western end suggest NW-SE shortening, which is inconsistent with left lateral strain partitioning along the fault zone. The limited deformation of older strata and inconsistent strain partitioning may be explained by a westerly propagation of the fault system from the southwest end. The limited geomorphic structural expression along the North Boqueron Bay Fault segment could also be because most of the displacement along the fault zone is older than the Holocene and that the rate of displacement is low, such that the development of fault escarpments and deformation all along the fault zone has yet to occur.

The interplay between subduction and lateral extrusion: A case study for the European Eastern Alps based on analogue models

NASA Astrophysics Data System (ADS)

van Gelder, I. E.; Willingshofer, E.; Sokoutis, D.; Cloetingh, S. A. P. L.

2017-08-01

A series of analogue experiments simulating intra-continental subduction contemporaneous with lateral extrusion of the upper plate are performed to study the interference between these two processes at crustal levels and in the lithospheric mantle. The models demonstrate that intra-continental subduction and coeval lateral extrusion of the upper plate are compatible processes leading to similar deformation structures within the extruding region as compared to the classical setup, lithosphere-scale indentation. Strong coupling across the subduction boundary allows for the transfer of stresses to the upper plate, where strain regimes are characterized by crustal thickening near a confined margin and dominated by lateral displacement of material near a weak lateral confinement. The strain regimes propagate laterally during ongoing convergence creating an area of overlap characterized by transpression. When subduction is oblique to the convergence direction, the upper plate is less deformed and as a consequence the amount of lateral extrusion decreases. In addition, strain is partitioned along the oblique plate boundary resulting in less subduction in expense of right lateral displacement close to the weak lateral confinement. Both oblique and orthogonal subduction models have a strong resemblance to lateral extrusion tectonics of the Eastern Alps (Europe), where subduction of the adjacent Adriatic plate beneath the Eastern Alps is debated. Our results imply that subduction of Adria is a valid mechanisms to induce extrusion-type deformation within the Eastern Alps lithosphere. Furthermore, our findings suggest that the Oligocene to Late Miocene structural evolution of the Eastern Alps reflects a phase of oblique subduction followed by a later stage of orthogonal subduction conform a Miocene shift in the plate motion of Adria. Oblique subduction also provides a viable mechanism to explain the rapid decrease in slab length of the Adriatic plate beneath the Eastern Alps towards the Pannonian Basin.

Compensatory but not anticipatory adjustments are altered in older adults during lateral postural perturbations.

PubMed

Claudino, Renato; dos Santos, Eloá C C; Santos, Marcio J

2013-08-01

This study investigated anticipatory postural adjustments (APAs) and compensatory postural adjustments (CPAs) and their relationship in older adults during lateral postural perturbations. Unpredictable and predictable postural disturbances were induced by a swinging pendulum that impacted at the shoulder level of two groups of older adults, non-fallers (20) and fallers (20), and in a group of young control subjects (20). The electromyographic (EMG) activity of the postural muscles and the center of pressure (COP) displacement were recorded and quantified within the time intervals typical for APAs and CPAs. Both groups of older adults (non-fallers and fallers) showed higher magnitude of EMG activity in the lateral muscles and increased COP displacement, particularly, during the CPAs time interval when compared to the young group. Older adults, however, were able to change the electrical activity of the muscles during the predictable task by generating APAs with similar magnitudes of those found in young subjects. Compensatory but not anticipatory adjustments are altered in older adults during predictable lateral postural perturbations. These findings provide new data on the role of APAs and CPAs in their relationship in older adults during external lateral perturbations and may advance current rehabilitative management strategies to improve balance control in older individuals. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Lateral shearing optical gradient force in coupled nanobeam photonic crystal cavities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Du, Han; Zhang, Xingwang; Chau, Fook Siong

2016-04-25

We report the experimental observation of lateral shearing optical gradient forces in nanoelectromechanical systems (NEMS) controlled dual-coupled photonic crystal (PhC) nanobeam cavities. With an on-chip integrated NEMS actuator, the coupled cavities can be mechanically reconfigured in the lateral direction while maintaining a constant coupling gap. Shearing optical gradient forces are generated when the two cavity centers are laterally displaced. In our experiments, positive and negative lateral shearing optical forces of 0.42 nN and 0.29 nN are observed with different pumping modes. This study may broaden the potential applications of the optical gradient force in nanophotonic devices and benefit the futuremore » nanooptoelectromechanical systems.« less

Kaltag fault, northern Yukon, Canada: Constraints on evolution of Arctic Alaska

NASA Astrophysics Data System (ADS)

Lane, Larry S.

1992-07-01

The Kaltag fault has been linked to several strike-slip models of evolution of the western Arctic Ocean. Hundreds of kilometres of Cretaceous-Tertiary displacement have been hypothesized in models that emplace Arctic Alaska into its present position by either left- or right-lateral strike slip. However, regional-scale displacement is precluded by new potential-field data. Postulated transform emplacement of Arctic Alaska cannot be accommodated by motion on the Kaltag fault or adjacent structures. The Kaltag fault of the northern Yukon is an eastward extrapolation of its namesake in west-central Alaska; however, a connection cannot be demonstrated. Cretaceous-Tertiary displacement on the Alaskan Kaltag fault is probably accommodated elsewhere.

Tactile suppression of displacement.

PubMed

Ziat, Mounia; Hayward, Vincent; Chapman, C Elaine; Ernst, Marc O; Lenay, Charles

2010-10-01

In vision, the discovery of the phenomenon of saccadic suppression of displacement has made important contributions to the understanding of the stable world problem. Here, we report a similar phenomenon in the tactile modality. When scanning a single Braille dot with two fingers of the same hand, participants were asked to decide whether the dot was stationary or whether it was displaced from one location to another. The stimulus was produced by refreshable Braille devices that have dots that can be swiftly raised and recessed. In some conditions, the dot was stationary. In others, a displacement was created by monitoring the participant's finger position and by switching the dot activation when it was not touched by either finger. The dot displacement was of either 2.5 mm or 5 mm. We found that in certain cases, displaced dots were felt to be stationary. If the displacement was orthogonal to the finger movements, tactile suppression occurred effectively when it was of 2.5 mm, but when the displacement was of 5 mm, the participants easily detected it. If the displacement was medial-lateral, the suppression effect occurred as well, but less often when the apparent movement of the dot opposed the movement of the finger. In such cases, the stimulus appeared sooner than when the brain could predict it from finger movement, supporting a predictive rather than a postdictive differential processing hypothesis.

Proton Lateral Broadening Distribution Comparisons Between GRNTRN, MCNPX, and Laboratory Beam Measurements

NASA Technical Reports Server (NTRS)

Mertens, Christopher J.; Moyers, Michael F.; Walker, Steven A.; Tweed, John

2010-01-01

Recent developments in NASA s deterministic High charge (Z) and Energy TRaNsport (HZETRN) code have included lateral broadening of primary ion beams due to small-angle multiple Coulomb scattering, and coupling of the ion-nuclear scattering interactions with energy loss and straggling. This new version of HZETRN is based on Green function methods, called GRNTRN, and is suitable for modeling transport with both space environment and laboratory boundary conditions. Multiple scattering processes are a necessary extension to GRNTRN in order to accurately model ion beam experiments, to simulate the physical and biological-effective radiation dose, and to develop new methods and strategies for light ion radiation therapy. In this paper we compare GRNTRN simulations of proton lateral broadening distributions with beam measurements taken at Loma Linda University Proton Therapy Facility. The simulated and measured lateral broadening distributions are compared for a 250 MeV proton beam on aluminum, polyethylene, polystyrene, bone substitute, iron, and lead target materials. The GRNTRN results are also compared to simulations from the Monte Carlo MCNPX code for the same projectile-target combinations described above.

[Fracture Type and Injury-to-Surgery Interval as Risk Factors for Avascular Necrosis of the Femoral Head after Internal Fixation of Intracapsular Femoral Neck Fracture].

PubMed

Popelka, O; Skála-Rosenbaum, J; Bartoška, R; Waldauf, P; Krbec, M; Džupa, V

2015-01-01

The aim of the study was to investigate the occurrence of avascular necrosis (AVN) of the femoral head following the osteosynthesis of intracapsular fracture of the femoral neck in relation to the time interval between injury and surgery and the type of fracture. The data of patients with intracapsular fractures of the femoral neck surgically treated in the period from 2001 to 2011 were reviewed. Of 1555 patients treated for this fracture, 125 (7%) underwent osteosynthesis. The evaluated group included 115 patients who came for examination at one-year follow-up. There were 59 (52%) women and 56 (48%) men. Dynamic hip screw (DHS) osteosynthesis with an anti-rotation screw was performed in 103 patients and lag-screw osteosynthesis involving three parallel cannulated cancellous screws was employed in 12 patients. The patients were allocated to groups according to the injury-to-surgery interval and to sub-groups on the basis of the Garden classification of femoral fracture stage. In the group of 58 patients treated within 6 h of injury, AVN developed in 10 (17%). When the type of fracture was considered, 4% of the non-displaced fractures and 30% of the displaced fractures developed AVN. The patients with Garden stage I and II (non-displaced) fractures treated within 6 h of injury had a significantly lower risk of AVN development than those with Garden stage III or IV (displaced) fractures. The group treated between 6 and 24 post-injury hours comprised 21 patients, of whom four (19%) had AVN. In non-displaced and displaced fracture sub-groups, 25% of the patients in the former and 16% in the latter had AVN. The stage of displacement had no effect on AVN development. The two groups together (patients treated by 24 h) had a significantly lower AVN incidence than the patients treated after 24 h (p = 0.0025). In this group of 36 patients, 16 had AVN (44%) and the fracture stage made no significant difference (p = 0.6985; nondisplacement sub-group, 41%; displacement sub-group, 55%). The study showed a significantly lower AVN occurrence in the patients surgically treated within 24 h of injury. In the patients treated within 6 h of injury, AVN incidence was significantly lower in the patients with non-displaced fractures, as compared with those who had displaced fractures. This was not true for the two patient groups treated later (6-24 and later than 24 h) in which the differences between AVN development after non-displaced fractures and that after displaced fractures were similar.

Percutaneous discal cyst rupture in a professional football player using sublaminar epidural injection for thecal sac displacement.

PubMed

Friedman, Michael V; Park, Andrew; Bumpass, David; Jennings, Jack W; Matava, Matthew J

2015-01-01

A case of percutaneous discal cyst rupture in a 25-year-old professional American football player is reported. The patient presented with a 3-day history of severe left-sided back pain. Magnetic resonance imaging examination demonstrated a discal cyst effacing the left L4-L5 lateral recess, with interposed thecal sac. A sublaminar epidural injection was performed displacing the thecal sac, exposing the discal cyst, and allowing for percutaneous perforation. The patient had complete resolution of symptoms after discal cyst rupture and was able to compete in a professional football game 3 days later. Computed tomography-guided percutaneous rupture is a therapeutic modality that may be considered for treatment of a symptomatic discal cyst. Copyright © 2015 SIR. Published by Elsevier Inc. All rights reserved.

Design optimization and tolerance analysis of a spot-size converter for the taper-assisted vertical integration platform in InP.

PubMed

Tolstikhin, Valery; Saeidi, Shayan; Dolgaleva, Ksenia

2018-05-01

We report on the design optimization and tolerance analysis of a multistep lateral-taper spot-size converter based on indium phosphide (InP), performed using the Monte Carlo method. Being a natural fit to (and a key building block of) the regrowth-free taper-assisted vertical integration platform, such a spot-size converter enables efficient and displacement-tolerant fiber coupling to InP-based photonic integrated circuits at a wavelength of 1.31 μm. An exemplary four-step lateral-taper design featuring 0.35 dB coupling loss at optimal alignment of a standard single-mode fiber; ≥7  μm 1 dB displacement tolerance in any direction in a facet plane; and great stability against manufacturing variances is demonstrated.

Centrifugally activated bearing for high-speed rotating machinery

DOEpatents

Post, Richard F.

1994-01-01

A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation.

Evaluation of the transverse oscillation technique for cardiac phased-array imaging: A theoretical study

PubMed Central

Bottenus, Nick; D’hooge, Jan; Trahey, Gregg E.

2017-01-01

The transverse oscillation (TO) technique can improve the estimation of tissue motion perpendicular to the ultrasound beam direction. TOs can be introduced using plane wave (PW) insonification and bi-lobed Gaussian apodisation (BA) on receive (abbreviated as PWTO). Furthermore, the TO frequency can be doubled after a heterodyning demodulation process is performed (abbreviated as PWTO*). This study is concerned with identifying the limitations of the PWTO technique in the specific context of myocardial deformation imaging with phased arrays and investigating the conditions in which it remains advantageous over traditional focused (FOC) beamforming. For this purpose, several tissue phantoms were simulated using Field II, undergoing a wide range of displacement magnitudes and modes (lateral, axial and rotational motion). The Cramer-Rao lower bound (CRLB) was used to optimize TO beamforming parameters and theoretically predict the fundamental tracking performance limits associated with the FOC, PWTO and PWTO* beamforming scenarios. This framework was extended to also predict performance for BA functions which are windowed by the physical aperture of the transducer, leading to higher lateral oscillations. It was found that windowed BA functions resulted in lower jitter errors compared to tradional BA functions. PWTO* outperformed FOC at all investigated SNR levels but only up to a certain displacement, with the advantage rapidly decreasing when SNR increased. These results suggest that PWTO* improves lateral tracking performance, but only when inter-frame displacements remain relatively low. The study concludes by translating these findings to a clinical environment by suggesting optimal scanner settings. PMID:27810806

Hook plate fixation of acute displaced lateral clavicle fractures: mid-term results and a brief literature overview

PubMed Central

2012-01-01

Background The clavicle hook plate achieves like most other operative techniques, a high percentage of union and a low percentage of complications however concerns about long term complications still exist, particularly the involvement of the acromioclavicular joint. Methods To evaluate the results and long term effects in use of this plate we performed a retrospective analysis with a mean follow up of 65 months (5.4 years) of 28 consecutive patients with acute displaced lateral clavicle fractures, treated with the clavicle hook plate. Results Short term functional results in all patients were good to excellent. All but one patient had a united fracture (96%). Nine patients (32%) developed impingement symptoms and in 7 patients (25%) subacromial osteolysis was found. These findings resolved after plate removal. Twenty-four patients were re-evaluated at a mean follow-up period of 5.4 years. The Constant-Murley score was 97 and the DASH score was 3.5. Four patients (14%) developed acromioclavicular joint arthrosis of which one was symptomatic. Three patients (11%) had extra articular ossifications of which one was symptomatic. There was no relation between the impingement symptoms, subacromial osteolysis and development of acromioclavicular joint arthrosis or extra articular ossifications. Conclusions The clavicle hook plate is a good primary treatment option for the acute displaced lateral clavicle fracture with few complications. At mid term the results are excellent and no long term complications can be addressed to the use of the plate. PMID:22236647

Predictive Lateral Logic for Numerical Entry Guidance Algorithms

NASA Technical Reports Server (NTRS)

Smith, Kelly M.

2016-01-01

Recent entry guidance algorithm development123 has tended to focus on numerical integration of trajectories onboard in order to evaluate candidate bank profiles. Such methods enjoy benefits such as flexibility to varying mission profiles and improved robustness to large dispersions. A common element across many of these modern entry guidance algorithms is a reliance upon the concept of Apollo heritage lateral error (or azimuth error) deadbands in which the number of bank reversals to be performed is non-deterministic. This paper presents a closed-loop bank reversal method that operates with a fixed number of bank reversals defined prior to flight. However, this number of bank reversals can be modified at any point, including in flight, based on contingencies such as fuel leaks where propellant usage must be minimized.

Proximal metatarsal osteotomies: a comparative geometric analysis conducted on sawbone models.

PubMed

Nyska, Meir; Trnka, Hans-Jörg; Parks, Brent G; Myerson, Mark S

2002-10-01

We evaluated the change in position of the first metatarsal head using a three-dimensional digitizer on sawbone models. Crescentic, closing wedge, oblique shaft (Ludloff 8 degrees and 16 degrees), reverse oblique shaft (Mau 8 degrees and 16 degrees), rotational "Z" (Scarf), and proximal chevron osteotomies were performed and secured using 3-mm screws. The 16 degrees Ludloff provided the most lateral shift (9.5 mm) and angular correction (14.5 degrees) but also produced the most elevation (1.4 mm) and shortening (2.9 mm). The 8 degrees Ludloff provided lateral and angular corrections similar to those of the crescentic and closing wedge osteotomies with less elevation and shortening. Because the displacement osteotomies (Scarf, proximal chevron) provided less angular correction, the same lateral displacement, and less shortening than the basilar angular osteotomies, based upon this model they can be more reliably used for a patient with a mild to moderate deformity, a short first metatarsal, or an intermediate deformity with a large distal metatarsal articular angle. These results can serve as recommendations for selecting the optimal osteotomy with which to correct a deformation.

Tadpole-shaped lateralized parietal atretic cephalocele associated with an ipsilateral lacrimal gland fistula and schizencephalic clefts.

PubMed

Murakami, Nobuya; Morioka, Takato; Suzuki, Satoshi O; Mukae, Nobutaka; Hashiguchi, Kimiaki; Iihara, Koji

2017-02-01

Parietal atretic cephalocele (AC) and its associated intracranial venous anomalies, such as vertical embryonic positioning of the straight sinus (VEP of SS), have, in previous reports, been exclusively restricted to the midline. We report a patient with lateralized parietal AC on the right side. The AC was in the shape of a tadpole, with a large head and a long tail, extending to the proximity of the right external canthus, where a lacrimal gland fistula was observed. The superior sagittal sinus and VEP of SS were also displaced to the right side, although the sagittal suture was located at the midline. Schizencephalic clefts in the right posterior cortex were also observed. The parietal AC, which was initially located in the midline, could conceivably have been displaced to the right side by other developmental processes. However, the relationship between lateralized AC and associated multiple anomalies on the ipsilateral side is difficult to explain monogenetically. Our case study indicates that AC might have a broader spectrum of clinical symptoms than was once thought to be the case.

Clinically Detectable Dental Identifiers Observed in Intra-oral Photographs and Extra-oral Radiographs, Validated for Human Identification Purposes.

PubMed

Angelakopoulos, Nikolaos; Franco, Ademir; Willems, Guy; Fieuws, Steffen; Thevissen, Patrick

2017-07-01

Screening the prevalence and pattern of dental identifiers contributes toward the process of human identification. This research investigated the uniqueness of clinical dental identifiers in photographs and radiographs. Panoramic and lateral cephalometric radiographs and five intra-oral photographs of 1727 subjects were used. In a target set, two observers examined different subjects. In a subset, both observers examined the same subjects (source set). The distance between source and target subjects was quantified for each identifier. The percentage of subjects in the target set being at least as close as the correct subject was assessed. The number of molars (34.6%), missing teeth (42%), and displaced teeth (59.9%) were the most unique identifiers in photographs and panoramic and lateral cephalometric radiographs, respectively. The pattern of rotated teeth (14.9%) was the most unique in photographs, while displaced teeth was in panoramic (37.6%) and lateral cephalometric (54.8%) radiographs. Morphological identifiers were the most unique, highlighting their importance for human identifications. © 2016 American Academy of Forensic Sciences.

Nonlinear quasi-static analysis of ultra-deep-water top-tension riser

NASA Astrophysics Data System (ADS)

Gao, Guanghai; Qiu, Xingqi; Wang, Ke; Liu, Jianjun

2017-09-01

In order to analyse the ultra-deep-water top-tension riser deformation in drilling conditions, a nonlinear quasi-static analysis model and equation are established. The riser in this model is regarded as a simply supported beam located in the vertical plane and is subjected to non-uniform axial and lateral forces. The model and the equation are solved by the finite element method. The effects of riser outside diameter, top tension ratio, sea surface current velocity, drag force coefficient, floating system drift distance and water depth on the riser lateral displacement are discussed. Results show that the riser lateral displacement increase with the increase in the sea surface current velocity, drag force coefficient and water depth, whereas decrease with the increase in the riser outside diameter, top tension ratio. The top tension ratio has an important influence on the riser deformation and it should be set reasonably under different circumstances. The drift of the floating system has a complicated influence on the riser deformation and it should avoid a large drift distance in the proceedings of drilling and production.

Seismic hazard study for selected sites in New Mexico and Nevada

NASA Astrophysics Data System (ADS)

Johnston, J. C.

1983-12-01

Seismic hazard evaluations were conducted for specific sites in New Mexico and Nevada. For New Mexico, a model of seismicity was developed from historical accounts of medium to large shocks and the current microactivity record from local networks. Ninety percent confidence levels at Albuquerque and Roswell were computed to be 56 gals for a 10-year period and 77 gals for a 20-year period. Values of ground motion for Clovis were below these values. Peak velocity and displacement were also computed for each site. Deterministic spectra based on the estimated maximum credible earthquake for the zones which the sites occupy were also computed. For the sites in Nevada, the regionalizations used in Battis (1982) for the uniform seismicity model were slightly modified. For 10- and 20-year time periods, peak acceleration values for Indian Springs were computed to be 94 gals and 123 gals and for Hawthorne 206 gals and 268 gals. Deterministic spectra were also computed. The input parameters were well determined for the analysis for the Nevada sites because of the abundance of data. The values computed for New Mexico, however, are likely upper limits. As more data are collected from the area of the Rio Grande rift zone, the pattern of seismicity will become better understood. At this time a more detailed, and thus more accurate, model may emerge.

Neo-deterministic seismic hazard assessment in North Africa

NASA Astrophysics Data System (ADS)

Mourabit, T.; Abou Elenean, K. M.; Ayadi, A.; Benouar, D.; Ben Suleman, A.; Bezzeghoud, M.; Cheddadi, A.; Chourak, M.; ElGabry, M. N.; Harbi, A.; Hfaiedh, M.; Hussein, H. M.; Kacem, J.; Ksentini, A.; Jabour, N.; Magrin, A.; Maouche, S.; Meghraoui, M.; Ousadou, F.; Panza, G. F.; Peresan, A.; Romdhane, N.; Vaccari, F.; Zuccolo, E.

2014-04-01

North Africa is one of the most earthquake-prone areas of the Mediterranean. Many devastating earthquakes, some of them tsunami-triggering, inflicted heavy loss of life and considerable economic damage to the region. In order to mitigate the destructive impact of the earthquakes, the regional seismic hazard in North Africa is assessed using the neo-deterministic, multi-scenario methodology (NDSHA) based on the computation of synthetic seismograms, using the modal summation technique, at a regular grid of 0.2 × 0.2°. This is the first study aimed at producing NDSHA maps of North Africa including five countries: Morocco, Algeria, Tunisia, Libya, and Egypt. The key input data for the NDSHA algorithm are earthquake sources, seismotectonic zonation, and structural models. In the preparation of the input data, it has been really important to go beyond the national borders and to adopt a coherent strategy all over the area. Thanks to the collaborative efforts of the teams involved, it has been possible to properly merge the earthquake catalogues available for each country to define with homogeneous criteria the seismogenic zones, the characteristic focal mechanism associated with each of them, and the structural models used to model wave propagation from the sources to the sites. As a result, reliable seismic hazard maps are produced in terms of maximum displacement ( D max), maximum velocity ( V max), and design ground acceleration.

Diffusive and subdiffusive dynamics of indoor microclimate: a time series modeling.

PubMed

Maciejewska, Monika; Szczurek, Andrzej; Sikora, Grzegorz; Wyłomańska, Agnieszka

2012-09-01

The indoor microclimate is an issue in modern society, where people spend about 90% of their time indoors. Temperature and relative humidity are commonly used for its evaluation. In this context, the two parameters are usually considered as behaving in the same manner, just inversely correlated. This opinion comes from observation of the deterministic components of temperature and humidity time series. We focus on the dynamics and the dependency structure of the time series of these parameters, without deterministic components. Here we apply the mean square displacement, the autoregressive integrated moving average (ARIMA), and the methodology for studying anomalous diffusion. The analyzed data originated from five monitoring locations inside a modern office building, covering a period of nearly one week. It was found that the temperature data exhibited a transition between diffusive and subdiffusive behavior, when the building occupancy pattern changed from the weekday to the weekend pattern. At the same time the relative humidity consistently showed diffusive character. Also the structures of the dependencies of the temperature and humidity data sets were different, as shown by the different structures of the ARIMA models which were found appropriate. In the space domain, the dynamics and dependency structure of the particular parameter were preserved. This work proposes an approach to describe the very complex conditions of indoor air and it contributes to the improvement of the representative character of microclimate monitoring.

Stochastic reduced order models for inverse problems under uncertainty

PubMed Central

Warner, James E.; Aquino, Wilkins; Grigoriu, Mircea D.

2014-01-01

This work presents a novel methodology for solving inverse problems under uncertainty using stochastic reduced order models (SROMs). Given statistical information about an observed state variable in a system, unknown parameters are estimated probabilistically through the solution of a model-constrained, stochastic optimization problem. The point of departure and crux of the proposed framework is the representation of a random quantity using a SROM - a low dimensional, discrete approximation to a continuous random element that permits e cient and non-intrusive stochastic computations. Characterizing the uncertainties with SROMs transforms the stochastic optimization problem into a deterministic one. The non-intrusive nature of SROMs facilitates e cient gradient computations for random vector unknowns and relies entirely on calls to existing deterministic solvers. Furthermore, the method is naturally extended to handle multiple sources of uncertainty in cases where state variable data, system parameters, and boundary conditions are all considered random. The new and widely-applicable SROM framework is formulated for a general stochastic optimization problem in terms of an abstract objective function and constraining model. For demonstration purposes, however, we study its performance in the specific case of inverse identification of random material parameters in elastodynamics. We demonstrate the ability to efficiently recover random shear moduli given material displacement statistics as input data. We also show that the approach remains effective for the case where the loading in the problem is random as well. PMID:25558115

Lateral offsets on surveyed cultural features resulting from the 1999 İzmit and Düzce earthquakes, Turkey

USGS Publications Warehouse

Rockwell, Thomas K.; Lindvall, Scott; Dawson, Tim; Langridge, Rob; Lettis, William; Klinger, Yann

2002-01-01

Surveys of multiple tree lines within groves of poplar trees, planted in straight lines across the fault prior to the earthquake, show surprisingly large lateral variations. In one grove, slip increases by nearly 1.8 m, or 35% of the maximum measured value, over a lateral distance of nearly 100 m. This and other observations along the 1999 ruptures suggest that the lateral variability of slip observed from displaced geomorphic features in many earthquakes of the past may represent a combination of (1) actual differences in slip at the surface and (2) the difficulty in recognizing distributed nonbrittle deformation.

Interpersonal dynamics and relative positioning to scoring target of performers in 1 vs. 1 sub-phases of team sports.

PubMed

Esteves, Pedro T; Araújo, Duarte; Davids, Keith; Vilar, Luís; Travassos, Bruno; Esteves, Carlos

2012-01-01

In this study, we examined the effects of relative positioning of attacker-defender dyads to the basket on interpersonal coordination tendencies in basketball. To achieve this aim, four right-hand dominant basketball players performed in a 1 vs. 1 sub-phase, at nine different playing locations relative to the basket (from 0° to 180°, in 20° increments). Performers' movement displacement trajectories were video-recorded and digitized in 162 trials. Results showed that interpersonal coordination tendencies changed according to the scaling of the relative position of performers to the basket. Stable in-phase modes of coordination were observed between performers' longitudinal and lateral displacements (50.47% and 43.02%) on the left side of the court. On the right side of the court, a shift in the dominant mode of coordination was observed to a defender lead-lag of -30°, both for longitudinal and lateral displacements (30.51% and 32.65%). These results suggest how information about dribbler hand dominance and relative position to the basket may have constrained attacker-defender coordination tendencies in 1 vs. 1 sub-phases of basketball.

Manual displacement of the uterus during Caesarean section.

PubMed

Kundra, P; Khanna, S; Habeebullah, S; Ravishankar, M

2007-05-01

Ninety ASA 1 and 2 pregnant women with term singleton pregnancies and no maternal and fetal complications, scheduled for elective or emergency Caesarean section, were randomly allocated to group LT (15 degrees left lateral table tilt, n = 45) and group MD (leftward manual displacement, n = 45). Subarachnoid block was established with a 25-gauge spinal needle at the L3-L4 interspace using 1.5 ml of 0.5% hyperbaric bupivacaine. A median sensory level of T6 was observed in both groups but the incidence of hypotension was markedly lower in group MD when compared to group LT (4.4% vs 40%; p < 0.001) with a significant reduction in mean (SD) ephedrine requirement (6 (0) vs 11.3 (4.9) mg; p < 0.001). The mean (SD) fall in systolic blood pressure was 28.8 (7.3) mmHg in group LT and 20 (12.7) mmHg in group MD. The time to maximum fall in systolic blood pressure was similar in both groups (4.5 min). We conclude that manual displacement of the uterus effectively reduces the incidence of hypotension and ephedrine requirements when compared to 15 degrees left lateral table tilt in parturients undergoing Caesarean section.

Effect of implant angulation and impression technique on impressions of NobelActive implants.

PubMed

Alexander Hazboun, Gillian Brewer; Masri, Radi; Romberg, Elaine; Kempler, Joanna; Driscoll, Carl F

2015-05-01

How the configuration of the NobelActive internal conical connection affects implant impressions is uncertain. The purpose of this study was to measure the effect in vitro of closed and open tray impression techniques for NobelActive implants placed at various angulations. Six NobelActive implants were placed in a master maxillary cast as follows: 0 degrees of angulation to a line drawn perpendicular to the occlusal plane in the first molar area, 15 degrees of angulation to a line drawn perpendicular to the occlusal plane in the first premolar area, and 30 degrees of angulation to a line drawn perpendicular to the occlusal plane in the lateral incisor area. Twelve open tray and 12 closed tray impressions were made. Occlusal, lateral, and frontal view photographs of the resulting casts were used to measure the linear and angular displacement of implant analogs. Statistical analysis was performed with a factorial analysis of variance (ANOVA), followed by the Tukey HSD test (α=.05). No significant difference was found in the impressions made of NobelActive implants with the open or closed tray technique (linear displacement: F=0.93, P=.34; angular displacement: F=2.09, P=.15). In addition, implant angulation (0, 15, or 30 degrees) had no effect on the linear or angular displacement of impressions (linear displacement: F=2.72, P=.07; angular displacement: F=0.86, P=.43). Finally, no significant interaction was found between impression technique and implant angulation on NobelActive implants (F=0.25, P=.77; F=1.60, P=.20). Within the limitations of this study, impression technique (open vs closed tray) and implant angulation (0, 15, and 30 degrees) had no significant effect on in vitro impressions of NobelActive implants. Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Serial biomechanical comparison of edematous, normal, and collagen crosslinked human donor corneas using optical coherence elastography

PubMed Central

Ford, Matthew R.; Roy, Abhijit Sinha; Rollins, Andrew M.; Dupps, William J.

2014-01-01

PURPOSE To noninvasively evaluate the effects of corneal hydration and collagen crosslinking (CXL) on the mechanical behavior of the cornea. SETTING Cleveland Clinic Cole Eye Institute, Cleveland, Ohio, USA. DESIGN Experimental study. METHODS An optical coherence elastography (OCE) technique was used to measure the displacement behavior of 5 pairs of debrided human donor globes in 3 serial states as follows: edematous, normal thickness, and after riboflavin–ultraviolet-A–mediated CXL. During micromotor-controlled axial displacements with a curved goniolens at physiologic intraocular pressure (IOP), serial optical coherence tomography scans were obtained to allow high-resolution intrastromal speckle tracking and displacement measurements over the central 4.0 mm of the cornea. RESULTS With no imposed increase in IOP, the mean lateral to imposed axial displacement ratios were 0.035 μm/μm ± 0.037 (SD) in edematous corneas, 0.021 ± 0.02 μm/μm in normal thickness corneas, and 0.014 ± 0.009 μm/μm in post-CXL corneas. The differences were statistically significant (P<.05, analysis of variance) and indicated a 40% increase in lateral stromal resistance with deturgescence and a further 33% mean increase in relative stiffness with CXL. CONCLUSIONS Serial perturbations of the corneal hydration state and CXL had significant effects on corneal biomechanical behavior. With an axially applied stress from a nonapplanating contact lens, displacements along the direction of the collagen lamellae were 2 orders of magnitude lower than axial deformations. These experiments show the ability of OCE to quantify clinically relevant mechanical property differences under physiologic conditions. Financial Disclosures Proprietary or commercial disclosures are listed after the references. PMID:24767794

GPR investigations along the North Anatolian Fault near Izmit (Turkey): Constraints on the right-lateral movement and slip history

NASA Astrophysics Data System (ADS)

Ferry, M.; Meghraoui, M.; Rockwell, T. K.; Kozaci, Ö.; Akyuz, S.; Girard, J.-F.; Barka, A.

2003-04-01

The 1999 Ms 7.4 Izmit earthquake produced more than 110 km of surface rupture along the North Anatolian fault. We present here ground-penetrating radar (GPR) profiles surveyed across and parallel to the 1999 Izmit earthquake ruptures at two sites along the Izmit-Sapanca segment. Fine sandy and coarse gravels favor the penetration depth and processed radar profiles image clearly visible reflectors within the uppermost 10 m. In Köseköy, they document cumulative right-lateral offset of a stream channel by the fault. Old fluvial channel deposits also visible in trenches show a maximum 13.5 to 14 m lateral displacement. Younger channel units display 4 m of right-lateral displacement at 2.5 m depth and correlation with dated trench units yields an average slip rate of 15 mm/yr. At site 2, GPR profiles display the successive faulting of a medieval Ottoman Canal which excavation probably took place in 1591 A.D.. GPR profiles image the corresponding surface as well as numerous faults that affect it. A following trench study confirmed these results as they provide consistent results with the occurrence of three faulting events post-1591 A.D., one of which probably as large as the 1999 Izmit earthquake.

Locked nailing for the treatment of displaced articular fractures of the calcaneus: description of a new procedure with calcanail(®).

PubMed

Goldzak, Mario; Mittlmeier, Thomas; Simon, Patrick

2012-05-01

Although open reduction and internal fixation is considered the best method for treating displaced articular fractures of the calcaneus, lateral approach is at high risk for wound healing complications. For this reason, the authors developed a posterior approach and a new implant to perform both intrafocal reduction and internal fixation. The aim of this technical note is to describe this method of treatment for displaced articular fractures of the calcaneus, which offered the following advantages: (a) the creation of a working channel that provides also a significant bone autograft, (b) the intrafocal reduction of the displaced articular surface, (c) the insertion of a locking nail that maintains the reduced articular surface at the right height, (d) the possibility to switch from an ORIF to a reconstruction arthrodesis with the same approach and instrumentation in case of severely damaged posterior facet.

Critical factors in displacement ductility assessment of high-strength concrete columns

NASA Astrophysics Data System (ADS)

Taheri, Ali; Moghadam, Abdolreza S.; Tasnimi, Abass Ali

2017-12-01

Ductility of high-strength concrete (HSC) columns with rectangular sections was assessed in this study by reviewing experimental data from the available literature. Up to 112 normal weights concrete columns with strength in the range of 50-130 MPa were considered and presented as a database. The data included the results of column testes under axial and reversed lateral loading. Displacement ductility of HSC columns was evaluated in terms of their concrete and reinforcement strengths, bar arrangement, volumetric ratio of transverse reinforcement, and axial loading. The results indicated that the confinement requirements and displacement ductility in HSC columns are more sensitive than those in normal strength concrete columns. Moreover, ductility is descended by increasing concrete strength. However, it was possible to obtain ductile behavior in HSC columns through proper confinement. Furthermore, this study casts doubt about capability of P/ A g f c' ratio that being inversely proportional to displacement ductility of HSC columns.

Minimally Invasive Calcaneal Displacement Osteotomy Site Using a Reference Kirschner Wire: A Technique Tip.

PubMed

Lee, Moses; Guyton, Gregory P; Zahoor, Talal; Schon, Lew C

2016-01-01

As a standard open approach, the lateral oblique incision has been widely used for calcaneal displacement osteotomy. However, just as with other orthopedic procedures that use an open approach, complications, including wound healing problems and neurovascular injury in the heel, have been reported. To help avoid these limitations, a percutaneous technique using a Shannon burr for calcaneal displacement osteotomy was introduced. However, relying on a free-hand technique without direct visualization at the osteotomy site has been a major obstacle for this technique. To address this problem, we developed a technical tip using a reference Kirschner wire. A reference Kirschner wire technique provides a reliable and accurate guide for minimally invasive calcaneal displacement osteotomy. Also, the technique should be easy to learn for surgeons new to the procedure. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

Ecological Succession Pattern of Fungal Community in Soil along a Retreating Glacier

PubMed Central

Tian, Jianqing; Qiao, Yuchen; Wu, Bing; Chen, Huai; Li, Wei; Jiang, Na; Zhang, Xiaoling; Liu, Xingzhong

2017-01-01

Accelerated by global climate changing, retreating glaciers leave behind soil chronosequences of primary succession. Current knowledge of primary succession is mainly from studies of vegetation dynamics, whereas information about belowground microbes remains unclear. Here, we combined shifts in community assembly processes with microbial primary succession to better understand mechanisms governing the stochastic/deterministic balance. We investigated fungal succession and community assembly via high-throughput sequencing along a well-established glacier forefront chronosequence that spans 2–188 years of deglaciation. Shannon diversity and evenness peaked at a distance of 370 m and declined afterwards. The response of fungal diversity to distance varied in different phyla. Basidiomycota Shannon diversity significantly decreased with distance, while the pattern of Rozellomycota Shannon diversity was unimodal. Abundance of most frequencies OTU2 (Cryptococcus terricola) increased with successional distance, whereas that of OTU65 (Tolypocladium tundrense) decreased. Based on null deviation analyses, composition of the fungal community was initially governed by deterministic processes strongly but later less deterministic processes. Our results revealed that distance, altitude, soil microbial biomass carbon, soil microbial biomass nitrogen and NH4+–N significantly correlated with fungal community composition along the chronosequence. These results suggest that the drivers of fungal community are dynamics in a glacier chronosequence, that may relate to fungal ecophysiological traits and adaptation in an evolving ecosystem. The information will provide understanding the mechanistic underpinnings of microbial community assembly during ecosystem succession under different scales and scenario. PMID:28649234

Ecological Succession Pattern of Fungal Community in Soil along a Retreating Glacier.

PubMed

Tian, Jianqing; Qiao, Yuchen; Wu, Bing; Chen, Huai; Li, Wei; Jiang, Na; Zhang, Xiaoling; Liu, Xingzhong

2017-01-01

Accelerated by global climate changing, retreating glaciers leave behind soil chronosequences of primary succession. Current knowledge of primary succession is mainly from studies of vegetation dynamics, whereas information about belowground microbes remains unclear. Here, we combined shifts in community assembly processes with microbial primary succession to better understand mechanisms governing the stochastic/deterministic balance. We investigated fungal succession and community assembly via high-throughput sequencing along a well-established glacier forefront chronosequence that spans 2-188 years of deglaciation. Shannon diversity and evenness peaked at a distance of 370 m and declined afterwards. The response of fungal diversity to distance varied in different phyla. Basidiomycota Shannon diversity significantly decreased with distance, while the pattern of Rozellomycota Shannon diversity was unimodal. Abundance of most frequencies OTU2 ( Cryptococcus terricola ) increased with successional distance, whereas that of OTU65 ( Tolypocladium tundrense ) decreased. Based on null deviation analyses, composition of the fungal community was initially governed by deterministic processes strongly but later less deterministic processes. Our results revealed that distance, altitude, soil microbial biomass carbon, soil microbial biomass nitrogen and [Formula: see text]-N significantly correlated with fungal community composition along the chronosequence. These results suggest that the drivers of fungal community are dynamics in a glacier chronosequence, that may relate to fungal ecophysiological traits and adaptation in an evolving ecosystem. The information will provide understanding the mechanistic underpinnings of microbial community assembly during ecosystem succession under different scales and scenario.

A Cane Improves Postural Recovery From an Unpracticed Slip During Walking in People With Parkinson Disease

PubMed Central

Saengsirisuwan, Vitoon; Carlson-Kuhta, Patricia; Horak, Fay B.

2012-01-01

Background Little is known about the effects of use of a cane on balance during perturbed gait or whether people with Parkinson disease (PD) benefit from using a cane. Objectives The purpose of this study was to evaluate the effects of cane use on postural recovery from a slip due to repeated surface perturbations in individuals with PD compared with age- and sex-matched individuals who were healthy. Design This was a prospective study with 2 groups of participants. Methods Fourteen individuals with PD (PD group) and 11 individuals without PD (control group) walked across a platform that translated 15 cm rightward at 30 cm/s during the single-limb support phase of the right foot. Data from 15 trials in 2 conditions (ie, with and without an instrumented cane in the right hand) were collected in random order. Outcome measures included lateral displacement of body center of mass (COM) due to the slip and compensatory step width and length after the perturbation. Results Cane use improved postural recovery from the first untrained slip, characterized by smaller lateral COM displacement, in the PD group but not in the control group. The beneficial effect of cane use, however, occurred only during the first perturbation, and those individuals in the PD group who demonstrated the largest COM displacement without a cane benefited the most from use of a cane. Both PD and control groups gradually decreased lateral COM displacement across slip exposures, but a slower learning rate was evident in the PD group participants, who required 6, rather than 3, trials for adapting balance recovery. Limitations Future studies are needed to examine the long-term effects of repeated slip training in people with PD. Conclusions Use of a cane improved postural recovery from an unpracticed slip in individuals with PD. Balance in people with PD can be improved by training with repeated exposures to perturbations. PMID:22628583

A cane improves postural recovery from an unpracticed slip during walking in people with Parkinson disease.

PubMed

Boonsinsukh, Rumpa; Saengsirisuwan, Vitoon; Carlson-Kuhta, Patricia; Horak, Fay B

2012-09-01

Little is known about the effects of use of a cane on balance during perturbed gait or whether people with Parkinson disease (PD) benefit from using a cane. The purpose of this study was to evaluate the effects of cane use on postural recovery from a slip due to repeated surface perturbations in individuals with PD compared with age- and sex-matched individuals who were healthy. This was a prospective study with 2 groups of participants. Fourteen individuals with PD (PD group) and 11 individuals without PD (control group) walked across a platform that translated 15 cm rightward at 30 cm/s during the single-limb support phase of the right foot. Data from 15 trials in 2 conditions (ie, with and without an instrumented cane in the right hand) were collected in random order. Outcome measures included lateral displacement of body center of mass (COM) due to the slip and compensatory step width and length after the perturbation. Cane use improved postural recovery from the first untrained slip, characterized by smaller lateral COM displacement, in the PD group but not in the control group. The beneficial effect of cane use, however, occurred only during the first perturbation, and those individuals in the PD group who demonstrated the largest COM displacement without a cane benefited the most from use of a cane. Both PD and control groups gradually decreased lateral COM displacement across slip exposures, but a slower learning rate was evident in the PD group participants, who required 6, rather than 3, trials for adapting balance recovery. Future studies are needed to examine the long-term effects of repeated slip training in people with PD. Use of a cane improved postural recovery from an unpracticed slip in individuals with PD. Balance in people with PD can be improved by training with repeated exposures to perturbations.

Cerebellar inactivation impairs memory of learned prism gaze-reach calibrations.

PubMed

Norris, Scott A; Hathaway, Emily N; Taylor, Jordan A; Thach, W Thomas

2011-05-01

Three monkeys performed a visually guided reach-touch task with and without laterally displacing prisms. The prisms offset the normally aligned gaze/reach and subsequent touch. Naive monkeys showed adaptation, such that on repeated prism trials the gaze-reach angle widened and touches hit nearer the target. On the first subsequent no-prism trial the monkeys exhibited an aftereffect, such that the widened gaze-reach angle persisted and touches missed the target in the direction opposite that of initial prism-induced error. After 20-30 days of training, monkeys showed long-term learning and storage of the prism gaze-reach calibration: they switched between prism and no-prism and touched the target on the first trials without adaptation or aftereffect. Injections of lidocaine into posterolateral cerebellar cortex or muscimol or lidocaine into dentate nucleus temporarily inactivated these structures. Immediately after injections into cortex or dentate, reaches were displaced in the direction of prism-displaced gaze, but no-prism reaches were relatively unimpaired. There was little or no adaptation on the day of injection. On days after injection, there was no adaptation and both prism and no-prism reaches were horizontally, and often vertically, displaced. A single permanent lesion (kainic acid) in the lateral dentate nucleus of one monkey immediately impaired only the learned prism gaze-reach calibration and in subsequent days disrupted both learning and performance. This effect persisted for the 18 days of observation, with little or no adaptation.

Cerebellar inactivation impairs memory of learned prism gaze-reach calibrations

PubMed Central

Hathaway, Emily N.; Taylor, Jordan A.; Thach, W. Thomas

2011-01-01

Three monkeys performed a visually guided reach-touch task with and without laterally displacing prisms. The prisms offset the normally aligned gaze/reach and subsequent touch. Naive monkeys showed adaptation, such that on repeated prism trials the gaze-reach angle widened and touches hit nearer the target. On the first subsequent no-prism trial the monkeys exhibited an aftereffect, such that the widened gaze-reach angle persisted and touches missed the target in the direction opposite that of initial prism-induced error. After 20–30 days of training, monkeys showed long-term learning and storage of the prism gaze-reach calibration: they switched between prism and no-prism and touched the target on the first trials without adaptation or aftereffect. Injections of lidocaine into posterolateral cerebellar cortex or muscimol or lidocaine into dentate nucleus temporarily inactivated these structures. Immediately after injections into cortex or dentate, reaches were displaced in the direction of prism-displaced gaze, but no-prism reaches were relatively unimpaired. There was little or no adaptation on the day of injection. On days after injection, there was no adaptation and both prism and no-prism reaches were horizontally, and often vertically, displaced. A single permanent lesion (kainic acid) in the lateral dentate nucleus of one monkey immediately impaired only the learned prism gaze-reach calibration and in subsequent days disrupted both learning and performance. This effect persisted for the 18 days of observation, with little or no adaptation. PMID:21389311

Effect of lordosis angle change after lumbar/lumbosacral fusion on sacrum angular displacement: a finite element study.

PubMed

Mao, Ningfang; Shi, Jian; He, Dawei; Xie, Yang; Bai, Yushu; Wei, Xianzhao; Shi, Zhicai; Li, Ming

2014-11-01

To assess and characterize the sacrum angular displacements in response to lumbar lordosis after lumbar/lumbosacral fusion. A finite element model of the lower lumbar spine-pelvis was established and used to simulate the posterior fusion at L3-L5 and L4-S1. The lordosis angle in the fusion segments was set to five different conditions with respect to the intact model: 10° less than intact, 5° less than intact, same as intact, 5° more than intact, and 10° more than intact. Variations of the sacrum angular displacements with lordosis changes were analyzed under loading setting of axial compression, flexion, extension, lateral bending, and axial rotation. Compared with the intact lordosis, both increased and decreased lumbar lordosis angles caused the sacrum angular displacements to be increased. The lordosis angle increased by 10° induced the most substantial increase in sacrum angular displacements. In addition, the sacrum angular displacements of the L4-S1 fusion model at different lordosis angles were higher than those of the L3-L5 fusion model. The sacrum angular displacements occur as a result of the fusion surgery (L4-S1) and the changes in lumbar lordosis.

Noninvasive Vascular Displacement Estimation for Relative Elastic Modulus Reconstruction in Transversal Imaging Planes

PubMed Central

Hansen, Hendrik H.G.; Richards, Michael S.; Doyley, Marvin M.; de Korte, Chris L.

2013-01-01

Atherosclerotic plaque rupture can initiate stroke or myocardial infarction. Lipid-rich plaques with thin fibrous caps have a higher risk to rupture than fibrotic plaques. Elastic moduli differ for lipid-rich and fibrous tissue and can be reconstructed using tissue displacements estimated from intravascular ultrasound radiofrequency (RF) data acquisitions. This study investigated if modulus reconstruction is possible for noninvasive RF acquisitions of vessels in transverse imaging planes using an iterative 2D cross-correlation based displacement estimation algorithm. Furthermore, since it is known that displacements can be improved by compounding of displacements estimated at various beam steering angles, we compared the performance of the modulus reconstruction with and without compounding. For the comparison, simulated and experimental RF data were generated of various vessel-mimicking phantoms. Reconstruction errors were less than 10%, which seems adequate for distinguishing lipid-rich from fibrous tissue. Compounding outperformed single-angle reconstruction: the interquartile range of the reconstructed moduli for the various homogeneous phantom layers was approximately two times smaller. Additionally, the estimated lateral displacements were a factor of 2–3 better matched to the displacements corresponding to the reconstructed modulus distribution. Thus, noninvasive elastic modulus reconstruction is possible for transverse vessel cross sections using this cross-correlation method and is more accurate with compounding. PMID:23478602

Synchrotron X-ray studies of epitaxial ferroelectric thin films and nanostructures

NASA Astrophysics Data System (ADS)

Klug, Jeffrey A.

The study of ferroelectric thin films is a field of considerable scientific and technological interest. In this dissertation synchrotron x-ray techniques were applied to examine the effects of lateral confinement and epitaxial strain in ferroelectric thin films and nanostructures. Three materials systems were investigated: laterally confined epitaxial BiFeO3 nanostructures on SrTiO3 (001), ultra-thin commensurate SrTiO 3 films on Si (001), and coherently strained films of BaTiO3 on DyScO3 (110). Epitaxial films of BiFeO3 were deposited by radio frequency magnetron sputtering on SrRuO3 coated SrTiO 3 (001) substrates. Laterally confined nanostructures were fabricated using focused ion-beam processing and subsequently characterized with focused beam x-ray nanodiffraction measurements with unprecedented spatial resolution. Results from a series of rectangular nanostructures with lateral dimensions between 500 nm and 1 mum and a comparably-sized region of the unpatterned BiFeO3 film revealed qualitatively similar distributions of local strain and lattice rotation with a 2-3 times larger magnitude of variation observed in those of the nanostructures compared to the unpatterned film. This indicates that lateral confinement leads to enhanced variation in the local strain and lattice rotation fields in epitaxial BiFeO3 nanostructures. A commensurate 2 nm thick film of SrTiO3 on Si was characterized by the x-ray standing wave (XSW) technique to determine the Sr and Ti cation positions in the strained unit cell in order to verify strain-induced ferroelectricity in SrTiO3/Si. A Si (004) XSW measurement at 10°C indicated that the average Ti displacement from the midpoint between Sr planes was consistent in magnitude to that predicted by a density functional theory (DFT) calculated ferroelectric structure. The Ti displacement determined from a 35°C measurement better matched a DFT-predicted nonpolar structure. The thin film extension of the XSW technique was employed to measure the polar displacement of the Ba cations in a 50 nm thick coherently strained BaTiO3 film on DyScO3 (110). An analysis assuming a bulk-like ratio between the Ti and Ba displacements found that the polar shift of Ba cations was larger than in bulk BaTiO3, which was consistent with strain-induced enhancement of ferroelectric polarization in BaTiO3/DyScO3 (110).

Determination of Stent Frame Displacement After Endovascular Aneurysm Sealing.

PubMed

van Veen, Ruben; van Noort, Kim; Schuurmann, Richte C L; Wille, Jan; Slump, Cornelis H; de Vries, Jean-Paul P M

2018-02-01

To describe and validate a new methodology for visualizing and quantifying 3-dimensional (3D) displacement of the stent frames of the Nellix endosystem after endovascular aneurysm sealing (EVAS). The 3D positions of the stent frames were registered to 5 fixed anatomical landmarks on the post-EVAS computed tomography (CT) scans, facilitating comparison of the position and shape of the stent frames between consecutive follow-up scans. Displacement of the proximal and distal ends of the stent frames, the entire stent frame trajectories, as well as changes in distance between the stent frames were determined for 6 patients with >5-mm displacement and 6 patients with <5-mm displacement at 1-year follow-up. The measurements were performed by 2 independent observers; the intraclass correlation coefficient (ICC) was used to determine interobserver variability. Three types of displacement were identified: displacement of the proximal and/or distal end of the stent frames, lateral displacement of one or both stent frames, and stent frame buckling. The ICC ranged from good (0.750) to excellent (0.958). No endoleak or migration was detected in the 12 patients on conventional CT angiography at 1 year. However, of the 6 patients with >5-mm displacement on the 1-year CT as determined by the new methodology, 2 went on to develop a type Ia endoleak in longer follow-up, and displacement progressed to >15 mm for 2 other patients. No endoleak or progressive displacement was appreciated for the patients with <5-mm displacement. The sac anchoring principle of the Nellix endosystem may result in several types of displacement that have not been observed during surveillance of regular endovascular aneurysm repairs. The presented methodology allows precise 3D determination of the Nellix endosystems and can detect subtle displacement better than standard CT angiography. Displacement >5 mm on the 1-year CT scans reconstructed with the new methodology may forecast impaired sealing and anchoring of the Nellix endosystem.

Articulated dental cast analysis of asymptomatic and symptomatic populations

PubMed Central

Cordray, Frank E

2016-01-01

Dental instrumentation has long provided insight into the mechanism of musculo-skeletal function of the gnathic system. While large population studies associate dental arch displacement (DAD), especially laterally, with symptoms, mandibular condyle displacement (CD) resulting from DAD has not been targeted as possibly etiologic in the production of common muscle contraction headache (CMCH) and temporo-mandibular dysfunction (TMD). The objective was to evaluate the three-dimensional nature of DAD and CD between the seated condylar position (SCP) and the intercuspal position (ICP) and to compare results derived from large deprogrammed asymptomatic and symptomatic populations. A total of 1 192 sets of dental casts collected from asymptomatic and symptomatic populations were articulated in the SCP. The initial occlusal contact, DAD, and condylar displacement were evaluated for frequency, direction, and magnitude of displacement between the SCP and ICP. The data revealed significant displacement between the SCP and ICP of the condyles (displaced most frequently inferior (down) and posterior (distal)) and substantially increased frequency and magnitude of displacement of the dental arches (with posterior premature occlusal contacts, increased overjet, decreased overbite, midline differences, and occlusal classification changes) in symptomatic subjects. These discrepancies were statistically significant and clinically significant. The data support the concept of increased DAD and CD with dysfunction. Transverse condylar displacement, commonly presenting with dental cross bite, may be associated with CMCH and TMD. Displacement of the mandibular condyle may be an etiologic factor in CMCH and dysfunction of the temporo-mandibular joint. PMID:27357324

Analysis of Thermal Track Buckling in the Lateral Plane

DOT National Transportation Integrated Search

1976-09-01

The post-buckling equilibrium states are determined analytically. To obtain a consistent formulation of the problem, use is made of the principle of virtual displacements and the variational calculus for variable matching points. The obtained formula...

Regional scale landslide risk assessment with a dynamic physical model - development, application and uncertainty analysis

NASA Astrophysics Data System (ADS)

Luna, Byron Quan; Vidar Vangelsten, Bjørn; Liu, Zhongqiang; Eidsvig, Unni; Nadim, Farrokh

2013-04-01

Landslide risk must be assessed at the appropriate scale in order to allow effective risk management. At the moment, few deterministic models exist that can do all the computations required for a complete landslide risk assessment at a regional scale. This arises from the difficulty to precisely define the location and volume of the released mass and from the inability of the models to compute the displacement with a large amount of individual initiation areas (computationally exhaustive). This paper presents a medium-scale, dynamic physical model for rapid mass movements in mountainous and volcanic areas. The deterministic nature of the approach makes it possible to apply it to other sites since it considers the frictional equilibrium conditions for the initiation process, the rheological resistance of the displaced flow for the run-out process and fragility curve that links intensity to economic loss for each building. The model takes into account the triggering effect of an earthquake, intense rainfall and a combination of both (spatial and temporal). The run-out module of the model considers the flow as a 2-D continuum medium solving the equations of mass balance and momentum conservation. The model is embedded in an open source environment geographical information system (GIS), it is computationally efficient and it is transparent (understandable and comprehensible) for the end-user. The model was applied to a virtual region, assessing landslide hazard, vulnerability and risk. A Monte Carlo simulation scheme was applied to quantify, propagate and communicate the effects of uncertainty in input parameters on the final results. In this technique, the input distributions are recreated through sampling and the failure criteria are calculated for each stochastic realisation of the site properties. The model is able to identify the released volumes of the critical slopes and the areas threatened by the run-out intensity. The obtained final outcome is the estimation of individual building damage and total economic risk. The research leading to these results has received funding from the European Community's Seventh Framework Programme [FP7/2007-2013] under grant agreement No 265138 New Multi-HAzard and MulTi-RIsK Assessment MethodS for Europe (MATRIX).

Large scale Brownian dynamics of confined suspensions of rigid particles

NASA Astrophysics Data System (ADS)

Sprinkle, Brennan; Balboa Usabiaga, Florencio; Patankar, Neelesh A.; Donev, Aleksandar

2017-12-01

We introduce methods for large-scale Brownian Dynamics (BD) simulation of many rigid particles of arbitrary shape suspended in a fluctuating fluid. Our method adds Brownian motion to the rigid multiblob method [F. Balboa Usabiaga et al., Commun. Appl. Math. Comput. Sci. 11(2), 217-296 (2016)] at a cost comparable to the cost of deterministic simulations. We demonstrate that we can efficiently generate deterministic and random displacements for many particles using preconditioned Krylov iterative methods, if kernel methods to efficiently compute the action of the Rotne-Prager-Yamakawa (RPY) mobility matrix and its "square" root are available for the given boundary conditions. These kernel operations can be computed with near linear scaling for periodic domains using the positively split Ewald method. Here we study particles partially confined by gravity above a no-slip bottom wall using a graphical processing unit implementation of the mobility matrix-vector product, combined with a preconditioned Lanczos iteration for generating Brownian displacements. We address a major challenge in large-scale BD simulations, capturing the stochastic drift term that arises because of the configuration-dependent mobility. Unlike the widely used Fixman midpoint scheme, our methods utilize random finite differences and do not require the solution of resistance problems or the computation of the action of the inverse square root of the RPY mobility matrix. We construct two temporal schemes which are viable for large-scale simulations, an Euler-Maruyama traction scheme and a trapezoidal slip scheme, which minimize the number of mobility problems to be solved per time step while capturing the required stochastic drift terms. We validate and compare these schemes numerically by modeling suspensions of boomerang-shaped particles sedimented near a bottom wall. Using the trapezoidal scheme, we investigate the steady-state active motion in dense suspensions of confined microrollers, whose height above the wall is set by a combination of thermal noise and active flows. We find the existence of two populations of active particles, slower ones closer to the bottom and faster ones above them, and demonstrate that our method provides quantitative accuracy even with relatively coarse resolutions of the particle geometry.

Pelvic crescent fractures: variations in injury mechanism and radiographic pattern.

PubMed

Gehlert, Rick J; Xing, Zhiqing; DeCoster, Thomas A

2014-01-01

Pelvic crescent fracture, also known as sacroiliac fracture-dislocation, is traditionally considered as a lateral compression injury and a vertically stable injury. Thirty consecutive cases were analyzed and it was found that 63% of cases were caused by lateral compression (LC), 27% by anteroposterior compression (APC), and 10% by vertical shear (VS). APC and VS injuries cause significant displacement of the anterior iliac fragment, but 21% of LC injury cases showed minimal displacement and were treated successfully with nonoperative treatment. Different injury mechanisms also produce different types of pelvic instability. More important, different injury mechanisms produce distinct radiographic fracture patterns regarding the obliquity of the fracture line and fracture surface. These differences in the fracture pattern will influence the decision of internal fixation options. Therefore, treatment of pelvic crescent fractures should be based on individual analysis of injury mechanism and radiographic fracture pattern.

Centrifugally activated bearing for high-speed rotating machinery

DOEpatents

Post, R.F.

1994-02-15

A centrifugally activated bearing is disclosed. The bearing includes an annular member that extends laterally and radially from a central axis. A rotating member that rotates about the central axis relative to the annular member is also included. The rotating member has an interior chamber that surrounds the central axis and in which the annular member is suspended. Furthermore, the interior chamber has a concave shape for retaining a lubricant therein while the rotating member is at rest and for retaining a lubricant therein while the rotating member is rotating. The concave shape is such that while the rotating member is rotating a centrifugal force causes a lubricant to be forced away from the central axis to form a cylindrical surface having an axis collinear with the central axis. This centrifugally displaced lubricant provides restoring forces to counteract lateral displacement during operation. 4 figures.

Geologic structure in California: Three studies with ERTS-1 imagery

NASA Technical Reports Server (NTRS)

Lowman, P. D., Jr.

1974-01-01

Results are presented of three early applications of imagery from the NASA Earth Resources Technology Satellite to geologic studies in California. In the Coast Ranges near Monterey Bay, numerous linear drainage features possibly indicating unmapped fracture zones were mapped within one week after launch of the satellite. A similar study of the Sierra Nevada near Lake Tahoe revealed many drainage features probably formed along unmapped joint or faults in granitic rocks. The third study, in the Peninsular Ranges, confirmed existence of several major faults not shown on published maps. One of these, in the Sawtooth Range, crosses in Elsinore fault without lateral offset; associated Mid-Cretaceous structures have also been traced continuously across the fault without offset. It therefore appears that displacement along the Elsinore fault has been primarily of a dip-slip nature, at least in this area, despite evidence for lateral displacement elsewhere.

Static testing of a bridge using an interferometric radar: the case study of "Ponte degli Alpini," Belluno, Italy.

PubMed

Dei, Devis; Mecatti, Daniele; Pieraccini, Massimiliano

2013-01-01

Ground-based radar interferometry is an increasingly popular technique for monitoring civil infrastructures. In this paper, the static testing of a bridge is reported. It was an 8-span bridge, 297 m long, named "Ponte degli Alpini," crossing the valley of the Ardo River. The radar has been used for testing a lateral span and a central span. The obtained results present elements of novelty not previously reported in the literature. In fact, some displacement measurements of the lateral span have been affected by a horizontal shift that has to be taken into account for a correct interpretation of the measured data. Furthermore, the measurements of the central span have been carried out with the radar positioned transversally with respect to the bridge deck; this unusual arrangement has allowed for obtaining displacement maps less geometrically distorted with respect to other cases reported in the literature.

Probabilistic Structural Evaluation of Uncertainties in Radiator Sandwich Panel Design

NASA Technical Reports Server (NTRS)

Kuguoglu, Latife; Ludwiczak, Damian

2006-01-01

The Jupiter Icy Moons Orbiter (JIMO) Space System is part of the NASA's Prometheus Program. As part of the JIMO engineering team at NASA Glenn Research Center, the structural design of the JIMO Heat Rejection Subsystem (HRS) is evaluated. An initial goal of this study was to perform sensitivity analyses to determine the relative importance of the input variables on the structural responses of the radiator panel. The desire was to let the sensitivity analysis information identify the important parameters. The probabilistic analysis methods illustrated here support this objective. The probabilistic structural performance evaluation of a HRS radiator sandwich panel was performed. The radiator panel structural performance was assessed in the presence of uncertainties in the loading, fabrication process variables, and material properties. The stress and displacement contours of the deterministic structural analysis at mean probability was performed and results presented. It is followed by a probabilistic evaluation to determine the effect of the primitive variables on the radiator panel structural performance. Based on uncertainties in material properties, structural geometry and loading, the results of the displacement and stress analysis are used as an input file for the probabilistic analysis of the panel. The sensitivity of the structural responses, such as maximum displacement and maximum tensile and compressive stresses of the facesheet in x and y directions and maximum VonMises stresses of the tube, to the loading and design variables is determined under the boundary condition where all edges of the radiator panel are pinned. Based on this study, design critical material and geometric parameters of the considered sandwich panel are identified.

Developments in label-free microfluidic methods for single-cell analysis and sorting.

PubMed

Carey, Thomas R; Cotner, Kristen L; Li, Brian; Sohn, Lydia L

2018-04-24

Advancements in microfluidic technologies have led to the development of many new tools for both the characterization and sorting of single cells without the need for exogenous labels. Label-free microfluidics reduce the preparation time, reagents needed, and cost of conventional methods based on fluorescent or magnetic labels. Furthermore, these devices enable analysis of cell properties such as mechanical phenotype and dielectric parameters that cannot be characterized with traditional labels. Some of the most promising technologies for current and future development toward label-free, single-cell analysis and sorting include electronic sensors such as Coulter counters and electrical impedance cytometry; deformation analysis using optical traps and deformation cytometry; hydrodynamic sorting such as deterministic lateral displacement, inertial focusing, and microvortex trapping; and acoustic sorting using traveling or standing surface acoustic waves. These label-free microfluidic methods have been used to screen, sort, and analyze cells for a wide range of biomedical and clinical applications, including cell cycle monitoring, rapid complete blood counts, cancer diagnosis, metastatic progression monitoring, HIV and parasite detection, circulating tumor cell isolation, and point-of-care diagnostics. Because of the versatility of label-free methods for characterization and sorting, the low-cost nature of microfluidics, and the rapid prototyping capabilities of modern microfabrication, we expect this class of technology to continue to be an area of high research interest going forward. New developments in this field will contribute to the ongoing paradigm shift in cell analysis and sorting technologies toward label-free microfluidic devices, enabling new capabilities in biomedical research tools as well as clinical diagnostics. This article is categorized under: Diagnostic Tools > Biosensing Diagnostic Tools > Diagnostic Nanodevices. © 2018 Wiley Periodicals, Inc.

Surface faulting along the Superstition Hills fault zone and nearby faults associated with the earthquakes of 24 November 1987

USGS Publications Warehouse

Sharp, R.V.

1989-01-01

The M6.2 Elmore Desert Ranch earthquake of 24 November 1987 was associated spatially and probably temporally with left-lateral surface rupture on many northeast-trending faults in and near the Superstition Hills in western Imperial Valley. Three curving discontinuous principal zones of rupture among these breaks extended northeastward from near the Superstition Hills fault zone as far as 9km; the maximum observed surface slip, 12.5cm, was on the northern of the three, the Elmore Ranch fault, at a point near the epicenter. Twelve hours after the Elmore Ranch earthquake, the M6.6 Superstition Hills earthquake occurred near the northwest end of the right-lateral Superstition Hills fault zone. We measured displacements over 339 days at as many as 296 sites along the Superstition Hills fault zone, and repeated measurements at 49 sites provided sufficient data to fit with a simple power law. The overall distributions of right-lateral displacement at 1 day and the estimated final slip are nearly symmetrical about the midpoint of the surface rupture. The average estimated final right-lateral slip for the Superstition Hills fault zone is ~54cm. The average left-lateral slip for the conjugate faults trending northeastward is ~23cm. The southernmost ruptured member of the Superstition Hills fault zone, newly named the Wienert fault, extends the known length of the zone by about 4km. -from Authors

Rapid sampling of stochastic displacements in Brownian dynamics simulations

NASA Astrophysics Data System (ADS)

Fiore, Andrew M.; Balboa Usabiaga, Florencio; Donev, Aleksandar; Swan, James W.

2017-03-01

We present a new method for sampling stochastic displacements in Brownian Dynamics (BD) simulations of colloidal scale particles. The method relies on a new formulation for Ewald summation of the Rotne-Prager-Yamakawa (RPY) tensor, which guarantees that the real-space and wave-space contributions to the tensor are independently symmetric and positive-definite for all possible particle configurations. Brownian displacements are drawn from a superposition of two independent samples: a wave-space (far-field or long-ranged) contribution, computed using techniques from fluctuating hydrodynamics and non-uniform fast Fourier transforms; and a real-space (near-field or short-ranged) correction, computed using a Krylov subspace method. The combined computational complexity of drawing these two independent samples scales linearly with the number of particles. The proposed method circumvents the super-linear scaling exhibited by all known iterative sampling methods applied directly to the RPY tensor that results from the power law growth of the condition number of tensor with the number of particles. For geometrically dense microstructures (fractal dimension equal three), the performance is independent of volume fraction, while for tenuous microstructures (fractal dimension less than three), such as gels and polymer solutions, the performance improves with decreasing volume fraction. This is in stark contrast with other related linear-scaling methods such as the force coupling method and the fluctuating immersed boundary method, for which performance degrades with decreasing volume fraction. Calculations for hard sphere dispersions and colloidal gels are illustrated and used to explore the role of microstructure on performance of the algorithm. In practice, the logarithmic part of the predicted scaling is not observed and the algorithm scales linearly for up to 4 ×106 particles, obtaining speed ups of over an order of magnitude over existing iterative methods, and making the cost of computing Brownian displacements comparable to the cost of computing deterministic displacements in BD simulations. A high-performance implementation employing non-uniform fast Fourier transforms implemented on graphics processing units and integrated with the software package HOOMD-blue is used for benchmarking.

Rapid sampling of stochastic displacements in Brownian dynamics simulations with stresslet constraints.

PubMed

Fiore, Andrew M; Swan, James W

2018-01-28

Brownian Dynamics simulations are an important tool for modeling the dynamics of soft matter. However, accurate and rapid computations of the hydrodynamic interactions between suspended, microscopic components in a soft material are a significant computational challenge. Here, we present a new method for Brownian dynamics simulations of suspended colloidal scale particles such as colloids, polymers, surfactants, and proteins subject to a particular and important class of hydrodynamic constraints. The total computational cost of the algorithm is practically linear with the number of particles modeled and can be further optimized when the characteristic mass fractal dimension of the suspended particles is known. Specifically, we consider the so-called "stresslet" constraint for which suspended particles resist local deformation. This acts to produce a symmetric force dipole in the fluid and imparts rigidity to the particles. The presented method is an extension of the recently reported positively split formulation for Ewald summation of the Rotne-Prager-Yamakawa mobility tensor to higher order terms in the hydrodynamic scattering series accounting for force dipoles [A. M. Fiore et al., J. Chem. Phys. 146(12), 124116 (2017)]. The hydrodynamic mobility tensor, which is proportional to the covariance of particle Brownian displacements, is constructed as an Ewald sum in a novel way which guarantees that the real-space and wave-space contributions to the sum are independently symmetric and positive-definite for all possible particle configurations. This property of the Ewald sum is leveraged to rapidly sample the Brownian displacements from a superposition of statistically independent processes with the wave-space and real-space contributions as respective covariances. The cost of computing the Brownian displacements in this way is comparable to the cost of computing the deterministic displacements. The addition of a stresslet constraint to the over-damped particle equations of motion leads to a stochastic differential algebraic equation (SDAE) of index 1, which is integrated forward in time using a mid-point integration scheme that implicitly produces stochastic displacements consistent with the fluctuation-dissipation theorem for the constrained system. Calculations for hard sphere dispersions are illustrated and used to explore the performance of the algorithm. An open source, high-performance implementation on graphics processing units capable of dynamic simulations of millions of particles and integrated with the software package HOOMD-blue is used for benchmarking and made freely available in the supplementary material.

Evaluation of the Transverse Oscillation Technique for Cardiac Phased Array Imaging: A Theoretical Study.

PubMed

Heyde, Brecht; Bottenus, Nick; D'hooge, Jan; Trahey, Gregg E

2017-02-01

The transverse oscillation (TO) technique can improve the estimation of tissue motion perpendicular to the ultrasound beam direction. TOs can be introduced using plane wave (PW) insonification and bilobed Gaussian apodization (BA) on receive (abbreviated as PWTO). Furthermore, the TO frequency of PWTO can be doubled after a heterodyning demodulation process is performed (abbreviated as PWTO*). This paper is concerned with identifying the limitations of the PWTO technique in the specific context of myocardial deformation imaging with phased arrays and investigating the conditions in which it remains advantageous over traditional focused (FOC) beamforming. For this purpose, several tissue phantoms were simulated using Field II, undergoing a wide range of displacement magnitudes and modes (lateral, axial, and rotational motions). The Cramer-Rao lower bound was used to optimize TO beamforming parameters and theoretically predict the fundamental tracking performance limits associated with the FOC, PWTO, and PWTO* beamforming scenarios. This framework was extended to also predict the performance for BA functions that are windowed by the physical aperture of the transducer, leading to higher lateral oscillations. It was found that windowed BA functions resulted in lower jitter errors compared with traditional BA functions. PWTO* outperformed FOC at all investigated signal-to-noise ratio (SNR) levels but only up to a certain displacement, with the advantage rapidly decreasing when the SNR increased. These results suggest that PWTO* improves lateral tracking performance, but only when interframe displacements remain relatively low. This paper concludes by translating these findings into a clinical environment by suggesting optimal scanner settings.

Surgical treatment of displaced intra-articular calcaneal fracture using a single small lateral approach

PubMed Central

El-Adl, Gamal; Hassanin, Ehab Y.; Abdellatif, M-Serry

2010-01-01

The objective of this study was to evaluate the outcome of semi-open reduction and minimal internal fixation through a single small lateral approach as a minimally invasive technique for treatment of displaced intra-articular calcaneal fractures. This prospective study was conducted on eighteen patients (16 men and 2 women). The average age was 37.7 (22–55). The most common cause of injury was a fall from height in fourteen patients. Patients were operated on within a mean time of 4.8 days of admission (1–11 days) and were followed up for an average period of 24.1 months (6–39 months). Patients were evaluated clinically using the Creighton-Nebraska Heath Foundation Assessment score of Crosby and Fitzgibbons (J Bone Joint Surg (Am) 72-A:852–859, 1990). The scoring system proposed by Knirk and Jupiter was used for radiological assessment of the posterior subtalar joint (Knirk and Jupiter in J Bone Joint Surg (Am) 68-A: 647–659, 1986). The skin incision healed in all cases without necrosis, infection, or sural nerve injury. All fractures healed after an average of 8 weeks (7–10 weeks), and patients returned to the routine daily activities after an average time of 4.3 months (3–7 months). In conclusion, semi-open reduction and minimal internal fixation through a small lateral approach is an effective treatment for carefully selected cases of displaced intra-articular calcaneal fractures. PMID:21811904

Two-Dimensional Boundary Element Method Application for Surface Deformation Modeling around Lembang and Cimandiri Fault, West Java

NASA Astrophysics Data System (ADS)

Mahya, M. J.; Sanny, T. A.

2017-04-01

Lembang and Cimandiri fault are active faults in West Java that thread people near the faults with earthquake and surface deformation risk. To determine the deformation, GPS measurements around Lembang and Cimandiri fault was conducted then the data was processed to get the horizontal velocity at each GPS stations by Graduate Research of Earthquake and Active Tectonics (GREAT) Department of Geodesy and Geomatics Engineering Study Program, ITB. The purpose of this study is to model the displacement distribution as deformation parameter in the area along Lembang and Cimandiri fault using 2-dimensional boundary element method (BEM) using the horizontal velocity that has been corrected by the effect of Sunda plate horizontal movement as the input. The assumptions that used at the modeling stage are the deformation occurs in homogeneous and isotropic medium, and the stresses that acted on faults are in elastostatic condition. The results of modeling show that Lembang fault had left-lateral slip component and divided into two segments. A lineament oriented in southwest-northeast direction is observed near Tangkuban Perahu Mountain separating the eastern and the western segments of Lembang fault. The displacement pattern of Cimandiri fault shows that Cimandiri fault is divided into the eastern segment with right-lateral slip component and the western segment with left-lateral slip component separated by a northwest-southeast oriented lineament at the western part of Gede Pangrango Mountain. The displacement value between Lembang and Cimandiri fault is nearly zero indicating that Lembang and Cimandiri fault are not connected each other and this area is relatively safe for infrastructure development.

Estuarine Channel Evolution in Response to Closure of Secondary Basins: An Observational and Morphodynamic Modeling Study of the Western Scheldt Estuary

NASA Astrophysics Data System (ADS)

Nnafie, A.; Van Oyen, T.; De Maerschalck, B.; van der Vegt, M.; Wegen, M. van der

2018-01-01

The fringes of estuaries are often characterized by the presence of side embayments (secondary basins), with dimensions in the order of hundreds of meters to tens of kilometers. The presence of secondary basins significantly alters the hydrodynamic and sediment characteristics in the main estuary, implying that loss of secondary basin area due to human interventions might affect the estuarine morphodynamics. Analysis of historical bathymetric data of the Western Scheldt Estuary (Netherlands) suggests that closure of its secondary basins has triggered the observed lateral displacement of the nearby channels. This analysis motivated investigation of the impact of secondary basins on decadal evolution of estuarine channels, using the numerical model Delft3D. Model results show that channels that form near a secondary basin are located farther away from the bank of the estuary with respect to their positions in the case without a basin. Overall, results in cases with two or three basins are similar to those in case with one single basin. The wider the basin, the farther away the nearby channel forms. Removing a secondary basin causes a lateral displacement of the nearby channel toward the bank, indicating that the observed lateral displacement of channels in the Western Scheldt is triggered by closure of its secondary basins. The physical explanation is that tidal currents in the main estuary are weaker and more rotary near secondary basins, favoring sediment deposition and shoal development at these locations. Model results are particularly relevant for estuaries with moderate to high friction and converging width.

Occupant Kinematics in Simulated Autonomous Driving Vehicle Collisions: Influence of Seating Position, Direction and Angle.

PubMed

Kitagawa, Yuichi; Hayashi, Shigeki; Yamada, Katsunori; Gotoh, Mitsuaki

2017-11-01

This two-part study analyzed occupant kinematics in simulated collisions of future automated driving vehicles in terms of seating configuration. In part one, a frontal collision was simulated with four occupants with the front seats reversed. The left front seat occupant was unbelted while the others were belted. In part two of the study, occupant restraint was examined in various seating configurations using a single seat model with a three-point seatbelt. The seat direction with respect to impact was considered as forward, rearward, and lateral facing in 45 degree increments. The effect of seat recline was also studied in the forward-facing and rear-facing cases by assuming three positions: driving position, resting position and relaxed position. Occupants were represented by human body finite element models. The results of part one showed that the front seat (rear-facing) occupants were restrained by the seatback, resulting in T1 forward displacement less than 100 mm; the rear seat occupants were restrained by the seatbelt resulting larger T1 forward displacement more than 500 mm. The results of the part two showed the directional dependence of occupant restraint. Greater T1 displacements were observed when the occupant faced lateral or front oblique. However, the seatbelt provided some restraint in all directions considered. The seatback generated contact force to the occupant when it was in the impact direction, including the lateral directions. The relaxed position allowed increased excursion compared to the driving position when the occupant faced rearward, but the magnitude of this increase was lower with lower impact speed.

Macrovascular Decompression of the Brainstem and Cranial Nerves: Evolution of an Anteromedial Vertebrobasilar Artery Transposition Technique.

PubMed

Choudhri, Omar; Connolly, Ian D; Lawton, Michael T

2017-08-01

Tortuous and dolichoectatic vertebrobasilar arteries can impinge on the brainstem and cranial nerves to cause compression syndromes. Transposition techniques are often required to decompress the brainstem with dolichoectatic pathology. We describe our evolution of an anteromedial transposition technique and its efficacy in decompressing the brainstem and relieving symptoms. To present the anteromedial vertebrobasilar artery transposition technique for macrovascular decompression of the brainstem and cranial nerves. All patients who underwent vertebrobasilar artery transposition were identified from the prospectively maintained database of the Vascular Neurosurgery service, and their medical records were reviewed retrospectively. The extent of arterial displacement was measured pre- and postoperatively on imaging. Vertebrobasilar arterial transposition and macrovascular decompression was performed in 12 patients. Evolution in technique was characterized by gradual preference for the far-lateral approach, use of a sling technique with muslin wrap, and an anteromedial direction of pull on the vertebrobasilar artery with clip-assisted tethering to the clival dura. With this technique, mean lateral displacement decreased from 6.6 mm in the first half of the series to 3.8 mm in the last half of the series, and mean anterior displacement increased from 0.8 to 2.5 mm, with corresponding increases in satisfaction and relief of symptoms. Compressive dolichoectatic pathology directed laterally into cranial nerves and posteriorly into the brainstem can be corrected with anteromedial transposition towards the clivus. Our technique accomplishes this anteromedial transposition from an inferolateral surgical approach through the vagoaccessory triangle, with sling fixation to clival dura using aneurysm clips. Copyright © 2017 by the Congress of Neurological Surgeons

A neuromechanical strategy for mediolateral foot placement in walking humans.

PubMed

Rankin, Bradford L; Buffo, Stephanie K; Dean, Jesse C

2014-07-15

Stability is an important concern during human walking and can limit mobility in clinical populations. Mediolateral stability can be efficiently controlled through appropriate foot placement, although the underlying neuromechanical strategy is unclear. We hypothesized that humans control mediolateral foot placement through swing leg muscle activity, basing this control on the mechanical state of the contralateral stance leg. Participants walked under Unperturbed and Perturbed conditions, in which foot placement was intermittently perturbed by moving the right leg medially or laterally during the swing phase (by ∼50-100 mm). We quantified mediolateral foot placement, electromyographic activity of frontal-plane hip muscles, and stance leg mechanical state. During Unperturbed walking, greater swing-phase gluteus medius (GM) activity was associated with more lateral foot placement. Increases in GM activity were most strongly predicted by increased mediolateral displacement between the center of mass (CoM) and the contralateral stance foot. The Perturbed walking results indicated a causal relationship between stance leg mechanics and swing-phase GM activity. Perturbations that reduced the mediolateral CoM displacement from the stance foot caused reductions in swing-phase GM activity and more medial foot placement. Conversely, increases in mediolateral CoM displacement caused increased swing-phase GM activity and more lateral foot placement. Under both Unperturbed and Perturbed conditions, humans controlled their mediolateral foot placement by modulating swing-phase muscle activity in response to the mechanical state of the contralateral leg. This strategy may be disrupted in clinical populations with a reduced ability to modulate muscle activity or sense their body's mechanical state.

Lateral clavicle fracture with coracoclavicular ligament injury: a biomechanical study of 4 different repair techniques.

PubMed

Alaee, Farhang; Apostolakos, John; Singh, Hardeep; Holwein, Christian; Diermeier, Theresa; Cote, Mark P; Beitzel, Knut; Imhoff, Andreas B; Mazzocca, Augustus D; Voss, Andreas

2017-07-01

To investigate the biomechanical performance of four different methods used for coracoclavicular (CC) ligament reconstruction in a lateral clavicle fracture repair. Native displacement, translation, and rotation at the acromioclavicular joint of 24 fresh-frozen cadaveric shoulders were tested. A reproducible fracture in the lateral third of the clavicle was created by dissecting both CC ligaments. Each specimen was then repaired with plate fixation of the fracture and the following CC repair technique: (1) Cortical button. (2) Suture anchor and plate button. (3) Suture anchor no plate button, and (4) Suture around coracoid. All reconstructed specimens were then re-tested for displacement, translation, and load to failure, and compared to their native results. Groups 1 and 3 were investigated for rotational load. There was no difference in load to failure between the repaired groups (p: ns). Group 1 showed less superior and anterior translations (p < 0.05). Group 2 showed significantly less superior translation (p = 0.003), but no significance with anterior and posterior translations to the native joint. Group 3 showed less superior and posterior translations (p = 0.005 and p = 0.039). Anterior and posterior translations were increased in group 4 (p < 0.05). The biomechanical analyses did not show any significance in load to failure or displacement after cyclic loading among the study groups. All repairs were effective in preventing superior translation. Groups 1 and 2 demonstrated increased horizontal stability compared to the native state. All 4 methods are clinically viable options for CC ligament repair.

Impact of bracket displacement or rotation during bonding and time of removal of excess adhesive on the bracket-enamel bond strength.

PubMed

Oliveira, Adauê S; Barwaldt, Caroline K; Bublitz, Luana S; Moraes, Rafael R

2014-06-01

This study investigated the the influence of bracket displacement or rotation during fixation and the time of excess adhesive removal from around the bracket on bond strength to enamel. Stainless steel brackets were bonded to the buccal faces of bovine incisors using Transbond XT® adhesive resin. The teeth were divided into five groups (n = 20). In the control group, no displacement or rotation of the bracket was carried out. In the Displac-A group, excess adhesive was removed after the bracket was displaced 2 mm incisally. In the B-Displac group, excess adhesive was removed before the bracket was displaced incisally. In the Rotat-A group, excess adhesive was removed after the bracket was rotated 45°. In the B-Rotat group, excess adhesive was removed before the bracket was rotated. Photoactivation was carried out on the lateral sides of the bracket. A shear test was conducted 10 min after fixation using a knife-edged chisel. Bond strength data were analysed using ANOVA and Fisher's test (5%). The adhesive remnant index (ARI) was scored under magnification. ARI data were analysed using the Kruskal-Wallis test (5%). No significant differences were detected among the Control, Displac-A, Rotat-A and B-Rotat groups. The B-Displac group showed lower bond strength than all of the other groups, except Displac-A. No significant differences were observed in ARI scores across groups. Displacements of the brackets during fixation did not seem to affect the enamel bond strength when excess adhesive is removed after the final positioning of the bracket. © 2014 British Orthodontic Society.

Flexural support member having a high ratio of lateral-to-axial stiffness

DOEpatents

Haas, W.M.B.

1983-06-23

A convoluted flexible support structure is provided which is capable of supplying a lateral to axial spring rate in excess of 1000 to 1. A support member in the form of a steel disc having a specified number of rather large radius, concentric convolutions and a thickness in the range of from about 0.01 to 0.02 inch has an axial stiffness of about 50 pounds/inch while the lateral stiffness is about 100,000 pounds/inch. The support member may be used to support a vibration device where the lateral motion of the vibrator must be highly restricted while providing relatively free axial displacement of about +-0.25 inch.

Flexural support member having a high ratio of lateral-to-axial stiffness

DOEpatents

Haas, Wendall M. B.

1985-01-01

A convoluted flexible support structure is provided which is capable of supplying a lateral to axial spring rate in excess of 1,000 to 1. A support member in the form of a steel disc having a specified number of rather large radius, concentric convolutions and a thickness in the range of from about 0.01 to 0.02 inch has an axial stiffness of about 50 pounds/inch while the lateral stiffness is about 100,000 pounds/inch. The support member may be used to support a vibration device where the lateral motion of the vibrator must be highly restricted while providing relatively free axial displacement of about .+-.0.25 inch.

Formation, levitation, and stability of prominences in the magnetized solar atmosphere

NASA Technical Reports Server (NTRS)

Drake, J. F.; Mok, Y.; Van Hoven, G.

1993-01-01

The dynamic formation of prominences in the initial magnetothermal equilibrium and their stability to sideward displacements are investigated focusing on the structure of the 2D solar atmosphere in the presence of coronal arcades or loops. A model based on 2D magnetohydrodynamic equations takes into account gravity, compressible flows, heating, radiation, anisotropic thermal conduction, and coupling to a deep chromosphere. It is found that prominences in simple arcades characterized by magnetic field with significant curvature at the apex are unstable to a lateral displacement.

[Operative treatment of displaced intra-articular calcaneal fractures].

PubMed

Zwipp, H; Rammelt, S; Amlang, M; Pompach, M; Dürr, C

2013-12-01

Anatomic reduction of displaced intra-articular calcaneal fractures with restoration of height, length, and axial alignment and reconstruction of the subtalar and calcaneocuboid joints. Displaced intra-articular calcaneal fractures with incongruity of the posterior facet of the subtalar joint, loss of height, and axial malalignment. High perioperative risk, soft tissue infection, advanced peripheral arterial disease (stage III), neurogenic osteoarthropathy, poor patient compliance (e. g., substance abuse). Extended lateral approach with the patient placed on the uninjured side. Reduction of the anatomic shape and joint surfaces according to the preoperative CT-based planning. Reduction of the medial wall and step-wise reconstruction of the posterior facet from medial to lateral. Reduction of the tuberosity and anterior process fragments to the posterior joint block and temporary fixation with Kirschner wires. Internal fixation with an anatomic lateral plate in a locking or nonlocking mode. Alternatively less invasive internal fixation with a calcaneus nail over a sinus tarsi approach for less severe fracture types. The lower leg is immobilized in a brace until the wound is healed. Range of motion exercises of the ankle and subtalar joints are initiated on the second postoperative day. Patients are mobilized in their own shoe with partial weight bearing of 20 kg for 6-12 weeks depending on fracture severity and bone quality. Over a 4-year period, 163 patients with 184 displaced, intra-articular calcaneal fractures were treated with a lateral plate via an extended approach. In all, 102 patients with 116 fractures were followed for a mean of 8 years. A surgical revision was necessary in 4 cases (3.4%) of postoperative hematoma, 2 (1.7%) superficial and 5 (4.3%) deep infections. Of the latter, 2 patients needed a free flap for definite wound coverage, no calcanectomy or amputation was needed. Secondary subtalar fusion for symptomatic posttraumatic arthritis was performed in 9 cases (7.8%). At follow-up, the AOFAS Ankle/Hindfoot Score averaged 70.2, the Zwipp Score averaged 76.0, the German versions of the Foot Function Index and SF-36 physical component averaged 32.8 and 42.2, respectively. Scores were significantly lower with increasing fracture severity according to the Sanders and Zwipp classifications, bilateral fractures, open fractures, and with work-related injuries. With less invasive fixation using a calcaneal nail, superficial wound edge necrosis was seen in 2 of 75 cases (2.7%).

Development and validation of a lateral MREs isolator

NASA Astrophysics Data System (ADS)

Xing, Zhi-Wei; Yu, Miao; Fu, Jie; Zhao, Lu-Jie

2015-02-01

A novel lateral vibration isolator utilizing magnetorheological elastomers (MREs) with the field-dependent damping and stiffness was proposed in order to improve the adaptive performance. First, soft silicone rubber MREs with a highly adjustable shear storage modulus was fabricated. Then, the lateral MREs isolator was developed with a unique laminated structure of MRE layers and steel plates, which enables to withstand large vertical loads and adapts to the situation of large lateral displacement. Also, the electromagnetic analysis and design employed electromagnetic finite element method (FEM) to optimize magnetic circuit inside the proposed device. To evaluate the effectiveness of the lateral MREs isolator, a series of experimental tests were carried out under various applied magnetic fields. Experimental results show that the proposed MREs isolator can triumphantly change the lateral stiffness and equivalent damping up to 140% and 125%, respectively. This work demonstrates the performance of the designed lateral MREs isolator and its capacity in vibration mitigation for the complex situation.

The use of the SRIM code for calculation of radiation damage induced by neutrons

NASA Astrophysics Data System (ADS)

Mohammadi, A.; Hamidi, S.; Asadabad, Mohsen Asadi

2017-12-01

Materials subjected to neutron irradiation will being evolve to structural changes by the displacement cascades initiated by nuclear reaction. This study discusses a methodology to compute primary knock-on atoms or PKAs information that lead to radiation damage. A program AMTRACK has been developed for assessing of the PKAs information. This software determines the specifications of recoil atoms (using PTRAC card of MCNPX code) and also the kinematics of interactions. The deterministic method was used for verification of the results of (MCNPX+AMTRACK). The SRIM (formely TRIM) code is capable to compute neutron radiation damage. The PKAs information was extracted by AMTRACK program, which can be used as an input of SRIM codes for systematic analysis of primary radiation damage. Then the Bushehr Nuclear Power Plant (BNPP) radiation damage on reactor pressure vessel is calculated.

SAR-revealed slip partitioning on a bending fault plane for the 2014 Northern Nagano earthquake at the northern Itoigawa-Shizuoka tectonic line

NASA Astrophysics Data System (ADS)

Kobayashi, Tomokazu; Morishita, Yu; Yarai, Hiroshi

2018-05-01

By applying conventional cross-track synthetic aperture radar interferometry (InSAR) and multiple aperture InSAR techniques to ALOS-2 data acquired before and after the 2014 Northern Nagano, central Japan, earthquake, a three-dimensional ground displacement field has been successfully mapped. Crustal deformation is concentrated in and around the northern part of the Kamishiro Fault, which is the northernmost section of the Itoigawa-Shizuoka tectonic line. The full picture of the displacement field shows contraction in the northwest-southeast direction, but northeastward movement along the fault strike direction is prevalent in the northeast portion of the fault, which suggests that a strike-slip component is a significant part of the activity of this fault, in addition to a reverse faulting. Clear displacement discontinuities are recognized in the southern part of the source region, which falls just on the previously known Kamishiro Fault trace. We inverted the SAR and GNSS data to construct a slip distribution model; the preferred model of distributed slip on a two-plane fault surface shows a combination of reverse and left-lateral fault motions on a bending east-dipping fault surface with a dip of 30° in the shallow part and 50° in the deeper part. The hypocenter falls just on the estimated deeper fault plane where a left-lateral slip is inferred, whereas in the shallow part, a reverse slip is predominant, which causes surface ruptures on the ground. The slip partitioning may be accounted for by shear stress resulting from a reverse fault slip with left-lateral component at depth, for which a left-lateral slip is suppressed in the shallow part where the reverse slip is inferred. The slip distribution model with a bending fault surface, instead of a single fault plane, produces moment tensor solution with a non-double couple component, which is consistent with the seismically estimated mechanism.

Biomechanical comparison of four C1 to C2 rigid fixative techniques: anterior transarticular, posterior transarticular, C1 to C2 pedicle, and C1 to C2 intralaminar screws.

PubMed

Lapsiwala, Samir B; Anderson, Paul A; Oza, Ashish; Resnick, Daniel K

2006-03-01

We performed a biomechanical comparison of several C1 to C2 fixation techniques including crossed laminar (intralaminar) screw fixation, anterior C1 to C2 transarticular screw fixation, C1 to 2 pedicle screw fixation, and posterior C1 to C2 transarticular screw fixation. Eight cadaveric cervical spines were tested intact and after dens fracture. Four different C1 to C2 screw fixation techniques were tested. Posterior transarticular and pedicle screw constructs were tested twice, once with supplemental sublaminar cables and once without cables. The specimens were tested in three modes of loading: flexion-extension, lateral bending, and axial rotation. All tests were performed in load and torque control. Pure bending moments of 2 nm were applied in flexion-extension and lateral bending, whereas a 1 nm moment was applied in axial rotation. Linear displacements were recorded from extensometers rigidly affixed to the C1 and C2 vertebrae. Linear displacements were reduced to angular displacements using trigonometry. Adding cable fixation results in a stiffer construct for posterior transarticular screws. The addition of cables did not affect the stiffness of C1 to C2 pedicle screw constructs. There were no significant differences in stiffness between anterior and posterior transarticular screw techniques, unless cable fixation was added to the posterior construct. All three posterior screw constructs with supplemental cable fixation provide equal stiffness with regard to flexion-extension and axial rotation. C1 lateral mass-C2 intralaminar screw fixation restored resistance to lateral bending but not to the same degree as the other screw fixation techniques. All four screw fixation techniques limit motion at the C1 to 2 articulation. The addition of cable fixation improves resistance to flexion and extension for posterior transarticular screw fixation.

Is latero-medial patellar mobility related to the range of motion of the knee joint after total knee arthroplasty?

PubMed

Ota, Susumu; Nakashima, Takeshi; Morisaka, Ayako; Omachi, Takaaki; Ida, Kunio; Kawamura, Morio

2010-12-01

Diminished range of motion (ROM) of the knee joint after total knee arthroplasty (TKA) is thought to be related to reduced patellar mobility. This has not been confirmed clinically due to a lack of quantitative methods adequate for measuring patellar mobility. We investigated the relationship between patellar mobility by a reported quantitative method and knee joint ROM after TKA. Forty-nine patients [osteoarthritis--OA: 29 knees; rheumatoid arthritis--RA: 20 knees] were examined after TKA. Respective medial and lateral patellar mobility was measured 1 and 6 months postoperatively using a patellofemoral arthrometer (PFA). Knee joint ROM was also measured in each of those 2 sessions. Although the flexion and extension of the knee joints improved significantly from 1 to 6 months after TKA, the medial and lateral patellar displacements (LPDs) failed to improve during that same period. Moreover, only the changes in knee flexion and medial patellar displacement (MPD) between the two sessions were positively correlated (r = 0.31, p < 0.05). However, our findings demonstrated that medial and lateral patellar mobility had no sufficient longitudinal relationship with knee ROM after TKA. Copyright © 2010 Elsevier Ltd. All rights reserved.

Helicopter rotor wake geometry and its influence in forward flight. Volume 2: Wake geometry charts

NASA Technical Reports Server (NTRS)

Egolf, T. A.; Landgrebe, A. J.

1983-01-01

Isometric and projection view plots, inflow ratio nomographs, undistorted axial displacement nomographs, undistorted longitudinal and lateral coordinates, generalized axial distortion nomographs, blade/vortex passage charts, blade/vortex intersection angle nomographs, and fore and aft wake boundary charts are discussed. Example condition, in flow ratio, undistorted axial location, longitudinal and lateral coordinates, axial coordinates distortions, blade/tip vortex intersections, angle of intersection, and fore and aft wake boundaries are also discussed.

Spontaneous displacement of olecranon fracture through geode salvaged by elbow replacement.

PubMed

Jaiswal, Anuj; Thakur, Raman; Relwani, Jaikumar; Ogufere, Wallace

2010-04-01

We present a case of pathological fracture of olecranon through a giant geode. Fracture was initially undisplaced and was treated conservatively. It later progressed to a transolecranon dislocation as a result of a pseudarthrosis at the fracture site. The patient presented 4 years later when she developed symptoms of ulnar nerve palsy. She was treated by a total elbow arthroplasty with ulnar nerve transposition. The current report highlights this unusual case and reviews the relevant literature.

A prospective study on gait-related intrinsic risk factors for lower leg overuse injuries.

PubMed

Ghani Zadeh Hesar, N; Van Ginckel, A; Cools, A; Peersman, W; Roosen, P; De Clercq, D; Witvrouw, E

2009-12-01

To determine prospectively gait-related risk factors for lower leg overuse injury (LLOI). A prospective cohort study. Male and female recruits from a start-to-run (STR) programme during a 10-week training period. 131 healthy subjects (20 men and 111 women), without a history of any lower leg complaint, participated in the study. Before the start of the 10-week STR programme, plantar force measurements during running were performed. During STR, lower leg injuries were diagnosed and registered by a sports physician. Plantar force measurements during running were performed using a footscan pressure plate. During the STR, 27 subjects (five men and 22 women) developed a LLOI. Logistic regression analysis revealed that subjects who developed a LLOI had a significantly more laterally directed force distribution at first metatarsal contact and forefoot flat, a more laterally directed force displacement in the forefoot contact phase, foot flat phase and at heel-off. These subjects also had a delayed change of the centre of force (COF) at forefoot flat, a higher force and loading underneath the lateral border of the foot, and a significantly higher directed force displacement of the COF at forefoot flat. These findings suggest that a less pronated heel strike and a more laterally directed roll-off can be considered as risk factors for LLOI. Clinically, the results of this study can be considered important in identifying individuals at risk of LLOI.

Lateral support systems and underpinning, volume III : construction methods.

DOT National Transportation Integrated Search

1976-04-01

This report provides current information and design guidelines on cut-and-cover tunneling for practicing engineers. The main emphasis is on the geotechnical aspects of engineering. Included in this volume is a state-of-the-art summary of displacement...

Lateral Support Systems And Underpinning. Volume II. Design Fundamentals

DOT National Transportation Integrated Search

1976-04-01

This report provides current information and design guidelines on cut-and-cover tunneling for practicing engineers. The main emphasis is on the geotechnical aspects of engineering. Included in this volume is a state-of-the-art summary of displacement...

Saffman-Taylor Instability and the Inner Splitting Mechanism

NASA Astrophysics Data System (ADS)

Oliveira, Rafael; Meiburg, Eckart

2017-11-01

The classical miscible displacement experiments of Wooding (1969) exhibit an inner splitting phenomenon that remained unexplained for over 40 years. 3D Navier-Stokes simulations presented in, were the first ones to reproduce these experimental observations numerically, and to demonstrate that they are linked to concentrated streamwise vortices. The origin of these concentrated streamwise vortices remained a mystery, however. The current investigation, published at, finally resolves this long-standing issue. Towards this end, we compare 3D Navier-Stokes simulation results for neutrally buoyant, viscously unstable displacements and gravitationally unstable, constant viscosity ones. Only the former exhibit the generation of streamwise vorticity. The simulation results present conclusive evidence that it is caused by the lateral displacement of the more viscous fluid by the less viscous one, with the variable viscosity terms playing a dominant role.

Displacement fields from point cloud data: Application of particle imaging velocimetry to landslide geodesy

USGS Publications Warehouse

Aryal, Arjun; Brooks, Benjamin A.; Reid, Mark E.; Bawden, Gerald W.; Pawlak, Geno

2012-01-01

Acquiring spatially continuous ground-surface displacement fields from Terrestrial Laser Scanners (TLS) will allow better understanding of the physical processes governing landslide motion at detailed spatial and temporal scales. Problems arise, however, when estimating continuous displacement fields from TLS point-clouds because reflecting points from sequential scans of moving ground are not defined uniquely, thus repeat TLS surveys typically do not track individual reflectors. Here, we implemented the cross-correlation-based Particle Image Velocimetry (PIV) method to derive a surface deformation field using TLS point-cloud data. We estimated associated errors using the shape of the cross-correlation function and tested the method's performance with synthetic displacements applied to a TLS point cloud. We applied the method to the toe of the episodically active Cleveland Corral Landslide in northern California using TLS data acquired in June 2005–January 2007 and January–May 2010. Estimated displacements ranged from decimeters to several meters and they agreed well with independent measurements at better than 9% root mean squared (RMS) error. For each of the time periods, the method provided a smooth, nearly continuous displacement field that coincides with independently mapped boundaries of the slide and permits further kinematic and mechanical inference. For the 2010 data set, for instance, the PIV-derived displacement field identified a diffuse zone of displacement that preceded by over a month the development of a new lateral shear zone. Additionally, the upslope and downslope displacement gradients delineated by the dense PIV field elucidated the non-rigid behavior of the slide.

Pulsed focused ultrasound-induced displacements in confined in vitro blood clots.

PubMed

Wright, Cameron C; Hynynen, Kullervo; Goertz, David E

2012-03-01

Ultrasound has been shown to potentiate the effects of tissue plasminogen activator to improve clot lysis in a range of in vitro and in vivo studies as well as in clinical trials. One possible mechanism of action is acoustic radiation force-induced clot displacements. In this study, we investigate the temporal and spatial dynamics of clot displacements and strain initiated by focused ultrasound pulses. Displacements were produced by a 1.51 MHz f-number 1 transducer over a range of acoustic powers (1-85 W) in clots constrained within an agar vessel phantom channel. Displacements were tracked during and after a 5.45 ms therapy pulse using a 20 MHz high-frequency ultrasound imaging probe. Peak thrombus displacements were found to be linear as a function of acoustic power up to 60 W before leveling off near 128 μm for the highest transmit powers. The time to peak displacement and recovery time of blood clots was largely independent of acoustic powers with measured values near 2 ms. A linear relationship between peak axial strain and transmit power was observed, reaching a peak value of 11% at 35 W. The peak strain occurred ~0.75 mm from the focal zone for all powers investigated in both lateral and axial directions. These results indicate that substantial displacements can be induced by focused ultrasound in confined blood clots, and that the spatial and temporal displacement patterns are complex and highly dependent on exposure conditions, which has implications for future work investigating their link to clot lysis and for developing approaches to exploit these effects.

Impact of forced displacement during World War II on the present-day mental health of the elderly: a population-based study.

PubMed

Kuwert, Philipp; Brähler, Elmar; Glaesmer, Heide; Freyberger, Harald Jürgen; Decker, Oliver

2009-08-01

The effects of traumatization among the elderly is a neglected topic in research and clinical settings. Forced displacement of civilians is one of the main traumatic features of modern armed conflict. Roughly 12 million German people were displaced in World War II (WWII) and to our knowledge there has been no representative study investigating the mental health outcomes of such trauma in the elderly population. The survey assessed whether current depression, anxiety, resilience and life satisfaction were significantly associated with forced displacement in WWII. A nationwide representative face-to-face household survey was conducted in Germany. A representative sample of the German population aged 61 years or older (N = 1513 participants, N = 239 displaced in WWII) was approached using 258 sample points. Measurements included depressive symptoms (PHQ-2), anxiety (GAD-7), resilience (RS-11), general and domain-specific life satisfaction (FLZ(M)) and sociodemographic variables. Forced displacement in WWII is significantly associated with higher levels of anxiety and lower levels of resilience and life satisfaction 60 years later. In regression analyses, forced displacement in WWII significantly predicted current anxiety (beta 0.07; p < 0.01), life satisfaction (beta -0.06; p < 0.05) and resilience (beta -0.07; p < 0.01). To our knowledge this is the first nationwide representative survey to examine the late-life effects of forced displacement, particularly of persons displaced during WWII in Germany. Further research is needed to identify mediating variables and to evaluate psychotherapeutic interventions in elderly trauma survivors.

Oblique Northeastward Lateral Extrusion of a Crustal Block in North-central Taiwan: a Mechanism for Syn-tectonic Extension

NASA Astrophysics Data System (ADS)

Gourley, J. R.; Byrne, T.

2005-12-01

An integrated data set of earthquake locations (Taiwan's Central Weather Bureau), focal mechanisms from the Broadband Array of Taiwan Seismicity (BATS), GPS velocities and geologic data are combined to constrain the geometry and kinematics of a crustal block within the metamorphic basement of Taiwan's northeastern Central Range. The active block is bounded by two parallel seismic zones that accommodate uplift and northeastward oblique lateral extrusion. The western shear zone is a region that dips vertically to steeply west and projects generally to the western boundary between the Slate Belt and pre-Tertiary metamorphic basement. BATS focal mechanisms consistently show east-side-up, left-lateral normal displacements. Late-stage geologic structures published previously show left-lateral faulting followed by east-west extension. The eastern shear zone dips vertically to steeply west and projects to the eastern boundary of the metamorphic basement, which correlates with the eastern mountain front in this area. BATS focal mechanisms show west-side-up reverse displacements. The kinematics of these two zones define a crustal scale block that is interpreted to be moving up and northeast towards the Okinawa Trough. The extrusion of this crustal block may be driven in part by the topographic difference between the Central Range and the Okinawa Trough, as well as by the active collision between the Philippine Sea Plate and the Eurasian basement high. This proposed northeastern lateral extrusion mirrors the active lateral extrusion in southwestern Taiwan which is observed on the southern side of the Eurasian basement high collision. The involvement of the basement high in the collision and adjacent regions appears to be an important factor in understanding local structural variations in the arc-continent collision and should be considered in both forward and reverse modeling of Taiwan deformation.

Older adults prioritize postural stability in the anterior-posterior direction to regain balance following volitional lateral step.

PubMed

Porter, Shaun; Nantel, Julie

2015-02-01

Postural control in the medial-lateral (ML) direction is of particular interest regarding the assessment of changes in postural control, as it is highly related to the risk of falling. To determine the postural strategies used to regain balance following a voluntary lateral step and compare these strategies between young and older adults. Sixteen older adults (60-90 years) and 14 young adults (20-40 years) were asked to stand quietly for 30s, walk in place and then take a lateral step and stand quietly (30s). Balance Post was divided into 10s intervals. Center of pressure displacement (CoP) and velocity (VCoP) in the anterio-posterior (AP) and ML directions were analyzed. In both groups, CoP and VCoP in AP and ML increased in Post1 compared to Pre (P<0.001). Dissimilar to young adults, VCoP-Post2, Post3 ML were larger than Pre (P=0.01) in older adults. Age correlated with all VCoP (Pre and Post) in both ML (P<0.05) and AP directions (P<0.01). Dissimilar to young adults, older adults use different postural strategies in ML and AP directions and prioritized postural stability in the AP direction to recover balance after completing a lateral step. In the ML direction, older adults took up to 30s to regain balance. Considering that age was related to larger CoP displacement and velocity, the AP strategy to recover postural balance following a lateral step could become less efficient as older adults age and therefore increasing the risk of falls. Copyright © 2015 Elsevier B.V. All rights reserved.

Axial linear patellar displacement: a new measurement of patellofemoral congruence.

PubMed

Urch, Scott E; Tritle, Benjamin A; Shelbourne, K Donald; Gray, Tinker

2009-05-01

The tools for measuring the congruence angle with digital radiography software can be difficult to use; therefore, the authors sought to develop a new, easy, and reliable method for measuring patellofemoral congruence. The abstract goes here and covers two columns. The abstract goes The linear displacement measurement will correlate well with the congruence angle measurement. here and covers two columns. Cohort study (diagnosis); Level of evidence, 2. On Merchant view radiographs obtained digitally, the authors measured the congruence angle and a new linear displacement measurement on preoperative and postoperative radiographs of 31 patients who suffered unilateral patellar dislocations and 100 uninjured subjects. The linear displacement measurement was obtained by drawing a reference line across the medial and lateral trochlear facets. Perpendicular lines were drawn from the depth of the sulcus through the reference line and from the apex of the posterior tip of the patella through the reference line. The distance between the perpendicular lines was the linear displacement measurement. The measurements were obtained twice at different sittings. The observer was blinded as to the previous measurements to establish reliability. Measurements were compared to determine whether the linear displacement measurement correlated with congruence angle. Intraobserver reliability was above r(2) = .90 for all measurements. In patients with patellar dislocations, the mean congruence angle preoperatively was 33.5 degrees , compared with 12.1 mm for linear displacement (r(2) = .92). The mean congruence angle postoperatively was 11.2 degrees, compared with 4.0 mm for linear displacement (r(2) = .89). For normal subjects, the mean congruence angle was -3 degrees and the mean linear displacement was 0.2 mm. The linear displacement measurement was found to correlate with congruence angle measurements and may be an easy and useful tool for clinicians to evaluate patellofemoral congruence objectively.

Comparing (semi-) analytic solutions used to model the impact of deep carbon injection on the displacement and pressurization of the resident brine

NASA Astrophysics Data System (ADS)

Bandilla, K.; Kraemer, S. R.

2009-12-01

Injection of carbon dioxide into deep saline formations is seen as one possible technology for mitigating carbon emissions from utilities. The safety of the sequestered carbon dioxide is the focus of many studies with leakage through faults or abandoned wells as some of the main failure mechanisms. The focus of this study is on the displacement of resident brine and the resulting changes in pressure due to the injection of large volumes of super-critical phase carbon dioxide into the subsurface. The movement of brine becomes important if it travels vertically and reaches an existing or potential underground source of drinking water where an increase in salt content may threaten the viability of the drinking water source. Vertical displacement of brine may occur slowly through confining layers, or more rapidly through faults and abandoned wells. This presentation compares several (semi-) analytic solutions to determine their applicability to the problem of brine pressurization and displacement. The goal is to find ranges of formation parameters (e.g., formation seal conductivity, distance to lateral boundary, … ) for which simplifying assumption are justifiable Each simplification in the conceptual model (e.g., neglecting the lateral boundary turns a bounded domain into an infinite one) leads to a simpler (semi-) analytic solution. The process involves a solution hierarchy from the most complex solution down to the basic Theis solution. A software tool-kit implementing several (semi-) analytic solutions was developed for this study to facilitate the comparison of the solutions.

Balance and Muscle Strength in Elderly Women Who Dance Samba

PubMed Central

Serra, Marcos Maurício; Alonso, Angelica Castilho; Peterson, Mark; Mochizuki, Luis; Greve, Júlia Maria D'Andréa; Garcez-Leme, Luiz Eugênio

2016-01-01

Considering the growth of the aging population, and the increasing risk for falls and related morbidity, it is vital to seek efficient, comprehensive, and culturally relevant prevention programs for elderly people to reduce risks for falls. The aim of the present study was to evaluate the postural balance and muscle strength among women participating in the "Wing of Baianas" in the carnival parades. One hundred and ten women, with an average age of 67.4±5.9 years, were divided into two groups: Baianas group—elderly participants of the carnival parades in the “Wing of Baianas”, and a Control group of women who do not dance samba. Assessments included a physical activity questionnaire, isokinetic muscle strength testing for the knee extensors and flexors, and a postural balance assessment completed on a force platform. There were no differences between groups, for postural balance outcomes, during the eyes open condition; however, with eyes closed, there was a significant effect between groups (Baianas vs Control) in all variables. The Baianas group showed less medio-lateral displacement (p < 0.04); and anteroposterior displacement (p < 0.007); larger amplitudes of medio-lateral displacement (p < 0.001); and anteroposterior displacement (p < 0.001); increased mean velocity (p < 0.01); and elliptical area (p < 0.01) There were no differences in the isokinetic peak torque corrected by body weight, total work and flexor/extensor ratio. Participation in the Wing of Baianas is associated with better balance with closed eyes, but there were no differences between dancers and non-dancers for muscle strength. PMID:27906984

Balance and Muscle Strength in Elderly Women Who Dance Samba.

PubMed

Serra, Marcos Maurício; Alonso, Angelica Castilho; Peterson, Mark; Mochizuki, Luis; Greve, Júlia Maria D'Andréa; Garcez-Leme, Luiz Eugênio

2016-01-01

Considering the growth of the aging population, and the increasing risk for falls and related morbidity, it is vital to seek efficient, comprehensive, and culturally relevant prevention programs for elderly people to reduce risks for falls. The aim of the present study was to evaluate the postural balance and muscle strength among women participating in the "Wing of Baianas" in the carnival parades. One hundred and ten women, with an average age of 67.4±5.9 years, were divided into two groups: Baianas group-elderly participants of the carnival parades in the "Wing of Baianas", and a Control group of women who do not dance samba. Assessments included a physical activity questionnaire, isokinetic muscle strength testing for the knee extensors and flexors, and a postural balance assessment completed on a force platform. There were no differences between groups, for postural balance outcomes, during the eyes open condition; however, with eyes closed, there was a significant effect between groups (Baianas vs Control) in all variables. The Baianas group showed less medio-lateral displacement (p < 0.04); and anteroposterior displacement (p < 0.007); larger amplitudes of medio-lateral displacement (p < 0.001); and anteroposterior displacement (p < 0.001); increased mean velocity (p < 0.01); and elliptical area (p < 0.01) There were no differences in the isokinetic peak torque corrected by body weight, total work and flexor/extensor ratio. Participation in the Wing of Baianas is associated with better balance with closed eyes, but there were no differences between dancers and non-dancers for muscle strength.

Jackpot Structural Features: Rollover Effect and Goal-Gradient Effect in EGM Gambling.

PubMed

Li, En; Rockloff, Matthew J; Browne, Matthew; Donaldson, Phillip

2016-06-01

Relatively little research has been undertaken on the influence of jackpot structural features on electronic gaming machine (EGM) gambling behavior. This study considered two common features of EGM jackpots: progressive (i.e., the jackpot incrementally growing in value as players make additional bets), and deterministic (i.e., a guaranteed jackpot after a fixed number of bets, which is determined in advance and at random). Their joint influences on player betting behavior and the moderating role of jackpot size were investigated in a crossed-design experiment. Using real money, players gambled on a computer simulated EGM with real jackpot prizes of either $500 (i.e., small jackpot) or $25,000 (i.e., large jackpot). The results revealed three important findings. Firstly, players placed the largest bets (20.3 % higher than the average) on large jackpot EGMs that were represented to be deterministic and non-progressive. This finding was supportive of a hypothesized 'goal-gradient effect', whereby players might have felt subjectively close to an inevitable payoff for a high-value prize. Secondly, large jackpots that were non-deterministic and progressive also promoted high bet sizes (17.8 % higher than the average), resembling the 'rollover effect' demonstrated in lottery betting, whereby players might imagine that their large bets could be later recouped through a big win. Lastly, neither the hypothesized goal-gradient effect nor the rollover effect was evident among players betting on small jackpot machines. These findings suggest that certain high-value jackpot configurations may have intensifying effects on player behavior.

The relationship between apical root resorption and orthodontic tooth movement in growing subjects.

PubMed

Xu, Tianmin; Baumrind, S

2002-07-01

To investigate the relationship between apical root resorption and orthodontic tooth movement in growing subjects. 58 growing subjects were collected randomly into the study sample and another 40 non-treated cases were used as control. The apical resoption of the upper central incisors was measured on periapical film and the incisor displacement was measured on lateral cephalogram. Using multiple linear regression analysis to examine the relationship between root resoption and the displacement of the upper incisor apex in each of four direction (retraction, advancement, intrusion and extrusion). The statistically significant negative association were found between resorption and both intrusion (P < 0.001) and extrusion (P < 0.05), but no significant association was found between resorption and both retraction and advancement. The regression analysis implied an average of 2.29 mm resorption in the absence of apical displacement. The likelihood that the magnitude of displacement of the incisor root is positively associated with root resoption in the population of treated growing subjects is very small.

Modeling right-lateral offset of a Late Pleistocene terrace riser along the Polaris fault using ground based LiDAR imagery

NASA Astrophysics Data System (ADS)

Howle, J. F.; Bawden, G. W.; Hunter, L. E.; Rose, R. S.

2009-12-01

High resolution (centimeter level) three-dimensional point-cloud imagery of offset glacial outwash deposits were collected by using ground based tripod LiDAR (T-LiDAR) to characterize the cumulative fault slip across the recently identified Polaris fault (Hunter et al., 2009) near Truckee, California. The type-section site for the Polaris fault is located 6.5 km east of Truckee where progressive right-lateral displacement of middle to late Pleistocene deposits is evident. Glacial outwash deposits, aggraded during the Tioga glaciation, form a flat lying ‘fill’ terrace on both the north and south sides of the modern Truckee River. During the Tioga deglaciation melt water incised into the terrace producing fluvial scarps or terrace risers (Birkeland, 1964). Subsequently, the terrace risers on both banks have been right-laterally offset by the Polaris fault. By using T-LiDAR on an elevated tripod (4.25 m high), we collected 3D high-resolution (thousands of points per square meter; ± 4 mm) point-cloud imagery of the offset terrace risers. Vegetation was removed from the data using commercial software, and large protruding boulders were manually deleted to generate a bare-earth point-cloud dataset with an average data density of over 240 points per square meter. From the bare-earth point cloud we mathematically reconstructed a pristine terrace/scarp morphology on both sides of the fault, defined coupled sets of piercing points, and extracted a corresponding displacement vector. First, the Polaris fault was approximated as a vertical plane that bisects the offset terrace risers, as well as bisecting linear swales and tectonic depressions in the outwash terrace. Then, piercing points to the vertical fault plane were constructed from the geometry of the geomorphic elements on either side of the fault. On each side of the fault, the best-fit modeled outwash plane is projected laterally and the best-fit modeled terrace riser projected upward to a virtual intersection in space, creating a vector. These constructed vectors were projected to intersection with the fault plane, defining statistically significant piercing points. The distance between the coupled set of piercing points, within the plane of the fault, is the cumulative displacement vector. To assess the variability of the modeled geomorphic surfaces, including surface roughness and nonlinearity, we generated a suite of displacement models by systematically incorporating larger areas of the model domain symmetrically about the fault. Preliminary results of 10 models yield an average cumulative displacement of 5.6 m (1 Std Dev = 0.31 m). As previously described, Tioga deglaciation melt water incised into the outwash terrace leaving terrace risers that were subsequently offset by the Polaris fault. Therefore, the age of the Tioga outwash terrace represents a maximum limiting age of the tectonic displacement. Using regional age constraints of 15 to 13 kya for the Tioga outwash terrace (Benson et al., 1990; Clark and Gillespie, 1997; James et al., 2002) and the above model results, we estimate a preliminary minimum fault slip rate of 0.40 ± 0.05 mm/yr for the Polaris type-section site.

A Retrospective Study of Association between Peg-shaped Maxillary Lateral Incisors and Dental Anomalies.

PubMed

Kim, Jae-Hwan; Choi, Nam-Ki; Kim, Seon-Mi

The purpose of this study was to investigate the prevalence of peg-shaped maxillary lateral incisors and the incidence of associated dental anomalies in children. We investigated the prevalence of peg-laterals and incidence of associated dental anomalies in 3,834 children aged 7-15 who visited the Department of Pediatric Dentistry from January 2010 to December 2015 and underwent panoramic radiographs. The prevalence of peg-laterals was 1.69% in boys, 1.75% in girls, and 1.72% overall. Among children with peg-laterals, the frequencies of associated dental anomalies were as follows: congenitally missing teeth, 31.8%; dens invaginatus, 19.7%; palatally displaced canines, 12.1%; supernumerary teeth, 7.6%; and transposition, 7.6%. As children with peg-laterals have a higher incidence of other dental anomalies, careful consideration is needed when planning diagnosis and treatment.

METHOD AND MEANS FOR SUPPORTING REACTOR FUEL CONTAINERS IN AN ASSEMBLY

DOEpatents

Currier, E.L. Jr.; Nicklas, J.H.; Coombs, C.A.

1962-12-11

This patent relates to means for supporting fuelcontaining tubes in an assembly which include grid means at either end of the fuel element assembly antl improved grid means intermediate of the ends to provide support against lateral displacement. (AEC)

Impact of Hurricane Katrina on roadways in the New Orleans Area : technical assistance report.

DOT National Transportation Integrated Search

2007-03-01

On August 29, 2005, Hurricane Katrina devastated New Orleans and southeastern Louisiana, leaving hundreds of thousands either displaced or homeless. Nearly four weeks later, Hurricane Rita made landfall in the southwestern portion of the state, furth...

Walking more slowly than with normal velocity: The influence on trunk and pelvis kinematics in young and older healthy persons.

PubMed

Swinnen, Eva; Baeyens, Jean-Pierre; Pintens, Seppe; Buyl, Ronald; Goossens, Maggie; Meeusen, Romain; Kerckhofs, Eric

2013-08-01

Few studies have addressed trunk and pelvis movements during gait, although they play an important role in gait control. The aim of this study was to compare trunk and pelvis kinematics between slower walking (1, 2, 3, 4kmph) and normal walking (5kmph), and between healthy adults who were young (n=15, 20-30years) and older (n=17, 50-60years). After 4min of treadmill walking, the 3-dimensional trunk and pelvis kinematics was measured (Polhemus Liberty™, 250Hz). A repeated measures ANOVA with simple contrasts was used to look for differences between the velocity conditions of walking and independent t-testing for comparison between the age groups (significance level: 5%, SPSS20). Walking more slowly than with normal velocity induces (1) a decrease in vertical center of mass of the trunk displacement, trunk lateral flexion and axial rotation and pelvis lateral and antero-posterior tilting, and (2) an increase in lateral and antero-posterior center of mass of the trunk displacement. Compared to young persons, older persons show: (1) larger pelvis axial rotations and trunk lateral and antero-posterior movements, and (2) smaller pelvis lateral tilting and trunk vertical movements and rotations. The literature reports that patients often walk slowly and that older persons show different gait patterns compared to young persons. This study shows that there are changes in trunk and pelvis kinematics (1) when walking more slowly than with normal velocity and (2) in older persons compared to young persons. These data could be taken into account in gait rehabilitation. © 2013.

Off-fault ground ruptures in the Santa Cruz Mountains, California: Ridge-top spreading versus tectonic extension during the 1989 Loma Prieta earthquake

USGS Publications Warehouse

Ponti, Daniel J.; Wells, Ray E.

1991-01-01

The Ms 7.1 Loma Prieta earthquake of 18 October 1989 produced abundant ground ruptures in an 8 by 4 km area along Summit Road and Skyland Ridge in the Santa Cruz Mountains. Predominantly extensional fissures formed a left-stepping, crudely en echelon pattern along ridges of the hanging-wall block southwest of the San Andreas fault, about 12 km northwest of the epicenter. The fissures are subparallel to the San Andreas fault and appear to be controlled by bedding planes, faults, joints, and other weak zones in the underlying Tertiary sedimentary strata of the hanging-wall block. The pattern of extensional fissures is generally consistent with tectonic extension across the crest of the uplifted hanging-wall block. Also, many displacements in Laurel Creek canyon and along the San Andreas and Sargent faults are consistent with right-lateral reverse faulting inferred for the mainshock. Additional small tensile failures along the axis of the Laurel anticline may reflect growth of the fold during deep-seated compression. However, the larger ridge-top fissures commonly have displacements that are parallel to the north-northeast regional slope directions and appear inconsistent with east-northeast extension expected from this earthquake. Measured cumulative displacements across the ridge crests are at least 35 times larger than that predicted by the geodetically determined surface deformation. These fissures also occur in association with ubiquitous landslide complexes that were reactivated by the earthquake to produce the largest concentration of co-seismic slope failures in the epicentral region. The anomalously large displacements and the apparent slope control of the geometry and displacement of many co-seismic surface ruptures lead us to conclude that gravity is an important driving force in the formation of the ridge-top fissures. Shaking-induced gravitational spreading of ridges and downslope movement may account for 90¿ or more of the observed displacements on the linear fissures. Similar fissures occurred in the same area and elsewhere near the San Andreas fault during the predominantly right-lateral 1906 San Francisco earthquake and suggest that the Loma Prieta ground ruptures may, in large part, be independent of fault kinematics.

Delayed retrieval of a displaced maxillary third molar from infratemporal space via trans-sinusoidal approach: a case report and the review of the literature.

PubMed

Sencimen, Metin; Gülses, Aydin; Secer, Sencer; Zerener, Tamer; Özarslantürk, Savaş

2017-03-01

The aim of this case report is to present the trans-sinusoidal pathway used to remove a displaced maxillary third molar from the infratemporal fossa and review the English literature regarding the techniques used. A 21-year-old male patient was referred with the findings of an oroantral fistula on the left maxillary vestibular first molar region and slight restriction of mouth opening. The patient underwent a maxillary sinus surgery in order to remove a sinus retention cyst via Caldwell-Luc access in a dental clinic 4 years ago. A computerized tomography scan showed the inverted third molar to be located in the infratemporal fossa, just between zygomatic arch and lateral pterygoid plate. The tooth was accessed through the remaining lateral bone defect from the Caldwell-Luc approach of the lateral sinus wall. The bone defect was extended. The posterior bony wall of the maxillary sinus was removed via a surgical burr. After that, the displaced tooth was exposed. The tooth was mobilized via Warwick James elevator downwards and removed with a forceps. Access for surgical removal of the tooth from the infratemporal fossa is not only difficult but also has potential for morbidity due to the structures running through it. Wide incision in the maxillary sulcus and blunt dissection are reported with lower success rates and usually necessitate a second intervention via extraoral route. Trans-sinusoidal approach might be an old fashioned but relatively successfully attempt in the removal of the upper third molars from the infratemporal fossa. Considering the time of removal, if no symptoms were present, it is beneficial to wait for a couple of weeks thus facilitating development of fibrous surrounding around the tooth.

Definition and measurement of rider-intrinsic physical attributes influencing all-terrain vehicle safety.

PubMed

Mattei, Tobias A; Bond, Brandon J; Hafner, John W; Morris, Martin J; Travis, Jennifer; Hannah, Greg; Webster, Jim; Lin, Julian J

2011-11-01

All-terrain vehicle (ATV) usage has grown tremendously over the years, reaching 9.5 million vehicles in use in 2007. Accompanying this growth has been a concomitant increase in rider morbidity (including traumatic brain and spine injuries) and death, especially in children. The purpose of this study was to define and measure, through field testing, those physical attributes intrinsic to riders, such as height, weight, and wingspan, which may have implications for ATV riders' safety. Three field tests (J-hook, brake, and bump) were developed and performed to allow direct measurement of the lateral, longitudinal, and vertical dynamics in 5 riders of varying heights, weights, and wingspans. Two ATVs, a utility and a sport model, were tested for further comparisons. Data were acquired using a comprehensive data acquisition system attached to the ATVs. Assignment of individual rider/ATV test safety ratings and a rider/ATV Total Safety Rating were made from the results of these field tests. The J-hook test results demonstrated that larger rider wingspans positively influence ATV rider safety and mitigate against lateral instability. From the brake test it was determined that a 10-in (25.4-cm) longitudinal displacement, such as that experienced during a sharp deceleration, for a rider of any height or weight, breached the level of defined safety. As rider weight increased, displacement decreased. The bump test provided evidence that increased rider weight also mitigates against vertical displacement. Individuals with light weights and small wingspans, such as those in the pediatric population, are under considerable risk of injury when operating an ATV due to lateral, longitudinal, and vertical operational instability.

Neuroanatomical Predictors of Awakening in Acutely Comatose Patients

PubMed Central

Kowalski, Robert G.; Buitrago, Manuel M.; Duckworth, Josh; Chonka, Zachary D.; Puttgen, H. Adrian; Stevens, Robert D.; Geocadin, Romergryko G.

2016-01-01

Objective Lateral brain displacement has been associated with loss of consciousness and poor outcome in a range of acute neurologic disorders. We studied the association between lateral brain displacement and awakening from acute coma. Methods This prospective observational study included all new onset coma patients admitted to the Neurosciences Critical Care Unit (NCCU) over 12 consecutive months. Head computed tomography (CT) scans were analyzed independently at coma onset, after awakening, and at follow-up. Primary outcome measure was awakening, defined as the ability to follow commands before hospital discharge. Secondary outcome measures were discharge Glasgow Coma Scale (GCS), modified Rankin Scale, Glasgow Outcome Scale, and hospital and NCCU lengths of stay. Results Of the 85 patients studied, the mean age was 58 ± 16 years, 51% were female, and 78% had cerebrovascular etiology of coma. Fifty-one percent of patients had midline shift on head CT at coma onset and 43 (51%) patients awakened. In a multivariate analysis, independent predictors of awakening were younger age (odds ratio [OR] = 1.039, 95% confidence interval [CI] = 1.002–1.079, p = 0.040), higher GCS score at coma onset (OR = 1.455, 95% CI = 1.157–1.831, p = 0.001), nontraumatic coma etiology (OR = 4.464, 95% CI = 1.011–19.608, p = 0.048), lesser pineal shift on follow-up CT (OR = 1.316, 95% CI = 1.073–1.615, p = 0.009), and reduction or no increase in pineal shift on follow-up CT (OR = 11.628, 95% CI = 2.207–62.500, p = 0.004). Interpretation Reversal and/or limitation of lateral brain displacement are associated with acute awakening in comatose patients. These findings suggest objective parameters to guide prognosis and treatment in patients with acute onset of coma. PMID:25628166

An Integral Prediction Method for Three-Dimensional Turbulent Boundary Layers on Rotating Blades.

DTIC Science & Technology

1981-06-01

in’siscid streamline 6 Boundary-dyer thickness 61 StreamwNise displacement thickness. 61 f (I -)d (- ro,,,,isk displacement tikes 0 D~istance along thle...hl 󈧦 h2 ar)+(Uhl al, + 2w3 2022 a U + - 61 + _ I- 022+dl) =-Cf2U Uh 2 8 1 In equations 3a and 3b, 011, 012 , 021 , 022 , dl, and 62 are the momentum...K2 (6-6w)-62 ( h2U arl ( 61 ) Details of the cntrainment function are given in a later section of this paper. ADDITIONAL RELATIONSHIPS Further

Three-dimensional records of surface displacement on the Superstition Hills fault zone associated with the earthquakes of 24 November 1987

USGS Publications Warehouse

Sharp, R.V.; Saxton, J.L.

1989-01-01

Seven quadrilaterals, constructed at broadly distributed points on surface breaks within the Superstition Hills fault zone, were repeatedly remeasured after the pair of 24 November 1987 earthquakes to monitor the growing surface displacement. Changes in the dimensions of the quadrilaterals are recalculated to right-lateral and extensional components at millimeter resolution, and vertical components of change are resolved at 0.2mm precision. The displacement component data for four of the seven quadrilaterals record the complete fault movement with respect to an October 1986 base. The three-dimensional motion vectors all describe nearly linear trajectories throughout the observation period, and they indicate smooth shearing on their respective fault surfaces. The inclination of the shear surfaces is generally nearly vertical, except near the south end of the Superstition Hills fault zone where two strands dip northeastward at about 70??. Surface displacement on these strands is right reverse. Another kind of deformation, superimposed on the fault displacements, has been recorded at all quadrilateral sites. It consists of a northwest-southeast contraction or component of contraction that ranged from 0 to 0.1% of the quadrilateral lengths between November 1987 and April 1988. -from Authors

Work-family conflict, emotional exhaustion, and displaced aggression toward others: the moderating roles of workplace interpersonal conflict and perceived managerial family support.

PubMed

Liu, Yihao; Wang, Mo; Chang, Chu-Hsiang; Shi, Junqi; Zhou, Le; Shao, Ruodan

2015-05-01

Taking a resource-based self-regulation perspective, this study examined afternoon emotional exhaustion as a mediator linking the within-person relations between morning work-family conflict and later employee displaced aggression in the work and family domains. In addition, it examined resource-related contextual factors as moderators of these relations. The theoretical model was tested using daily diary data from 125 employees. Data were collected at 4 time points during each workday for 3 consecutive weeks. Multilevel modeling analysis showed that morning family-to-work conflict was positively related to afternoon emotional exhaustion, which in turn predicted displaced aggression toward supervisors and coworkers in the afternoon and displaced aggression toward family members in the evening. In addition, morning workplace interpersonal conflict exacerbated the impact of morning work-to-family conflict on afternoon emotional exhaustion, whereas perceived managerial family support alleviated the impact of morning family-to-work conflict on afternoon emotional exhaustion. These findings indicate the importance of adopting a self-regulation perspective to understand work-family conflict at work and its consequences (i.e., displaced aggression) in both work and family domains. (c) 2015 APA, all rights reserved.

Scenario earthquake hazards for the Long Valley Caldera-Mono Lake area, east-central California (ver. 2.0, January 2018)

USGS Publications Warehouse

Chen, Rui; Branum, David M.; Wills, Chris J.; Hill, David P.

2014-06-30

As part of the U.S. Geological Survey’s (USGS) multi-hazards project in the Long Valley Caldera-Mono Lake area, the California Geological Survey (CGS) developed several earthquake scenarios and evaluated potential seismic hazards, including ground shaking, surface fault rupture, liquefaction, and landslide hazards associated with these earthquake scenarios. The results of these analyses can be useful in estimating the extent of potential damage and economic losses because of potential earthquakes and also for preparing emergency response plans.The Long Valley Caldera-Mono Lake area has numerous active faults. Five of these faults or fault zones are considered capable of producing magnitude ≥6.7 earthquakes according to the Uniform California Earthquake Rupture Forecast, Version 2 (UCERF 2) developed by the 2007 Working Group on California Earthquake Probabilities (WGCEP) and the USGS National Seismic Hazard Mapping Program. These five faults are the Fish Slough, Hartley Springs, Hilton Creek, Mono Lake, and Round Valley Faults. CGS developed earthquake scenarios for these five faults in the study area and for the White Mountains Fault Zone to the east of the study area.In this report, an earthquake scenario is intended to depict the potential consequences of significant earthquakes. A scenario earthquake is not necessarily the largest or most damaging earthquake possible on a recognized fault. Rather it is both large enough and likely enough that emergency planners should consider it in regional emergency response plans. In particular, the ground motion predicted for a given scenario earthquake does not represent a full probabilistic hazard assessment, and thus it does not provide the basis for hazard zoning and earthquake-resistant building design.Earthquake scenarios presented here are based on fault geometry and activity data developed by the WGCEP, and are consistent with the 2008 Update of the United States National Seismic Hazard Maps (NSHM). Alternatives to the NSHM scenario were developed for the Hilton Creek and Hartley Springs Faults to account for different opinions in how far these two faults extend into Long Valley Caldera. For each scenario, ground motions were calculated using the current standard practice: the deterministic seismic hazard analysis program developed by Art Frankel of USGS and three Next Generation Ground Motion Attenuation (NGA) models. Ground motion calculations incorporated the potential amplification of seismic shaking by near-surface soils defined by a map of the average shear wave velocity in the uppermost 30 m (VS30) developed by CGS.In addition to ground shaking and shaking-related ground failure such as liquefaction and earthquake induced landslides, earthquakes cause surface rupture displacement, which can lead to severe damage of buildings and lifelines. For each earthquake scenario, potential surface fault displacements are estimated using deterministic and probabilistic approaches. Liquefaction occurs when saturated sediments lose their strength because of ground shaking. Zones of potential liquefaction are mapped by incorporating areas where loose sandy sediments, shallow groundwater, and strong earthquake shaking coincide in the earthquake scenario. The process for defining zones of potential landslide and rockfall incorporates rock strength, surface slope, and existing landslides, with ground motions caused by the scenario earthquake.Each scenario is illustrated with maps of seismic shaking potential and fault displacement, liquefaction, and landslide potential. Seismic shaking is depicted by the distribution of shaking intensity, peak ground acceleration, and 1.0-second spectral acceleration. One-second spectral acceleration correlates well with structural damage to surface facilities. Acceleration greater than 0.2 g is often associated with strong ground shaking and may cause moderate to heavy damage. The extent of strong shaking is influenced by subsurface fault dip and near surface materials. Strong shaking is more widespread in the hanging wall regions of a normal fault. Larger ground motions also occur where young alluvial sediments amplify the shaking. Both of these effects can lead to strong shaking that extends farther from the fault on the valley side than on the hill side.The effect of fault rupture displacements may be localized along the surface trace of the mapped earthquake fault if fault geometry is simple and the fault traces are accurately located. However, surface displacement hazards can spread over a few hundred meters to a few kilometers if the earthquake fault has numerous splays or branches, such as the Hilton Creek Fault. Faulting displacements are estimated to be about 1 meter along normal faults in the study area and close to 2 meters along the White Mountains Fault Zone.All scenarios show the possibility of widespread ground failure. Liquefaction damage would likely occur in the areas of higher ground shaking near the faults where there are sandy/silty sediments and the depth to groundwater is 6.1 meters (20 feet) or less. Generally, this means damage is most common near lakes and streams in the areas of strongest shaking. Landslide potential exists throughout the study region. All steep slopes (>30 degrees) present a potential hazard at any level of shaking. Lesser slopes may have landslides within the areas of the higher ground shaking. The landslide hazard zones also are likely sources for snow avalanches during winter months and for large boulders that can be shaken loose and roll hundreds of feet down hill, which happened during the 1980 Mammoth Lakes earthquakes.Whereas methodologies used in estimating ground shaking, liquefaction, and landslides are well developed and have been applied in published hazard maps; methodologies used in estimating surface fault displacement are still being developed. Therefore, this report provides a more in-depth and detailed discussion of methodologies used for deterministic and probabilistic fault displacement hazard analyses for this project.

Disc displacement and changes in condylar position

PubMed Central

Ikeda, K; Kawamura, A

2013-01-01

Objectives: To determine whether disc displacement (DD) can be a factor causing changes in condylar position in the glenoid fossa, using limited cone beam CT (LCBCT) images taken in the same time period as MRI that verified DD. Methods: The study included 60 joints in 57 male and female subjects aged 12–20 years (mean age 14.8 years). Subjects fulfilling the inclusion criteria were enrolled from a pool of post-orthodontic patients, and divided into four groups according to their disc status confirmed by MRI: partial DD (PDD), total DD with reduction (TDDWR), lateral DD (LDD) and medial DD (MDD). Changes in joint space from previously reported norms were measured on LCBCT images. Results: In PDD, the condyles were displaced posteriorly in the fossae with a mean anterior space of 2.7 ± 0.5 mm (normal 1.3 ± 0.2 mm) and a posterior space of 1.8 ± 0.4 mm (normal 2.1 ± 0.3 mm). In TDDWR, the condyles were displaced not only posteriorly as observed in PDD, but also vertically with a reduced superior space of 1.9 ± 0.4 mm (normal 2.5 ± 0.5 mm). In LDD, the lateral space was significantly increased to 2.5 ± 0.3 mm (normal 1.8 ± 0.4 mm), while central and medial spaces were significantly decreased to 2.2 ± 0.5 mm (normal 2.7 ± 0.5 mm) and 1.7 ± 0.4 mm (normal 2.4 ± 0.5 mm), respectively. In MDD, the medial space was increased and the lateral and central spaces were significantly decreased. Conclusions: These results indicate that DD in adolescents and young adults can cause the condyle to change its position in the fossa with alterations in joint space which depend on the direction and extent of DD. PMID:22933537

Manual and automatic control of surface effect ships. [operator steering servomechanisms analysis

NASA Technical Reports Server (NTRS)

Clement, W. F.; Shanahan, J. J.; Allen, R. W.

1975-01-01

A recent investigation of crew performance in the motion environment of a large generic high speed surface effect ship by means of a motion base simulation addressed some of the helmsman's control task with an external forward visual field of the seascape and navigation and steering displays in the pilot house. In addition to the primary steering control task, a subcritical speed tracking task provided a secondary surrogate for trimming the water speed of the craft. The results of helsmen's steering describing function measurements are presented, and some suggestions for their interpretation are offered. The likely steering loop closures comprise heading and lateral displacement for the course keeping task investigated. Also discussed is the manner in which these loop closures were implemented for automatic steering of the surface effect ship. Regardless of the influence of workload, steering technique, water speed and sea state, the helmsmen apparently adopted a disturbance regulation bandwidth of about 0.2 rad/sec for lateral displacement.

Marked lateral deviation of the phrenic nerve due to variant origin and course of the thyrocervical trunk: a cadaveric study.

PubMed

Ogami, Keiko; Saiki, K; Okamoto, K; Wakebe, T; Manabe, Y; Imamura, T; Tsurumoto, T

2016-05-01

Phrenic nerve impairment can often lead to serious respiratory disorders under various pathological conditions. During routine dissection of an 88-year-old Japanese male cadaver, a victim of heart failure, we recognized an extremely rare variation of the right thyrocervical trunk arising from the subclavian artery laterally to the anterior scalene muscle. In addition to that, the ipsilateral phrenic nerve was drawn and displaced remarkably laterad by this vessel. We examined all of the branches arising from subclavian arteries, phrenic nerves and diaphragm muscles. The embryological background of this arterial variation is considered. The marked displacement with prolonged strain had a potential to cause phrenic nerve impairment with an atrophic change of the diaphragm muscle. Recently many image diagnostic technologies have been developed and are often used. However, it is still possible that rare variations like this case may be overlooked and can only be recognized by intimate regional examination while keeping these rare variations in mind.

Displacement of ureteral orifices following anterior colporrhaphy.

PubMed

Dain, Lena; Auslander, Ron; Lissak, Arie; Lavie, Ofer; Abramov, Yoram

2010-01-01

It is currently unknown whether ureteral orifices maintain their anatomic location after reconstructive pelvic surgeries. We therefore aimed to assess ureteral orifices' location after anterior colporrhaphy. Between August and December 2007, patients undergoing anterior colporrhaphy for advanced cystocele in our institution underwent cystoscopy with intravenous dye injection and placement of ureteral catheters before and after the surgery. Each ureteral orifice location was marked on an X-Y coordinate on the posterior bladder wall before and after surgery. Thirteen women aged 44-80 years were included in the study. Postoperatively, ureteral orifices were noted to migrate 0.65 +/- 0.3 cm caudally (closer to the urethrovesical junction) (p = 0.002) and 0.32 +/- 0.5 cm laterally (p < 0.05). Anterior colporrhaphy is associated with significant caudal and lateral displacement of both ureteral orifices. These findings are of potential importance for pelvic reconstructive surgeons and may facilitate faster cystoscopic evaluation of ureteral patency postoperatively. They may also have implications on the angle of the preferred optical equipment to be used.

Temporal variation of meandering intensity and domain-wide lateral oscillations of the Gulf Stream

NASA Technical Reports Server (NTRS)

Lee, Tong; Cornillon, Peter

1995-01-01

The path of the Gulf Stream exhibits two modes of variability: wavelike spatial meanders associated with instability processes and large-sale lateral shifts of the path presumably due to atmospheric forcing. The objectives of this study are to examine the temporal variation of the intensity of spatial meandering in the stream, to characterize large-scale lateral oscillations in the stream's path, and to study the correlation betwen these two dynamically distinct modes of variability. The data used for this analysis are path displacemets ofthe Gulf Stream between 75 deg and 60 deg W obtained from AVHRR-derived (Advanced Very High Resolution Radiometer) infrared images for the period April 1982 through December 1989. Meandering intensity, measured by the spatial root-mean-sqaure displacement of the stream path, displays a 9-month dominant periodicity which is persistent through the study period. The 9-month fluctuation in meandering intensity may be related to the interaction of Rosseby waves with the stream. Interannual variation of meandering intensity is also found to be significant, with meandering being mich more intense during 1985 than it was in 1987. Annual variation, however,is weak and not well-defined.The spatially averaged position of the stream, which reflects nonmeandering large-scale lateral oscillations of the stream path, is dominated by an annual cycle. On average, the mean position is farthest north in November and farthest south in April. The first empirical orthogonal function mode of the space-time path displacements represents lateral oscillatins that are in-phase over the space-time domain. Interannual oscillations are also observed and are found to be weaker than the annual oscillation. The eigenvalue of the first mode indicates that about 21.5% of the total space-time variability of the stream path can be attibuted to domain-wide lateral oscillation. The correlation between meandering intensity and domain-wide lateral oscillations is very weak.

Deterministic chaotic dynamics of Raba River flow (Polish Carpathian Mountains)

NASA Astrophysics Data System (ADS)

Kędra, Mariola

2014-02-01

Is the underlying dynamics of river flow random or deterministic? If it is deterministic, is it deterministic chaotic? This issue is still controversial. The application of several independent methods, techniques and tools for studying daily river flow data gives consistent, reliable and clear-cut results to the question. The outcomes point out that the investigated discharge dynamics is not random but deterministic. Moreover, the results completely confirm the nonlinear deterministic chaotic nature of the studied process. The research was conducted on daily discharge from two selected gauging stations of the mountain river in southern Poland, the Raba River.

Apical root resorption in orthodontically treated adults.

PubMed

Baumrind, S; Korn, E L; Boyd, R L

1996-09-01

This study analyzed the relationship in orthodontically treated adults between upper central incisor displacement measured on lateral cephalograms and apical root resorption measured on anterior periapical x-ray films. A multiple linear regression examined incisor displacements in four directions (retraction, advancement, intrusion, and extrusion) as independent variables, attempting to account for observed differences in the dependent variable, resorption. Mean apical resorption was 1.36 mm (sd +/- 1.46, n = 73). Mean horizontal displacement of the apex was -0.83 mm (sd +/- 1.74, n = 67); mean vertical displacement was 0.19 mm (sd +/- 1.48, n = 67). The regression coefficients for the intercept and for retraction were highly significant; those for extrusion, intrusion, and advancement were not. At the 95% confidence level, an average of 0.99 mm (se = +/- 0.34) of resorption was implied in the absence of root displacement and an average of 0.49 mm (se = +/- 0.14) of resorption was implied per millimeter of retraction. R2 for all four directional displacement variables (DDVs) taken together was only 0.20, which implied that only a relatively small portion of the observed apical resorption could be accounted for by tooth displacement alone. In a secondary set of univariate analyses, the associations between apical resorption and each of 14 additional treatment-related variables were examined. Only Gender, Elapsed Time, and Total Apical Displacement displayed statistically significant associations with apical resorption. Additional multiple regressions were then performed in which the data for each of these three statistically significant variables were considered separately, with the data for the four directional displacement variables. The addition of information on Elapsed Time or Total Apical Displacement did not explain a significant additional portion of the variability in apical resorption. On the other hand, the addition of information on Gender to the information on the four directional displacement variables yielded an R2 value of 0.35, which indicated that these variables taken together could account for approximately a third of the observed variability in apical resorption in this sample.

Probabilistic finite elements for transient analysis in nonlinear continua

NASA Technical Reports Server (NTRS)

Liu, W. K.; Belytschko, T.; Mani, A.

1985-01-01

The probabilistic finite element method (PFEM), which is a combination of finite element methods and second-moment analysis, is formulated for linear and nonlinear continua with inhomogeneous random fields. Analogous to the discretization of the displacement field in finite element methods, the random field is also discretized. The formulation is simplified by transforming the correlated variables to a set of uncorrelated variables through an eigenvalue orthogonalization. Furthermore, it is shown that a reduced set of the uncorrelated variables is sufficient for the second-moment analysis. Based on the linear formulation of the PFEM, the method is then extended to transient analysis in nonlinear continua. The accuracy and efficiency of the method is demonstrated by application to a one-dimensional, elastic/plastic wave propagation problem. The moments calculated compare favorably with those obtained by Monte Carlo simulation. Also, the procedure is amenable to implementation in deterministic FEM based computer programs.

How to avoid simulation sickness in virtual environments during user displacement

NASA Astrophysics Data System (ADS)

Kemeny, A.; Colombet, F.; Denoual, T.

2015-03-01

Driving simulation (DS) and Virtual Reality (VR) share the same technologies for visualization and 3D vision and may use the same technics for head movement tracking. They experience also similar difficulties when rendering the displacements of the observer in virtual environments, especially when these displacements are carried out using driver commands, including steering wheels, joysticks and nomad devices. High values for transport delay, the time lag between the action and the corresponding rendering cues and/or visual-vestibular conflict, due to the discrepancies perceived by the human visual and vestibular systems when driving or displacing using a control device, induces the so-called simulation sickness. While the visual transport delay can be efficiently reduced using high frequency frame rate, the visual-vestibular conflict is inherent to VR, when not using motion platforms. In order to study the impact of displacements on simulation sickness, we have tested various driving scenarios in Renault's 5-sided ultra-high resolution CAVE. First results indicate that low speed displacements with longitudinal and lateral accelerations under a given perception thresholds are well accepted by a large number of users and relatively high values are only accepted by experienced users and induce VR induced symptoms and effects (VRISE) for novice users, with a worst case scenario corresponding to rotational displacements. These results will be used for optimization technics at Arts et Métiers ParisTech for motion sickness reduction in virtual environments for industrial, research, educational or gaming applications.

Tradeoff methods in multiobjective insensitive design of airplane control systems

NASA Technical Reports Server (NTRS)

Schy, A. A.; Giesy, D. P.

1984-01-01

The latest results of an ongoing study of computer-aided design of airplane control systems are given. Constrained minimization algorithms are used, with the design objectives in the constraint vector. The concept of Pareto optimiality is briefly reviewed. It is shown how an experienced designer can use it to find designs which are well-balanced in all objectives. Then the problem of finding designs which are insensitive to uncertainty in system parameters are discussed, introducing a probabilistic vector definition of sensitivity which is consistent with the deterministic Pareto optimal problem. Insensitivity is important in any practical design, but it is particularly important in the design of feedback control systems, since it is considered to be the most important distinctive property of feedback control. Methods of tradeoff between deterministic and stochastic-insensitive (SI) design are described, and tradeoff design results are presented for the example of the a Shuttle lateral stability augmentation system. This example is used because careful studies have been made of the uncertainty in Shuttle aerodynamics. Finally, since accurate statistics of uncertain parameters are usually not available, the effects of crude statistical models on SI designs are examined.

Establishing and storing of deterministic quantum entanglement among three distant atomic ensembles.

PubMed

Yan, Zhihui; Wu, Liang; Jia, Xiaojun; Liu, Yanhong; Deng, Ruijie; Li, Shujing; Wang, Hai; Xie, Changde; Peng, Kunchi

2017-09-28

It is crucial for the physical realization of quantum information networks to first establish entanglement among multiple space-separated quantum memories and then, at a user-controlled moment, to transfer the stored entanglement to quantum channels for distribution and conveyance of information. Here we present an experimental demonstration on generation, storage, and transfer of deterministic quantum entanglement among three spatially separated atomic ensembles. The off-line prepared multipartite entanglement of optical modes is mapped into three distant atomic ensembles to establish entanglement of atomic spin waves via electromagnetically induced transparency light-matter interaction. Then the stored atomic entanglement is transferred into a tripartite quadrature entangled state of light, which is space-separated and can be dynamically allocated to three quantum channels for conveying quantum information. The existence of entanglement among three released optical modes verifies that the system has the capacity to preserve multipartite entanglement. The presented protocol can be directly extended to larger quantum networks with more nodes.Continuous-variable encoding is a promising approach for quantum information and communication networks. Here, the authors show how to map entanglement from three spatial optical modes to three separated atomic samples via electromagnetically induced transparency, releasing it later on demand.

[The retrocapital osteotomy ("chevron") for correction of splayfoot with hallux valgus].

PubMed

Gabel, Michael

2008-12-01

Surgical treatment of hallux valgus deformity with a distal osteotomy of the first metatarsal to address an increased intermetatarsal angle (IMA) I-II. This procedure is combined with a soft-tissue procedure at the first metatarsophalangeal joint: realignment of the first ray, lateral displacement of the first metatarsal head above the sesamoids, rebalancing of the soft tissues at the metatarsophalangeal joint. Pain and soft-tissue inflammation at the bunion, impaired function of the metatarsophalangeal joint, and lateral deviation of the hallux. IMA I-II 10 degrees. Symptomatic osteoarthritis of the first metatarsophalangeal joint, assessed clinically or radiographically. Acute inflammation of the forefoot, osteoporosis of the first metatarsal. Vascular disturbance. Cosmetic indication only. Relative: hypermobility of the first ray, valgus malalignment of the hindfoot, previous retrocapital osteotomy. Lateral soft-tissue release. Resection of the medial pseudoexostosis. V-shaped osteotomy of the distal metatarsal I. Exostosectomy. Lateral displacement of the first metatarsal head. Screw fixation. Realignment of the metatarsophalangeal joint by tightening of the medial soft tissues. Postoperative shoe with full weight bearing. Active exercises of the foot and hallux. Physiotherapy. Prophylaxis of deep vein thrombosis depending on the degree of mobility. Radiographic control after 6 weeks. Bandage or orthosis to maintain toe alignment. IMA I-II was reduced from 13.6 degrees preoperatively to 6.6 degrees postoperatively. HVA decreased from 29.8 degrees to 8.2 degrees postoperatively.

The Distal Humerus Axial View: Assessment of Displacement in Medial Epicondyle Fractures.

PubMed

Souder, Christopher D; Farnsworth, Christine L; McNeil, Natalie P; Bomar, James D; Edmonds, Eric W

2015-01-01

The assessment and treatment of childhood medial epicondyle humerus fractures continues to be associated with significant debate. Several studies demonstrate that standard radiographic views are unable to accurately portray the true displacement. Without reliable ways to assess the amount of displacement, how can we debate treatment and outcomes? This study introduces a novel imaging technique for the evaluation of medial epicondyle fractures. An osteotomy of a cadaveric humerus was performed to simulate a medial epicondyle fracture. Plain radiographs were obtained with the fracture fragment displaced anteriorly in 2-mm increments between 0 and 18 mm. Anteroposterior (AP), internal oblique (IR), lateral (LAT), and distal humerus axial (AXIAL) views were performed. Axial images were obtained by positioning the central ray above the shoulder at 15 to 20 degrees from the long axis of the humerus, centered on the distal humerus. Displacement (mm) was measured by 7 orthopaedic surgeons on digital radiographs. At 10 mm displacement, AP views underestimated displacement by 5.5±0.6 mm and IR views underestimated by 3.8±2.1 mm. On LAT views, readers were not able to visualize fragments with <10 mm displacement. Displacement ≥10 mm from LAT views was overestimated by 1 reader by up to 4.6 mm and underestimated by others by up to 18.0 mm. AXIAL images more closely estimated the true amount of displacement, with a mean 1.5±1.1 mm error in measurement for <10 mm displacement and a mean 0.8±0.7 mm error for displacements of ≥10 mm. AXIAL measurements correlated strongly with the actual displacement (r=0.998, P<0.05); AP measurements did not (r=0.655, P=0.55). Intraclass correlation coefficient (ICC) was 0.257 for AP and IR measurements; ICC was 0.974 for AXIAL measurements. Standard imaging, consisting of AP, IR, and LAT radiographs, consistently underestimates the actual displacement of medial epicondyle humerus fractures. The newly described AXIAL projection more accurately and reliably demonstrated the true displacement while reducing the need for advanced imaging such as computed tomography. This simple view can be easily obtained at a clinic visit, enhancing the surgeon's ability to determine the true displacement.

Rectus Pulley Displacements without Abnormal Oblique Contractility Explain Strabismus in Superior Oblique Palsy.

PubMed

Suh, Soh Youn; Le, Alan; Clark, Robert A; Demer, Joseph L

2016-06-01

Using high-resolution magnetic resonance imaging (MRI), we investigated whether rectus pulleys are significantly displaced in superior oblique (SO) palsy and whether displacements account for strabismus patterns. Prospective case-control study. Twenty-four patients diagnosed with SO palsy based on atrophy of the SO muscle on MRI and 19 age-matched orthotropic control subjects. High-resolution, surface coil MRI scans were obtained in multiple, contiguous, quasicoronal planes during monocular central gaze fixation. Pulley locations in oculocentric coordinates in the following subgroups of patients with SO palsy were compared with normal results in subgroups of patients with SO palsy: unilateral versus bilateral, congenital versus acquired, and isotropic (round) versus anisotropic (elongated) SO atrophy. Expected effects of pulley displacements were modeled using Orbit 1.8 (Eidactics, San Francisco, CA) computational simulation. Rectus pulley positions and ocular torsion. Rectus pulleys typically were displaced in SO palsy. In unilateral SO palsy, on average the medial rectus (MR) pulley was displaced 1.1 mm superiorly, the superior rectus (SR) pulley was displaced 0.8 mm temporally, and the inferior rectus (IR) pulley was displaced 0.6 mm superiorly and 0.9 mm nasally from normal. Displacements were similar in bilateral SO palsy, with the SR pulley additionally displaced 0.9 mm superiorly. However, the lateral rectus pulley was not displaced in either unilateral or bilateral SO palsy. The SR and MR pulleys were displaced in congenital SO palsy, whereas the IR and MR pulleys were displaced in acquired palsy. Pulley positions did not differ between isotropic and anisotropic palsy or between patients with cyclotropia of less than 7° versus cyclotropia of 7° or more. Simulations predicted that the observed pulley displacements alone could cause patterns of incomitant strabismus typical of SO palsy, without requiring any abnormality of SO or inferior oblique strength. Rectus pulley displacements alone, without abnormal oblique muscle contractility, can create the clinical patterns of incomitant strabismus in SO palsy. This finding supports accumulating evidence that clinical binocular misalignment patterns are not reliable indicators of contractile function of the SO muscle. Ocular torsion does not correlate with and thus cannot account for pulley displacements in SO palsy. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

14 CFR 61.68 - Category III pilot authorization requirements.

Code of Federal Regulations, 2013 CFR

2013-01-01

... height, as applicable, including use of a radar altimeter; (iii) Recognition of and proper reaction to...; and (xii) Recognition of, and reaction to, airborne or ground system faults or abnormalities... adverse lateral touchdown displacement allowing a safe landing on the runway; and (D) In weather...

14 CFR 61.68 - Category III pilot authorization requirements.

Code of Federal Regulations, 2014 CFR

2014-01-01

... height, as applicable, including use of a radar altimeter; (iii) Recognition of and proper reaction to...; and (xii) Recognition of, and reaction to, airborne or ground system faults or abnormalities... adverse lateral touchdown displacement allowing a safe landing on the runway; and (D) In weather...

14 CFR 61.68 - Category III pilot authorization requirements.

Code of Federal Regulations, 2012 CFR

2012-01-01

... height, as applicable, including use of a radar altimeter; (iii) Recognition of and proper reaction to...; and (xii) Recognition of, and reaction to, airborne or ground system faults or abnormalities... adverse lateral touchdown displacement allowing a safe landing on the runway; and (D) In weather...

A low-temperature ductile shear zone: The gypsum-dominated western extension of the brittle Fella-Sava Fault, Southern Alps.

PubMed

Bartel, Esther Maria; Neubauer, Franz; Heberer, Bianca; Genser, Johann

2014-12-01

Based on structural and fabric analyses at variable scales we investigate the evaporitic gypsum-dominated Comeglians-Paularo shear zone in the Southern Alps (Friuli). It represents the lateral western termination of the brittle Fella-Sava Fault. Missing dehydration products of gypsum and the lack of annealing indicate temperatures below 100 °C during development of the shear zone. Despite of such low temperatures the shear zone clearly exhibits mylonitic flow, thus evidencing laterally coeval activity of brittle and viscous deformation. The dominant structures within the gypsum rocks of the Lower Bellerophon Formation are a steeply to gently S-dipping foliation, a subhorizontal stretching lineation and pure shear-dominated porphyroclast systems. A subordinate simple shear component with dextral displacement is indicated by scattered σ-clasts. Both meso- and microscale structures are characteristic of a subsimple shear type of deformation with components of both coaxial and non-coaxial strain. Shortening in a transpressive regime was accommodated by right-lateral displacement and internal pure shear deformation within the Comeglians-Paularo shear zone. The shear zone shows evidence for a combination of two stretching faults, where stretching occurred in the rheologically weaker gypsum member and brittle behavior in enveloping lithologies.

Detection of passive movement of the arytenoid cartilage in unilateral vocal-fold paralysis by laryngoscopic observation: useful diagnostic findings.

PubMed

Okamoto, Isaku; Tokashiki, Ryoji; Hiramatsu, Hiroyuki; Motohashi, Ray; Suzuki, Mamoru

2012-02-01

In a previous study of patients with unilateral vocal-fold paralysis (UVFP), three-dimensional computed tomography (3DCT) revealed passive movement during phonation, with the arytenoid cartilage on the paralyzed side pushed to the unaffected side and deviated upwards. The present work compares the 3DCT findings with those obtained by 2-dimensional endoscopy to visualize the vertical passive movement of the arytenoid cartilage. The study population consisted of 23 patients with UVFP and two with laryngeal deviation but normal movement of the vocal folds. Two endoscopic findings represented cranial deviation during phonation: posterior deviation of the arytenoid hump and lateral deviation of the muscular process. These two findings were classified into four grades, ranging from 0 (normal) to 3 (severe). Cranial displacement detected by 3DCT was also classified into four grades. Significant correlations were found between the 3DCT-determined grade of cranial displacement of the arytenoid cartilage and the grade assigned based on the two endoscopic findings. Moreover, lateral deviation of the muscular process was more significantly correlated with 3DCT grade than with endoscopic grade. Thus, endoscopic findings may be useful in the diagnosis of vocal-fold paralysis, and passive lateral deviation of the muscular process as an indicator of UVFP.

Applying a pelvic corrective force induces forced use of the paretic leg and improves paretic leg EMG activities of individuals post-stroke during treadmill walking.

PubMed

Hsu, Chao-Jung; Kim, Janis; Tang, Rongnian; Roth, Elliot J; Rymer, William Z; Wu, Ming

2017-10-01

To determine whether applying a mediolateral corrective force to the pelvis during treadmill walking would enhance muscle activity of the paretic leg and improve gait symmetry in individuals with post-stroke hemiparesis. Fifteen subjects with post-stroke hemiparesis participated in this study. A customized cable-driven robotic system based over a treadmill generated a mediolateral corrective force to the pelvis toward the paretic side during early stance phase. Three different amounts of corrective force were applied. Electromyographic (EMG) activity of the paretic leg, spatiotemporal gait parameters and pelvis lateral displacement were collected. Significant increases in integrated EMG of hip abductor, medial hamstrings, soleus, rectus femoris, vastus medialis and tibialis anterior were observed when pelvic corrective force was applied, with pelvic corrective force at 9% of body weight inducing greater muscle activity than 3% or 6% of body weight. Pelvis lateral displacement was more symmetric with pelvic corrective force at 9% of body weight. Applying a mediolateral pelvic corrective force toward the paretic side may enhance muscle activity of the paretic leg and improve pelvis displacement symmetry in individuals post-stroke. Forceful weight shift to the paretic side could potentially force additional use of the paretic leg and improve the walking pattern. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Matrix isolation apparatus with extended sample collection capability

DOEpatents

Reedy, Gerald T.

1987-01-01

A gas-sample collection device provides for the matrix isolation of increased amounts of a sample material for spectrographic analysis from a gas chromatographic separation. The device includes an evacuated sample collection chamber containing a disc-like specular carousel having a generally circular lateral surface upon which the sample is deposited in an inert gas matrix for infrared (IR) spectral analysis. The evacuated sample chamber is mounted in a fixed manner and is coupled to and supports a rotating cryostatic coupler which, in turn, supports the specular carousel within the collection chamber. A rotational drive system connected to the cryostatic coupler provides for its rotational displacement as well as that of the sample collecting carousel. In addition, rotation of the cryostatic coupler effects vertical displacement of the carousel to permit the collection of an extended sample band in a helical configuration on the entire lateral surface of the carousel. The various components of the carousel's angular/linear displacement drive system are located exterior to the cryostatic coupler for easy access and improved operation. The cryostatic coupler includes a 360.degree. rotary union assembly for permitting the delivery of a high pressure working fluid to the cryostatic coupler in a continuous flow manner for maintaining the specular carousel at a low temperature, e.g., 10.degree.-20.degree. K., for improved uninterrupted gas sample collection and analysis.

Effects of muscle activation on shear between human soleus and gastrocnemius muscles.

PubMed

Finni, T; Cronin, N J; Mayfield, D; Lichtwark, G A; Cresswell, A G

2017-01-01

Lateral connections between muscles provide pathways for myofascial force transmission. To elucidate whether these pathways have functional roles in vivo, we examined whether activation could alter the shear between the soleus (SOL) and lateral gastrocnemius (LG) muscles. We hypothesized that selective activation of LG would decrease the stretch-induced shear between LG and SOL. Eleven volunteers underwent a series of knee joint manipulations where plantar flexion force, LG, and SOL muscle fascicle lengths and relative displacement of aponeuroses between the muscles were obtained. Data during a passive full range of motion were recorded, followed by 20° knee extension stretches in both passive conditions and with selective electrical stimulation of LG. During active stretch, plantar flexion force was 22% greater (P < 0.05) and relative displacement of aponeuroses was smaller than during passive stretch (P < 0.05). Soleus fascicle length changes did not differ between passive and active stretches but LG fascicles stretched less in the active than passive condition when the stretch began at angles of 70° and 90° of knee flexion (P < 0.05). The activity-induced decrease in the relative displacement of SOL and LG suggests stronger (stiffer) connectivity between the two muscles, at least at flexed knee joint angles, which may serve to facilitate myofascial force transmission. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Rapid sampling of stochastic displacements in Brownian dynamics simulations with stresslet constraints

NASA Astrophysics Data System (ADS)

Fiore, Andrew M.; Swan, James W.

2018-01-01

Brownian Dynamics simulations are an important tool for modeling the dynamics of soft matter. However, accurate and rapid computations of the hydrodynamic interactions between suspended, microscopic components in a soft material are a significant computational challenge. Here, we present a new method for Brownian dynamics simulations of suspended colloidal scale particles such as colloids, polymers, surfactants, and proteins subject to a particular and important class of hydrodynamic constraints. The total computational cost of the algorithm is practically linear with the number of particles modeled and can be further optimized when the characteristic mass fractal dimension of the suspended particles is known. Specifically, we consider the so-called "stresslet" constraint for which suspended particles resist local deformation. This acts to produce a symmetric force dipole in the fluid and imparts rigidity to the particles. The presented method is an extension of the recently reported positively split formulation for Ewald summation of the Rotne-Prager-Yamakawa mobility tensor to higher order terms in the hydrodynamic scattering series accounting for force dipoles [A. M. Fiore et al., J. Chem. Phys. 146(12), 124116 (2017)]. The hydrodynamic mobility tensor, which is proportional to the covariance of particle Brownian displacements, is constructed as an Ewald sum in a novel way which guarantees that the real-space and wave-space contributions to the sum are independently symmetric and positive-definite for all possible particle configurations. This property of the Ewald sum is leveraged to rapidly sample the Brownian displacements from a superposition of statistically independent processes with the wave-space and real-space contributions as respective covariances. The cost of computing the Brownian displacements in this way is comparable to the cost of computing the deterministic displacements. The addition of a stresslet constraint to the over-damped particle equations of motion leads to a stochastic differential algebraic equation (SDAE) of index 1, which is integrated forward in time using a mid-point integration scheme that implicitly produces stochastic displacements consistent with the fluctuation-dissipation theorem for the constrained system. Calculations for hard sphere dispersions are illustrated and used to explore the performance of the algorithm. An open source, high-performance implementation on graphics processing units capable of dynamic simulations of millions of particles and integrated with the software package HOOMD-blue is used for benchmarking and made freely available in the supplementary material (ftp://ftp.aip.org/epaps/journ_chem_phys/E-JCPSA6-148-012805)

Three-dimensional ultrasound strain imaging of skeletal muscles

NASA Astrophysics Data System (ADS)

Gijsbertse, K.; Sprengers, A. M. J.; Nillesen, M. M.; Hansen, H. H. G.; Lopata, R. G. P.; Verdonschot, N.; de Korte, C. L.

2017-01-01

In this study, a multi-dimensional strain estimation method is presented to assess local relative deformation in three orthogonal directions in 3D space of skeletal muscles during voluntary contractions. A rigid translation and compressive deformation of a block phantom, that mimics muscle contraction, is used as experimental validation of the 3D technique and to compare its performance with respect to a 2D based technique. Axial, lateral and (in case of 3D) elevational displacements are estimated using a cross-correlation based displacement estimation algorithm. After transformation of the displacements to a Cartesian coordinate system, strain is derived using a least-squares strain estimator. The performance of both methods is compared by calculating the root-mean-squared error of the estimated displacements with the calculated theoretical displacements of the phantom experiments. We observe that the 3D technique delivers more accurate displacement estimations compared to the 2D technique, especially in the translation experiment where out-of-plane motion hampers the 2D technique. In vivo application of the 3D technique in the musculus vastus intermedius shows good resemblance between measured strain and the force pattern. Similarity of the strain curves of repetitive measurements indicates the reproducibility of voluntary contractions. These results indicate that 3D ultrasound is a valuable imaging tool to quantify complex tissue motion, especially when there is motion in three directions, which results in out-of-plane errors for 2D techniques.

Geometry and kinematics of the eastern Lake Mead fault system in the Virgin Mountains, Nevada and Arizona

USGS Publications Warehouse

Beard, Sue; Campagna, David J.; Anderson, R. Ernest

2010-01-01

The Lake Mead fault system is a northeast-striking, 130-km-long zone of left-slip in the southeast Great Basin, active from before 16 Ma to Quaternary time. The northeast end of the Lake Mead fault system in the Virgin Mountains of southeast Nevada and northwest Arizona forms a partitioned strain field comprising kinematically linked northeast-striking left-lateral faults, north-striking normal faults, and northwest-striking right-lateral faults. Major faults bound large structural blocks whose internal strain reflects their position within a left step-over of the left-lateral faults. Two north-striking large-displacement normal faults, the Lakeside Mine segment of the South Virgin–White Hills detachment fault and the Piedmont fault, intersect the left step-over from the southwest and northeast, respectively. The left step-over in the Lake Mead fault system therefore corresponds to a right-step in the regional normal fault system.Within the left step-over, displacement transfer between the left-lateral faults and linked normal faults occurs near their junctions, where the left-lateral faults become oblique and normal fault displacement decreases away from the junction. Southward from the center of the step-over in the Virgin Mountains, down-to-the-west normal faults splay northward from left-lateral faults, whereas north and east of the center, down-to-the-east normal faults splay southward from left-lateral faults. Minimum slip is thus in the central part of the left step-over, between east-directed slip to the north and west-directed slip to the south. Attenuation faults parallel or subparallel to bedding cut Lower Paleozoic rocks and are inferred to be early structures that accommodated footwall uplift during the initial stages of extension.Fault-slip data indicate oblique extensional strain within the left step-over in the South Virgin Mountains, manifested as east-west extension; shortening is partitioned between vertical for extension-dominated structural blocks and south-directed for strike-slip faults. Strike-slip faults are oblique to the extension direction due to structural inheritance from NE-striking fabrics in Proterozoic crystalline basement rocks.We hypothesize that (1) during early phases of deformation oblique extension was partitioned to form east-west–extended domains bounded by left-lateral faults of the Lake Mead fault system, from ca. 16 to 14 Ma. (2) Beginning ca. 13 Ma, increased south-directed shortening impinged on the Virgin Mountains and forced uplift, faulting, and overturning along the north and west side of the Virgin Mountains. (3) By ca. 10 Ma, initiation of the younger Hen Spring to Hamblin Bay fault segment of the Lake Mead fault system accommodated westward tectonic escape, and the focus of south-directed shortening transferred to the western Lake Mead region. The shift from early partitioned oblique extension to south-directed shortening may have resulted from initiation of right-lateral shear of the eastern Walker Lane to the west coupled with left-lateral shear along the eastern margin of the Great Basin.

Variable-order fractional MSD function to describe the evolution of protein lateral diffusion ability in cell membranes

NASA Astrophysics Data System (ADS)

Yin, Deshun; Qu, Pengfei

2018-02-01

Protein lateral diffusion is considered anomalous in the plasma membrane. And this diffusion is related to membrane microstructure. In order to better describe the property of protein lateral diffusion and find out the inner relationship between protein lateral diffusion and membrane microstructure, this article applies variable-order fractional mean square displacement (f-MSD) function for characterizing the anomalous diffusion. It is found that the variable order can reflect the evolution of diffusion ability. The results of numerical simulation demonstrate variable-order f-MSD function can predict the tendency of anomalous diffusion during the process of confined diffusion. It is also noted that protein lateral diffusion ability during the processes of confined and hop diffusion can be split into three parts. In addition, the comparative analyses reveal that the variable order is related to the confinement-domain size and microstructure of compartment boundary too.

Rules and Self-Organizing Properties of Post-embryonic Plant Organ Cell Division Patterns.

PubMed

von Wangenheim, Daniel; Fangerau, Jens; Schmitz, Alexander; Smith, Richard S; Leitte, Heike; Stelzer, Ernst H K; Maizel, Alexis

2016-02-22

Plants form new organs with patterned tissue organization throughout their lifespan. It is unknown whether this robust post-embryonic organ formation results from stereotypic dynamic processes, in which the arrangement of cells follows rigid rules. Here, we combine modeling with empirical observations of whole-organ development to identify the principles governing lateral root formation in Arabidopsis. Lateral roots derive from a small pool of founder cells in which some take a dominant role as seen by lineage tracing. The first division of the founders is asymmetric, tightly regulated, and determines the formation of a layered structure. Whereas the pattern of subsequent cell divisions is not stereotypic between different samples, it is characterized by a regular switch in division plane orientation. This switch is also necessary for the appearance of patterned layers as a result of the apical growth of the primordium. Our data suggest that lateral root morphogenesis is based on a limited set of rules. They determine cell growth and division orientation. The organ-level coupling of the cell behavior ensures the emergence of the lateral root's characteristic features. We propose that self-organizing, non-deterministic modes of development account for the robustness of plant organ morphogenesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

The effect of lateral eccentricity on failure loads, kinematics, and canal occlusions of the cervical spine in axial loading.

PubMed

Van Toen, C; Melnyk, A D; Street, J; Oxland, T R; Cripton, P A

2014-03-21

Current neck injury criteria do not include limits for lateral bending combined with axial compression and this has been observed as a clinically relevant mechanism, particularly for rollover motor vehicle crashes. The primary objectives of this study were to evaluate the effects of lateral eccentricity (the perpendicular distance from the axial force to the centre of the spine) on peak loads, kinematics, and spinal canal occlusions of subaxial cervical spine specimens tested in dynamic axial compression (0.5 m/s). Twelve 3-vertebra human cadaver cervical spine specimens were tested in two groups: low and high eccentricity with initial eccentricities of 1 and 150% of the lateral diameter of the vertebral body. Six-axis loads inferior to the specimen, kinematics of the superior-most vertebra, and spinal canal occlusions were measured. High speed video was collected and acoustic emission (AE) sensors were used to define the time of injury. The effects of eccentricity on peak loads, kinematics, and canal occlusions were evaluated using unpaired Student t-tests. The high eccentricity group had lower peak axial forces (1544 ± 629 vs. 4296 ± 1693 N), inferior displacements (0.2 ± 1.0 vs. 6.6 ± 2.0 mm), and canal occlusions (27 ± 5 vs. 53 ± 15%) and higher peak ipsilateral bending moments (53 ± 17 vs. 3 ± 18 Nm), ipsilateral bending rotations (22 ± 3 vs. 1 ± 2°), and ipsilateral displacements (4.5 ± 1.4 vs. -1.0 ± 1.3 mm, p<0.05 for all comparisons). These results provide new insights to develop prevention, recognition, and treatment strategies for compressive cervical spine injuries with lateral eccentricities. © 2013 Published by Elsevier Ltd.

Relationship Between Head-Turn Gait Speed and Lateral Balance Function in Community-Dwelling Older Adults.

PubMed

Singh, Harshvardhan; Sanders, Ozell; McCombe Waller, Sandy; Bair, Woei-Nan; Beamer, Brock; Creath, Robert A; Rogers, Mark W

2017-10-01

To determine and compare gait speed during head-forward and side-to-side head-turn walking in individuals with lower versus greater lateral balance. Cross-sectional study. University research laboratory. Older adults (N=93; 42 men, 51 women; mean age ± SD, 73 ± 6.08y) who could walk independently. (1) Balance tolerance limit (BTL), defined as the lowest perturbation intensity where a multistep balance recovery pattern was first evoked in response to randomized lateral waist-pull perturbations of standing balance to the left and right sides, at 6 different intensities (range from level 2: 4.5-cm displacement at 180cm/s 2 acceleration, to level 7: 22.5-cm displacement at 900cm/s 2 acceleration); (2) gait speed, determined using an instrumented gait mat; (3) balance, evaluated with the Activities-specific Balance Confidence Scale; and (4) mobility, determined with the Timed Up and Go (TUG). Individuals with low versus high BTL had a slower self-selected head-forward gait speed and head-turn gait speed (P=.002 and P<.001, respectively); the magnitude of difference was greater in head-turn gait speed than head-forward gait speed (Cohen's d=1.0 vs 0.6). Head-turn gait speed best predicted BTL. BTL was moderately and positively related (P=.003) to the ABC Scale and negatively related (P=.017) to TUG. Head-turn gait speed is affected to a greater extent than head-forward gait speed in older individuals with poorer lateral balance and at greater risk of falls. Moreover, head-turn gait speed can be used to assess the interactions of limitations in lateral balance function and gait speed in relation to fall risk in older adults. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

FRACOR-software toolbox for deterministic mapping of fracture corridors in oil fields on AutoCAD platform

NASA Astrophysics Data System (ADS)

Ozkaya, Sait I.

2018-03-01

Fracture corridors are interconnected large fractures in a narrow sub vertical tabular array, which usually traverse entire reservoir vertically and extended for several hundreds of meters laterally. Fracture corridors with their huge conductivities constitute an important element of many fractured reservoirs. Unlike small diffuse fractures, actual fracture corridors must be mapped deterministically for simulation or field development purposes. Fracture corridors can be identified and quantified definitely with borehole image logs and well testing. However, there are rarely sufficient image logs or well tests, and it is necessary to utilize various fracture corridor indicators with varying degrees of reliability. Integration of data from many different sources, in turn, requires a platform with powerful editing and layering capability. Available commercial reservoir characterization software packages, with layering and editing capabilities, can be cost intensive. CAD packages are far more affordable and may easily acquire the versatility and power of commercial software packages with addition of a small software toolbox. The objective of this communication is to present FRACOR, a software toolbox which enables deterministic 2D fracture corridor mapping and modeling on AutoCAD platform. The FRACOR toolbox is written in AutoLISPand contains several independent routines to import and integrate available fracture corridor data from an oil field, and export results as text files. The resulting fracture corridor maps consists mainly of fracture corridors with different confidence levels from combination of static and dynamic data and exclusion zones where no fracture corridor can exist. The exported text file of fracture corridors from FRACOR can be imported into an upscaling programs to generate fracture grid for dual porosity simulation or used for field development and well planning.

Developmental logics: Brain science, child welfare, and the ethics of engagement in Japan.

PubMed

Goldfarb, Kathryn E

2015-10-01

This article explores the unintended consequences of the ways scholars and activists take up the science of child development to critique the Japanese child welfare system. Since World War II, Japan has depended on a system of child welfare institutions (baby homes and children's homes) to care for state wards. Opponents of institutional care advocate instead for family foster care and adoption, and cite international research on the developmental harms of institutionalizing newborns and young children during the "critical period" of the first few years. The "critical period" is understood as the time during which the caregiving a child receives shapes neurological development and later capacity to build interpersonal relationships. These discourses appear to press compellingly for system reform, the proof resting on seemingly objective knowledge about child development. However, scientific evidence of harm is often mobilized in tandem with arguments that the welfare system is rooted in Japanese culture, suggesting durability and resistance to change. Further, reform efforts that use universalizing child science as "proof" of the need for change are prone to slip into deterministic language that pathologizes the experiences of people who grew up in the system. This article explores the reasons why deterministic models of child development, rather than more open-ended models like neuroplasticity, dominate activist rhetorics. It proposes a concept, "ethics of engagement," to advocate for attention to multiple scales and domains through which interpersonal ties are experienced and embodied over time. Finally, it suggests the possibility of child welfare reform movements that take seriously the need for caring and transformative relationships throughout life, beyond the first "critical years," that do not require deterministic logics of permanent delay or damage. Copyright © 2014 Elsevier Ltd. All rights reserved.

Metallic-thin-film instability with spatially correlated thermal noise.

PubMed

Diez, Javier A; González, Alejandro G; Fernández, Roberto

2016-01-01

We study the effects of stochastic thermal fluctuations on the instability of the free surface of a flat liquid metallic film on a solid substrate. These fluctuations are represented by a stochastic noise term added to the deterministic equation for the film thickness within the long-wave approximation. Unlike the case of polymeric films, we find that this noise, while remaining white in time, must be colored in space, at least in some regimes. The corresponding noise term is characterized by a nonzero correlation length, ℓ_{c}, which, combined with the size of the system, leads to a dimensionless parameter β that accounts for the relative importance of the spatial correlation (β∼ℓ_{c}^{-1}). We perform the linear stability analysis (LSA) of the film both with and without the noise term and find that for ℓ_{c} larger than some critical value (depending on the system size), the wavelength of the peak of the spectrum is larger than that corresponding to the deterministic case, while for smaller ℓ_{c} this peak corresponds to smaller wavelength than the latter. Interestingly, whatever the value of ℓ_{c}, the peak always approaches the deterministic one for larger times. We compare LSA results with the numerical simulations of the complete nonlinear problem and find a good agreement in the power spectra for early times at different values of β. For late times, we find that the stochastic LSA predicts well the position of the dominant wavelength, showing that nonlinear interactions do not modify the trends of the early linear stages. Finally, we fit the theoretical spectra to experimental data from a nanometric laser-melted copper film and find that at later times, the adjustment requires smaller values of β (larger space correlations).

Metallic-thin-film instability with spatially correlated thermal noise

NASA Astrophysics Data System (ADS)

Diez, Javier A.; González, Alejandro G.; Fernández, Roberto

2016-01-01

We study the effects of stochastic thermal fluctuations on the instability of the free surface of a flat liquid metallic film on a solid substrate. These fluctuations are represented by a stochastic noise term added to the deterministic equation for the film thickness within the long-wave approximation. Unlike the case of polymeric films, we find that this noise, while remaining white in time, must be colored in space, at least in some regimes. The corresponding noise term is characterized by a nonzero correlation length, ℓc, which, combined with the size of the system, leads to a dimensionless parameter β that accounts for the relative importance of the spatial correlation (β ˜ℓc-1 ). We perform the linear stability analysis (LSA) of the film both with and without the noise term and find that for ℓc larger than some critical value (depending on the system size), the wavelength of the peak of the spectrum is larger than that corresponding to the deterministic case, while for smaller ℓc this peak corresponds to smaller wavelength than the latter. Interestingly, whatever the value of ℓc, the peak always approaches the deterministic one for larger times. We compare LSA results with the numerical simulations of the complete nonlinear problem and find a good agreement in the power spectra for early times at different values of β . For late times, we find that the stochastic LSA predicts well the position of the dominant wavelength, showing that nonlinear interactions do not modify the trends of the early linear stages. Finally, we fit the theoretical spectra to experimental data from a nanometric laser-melted copper film and find that at later times, the adjustment requires smaller values of β (larger space correlations).

40 CFR 86.150-98 - Refueling test procedure; overview.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles and New Light-Duty Trucks and New Otto-Cycle... generation or displacement of fuel tank vapor during vehicle refueling. The refueling emissions shall be...

Consequences of U.S. Navy Diving Mishaps: Air Embolism and Barotrauma.

DTIC Science & Technology

1985-12-01

diver), displacement of the intervertebral disc (I diver), and various combinations of hearing impairment, otitis ", media , otitis externa, and other...hospitalization for otitis media , otitis externa, and other diseases of the ear and mastoid process (8 days later)/ released from active duty (2 yrs, 4

Proprioceptive versus Visual Control in Autistic Children.

ERIC Educational Resources Information Center

Masterton, B. A.; Biederman, G. B.

1983-01-01

The autistic children's presumed preference for proximal over distal sensory input was studied by requiring that "autistic," retarded, and "normal" children (7-15 years old) adapt to lateral displacement of the visual field. Only autistic Ss demonstrated transfer of adaptation to the nonadapted hand, indicating reliance on proprioception rather…

[Sensitivity of four representative angular cephalometric measures].

PubMed

Xü, T; Ahn, J; Baumrind, S

2000-05-01

Examined the sensitivity of four representative cephalometric angles to the detection of different vectors of craniofacial growth. Landmark coordinate data from a stratified random sample of 48 adolescent subjects were used to calculate conventional values for changes between the pretreatment and end-of-treatment lateral cephalograms. By modifying the end-of-treatment coordinate values appropriately, the angular changes could be recalculated reflecting three hypothetical situations: Case 1. What if there were no downward landmark displacement between timepoints? Case 2. What if there were no forward landmark displacement between timepoints? Case 3. What if there were no Nasion change? These questions were asked for four representative cephalometric angles: SNA, ANB, NAPg and UI-SN. For Case 1, the associations (r) between the baseline and the modified measure for the three angles were very highly significant (P < 0.001) with r2 values no lower than 0.94! For Case 2, however, the associations were much weaker and no r value reached significance. These angular measurements are less sensitive for measuring downward landmark displacement than they are for measuring forward landmark displacement.

One Year Later: Mental Illness Prevalence and Disparities Among New Orleans Residents Displaced by Hurricane Katrina

PubMed Central

VanLandingham, Mark

2009-01-01

Objectives. We examined whether there were high levels of mental illness among displaced New Orleans, LA, residents in the fall of 2006, 1 year after Hurricane Katrina. Methods. We used data from the Displaced New Orleans Residents Pilot Study, which measured the prevalence of probable mild or moderate and serious mental illness among a representative sample of people who resided in New Orleans at the time of the hurricane, including people who evacuated the city and did not return. We also analyzed disparities in mental illness by race, education, and income. Results. We found high rates of mental illness in our sample and major disparities in mental illness by race, education, and income. Severe damage to or destruction of an individual's home was a major covariate of mental illness. Conclusions. The prevalence of mental illness remained high in the year following Hurricane Katrina, in contrast to the pattern found after other disasters. Economic losses and displacement may account for this finding as well as the disparity in mental illness between Blacks and Whites. PMID:19890178

Acoustic Emission Parameters of Three Gorges Sandstone during Shear Failure

NASA Astrophysics Data System (ADS)

Xu, Jiang; Liu, Yixin; Peng, Shoujian

2016-12-01

In this paper, an experimental investigation of sandstone samples from the Three Gorges during shear failure was conducted using acoustic emission (AE) and direct shear tests. The AE count rate, cumulative AE count, AE energy, and amplitude of the sandstone samples were determined. Then, the relationships among the AE signals and shearing behaviors of the samples were analyzed in order to detect micro-crack initiation and propagation and reflect shear failure. The results indicated that both the shear strength and displacement exhibited a logarithmic relationship with the displacement rate at peak levels of stress. In addition, the various characteristics of the AE signals were apparent in various situations. The AE signals corresponded with the shear stress under different displacement rates. As the displacement rate increased, the amount of accumulative damage to each specimen decreased, while the AE energy peaked earlier and more significantly. The cumulative AE count primarily increased during the post-peak period. Furthermore, the AE count rate and amplitude exhibited two peaks during the peak shear stress period due to crack coalescence and rock bridge breakage. These isolated cracks later formed larger fractures and eventually caused ruptures.

Changes in mental disorder prevalence among conflict-affected populations: a prospective study in Sri Lanka (COMRAID-R).

PubMed

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

2015-03-10

Longitudinal data are lacking on mental health trajectories following conflict resolution and return migration. COMRAID-R is a follow-up study of Muslims displaced by conflict from Northern Sri Lanka 20 years ago who are now beginning to return. Of 450 participants in displacement interviewed in 2011, 338 (75.1%) were re-interviewed a year later, and a supplementary random sample (n = 228) was drawn from return migrants with a comparable displacement history. Common mental disorder (CMD; Patient Health Questionnaire) and post-traumatic stress disorder (CIDI-subscale) were measured. A CMD prevalence of 18.8% (95%CI 15.2-22.5) at baseline had reduced to 8.6% (5.6-11.7) at follow-up in those remaining in displacement, and was 10.3% (6.5-14.1) in return migrants. PTSD prevalences were 2.4%, 0.3% and 1.6% respectively. We observed a substantial decrease in CMD prevalence in this population over a short period, which may reflect the prospect of return migration and associated optimism following conflict resolution.

Results of aircraft open-loop tests of an experimental magnetic leader cable system for guidance during roll-out and turnoff

NASA Technical Reports Server (NTRS)

Bundick, W. Thomas; Middleton, David B.; Poole, William L.

1990-01-01

An experimental magnetic leader cable (MLC) system designed to measure aircraft lateral displacement from centerline and heading relative to centerline during rollout, turnoff, and taxi was tested at NASA's Wallops Flight Facility using NASA's Transport System Research Vehicle (TSRV), a modified B-737. The MLC system consisted of ground equipment that produced a magnetic field about a wire along runway centerline and airborne equipment that detected the strength and direction of this field and computed displacement and heading. Results of these tests indicate that estimates of aircraft displacement from centerline produced by the magnetic leader cable system using either of the two algorithms appear to be adequate for use by an automatic control system during rollout, turnoff, and taxi. Estimates of heading, however, are not sufficiently accurate for use, probably because of distortion of the magnetic field by the metal aircraft.

The effect of pre-cure bracket movement on shear bond strength during placement of orthodontic brackets, an in vitro study.

PubMed

Tam, Byron; Bollu, Prashanti; Chaudhry, Kishore; Subramani, Karthikeyan

2017-10-01

The purpose of this study was to determine the influence of linear and rotational pre-cure bracket displacement during the bonding procedure on shear bond strength (SBS) of orthodontic brackets. Stainless steel orthodontic premolar brackets were bonded to the buccal surfaces of 50 human pre-molars with a conventional two-step bonding protocol. Extracted human pre-molars were divided into 5 groups (n=10/group). In the Control Group, the brackets were bonded with no pre-cure bracket displacement or rotation. The Rotation Group was bonded with 45 degrees of pre-cure rotation. The Displacement Group was bonded with 2mm pre-cure linear displacement. The Rotation-Displacement Group was bonded with pre-cure movements of 45º counter-clockwise rotation and 2mm displacement. The Slippage Group was bonded with 2mm each of mesial and distal pre-cure linear displacement. Photo-activation was carried out on the lateral sides of the bracket. Shear debonding force was measured, 24 hours after initial bonding, with an Instron universal testing machine using a knife-edged chisel. Data was analyzed using one-way ANOVA test. Adhesive Remnant Index (ARI) was scored under 15x magnification. The ARI data was analyzed using the Chi-square test ( p -value < 0.05). No statistically significant differences were detected among the control and experimental groups ( p = 0.331). The rotation and displacement group showed the highest mean SBS than all other groups. Mean SBS for all groups were above the clinically acceptable range. No statistically significant differences were detected in ARI scores among groups ( p = 0.071). Linear and rotational pre-cure bracket displacements do not appear to effect the shear bond strength of orthodontic brackets. Key words: Shear bond strength, orthodontic bracket, displacement, rotation, adhesive remnant index, pre-cure movement.

Comparison of the different kinematic patterns during lateral bending between subjects with and without recurrent low back pain.

PubMed

Sung, Paul S; Danial, Pamela; Lee, Dongchul C

2016-10-01

Lateral bending is a prerequisite for various functional activities of daily life, which require combined three-dimensional motion. Even though a number of studies have evaluated spinal kinematic changes during lateral bending, the literature reveals a lack of data based on limb dominance. The purpose of this study was to compare kinematic angular displacement of the spinal regions for dominant and non-dominant lateral bending in subjects with and without recurrent low back pain. Forty-four right hand dominant individuals with recurrent low back pain (43.1 [17.4] years) and without low back pain (39.7 [18.7] years) participated in this study. All participants were asked to perform trunk lateral bending to the dominant and non-dominant sides with a bar, three times repeatedly. The outcome measures included three-dimensional angular displacements for the three regions of the spine (upper thorax, lower thorax, and lumbar spine). Lumbar rotation (degrees) increased to the dominant side in the low back pain group (9.29 [1.06]) compared to the control group (6.20 [1.02]) with increased rotation in the upper thorax as well (t=-2.09, p=0.04). However, the upper thorax rotation increased in the low back pain group to the non-dominant side (t=2.08, p=0.03) and to the dominant side (t=-2.35, p=0.02). There was a group interaction with planes (F=5.82, p=0.02) during lateral bending. Although lower thorax motion was not different between groups, increased lumbar spine and upper thorax rotations to the dominant side in the low back pain group were evident during lateral bending. This directional asymmetry should be carefully monitored to understand increased lumbar rotation to the dominant side in subjects with recurrent low back pain. The interactions between group and plane explain compensation strategies through increased lumbar rotation to the dominant side with decreased lateral bending of the upper thorax in subjects with recurrent low back pain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Seventy-meter antenna performance predictions: GTD analysis compared with traditional ray-tracing methods

NASA Technical Reports Server (NTRS)

Schredder, J. M.

1988-01-01

A comparative analysis was performed, using both the Geometrical Theory of Diffraction (GTD) and traditional pathlength error analysis techniques, for predicting RF antenna gain performance and pointing corrections. The NASA/JPL 70 meter antenna with its shaped surface was analyzed for gravity loading over the range of elevation angles. Also analyzed were the effects of lateral and axial displacements of the subreflector. Significant differences were noted between the predictions of the two methods, in the effect of subreflector displacements, and in the optimal subreflector positions to focus a gravity-deformed main reflector. The results are of relevance to future design procedure.

Single-Point Attachment Wind Damper for Launch Vehicle On-Pad Motion

NASA Technical Reports Server (NTRS)

Hrinda, Glenn A.

2009-01-01

A single-point-attachment wind-damper device is proposed to reduce on-pad motion of a cylindrical launch vehicle. The device is uniquely designed to attach at only one location along the vehicle and capable of damping out wind gusts from any lateral direction. The only source of damping is from two viscous dampers in the device. The effectiveness of the damper design in reducing vehicle displacements is determined from transient analysis results using an Ares I-X launch vehicle. Combinations of different spring stiffnesses and damping are used to show how the vehicle's displacement response is significantly reduced during a wind gust.

Transmission electron diffraction determination of the Ge(001)-(2 × 1) surface structure

NASA Astrophysics Data System (ADS)

Collazo-Davila, C.; Grozea, D.; Landree, E.; Marks, L. D.

1997-04-01

The lateral displacements in the Ge(001)-(2 × 1) surface reconstruction have been determined using transmission electron diffraction (TED). The best-fit model includes displacements extending six layers into the bulk. The atomic positions found agree with X-ray studies to within a few hundredths of an ångström. With the positions determined so precisely, it is suggested that the Ge(001)-(2 × 1) surface can now serve as a standard for comparison with theoretical surface structure calculations. The results from the currently available theoretical studies on the surface are compared with the experimentally determined structure.

Surgical correction of severe strabismus and enophthalmos secondary to zygomatic arch fracture in a dog.

PubMed

Konrade, Kricket A; Clode, Alison B; Michau, Tammy M; Roe, Simon C; Trumpatori, Brian J; Krug, William V; Gilger, Brian C

2009-01-01

A grossly displaced segmental zygomatic arch fracture with marked ventro-lateral deviation of the left globe was diagnosed in a 3-month-old male German Shepherd dog following a bite injury. The fracture was approached via a modified lateral orbitotomy and a fragment of the lacrimal bone removed. The rostral portion of the fracture was stabilized with a 5-hole 2.0 dynamic compression plate bone plate. The surgical correction achieved sufficient skeletal fixation for proper anatomical reduction of the globe and excellent cosmetic and functional outcomes.

Traumatic corneal flap displacement after laser in situ keratomileusis (LASIK).

PubMed

Tsai, Tsung-Han; Peng, Kai-Ling; Lin, Chien-Jen

2017-01-01

Laser in situ keratomileusis (LASIK) is the most common and popular procedure performed for the correction of refractive errors in the last two decades. We report a case of traumatic flap displacement with flap folding which occurred 3 years after LASIK was performed. Previous literature suggests that vision prognosis would be closely related to proper and prompt management of traumatic flap displacement with flap folding 3 years after LASIK. A 23-year-old female presented to our hospital who had undergone uneventful LASIK in both eyes 3 years prior. Unfortunately, she had suffered a blunt trauma in her right eye in a car accident. A late onset of corneal flap displacement was found with upper and lower portion of the flap being folded inside the corneal bed. Surgical intervention for debridement with subsequent reposition of corneal flap was performed as soon as possible in the operating room. A bandage contact lens was placed, and topical antibiotic and corticosteroids were given postoperatively. Two days after the operation, the displaced corneal flap was found to be well attached smoothly on the corneal bed without folds. The best-corrected visual acuity was 6/6 with refraction of -0.75 D to 1.0 D ×175° in her right eye 1 month later. We reviewed a total of 19 published cases of late-onset traumatic flap dislocations or displacements after LASIK with complete data from 2000 to 2014. Traumatic displacement of corneal flaps after LASIK may occur after blunt injury with specific direction of force to the flap margin, especially tangential one. According to the previous literature, late-onset traumatic flap displacement may happen at any time after LASIK and be caused by various types of injuries. Fortunately, good visual function could mostly be restored with immediate and proper management.

Needle detection in ultrasound using the spectral properties of the displacement field: a feasibility study

NASA Astrophysics Data System (ADS)

Beigi, Parmida; Salcudean, Tim; Rohling, Robert; Lessoway, Victoria A.; Ng, Gary C.

2015-03-01

This paper presents a new needle detection technique for ultrasound guided interventions based on the spectral properties of small displacements arising from hand tremour or intentional motion. In a block-based approach, the displacement map is computed for each block of interest versus a reference frame, using an optical flow technique. To compute the flow parameters, the Lucas-Kanade approach is used in a multiresolution and regularized form. A least-squares fit is used to estimate the flow parameters from the overdetermined system of spatial and temporal gradients. Lateral and axial components of the displacement are obtained for each block of interest at consecutive frames. Magnitude-squared spectral coherency is derived between the median displacements of the reference block and each block of interest, to determine the spectral correlation. In vivo images were obtained from the tissue near the abdominal aorta to capture the extreme intrinsic body motion and insertion images were captured from a tissue-mimicking agar phantom. According to the analysis, both the involuntary and intentional movement of the needle produces coherent displacement with respect to a reference window near the insertion site. Intrinsic body motion also produces coherent displacement with respect to a reference window in the tissue; however, the coherency spectra of intrinsic and needle motion are distinguishable spectrally. Blocks with high spectral coherency at high frequencies are selected, estimating a channel for needle trajectory. The needle trajectory is detected from locally thresholded absolute displacement map within the initial estimate. Experimental results show the RMS localization accuracy of 1:0 mm, 0:7 mm, and 0:5 mm for hand tremour, vibrational and rotational needle movements, respectively.

Kinematic measurements of the vocal-fold displacement waveform in typical children and adult populations: quantification of high-speed endoscopic videos.

PubMed

Patel, Rita; Donohue, Kevin D; Unnikrishnan, Harikrishnan; Kryscio, Richard J

2015-04-01

This article presents a quantitative method for assessing instantaneous and average lateral vocal-fold motion from high-speed digital imaging, with a focus on developmental changes in vocal-fold kinematics during childhood. Vocal-fold vibrations were analyzed for 28 children (aged 5-11 years) and 28 adults (aged 21-45 years) without voice disorders. The following kinematic features were analyzed from the vocal-fold displacement waveforms: relative velocity-based features (normalized average and peak opening and closing velocities), relative acceleration-based features (normalized peak opening and closing accelerations), speed quotient, and normalized peak displacement. Children exhibited significantly larger normalized peak displacements, normalized average and peak opening velocities, normalized average and peak closing velocities, peak opening and closing accelerations, and speed quotient compared to adult women. Values of normalized average closing velocity and speed quotient were higher in children compared to adult men. When compared to adult men, developing children typically have higher estimates of kinematic features related to normalized displacement and its derivatives. In most cases, the kinematic features of children are closer to those of adult men than adult women. Even though boys experience greater changes in glottal length and pitch as they mature, results indicate that girls experience greater changes in kinematic features compared to boys.

Displacement of a dental implant into the maxillary sinus after internal sinus floor elevation: report of a case and review of literature.

PubMed

Ding, Xiaojun; Wang, Qing; Guo, Xuehua; Yu, Youcheng

2015-01-01

Dental implant placement in the posterior maxilla may be complicated by implant migration into the maxillary sinus. To report the clinical and radiological characteristics of a patient who experienced dental implant displacement into the maxillary sinus following sinus floor elevation, and to compare our findings with those of other published reports of the displacement of dental implants. Implant placement and maxillary sinus elevation were performed simultaneously. The location of the displaced implant was monitored for 8 years, until the ectopic implant was surgically removed using the lateral window approach. The contributing factors, treatment modality, and clinical outcome for our patient were compared with those of patients reported in the literature. The clinical characteristics of our case were similar to those of patients with displaced implants who were also asymptomatic for long periods. The clinical outcome of our case was consistent with that of patients who underwent similar surgeries. Transnasal endoscopic removal of an ectopic implant may be suitable in cases in which the ectopic implant is accessible. Transoral direct approaches are adequate in most cases in which endoscopic approaches may be confounded. The bony-window transoral technique may allow the removal of large implants.

Relationship between friction force and orthodontic force at the leveling stage using a coated wire.

PubMed

Murayama, Masaki; Namura, Yasuhiro; Tamura, Takahiko; Iwai, Hiroaki; Shimizu, Noriyoshi

2013-01-01

The relationship between orthodontic force and friction produced from an archwire and brackets affects the sliding of the wire in the leveling stage. The purpose of this study was to evaluate the relationship between force and friction in a small esthetic nickel-titanium (Ni-Ti) wire. Five esthetic wires (three coated and two plated) and two small, plain Ni-Ti wires (0.012 and 0.014 inches) were used. We performed a three-point bending test according to ISO 15841 and the drawing test with a dental arch model designed with upper linguoversion of the lateral incisor in the arch (displacements of 0.5, 1.0, 2.0 and 3.0 mm), and evaluated the relationship between them. Unloading bending forces of all wires at displacements of less than 1.0 mm were larger than friction forces, but all friction forces at displacements exceeding 2.0 mm were larger than unloading bending forces. The arch likely expands when displacement from the proximal brackets exceeds 1.0 mm. The friction force of a martensite 0.014-inch Ni-Ti wire was significantly greater than those of the other esthetic and austenitic wires. A wire with the smallest possible friction force should be used in cases with more than 1.0 mm displacement.

'Life under the tent is not safe, especially for young women': understanding intersectional violence among internally displaced youth in Leogane, Haiti.

PubMed

Logie, Carmen H; Daniel, CarolAnn; Ahmed, Uzma; Lash, Rebecca

Haiti's 2010 earthquake devastated social, health, and economic infrastructure and left 2 million persons homeless. Over 6 years later 61,000 people remain displaced, most lacking protection, services, and durable solutions. Structural contexts elevate risks of gender-based violence (GBV) targeting internally displaced (ID) girls and women. We used an intersectionality framework to explore lived experiences and understanding of violence among ID young men and women in Leogane, Haiti. We conducted six focus groups, three with ID young women (n = 30) and three with ID young men (n = 30) aged 18-24 years, and 11 in-depth individual interviews with frontline workers in Leogane. Focus groups and interviews were conducted in Kreyol, transcribed verbatim, translated into English, and analyzed using narrative thematic techniques. Findings revealed violence experienced by ID youth was (re)produced at the intersection of gender, poverty, displacement, and age. Multi-level forms of violence included structural (e.g. poverty), community (e.g. gender norms, and interpersonal (e.g. family expectations) dimensions. Coping strategies spanned intrapersonal (hope), community (social support), and structural (employment/education) dimensions. Interventions to reduce violence should be tailored to address the social inequities that emerge at the intersection of youth, poverty, displacement, and hegemonic gender norms.

On the Morphological Description of Tracheal and Esophageal Displacement and Its Phylogenetic Distribution in Avialae

PubMed Central

Klingler, Jeremy J.

2016-01-01

This research examines the evolution and phylogenetic distribution of a peculiar and often overlooked character seen in birds, herein called tracheal and esophageal displacement. Tracheal and esophageal displacement refers to an asymmetrically situated trachea and/or esophagus along the length of the neck. This contrasts with what would be perceived as the “normal” (midsagittal) placement of these organs, wherein the two organs are situated along the ventral midline of the neck with no deviation. A total of forty-two bird species were examined (thirty-six of which came from dissections whereas six came from comments from previous literature or personal observations), as well as turtles, lizards, crocodylians, and mammals. This study found that essentially all birds have a laterally displaced trachea and/or esophagus. Lizards and mammals were seen to have normal, midsagittally placed tracheae and esophagi. Crocodylians were interesting in that alligators were defined by a normally situated trachea and esophagus whereas some crocodiles were characterized by displacement. In birds, the displacement may occur gradually along the neck, or it may happen immediately upon exiting the oropharynx. Displacement of these organs in birds is the result of a heavily modified neck wherein muscles that restrict mobility of the trachea and esophagus in lizards, alligators, and mammals (e.g., m. episternocleidomastoideus, m. omohyoideus, and m. sternohyoideus) no longer substantially restrict positions of the trachea and esophagus in birds. Rather, these muscles are modified in ways which may assist with making tracheal movements. The implications of this study may provide interesting insights for future comparisons in extinct taxa. PMID:27648952

The Tonalá fault in southeastern Mexico: Evidence that the Central America forearc sliver is not being detached?

NASA Astrophysics Data System (ADS)

Guzman-Speziale, M.; Molina-Garza, R. S.

2012-12-01

The Tonalá fault is a NW-SE oriented feature that flanks the Chiapas Massif on its southwestern side. Several authors coincide that the fault originally developed as a right-lateral structure in the Jurassic, but was reactivated as a left-lateral fault in the Miocene. Seismicity along the fault is low: Only one earthquake with magnitude 5.0 or larger is reported along the Tonalá fault in the years 1964 to present. Fault-plane solutions determined by the Mexican Seismological Survey for earthquakes along the fault show left-lateral, strike-slip faulting. The Tonalá fault lies on the northwestern continuation of the Central America volcanic arc. The volcanic arc is the site of medium-sized (magnitudes up to 6.5) shallow, right-lateral, strike-slip earthquakes. This has led several workers to propose that the forearc sliver is being detached from the Caribbean plate along the arc, moving northward. GPS studies have confirmed relative motion between the Chortis block and the forearc sliver. Recent and current motion along the Tonalá fault is in contradiction with motion and detachment of the forearc sliver along the Central America volcanic arc. Left-lateral motion along it cannot accomodate northwest displacement of the forearc sliver. Motion of the Central America forearc would require NW directed compression between the continental shelf of Chiapas and the forearc itself, which is not observed. Therefore, either another fault (or faults) accomodates right-lateral motion and detachment of the forearc sliver, or the sliver is not being detached and relative motion between the forearc sliver and the Chortis block corresponds to displacement of the latter. We suggest that, as proposed by previous authors, the Tonalá fault is instead part of a fault system that runs from the state of Oaxaca (the Valle Nacional fault), forming an arc concave to the northeast, and running perpendicular to the maximum slope of subduction in the area.

Longitudinal evaluation of corticospinal tract in patients with resected brainstem cavernous malformations using high-definition fiber tractography and diffusion connectometry analysis: preliminary experience.

PubMed

Faraji, Amir H; Abhinav, Kumar; Jarbo, Kevin; Yeh, Fang-Cheng; Shin, Samuel S; Pathak, Sudhir; Hirsch, Barry E; Schneider, Walter; Fernandez-Miranda, Juan C; Friedlander, Robert M

2015-11-01

Brainstem cavernous malformations (CMs) are challenging due to a higher symptomatic hemorrhage rate and potential morbidity associated with their resection. The authors aimed to preoperatively define the relationship of CMs to the perilesional corticospinal tracts (CSTs) by obtaining qualitative and quantitative data using high-definition fiber tractography. These data were examined postoperatively by using longitudinal scans and in relation to patients' symptomatology. The extent of involvement of the CST was further evaluated longitudinally using the automated "diffusion connectometry" analysis. Fiber tractography was performed with DSI Studio using a quantitative anisotropy (QA)-based generalized deterministic tracking algorithm. Qualitatively, CST was classified as being "disrupted" and/or "displaced." Quantitative analysis involved obtaining mean QA values for the CST and its perilesional and nonperilesional segments. The contralateral CST was used for comparison. Diffusion connectometry analysis included comparison of patients' data with a template from 90 normal subjects. Three patients (mean age 22 years) with symptomatic pontomesencephalic hemorrhagic CMs and varying degrees of hemiparesis were identified. The mean follow-up period was 37.3 months. Qualitatively, CST was partially disrupted and displaced in all. Direction of the displacement was different in each case and progressively improved corresponding with the patient's neurological status. No patient experienced neurological decline related to the resection. The perilesional mean QA percentage decreases supported tract disruption and decreased further over the follow-up period (Case 1, 26%-49%; Case 2, 35%-66%; and Case 3, 63%-78%). Diffusion connectometry demonstrated rostrocaudal involvement of the CST consistent with the quantitative data. Hemorrhagic brainstem CMs can disrupt and displace perilesional white matter tracts with the latter occurring in unpredictable directions. This requires the use of tractography to accurately define their orientation to optimize surgical entry point, minimize morbidity, and enhance neurological outcomes. Observed anisotropy decreases in the perilesional segments are consistent with neural injury following hemorrhagic insults. A model using these values in different CST segments can be used to longitudinally monitor its craniocaudal integrity. Diffusion connectometry is a complementary approach providing longitudinal information on the rostrocaudal involvement of the CST.

Structural Deterministic Safety Factors Selection Criteria and Verification

NASA Technical Reports Server (NTRS)

Verderaime, V.

1992-01-01

Though current deterministic safety factors are arbitrarily and unaccountably specified, its ratio is rooted in resistive and applied stress probability distributions. This study approached the deterministic method from a probabilistic concept leading to a more systematic and coherent philosophy and criterion for designing more uniform and reliable high-performance structures. The deterministic method was noted to consist of three safety factors: a standard deviation multiplier of the applied stress distribution; a K-factor for the A- or B-basis material ultimate stress; and the conventional safety factor to ensure that the applied stress does not operate in the inelastic zone of metallic materials. The conventional safety factor is specifically defined as the ratio of ultimate-to-yield stresses. A deterministic safety index of the combined safety factors was derived from which the corresponding reliability proved the deterministic method is not reliability sensitive. The bases for selecting safety factors are presented and verification requirements are discussed. The suggested deterministic approach is applicable to all NASA, DOD, and commercial high-performance structures under static stresses.

The Rome trough and evolution of the Iapetean margin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walker, D.; Hamilton-Smith, T.; Drahovzal, J.A.

1991-08-01

Recent structural mapping of the Rome trough suggests a complex structure very different from the symmetrical and laterally continuous graben commonly depicted. Early and Middle Cambrian extension in the Rome trough of eastern Kentucky and adjacent areas resulted in a series of alternately facing half-grabens with variable displacement. These half-grabens are bounded by southwest-northeast-trending normal faults (e.g., Kentucky River and Warfield faults), which are laterally continuous only on the order to tens of kilometers. The Rome trough is laterally segmented by north-south-trending faults (e.g., Lexington fault) commonly expressed as flexures in younger rocks (e.g., Burning Springs anticline and Floyd Countymore » channel). Many of these north-south-trending faults have significant left-lateral displacement, and probably represent reactivated thrust faults of the Grenville tectonic front. The Rome trough and the associated Mississippi Valley, Rough Creek, and Birmingham fault systems were initiated during an Early Cambrian shift in sea-floor spreading from the Blue Ridge-Pine Mountain rift to the Ouachita rift along the Alabama-Oklahoma transform fault. These fault systems have been proposed as having originated from extensional stress propagated northward from the Ouachita rift across the transform fault. In the alternate model proposed here, faulting was brittle, extensional failure resulting form subsidence and flexure of the continental margin to the east. Following initiation of sea-floor spreading at the Blue Ridge-Pine Mountain rift in the latest Proterozoic, margin subsidence in the presence of the Alabama-Oklahoma transform boundary and the inherited Grenville tectonic front resulted in this interior cratonic fault system.« less

Changing Locus of Control: Steelworkers Adjusting to Forced Unemployment

ERIC Educational Resources Information Center

Legerski, Elizabeth Miklya; Cornwall, Marie; O'Neil, Brock

2006-01-01

Using an abbreviated version of Levenson's (1981) locus of control scale, we examine change over time in the locus of control of displaced steelworkers. The first data collection occurred approximately six months after plant shutdown, the second occurred a year later. Utilizing a multidimensional measurement model, we test the major assumption…

Multiple Cross Displacement Amplification Combined with Gold Nanoparticle-Based Lateral Flow Biosensor for Detection of Vibrio parahaemolyticus

PubMed Central

Wang, Yi; Li, Hui; Li, Dongxun; Li, Kewei; Wang, Yan; Xu, Jianguo; Ye, Changyun

2016-01-01

Vibrio parahaemolyticus (V. parahaemolyticus) is a marine seafood-borne pathogen causing severe illnesses in humans and aquatic animals. In the present study, multiple cross displacement amplification was combined with a lateral flow biosensor (MCDA-LFB) to detect the toxR gene of V. parahaemolyticus in DNA extracts from pure cultures and spiked oyster homogenates. Amplification was carried out at a constant temperature (62°C) for only 30 min, and amplification products were directly applied to the biosensor. The entire process, including oyster homogenate processing (30 min), isothermal amplification (30 min) and results indicating (∼2 min), could be completed within 65 min. Amplification product was detectable from as little as 10 fg of pure V. parahaemolyticus DNA and from approximately 4.2 × 102 CFU in 1 mL of oyster homogenate. No cross-reaction with other Vibrio species and with non-Vibrio species was observed. Therefore, the MCDA-LFB method established in the current report is suitable for the rapid screening of V. parahaemolyticus in clinical, food, and environmental samples. PMID:28066368

The Constantine (northeast Algeria) earthquake of October 27, 1985: surface ruptures and aftershock study

NASA Astrophysics Data System (ADS)

Bounif, A.; Haessler, H.; Meghraoui, M.

1987-10-01

An earthquake of magnitude Ms = 6.0 (CSEM, Strasbourg) occurred at Constantine (Algeria) on 27 October 1985. This seismic event is the strongest felt in the Tellian Atlas since the El Asnam seismic crisis of October 10, 1980. A team from the Centre de Recherche d'Astronomie, d'Astrophysique et de Géophysique (CRAAG, Algeria), utilising 8 portable stations, registered the activity a few days after the main shock. The aftershocks follow a N045° direction, and show the existence of three ruptured segments. Cross sections display a remarkable vertical fault plane and suggest asperities in the rupture process. Surface breaks were found affecting Quaternary deposits. The principal segment is about 3.8 km long showing “enéchelon” cracks with left-lateral displacement while the main direction of the rupture is N055°. Although the vertical motion is small, the northwestern block shows a normal component of the main surface faulting, while the left-lateral displacement is about 10 cm. The strike-slip focal mechanism solution determined from the global seismic network and field observations are in good agreement.

An orthogonal return method for linearly polarized beam based on the Faraday effect and its application in interferometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Benyong, E-mail: chenby@zstu.edu.cn; Zhang, Enzheng; Yan, Liping

2014-10-15

Correct return of the measuring beam is essential for laser interferometers to carry out measurement. In the actual situation, because the measured object inevitably rotates or laterally moves, not only the measurement accuracy will decrease, or even the measurement will be impossibly performed. To solve this problem, a novel orthogonal return method for linearly polarized beam based on the Faraday effect is presented. The orthogonal return of incident linearly polarized beam is realized by using a Faraday rotator with the rotational angle of 45°. The optical configuration of the method is designed and analyzed in detail. To verify its practicabilitymore » in polarization interferometry, a laser heterodyne interferometer based on this method was constructed and precision displacement measurement experiments were performed. These results show that the advantage of the method is that the correct return of the incident measuring beam is ensured when large lateral displacement or angular rotation of the measured object occurs and then the implementation of interferometric measurement can be ensured.« less

The initiation of lateral roots in the primary roots of maize (Zea mays L.) implies a reactivation of cell proliferation in a group of founder pericycle cells.

PubMed

Alarcón, M Victoria; Lloret, Pedro G; Martín-Partido, Gervasio; Salguero, Julio

2016-03-15

The initiation of lateral roots (LRs) has generally been viewed as a reactivation of proliferative activity in pericycle cells that are committed to initiate primordia. However, it is also possible that pericycle founder cells that initiate LRs never cease proliferative activity but rather are displaced to the most distal root zones while undertaking successive stages of LR initiation. In this study, we tested these two alternative hypotheses by examining the incorporation of 5-bromo-2'-deoxyuridine (BrdU) into the DNA of meristematic root cells of Zea mays. According to the values for the length of the cell cycle and values for cell displacement along the maize root, our results strongly suggest that pericycle cells that initiate LR primordia ceased proliferative activity upon exiting the meristematic zone. This finding is supported by the existence of a root zone between 4 and 20mm from the root cap junction, in which neither mitotic cells nor labelled nuclei were observed in phloem pericycle cells. Copyright © 2016 Elsevier GmbH. All rights reserved.

Phanerozoic strike-slip faulting in the continental interior platform of the United States: Examples from the Laramide Orogen, midcontinent, and Ancestral Rocky Mountains

USGS Publications Warehouse

Marshak, S.; Nelson, W.J.; McBride, J.H.

2003-01-01

The continental interior platform of the United States is that part of the North American craton where a thin veneer of Phanerozoic strata covers Precambrian crystalline basement. N- to NE-trending and W- to NW-trending fault zones, formed initially by Proterozoic/Cambrian rifting, break the crust of the platform into rectilinear blocks. These zones were reactivated during the Phanerozoic, most notably in the late Palaeozoic Ancestral Rockies event and the Mesozoic-Cenozoic Laramide orogeny - some remain active today. Dip-slip reactivation can be readily recognized in cross section by offset stratigraphic horizons and monoclinal fault-propagation folds. Strike-slip displacement is hard to document because of poor exposure. Through offset palaeochannels, horizontal slip lineations, and strain at fault bends locally demonstrate strike-slip offset, most reports of strike-slip movements for interior-platform faults are based on occurrence of map-view belts of en echelon faults and anticlines. Each belt overlies a basement-penetrating master fault, which typically splays upwards into a flower structure. In general, both strike-slip and dip-slip components of displacement occur in the same fault zone, so some belts of en echelon structures occur on the flanks of monoclinal folds. Thus, strike-slip displacement represents the lateral components of oblique fault reactivation: dip-slip and strike-slip components are the same order of magnitude (tens of metres to tens of kilometres). Effectively, faults with strike-slip components of displacement act as transfers accommodating jostling of rectilinear crustal blocks. In this context, the sense of slip on an individual strike-slip fault depends on block geometry, not necessarily on the trajectory of regional ??1. Strike-slip faulting in the North American interior differs markedly from that of southern and central Eurasia, possibly because of a contrast in lithosphere strength. Weak Eurasia strained significantly during the Alpine-Himalayan collision, forcing crustal blocks to undergo significant lateral escape. The strong North American craton strained relatively little during collisional-convergent orogeny, so crustal blocks underwent relatively small displacements.

Tumor, Lymph Node, and Lymph Node-to-Tumor Displacements Over a Radiotherapy Series: Analysis of Interfraction and Intrafraction Variations Using Active Breathing Control (ABC) in Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weiss, Elisabeth, E-mail: eweiss@mcvh-vcu.edu; Robertson, Scott P.; Mukhopadhyay, Nitai

2012-03-15

Purpose: To estimate errors in soft tissue-based image guidance due to relative changes between primary tumor (PT) and affected lymph node (LN) position and volume, and to compare the results with bony anatomy-based displacements of PTs and LNs during radiotherapy of lung cancer. Methods and Materials: Weekly repeated breath-hold computed tomography scans were acquired in 17 lung cancer patients undergoing radiotherapy. PTs and affected LNs were manually contoured on all scans after rigid registration. Interfraction and intrafraction displacements in the centers of mass of PTs and LNs relative to bone, as well as LNs relative to PTs (LN-PT), were calculated.more » Results: The mean volume after 5 weeks was 65% for PTs and 63% for LNs. Systematic and random interfraction displacements were 2.6 to 4.6 mm and 2.7 to 2.9 mm, respectively, for PTs; 2.4 to 3.8 mm and 1.4 to 2.7 mm, respectively, for LNs; and 2.3 to 3.9 mm and 1.9 to 2.8 mm, respectively, for LN-PT. Systematic and random intrafraction displacements were less than 1 mm except in the superoinferior direction. Interfraction LN-PT displacements greater than 3 mm were observed in 67% of fractions and require a safety margin of 12 mm in the lateral direction, 11 mm in the anteroposterior direction, and 9 mm in the superoinferior direction. LN-PT displacements displayed significant time trends (p < 0.0001) and depended on the presence of pathoanatomic conditions of the ipsilateral lung, such as atelectasis. Conclusion: Interfraction LN-PT displacements were mostly systematic and comparable to bony anatomy-based displacements of PTs or LNs alone. Time trends, large volume changes, and the influence of pathoanatomic conditions underline the importance of soft tissue-based image guidance and the potential of plan adaptation.« less

Lateral movements in Rayleigh-Taylor instabilities due to frontiers. Numerical analysis

NASA Astrophysics Data System (ADS)

Fernandez, D.; Binda, L.; Zalts, A.; El Hasi, C.; D'Onofrio, A.

2018-01-01

Numerical simulations were performed for Rayleigh-Taylor (RT) hydrodynamic instabilities when a frontier is present. The frontier formed by the interface between two fluids prevents the free movement of the fingers created by the instability. As a consequence, transversal movements at the rear of the fingers are observed in this area. These movements produce collapse of the fingers (two or more fingers join in one finger) or oscillations in the case that there is no collapse. The transversal velocity of the fingers, the amplitude of the oscillations, and the wave number of the RT instabilities as a function of the Rayleigh number (Ra) were studied near the frontier. We verified numerically that in classical RT instabilities, without a frontier, these lateral movements do not occur; only with a physical frontier, the transversal displacements of the fingers appear. The transverse displacement velocity and the initial wave number increase with Ra. This leads to the collapse of the fingers, diminishing the wave number of the instabilities at the interface. Instead, no significant changes in the amplitude of the oscillations are observed modifying Ra. The numerical results are independent of the type or origin of the frontier (gas-liquid, liquid-liquid, or solid-liquid). The numerical results are in good agreement with the experimental results reported by Binda et al. [Chaos 28, 013107 (2018)]. Based on these results, it was possible to determine the cause of the transverse displacements, which had not been explained until now.

Development of p-y curves of laterally loaded piles in cohesionless soil.

PubMed

Khari, Mahdy; Kassim, Khairul Anuar; Adnan, Azlan

2014-01-01

The research on damages of structures that are supported by deep foundations has been quite intensive in the past decade. Kinematic interaction in soil-pile interaction is evaluated based on the p-y curve approach. Existing p-y curves have considered the effects of relative density on soil-pile interaction in sandy soil. The roughness influence of the surface wall pile on p-y curves has not been emphasized sufficiently. The presented study was performed to develop a series of p-y curves for single piles through comprehensive experimental investigations. Modification factors were studied, namely, the effects of relative density and roughness of the wall surface of pile. The model tests were subjected to lateral load in Johor Bahru sand. The new p-y curves were evaluated based on the experimental data and were compared to the existing p-y curves. The soil-pile reaction for various relative density (from 30% to 75%) was increased in the range of 40-95% for a smooth pile at a small displacement and 90% at a large displacement. For rough pile, the ratio of dense to loose relative density soil-pile reaction was from 2.0 to 3.0 at a small to large displacement. Direct comparison of the developed p-y curve shows significant differences in the magnitude and shapes with the existing load-transfer curves. Good comparison with the experimental and design studies demonstrates the multidisciplinary applications of the present method.

Development of p-y Curves of Laterally Loaded Piles in Cohesionless Soil

PubMed Central

Khari, Mahdy; Kassim, Khairul Anuar; Adnan, Azlan

2014-01-01

The research on damages of structures that are supported by deep foundations has been quite intensive in the past decade. Kinematic interaction in soil-pile interaction is evaluated based on the p-y curve approach. Existing p-y curves have considered the effects of relative density on soil-pile interaction in sandy soil. The roughness influence of the surface wall pile on p-y curves has not been emphasized sufficiently. The presented study was performed to develop a series of p-y curves for single piles through comprehensive experimental investigations. Modification factors were studied, namely, the effects of relative density and roughness of the wall surface of pile. The model tests were subjected to lateral load in Johor Bahru sand. The new p-y curves were evaluated based on the experimental data and were compared to the existing p-y curves. The soil-pile reaction for various relative density (from 30% to 75%) was increased in the range of 40–95% for a smooth pile at a small displacement and 90% at a large displacement. For rough pile, the ratio of dense to loose relative density soil-pile reaction was from 2.0 to 3.0 at a small to large displacement. Direct comparison of the developed p-y curve shows significant differences in the magnitude and shapes with the existing load-transfer curves. Good comparison with the experimental and design studies demonstrates the multidisciplinary applications of the present method. PMID:24574932

Defining the lateral and accessory views of the patella: an anatomic and radiographic study with implications for fracture treatment.

PubMed

Berkes, Marschall B; Little, Milton T M; Pardee, Nadine C; Lazaro, Lionel E; Helfet, David L; Lorich, Dean G

2013-12-01

The majority of orthopaedic surgeons rely on a lateral fluoroscopic image to assess reduction during patella fracture osteosynthesis. However, a comprehensive radiographic description of the lateral view of the patella has not been performed previously, and no accessory views to better visualize specific anatomic features have been developed. The purpose of this study was to provide a detailed anatomic description of all radiographic features of the true lateral of the patella, describe reproducible accessory views for assessing specific features of the patella, and demonstrate their utility in a fracture model. Twelve cadaver knee specimens free of patellofemoral pathology were used, and imaging was performed using standard C-arm fluoroscopy. For each specimen, a true lateral radiographic projection of the patella was obtained and distinct features were noted. Next, an arthrotomy was made and steel wire was contoured and fixed to various anatomic regions of the patella so as to obliterate the radiographic densities on the true lateral projection, thus confirming their anatomic correlation. Ideal views of the lateral and medial facets themselves were determined using radiographic markers and varying amounts of internal or external rotation of the specimen. Last, a transverse osteotomy was created in each patella and the ability of the true lateral and accessory views to detect malreduction was assessed. The true lateral projection of the patella was obtained with the limb in neutral alignment. Constant radiographic features of the lateral view of the patella include the articular tangent, a secondary articular density of variable length, and a dorsal cortical density. The articular tangent was produced by the central ridge between the medial and lateral facets in all specimens. The secondary articular density was created by a confluence of the edge of the lateral and edge of the medial facets in 5 patellas, a confluence of the edge of the lateral facet and the intersection of the odd and medial facets in 6 patellas, and the edge of the lateral facet alone in 1 patella. The edge of the lateral facet gave a constant contribution to the appearance of the secondary articular density in all cases. A distinct accessory view of the tangent of the lateral facet could be seen with an average of 17 degrees of patella external rotation (range, 12-35 degrees), and the tangent of the medial facet with an average of 26.5 degrees of internal rotation (range, 15-45 degrees). These accessory views were better able to visualize malreduction than the single lateral projection in a fracture model in all specimens. Described here is a comprehensive description of the true lateral radiographic view of the patella and accessory views. These views can be used in the evaluation of minimally displaced patella fractures if a computerized tomography is not desired to better assess the true amount of displacement and when assessing intraoperative reduction during patella fracture osteosynthesis.

Fault geometries illuminated from seismicity in central Taiwan: Implications for crustal scale structural boundaries in the northern Central Range

NASA Astrophysics Data System (ADS)

Gourley, Jonathan R.; Byrne, Timothy; Chan, Yu-Chang; Wu, Francis; Rau, Ruey-Juin

2007-12-01

Data sets of collapsed earthquake locations, earthquake focal mechanisms, GPS velocities and geologic data are integrated to constrain the geometry and kinematics of a crustal block within the accreted continental margin rocks of Taiwan's northeastern Central Range. This block is laterally extruding and exhuming towards the north-northeast. The block is bound on the west-southwest by the previously recognized Sanyi-Puli seismic zone and on the east by a vertical seismic structure that projects to the eastern mountain front of the Central Range. Focal mechanisms from the Broadband Array of Taiwan Seismicity (BATS) catalog consistently show west-side-up reverse displacements for this fault zone. A second vertical structure is recognized beneath the Slate Belt-Metamorphic Belt boundary as a post-Chi-Chi relaxation oblique normal fault. BATS focal mechanisms show east-side-up, normal displacements with a minor left-lateral component. The vertical and lateral extrusion of this crustal block may be driven by the current collision between the Philippine Sea Plate and the Puli basement high indenter on the Eurasian Plate and/or trench rollback along the Ryukyu subduction zone. In addition, the vertical extent of the two shear zones suggests that a basal décollement below the eastern Central Range is deeper than previously proposed and may extend below the brittle-ductile transition.

Primate translational vestibuloocular reflexes. IV. Changes after unilateral labyrinthectomy

NASA Technical Reports Server (NTRS)

Angelaki, D. E.; Newlands, S. D.; Dickman, J. D.

2000-01-01

The effects of unilateral labyrinthectomy on the properties of the translational vestibuloocular reflexes (trVORs) were investigated in rhesus monkeys trained to fixate near targets. Translational motion stimuli consisted of either steady-state lateral and fore-aft sinusoidal oscillations or short-lasting transient displacements. During small-amplitude, steady-state sinusoidal lateral oscillations, a small decrease in the horizontal trVOR sensitivity and its dependence on viewing distance was observed during the first week after labyrinthectomy. These deficits gradually recovered over time. In addition, the vertical response component increased, causing a tilt of the eye velocity vector toward the lesioned side. During large, transient lateral displacements, the deficits were larger and longer lasting. Responses after labyrinthectomy were asymmetric, with eye velocity during movements toward the side of the lesion being more compromised. The most profound effect of the lesions was observed during fore-aft motion. Whereas responses were kinematically appropriate for fixation away from the side of the lesion (e.g., to the left after right labyrinthectomy), horizontal responses were anticompensatory during fixation at targets located ipsilateral to the side of the lesion (e.g., for targets to the right after right labyrinthectomy). This deficit showed little recovery during the 3-mo post-labyrinthectomy testing period. These results suggest that inputs from both labyrinths are important for the proper function of the trVORs, although the details of how bilateral signals are processed and integrated remain unknown.

The Neuro-Mechanical Processes That Underlie Goal-Directed Medio-Lateral APA during Gait Initiation.

PubMed

Honeine, Jean-Louis; Schieppati, Marco; Crisafulli, Oscar; Do, Manh-Cuong

2016-01-01

Gait initiation (GI) involves passing from bipedal to unipedal stance. It requires a rapid movement of the center of foot pressure (CoP) towards the future swing foot and of the center of mass (CoM) in the direction of the stance foot prior to the incoming step. This anticipatory postural adjustment (APA) allows disengaging the swing leg from the ground and establishing favorable conditions for stepping. This study aimed to describe the neuro-mechanical process that underlies the goal-directed medio-lateral (ML) APA. We hypothesized that controlled knee flexion of the stance leg contributes to the initial ML displacement of the CoP and to the calibration of the first step. Fourteen subjects initiated gait starting from three different initial stance widths of 15 cm (Small), 30 cm (Medium), and 45 cm (Large). Optoelectronic, force platform and electromyogram (EMG) measurements were performed. During APA, soleus activity diminished bilaterally, while tibialis anterior (TA) activity increased, more so in the stance leg than in the swing leg, and to a larger extent with increasing initial stance width. Knee flexion of the stance leg was observed during APA and correlated with the ML CoP displacement towards the swing leg. ML CoP and CoM displacements during APA increased with increasing stance width. The activity of stance-leg TA was correlated with the degree of knee flexion. Swing-leg tensor fasciae latae (TFL) was also active during APA. Across subjects, when stance-leg tibialis activity was low, TFL activity was large and vice versa. The modulation of the ML CoP position during APA allowed the gravity-driven torque to place the CoM just lateral to the stance foot during step execution. Accordingly, the gravity-driven torque, the ML CoM velocity during step execution, and the step width at foot contact (FC) were lower in the Small and greater in the Large condition. Consequently, the position of the stepping foot at FC remained close to the sagittal plane in all three conditions. Conclusively, coordinated activation of hip abductors and ankle dorsiflexors during APA displaces the CoP towards the swing leg, and sets the contact position for the swing foot.

The Neuro-Mechanical Processes That Underlie Goal-Directed Medio-Lateral APA during Gait Initiation

PubMed Central

Honeine, Jean-Louis; Schieppati, Marco; Crisafulli, Oscar; Do, Manh-Cuong

2016-01-01

Gait initiation (GI) involves passing from bipedal to unipedal stance. It requires a rapid movement of the center of foot pressure (CoP) towards the future swing foot and of the center of mass (CoM) in the direction of the stance foot prior to the incoming step. This anticipatory postural adjustment (APA) allows disengaging the swing leg from the ground and establishing favorable conditions for stepping. This study aimed to describe the neuro-mechanical process that underlies the goal-directed medio-lateral (ML) APA. We hypothesized that controlled knee flexion of the stance leg contributes to the initial ML displacement of the CoP and to the calibration of the first step. Fourteen subjects initiated gait starting from three different initial stance widths of 15 cm (Small), 30 cm (Medium), and 45 cm (Large). Optoelectronic, force platform and electromyogram (EMG) measurements were performed. During APA, soleus activity diminished bilaterally, while tibialis anterior (TA) activity increased, more so in the stance leg than in the swing leg, and to a larger extent with increasing initial stance width. Knee flexion of the stance leg was observed during APA and correlated with the ML CoP displacement towards the swing leg. ML CoP and CoM displacements during APA increased with increasing stance width. The activity of stance-leg TA was correlated with the degree of knee flexion. Swing-leg tensor fasciae latae (TFL) was also active during APA. Across subjects, when stance-leg tibialis activity was low, TFL activity was large and vice versa. The modulation of the ML CoP position during APA allowed the gravity-driven torque to place the CoM just lateral to the stance foot during step execution. Accordingly, the gravity-driven torque, the ML CoM velocity during step execution, and the step width at foot contact (FC) were lower in the Small and greater in the Large condition. Consequently, the position of the stepping foot at FC remained close to the sagittal plane in all three conditions. Conclusively, coordinated activation of hip abductors and ankle dorsiflexors during APA displaces the CoP towards the swing leg, and sets the contact position for the swing foot. PMID:27642280

Digital image measurement of specimen deformation based on CCD cameras and Image J software: an application to human pelvic biomechanics

NASA Astrophysics Data System (ADS)

Jia, Yongwei; Cheng, Liming; Yu, Guangrong; Lou, Yongjian; Yu, Yan; Chen, Bo; Ding, Zuquan

2008-03-01

A method of digital image measurement of specimen deformation based on CCD cameras and Image J software was developed. This method was used to measure the biomechanics behavior of human pelvis. Six cadaveric specimens from the third lumbar vertebra to the proximal 1/3 part of femur were tested. The specimens without any structural abnormalities were dissected of all soft tissue, sparing the hip joint capsules and the ligaments of the pelvic ring and floor. Markers with black dot on white background were affixed to the key regions of the pelvis. Axial loading from the proximal lumbar was applied by MTS in the gradient of 0N to 500N, which simulated the double feet standing stance. The anterior and lateral images of the specimen were obtained through two CCD cameras. Based on Image J software, digital image processing software, which can be freely downloaded from the National Institutes of Health, digital 8-bit images were processed. The procedure includes the recognition of digital marker, image invert, sub-pixel reconstruction, image segmentation, center of mass algorithm based on weighted average of pixel gray values. Vertical displacements of S1 (the first sacral vertebrae) in front view and micro-angular rotation of sacroiliac joint in lateral view were calculated according to the marker movement. The results of digital image measurement showed as following: marker image correlation before and after deformation was excellent. The average correlation coefficient was about 0.983. According to the 768 × 576 pixels image (pixel size 0.68mm × 0.68mm), the precision of the displacement detected in our experiment was about 0.018 pixels and the comparatively error could achieve 1.11\\perthou. The average vertical displacement of S1 of the pelvis was 0.8356+/-0.2830mm under vertical load of 500 Newtons and the average micro-angular rotation of sacroiliac joint in lateral view was 0.584+/-0.221°. The load-displacement curves obtained from our optical measure system matched the clinical results. Digital image measurement of specimen deformation based on CCD cameras and Image J software has good perspective for application in biomechanical research, which has the advantage of simple optical setup, no-contact, high precision, and no special requirement of test environment.

Probabilistic vs. deterministic fiber tracking and the influence of different seed regions to delineate cerebellar-thalamic fibers in deep brain stimulation.

PubMed

Schlaier, Juergen R; Beer, Anton L; Faltermeier, Rupert; Fellner, Claudia; Steib, Kathrin; Lange, Max; Greenlee, Mark W; Brawanski, Alexander T; Anthofer, Judith M

2017-06-01

This study compared tractography approaches for identifying cerebellar-thalamic fiber bundles relevant to planning target sites for deep brain stimulation (DBS). In particular, probabilistic and deterministic tracking of the dentate-rubro-thalamic tract (DRTT) and differences between the spatial courses of the DRTT and the cerebello-thalamo-cortical (CTC) tract were compared. Six patients with movement disorders were examined by magnetic resonance imaging (MRI), including two sets of diffusion-weighted images (12 and 64 directions). Probabilistic and deterministic tractography was applied on each diffusion-weighted dataset to delineate the DRTT. Results were compared with regard to their sensitivity in revealing the DRTT and additional fiber tracts and processing time. Two sets of regions-of-interests (ROIs) guided deterministic tractography of the DRTT or the CTC, respectively. Tract distances to an atlas-based reference target were compared. Probabilistic fiber tracking with 64 orientations detected the DRTT in all twelve hemispheres. Deterministic tracking detected the DRTT in nine (12 directions) and in only two (64 directions) hemispheres. Probabilistic tracking was more sensitive in detecting additional fibers (e.g. ansa lenticularis and medial forebrain bundle) than deterministic tracking. Probabilistic tracking lasted substantially longer than deterministic. Deterministic tracking was more sensitive in detecting the CTC than the DRTT. CTC tracts were located adjacent but consistently more posterior to DRTT tracts. These results suggest that probabilistic tracking is more sensitive and robust in detecting the DRTT but harder to implement than deterministic approaches. Although sensitivity of deterministic tracking is higher for the CTC than the DRTT, targets for DBS based on these tracts likely differ. © 2017 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Open versus closed reduction: diacapitular fractures of the mandibular condyle.

PubMed

Chrcanovic, Bruno Ramos

2012-09-01

The purpose of the study was to review the literature regarding the evolution of current thoughts on management of diacapitular fractures (DFs) of the mandibular condyle. An electronic search in PubMed was undertaken in March 2012. The titles and abstracts from these results were read to identify studies within the selection criteria. Eligibility criteria included studies reporting clinical series of DFs, including both animal and human studies, without date or language restrictions. The search strategy initially yielded 108 references. Twenty-eight studies were identified without repetition within the selection criteria. Additional hand-searching of the reference lists of selected studies yielded three additional papers. The current indications for open reduction and internal fixation (ORIF) of DFs described in the literature are: (a) fractures affecting the lateral condyle with reduction of mandibular height; (b) fractures in which the proximal fragment dislocates laterally out of the glenoid fossa, which cannot be reduced by closed or open treatment of another part of the mandibular fracture. The indications for conservative treatment are: (a) fractures that do not shorten the condylar height (a fracture with displacement of the medial parts of the condyle); (b) undisplaced fractures; (c) comminution of the condylar head, when the bony fragments are too small for stable fixation; and (d) fractures in children. As the temporomandibular joint disk plays an important role as a barrier preventing ankylosis, it is important to reposition the disk (if displaced/dislocated) during the surgical treatment of DFs. The lateral pterygoid muscle should never be stripped from the medially displaced fragment because its desinsertion disrupts circulation to the medial bony fragment, and also because this muscle helps to restore the muscle function after surgery. ORIF of selected DFs improves prognosis by anatomical bone and soft tissue recovery when combined with physical therapy. If conducted properly, surgical treatment of DFs is a safe and predictable procedure and yields good results.

Temporal evolution of surface rupture deduced from coseismic multi-mode secondary fractures: Insights from the October 8, 2005 (Mw 7.6) Kashmir earthquake, NW Himalaya

NASA Astrophysics Data System (ADS)

Sayab, Mohammad; Khan, Muhammad Asif

2010-10-01

Detailed rupture-fracture analyses of some of the well-studied earthquakes have revealed that the geometrical arrangement of secondary faults and fractures can be used as a geological tool to understand the temporal evolution of slip produced during the mainshock. The October 8, 2005 Mw 7.6 Kashmir earthquake, NW Himalaya, surface rupture provides an opportunity to study a complex network of secondary fractures developed on the hanging wall of the fault scarp. The main fault scarp is clearly thrust-type, rupture length is ~ 75 ± 5 km and the overall trend of the rupture is NW-SE. We present the results of our detailed structural mapping of secondary faults and fractures at 1:100 scale, on the hanging wall of the southern end of the rupture in the vicinity of the Sar Pain. Secondary ruptures can be broadly classified as two main types, 1) normal faults and, (2) right-lateral strike-slip 'Riedel' fractures. The secondary normal faults are NW-SE striking, with a maximum 3.3 meter vertical displacement and 2.5 meter horizontal displacement. Estimated total horizontal extension across the secondary normal faults is 3.1-3.5%. We propose that the bending-moment and coseismic stress relaxation can explain the formation of secondary normal faults on the hanging wall of the thrust fault. The strike-slip 'Riedel' fractures form distinct sets of tension (T) and shear fractures (R', R, Y) with right-lateral displacement. Field observations revealed that the 'Riedel' fractures (T) cut the secondary normal faults. In addition, there is kinematic incompatibility and magnitude mismatch between the secondary normal faults and strike-slip 'Riedel' fractures. The cross-cutting relationship, geometric and magnitude incoherence implies a temporal evolution of slip from dip- to strike-slip during the mainshock faulting. The interpretation is consistent with the thrust fault plane solution with minor right-lateral strike-slip component.

Rotation Elastogram Estimation Using Synthetic Transmit-aperture Technique: A Feasibility Study.

PubMed

B, Lokesh; Chintada, Bhaskara Rao; Thittai, Arun Kumar

2017-05-01

It is well-documented in literature that benign breast lesions, such as fibroadenomas, are loosely bonded to their surrounding tissue and tend to slip under a small quasi-static compression, whereas malignant lesions being firmly bonded to their surrounding tissue do not slip. Recent developments in quasi-static ultrasound elastography have shown that an image of the axial-shear strain distribution can provide information about the bonding condition at the lesion-surrounding tissue boundary. Further studies analyzing the axial-shear strain elastograms revealed that nonzero axial-shear strain values appear inside the lesion, referred to as fill-in, only when a lesion is loosely bonded and asymmetrically oriented to the axis of compression. It was argued that the fill-in observed in axial-shear strain elastogram is a surrogate of the actual rigid-body rotation undergone by such a benign lesion due to slip boundary condition. However, it may be useful and perhaps easy to interpret, if the actual rigid-body rotation of the lesion can itself be visualized directly. To estimate this rotation tensor and its spatial distribution map (called a Rotation Elastogram [RE]), it would be necessary to improve the quality of lateral displacement estimates. Recently, it has been shown in the context of Non-Invasive Vascular Elastography (NIVE) that the Synthetic Transmit Aperture (STA) technique can be adapted for elastography to improve the lateral displacement estimates. Therefore, the focus of this work was to investigate the feasibility of employing the STA technique to improve the lateral displacement estimation and assess the resulting improvement in the RE quality. This investigation was done using both simulation and experimental studies. The image quality metric of contrast-to-noise ratio (CNR) was used to evaluate the quality of rotation elastograms. The results demonstrate that the contrast appeared in RE only in the case of loosely bonded inclusion, and the quality of RE improved considerably by employing the STA technique.

Nonlinear Dynamic Characteristics of the Railway Vehicle

NASA Astrophysics Data System (ADS)

Uyulan, Çağlar; Gokasan, Metin

2017-06-01

The nonlinear dynamic characteristics of a railway vehicle are checked into thoroughly by applying two different wheel-rail contact model: a heuristic nonlinear friction creepage model derived by using Kalker 's theory and Polach model including dead-zone clearance. This two models are matched with the quasi-static form of the LuGre model to obtain more realistic wheel-rail contact model. LuGre model parameters are determined using nonlinear optimization method, which it's objective is to minimize the error between the output of the Polach and Kalker model and quasi-static LuGre model for specific operating conditions. The symmetric/asymmetric bifurcation attitude and stable/unstable motion of the railway vehicle in the presence of nonlinearities which are yaw damping forces in the longitudinal suspension system are analyzed in great detail by changing the vehicle speed. Phase portraits of the lateral displacement of the leading wheelset of the railway vehicle are drawn below and on the critical speeds, where sub-critical Hopf bifurcation take place, for two wheel-rail contact model. Asymmetric periodic motions have been observed during the simulation in the lateral displacement of the wheelset under different vehicle speed range. The coexistence of multiple steady states cause bounces in the amplitude of vibrations, resulting instability problems of the railway vehicle. By using Lyapunov's indirect method, the critical hunting speeds are calculated with respect to the radius of the curved track parameter changes. Hunting, which is defined as the oscillation of the lateral displacement of wheelset with a large domain, is described by a limit cycle-type oscillation nature. The evaluated accuracy of the LuGre model adopted from Kalker's model results for prediction of critical speed is higher than the results of the LuGre model adopted from Polach's model. From the results of the analysis, the critical hunting speed must be resolved by investigating the track tests under various kind of excitations.

Effect of Pneumoperitoneum and Lateral Position on Oropharyngeal Seal Pressures of Proseal LMA in Laparoscopic Urological Procedures.

PubMed

Rustagi, Preeti; Patkar, Geeta A; Ourasang, Anil Kumar; Tendolkar, Bharati A

2017-02-01

A sustained and effective oropharyngeal sealing with supraglottic airway is required to maintain the ventilation during laparoscopic surgery. Previous studies have observed the Oropharyngeal Seal Pressure (OSP) for Proseal Laryngeal Mask Airway (PLMA) after pneumoperitoneum in supine and trendelenburg position, where PLMA was found to be an effective airway device. This study was conducted with ProSeal LMA, for laparoscopic Urologic procedures done in lateral position. To measure OSP in supine and lateral position and to observe the effect of pneumoperitoneum in lateral position on OSP. Secondary objectives were to assess adequacy of ventilation and incidence of adverse events. A total number of 25 patients of American Society of Anaesthesiologists (ASA) physical status II and I were enrolled. After induction of anaesthesia using a standardized protocol, PLMA was inserted. Ryle's tube was inserted through drain tube. The position of PLMA was confirmed with ease of insertion of Ryle's tube and fibreoptic grading of vocal cords. Patients were then put in lateral position. The OSP was measured in supine position. This value was baseline comparison for OSP in lateral position and that after pneumoperitoneum. We assessed the efficacy of PLMA for ventilation, after carboperitoneum in lateral position (peak airway pressure, End Tidal Carbon dioxide (EtCO 2 ), SPO 2 ). Incidence of adverse effects (displacement of device, gastric insufflation, regurgitation, coughing, sore throat, blood on device, trauma) was also noted. The OSP was above Peak Airway Pressure (PAP) in supine (22.1±5.4 and 15.4±4.49cm of H 2 O) and lateral position (22.6±5.3 and 16.1±4.6). After pneumoperitoneum, which was in lateral position, there was statistically significant (p-value <0.05) increase in both PAP (19.96±4.015) and OSP (24.32±4.98, p-value 0.03). There was no intraoperative displacement of PLMA. There was no event of suboptimal oxygenation. EtCO 2 was always within normal limits. Gastric insufflation was present in one patient. One patient had coughing and blood was detected on device. Three patients had throat discomfort post-operatively. In this study, Oropharyngeal seal pressures with PLMA were found to increase after pneumoperitoneum in lateral position. PLMA forms an effective seal around airway and is an efficient and safe alternative for airway management in urological laparoscopic surgeries done in lateral position.

Orbital tuberculosis in childhood with intracranial extension: a case report.

PubMed

Tuli, Navneet

2010-01-28

The common causes of orbital masses in pediatric age group include pseudotumour, lymphomas, hemangioma and dermoid cyst. Orbital tuberculosis is rare especially in children. We report a case of 5 year old child who presented with proptosis and gross diminution of vision due to orbital tuberculoma. Ocular examination of the left eye revealed proptosis with the eyeball displaced downwards and forwards. Vision was counting finger close to face. CT Scan showed an extraconal soft tissue mass along posteromedial side of left orbit with lateral displacement of medial rectus muscle. On antitubercular treatment, proptosis regressed and visual recovery was observed over a period of six month vision, in the left eye at the last followup was 20/30.

Co-seismic strike-slip surface rupture and displacement produced by the 2010 Mw 6.9 Yushu earthquake, China, and implications for Tibetan tectonics

NASA Astrophysics Data System (ADS)

Lin, A.; Rao, G.; Jia, D.; Wu, X.; Yan, B.; Ren, Z.

2010-12-01

The magnitude (Mw) 6.9 (Ms 7.1) Yushu earthquake occurred on 14 April 2010 in the Yushu area, central Tibetan Plateau, killing approximately 3000 people (including 270 missing) and causing widespread damage in the high mountain regions of the central Tibetan Plateau. The Yushu earthquake is comparable with the 1997 Mw 7.6 Manyi earthquake, the 2001 Mw 7.8 Kunlun earthquake, and the 2008 Mw 7.9 Wenchuan earthquake, which all occurred in the northern and eastern Tibetan Plateau, in terms of their magnitude and seismotectonic environment, related to the eastward extrusion of the Tibetan Plateau in response to continental collision between the Indian and Eurasian plates. Although some prompt reports related to ground deformation and the focal mechanism were published in the Chinese literature soon after the Yushu earthquake, there are scarce data related to the nature of co-seismic strike-slip rupturing structures and displacement distributions because the co-seismic surface ruptures were produced mainly in remote, high mountain regions of the Tibetan Plateau (average elevation >4000 m) and roads to the epicentral area were damaged, which made it difficult to gain access to the area and to undertake fieldwork immediately after the earthquake. Field investigations reveal that the earthquake produced a 33-km-long surface rupture zone, with dominantly left-lateral strike-slip along the Yushu Fault of the pre-existing strike-slip Ganzi-Yushu Fault Zone. The co-seismic surface ruptures are characterized by discontinuous shear faults, right-stepping en echelon tensional cracks, and left-stepping mole track structures that indicate a left-lateral strike-slip shear sense for the seismic fault. Field measurements indicate co-seismic left-lateral strike-slip displacements of approximately 0.3-3.2 m (typically 1-2 m), accompanied by a minor vertical component of <0.6 m. The present results show that (i) the Yushu earthquake occurred upon the pre-existing active Ganzi-Yushu Fault Zone, which controlled the spatial distribution of co-seismic surface ruptures and displacements; (ii) the left-lateral strike-slip motion indicates that the Ganzi-Yushu Fault Zone partitions deformation into eastward extrusion and northeastward shortening of the central Tibetan Plateau to accommodate the continuing penetration of the Indian plate into the Eurasian plate. Our findings confirm that present-day strain energy related to continental deformation in the central Tibetan Plateau, generated by collision between the Indian and Eurasian plates, is mainly released by strike-slip faulting along active strike-slip faults, and that the Ganzi-Yushu Fault Zone plays an important role in this crustal deformation, generating strong earthquakes that help to release the accumulated strain energy.

On the strong influence of molecular interactions over large distances

NASA Astrophysics Data System (ADS)

Pfennig, Andreas

2018-03-01

Molecular-dynamics simulations of liquid water show deterministic chaos, i.e. an intentionally introduced molecular position shift of an individual molecule increases exponentially by a factor of 10 in 0.23 ps. This is a Lyaponov instability. As soon as it reaches molecular scale, the direction of the resulting shift in molecular motions is unpredictable. The influence of any individual distant particle on an observed molecule will be minute, but the effect will quickly increase to molecular scale and beyond due to this exponential growth. Consequently, any individual particle in the universe will affect the behavior of any molecule within at most 33 ps after the interaction reaches it. A larger distance of the faraway particle does not decrease the influence on an observed molecule, but the effect reaches molecular scale only some ps later. Thus in evaluating the interactions, nearby and faraway molecules have to be equally accounted for. The consequences of this quickly reacting network of interactions on universal scale are fundamental. Even in a strictly deterministic view, molecular behavior is principally unpredictable, and thus has to be regarded random. Corresponding statements apply for any particles interacting. This result leads to a fundamental rethinking of the structure of interactions of molecules and particles as well as the behavior of reality.

Vibrations of Railroad Due to The Passage of The Underground Train

NASA Astrophysics Data System (ADS)

Konowrocki, Robert; Bajer, Czesław

2010-03-01

In the paper we present results of vibration measurements in the train and on the base of the railroad in tunnels of Warsaw Underground. Measurements were performed at straight and curved sections of the track. The paper is focused on the influence of the lateral slip in rail/wheel contact zone on the generation of vibrations and a noise. Vibrations were analyzed in terms of accelerations, velocities or displacements as a function of time and frequency. Results ware compared with the experiment of rolling of the wheel with lateral sleep. In both cases we observed double periodic oscillations.

Comparison of Q3s ATD biomechanical responses to pediatric volunteers.

PubMed

Ita, Meagan; Kang, Yun-Seok; Seacrist, Thomas; Dahle, Eric; Bolte, John

2014-01-01

The biofidelity of pediatric anthropomorphic test devices (ATDs) continues to be evaluated with scaled-down adult data, a methodology that requires inaccurate assumptions about the likeness of biomechanical properties of children and adults. Recently, evaluation of pediatric ATDs by comparison of pediatric volunteer (PV) data has emerged as a valuable and practical alternative to the use of scaled adult data. This study utilized existing PV data to evaluate a 3-year-old side impact ATD, the Q3s. Though ATDs have been compared to volunteer responses in frontal impacts, this study is the first to extend ATD-PV comparison methods to the Q3s ATD and among the first to extend these methods to side impacts. Previously conducted experiments were replicated in order to make a direct comparison between the Q3s and PVs. PV data were used from 4- to 7-year-olds (shoulder tests, n=14) and 6- to 8-year-olds (sled tests, n=7). Force-deflection data were captured during quasistatic shoulder tests through manual displacement of the shoulder joint. Resulting shoulder stiffness was compared between the Q3s and PVs. Low-speed far-side sled tests were conducted with the Q3s at lateral (90°) and oblique (60°) impacts. Primary outcomes of interest included (1) lateral displacement of the torso, (2) torso rollout angle, and (3) kinematic trajectories of the head and neck. The Q3s exhibited shoulder stiffness values at least 32 N/mm greater than the PVs for all conditions (PV muscle tensed and relaxed, deflection calculated for full- and half-thoracic). In lateral sled tests, the Q3s demonstrated increased coronal torso rollout (Q3s: 49.2°; PVs: 35.7°±12.4°) and lateral (ΔY) movement of the top of the head (Q3s: -389 mm; PVs: -320±23 mm) compared to PVs. In oblique trials, the Q3s achieved significantly decreased lateral torso displacement (Q3s: 153.3 mm; PVs: 193.6±25.6 mm) and top of the head forward (ΔX) motion (Q3s: 68 mm; PVs: 133 ± 20 mm) compared to PVs. In all tests, greater downward (ΔZ) excursions of C4 and T1 were observed in the Q3s relative to PVs. Increased Q3s shoulder stiffness could affect head-neck kinematics as well as thorax responses because unrealistic force can be transmitted to the spine from the shoulder. Q3s and PV trajectories were of similar shape, although Q3s head kinematics displayed rigid body motion followed by independent lateral bending of the head, suggesting cervical and thoracic spine rigidity compared to PVs.

Edema and Seed Displacements Affect Intraoperative Permanent Prostate Brachytherapy Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Westendorp, Hendrik, E-mail: r.westendorp@radiotherapiegroep.nl; Nuver, Tonnis T.; Department of Radiation Oncology, Radiotherapiegroep Behandellocatie Deventer, Deventer

Purpose: We sought to identify the intraoperative displacement patterns of seeds and to evaluate the correlation of intraoperative dosimetry with day 30 for permanent prostate brachytherapy. Methods and Materials: We analyzed the data from 699 patients. Intraoperative dosimetry was acquired using transrectal ultrasonography (TRUS) and C-arm cone beam computed tomography (CBCT). Intraoperative dosimetry (minimal dose to 40%-95% of the volume [D{sub 40}-D{sub 95}]) was compared with the day 30 dosimetry for both modalities. An additional edema-compensating comparison was performed for D{sub 90}. Stranded seeds were linked between TRUS and CBCT using an automatic and fast linking procedure. Displacement patterns weremore » analyzed for each seed implantation location. Results: On average, an intraoperative (TRUS to CBCT) D{sub 90} decline of 10.6% ± 7.4% was observed. Intraoperative CBCT D{sub 90} showed a greater correlation (R{sup 2} = 0.33) with respect to Day 30 than did TRUS (R{sup 2} = 0.17). Compensating for edema, the correlation increased to 0.41 for CBCT and 0.38 for TRUS. The mean absolute intraoperative seed displacement was 3.9 ± 2.0 mm. The largest seed displacements were observed near the rectal wall. The central and posterior seeds showed less caudal displacement than lateral and anterior seeds. Seeds that were implanted closer to the base showed more divergence than seeds close to the apex. Conclusions: Intraoperative CBCT D{sub 90} showed a greater correlation with the day 30 dosimetry than intraoperative TRUS. Edema seemed to cause most of the systematic difference between the intraoperative and day 30 dosimetry. Seeds near the rectal wall showed the most displacement, comparing TRUS and CBCT, probably because of TRUS probe–induced prostate deformation.« less

Three Dimensional Vibration Characteristics of the Permanent Magnet-HTSC Magnetic Bearing

NASA Astrophysics Data System (ADS)

Ohashi, Shunsuke

The three dimensional vibration of the rotor in a HTSC-permanent magnet bearing system is studied. We have developed the magnetic bearing system which can revolve up to 12,000rpm, and three dimensional vibration of the rotor is measured with laser displacement sensors. To consider the rotor vibration under the mechanical resonance state, static lateral and vertical pinning force of the magnetic bearing is measured. From the results, resonance frequency is given. There are two factors of mechanical resonance caused by the magnetic bearing. One is lateral equivalent spring and the other is vertical one. Influence of the resonance caused by the lateral spring is large, and that by the vertical one is small. Three dimensional vibration of the rotor position around the mechanical resonance frequency is measured. Because revolution of the rotor increases lateral force to the center, resonance frequency given from the free revolution experiment becomes larger than that from pinning force measurement.

Implant-supported mandibular splinting affects temporomandibular joint biomechanics.

PubMed

Zaugg, Balthasar; Hämmerle, Christoph H F; Palla, Sandro; Gallo, Luigi M

2012-08-01

Mandibular functional movements lead to complex deformations of bony structures. The aim of this study was to test whether mandibular splinting influences condylar kinematics and temporomandibular joint (TMJ) loading patterns. Six subjects were analyzed by means of dynamic stereometry during jaw opening-closing with mandibles unconstrained as well as splinted transversally by a cast metal bar fixed bilaterally to two implant pairs in the (pre)molar region. Statistical analysis was performed by means of ANOVAs for repeated measurements (significance level α=0.05). Transversal splinting reduced mandibular deformation during jaw opening-closing as measured between two implants in the (pre)molar region on each side of the mandible significantly by 54%. Furthermore, splinting significantly reduced the distance between lateral condylar poles (average displacement vector magnitude of each pole: 0.84±0.36 mm; average mediolateral displacement component: 45±28% of the magnitude) and led to a medial displacement of their trajectories as well as a mediolateral displacement of stress-field paths. During jaw opening-closing, splinting of the mandible leads to a significant reduction of mandibular deformation and intercondylar distance and to altered stress-field paths, resulting in changed loading patterns of the TMJ structures. © 2011 John Wiley & Sons A/S.

A computational biomechanical analysis to assess the trade-off between chest deflection and spine translation in side impact.

PubMed

Pipkorn, Bengt; Subit, Damien; Donlon, John Paul; Sunnevång, Cecilia

2014-01-01

The objective of this study is to evaluate how the impact energy is apportioned between chest deflection and translation of the vehicle occupant for various side impact conditions. The Autoliv Total Human Model for Safety (modified THUMS v1.4) was subjected to localized lateral constant velocity impacts to the upper body. First, the impact tests performed on postmortem human subjects (PMHS) were replicated to evaluate THUMS biofidelity. In these tests, a 75-mm-tall flat probe impacted the thorax at 3 m/s at 3 levels (shoulder, upper chest, and mid-chest) and 3 angles (lateral, +15° posterolateral, and -15° anterolateral), for a stroke of 72 mm. Second, a parametric analysis was performed: the Autoliv THUMS response to a 250-mm impact was evaluated for varying impact levels (shoulder to mid-thorax by 50-mm increments), obliquity (0° [pure lateral] to +20° [posterior impacts] and to -20° [anterior impacts], by 5° steps), and impactor pitch (from 0 to 25° by 5° steps). A total of 139 simulations were run. The impactor force, chest deflection, spine displacement, and spine velocity were calculated for each simulation. The Autoliv THUMS biofidelity was found acceptable. Overall, the predictions from the model were in good agreement with the PMHS results. The worst ratings were observed for the anterolateral impacts. For the parametric analysis, maximum chest deflection (MCD) and maximum spine displacement (MSD) were found to consistently follow opposite trends with increasing obliquity. This trend was level dependent, with greater MCD (lower MSD) for the higher impact levels. However, the spine velocity for the 250-mm impactor stroke followed an independent trend that could not be linked to MCD or MSD. This suggests that the spine velocity, which can be used as a proxy for the thorax kinetic energy, needs to be included in the design parameters of countermeasures for side impact protection. The parametric analysis reveals a trade-off between the deformation of the chest (and therefore the risk of rib fracture) and the lateral translation of the spine: reducing the maximum chest deflection comes at the cost of increasing the occupant lateral displacement. The trade-off between MCD and MSD is location dependent, which suggests that an optimum point of loading on the chest for the action of a safety system can be found.

Deterministic quantum dense coding networks

NASA Astrophysics Data System (ADS)

Roy, Saptarshi; Chanda, Titas; Das, Tamoghna; Sen(De), Aditi; Sen, Ujjwal

2018-07-01

We consider the scenario of deterministic classical information transmission between multiple senders and a single receiver, when they a priori share a multipartite quantum state - an attempt towards building a deterministic dense coding network. Specifically, we prove that in the case of two or three senders and a single receiver, generalized Greenberger-Horne-Zeilinger (gGHZ) states are not beneficial for sending classical information deterministically beyond the classical limit, except when the shared state is the GHZ state itself. On the other hand, three- and four-qubit generalized W (gW) states with specific parameters as well as the four-qubit Dicke states can provide a quantum advantage of sending the information in deterministic dense coding. Interestingly however, numerical simulations in the three-qubit scenario reveal that the percentage of states from the GHZ-class that are deterministic dense codeable is higher than that of states from the W-class.

Intra-continental subduction and contemporaneous lateral extrusion of the upper plate: insights into Alps-Adria interactions

NASA Astrophysics Data System (ADS)

van Gelder, Inge; Willingshofer, Ernst; Sokoutis, Dimitrios; Cloetingh, Sierd

2017-04-01

A series of physical analogue experiments were performed to simulate intra-continental subduction contemporaneous with lateral extrusion of the upper plate to study the interferences between these two processes at crustal levels and in the lithospheric mantle. The lithospheric-scale models are specifically designed to represent the collision of the Adriatic microplate with the Eastern Alps, simulated by an intra-continental weak zone to initiate subduction and a weak confined margin perpendicular to the direction of convergence in order to allow for extrusion of the lithosphere. The weak confined margin is the analog for the opening of the Pannonian back-arc basin adjacent to the Eastern Alps with the direction of extension perpendicular to the strike of the orogen. The models show that intra-continental subduction and coeval lateral extrusion of the upper plate are compatible processes. The obtained deformation structures within the extruding region are similar compared to the classical setup where lateral extrusion is provoked by lithosphere-scale indentation. In the models a strong coupling across the subduction boundary allows for the transfer of abundant stresses to the upper plate, leading to laterally varying strain regimes that are characterized by crustal thickening near a confined margin and dominated by lateral displacement of material near a weak lateral confinement. During ongoing convergence the strain regimes propagate laterally, thereby creating an area of overlap characterized by transpression. In models with oblique subduction, with respect to the convergence direction, less deformation of the upper plate is observed and as a consequence the amount of lateral extrusion decreases. Additionally, strain is partitioned along the oblique plate boundary leading to less subduction in expense of right lateral displacement close to the weak lateral confinement. Both oblique and orthogonal subduction models have a strong resemblance to lateral extrusion tectonics of the Eastern Alps, where subduction of the adjacent Adriatic plate beneath the Eastern Alps is debated. Our results highlight that both indentation and subduction of Adria are valid collisional mechanisms to provoke lateral extrusion-type deformation within the Eastern Alps lithosphere, i.e. the upper plate. Moreover, the insights suggest that the Oligocene to Late Miocene structural evolution of the Eastern Alps is best described by phases of oblique and subsequent orthogonal subduction which is in line with Miocene rotations of the Adriatic plate. Furthermore, oblique subduction of the Adriatic plate provides a viable mechanism to explain the rapid decrease in slab length beneath the Eastern Alps towards the Pannonian Basin, also implying that the Adriatic slab can behave and form independently with regards to the adjacent subduction of Adria beneath the Dinarides.

‘Life under the tent is not safe, especially for young women’: understanding intersectional violence among internally displaced youth in Leogane, Haiti

PubMed Central

Logie, Carmen H.; Daniel, CarolAnn; Ahmed, Uzma; Lash, Rebecca

2017-01-01

ABSTRACT Background: Haiti’s 2010 earthquake devastated social, health, and economic infrastructure and left 2 million persons homeless. Over 6 years later 61,000 people remain displaced, most lacking protection, services, and durable solutions. Structural contexts elevate risks of gender-based violence (GBV) targeting internally displaced (ID) girls and women. Objective: We used an intersectionality framework to explore lived experiences and understanding of violence among ID young men and women in Leogane, Haiti. Methods: We conducted six focus groups, three with ID young women (n = 30) and three with ID young men (n = 30) aged 18–24 years, and 11 in-depth individual interviews with frontline workers in Leogane. Focus groups and interviews were conducted in Kreyol, transcribed verbatim, translated into English, and analyzed using narrative thematic techniques. Results: Findings revealed violence experienced by ID youth was (re)produced at the intersection of gender, poverty, displacement, and age. Multi-level forms of violence included structural (e.g. poverty), community (e.g. gender norms, and interpersonal (e.g. family expectations) dimensions. Coping strategies spanned intrapersonal (hope), community (social support), and structural (employment/education) dimensions. Conclusions: Interventions to reduce violence should be tailored to address the social inequities that emerge at the intersection of youth, poverty, displacement, and hegemonic gender norms. PMID:28219254

[Three-dimensional finite element analysis of maxillary anterior teeth retraction force system in light wire technique].

PubMed

Zhang, Xiangfeng; Wang, Chao; Xia, Xi; Deng, Feng; Zhang, Yi

2015-06-01

This study aims to construct a three-dimensional finite element model of a maxillary anterior teeth retraction force system in light wire technique and to investigate the difference of hydrostatic pressure and initial displacement of upper anterior teeth under different torque values of tip back bend. A geometric three-dimensional model of the maxillary bone, including all the upper teeth, was achieved via CT scan. To construct the force model system, lingual brackets and wire were constructed by using the Solidworks. Brackets software, and wire were assembled to the teeth. ANASYS was used to calculate the hydrostatic pressure and the initial displacement of maxillary anterior teeth under different tip-back bend moments of 15, 30, 45, 60, and 75 Nmm when the class II elastic force was 0.556 N. Hydrostatic pressure was concentrated in the root apices and cervical margin of upper anterior teeth. Distal tipping and relative intrusive displacement were observed. The hydrostatic pressure and initial displacement of upper canine were greater than in the central and lateral incisors. This hydrostatic pressure and initial intrusive displacement increased with an increase in tip-back bend moment. Lingual retraction force system of maxillary anterior teeth in light wire technique can be applied safely and controllably. The type and quantity of teeth movement can be controlled by the alteration of tip-back bend moment.

Radiotherapy setup displacements in breast cancer patients: 3D surface imaging experience.

PubMed

Cravo Sá, Ana; Fermento, Ana; Neves, Dalila; Ferreira, Sara; Silva, Teresa; Marques Coelho, Carina; Vaandering, Aude; Roma, Ana; Quaresma, Sérgio; Bonnarens, Emmanuel

2018-01-01

In this study, we intend to compare two different setup procedures for female breast cancer patients. Imaging in radiotherapy provides a precise localization of the tumour, increasing the accuracy of the treatment delivery in breast cancer. Twenty breast cancer patients who underwent whole breast radiotherapy (WBRT) were selected for this study. Patients were divided into two groups of ten. Group one (G1) was positioned by tattoos and then the patient positioning was adjusted with the aid of AlignRT (Vision RT, London, UK). In group two (G2), patients were positioned only by tattoos. For both groups, the first 15 fractions were analyzed, a daily kilovoltage (kV) cone beam computed tomography (CBCT) image was made and then the rotational and translational displacements and, posteriorly, the systematic ( Σ ) and random ( σ ) errors were analyzed. The comparison of CBCT displacements for the two groups showed a statistically significant difference in the translational left-right (LR) direction ( ρ  = 0.03), considering that the procedure with AlignRT system has smaller lateral displacements. The results of systematic ( Σ ) and random ( σ ) errors showed that for translational displacements the group positioned only by tattoos (G2) demonstrated higher values of errors when compared with the group positioned with the aid of AlignRT (G1). AlignRT could help the positioning of breast cancer patients; however, it should be used with another imaging method.

Relationship between friction force and orthodontic force at the leveling stage using a coated wire

PubMed Central

MURAYAMA, Masaki; NAMURA, Yasuhiro; TAMURA, Takahiko; IWAI, Hiroaki; SHIMIZU, Noriyoshi

2013-01-01

The relationship between orthodontic force and friction produced from an archwire and brackets affects the sliding of the wire in the leveling stage. Objective The purpose of this study was to evaluate the relationship between force and friction in a small esthetic nickel-titanium (Ni-Ti) wire. Material and Methods Five esthetic wires (three coated and two plated) and two small, plain Ni-Ti wires (0.012 and 0.014 inches) were used. We performed a three-point bending test according to ISO 15841 and the drawing test with a dental arch model designed with upper linguoversion of the lateral incisor in the arch (displacements of 0.5, 1.0, 2.0 and 3.0 mm), and evaluated the relationship between them. Results Unloading bending forces of all wires at displacements of less than 1.0 mm were larger than friction forces, but all friction forces at displacements exceeding 2.0 mm were larger than unloading bending forces. The arch likely expands when displacement from the proximal brackets exceeds 1.0 mm. The friction force of a martensite 0.014-inch Ni-Ti wire was significantly greater than those of the other esthetic and austenitic wires. Conclusions A wire with the smallest possible friction force should be used in cases with more than 1.0 mm displacement. PMID:24473722

Deformation analysis of Aceh April 11{sup th} 2012 earthquake using GPS observation data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maulida, Putra, E-mail: putra.maulida@gmail.com; Meilano, Irwan; Sarsito, Dina A.

This research tries to estimate the co-seismic deformation of intraplate earthquake occurred off northern Sumatra coast which is about 100-200 km southwest of Sumatrasubduction zone. The earthquake mechanism was strike-slip with magnitude 8.6 and triggering aftershock with magnitude 8.2 two hours later. We estimated the co-seismic deformation by using the GPS (Global Positioning System) continuous data along western Sumatra coast. The GPS observation derived from Sumatran GPS Array (SuGAr) and Geospatial Information Agency (BIG). For data processing we used GPS Analyze at Massachusetts Institute of Technology (GAMIT) software and Global Kalman Filter (GLOBK) to estimate the co-seismic deformation. From themore » GPS daily solution, the result shows that the earthquake caused displacement for the GPS stations in Sumatra. GPS stations in northern Sumatra showed the displacement to the northeast with the average displacement was 15 cm. The biggest displacement was found at station BSIM which is located at Simeuleu Island off north west Sumatra coast. GPS station in middle part of Sumatra, the displacement was northwest. The earthquake also caused subsidence for stations in northern Sumatra, but from the time series there was not sign of subsidence was found at middle part of Sumatra. In addition, the effect of the earthquake was worldwide and affected the other GPS Stations around Hindia oceanic.« less

Characterization of radiographic features of consecutive lumbar spondylolisthesis.

PubMed

Sun, Yapeng; Wang, Hui; Yang, Dalong; Zhang, Nan; Yang, Sidong; Zhang, Wei; Ding, Wenyuan

2016-11-01

Radiographic features of consecutive lumbar spondylolisthesis were retrospectively analyzed in a total of 17 patients treated for this condition at the Third Hospital of Hebei Medical University from June 2005 to March 2012.To investigate the radiographic features, pelvic compensatory mechanisms, and possible underlying etiologies of consecutive lumbar spondylolisthesis.To the best of our knowledge, there is no previous report concerning the characteristics of consecutive lumbar spondylolisthesis.The Taillard index and the lumbar lordosis (LL), pelvic incidence (PI), sacrum slope (SS), and pelvic tilt (PT) were determined on lateral X-ray images, and the angular displacement was analyzed on flexion-extension X-ray images. Correlation between LL and various pelvic parameters and correlation between Taillard index and angular displacement were assessed by Pearson correlation analysis.A total of 20 cases of isthmic spondylolisthesis and 14 of degenerative spondylolisthesis were retrospectively studied in 17 patients. The Taillard index and the angular displacement in the lower vertebrae were both larger than those in the upper vertebrae. Statistical analysis revealed that LL was correlated with PI and PT, whereas PI was correlated with PT and SS. However, no correlation was identified between Taillard index and angular displacement.In consecutive lumbar spondylolisthesis, the degree of vertebral slip and the angular displacement of the lower vertebrae were both greater than those of the upper vertebrae, indicating that the compensatory mechanism of the pelvis plays an important role in maintaining sagittal balance.

Characterization of radiographic features of consecutive lumbar spondylolisthesis

PubMed Central

Sun, Yapeng; Wang, Hui; Yang, Dalong; Zhang, Nan; Yang, Sidong; Zhang, Wei; Ding, Wenyuan

2016-01-01

Abstract Radiographic features of consecutive lumbar spondylolisthesis were retrospectively analyzed in a total of 17 patients treated for this condition at the Third Hospital of Hebei Medical University from June 2005 to March 2012. To investigate the radiographic features, pelvic compensatory mechanisms, and possible underlying etiologies of consecutive lumbar spondylolisthesis. To the best of our knowledge, there is no previous report concerning the characteristics of consecutive lumbar spondylolisthesis. The Taillard index and the lumbar lordosis (LL), pelvic incidence (PI), sacrum slope (SS), and pelvic tilt (PT) were determined on lateral X-ray images, and the angular displacement was analyzed on flexion–extension X-ray images. Correlation between LL and various pelvic parameters and correlation between Taillard index and angular displacement were assessed by Pearson correlation analysis. A total of 20 cases of isthmic spondylolisthesis and 14 of degenerative spondylolisthesis were retrospectively studied in 17 patients. The Taillard index and the angular displacement in the lower vertebrae were both larger than those in the upper vertebrae. Statistical analysis revealed that LL was correlated with PI and PT, whereas PI was correlated with PT and SS. However, no correlation was identified between Taillard index and angular displacement. In consecutive lumbar spondylolisthesis, the degree of vertebral slip and the angular displacement of the lower vertebrae were both greater than those of the upper vertebrae, indicating that the compensatory mechanism of the pelvis plays an important role in maintaining sagittal balance. PMID:27861359

Kinematic Measurements of the Vocal-Fold Displacement Waveform in Typical Children and Adult Populations: Quantification of High-Speed Endoscopic Videos

PubMed Central

Donohue, Kevin D.; Unnikrishnan, Harikrishnan; Kryscio, Richard J.

2015-01-01

Purpose This article presents a quantitative method for assessing instantaneous and average lateral vocal-fold motion from high-speed digital imaging, with a focus on developmental changes in vocal-fold kinematics during childhood. Method Vocal-fold vibrations were analyzed for 28 children (aged 5–11 years) and 28 adults (aged 21–45 years) without voice disorders. The following kinematic features were analyzed from the vocal-fold displacement waveforms: relative velocity-based features (normalized average and peak opening and closing velocities), relative acceleration-based features (normalized peak opening and closing accelerations), speed quotient, and normalized peak displacement. Results Children exhibited significantly larger normalized peak displacements, normalized average and peak opening velocities, normalized average and peak closing velocities, peak opening and closing accelerations, and speed quotient compared to adult women. Values of normalized average closing velocity and speed quotient were higher in children compared to adult men. Conclusions When compared to adult men, developing children typically have higher estimates of kinematic features related to normalized displacement and its derivatives. In most cases, the kinematic features of children are closer to those of adult men than adult women. Even though boys experience greater changes in glottal length and pitch as they mature, results indicate that girls experience greater changes in kinematic features compared to boys. PMID:25652615

Reactive Balance Control in Response to Perturbation in Unilateral Stance: Interaction Effects of Direction, Displacement and Velocity on Compensatory Neuromuscular and Kinematic Responses

PubMed Central

Freyler, Kathrin; Gollhofer, Albert; Colin, Ralf; Brüderlin, Uli; Ritzmann, Ramona

2015-01-01

Unexpected sudden perturbations challenge postural equilibrium and require reactive compensation. This study aimed to assess interaction effects of the direction, displacement and velocity of perturbations on electromyographic (EMG) activity, centre of pressure (COP) displacement and joint kinematics to detect neuromuscular characteristics (phasic and segmental) and kinematic strategies of compensatory reactions in an unilateral balance paradigm. In 20 subjects, COP displacement and velocity, ankle, knee and hip joint excursions and EMG during short (SLR), medium (MLR) and long latency response (LLR) of four shank and five thigh muscles were analysed during random surface translations varying in direction (anterior-posterior (sagittal plane), medial-lateral (frontal plane)), displacement (2 vs. 3cm) and velocity (0.11 vs. 0.18m/s) of perturbation when balancing on one leg on a movable platform. Phases: SLR and MLR were scaled to increased velocity (P<0.05); LLR was scaled to increased displacement (P<0.05). Segments: phasic interrelationships were accompanied by segmental distinctions: distal muscles were used for fast compensation in SLR (P<0.05) and proximal muscles to stabilise in LLR (P<0.05). Kinematics: ankle joints compensated for both increasing displacement and velocity in all directions (P<0.05), whereas knee joint deflections were particularly sensitive to increasing displacement in the sagittal (P<0.05) and hip joint deflections to increasing velocity in the frontal plane (P<0.05). COP measures increased with increasing perturbation velocity and displacement (P<0.05). Interaction effects indicate that compensatory responses are based on complex processes, including different postural strategies characterised by phasic and segmental specifications, precisely adjusted to the type of balance disturbance. To regain balance after surface translation, muscles of the distal segment govern the quick regain of equilibrium; the muscles of the proximal limb serve as delayed stabilisers after a balance disturbance. Further, a kinematic distinction regarding the compensation for balance disturbance indicated different plane- and segment-specific sensitivities with respect to the determinants displacement and velocity. PMID:26678061

Evidence of Non-Linear Elasticity of the Crust from the Mw7.6 Manyi (Tibet) Earthquake Surface Displacement Field

NASA Technical Reports Server (NTRS)

Peltzer, G.; Crampe, F.; King, G.

1999-01-01

Satellite synthetic aperture radar (SAR) interferometry shows that the magnitude 7.6 Manyi earthquake of 8 November 1997 produces a 170 km-long surface break with up to 7m of left-lateral slip, reactivating a North 76 degrees East quaternary fault in western Tibet.

Scale-invariant Green-Kubo relation for time-averaged diffusivity

NASA Astrophysics Data System (ADS)

Meyer, Philipp; Barkai, Eli; Kantz, Holger

2017-12-01

In recent years it was shown both theoretically and experimentally that in certain systems exhibiting anomalous diffusion the time- and ensemble-averaged mean-squared displacement are remarkably different. The ensemble-averaged diffusivity is obtained from a scaling Green-Kubo relation, which connects the scale-invariant nonstationary velocity correlation function with the transport coefficient. Here we obtain the relation between time-averaged diffusivity, usually recorded in single-particle tracking experiments, and the underlying scale-invariant velocity correlation function. The time-averaged mean-squared displacement is given by 〈δ2¯〉 ˜2 DνtβΔν -β , where t is the total measurement time and Δ is the lag time. Here ν is the anomalous diffusion exponent obtained from ensemble-averaged measurements 〈x2〉 ˜tν , while β ≥-1 marks the growth or decline of the kinetic energy 〈v2〉 ˜tβ . Thus, we establish a connection between exponents that can be read off the asymptotic properties of the velocity correlation function and similarly for the transport constant Dν. We demonstrate our results with nonstationary scale-invariant stochastic and deterministic models, thereby highlighting that systems with equivalent behavior in the ensemble average can differ strongly in their time average. If the averaged kinetic energy is finite, β =0 , the time scaling of 〈δ2¯〉 and 〈x2〉 are identical; however, the time-averaged transport coefficient Dν is not identical to the corresponding ensemble-averaged diffusion constant.

Noncontact on-machine measurement system based on capacitive displacement sensors for single-point diamond turning

NASA Astrophysics Data System (ADS)

Li, Xingchang; Zhang, Zhiyu; Hu, Haifei; Li, Yingjie; Xiong, Ling; Zhang, Xuejun; Yan, Jiwang

2018-04-01

On-machine measurements can improve the form accuracy of optical surfaces in single-point diamond turning applications; however, commercially available linear variable differential transformer sensors are inaccurate and can potentially scratch the surface. We present an on-machine measurement system based on capacitive displacement sensors for high-precision optical surfaces. In the proposed system, a position-trigger method of measurement was developed to ensure strict correspondence between the measurement points and the measurement data with no intervening time-delay. In addition, a double-sensor measurement was proposed to reduce the electric signal noise during spindle rotation. Using the proposed system, the repeatability of 80-nm peak-to-valley (PV) and 8-nm root-mean-square (RMS) was achieved through analyzing four successive measurement results. The accuracy of 109-nm PV and 14-nm RMS was obtained by comparing with the interferometer measurement result. An aluminum spherical mirror with a diameter of 300 mm was fabricated, and the resulting measured form error after one compensation cut was decreased to 254 nm in PV and 52 nm in RMS. These results confirm that the measurements of the surface form errors were successfully used to modify the cutting tool path during the compensation cut, thereby ensuring that the diamond turning process was more deterministic. In addition, the results show that the noise level was significantly reduced with the reference sensor even under a high rotational speed.

Causal reasoning with mental models

PubMed Central

Khemlani, Sangeet S.; Barbey, Aron K.; Johnson-Laird, Philip N.

2014-01-01

This paper outlines the model-based theory of causal reasoning. It postulates that the core meanings of causal assertions are deterministic and refer to temporally-ordered sets of possibilities: A causes B to occur means that given A, B occurs, whereas A enables B to occur means that given A, it is possible for B to occur. The paper shows how mental models represent such assertions, and how these models underlie deductive, inductive, and abductive reasoning yielding explanations. It reviews evidence both to corroborate the theory and to account for phenomena sometimes taken to be incompatible with it. Finally, it reviews neuroscience evidence indicating that mental models for causal inference are implemented within lateral prefrontal cortex. PMID:25389398

Causal reasoning with mental models.

PubMed

Khemlani, Sangeet S; Barbey, Aron K; Johnson-Laird, Philip N

2014-01-01

This paper outlines the model-based theory of causal reasoning. It postulates that the core meanings of causal assertions are deterministic and refer to temporally-ordered sets of possibilities: A causes B to occur means that given A, B occurs, whereas A enables B to occur means that given A, it is possible for B to occur. The paper shows how mental models represent such assertions, and how these models underlie deductive, inductive, and abductive reasoning yielding explanations. It reviews evidence both to corroborate the theory and to account for phenomena sometimes taken to be incompatible with it. Finally, it reviews neuroscience evidence indicating that mental models for causal inference are implemented within lateral prefrontal cortex.

Freeform metrology using subaperture stitching interferometry

NASA Astrophysics Data System (ADS)

Supranowitz, Chris; Lormeau, Jean-Pierre; Maloney, Chris; Murphy, Paul; Dumas, Paul

2016-11-01

As applications for freeform optics continue to grow, the need for high-precision metrology is becoming more of a necessity. Currently, coordinate measuring machines (CMM) that implement touch probes or optical probes can measure the widest ranges of shapes of freeform optics, but these measurement solutions often lack sufficient lateral resolution and accuracy. Subaperture stitching interferometry (SSI™) extends traditional Fizeau interferometry to provide accurate, high-resolution measurements of flats, spheres, and aspheres, and development is currently on-going to enable measurements of freeform surfaces. We will present recent freeform metrology results, including repeatability and cross-test data. We will also present MRF® polishing results where the stitched data was used as the input "hitmap" to the deterministic polishing process.

Probabilistic Modeling of the Renal Stone Formation Module

NASA Technical Reports Server (NTRS)

Best, Lauren M.; Myers, Jerry G.; Goodenow, Debra A.; McRae, Michael P.; Jackson, Travis C.

2013-01-01

The Integrated Medical Model (IMM) is a probabilistic tool, used in mission planning decision making and medical systems risk assessments. The IMM project maintains a database of over 80 medical conditions that could occur during a spaceflight, documenting an incidence rate and end case scenarios for each. In some cases, where observational data are insufficient to adequately define the inflight medical risk, the IMM utilizes external probabilistic modules to model and estimate the event likelihoods. One such medical event of interest is an unpassed renal stone. Due to a high salt diet and high concentrations of calcium in the blood (due to bone depletion caused by unloading in the microgravity environment) astronauts are at a considerable elevated risk for developing renal calculi (nephrolithiasis) while in space. Lack of observed incidences of nephrolithiasis has led HRP to initiate the development of the Renal Stone Formation Module (RSFM) to create a probabilistic simulator capable of estimating the likelihood of symptomatic renal stone presentation in astronauts on exploration missions. The model consists of two major parts. The first is the probabilistic component, which utilizes probability distributions to assess the range of urine electrolyte parameters and a multivariate regression to transform estimated crystal density and size distributions to the likelihood of the presentation of nephrolithiasis symptoms. The second is a deterministic physical and chemical model of renal stone growth in the kidney developed by Kassemi et al. The probabilistic component of the renal stone model couples the input probability distributions describing the urine chemistry, astronaut physiology, and system parameters with the physical and chemical outputs and inputs to the deterministic stone growth model. These two parts of the model are necessary to capture the uncertainty in the likelihood estimate. The model will be driven by Monte Carlo simulations, continuously randomly sampling the probability distributions of the electrolyte concentrations and system parameters that are inputs into the deterministic model. The total urine chemistry concentrations are used to determine the urine chemistry activity using the Joint Expert Speciation System (JESS), a biochemistry model. Information used from JESS is then fed into the deterministic growth model. Outputs from JESS and the deterministic model are passed back to the probabilistic model where a multivariate regression is used to assess the likelihood of a stone forming and the likelihood of a stone requiring clinical intervention. The parameters used to determine to quantify these risks include: relative supersaturation (RS) of calcium oxalate, citrate/calcium ratio, crystal number density, total urine volume, pH, magnesium excretion, maximum stone width, and ureteral location. Methods and Validation: The RSFM is designed to perform a Monte Carlo simulation to generate probability distributions of clinically significant renal stones, as well as provide an associated uncertainty in the estimate. Initially, early versions will be used to test integration of the components and assess component validation and verification (V&V), with later versions used to address questions regarding design reference mission scenarios. Once integrated with the deterministic component, the credibility assessment of the integrated model will follow NASA STD 7009 requirements.

Deformation of allochthonous salt and evolution of related salt-structural systems, eastern Louisiana Gulf Coast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schuster, D.C.

1996-12-31

Salt tectonics in the northern Gulf of Mexico involves both vertical diapirism and lateral silling or flow of salt into wings and tablets (sheets). Combinations of these two modes of salt deformation, concurrent with sediment loading and salt evacuation, have produced complex structures in the coastal and offshore region of southeastern Louisiana, a prolific oil and gas province. Many large growth faults and salt domes in the study area root into intra-Tertiary salt welds that were formerly occupied by allochthonous salt tablets. Two end-member structural systems involving evacuation of former tabular salt are recognized: roho systems and stepped counter-regional systems.more » Both end-member systems share a similar multi-staged evolution, including (1) initial formation of a south-leaning salt dome or wall sourced from the Jurassic salt level; (2) progressive development into a semi-tabular allochthonous salt body; and (3) subsequent loading, evacuation, and displacement of the tabular salt into secondary domes. In both systems, it is not uncommon to find salt displaced as much as 16-24 km south of its autochthonous source, connected by a horizontal salt weld to an updip, deflated counter-regional feeder. Although both end-member structural systems may originate before loading of allochthonous salt having grossly similar geometry, their final structural configurations after loading and salt withdrawal are distinctly different. Roho systems are characterized by large-displacement, listric, south-dipping growth faults that sole into intra-Tertiary salt welds marked by high-amplitude reflections continuous with residual salt masses. Salt from the former salt tablets has been loaded and squeezed laterally and downdip. Stepped counter-regional systems, in contrast, comprise large salt domes and adjacent large-displacement, north-dipping growth faults that sole into intra-Tertiary salt welds before stepping down again farther north.« less

Decreased Anticipatory Postural Adjustments During Gait Initiation Acutely Postconcussion.

PubMed

Buckley, Thomas A; Oldham, Jessie R; Munkasy, Barry A; Evans, Kelsey M

2017-10-01

To investigate anticipatory postural adjustments (APAs) during the transitional movement task of gait initiation (GI) in individuals acutely after a concussion. Cohort study. University research center. A population-based sample of participants (N=84) divided into 2 equal groups of acutely postconcussion and healthy student athletes. Participants were tested on 2 occasions: a preinjury baseline test and then the concussion group was retested acutely postconcussion and the healthy student athlete group again at a similar time. All participants completed 5 trials of GI on 4 forceplates. The dependent variables were the displacement and velocity of the center of pressure (COP) during the APA phase and initial step kinematics. Comparisons were made with a 2 (group) × 2 (time) repeated-measures analysis of variance. There was a significant interaction for COP posterior displacement (P<.001) and lateral displacement (P<.001). Posteriorly, post hoc testing identified a significant reduction in the concussion group (pretest: 5.7±1.6cm; posttest: 2.6±2.1cm; P<.001), but no difference in the healthy student athlete group (pretest: 4.0±1.6cm; posttest: 4.0±2.5cm; P=.921). Laterally, post hoc testing identified a significant reduction in the concussion group (pretest: 5.8±2.1cm; posttest: 3.8±1.8cm; P<.001), but no difference in the healthy student athlete group (pretest: 5.0±2.5cm; posttest: 5.2±2.4cm; P=.485). The results of this study suggest difficulty in the planning and execution of GI acutely postconcussion, and posterior APA displacement and velocity are highly effective measures of impaired postural control. Finally, the APA phase is linked to the supplementary motor area, which suggests a supraspinal contribution to postconcussion impaired postural control. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Strain pattern represented by scarps formed during the earthquakes of October 2, 1915, Pleasant Valley, Nevada

USGS Publications Warehouse

Wallace, R.E.

1979-01-01

The pattern of scarps developed during the earthquakes of October 2, 1915, in Pleasant Valley, Nevada, may have formed as a result of a modern stress system acting on a set of fractures produced by an earlier stress system which was oriented differently. Four major scarps developed in a right-stepping, en-echelon pattern suggestive of left-lateral slip across the zone and an extension axis oriented approximately S85??W. The trend of the zone is N25??E. However, the orientation of simple dip-slip on most segments trending approximately N20-40?? E and a right-lateral component of displacement on several N- and NW-trending segments of the scarps indicate that the axis of regional extension was oriented between N50?? and 70?? W, normal to the zone. The cumulative length of the scarps is 60 km, average vertical displacement 2 m, and the maximum vertical displacement near the Pearce School site 5.8 m. Almost everywhere the 1915 scarps formed along an older scarp line, and in some places older scarps represent multiple previous events. The most recent displacement event prior to 1915 is interpreted to have occurred more than 6600 years ago, but possibly less than 20,000 years ago. Some faults expressed by older scarps that trend northwest were not reactivated in 1915, possibly because they are oriented at a low angle with respect to the axis of modern regional extension. The 1915 event occurred in an area of overlap of three regional fault trends oriented northwest, north, and northeast and referred to, respectively, as the Oregon-Nevada, Northwest Nevada, and Midas-Battle Moutain trends. Each of these trends may have developed at a different time; the Oregon-Nevada trend was possibly the earliest and developed in Late Miocene time (Stewart et al. 1975). Segments of the 1915 scarps are parallel to each of these trends, suggesting influence by older sets of fractures. ?? 1979.

Ankle joint pressure changes in a pes cavovarus model: supramalleolar valgus osteotomy versus lateralizing calcaneal osteotomy.

PubMed

Schmid, Timo; Zurbriggen, Sebastian; Zderic, Ivan; Gueorguiev, Boyko; Weber, Martin; Krause, Fabian G

2013-09-01

A fixed cavovarus foot deformity can be associated with anteromedial ankle arthrosis due to elevated medial joint contact stresses. Supramalleolar valgus osteotomies (SMOT) and lateralizing calcaneal osteotomies (LCOT) are commonly used to treat symptoms by redistributing joint contact forces. In a cavovarus model, the effects of SMOT and LCOT on the lateralization of the center of force (COF) and reduction of the peak pressure in the ankle joint were compared. A previously published cavovarus model with fixed hindfoot varus was simulated in 10 cadaver specimens. Closing wedge supramalleolar valgus osteotomies 3 cm above the ankle joint level (6 and 11 degrees) and lateral sliding calcaneal osteotomies (5 and 10 mm displacement) were analyzed at 300 N axial static load (half body weight). The COF migration and peak pressure decrease in the ankle were recorded using high-resolution TekScan pressure sensors. A significant lateral COF shift was observed for each osteotomy: 2.1 mm for the 6 degrees (P = .014) and 2.3 mm for the 11 degrees SMOT (P = .010). The 5 mm LCOT led to a lateral shift of 2.0 mm (P = .042) and the 10 mm LCOT to a shift of 3.0 mm (P = .006). Comparing the different osteotomies among themselves no significant differences were recorded. No significant anteroposterior COF shift was seen. A significant peak pressure reduction was recorded for each osteotomy: The SMOT led to a reduction of 29% (P = .033) for the 6 degrees and 47% (P = .003) for the 11 degrees osteotomy, and the LCOT to a reduction of 41% (P = .003) for the 5 mm and 49% (P = .002) for the 10 mm osteotomy. Similar to the COF lateralization no significant differences between the osteotomies were seen. LCOT and SMOT significantly reduced anteromedial ankle joint contact stresses in this cavovarus model. The unloading effects of both osteotomies were equivalent. More correction did not lead to significantly more lateralization of the COF or more reduction of peak pressure but a trend was seen. In patients with fixed cavovarus feet, both SMOT and LCOT provided equally good redistribution of elevated ankle joint contact forces. Increasing the amount of displacement did not seem to equally improve the joint pressures. The site of osteotomy could therefore be chosen on the basis of surgeon's preference, simplicity, or local factors in case of more complex reconstructions.

B4 2 After, 3D Deformation Field From Matching Pre- To Post-Event Aerial LiDAR Point Clouds, The 2010 El Mayor-Cucapah M7.2 Earthquake Case

NASA Astrophysics Data System (ADS)

Hinojosa-Corona, A.; Nissen, E.; Limon-Tirado, J. F.; Arrowsmith, R.; Krishnan, A.; Saripalli, S.; Oskin, M. E.; Glennie, C. L.; Arregui, S. M.; Fletcher, J. M.; Teran, O. J.

2013-05-01

Aerial LiDAR surveys reconstruct with amazing fidelity the sinuosity of terrain relief. In this research we explore the 3D deformation field at the surface after a big earthquake (M7.2) by comparing pre- to post-event aerial LiDAR point clouds. The April 4 2010 earthquake produced a NW-SE surface rupture ~110km long with right-lateral normal slip up to 3m in magnitude over a very favorable target: scarcely vegetated and unaltered desert mountain range, sierras El Mayor and Cucapah, in northern Baja California, close to the US-México border. It is a plate boundary region between the Pacific and North American plates. The pre-event LiDAR with lower point density (0.013-0.033 pts m-2) required filtering and post-processing before comparing with the denser (9-18 pts m-2) more accurate post event dataset. The 3D surface displacement field was determined using an adaptation of the Iterative Closest Point (ICP) algorithm, implemented in the open source Point Cloud Library (PCL). The LiDAR datasets are first split into a grid of windows, and for each one, ICP iteratively converges on the rigid body transformation (comprising translations and rotations) that best aligns the pre- to post-event points. Perturbing the pre- and post-event point clouds independently with a synthetic right lateral inverse displacements of known magnitude along a proposed fault, ICP recovered the synthetically introduced translations. Windows with dimensions of 100-200m gave the best results for datasets with these densities. The simplified surface rupture photo interpreted and mapped in the field, delineates very well the vertical displacements patterns unveiled by ICP. The method revealed block rotations, some with clockwise and others counter clockwise direction along the simplified surface rupture. As ground truth, displacements from ICP have similar values as those measured in the field along the main rupture by Fletcher and collaborators. The vertical component was better estimated than the horizontal having the latter problems in flat areas as expected. Hybrid approaches, as simple differencing, could be taken in these areas. Outliers were removed from results. ICP detected extraction from quarries developed between the two dates of LiDAR collection and expressed as a negative vertical displacement close to the sites. To improve the accuracy of the 3D displacement field, we intend to reprocess the pre-event source survey data to reduce the systematic error introduced by the sensor. Multidisciplinary approach will be needed to make tectonic inferences from the 3D displacement field revealed by ICP, about the processes at depth expressed at surface.

Use of first derivative of displacement vs. force profiles to determine deformation behavior of compressed powders.

PubMed

Gharaibeh, Shadi F; Aburub, Aktham

2013-03-01

Displacement (D) vs. force (F) profiles obtained during compaction of powders have been reported by several researchers. These profiles are usually used to obtain mechanical energies associated with the compaction of powders. In this work, we obtained displacement-force data associated with the compression of six powders; Avicel PH101, Avicel PH301, pregelatinized corn starch, anhydrous lactose, dicalcium phosphate, and mannitol. The first three powders are known to deform predominantly by plastic behavior while the later ones are known to deform predominantly by brittle fracture. Displacement-force data was utilized to perform in-die Heckel analysis and to calculate the first derivative (dD/dF) of displacement-force plots. First derivative results were then plotted against mean force (F') at each point and against 1/F' at compression forces between 1 and 20 kN. Results of the in-die Heckle analysis are in very good agreement with the known deformation behavior of the compressed materials. First derivative plots show that materials that deform predominantly by plastic behavior have first derivative values (0.0006-0.0016 mm/ N) larger than those of brittle materials (0.0004 mm/N). Moreover, when dD/dF is plotted against 1/F' for each powder, a linear correlation can be obtained (R2=>0.98). The slopes of the dD/dF vs. 1/F' plots for plastically deforming materials are relatively larger than those for materials that deform by brittle behavior. It is concluded that first derivative plots of displacement-force profiles can be used to determine deformation behavior of powders.

Action of the isolated canine diaphragm on the lower ribs at high lung volumes.

PubMed

De Troyer, André; Wilson, Theodore A

2014-10-15

The normal diaphragm has an inspiratory action on the lower ribs, but subjects with chronic obstructive pulmonary disease commonly have an inward displacement of the lateral portions of the lower rib cage during inspiration. This paradoxical displacement, conventionally called 'Hoover's sign', has traditionally been attributed to the direct action of radially oriented diaphragmatic muscle fibres. In the present study, the inspiratory intercostal muscles in all interspaces in anaesthetized dogs were severed so that the diaphragm was the only muscle active during inspiration. The displacements of the lower ribs along the craniocaudal and laterolateral axes and the changes in pleural pressure (∆Ppl) and transdiaphragmatic pressure were measured during occluded breaths and mechanical ventilation at different lung volumes between functional residual capacity (FRC) and total lung capacity. From these data, the separate effects on rib displacement of ∆Ppl and of the force exerted by the diaphragm on the ribs were determined. Isolated spontaneous diaphragm contraction at FRC displaced the lower ribs cranially and outward, but this motion was progressively reversed into a caudal and inward motion as lung volume increased. However, although the force exerted by the diaphragm on the ribs decreased with increasing volume, it continued to displace the ribs cranially and outward. These observations suggest that Hoover's sign is usually caused by the decrease in the zone of apposition and, thus, by the dominant effect of ∆Ppl on the lower ribs, rather than an inward pull from the diaphragm. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

Variational approach to probabilistic finite elements

NASA Technical Reports Server (NTRS)

Belytschko, T.; Liu, W. K.; Mani, A.; Besterfield, G.

1991-01-01

Probabilistic finite element methods (PFEM), synthesizing the power of finite element methods with second-moment techniques, are formulated for various classes of problems in structural and solid mechanics. Time-invariant random materials, geometric properties and loads are incorporated in terms of their fundamental statistics viz. second-moments. Analogous to the discretization of the displacement field in finite element methods, the random fields are also discretized. Preserving the conceptual simplicity, the response moments are calculated with minimal computations. By incorporating certain computational techniques, these methods are shown to be capable of handling large systems with many sources of uncertainties. By construction, these methods are applicable when the scale of randomness is not very large and when the probabilistic density functions have decaying tails. The accuracy and efficiency of these methods, along with their limitations, are demonstrated by various applications. Results obtained are compared with those of Monte Carlo simulation and it is shown that good accuracy can be obtained for both linear and nonlinear problems. The methods are amenable to implementation in deterministic FEM based computer codes.

Variational approach to probabilistic finite elements

NASA Astrophysics Data System (ADS)

Belytschko, T.; Liu, W. K.; Mani, A.; Besterfield, G.

1991-08-01

Probabilistic finite element methods (PFEM), synthesizing the power of finite element methods with second-moment techniques, are formulated for various classes of problems in structural and solid mechanics. Time-invariant random materials, geometric properties and loads are incorporated in terms of their fundamental statistics viz. second-moments. Analogous to the discretization of the displacement field in finite element methods, the random fields are also discretized. Preserving the conceptual simplicity, the response moments are calculated with minimal computations. By incorporating certain computational techniques, these methods are shown to be capable of handling large systems with many sources of uncertainties. By construction, these methods are applicable when the scale of randomness is not very large and when the probabilistic density functions have decaying tails. The accuracy and efficiency of these methods, along with their limitations, are demonstrated by various applications. Results obtained are compared with those of Monte Carlo simulation and it is shown that good accuracy can be obtained for both linear and nonlinear problems. The methods are amenable to implementation in deterministic FEM based computer codes.

Variational approach to probabilistic finite elements

NASA Technical Reports Server (NTRS)

Belytschko, T.; Liu, W. K.; Mani, A.; Besterfield, G.

1987-01-01

Probabilistic finite element method (PFEM), synthesizing the power of finite element methods with second-moment techniques, are formulated for various classes of problems in structural and solid mechanics. Time-invariant random materials, geometric properties, and loads are incorporated in terms of their fundamental statistics viz. second-moments. Analogous to the discretization of the displacement field in finite element methods, the random fields are also discretized. Preserving the conceptual simplicity, the response moments are calculated with minimal computations. By incorporating certain computational techniques, these methods are shown to be capable of handling large systems with many sources of uncertainties. By construction, these methods are applicable when the scale of randomness is not very large and when the probabilistic density functions have decaying tails. The accuracy and efficiency of these methods, along with their limitations, are demonstrated by various applications. Results obtained are compared with those of Monte Carlo simulation and it is shown that good accuracy can be obtained for both linear and nonlinear problems. The methods are amenable to implementation in deterministic FEM based computer codes.

Probabilistic structural analysis methods for improving Space Shuttle engine reliability

NASA Technical Reports Server (NTRS)

Boyce, L.

1989-01-01

Probabilistic structural analysis methods are particularly useful in the design and analysis of critical structural components and systems that operate in very severe and uncertain environments. These methods have recently found application in space propulsion systems to improve the structural reliability of Space Shuttle Main Engine (SSME) components. A computer program, NESSUS, based on a deterministic finite-element program and a method of probabilistic analysis (fast probability integration) provides probabilistic structural analysis for selected SSME components. While computationally efficient, it considers both correlated and nonnormal random variables as well as an implicit functional relationship between independent and dependent variables. The program is used to determine the response of a nickel-based superalloy SSME turbopump blade. Results include blade tip displacement statistics due to the variability in blade thickness, modulus of elasticity, Poisson's ratio or density. Modulus of elasticity significantly contributed to blade tip variability while Poisson's ratio did not. Thus, a rational method for choosing parameters to be modeled as random is provided.

How a small noise generates large-amplitude oscillations of volcanic plug and provides high seismicity

NASA Astrophysics Data System (ADS)

Alexandrov, Dmitri V.; Bashkirtseva, Irina A.; Ryashko, Lev B.

2015-04-01

A non-linear behavior of dynamic model of the magma-plug system under the action of N-shaped friction force and stochastic disturbances is studied. It is shown that the deterministic dynamics essentially depends on the mutual arrangement of an equilibrium point and the friction force branches. Variations of this arrangement imply bifurcations, birth and disappearance of stable limit cycles, changes of the stability of equilibria, system transformations between mono- and bistable regimes. A slope of the right increasing branch of the friction function is responsible for the formation of such regimes. In a bistable zone, the noise generates transitions between small and large amplitude stochastic oscillations. In a monostable zone with single stable equilibrium, a new dynamic phenomenon of noise-induced generation of large amplitude stochastic oscillations in the plug rate and pressure is revealed. A beat-type dynamics of the plug displacement under the influence of stochastic forcing is studied as well.

A nonlinear dynamics of trunk kinematics during manual lifting tasks.

PubMed

Khalaf, Tamer; Karwowski, Waldemar; Sapkota, Nabin

2015-01-01

Human responses at work may exhibit nonlinear properties where small changes in the initial task conditions can lead to large changes in system behavior. Therefore, it is important to study such nonlinearity to gain a better understanding of human performance under a variety of physical, perceptual, and cognitive tasks conditions. The main objective of this study was to investigate whether the human trunk kinematics data during a manual lifting task exhibits nonlinear behavior in terms of determinist chaos. Data related to kinematics of the trunk with respect to the pelvis were collected using Industrial Lumbar Motion Monitor (ILMM), and analyzed applying the nonlinear dynamical systems methodology. Nonlinear dynamics quantifiers of Lyapunov exponents and Kaplan-Yorke dimensions were calculated and analyzed under different task conditions. The study showed that human trunk kinematics during manual lifting exhibits chaotic behavior in terms of trunk sagittal angular displacement, velocity and acceleration. The findings support the importance of accounting for nonlinear dynamical properties of biomechanical responses to lifting tasks.

Workshop on Structural Dynamics and Control Interaction of Flexible Structures

NASA Technical Reports Server (NTRS)

Davis, L. P.; Wilson, J. F.; Jewell, R. E.

1987-01-01

The Hubble Space Telescope features the most exacting line of sight jitter requirement thus far imposed on a spacecraft pointing system. Consideration of the fine pointing requirements prompted an attempt to isolate the telescope from the low level vibration disturbances generated by the attitude control system reaction wheels. The primary goal was to provide isolation from axial component of wheel disturbance without compromising the control system bandwidth. A passive isolation system employing metal springs in parallel with viscous fluid dampers was designed, fabricated, and space qualified. Stiffness and damping characteristics are deterministic, controlled independently, and were demonstrated to remain constant over at least five orders of input disturbance magnitude. The damping remained purely viscous even at the data collection threshold of .16 x .000001 in input displacement, a level much lower than the anticipated Hubble Space Telescope disturbance amplitude. Vibration attenuation goals were obtained and ground test of the vehicle has demonstrated the isolators are transparent to the attitude control system.

Ion beam figuring of highly steep mirrors with a 5-axis hybrid machine tool

NASA Astrophysics Data System (ADS)

Yin, Xiaolin; Tang, Wa; Hu, Haixiang; Zeng, Xuefeng; Wang, Dekang; Xue, Donglin; Zhang, Feng; Deng, Weijie; Zhang, Xuejun

2018-02-01

Ion beam figuring (IBF) is an advanced and deterministic method for optical mirror surface processing. The removal function of IBF varies with the different incident angles of ion beam. Therefore, for the curved surface especially the highly steep one, the Ion Beam Source (IBS) should be equipped with 5-axis machining capability to remove the material along the normal direction of the mirror surface, so as to ensure the stability of the removal function. Based on the 3-RPS parallel mechanism and two dimensional displacement platform, a new type of 5-axis hybrid machine tool for IBF is presented. With the hybrid machine tool, the figuring process of a highly steep fused silica spherical mirror is introduced. The R/# of the mirror is 0.96 and the aperture is 104mm. The figuring result shows that, PV value of the mirror surface error is converged from 121.1nm to32.3nm, and RMS value 23.6nm to 3.4nm.

Computational modeling of the nonlinear stochastic dynamics of horizontal drillstrings

NASA Astrophysics Data System (ADS)

Cunha, Americo; Soize, Christian; Sampaio, Rubens

2015-11-01

This work intends to analyze the nonlinear stochastic dynamics of drillstrings in horizontal configuration. For this purpose, it considers a beam theory, with effects of rotatory inertia and shear deformation, which is capable of reproducing the large displacements that the beam undergoes. The friction and shock effects, due to beam/borehole wall transversal impacts, as well as the force and torque induced by bit-rock interaction, are also considered in the model. Uncertainties of bit-rock interaction model are taken into account using a parametric probabilistic approach. Numerical simulations have shown that the mechanical system of interest has a very rich nonlinear stochastic dynamics, which generate phenomena such as bit-bounce, stick-slip, and transverse impacts. A study aiming to maximize the drilling process efficiency, varying drillstring velocities of translation and rotation is presented. Also, the work presents the definition and solution of two optimizations problems, one deterministic and one robust, where the objective is to maximize drillstring rate of penetration into the soil respecting its structural limits.

Assessment of dynamic smile and gingival contour in young Chinese people.

PubMed

Zhang, Yan-Ling; Le, Di; Hu, Wen-Jie; Zhang, Hao; Liang, Ling-Zhi; Chung, Kwok-Hung; Cao, Zhan-Qiang

2015-08-01

This study aimed to classify the dynamic smile and to quantify the gingival line (GL), as well as apico-coronal displacement of the gingival zenith (GZ), in the maxillary anterior dentition in a young Chinese population. Two-hundred young Chinese subjects (100 men and 100 women; 20-35 years of age) with healthy dentogingival tissue were recruited. The dynamic smile process was captured using a digital camera. The smile type, GL type, the vertical distance of the GZ between the canine and the central incisor on the same side and the GZ of the lateral incisor-GL relationship were measured using a self-developed smile-analysis method. The kappa statistics was used to examine the reliability of the data recorded by the rater. The Pearson chi-square test was used to analyse the differences between subjects regarding the frequencies of smile type and GL type at α = 0.05. Data revealed that 45.5% of subjects had a high smile and 45.5% had an average smile; 58.2% of the subjects presented an upwards GL. The GZ of canine teeth was 0.33 mm apical to the corresponding central incisor and no significant difference between both sides of the GZ was observed. The GZ of the lateral incisor was located coronal to the GL in 87.9% of samples. The vertical distance between the GZ of the lateral incisor and the GL was 0.59 mm and no statistically significant difference was detected. The most common findings were a high or average smile type, combined with an upward GL. In the majority of subjects, the GZ of the lateral incisor is coronal to the GL. The apico-coronal displacement of the GZ showed bilateral symmetry. © 2015 FDI World Dental Federation.

Kinematic analysis of a posterior-stabilized knee prosthesis.

PubMed

Zhao, Zhi-Xin; Wen, Liang; Qu, Tie-Bing; Hou, Li-Li; Xiang, Dong; Bin, Jia

2015-01-20

The goal of total knee arthroplasty (TKA) is to restore knee kinematics. Knee prosthesis design plays a very important role in successful restoration. Here, kinematics models of normal and prosthetic knees were created and validated using previously published data. Computed tomography and magnetic resonance imaging scans of a healthy, anticorrosive female cadaver were used to establish a model of the entire lower limbs, including the femur, tibia, patella, fibula, distal femur cartilage, and medial and lateral menisci, as well as the anterior cruciate, posterior cruciate, medial collateral, and lateral collateral ligaments. The data from the three-dimensional models of the normal knee joint and a posterior-stabilized (PS) knee prosthesis were imported into finite element analysis software to create the final kinematic model of the TKA prosthesis, which was then validated by comparison with a previous study. The displacement of the medial/lateral femur and the internal rotation angle of the tibia were analyzed during 0-135° flexion. Both the output data trends and the measured values derived from the normal knee's kinematics model were very close to the results reported in a previous in vivo study, suggesting that this model can be used for further analyses. The PS knee prosthesis underwent an abnormal forward displacement compared with the normal knee and has insufficient, or insufficiently aggressive, "rollback" compared with the lateral femur of the normal knee. In addition, a certain degree of reverse rotation occurs during flexion of the PS knee prosthesis. There were still several differences between the kinematics of the PS knee prosthesis and a normal knee, suggesting room for improving the design of the PS knee prosthesis. The abnormal kinematics during early flexion shows that the design of the articular surface played a vital role in improving the kinematics of the PS knee prosthesis.