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Sample records for plate forces provide

  1. Casimir force between metal plate and dielectric plate

    Institute of Scientific and Technical Information of China (English)

    刘中柱; 邵成刚; 罗俊

    1999-01-01

    The Casimir effect between metal plate and dielectric plate is discussed with 1+1-dimensional potential model without using cut-off method. Calculation shows that the Casimir force between metal plate and dielectric plate is determined not only by the potential V0, the dielectric thickness and the distance α between the metal plate and dielectric plate, but also by the dimension of the vessel. When α is far less than the dimension of the vessel, the Casimir force Fc∝α(-1); conversely Fc∝α-2. This result is significant for Casimir force experiment.

  2. Global Plate Driving Forces at 50Ma

    Science.gov (United States)

    Butterworth, N. P.; Quevedo, L. E.; Müller, R. D.

    2011-12-01

    We apply a novel workflow utilising the BEM-Earth geodynamic software to analyse the global coupled plate-mantle dynamics at 50 Ma. A subduction history model based on kinematic data going as far back as 80 Ma was developed using the GPlates software. Advection of the plates into the mantle takes into account the absolute plate motions and lithospheric thickness derived from its age to produce an estimated density heterogeneity initial model condition in the upper mantle. The resulting global model consists of regions of a mantle viscosity and density structure that is post-processed to ensure smooth non-overlapping 3D surfaces. BEM-Earth is then free to evolve the model toward the 50 Ma solution. The evolution of the model is driven by self-consistent buoyancy driven mantle dynamics. We use the model velocity output to quantify changes in forces driving the plates before and after 50 Ma. We analyse the rapid change in plate motion of India, Africa and plates in the Pacific Ocean basin by considering slab-pull, ridge-push and mantle drag/suction forces that naturally result from such top-down driven mantle flow. We compare the results with plate kinematic reconstructions and other geological observations.

  3. Casimir Force Correction Between Parallel Polysilicon Plates

    Institute of Scientific and Technical Information of China (English)

    丁建宁; 孟永钢; 温诗铸

    2002-01-01

    Both the size of the components and the separation between them in some microelectromechanical systems (MEMS) are already in the sub-micrometer regime, where quantum mechanical effects such as the Casimir effect will need to be considered. This paper theoretically analyzes the roughness, electrical conductivity, and temperature corrections due to the Casimir force between two parallel polysilicon plates. The theoretical results show that the combined effects of roughness, conductivity and temperature cause a maximum relative error of the Casimir force per unit area of 26.2% between parallel polysilicon plates separated by 1 μm. Therefore, the surface roughness and finite conductivity corrections should be taken into account when calculating precise Casimir forces with separations on the order of 1 μm.

  4. Inversion for the driving forces of plate tectonics

    Science.gov (United States)

    Richardson, R. M.

    1983-01-01

    Inverse modeling techniques have been applied to the problem of determining the roles of various forces that may drive and resist plate tectonic motions. Separate linear inverse problems have been solved to find the best fitting pole of rotation for finite element grid point velocities and to find the best combination of force models to fit the observed relative plate velocities for the earth's twelve major plates using the generalized inverse operator. Variance-covariance data on plate motion have also been included. Results emphasize the relative importance of ridge push forces in the driving mechanism. Convergent margin forces are smaller by at least a factor of two, and perhaps by as much as a factor of twenty. Slab pull, apparently, is poorly transmitted to the surface plate as a driving force. Drag forces at the base of the plate are smaller than ridge push forces, although the sign of the force remains in question.

  5. Inversion for the driving forces of plate tectonics

    Science.gov (United States)

    Richardson, R. M.

    1983-01-01

    Inverse modeling techniques have been applied to the problem of determining the roles of various forces that may drive and resist plate tectonic motions. Separate linear inverse problems have been solved to find the best fitting pole of rotation for finite element grid point velocities and to find the best combination of force models to fit the observed relative plate velocities for the earth's twelve major plates using the generalized inverse operator. Variance-covariance data on plate motion have also been included. Results emphasize the relative importance of ridge push forces in the driving mechanism. Convergent margin forces are smaller by at least a factor of two, and perhaps by as much as a factor of twenty. Slab pull, apparently, is poorly transmitted to the surface plate as a driving force. Drag forces at the base of the plate are smaller than ridge push forces, although the sign of the force remains in question.

  6. Non-equilibrium Casimir force between vibrating plates.

    Directory of Open Access Journals (Sweden)

    Andreas Hanke

    Full Text Available We study the fluctuation-induced, time-dependent force between two plates confining a correlated fluid which is driven out of equilibrium mechanically by harmonic vibrations of one of the plates. For a purely relaxational dynamics of the fluid we calculate the fluctuation-induced force generated by the vibrating plate on the plate at rest. The time-dependence of this force is characterized by a positive lag time with respect to the driving. We obtain two distinctive contributions to the force, one generated by diffusion of stress in the fluid and another related to resonant dissipation in the cavity. The relation to the dynamic Casimir effect of the electromagnetic field and possible experiments to measure the time-dependent Casimir force are discussed.

  7. A Development of Force Plate for Biomechanics Analysis of Standing and Walking

    Science.gov (United States)

    Wardoyo, S.; Hutajulu, P. T.; Togibasa, O.

    2016-08-01

    Force plates are known as an excellent teaching aid to demonstrate the kinematics and dynamics of motion and commonly used in biomechanics laboratories to measure ground forces involved in the motion of human. It is consist of a metal plate with sensors attached to give an electrical output proportional to the force on the plate. Moreover, force plates are useful for examining the kinetic characteristics of an athlete's movement. They provide information about the external forces involved in movement that can aid a coach or sports scientist to quantitatively evaluate the athlete's skill development. In this study, we develop our prototype of force plate with less than 100,- simply by using flexible force transducer attached inside rubber matt, in the form of square blocks (dimension: 250 mm × 150 mm × 10 mm), with maximum load up to 60 kg. The handmade force plate was tested by applying biomechanics analysis for standing and walking. The testing was done on Experimental Soccer Courses’ students at the Department of Physical Education, Health and Recreation, University of Cenderawasih. The design of the force plate system together with biomechanics analysis will be discussed.

  8. Plates of the dinosaur stegosaurus: forced convection heat loss fins?

    Science.gov (United States)

    Farlow, J O; Thompson, C V; Rosner, D E

    1976-06-11

    It is suggested that the plates along the arched back and tail of Stegosaurus served an important thermoregulatory function as forced convection "fins." Wind tunnel experiments on finned models, internal heat conduction calculations, and direct observations of the morphology and internal structure of stegosaur plates support this hypothesis, demonstrating the comparative effectiveness of the plates as heat dissipaters, controllable through input blood flow rate, temperature, and body orientation (with respect to wind).

  9. Forces Between a Permanent Magnet and a Soft Magnetic Plate

    DEFF Research Database (Denmark)

    Beleggia, Marco; Vokoun, David; De Graef, Marc

    2012-01-01

    Forces between a hard/permanent magnet of arbitrary shape and an ideally soft magnetic plate in close proximity are derived analytically from the image method applied to magnetostatics. We found that the contact force, defined as the force required to detach the hard magnet from the plate......, coincides with that between two identical touching permanent magnets. Furthermore, if the hard and the soft magnets are displaced by some amount, their attraction equals that between two identical permanent magnets displaced by twice that amount. Experimental results are presented that validate...

  10. Heel strike detection using split force-plate treadmill.

    Science.gov (United States)

    Rouhani, Hossein; Abe, Masaki O; Nakazawa, Kimitaka; Popovic, Milos R; Masani, Kei

    2015-03-01

    A common source of error when detecting heel-strike moments utilizing split force-plate treadmills is unwillingly stepping on contra-lateral force-plate. In this study, we quantified this error when heel-strike was detected based on such erroneous data and compared three methods to investigate how well the heel-strikes and stride-intervals were detected with erroneous data. Eleven subjects walked on a split force-plate treadmill for more than 20min. We used 20N and 50% body-weight thresholds to detect the heel-strike moments (HS20N and HS50%, respectively). Besides, we used linear approximation to estimate the unaffected force profile from affected force-plate data, and subsequently to detect the heel-strike moments (HSest). We used heel-strike moments detected by a foot-switch as a reference to compare accuracy of HS20N, HS50% and HSest. HS20N and HSest detected heel-strike moments accurately for unaffected force-plate data (median(max) errors for all subjects: 9(23) and 9(37) ms) but HS50% showed significantly larger errors (52(74) ms). Unlike HS50% and HSest, HS20N was considerably affected by the affected force-plate data (23(68) ms). The error in stride-interval measurement was relatively small using any methods for unaffected force-plate data (3(7), 6(8), and 6(12) ms), while stride-interval errors were large for some subjects when using HS20N for affected data (6(175) ms). We concluded that unwillingly stepping on contra-lateral force-plate occurred a few percent and up to 37.7% of all strides (median: 12.9%). Our proposed method (HSest) robustly showed small errors for heel-strike detection and stride-interval calculation consistently among subjects, while HS50% and HS20N showed large errors depending on subjects.

  11. A force plate based method for the calibration of force/torque sensors

    NARCIS (Netherlands)

    Faber, Gert S.; Chang, Chien-Chi; Kingma, Idsart; Schepers, H. Martin; Herber, Sebastiaan; Veltink, Peter H.; Dennerlein, Jack T.

    2012-01-01

    This study describes a novel calibration method for six-degrees-of-freedom force/torque sensors (FTsensors) using a pre-calibrated force plate (FP) as a reference measuring device. In this calibration method, the FTsensor is rigidly connected to a FP and force/torque data are synchronously recorded

  12. Normative values for a video-force plate assessment of postural control in athletic children.

    Science.gov (United States)

    Howell, David R; Meehan, William P

    2016-07-01

    The objective of this study was to provide normative data for young athletes during the three stances of the modified Balance Error Scoring System (mBESS) using an objective video-force plate system. Postural control was measured in 398 athletes between 8 and 18 years of age during the three stances of the mBESS using a video-force plate rating system. Girls exhibited better postural control than boys during each stance of the mBESS. Age was not significantly associated with postural control. We provide normative data for a video-force plate assessment of postural stability in pediatric athletes during the three stances of the mBESS.

  13. Study on Scattering Wave Force of Horizontal and Vertical Plate Type Breakwaters

    Institute of Scientific and Technical Information of China (English)

    WANG Ke; ZHANG Xi; GAO Xin

    2011-01-01

    The interaction between wave and horizontal and vertical plates is investigated by the boundary element method,and the relations of wave exciting force with plate thickness,submergence and length are obtained.It is found that:1)The efficient wave exciting force exists while plate submergence is less than 0.5 m,and the plate is very thin with order O(0.005 m).2) The maximum heave wave exciting force exists,and it is the main factor for surface and submerged horizontal plate while the roll force can be ignored.3) The maximum sway wave exciting force exists,it is the main factor for surface or submerged vertical plate,and the roll force is about 20 times of horizontal plate.

  14. Force sensor for chameleon and Casimir force experiments with parallel-plate configuration

    CERN Document Server

    Almasi, Attaallah; Iannuzzi, Davide; Sedmik, René I P

    2015-01-01

    The search for non-Newtonian forces has been pursued following many different paths. Recently it was suggested that hypothetical chameleon interactions, which might explain the mechanisms behind dark energy, could be detected in a high-precision force measurement. In such an experiment, interactions between parallel plates kept at constant separation could be measured as a function of the pressure of an ambient gas, thereby identifying chameleon interactions by their unique inverse dependence on the local mass density. During the past years we have been developing a new kind of setup complying with the high requirements of the proposed experiment. In this article we present the first and most important part of this setup -- the force sensor. We discuss its design, fabrication, and characterization. From the results of the latter we derive limits on chameleon interaction parameters that could be set by the forthcoming experiment. Finally, we describe the opportunity to use the same setup to measure Casimir for...

  15. Tethyan collision forces and the stress field of the Eurasian plate

    NARCIS (Netherlands)

    Warners-Ruckstuhl, K.N.; Govers, R.; Wortel, R.

    2013-01-01

    Resistive forces along convergent plate boundaries have a major impact on surface deformation, most visibly at collisional plate boundaries. Although quantification of these forces is key to understanding the evolution and present state of mountain belts, they remain highly uncertain due to the comp

  16. Identification of impact force acting on composite laminated plates using the radiated sound measured with microphones

    Science.gov (United States)

    Atobe, Satoshi; Nonami, Shunsuke; Hu, Ning; Fukunaga, Hisao

    2017-09-01

    Foreign object impact events are serious threats to composite laminates because impact damage leads to significant degradation of the mechanical properties of the structure. Identification of the location and force history of the impact that was applied to the structure can provide useful information for assessing the structural integrity. This study proposes a method for identifying impact forces acting on CFRP (carbon fiber reinforced plastic) laminated plates on the basis of the sound radiated from the impacted structure. Identification of the impact location and force history is performed using the sound pressure measured with microphones. To devise a method for identifying the impact location from the difference in the arrival times of the sound wave detected with the microphones, the propagation path of the sound wave from the impacted point to the sensor is examined. For the identification of the force history, an experimentally constructed transfer matrix is employed to relate the force history to the corresponding sound pressure. To verify the validity of the proposed method, impact tests are conducted by using a CFRP cross-ply laminate as the specimen, and an impulse hammer as the impactor. The experimental results confirm the validity of the present method for identifying the impact location from the arrival time of the sound wave detected with the microphones. Moreover, the results of force history identification show the feasibility of identifying the force history accurately from the measured sound pressure using the experimental transfer matrix.

  17. Novel parallel plate condenser for single particle electrostatic force measurements in atomic force microscope

    KAUST Repository

    Kwek, Jin Wang

    2011-07-01

    A combination of small parallel plate condenser with Indium Tin Oxide (ITO) glass slides as electrodes and an atomic force microscope (AFM) is used to characterize the electrostatic behavior of single glass bead microparticles (105-150 μm) glued to the AFM cantilever. This novel setup allows measurements of the electrostatic forces acting on a particle in an applied electrical field to be performed in ambient air conditions. By varying the position of the microparticle between the electrodes and the strength of the applied electric field, the relative contributions of the particle net charge, induced and image charges were investigated. When the microparticle is positioned in the middle of the electrodes, the force acting on the microparticle was linear with the applied electric field and proportional to the microparticle net charge. At distances close to the bottom electrode, the force follows a parabolic relationship with the applied electric field reflecting the contributions of induced and image charges. The method can be used for the rapid evaluation of the charging and polarizability properties of the microparticle as well as an alternative to the conventional Faraday\\'s pail technique. © 2011 Elsevier B.V.

  18. Global Models of Ridge-Push Force, Geoid, and Lithospheric Strength of Oceanic plates

    Science.gov (United States)

    Mahatsente, Rezene

    2017-08-01

    An understanding of the transmission of ridge-push related stresses in the interior of oceanic plates is important because ridge-push force is one of the principal forces driving plate motion. Here, I assess the transmission of ridge-push related stresses in oceanic plates by comparing the magnitude of the ridge-push force to the integrated strength of oceanic plates. The strength is determined based on plate cooling and rheological models. The strength analysis includes low-temperature plasticity (LTP) in the upper mantle and assumes a range of possible tectonic conditions and rheology in the plates. The ridge-push force has been derived from the thermal state of oceanic lithosphere, seafloor depth and crustal age data. The results of modeling show that the transmission of ridge-push related stresses in oceanic plates mainly depends on rheology and predominant tectonic conditions. If a lithosphere has dry rheology, the estimated strength is higher than the ridge-push force at all ages for compressional tectonics and at old ages (>75 Ma) for extension. Therefore, under such conditions, oceanic plates may not respond to ridge-push force by intraplate deformation. Instead, the plates may transmit the ridge-push related stress in their interior. For a wet rheology, however, the strength of young lithosphere (tectonics. In this case, the ridge-push related stress may dissipate in the interior of oceanic plates and diffuses by intraplate deformation. The state of stress within a plate depends on the balance of far-field and intraplate forces.

  19. Application of Laser Ranging and VLBI Data to a Study of Plate Tectonic Driving Forces

    Science.gov (United States)

    Solomon, S. C.

    1980-01-01

    The conditions under which changes in plate driving or resistive forces associated with plate boundary earthquakes are measurable with laser ranging or very long base interferometry were investigated. Aspects of plate forces that can be characterized by such measurements were identified. Analytic solutions for two dimensional stress diffusion in a viscoelastic plate following earthquake faulting on a finite fault, finite element solutions for three dimensional stress diffusion in a viscoelastic Earth following earthquake faulting, and quantitative constraints from modeling of global intraplate stress on the magnitude of deviatoric stress in the lithosphere are among the topics discussed.

  20. A force plate based method for the calibration of force/torque sensors.

    Science.gov (United States)

    Faber, Gert S; Chang, Chien-Chi; Kingma, Idsart; Schepers, H Martin; Herber, Sebastiaan; Veltink, Peter H; Dennerlein, Jack T

    2012-04-30

    This study describes a novel calibration method for six-degrees-of-freedom force/torque sensors (FTsensors) using a pre-calibrated force plate (FP) as a reference measuring device. In this calibration method, the FTsensor is rigidly connected to a FP and force/torque data are synchronously recorded while a dynamic functional loading procedure is applied by the researcher. Based on these data an accurate calibration matrix for the FTsensor can easily be obtained via least-squares optimization. Using this calibration method, this study further investigated what loading methods are appropriate for the calibration of FTsensors intended for ambulatory measurement of ground reaction forces (GRFs). Seven different loading methods were compared (e.g., walking, pushing while standing on the FTsensor). Calibration matrices were calculated based on the raw data from the seven loading methods individually and all loading methods combined. Performance of these calibration matrices was subsequently compared in an in situ trial. During the in situ trial, five common work tasks (e.g., walking, manual lifting, pushing) were performed by an experimenter, while standing on the FP wearing a "ForceShoe" with two calibrated FTsensors attached to its sole. Root-mean-square differences (RMSDs) between the FTsensor and FP outcomes were calculated over all tasks. Using the calibration matrices based on all loading methods combined resulted in small RMSDs (GRF: <8 N, center of pressure: <2 mm). Using the calibration matrices based on "pushing against manual resistance" resulted in similar RMSDs, proving it to be the best single loading method.

  1. Numerical Solution of Membrane Forces for A Free-Free Floating Plate with Large Deflection

    Institute of Scientific and Technical Information of China (English)

    陈徐均; 崔维成; 宋皓; 汤雪峰

    2003-01-01

    Considering that the thickness of a pontoon-type very large floating structure (VLFS) is very small in comparison with the length and width, VLFS can be modeled as a thin plate. In theory, the displacements and the membrane forces of a plate with large deflection are all the functions of the second-order differentials of the Ariy stress function. With these characteristics considered, the Ariy stress function of a floating free-free plate is calculated by setting the virtual values of three of the corner points. The finite difference method is chosen to solve the problem. When the Ariy stress function of the plate is obtained, the membrane forces can easily be calculated. Comparisons between the forces induced by the membrane forces and by the fluid are considered. It is shown that the membrane forces can not be neglected in many cases.

  2. The restoring force on a dielectric in a parallel plate capacitor

    Science.gov (United States)

    Staunton, L. P.

    2014-09-01

    We investigate the restoring force on a dielectric slab being pulled from within the volume of a parallel plate capacitor connected to a battery. Using a conformal mapping to treat the fringing electric field exactly, we numerically obtain an expected Hooke's Law restoring force for small displacements, and a diminishing force for a displacement up to half the length of the dielectric.

  3. Correlation between retention force of experimental plates and viscosity of experimental fluids

    Directory of Open Access Journals (Sweden)

    Mladenović Dragan

    2011-01-01

    Full Text Available Introduction. Saliva viscosity plays a significant role in the biophysical segment of the total retention potential of total dentures. Objective. The aim of the paper was to establish the dependence of dynamic retention force of experimental plates on experimental fluid viscosity and especially time dependence of these parameters, following at the same time relative changes of the distance between the experimental plate and dentures support established by the dislocation of the experimental plate in both directions. Methods. For experimental verification we used an original device with the aim to enable in vivo simulation on the phantom made of the upper total denture prosthesis support and experimental plate. The experiment consisted of two parts. In the first part we determined the value of the dynamic retention force with plates without and with achieved ventilation effect. In the second part we determined time dependence of the dynamic retention force of experimental plates on the viscosity of experimental fluids that had been priorly determined on identical samples (8 ml of experimental fluid samples using a rotational viscometer (Haake RV-12 with a sensor (MV, Germany. Results Under the conditions of variable viscosity rates of seven experimental fluids (from 0.02 to 1309.04 mPa•s, we registered the time dependence of dynamic retention force of the experimental plate related to fluid viscosity during the action of the continual dislocating force of the separating directions. In addition, the maximal height of the dislocation of the experimental plate was registered. The dynamic retention force, manifested by the separating direction of the experimental plate dislocation, was increased concurrently with increased viscosity. Conclusion. The increase of dynamic retention force depends directly on medium viscosity. Close border values of fluid viscosity above the investigated ones, the impossibility of experimental layer thinning and the

  4. Evaluation of motion platform embedded with force plate-instrumented treadmill

    National Research Council Canada - National Science Library

    Emily H Sinitski; Edward D Lemaire; Natalie Baddour

    2015-01-01

    ... with a dual-belt treadmill and two force plates. The goal of this article was to investigate the performance characteristics associated with a treadmill-motion platform configuration and how system operation can affect the data collected...

  5. A new method to assess temporal features of gait initiation with a single force plate.

    Science.gov (United States)

    Moineau, Bastien; Boisgontier, Matthieu P; Barbieri, Guillaume; Nougier, Vincent

    2014-01-01

    The aim of this study was to investigate whether time of toe-off and heel-contact during gait initiation could be assessed with a single force plate. Twenty subjects performed ten self-paced gait initiations and seven other subjects performed ten gait initiations in four new conditions (slow, fast, obstacle and splint). Several force-plate parameters were measured with a single force plate, and actual toe-off and heel-contact were assessed with a motion analysis system. Results showed strong temporal correlations and closeness (r=.86-.99, mean error=3-86 ms) between two force-plate parameters and the kinematics events (toe-off and heel-contact). These new parameters may be of interest to easily measure duration of anticipatory postural adjustments and swing phase during clinical assessments.

  6. Two rods confined by positive plates: effective forces and charge distribution profiles

    Energy Technology Data Exchange (ETDEWEB)

    Odriozola, G; Jimenez-Angeles, F; Lozada-Cassou, M [Programa de IngenierIa Molecular, Instituto Mexicano del Petroleo, Lazaro Cardenas 152, 07730 Mexico, DF (Mexico)

    2006-09-13

    The effect of confinement on the interaction force between two negatively charged rods is studied through Monte Carlo simulations. Confinement is produced by two parallel, charged or uncharged plates. The system is immersed in a 0.1 M 1-1 restricted primitive model electrolyte. The effect on the rod-rod effective force by the plate charge distribution is analysed. A strong modification of the rod-rod effective force due to confinement is found, as compared to the bulk case. In particular, rod-rod attraction was found for plates having a charge equal to that of fully charged bilipid bilayers. In spite of the simplicity of the model, these results agree with some DNA-phospholipid experimental observations. On the other hand, for a model having the plate charges fixed on a grid, very long range, oscillatory rod-rod effective forces were obtained.

  7. Forced-choice testing provides evidence of malingering.

    Science.gov (United States)

    Binder, L M

    1992-04-01

    Assessment of motivation using forced-choice testing is described and illustrated with case reports. Two injured workers with protracted disability complained of numbness and loss of sensation in their fingers. Each patient received a forced-choice, multiple-choice finger graphesthesia test, with a 0.5 probability of guessing correctly on each item. Both patients performed significantly below the chance level, indicating that they had deliberately provided wrong answers. One patient did not exaggerate until the difficulty level of the task was enhanced. Forced-choice testing, particularly with enhancement of difficulty levels, is proposed as a specific measure to detect faked poor performance. Identification of malingering reduces the risk of iatrogenic damage. The subjective complaints of malingerers must be viewed with skepticism.

  8. EXPERIMENTAL STUDY ON TOTAL UPLIFT FORCES OF WAVES ON HORIZONTAL PLATES

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yi-ren; CHEN Guo-ping; WANG Deng-ting

    2004-01-01

    The total uplift forces of waves acting on hori zontal plates are the important basis for the design of maritime hollow-trussed structures. In this paper, an experimental study on the total uplift forces of waves on horizontal plates was conducted by a series of model tests. The results show that the maximum total uplift forces do not necessarily occur with the maximum impact pressure intensity synchronously.On the basis of the test results, formation mechanism of the total uplift forces of waves as well as its influencing factors were analyzed in detail, and an equation for calculation of the maximum total uplift forces of waves on plates was put forward. Lots of test data shows the present equation is in good agreement with the test results.

  9. Forced Response of Polar Orthotropic Tapered Circular Plates Resting on Elastic Foundation

    Directory of Open Access Journals (Sweden)

    A. H. Ansari

    2016-01-01

    Full Text Available Forced axisymmetric response of polar orthotropic circular plates of linearly varying thickness resting on Winkler type of elastic foundation has been studied on the basis of classical plate theory. An approximate solution of problem has been obtained by Rayleigh Ritz method, which employs functions based upon the static deflection of polar orthotropic circular plates. The effect of transverse loadings has been studied for orthotropic circular plate resting on elastic foundation. The transverse deflections and bending moments are presented for various values of taper parameter, rigidity ratio, foundation parameter, and flexibility parameter under different types of loadings. A comparison of results with those available in literature shows an excellent agreement.

  10. Forced Convective Heat Transfer in a Porous Plate Channel

    Institute of Scientific and Technical Information of China (English)

    PeixueJiang; ZhanWang; 等

    1997-01-01

    Fored convective heat transfer in a plate channel filled with metallic spherical particales was investigated experimentally and numerically.The test section ,58mm×80mm×50mm in size,was heated by a 0.4mm thick plate electrical heater,The coolant water flow rate ranged from 0.015 to 0.833 kg/s.The local wall temperature distribution was measured along with the inlet and outlet fliud temperatures and pressures.The results illustrate the heat transfer augmentation and increased pressure drop caused by the porous medium.The heat transfer coefficient was increased 5-12 times by the porous media although the hydraulic resistance was increased even more.The Nusselt number and the heat transfer coefficient increased with decreasing particle diameter,while the pressure drop decreased as the particle diameter increased.It was found that,for the conditions studied(metallic packed bed),the effect of thermal dispersion did not need to be considered in the physical model,as opposed to a non-metallic packed bed,where thermal dispersion is important.

  11. Dynamic Correction Algorithm of Rolling Force in Plate Rolling

    Institute of Scientific and Technical Information of China (English)

    QIU Hong-lei; WANG Jun; HU Xian-lei; WANG Zhao-dong; WANG Guo-dong

    2005-01-01

    Based on the Shougang plat mill project, an on-line dynamic correction algorithm was analyzed. This algorithm can adjust model coefficients better because the reasonable correction is based on the measured and calculated rolling force. The results of application on site show that this on-line dynamic correction algorithm is effective.

  12. Experimental Study and System Identification of Hydrodynamic Force Acting on Heave Damping Plate

    Institute of Scientific and Technical Information of China (English)

    JI Heng-teng; FAN Ju; HUANG Xiang-lu

    2008-01-01

    Although Morison equation is often applied for simulating hydrodynamic force of marine structure, it may give poor results when non-linear behavior is severe or random wave is encountered. This leads to some modifications of Morison equation or other methods for predicting hydrodynamic force. One of them is the system identification technique. In this paper, NARMAX model theory is firstly used to identify the hydrodynamic system of heave damping plates, which are commonly installed on spar platform. Both linear and non-linear models are obtained. The comparisons between the predicted results and measured data indicate that NARMAX model can predict hydrodynamic force of a heave damping plate very well. The measured data for identification originate from forced oscillation tests, which are random records with given spectrum. The forced oscillation forms in experiment also contain simple harmonic, multi-frequency ones.

  13. Limit State Analysis of Reinforced Concrete Plates subjected to in-plane forces

    DEFF Research Database (Denmark)

    Poulsen, Peter Noe; Damkilde, Lars

    2000-01-01

    A finite element formulation of rigid-plastic plates subjected to in-plane forces is developed using stress-based elements and linear programming. Three elements are established, namely a triangular plate element, a bar element and a beam element. The problem is formulated as a lower bound solution......, and the dual variables are interpreted as displacements. Both load and material optimization are formulated. The method is applied to concrete plate structures modelling both the distributed and the concentrated reinforcement. An efficient computational scheme is used, thereby reducing the size of the problem...

  14. Stress State Of Plate With Incisions Under The Action Of Oscillating Concentrated Forces

    Directory of Open Access Journals (Sweden)

    Shvabyuk Vasyl’

    2015-09-01

    Full Text Available This paper proposes the novel technique for analysis of dynamic stress state of multi-connected infinite plates under the action of oscillating forces. Calculation of dynamic stresses at the incisions of plates is held using the boundary-integral equation method and the theory of complex variable functions. The numerical implementation of the developed algorithmis based on the method of mechanical quadratures and collocation technique. The algorithm is effective in the analysis of the stress state caused by steady-state vibrations of plates.

  15. Application of laser ranging and VLBI data to a study of plate tectonic driving forces. [finite element method

    Science.gov (United States)

    Solomon, S. C.

    1980-01-01

    The measurability of changes in plate driving or resistive forces associated with plate boundary earthquakes by laser rangefinding or VLBI is considered with emphasis on those aspects of plate forces that can be characterized by such measurements. Topics covered include: (1) analytic solutions for two dimensional stress diffusion in a plate following earthquake faulting on a finite fault; (2) two dimensional finite-element solutions for the global state of stress at the Earth's surface for possible plate driving forces; and (3) finite-element solutions for three dimensional stress diffusion in a viscoelastic Earth following earthquake faulting.

  16. Non-linear resonances in the forced responses of plates. I - Symmetric responses of circular plates

    Science.gov (United States)

    Sridhar, S.; Mook, D. T.; Nayfeh, A. H.

    1975-01-01

    The dynamic analogue of the von Karman equations is used to study the symmetric response of a circular plate to a harmonic excitation when the frequency of the excitation is near one of the natural frequencies. It is shown that, in general, when there is no internal resonance (i.e., the natural frequencies are not commensurable), only the mode having a frequency near that of the excitation is strongly excited (i.e., is needed to represent the response in the first approximation). A clamped, circular plate is used as a numerical example to show that, when there is an internal resonance, more than one of the modes involved in this resonance can be strongly excited; moreover, when more than one mode is strongly excited, the lower modes can dominate the response, even when the frequency of the excitation is near that of the highest mode. This possibility was not revealed by any of the earlier studies which were based on the same governing equations.

  17. Highly asymmetric interaction forces induced by acoustic waves in coupled plate structures

    CERN Document Server

    Fan, Xiying; Zhang, Shenwei; Ke, Manzhu; Liu, Zhengyou

    2015-01-01

    Mutual forces can be induced between coupled structures when illuminated by external acoustic waves. In this Letter, we propose a concept of asymmetric interaction between two coupled plate-like structures, which is generated by oppositely incident plane waves. Besides the striking contrast in magnitude, the mutual force induced by one of the incidences can be tuned extremely strong due to the resonant excitation of the flexural plate modes. The highly asymmetric interaction with enhanced strength in single side should be potentially useful, such as in designing ultrasound instruments and sensors.

  18. Calculating forces on thin flat plates with incomplete vorticity-field data

    Science.gov (United States)

    Limacher, Eric; Morton, Chris; Wood, David

    2016-11-01

    Optical experimental techniques such as particle image velocimetry (PIV) permit detailed quantification of velocities in the wakes of bluff bodies. Patterns in the wake development are significant to force generation, but it is not trivial to quantitatively relate changes in the wake to changes in measured forces. Key difficulties in this regard include: (i) accurate quantification of velocities close to the body, and (ii) the effect of missing velocity or vorticity data in regions where optical access is obscured. In the present work, we consider force formulations based on the vorticity field, wherein mathematical manipulation eliminates the need for accurate near-body velocity information. Attention is restricted to nominally two dimensional problems, namely (i) a linearly accelerating flat plate, investigated using PIV in a water tunnel, and (ii) a pitching plate in a freestream flow, as investigated numerically by Wang & Eldredge (2013). The effect of missing vorticity data on the pressure side of the plate has a significant impact on the calculation of force for the pitching plate test case. Fortunately, if the vorticity on the pressure side remains confined to a thin boundary layer, simple corrections can be applied to recover a force estimate.

  19. Analytical solution of conjugate turbulent forced convection boundary layer flow over plates

    Directory of Open Access Journals (Sweden)

    Joneydi Shariatzadeh Omid

    2016-01-01

    Full Text Available A conjugate (coupled forced convection heat transfer from a heated conducting plate under turbulent boundary layer flow is considered. A heated plate of finite thickness is cooled under turbulent forced convection boundary layer flow. Because the conduction and convection boundary layer flow is coupled (conjugated in the problem, a semi-analytical solution based on Differential Transform Method (DTM is presented for solving the non-linear integro-differential equation occurring in the problem. The main conclusion is that in the conjugate heat transfer case the temperature distribution of the plate is flatter than the one in the non-conjugate case. This feature is more pronounced under turbulent flow when compared with the laminar flow.

  20. A feedback control system for vibration of magnetostrictive plate subjected to follower force using sinusoidal shear

    Directory of Open Access Journals (Sweden)

    A. Ghorbanpour Arani

    2016-03-01

    Full Text Available In this research, the vibrational behavior of magnetostrictive plate (MsP as a smart component is studied. The plate is subjected to an external follower force and a magnetic field in which the vibration response of MsP has been investigated for both loading combinations. The velocity feedback gain parameter is evaluated to study the effect of magnetic field which is generated by the coil. Sinusoidal shear deformation theory is utilized due to its accuracy of polynomial function with respect to other plate theories. Equations of motion are derived using Hamilton’s principle and solved by differential quadrature method (DQM considering general boundary conditions. The effects of aspect ratio, thickness ratio, follower force and velocity feedback gain are investigated on the frequency response of MsP. Results indicate that magneto-mechanical coupling in MsM helps to control vibrational behaviors of systems such as electro-hydraulic actuator, wireless linear Motors and sensors.

  1. Nonlinear Forced Vibration Analysis for Thin Rectangular Plate on Nonlinear Elastic Foundation

    Directory of Open Access Journals (Sweden)

    Zhong Zhengqiang

    2013-02-01

    Full Text Available Nonlinear forced vibration is analyzed for thin rectangular plate with four free edges on nonlinear elastic foundation. Based on Hamilton variation principle, equations of nonlinear vibration motion for thin rectangular plate under harmonic loads on nonlinear elastic foundation are established. In the case of four free edges, viable expressions of trial functions for this specification are proposed, satisfying all boundary conditions. Then, equations are transformed to a system of nonlinear algebraic equations by using Galerkin method and are solved by using harmonic balance method. In the analysis of numerical computations, the effect on the amplitude-frequency characteristic curve due to change of the structural parameters of plate, parameters of foundation and parameters of excitation force are discussed.

  2. Analytical Solution of Forced-Convective Boundary-Layer Flow over a Flat Plate

    DEFF Research Database (Denmark)

    Mirgolbabaei, H.; Barari, Amin; Ibsen, Lars Bo

    2010-01-01

    In this letter, the problem of forced convection heat transfer over a horizontal flat plate is investigated by employing the Adomian Decomposition Method (ADM). The series solution of the nonlinear differential equations governing on the problem is developed. Comparison between results obtained...

  3. Three-dimensional flow structures and unsteady forces on pitching and surging revolving flat plates

    NARCIS (Netherlands)

    Percin, M.; Van Oudheusden, B.W.

    2015-01-01

    Tomographic particle image velocimetry was used to explore the evolution of three-dimensional flow structures of revolving low-aspect-ratio flat plates in combination with force measurements at a Reynolds number of 10,000. Two motion kinematics are compared that result in the same terminal condition

  4. Analytical Solution of Forced-Convective Boundary-Layer Flow over a Flat Plate

    DEFF Research Database (Denmark)

    Mirgolbabaei, H.; Barari, Amin; Ibsen, Lars Bo;

    2010-01-01

    In this letter, the problem of forced convection heat transfer over a horizontal flat plate is investigated by employing the Adomian Decomposition Method (ADM). The series solution of the nonlinear differential equations governing on the problem is developed. Comparison between results obtained...

  5. Three-dimensional flow structures and unsteady forces on pitching and surging revolving flat plates

    NARCIS (Netherlands)

    Percin, M.; Van Oudheusden, B.W.

    2015-01-01

    Tomographic particle image velocimetry was used to explore the evolution of three-dimensional flow structures of revolving low-aspect-ratio flat plates in combination with force measurements at a Reynolds number of 10,000. Two motion kinematics are compared that result in the same terminal condition

  6. Free and forced vibration control of piezoelectric FGM plate subjected to electro-mechanical loading

    Science.gov (United States)

    Jadhav, Priyanka A.; Bajoria, Kamal M.

    2013-06-01

    This paper investigates the free and forced vibration analysis of a newly introduced metal based functionally graded (FG) plate integrated with a piezoelectric actuator and sensor at the top and bottom faces respectively. The material properties of the FG plate are assumed to be graded along the thickness direction according to a simple power law distribution in terms of the volume fraction of the constituents, while the Poisson ratio is assumed to be constant. The plate is simply supported at all edges. The finite element model is based on higher order shear deformation theory (HOST), the von Karman hypothesis and degenerated shell elements. The displacement component of the present model is expanded in Taylor’s series in terms of the thickness co-ordinate. The Hamilton principle is used to derive the equation of motion for the piezoelectric functionally graded material (FGM) plate. The free and forced vibration analysis of the simply supported piezoelectric FG plate is carried out to present the effect of the power law index and the piezoelectric layer. The present analysis is carried out on a newly introduced FGM, which is a mixture of aluminum and stainless steel. Stainless steel is a high strength material but it can rust in extreme cases, and aluminum does not rust but it is a low strength material. The FGM exhibits corrosion resistance as well as the high strength property in a single material. This new FGM will definitely help in the construction as well as the metal industry.

  7. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    ’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through......Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  8. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty......’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  9. Evaluation of motion platform embedded with dual belt treadmill instrumented with two force plates.

    Science.gov (United States)

    Sinitski, Emily H; Lemaire, Edward D; Baddour, Natalie

    2015-01-01

    Motek Medical's Computer Aided Rehabilitation Environment (CAREN)-Extended system is a virtual environment primarily used in physical rehabilitation and biomechanical research. This virtual environment consists of a 180 degree projection screen used to display a virtual scene, a 12-camera motion capture system, and a six degree of freedom actuated platform equipped with a dual-belt treadmill and two force plates. The goal of this article was to investigate the performance characteristics associated with a "treadmill-motion platform" configuration and how system operation can affect the data collected. Platform static and dynamic characteristics were evaluated by translating or rotating the platform over progressively larger distances and comparing input and measured values. Treadmill belt speed was assessed with and without a person walking on the platform and at different orientations. Force plate measurements were examined when the treadmill was in operation, during ambulation, and over time to observe the baseline drift. Platform acceleration was dependent on the distance travelled and system settings. Treadmill speed variability was greatest at faster speeds. Force plate measurements were affected by platform and treadmill operation, contralateral impact forces during gait, and baseline drift. Knowledge of performance characteristics and their effect on outcome data is crucial for effective design of CAREN research protocols and rehabilitation scenarios.

  10. Multi-axis force sensing using a resonant composite piezoelectric plate: model and experiments

    Science.gov (United States)

    Castaño-Cano, Davinson; Grossard, Mathieu; Hubert, Arnaud

    2015-05-01

    Wrist force/torque sensors used in robotic applications increase the performances and flexibility of the automated tasks. They also offer new possibilities in the manufacturing process, where physical contact between the work-piece and environment is required. The wide spreading of these sensors is for now restricted by their features. As an alternative to the existing strain-gauges force sensors, this paper presents a resonant composite structure, which is sensitive to multiple components of force that are considered via the pre-stress effect. Structurally bonded piezoelectric patches are used to bring the structure to its resonance, which is shifted according to applied forces. The relationship between force and frequency shift is modelled considering the multi-physics of this smart structure. This model is built using Hamilton's principle and takes into account pre-stress phenomena. A finite element model (FEM) based on Mindlin theory for plates, has been derived from the analytical model. The FEM model is implemented in MATLAB and compared with commercial FE software. Finally, an experimental prototype validates the model, and shows that it is possible to measure multiple force-components with one single sensing element such as a plate.

  11. A numerical modeling for the wave forcing of floating thin plate

    Energy Technology Data Exchange (ETDEWEB)

    Basirat Tabrizi, H. [Amirkabir Univ. of Technology, Mechanical Engineering Dept., Tehran (Iran, Islamic Republic of)]. E-mail: hbasirat@aut.ac.ir, H.Basirat@dal.ca; Kouchaki Motlaq, M. [Islamic Azad Univ., Dept. of Graduate Studies, Arak (Iran, Islamic Republic of)

    2004-07-01

    A finite difference scheme based on central difference, which is applicable to the thin plate floating on intermediate depth water subjected to wave force, is developed. The floating structure analyzed as a plate with unit width and expressed by an elastic bending theory. The fluid flow expressed as an incompressible, inviscid and steady that the potential theory can apply. Here, the water wave elevation assumed the same as the bending displacement structure at the interface. The distribution of the displacement amplitude of structure and the wave amplitude varies in a wavy pattern in the middle part and increases greatly near the edge of plate. The present method verified by comparing quantitatively with the reported experimental and theoretical results of others. (author)

  12. Study provides data on active plate tectonics in southeast Asia region

    Science.gov (United States)

    Wilson, P.; Rais, J.; Reigber, Ch.; Reinhart, E.; Ambrosius, B. A. C.; Le Pichon, X.; Kasser, M.; Suharto, P.; Majid, Dato'Abdul; Yaakub, Dato'Paduka Awang Haji Othman Bin Haji; Almeda, R.; Boonphakdee, C.

    A major geodynamic study has provided significant new information about the location of active plate boundaries in and around Southeast Asia, as well as deformation processes in the Sulawesi region of Indonesia and tectonic activity in the Philippine archipelago. Results also have confirmed the existence of the so-called Sunda Block, which appears to be rotating with respect to adjacent plates.The study, known as the Geodynamics of South and South-East Asia (GEODYSSEA) project, has been a joint venture of the European Commission and the Association of South- East Asian Nations. It began in 1991 and involved a large team of European and Asian scientists and technicians studying the complex geodynamic processes and natural hazards of the region from the Southeast Asia mainland to the Philippines to northern Australia. Earthquakes, volcanic eruptions, tsunamis, and tectonically induced landslides endanger the lives of millions of people in the region, and the tectonic activity behind these natural hazards results from the convergence and collision of the Eurasian, Philippine, and Indo-Australian Plates at relative velocities of up to 10 cm per year.

  13. Elastoplastic analysis for infinite plate with centric crack loaded by two pairs of point shear forces

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiao-ping; LING Tong-hua

    2005-01-01

    The near crack line analysis method was used to investigate a crack loaded by two pairs of point shear forces in an infinite plate in an elastic-perfectly plastic solid, and the analytical solution was obtained. The solutions include: the unit normal vector of the elastic-plastic boundary near the crack line, the elastic-plastic stress fields near crack line, law that the length of the plastic zone along the crack line is varied with an external loads, and the bearing capacity of an infinite plate with a center crack loaded by two pairs of point shear forces. The results are sufficiently precise near the crack line because the assumptions of the small scale yielding theory have not been made and no other assumption have been taken.

  14. A wearable force plate system for the continuous measurement of triaxial ground reaction force in biomechanical applications

    Science.gov (United States)

    Liu, Tao; Inoue, Yoshio; Shibata, Kyoko

    2010-08-01

    The ambulatory measurement of ground reaction force (GRF) and human motion under free-living conditions is convenient, inexpensive and never restricted to gait analysis in a laboratory environment and is therefore much desired by researchers and clinical doctors in biomedical applications. A wearable force plate system was developed by integrating small triaxial force sensors and three-dimensional (3D) inertial sensors for estimating dynamic triaxial GRF in biomechanical applications. The system, in comparison to existent systems, is characterized by being lightweight, thin and easy-to-wear. A six-axial force sensor (Nitta Co., Japan) was used as a verification measurement device to validate the static accuracy of the developed force plate. To evaluate the precision during dynamic gait measurements, we compared the measurements of the triaxial GRF and the center of pressure (CoP) by using the developed system with the reference measurements made using a stationary force plate and an optical motion analysis system. The root mean square (RMS) differences of the two transverse components (x- and y-axes) and the vertical component (z-axis) of the GRF were 4.3 ± 0.9 N, 6.0 ± 1.3 N and 12.1 ± 1.1 N, respectively, corresponding to 5.1 ± 1.1% and 6.5 ± 1% of the maximum of each transverse component and 1.3 ± 0.2% of the maximum vertical component of GRF. The RMS distance between the two systems' CoP traces was 3.2 ± 0.8 mm, corresponding to 1.2 ± 0.3% of the length of the shoe. Moreover, based on the results of the assessment of the influence of the system on natural gait, we found that gait was almost never affected. Therefore, the wearable system as an alternative device can be a potential solution for measuring CoP and triaxial GRF in non-laboratory environments.

  15. Effect of volumetric electromagnetic forces on shock wave structure of hypersonic air flow near plate

    Science.gov (United States)

    Fomichev, Vladislav; Yadrenkin, Mikhail; Shipko, Evgeny

    2016-10-01

    Summarizing of experimental studies results of the local MHD-interaction at hypersonic air flow near the plate is presented. Pulsed and radiofrequency discharge have been used for the flow ionization. It is shown that MHD-effect on the shock-wave structure of the flow is significant at test conditions. Using of MHD-interaction parameter enabled to defining characteristic modes of MHD-interaction by the force effect: weak, moderate and strong.

  16. Analyzing excitation forces acting on a plate based on measured acoustic pressure.

    Science.gov (United States)

    Wu, Sean F; Zhou, Pan

    2016-07-01

    This paper presents a theoretical study on "seeing" through an elastic structure to uncover the root cause of sound and vibration by using nearfield acoustical holography (NAH) and normal modes expansion. This approach is of generality because vibro-acoustic responses on the surface of a vibrating structure can always be reconstructed, exactly or approximately. With these vibro-acoustic responses, excitation forces acting on the structure can always be determined, analytically or numerically, given any set of boundary conditions. As an example, the explicit formulations for reconstructing time-harmonic excitation forces, including point, line and surface forces, and their arbitrary combinations acting on a rectangular thin plate in vacuum mounted on an infinite baffle are presented. The reason for choosing this example is that the analytic solutions to vibro-acoustic responses are available, and in-depth analyses of results are possible. Results demonstrate that this approach allows one to identify excitation forces based on measured acoustic pressures and reveal their characteristics such as locations, types and amplitudes, as if one could "see" excitation forces acting behind the plate based on acoustic pressure measured on the opposite side. This approach is extendable to general elastic structures, except that in such circumstance numerical results must be sought.

  17. Porosity-dependent nonlinear forced vibration analysis of functionally graded piezoelectric smart material plates

    Science.gov (United States)

    Qing Wang, Yan; Zu, Jean W.

    2017-10-01

    This work investigates the porosity-dependent nonlinear forced vibrations of functionally graded piezoelectric material (FGPM) plates by using both analytical and numerical methods. The FGPM plates contain porosities owing to the technical issues during the preparation of FGPMs. Two types of porosity distribution, namely, even and uneven distribution, are considered. A modified power law model is adopted to describe the material properties of the porous FGPM plates. Using D’Alembert’s principle, the out-of-plane equation of motion is derived by taking into account the Kármán nonlinear geometrical relations. After that, the Galerkin method is used to discretize the equation of motion, resulting in a set of ordinary differential equations with respect to time. These ordinary differential equations are solved analytically by employing the harmonic balance method. The approximate analytical results are verified by using the adaptive step-size fourth-order Runge–Kutta method. By means of the perturbation technique, the stability of approximate analytical solutions is examined. An interesting nonlinear broadband vibration phenomenon is detected in the FGPM plates with porosities. Nonlinear frequency-response characteristics of the present smart structures are investigated for various system parameters including the porosity type, the porosity volume fraction, the electric potential, the external excitation, the damping and the constituent volume fraction. It is found that these parameters have significant effects on the nonlinear vibration characteristics of porous FGPM plates.

  18. Film Condensation with and Without Body Force in Boundary-Layer Flow of Vapor Over a Flat Plate

    Science.gov (United States)

    Chung, Paul M.

    1961-01-01

    Laminar film condensation under the simultaneous influence of gas-liquid interface shear and body force (g force) is analyzed over a flat plate. Important parameters governing condensation and heat transfer of pure vapor are determined. Mixtures of condensable vapor and noncondensable gas are also analyzed. The conditions under which the body force has a significant influence on condensation are determined.

  19. Pull-in voltage of microswitch rough plates in the presence of electromagnetic and acoustic Casimir forces

    NARCIS (Netherlands)

    Palasantzas, George

    2007-01-01

    In this work, we investigate the combined influence of electromagnetic and acoustic Casimir forces on the pull-in voltage of microswitches with self-affine rough plates. It is shown that for plate separations within the micron range the acoustic term arising from pressure fluctuations can influence

  20. Pull-in voltage of microswitch rough plates in the presence of electromagnetic and acoustic Casimir forces

    NARCIS (Netherlands)

    Palasantzas, George

    2007-01-01

    In this work, we investigate the combined influence of electromagnetic and acoustic Casimir forces on the pull-in voltage of microswitches with self-affine rough plates. It is shown that for plate separations within the micron range the acoustic term arising from pressure fluctuations can influence

  1. Forced Convective Air Cooling from Electronic Component Arrays in a Parallel Plate Channel

    Institute of Scientific and Technical Information of China (English)

    D.Y.Cai; Y.P.Gan; 等

    1994-01-01

    This paper discusses air forced convection heat transfer from inline protruding elements arranged in eight rows.The streamwise and spanwise spacings between elements were varied using a splitter plate that can be positioned at three different modular configurations.A set of empirical formulas was presented to correlate the experimental data for the design of air cooling systems.Arrays of componets with one odd-size module have been tested also.Experimental results show that blocks near the entrance and behind the odd-size module have improved performance compared with uniform arrangements.Accordingly,temperature sensitive components are suggested to be arranged in these locations.

  2. The forced vibrations of three-layer orthotropic plate at incomplete contact between bottom layers

    Directory of Open Access Journals (Sweden)

    Aghalovyan L. A.

    2007-09-01

    Full Text Available The three-dimensional dynamic problem of the elasticity theory on forced vibration of orthotropic plate at incomplete contact between bottom layers and at full contact between the top layers is solved by the asymptotic method. The bottom obverse surface is subject to external dynamic influences, and top - is rigidly fixed. The common asymptotic solution of the problem is found. The closed solution for particular type of problems is found. It is known, that constant tangential displacements acting to the third layer do not influence in stress-strain state of the first and second layer. The resonance arising conditions are established.

  3. The Influence of Flexibility Coefficient on the Size of Internal Forces and Deformations in Circular Plates on Elastic Medium

    Directory of Open Access Journals (Sweden)

    Şandru Mirela

    2016-09-01

    Full Text Available This paper presents an analytical study which deals with the behavior of the circular plates in bending theory, considering the soil-structure interaction under Winkler's hypothesis. It was intended to illustrate the variation of internal forces and deformations according to the flexibility coefficient of plates considering three models: a fixed solid circular plate subjected to a uniformly distributed load, a fixed solid circular plate acted by a displacement applied on the exterior contour and a solid plate subjected to a temperature gradient. For this study the computation relations were written as a product between a dimensional and a non-dimensional factor, the last one indicating the variation of internal forces and deformations. For each type of action there are presented results obtained using the finite element method to illustrate the differences between this method and the analytical computation.

  4. Subducting an old subduction zone sideways provides insights into what controls plate coupling

    Science.gov (United States)

    Reyners, Martin; Eberhart-Phillips, Donna; Bannister, Stephen

    2017-05-01

    The Hikurangi Plateau has had two episodes of subduction beneath New Zealand - firstly at ca. 100 Ma during north-south convergence with Gondwana, and currently during east-west convergence between the Pacific and Australian plates. As a result of this ninety-degree change in convergence direction, an old subduction zone is now being subducted sideways, and the tectonic history of the subducted plate varies dramatically along the strike of the Hikurangi Margin. Here we identify the location of the underplated Hikurangi Plateau along the shallow part of the Hikurangi Margin, using results from both relocated seismicity and seismic tomography. Next we decipher the tectonic history of the plateau along strike, particularly in terms of the hydration state of the plateau, and the nature of any sedimentary rock units capping the plateau. We then use this information to understand plate coupling at two scales: on the large scale, the southward transition from typical subduction in the North Island to continental collision in the South Island; and at a smaller scale, the strong lateral change from a high deficit in slip rate at the plate interface in the southern North Island to a low deficit in slip rate in the northeastern North Island. We find that the southward transition from subduction to continental collision is controlled by the plateau being more dehydrated to the south, as a result of being more deeply subducted at the Gondwana margin. The southward transition from localized slip at the plate interface to distributed upper plate deformation with no active plate interface occurs in Cook Strait and is relatively sharp. The high deficit in slip rate at the plate interface in the southern North Island is likely due to a relatively smooth plate interface from sedimentary rocks capping the Hikurangi Plateau, an impermeable terrane in the overlying plate, and the hydrated plateau acting in concert to produce an interseismically sealed plate interface. Further northeast

  5. ELECTRICALLY FORCED THICKNESS-SHEAR VIBRATIONS OF QUARTZ PLATE WITH NONLINEAR COUPLING TO EXTENSION

    Institute of Scientific and Technical Information of China (English)

    Rongxing Wu; Jiashi Yang; Jianke Du; Ji Wang

    2008-01-01

    We study electrically forced nonlinear thickness-shear vibrations of a quartz plate resonator with relatively large amplitude. It is shown that thickness-shear is nonlinearly coupled to extension due to the well-known Poynting effect in nonlinear elasticity. This coupling is relatively strong when the resonant frequency of the extensional mode is about twice the resonant frequency of the thickness-shear mode. This happens when the plate length/thickness ratio assumes certain values. With this nonlinear coupling, the thickness-shear motion is no longer sinusoidal. Coupling to extension also affects energy trapping which is related to device mounting. When damping is 0.01, nonlinear coupling causes a frequency shift of the order of 10-e which is not insignificant,and an amplitude change of the order of 10-8. The effects are expected to be stronger under real damping of 10-5 or larger. To avoid nonlinear coupling to extension, certain values of the aspect ratio of the plate should be avoided.

  6. Comparison of friction force between corroded and noncorroded titanium nitride plating of metal brackets.

    Science.gov (United States)

    Kao, Chia-Tze; Guo, Jia-Uei; Huang, Tsui-Hsien

    2011-05-01

    Titanium nitride (TiN) plating is a method to prevent metal corrosion and can increase the surface smoothness. The purpose of this study was to evaluate the friction forces between the orthodontic bracket, with or without TiN plating, and stainless steel wire after it was corroded in fluoride-containing solution. In total, 540 metal brackets were divided into a control group and a TiN-coated experimental group. The electrochemical corrosion was performed in artificial saliva with 1.23% acidulated phosphate fluoride (APF) as the electrolytes. Static and kinetic friction were measured by an EZ-test machine (Shimadazu, Tokyo, Japan) with a crosshead speed of 10 mm per minute over a 5-mm stretch of stainless steel archwire. The data were analyzed by using unpaired t test and analysis of variance (ANOVA). Both the control and TiN-coated groups' corrosion potential was higher with 1.23% APF solution than with artificial solution (P TiN-coated brackets groups showed a statistically significant difference (P TiN-coated brackets showed a statistical difference (P TiN-coated metal brackets, with corrosion or without corrosion, cannot reduce the frictional force. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  7. Rolling Force Prediction in Heavy Plate Rolling Based on Uniform Differential Neural Network

    Directory of Open Access Journals (Sweden)

    Fei Zhang

    2016-01-01

    Full Text Available Accurate prediction of the rolling force is critical to assuring the quality of the final product in steel manufacturing. Exit thickness of plate for each pass is calculated from roll gap, mill spring, and predicted roll force. Ideal pass scheduling is dependent on a precise prediction of the roll force in each pass. This paper will introduce a concept that allows obtaining the material model parameters directly from the rolling process on an industrial scale by the uniform differential neural network. On the basis of the characteristics that the uniform distribution can fully characterize the solution space and enhance the diversity of the population, uniformity research on differential evolution operator is made to get improved crossover with uniform distribution. When its original function is transferred with a transfer function, the uniform differential evolution algorithms can quickly solve complex optimization problems. Neural network structure and weights threshold are optimized by uniform differential evolution algorithm, and a uniform differential neural network is formed to improve rolling force prediction accuracy in process control system.

  8. Iterative methods for obtaining solvation structures on a solid plate: The methods for Surface Force Apparatus and Atomic Force Microscopy in Liquids

    CERN Document Server

    Amano, Ken-ich

    2013-01-01

    We propose iterative methods for obtaining solvation structures on a solid plate which use force distributions measured by surface force apparatus (SFA) and atomic force microscopy (AFM) as input data. Two model systems are considered here. In the model system for SFA, the same two solid plates are immersed in a solvent, and a probe tip and a solid plate are immersed in a solvent in the model system for AFM. Advantages of the iterative methods are as follows: The iterative method for SFA can obtain the solvation structure, for example, in a Lennard-Jones liquid; The iterative method for AFM can obtain the solvation structure without an input datum of solvation structure around the probe tip.

  9. Low-Stress Upper Plate Near Subduction Zones and Implications for Temporal Changes in Loading Forces

    Science.gov (United States)

    Wang, K.; Hu, Y.; Yoshida, K.

    2016-12-01

    Subduction megathrusts are weak, often with effective friction coefficients as low as 0.03. Consequently, differential stress (S1 - S3) in the nearby upper plate is low. Compression due to plate coupling and tension due to gravity are in a subtle balance that can be tipped by small perturbations. For example, the 2011 M=9 Tohoku-oki earthquake, which has a rupture-zone-average stress drop of only a few MPa, switched offshore margin-normal stress from compression to tension and affected seismicity pattern and stress directions of various parts of the land area. The low differential stress is also reflected in spatial variations of stresses, such as with changes in topography. In the Andes, crustal earthquake focal mechanisms change from thrust-faulting in low-elevation areas to normal-faulting in high-elevation areas. Given the lack of evidence for a pervasively weak crust, the low differential stress may indicate that in general the crust near subduction zones is not critically stressed. If so, crustal earthquakes do not represent pervasive failure but only local failure due to stress, material, and fluid pressure heterogeneity. If distributed permanent deformation that creates topography is not the norm, it either happens in brief episodes or took place in the past. The outer wedge may enter a compressively or extensionally critical state due to coseismic strengthening or weakening, respectively, of the shallow megathrust in largest interplate earthquakes. Temporal changes in loading forces must occur also at much larger temporal and spatial scales in response to changes in the nature of the subducting plate and other tectonic conditions. We propose that submarine wedges and high topography in the upper plate attain their geometry in geologically brief episodes of high differential stress. They normally stay in a low-stress stable state, but their geometry often reflects high-stress episodes of critical states in the past. In other words, rocks have a sustained

  10. Elastic-plastic contact force history and response characteristics of circular plate subjected to impact by a projectile

    Institute of Scientific and Technical Information of China (English)

    L. B. Chen; F. Xi; J. L. Yang

    2007-01-01

    A new elastic-plastic impact-contact model is proposed in this paper. By adopting the principle of minimum acceleration for elastic-plastic continue at finite deformation,and with the aid of finite difference method, the proposed model is applied in the problem of dynamic response of a clamped thin circular plate subjected to a projectile impact centrally. The impact force history and response characte-ristics of the target plate is studied in detail. The theoreti-cal predictions of the impact force and plate deflection are in good agreements with those of LDA experimental data.Linear expressions of the maximum impact force/transverse deflection versus impact velocity are given on the basis of the theoretical results.

  11. Experiments on forced convection form a horizontal heated plate in a packed bed of glass spheres

    Energy Technology Data Exchange (ETDEWEB)

    Renken, K.J. (Univ. of Wisconsin, Milwaukee (USA)); Poulikakos, D. (Univ. of Illinois, Chicago (USA))

    1989-02-01

    This paper presents an experimental investigation of boundary-layer forced convective heat transfer from a flat isothermal plate in a packed bed of spheres. Extensive experimental results are reported for the thermal boundary-layer thickness, the temperature field, and the local wall heat flux (represented by the local Nusselt number). Theoretical findings of previous investigations using the Darcy flow model as well as a general model for themomentum equation accouting for flow inertia and macroscopic shear wtih and without variable porosity are used to evaluate the theoretical models. Several trends are revealed regarding the conditions of validity of these flow models. Overall the general flow model including variable porosity appears to perform better, even through the need for serious improvements in modeling becomes apparent.

  12. Thermally developing forced convection and the corresponding thermal stresses in a porous plate channel

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao; LIU Xuemei

    2007-01-01

    Based on the Darcy fluid model, by considering the effects of viscous dissipation due to the interaction between solid skeleton and pore fluid flow and thermal conduction in the direction of the fluid flow, the thermally developing forced convection of the local thermal equili- brium and the corresponding thermal stresses in a semi- infmite saturated porous plate channel are investigated in this paper. The expressions of temperature, local Nusselt number and corresponding thermal stresses are obtained by means of the Fourier series, and the distributions of the same are also shown. Furthermore, influences of the Péclet number (Pe) and Brinkman number (Br) on temperature, Nusselt number (Nu) and thermal stress are revealed numerically.

  13. Forced Convection Heat Transfer in Plate Channels Filled with Packed Beds or Sintered Porous Media

    Institute of Scientific and Technical Information of China (English)

    姜培学; 李勐; 任泽霈

    2002-01-01

    In the present work, forced convection heat transfer in plate channels filled with metallic or non-metallic particles (packed beds) or sintered porous media is simulated numerically using a thermal non-equilibrium model. The numerical simulation results are compared with experimental data. The difference between convection heat transfer in packed beds and in sintered porous media and the effects of the boundary condition assumptions are investigated. The results show that the numerical simulation of convection heat transfer of air or water in packed beds using the local thermal non-equilibrium model and the variable porosity model agrees well with the experimental data. The convection heat transfer coefficient in sintered porous media is much higher than that in packed beds. In the numerical simulation of convection heat transfer in sintered porous media, the boundary conditions on the wall should be that the particle temperatures are equal to the fluid temperature.

  14. Study of natural and forced heat transfer coefficients on a vertical heated plate

    Directory of Open Access Journals (Sweden)

    Stefan-Mugur SIMIONESCU

    2015-12-01

    Full Text Available Infrared thermography measurement technique is a methodology which detects infrared energy emitted from an object, converts it to temperature, and displays images of temperature distribution. It is a powerful non-invasive methodology for the analysis of surface temperature measurements. The infrared camera represents a truly two-dimensional transducer, allowing for considerably high accurate measurements of surface temperature maps even in the presence of relatively high spatial gradients. The infrared thermography measurement technique is used in this experimental study to estimate the heat transfer coefficient over a flat plate. The main objective of this study was to get insights about the heat transfer in solids and on solid surfaces and its quantitative measurement. An infrared camera was used to calculate the temperature distribution for the evaluation of the heat transfer coefficient. Two study cases were taken into account: a first case without any fluid jet is calculated, where natural convection over the plate emerges due to the buoyancy effect, and a second case where a circular air jet is impinged on the surface - in this case the forced convection heat transfer coefficient has been evaluated.

  15. Solar energy dryer kinetics using flat-plate finned collector and forced convection for potato drying

    Science.gov (United States)

    Batubara, Fatimah; Misran, Erni; Dina, Sari Farah; Heppy

    2017-06-01

    Research on potato drying using the indirect solar dryer with flat-plate finned collector and forced convection has been done. The research was conducted at the outdoor field of Laboratory of Institute for Research and Standardization of Industry on June 14th-23rd, 2016 from 9:00 am to 4:00 pm. This research aims to obtain the drying kinetics model of potato (Solanumtuberosum L.) using an indirect solar dryer's (ISD) with flat plate-finned collector and forced convection. The result will be compared to the open sun drying (OSD) method. Weather conditions during the drying process took place as follows; surrounding air temperature was in the range 27 to 34.7 °C, relative humidity (RH) 29.5 to 61.0% and the intensity of solar radiation 105.6 to 863.1 Watt/m2. The dried potato thicknesses were 1.0 cm, 1.5 cm and 2.0 cm, with the average initial water content of 76.46%. The average temperature in the collector chamber ranged from 42.2 to 57.4 °C and the drying chamber was at 46.2 °C. The best drying result was obtained from a sample size of 1 cm thickness using the IDS method with an average drying rate of 0.018 kg H2O per kg dry-weight.hour and the water content was constant at 5.02% in 21 hours of drying time. The most suitable kinetics model is Page model, equation MR = exp (-0.049 t1,336) for 1.0 cm thickness, exp (-0.066 t1,222) for 1.5 cm thickness and exp (-0.049 t1,221) for 2.0 cm thickness. The quality of potato drying using ISD method is better than using OSD which can be seen from the color produced.

  16. Force plate targeting has no effect on spatiotemporal gait measures and their variability in young and healthy population.

    Science.gov (United States)

    Verniba, Dmitry; Vergara, Martin E; Gage, William H

    2015-02-01

    Force plate targeting has been referenced as a confounding factor in gait research, but the literature is sparse. Asking participants to target force plates is a convenient strategy to increase the number of acceptable trials, but may inadvertently alter the motor control of gait and limit external validity. This study aimed to investigate the effect of visual targeting on spatiotemporal, kinematic, and kinetic measures of gait and their variability. Young healthy participants were asked to traverse a walkway with three embedded hidden force plates. Starting from a participant-specific initial position and leading with the same foot each time, participants performed series of natural walking trials (no targeting and unaware of the hidden force plates), followed by targeting walking trials. For the targeting trials, participants were asked to step completely within the bounds of a tape outline (∼50cm×45cm), which coincided with the position of the last hidden force plate. The results demonstrated evidence of targeting during targeting trials; compared to natural walking trials, mean heel-target distance variability for targeting trials decreased progressively for the steps approaching the targeting step, reaching significance (ptarget (41%), and post-target steps (39%). Despite visual targeting, no significant differences between targeting and natural trials were detected in spatiotemporal, kinematic, and kinetic gait measures, or the variability of the measures. When the experimental set-up was tailored to the individual participant's gait variables (step/stride length), visual targeting of the force plates appeared to have no effect on the magnitude or variability of any gait measures.

  17. Moments About Body Centered Coordinate Axes At Limb Joints From Force Plate And Biplane Photography Measurements

    Science.gov (United States)

    Balakrishnan, S.; Thornton-Trump, A. B.; Brodland, G. W.

    1983-07-01

    Traditional locomotion analysis considers motion in a translating coordinate frame and the analysis is performed primarily in the sagittal plane. The results of several studies in the present work have shown that the aspect of symmetry is rarely present in pathological gait. Loss of function in one plane of movement gives rise to larger motions in other planes. This brings into focus the necessity for three dimensional measurement for adequately representing pathological gait. Description of quantities associated with gait in the appropriate moving frame of each segment would be closer to joint angulation of limb segments. Although this description has been attempted by a few researchers, the assumption of small angle theory and vectorial addition of rotation angles commonly employed for defining the rotation matrices is not applicable to pathological gait. The present work illustrates the use of biplane photography for displacement measurement in human movement. Transformations based on Eulerian angle rotations are derived based on biplane measurements. From the three dimensional ground reaction forces measured by a force plate, moments about the moving upper body coordinate axes are computed through a three dimensional mathematical model.

  18. Transient-forced convection film boiling on an isothermal flat plate.

    Science.gov (United States)

    Nagendra, H. R.

    1972-01-01

    Development of a new approach for the solution of transient-forced convection film boiling on an isothermal flat plate using the boundary layer model. The similarity variables are used to convert the governing partial differential equations to ordinary ones. The results of numerical solutions of these ordinary equations indicate that the transient process can be classified as one-dimensional conduction, intermediate, and the steady-state regions. The time required for the one-dimensional conduction and the time necessary to attain a steady-state condition are obtained. The use of local similarity approximations for the intermediate regime facilitates prediction of complete boundary layer growth. Using the ratio of time at any instant to the steady-state time as abscissa, the curves representing the boundary layer growth can be merged into a single mean curve within 5%. Further, the analysis shows that the average rate of heat transfer during transient is 50 to 100% higher than those at steady state. The average rate of vapor convected away is 10 to 15% lower than at steady state while the average rate of accumulation to form the vapor layer is 1 to 14 times larger.

  19. Promoting the wellbeing of lesbian, gay, bisexual and transgender forced migrants in Canada: providers' perspectives.

    Science.gov (United States)

    Kahn, Sarilee; Alessi, Edward; Woolner, Leah; Kim, Hanna; Olivieri, Christina

    2017-10-01

    Researchers are beginning to document the experiences of lesbian, gay, bisexual and transgender (LGBT) forced migrants in settlement. However, studies exploring the perceptions of service providers working with this vulnerable population are limited. These may shed light on the challenges of meeting the needs of LGBT forced migrants, especially mental health issues and problems. This qualitative study elicited the views of 22 Canadian service providers, including advocates, lawyers and mental health practitioners, who serve LGBT forced migrants. Grounded theory analysis revealed the following four themes: facilitating safety, buffering rejection; tracking avoidance patterns; interpreting mental health; and negotiating identity paradigms. Participants' accounts suggest that LGBT forced migrants may be best served by providers who understand the exigencies of establishing trust and safety for their clients; recognise their clients' nuanced social support needs; facilitate the refugee claims process; grasp the complexity of their clients' mental health challenges; and interrogate their own cultural biases regarding sexual orientations and gender identities.

  20. Numerical manifold method for the forced vibration of thin plates during bending.

    Science.gov (United States)

    Jun, Ding; Song, Chen; Wei-Bin, Wen; Shao-Ming, Luo; Xia, Huang

    2014-01-01

    A novel numerical manifold method was derived from the cubic B-spline basis function. The new interpolation function is characterized by high-order coordination at the boundary of a manifold element. The linear elastic-dynamic equation used to solve the bending vibration of thin plates was derived according to the principle of minimum instantaneous potential energy. The method for the initialization of the dynamic equation and its solution process were provided. Moreover, the analysis showed that the calculated stiffness matrix exhibited favorable performance. Numerical results showed that the generalized degrees of freedom were significantly fewer and that the calculation accuracy was higher for the manifold method than for the conventional finite element method.

  1. Numerical Manifold Method for the Forced Vibration of Thin Plates during Bending

    Directory of Open Access Journals (Sweden)

    Ding Jun

    2014-01-01

    Full Text Available A novel numerical manifold method was derived from the cubic B-spline basis function. The new interpolation function is characterized by high-order coordination at the boundary of a manifold element. The linear elastic-dynamic equation used to solve the bending vibration of thin plates was derived according to the principle of minimum instantaneous potential energy. The method for the initialization of the dynamic equation and its solution process were provided. Moreover, the analysis showed that the calculated stiffness matrix exhibited favorable performance. Numerical results showed that the generalized degrees of freedom were significantly fewer and that the calculation accuracy was higher for the manifold method than for the conventional finite element method.

  2. Forced convection on a heated horizontal flat plate with finite thermal conductivity in a non-Darcian porous medium

    Energy Technology Data Exchange (ETDEWEB)

    Luna, N. [Direccion de Operacion Petrolera, Direccion General de Exploracion y Explotacion de Hidrocarburos, Secretaria de Energia, 03100 Mexico DF (Mexico); Mendez, F. [Facultad de Ingenieria, UNAM, 04510 Mexico DF (Mexico)

    2005-07-01

    The steady-state analysis of conjugated heat transfer process for the hydrodynamically developed forced convection flow on a heated flat plate embedded in a porous medium is studied. The governing equations for the fluid-saturated porous medium are solved analytically using the integral boundary layer approximation. This integral solution is coupled to the energy equation for the flat plate, where the longitudinal heat conduction effects are taken into account. The resulting equations are then reduced to an integro-differential equation which is solved by regular perturbation techniques and numerical methods. The analytical and numerical predictions for the temperature profile of the plate and appropriate local and average Nusselt numbers are plotted for finite values of the conduction parameter, {alpha}, which represents the presence of the longitudinal heat conduction effects. (authors)

  3. Casimir force between a half-space and a plate of finite thickness

    Science.gov (United States)

    Høye, Johan S.; Brevik, Iver

    2016-05-01

    Zero-frequency Casimir theory is analyzed from different viewpoints, with the aim of obtaining further insight into the delicate Drude-plasma issue that turns up when one considers thermal corrections to the Casimir force. The problem is essentially that the plasma model, physically inferior in comparison to the Drude model since it leaves out dissipation in the material, apparently gives the best results when comparing with recent experiments. Our geometric setup is quite conventional, namely, a dielectric plate separated from a dielectric half-space by a vacuum gap, both media being made of the same material. Our investigation is divided into the following categories: (1) Making use of the statistical-mechanical method developed by J. S. Høye and I. Brevik [Physica A (Amsterdam, Neth.) 259, 165 (1998), 10.1016/S0378-4371(98)00249-0], implying that the quantized electromagnetic field is replaced by interaction between dipole moments oscillating in harmonic potentials, we first verify that the Casimir force is in agreement with the Drude prediction. No use of Fresnel's reflection coefficients is made at this stage. (2) Then turning to the field-theoretic description implying use of the reflection coefficients, we derive results in agreement with the forgoing when first setting the frequency equal to zero, before letting the permittivity become large. With the plasma relation the reflection coefficient for TE zero-frequency modes depends on the component of the wave vector parallel to the surfaces and lies between 0 and 1. This contradicts basic electrostatic theory. (3) Turning to high-permeability magnetic materials, the TE zero-frequency mode describes the static magnetic field in the same way the TM zero-frequency modes describe the static electric fields in electrostatics. With the plasma model magnetic fields, except for a small part, cannot pass through metals; that is, metals effectively become superconductors. However, recent experimental results clearly

  4. Elastic-plastic analytical solution for centric crack loaded by two pairs of point shear forces in finite plate

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiao-ping; LING Tong-hua

    2006-01-01

    The near crack line analysis method was used to investigate a centric crack loaded by two pairs of point shear forces in a finite plate, and the analytical solution was obtained. The solution includes the unit normal vector of the elastic-plastic boundary near the crack line, the elastic-plastic stress fields near the crack line, the variations of the length of the plastic zone along the crack line with an external load, and the bearing capacity of a finite plate with a centric crack loaded by two pairs of point shear forces. The results are sufficiently precise near the crack line because the assumptions of small scale yielding theory have not been made and no other assumptions are taken.

  5. Buckling and Vibration of Non-Homogeneous Rectangular Plates Subjected to Linearly Varying In-Plane Force

    Directory of Open Access Journals (Sweden)

    Roshan Lal

    2013-01-01

    Full Text Available The present work analyses the buckling and vibration behaviour of non-homogeneous rectangular plates of uniform thickness on the basis of classical plate theory when the two opposite edges are simply supported and are subjected to linearly varying in-plane force. For non-homogeneity of the plate material it is assumed that young's modulus and density of the plate material vary exponentially along axial direction. The governing partial differential equation of motion of such plates has been reduced to an ordinary differential equation using the sine function for mode shapes between the simply supported edges. This resulting equation has been solved numerically employing differential quadrature method for three different combinations of clamped, simply supported and free boundary conditions at the other two edges. The effect of various parameters has been studied on the natural frequencies for the first three modes of vibration. Critical buckling loads have been computed. Three dimensional mode shapes have been presented. Comparison has been made with the known results.

  6. MHD forced convective laminar boundary layer flow from a convectively heated moving vertical plate with radiation and transpiration effect.

    Science.gov (United States)

    Uddin, Md Jashim; Khan, Waqar A; Ismail, A I Md

    2013-01-01

    A two-dimensional steady forced convective flow of a Newtonian fluid past a convectively heated permeable vertically moving plate in the presence of a variable magnetic field and radiation effect has been investigated numerically. The plate moves either in assisting or opposing direction to the free stream. The plate and free stream velocities are considered to be proportional to x(m) whilst the magnetic field and mass transfer velocity are taken to be proportional to x((m-1)/2) where x is the distance along the plate from the leading edge of the plate. Instead of using existing similarity transformations, we use a linear group of transformations to transform the governing equations into similarity equations with relevant boundary conditions. Numerical solutions of the similarity equations are presented to show the effects of the controlling parameters on the dimensionless velocity, temperature and concentration profiles as well as on the friction factor, rate of heat and mass transfer. It is found that the rate of heat transfer elevates with the mass transfer velocity, convective heat transfer, Prandtl number, velocity ratio and the magnetic field parameters. It is also found that the rate of mass transfer enhances with the mass transfer velocity, velocity ratio, power law index and the Schmidt number, whilst it suppresses with the magnetic field parameter. Our results are compared with the results existing in the open literature. The comparisons are satisfactory.

  7. Laminar forced convection with viscous dissipation in a Couette-Poiseuille flow between parallel plates

    Energy Technology Data Exchange (ETDEWEB)

    Aydin, Orhan; Avci, Mete [Karadeniz Technical University, Trabzon (Turkey). Department of Mechanical Engineering

    2006-08-15

    In this study, analytical solutions are obtained to predict laminar heat-convection in a Couette-Poiseuille flow between two plane parallel plates with a simultaneous pressure gradient and an axial movement of the upper plate. A Newtonian fluid with constant properties is considered with an emphasis on the viscous-dissipation effect. Both hydrodynamically and thermally fully-developed flow cases are investigated. The axial heat-conduction in the fluid is neglected. Two different orientations of the thermal boundary-conditions are considered: the constant heat-flux at the upper plate with an adiabatic lower plate (Case A) and the constant heat-flux at the lower plate with an adiabatic upper plate (Case B). For different values of the relative velocity of the upper plate, the effect of the modified Brinkman number on the temperature distribution and the Nusselt number are discussed. Comparison of the present analytical results for a special case with those available in the literature indicates an excellent agreement. (author)

  8. Some Exact Solutions of Boundary Layer Flows along a Vertical Plate with Buoyancy Forces Combined with Lorentz Forces under Uniform Suction

    Directory of Open Access Journals (Sweden)

    Asterios Pantokratoras

    2008-01-01

    Full Text Available Exact analytical solutions of boundary layer flows along a vertical porous plate with uniform suction are derived and presented in this paper. The solutions concern the Blasius, Sakiadis, and Blasius-Sakiadis flows with buoyancy forces combined with either MHD Lorentz or EMHD Lorentz forces. In addition, some exact solutions are presented specifically for water in the temperature range of 0∘C≤≤8∘C, where water density is nearly parabolic. Except for their use as benchmarking means for testing the numerical solution of the Navier-Stokes equations, the presented exact solutions with EMHD forces have use in flow separation control in aeronautics and hydronautics, whereas the MHD results have applications in process metallurgy and fusion technology. These analytical solutions are valid for flows with strong suction.

  9. Report of the Task Force on Providing Library Services to Extended Campus Students.

    Science.gov (United States)

    Strickler, Sally Ann Koenig; And Others

    This task force report proposes a plan for providing campus-quality library services to students at three sites of Western Kentucky University's extended campus program which would offer access to main library services and collections rather than the traditional assembling of additional library collections in off-site locations. Elements of the…

  10. The Army Did Not Properly Account For and Manage Force Provider Equipment in Afghanistan

    Science.gov (United States)

    2014-07-31

    July 31, 2014 MEMORANDUM FOR AUDITOR GENERAL, DEPARTMENT OF THE ARMY SUBJECT: The Army Did Not Properly Account For and Manage Force Provider...transferred to another unit during unit rotations . Finally, the unit uses TPE planner in PBUSE to determine the disposition of their FP equipment

  11. The forced sound transmission of finite ribbed plates, investigating the influence of point connections and periodicity

    DEFF Research Database (Denmark)

    Brunskog, Jonas

    2015-01-01

    Many engineering structures consist of plates being stiffened by ribs. The ribs can be connected to the plate in a line connection (welded or glued) or in point connections (screwed). It is well known that the rib stiffeners can significantly change the vibration field and the radiation behavior...... been derived, using a variational technique based on integral-differential equations of the fluid loaded plate. In this way an optimal solution is derived, using a very simple initial guess of the vibration field. The finite plate is assumed being mounted in a rigid baffle. The approach is based...... the model. The influence of point versus line connections, as well as periodicity effects, is investigated....

  12. Forced convection heat transfer of Couette-Poiseuille flow of nonlinear viscoelastic fluids between parallel plates

    Energy Technology Data Exchange (ETDEWEB)

    Hashemabadi, S.H. [Iran Univ. of Science and Technology, Dept. of Chemical Engineering, Tehran (Iran); Etemad, S.Gh. [Isfahan Univ. of Technology, Dept. of Chemical Engineering, Isfahan (Israel); Thibault, J. [Ottawa Univ., Dept. of Chemical Engineering, Ottawa, ON (Canada)

    2004-08-01

    Heat transfer to viscoelastic fluids is frequently encountered in various industrial processing. In this investigation an analytical solution was obtained to predict the fully developed, steady and laminar heat transfer of viscoelastic fluids between parallel plates. One of the plates was stationary and was subjected to a constant heat flux. The other plate moved with constant velocity and was insulated. The simplified Phan-Thien-Tanner (SPTT) model, believed to be a more realistic model for viscoelastic fluids, was used to represent the rheological behavior of the fluid. The energy equation was solved for a wide range of Brinkman number, dimensionless viscoelastic group, and dimensionless pressure drop. Results highlight the strong effects of these parameters on the heat transfer rate. (Author)

  13. Lateral Casimir forces on parallel plates and concentric cylinders with corugations

    CERN Document Server

    Cavero-Pelaez, Ines; Parashar, Prachi; Shajesh, K V

    2008-01-01

    In this paper we are giving a quantitative description of two different configurations for noncontact gears. We consider the solutions from a perturbative calculation for two semitransparent parallel plates and concentric cylinders both with corrugations on the inner surfaces. In the case of corrugated parallel plates we discuss results from first- and second-order perturbation calculation in the corrugation amplitudes and we will concentrate on the first-order perturbation for the case of the corrugated concentric cylinders (the second order calculation is under study), both for the weak and strong couplings. We compare the perturbative results with the results from the PFA and an exact weak coupling calculation.

  14. Non-contact gears: I. Next-to-leading order contribution to lateral Casimir force between corrugated parallel plates

    CERN Document Server

    Cavero-Pelaez, Ines; Parashar, Prachi; Shajesh, K V

    2008-01-01

    We calculate the lateral Casimir force between corrugated parallel plates, described by $\\delta$-function potentials, interacting through a scalar field, using the multiple scattering formalism. The contributions to the Casimir energy due to uncorrugated parallel plates is treated as a background from the outset. We derive the leading- and next-to-leading-order contribution to the lateral Casimir force for the case when the corrugation amplitudes are small in comparison to corrugation wavelengths. We present explicit results in terms of finite integrals for the case of the Dirichlet limit, and exact results for the weak-coupling limit, for the leading- and next-to-leading-orders. The correction due to the next-to-leading contribution is significant. In the weak coupling limit we calculate the lateral Casimir force exactly in terms of a single integral which we evaluate numerically. Exact results for the case of the weak limit allows us to estimate the error in the perturbative results. We show that the error ...

  15. Effect of Chord Splice Joints on Force Distribution and Deformations in Trusses with Punched Metal Plate Fasteners

    DEFF Research Database (Denmark)

    Ellegaard, Peter

    2007-01-01

    The span of roof trusses with punched metal plate fasteners (nail plates) makes it often necessary to use splice joints in the top and bottom chords. In the finite element models used for design of the trusses these splice joints are normally assumed to be either rotationally stiff or pinned - th...... of splice joints on section forces and displacements are discussed considering the results from finite element calculations for a fink truss. It seems that the guidelines for treating splice joints as rotationally stiff do not necessarily lead to more realistic truss models....... - their real behaviour is semi-rigid. The influence of splice joints on the distribution of member forces and rotations in the splice joints is investigated in this paper. A finite element program, TrussLab, where the splice joints are given semi-rigid properties is used to analyse the effect of splice joints...... if their deformation has no significant effect upon the distribution of member forces according to Eurocode 5. Two simple guidelines for the design and location of splice joints are given in Eurocode 5 for treating the splice joints as rotationally stiff. The reasonability of these guidelines and the influence...

  16. Military Suicide: Developing an Understanding of Basic Issues to Provide a Lower Risk Force

    Science.gov (United States)

    2017-05-25

    deployment since risk levels decrease upon return . Additionally, the group at highest risk had the shortest term of service which is similar to the trends...Military Suicide: Developing an Understanding of Basic Issues to Provide a Lower Risk Force A Monograph by COL Eric M. Remoy United States Army...if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 25

  17. A Systems Engineering Approach in Providing Air Defense Support to Ground Combat Vehicle Maneuver Forces

    Science.gov (United States)

    2015-03-01

    http://www.strategypage.com/dls/ articles /SLAMRAAM-Dies-From-Loneliness-2- 5-2011.asp. Federation of American Scientists . 2000. “M6 Bradley Linebacker...MANPADS-under-armor (MUA) concept was adopted to provide mobile air defense to maneuver forces (Federation of American Scientists 2000). This involved... swim in water. The functional hierarchy for the Move function is shown in Figure 17. 39 Figure 17. Functional Hierarchy for F.3 Move d

  18. Followup Audit: Additional Actions Needed to Effectively Provide Complete Audit Trails for Air Force Journal Vouchers

    Science.gov (United States)

    2015-07-10

    objective was to determine whether Defense Finance and Accounting Service (DFAS) Columbus officials modified the journal vouchers (JV) for the Air Force... Journal Vouchers (Report No. DODIG-2015-145) We are providing this report for your information and use. Defense Finance and Accounting Service...objective was to determine whether Defense Finance and Accounting Service (DFAS) Columbus officials modified the journal vouchers (JV) for the Air

  19. Measuring the efficacy of flunixin meglumine and meloxicam for lame sows using a GAITFour pressure mat and an embedded microcomputer-based force plate system.

    Science.gov (United States)

    Pairis-Garcia, M D; Johnson, A K; Abell, C A; Coetzee, J F; Karriker, L A; Millman, S T; Stalder, K J

    2015-05-01

    Pain associated with lameness on farm is a negative affective state and has a detrimental impact on individual farm animal welfare. Animal pain can be managed utilizing husbandry tools and through pharmacological approaches. Nonsteroidal anti-inflammatory drugs including meloxicam and flunixin meglumine are compounds used in many species for pain management because they are easy to administer, long lasting, and cost-effective. Assessing an animal's biomechanical parameters using such tools as the embedded microcomputer-based force plate system and GAITFour pressure mat gait analysis walkway system provides an objective, sensitive, and precise means to detect animals in lame states. The objectives of this study were to determine the efficacy of meloxicam and flunixin meglumine for pain mitigation in lame sows using the embedded microcomputer-based force plate system and GAITFour pressure mat gait analysis walkway system. Lameness was induced in 24 mature mixed-parity sows using a chemical synovitis model and compared 3 treatments: meloxicam (1.0 mg/kg per os), flunixin meglumine (2.2 mg/kg intramuscular) and sterile saline (intramuscular). Weight distribution (kg) for each foot was collected twice per second for a total of 5 min for each time point using the embedded microcomputer-based force plate system. Stride time, stride length, maximum pressure, activated sensors, and stance time were collected using 3 quality walks (readings) for each time point using the GAITFour pressure mat gait analysis walkway system. Sows administered flunixin meglumine or meloxicam tolerated more weight on their lame leg compared with saline sows (P meloxicam had smaller differences in stance time, maximum pressure, and activated sensors between the sound and lame legs compared with saline-treated sows between 37 and 60 h after lameness induction (P meloxicam administration mitigated pain sensitivity in sows after lameness induction when pain sensitivity was evaluated with the embedded

  20. Experimental investigation of forced-convection in a finned rhombic tube of the flat-plate solar collectors

    DEFF Research Database (Denmark)

    Taherian, Hessam; Yazdanshenas, Eshagh

    2006-01-01

    Due to scarcity of literature on forced-convection heat transfer in a solar collector with rhombic cross-section absorbing tubes, a series of experiments was arranged and conducted to determine heat transfer coefficient. In this study, a typical rhombic cross-section finned tube of flat......-plate collectors used as the test section. Two correlations were proposed for the Nusselt number as a function of the Reynolds number and the Prandtl number based on hydraulic diameter for various heat fluxes. The temperature distribution along the finned tube for the fluid and the wall were also illustrated....

  1. Influence of Damping on the Dynamical Behavior of the Electrostatic Parallel-plate and Torsional Actuators with Intermolecular Forces

    OpenAIRE

    Ya-Pu Zhao; Wen-Hui Lin

    2007-01-01

    The influence of damping on the dynamical behavior of the electrostatic parallel-plate and torsional actuators with the van der Waals (vdW) or Casimir force (torque) is presented. The values of the pull-in parameters and the number of the equilibrium points do not change whether there is damping or not. The ability of equilibrium points is varied with the appearance of damping. One equilibrium point is an unstable saddle with a different damping coefficient, the other equilibrium point is a s...

  2. Combined radiative and natural or forced convective heat transfer between parallel vertical plates with two-dimensional discrete heat sources

    Energy Technology Data Exchange (ETDEWEB)

    Nickell, T.W.

    1988-01-01

    This study numerically analyzes combined radiative and natural or forced convective heat transfer between vertical parallel plates with two-dimensional discrete heat sources. The numerical method was verified by comparing its results with other published experimental data and the agreement was excellent. It is shown that radiative heat transfer is a significant and useful mode of heat transfer in combination with both natural and forced convection in this situation and cannot be neglected. Radiative heat transfer accounted for 50-60% or more of the total heat transfer in some cases, and usually approximately 30-35% on the top of a discrete heat source. This fact can be used to advantage in the thermal design of electronic circuit boards.

  3. On a character of the forced vibrations of two-layer plate in the second boundary value problem

    Directory of Open Access Journals (Sweden)

    Poghosyan H. M.

    2007-06-01

    Full Text Available The three-dimensional dynamic problem of the elasticity theory on forced vibration of orthotropic plate at coulomb friction between layers is solved by the asymptotic method. The bottom obverse surface is subject to external dynamic influences, and top - is rigidly fixed. The common asymptotic solution of the problem is found. The closed solution for particular type of problems is found. The resonance arising conditions are established. It is known, that constant tangential displacements acting to the second layer do not influence in stress-strain state of the first layer. It is shown, that the same phenomenon with the big accuracy remains in force at linearly varying on coordinates influences.

  4. Making precise predictions of the Casimir force between metallic plates via a generalized Kramers-Kronig transform

    CERN Document Server

    Bimonte, Giuseppe

    2010-01-01

    The possibility of making precise predictions for the Casimir force is essential for addressing the striking contradiction that has arisen between the a new large distance Casimir experiment with gold plates, that has been interpreted as being consistent with the so-called Drude prescription and to rule out the plasma prescription, and a series of older precise short distance experiments, which were instead interpreted as being consistent with the plasma prescription and to rule out the Drude one. In a previous paper by the author [Phys. Rev. A {\\bf 81}, 062501 (2010)] it was shown that a precise prediction of the Casimir force is possible in principle by a simple modification of the standard Kramers-Kronig relations, involving suitable analytic window functions, solely on the basis of experimental optical data in the frequency interval where they are available, without using uncontrolled data extrapolations towards zero frequency that are necessary with standard Kramers-Kronig relations. In the present paper...

  5. AN EXACT ANALYSIS OF FORCED THICKNESS-TWIST VIBRATIONS OF MULTI-LAYERED PIEZOELECTRIC PLATES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This paper deals with the thickness-twist vibration of a multi-layered rectangular piezoelectric plate of crystals of 6 mm symmetry or polarized ceramics. An exact solution is obtained from the three-dimensional equations of linear piezoelectricity. The solution is useful to the understanding and design of composite piezoelectric devices. A piezoelectric resonator, a piezoelectric transformer, and a piezoelectric generator are analyzed as examples.

  6. Forced-Air Warming Provides Better Control of Body Temperature in Porcine Surgical Patients

    Directory of Open Access Journals (Sweden)

    Brian T. Dent

    2016-09-01

    Full Text Available Background: Maintaining normothermia during porcine surgery is critical in ensuring subject welfare and recovery, reducing the risk of immune system compromise and surgical-site infection that can result from hypothermia. In humans, various methods of patient heating have been demonstrated to be useful, but less evaluation has been performed in techniques to prevent hypothermia perioperatively in pigs. Methods: We compared body temperature regulation during surgery before and after modification of the ambient temperature of the operating laboratories. Three different methods of heating were then compared; a standard circulating water mattress, a resistive fabric blanket, and a forced hot air system. The primary measure was percentage of temperature readings outside a specification range of 36.7–40.0 °C. Results: Tighter control of the ambient temperature while using a circulating water mattress reduced the occurrence of out-of-specification body temperature readings from 20.8% to 5.0%, with most of these the result of hypothermia. Use of a resistive fabric blanket further reduced out-of-specification readings to 1.5%, with a slight increase in the occurrence of hyperthermia. Use of a forced air system reduced out-of-specification readings to less 0.1%. Conclusions: Maintenance of normothermia perioperatively in pig can be improved by tightly controlling ambient temperatures. Use of a resistive blanket or a forced air system can lead to better control than a circulating water mattress, with the forced air system providing a faster response to temperature variations and less chance of hyperthermia.

  7. Laminar Forced Convection Heat and Mass Transfer of Humid Air across a Vertical Plate with Condensation

    Institute of Scientific and Technical Information of China (English)

    李成; 李俊明

    2011-01-01

    Condensation of humid air along a vertical plate was numerically investigated, with the mathematical model built on the full boundary layer equations and the film-wise condensation assumption. The velocity, heat and mass transfer characteristics at the gas-liquid interface were numerical analyzed and the results indicated that it was not reasonable to neglect the condensate film from the point of its thickness only. The condensate film thickness, interface temperature drop and the interface tangential velocity affect the physical fields weakly. However, the subcooling and the interface normal velocity were important factors to be considered before the simplification was made. For higher wall temperature, the advective mass transfer contributed much to the total mass transfer. Therefore, the boundary conditions were the key to judge the rationality of neglecting the condensate film for numerical solutions. The numerical results were checked by comparing with experiments and correlations.

  8. TEMPERATURE PROFILES OF LOCAL THERMAL NONEQUILIBRIUM FOR THERMAL DEVELOPING FORCED CONVECTION IN POROUS MEDIUM PARALLEL PLATE CHANNEL

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao; LIU Xue-mei

    2006-01-01

    Based on the two-energy equation model, taking into account viscous dissipation due to the interaction between solid skeleton and pore fluid flow, temperature expressions of the solid skeleton and pore fluid flow are obtained analytically for the thermally developing forced convection in a saturated porous medium parallel plate channel,with walls being at constant temperature. It is proved that the temperatures of the two phases for the local thermal nonequilibrium approach to the temperature derived from the one-energy equation model for the local thermal equilibrium when the heat exchange coefficient goes to infinite. The temperature profiles are shown in figures for different dimensionless parameters and the effects of the parameters on the local thermal nonequilibrium are revealed by parameter study.

  9. Influence of Damping on the Dynamical Behavior of the Electrostatic Parallel-plate and Torsional Actuators with Intermolecular Forces

    Science.gov (United States)

    Lin, Wen-Hui; Zhao, Ya-Pu

    2007-01-01

    The influence of damping on the dynamical behavior of the electrostatic parallel-plate and torsional actuators with the van der Waals (vdW) or Casimir force (torque) is presented. The values of the pull-in parameters and the number of the equilibrium points do not change whether there is damping or not. The ability of equilibrium points is varied with the appearance of damping. One equilibrium point is an unstable saddle with a different damping coefficient, the other equilibrium point is a stable node when the damping coefficient is greater than some critical value, and otherwise it is a stable focus. Then there are two heteroclinic orbits passing from the unstable saddle point to the stable node or focus.

  10. Exact similarity solutions for forced convection flow over horizontal plate in saturated porous medium with temperature-dependent viscosity

    Science.gov (United States)

    Guedda, M.; Benlahsen, M.; Sriti, M.; Achemlal, D.

    2017-09-01

    In this paper, we revisit a mathematical model representing a two-dimensional forced convection boundary-layer flow over a horizontal impermeable plate with a variable heat flux and viscosity. It is assumed that the fluid viscosity varies as an inverse linear function of temperature, the free stream velocity varies as an inverse linear of x and the wall heat flux varies with x as x^{λ}; where λ > -1 and x measures the distance along the surface. Analytical local similarity solutions are presented which reveal that there are two competing effects: λ and θe; where θe is the variable viscosity parameter. It has been shown that for θe > 0 dual solutions exist and boundary separation occurs, while a unique local similarity solution exists for any θe < 0.

  11. Influence of Damping on the Dynamical Behavior of the Electrostatic Parallel-plate and Torsional Actuators with Intermolecular Forces

    Directory of Open Access Journals (Sweden)

    Ya-Pu Zhao

    2007-11-01

    Full Text Available The influence of damping on the dynamical behavior of the electrostaticparallel-plate and torsional actuators with the van der Waals (vdW or Casimir force(torque is presented. The values of the pull-in parameters and the number of theequilibrium points do not change whether there is damping or not. The ability ofequilibrium points is varied with the appearance of damping. One equilibrium point is anunstable saddle with a different damping coefficient, the other equilibrium point is astable node when the damping coefficient is greater than some critical value, andotherwise it is a stable focus. Then there are two heteroclinic orbits passing from theunstable saddle point to the stable node or focus.

  12. Long-and Short-Term Self-Learning Models of Rolling Force in Rolling Process Without Gaugemeter of Plate

    Institute of Scientific and Technical Information of China (English)

    ZHU Fu-wen; ZENG Qing-liang; HU Xian-lei; LI Xi-an; LIU Xiang-hua

    2009-01-01

    .Owing to a lack of gaugemeter and the variety of steel grades and standards in some plate mills,the longand short-term self-learning models of rolling force based on gauge soft-measuring with high precision were brought up.The soft-measuring method and target value locked method were used in these models to confirm the actual exit gauge of passes,and thick layer division and exponential smoothing method were used to dispose the deformation resistance parameter,which could be calculated from the actual data of the rolling process.The correlative mathematical methods can also be adapted to self-learning with gaugemeter.The models were applied to the process control system of AGC (automatic gauge control) reconstruction on 2 800 mm finishing mill of Anyang steel and favorable effect was obtained.

  13. Consistency of Field-Based Measures of Neuromuscular Control Using Force-Plate Diagnostics in Elite Male Youth Soccer Players.

    Science.gov (United States)

    Read, Paul J; Oliver, Jon L; Croix, Mark Ba De Ste; Myer, Gregory D; Lloyd, Rhodri S

    2016-12-01

    Read, P, Oliver, JL, Croix, MD, Myer, GD, and Lloyd, RS. Consistency of field-based measures of neuromuscular control using force-plate diagnostics in elite male youth soccer players. J Strength Cond Res 30(12): 3304-3311, 2016-Deficits in neuromuscular control during movement patterns such as landing are suggested pathomechanics that underlie sport-related injury. A common mode of assessment is measurement of landing forces during jumping tasks; however, these measures have been used less frequently in male youth soccer players, and reliability data are sparse. The aim of this study was to examine the reliability of a field-based neuromuscular control screening battery using force-plate diagnostics in this cohort. Twenty-six pre-peak height velocity (PHV) and 25 post-PHV elite male youth soccer players completed a drop vertical jump (DVJ), single-leg 75% horizontal hop and stick (75%HOP), and single-leg countermovement jump (SLCMJ). Measures of peak landing vertical ground reaction force (pVGRF), time to stabilization, time to pVGRF, and pVGRF asymmetry were recorded. A test-retest design was used, and reliability statistics included change in mean, intraclass correlation coefficient, and coefficient of variation (CV). No significant differences in mean score were reported for any of the assessed variables between test sessions. In both groups, pVGRF and asymmetry during the 75%HOP and SLCMJ demonstrated largely acceptable reliability (CV ≤ 10%). Greater variability was evident in DVJ pVGRF and all other assessed variables, across the 3 protocols (CV range = 13.8-49.7%). Intraclass correlation coefficient values ranged from small to large and were generally higher in the post-PHV players. The results of this study suggest that pVGRF and asymmetry can be reliably assessed using a 75%HOP and SLCMJ in this cohort. These measures could be used to support a screening battery for elite male youth soccer players and for test-retest comparison.

  14. Using EarthScope Construction of the Plate Boundary Observatory to Provide Locally Based Experiential Education and Outreach

    Science.gov (United States)

    Jackson, M.; Eriksson, S.; Barbour, K.; Venator, S.; Mencin, D.; Prescott, W.

    2006-12-01

    EarthScope is an NSF-funded, national science initiative to explore the structure and evolution of the North American continent and to understand the physical processes controlling earthquakes and volcanoes. This large-scale experiment provides locally based opportunities for education and outreach which engage students at various levels and the public. UNAVCO is responsible for the Plate Boundary Observatory (PBO) component of EarthScope. PBO includes the installation and operations and maintenance of large networks of Global Positioning Satellite (GPS), strainmeter, seismometer, and tiltmeter instruments and the acquisition of satellite radar imagery, all of which will be used to measure and map the smallest movements across faults, the magma movement inside active volcanoes and the very wide areas of deformation associated with plate tectonic motion. UNAVCO, through its own education and outreach activities and in collaboration with the EarthScope E&O Program, uses the PBO construction activities to increase the understanding and public appreciation of geodynamics, earth deformation processes, and their relevance to society. These include programs for public outreach via various media, events associated with local installations, a program to employ students in the construction of PBO, and development of curricular materials by use in local schools associated with the EarthScope geographic areas of focus. PBO provides information to the media to serve the needs of various groups and localities, including interpretive centers at national parks and forests, such as Mt. St. Helens. UNAVCO staff contributed to a television special with the Spanish language network Univision Aquí y Ahora program focused on the San Andreas Fault and volcanoes in Alaska. PBO participated in an Education Day at the Pathfinder Ranch Science and Outdoor Education School in Mountain Center, California. Pathfinder Ranch hosts two of the eight EarthScope borehole strainmeters in the Anza

  15. Loadcell supports for a dynamic force plate. [using piezoelectric tranducers and electromyography to study human gait

    Science.gov (United States)

    Keller, C. W.; Musil, L. M.; Hagy, J. L.

    1975-01-01

    An apparatus was developed to accurately measure components of force along three mutually perpendicular axes, torque, and the center of pressure imposed by the foot of a subject walking over its surface. The data obtained were used to supplement high-speed motion picture and electromyographic (EMG) data for in-depth studies of normal or abnormal human gait. Significant features of the design (in particular, the mechanisms used to support the loadcell transducers) are described. Results of the development program and typical data obtained with the device are presented and discussed.

  16. Forced Convective Heat Transfer in a Plate Channel Filled with Solid Particles

    Institute of Scientific and Technical Information of China (English)

    Pei-XueJiang; Ze-PeiRen; 等

    1996-01-01

    A numerical study of fluid flow and convective heat transfer in a plate channel filled with solid(metallic)perticles is presented in this paper,The study uses the thermal equilibrium model and a newly developed numerical model which does not assume idealized local thermal equilibrium between the solid particles and the fluid.The numerical simulation results are compared with the experimental data in reference[2].The paper investigates the effects of the assumption of local thermal equilibrium versus non-thermal equilibrium,the thermal conductivity of the solid particles and the particle diameter on convective heat transfer.For the conditions studied.the convective heat transfer and the temperature filed assuming local thermal equilibrium are much different from that for the non-thermal equilibrium assumption when the difference between the solid and fluid thermal conductivities is large,The relative values of the thermal conductivities of the solid particles and the fluid also have a profound effect on the temperature distribution in the channel.The pressure drop decreases as the particle diameter increases and the convective heat transfer coefficient may decrease of increase as the particle diameter increasws depending on the values of ε,λs,λf,λd,αu,ρu.

  17. On the correlation between force production and the flow field around a flapping flat-plate wing

    Science.gov (United States)

    Öz, Sören; Krishna, Swathi; Mulleners, Karen

    2015-11-01

    One of the several sophisticated flight skills that insects exhibit is hovering, which is accomplished largely by modulating the wing kinematics and thereby the flow field around the wings. Along with the prolonged attachment of the leading edge vortex, the wing reversal mechanisms form the basis by which insects regulate the magnitude and direction of forces produced. The duration and starting point of these directional flips are studied in the current experimental investigation. Particle image velocimetry is conducted to evaluate the flow features inherent to changes in wing reversal during the stroke of a flat plate, which is modelled based on hoverfly characteristics. The duration of rotation is one-third of the total time period. A +10% phase shift is used for delayed rotation, a -10% phase shift for advanced rotation. Phase-averaged data is analysed to understand the influence of a delayed or advanced rotation on the formation and evolution of large and small scale structures, their interactions with the wing, and disintegration. Additionally, force data is used to quantify the effects of phase-shift in terms of lift and drag variation and is correlated with the vortex dynamics.

  18. Magnetic forces and magnetized biomaterials provide dynamic flux information during bone regeneration.

    Science.gov (United States)

    Russo, Alessandro; Bianchi, Michele; Sartori, Maria; Parrilli, Annapaola; Panseri, Silvia; Ortolani, Alessandro; Sandri, Monica; Boi, Marco; Salter, Donald M; Maltarello, Maria Cristina; Giavaresi, Gianluca; Fini, Milena; Dediu, Valentin; Tampieri, Anna; Marcacci, Maurilio

    2016-03-01

    The fascinating prospect to direct tissue regeneration by magnetic activation has been recently explored. In this study we investigate the possibility to boost bone regeneration in an experimental defect in rabbit femoral condyle by combining static magnetic fields and magnetic biomaterials. NdFeB permanent magnets are implanted close to biomimetic collagen/hydroxyapatite resorbable scaffolds magnetized according to two different protocols . Permanent magnet only or non-magnetic scaffolds are used as controls. Bone tissue regeneration is evaluated at 12 weeks from surgery from a histological, histomorphometric and biomechanical point of view. The reorganization of the magnetized collagen fibers under the effect of the static magnetic field generated by the permanent magnet produces a highly-peculiar bone pattern, with highly-interconnected trabeculae orthogonally oriented with respect to the magnetic field lines. In contrast, only partial defect healing is achieved within the control groups. We ascribe the peculiar bone regeneration to the transfer of micro-environmental information, mediated by collagen fibrils magnetized by magnetic nanoparticles, under the effect of the static magnetic field. These results open new perspectives on the possibility to improve implant fixation and control the morphology and maturity of regenerated bone providing "in site" forces by synergically combining static magnetic fields and biomaterials.

  19. The moving plate capacitor paradox

    Science.gov (United States)

    Davis, B. R.; Abbott, D.; Parrondo, J. M. R.

    2000-03-01

    For the first time we describe an apparent paradox concerning a moving plate capacitor driven by thermal noise from a resistor. A demon restores the plates of the capacitor to their original position, only when the voltage across the capacitor is small—hence only small forces are present for the demon to work against. The demon has to work harder than this to avoid the situation of perpetual motion, but the question is how? We explore the concept of a moving plate capacitor, driven by noise, a step further by examining the case where the restoring force on the capacitor plates is provided by a simple spring, rather than some unknown demon. We display simulation results with interesting behavior, particularly where the capacitor plates collide with each other.

  20. Sila kojom vazduh pritiska pokretnu ploču/Force of the air pressure on a moving plate

    Directory of Open Access Journals (Sweden)

    Leonid Ivanovich Gretchihin

    2014-10-01

    Full Text Available U radu je razrađena matematički model gasodinamičkog opstrujavanja ravne ploče pri njenom kretanju sa pozitivnim i negativnim napadnim uglom. Pokazano je da pri malim brzinama kretanja, silu uzgona i čeoni otpor određuje gasodinamički tok vazduha u izlaznoj oblasti opstrujavanja, a pri brzinama kretanja koje su bliske brzini zvuka odlučujuću ulogu vrši uzajamno udarno dejstvo ploče sa molekulima okružujuće sredine u ulaznoj oblasti opstrujavanja. Otcepljena struja iza ploče se ne pojavljuje pri malim brzinama kretanja. Određeni su uslovi kada čeoni otpor i sila uzgona ploče menjaju znak. / (ruski Razrabotana matematičeskaja model' gazodinamičeskogo obtekanija ploskoj plastiny pri ee dviženii s položitel'nym i otricatel'nym uglom ataki. Pokazano, čto pri malyh skorostjah dviženija plastiny pod''emnaja sila i lobovoe soprotivlenie opredeljajutsja gazodinamikoj tečenija vozduha v tyl'noj oblasti, a pri skorostjah dviženija blizkih k skorosti zvuka rešajuščuju rol' vypolnjaet udarnoe vzaimodejstvie plastiny s molekulami okružajuščej sredy v perednej oblasti. Sryvnoe tečenie za plastinoj pri malyh skorostjah dviženija ne voznikaet. Opredeleny uslovija, kogda lobovoe soprotivlenie i pod''emnaja sila plastiny izmenjaet znak. / This paper developed a mathematical model of gas dynamic fluid flow for a flat plate during its movement with positive and negative angles of attack. It is shown that at low velocities, the lifting force and the frontal resistance are determined by gasdynamic air flow in the fluid flow exit areawhile at velocities close to the speed of sound the decisive role is played by a mutualeffect of the pplate coliding with molecules of the surrounding environment in the fluid flow incidence field. The airflow behind the plate does not appear at low velocities. The conditions when the frontal resistance and the lifting force change the sign are determined.

  1. Plate shell structures - statics and stability

    DEFF Research Database (Denmark)

    Almegaard, Henrik

    2008-01-01

    This paper describes the basic structural system, statics and spatial stability of plate shells. The structural system can be considered as a single layer of planar elements, where each element only transfers in-plane (membrane) forces to its neighbouring elements. External out-of-plane loads...... are carried into the structure as in-plane forces by plate action in each element. These in-plane forces are then carried through the plate structure to the supports as in-plane forces by membrane action. The consequence is that the spatial stability of the structure can be simply analysed by considering...... the plate system as only subject to in-plane loads. The stability of such systems is based on the fact that each plane element is held fixed in space by three fixed support lines and that these support lines can be provided by three plane neighbour elements. This means that the spatial stability of a plate...

  2. Forces and Moments on Flat Plates of Small Aspect Ratio with Application to PV Wind Loads and Small Wind Turbine Blades

    Directory of Open Access Journals (Sweden)

    Xavier Ortiz

    2015-03-01

    Full Text Available To improve knowledge of the wind loads on photovoltaic structures mounted on flat roofs at the high angles required in high latitudes, and to study starting flow on low aspect ratio wind turbine blades, a series of wind tunnel tests were undertaken. Thin flat plates of aspect ratios between 0.4 and 9.0 were mounted on a sensitive three-component instantaneous force and moment sensor. The Reynolds numbers varied from 6 × 104 to 2 × 105. Measurements were made for angles of attack between 0° and 90° both in the free stream and in wall proximity with increased turbulence and mean shear. The ratio of drag to lift closely follows the inverse tangent of the angle of incidence for virtually all measurements. This implies that the forces of interest are due largely to the instantaneous pressure distribution around the plate and are not significantly influenced by shear stresses. The instantaneous forces appear most complex for the smaller aspect ratios but the intensity of the normal force fluctuations is between 10% and 20% in the free-steam but can exceed 30% near the wall. As the wind tunnel floor is approached, the lift and drag reduce with increasing aspect ratio, and there is a reduction in the high frequency components of the forces. It is shown that the centre of pressure is closer to the centre of the plates than the quarter-chord position for nearly all cases.

  3. Effect of Magnetic Field on Entropy Generation Due to Laminar Forced Convection Past a Horizontal Flat Plate

    Directory of Open Access Journals (Sweden)

    Moh'd A. Al-Nimr

    2004-06-01

    Full Text Available Magnetic field effect on local entropy generation due to steady two-dimensional laminar forced convection flow past a horizontal plate was numerically investigated. This study was focused on the entropy generation characteristics and its dependency on various dimensionless parameters. The effect of various dimensionless parameters, such as Hartmann number (Ha, Eckert number (Ec, Prandtl number (Pr, Joule heating parameter (R and the free stream temperature parameter (θ∞ on the entropy generation characteristics is analyzed. The dimensionless governing equations in Cartesian coordinate were solved by an implicit finite difference technique. The solutions were carried out for Ha2=0.5-3, Ec=0.01-0.05, Pr=1-5 and θ∞=1.1-2.5. It was found that, the entropy generation increased with increasing Ha, Ec and R. While, increasing the free stream temperature parameter, and Prandtl number tend to decrease the local entropy generation.

  4. Material dependence of Casimir interaction between a sphere and a plate: First analytic correction beyond proximity force approximation

    CERN Document Server

    Teo, L P

    2013-01-01

    We derive analytically the asymptotic behavior of the Casimir interaction between a sphere and a plate when the distance between them, $d$, is much smaller than the radius of the sphere, $R$. The leading order and next-to-leading order terms are derived from the exact formula for the Casimir interaction energy. They are found to depend nontrivially on the dielectric functions of the objects. As expected, the leading order term coincides with that derived using the proximity force approximation. The result on the next-to-leading order term complements that found by Bimonte, Emig and Kardar [Appl. Phys. Lett. \\textbf{100}, 074110 (2012)] using derivative expansion. Numerical results are presented when the dielectric functions are given by the plasma model or the Drude model, with the plasma frequency (for plasma and Drude models) and relaxation frequency (for Drude model) given respectively by 9eV and 0.035eV, the conventional values used for gold metal. It is found that if plasma model is used instead of Drude...

  5. Fully automated synthesis of (phosphopeptide arrays in microtiter plate wells provides efficient access to protein tyrosine kinase characterization

    Directory of Open Access Journals (Sweden)

    Goldstein David J

    2005-01-01

    Full Text Available Abstract Background Synthetic peptides have played a useful role in studies of protein kinase substrates and interaction domains. Synthetic peptide arrays and libraries, in particular, have accelerated the process. Several factors have hindered or limited the applicability of various techniques, such as the need for deconvolution of combinatorial libraries, the inability or impracticality of achieving full automation using two-dimensional or pin solid phases, the lack of convenient interfacing with standard analytical platforms, or the difficulty of compartmentalization of a planar surface when contact between assay components needs to be avoided. This paper describes a process for synthesis of peptides and phosphopeptides on microtiter plate wells that overcomes previous limitations and demonstrates utility in determination of the epitope of an autophosphorylation site phospho-motif antibody and utility in substrate utilization assays of the protein tyrosine kinase, p60c-src. Results The overall reproducibility of phospho-peptide synthesis and multiplexed EGF receptor (EGFR autophosphorylation site (pY1173 antibody ELISA (9H2 was within 5.5 to 8.0%. Mass spectrometric analyses of the released (phosphopeptides showed homogeneous peaks of the expected molecular weights. An overlapping peptide array of the complete EGFR cytoplasmic sequence revealed a high redundancy of 9H2 reactive sites. The eight reactive phospopeptides were structurally related and interestingly, the most conserved antibody reactive peptide motif coincided with a subset of other known EGFR autophosphorylation and SH2 binding motifs and an EGFR optimal substrate motif. Finally, peptides based on known substrate specificities of c-src and related enzymes were synthesized in microtiter plate array format and were phosphorylated by c-Src with the predicted specificities. The level of phosphorylation was proportional to c-Src concentration with sensitivities below 0.1 Units of

  6. OPLS3: A Force Field Providing Broad Coverage of Drug-like Small Molecules and Proteins.

    Science.gov (United States)

    Harder, Edward; Damm, Wolfgang; Maple, Jon; Wu, Chuanjie; Reboul, Mark; Xiang, Jin Yu; Wang, Lingle; Lupyan, Dmitry; Dahlgren, Markus K; Knight, Jennifer L; Kaus, Joseph W; Cerutti, David S; Krilov, Goran; Jorgensen, William L; Abel, Robert; Friesner, Richard A

    2016-01-12

    The parametrization and validation of the OPLS3 force field for small molecules and proteins are reported. Enhancements with respect to the previous version (OPLS2.1) include the addition of off-atom charge sites to represent halogen bonding and aryl nitrogen lone pairs as well as a complete refit of peptide dihedral parameters to better model the native structure of proteins. To adequately cover medicinal chemical space, OPLS3 employs over an order of magnitude more reference data and associated parameter types relative to other commonly used small molecule force fields (e.g., MMFF and OPLS_2005). As a consequence, OPLS3 achieves a high level of accuracy across performance benchmarks that assess small molecule conformational propensities and solvation. The newly fitted peptide dihedrals lead to significant improvements in the representation of secondary structure elements in simulated peptides and native structure stability over a number of proteins. Together, the improvements made to both the small molecule and protein force field lead to a high level of accuracy in predicting protein-ligand binding measured over a wide range of targets and ligands (less than 1 kcal/mol RMS error) representing a 30% improvement over earlier variants of the OPLS force field.

  7. Earth's Decelerating Tectonic Plates

    Energy Technology Data Exchange (ETDEWEB)

    Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

    2008-08-22

    Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

  8. Earth's Decelerating Tectonic Plates

    Energy Technology Data Exchange (ETDEWEB)

    Forte, A M; Moucha, R; Rowley, D B; Quere, S; Mitrovica, J X; Simmons, N A; Grand, S P

    2008-08-22

    Space geodetic and oceanic magnetic anomaly constraints on tectonic plate motions are employed to determine a new global map of present-day rates of change of plate velocities. This map shows that Earth's largest plate, the Pacific, is presently decelerating along with several other plates in the Pacific and Indo-Atlantic hemispheres. These plate decelerations contribute to an overall, globally averaged slowdown in tectonic plate speeds. The map of plate decelerations provides new and unique constraints on the dynamics of time-dependent convection in Earth's mantle. We employ a recently developed convection model constrained by seismic, geodynamic and mineral physics data to show that time-dependent changes in mantle buoyancy forces can explain the deceleration of the major plates in the Pacific and Indo-Atlantic hemispheres.

  9. Evaluation of force plate-less estimation of the trajectory of the centre of pressure during gait. Comparison of two anthropometric models.

    Science.gov (United States)

    Pillet, Hélène; Bonnet, Xavier; Lavaste, François; Skalli, Wafa

    2010-02-01

    The estimation of the trajectory of the centre of pressure during gait is possible without using force plate by modelling the whole body as a multi-segment chain. The kinematics and inertial parameters of each segment are necessary to determine the ground reaction forces and moments. The position of the centre of pressure can then be calculated at each frame of time. The objective of the study was to evaluate the accuracy of the estimation of the position of the centre of pressure during gait obtained without force plate data. Segment inertial parameters were determined using a proportional model and a geometric model. The modelling and calculations were computed for six volunteers and the estimated centres of pressure were compared to the centre of pressure measured using force plates considered as the gold standard. The estimation was better using the geometric model with an accuracy of 33 mm (4.1% of the peak-to-peak amplitude) on the longitudinal axis and 14.2 mm (12.9% of the peak-to-peak amplitude) on the lateral axis.

  10. One dimension spring supported ball on top of a sinusoidal vibrating plate: A forced oscillation simulation using molecular dynamics method

    CERN Document Server

    Viridi, Sparisoma; Hidayat, Wahyu; Singarimbun, Alamta; Balkis, Sitti

    2011-01-01

    A ball supported by a spring is set on top of a plate which is sinusoidal vibrated. The motion is limited to one dimension motion. It is assumed that the spring is an ideal one with zero mass. The vibrating plate is considered much heavier than the ball, so that the ball motion has no influence on the plate motion. Plate vibration frequency is varied around the frequency of ball-spring system. Resonance phenomenon is reported, which needs a phase match condition to occur.

  11. Plate boundary forces in the vicinity of Trinidad-the-transition from transpression to transtension in the Southern Caribbean plate boundary zones

    Energy Technology Data Exchange (ETDEWEB)

    Algar, S.T.; Pindell, J.L. (Dartmouth College, Hanover, NH (United States))

    1993-02-01

    Deformation in the southern Caribbean plate boundary zones as recorded in the Northern Range of Trinidad initiated in the Oligocene with northward vergent gravity sliding of Northern Range sediments due to uplift and oversteepening of the previously passive margin by the eastward migration of the Caribbean flexural forebulge. Progressive east-southeast transvergence of the Caribbean Plate with respect to South America overthrust incorporated the Northern Range sediments into the Caribbean accretionary prism, thrusting them south-southeast to produce a Middle Miocene transpressive foreland fold and thrust belt in southern Trinidad. Late Miocene deformation within Trinidad was increasingly dominated by right-lateral strike-slop (RLSS) faulting, at the expense of transpressive compressional features. Right-stepping of RLSS motion initiated the Gulf of Paria and Caroni pull-apart basins, Since Early Pliocene these basins and other areas to the north of Trinidad have undergone north-south extension in addition to east-west trending RLSS. Such extension caused the northward withdrawal of Caribbean terranes from atop of the Northern Range, Resulting in rapid isostatically induced uplift (approximately 0.5 mmyr[sup -1]). This change in deformation style may relate to a hitherto unrecognized shift in the relative motion of the eastern Caribbean Plate with respect to South America: from east-southeast-directed transpression to east-northeast-directed transtension.

  12. In situ cannulation, microgrid follow-up and low-density plating provide first passage endothelial cell masscultures for in vitro lining.

    Science.gov (United States)

    Zilla, P; Fasol, R; Dudeck, U; Siedler, S; Preiss, P; Fischlein, T; Müller-Glauser, W; Baitella, G; Sanan, D; Odell, J

    1990-08-01

    A rapid and reliable harvest and culture technique was developed to provide a sufficient number of autologous endothelial cells for the confluent in vitro lining of cardiovascular prostheses. Enzymatic endothelial cell detachment was achieved by the in situ application of collagenase to short vessel segments. This harvest technique resulted in a complete lack of contaminating smooth muscle cells in all of 124 cultures from nonhuman primates and 13 cultures from human adults. The use of a microgrid technique enabled the daily in situ quantification of available endothelial cells. To assess ideal plating densities after passage the population doubling time was continuously related to the cell density. Surprisingly, a low plating density of 1.5 X 10(3) endothelial cells/cm2 achieved 43% shorter cell cycles than the usual plating density of 1.0 X 10(4) endothelial cells/cm2. Moreover, low density plating enabled mass cultures after one single cell passage, thereby reducing the cell damaging effect of trypsin. When the growth characteristics of endothelial cells from five anatomically different vessel sites were compared, the external jugular vein--which would be easily accessible and dispensable in each patient--proved to be an excellent source for endothelial cell cultures. By applying in situ administration of collagenase, low density plating and microgrid follow-up to adult human saphenous vein endothelial cells, 14,000,000 first passage endothelial cells--sufficient for the in vitro lining of long vascular prostheses--were obtained 26.2 days after harvest. (95% confidence interval:22.3 to 32.2 days).

  13. Evidence of a plate-wide tectonic pressure pulse provided by extensometric monitoring in the Balkan Mountains (Bulgaria

    Directory of Open Access Journals (Sweden)

    Briestenský Miloš

    2015-10-01

    Full Text Available The EU-TecNet monitoring network uses customized three-dimensional extensometers to record transient deformations across individual faults. This paper presents the first results from two newly established monitoring points in the Balkan Mountains in Bulgaria. The data from Saeva Dupka, recorded across an EEN-WWS striking fault, show sinistral strike-slip along the fault and subsidence of the southern block. Much of the subsidence occurred around the time of the distal MW = 5.6 Pernik Earthquake. An important transient deformation event, which began in autumn 2012, was reflected by significant compression and following extension, across the monitored fault. The data from Bacho Kiro, recorded across a NE–SW striking fault, show sinistral strike-slip along the fault and subsidence of the north-western block. The same important deformation event was reflected by changes in the strike-slip, dip-slip, and horizontal opening/closing trends. These results have been compared to data from other monitoring points in the Western Carpathians, External Dinarides, and Tian Shan. Many of the sites show evidence of simultaneous displacement anomalies and this observation is interpreted as a reflection of the plate-wide propagation of a tectonic pressure pulse towards the end of 2012.

  14. Efficacy of a trunk orthosis with joints providing resistive force on low-back load in elderly persons during static standing.

    Science.gov (United States)

    Katsuhira, Junji; Matsudaira, Ko; Yasui, Tadashi; Iijima, Shinno; Ito, Akihiro

    2015-01-01

    Postural alignment of elderly people becomes poor due to aging, possibly leading to low-back pain and spinal deformity. Although there are several interventions for treating these conditions, no previous study has reported the effectiveness of a spinal orthosis or lumbosacral orthosis (LSO) in healthy elderly people without specific spinal deformity. We therefore developed a trunk orthosis to decrease low-back muscle activity while training good postural alignment through resistive force provided by joints with springs (here, called the ORF, which stands for orthosis with joints providing resistive force) as a preventive method against abnormal posture and low-back pain in healthy elderly persons. Fifteen community-dwelling elderly men participated in this study. Participants stood freely for 10 seconds in a laboratory setting under three conditions: without an orthosis, with the ORF, and with an LSO. The Damen corset LSO was selected as it is frequently prescribed for patients with low-back pain. Postural alignment during static standing was recorded using a three-dimensional motion capture system employing infrared cameras. Two force plates were used to record center of pressure. Electromyograms were obtained for bilateral erector spinae (ES), left internal abdominal oblique, and right gluteus medius muscles. Pelvis forward tilt angle tended to increase while wearing the ORF and decrease while wearing the LSO, but these results were not significant compared to no orthosis. Thorax extension angle and thorax angle on pelvis coordinate system significantly increased while wearing the ORF compared to the other two conditions. ES activity significantly decreased while wearing the ORF compared to the other two conditions. Internal oblique activity was significantly smaller while wearing the LSO than with no orthosis. Center of pressure did not significantly differ among the conditions. The ORF significantly improved trunk alignment and decreased ES activity in healthy

  15. Final Report of the National Black Health Providers Task Force on High Blood Pressure Education and Control.

    Science.gov (United States)

    Public Health Service (DHHS), Rockville, MD.

    This is the final report of National Black Health Providers Task Force (NBHPTF) on High Blood Pressure Education and Control. The first chapter of the report recounts the history of the NBHPTF and its objectives. In the second chapter epidemiological evidence is presented to demonstrate the need for a suggested 20 year plan aimed at controlling…

  16. Sit-stand and stand-sit transitions in older adults and patients with Parkinson's disease: event detection based on motion sensors versus force plates.

    Science.gov (United States)

    Zijlstra, Agnes; Mancini, Martina; Lindemann, Ulrich; Chiari, Lorenzo; Zijlstra, Wiebren

    2012-10-07

    Motion sensors offer the possibility to obtain spatiotemporal measures of mobility-related activities such as sit-stand and stand-sit transitions. However, the application of new sensor-based methods for assessing sit-stand-sit performance requires the detection of crucial events such as seat on/off in the sensor-based data. Therefore, the aim of this study was to evaluate the agreement of detecting sit-stand and stand-sit events based on a novel body-fixed-sensor method with a force-plate based analysis. Twelve older adults and 10 patients with mild to moderate Parkinson's disease with mean age of 70 years performed sit-stand-sit movements while trunk movements were measured with a sensor-unit at vertebrae L2-L4 and reaction forces were measured with separate force plates below the feet and chair. Movement onsets and ends were determined. In addition, seat off and seat on were determined based on forces acting on the chair. Data analysis focused on the agreement of the timing of sit-stand and stand-sit events as detected by the two methods. For the start and end of standing-up, only small delays existed for the start of forward trunk rotation and end of backward trunk rotation compared to movement onset/end as detected in the force-plate data. The end of forward trunk rotation had a small and consistent delay compared to seat off, whereas during sitting-down, the end of forward trunk rotation occurred earlier in relation to seat on. In detecting the end of sitting-down, backward trunk rotation ended after reaching the minimum in the below-feet vertical force signal. Since only small time differences existed between the two methods for detecting the start of sitting-down, longer movement durations were found for the sensor-based method. Relative agreement between the two methods in assessing movement duration was high (i.e. ICCs ≥ 0.75), except for duration of standing-up in the Parkinson's patients (ICC = 0.61). This study demonstrated high agreement of

  17. Sit-stand and stand-sit transitions in older adults and patients with Parkinson’s disease: event detection based on motion sensors versus force plates

    Science.gov (United States)

    2012-01-01

    Background Motion sensors offer the possibility to obtain spatiotemporal measures of mobility-related activities such as sit-stand and stand-sit transitions. However, the application of new sensor-based methods for assessing sit-stand-sit performance requires the detection of crucial events such as seat on/off in the sensor-based data. Therefore, the aim of this study was to evaluate the agreement of detecting sit-stand and stand-sit events based on a novel body-fixed-sensor method with a force-plate based analysis. Methods Twelve older adults and 10 patients with mild to moderate Parkinson’s disease with mean age of 70 years performed sit-stand-sit movements while trunk movements were measured with a sensor-unit at vertebrae L2-L4 and reaction forces were measured with separate force plates below the feet and chair. Movement onsets and ends were determined. In addition, seat off and seat on were determined based on forces acting on the chair. Data analysis focused on the agreement of the timing of sit-stand and stand-sit events as detected by the two methods. Results For the start and end of standing-up, only small delays existed for the start of forward trunk rotation and end of backward trunk rotation compared to movement onset/end as detected in the force-plate data. The end of forward trunk rotation had a small and consistent delay compared to seat off, whereas during sitting-down, the end of forward trunk rotation occurred earlier in relation to seat on. In detecting the end of sitting-down, backward trunk rotation ended after reaching the minimum in the below-feet vertical force signal. Since only small time differences existed between the two methods for detecting the start of sitting-down, longer movement durations were found for the sensor-based method. Relative agreement between the two methods in assessing movement duration was high (i.e. ICCs ≥ 0.75), except for duration of standing-up in the Parkinson’s patients (ICC = 0.61). Conclusions

  18. Novel pedicle screw and plate system provides superior stability in unilateral fixation for minimally invasive transforaminal lumbar interbody fusion: an in vitro biomechanical study.

    Directory of Open Access Journals (Sweden)

    Jie Li

    Full Text Available This study aims to compare the biomechanical properties of the novel pedicle screw and plate system with the traditional rod system in asymmetrical posterior stabilization for minimally invasive transforaminal lumbar interbody fusion (MI-TLIF. We compared the immediate stabilizing effects of fusion segment and the strain distribution on the vertebral body.Seven fresh calf lumbar spines (L3-L6 were tested. Flexion/extension, lateral bending, and axial rotation were induced by pure moments of ± 5.0 Nm and the range of motion (ROM was recorded. Strain gauges were instrumented at L4 and L5 vertebral body to record the strain distribution under flexion and lateral bending (LB. After intact kinematic analysis, a right sided TLIF was performed at L4-L5. Then each specimen was tested for the following constructs: unilateral pedicle screw and rod (UR; unilateral pedicle screw and plate (UP; UR and transfacet pedicle screw (TFS; UP and TFS; UP and UR.All instrumented constructs significantly reduced ROM in all motion compared with the intact specimen, except the UR construct in axial rotation. Unilateral fixation (UR or UP reduced ROM less compared with the bilateral fixation (UP/UR+TFS, UP+UR. The plate system resulted in more reduction in ROM compared with the rod system, especially in axial rotation. UP construct provided more stability in axial rotation compared with UR construct. The strain distribution on the left and right side of L4 vertebral body was significantly different from UR and UR+TFS construct under flexion motion. The strain distribution on L4 vertebral body was significantly influenced by different fixation constructs.The novel plate could provide sufficient segmental stability in axial rotation. The UR construct exhibits weak stability and asymmetrical strain distribution in fusion segment, while the UP construct is a good alternative choice for unilateral posterior fixation of MI-TLIF.

  19. Should health care providers be forced to apologise after things go wrong?

    Science.gov (United States)

    McLennan, Stuart; Walker, Simon; Rich, Leigh E

    2014-12-01

    The issue of apologising to patients harmed by adverse events has been a subject of interest and debate within medicine, politics, and the law since the early 1980s. Although apology serves several important social roles, including recognising the victims of harm, providing an opportunity for redress, and repairing relationships, compelled apologies ring hollow and ultimately undermine these goals. Apologies that stem from external authorities' edicts rather than an offender's own self-criticism and moral reflection are inauthentic and contribute to a "moral flabbiness" that stunts the moral development of both individual providers and the medical profession. Following a discussion of a recent case from New Zealand in which a midwife was required to apologise not only to the parents but also to the baby, it is argued that rather than requiring health care providers to apologise, authorities should instead train, foster, and support the capacity of providers to apologise voluntarily.

  20. Force

    CERN Document Server

    Graybill, George

    2007-01-01

    Forces are at work all around us. Discover what a force is, and different kinds of forces that work on contact and at a distance. We use simple language and vocabulary to make this invisible world easy for students to ""see"" and understand. Examine how forces ""add up"" to create the total force on an object, and reinforce concepts and extend learning with sample problems.

  1. Provider accountability as a driving force towards physician–hospital integration: a systematic review

    Directory of Open Access Journals (Sweden)

    Jeroen Trybou

    2015-04-01

    Full Text Available Background: Hospitals and physicians lie at the heart of our health care delivery system. In general, physicians provide medical care and hospitals the resources to deliver health care. In the past two decades many countries have adopted reforms in which provider financial risk bearing is increased. By making providers financially accountable for the delivered care integrated care delivery is stimulated. Purpose: To assess the evidence base supporting the relationship between provider financial risk bearing and physician–hospital integration and to identify the different types of methods used to measure physician–hospital integration to evaluate the functional value of these integrative models. Results: Nine studies met the inclusion criteria. The evidence base is mixed and inconclusive. Our methodological analysis of previous research shows that previous studies have largely focused on the formal structures of physician–hospital arrangements as an indicator of physician–hospital integration. Conclusion: The link between provider financial risk bearing and physician–hospital integration can at this time be supported merely on the basis of theoretical insights of agency theory rather than empirical research. Physician–hospital integration measurement has concentrated on the prevalence of contracting vehicles that enables joint bargaining in a managed care environment but without realizing integration and cooperation between hospital and physicians. Therefore, we argue that these studies fail to shed light on the impact of risk shifting on the hospital–physician relationship accurately.

  2. Provider accountability as a driving force towards physician–hospital integration: a systematic review

    Directory of Open Access Journals (Sweden)

    Jeroen Trybou

    2015-04-01

    Full Text Available Background: Hospitals and physicians lie at the heart of our health care delivery system. In general, physicians provide medical care and hospitals the resources to deliver health care. In the past two decades many countries have adopted reforms in which provider financial risk bearing is increased. By making providers financially accountable for the delivered care integrated care delivery is stimulated.Purpose: To assess the evidence base supporting the relationship between provider financial risk bearing and physician–hospital integration and to identify the different types of methods used to measure physician–hospital integration to evaluate the functional value of these integrative models.Results: Nine studies met the inclusion criteria. The evidence base is mixed and inconclusive. Our methodological analysis of previous research shows that previous studies have largely focused on the formal structures of physician–hospital arrangements as an indicator of physician–hospital integration.Conclusion: The link between provider financial risk bearing and physician–hospital integration can at this time be supported merely on the basis of theoretical insights of agency theory rather than empirical research. Physician–hospital integration measurement has concentrated on the prevalence of contracting vehicles that enables joint bargaining in a managed care environment but without realizing integration and cooperation between hospital and physicians. Therefore, we argue that these studies fail to shed light on the impact of risk shifting on the hospital–physician relationship accurately.

  3. Use of force plate analysis to compare the analgesic effects of intravenous administration of phenylbutazone and flunixin meglumine in horses with navicular syndrome.

    Science.gov (United States)

    Erkert, Ronald S; MacAllister, Charles G; Payton, Mark E; Clarke, Cyril R

    2005-02-01

    To use force plate analysis to evaluate the analgesic efficacies of flunixin meglumine and phenylbutazone administered i.v. at typical clinical doses in horses with navicular syndrome. 12 horses with navicular syndrome that were otherwise clinically normal. Horses received flunixin (1.1 mg/kg), phenylbutazone (4.4 mg/kg), or physiologic saline (0.9% NaCI; 1 mL/45 kg) solution administered IV once daily for 4 days with a 14-day washout period between treatments (3 treatments/horse). Before beginning treatment (baseline) and 6, 12, 24, and 30 hours after the fourth dose of each treatment, horses were evaluated by use of the American Association of Equine Practitioners lameness scoring system (half scores permitted) and peak vertical force of the forelimbs was measured via a force plate. At 6, 12, and 24 hours after the fourth treatment, subjective lameness evaluations and force plate data indicated significant improvement in lameness from baseline values in horses treated with flunixin or phenylbutazone, compared with control horses; at those time points, the assessed variables in flunixin- or phenylbutazone-treated horses were not significantly different. In horses with navicular syndrome treated once daily for 4 days, typical clinical doses of flunixin and phenylbutazone resulted in similar significant improvement in lameness at 6, 12, and 24 hours after the final dose, compared with findings in horses treated with saline solution. The effect of flunixin or phenylbutazone was maintained for at least 24 hours. Flunixin meglumine and phenylbutazone appear to have similar analgesic effects in horses with navicular syndrome.

  4. Supercritical CO2 assisted electroless plating on polypropylene substrate-effect of injection speed on adhesive force of metal to polymer

    Science.gov (United States)

    Ohshima, Masahiro; Tsubouchi, Kensuke; Ishihara, Shota; Hikima, Yuta; Tengsuwan, Siwach

    2016-03-01

    The aqueous plating solution cannot be diffused into a plain polypropylene (PP) substrate and consequently Ni-P metal layer cannot be formed by electroless plating on the PP substrate with a satisfied degree of adhesive force unless the hydrophilicity of the substrate surface was increased. A block copolymer PP-b-polyethylene oxide (PP-b-PEO) was used to increase the hydrophilicity of the surface and the adhesive force of the metal layer to the satisfactory level. Our previous study showed the morphology of PP-b-PEO domain near the surface of substrate strongly affected the adhesiveness of the metal layer to the substrate. The degrees of elongation and orientation of the PP-b-PEO domains in PP matrix were the key factors of determining the thickness of the metal-PP composite layer and the resulting adhesive strength. In this study, the effect of injection molding condition on the degrees of elongation and orientation was investigated: PP/PP-b-PEO blend substrates were prepared by injection molding at different injection speed. The higher injection speed increased the degrees of elongation and orientation of copolymer and formed multilayered structure of the copolymer domains. It could produce the electroless plating PP substrate with the higher adhesive strength of the Ni-P metal layer to the PP substrate.

  5. Approach to Deep Plate Loading Test of Self-reaction Force Method%自反力法深层平板载荷试验探讨

    Institute of Scientific and Technical Information of China (English)

    王晓伟; 林泽耿; 刘炳凯

    2014-01-01

    This article took a project of Guangdong as an example, introduced the technique of deep plate loading test of self-reaction force method in detail,and compared with the traditional method of deep plate loading test,and finally,problems that need to pay attention to deep plate loading test of self-reaction force method were put forward from the processing technology at the bottom of testing hole,keeping test hole straight,keeping stability of hole wall,and so on.%以广东某工程为例,详细介绍采用自反力法进行深层平板载荷试验测试技术,并将该方法与传统法深层平板载荷试验进行比较,最后从测试孔的孔底处理技术、测孔保直、孔壁稳定等方面提出采用自反力法进行深层平板载荷试验需要注意的问题。

  6. The Operational Preparedness of United States Air Force Certified Registered Nurse Anesthetists to Provide Trauma Anesthesia

    Science.gov (United States)

    1999-10-01

    deployed in field hospitals and must be well versed in the management of trauma (Bellamy, 1995 ). To this end, the anesthesia provider needs to be trained...result of aggression encountered during peacekeeping missions such as those recently undertaken. Bellamy ( 1995 ) has shown that ninety percent of combat...Flavel, Brown, Schon, Spiro and Vygotsky . In this model, McAulife states that the best way to learn and instruct others is by a method of case based

  7. Similarity Solution for Combined Free-Forced Convection Past a Vertical Porous Plate in a Porous Medium with a Convective Surface Boundary Condition

    Directory of Open Access Journals (Sweden)

    Garg P.

    2016-12-01

    Full Text Available This paper studies the mathematical implications of the two dimensional viscous steady laminar combined free-forced convective flow of an incompressible fluid over a semi infinite fixed vertical porous plate embedded in a porous medium. It is assumed that the left surface of the plate is heated by convection from a hot fluid which is at a temperature higher than the temperature of the fluid on the right surface of the vertical plate. To achieve numerical consistency for the problem under consideration, the governing non linear partial differential equations are first transformed into a system of ordinary differential equations using a similarity variable and then solved numerically under conditions admitting similarity solutions. The effects of the physical parameters of both the incompressible fluid and the vertical plate on the dimensionless velocity and temperature profiles are studied and analysed and the results are depicted both graphically and in a tabular form. Finally, algebraic expressions and the numerical values are obtained for the local skin-friction coefficient and the local Nusselt number.

  8. The Homogeneus Forcing of Mercury Oxidation to provide Low-Cost Capture

    Energy Technology Data Exchange (ETDEWEB)

    John Kramlich; Linda Castiglone

    2007-06-30

    Trace amounts of mercury are found in all coals. During combustion, or during thermal treatment in advanced coal processes, this mercury is vaporized and can be released to the atmosphere with the ultimate combustion products. This has been a cause for concern for a number of years, and has resulted in a determination by the EPA to regulate and control these emissions. Present technology does not, however, provide inexpensive ways to capture or remove mercury. Mercury that exits the furnace in the oxidized form (HgCl{sub 2}) is known to much more easily captured in existing pollution control equipment (e.g., wet scrubbers for SO{sub 2}), principally due to its high solubility in water. Work funded by DOE has helped understand the chemical kinetic processes that lead to mercury oxidation in furnaces. The scenario is as follows. In the flame the mercury is quantitatively vaporized as elemental mercury. Also, the chlorine in the fuel is released as HCl. The direct reaction Hg+HCl is, however, far too slow to be of practical consequence in oxidation. The high temperature region does supports a small concentration of atomic chlorine. As the gases cool (either in the furnace convective passes, in the quench prior to cold gas cleanup, or within a sample probe), the decay in Cl atom is constrained by the slowness of the principal recombination reaction, Cl+Cl+M{yields}Cl{sub 2}+M. This allows chlorine atom to hold a temporary, local superequilibrium concentration . Once the gases drop below about 550 C, the mercury equilibrium shifts to favor HgCl{sub 2} over Hg, and this superequilibrium chlorine atom promotes oxidation via the fast reactions Hg+Cl+M{yields}HgCl+M, HgCl+Cl+M{yields}HgCl{sub 2}+M, and HgCl+Cl{sub 2}{yields}HgCl{sub 2}+Cl. Thus, the high temperature region provides the Cl needed for the reaction, while the quench region allows the Cl to persist and oxidize the mercury in the absence of decomposition reactions that would destroy the HgCl{sub 2}. Promoting

  9. The Homogeneous Forcing of Mercury Oxidation to Provide Low-Cost Capture

    Energy Technology Data Exchange (ETDEWEB)

    John C. Kramlich; Linda Castiglone

    2006-04-01

    to extrapolate the findings to nonisothermal conditions typical of boiler environments. This would provide guidance on where to inject the oxidation promoters in a practical boiler, and how much promoter is required.

  10. Development and Demonstration of a Device to Determine Thrust by Measuring the Force on a Target Plate in the Exhaust of a Plasma Thruster

    Science.gov (United States)

    Chavers, Greg; Chang-Diaz, Franklin

    2004-01-01

    A device has been developed to measure the force on a target plate by an impacting beam of charged and neutral particles. This device, an impact thrust stand, was developed to allow thrusters at low TRL, levels to be easily tested without the expense of developing a flight prototype of the thruster to be placed on a conventional thrust stand. The impact thrust stand was developed for the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) but has been tested and calibrated using several devices including Hall thrusters. The calibration and comparison of the impact thrust stand against conventional thrust stands will be discussed in this paper.

  11. Unsteady forced and free convective MHD flow past an infinite vertical porous plate with constant suction and oscillatory wall temperature

    Energy Technology Data Exchange (ETDEWEB)

    Soundalgekar, V.M. (Indian Inst. of Technology, Bombay); Shende, S.R. (Walchand Coll. of Engineering, Sangli, India)

    1980-01-01

    A two-dimensional unsteady flow of a viscous, incompressible, electrically conducting fluid past an infinite vertical porous plate has been carried out under the following conditions: (1) constant suction at the plate; (2) the wall temperature oscillating in time about a non-zero mean; (3) constant free-stream; and (4) transversely applied uniform magnetic field. Approximate solutions to coupled non-linear equations governing the flow have been derived for the transient velocity, the transient temperature, the amplitude and phase of the skin friction and the rate of heat transfer. The velocity and the temperature have been shown on graphs and the numerical values of the amplitude and phase are entered in tables. It has been observed that the amplitude of the skin friction and the rate of heat transfer decrease due to the application of the transverse magnetic field, but increase due to increasing the Grashof number.

  12. Efficacy of a trunk orthosis with joints providing resistive force on low-back load in elderly persons during static standing

    Directory of Open Access Journals (Sweden)

    Katsuhira J

    2015-09-01

    Full Text Available Junji Katsuhira,1 Ko Matsudaira,2 Tadashi Yasui,3 Shinno Iijima,4 Akihiro Ito4 1Department of Nursing and Rehabilitation Science at Odawara, International University of Health and Welfare, Odawara, Kanagawa, 2Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical and Research Center, The University of Tokyo, Tokyo, 3Kawamura-Gishi Company, Ltd., Daito-shi, Osaka, 4Graduate School of International University of Health and Welfare, Otawara, Tochigi, Japan Purpose: Postural alignment of elderly people becomes poor due to aging, possibly leading to low-back pain and spinal deformity. Although there are several interventions for treating these conditions, no previous study has reported the effectiveness of a spinal orthosis or lumbosacral orthosis (LSO in healthy elderly people without specific spinal deformity. We therefore developed a trunk orthosis to decrease low-back muscle activity while training good postural alignment through resistive force provided by joints with springs (here, called the ORF, which stands for orthosis with joints providing resistive force as a preventive method against abnormal posture and low-back pain in healthy elderly persons. Patients and methods: Fifteen community-dwelling elderly men participated in this study. Participants stood freely for 10 seconds in a laboratory setting under three conditions: without an orthosis, with the ORF, and with an LSO. The Damen corset LSO was selected as it is frequently prescribed for patients with low-back pain. Postural alignment during static standing was recorded using a three-dimensional motion capture system employing infrared cameras. Two force plates were used to record center of pressure. Electromyograms were obtained for bilateral erector spinae (ES, left internal abdominal oblique, and right gluteus medius muscles. Results: Pelvis forward tilt angle tended to increase while wearing the ORF and decrease while wearing the LSO, but these

  13. A numerical analysis of forces exerted by laminar flow on spreading cells in a parallel plate flow chamber assay.

    Science.gov (United States)

    Olivier, L A; Truskey, G A

    1993-10-01

    Exposure of spreading anchorage-dependent cells to laminar flow is a common technique to measure the strength of cell adhesion. Since cells protrude into the flow stream, the force exerted by the fluid on the cells is a function of cell shape. To assess the relationship between cell shape and the hydrodynamic force on adherent cells, we obtained numerical solutions of the velocity and stress fields around bovine aortic endothelial cells during various stages of spreading and calculated the force required to detach the cells. Morphometric parameters were obtained from light and scanning electron microscopy measurements. Cells were assumed to have a constant volume, but the surface area increased during spreading until the membrane was stretched taut. Two-dimensional models of steady flow were generated using the software packages ANSYS (mesh generation) and FIDAP (problem solution). The validity of the numerical results was tested by comparison with published results for a semicircle in contact with the surface. The drag force and torque were greatest for round cells making initial contact with the surface. During spreading, the drag force and torque declined by factors of 2 and 20, respectively. The calculated forces and moments were used in adhesion models to predict the wall shear stress at which the cells detached. Based upon published values for the bond force and receptor number, round cells should detach at shear stresses between 2.5 and 6 dyn/cm(2), whereas substantially higher stresses are needed to detach spreading and fully spread cells. Results from the simulations indicate that (1) the drag force varies little with cell shape whereas the torque is very sensitive to cell shape, and (2) the increase in the strength of adhesion during spreading is due to increased contact area and receptor densities within the contact area.

  14. Influence of inclined Lorentz force on micropolar fluids in a square cavity with uniform and nonuniform heated thin plate

    Science.gov (United States)

    Periyadurai, K.; Muthtamilselvan, M.; Doh, Deog-Hee

    2016-12-01

    In the present study, the effect of inclined magnetic field on natural convection of micro-polar fluid in a square cavity with uniform and nonuniform heated thin plate built in centrally is investigated numerically. The vertical walls are cooled while the top and bottom walls are insulated. The thin plate is assumed to be isothermal with a linearly varying temperature. The governing equations were solved by finite volume method using second order central difference scheme and upwind differencing scheme. The numerical investigation is carried out for different governing parameters namely, the Hartmann number, inclination angle of magnetic field, Rayleigh number, vortex viscosity and source non-uniformity parameters. The result shows that the heat transfer rate is decreased when increasing Hartmann number, inclination angle of magnetic field and vortex viscosity parameter. It is found that the non-uniformity parameter affects the fluid flow and temperature distribution especially for the high Rayleigh numbers. Finally, the overall heat transfer rate of micro-polar fluids is found to be smaller than that of Newtonian fluid.

  15. Reliability and Validity of Kinetic and Kinematic Parameters Determined With Force Plates Embedded Under Soil-Filled Baseball Mound.

    Science.gov (United States)

    Yanai, Toshimasa; Matsuo, Akifumi; Maeda, Akira; Nakamoto, Hiroki; Mizutani, Mirai; Kanehisa, Hiroaki; Fukunaga, Tetsuo

    2017-01-13

    We developed a force measurement system in a soil-filled mound for measuring ground reaction forces (GRFs) acting on baseball pitchers and examined the reliability and validity of kinetic and kinematic parameters determined from the GRFs. Three soil-filled trays of dimensions that satisfied the official baseball rules were fixed onto three force platforms. Eight collegiate pitchers wearing baseball shoes with metal cleats were asked to throw 5 fastballs with maximum effort from the mound toward a catcher. The reliability of each parameter was determined for each subject as the coefficient of variation across the 5 pitches. The validity of the measurements was tested by comparing the outcomes either with the true values or the corresponding values computed from a motion capture system. The coefficients of variation in the repeated measurements of the peak forces ranged from 0.00 to 0.17, and were smaller for the pivot foot than the stride foot. The mean absolute errors in the impulses determined over entire duration of pitching motion were 5.3 N·s, 1.9 N·s, and 8.2 N·s for the X-, Y-, and Z-directions, respectively. These results suggest that the present method is reliable and valid for determining selected kinetic and kinematic parameters for analyzing pitching performance.

  16. Providing haptic feedback in robot-assisted minimally invasive surgery: a direct optical force-sensing solution for haptic rendering of deformable bodies.

    Science.gov (United States)

    Ehrampoosh, Shervin; Dave, Mohit; Kia, Michael A; Rablau, Corneliu; Zadeh, Mehrdad H

    2013-01-01

    This paper presents an enhanced haptic-enabled master-slave teleoperation system which can be used to provide force feedback to surgeons in minimally invasive surgery (MIS). One of the research goals was to develop a combined-control architecture framework that included both direct force reflection (DFR) and position-error-based (PEB) control strategies. To achieve this goal, it was essential to measure accurately the direct contact forces between deformable bodies and a robotic tool tip. To measure the forces at a surgical tool tip and enhance the performance of the teleoperation system, an optical force sensor was designed, prototyped, and added to a robot manipulator. The enhanced teleoperation architecture was formulated by developing mathematical models for the optical force sensor, the extended slave robot manipulator, and the combined-control strategy. Human factor studies were also conducted to (a) examine experimentally the performance of the enhanced teleoperation system with the optical force sensor, and (b) study human haptic perception during the identification of remote object deformability. The first experiment was carried out to discriminate deformability of objects when human subjects were in direct contact with deformable objects by means of a laparoscopic tool. The control parameters were then tuned based on the results of this experiment using a gain-scheduling method. The second experiment was conducted to study the effectiveness of the force feedback provided through the enhanced teleoperation system. The results show that the force feedback increased the ability of subjects to correctly identify materials of different deformable types. In addition, the virtual force feedback provided by the teleoperation system comes close to the real force feedback experienced in direct MIS. The experimental results provide design guidelines for choosing and validating the control architecture and the optical force sensor.

  17. Thermodynamic energy exchange in a moving plate capacitor.

    Science.gov (United States)

    Davis, B. R.; Abbott, D.; Parrondo, J. M. R.

    2001-09-01

    In this paper we describe an apparent paradox concerning a moving plate capacitor driven by thermal noise from a resistor. The plates are attracted together, but a demon restores the plates of the capacitor to their original position when the voltage across the capacitor is small-hence only small forces are present for the demon to work against. The demon has to work harder than this to avoid the situation of perpetual motion, but the open question is how? This is unsolved, however we explore the concept of a moving plate capacitor by examining the case where it is still excited by thermal noise, but where the restoring force on the capacitor plates is provided by a simple spring rather than some unknown demon. We display simulation results with interesting behavior, particularly where the capacitor plates collide with each other. (c) 2001 American Institute of Physics.

  18. Interplay between geometry and temperature for inclined Casimir plates

    CERN Document Server

    Weber, Alexej

    2009-01-01

    We provide further evidence for the nontrivial interplay between geometry and temperature in the Casimir effect. We investigate the temperature dependence of the Casimir force between an inclined semi-infinite plate above an infinite plate in D dimensions using the worldline formalism. Whereas the high-temperature behavior is always found to be linear in T in accordance with dimensional-reduction arguments, different power-law behaviors at small temperatures emerge. Unlike the case of infinite parallel plates, which shows the well-known T^D behavior of the force, we find a T^{D-1} behavior for inclined plates, and a ~T^{D-0.3} behavior for the edge effect in the limit where the plates become parallel. The strongest temperature dependence ~T^{D-2} occurs for the Casimir torque of inclined plates. Numerical as well as analytical worldline results are presented.

  19. Thermodynamic energy exchange in a moving plate capacitor

    Science.gov (United States)

    Davis, B. R.; Abbott, D.; Parrondo, J. M. R.

    2001-09-01

    In this paper we describe an apparent paradox concerning a moving plate capacitor driven by thermal noise from a resistor. The plates are attracted together, but a demon restores the plates of the capacitor to their original position when the voltage across the capacitor is small—hence only small forces are present for the demon to work against. The demon has to work harder than this to avoid the situation of perpetual motion, but the open question is how? This is unsolved, however we explore the concept of a moving plate capacitor by examining the case where it is still excited by thermal noise, but where the restoring force on the capacitor plates is provided by a simple spring rather than some unknown demon. We display simulation results with interesting behavior, particularly where the capacitor plates collide with each other.

  20. A forced damped oscillation framework for undulatory swimming provides new insights into how propulsion arises in active and passive swimming.

    Directory of Open Access Journals (Sweden)

    Amneet Pal Singh Bhalla

    Full Text Available A fundamental issue in locomotion is to understand how muscle forcing produces apparently complex deformation kinematics leading to movement of animals like undulatory swimmers. The question of whether complicated muscle forcing is required to create the observed deformation kinematics is central to the understanding of how animals control movement. In this work, a forced damped oscillation framework is applied to a chain-link model for undulatory swimming to understand how forcing leads to deformation and movement. A unified understanding of swimming, caused by muscle contractions ("active" swimming or by forces imparted by the surrounding fluid ("passive" swimming, is obtained. We show that the forcing triggers the first few deformation modes of the body, which in turn cause the translational motion. We show that relatively simple forcing patterns can trigger seemingly complex deformation kinematics that lead to movement. For given muscle activation, the forcing frequency relative to the natural frequency of the damped oscillator is important for the emergent deformation characteristics of the body. The proposed approach also leads to a qualitative understanding of optimal deformation kinematics for fast swimming. These results, based on a chain-link model of swimming, are confirmed by fully resolved computational fluid dynamics (CFD simulations. Prior results from the literature on the optimal value of stiffness for maximum speed are explained.

  1. A forced damped oscillation framework for undulatory swimming provides new insights into how propulsion arises in active and passive swimming.

    Science.gov (United States)

    Bhalla, Amneet Pal Singh; Griffith, Boyce E; Patankar, Neelesh A

    2013-01-01

    A fundamental issue in locomotion is to understand how muscle forcing produces apparently complex deformation kinematics leading to movement of animals like undulatory swimmers. The question of whether complicated muscle forcing is required to create the observed deformation kinematics is central to the understanding of how animals control movement. In this work, a forced damped oscillation framework is applied to a chain-link model for undulatory swimming to understand how forcing leads to deformation and movement. A unified understanding of swimming, caused by muscle contractions ("active" swimming) or by forces imparted by the surrounding fluid ("passive" swimming), is obtained. We show that the forcing triggers the first few deformation modes of the body, which in turn cause the translational motion. We show that relatively simple forcing patterns can trigger seemingly complex deformation kinematics that lead to movement. For given muscle activation, the forcing frequency relative to the natural frequency of the damped oscillator is important for the emergent deformation characteristics of the body. The proposed approach also leads to a qualitative understanding of optimal deformation kinematics for fast swimming. These results, based on a chain-link model of swimming, are confirmed by fully resolved computational fluid dynamics (CFD) simulations. Prior results from the literature on the optimal value of stiffness for maximum speed are explained.

  2. A Forced Damped Oscillation Framework for Undulatory Swimming Provides New Insights into How Propulsion Arises in Active and Passive Swimming

    Science.gov (United States)

    Bhalla, Amneet Pal Singh; Griffith, Boyce E.; Patankar, Neelesh A.

    2013-01-01

    A fundamental issue in locomotion is to understand how muscle forcing produces apparently complex deformation kinematics leading to movement of animals like undulatory swimmers. The question of whether complicated muscle forcing is required to create the observed deformation kinematics is central to the understanding of how animals control movement. In this work, a forced damped oscillation framework is applied to a chain-link model for undulatory swimming to understand how forcing leads to deformation and movement. A unified understanding of swimming, caused by muscle contractions (“active” swimming) or by forces imparted by the surrounding fluid (“passive” swimming), is obtained. We show that the forcing triggers the first few deformation modes of the body, which in turn cause the translational motion. We show that relatively simple forcing patterns can trigger seemingly complex deformation kinematics that lead to movement. For given muscle activation, the forcing frequency relative to the natural frequency of the damped oscillator is important for the emergent deformation characteristics of the body. The proposed approach also leads to a qualitative understanding of optimal deformation kinematics for fast swimming. These results, based on a chain-link model of swimming, are confirmed by fully resolved computational fluid dynamics (CFD) simulations. Prior results from the literature on the optimal value of stiffness for maximum speed are explained. PMID:23785272

  3. A NUMERICAL STUDY OF FORCED CONVECTION HEAT TRANSFER OVER A SERIES OF FLAT TUBES BETWEEN PARALLEL PLATES

    Directory of Open Access Journals (Sweden)

    M.M. Rahman

    2012-12-01

    Full Text Available This paper presents the numerical study on two-dimensional forced convection heat transfer across three in-line flat tubes confined in a channel under incompressible, steady-state conditions. This system is solved in body-fitted coordinates (BFC using the finite volume method (FVM. The constant heat flux is imposed on the surface of the tubes as the thermal boundary conditions. The range of the longitudinal pitch-to-diameter ratio (SL/Ds of 2.0–4.0 is considered, the Reynolds number varies within the range 25–300, and the Prandtl number is taken as 0.7. The temperature contours, local Nusselt number distributions at the tube surface and mean Nusselt number were analyzed. The strength of the heat transfer between the surface of the tubes and the air flow increases with an increase in Reynolds number and pitch-to-diameter ratio.

  4. Propulsive performance of a passively flapping plate in a uniform flow

    Institute of Scientific and Technical Information of China (English)

    韩瑞; 张杰; 曹垒; 陆夕云

    2015-01-01

    Propulsive performance of a passively flapping plate in a uniform viscous flow has been studied numerically by means of a multiblock lattice Boltzmann method. The passively flapping plate is modeled by a rigid plate with a torsion spring acting about the pivot at the leading-edge of the plate, which is called a lumped-torsional-flexibility model. When the leading-edge is forced to take a vertical oscillation, the plate pitches passively due to the fluid-plate interaction. Based on our numerical simulations, various fundamental mechanisms dictating the propulsive performance, including the forces on the plate, power consumption, propulsive efficiency and vortical structures, have been studied. It is found that the torsional flexibility of the passively pitching plate can improve the propulsive performance. The results obtained in this study provide some physical insights into the understanding of the propulsive behaviors of swimming and flying animals.

  5. Abrupt plate accelerations shape rifted continental margins

    Science.gov (United States)

    Brune, Sascha; Williams, Simon E.; Butterworth, Nathaniel P.; Müller, R. Dietmar

    2016-08-01

    Rifted margins are formed by persistent stretching of continental lithosphere until breakup is achieved. It is well known that strain-rate-dependent processes control rift evolution, yet quantified extension histories of Earth’s major passive margins have become available only recently. Here we investigate rift kinematics globally by applying a new geotectonic analysis technique to revised global plate reconstructions. We find that rifted margins feature an initial, slow rift phase (less than ten millimetres per year, full rate) and that an abrupt increase of plate divergence introduces a fast rift phase. Plate acceleration takes place before continental rupture and considerable margin area is created during each phase. We reproduce the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The extension models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength-velocity feedback, which can be robustly inferred for diverse lithosphere configurations and rheologies. Our results explain differences between proximal and distal margin areas and demonstrate that abrupt plate acceleration during continental rifting is controlled by the nonlinear decay of the resistive rift strength force. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time.

  6. Abrupt plate accelerations shape rifted continental margins.

    Science.gov (United States)

    Brune, Sascha; Williams, Simon E; Butterworth, Nathaniel P; Müller, R Dietmar

    2016-08-11

    Rifted margins are formed by persistent stretching of continental lithosphere until breakup is achieved. It is well known that strain-rate-dependent processes control rift evolution, yet quantified extension histories of Earth's major passive margins have become available only recently. Here we investigate rift kinematics globally by applying a new geotectonic analysis technique to revised global plate reconstructions. We find that rifted margins feature an initial, slow rift phase (less than ten millimetres per year, full rate) and that an abrupt increase of plate divergence introduces a fast rift phase. Plate acceleration takes place before continental rupture and considerable margin area is created during each phase. We reproduce the rapid transition from slow to fast extension using analytical and numerical modelling with constant force boundary conditions. The extension models suggest that the two-phase velocity behaviour is caused by a rift-intrinsic strength--velocity feedback, which can be robustly inferred for diverse lithosphere configurations and rheologies. Our results explain differences between proximal and distal margin areas and demonstrate that abrupt plate acceleration during continental rifting is controlled by the nonlinear decay of the resistive rift strength force. This mechanism provides an explanation for several previously unexplained rapid absolute plate motion changes, offering new insights into the balance of plate driving forces through time.

  7. Multi-state Beef Reproduction Task Force provides science-based recommendations for the application of reproductive technologies.

    Science.gov (United States)

    Johnson, S K; Funston, R N; Hall, J B; Kesler, D J; Lamb, G C; Lauderdale, J W; Patterson, D J; Perry, G A; Strohbehn, D R

    2011-09-01

    Since its formation, the Beef Reproduction Task Force (BRTF) has worked to enhance productivity and profitability of US beef herds by integrating research and extension efforts with the intent of more effectively transferring the use of reproductive technologies to the field. A key early step was to coordinate efforts in identifying effective breeding management protocols for beef cattle and to clarify their associated acronyms. A short list of recommended protocols and their acronyms for synchronization of estrus and ovulation in beef cattle was developed based on results from peer-reviewed, published research and a comprehensive review of data collected from the field. The list of recommended protocols was developed by the BRTF in cooperation with veterinarians and cattle AI industries. These protocols and their acronyms are presented uniformly in all of the major AI sire directories and are available online at http://www.beefrepro.info. Protocol updates are made annually to incorporate the most recent research findings related to estrous cycle control in beef cattle. The Estrus Synchronization Planner, a software program developed in cooperation with the Iowa Beef Center, now reflects these same recommendations. Beginning in 2002, the BRTF hosted and presented 11 educational workshops to more than 1,900 attendees in key cow-calf states. These Applied Reproductive Strategies in Beef Cattle workshops targeted beef producers, AI industry personnel, veterinarians, allied industry representatives, and academicians. A national media sponsor provided online coverage of the last 3 workshops at http://www.appliedreprostrategies.com. A postmeeting evaluation, developed to assess application of information from 2 recent workshops, was returned by 55% of those contacted (n = 150). Attendees averaged 16 (± 13.4 SD) yr of AI experience, and 80% of respondents represented more than 100 cows. Respondents were asked to estimate the value of AI-sired calves compared with natural

  8. Plate Tearing by a Cone

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1997-01-01

    The present paper is concerned with steady-state plate tearing by a cone. This is a scenario where a cone is forced through a ductile metal plate with a constant lateral tip penetration in a motion in the plane of the plate. The considered process could be an idealisaton of the damage, which...

  9. Plate Tearing by a Cone

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    1998-01-01

    The present paper is concerned with steady-state plate tearing by a cone. This is a scenario where a cone is forced through a ductile metal plate with a constant lateral tip penetration in a motion in the plane of the plate. The considered process could be an idealisation of the damage, which...

  10. How mantle slabs drive plate tectonics.

    Science.gov (United States)

    Conrad, Clinton P; Lithgow-Bertelloni, Carolina

    2002-10-04

    The gravitational pull of subducted slabs is thought to drive the motions of Earth's tectonic plates, but the coupling between slabs and plates is not well established. If a slab is mechanically attached to a subducting plate, it can exert a direct pull on the plate. Alternatively, a detached slab may drive a plate by exciting flow in the mantle that exerts a shear traction on the base of the plate. From the geologic history of subduction, we estimated the relative importance of "pull" versus "suction" for the present-day plates. Observed plate motions are best predicted if slabs in the upper mantle are attached to plates and generate slab pull forces that account for about half of the total driving force on plates. Slabs in the lower mantle are supported by viscous mantle forces and drive plates through slab suction.

  11. Right-but not left-paw use in female rats provides advantage in forced swim tests.

    Science.gov (United States)

    Soyman, Efe; Tunckol, Elcin; Lacin, Emre; Canbeyli, Resit

    2015-10-15

    Left- and right-pawed adult female Wistar rats were subjected to forced swimming on two consecutive days. Compared to the right-pawed group, left- pawed rats displayed significantly increased immobility from the first to the second swim test and remained significantly more immobile in the second swim test. Both groups performed similarly in spatial learning in the Morris water maze suggesting that left- pawed rats are differentially and specifically susceptible to depressogenic treatment.

  12. Obliquity along plate boundaries

    Science.gov (United States)

    Philippon, Mélody; Corti, Giacomo

    2016-12-01

    Most of the plate boundaries are activated obliquely with respect to the direction of far field stresses, as roughly only 8% of the plate boundaries total length shows a very low obliquity (ranging from 0 to 10°, sub-orthogonal to the plate displacement). The obliquity along plate boundaries is controlled by (i) lateral rheological variations within the lithosphere and (ii) consistency with the global plate circuit. Indeed, plate tectonics and magmatism drive rheological changes within the lithosphere and consequently influence strain localization. Geodynamical evolution controls large-scale mantle convection and plate formation, consumption, and re-organization, thus triggering plate kinematics variations, and the adjustment and re-orientation of far field stresses. These geological processes may thus result in plate boundaries that are not perpendicular but oblique to the direction of far field stresses. This paper reviews the global patterns of obliquity along plate boundaries. Using GPlate, we provide a statistical analysis of present-day obliquity along plate boundaries. Within this framework, by comparing natural examples and geological models, we discuss deformation patterns and kinematics recorded along oblique plate boundaries.

  13. Acute high-grade acromioclavicular joint injuries treatment: Arthroscopic non-rigid coracoclavicular fixation provides better quality of life outcomes than hook plate ORIF.

    Science.gov (United States)

    Natera-Cisneros, L; Sarasquete-Reiriz, J; Escolà-Benet, A; Rodriguez-Miralles, J

    2016-02-01

    Treatment of acute high-grade acromioclavicular joint (ACJ) injuries with metal hardware alters the biomechanics of the ACJ, implying a second surgery for hardware removal. The period during which the plate is present involves functional limitations, pain and a risk factor for the development of hardware-related-injuries. Arthroscopy-assisted procedures compared to open-metal hardware techniques offer: less morbidity, the possibility to treat associated lesions and no need for a second operation. The aim was to compare the Quality of life (QoL) of patients with acute high-grade ACJ injuries (Rockwood grade III-V), managed arthroscopically with a non-rigid coracoclavicular (CC) fixation versus the QoL of patients managed with a hook plate, 24 months or more after their shoulder injury. A retrospective revision of high-grade ACJ injuries managed in three institutions was performed. Patients treated by means of an arthroscopy-assisted CC fixation or by means of a hook plate were included. The inclusion period was between 2008 and 2012. The QoL was evaluated at the last follow-up visit by means of the SF36, the visual analog scale (VAS), the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, the Constant score and the global satisfaction (scale from 0 to 10). The presence of scapular dyskinesis and remaining vertical instability were evaluated. Comparison between groups was performed. Thirty-one patients were included: 20 arthroscopy-group (ARTH group: 3 Rockwood III, 3 IV and 14 V) and 11 hook plate-group (HOOK group: 5 Rockwood III and 6 V). The mean age was 36 [25-52] year-old for the ARTH group and 41 [19-55] for the HOOK group (P=0.185). The mean results of the questionnaires were: (1) physical SF36 score (ARTH group 58.24±2.16 and HOOK group 53.70±4.33, P<0.001); (2) mental SF36 score (ARTH group 56.15±2.21 and HOOK group 53.06±6.10, P=0.049); (3) VAS (ARTH group 0.40±0.50 and HOOK group 1.45±1.51, P=0.007); (4) DASH (ARTH group 2.98±2.03 and

  14. Review and Response to the Final Report of the National Black Health Providers Task Force on High Blood Pressure Education and Control.

    Science.gov (United States)

    Public Health Service (DHHS), Rockville, MD.

    This report presents the National Heart, Lung, and Blood Institute's (NHLBI) review of and response to the final report of the National Black Health Providers Task Force on High Blood Pressure Education and Control. The response includes a statement of NHLBI's involvement in health research, and descriptions of what steps can be taken to solve the…

  15. Dialysis purification of integrase-DNA complexes provides high-resolution atomic force microscopy images: dimeric recombinant HIV-1 integrase binding and specific looping on DNA.

    Directory of Open Access Journals (Sweden)

    Tatsuaki Tsuruyama

    Full Text Available It remains difficult to obtain high-resolution atomic force microscopy images of HIV-1 integrase bound to DNA in a dimeric or tetrameric fashion. We therefore constructed specific target DNAs to assess HIV-1 integrase binding and purified the complex by dialysis prior to analysis. Our resulting atomic force microscopy analyses indicated precise size of binding human immunodeficiency virus type 1 (HIV-1 recombinant integrase in a tetrameric manner, inducing formation of a loop-like or figure-eight-like secondary structure in the target DNA. Our findings regarding the target DNA secondary structure provide new insights into the intermediate states of retroviral integration.

  16. Dialysis purification of integrase-DNA complexes provides high-resolution atomic force microscopy images: dimeric recombinant HIV-1 integrase binding and specific looping on DNA.

    Science.gov (United States)

    Tsuruyama, Tatsuaki; Nakai, Tonau; Ohmori, Rei; Ozeki, Munetaka; Tamaki, Keiji; Yoshikawa, Kenichi

    2013-01-01

    It remains difficult to obtain high-resolution atomic force microscopy images of HIV-1 integrase bound to DNA in a dimeric or tetrameric fashion. We therefore constructed specific target DNAs to assess HIV-1 integrase binding and purified the complex by dialysis prior to analysis. Our resulting atomic force microscopy analyses indicated precise size of binding human immunodeficiency virus type 1 (HIV-1) recombinant integrase in a tetrameric manner, inducing formation of a loop-like or figure-eight-like secondary structure in the target DNA. Our findings regarding the target DNA secondary structure provide new insights into the intermediate states of retroviral integration.

  17. Horizontal versus vertical plate motions

    Directory of Open Access Journals (Sweden)

    M. Cuffaro

    2006-07-01

    Full Text Available We review both present and past motions at major plate boundaries, which have the horizontal component in average 10 to 100 times faster (10–100 mm/yr than the vertical component (0.01–1 mm/yr in all geodynamic settings. The steady faster horizontal velocity of the lithosphere with respect to the upward or downward velocities at plate boundaries supports dominating tangential forces acting on plates. This suggests a passive role of plate boundaries with respect to far field forces determining the velocity of plates. The forces acting on the lithosphere can be subdivided in coupled and uncoupled, as a function of the shear at the lithosphere base. Higher the asthenosphere viscosity, more significant should be the coupled forces, i.e., the mantle drag and the trench suction. Lower the asthenosphere viscosity, more the effects of uncoupled forces might result determinant, i.e., the ridge push, the slab pull and the tidal drag. Although a combination of all forces acting on the lithosphere is likely, the decoupling between lithosphere and mantle suggests that a torque acts on the lithosphere independently of the mantle drag. Slab pull and ridge push are candidates for generating this torque, but, unlike these boundary forces, the advantage of the tidal drag is to be a volume force, acting simultaneously on the whole plates, and being the decoupling at the lithosphere base controlled by lateral variations in viscosity of the low-velocity layer.

  18. THE POLISH BUSINESS ENVIRONMENT FOR LANGUAGE SERVICE PROVIDERS IN VIEW OF THE PORTER’S FIVE FORCES MODEL

    OpenAIRE

    Kowalska, Monika

    2014-01-01

    After the Polish accession to the European Union in 2004, language services have considerably grown in importance. Intensive contacts with foreign companies and institutions coupled with information technology developments have increased the role of English as a linguistic medium of international cooperation. The overall aim of this paper is to examine the Polish business environment for Language Service Providers (LSPs) offering specialized English courses and translation services (EN-PL and...

  19. Numerical Wave Flume Study on Wave Motion Around Submerged Plates

    Institute of Scientific and Technical Information of China (English)

    齐鹏; 侯一筠

    2003-01-01

    Nonlinear interaction between surface waves and a submerged horizontal plate is investigated in the absorbed numerical wave flume developed based on the volume of fluid (VOF) method. The governing equations of the numerical model are the continuity equation and the Reynolds-Averaged Navier-Stokes (RANS) equations with the k-ε turbulence equations. Incident waves are generated by an absorbing wave-maker that eliminates the waves reflected from structures. Results are obtained for a range of parameters, with consideration of the condition under which the reflection coefficient becomes maximal and the transmission coefficient minimal. Wave breaking over the plate, vortex shedding downwave, and pulsating flow below the plate are observed. Time-averaged hydrodynamic force reveals a negative drift force. All these characteristics provide a reference for construction of submerged plate breakwaters.

  20. Sign change in the net force in sphere-plate and sphere-sphere systems immersed in nonpolar critical fluid due to the interplay between the critical Casimir and dispersion van der Waals forces

    Science.gov (United States)

    Valchev, Galin; Dantchev, Daniel

    2017-08-01

    We study systems in which both long-ranged van der Waals and critical Casimir interactions are present. The latter arise as an effective force between bodies when immersed in a near-critical medium, say a nonpolar one-component fluid or a binary liquid mixture. They are due to the fact that the presence of the bodies modifies the order parameter profile of the medium between them as well as the spectrum of its allowed fluctuations. We study the interplay between these forces, as well as the total force (TF) between a spherical colloid particle and a thick planar slab and between two spherical colloid particles. We do that using general scaling arguments and mean-field-type calculations utilizing the Derjaguin and the surface integration approaches. They both are based on data of the forces between two parallel slabs separated at a distance L from each other, confining the fluctuating fluid medium characterized by its temperature T and chemical potential μ . The surfaces of the colloid particles and the slab are coated by thin layers exerting strong preference to the liquid phase of the fluid, or one of the components of the mixture, modeled by strong adsorbing local surface potentials, ensuring the so-called (+,+) boundary conditions. On the other hand, the core region of the slab and the particles influence the fluid by long-ranged competing dispersion potentials. We demonstrate that for a suitable set of colloids-fluid, slab-fluid, and fluid-fluid coupling parameters, the competition between the effects due to the coatings and the core regions of the objects involved result, when one changes T , μ , or L , in sign change of the Casimir force (CF) and the TF acting between the colloid and the slab, as well as between the colloids. This can be used for governing the behavior of objects, say colloidal particles, at small distances, say in colloid suspensions for preventing flocculation. It can also provide a strategy for solving problems with handling, feeding

  1. Modal damping factor detected with an impulse-forced vibration method provides additional information on osseointegration during dental implant healing.

    Science.gov (United States)

    Feng, Sheng-Wei; Chang, Wei-Jen; Lin, Che-Tong; Lee, Sheng-Yang; Teng, Nai-Chia; Huang, Haw-Ming

    2015-01-01

    To evaluate whether resonance frequency (RF) analysis combined with modal damping factor (MDF) analysis provides additional information on dental implant healing status. In in vitro tests, epoxy resin was used to simulate the implant healing process. The RF and MDF values of the implants were measured during the entire polymerization process. Implant stability quotient (ISQ) and Periotest values (PTVs) from Ostell and Periotest devices were used to validate the apparatus. In in vivo experiments, vibrational analysis was performed on 17 dental implants in 12 patients. The RF and MDF values of the tested implants were recorded during the first 10 weeks after surgery. The effects of jaw types and primary stability on MDF healing curves were analyzed. In the in vitro model, the RF values obtained from the apparatus used in this study were similar to those obtained from the Osstell device. Unlike the Periotest healing curve, the MDF curve showed a 1.8-fold increase during the early phase. In clinical experiments, the mean RF values were unchanged during the first 2 weeks and increased continuously until 6 weeks. The corresponding mean MDF value decreased over time and reached 0.045 ± 0.011 at 10 weeks, which is approximately 50% lower than the initial value. Although the RF values of the implants with higher initial frequency remained unchanged during the healing period, the MDF values decreased significantly. Analysis of RF combined with MDF provides additional information on dental implant healing status. MDF analysis can detect changes in the implant/bone complex during the healing period even in implants with higher RF values.

  2. Under Wind Load Function the Curtain Wall Aluminum Plate Internal Force and Distortion Calculation%风荷载作用下幕墙铝板内力和变形的计算

    Institute of Scientific and Technical Information of China (English)

    毛伙南

    2012-01-01

    The survey of unit type curtain wall is researched. Using the ANSYS software, the internal force and displacement of the unit type plate structure which are composed of the trough type aluminum plate and S stiffening ribs (portal type frame) are calculated. The stiffening rib and the aluminum plate corner partial rivet loosens by the rigid joint turns the hinge point is studied. The computation model is built and its biggest internal force and displacement are obtained. Finally, the practical application is in troduced.%阐述了槽型铝板和加劲肋构成的单元式幕墙的内力及变形计算.采用ANSYS软件对单元板块由槽型铝板与5条加劲肋组成的结构的内力和变形进行计算,研究了加劲肋转角处由于局部铆钉松脱由刚结点变成铰接点后其计算模型发生改变的应力及位移计算,最后介绍实际应用.

  3. Intra Plate Stresses Using Finite Element Modelling

    Directory of Open Access Journals (Sweden)

    Jayalakshmi S.

    2016-10-01

    Full Text Available One of the most challenging problems in the estimation of seismic hazard is the ability to quantify seismic activity. Empirical models based on the available earthquake catalogue are often used to obtain activity of source regions. The major limitation with this approach is the lack of sufficient data near a specified source. The non-availability of data poses difficulties in obtaining distribution of earthquakes with large return periods. Such events recur over geological time scales during which tectonic processes, including mantle convection, formation of faults and new plate boundaries, are likely to take place. The availability of geometries of plate boundaries, plate driving forces, lithospheric stress field and GPS measurements has provided numerous insights on the mechanics of tectonic plates. In this article, a 2D finite element model of Indo-Australian plate is developed with the focus of representing seismic activity in India. The effect of large scale geological features including sedimentary basins, fold belts and cratons on the stress field in India is explored in this study. In order to address long term behaviour, the orientation of stress field and tectonic faults of the present Indo-Australian plate are compared with a reconstructed stress field from the early Miocene (20 Ma.

  4. Whole-grain intake in middle school students achieves dietary guidelines for Americans and MyPlate recommendations when provided as commercially available foods: a randomized trial.

    Science.gov (United States)

    Radford, Allyson; Langkamp-Henken, Bobbi; Hughes, Christine; Christman, Mary C; Jonnalagadda, Satya; Boileau, Thomas W; Thielecke, Frank; Dahl, Wendy J

    2014-09-01

    In accordance with the 2010 Dietary Guidelines for Americans, at least half of total grain intake should be whole grains. Adolescents are currently not consuming the recommended daily intake of whole grains. Research is needed to determine whether whole grains are acceptable to adolescents and whether changing their food environment to include whole-grain foods will improve intake. The aim of this study was to determine the effect of providing refined-grain or whole-grain foods to adolescents, with encouragement to eat three different grain-based foods per day, on total grain and whole-grain intakes. Middle school students (n=83; aged 11 to 15 years) were randomly assigned to either refined-grain or whole-grain foods for 6 weeks. Participants and their families were provided with weekly grains (eg, bread, pasta, and cereals), and participants were provided grain snacks at school. Intake of grains in ounce equivalents (oz eq) was determined through eight baseline and intervention targeted 24-hour diet recalls. Participants consumed 1.1±1.3 oz eq (mean±standard deviation) of whole grains at baseline, out of 5.3±2.4 oz eq of total grains. During intervention, whole-grain intake increased in the whole-grain group (0.9±1.0 to 3.9±1.8 oz eq/day), whereas those in the refined-grain group reduced whole-grain intake (1.3±1.6 to 0.3±0.3 oz eq/day; Pgrain intake achieved was 6.4±2.1 oz eq/day and did not differ across intervention groups. Providing adolescents with whole-grain foods in their school and home environments was an effective means of achieving recommendations.

  5. 49 CFR 236.779 - Plate, top.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Plate, top. 236.779 Section 236.779 Transportation... OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Definitions § 236.779 Plate, top. A metal plate secured to a locking bracket to prevent the cross locking from being forced out of the...

  6. Ridge-spotting: A new test for Pacific absolute plate motion models

    Science.gov (United States)

    Wessel, Paul; Müller, R. Dietmar

    2016-06-01

    Relative plate motions provide high-resolution descriptions of motions of plates relative to other plates. Yet geodynamically, motions of plates relative to the mantle are required since such motions can be attributed to forces (e.g., slab pull and ridge push) acting upon the plates. Various reference frames have been proposed, such as the hot spot reference frame, to link plate motions to a mantle framework. Unfortunately, both accuracy and precision of absolute plate motion models lag behind those of relative plate motion models. Consequently, it is paramount to use relative plate motions in improving our understanding of absolute plate motions. A new technique called "ridge-spotting" combines absolute and relative plate motions and examines the viability of proposed absolute plate motion models. We test the method on six published Pacific absolute plate motions models, including fixed and moving hot spot models as well as a geodynamically derived model. Ridge-spotting reconstructs the Pacific-Farallon and Pacific-Antarctica ridge systems over the last 80 Myr. All six absolute plate motion models predict large amounts of northward migration and monotonic clockwise rotation for the Pacific-Farallon ridge. A geodynamic implication of our ridge migration predictions is that the suggestion that the Pacific-Farallon ridge may have been pinned by a large mantle upwelling is not supported. Unexpected or erratic ridge behaviors may be tied to limitations in the models themselves or (for Indo-Atlantic models) discrepancies in the plate circuits used to project models into the Pacific realm. Ridge-spotting is promising and will be extended to include more plates and other ocean basins.

  7. Hydroelasticity of a Floating Plate

    DEFF Research Database (Denmark)

    Chen, X.; Jensen, Jørgen Juncher; Cui, W.

    2003-01-01

    The membrane forces are included in the hydroelastic analysis of a floating plate undergoing large vertical deflections in regular monochromatic multidirectional waves. The first-order vertical displacements induced by the linear wave exciting forces are calculated by the mode expansion method...... in the frequency domain. The second-order vertical displacements induced by the membrane forces are calculated by the von Karman plate theory. The results show that the membrane contribution both in terms of the axial stresses and the effect on the bending stresses can be important...

  8. Kinesiological study of the push-up motion in spinal cord injury patients: involving measurement of hand pressure applied to a force plate.

    Directory of Open Access Journals (Sweden)

    Kotani Y

    2002-04-01

    Full Text Available We studied the pressure exerted by hands during push-ups in 21 paraplegic and 2 tetraplegic patients employing 4 different hand positions. In the fingers-spread position, the initial force exerted was a vertical force (Fz, followed by a medio-lateral force (Fy and then an antero-posterior force (Fx. In the other 3 positions, the order of force type exertion was Fz, Fx, and then Fy. All subjects with neurological injury levels above T4 and subjects between T5 and T10 without spinal instrumentation could not push themselves up in the fingers-spread position. The fact that Fy is initiated before Fx in the fingers-spread position indicates that lateral balancing of the trunk is critical in this position, thus explaining why subjects without spinal instrumentation with neurological injury at a level higher than T10 could not control their spinal columns while performing push-ups. In contrast, antero-posterior balancing takes priority in the other hand positions. We believe that spinal instrumentation helps balance the trunk in the lateral direction, converting the thoracic spine into a rigid body in subjects with neurological injury at levels above T10.

  9. Strong plate coupling along the Nazca-South America convergent margin

    Science.gov (United States)

    Iaffaldano, Giampiero; Bunge, Hans-Peter

    2008-06-01

    The force balance in plate tectonics is fundamentally importantbut poorly known. Here, we show that two prominent and seeminglyunrelated observations—trench-parallel gravity anomaliesalong the Nazca-South America margin that coincide withthe rupture zones of great earthquakes, and a rapid slowdownof Nazca-South America convergence over the past 10 m.y.—providekey insights. Both result from rapid Miocene-Pliocene upliftof the Andes and provide quantitative measures of the magnitudeand distribution of plate coupling along the Nazca-SouthAmerica margin. We compute the plate-tectonic force budget usingglobal models of the faulted lithosphere coupled to high-resolutionmantle circulation models and find that Andean-related plate-marginforces are comparable to plate-driving forces from the mantle,and they have sufficient magnitude to account for pronouncedbathymetry variations along the trench. Our results suggestthat plate coupling, gravity anomalies, and bathymetry variationsalong a given trench are all controlled by long-term stressvariations in the upper portion of plate boundaries and thatan explicit budget of driving and resisting forces in platetectonics can be obtained. For the convergent margin consideredhere, spatial variations in the effective coefficient of frictionassociated with the distribution of lubricating sediments enteringthe trench are, by comparison, of minor importance.

  10. Vehicle License Plate Recognition Syst

    Directory of Open Access Journals (Sweden)

    Meenakshi,R. B. Dubey

    2012-12-01

    Full Text Available The vehicle license plate recognition system has greater efficiency for vehicle monitoring in automatic zone access control. This Plate recognition system will avoid special tags, since all vehicles possess a unique registration number plate. A number of techniques have been used for car plate characters recognition. This system uses neural network character recognition and pattern matching of characters as two character recognition techniques. In this approach multilayer feed-forward back-propagation algorithm is used. The performance of the proposed algorithm has been tested on several car plates and provides very satisfactory results.

  11. Micro-channel plate detector

    Science.gov (United States)

    Elam, Jeffrey W.; Lee, Seon W.; Wang, Hsien -Hau; Pellin, Michael J.; Byrum, Karen; Frisch, Henry J.

    2015-09-22

    A method and system for providing a micro-channel plate detector. An anodized aluminum oxide membrane is provided and includes a plurality of nanopores which have an Al coating and a thin layer of an emissive oxide material responsive to incident radiation, thereby providing a plurality of radiation sensitive channels for the micro-channel plate detector.

  12. The dynamics of Cenozoic and Mesozoic plate motions

    OpenAIRE

    Lithgow-Bertelloni, C.; Richards, M. A.

    1998-01-01

    Our understanding of the dynamics of plate motions is based almost entirely upon modeling of present-day plate motions. A fuller understanding, however, can be derived from consideration of the history of plate motions. Here we investigate the kinematics of the last 120 Myr of plate motions and the dynamics of Cenozoic motions, paying special attention to changes in the character of plate motions and plate-driving forces. We analyze the partitioning of the observed surface velocity field into...

  13. Combined Effect of Buoyancy Force and Navier Slip on MHD Flow of a Nanofluid over a Convectively Heated Vertical Porous Plate

    Directory of Open Access Journals (Sweden)

    Winifred Nduku Mutuku-Njane

    2013-01-01

    Full Text Available We examine the effect of magnetic field on boundary layer flow of an incompressible electrically conducting water-based nanofluids past a convectively heated vertical porous plate with Navier slip boundary condition. A suitable similarity transformation is employed to reduce the governing partial differential equations into nonlinear ordinary differential equations, which are solved numerically by employing fourth-order Runge-Kutta with a shooting technique. Three different water-based nanofluids containing copper (Cu, aluminium oxide (Al2O3, and titanium dioxide (TiO2 are taken into consideration. Graphical results are presented and discussed quantitatively with respect to the influence of pertinent parameters, such as solid volume fraction of nanoparticles (φ, magnetic field parameter (Ha, buoyancy effect (Gr, Eckert number (Ec, suction/injection parameter (fw, Biot number (Bi, and slip parameter (β, on the dimensionless velocity, temperature, skin friction coefficient, and heat transfer rate.

  14. Steel-plate composite (SC) walls for safety related nuclear facilities: Design for in-plane forces and out-of-plane moments

    Energy Technology Data Exchange (ETDEWEB)

    Varma, Amit H., E-mail: ahvarma@purdue.edu [Bowen Laboratory, School of Civil Engineering, Purdue University, West Lafayette, IN (United States); Malushte, Sanjeev R., E-mail: smalusht@bechtel.com [Bechtel Power Corporation, Frederick, MD (United States); Sener, Kadir C., E-mail: ksener@purdue.edu [Bowen Laboratory, School of Civil Engineering, Purdue University, West Lafayette, IN (United States); Lai, Zhichao, E-mail: laiz@purdue.edu [Bowen Laboratory, School of Civil Engineering, Purdue University, West Lafayette, IN (United States)

    2014-04-01

    Steel-concrete (SC) composite walls being considered and used as an alternative to conventional reinforced concrete (RC) walls in safety-related nuclear facilities due to their construction economy and structural efficiency. However, there is a lack of standardized codes for SC structures, and design guidelines and approaches are still being developed. This paper presents the development and verification of: (a) mechanics based model, and (b) detailed nonlinear finite element model for predicting the behavior and failure of SC wall panels subjected to combinations of in-plane forces. The models are verified using existing test results, and the verified models are used to explore the behavior of SC walls subjected to combinations of in-plane forces and moments. The results from these investigations are used to develop an interaction surface in principle force (S{sub p1}–S{sub p2}) space that can be used to design or check the adequacy of SC wall panels. The interaction surface is easy to develop since it consists of straight line segments connecting anchor points defined by the SC wall section strengths in axial tension, in-plane shear, and compression. Both models and the interaction surface (for design) developed in this paper are recommended for future work. However, in order to use these approaches, the SC wall section should be detailed with adequate shear connector and tie bar strength and spacing to prevent non-ductile failure modes.

  15. Analysis and Design of Circular Plate MR Fluids Brake

    Institute of Scientific and Technical Information of China (English)

    Yang Yan; Lin Chang-Hua; Li Hui; Zhou Jing

    2004-01-01

    A magnetorheological (MR) fluids brake is a device to achieve brake by shear force of MR fluids. A MR rotary brake has the property that its braking torque changes quickly in response to an external magnetic field. In this study, the design method of the circular plate MR fluids brake is investigated theoretically. The equation of the torque transmitted by the MR fluids in the brake is derived to provide the theoretical foundation in the design of the brake. Based on this equation, after mathematically manipulated, the calculations of the volume, thickness and width of the MR fluids within the circular plate MR fluids brake are yield.

  16. Plate tectonics conserves angular momentum

    Directory of Open Access Journals (Sweden)

    C. Bowin

    2009-03-01

    Full Text Available A new combined understanding of plate tectonics, Earth internal structure, and the role of impulse in deformation of the Earth's crust is presented. Plate accelerations and decelerations have been revealed by iterative filtering of the quaternion history for the Euler poles that define absolute plate motion history for the past 68 million years, and provide an unprecedented precision for plate angular rotation variations with time at 2-million year intervals. Stage poles represent the angular rotation of a plate's motion between adjacent Euler poles, and from which the maximum velocity vector for a plate can be determined. The consistent maximum velocity variations, in turn, yield consistent estimates of plate accelerations and decelerations. The fact that the Pacific plate was shown to accelerate and decelerate, implied that conservation of plate tectonic angular momentum must be globally conserved, and that is confirmed by the results shown here (total angular momentum ~1.4 E+27 kgm2s−1. Accordingly, if a plate decelerates, other plates must increase their angular momentums to compensate. In addition, the azimuth of the maximum velocity vectors yields clues as to why the "bend" in the Emperor-Hawaiian seamount trend occurred near 46 Myr. This report summarizes processing results for 12 of the 14 major tectonic plates of the Earth (except for the Juan de Fuca and Philippine plates. Plate accelerations support the contention that plate tectonics is a product of torques that most likely are sustained by the sinking of positive density anomalies due to phase changes in subducted gabbroic lithosphere at depth in the upper lower mantle (above 1200 km depth. The tectonic plates are pulled along by the sinking of these positive mass anomalies, rather than moving at near constant velocity on the crests of convection cells driven by rising heat. These results imply that spreading centers are primarily passive reactive

  17. Multiple-Dynode-Layer Microchannel Plate

    Science.gov (United States)

    Woodgate, Bruce E.

    1990-01-01

    Improved microchannel-plate electron image amplifier made of stack of discrete microchannel-plate layers. New plates easier to manufacture because no need to etch long, narrow holes, to draw and bundle thin glass tubes, or to shear plates to give microchannels curvatures necessary for reduction of undesired emission of ions. Discrete dynode layers stacked with slight offset from layer to layer to form microchannel plate with curved channels. Provides for relatively fast recharging of microchannel dynodes, with consequent enhancement of performance.

  18. Effects of a sliding plate on morphology of the epiphyseal plate in goat distal femur.

    Science.gov (United States)

    Lin, Da-sheng; Lian, Ke-jian; Hong, Jia-yuan; Ding, Zhen-qi; Zhai, Wen-liang

    2012-01-01

    The aim of this study was to observe the effects of a sliding plate on the morphology of the epiphyseal plate in goat distal femur. Eighteen premature female goats were divided randomly into sliding plate, regular plate and control groups. Radiographic analysis and histological staining were performed to evaluate the development of epiphyseal plate at 4 and 8 weeks after surgery. In the sliding plate group, the plate extended accordingly as the epiphyseal plate grows, and the epiphyseal morphology was kept essential normal. However, the phenomenon of the epiphyseal growth retardation and premature closure were very common in the regular plate group. In addition, the sliding plate group exhibited more normal histologic features and Safranin O staining compared to the regular plate group. Our results suggest that the sliding plate can provide reliable internal fixation of epiphyseal fracture without inhibiting epiphyseal growth.

  19. Effects of a Sliding Plate on Morphology of the Epiphyseal Plate in Goat Distal Femur

    Directory of Open Access Journals (Sweden)

    Da-sheng LIN, Ke-jian LIAN, Jia-yuan HONG, Zhen-qi DING, Wen-liang ZHAI

    2012-01-01

    Full Text Available The aim of this study was to observe the effects of a sliding plate on the morphology of the epiphyseal plate in goat distal femur. Eighteen premature female goats were divided randomly into sliding plate, regular plate and control groups. Radiographic analysis and histological staining were performed to evaluate the development of epiphyseal plate at 4 and 8 weeks after surgery. In the sliding plate group, the plate extended accordingly as the epiphyseal plate grows, and the epiphyseal morphology was kept essential normal. However, the phenomenon of the epiphyseal growth retardation and premature closure were very common in the regular plate group. In addition, the sliding plate group exhibited more normal histologic features and Safranin O staining compared to the regular plate group. Our results suggest that the sliding plate can provide reliable internal fixation of epiphyseal fracture without inhibiting epiphyseal growth.

  20. Real Plates and Dubious Microplates

    Science.gov (United States)

    Kogan, M. G.; Steblov, G. M.

    2008-12-01

    From the onset of plate tectonics, the existence of most of the plates was never put in doubt, although the boundaries of some plates, like Africa, were later revised. There are however, two microplates in northeast Asia, the Amurian and Okhotsk, whose existence and the sense of rotation was revised several times. The rms value of plate-residual GPS velocities is 0.5-0.9 mm/a for sets of stations representing the motion of the following plates: Antarctic, Australian, Eurasian, North American, Nubian, Pacific, and South American. This value can be regarded as an upper bound on deviation of real plates from infinite stiffness. The rms value of plate-residual GPS velocities is 1.2-1.8 mm/a for the Indian, Nazca, and Somalian plates. Higher rms values for India and Nazca are attributed to the noisier data. The higher rms value for Somalia appears to arise from the distributed deformation to the east of the East African Rift; whether this statement is true can only be decided from observations of denser network in the future. From the analysis of plate-residual GPS velocities, the Canadian Arctic and northeastern Siberia belong to the North American plate. The detailed GPS survey on Sakhalin Island shows that the Sea of Okhotsk region also belongs to the North American plate while the region to the west of it belongs to the Eurasian plate. These results provide a constraint on the geometry of the North American plate and put in doubt the existence of smaller plates in northeast Asia.

  1. Hydrodynamic Boundary Conditions and Dynamic Forces between Bubbles and Surfaces

    Science.gov (United States)

    Manor, Ofer; Vakarelski, Ivan U.; Tang, Xiaosong; O'Shea, Sean J.; Stevens, Geoffrey W.; Grieser, Franz; Dagastine, Raymond R.; Chan, Derek Y. C.

    2008-07-01

    Dynamic forces between a 50μm radius bubble driven towards and from a mica plate using an atomic force microscope in electrolyte and in surfactant exhibit different hydrodynamic boundary conditions at the bubble surface. In added surfactant, the forces are consistent with the no-slip boundary condition at the mica and bubble surfaces. With no surfactant, a new boundary condition that accounts for the transport of trace surface impurities explains variations of dynamic forces at different speeds and provides a direct connection between dynamic forces and surface transport effects at the air-water interface.

  2. 超声红外热像技术中预紧力对金属平板振动特性的影响%Effect of Engagement Force on Vibration Characteristics of Metal Plate in Sonic Infrared Imaging

    Institute of Scientific and Technical Information of China (English)

    张超省; 冯辅周; 闵庆旭; 王鹏飞

    2016-01-01

    During sonic infrared imaging testing, vibration of the target under sonic pulse excitation directly determines heating of defect area. Engagement force between horn and target is one of primary factors affecting vibration characteristics of the target. The analysis of experimental results shows that the increase of engagement force makes the vibration energy undergo a gradual increase process with two small instability ranges, and the vibration spectrum undergo a development process from chaotic vibration into subharmonic vibration, quasi-subharmonics vibration and superharmonics vibration. Based on these phenomena, a finite element model corresponding to experiment conditions is established and transient dynamic analyses are performed by an explicit finite element method. In the finite element model, a piezoelectric-force analogy method is employed to simulate the inverse piezoelectric effect of piezoelectric ceramic discs, and dynamic relaxation is used to simulate the experiment conditions more vividly. The simulation results further verdict experimental results and reveal that the increase of engagement force changes the status of contact force between ultrasonic horn and test plate, which further changes the vibration energy distribution and vibration spectrum of test plate. The conclusions are helpful for controlling vibration status through engagement force, which will be used to determine the test conditions of sonic infrared imaging.%在超声红外热像检测过程中,超声脉冲激励下被测对象的振动状态直接决定了缺陷区域的生热效果,而工具杆与被测对象之间的预紧力是影响被测对象振动状态的重要因素之一。试验结果表明:预紧力的增大使得振动能量呈上升趋势并伴随着小范围不稳定,同时被测对象的振动频谱由混沌振动开始,经历次谐波、准次谐波后达到超谐波振动状态。针对上述现象,采用显式动力学方法建立了与试验条

  3. Fringe Capacitance of a Parallel-Plate Capacitor.

    Science.gov (United States)

    Hale, D. P.

    1978-01-01

    Describes an experiment designed to measure the forces between charged parallel plates, and determines the relationship among the effective electrode area, the measured capacitance values, and the electrode spacing of a parallel plate capacitor. (GA)

  4. Plate tectonics, damage and inheritance.

    Science.gov (United States)

    Bercovici, David; Ricard, Yanick

    2014-04-24

    The initiation of plate tectonics on Earth is a critical event in our planet's history. The time lag between the first proto-subduction (about 4 billion years ago) and global tectonics (approximately 3 billion years ago) suggests that plates and plate boundaries became widespread over a period of 1 billion years. The reason for this time lag is unknown but fundamental to understanding the origin of plate tectonics. Here we suggest that when sufficient lithospheric damage (which promotes shear localization and long-lived weak zones) combines with transient mantle flow and migrating proto-subduction, it leads to the accumulation of weak plate boundaries and eventually to fully formed tectonic plates driven by subduction alone. We simulate this process using a grain evolution and damage mechanism with a composite rheology (which is compatible with field and laboratory observations of polycrystalline rocks), coupled to an idealized model of pressure-driven lithospheric flow in which a low-pressure zone is equivalent to the suction of convective downwellings. In the simplest case, for Earth-like conditions, a few successive rotations of the driving pressure field yield relic damaged weak zones that are inherited by the lithospheric flow to form a nearly perfect plate, with passive spreading and strike-slip margins that persist and localize further, even though flow is driven only by subduction. But for hotter surface conditions, such as those on Venus, accumulation and inheritance of damage is negligible; hence only subduction zones survive and plate tectonics does not spread, which corresponds to observations. After plates have developed, continued changes in driving forces, combined with inherited damage and weak zones, promote increased tectonic complexity, such as oblique subduction, strike-slip boundaries that are subparallel to plate motion, and spalling of minor plates.

  5. A forced running wheel system with a microcontroller that provides high-intensity exercise training in an animal ischemic stroke model

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C.C. [Department of Electrical Engineering, National Cheng-Kung University, Tainan, Taiwan (China); Chang, M.W. [Department of Electrical Engineering, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Chang, C.P. [Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan (China); Chan, S.C.; Chang, W.Y.; Yang, C.L. [Department of Electrical Engineering, National Cheng-Kung University, Tainan, Taiwan (China); Lin, M.T. [Department of Medical Research, Chi Mei Medical Center, Tainan, Taiwan (China)

    2014-08-15

    We developed a forced non-electric-shock running wheel (FNESRW) system that provides rats with high-intensity exercise training using automatic exercise training patterns that are controlled by a microcontroller. The proposed system successfully makes a breakthrough in the traditional motorized running wheel to allow rats to perform high-intensity training and to enable comparisons with the treadmill at the same exercise intensity without any electric shock. A polyvinyl chloride runway with a rough rubber surface was coated on the periphery of the wheel so as to permit automatic acceleration training, and which allowed the rats to run consistently at high speeds (30 m/min for 1 h). An animal ischemic stroke model was used to validate the proposed system. FNESRW, treadmill, control, and sham groups were studied. The FNESRW and treadmill groups underwent 3 weeks of endurance running training. After 3 weeks, the experiments of middle cerebral artery occlusion, the modified neurological severity score (mNSS), an inclined plane test, and triphenyltetrazolium chloride were performed to evaluate the effectiveness of the proposed platform. The proposed platform showed that enhancement of motor function, mNSS, and infarct volumes was significantly stronger in the FNESRW group than the control group (P<0.05) and similar to the treadmill group. The experimental data demonstrated that the proposed platform can be applied to test the benefit of exercise-preconditioning-induced neuroprotection using the animal stroke model. Additional advantages of the FNESRW system include stand-alone capability, independence of subjective human adjustment, and ease of use.

  6. A forced running wheel system with a microcontroller that provides high-intensity exercise training in an animal ischemic stroke model.

    Science.gov (United States)

    Chen, C C; Chang, M W; Chang, C P; Chan, S C; Chang, W Y; Yang, C L; Lin, M T

    2014-10-01

    We developed a forced non-electric-shock running wheel (FNESRW) system that provides rats with high-intensity exercise training using automatic exercise training patterns that are controlled by a microcontroller. The proposed system successfully makes a breakthrough in the traditional motorized running wheel to allow rats to perform high-intensity training and to enable comparisons with the treadmill at the same exercise intensity without any electric shock. A polyvinyl chloride runway with a rough rubber surface was coated on the periphery of the wheel so as to permit automatic acceleration training, and which allowed the rats to run consistently at high speeds (30 m/min for 1 h). An animal ischemic stroke model was used to validate the proposed system. FNESRW, treadmill, control, and sham groups were studied. The FNESRW and treadmill groups underwent 3 weeks of endurance running training. After 3 weeks, the experiments of middle cerebral artery occlusion, the modified neurological severity score (mNSS), an inclined plane test, and triphenyltetrazolium chloride were performed to evaluate the effectiveness of the proposed platform. The proposed platform showed that enhancement of motor function, mNSS, and infarct volumes was significantly stronger in the FNESRW group than the control group (P<0.05) and similar to the treadmill group. The experimental data demonstrated that the proposed platform can be applied to test the benefit of exercise-preconditioning-induced neuroprotection using the animal stroke model. Additional advantages of the FNESRW system include stand-alone capability, independence of subjective human adjustment, and ease of use.

  7. Particle Transport in Parallel-Plate Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rader, D.J.; Geller, A.S.

    1999-08-01

    A major cause of semiconductor yield degradation is contaminant particles that deposit on wafers while they reside in processing tools during integrated circuit manufacturing. This report presents numerical models for assessing particle transport and deposition in a parallel-plate geometry characteristic of a wide range of single-wafer processing tools: uniform downward flow exiting a perforated-plate showerhead separated by a gap from a circular wafer resting on a parallel susceptor. Particles are assumed to originate either upstream of the showerhead or from a specified position between the plates. The physical mechanisms controlling particle deposition and transport (inertia, diffusion, fluid drag, and external forces) are reviewed, with an emphasis on conditions encountered in semiconductor process tools (i.e., sub-atmospheric pressures and submicron particles). Isothermal flow is assumed, although small temperature differences are allowed to drive particle thermophoresis. Numerical solutions of the flow field are presented which agree with an analytic, creeping-flow expression for Re < 4. Deposition is quantified by use of a particle collection efficiency, which is defined as the fraction of particles in the reactor that deposit on the wafer. Analytic expressions for collection efficiency are presented for the limiting case where external forces control deposition (i.e., neglecting particle diffusion and inertia). Deposition from simultaneous particle diffusion and external forces is analyzed by an Eulerian formulation; for creeping flow and particles released from a planar trap, the analysis yields an analytic, integral expression for particle deposition based on process and particle properties. Deposition from simultaneous particle inertia and external forces is analyzed by a Lagrangian formulation, which can describe inertia-enhanced deposition resulting from particle acceleration in the showerhead. An approximate analytic expression is derived for particle

  8. Chaos control for the plates subjected to subsonic flow

    Science.gov (United States)

    Norouzi, Hamed; Younesian, Davood

    2016-07-01

    The suppression of chaotic motion in viscoelastic plates driven by external subsonic air flow is studied. Nonlinear oscillation of the plate is modeled by the von-Kármán plate theory. The fluid-solid interaction is taken into account. Galerkin's approach is employed to transform the partial differential equations of the system into the time domain. The corresponding homoclinic orbits of the unperturbed Hamiltonian system are obtained. In order to study the chaotic behavior of the plate, Melnikov's integral is analytically applied and the threshold of the excitation amplitude and frequency for the occurrence of chaos is presented. It is found that adding a parametric perturbation to the system in terms of an excitation with the same frequency of the external force can lead to eliminate chaos. Variations of the Lyapunov exponent and bifurcation diagrams are provided to analyze the chaotic and periodic responses. Two perturbation-based control strategies are proposed. In the first scenario, the amplitude of control forces reads a constant value that should be precisely determined. In the second strategy, this amplitude can be proportional to the deflection of the plate. The performance of each controller is investigated and it is found that the second scenario would be more efficient.

  9. Strong plate coupling along the Nazca/South America convergent margin

    Science.gov (United States)

    Iaffaldano, G.; Bunge, H.

    2007-12-01

    The force balance in plate tectonics is fundamentally important, but poorly known. Much information on the dynamics is embedded in the record of past and present plate velocities, featured with long- as well as short- term variations, but a precise budget, in particular of resistive coupling forces along convergent margins, is hard to come by. Building on substantial, yet separate progress in modeling lithosphere dynamics and mantle convection, we couple global lithosphere models with high-resolution (more than 100 million grid points) 3-D circulation models of Earth's mantle and demonstrate that an accurate budget of plate boundary forces can be obtained. We prove the effectiveness of our approach by computing a detailed force budget along the Nazca/South America subduction zone, showing that a large portion of it comes from the recent uplift of the Andes. We find that forces computed with our global, coupled models provide simultaneous explanations for three seemingly unrelated key observations along the South American margin: (1) trench parallel gravity anomalies, (2) pronounced bathymetry variations, as well as (3) a substantial reduction in Nazca/South America plate convergence recorded over the past 10 million years. All these observations can be explained from along- trench, lateral and temporal variations in plate coupling forces that are predicted from our simulations. Interestingly enough, the distribution of great earthquakes such as the recent M 8.0 event of Peru coincides with moderate to low coupling between subducting and overriding plates. For the same convergent margin we also show that frictional forcing due to trench sediment infill is, by comparison, of minor importance. Finally, we provide an intriguing explanation for the peculiar convex shape of the South American margin. Paleomagnetic and geodetic data indicate substantial rotation over the past m.y. and continuing at present day. We tie the bend of the margin to variations in plate coupling

  10. Clinical Analysis of Internal Fixation Treatment of Intra-articular Calcaneal Fractures with Titanium Plate.

    Science.gov (United States)

    Chen, Xiao-Dong; Zhang, Chang-Chun; Li, Zhao-Cheng; Zhang, Heng; Zhou, Xin-She; Deng, Min

    2015-05-01

    To explore the clinical effect of internal fixation treatment of intra-articular calcaneal fractures with titanium plate, we used open reduction and internal fixation with titanium plate to 48 treated feet from 42 patients with intra-articular calcaneal fractures. The efficacy of surgical treatment was evaluated based on assessment of pain, function, and line of force aspects according to the American Orthopedic Foot and Ankle Society scoring system. Our data show that internal fixation with titanium plate is an effective treatment for calcaneal fractures. It provides satisfactory reduction, reliable fixation, and early rehabilitation.

  11. Dynamics of Tectonic Plates

    CERN Document Server

    Pechersky, E; Sadowski, G; Yambartsev, A

    2014-01-01

    We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend on features of resistant forces.

  12. Create Your Plate

    Medline Plus

    Full Text Available ... A A A Listen En Español Create Your Plate Create Your Plate is a simple and effective ... and that your options are endless. Create Your Plate! Click on the plate sections below to add ...

  13. Efficient transport of droplet sandwiched between saw-tooth plates.

    Science.gov (United States)

    Wang, Liya; Wu, Hengan; Wang, Fengchao

    2016-01-15

    The transport of droplet sandwiched between smooth and saw-tooth plates was investigated using molecular dynamics method. The repeated opening and closing of the plates result in sequential stretching and squeezing of the droplet, which provide the driving force. The asymmetrical saw tooth obstructs the backward motion of the droplet, and gives rise to a net forward displacement of the droplet in every opening and closing cycle. This unidirectional motion facilitates the efficient droplet transport, which is referred to as the ratchet-like effect in this work. Our simulations also reveal that the influence of the surface wettability on the droplet transport is different for saw-tooth and smooth plates. Droplet transport efficiency exhibits monotonic decrease with the increase of the solid-liquid interactions for saw-tooth plates. While for smooth plates, unidirectional droplet movement was only observed for certain solid-liquid interactions. Taken together these simulation results and theoretical analysis, we demonstrate that hydrophobic saw-tooth plates can improve the transport efficiency significantly. These findings not only enhance our understanding of the droplet transport from atomistic scale, but also are beneficial to practical applications in designing of micro- and nano-fluidic systems.

  14. Biomechanical Analysis of Implanted Clavicle Hook Plates With Different Implant Depths and Materials in the Acromioclavicular Joint: A Finite Element Analysis Study.

    Science.gov (United States)

    Lee, Cheng-Hung; Shih, Cheng-Min; Huang, Kui-Chou; Chen, Kun-Hui; Hung, Li-Kun; Su, Kuo-Chih

    2016-11-01

    Clinical implantation of clavicle hook plates is often used as a treatment for acromioclavicular joint dislocation. However, it is not uncommon to find patients that have developed acromion osteolysis or had peri-implant fracture after hook plate fixation. With the aim of preventing complications or fixation failure caused by implantation of inappropriate clavicle hook plates, the present study investigated the biomechanics of clavicle hook plates made of different materials and with different hook depths in treating acromioclavicular joint dislocation, using finite element analysis (FEA). This study established four parts using computer models: the clavicle, acromion, clavicle hook plate, and screws, and these established models were used for FEA. Moreover, implantations of clavicle hook plates made of different materials (stainless steel and titanium alloy) and with different depths (12, 15, and 18 mm) in patients with acromioclavicular joint dislocation were simulated in the biomechanical analysis. The results indicate that deeper implantation of the clavicle hook plate reduces stress on the clavicle, and also reduces the force applied to the acromion by the clavicle hook plate. Even though a clavicle hook plate made of titanium alloy (a material with a lower Young's modulus) reduces the force applied to the acromion by the clavicle hook plate, slightly higher stress on the clavicle may occur. The results obtained in this study provide a better reference for orthopedic surgeons in choosing different clavicle hook plates for surgery. Copyright © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  15. Anisotropic magnetocapacitance in ferromagnetic-plate capacitors

    Science.gov (United States)

    Haigh, J. A.; Ciccarelli, C.; Betz, A. C.; Irvine, A.; Novák, V.; Jungwirth, T.; Wunderlich, J.

    2015-04-01

    The capacitance of a parallel-plate capacitor can depend on the applied magnetic field. Previous studies have identified capacitance changes induced via classical Lorentz force or spin-dependent Zeeman effects. Here we measure a magnetization direction-dependent capacitance in parallel-plate capacitors where one plate is a ferromagnetic semiconductor, gallium manganese arsenide. This anisotropic magnetocapacitance is due to the anisotropy in the density of states dependent on the magnetization through the strong spin-orbit interaction.

  16. Dynamic stiffness matrix of a rectangular plate for the general case

    Science.gov (United States)

    Banerjee, J. R.; Papkov, S. O.; Liu, X.; Kennedy, D.

    2015-04-01

    The dynamic stiffness matrix of a rectangular plate for the most general case is developed by solving the bi-harmonic equation and finally casting the solution in terms of the force-displacement relationship of the freely vibrating plate. Essentially the frequency dependent dynamic stiffness matrix of the plate when all its sides are free is derived, making it possible to achieve exact solution for free vibration of plates or plate assemblies with any boundary conditions. Previous research on the dynamic stiffness formulation of a plate was restricted to the special case when the two opposite sides of the plate are simply supported. This restriction is quite severe and made the general purpose application of the dynamic stiffness method impossible. The theory developed in this paper overcomes this long-lasting restriction. The research carried out here is basically fundamental in that the bi-harmonic equation which governs the free vibratory motion of a plate in harmonic oscillation is solved in an exact sense, leading to the development of the dynamic stiffness method. It is significant that the ingeniously sought solution presented in this paper is completely general, covering all possible cases of elastic deformations of the plate. The Wittrick-Williams algorithm is applied to the ensuing dynamic stiffness matrix to provide solutions for some representative problems. A carefully selected sample of mode shapes is also presented.

  17. Finite Temperature Casimir Effect for Corrugated Plates

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yan; SHAO Cheng-Gang; LUO Jun

    2006-01-01

    @@ Using the path-integral method, the corrections to the Casimir energy due to the combined effect of surface roughness and the finite temperature are calculated. For the specific case of two sinusoidally corrugated plates,the lateral Casimir force at finite temperature is obtained. The amplitude of the lateral Casimir force has a maximum at an optimal wavelength of λ≈ 2H with the mean plate distance H. This optimal parameter relation is almost independent of temperature.

  18. Dispersion Forces

    CERN Document Server

    Buhmann, Stefan Yoshi

    2012-01-01

    In this book, a modern unified theory of dispersion forces on atoms and bodies is presented which covers a broad range of advanced aspects and scenarios. Macroscopic quantum electrodynamics is shown to provide a powerful framework for dispersion forces which allows for discussing general properties like their non-additivity and the relation between microscopic and macroscopic interactions. It is demonstrated how the general results can be used to obtain dispersion forces on atoms in the presence of bodies of various shapes and materials. Starting with a brief recapitulation of volume I, this volume II deals especially with bodies of irregular shapes, universal scaling laws, dynamical forces on excited atoms, enhanced forces in cavity quantum electrodynamics, non-equilibrium forces in thermal environments and quantum friction. The book gives both the specialist and those new to the field a thorough overview over recent results in the field. It provides a toolbox for studying dispersion forces in various contex...

  19. Plate Tectonics as a Far-From-Equilibrium Self-Organized Dissipative System

    Science.gov (United States)

    Anderson, D. L.

    2001-12-01

    A fluid above the critical Rayleigh number is far from equilibrium and spontaneously organizes itself into patterns involving the collective motion of large numbers of molecules which are resisted by the viscosity of the fluid. No external template is involved in forming the pattern. In 1928 Pearson showed that Bénard's experiments were driven by variations in surface tension at the top of the fluid and the surface motions drove convection in the fluid. In this case, the surface organized itself AND the underlying fluid. Both internal buoyancy driven flow and flow driven by surface forces can be far-from-equilibrium self-organized open systems that receive energy and matter from the environment. In the Earth, the cold thermal boundary layer at the surface drives plate tectonics and introduces temperature, shear and pressure gradients into the mantle that drive mantle convection. The mantle provides energy and material but may not provide the template. Plate tectonics is therefore a candidate for a far-from-equilibrium dissipative self-organizing system. Alternatively, one could view mantle convection as the self-organized system and the plates as simply the surface manifestation. Lithospheric architecture also imposes lateral temperature gradients onto the mantle which can drive and organize flow. Far-from-equilibrium self-organization requires; an open system, interacting parts, nonlinearities or feedbacks, an outside steady source of energy or matter, multiple possible states and a source of dissipation. In uniform fluids viscosity is the source of dissipation. Sources of dissipation in the plate system include bending, breaking, folding, shearing, tearing, collision and basal drag. These can change rapidly, in contrast to plate driving forces, and introduce the sort of fluctuations that can reorganize far-from-equilibrium systems. Global plate reorganizations can alternatively be thought of as convective overturns of the mantle, or thermal weakening of plates

  20. Nonlinear Resonance of the Rotating Circular Plate under Static Loads in Magnetic Field

    Institute of Scientific and Technical Information of China (English)

    HU Yuda; WANG Tong

    2015-01-01

    The rotating circular plate is widely used in mechanical engineering, meanwhile the plates are often in the electromagnetic field in modern industry with complex loads. In order to study the resonance of a rotating circular plate under static loads in magnetic field, the nonlinear vibration equation about the spinning circular plate is derived according to Hamilton principle. The algebraic expression of the initial deflection and the magneto elastic forced disturbance differential equation are obtained through the application of Galerkin integral method. By mean of modified Multiple scale method, the strongly nonlinear amplitude-frequency response equation in steady state is established. The amplitude frequency characteristic curve and the relationship curve of amplitude changing with the static loads and the excitation force of the plate are obtained according to the numerical calculation. The influence of magnetic induction intensity, the speed of rotation and the static loads on the amplitude and the nonlinear characteristics of the spinning plate are analyzed. The proposed research provides the theory reference for the research of nonlinear resonance of rotating plates in engineering.

  1. Indonesian Landforms and Plate Tectonics

    Directory of Open Access Journals (Sweden)

    Herman Th. Verstappen

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v5i3.103The horizontal configuration and vertical dimension of the landforms occurring in the tectonically unstable parts of Indonesia were resulted in the first place from plate tectonics. Most of them date from the Quaternary and endogenous forces are ongoing. Three major plates – the northward moving Indo-Australian Plate, the south-eastward moving SE-Asian Plate and the westward moving Pacific Plate - meet at a plate triple-junction situated in the south of New Guinea’s Bird’s Head. The narrow North-Moluccan plate is interposed between the Asia and Pacific. It tapers out northward in the Philippine Mobile Belt and is gradually disappearing. The greatest relief amplitudes occur near the plate boundaries: deep ocean trenches are associated with subduction zones and mountain ranges with collision belts. The landforms of the more stable areas of the plates date back to a more remote past and, where emerged, have a more subdued relief that is in the first place related to the resistance of the rocks to humid tropical weathering Rising mountain ranges and emerging island arcs are subjected to rapid humid-tropical river erosions and mass movements. The erosion products accumulate in adjacent sedimentary basins where their increasing weight causes subsidence by gravity and isostatic compensations. Living and raised coral reefs, volcanoes, and fault scarps are important geomorphic indicators of active plate tectonics. Compartmental faults may strongly affect island arcs stretching perpendicular to the plate movement. This is the case on Java. Transcurrent faults and related pull-apart basins are a leading factor where plates meet at an angle, such as on Sumatra. The most complicated situation exists near the triple-junction and in the Moluccas. Modern research methods, such as GPS measurements of plate movements and absolute dating of volcanic outbursts and raised coral reefs are important tools. The mega-landforms resulting

  2. Indonesian Landforms and Plate Tectonics

    Directory of Open Access Journals (Sweden)

    Herman Th. Verstappen

    2014-06-01

    Full Text Available DOI: 10.17014/ijog.v5i3.103The horizontal configuration and vertical dimension of the landforms occurring in the tectonically unstable parts of Indonesia were resulted in the first place from plate tectonics. Most of them date from the Quaternary and endogenous forces are ongoing. Three major plates – the northward moving Indo-Australian Plate, the south-eastward moving SE-Asian Plate and the westward moving Pacific Plate - meet at a plate triple-junction situated in the south of New Guinea’s Bird’s Head. The narrow North-Moluccan plate is interposed between the Asia and Pacific. It tapers out northward in the Philippine Mobile Belt and is gradually disappearing. The greatest relief amplitudes occur near the plate boundaries: deep ocean trenches are associated with subduction zones and mountain ranges with collision belts. The landforms of the more stable areas of the plates date back to a more remote past and, where emerged, have a more subdued relief that is in the first place related to the resistance of the rocks to humid tropical weathering Rising mountain ranges and emerging island arcs are subjected to rapid humid-tropical river erosions and mass movements. The erosion products accumulate in adjacent sedimentary basins where their increasing weight causes subsidence by gravity and isostatic compensations. Living and raised coral reefs, volcanoes, and fault scarps are important geomorphic indicators of active plate tectonics. Compartmental faults may strongly affect island arcs stretching perpendicular to the plate movement. This is the case on Java. Transcurrent faults and related pull-apart basins are a leading factor where plates meet at an angle, such as on Sumatra. The most complicated situation exists near the triple-junction and in the Moluccas. Modern research methods, such as GPS measurements of plate movements and absolute dating of volcanic outbursts and raised coral reefs are important tools. The mega-landforms resulting

  3. Lithographic plate setting device for printing machines; Insatsuki no inban toritsuke sochi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-04-20

    A lithographic plate is set on a plate trunk by clamping a plate with a hook for setting the lithographic plate on a clamp plate and hanging a standard hole of the lithographic plate on the hook. However, the plate hanged on a hook may be off the hook during the hanging work, taking much time for setting a lithographic plate. This invention provides a standard pin for plate positioning and a plate for holding a lithographic plate on the upper side of a clamp plate, the latter covering the former, and inserts the lithographic plate end having the standard hole between the plate for holding the lithographic plate and clamp plate, to fit the standard hole into the standard pin. This allows the lithographic plate to be easily set on the plate trunk, and prevents the lithographic plate from being off the standard pin, once it is inserted. (translated by NEDO)

  4. Bronze Plates

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    During the Spring and Autumn, and the Warring States Periods (770 -221 B.C.) tribes in the western borders such as Wu Shi, Yi Qu, Gou Yan etc. led a nomadic life and were accomplished hunters. According to historical records, these tribesmen were trained in archery, hunting and riding from a very early age. Their gallantry, endurance and worship of force were cultivated from childhood.

  5. SAMI Automated Plug Plate Configuration

    CERN Document Server

    Lorente, Nuria P F; Goodwin, Michael

    2012-01-01

    The Sydney-AAO Multi-object Integral field spectrograph (SAMI) is a prototype wide-field system at the Anglo-Australian Telescope (AAT) which uses a plug-plate to mount its 13 x 61-core imaging fibre bundles (hexabundles) in the optical path at the telescope's prime focus. In this paper we describe the process of determining the positions of the plug-plate holes, where plates contain three or more stacked observation configurations. The process, which up until now has involved several separate processes and has required significant manual configuration and checking, is now being automated to increase efficiency and reduce error. This is carried out by means of a thin Java controller layer which drives the configuration cycle. This layer controls the user interface and the C++ algorithm layer where the plate configuration and optimisation is carried out. Additionally, through the Aladin display package, it provides visualisation and facilitates user verification of the resulting plates.

  6. Coupling Motion and Energy Harvesting of Two Side-by-Side Flexible Plates in a 3D Uniform Flow

    Directory of Open Access Journals (Sweden)

    Dibo Dong

    2016-05-01

    Full Text Available The fluid-structure interaction problems of two side-by-side flexible plates with a finite aspect ratio in a three-dimensional (3D uniform flow are numerically studied. The plates’ motions are entirely passive under the force of surrounding fluid. By changing the aspect ratio and transverse distance, the coupling motions, drag force and energy capture performance are analyzed. The mechanisms underlying the plates’ motion and flow characteristics are discussed systematically. The adopted algorithm is verified and validated by the simulation of flow past a square flexible plate. The results show that the plate’s passive flapping behavior contains transverse and spanwise deformation, and the flapping amplitude is proportional to the aspect ratio. In the side-by-side configuration, three distinct coupling modes of the plates’ motion are identified, including single-plate mode, symmetrical flapping mode and decoupled mode. The plate with a lower aspect ratio may suffer less drag force and capture less bending energy than in the isolated situation. The optimized selection for obtaining higher energy conversion efficiency is the plate flapping in single-plate mode, especially the plate with a higher aspect ratio. The findings of this work provide several new physical insights into the understanding of fish schooling and are expected to inspire the developments of underwater robots or energy harvesters.

  7. Lasting mantle scars lead to perennial plate tectonics.

    Science.gov (United States)

    Heron, Philip J; Pysklywec, Russell N; Stephenson, Randell

    2016-06-10

    Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a 'perennial' phenomenon.

  8. Lasting mantle scars lead to perennial plate tectonics

    Science.gov (United States)

    Heron, Philip J.; Pysklywec, Russell N.; Stephenson, Randell

    2016-06-01

    Mid-ocean ridges, transform faults, subduction and continental collisions form the conventional theory of plate tectonics to explain non-rigid behaviour at plate boundaries. However, the theory does not explain directly the processes involved in intraplate deformation and seismicity. Recently, damage structures in the lithosphere have been linked to the origin of plate tectonics. Despite seismological imaging suggesting that inherited mantle lithosphere heterogeneities are ubiquitous, their plate tectonic role is rarely considered. Here we show that deep lithospheric anomalies can dominate shallow geological features in activating tectonics in plate interiors. In numerical experiments, we found that structures frozen into the mantle lithosphere through plate tectonic processes can behave as quasi-plate boundaries reactivated under far-field compressional forcing. Intraplate locations where proto-lithospheric plates have been scarred by earlier suturing could be regions where latent plate boundaries remain, and where plate tectonics processes are expressed as a `perennial' phenomenon.

  9. Self-propulsion of a three-dimensional flapping flexible plate

    Institute of Scientific and Technical Information of China (English)

    唐超; 陆夕云

    2016-01-01

    The self-propulsion of a 3-D flapping flexible plate in a stationary fluid is numerically studied by an immersed boundary- lattice Boltzmann method for the fluid flow and a finite element method for the plate motion. When the leading-edge of the plate is forced to heave sinusoidally, the entire plate starts to move freely as a result of the fluid-structure interaction. Based on our simula- tion and analysis on the dynamical behaviors of the flapping flexible plate, we have found that the effect of plate aspect ratio on its propulsive properties can be divided into three typical regimes which are related to the plate flexibility, i.e. stiff, medium flexible, and more flexible regime. It is also identified that a suitable structure flexibility, corresponding to the medium flexible regime, can improve the propulsive speed and efficiency. The wake behind the flapping plate is investigated for several aspect ratios to demon- strate some typical vortical structures. The results obtained in this study can provide some physical insights into the understanding of the propulsive mechanisms in the flapping-based locomotion.

  10. 46 CFR 195.11-20 - Marking and label plate.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Marking and label plate. 195.11-20 Section 195.11-20... plate. (a) All vans shall be provided with a label plate stating light weight, gross weight, and power requirements where applicable. (b) For vans subject to inspection label plates shall provide space for the date...

  11. Casimir densities for parallel plate in the Domain Wall background

    CERN Document Server

    Setare, M R

    2003-01-01

    The Casimir forces on two parallel plates in conformally flat domain wall background due to conformally coupled massless scalar field satisfying mixed boundary conditions on the plates is investigated. In the general case of mixed boundary conditions formulae are derived for the vacuum expectation values of the energy-momentum tensor and vacuum forces acting on boundaries.

  12. Microchannel plate streak camera

    Science.gov (United States)

    Wang, Ching L.

    1989-01-01

    An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 KeV x-rays.

  13. Line Heat-Source Guarded Hot Plate

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The 1-meter guarded hot-plate apparatus measures thermal conductivity of building insulation. This facility provides for absolute measurement of thermal...

  14. Line Heat-Source Guarded Hot Plate

    Data.gov (United States)

    Federal Laboratory Consortium — Description:The 1-meter guarded hot-plate apparatus measures thermal conductivity of building insulation. This facility provides for absolute measurement of thermal...

  15. Constraints on plate tectonics initiation from scaling laws for single-cell convection

    Science.gov (United States)

    Wong, Teresa; Solomatov, Viatcheslav S.

    2016-08-01

    The Earth is the only planet known to have plate tectonics, while other planets are covered with a stagnant lid. On the Earth, the initiation of subduction, which is thought to be the fundamental process for plate tectonics initiation, is caused not only by the negative buoyancy of the lithosphere but also by the forces from plate motions. However, for planets which do not have plate tectonics, the very first episode of lithospheric failure has to be caused by forces other than plate motions. Sublithospheric convection has been proposed as a possible mechanism that provides lithospheric instability through inducing stresses in the lithosphere, and lithospheric failure can occur when the yield stress is below a critical value. We test the applicability of scaling laws for the critical yield stress obtained in single-cell convection simulations to strongly time-dependent multi-cell systems. We show that with an appropriate choice of characteristic aspect ratio for the convective system, the scaling laws from single-cell simulations can be used to evaluate the conditions on the terrestrial planets in the inner Solar System for plate tectonics to exist. In agreement with previous studies, the estimated values for critical yield stress and coefficient of friction are much lower than the expected values for the Earth's lithosphere.

  16. Performance Study of Modified Savonius Water Turbine with Two Deflector Plates

    Directory of Open Access Journals (Sweden)

    Golecha Kailash

    2012-01-01

    Full Text Available Savonius rotor is a vertical axis rotor with simple in design and easy to fabricate at lower cost. The rotation of the rotor is due to the drag difference between the advancing blade and returning blade. Net driving force can be increased by reducing the reverse force on the returning blade or increasing the positive force on the advancing blade. Former can be realized by providing a flow obstacle to the returning blade and latter can be realized by concentrating the flow towards the advancing blade. The objective of the present work is to identify the optimal position of the deflector plate (on advancing blade side placed upstream to the flow which would result in increase in power generated by the rotor. Tests are conducted to identify the optimum position of the deflector plate on the advancing blade side in the presence of a deflector plate on the returning blade side at its optimum position. Results suggest that two deflector plates placed at their optimal positions upstream to the flow increase the coefficient of power to 0.35. This is significantly higher than the coefficient of power of 0.14 observed for the rotor without deflector plates.

  17. Forelimb and hindlimb ground reaction forces of walking cats: assessment and comparison with walking dogs.

    Science.gov (United States)

    Corbee, R J; Maas, H; Doornenbal, A; Hazewinkel, H A W

    2014-10-01

    The primary aim of this study was to assess the potential of force plate analysis for describing the stride cycle of the cat. The secondary aim was to define differences in feline and canine locomotion based on force plate characteristics. Ground reaction forces of 24 healthy cats were measured and compared with ground reaction forces of 24 healthy dogs. Force-time waveforms in cats generated by force plate analysis were consistent, as reflected by intra-class correlation coefficients for peak vertical force, peak propulsive force and peak braking force (0.94-0.95, 0.85-0.89 and 0.89-0.90, respectively). Compared with dogs, cats had a higher peak vertical force during the propulsion phase (cat, 3.89 ± 0.19 N/kg; dog, 3.03 ± 0.16 N/kg), and a higher hindlimb propulsive force (cat, -1.08 ± 0.13 N/kg; dog, (-0.87 ± 0.13 N/kg) and hindlimb impulse (cat, -0.18 ± 0.03 N/kg; dog, -0.14 ± 0.02 N/kg). Force plate analysis is a valuable tool for the assessment of locomotion in cats, because it can be applied in the clinical setting and provides a non-invasive and objective measurement of locomotion characteristics with high repeatability in cats, as well as information about kinetic characteristics. Differences in force-time waveforms between cats and dogs can be explained by the more crouched position of cats during stance and their more compliant gait compared with dogs. Feline waveforms of the medio-lateral ground reaction forces also differ between cats and dogs and this can be explained by differences in paw supination-pronation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. The concept of locking plates.

    Science.gov (United States)

    Cronier, P; Pietu, G; Dujardin, C; Bigorre, N; Ducellier, F; Gerard, R

    2010-05-01

    After a short historical review of locking bone plates since their inception more than a century ago to the success of the concept less than 15 years ago with today's plates, the authors present the main locking mechanisms in use. In the two broad categories - plates with fixed angulation and those with variable angulation - the screw head is locked in the plate with a locknut by screwing in a threaded chamber on the plate or by screwing through an adapted ring. The authors then provide a concrete explanation, based on simple mechanical models, of the fundamental differences between conventional bone plates and locking plates and why a locking screw system presents greater resistance at disassembly, detailing the role played by the position and number of screws. The advantages of epiphyseal fixation are then discussed, including in cases of mediocre-quality bone. For teaching purposes, the authors also present assembly with an apple fixed with five locking screws withstanding a 47-kg axial load with no resulting disassembly. The principles of plate placement are detailed for both the epiphysis and diaphysis, including the number and position of screws and respect of the soft tissues, with the greatest success assured by the minimally invasive and even percutaneous techniques. The authors then present the advantages of locking plates in fixation of periprosthetic fractures where conventional osteosynthesis often encounters limited success. Based on simplified theoretical cases, the economic impact in France of this type of implant is discussed, showing that on average it accounts for less than 10% of the overall cost of this pathology to society. Finally, the possible problems of material ablation are discussed as well as the means to remediate these problems.

  19. Processless offset printing plates

    Directory of Open Access Journals (Sweden)

    Sanja Mahović Poljaček

    2015-06-01

    Full Text Available With the implementation of platesetters in the offset printing plate making process, imaging of the printing plate became more stable and ensured increase of the printing plate quality. But as the chemical processing of the printing plates still highly influences the plate making process and the graphic reproduction workflow, development of printing plates that do not require chemical processing for offset printing technique has been one of the top interests in graphic technology in the last few years. The main reason for that came from the user experience, where majority of the problems with plate making process could be connected with the chemical processing of the printing plate. Furthermore, increased environmental standards lead to reducing of the chemicals used in the industrial processes. Considering these facts, different types of offset printing plates have been introduced to the market today. This paper presents some of the processless printing plates.

  20. The emergence of seismic cycles from stress feedback between intra-plate faulting and far-field tectonic loading

    Science.gov (United States)

    So, Byung-Dal; Capitanio, Fabio A.

    2016-08-01

    Using numerical modeling we show the emergence of cyclic slip behavior of faults from stress feedback through an idealized fault, its surrounding plates and far-field tectonic stress. The tectonic stress is exerted on the fault through a force applied along an idealized plate margin, acting on the fault, resulting from the interactions of viscous embedding and external plates. We find that, in such coupled system, the interaction of plates results into feedback with periodic deformation, slip along the fault and episodic plate margin motions. The viscosity of the embedding and loading plates primarily control the stress-loading time and hence the slip recurrence interval. For an Earth-like range of lithospheric viscosities, we derive a power-law with negative exponent, -0.99 to -0.5, scaling the recurrence period with loading-rate, providing an explanation for the observables from paleoseismology and geodesy. The feedback between single fault and far-field stress that arises from interactions of deforming plates provides a context to understand the earthquake cycle within continents, while reconciling the short-term seismic deformation to the long-term plate tectonics frame.

  1. Optimizing Casimir torque between corrugated metallic plates

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Robson B. [Universidade Federal Fluminense, Niteroi, RJ (Brazil); Maia Neto, Paulo A. [Instituto de Fisica, Universidade Federal do Rio de Janeiro, RJ (Brazil)

    2013-07-01

    Full text: The Casimir effect plays a major role in micro- and nano-electromechanical systems (MEMS and NEMS). Besides the normal Casimir force between metallic or dielectric plates, the observation of the lateral Casimir force between corrugated plates opens novel possibilities of micro-mechanical control. The lateral force results from breaking the translational symmetry along directions parallel to the plates by imprinting periodic corrugations on both metallic plates. As the rotational symmetry is broken by this geometry, a Casimir torque arises when the corrugations are not aligned. We calculate the Casimir torque between two parallel metallic plates with surface profiles in the form of 'fans' with arbitrary relative spatial orientation. As compared to the case of anisotropic dielectric plates, the torque per unit area is increased by up to three orders of magnitude for a given separation distance. The experiment proposed here can be performed with torsion pendulum techniques for separation distances as large as 1 μm. From the point of view of fundamental physics, this torque makes possible a precise experimental investigation of the non-trivial geometry dependence of the Casimir effect. We follow the scattering approach and calculate the Casimir energy up to second order in the corrugation amplitudes, taking into account nonspecular reflections, polarization mixing and the finite conductivity of the metals. We investigate the experimental conditions that optimize the effect. (author)

  2. Under Wind Load Numerical Simulation of Internal Force and Distortion on Curtain Wall Corner Type Aluminum Plate%转角型幕墙铝板风荷载作用下内力和变形的数值模拟

    Institute of Scientific and Technical Information of China (English)

    崔传芹

    2015-01-01

    阐述了转角型铝板和加劲肋构成的铝板幕墙的内力及变形计算,采用ANSYS软件,对板块由转角型铝板与5条加劲肋组成的复合结构的内力和变形进行计算,研究了加劲肋与铝板转角处由于局部铆钉松脱由刚结点变成铰接点后,其计算模型发生改变的应力及位移计算,最后介绍实际应用。%Using the ANSYS software, the internal force and displacement of the corner type plate structure which are composed of the trough type aluminum plate and 5 stiffening ribs are calculated. The stiffening rib and the aluminum plate corner partial rivet loosens by the rigid joint turns the hinge point is studied. The computation model is built and its biggest internal force and displacement are obtained. Finally,the practical application is introduced.

  3. Buckling analysis of a laminate plate

    Directory of Open Access Journals (Sweden)

    Mamuzić, I.

    2008-04-01

    Full Text Available The paper deals with a modeling of laminate plates and with their buckling analysis. To predict the inception of buckling for plates in plane resultant forces must be included. The buckling analysis is made by the help of finite element method in program COSMOS/M. For rectangular laminate plate consisting of 4 layers with symmetric and antisymmetric stacking sequence a buckling analysis is carried out. In the illustrative example there are depicted buckling modes for symmetric laminates [30/-30]s, [45/-45]s, [60/-60]s, [90/-90]s and results of the buckling analysis for the symmetric and antisymmetric laminates.

  4. Horizontally oriented plates in clouds

    CERN Document Server

    Bréon, François-Marie

    2011-01-01

    Horizontally oriented plates in clouds generate a sharp specular reflectance signal in the glint direction, often referred to as "subsun". This signal (amplitude and width) may be used to analyze the relative area fraction of oriented plates in the cloud top layer and their characteristic tilt angle to the horizontal. We make use of spaceborne measurements from the POLDER instrument to provide a statistical analysis of these parameters. More than half of the clouds show a detectable maximum reflectance in the glint direction, although this maximum may be rather faint. The typical effective fraction (area weighted) of oriented plates in clouds lies between 10-3 and 10-2. For those oriented plates, the characteristic tilt angle is less than 1 degree in most cases. These low fractions imply that the impact of oriented plates on the cloud albedo is insignificant. The largest proportion of clouds with horizontally oriented plates is found in the range 500-700 hPa, in agreement with typical in situ observation of p...

  5. Flow of nanofluid past a Riga plate

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, Adeel, E-mail: adeelahmed@comsats.edu.pk [Department of Mathematics, COMSATS Institute of Information Technology, Park Road, Chak Shahzad, 44000 Islamabad (Pakistan); Laboratoire J.A. Dieudonné, Université de Nice Sophia Antipolis, Parc Valrose, 06108 Nice (France); Asghar, Saleem [Department of Mathematics, COMSATS Institute of Information Technology, Park Road, Chak Shahzad, 44000 Islamabad (Pakistan); Department of Mathematics, King Abdul Aziz University, Jeddah (Saudi Arabia); Afzal, Sumaira [Department of Mathematics, COMSATS Institute of Information Technology, Park Road, Chak Shahzad, 44000 Islamabad (Pakistan)

    2016-03-15

    This paper studies the mixed convection boundary layer flow of a nanofluid past a vertical Riga plate in the presence of strong suction. The mathematical model incorporates the Brownian motion and thermophoresis effects due to nanofluid and the Grinberg-term for the wall parallel Lorentz force due to Riga plate. The analytical solution of the problem is presented using the perturbation method for small Brownian and thermophoresis diffusion parameters. The numerical solution is also presented to ensure the reliability of the asymptotic method. The comparison of the two solutions shows an excellent agreement. The correlation expressions for skin friction, Nusselt number and Sherwood number are developed by performing linear regression on the obtained numerical data. The effects of nanofluid and the Lorentz force due to Riga plate, on the skin friction are discussed. - Highlights: • Mixed convection flow of a nanofluid past a vertical Riga plate. • The Brownian motion and thermophoresis effects due to nanofluid are incorporated. • Grinberg-term represents the wall parallel Lorentz force due to Riga plate. • The correlation expressions for skin friction, Nusselt and Sherwood numbers are developed. • The effects of nanofluid and the Lorentz force on the skin friction are discussed.

  6. Evaluation of the overweight/obese child--practical tips for the primary health care provider: recommendations from the Childhood Obesity Task Force of the European Association for the Study of Obesity

    DEFF Research Database (Denmark)

    Baker, Jennifer L; Farpour-Lambert, Nathalie J; Nowicka, Paulina

    2010-01-01

    in the primary care setting. The tips and tools provided are based on data from the recent body of work that has been published in this field, official statements of several scientific societies along with expert opinion provided by the members of the Childhood Obesity Task Force (COTF) of the European......The prevalence of obesity among children and adolescents is on the rise. The majority of overweight or obese children are treated by primary health care providers including paediatricians, family practitioners, dieticians, nurses, and school health services - and not by specialists. The majority...... of obese children have no underlying medical disorder causing their obesity yet a significant proportion might suffer from obesity-related co-morbidities. This text is aimed at providing simple and practical tools for the identification and management of children with or at risk of overweight and obesity...

  7. Classical Casimir interaction of a perfectly conducting sphere and plate

    Science.gov (United States)

    Bimonte, Giuseppe

    2017-03-01

    We study the Casimir interaction between a perfectly conducting sphere and plate in the classical limit of high temperatures. By taking the small-distance expansion of the exact scattering formula, we compute the leading correction to the Casimir energy beyond the commonly employed proximity force approximation. We find that for a sphere of radius R at a distance d from the plate the correction is of the form ln2(d /R ), in agreement with indications from recent large-scale numerical computations. We develop a fast-converging numerical scheme for computing the Casimir interaction to high precision, based on bispherical partial waves, and we verify that the short-distance formula provides precise values of the Casimir energy also for fairly large distances.

  8. Buckling of Flat Thin Plates under Combined Loading

    Directory of Open Access Journals (Sweden)

    Ion DIMA

    2015-03-01

    Full Text Available This article aims to provide a quick methodology to determine the critical values of the forces applied to the central plane of a flat isotropic plate at which a change to the stable configuration of equilibrium occurs. Considering the variety of shapes, boundary conditions and loading combinations, the article does not intend to make an exhaustive presentation of the plate buckling. As an alternative, there will be presented only the most used configurations such as: rectangular flat thin plates, boundary conditions with simply supported (hinged or clamped (fixed edges, combined loadings with single compression or single shear or combination between them, compression and shear, with or without transverse loading, encountered at wings and control surfaces shell of fin and rudder or stabilizer and elevator. The reserve factor and the critical stresses will be calculated using comparatively two methods, namely the methodology proposed by the present article and ASSIST 6.6.2.0 – AIRBUS France software, a dedicated software to local calculations, for a simply supported plate under combined loading, compression on the both sides and shear.

  9. Microporous microchannel plates and method of manufacturing same

    Energy Technology Data Exchange (ETDEWEB)

    Beetz, C.P. Jr.; Boerstler, R.W.; Steinbeck, J.; Winn, D.R.

    2000-04-04

    A microchannel plate and method of manufacturing same is provided. The microchannel plate includes a plate consisting of an anodized material and a plurality of channels which are formed during the anodization of the material and extend between the two sides of the plate. Electrodes are also disposed on each side of the plate for generating an electrical field within the channels. Preferably, the material is alumina and the channels are activated such that the channel walls are conductive and highly secondary emissive.

  10. Microporous microchannel plates and method of manufacturing same

    Energy Technology Data Exchange (ETDEWEB)

    Beetz, Jr., Charles P. (New Milford, CT); Boerstler, Robert W. (Woodbury, CT); Steinbeck, John (Fitzwilliam, NH); Winn, David R. (Wilton, CT)

    2000-01-01

    A microchannel plate and method of manufacturing same is provided. The microchannel plate includes a plate consisting of an anodized material and a plurality of channels which are formed during the anodization of the material and extend between the two sides of the plate. Electrodes are also disposed on each side of the plate for generating an electrical field within the channels. Preferably, the material is alumina and the channels are activated such that the channel walls are conductive and highly secondary emissive.

  11. Microporous microchannel plates and method of manufacturing same

    Science.gov (United States)

    Beetz, Jr., Charles P.; Boerstler, Robert W.; Steinbeck, John; Winn, David R.

    2000-01-01

    A microchannel plate and method of manufacturing same is provided. The microchannel plate includes a plate consisting of an anodized material and a plurality of channels which are formed during the anodization of the material and extend between the two sides of the plate. Electrodes are also disposed on each side of the plate for generating an electrical field within the channels. Preferably, the material is alumina and the channels are activated such that the channel walls are conductive and highly secondary emissive.

  12. Geoid Data and Implications for Plate Tectonic Dynamics

    Science.gov (United States)

    Richardson, R. M.; Coblentz, D. D.

    2013-12-01

    Western U.S.) and geoid lows (e.g., the Congo Basin in Africa). All three of these geoid studies have implications for our understanding of the dynamics of plate tectonics. The 10-15 m geoid highs associated globally with ridges are consistent with a net force of ~3x1012 N/m due to 'ridge push.' Converting gradients in the oceanic 'lithospheric' geoid produce net torques on the plates consistent with this magnitude of 'ridge push.' The 6-9 meter geoid step up across passive continental margins is important for two reasons. First, it is consistent with a reduction of the ridge force acting on the continents, as evidenced by increased strike slip and normal deformation on the continents compared to oceanic lithosphere. Second, the very fact that such a small geoid step can affect tectonic style is evidence that even relatively small forces, like the ridge force compared to the negative buoyancy of subducted lithosphere, can be important in plate dynamics. Furthermore, the predicted intraplate stresses computed using a finite-element analysis of a lithospheric shell under traction from the gravitational potential energy forces associated with the lithospheric geoid provide a remarkably good fit between the predicted and observed intraplate stress field at long wavelengths (~1000km) and indicates that tectonic forces associated with the lithospheric density moment play an important role in global geodynamics.

  13. Pre-Stressing Timber-Based Plate Tensegrity Structures

    DEFF Research Database (Denmark)

    Falk, Andreas; Kirkegaard, Poul Henning

    2012-01-01

    Tensile structures occur in numerous varieties utilising combinations of tension and compression. Introducing structural plates in the basic tensegrity unit and tensegric assemblies varies the range of feasible topologies and provides the structural system with an integrated surface. The present...... paper considers the concept of plate tensegrity based on CLT plates (cross-laminated timber). It combines the principles of tensegrity with the principles of plate shells and is characterised by a plate shell stabilised by struts and cables. The paper deals with material aspects and robustness of timber......-based plate shells and outlines needs, methods and effects of controlling cable stresses for secured capacity, form and function of plate tensegrity....

  14. Create Your Plate

    Medline Plus

    Full Text Available ... steps to get started: Using your dinner plate, put a line down the middle of the plate. ... vegetables . Now in one of the small sections, put grains and starchy foods. See this list of ...

  15. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets ... 2016 Articles from Diabetes Forecast® magazine: wcie-meal-planning, In this section Food Planning Meals Diabetes Meal ...

  16. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal ... Healthy Diet Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook ...

  17. Food guide plate

    Science.gov (United States)

    ... chips or cookies. VEGETABLES: MAKE HALF OF YOUR PLATE FRUITS AND VEGETABLES Vegetables can be raw, fresh, ... as a snack. FRUITS: MAKE HALF OF YOUR PLATE FRUITS AND VEGETABLES Fruits can be fresh, canned, ...

  18. Growth Plate Fractures

    Science.gov (United States)

    ... the most widely used by doctors is the Salter-Harris system, described below. Type I Fractures These ... incidence of growth plate fractures peaks in adolescence. Salter-Harris classification of growth plate fractures. AAOS does ...

  19. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook ... Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook with Heart- ...

  20. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook ... Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook with Heart- ...

  1. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets you still choose the foods you want, but changes the portion sizes so you are getting larger ...

  2. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets ... Sleeve Custom jerseys for your Tour de Cure team benefits the cause. Ask the Experts: Learn to ...

  3. Evaluation of the overweight/obese child--practical tips for the primary health care provider: recommendations from the Childhood Obesity Task Force of the European Association for the Study of Obesity

    DEFF Research Database (Denmark)

    Baker, Jennifer L; Farpour-Lambert, Nathalie J; Nowicka, Paulina

    2010-01-01

    The prevalence of obesity among children and adolescents is on the rise. The majority of overweight or obese children are treated by primary health care providers including paediatricians, family practitioners, dieticians, nurses, and school health services - and not by specialists. The majority...... in the primary care setting. The tips and tools provided are based on data from the recent body of work that has been published in this field, official statements of several scientific societies along with expert opinion provided by the members of the Childhood Obesity Task Force (COTF) of the European...... Association for the Study of Obesity (EASO). We have attempted to use an evidence-based approach while allowing flexibility for the practicing clinician in domains where evidence is currently lacking and ensuring that treating the obese child involves the entire family as well....

  4. Accelerated plate tectonics.

    Science.gov (United States)

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence.

  5. Create Your Plate

    Medline Plus

    Full Text Available ... Reset Plate Share Create Your Plate ! Share: Seven Simple Steps to Create Your Plate It's simple and effective for both managing diabetes and losing ... en.html Have Type 2 Diabetes? Our free program will help you live well. More from diabetes. ...

  6. Interface contact profiles of a novel locking plate and its effect on fracture healing in goat

    Institute of Scientific and Technical Information of China (English)

    WEI Da-cheng; ZHAO Yu-feng; XING Shu-xing; WANG Ai-min

    2010-01-01

    Objective: To evaluate the interface characteristics of the new-designed locking plate (LP) and limited contact-dynamic compression plate (LC-DCP) and compare the fracture healing between LP and LC-DCP in a goat tibia fracture model.Methods: Eight-hole LP and LC-DCP were applied to fix flesh goat tibiae in a reproducible manner. The average pressure, force and interface contact area were calculated using Fuji prescale pressure sensitive film interposed among the plate and the bone and image analysis system. Eighthole LP and LC-DCP were applied to each tibia in a goat tibia fracture model. The fracture healing was evaluated by X-ray photography at postoperative 8 weeks. The goats were sacrificed at postoperative 12 weeks. Three-point bending test was conducted in the tibiae.Results: The interface contact of LP system was smaller than that ofLC-DCP (P<0.05), while interface contact force of LP system was higher than that of LC-DCP (P<0.05). Radiographs revealed that the fracture line disappeared in the LP group, while the fracture line was visible in DCP group at postoperative 8 weeks. At postoperative 12 weeks, the bending strength and bending load of fractured tibia were higher in LP group than in DCP group, respectively.Conclusion: The new-designed locking plate can significantly decrease the contact area on the bone interface,which further provides better fracture healing than conventional plates.

  7. Analytical solution for multilayer plates using general layerwise plate theory

    Directory of Open Access Journals (Sweden)

    Vuksanović Đorđe M.

    2005-01-01

    Full Text Available This paper deals with closed-form solution for static analysis of simply supported composite plate, based on generalized laminate plate theory (GLPT. The mathematical model assumes piece-wise linear variation of in-plane displacement components and a constant transverse displacement through the thickness. It also include discrete transverse shear effect into the assumed displacement field, thus providing accurate prediction of transverse shear stresses. Namely, transverse stresses satisfy Hook's law, 3D equilibrium equations and traction free boundary conditions. With assumed displacement field, linear strain-displacement relation, and constitutive equations of the lamina, equilibrium equations are derived using principle of virtual displacements. Navier-type closed form solution of GLPT, is derived for simply supported plate, made of orthotropic laminae, loaded by harmonic and uniform distribution of transverse pressure. Results are compared with 3D elasticity solutions and excellent agreement is found.

  8. Angular shear plate

    Science.gov (United States)

    Ruda, Mitchell C [Tucson, AZ; Greynolds, Alan W [Tucson, AZ; Stuhlinger, Tilman W [Tucson, AZ

    2009-07-14

    One or more disc-shaped angular shear plates each include a region thereon having a thickness that varies with a nonlinear function. For the case of two such shear plates, they are positioned in a facing relationship and rotated relative to each other. Light passing through the variable thickness regions in the angular plates is refracted. By properly timing the relative rotation of the plates and by the use of an appropriate polynomial function for the thickness of the shear plate, light passing therethrough can be focused at variable positions.

  9. Rapidly Moving Divertor Plates In A Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    S. Zweben

    2011-05-16

    It may be possible to replace conventional actively cooled tokamak divertor plates with a set of rapidly moving, passively cooled divertor plates on rails. These plates would absorb the plasma heat flux with their thermal inertia for ~10-30 sec, and would then be removed from the vessel for processing. When outside the tokamak, these plates could be cooled, cleaned, recoated, inspected, and then returned to the vessel in an automated loop. This scheme could provide nearoptimal divertor surfaces at all times, and avoid the need to stop machine operation for repair of damaged or eroded plates. We describe various possible divertor plate designs and access geometries, and discuss an initial design for a movable and removable divertor module for NSTX-U.

  10. Actively controlling coolant-cooled cold plate configuration

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Parida, Pritish R.

    2016-04-26

    Cooling apparatuses are provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The cooling apparatus includes the cold plate and a controller. The cold plate couples to one or more electronic components to be cooled, and includes an adjustable physical configuration. The controller dynamically varies the adjustable physical configuration of the cold plate based on a monitored variable associated with the cold plate or the electronic component(s) being cooled by the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, for example, optimally cool the electronic component(s), and at the same time, reduce cooling power consumption used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the cold plate, the positioning of which may be adjusted based on the monitored variable.

  11. Plate Tectonic Cycle. K-6 Science Curriculum.

    Science.gov (United States)

    Blueford, J. R.; And Others

    Plate Tectonics Cycle is one of the units of a K-6 unified science curriculum program. The unit consists of four organizing sub-themes: (1) volcanoes (covering formation, distribution, and major volcanic groups); (2) earthquakes (with investigations on wave movements, seismograms and sub-suface earth currents); (3) plate tectonics (providing maps…

  12. Quality Assurance of Process Free Thermal Plates

    Directory of Open Access Journals (Sweden)

    Thomas Hoffmann-Walbeck

    2015-09-01

    Full Text Available In this paper a method for manual processing of process free printing plates is defined which ensures reproducible results. This decoating procedure can help print service providers with certain quality checks (like linearization that are otherwise more expensive or even not feasible altogether for such plates. This method holds for quality assurance only and is not suitable for the actual production.

  13. Flow of nanofluid past a Riga plate

    Science.gov (United States)

    Ahmad, Adeel; Asghar, Saleem; Afzal, Sumaira

    2016-03-01

    This paper studies the mixed convection boundary layer flow of a nanofluid past a vertical Riga plate in the presence of strong suction. The mathematical model incorporates the Brownian motion and thermophoresis effects due to nanofluid and the Grinberg-term for the wall parallel Lorentz force due to Riga plate. The analytical solution of the problem is presented using the perturbation method for small Brownian and thermophoresis diffusion parameters. The numerical solution is also presented to ensure the reliability of the asymptotic method. The comparison of the two solutions shows an excellent agreement. The correlation expressions for skin friction, Nusselt number and Sherwood number are developed by performing linear regression on the obtained numerical data. The effects of nanofluid and the Lorentz force due to Riga plate, on the skin friction are discussed.

  14. Numerical Investigation on Submerged Horizontal Plate

    Institute of Scientific and Technical Information of China (English)

    康海贵; 王科

    2001-01-01

    Hydrodynamic characters on a horizontal, thin, rigid plate located beneath the free surface are numerically investigated. Assuming a linear, time-harmonic potential flow and utilizing Green identity, the governing Laplace equation can be simplified into Fredholm integral equation ofthe second kind. Supposing linear-order discontinuous elements along intersecting vertical boundaries, and by use of the boundary element method, numerical solution about source strength distribution on the plate can be changed into a series of algebraic equations. The 3D Green function is introduced to set up the integral equations, and the GMRES solver is performed for solving the large dense linear system of equations. The added-mass, damping force and exciting force are evaluated directly from the equations. It is found that the added-mass coefficient becomes negative for a range of frequencies when the plate is sufficiently close to the free surface.

  15. Outcome of Femoral Plate Osteosynthesis in a Teaching Hospital in ...

    African Journals Online (AJOL)

    Valued eMachines Customer

    The scope of femoral fracture is wide and generally high energy forces are involved with multi- system trauma in ... concentration and packed cell volumes. One hundred and .... Alternatives include traction with or without cast bracing, plate.

  16. Convection pattern and stress system under the African plate

    Science.gov (United States)

    Liu, H.-S.

    1977-01-01

    Studies on tectonic forces from satellite-derived gravity data have revealed a subcrustal stress system which provides a unifying mechanism for uplift, depression, rifting, plate motion and ore formation in Africa. The subcrustal stresses are due to mantle convection. Seismicity, volcanicity and kimberlite magmatism in Africa and the development of the African tectonic and magnetic features are explained in terms of this single stress system. The tensional stress fields in the crust exerted by the upwelling mantle flows are shown to be regions of structural kinship characterized by major concentration of mineral deposits. It is probable that the space techniques are capable of detecting and determining the tectonic forces in the crust of Africa.

  17. Generalized Fibonacci zone plates

    CERN Document Server

    Ke, Jie; Zhu, Jianqiang

    2015-01-01

    We propose a family of zone plates which are produced by the generalized Fibonacci sequences and their axial focusing properties are analyzed in detail. Compared with traditional Fresnel zone plates, the generalized Fibonacci zone plates present two axial foci with equal intensity. Besides, we propose an approach to adjust the axial locations of the two foci by means of different optical path difference, and further give the deterministic ratio of the two focal distances which attributes to their own generalized Fibonacci sequences. The generalized Fibonacci zone plates may allow for new applications in micro and nanophotonics.

  18. A REVIEW PAPER ON RECOGNIZE AUTOMATIC NUMBER PLATE AND BLURRED NUMBER PLATES

    OpenAIRE

    Aarti Soni*, Dr.Raman Chadha, Sukhmeet Kaur

    2016-01-01

    This review paper provides a brief survey on various recognition techniques for automatic number plate recognition (ANPR) in image processing. ANPR is real –time embedded system which uses number plate to identify the vehicle. This expertise is in advance popularity in security and traffic installations. License plate recognition system is an application of computer vision. Computer vision is a method of using a computer to take out high level information from a digital image. The usele...

  19. Medicare Provider Data - Hospice Providers

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Hospice Utilization and Payment Public Use File provides information on services provided to Medicare beneficiaries by hospice providers. The Hospice PUF...

  20. The Light Velocity Casimir Effect Does the Velocity of Light Increase when Propagating Between the Casimir Plates?

    CERN Document Server

    Ostoma, T; Ostoma, Tom; Trushyk, Mike

    1999-01-01

    We propose experiments that might be set up to detect the increase in the velocity of light in a vacuum in the laboratory frame for photons travelling between (and perpendicular to) the Casimir plates in a vacuum. The Casimir plates are two closely spaced, conductive plates, where an attractive force is observed to exist between the plates called the 'Casimir Force'. We propose that the velocity of light in a vacuum increases when propagating between two transparent Casimir Plates. We call this effect the 'Light Velocity Casimir Effect' or LVC effect. The LVC effect happens because the vacuum energy density in between the plates is lower than that outside the Casimir plates. The conductive plates disallow certain frequencies of electrically charged virtual particles to exist inside the plates, thus lowering the inside vacuum particle density, compared to the density outside the plates. The reduced (electrically charged) virtual particle density results in fewer photon scattering events inside the plates, whic...

  1. Transversal vibrations of double-plate systems

    Institute of Scientific and Technical Information of China (English)

    Katica(Stevanovi(c)) Hedrih

    2006-01-01

    This paper presents an analytical and numerical analysis of free and forced transversal vibrations of an elastically connected double-plate system. Analytical solutions of a system of coupled partial differential equations, which describe corresponding dynamical free and forced processes, are obtained using Bernoulli's particular integral and Lagrange's method of variation constants. It is shown that one-mode vibrations correspond to two-frequency regime for free vibrations induced by initial conditions and to three-frequency regime for forced vibrations induced by one-frequency external excitation and corresponding initial conditions. The analytical solutions show that the elastic connection between plates leads to the appearance of twofrequency regime of time function, which corresponds to one eigenamplitude function of one mode, and also that the time functions of different vibration modes are uncoupled, for each shape of vibrations. It has been proven that for both elastically connected plates, for every pair of m and n. two possibilities for appearance of the resonance dynamical states, as well as for appearance of the dynamical absorption, are present. Using the MathCad program, the corresponding visualizations of the characteristic forms of the plate middle surfaces through time are presented.

  2. Atomic Force Microscope Mediated Chromatography

    Science.gov (United States)

    Anderson, Mark S.

    2013-01-01

    sliding plate system, consisting of two flat surfaces, one of which has a recessed channel. A fluid flow is produced by axially sliding one plate past another, where the fluid has mechanical shear forces imposed at each point along the channel length. The shear-induced flow rates are very reproducible, and do not have pressure or voltage gradient limitations. SDC opens up a new range of enhanced separation kinetics by permitting the sample confinement with submicron dimensions. Small, highly confined liquid is advantageous for chromatographic separation because the separation rate is known to scale according to the square of the confined sample diameter. In addition, because shear-driven flows are not limited by fluid velocity, shear-driven liquid chromatography may provide up to 100,000 plate efficiency.

  3. Validating the BTrackS Balance Plate as a low cost alternative for the measurement of sway-induced center of pressure.

    Science.gov (United States)

    O'Connor, Shawn M; Baweja, Harsimran S; Goble, Daniel J

    2016-12-08

    The BTrackS Balance Plate (BBP) is a low-cost force plate that provides objective balance assessment and true portability for the user. Given that this technology is relatively new, the purpose of the present study was to provide the first center of pressure (COP) validation of the BBP. Two BBP devices (one new and one used) were compared with a laboratory-grade force plate (LFP) during simultaneous collection of COP that was induced by an inverted pendulum device with human-like sway characteristics. The results of this study showed almost perfect agreement between the BBP devices and the LFP (ICC>0.999), as well as a high degree of BBP accuracy (cost solution for objective balance testing in the laboratory or clinic.

  4. GENERALIZED VARIATIONAL PRINCIPLESFOR VISCOELASTIC THIN AND THICK PLATES WITH DAMAGE

    Institute of Scientific and Technical Information of China (English)

    ShengDongfa; ChengChangjun

    2004-01-01

    From the constitutive model with generalized force fields for a viscoelastic body with damage, the differential equations of motion for thin and thick plates with damage are derived under arbitrary boundary conditions. The convolution-type functionals for the bending of viscoelastic thin and thick plates with damage are presented, and the corresponding generalized variational principles are given. From these generalized principles, all the basic equations of the displacement and damage variables and initial and boundary conditions can be deduced. As an example, we compare the difference between the dynamical properties of plates with and without damage and consider the effect of damage on the dynamical properties of plates.

  5. Flutter suppression of plates using passive constrained viscoelastic layers

    Science.gov (United States)

    Cunha-Filho, A. G.; de Lima, A. M. G.; Donadon, M. V.; Leão, L. S.

    2016-10-01

    Flutter in aeronautical panels is a self-excited aeroelastic phenomenon which occurs during supersonic flights due to dynamic instability of inertia, elastic and aerodynamic forces of the system. In the flutter condition, when the critical aerodynamic pressure is reached, the vibration amplitudes of the panel become dynamically unstable and increase exponentially with time, significantly affecting the fatigue life of the existing aeronautical components. Thus, in this paper, the interest is to investigate the possibility reducing the effects of the supersonic aeroelastic instability of rectangular plates by applying passive constrained viscoelastic layers. The rationale for such study is the fact that as the addition of viscoelastic materials provides decreased vibration amplitudes it becomes important to quantify the suppression of plate flutter coalescence modes that can be obtained. Moreover, despite the fact that much research on the suppression of panel flutter has been carried out by using passive, semi-active and active control techniques, few works have been proposed to deal with the problem of predicting the flutter boundary of aeroviscoelastic systems, since they must conveniently account for the frequency- and temperature-dependent behavior of the viscoelastic material. After the presentation of the theoretical foundations of the methodology, the description of a numerical study on the flutter analysis of a three-layer sandwich plate is addressed.

  6. Finite element model calibration of a nonlinear perforated plate

    Science.gov (United States)

    Ehrhardt, David A.; Allen, Matthew S.; Beberniss, Timothy J.; Neild, Simon A.

    2017-03-01

    This paper presents a case study in which the finite element model for a curved circular plate is calibrated to reproduce both the linear and nonlinear dynamic response measured from two nominally identical samples. The linear dynamic response is described with the linear natural frequencies and mode shapes identified with a roving hammer test. Due to the uncertainty in the stiffness characteristics from the manufactured perforations, the linear natural frequencies are used to update the effective modulus of elasticity of the full order finite element model (FEM). The nonlinear dynamic response is described with nonlinear normal modes (NNMs) measured using force appropriation and high speed 3D digital image correlation (3D-DIC). The measured NNMs are used to update the boundary conditions of the full order FEM through comparison with NNMs calculated from a nonlinear reduced order model (NLROM). This comparison revealed that the nonlinear behavior could not be captured without accounting for the small curvature of the plate from manufacturing as confirmed in literature. So, 3D-DIC was also used to identify the initial static curvature of each plate and the resulting curvature was included in the full order FEM. The updated models are then used to understand how the stress distribution changes at large response amplitudes providing a possible explanation of failures observed during testing.

  7. Blue Willow Story Plates

    Science.gov (United States)

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  8. Create Your Plate

    Medline Plus

    Full Text Available ... In Memory In Honor Become a Member En Español Type 1 Type 2 About Us Online Community ... Page Text Size: A A A Listen En Español Create Your Plate Create Your Plate is a ...

  9. Create Your Plate

    Medline Plus

    Full Text Available ... Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal Planning ... Planning Meals Diabetes Meal Plans and a Healthy Diet Create Your Plate Meal Planning for Vegetarian Diets ...

  10. Matter-screened Casimir force and Casimir-Polder force in planar structures

    CERN Document Server

    Raabe, C; Raabe, Christian; Welsch, Dirk-Gunnar

    2005-01-01

    Using a recently developed theory of the Casimir force (Raabe C and Welsch D-G 2005 Phys. Rev. A 71 013814), we calculate the force that acts on a plate in front of a planar wall and the force that acts on the plate in the case where the plate is part of matter that fills the space in front of the wall. We show that in the limit of a dielectric plate whose permittivity is close to unity, the force obtained in the former case reduces to the ordinary, i.e., unscreened Casimir-Polder force acting on isolated atoms. In the latter case, the theory yields the Casimir-Polder force that is screened by the surrounding matter.

  11. Fuzzy Vibration Control of a Smart Plate

    Science.gov (United States)

    Muradova, Aliki D.; Stavroulakis, Georgios E.

    2013-04-01

    Vibration suppression of a smart thin elastic rectangular plate is considered. The plate is subjected to external disturbances and generalized control forces, produced, for instance, by electromechanical feedback. A nonlinear controller is designed, based on fuzzy inference. The initial-boundary value problem is spatially discretized by means of the time spectral method. The implicit Newmark-beta method is employed for time integration. Two numerical algorithms are proposed. The techniques have been implemented within MATLAB with the use of the Fuzzy Logic Toolbox. Representative numerical results are given.

  12. Energy of plate tectonics calculation and projection

    Directory of Open Access Journals (Sweden)

    N. H. Swedan

    2013-02-01

    Full Text Available Mathematics and observations suggest that the energy of the geological activities resulting from plate tectonics is equal to the latent heat of melting, calculated at mantle's pressure, of the new ocean crust created at midocean ridges following sea floor spreading. This energy varies with the temperature of ocean floor, which is correlated with surface temperature. The objective of this manuscript is to calculate the force that drives plate tectonics, estimate the energy released, verify the calculations based on experiments and observations, and project the increase of geological activities with surface temperature rise caused by climate change.

  13. Creation of the Cocos and Nazca plates by fission of the Farallon plate

    Science.gov (United States)

    Lonsdale, Peter

    2005-08-01

    -Nazca spreading was a linear feature that, at least through the 680 km of ruptured Oligocene lithosphere known to have avoided subduction, did not follow any pre-existing feature on the Farallon plate, e.g., a "fracture zone" trail of a transform fault. (iv) The margins of surviving parts of the plate-splitting fracture have narrow shoulders raised by uplift of unloaded footwalls, and partially buried by fissural volcanism. (v) Cocos-Nazca spreading began at 23 Ma; reports of older Cocos-Nazca crust in the eastern Panama Basin were based on misidentified magnetic anomalies. There is increased evidence that the driving force for the 23 Ma fission of the Farallon plate was the divergence of slab-pull stresses at the Middle America and South America subduction zones. The timing and location of the split may have been influenced by (i) the increasingly divergent northeast slab pull at the Middle America subduction zone, which lengthened and reoriented because of motion between the North America and Caribbean plates; (ii) the slightly earlier detachment of a northern part of the plate that had been entering the California subduction zone, contributing a less divergent plate-driving stress; and (iii) weakening of older parts of the plate by the Galapagos hotspot, which had come to underlie the equatorial region, midway between the risecrest and the two subduction zones, by the Late Oligocene.

  14. THE EFFECT OF SUPPORT PLATE ON DRILLING-INDUCED DELAMINATION

    Directory of Open Access Journals (Sweden)

    Navid Zarif Karimi

    2016-02-01

    Full Text Available Delamination is considered as a major problem in drilling of composite materials, which degrades the mechanical properties of these materials. The thrust force exerted by the drill is considered as the major cause of delamination; and one practical approach to reduce delamination is to use a back-up plate under the specimen. In this paper, the effect of exit support plate on delamination in twist drilling of glass fiber reinforced composites is studied. Firstly, two analytical models based on linear fracture mechanics and elastic bending theory of plates are described to find critical thrust forces at the beginning of crack growth for drilling with and without back-up plate. Secondly, two series of experiments are carried out on glass fiber reinforced composites to determine quantitatively the effect of drilling parameters on the amount of delamination. Experimental findings verify a large reduction in the amount of delaminated area when a back-up plate is placed under the specimen.

  15. Features of Flow Past Square Cylinder with a Perforated Plate

    Institute of Scientific and Technical Information of China (English)

    汪健生; 徐亚坤; 程浩杰

    2016-01-01

    A numerical investigation was performed on the reduction of the fluid forces acting on the square cylin-der in the laminar flow regime with a perforated plate. The effects of geometric parameters such as the distance between the square cylinder and the perforated plate on the wake of the square cylinder were discussed. Further-more, the flow characteristics such as the drag coefficient, lift coefficient, Strouhal number and flow pattern were obtained. It can be concluded that the drag force of the square cylinder reduces to some extent due to the addition of the perforated plate. The flow structure varies when the perforated plate is located behind the square cylinder. Moreover, the recirculation zone augments with the increase ofL/D, and the vortex trace on the upper and lower surface of the square cylinder moves gradually backwards until a stable recirculation zone formed between the square cylinder and the perforated plate.

  16. Diffuse oceanic plate boundaries: Strain rates, vertically averaged rheology, and comparisons with narrow plate boundaries and stable plate interiors

    Science.gov (United States)

    Gordon, Richard G.

    Diffuse plate boundaries occur in both oceanic and continental lithosphere and cover ≈ 15% of Earth's solid surface. The fastest plate speeds accommodated across diffuse oceanic plate boundaries are ≈ 15 mm/yr. The smallest strain rates averaged across narrow plate boundaries are at least 102 times larger than the largest strain rates across diffuse oceanic plate boundaries and at least 102 times larger than those across stable plate interiors. The effective viscosity (ηeff) of the lithosphere is estimated from the ratio of vertically averaged shear stresses to strain rates for three tectonic settings: (i) oceanic transform fault zones, for which ηeff = 3 ×1016 to 5×1019 Pa s, comparable to estimates for the asthenosphere, (ii) diffuse oceanic plate boundaries, for which ηeff = 1×1023 to 6×l023 Pa s, ≈ 10 times larger than for diffuse continental plate boundaries, and (iii) stable plate interiors, for which ηeff = 1x1024 to 2×1027 Pa s. The rheology of oceanic lithosphere over times longer than earthquake cycles is modeled as a plastic layer overlying a layer that deforms by creeping flow [Martinod and Davy, 1992]. Oceanic lithosphere deforms when the yield strength of the upper lithosphere is exceeded. The vertically averaged rheology of deforming oceanic lithosphere can be approximated by a power-law fluid for which ɛ. ∝ (τs)n where ɛ. is the rate of shear strain and τs is the shear stress. If the ratio of the yield strength of the upper lithosphere to the force required to deform the lower lithosphere at a strain rate of 10-16 s-1 is varied from 10-2 to 102 , the calculated value of n varies from ≈3 to ≈300. The map-view aspect ratio of a deforming zone in a thin sheet of power-law fluid is proportional to n-½ [England et al., 1985]. A profile of displacement versus distance inferred from a seismic profile across the Central Indian Basin (India-Capricorn diffuse oceanic plate boundary), where the lithosphere is about 60-Myr old

  17. Providing affinity

    DEFF Research Database (Denmark)

    Guglielmi, Michel; Johannesen, Hl

    2004-01-01

    This paper will introduce a project sourced by an ideas competition called Landmark East England. It was open to anyone with the ability to develop and deliver a visionary idea for a landmark. A sustainable icon representing a new region in England, which comprises Bedfordshire, Cambridgeshire......, Essex, Hertfordshire, Norfolk and Suffolk. Research found that there was a lack of identity or sense of belonging and nothing anchoring people to the region as a whole. Common affinity is somehow forced to the people of East England and thereby we came to the conclusion that a single landmark...... or a series of landmarks would do little to achieve true affinity. Therefore, we based our design strategy in trying to elaborate an alternatereality based on fabulation, virtualization and narratives that we subtly interweaved into architectonic structures (fabric) of the real. We have created plots...

  18. A new refined theory of plates with transverse shear deformation for moderately thick and thick plates

    CERN Document Server

    Valle, Jose Miguel Martinez

    2015-01-01

    In this paper we propose a new refined shear deformation plate theory which possesses a series of desirable features, the most salient of which are as follows: (i) The loads, which are generally considered to be applied on the middle surface of the plate, act on the upper surface of the plate; (ii) The equations are applicable to the calculation of the stresses in isotropic plates and provide the same order of accuracy as several theories with second order shear deformation effects; (iii) It constitutes a theory, in the sense defined by Love, since it gives easy expressions for application to problems in different fields in architecture and civil engineering

  19. Vibrations of a Mindlin plate subjected to a pair of inertial loads moving in opposite directions

    Science.gov (United States)

    Dyniewicz, Bartłomiej; Pisarski, Dominik; Bajer, Czesław I.

    2017-01-01

    A Mindlin plate subjected to a pair of inertial loads traveling at a constant high speed in opposite directions along arbitrary trajectory, straight or curved, is presented. The masses represent vehicles passing a bridge or track plates. A numerical solution is obtained using the space-time finite element method, since it allows a clear and simple derivation of the characteristic matrices of the time-stepping procedure. The transition from one spatial finite element to another must be energetically consistent. In the case of the moving inertial load the classical time-integration schemes are methodologically difficult, since we consider the Dirac delta term with a moving argument. The proposed numerical approach provides the correct definition of force equilibrium in the time interval. The given approach closes the problem of the numerical analysis of vibration of a structure subjected to inertial loads moving arbitrarily with acceleration. The results obtained for a massless and an inertial load traveling over a Mindlin plate at various speeds are compared with benchmark results obtained for a Kirchhoff plate. The pair of inertial forces traveling in opposite directions causes displacements and stresses more than twice as large as their corresponding quantities observed for the passage of a single mass.

  20. Solving the problem of elasticity for round thick plates at axially symmetric strain

    Directory of Open Access Journals (Sweden)

    Oleksiy Hvertsev

    2016-12-01

    Full Text Available An exact solution of the equations of elasticity for round plates loaded axially symmetric. The problem of bending round plates, which are under the influence of normal forces attached to any law to load any type of resistance. It is shown that pasture circular plate under axially symmetric load leads to appearance of temperature field.

  1. Post-buckling capacity of bi-axially loaded rectangular steel plates

    DEFF Research Database (Denmark)

    Jönsson, Jeppe; Bondum, T. H.

    2012-01-01

    Results from a detailed numerical investigation of the post-buckling behaviour of rectangular simply supported steel plates subjected to biaxial in-plane loading are presented. The Steel plates are loaded through forced edge displacements. The effects of initial imperfections, aspect ratio, plate...

  2. Experiments to investigate lift production mechanisms on pitching flat plates

    Science.gov (United States)

    Stevens, P. R. R. J.; Babinsky, H.

    2017-01-01

    Pitching flat plates are a useful simplification of flapping wings, and their study can provide useful insights into unsteady force generation. Non-circulatory and circulatory lift producing mechanisms for low Reynolds number pitching flat plates are investigated. A series of experiments are designed to measure forces and study the unsteady flowfield development. Two pitch axis positions are investigated, namely a leading edge and a mid-chord pitch axis. A novel PIV approach using twin laser lightsheets is shown to be effective at acquiring full field of view velocity data when an opaque wing model is used. Leading-edge vortex (LEV) circulations are extracted from velocity field data, using a Lamb-Oseen vortex fitting algorithm. LEV and trailing-edge vortex positions are also extracted. It is shown that the circulation of the LEV, as determined from PIV data, approximately matches the general trend of an unmodified Wagner function for a leading edge pitch axis and a modified Wagner function for a mid-chord pitch axis. Comparison of experimentally measured lift correlates well with the prediction of a reduced-order model for a LE pitch axis.

  3. Electroless metal plating of plastics

    Science.gov (United States)

    Krause, Lawrence J.

    1984-01-01

    Process for plating main group metals on aromatic polymers is carried out by the use of a nonaqueous solution of a salt of an alkali metal in a positive valence state and a main group metal in a negative valence state with contact between the solution and polymer providing a redox reaction causing the deposition of the main group metal and the reduction of the polymer. Products from the process exhibit useful decorative and electrical properties.

  4. Grain-damage hysteresis and plate tectonic states

    Science.gov (United States)

    Bercovici, David; Ricard, Yanick

    2016-04-01

    Shear localization in the lithosphere is an essential ingredient for understanding how and why plate tectonics is generated from mantle convection on terrestrial planets. The theoretical model for grain-damage and pinning in two-phase polycrystalline rocks provides a frame-work for understanding lithospheric shear weakening and plate-generation, and is consistent with laboratory and field observations of mylonites. Grain size evolves through the competition between coarsening, which drives grain-growth, and damage, which drives grain reduction. The interface between crystalline phases controls Zener pinning, which impedes grain growth. Damage to the interface enhances the Zener pinning effect, which then reduces grain-size, forcing the rheology into the grain-size-dependent diffusion creep regime. This process thus allows damage and rheological weakening to co-exist, providing a necessary positive self-weakening feedback. Moreover, because pinning inhibits grain-growth it promotes shear-zone longevity and plate-boundary inheritance. However, the suppression of interface damage at low interface curvature (wherein inter-grain mixing is inefficient and other energy sinks of deformational work are potentially more facile) causes a hysteresis effect, in which three possible equilibrium grain-sizes for a given stress coexist: (1) a stable, large-grain, weakly-deforming state, (2) a stable, small-grain, rapidly-deforming state analogous to ultramylonites, and (3) an unstable, intermediate grain-size state perhaps comparable to protomylonites. A comparison of the model to field data suggests that shear-localized zones of small-grain mylonites and ultra-mylonites exist at a lower stress than the co-existing large-grain porphyroclasts, rather than, as predicted by paleopiezometers or paleowattmeters, at a much higher stress; this interpretation of field data thus allows localization to relieve instead of accumulate stress. The model also predicts that a lithosphere that

  5. License Plate Recognition for Parking Control System by Mathematical Morphology

    Institute of Scientific and Technical Information of China (English)

    Javier Ortiz; Alberto Gómez

    2014-01-01

    Nowadays, license plate recognition for parking systems is a critical task to provide automatic control of customers and payment. This paper introduces a new method for automatic recognition of license plates of vehicles by mathematical morphology. The proposed method can provide the license plate number of the plates in different light conditions, colors, sizes, and inclination (angles). The algorithm can recognize the license plates of European Union vehicles quickly and correctly. The pattern learning of mathematical skeletons has high efficiency in the process. The performance of the algorithm is demonstrated well by the test in a parking control system.

  6. On a consistent finite-strain plate theory based on 3-D energy principle

    CERN Document Server

    Dai, Hui-Hui

    2014-01-01

    This paper derives a finite-strain plate theory consistent with the principle of stationary three-dimensional (3-D) potential energy under general loadings with a third-order error. Staring from the 3-D nonlinear elasticity (with both geometrical and material nonlinearity) and by a series expansion, we deduce a vector plate equation with three unknowns, which exhibits the local force-balance structure. The success relies on using the 3-D field equations and bottom traction condition to derive exact recursion relations for the coefficients. Associated weak formulations are considered, leading to a 2-D virtual work principle. An alternative approach based on a 2-D truncated energy is also provided, which is less consistent than the first plate theory but has the advantage of the existence of a 2-D energy function. As an example, we consider the pure bending problem of a hyperelastic block. The comparison between the analytical plate solution and available exact one shows that the plate theory gives second-order...

  7. Pixelated neutron image plates

    Science.gov (United States)

    Schlapp, M.; Conrad, H.; von Seggern, H.

    2004-09-01

    Neutron image plates (NIPs) have found widespread application as neutron detectors for single-crystal and powder diffraction, small-angle scattering and tomography. After neutron exposure, the image plate can be read out by scanning with a laser. Commercially available NIPs consist of a powder mixture of BaFBr : Eu2+ and Gd2O3 dispersed in a polymer matrix and supported by a flexible polymer sheet. Since BaFBr : Eu2+ is an excellent x-ray storage phosphor, these NIPs are particularly sensitive to ggr-radiation, which is always present as a background radiation in neutron experiments. In this work we present results on NIPs consisting of KCl : Eu2+ and LiF that were fabricated into ceramic image plates in which the alkali halides act as a self-supporting matrix without the necessity for using a polymeric binder. An advantage of this type of NIP is the significantly reduced ggr-sensitivity. However, the much lower neutron absorption cross section of LiF compared with Gd2O3 demands a thicker image plate for obtaining comparable neutron absorption. The greater thickness of the NIP inevitably leads to a loss in spatial resolution of the image plate. However, this reduction in resolution can be restricted by a novel image plate concept in which a ceramic structure with square cells (referred to as a 'honeycomb') is embedded in the NIP, resulting in a pixelated image plate. In such a NIP the read-out light is confined to the particular illuminated pixel, decoupling the spatial resolution from the optical properties of the image plate material and morphology. In this work, a comparison of experimentally determined and simulated spatial resolutions of pixelated and unstructured image plates for a fixed read-out laser intensity is presented, as well as simulations of the properties of these NIPs at higher laser powers.

  8. Plate removal following orthognathic surgery.

    Science.gov (United States)

    Little, Mhairi; Langford, Richard Julian; Bhanji, Adam; Farr, David

    2015-11-01

    The objectives of this study are to determine the removal rates of orthognathic plates used during orthognathic surgery at James Cook University Hospital and describe the reasons for plate removal. 202 consecutive orthognathic cases were identified between July 2004 and July 2012. Demographics and procedure details were collected for these patients. Patients from this group who returned to theatre for plate removal between July 2004 and November 2012 were identified and their notes were analysed for data including reason for plate removal, age, smoking status, sex and time to plate removal. 3.2% of plates were removed with proportionally more plates removed from the mandible than the maxilla. 10.4% of patients required removal of one or more plate. Most plates were removed within the first post-operative year. The commonest reasons for plate removal were plate exposure and infection. The plate removal rates in our study are comparable to those seen in the literature.

  9. Anisotropic elastic plates

    CERN Document Server

    Hwu, Chyanbin

    2010-01-01

    As structural elements, anisotropic elastic plates find wide applications in modern technology. The plates here are considered to be subjected to not only in plane load but also transverse load. In other words, both plane and plate bending problems as well as the stretching-bending coupling problems are all explained in this book. In addition to the introduction of the theory of anisotropic elasticity, several important subjects have are discussed in this book such as interfaces, cracks, holes, inclusions, contact problems, piezoelectric materials, thermoelastic problems and boundary element a

  10. Plating in Top Agar

    OpenAIRE

    sprotocols

    2014-01-01

    1. Warm plates to room temperature before use. Cold plates causes the top agar to solidify irregularly. DO not warm plates to 37° as the top agar will take forever to solidify. - Prepare top agar as the appropriate liquid medium with 0.7% agar. Keeping 100 mL bottles is convenient. For phages, use λ top agar, which is less rich and yields bigger plaques. - Melt top agar in the microwave completely. Allow the agar to boil after liquification; incompletely melted agar looks liquid, but is...

  11. FORMATION OF LARGE-SCALE TECTONIC ELEMENTS FROM THE POSITION OF CENTRIFUGAL-INERTIAL FORCE ACTION

    Institute of Scientific and Technical Information of China (English)

    Molchanov Ⅴ. Ⅰ.; Paraev Ⅴ. Ⅴ.

    2005-01-01

    We describe the earlier unknown, when applied to global tectonics, centrifugal inertial mechanism of lithosphere plate moving under the effect of forces appearing as a result of Earth's planetary rotation. The mechanism stated gives an insight into global tectonics of plates with the indirect participation of emanation streams which, in their turn, are the derivatives of centrifugal and inertial forces of planetary motion. The application of this mechanism provides a logical explanation for the regularities of global tectogenesis including the formation of mountain ridges mainly of submeridional and sublatitudinal strike,and also the drift of continental plates from the east to the west and from the south to the north. The mechanism clarifies the significance of the Arctic and the Antarctic Circles as geodynamic barriers.

  12. A thermo-mechanical model of horizontal subduction below an overriding plate

    NARCIS (Netherlands)

    Hunen, Jeroen van; Berg, A.P. van den; Vlaar, N.J.

    2000-01-01

    Subduction of young oceanic lithosphere cannot be explained by the gravitational driving mechanisms of slab pull and ridge push. This deficiency of driving forces can be overcome by obduction of an actively overriding plate, which forces the young plate either to subduct or to collide. This

  13. A thermo-mechanical model of horizontal subduction below an overriding plate

    NARCIS (Netherlands)

    Hunen, Jeroen van; Berg, A.P. van den; Vlaar, N.J.

    2001-01-01

    Subduction of young oceanic lithosphere cannot be explained by the gravitational driving mechanisms of slab pull and ridge push. This deficiency of driving forces can be overcome by obduction of an actively overriding plate, which forces the young plate either to subduct or to collide. This mechanis

  14. Fractal zone plates with variable lacunarity.

    Science.gov (United States)

    Monsoriu, Juan; Saavedra, Genaro; Furlan, Walter

    2004-09-06

    Fractal zone plates (FZPs), i.e., zone plates with fractal structure, have been recently introduced in optics. These zone plates are distinguished by the fractal focusing structure they provide along the optical axis. In this paper we study the effects on this axial response of an important descriptor of fractals: the lacunarity. It is shown that this parameter drastically affects the profile of the irradiance response along the optical axis. In spite of this fact, the axial behavior always has the self-similarity characteristics of the FZP itself.

  15. Improved Zone Plate Coded Imaging Technique by Using Four Special Designed Gabor Zone Plates

    Institute of Scientific and Technical Information of China (English)

    CAO Lei-Feng; SHEN Yu-Ji; ZHENG Zhi-Jian; DING Yong-Kun

    2005-01-01

    @@ Direct-current component, high-order artifacts, and side lobe distortion provide serious drawbacks in the application of Fresnel zone plate coded imaging (ZPCI).The presentation provided here proposes a novel way to resolve all the above-mentioned problems.Four different Gabor zone plates are suggested to substitute the one Fresnel zone plate used in the conventional ZPCI.Perfect reconstruction will be obtained when integrally analysing the four coded images.Primary numerical simulation provided here shows good result.

  16. Evaluation of instrumented shoes for ambulatory assessment of ground reaction forces

    NARCIS (Netherlands)

    Liedtke, Christian; Fokkenrood, Steven A.W.; Menger, Jasper T.; Kooij, van der Herman; Veltink, Peter H.

    2007-01-01

    Currently, force plates or pressure sensitive insoles are the standard tools to measure ground reaction forces and centre of pressure data during human gait. Force plates, however, impose constraints on foot placement, and the available pressure sensitive insoles measure only one component of force.

  17. Time-domain flexural wave intensity estimation in orthotropic Kirchhoff plates

    Science.gov (United States)

    Halkyard, C. R.; Masson, P.

    2016-04-01

    In this paper, a method for estimating the vibrational energy flow associated with the flexural vibration of an orthotropic Kirchhoff plate, in the time-domain, is presented. The approach is based on the plane propagating wave solution to the equation of motion, and uses a Fourier series approximation of the wave field. The various linear and angular velocities, shear forces and moments that are needed to calculate the energy flow are estimated by digitally filtering and combining the outputs of an array of sensors. A similar approach is used to reconstruct the local wave field to provide an estimate of the wave propagation direction. The theoretical basis of the approach is described, and design considerations for the sensor array and for the filters used for parameter estimation are discussed. Simulations are presented for plane flexural waves and for transient transverse point force excitation of a range of orthotropic plates having different material properties, using a simulated array of velocity sensors. These simulations show that the method can provide accurate estimates of the magnitude and direction of the vibrational energy flow, as well as of the propagation direction of a single wave train or 'burst', provided that the sensor array is sufficiently distant from the excitation point. This is consistent with preliminary experimental measurements, also presented in this paper, performed on a composite orthotropic plate.

  18. Methodology for approximating material loss on structural plating subjected to dissimilar marine environments

    Science.gov (United States)

    Ernsting, Robert A.

    Non destructive measurement technologies such ultrasonic pulse echo are typically employed to measure remaining shell plating thickness for determining remaining life on marine structures. However, the technology provides total material loss across the shell plate and cannot distinguish how much material loss occurs on each plate side. By understanding material loss contribution on each plate side, engineers and maintenance personnel can have a better understanding of the environments influencing material loss, optimally plan, and schedule maintenance activities. This need is evermore important today as the U.S. proceeds to address its aging infrastructure problems. This research defines and tests a new maintenance inspection methodology called relative material loss (RML) used for distinguishing the material loss contribution on each shell plate side separating dissimilar marine environments. The RML methodology leverages actual "at sea" environmental and operational conditions and the relationships between to solve for material loss contribution. In much the same fashion as a structural engineer isolate joints on a truss and solve free body diagram equations to determine member forces, relative loss equations are defined across various environmental boundaries (such as shell plating) and solved simultaneously to suggest solutions. To demonstrate and test the RML theory, a case study is presented using a sixty five year old "at-sea" structure; a dry dock caisson gate. Both qualitative and quantitative techniques are used to valid the model. Shell plate material loss contribution profiles are defined using statistical and regression techniques and correlated to profiles of environmental factors known to influence marine corrosion. Spin off discoveries and recommendations for future research are included.

  19. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... but changes the portion sizes so you are getting larger portions of non-starchy vegetables and a ...

  20. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... 4/Box) Taking the guesswork out of portion control has never been easier. It can be a ...

  1. Tectonic Plate Movement.

    Science.gov (United States)

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  2. MyPlate

    Science.gov (United States)

    ... our stage of life, situations, preferences, access to food, culture, traditions, and the personal decisions we make over time. All your food and beverage choices count. MyPlate offers ideas and ...

  3. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... you have an easy portion control solution that works. Last Reviewed: October 8, 2015 Last Edited: September ...

  4. Designing Assemblies Of Plates

    Science.gov (United States)

    Williams, F. W.; Kennedy, D.; Butler, R.; Aston, G.; Anderson, M. S.

    1992-01-01

    VICONOPT calculates vibrations and instabilities of assemblies of prismatic plates. Designed for efficient, accurate analysis of buckling and vibration, and for optimum design of panels of composite materials. Written in FORTRAN 77.

  5. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal Planning What Can I Eat? Making Healthy Food Choices Diabetes Superfoods Non-starchy Vegetables Grains and Starchy Vegetables ...

  6. Create Your Plate

    Medline Plus

    Full Text Available ... Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning ... serving of dairy or both as your meal plan allows. Choose healthy fats in small amounts. For ...

  7. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Diabetes Get Started Safely Get And Stay Fit Types of Activity Weight Loss Assess Your Lifestyle ... manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing ...

  8. Create Your Plate

    Medline Plus

    Full Text Available ... Plate is a simple and effective way to manage your blood glucose levels and lose weight. With ... been easier. It can be a challenge to manage portion control wherever you are. Now, our best- ...

  9. Tectonic Plate Movement.

    Science.gov (United States)

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  10. Create Your Plate

    Medline Plus

    Full Text Available ... Carbohydrates Carbohydrate Counting Make Your Carbs Count Glycemic ... to manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing ...

  11. Highly conductive composites for fuel cell flow field plates and bipolar plates

    Science.gov (United States)

    Jang, Bor Z; Zhamu, Aruna; Song, Lulu

    2014-10-21

    This invention provides a fuel cell flow field plate or bipolar plate having flow channels on faces of the plate, comprising an electrically conductive polymer composite. The composite is composed of (A) at least 50% by weight of a conductive filler, comprising at least 5% by weight reinforcement fibers, expanded graphite platelets, graphitic nano-fibers, and/or carbon nano-tubes; (B) polymer matrix material at 1 to 49.9% by weight; and (C) a polymer binder at 0.1 to 10% by weight; wherein the sum of the conductive filler weight %, polymer matrix weight % and polymer binder weight % equals 100% and the bulk electrical conductivity of the flow field or bipolar plate is at least 100 S/cm. The invention also provides a continuous process for cost-effective mass production of the conductive composite-based flow field or bipolar plate.

  12. Origami - Folded Plate Structures

    OpenAIRE

    Buri, Hans Ulrich

    2010-01-01

    This research investigates new methods of designing folded plate structures that can be built with cross-laminated timber panels. Folded plate structures are attractive to both architects and engineers for their structural, spatial, and plastic qualities. Thin surfaces can be stiffened by a series of folds, and thus not only cover space, but also act as load bearing elements. The variation of light and shadow along the folded faces emphasizes the plas...

  13. Fractal multifiber microchannel plates

    Science.gov (United States)

    Cook, Lee M.; Feller, W. B.; Kenter, Almus T.; Chappell, Jon H.

    1992-01-01

    The construction and performance of microchannel plates (MCPs) made using fractal tiling mehtods are reviewed. MCPs with 40 mm active areas having near-perfect channel ordering were produced. These plates demonstrated electrical performance characteristics equivalent to conventionally constructed MCPs. These apparently are the first MCPs which have a sufficiently high degree of order to permit single channel addressability. Potential applications for these devices and the prospects for further development are discussed.

  14. Optically inscribed surface-relief zone plates in azo polymer films

    Institute of Scientific and Technical Information of China (English)

    Jun Yang; Bin Guo; Douguo Zhang; Pei Wang; Hai Ming

    2007-01-01

    We describe a simple and cost-effective holographic method for the fabrication of surface-relief zone plates.The zone plate is inscribed by interference between the first- and second-order diffracted waves from an ionetched Fresnel zone plate. The inscribed surface-relief zone plates are observed by atomic force microscope (AFM). The formation process of the surface grating and the mass diffusion in azo polymer are analyzed.

  15. Liquid repellency by a moving plate

    Science.gov (United States)

    Bouillant, Ambre; Anais Gauthier Team; David Quere Team; Christophe Clanet Team

    2016-11-01

    Moving solids can repel impacting drops, owing to their motion. Provided the solid velocity is larger than a threshold value, air entrained at the vicinity of the moving plate prevents the drop from wetting, and makes it bounce. In addition, the rebound is oblique, which enhances the evacuation of liquid. We discuss experiments and models on this theme, and extend them to case of small droplets (such as formed in a spray) found to be even more efficiently repelled by the moving plate.

  16. Plate tectonic raster reconstruction in GPlates

    OpenAIRE

    2014-01-01

    We describe a novel method implemented in the GPlates plate tectonic reconstruction software to interactively reconstruct arbitrarily high-resolution raster data to past geological times using a rotation model. The approach is based on the projection of geo-referenced raster data into a cube map followed by a reverse projection onto rotated tectonic plates on the surface of the globe. This decouples the rendering of a geo-referenced raster from its reconstruction, providing ...

  17. Hydrophobic Forces in Flotation

    OpenAIRE

    Pazhianur, Rajesh R

    1999-01-01

    An atomic force microscope (AFM) has been used to conduct force measurements to better understand the role of hydrophobic forces in flotation. The force measurements were conducted between a flat mineral substrate and a hydrophobic glass sphere in aqueous solutions. It is assumed that the hydrophobic glass sphere may simulate the behavior of air bubbles during flotation. The results may provide information relevant to the bubble-particle interactions occurring during flotation. The glass ...

  18. Vibration and Buckling of Web Plate of the Plate Girder

    OpenAIRE

    高橋, 和雄; 呉, 明強; 中澤, 聡志; 筑紫, 宏之

    1998-01-01

    The vibration and buckling of the web of the plate girder are studied in this paper. The small deflection theory of the thin plate is used. The finite strip method is employed to solve vibration and buckling of the plate girder. Natural frequenies of buckling properties are shown for various plate girder bridges.

  19. Geothermal Casimir phenomena for the sphere-plate and cylinder-plate configurations

    CERN Document Server

    Weber, Alexej

    2010-01-01

    We investigate the nontrivial interplay between geometry and temperature in the Casimir effect for the sphere-plate and cylinder-plate configurations. At low temperature, the thermal contribution to the Casimir force is dominated by this interplay, implying that standard approximation techniques such as the PFA are inapplicable even in the limit of small surface separation. Thermal fluctuations on scales of the thermal wavelength lead to a delocalization of the thermal force density at low temperatures. As a consequence, the temperature dependence strongly differs from naive expectations. Most prominently, thermal forces can develop non-monotonic behavior below a critical temperature. We perform a comprehensive study of such geothermal phenomena in these Casimir geometries, using analytical and numerical worldline techniques for Dirichlet scalar fluctuations.

  20. Vibration control of an elastic strip by a singular force

    Indian Academy of Sciences (India)

    Erol Uzal; Banu Korbahti

    2010-04-01

    Vibration characteristics of an elastic plate in the shape of an infinite strip are changed by applying a lateral concentrated force to the plate. The homogeneous, isotropic, elastic plate is infinite in the -direction and the sides are simply supported. The size of the force is changed in proportion to the displacement measured at a certain point of the plate. The proportionality constant serves as the control parameter. The mathematical formulation of this distributed control problem and its analytical solution in terms of the vibration frequencies of the plate are given. The vibration frequencies are plotted as a function of the control parameter.

  1. Actively controlling coolant-cooled cold plate configuration

    Energy Technology Data Exchange (ETDEWEB)

    Chainer, Timothy J.; Parida, Pritish R.

    2015-07-28

    A method is provided to facilitate active control of thermal and fluid dynamic performance of a coolant-cooled cold plate. The method includes: monitoring a variable associated with at least one of the coolant-cooled cold plate or one or more electronic components being cooled by the cold plate; and dynamically varying, based on the monitored variable, a physical configuration of the cold plate. By dynamically varying the physical configuration, the thermal and fluid dynamic performance of the cold plate are adjusted to, for example, optimally cool the one or more electronic components, and at the same time, reduce cooling power consumption used in cooling the electronic component(s). The physical configuration can be adjusted by providing one or more adjustable plates within the coolant-cooled cold plate, the positioning of which may be adjusted based on the monitored variable.

  2. The correct mechanism of lithospheric plates movement

    Science.gov (United States)

    Ostrihansky, L.

    2016-12-01

    Imagination that lithospheric plates move above low-viscous seismic low-velocity zone contradicts to reality but alternating movement of variations of the Earth's rotation deform plastic mantle. Because these deformations never return to original position and solidified ascending magma in mid-ocean ridge prevents return, the lithospheric plates move plunging to mantle by their own weight and move westward pushed by force of tidal friction enlarged by alternating movement of heavy and large-volume mantle. This imagination has been proven by calculating azimuths of Moon and opposite tidal bulging in a moment of earthquake. They resulted occurring on local eastern horizon when earthquake was triggered and also calculated tidal torques in their maximums coincided with earthquakes. To distinguish these tidal properties the earthquakes in Hindu Kush in westward moving Eurasian plate were examined and also in northward moving Indian plate. LOD graph has shown that in Hindu Kush tidal friction triggers earthquake almost every day and large earthquakes are triggered in large positive LOD anomalies corresponding to deceleration. In the Indian plate the calculated maximum tidal torques corresponding to accelerations (LOD minimums) coincided with the greatest earthquakes: with the Great Sumatra 2004, largest Nepal earthquake 1934, large earthquake Nepal 2015 evoked by resonance effect and others.

  3. Design of convex hull plate forming by pure line heating

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xue-biao; JI Zhuo-shang; LIU Yu-jun

    2004-01-01

    This paper presents a ship-hull plate forming way by pure line heating. The heating lines forming the required bending angle is determined by curvature analysis method. Heating along the calculated heating lines results in bland plate with initial transverse curvature. Then, the plate with desired convex shape can be obtained by heating in the longitudinal edge. This is the whole forming process by pure line heating. This paper presents a method of plane development for ship-hull plate with B-spline surface representation, and provides the shrinkage heating lines in the forming process. This forming way would facilitate temperature control and make plate forming automatically easy.

  4. Plating of proximal humeral fractures.

    Science.gov (United States)

    Martetschläger, Frank; Siebenlist, Sebastian; Weier, Michael; Sandmann, Gunther; Ahrens, Philipp; Braun, Karl; Elser, Florian; Stöckle, Ulrich; Freude, Thomas

    2012-11-01

    The optimal treatment for proximal humeral fractures is controversial. Few data exist concerning the influence of the surgical approach on the outcome. The purpose of this study was to evaluate the clinical and radiological outcomes of proximal humeral fractures treated with locking plate fixation through a deltopectoral vs an anterolateral deltoid-splitting approach. Of 86 patients who met the inclusion criteria, 70 were available for follow-up examination. Thirty-three patients were treated through a deltopectoral approach and 37 through an anterolateral deltoid-splitting approach. In all cases, open reduction and internal fixation with a PHILOS locking plate (Synthes, Umkirch, Germany) was performed. Clinical follow-up included evaluation of pain, shoulder mobility, and strength. Constant score and Disabilities of the Arm, Shoulder and Hand (DASH) score were assessed. A clinical neurological examination of the axillary nerve was also performed. Consolidation, reduction, and appearance of head necrosis were evaluated radiographically. After a mean follow-up of 33 months, Constant scores, DASH scores, and American Shoulder and Elbow Surgeons scores showed no significant differences between the groups. Clinical neurologic examination of the axillary nerve revealed no obvious damage to the nerve in either group. Deltopectoral and anterolateral detoid-splitting approaches for plate fixation of proximal humeral fractures are safe and provide similar clinical outcomes. The results of this study suggest that the approach can be chosen according to surgeon preference.

  5. Bending and stretching of plates

    CERN Document Server

    Mansfield, E H; Hemp, W S

    1964-01-01

    The Bending and Stretching of Plates deals with elastic plate theory, particularly on small- and large-deflexion theory. Small-deflexion theory concerns derivation of basic equations, rectangular plates, plates of various shapes, plates whose boundaries are amenable to conformal transformation, plates with variable rigidity, and approximate methods. Large-deflexion theory includes general equations and some exact solutions, approximate methods in large-deflexion theory, asymptotic large-deflexion theories for very thin plates. Asymptotic theories covers membrane theory, tension field theory, a

  6. Minimally Invasive Plate Osteosynthesis with Conventional Compression Plate for Diaphyseal Tibia Fracture

    Directory of Open Access Journals (Sweden)

    IM Anuar-Ramdhan

    2014-11-01

    Full Text Available The diaphyseal tibia fracture is best treated with intramedullary nail but in some cases where the nail is not applicable, plate fixation will be the next option of fixation. The extensile anterior approach is normally used for conventional compression plate fixation in tibia shaft fractures. The extensive surgical dissection may devitalizes the bony fragments and interfere with the fracture union as well as soft tissue healing. Minimally Invasive Plate Osteosynthesis (MIPO provides good preservation of blood supply and fracture hematoma at the fracture site thus promotes biological bone healing. The use of indirect reduction techniques and small skin incisions to introduce the plate is technically demanding and requires fluoroscopy exposures throughout the surgery, being some of its drawbacks. We recommend MIPO for conventional compression plate fixation in tibial shaft fractures in view of the reduced surgical trauma to the surrounding soft tissue and good functional outcome.

  7. Characterization of Tri-lab Tantalum Plate.

    Energy Technology Data Exchange (ETDEWEB)

    Buchheit, Thomas E.; Cerreta, Ellen K.; Deibler, Lisa Anne; Chen, Shu-Rong; Michael, Joseph R.

    2014-09-01

    This report provides a detailed characterization Tri-lab Tantalum (Ta) plate jointly purchased from HCStark Inc. by Sandia, Los Alamos and Lawrence Livermore National Laboratories. Data in this report was compiled from series of material and properties characterization experiments carried out at Sandia (SNL) and Los Alamos (LANL) Laboratories through a leveraged effort funded by the C2 campaign. Results include microstructure characterization detailing the crystallographic texture of the material and an increase in grain size near the end of the rolled plate. Mechanical properties evaluations include, compression cylinder, sub-scale tension specimen, micohardness and instrumented indentation testing. The plate was found to have vastly superior uniformity when compare with previously characterized wrought Ta material. Small but measurable variations in microstructure and properties were noted at the end, and at the top and bottom edges of the plate.

  8. This Dynamic Planet: World map of volcanoes, earthquakes, impact craters and plate tectonics

    Science.gov (United States)

    Simkin, Tom; Tilling, Robert I.; Vogt, Peter R.; Kirby, Stephen H.; Kimberly, Paul; Stewart, David B.

    2006-01-01

    Our Earth is a dynamic planet, as clearly illustrated on the main map by its topography, over 1500 volcanoes, 44,000 earthquakes, and 170 impact craters. These features largely reflect the movements of Earth's major tectonic plates and many smaller plates or fragments of plates (including microplates). Volcanic eruptions and earthquakes are awe-inspiring displays of the powerful forces of nature and can be extraordinarily destructive. On average, about 60 of Earth's 550 historically active volcanoes are in eruption each year. In 2004 alone, over 160 earthquakes were magnitude 6.0 or above, some of which caused casualties and substantial damage. This map shows many of the features that have shaped--and continue to change--our dynamic planet. Most new crust forms at ocean ridge crests, is carried slowly away by plate movement, and is ultimately recycled deep into the earth--causing earthquakes and volcanism along the boundaries between moving tectonic plates. Oceans are continually opening (e.g., Red Sea, Atlantic) or closing (e.g., Mediterranean). Because continental crust is thicker and less dense than thinner, younger oceanic crust, most does not sink deep enough to be recycled, and remains largely preserved on land. Consequently, most continental bedrock is far older than the oldest oceanic bedrock. (see back of map) The earthquakes and volcanoes that mark plate boundaries are clearly shown on this map, as are craters made by impacts of extraterrestrial objects that punctuate Earth's history, some causing catastrophic ecological changes. Over geologic time, continuing plate movements, together with relentless erosion and redeposition of material, mask or obliterate traces of earlier plate-tectonic or impact processes, making the older chapters of Earth's 4,500-million-year history increasingly difficult to read. The recent activity shown on this map provides only a present-day snapshot of Earth's long history, helping to illustrate how its present surface came to

  9. Influence of measurement noise on the PSO based localization of an impact occurring on elastic plates

    Directory of Open Access Journals (Sweden)

    El-Bakari A.

    2014-01-01

    Full Text Available This paper presents the application of particle swarm optimization algorithm to reconstruct the characteristics of impacts occurring on homogeneous and isotropic elastic plates and which cannot be reduced to a concentrated force. Solution of this inverse problem was achieved through minimizing a fitness function defined in terms of the root mean square error between the measured and the calculated responses. This included information provided by numerous sensors. The impacting force was assumed to result from uniformly distributed pressure acting over a rectangular patch. Use was made of the reciprocity theorem to decouple the localization problem from the deconvolution part intended to reconstruct the pressure time signal. The particle swarm optimization based model was found to be highly efficient in finding the impact zone location. Focus was done on the robustness aspect of force impact localization when an additive white noise is assumed to perturb response measurements.

  10. Capillary torque caused by a liquid droplet sandwiched between two plates.

    Science.gov (United States)

    Takei, Atsushi; Matsumoto, Kiyoshi; Shimoyama, Isao

    2010-02-16

    Capillary force makes a liquid droplet's surface have the minimum area. If the droplet is sandwiched between two plates, it exerts capillary force on the plates. The magnitude of the force depends on the shape of the sandwiched droplet, which is in turn determined by the shape of the plates and the volume of the liquid. The liquid's shape, however, is hard to determine analytically. In this paper, the torque caused by a droplet sandwiched between two noncircular plates is experimentally and theoretically analyzed. We patterned a magnetic material on the surface of the plates and used it to apply a magnetic force to the plates. The torque on the plates was measured. The torque caused by capillary force was calculated by observing the equilibrium between the capillary force and magnetic force. We obtained approximate theoretical solutions for the liquid's shape and torque and verified that they were in accordance with the experimental results. The experimental and theoretical results presented in this paper are useful for designing microdevices or self-assemblies actuated by capillary force.

  11. On electrostatically actuated NEMS/MEMS circular plates

    Science.gov (United States)

    Caruntu, Dumitru I.; Alvarado, Iris

    2011-04-01

    This paper deals with electrostatically actuated micro and nano-electromechanical (MEMS/NEMS) circular plates. The system under investigation consists of two bodies, a deformable and conductive circular plate placed above a fixed, rigid and conductive ground plate. The deformable circular plate is electrostatically actuated by applying an AC voltage between the two plates. Nonlinear parametric resonance and pull-in occur at certain frequencies and relatively large AC voltage, respectively. Such phenomena are useful for applications such as sensors, actuators, switches, micro-pumps, micro-tweezers, chemical and mass sensing, and micro-mirrors. A mathematical model of clamped circular MEMS/NEMS electrostatically actuated plates has been developed. Since the model is in the micro- and nano-scale, surface forces, van der Waals and/or Casimir, acting on the plate are included. A perturbation method, the Method of Multiple Scales (MMS), is used for investigating the case of weakly nonlinear MEMS/NEMS circular plates. Two time scales, fast and slow, are considered in this work. The amplitude-frequency and phase-frequency response of the plate in the case of primary resonance are obtained and discussed.

  12. Anterior cervical plating

    Directory of Open Access Journals (Sweden)

    Gonugunta V

    2005-01-01

    Full Text Available Although anterior cervical instrumentation was initially used in cervical trauma, because of obvious benefits, indications for its use have been expanded over time to degenerative cases as well as tumor and infection of the cervical spine. Along with a threefold increase in incidence of cervical fusion surgery, implant designs have evolved over the last three decades. Observation of graft subsidence and phenomenon of stress shielding led to the development of the new generation dynamic anterior cervical plating systems. Anterior cervical plating does not conclusively improve clinical outcome of the patients, but certainly enhances the efficacy of autograft and allograft fusion and lessens the rate of pseudoarthrosis and kyphosis after multilevel discectomy and fusions. A review of biomechanics, surgical technique, indications, complications and results of various anterior cervical plating systems is presented here to enable clinicians to select the appropriate construct design.

  13. License plate detection algorithm

    Science.gov (United States)

    Broitman, Michael; Klopovsky, Yuri; Silinskis, Normunds

    2013-12-01

    A novel algorithm for vehicle license plates localization is proposed. The algorithm is based on pixel intensity transition gradient analysis. Near to 2500 natural-scene gray-level vehicle images of different backgrounds and ambient illumination was tested. The best set of algorithm's parameters produces detection rate up to 0.94. Taking into account abnormal camera location during our tests and therefore geometrical distortion and troubles from trees this result could be considered as passable. Correlation between source data, such as license Plate dimensions and texture, cameras location and others, and parameters of algorithm were also defined.

  14. Quantitative morphometric study of the subaxial cervical vertebrae end plate.

    Science.gov (United States)

    Feng, Hang; Fang, Xiangyi; Huang, Dageng; Yu, Chengcheng; Zhao, Songchuan; Hao, Dingjun

    2017-02-01

    Cervical disc arthroplasty has been gradually adopted as an alternative for the treatment of cervical degenerative disease. However, there is a large discrepancy between footprints of currently available cervical disc prostheses and anatomic dimensions of cervical end plates. This study aimed to accurately and comprehensively quantify the three-dimensional (3D) anatomic morphology of the cervical vertebral end plate and provide a theoretical basis for designing appropriate disc prostheses. Moreover, we introduced a novel geometric and mechanical model for 3D reconstruction techniques of the cervical end plate. A descriptive study of the geometry of the middle and lower cervical vertebral end plates in cadaveric spines was carried out. A total of 138 cervical vertebral end plates were digitized using an optical 3D range scanning system, and then each end plate was reconstructed using the digitized image. For each end plate, the morphologic characteristics of six surface curves and the end plate concavity depth were symmetrically chosen and depicted. The cranial end plates (relative to the disc) were concave and the caudal end plates were relatively flat at all disc levels, with mean concavity depths of 2.04 and 0.69 mm, respectively. For the caudal end plates, the end plate concavity apex was most often (81.42%) located in the posterior portion, whereas in the cranial end plates, the distribution was relatively even. For the sagittal curves, the foremost point and the rearmost point on the middle curve had a more forward position than those in the left curve and the right curve. Regarding the frontal plane curves, the length of the middle curve was longer than that of the anterior curve and posterior curve. For the cranial end plate, the maximal mean depth was the middle curve, whereas for the caudal end plate, the maximum depth was the posterior curve. There is marked morphologic asymmetry, in that the cranial end plate is more concave than the corresponding

  15. Fracture Characteristics Analysis of Double-layer Rock Plates with Both Ends Fixed Condition

    Directory of Open Access Journals (Sweden)

    S. R. Wang

    2014-07-01

    Full Text Available In order to research on the fracture and instability characteristics of double-layer rock plates with both ends fixed, the three-dimension computational model of double-layer rock plates under the concentrated load was built by using PFC3D technique (three-dimension particle flow code, and the mechanical parameters of the numerical model were determined based on the physical model tests. The results showed the instability process of the double-layer rock plates had four mechanical response phases: the elastic deformation stage, the brittle fracture of upper thick plate arching stage, two rock-arch bearing stage and two rock-arch failure stage; moreover, with the rock plate particle radius from small to large change, the maximum vertical force of double rock-arch appeared when the particle size was a certain value. The maximum vertical force showed an upward trend with the increase of the rock plate temperature, and in the case of the same thickness the maximum vertical force increased with the increase of the upper rock plate thickness. When the boundary conditions of double-layer rock plates changed from the hinged support to the fixed support, the maximum horizontal force observably decreased, and the maximum vertical force showed small fluctuations and then tended towards stability with the increase of cohesive strength of double-layer rock plates.

  16. CFD Simulations of Oscillating Flow around Solid and Perforated Plates

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Damping plates have been used for truss spars in gulf of Mexico to reduce the heave motions. The plates are usually perforated with holes for the passage of marine risers, but the effects of the perforation have not been examined thoroughly. In the present study, a computational fluid dynamics investigation into the hydrodynamic forces is carried out by using FLUENT, which is on two-dimensional perforated plates with varying degrees of perforation in oscillating flow under small Keulegan-Carpenter (KC) number. The numerical results of the hydrodynamic coefficients are presented. The effects of both the perforation ratio (PR) and KC number on the hydrodynamic coefficients of the plates are discussed. Some results of the simulated flow patterns around the plates were also given and discussed.

  17. A Computational Model of Soil Adhesion and Resistance for a Non-smooth Bulldozing Plate

    Institute of Scientific and Technical Information of China (English)

    Shi Wei-ping; Ren Lu-quan; Tian Li-mei

    2005-01-01

    Adhesive forces exist between soil and the surfaces of soil-engaging components; they increase working resistance and energy consumption. This paper tries to find an approach to reduce the adhesion and resistance of bulldozing plate. A simplified mechanical model of adhesion and resistance between soil and a non-smooth bulldozing plate is proposed. The interaction force between moist soil and a non-smooth bulldozing plate is analyzed. The pressure and friction distribution on the bulldozing plate are computed, and the anti-adhesive effect of a corrugated bulldozing plate is simulated numerically.Numerical results show that the wavy bulldozing plate achieves an effective drag reduction in moist soil. The optimal wavy shape of the corrugated bulldozing plate with the minimal resistance is designed. The basic principle of reducing soil adhesion of the non-smooth surface is discovered.

  18. APPROXIMATE SOLUTIONS FOR TRANSIENT RESPONSE OF CONSTRAINED DAMPING LAMINATED CANTILEVER PLATE

    Institute of Scientific and Technical Information of China (English)

    Liuwei Mao; Anwen Wang; Mingyong Hu

    2010-01-01

    The series composed by beam mode function is used to approximate the displacement function of constrained damping of laminated cantilever plates,and the transverse deformation of the plate on which a concentrated force is acted is calculated using the principle of virtual work.By solving Lagrange's equation,the frequencies and model loss factors of free vibration of the plate are obtained,then the transient response of constrained damping of laminated cantilever plate is obtained,when the concentrated force is withdrawn suddenly.The theoretical calculations are compared with the experimental data,the results show:both the frequencies and the response time of theoretical calculation and its variational law with the parameters of the damping layer are identical with experimental results.Also,the response time of steel cantilever plate,unconstrained damping cantilever plate and constrained damping cantilever plate are brought into comparison,which shows that the constrained damping structure can effectively suppress the vibration.

  19. Electrostatic particle collector with improved features for installing and/or removing its collector plates

    Energy Technology Data Exchange (ETDEWEB)

    Siegfried, Matthew J.; Radford, Daniel R.; Huffman, Russell K.

    2017-04-04

    An electrostatic particle collector may generally include a housing having sidewalls extending lengthwise between a first end and a second end. The housing may define a plate slot that extends heightwise within the housing between a top end and a bottom end. The housing may further include a plate access window that provides access to the bottom end of the plate slot. The collector may also include a collector plate configured to be installed within the plate slot that extends heightwise between a top edge and a bottom edge. Additionally, when the collector plate is installed within the plate slot, the bottom edge of the collector plate may be accessible from an exterior of the housing via the plate access window so as to allow the bottom edge of the collector plate to be moved relative to the housing to facilitate removal of the collector plate from the housing.

  20. Biomechanical analysis of acromioclavicular joint dislocation treated with clavicle hook plates in different lengths.

    Science.gov (United States)

    Shih, Cheng-Min; Huang, Kui-Chou; Pan, Chien-Chou; Lee, Cheng-Hung; Su, Kuo-Chih

    2015-11-01

    Clavicle hook plates are frequently used in clinical orthopaedics to treat acromioclavicular joint dislocation. However, patients often exhibit acromion osteolysis and per-implant fracture after undergoing hook plate fixation. With the intent of avoiding future complications or fixation failure after clavicle hook plate fixation, we used finite element analysis (FEA) to investigate the biomechanics of clavicle hook plates of different materials and sizes when used in treating acromioclavicular joint dislocation. Using finite element analysis, this study constructed a model comprising four parts: clavicle, acromion, clavicle hook plate and screws, and used the model to simulate implanting different types of clavicle hook plates in patients with acromioclavicular joint dislocation. Then, the biomechanics of stainless steel and titanium alloy clavicle hook plates containing either six or eight screw holes were investigated. The results indicated that using a longer clavicle hook plate decreased the stress value in the clavicle, and mitigated the force that clavicle hook plates exert on the acromion. Using a clavicle hook plate material characterized by a smaller Young's modulus caused a slight increase in the stress on the clavicle. However, the external force the material imposed on the acromion was less than the force exerted on the clavicle. The findings of this study can serve as a reference to help orthopaedic surgeons select clavicle hook plates.

  1. Numerical prediction of the bearing capacity of plate anchors subjected to combined loads

    Directory of Open Access Journals (Sweden)

    Chunhui ZHANG

    2016-06-01

    Full Text Available To predict the bearing capacity of plate anchors subjected to combined loads, based on the assumption that there is no separation between the plate and soil, the numerical model of the motion and transformation of the plate anchor subjected to combined loads including the normal force, tangential force and bending moment loads in ABAQUS software is set up. The numerical model is proved by comparing the calculated bearing capacity with that of analytical solution. The numerical model is used to calculate the ultimate bearing capacity of the plate anchor subjected to the combined loads including the normal force, the tangential force and bending moment. The results show that murff model is used to preferably fit the ultimate bearing capacity envelope of plate anchors subjected to combined loads.

  2. Nuclear reactor alignment plate configuration

    Energy Technology Data Exchange (ETDEWEB)

    Altman, David A; Forsyth, David R; Smith, Richard E; Singleton, Norman R

    2014-01-28

    An alignment plate that is attached to a core barrel of a pressurized water reactor and fits within slots within a top plate of a lower core shroud and upper core plate to maintain lateral alignment of the reactor internals. The alignment plate is connected to the core barrel through two vertically-spaced dowel pins that extend from the outside surface of the core barrel through a reinforcement pad and into corresponding holes in the alignment plate. Additionally, threaded fasteners are inserted around the perimeter of the reinforcement pad and into the alignment plate to further secure the alignment plate to the core barrel. A fillet weld also is deposited around the perimeter of the reinforcement pad. To accomodate thermal growth between the alignment plate and the core barrel, a gap is left above, below and at both sides of one of the dowel pins in the alignment plate holes through with the dowel pins pass.

  3. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Type 2 About Us Online Community Meal Planning Sign In Search: Search More Sites Search ≡ Are ... Fitness Home Food MyFoodAdvisor Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten ...

  4. Create Your Plate

    Medline Plus

    Full Text Available ... Create Your Plate is a simple and effective way to manage your blood glucose levels and lose weight. With ... year of delicious meals to help prevent and manage diabetes. Healthy Recipes: ... to your day with this guide. Ways to Give: Wear Your Cause on Your Sleeve - ...

  5. The Plate Tectonics Project

    Science.gov (United States)

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  6. Create Your Plate

    Medline Plus

    Full Text Available ... tax-deductible gift today can fund critical diabetes research and support vital diabetes education services that improve the ... way to manage your blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ...

  7. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Type 2 About Us Online Community Meal Planning Sign In Search: Search More Sites Search ≡ Are ... Fitness Home Food MyFoodAdvisor Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten ...

  8. Create Your Plate

    Medline Plus

    Full Text Available ... tax-deductible gift today can fund critical diabetes research and support vital diabetes education services that improve the ... way to manage your blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ...

  9. Create Your Plate

    Medline Plus

    Full Text Available ... unsweetened tea or coffee. Featured Product Precise Portions® Go Healthy Travel Pack (4/Box) Taking the guesswork ... you are. Now, our best-selling, sectioned to-go plate with easy-sealing lid is offered in ...

  10. Create Your Plate

    Medline Plus

    Full Text Available ... manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing lid is offered in a 4-pack. Whether ... Research & Practice We Are Research Leaders We Support Your Doctor ...

  11. INL HIP Plate Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    B. H. Park; C. R. Clark; J. F. Jue

    2010-02-01

    This document outlines the process used to bond monolithic fuel plates by Hot Isostatic Pressing (HIP). This method was developed at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test Reactors (RERTR) program. These foils have been used in a number of irradiation experiments in support of the United States Global Threat Reduction Initiative (GTRI) program.

  12. The Plate Tectonics Project

    Science.gov (United States)

    Hein, Annamae J.

    2011-01-01

    The Plate Tectonics Project is a multiday, inquiry-based unit that facilitates students as self-motivated learners. Reliable Web sites are offered to assist with lessons, and a summative rubric is used to facilitate the holistic nature of the project. After each topic (parts of the Earth, continental drift, etc.) is covered, the students will…

  13. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals > Create Your Plate Share: Print Page Text Size: A A A Listen En Español Create ... somewhere in between, you have an easy portion control solution that works. Last Reviewed: October 8, 2015 Last Edited: ... Cost of Diabetes Advocate Toolkit Call to Congress Research & ...

  14. Benchmark for license plate character segmentation

    Science.gov (United States)

    Gonçalves, Gabriel Resende; da Silva, Sirlene Pio Gomes; Menotti, David; Shwartz, William Robson

    2016-09-01

    Automatic license plate recognition (ALPR) has been the focus of many researches in the past years. In general, ALPR is divided into the following problems: detection of on-track vehicles, license plate detection, segmentation of license plate characters, and optical character recognition (OCR). Even though commercial solutions are available for controlled acquisition conditions, e.g., the entrance of a parking lot, ALPR is still an open problem when dealing with data acquired from uncontrolled environments, such as roads and highways when relying only on imaging sensors. Due to the multiple orientations and scales of the license plates captured by the camera, a very challenging task of the ALPR is the license plate character segmentation (LPCS) step, because its effectiveness is required to be (near) optimal to achieve a high recognition rate by the OCR. To tackle the LPCS problem, this work proposes a benchmark composed of a dataset designed to focus specifically on the character segmentation step of the ALPR within an evaluation protocol. Furthermore, we propose the Jaccard-centroid coefficient, an evaluation measure more suitable than the Jaccard coefficient regarding the location of the bounding box within the ground-truth annotation. The dataset is composed of 2000 Brazilian license plates consisting of 14000 alphanumeric symbols and their corresponding bounding box annotations. We also present a straightforward approach to perform LPCS efficiently. Finally, we provide an experimental evaluation for the dataset based on five LPCS approaches and demonstrate the importance of character segmentation for achieving an accurate OCR.

  15. Corrosion test cell for bipolar plates

    Science.gov (United States)

    Weisbrod, Kirk R.

    2002-01-01

    A corrosion test cell for evaluating corrosion resistance in fuel cell bipolar plates is described. The cell has a transparent or translucent cell body having a pair of identical cell body members that seal against opposite sides of a bipolar plate. The cell includes an anode chamber and an cathode chamber, each on opposite sides of the plate. Each chamber contains a pair of mesh platinum current collectors and a catalyst layer pressed between current collectors and the plate. Each chamber is filled with an electrolyte solution that is replenished with fluid from a much larger electrolyte reservoir. The cell includes gas inlets to each chamber for hydrogen gas and air. As the gases flow into a chamber, they pass along the platinum mesh, through the catalyst layer, and to the bipolar plate. The gas exits the chamber through passageways that provide fluid communication between the anode and cathode chambers and the reservoir, and exits the test cell through an exit port in the reservoir. The flow of gas into the cell produces a constant flow of fresh electrolyte into each chamber. Openings in each cell body is member allow electrodes to enter the cell body and contact the electrolyte in the reservoir therein. During operation, while hydrogen gas is passed into one chamber and air into the other chamber, the cell resistance is measured, which is used to evaluate the corrosion properties of the bipolar plate.

  16. A Sandwich Method Using Kapandji Intrafocal Pinning to Facilitate Palmar Plating of Displaced Distal Radius Fractures.

    Science.gov (United States)

    Huang, Hui-Kuang; Huang, Yi-Chao; Wang, Jung-Pan; Chang, Ming-Chau

    2017-09-01

    The use of palmar plating in the treatment of dorsally displaced distal radius fracture is very common, and can result in a good functional outcome. We present an easy "sandwich method" to reduce the fracture and to facilitate osteosynthesis. Firstly, the dorsal Kapandji intrafocal wire was applied to achieve the reduction of the dorsally displaced fracture and provide a volar-directed force. Then the intra-articular fractures were reduced or the metaphyseal defect is stuffed with bone graft if necessary. Finally, the anatomical plate is used to buttress and push back the distal fragment to complete the osteosynthesis. The postoperative radiographic parameters, comparing with the contralateral noninjured side, could achieve similar radial height, radial inclination, volar tilt, and ulnar variance without significant difference.

  17. Vortex-Induced Vibrations of a Flexibly-Mounted Cyber-Physical Rectangular Plate

    Science.gov (United States)

    Onoue, Kyohei; Strom, Benjamin; Song, Arnold; Breuer, Kenneth

    2013-11-01

    We have developed a cyber-physical system to explore the vortex-induced vibration (VIV) behavior of a flat plate mounted on a virtual spring damper support. The plate is allowed to oscillate about its mid-chord and the measured angular position, velocity, and torque are used as inputs to a feedback control system that provides a restoring torque and can simulate a wide range of structural dynamic behavior. A series of experiments were carried out using different sized plates, and over a range of freestream velocities, equilibrium angles of attack, and simulated stiffness and damping. We observe a synchronization phenomenon over a wide range of parameter space, wherein the plate oscillates at moderate to large amplitude with a frequency dictated by the natural structural frequency of the system. Additionally, the existence of bistable states is reflected in the hysteretic response of the system. The cyber-physical damping extracts energy from the flow and the efficiency of this harvesting mechanism is characterized over a range of dimensionless stiffness and damping parameters. This research is funded by the Air Force Office of Scientific Research (AFOSR).

  18. Wave Interaction with Dual Circular Porous Plates

    Institute of Scientific and Technical Information of China (English)

    Arpita Mondal; R.Gayen

    2015-01-01

    In this paper we have investigated the reflection and the transmission of a system of two symmetric circular-arc-shaped thin porous plates submerged in deep water within the context of linear theory. The hypersingular integral equation technique has been used to analyze the problem mathematically. The integral equations are formulated by applying Green’s integral theorem to the fundamental potential function and the scattered potential function into a suitable fluid region, and then using the boundary condition on the porous plate surface. These are solved approximately using an expansion-cum-collocation method where the behaviour of the potential functions at the tips of the plates have been used. This method ultimately produces a very good numerical approximation for the reflection and the transmission coefficients and hydrodynamic force components. The numerical results are depicted graphically against the wave number for a variety of layouts of the arc. Some results are compared with known results for similar configurations of dual rigid plate systems available in the literature with good agreement.

  19. Wave interaction with dual circular porous plates

    Science.gov (United States)

    Mondal, Arpita; Gayen, R.

    2015-12-01

    In this paper we investigated the reflection and the transmission of a system of two symmetric circular-arc-shaped thin porous plates submerged in deep water within the context of linear theory. The hypersingular integral equation technique has been used to analyze the problem mathematically. The integral equations are formulated by applying Green's integral theorem to the fundamental potential function and the scattered potential function into a suitable fluid region, and then using the boundary condition on the porous plate surface. These are solved approximately using an expansion-cum-collocation method using the behaviour of the potential functions at the tips of the plates. This method ultimately produces a very good numerical approximation for the reflection and the transmission coefficients and hydrodynamic force components. The numerical results are depicted graphically against the wave number for a variety of layouts of the arc. Some results are compared with known results for similar configurations of dual rigid plate systems available in the literature with good agreement.

  20. Along-strike variation in subducting plate velocity induced by along-strike variation in overriding plate structure: Insights from 3D numerical models

    Science.gov (United States)

    Rodríguez-González, Juan; Billen, Magali I.; Negredo, Ana M.; Montesi, Laurent G. J.

    2016-10-01

    Subduction dynamics can be understood as the result of the balance between driving and resisting forces. Previous work has traditionally regarded gravitational slab pull and viscous mantle drag as the main driving and resistive forces for plate motion respectively. However, this paradigm fails to explain many of the observations in subduction zones. For example, subducting plate velocity varies significantly along-strike in many subduction zones and this variation is not correlated to the age of subducting lithosphere. Here we present three-dimensional and time-dependent numerical models of subduction. We show that along-strike variations of the overriding plate thermal structure can lead to along-strike variations in subducting plate velocity. In turn, velocity variations lead to significant migration of the Euler pole over time. Our results show that the subducting plate is slower beneath the colder portion of the overriding plate due to two related mechanisms. First, the mantle wedge beneath the colder portion of the overriding plate is more viscous, which increases mantle drag. Second, where the mantle wedge is more viscous, hydrodynamic suction increases, leading to a lower slab dip. Both factors contribute to decreasing subducting plate velocity in the region; therefore, if the overriding plate is not uniform, the resulting velocity varies significantly along-strike, which causes the Euler pole to migrate closer to the subducting plate. We present a new mechanism to explain observations of subducting plate velocity in the Cocos and Nazca plates. These results shed new light on the balance of forces that control subduction dynamics and prove that future studies should take into consideration the three-dimensional structure of the overriding plate.

  1. Error compensation of thin plate-shape part with prebending method in face milling

    Science.gov (United States)

    Yi, Wei; Jiang, Zhaoliang; Shao, Weixian; Han, Xiangcheng; Liu, Wenping

    2015-01-01

    Low weight and good toughness thin plate parts are widely used in modern industry, but its flexibility seriously impacts the machinability. Plenty of studies focus on the influence of machine tool and cutting tool on the machining errors. However, few researches focus on compensating machining errors through the fixture. In order to improve the machining accuracy of thin plate-shape part in face milling, this paper presents a novel method for compensating the surface errors by prebending the workpiece during the milling process. First, a machining error prediction model using finite element method is formulated, which simplifies the contacts between the workpiece and fixture with spring constraints. Milling forces calculated by the micro-unit cutting force model are loaded on the error prediction model to predict the machining error. The error prediction results are substituted into the given formulas to obtain the prebending clamping forces and clamping positions. Consequently, the workpiece is prebent in terms of the calculated clamping forces and positions during the face milling operation to reduce the machining error. Finally, simulation and experimental tests are carried out to validate the correctness and efficiency of the proposed error compensation method. The experimental measured flatness results show that the flatness improves by approximately 30 percent through this error compensation method. The proposed method not only predicts the machining errors in face milling thin plate-shape parts but also reduces the machining errors by taking full advantage of the workpiece prebending caused by fixture, meanwhile, it provides a novel idea and theoretical basis for reducing milling errors and improving the milling accuracy.

  2. Error Compensation of Thin Plate-shape Part with Prebending Method in Face Milling

    Institute of Scientific and Technical Information of China (English)

    YI Wei; JIANG Zhaoliang; SHAO Weixian; HAN Xiangcheng; LIU Wenping

    2015-01-01

    Low weight and good toughness thin plate parts are widely used in modern industry, but its flexibility seriously impacts the machinability. Plenty of studies focus on the influence of machine tool and cutting tool on the machining errors. However, few researches focus on compensating machining errors through the fixture. In order to improve the machining accuracy of thin plate-shape part in face milling, this paper presents a novel method for compensating the surface errors by prebending the workpiece during the milling process. First, a machining error prediction model using finite element method is formulated, which simplifies the contacts between the workpiece and fixture with spring constraints. Milling forces calculated by the micro-unit cutting force model are loaded on the error prediction model to predict the machining error. The error prediction results are substituted into the given formulas to obtain the prebending clamping forces and clamping positions. Consequently, the workpiece is prebent in terms of the calculated clamping forces and positions during the face milling operation to reduce the machining error. Finally, simulation and experimental tests are carried out to validate the correctness and efficiency of the proposed error compensation method. The experimental measured flatness results show that the flatness improves by approximately 30 percent through this error compensation method. The proposed method not only predicts the machining errors in face milling thin plate-shape parts but also reduces the machining errors by taking full advantage of the workpiece prebending caused by fixture, meanwhile, it provides a novel idea and theoretical basis for reducing milling errors and improving the milling accuracy.

  3. Nonlinear and chaotic vibration and stability analysis of an aero-elastic piezoelectric FG plate under parametric and primary excitations

    Science.gov (United States)

    Rezaee, Mousa; Jahangiri, Reza

    2015-05-01

    In this study, in the presence of supersonic aerodynamic loading, the nonlinear and chaotic vibrations and stability of a simply supported Functionally Graded Piezoelectric (FGP) rectangular plate with bonded piezoelectric layer have been investigated. It is assumed that the plate is simultaneously exposed to the effects of harmonic uniaxial in-plane force and transverse piezoelectric excitations and aerodynamic loading. It is considered that the potential distribution varies linearly through the piezoelectric layer thickness, and the aerodynamic load is modeled by the first order piston theory. The von-Karman nonlinear strain-displacement relations are used to consider the geometrical nonlinearity. Based on the Classical Plate Theory (CPT) and applying the Hamilton's principle, the nonlinear coupled partial differential equations of motion are derived. The Galerkin's procedure is used to reduce the equations of motion to nonlinear ordinary differential Mathieu equations. The validity of the formulation for analyzing the Limit Cycle Oscillation (LCO), aero-elastic stability boundaries is accomplished by comparing the results with those of the literature, and the convergence study of the FGP plate is performed. By applying the Multiple Scales Method, the case of 1:2 internal resonance and primary parametric resonance are taken into account and the corresponding averaged equations are derived and analyzed numerically. The results are provided to investigate the effects of the forcing/piezoelectric detuning parameter, amplitude of forcing/piezoelectric excitation and dynamic pressure, on the nonlinear dynamics and chaotic behavior of the FGP plate. It is revealed that under the certain conditions, due to the existence of bi-stable region of non-trivial solutions, system shows the hysteretic behavior. Moreover, in absence of airflow, it is observed that variation of control parameters leads to the multi periodic and chaotic motions.

  4. Notch sensitivity jeopardizes titanium locking plate fatigue strength.

    Science.gov (United States)

    Tseng, Wo-Jan; Chao, Ching-Kong; Wang, Chun-Chin; Lin, Jinn

    2016-12-01

    Notch sensitivity may compromise titanium-alloy plate fatigue strength. However, no studies providing head-to-head comparisons of stainless-steel or titanium-alloy locking plates exist. Custom-designed identically structured locking plates were made from stainless steel (F138 and F1314) or titanium alloy. Three screw-hole designs were compared: threaded screw-holes with angle edges (type I); threaded screw-holes with chamfered edges (type II); and non-threaded screw-holes with chamfered edges (type III). The plates' bending stiffness, bending strength, and fatigue life, were investigated. The stress concentration at the screw threads was assessed using finite element analyses (FEA). The titanium plates had higher bending strength than the F1314 and F138 plates (2.95:1.56:1) in static loading tests. For all metals, the type-III plate fatigue life was highest, followed by type-II and type-I. The type-III titanium plates had longer fatigue lives than their F138 counterparts, but the type-I and type-II titanium plates had significantly shorter fatigue lives. All F1314 plate types had longer fatigue lives than the type-III titanium plates. The FEA showed minimal stress difference (0.4%) between types II and III, but the stress for types II and III was lower (11.9% and 12.4%) than that for type I. The screw threads did not cause stress concentration in the locking plates in FEA, but may have jeopardized the fatigue strength, especially in the notch-sensitive titanium plates. Improvement to the locking plate design is necessary. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Motion of the Scotia sea plates

    Science.gov (United States)

    Thomas, C.; Livermore, R.; Pollitz, F.

    2003-01-01

    Earthquake data from the Scotia Arc to early 2002 are reviewed in the light of satellite gravity and other data in order to derive a model for the motion of plates in the Scotia Sea region. Events with magnitude ???5, which occurred on or near the boundaries of the Scotia and Sandwich plates, and for which Centroid Moment Tensor (CMT) solutions are available, are examined. The newer data fill some of the previous sampling gaps along the boundaries of the Scotia and Sandwich plates, and provide tighter constraints on relative motions. Variations in the width of the Brunhes anomaly on evenly spaced marine magnetic profiles over the East Scotia Ridge provide new estimates of Scotia-Sandwich plate spreading rates. Since there are no stable fracture zones in the east Scotia Sea, the mean azimuth of sea floor fabric mapped by sidescan is used to constrain the direction of spreading. 18 new rate estimates and four azimuths from the East Scotia Ridge are combined with 68 selected earthquake slip vectors from the boundaries of the Scotia Sea in a least-squares inversion for the best-fitting set of Euler poles and angular rotation rates describing the 'present-day' motions of the Scotia and Sandwich plates relative to South America and Antarctica. Our preferred model (TLP2003) gives poles that are similar to previous estimates, except for Scotia Plate motion with respect to South America, which is significantly different from earlier estimates; predicted rates of motion also differ slightly. Our results are much more robust than earlier work. We examine the implications of the model for motion and deformation along the various plate boundaries, with particular reference to the North and South Scotia Ridges, where rates are obtained by closure.

  6. Self-designed conical point contact plate and clinical application

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To design a new kind of conical point contact plate (CPCP) in treatment of diaphyseal fracture to avoid further dam age to the blood supply of the cortex.   Methods: There were 4 pairs of conicles with a diameter of 1. 5-4 mm beneath the plate symmetrically. The nibs of the conicles were embedd ed about 1-1.5 mm in the cortex by the axial force of screws. The conicle provided a gap about 2 mm between the plate and the bone so as not to compress the periosteum and cortex. And the periostem didnt need to be stripped off dur ing operation and there was no need of postoperative external fixation.   Results: Forty-two cases with diaphyseal fracture were stabili zed by using CPCP. The patients could do joint exercise without loading after operation. Partial weight bearing could be performed in 4-6 weeks postoperati vely. There was no obvious external callus in these cases. The average time of b one healing was 3 months in the tibia and forearm fracture and 4 months in the f emur. Complications such as infection, non-union or malunion etc. were not foun d. The implant was removed 6-10 months after operation.   Conclusions:  CPCP has the advantages of drastic reduction of the implant-to-bone interface virtually, elimination of the impairment of the periosteal blood supply, increase of the rate of healing and good stability whi ch meets the need of early functional exercise.

  7. Energy flow in plate assembles by hierarchical version of finite element method

    DEFF Research Database (Denmark)

    Wachulec, Marcin; Kirkegaard, Poul Henning

    method has been proposed. In this paper a modified hierarchical version of finite element method is used for modelling of energy flow in plate assembles. The formulation includes description of in-plane forces so that planes lying in different planes can be modelled. Two examples considered are: L......-corner of two rectangular plates an a I-shaped plate girder made of five plates. Energy distribution among plates due to harmonic load is studied and the comparison of performance between the hierarchical and standard finite element formulation is presented....

  8. Models of convection-driven tectonic plates - A comparison of methods and results

    Science.gov (United States)

    King, Scott D.; Gable, Carl W.; Weinstein, Stuart A.

    1992-01-01

    Recent numerical studies of convection in the earth's mantle have included various features of plate tectonics. This paper describes three methods of modeling plates: through material properties, through force balance, and through a thin power-law sheet approximation. The results obtained are compared using each method on a series of simple calculations. From these results, scaling relations between the different parameterizations are developed. While each method produces different degrees of deformation within the surface plate, the surface heat flux and average plate velocity agree to within a few percent. The main results are not dependent upon the plate modeling method and herefore are representative of the physical system modeled.

  9. CAD-CAM plates versus conventional fixation plates for primary mandibular reconstruction: A biomechanical in vitro analysis.

    Science.gov (United States)

    Rendenbach, Carsten; Sellenschloh, Kay; Gerbig, Lucca; Morlock, Michael M; Beck-Broichsitter, Benedicta; Smeets, Ralf; Heiland, Max; Huber, Gerd; Hanken, Henning

    2017-09-01

    CAD/CAM reconstruction plates have become a viable option for mandible reconstruction. The aim of this study was to determine whether CAD/CAM plates provide higher fatigue strength compared with conventional fixation systems. 1.0 mm miniplates, 2.0 mm conventional locking plates (DePuy Synthes, Umkirch, Germany), and 2.0 mm CAD/CAM plates (Materialise, Leuven, Belgium/DePuy Synthes) were used to reconstruct a polyurethane mandible model (Synbone, Malans, CH) with cortical and cancellous bone equivalents. Mastication was simulated via cyclic dynamic testing using a universal testing machine (MTS, Bionix, Eden Prairie, MN, USA) until material failure reached a rate of 1 Hz with increasing loads on the left side. No significant difference was found between the groups until a load of 300 N. At higher loads, vertical displacement differed increasingly, with a poorer performance of miniplates (p = 0.04). Plate breakage occurred in miniplates and conventional locking plates. Screw breakage was recorded as the primary failure mechanism in CAD/CAM plates. Stiffness was significantly higher with the CAD/CAM plates (p = 0.04). CAD/CAM plates and reconstruction plates provide higher fatigue strength than miniplates, and stiffness is highest in CAD/CAM systems. All tested fixation methods seem sufficiently stable for mandible reconstruction. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  10. Effect of process control mode on weld quality of friction stir welded plates

    Energy Technology Data Exchange (ETDEWEB)

    Shazly, Mostafa; Sorour, Sherif; Alian, Ahmed R. [Faculty of Engineering, The British University in Egypt, Cairo (Egypt)

    2016-01-15

    Friction stir welding (FSW) is a solid state welding process which requires no filler material where the heat input is generated by frictional energy between the tool and workpiece. The objective of the present work is to conduct a fully coupled thermomechanical finite element analysis based on Arbitrary Lagrangian Eulerian (ALE) formulation for both 'Force-Controlled' and 'Displacement-Controlled' FSW process to provide more detailed insight of their effect on the resulting joint quality. The developed finite element models use Johnson- Cook material model and temperature dependent physical properties for the welded plates. Efforts on proper modeling of the underlying process physics are done focusing on the heat generation of the tool/workpiece interface to overcome the shortcomings of previous investigations. Finite elements results show that 'Force-Controlled' FSW process provides better joint quality especially at higher traveling speed of the tool which comes to an agreement with published experimental results.

  11. Forelimb and hindlimb ground reaction forces of walking cats: Assessment and comparison with walking dogs

    NARCIS (Netherlands)

    Corbee, Ronald; Hazewinkel, Herman; Doornenbal, Arie; Maas, Huub

    2014-01-01

    The primary aim of this study was to assess the potential of force plate analysis for describing the stride cycle of the cat. The secondary aim was to define differences in feline and canine locomotion based on force plate characteristics. Ground reaction forces of 24 healthy cats were measured and

  12. Forelimb and hindlimb ground reaction forces of walking cats: Assessment and comparison with walking dogs

    NARCIS (Netherlands)

    Corbee, Ronald; Hazewinkel, Herman; Doornenbal, Arie; Maas, Huub

    2014-01-01

    The primary aim of this study was to assess the potential of force plate analysis for describing the stride cycle of the cat. The secondary aim was to define differences in feline and canine locomotion based on force plate characteristics. Ground reaction forces of 24 healthy cats were measured and

  13. MyPlate Food Guide

    Science.gov (United States)

    ... Choosing the Right Sport for You Shyness MyPlate Food Guide KidsHealth > For Teens > MyPlate Food Guide Print ... other sugary drinks. Avoid oversized portions. continue Five Food Groups Different food groups meet different nutrition needs. ...

  14. What Are Growth Plate Injuries?

    Science.gov (United States)

    ... plate injuries are:  Falling down  Competitive sports (like football)  Recreational activities. Other reasons for growth plate injuries are:  Child abuse  Injury from extreme cold (for ...

  15. Estimation of Local Delamination Buckling in Orthotropic Composite Plates Using Kirchhoff Plate Finite Elements

    Directory of Open Access Journals (Sweden)

    Zoltán Juhász

    2015-01-01

    Full Text Available We analyse the buckling process of composite plates with through-the-width delamination and straight crack front applying uniaxial compression. We are focusing on the mixed mode buckling case, where the non-uniform distribution of the in-plane forces controls the occurence of the buckling of the delaminated layers. For the analysis, semi-discrete finite elements will be derived based on the Lèvy-type method. The method of harmonic balance is used for taking into account the force distribution that is generally non uniform in-plane.

  16. On the relation between lithospheric strength and ridge push transmission in the Nazca plate

    Science.gov (United States)

    Mahatsente, R.; Ranalli, G.; Bolte, D.; Götze, H.-J.

    2012-01-01

    The ridge push force and the total lithospheric strength of the Nazca plate are compared along an East-West transect from the East Pacific Rise to the Peru-Chile trench at latitude 12°S. The thermal structure of the plate is estimated from the plate cooling model and constrained by heat flow, bathymetry, and geoid height data. The best fitting thermal model has a basal temperature of ˜1600 K and an asymptotic plate thickness (not reached because of the relatively young age of the plate at the trench) of ˜101 km. The ridge push force, also determined from the plate cooling model, is of the order of 1.5 TN m -1 at the trench. The total lithospheric strength as a function of age is estimated for a possible range of conditions (compressional/extensional intraplate tectonic regime, wet/dry rheology). A comparison of ridge push force with lithospheric strength, extended beyond the Nazca plate by considering different spreading rates and ages, shows that oceanic plates with dry rheology have strengths higher than the ridge push force at any age if the tectonic regime is compressional, and comparable if the regime is extensional. On the other hand, oceanic plates with wet rheology have strengths lower than the ridge push force, especially if the tectonic regime is extensional. Therefore, if the rheology is wet and mantle drag at the base of the plate is sufficiently strong, the ridge push force may result in intraplate deformation and be partly dissipated within the plate.

  17. Controlling Laminate Plate Elastic Behavior

    OpenAIRE

    Mareš, T.

    2004-01-01

    This paper aims to express the relation of a measure of laminate plate stiffness with respect to the fiber orientation of its plies. The inverse of the scalar product of the lateral displacement of the central plane and lateral loading of the plate is the measure of laminate plate stiffness. In the case of a simply supported rectangular laminate plate this measure of stiffness is maximized, and the optimum orientation of its plies is searched.

  18. Labor Force

    Science.gov (United States)

    Occupational Outlook Quarterly, 2012

    2012-01-01

    The labor force is the number of people ages 16 or older who are either working or looking for work. It does not include active-duty military personnel or the institutionalized population, such as prison inmates. Determining the size of the labor force is a way of determining how big the economy can get. The size of the labor force depends on two…

  19. Foxj1 regulates floor plate cilia architecture and modifies the response of cells to sonic hedgehog signalling

    Science.gov (United States)

    Cruz, Catarina; Ribes, Vanessa; Kutejova, Eva; Cayuso, Jordi; Lawson, Victoria; Norris, Dominic; Stevens, Jonathan; Davey, Megan; Blight, Ken; Bangs, Fiona; Mynett, Anita; Hirst, Elizabeth; Chung, Rachel; Balaskas, Nikolaos; Brody, Steven L.; Marti, Elisa; Briscoe, James

    2010-01-01

    Sonic hedgehog signalling is essential for the embryonic development of many tissues including the central nervous system, where it controls the pattern of cellular differentiation. A genome-wide screen of neural progenitor cells to evaluate the Shh signalling-regulated transcriptome identified the forkhead transcription factor Foxj1. In both chick and mouse Foxj1 is expressed in the ventral midline of the neural tube in cells that make up the floor plate. Consistent with the role of Foxj1 in the formation of long motile cilia, floor plate cells produce cilia that are longer than the primary cilia found elsewhere in the neural tube, and forced expression of Foxj1 in neuroepithelial cells is sufficient to increase cilia length. In addition, the expression of Foxj1 in the neural tube and in an Shh-responsive cell line attenuates intracellular signalling by decreasing the activity of Gli proteins, the transcriptional mediators of Shh signalling. We show that this function of Foxj1 depends on cilia. Nevertheless, floor plate identity and ciliogenesis are unaffected in mouse embryos lacking Foxj1 and we provide evidence that additional transcription factors expressed in the floor plate share overlapping functions with Foxj1. Together, these findings identify a novel mechanism that modifies the cellular response to Shh signalling and reveal morphological and functional features of the amniote floor plate that distinguish these cells from the rest of the neuroepithelium. PMID:21098568

  20. COMPACT SUPPORT THIN PLATE SPLINE ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    Li Jing; Yang Xuan; Yu Jianping

    2007-01-01

    Common tools based on landmarks in medical image elastic registration are Thin Plate Spline (TPS) and Compact Support Radial Basis Function (CSRBF). TPS forces the corresponding landmarks to exactly match each other and minimizes the bending energy of the whole image. However,in real application, such scheme would deform the image globally when deformation is only local.CSRBF needs manually determine the support size, although its deformation is limited local. Therefore,to limit the effect of the deformation, new Compact Support Thin Plate Spline algorithm (CSTPS) is approached, analyzed and applied. Such new approach gains optimal mutual information, which shows its registration result satisfactory. The experiments also show it can apply in both local and global elastic registration.

  1. Electronic Equipment Cold Plates

    Science.gov (United States)

    1976-04-01

    equations for such a flow regiae. For laainar flow and Moderate teaperature differwwe« between the well «nd coolant, a aodifled Sieder -Tate...con- figuration. The heat-transfer coefficients, therefore, were determined by using both the Sieder -Tate and McAdams equations and the coaputed...values used In the analytical predictions. As with th* previous cold Plates, the Sieder -Tate equation gave too low of values for the heat- transfer

  2. Elastic plate spallation

    Science.gov (United States)

    Oline, L.; Medaglia, J.

    1972-01-01

    The dynamic finite element method was used to investigate elastic stress waves in a plate. Strain displacement and stress strain relations are discussed along with the stiffness and mass matrix. The results of studying point load, and distributed load over small, intermediate, and large radii are reported. The derivation of finite element matrices, and the derivation of lumped and consistent matrices for one dimensional problems with Laplace transfer solutions are included. The computer program JMMSPALL is also included.

  3. Orifice plate cavitation mechanism and its influencing factors

    Directory of Open Access Journals (Sweden)

    Wan-zheng AI

    2010-09-01

    Full Text Available The orifice plate energy dissipater is an economic and highly efficient dissipater. However, there is a risk of cavitaion around the orifice plate flow. In order to provide references for engineering practice, we examined the cavitation mechanism around the orifice plate and its influencing factors by utilizing mathematical analysis methods to analyze the flow conditions around the orifice plate in view of gas bubble dynamics. Through the research presented in this paper, the following can be observed: The critical radius and the critical pressure of the gas nucleus in orifice plate flow increase with its initial state parameter ; the development speed of bubbles stabilizes at a certain value after experiencing a peak value and a small valley value; and the orifice plate cavitation is closely related to the distribution of the gas nucleus in flow. For computing the orifice plate cavitation number, we ought to take into account the effects of pressure fluctuation. The development time of the gas nucleus from the initial radius to the critical radius is about 10-7-10-5 s; therefore, the gas nucleus has sufficient time to develop into bubbles in the negative half-cycle of flow fluctuation. The orifice critical cavitation number is closely related to the orifice plate size, and especially closely related with the ratio of the orifice plate radius to the tunnel radius. The approximate formula for the critical cavitation number of the square orifice plate that only considers the main influencing factor was obtained by model experiments.

  4. High precision refractometry based on Fresnel diffraction from phase plates.

    Science.gov (United States)

    Tavassoly, M Taghi; Naraghi, Roxana Rezvani; Nahal, Arashmid; Hassani, Khosrow

    2012-05-01

    When a transparent plane-parallel plate is illuminated at a boundary region by a monochromatic parallel beam of light, Fresnel diffraction occurs because of the abrupt change in phase imposed by the finite change in refractive index at the plate boundary. The visibility of the diffraction fringes varies periodically with changes in incident angle. The visibility period depends on the plate thickness and the refractive indices of the plate and the surrounding medium. Plotting the phase change versus incident angle or counting the visibility repetition in an incident-angle interval provides, for a given plate thickness, the refractive index of the plate very accurately. It is shown here that the refractive index of a plate can be determined without knowing the plate thickness. Therefore, the technique can be utilized for measuring plate thickness with high precision. In addition, by installing a plate with known refractive index in a rectangular cell filled with a liquid and following the described procedures, the refractive index of the liquid is obtained. The technique is applied to measure the refractive indices of a glass slide, distilled water, and ethanol. The potential and merits of the technique are also discussed.

  5. Anatomic fit of six different radial head plates: comparison of precontoured low-profile radial head plates.

    Science.gov (United States)

    Burkhart, Klaus Josef; Nowak, Tobias E; Kim, Yoon-Joo; Rommens, Pol M; Müller, Lars P

    2011-04-01

    Bulky implants may lead to symptomatic soft tissue irritation after open reduction and internal fixation of radial head and neck fractures. The purpose of our study was to compare the anatomic fit of precontoured radial head plates. We stripped 22 embalmed human cadaveric radiuses of soft tissues. We investigated 6 radial head plates: (1) the Medartis radial head buttress plate (MBP), (2) the Medartis radial head rim plate (MRP), (3) the Synthes radial neck plate (SNP), (4) the Synthes radial head plate (SHP), (5) the Acumed radial head plate (AHP), and (6) the Wright radial head plate (WHP). Each plate was applied to each radial head at the place of best fit within the safe zone. We tested 4 parameters of anatomic fit: (1) plate-to-bone distance, (2) plate contact judged by 3 different observers, (3) pin-subchondral zone distance, and (4) plate-to-bone contact after adjustment of the plates. The MBP and MRP showed the lowest profile by objective measurements, the SNP and AHP had a moderate profile, and the SHP and WHP demonstrated the bulkiest profile. The subjective assessments also demonstrated the best fit for the MBP, a good fit for the SNP, a moderate fit for the MRP and AHP, and a poor fit for the SHP and WHP. The MBP, MRP, and AHP could always provide pin-subchondral zone contact, unlike the SHP, SNP, and WHP. After bending, significant improvement of plate-to-bone distance could only be seen for the MBP, MRP, and WHP. The ranking among plates remained the same except for the WHP, which showed a significantly lower plate-to-bone distance than the SHP. Currently available radial head implants are heterogeneous. The MBP and MRP showed the lowest profile and best anatomic fit. Owing to the complex radial head anatomy, to date there is no one radial head plate that perfectly fits all radial heads. Conformance of existing plates to the radial head and neck is not perfect. Careful plate selection and modification, when necessary, may minimize interference of this

  6. Subduction controls the distribution and fragmentation of Earth’s tectonic plates.

    Science.gov (United States)

    Mallard, Claire; Coltice, Nicolas; Seton, Maria; Müller, R Dietmar; Tackley, Paul J

    2016-07-07

    The theory of plate tectonics describes how the surface of Earth is split into an organized jigsaw of seven large plates of similar sizes and a population of smaller plates whose areas follow a fractal distribution. The reconstruction of global tectonics during the past 200 million years suggests that this layout is probably a long-term feature of Earth, but the forces governing it are unknown. Previous studies, primarily based on the statistical properties of plate distributions, were unable to resolve how the size of the plates is determined by the properties of the lithosphere and the underlying mantle convection. Here we demonstrate that the plate layout of Earth is produced by a dynamic feedback between mantle convection and the strength of the lithosphere. Using three-dimensional spherical models of mantle convection that self-consistently produce the plate size–frequency distribution observed for Earth, we show that subduction geometry drives the tectonic fragmentation that generates plates. The spacing between the slabs controls the layout of large plates, and the stresses caused by the bending of trenches break plates into smaller fragments. Our results explain why the fast evolution in small back-arc plates reflects the marked changes in plate motions during times of major reorganizations. Our study opens the way to using convection simulations with plate-like behaviour to unravel how global tectonics and mantle convection are dynamically connected.

  7. Subduction controls the distribution and fragmentation of Earth’s tectonic plates

    Science.gov (United States)

    Mallard, Claire; Coltice, Nicolas; Seton, Maria; Müller, R. Dietmar; Tackley, Paul J.

    2016-07-01

    The theory of plate tectonics describes how the surface of Earth is split into an organized jigsaw of seven large plates of similar sizes and a population of smaller plates whose areas follow a fractal distribution. The reconstruction of global tectonics during the past 200 million years suggests that this layout is probably a long-term feature of Earth, but the forces governing it are unknown. Previous studies, primarily based on the statistical properties of plate distributions, were unable to resolve how the size of the plates is determined by the properties of the lithosphere and the underlying mantle convection. Here we demonstrate that the plate layout of Earth is produced by a dynamic feedback between mantle convection and the strength of the lithosphere. Using three-dimensional spherical models of mantle convection that self-consistently produce the plate size-frequency distribution observed for Earth, we show that subduction geometry drives the tectonic fragmentation that generates plates. The spacing between the slabs controls the layout of large plates, and the stresses caused by the bending of trenches break plates into smaller fragments. Our results explain why the fast evolution in small back-arc plates reflects the marked changes in plate motions during times of major reorganizations. Our study opens the way to using convection simulations with plate-like behaviour to unravel how global tectonics and mantle convection are dynamically connected.

  8. Lower limb joint forces during walking on the level and slopes at different inclinations.

    Science.gov (United States)

    Alexander, Nathalie; Schwameder, Hermann

    2016-03-01

    Sloped walking is associated with an increase of lower extremity joint loading compared to level walking. Therefore, the aim of this study was to analyse lower limb joint compression forces as well as tibiofemoral joint shear forces during sloped walking at different inclinations. Eighteen healthy male participants (age: 27.0 ± 4.7 years, height: 1.80 ± 0.05 m, mass: 74.5 ± 8.2 kg) were asked to walk at a pre-set speed of 1.1m/s on a ramp (6 m × 1.5 m) at the slopes of -18°, -12°, -6°, 0°, 6°, 12° and 18°. Kinematic data were captured with a twelve-camera motion capture system (Vicon). Kinetic data were recorded with two force plates (AMTI) imbedded into a ramp. A musculoskeletal model (AnyBody) was used to compute lower limb joint forces. Results showed that downhill walking led to significantly increased hip, tibiofemoral and patellofemoral joint compression forces (pjoint compression forces (pjoint compression forces with increasing inclination (pligament could not be supported in the current study, since anterior tibiofemoral joint shear forces did not increase with the gradient. Due to diverse tibiofemoral joint shear force patterns in the literature, results should be treated with caution in general. Finally, lower limb joint force analyses provided more insight in the structure loading conditions during sloped walking than joint moment analyses.

  9. Polarizable force fields.

    Science.gov (United States)

    Antila, Hanne S; Salonen, Emppu

    2013-01-01

    This chapter provides an overview of the most common methods for including an explicit description of electronic polarization in molecular mechanics force fields: the induced point dipole, shell, and fluctuating charge models. The importance of including polarization effects in biomolecular simulations is discussed, and some of the most important achievements in the development of polarizable biomolecular force fields to date are highlighted.

  10. Large Deflections of Elastic Rectangular Plates

    Science.gov (United States)

    Razdolsky, A. G.

    2015-11-01

    It is known that elastic large deflections of thin plates are governed by von Karman nonlinear equations. The analytical solution of these equations in the general case is unfeasible. Samuel Levy, in 1942, showed that large deflections of the rectangular plate can be expressed as a double series of sine-shaped harmonics (deflection harmonics). However, this method gave no way of creating the computer algorithm of solving the problem. The stress function expression taken in the Levy's method must be revised to find the approach that takes into account of all possible products of deflection coefficients. The algorithm of solving the problem for the rectangular plate with an arbitrary aspect ratio under the action of the lateral distributed load is reported in this paper. The approximation of the plate deflection is taken in the form of double series proposed by Samuel Levy. However, the expression for the stress function is presented in the form that incorporates products of deflection coefficients in the explicit form in distinction to the Levy's expression. The number of harmonics in the deflection expression may be arbitrary. The algorithm provides composing the system of governing cubic equations, which includes the deflection coefficients in the explicit form. Solving the equation system is based on using the principle of minimum potential energy. A method of the gradient descent is applied to find the equilibrium state of the plate as the minimum point of the potential energy. A computer program is developed on the basis of the present algorithm. Numerical examples carried out for the plate model with 16 deflection harmonics illustrate the potentialities of the program. The results of solving the examples are presented in the graphical form for the plates with a different aspect ratio and may be used under designing thin-walled elements of airplane and ship structures.

  11. Petrologic implications of plate tectonics.

    Science.gov (United States)

    Yoder, H S

    1971-07-30

    Petrologists can make significant contributions to the plate tectonic concept. Fixing the stability fields of the principal rock types involved will provide the limits of pressure and temperature of the various environments. Experimental determination of the partition coefficients of the trace elements will be helpful. Studies of the partial melting behavior of possible parental materials in the absence and presence of water, especially the undersaturated region, will contribute to the understanding of magma production. Experimental observations on the rheological properties of the peridotites below and just above the solidus will lead to a better evaluation of the convective mechanism. Measurement of the fundamental properties of rocks, such as the density of solids and liquids at high pressures and temperatures, would contribute to understanding the concepts of diapiric rise, magma segregation, and the low-velocity zone. Broader rock sampling of the oceanic areas of all environments will do much to define the petrologic provinces. The field petrologist specializing in the Paleozoic regions and Precambrian shields can contribute by examining those regions for old plate boundaries and devising new criteria for their recognition.

  12. Wood zone plate fishnet metalens

    Directory of Open Access Journals (Sweden)

    Orazbayev Bakhtiyar

    2015-01-01

    Full Text Available Fresnel-zone plate lenses provide focusing performance while having low profile. Unfortunately, they usually display higher reflection losses than conventional dielectric lenses. Here, we demonstrate a low-profile Wood zone plate metalens based on the fishnet metamaterial working in a near-zero regime with an equivalent refractive index less than unity (nf = 0.51. The metalens is made of alternating dielectric and fishnet metamaterial concentric rings. The use of fishnet metamaterial allows reducing the reflections from the lens, while maintaining low profile, low cost and ease of manufacturing. The lens is designed to work at the W-band of the millimeter-waves range with a focal length FL = 22.8 mm (7.5 λ0 aiming at antenna or radar system applications. The focusing performance of the lens along with its radiation characteristics in a lens antenna configuration have been studied numerically and confirmed experimentally, showing a gain improvement of ~2.5 dB with respect to a fishnet Soret metalens.

  13. Convenient contrast enhancement by a hole-free phase plate

    DEFF Research Database (Denmark)

    Malac, Marek; Beleggia, Marco; Kawasaki, Masahiro

    2012-01-01

    Decrease of the irradiation dose needed to obtain a desired signal-to-noise ratio can be achieved by Zernike phase-plate imaging. Here we present results on a hole-free phase plate (HFPP) design that uses the incident electron beam to define the center of the plate, thereby eliminating the need...... for high precision alignment and with advantages in terms of ease of fabrication. The Zernike-like phase shift is provided by a charge distribution induced by the primary beam, rather than by a hole in the film. Compared to bright-field Fresnel-mode imaging, the hole-free phase plate (HFPP) results in two...

  14. Onset of the Mutual Thermal Effects of Solid Body and Nanofluid Flow over a Flat Plate Theoretical Study

    OpenAIRE

    A. Malvandi; Faraz Hedayati; Ganji, D.D.

    2015-01-01

    The falling and settling of solid particles in gases and liquids is a natural phenomenon happens in many industrial processes. This phenomenon has altered pure forced convection to a combination of heat conduction and heat convection in a flow over a plate. In this paper, the coupling of conduction (inside the plate) and forced convection of a non-homogeneous nanofluid flow (over a flat plate) is investigated, which is classified in conjugate heat transfer problems. Two-component four-equatio...

  15. Surgical approaches for minimally invasive plate osteosynthesis in dogs.

    Science.gov (United States)

    Pozzi, A; Lewis, D

    2009-01-01

    Fracture stabilisation techniques continue to evolve and to provide approaches which minimise the iatrogenic trauma associated with surgery. Minimally invasive plate osteosynthesis (MIPO) is a recently described method of biological internal fixation performed by introducing a bone plate via small insertional incisions that are made remote to the fracture site. The plate is slid adjacent to the bone in an epiperiosteal tunnel connecting the two insertional incisions. Screws are placed in the plate through the insertional incisions or via additional stab incisions made over the holes in the plate. In this paper we describe the surgical approaches used to perform MIPO in humeral, radial, femoral and tibial fractures in dogs. We found that these approaches allowed safe insertion of the plate without grossly damaging neuro-vascular structures. Further studies are needed to evaluate the clinical outcome of MIPO in dogs.

  16. Free vibration analysis of rectangular plates with central cutout

    Directory of Open Access Journals (Sweden)

    Kanak Kalita

    2016-12-01

    Full Text Available A nine-node isoparametric plate element in conjunction with first-order shear deformation theory is used for free vibration analysis of rectangular plates with central cutouts. Both thick and thin plate problems are solved for various aspect ratios and boundary conditions. In this article, primary focus is given to the effect of rotary inertia on natural frequencies of perforated rectangular plates. It is found that rotary inertia has significant effect on thick plates, while for thin plates the rotary inertia term can be ignored. It is seen that the numerical convergence is very rapid and based on comparison with experimental and analytical data from literature, it is proposed that the present formulation is capable of yielding highly accurate results. Finally, some new numerical solutions are provided here, which may serve as benchmark for future research on similar problems.

  17. Intermolecular and surface forces

    CERN Document Server

    Israelachvili, Jacob N

    2011-01-01

    This reference describes the role of various intermolecular and interparticle forces in determining the properties of simple systems such as gases, liquids and solids, with a special focus on more complex colloidal, polymeric and biological systems. The book provides a thorough foundation in theories and concepts of intermolecular forces, allowing researchers and students to recognize which forces are important in any particular system, as well as how to control these forces. This third edition is expanded into three sections and contains five new chapters over the previous edition.· starts fr

  18. Plate forming and break down pizza box

    Science.gov (United States)

    Pantisano, Frank; Devine, Scott M.

    1992-01-01

    A standard corrugated paper pizza box is provided with slit cuts cut through the top panel of the pizza box in a shape to form four circular serving plates with a beveled raised edge and cross slit cuts through the bottom panel of the pizza box separating the box into four essentially equal portions for easy disposal.

  19. Using plate mapping to examine portion size and plate composition for large and small divided plates.

    Science.gov (United States)

    Sharp, David E; Sobal, Jeffery; Wansink, Brian

    2014-12-01

    Does the size of a plate influence the serving of all items equally, or does it influence the serving of some foods - such as meat versus vegetables - differently? To examine this question, we used the new method of plate mapping, where people drew a meal on a paper plate to examine sensitivity to small versus large three-compartment divided plates in portion size and meal composition in a sample of 109 university students. The total drawn meal area was 37% bigger on large plates than small plates, which showed that the portion of plate coverage did not differ by plate size. Men and women drew bigger vegetable portions and men drew bigger meat portions on large plates when compared to small plates. These results suggest that men and women are differentially sensitive to plate size for overall meal size and for meal composition. Implications for decreasing portion size and improving meal balance are that plate size may influence portion size and change the proportions of foods served.

  20. Cascade impactor and jet plate for same

    Energy Technology Data Exchange (ETDEWEB)

    Dahlin, Robert S.; Farthing, William E.; Landham Jr., Edward C.

    2004-02-03

    A sampling system and method for sampling particulate matter from a high-temperature, high-pressure gas stream. A cyclone sampler for use at high temperatures and pressures, and having threadless sacrificial connectors is disclosed. Also disclosed is an improved cascade impactor including jet plates with integral spacers, and alignment features provided for aligning the jet plates with their associated collection substrates. An activated bauxite alkali collector is disclosed, and includes an alumina liner. The sampling system can be operated remotely or locally, and can be permanently installed or configured as a portable system.

  1. Fuel Cell Thermal Management Through Conductive Cooling Plates

    Science.gov (United States)

    Colozza, Anthony J.; Burke, Kenneth A.

    2008-01-01

    An analysis was performed to evaluate the concept of utilizing conductive cooling plates to remove heat from a fuel cell stack, as opposed to a conventional internal cooling loop. The potential advantages of this type of cooling system are reduced stack complexity and weight and increased reliability through the reduction of the number of internal fluid seals. The conductive cooling plates would extract heat from the stack transferring it to an external coolant loop. The analysis was performed to determine the required thickness of these plates. The analysis was based on an energy balance between the thermal energy produced within the stack and the heat removal from the cooling plates. To accomplish the energy balance, the heat flow into and along the plates to the cooling fluid was modeled. Results were generated for various numbers of cells being cooled by a single cooling plate. The results provided cooling plate thickness, mass, and operating temperature of the plates. It was determined that utilizing high-conductivity pyrolitic graphite cooling plates can provide a specific cooling capacity (W/kg) equivalent to or potentially greater than a conventional internal cooling loop system.

  2. The temporal evolution of a subducting plate in the lower mantle

    Science.gov (United States)

    Loiselet, C.; Grujic, D.; Braun, J.; Fullsack, P.; Thieulot, C.; Yamato, P.

    2009-04-01

    It is now widely accepted that some subducting slabs may cross the lower/upper mantle boundary to ground below the 660 km discontinuity. Indeed, geophysical data underline long and narrow traces of fast materials, associated with subducting slabs, from the upper mantle transition zone to mid-mantle depths that are visible beneath North and South America and southern Asia (Li et al, 2008). Furthermore, seismic tomography data (Van der Hilst et al., 1997; Karason and van der Hilst, 2000, 2001) show a large variety of slab geometries and of mantle flow patterns around subducting plate boundaries (e.g. the slab geometry in the lower mantle in the Tonga subduction zone). However, seismic tomography does not elucidate the temporal evolution of the slab behaviour and geometry during its descent through the upper and lower mantle. In this work, we therefore propose to study the deformation of a thin plate (slab) falling in a viscous fluid (mantle) by means of both analogue and numerical modelling. The combination of both analogue and numerical experiments provides important insights into the shape and attitude evolution of subducting slabs. Models bring information into the controls exerted by the rheology of the slab and the mantle and other physical parameters such as the density contrast between the slab and the surrounding mantle, on the rate at which this deformation takes place. We show that in function of a viscosity ratios between the plate and the surrounding fluid, the plate will acquire a characteristic shape. For the isoviscous case, the plate shape tends toward a bubble with long tails: a "jellyfish" form. The time necessary for the plate to acquire this shape is a function of the viscosity and density contrast between the slab and the mantle. To complete our approach, we have developed a semi-analytical model based on the solution of the Hadamar-Rybinski equations for the problem of a dense, yet isoviscous and thus deforming sphere. This model helps to better

  3. On the capillary interaction between solid plates forming menisci on the surface of a liquid

    Science.gov (United States)

    Saif, Taher A.

    2002-12-01

    A hydrophilic or a hydrophobic long rigid solid plate of finite width, forming a meniscus with a liquid in a uniform gravitational field is considered. The one-dimensional meniscus with prescribed heights of the triple point from the far-field liquid surface is investigated analytically using the Young Laplace equation. It is found that for a hydrophilic plate, the vertical force necessary to break the meniscus during removal of the plate from the liquid is larger than the force necessary to break the meniscus during submersion of the plate into the liquid. Furthermore, the capillary force on the plate reaches a maximum before the meniscus collapses during removal, but no maximum exists before collapse during submersion. The reverse is true when the plate is hydrophobic. The study is then extended to investigate the interaction force between two plates, each forming a meniscus with the liquid. The elevations of the plates from the far-field liquid surface are prescribed, in contrast to earlier studies where interaction between long cylinders floating under self weight was considered. Here, the menisci are determined exactly using the Young Laplace equation. It is shown that for prescribed plate elevations, there can be at most two possible pairs of menisci between them. Each pair bifurcates from a meniscus that is determined by the elevations of the plates and the gap between them. Furthermore, as known for solids floating under self-weight, the horizontal component of the interaction force is attractive for similar menisci (e.g. when the two plates are equally displaced in or out of the liquid), and repulsive when they form opposite menisci. It is shown that if the two menisci are of the same type, but not similar (e.g. one plate is pushed more into the liquid than the other), then the force is attractive at long distances, and may be repulsive at shorter distances with a stable equilibrium at a finite distance between the plates, depending on the elevations of

  4. On topology optimization of plates with prestress

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2001-01-01

    In this work, topology optimization is used to optimize the compliance or eigenvalues of prestressed plates. The prestress is accounted for by including the force equivalent to the prestressing and adding the initial stress stiffness matrix to the original stiffness matrix. The calculation...... of the sensitivities is complicated because of the initial stress stiffness matrix, but the computational cost can be kept low by using the adjoint method. The topology optimization problem is solved using the solid isotropic material with penalization (SIMP) method in combination with method of moving asymptotes (MMA...

  5. Topology optimization of laminated plates with prestress

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2002-01-01

    Laminated plates with different prestress in the layers are topology optimized. The objectives are to minimize the deflection due to the prestress or to minimize ordinary compliance. The prestress is accounted for by including the force equivalent to the prestressing and adding the initial stress...... stiffness matrix to the structural stiffness. The calculations of sensitivities are complicated not only by the prestress but also because we are dealing with laminates. The topology optimization problem is solved using a new penalization scheme as an alternative to the SIMP (power law) approach...

  6. Temperature field of steel plate cooling process after plate rolling

    Directory of Open Access Journals (Sweden)

    Huijun Feng, Lingen Chen, Fengrui Sun

    2015-01-01

    Full Text Available Based on numerical calculation with Matlab, the study on cooling process after plate rolling is carried out, and the temperature field distribution of the plate varying with the time is obtained. The effects of the plate thickness, final rolling temperature, cooling water temperature, average flow rate of the cooling water, carbon content of the plate and cooling method on the plate surface and central temperatures as well as final cooling temperature are discussed. For the same cooling time, the plate surface and central temperatures as well as their temperature difference increase; with the decrease in rolling temperature and the increase in average flow rate of the cooling water, the plate surface and central temperatures decrease. Compared with the single water cooling process, the temperature difference between the plate centre and surface based on intermittent cooling is lower. In this case, the temperature uniformity of the plate is better, and the corresponding thermal stress is lower. The fitting equation of the final cooling temperature with respect to plate thickness, final rolling temperature, cooling water temperature and average flow rate of the cooling water is obtained.

  7. Structure of colloidal sphere-plate mixtures

    Science.gov (United States)

    Doshi, N.; Cinacchi, G.; van Duijneveldt, J. S.; Cosgrove, T.; Prescott, S. W.; Grillo, I.; Phipps, J.; Gittins, D. I.

    2011-05-01

    In addition to containing spherical pigment particles, coatings usually contain plate-like clay particles. It is thought that these improve the opacity of the paint film by providing an efficient spacing of the pigment particles. This observation is counterintuitive, as suspensions of particles of different shapes and sizes tend to phase separate on increase of concentration. In order to clarify this matter a model colloidal system is studied here, with a sphere-plate diameter ratio similar to that found in paints. For dilute suspensions, small angle neutron scattering revealed that the addition of plates leads to enhanced density fluctuations of the spheres, in agreement with new theoretical predictions. On increasing the total colloid concentration the plates and spheres phase separate due to the disparity in their shape. This is in agreement with previous theoretical and experimental work on colloidal sphere-plate mixtures, where one particle acts as a depleting agent. The fact that no large scale phase separation is observed in coatings is ascribed to dynamic arrest in intimately mixed, or possibly micro-phase separated structures, at elevated concentration.

  8. Structure of colloidal sphere-plate mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Doshi, N; Cinacchi, G; Van Duijneveldt, J S; Cosgrove, T; Prescott, S W [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Grillo, I [Institut Laue-Langevin, 6 rue Jules Horowitz BP 156, 38042 Grenoble Cedex 9 (France); Phipps, J [Imerys Minerals Ltd, Par Moor Centre, Par Moor Road, Par, Cornwall PL24 2SQ (United Kingdom); Gittins, D I, E-mail: Giorgio.Cinacchi@bristol.ac.uk, E-mail: J.S.van-Duijneveldt@bristol.ac.uk [Imerys Performance and Filtration Minerals Ltd, 130 Castilian Drive, Goleta, CA 93117 (United States)

    2011-05-18

    In addition to containing spherical pigment particles, coatings usually contain plate-like clay particles. It is thought that these improve the opacity of the paint film by providing an efficient spacing of the pigment particles. This observation is counterintuitive, as suspensions of particles of different shapes and sizes tend to phase separate on increase of concentration. In order to clarify this matter a model colloidal system is studied here, with a sphere-plate diameter ratio similar to that found in paints. For dilute suspensions, small angle neutron scattering revealed that the addition of plates leads to enhanced density fluctuations of the spheres, in agreement with new theoretical predictions. On increasing the total colloid concentration the plates and spheres phase separate due to the disparity in their shape. This is in agreement with previous theoretical and experimental work on colloidal sphere-plate mixtures, where one particle acts as a depleting agent. The fact that no large scale phase separation is observed in coatings is ascribed to dynamic arrest in intimately mixed, or possibly micro-phase separated structures, at elevated concentration.

  9. Electroless nickel plating on stainless steels and aluminum

    Science.gov (United States)

    1966-01-01

    Procedures for applying an adherent electroless nickel plating on 303 SE, 304, and 17-7 PH stainless steels, and 7075 aluminum alloy was developed. When heat treated, the electroless nickel plating provides a hard surface coating on a high strength, corrosion resistant substrate.

  10. Application of Cosine Zone Plates to Image Encryption

    Institute of Scientific and Technical Information of China (English)

    GE Fan; CHEN Lin-Fei; ZHAO Dao-Mu

    2008-01-01

    @@ We analyse the diffraction result of optical field after Cosine zone plate, and theoretically deduce its transform matrix. Under some conditions, its diffraction distribution is a mixture of fractional Fourier spectra. Then we use Cosine zone plate and its diffraction result to image encryption. Possible optical image encryption and decryption implementations are proposed, and some numerical simulation results are also provided.

  11. Guided-mode resonant wave plates.

    Science.gov (United States)

    Magnusson, Robert; Shokooh-Saremi, Mehrdad; Johnson, Eric G

    2010-07-15

    We introduce half-wave and quarter-wave retarders based on the dispersion properties of guided-mode resonance elements. We design the wave plates using numerical electromagnetic models joined with the particle swarm optimization method. The wave plates operate in reflection. We provide computed results for reflectance and phase in the telecommunication spectral region near 1.55 microm wavelength. A surface-relief grating etched in glass and overcoated with silicon yields a half-wave plate with nearly equal amplitudes of the TE and TM polarization components and pi phase difference across a bandwidth exceeding 50 nm. Wider operational bandwidths are obtainable with more complex designs involving glass substrates and mixed silicon/hafnium dioxide resonant gratings. The results indicate a potential new approach to fashion optical retarders.

  12. 1/3 SUBHARMONIC SOLUTION OF ELLIPTICAL SANDWICH PLATES

    Institute of Scientific and Technical Information of China (English)

    李银山; 张年梅; 杨桂通

    2003-01-01

    The problem of nonlinear forced oscillations for elliptical sandwich plates is dealtwith. Based on the governing equations expressed in terms of five displacement components,the nonlinear dynamic equation of an elliptical sandwich plate under a harmonic force isderived. A superpositive-iterative harmonic balance ( SIHB ) method is presented for thesteady-state analysis of strongly nonlinear oscillators. In a periodic oscillation, the periodicsolutions can be expressed in the form of basic harmonics and bifurcate harmonics. Thus,an oscillation system which is described as a second order ordinary differential equation,can be expressed as fundamental differential equation with fundamental harmonics andincremental differential equation with derived harmonics. The 1/3 subharnonic solution ofan elliptical sandwich plate is investigated by using the methods of SIHB. The SIHB methodis compared with the numerical integration method. Finally, asymptotical stability of the1/3 subharmonic oscillations is inspected.

  13. An elastic plate on a thin viscous film

    CERN Document Server

    Trinh, Philippe H; Stone, Howard A

    2014-01-01

    We consider the steady-state analysis of a pinned elastic plate lying on the free surface of a thin viscous fluid, forced by the motion of a bottom substrate moving at constant speed. A mathematical model incorporating elasticity, viscosity, surface tension, and pressure forces is derived, and consists of a third-order Landau-Levich equation for the thin film, and a fifth-order beam equation for the plate. A numerical and asymptotic analysis is presented in the relevant limits of the elasticity and Capillary numbers. We demonstrate the emergence of boundary-layer effects near the ends of the plate, which are likely to be a generic phenomenon for singularly perturbed elastocapillary problems.

  14. EQUIVALENCE BETWEEN EXACT INTERNAL CONTROLLABILITY OF THE KIRCHHOFF PLATE-LIKE EQUATION AND THE WAVE EQUATION

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    When the rotatory inertia is taken into account, vibrations of a linear plate can be described by the Kirchhoff plate equation. Consider this equation with locally distributed control forces and some boundary condition which is the simply supported boundary condition for a rectangular plate. In this paper, the authors establish exact controllability of the system in terms of the equivalence to exact internal controllability of the wave equation, by means of a frequency domain characterization of exact controllability introduced recently in [11].

  15. Stresses due to an adhesion crack in T-shaped junction of two orthotropic plates

    Institute of Scientific and Technical Information of China (English)

    Dai-Heng Chen

    2012-01-01

    The general solution of streesses is derived for a T-shaped junction of two thin plates with an adhesion crack.The plates are orthotropic.A shear force is applied on the crack surface.The analysis is based on the supposition that the stresses in each plate can be approximated by a plane stress condition.The results obtained are verified by numerical calculation of FEM.

  16. Interaction of Lamb Waves with Domain Walls in an Iron Borate Plate

    Directory of Open Access Journals (Sweden)

    E.A. Zhukov

    2015-12-01

    Full Text Available This work presents the calculation results of the Lamb wave spectra in a plate of iron borate. Experimental data on how flexural vibrations in a borate plate influence its domain structure are provided.

  17. The Localized Instability of the Uniform Compressed Plate

    Directory of Open Access Journals (Sweden)

    Belubekyan V.M.

    2007-03-01

    Full Text Available The localized instability of the rectangular plate uniformly compressed by all edges are considered. The problem is solved also in the particular case when “follow” force is acting on the free edge. Non existence of localized instability in this case is shown.

  18. Study on the Hinge-joined Plate Method

    Directory of Open Access Journals (Sweden)

    Li Sha

    2015-01-01

    Full Text Available In order to verify and perfect the theory of hinge-joined plate method and make it serve the bridge design better, this paper was written based on an actual bridge, and the ANSYS finite element model was established. Compared the hinge-joined plate method results with the analysis results and through the investigation and data analysis, it could be found that the assumption that the hinge-joined plate theory for the board lateral force transmission is reasonable, but the assuming hinge joints that only withstand shear stress and just have the shear checking is unreasonable. At the same time, this paper also proved that the strength reduction getting from the old and new concrete interface should be taken into account when using the hinge-joined plate method to calculate the transverse distribution coefficient and the effects on overall stiffness that the joint depth and thickness of deck pavement to the beam bridge.

  19. Characterization of vortical gusts produced by a heaving plate

    Science.gov (United States)

    Hufstedler, Esteban; McKeon, Beverley J.

    2016-11-01

    To experimentally investigate the interaction between a wing and a spanwise vortical gust, a simple gust generator has been built and tested. This consists of a transversely heaving flat plate that changes direction to release a vortex, which then convects downstream to interact with a wing. Previous experiments have shown that, immediately downstream of the plate, the circulation of the generated vortex is proportional to the heaving speed of the plate. The forces that the gusts exert on a downstream wing were shown to be strongly repeatable and consistent with a passing vortex. This presentation will discuss the properties of the vortical gusts as they move downstream, and relate those properties to the important dimensionless parameters of the flow. These properties include the convection speed and circulation of the vortex, as well as the enstrophy due to the wake of the plate. This research is funded by the Gordon and Betty Moore Foundation through Grant GBMF#2645 to the California Institute of Technology.

  20. FRACTURE CALCULATION OF BENDING PLATES BY BOUNDARY COLLOCATION METHOD

    Institute of Scientific and Technical Information of China (English)

    王元汉; 伍佑伦; 余飞

    2003-01-01

    Fracture of Kirchhoff plates is analyzed by the theory of complex variables and boundary collocation method. The deflections, moments and shearing forces of the plates are assumed to be the functions of complex variables. The functions can satisfy a series of basic equations and governing conditions, such as the equilibrium equations in the domain, the boundary conditions on the crack surfaces and stress singularity at the crack tips. Thus, it ts only necessary to consider the boundary conditions on the external boundaries of the plate, which can be approximately satisfied by the collocation method and least square technique. Different boundary conditions and loading cases of the cracked plates are analyzed and calculated. Compared to other methods, the numerical examples show that the present method has many advantages such as good accuracy and less computer time This is an effective semi-analytical and semi-numerical method.

  1. Plate Full of Color

    Centers for Disease Control (CDC) Podcasts

    2008-08-04

    The Eagle Books are a series of four books that are brought to life by wise animal characters - Mr. Eagle, Miss Rabbit, and Coyote - who engage Rain That Dances and his young friends in the joy of physical activity, eating healthy foods, and learning from their elders about health and diabetes prevention. Plate Full of Color teaches the value of eating a variety of colorful and healthy foods.  Created: 8/4/2008 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 8/5/2008.

  2. Dynamics of Tectonic Plates

    OpenAIRE

    2014-01-01

    We suggest a model that describes a mutual dynamic of tectonic plates. The dynamic is a sort of stick-slip one which is modeled by a Markov random process. The process defines a microlevel of the dynamic. A macrolevel is obtained by a scaling limit which leads to a system of integro-differential equations which determines a kind of mean field systems. Conditions when Gutenberg-Richter empirical law are presented on the mean field level. These conditions are rather universal and do not depend ...

  3. Mechanical design of multiple zone plates precision alignment apparatus for hard X-ray focusing in twenty-nanometer scale

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Deming; Liu, Jie; Gleber, Sophie C.; Vila-Comamala, Joan; Lai, Barry; Maser, Jorg M.; Roehrig, Christian; Wojcik, Michael J.; Vogt, Franz Stefan

    2017-04-04

    An enhanced mechanical design of multiple zone plates precision alignment apparatus for hard x-ray focusing in a twenty-nanometer scale is provided. The precision alignment apparatus includes a zone plate alignment base frame; a plurality of zone plates; and a plurality of zone plate holders, each said zone plate holder for mounting and aligning a respective zone plate for hard x-ray focusing. At least one respective positioning stage drives and positions each respective zone plate holder. Each respective positioning stage is mounted on the zone plate alignment base frame. A respective linkage component connects each respective positioning stage and the respective zone plate holder. The zone plate alignment base frame, each zone plate holder and each linkage component is formed of a selected material for providing thermal expansion stability and positioning stability for the precision alignment apparatus.

  4. Mechanical design of multiple zone plates precision alignment apparatus for hard X-ray focusing in twenty-nanometer scale

    Science.gov (United States)

    Shu, Deming; Liu, Jie; Gleber, Sophie C.; Vila-Comamala, Joan; Lai, Barry; Maser, Jorg M.; Roehrig, Christian; Wojcik, Michael J.; Vogt, Franz Stefan

    2017-04-04

    An enhanced mechanical design of multiple zone plates precision alignment apparatus for hard x-ray focusing in a twenty-nanometer scale is provided. The precision alignment apparatus includes a zone plate alignment base frame; a plurality of zone plates; and a plurality of zone plate holders, each said zone plate holder for mounting and aligning a respective zone plate for hard x-ray focusing. At least one respective positioning stage drives and positions each respective zone plate holder. Each respective positioning stage is mounted on the zone plate alignment base frame. A respective linkage component connects each respective positioning stage and the respective zone plate holder. The zone plate alignment base frame, each zone plate holder and each linkage component is formed of a selected material for providing thermal expansion stability and positioning stability for the precision alignment apparatus.

  5. Capillary-force measurement on SiC surfaces

    NARCIS (Netherlands)

    Sedighi, M.; Svetovoy, V. B.; Palasantzas, G.

    2016-01-01

    Capillary forces have been measured by atomic force microscopy in the sphere-plate geometry, in a controlled humidity environment, between smooth silicon carbide and borosilicate glass spheres. The force measurements were performed as a function of the rms surface roughness similar to 4-14 nm mainly

  6. Influence of roughness on capillary forces between hydrophilic surfaces

    NARCIS (Netherlands)

    van Zwol, P. J.; Palasantzas, G.; De Hosson, J. Th. M.

    2008-01-01

    Capillary forces have been measured by atomic force microscopy in the plate-sphere setup between gold, borosilicate glass, GeSbTe, titanium, and UV-irradiated amorphous titanium-dioxide surfaces. The force measurements were performed as a function contact time and surface roughness in the range 0.2-

  7. Displacements and stresses in bending of circular perforated plate

    Science.gov (United States)

    Atanasiu, C.; Sorohan, St.

    2016-08-01

    The flat plates, perforated by a large number of holes are widely used in the engineering, especially in the component of the process equipment. Strength calculations and experimental methods used in the actual literature for study perforated plates, do not present the problem in all its complexity for stress distribution and displacements. Research and doctoral theses in last decades, with methods characteristic of the respective periods were engaged either perforated plates considered infinite and requested the median plane or rarely, plate loaded normal to the median plane, with a small number of holes. In this work the stress distribution and displacement is presented for a circular plate perforated by 96 holes arranged in a grid of squares, simply supported on the outline and loaded through a central concentrated force or by uniformly distributed load. It conducted a numerical analysis by finite element method (FEM) with a proper meshing of the plate and an experimental study by holographic interferometry. Holographic interferometry method permits to measure, with high accuracy, extremely small displacements and comparing the results with those obtained by FEM becomes sustainable. Supplementary, an analysis of a non-perforated plate with the same dimensions and stiffness, similar loaded, was performed, determining the coefficient of stress concentration for a particular arrangement of holes.

  8. A computer study of biodegradable plates for internal fixation of mandibular angle fractures

    NARCIS (Netherlands)

    Tams, J; Van Loon, JP; Otten, B; Bos, RRM

    2001-01-01

    Purpose: This computer-based study was performed to determine the suitability of small biodegradable plate systems for mandibular angle fractures. Materials and Methods: In a 3-dimensional computer model of the mandible, fracture mobility and plate strain were calculated for bite forces applied on 1

  9. General Observations of the Time-Dependent Flow Field Around Flat Plates in Free Fall

    DEFF Research Database (Denmark)

    Hærvig, Jakob; Jensen, Anna Lyhne; Pedersen, Marie Cecilie

    2015-01-01

    The free fall trajectories of flat plates are investigated in order to improve understanding of the forces acting on falling blunt objects. The long term goal is to develop a general applicable model to predict free fall trajectories. Numerically the free fall of a flat plate is investigated usin...

  10. Activities for Plate Tectonics using GeoMapApp

    Science.gov (United States)

    Goodwillie, A. M.

    2016-12-01

    The concept of plate tectonics is a fundamental component of our understanding of how Earth works yet authentic, high-quality geoscience data related to plate tectonics may not be readily available to all students. To compound matters, when data is accessible, students may not possess the skills or resources necessary to explore and analyse it. As a result, much emphasis at federal and state level is now placed upon encouraging students to work with more data and more technology more often and more rigourously. Easy-to-use digital platforms offer much potential for promoting inquiry-based learning at all levels of education. GeoMapApp is one such tool. Developed at Columbia University's Lamont-Doherty Earth Observatory, GeoMapApp (http://www.geomapapp.org) is a free resource that integrates a wide range of research-grade geoscience data in one intuitive map-based interface. Simple strategies for data manipulation, visualisation and presentation allow uses to explore the data in meaningful ways. Layering and transparency capabilities further allow learners to use GeoMapApp to compare multiple data sets at once, and high-impact Save Session functionality allows a GeoMapApp project to be saved for sharing or later use. In this presentation, activities related to plate tectonics will be highlighted. One GeoMapApp activity helps students investigate plate boundaries by exploring earthquake and volcano locations. Another requires students to calculate the rate of seafloor spreading using crustal age data in various ocean basins. A third uses the GeoMapApp layering technique to explore the influence of geological forces in shaping the landscape. Each activity shown can be done by students on an individual basis, as pairs, or as groups. Educators report that student use of GeoMapApp fosters an increased sense of data "ownership" amongst students, promotes STEM skills, and provides them with access to authentic research-grade geoscience data using the same cutting

  11. Casimir Torque in Inhomogeneous Dielectric Plates

    CERN Document Server

    Long, William

    2013-01-01

    In this work, we consider a torque caused by the well known quantum mechanical Casimir effect arising from quantized field fluctuations between plates with inhomogeneous, sharply discontinuous, dielectric properties. While the Casimir effect is a relatively well understood phenomenon, systems resulting in lateral or rotational forces are far less developed; to our knowledge, a theoretical study of discontinuous dielectric variants of such systems has not been attempted. We utilize a Proximity Force Approximation in conjunction with the Lifshitz dielectric formula to perform theoretical analyses of resultant torques in systems with bisected and quadrisected dielectric regions. We also develop a high precision Monte Carlo type numerical integrator to approximate our derived expressions. Our calculations of an energy density linear with the alignment angle result in a constant torque and have implications in NEMS (nano electromechanical systems) and MEMS (micro electromechanical systems), including a postulated ...

  12. Linear ultrasonic motor using quadrate plate transducer

    Institute of Scientific and Technical Information of China (English)

    Jiamei JIN; Chunsheng ZHAO

    2009-01-01

    A linear ultrasonic motor using a quadrate plate transducer was developed for precision positioning. This motor consists of two pairs of Pb(Zr, Ti)O3 piezo-electric ceramic elements, which are piezoelectrically excited into the second-bending mode of the motor stator's neutral surface in two orthogonal directions, on which the tops of four projections move along an elliptical trajectory, which in turn drives a contacted slider into linear motion via frictional forces. The coincident frequency of the stator is easily obtained for its coincident characteristic dimen-sion in two orthogonal directions. The performance characteristics achieved by the motor are: 1) a maximum linear speed of more than 60 mm/s; 2) a stroke of more than 150 mm; 3) a driving force of more than 5.0 N; and 4) a response time of about 2 ms.

  13. CMS Resistive plate Champers

    CERN Document Server

    Zainab, Karam

    2013-01-01

    There are many types of gas detectors which are used in CERN in LHC project, There is a main parts for the gas detectors which must be in all gas detectors types like Multiwire proportional chambers, such as the micromesh gaseous structure chamber (the MicroMegas), Gas-electron multiplier (GEM) detector, Resistive Plate Champers... Compact Muon Solenoid (CMS) experiment detecting muons which are powerful tool for recognizing signatures of interesting physics processes. The CMS detector uses: drift tube (DT), cathode strip chamber (CSC) and resistive plate chamber (RPC). Building RPC’s was my project in summer student program (hardware). RPC’s have advantages which are triggering detector and Excellent time resolution which reinforce the measurement of the correct beam crossing time. RPC’s Organized in stations :  RPC barrel (RB) there are 4 stations, namely RB1, RB2, RB3, and RB4  While in the RPC endcap (RE) the 3 stations are RE1, RE2, and RE3. In the endcaps a new starion will be added and this...

  14. Closed-form solution for free vibration of piezoelectric coupled annular plates using Levinson plate theory

    Science.gov (United States)

    Hosseini Hashemi, Sh.; Es'haghi, M.; Karimi, M.

    2010-04-01

    Free vibration analysis of annular moderately thick plates integrated with piezoelectric layers is investigated in this study for different combinations of soft simply supported, hard simply supported and clamped boundary conditions at the inner and outer edges of the annular plate on the basis of the Levinson plate theory (LPT). The distribution of electric potential along the thickness direction in the piezoelectric layer is assumed as a sinusoidal function so that the Maxwell static electricity equation is approximately satisfied. The differential equations of motion are solved analytically for various boundary conditions of the plate. In this study the closed-form solution for characteristic equations, displacement components of the plate and electric potential are derived for the first time in the literature. To demonstrate the accuracy of the present solution, comparison studies is first carried out with the available data in the literature and then natural frequencies of the piezoelectric coupled annular plate are presented for different thickness-radius ratios, inner-outer radius ratios, thickness of piezoelectric, material of piezoelectric and boundary conditions. Present analytical model provides design reference for piezoelectric material application, such as sensors, actuators and ultrasonic motors.

  15. Repulsive Casimir Force using metamaterials

    Science.gov (United States)

    Pappakrishnan, Venkatesh K.; Mundru, Pattabhiraju C.; Genov, Dentcho A.

    We investigate conditions for Casimir Force (CF) reversal between two parallel half-space metamaterial plates separated by air or vacuum at ambient temperatures. Practically, the Casimir effect can lead to stiction in nanoscale devices, degradation and decreased performance. While material realizations of repulsive CF has been proposed for high dielectric host materials, so far the CF reversal with air/vacuum as intermediate medium remain challenging. Here, we propose a two plate design based on artificial electromagnetic materials known as metamaterials. This configuration allows a simple analytical treatment that accurately describes the large and short distance asymptotics of CF and allows extraction of important parameters such as lower and upper cutoff gap distances that define the repulsive force window. A parametric study has been performed in terms of the plate's dielectric and magnetic plasma frequencies, plate separation distance and temperature. The parametric domain for achieving CF reversal is identified. If successfully implemented the proposed design could potentially result in frictionless bio-fluid transport devices, quantum levitation and coating for ultra-clean room environment.

  16. Computer simulation of viscous fingering in a lifting Hele-Shaw cell with grooved plates

    Indian Academy of Sciences (India)

    Sujata Tarafdar; Soma Nag; Tapati Dutta; Suparna Sinha

    2009-10-01

    We simulate viscous fingering generated by separating two plates with a constant force, in a lifting Hele-Shaw cell. Variation in the patterns for different fluid viscosity and lifting force is studied. Viscous fingering is strongly affected by anisotropy. We report a computer simulation study of fingering patterns, where circular or square grooves are etched on to the lower plate. Results are compared with experiments.

  17. Performance of the ATLAS resistive plate chambers

    Energy Technology Data Exchange (ETDEWEB)

    Cattani, Giordano, E-mail: giordano.cattani@cern.ch [INFN and University of Rome & #x27; Tor Vergata& #x27; , via della Ricerca Scientifica, 1 00133 Rome (Italy)

    2012-01-01

    An overview and results of the effort to monitor and measure the relevant quantities of the Resistive Plate Chamber detectors are presented, addressing in particular three aspects. First, the full exploitation of the high-precision tracking provided by ATLAS Monitored Drift Tubes when measuring the performance of the RPCs. Second, the use of a dedicated data stream to achieve the required statistics. Last, the central role of GRID facilities in providing the necessary computing resources.

  18. Solution of non-rectangular plates with macroelement method

    Science.gov (United States)

    Delyavskyy, Mykhaylo; Rosinski, Krystian

    2017-03-01

    New approach to static analysis of thin non-rectangular arbitrarily loaded plates, called the macroelement method, has been developed in this paper. Macroelement is a rectangular plate which entirely contains real plate. The mathematical model of macroelement was built. The equilibrium equations are performed for macroelement and boundary conditions are written on the line corresponding to contour of real plate in the nodes which are zero points of trigonometric functions, included in the macroelement model. The load is applied only to separate nodes on the surface of real plate, whereas the complement of a plate to macroelement is unloaded. Analysis of construction is reduced to solving a system of linear algebraic equations. The method provides better accuracy compared to finite element method and requires less equations. There is trapeze plate clamped at inclined edge and simply supported at opposite one considered in this paper. The other edges of the plate are free. Uniformly distributed load on the surface of real plate is taken into account.

  19. Nazca plate subduction, mantle flow and Cordilleras formation

    Science.gov (United States)

    Capitanio, Fabio A.

    2013-04-01

    The Nazca-South America convergence represents a unique natural laboratory to probe our understanding of subduction, mantle flow and stress coupling at Andean-type margins. Here, it is shown that the most fundamental balance of forces associated with the downgoing slab, the upper plates and the mantle can account for the Nazca plate motions, although it does not adequately explain the variations of the Cordilleran tectonics found along the ~6000 km wide margin. Using three-dimensional numerical models it is shown that trench-parallel gradients in both the driving and resisting forces are an essential component of the force balance, and necessary to reproduce the macroscopic features observed. When along-trench buoyancy variations similar to the Nazca plate's are included, the slab dips and upper plate deformations observed in the Nazca slab, in the Cordilleras and South American continent interiors can be reproduced. The models show that gradients in the resisting shear force along the trench can be as relevant, as they modulate the trench retreat to form the concave Bolivian Orocline. Pressure gradients in the mantle follow the Nazca buoyancy gradients, and effectively rearrange the flow introducing a trench-parallel component, similar to what suggested by seismic anisotropy in this area. Although they introduce only secondary variations to the primary subduction and mantle flow dynamics, the regional features of the Nazca and South American plates exert a primary control at the margin-local scale. This suggests that far-field forces, e.g. from spreading Atlantic or large-scale convection, should play a minor role in the formation of the Cordilleras.

  20. Gold nanowires fabricated by immersion plating.

    Science.gov (United States)

    Hsu, Chih-Chieh; Shen, Fang-Yee; Huang, Fon-Shan

    2008-05-14

    The growth mechanism of oriented Au nanowires fabricated by immersion plating was investigated. Both n-type crystal Si (c-Si) and amorphous Si (a-Si) with an electron-beam (E-beam) patterned resist nanotrench were immersed into the plating bath HAuCl(4)/HF. For the Au nanowires fabricated on c-Si, voids, nanograins, and clusters were observed at various plating conditions, time and temperature. The voids were often found in the center of the Au nanowires due to there being fewer nucleation sites on the c-Si surface. However, Au can easily nucleate on the surface of a-Si and form continuous Au nanowires with grain sizes about 10-50 nm. The resistivities of Au nanowires with width 105 nm fabricated on a-Si are about 4.4-6.5 µΩ cm. After annealing at 200 °C for 30 min in N(2) ambient, the resistivities are lowered to about 3.0-3.9 µΩ cm, measured in an atomic force microscope (AFM) in contact mode. The grain size of Au is in the range of ∼50-100 nm. A scanning electron microscope (SEM) examination and grazing incident x-ray diffraction (GIXRD) analysis were also carried out to study the morphology and crystalline structure of the Au nanowires.

  1. Climate forcings and feedbacks

    Science.gov (United States)

    Hansen, James

    1993-01-01

    Global temperature has increased significantly during the past century. Understanding the causes of observed global temperature change is impossible in the absence of adequate monitoring of changes in global climate forcings and radiative feedbacks. Climate forcings are changes imposed on the planet's energy balance, such as change of incoming sunlight or a human-induced change of surface properties due to deforestation. Radiative feedbacks are radiative changes induced by climate change, such as alteration of cloud properties or the extent of sea ice. Monitoring of global climate forcings and feedbacks, if sufficiently precise and long-term, can provide a very strong constraint on interpretation of observed temperature change. Such monitoring is essential to eliminate uncertainties about the relative importance of various climate change mechanisms including tropospheric sulfate aerosols from burning of coal and oil smoke from slash and burn agriculture, changes of solar irradiance changes of several greenhouse gases, and many other mechanisms. The considerable variability of observed temperature, together with evidence that a substantial portion of this variability is unforced indicates that observations of climate forcings and feedbacks must be continued for decades. Since the climate system responds to the time integral of the forcing, a further requirement is that the observations be carried out continuously. However, precise observations of forcings and feedbacks will also be able to provide valuable conclusions on shorter time scales. For example, knowledge of the climate forcing by increasing CFC's relative to the forcing by changing ozone is important to policymakers, as is information on the forcing by CO2 relative to the forcing by sulfate aerosols. It will also be possible to obtain valuable tests of climate models on short time scales, if there is precise monitoring of all forcings and feedbacks during and after events such as a large volcanic eruption

  2. Localised Plate Motion on Venus

    Science.gov (United States)

    Ghail, R. C.

    1996-03-01

    The volcanic and tectonic features observed in Dali Vinculum, Parga Vinculum and Imdr Regio are concentrated at long, narrow, curvilinear zones, with relatively minor volcanism and tectonism between these zones. These zones, whilst more diffuse than terrestrial plate boundaries, nevertheless define the margins of tectonic plates. In contrast to Earth, however, it appears that venusian plates are neither created nor destroyed by lateral motion. Rather, plates are thinned and intruded at vincula plate boundaries, vertically accreted by small-scale intra-plate (planitia) volcanism and perhaps destroyed by delamination of thickened crust in tesserae and montane regions such as Thetis Regio and Ishtar Terra. The diversity in age both between and within these three areas together with the evidence for infrequent, small scale resurfacing in the planitiae are difficult to reconcile with a non-uniformitarian geological process.

  3. Tectonics of the Easter plate

    Science.gov (United States)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  4. Tectonics of the Easter plate

    Science.gov (United States)

    Engeln, J. F.; Stein, S.

    1984-01-01

    A new model for the Easter plate is presented in which rift propagation has resulted in the formation of a rigid plate between the propagating and dying ridges. The distribution of earthquakes, eleven new focal mechanisms, and existing bathymetric and magnetic data are used to describe the tectonics of this area. Both the Easter-Nazca and Easter-Pacific Euler poles are sufficiently close to the Easter plate to cause rapid changes in rates and directions of motion along the boundaries. The east and west boundaries are propagating and dying ridges; the southwest boundary is a slow-spreading ridge and the northern boundary is a complex zone of convergent and transform motion. The Easter plate may reflect the tectonics of rift propagation on a large scale, where rigid plate tectonics requires boundary reorientation. Simple schematic models to illustrate the general features and processes which occur at plates resulting from large-scale rift propagation are used.

  5. Strong Force

    CERN Document Server

    Without the strong force, there could be no life. The carbon in living matter is synthesised in stars via the strong force. Lighter atomic nuclei become bound together in a process called nuclear fusion. A minor change in this interaction would make life impossible. As its name suggests, the strong force is the most powerful of the 4 forces, yet its sphere of influence is limited to within the atomic nucleus. Indeed it is the strong force that holds together the quarks inside the positively charged protons. Without this glue, the quarks would fly apart repulsed by electromagnetism. In fact, it is impossible to separate 2 quarks : so much energy is needed, that a second pair of quarks is produced. Text for the interactive: Can you pull apart the quarks inside a proton?

  6. Computational modelling of long bone fractures fixed with locking plates - How can the risk of implant failure be reduced?

    LENUS (Irish Health Repository)

    Nassiri, M

    2013-03-01

    The Locking Compression Plate (LCP) is part of a new plate generation requiring an adapted surgical technique and new thinking about commonly used concepts of internal fixation using plates. Knowledge of the fixation stability provided by these new plates is very limited and clarification is still necessary to determine how the mechanical stability and the risk of implant failure can best be controlled.

  7. Aluminum Manganese Molten Salt Plating

    Science.gov (United States)

    2006-06-01

    Dry fixture thoroughly with the air gun. Be especially careful to dry water out of crevices. Note: water is a contaminant to the plating process...easily destroyed if blown with the air. Be especially careful to dry water out of crevices. Note: water is a contaminant to the plating process and...especially careful to dry water out of crevices. 13. Carefully remove part from fixture. If residual plating solution is present at attachments points

  8. Plate tectonic raster reconstruction in GPlates

    Directory of Open Access Journals (Sweden)

    J. Cannon

    2014-03-01

    Full Text Available We describe a novel method implemented in the GPlates plate tectonic reconstruction software to interactively reconstruct arbitrarily high-resolution raster data to past geological times using a rotation model. The approach is based on the projection of geo-referenced raster data into a cube map followed by a reverse projection onto rotated tectonic plates on the surface of the globe. This decouples the rendering of a geo-referenced raster from its reconstruction, providing a number of benefits including a simple implementation and the ability to combine rasters with different geo-referencing or inbuilt raster projections. The cube map projection is accelerated by graphics hardware in a wide variety of computer systems manufactured over the last decade. Furthermore, by integrating a multi-resolution tile partitioning into the cube map we can provide on-demand tile streaming, level-of-detail rendering and hierarchical visibility culling enabling researchers to visually explore essentially unlimited resolution geophysical raster data attached to tectonic plates and reconstructed through geological time. This capability forms the basis for interactively building and improving plate reconstructions in an iterative fashion, particularly for tectonically complex regions.

  9. Glass-bead peen plating

    Science.gov (United States)

    Graves, J. R.

    1974-01-01

    Peen plating of aluminum, copper, and nickel powders was investigated. Only aluminum was plated successfully within the range of peen plating conditions studied. Optimum plating conditions for aluminum were found to be: (1) bead/powder mixture containing 25 to 35% powder by weight, (2) peening intensity of 0.007A as measured by Almen strip, and (3) glass impact bead diameter of at least 297 microns (0.0117 inches) for depositing-100 mesh aluminum powder. No extensive cleaning or substrate preparation is required beyond removing loose dirt or heavy oil.

  10. Biomechanical interactions of different mini-plate fixations and maxilla advancements in the Le Fort I Osteotomy: a finite element analysis.

    Science.gov (United States)

    Huang, Shao-Fu; Lo, Lun-Jou; Lin, Chun-Li

    2016-12-01

    This study investigates the biomechanical interaction of different mini-plate fixation types (shapes/sizes and patterns) with segmental advancement levels on the Le Fort I osteotomy using the non-linear finite element (FE) approach. Nine models were generated under a standard 1-piece LeFort I osteotomy for advancement with 3, 6 and 9 mm distances and four mini-plates with three fixation patterns including LL, LI, and II patterns placed on the maxillae models by integrating computed tomography images and computer-aided design system. The axial and oblique occlusal forces were 250 N applied to each premolar/molar and 125 N applied at 30° inclination to the tooth long axis and from palatal to buccal, respectively. The relative micro-movement values between the two maxillary bone segments and maximum mini-plate stress increased obviously with maxilla advancement increment and the increasing trend can be fitted by exponential curve. The corresponding values in II mini-plate fixation presented apparently high values in all simulated cases. The mini-plate stress concentration locations were found at the bending regions to increase high fracture risk. The mini-plate yield strength can be mapped to a critical (limited) advancement for three types of fixations for safe consideration. This study concluded that L-shaped mini-plates with lateral fixation are recommended to provide better stability. The risk for mini-plate fracture and bone relapse increases when maxillary advancement is larger than a critical value of 5 mm in the Le Fort I osteotomy.

  11. This dynamic earth: the story of plate tectonics

    Science.gov (United States)

    Kious, W. Jacquelyne; Tilling, Robert I.

    1996-01-01

    In the early 1960s, the emergence of the theory of plate tectonics started a revolution in the earth sciences. Since then, scientists have verified and refined this theory, and now have a much better understanding of how our planet has been shaped by plate-tectonic processes. We now know that, directly or indirectly, plate tectonics influences nearly all geologic processes, past and present. Indeed, the notion that the entire Earth's surface is continually shifting has profoundly changed the way we view our world.People benefit from, and are at the mercy of, the forces and consequences of plate tectonics. With little or no warning, an earthquake or volcanic eruption can unleash bursts of energy far more powerful than anything we can generate. While we have no control over plate-tectonic processes, we now have the knowledge to learn from them. The more we know about plate tectonics, the better we can appreciate the grandeur and beauty of the land upon which we live, as well as the occasional violent displays of the Earth's awesome power.This booklet gives a brief introduction to the concept of plate tectonics and complements the visual and written information in This Dynamic Planet (see Further reading), a map published in 1994 by the U.S. Geological Survey (USGS) and the Smithsonian Institution. The booklet highlights some of the people and discoveries that advanced the development of the theory and traces its progress since its proposal. Although the general idea of plate tectonics is now widely accepted, many aspects still continue to confound and challenge scientists. The earth-science revolution launched by the theory of plate tectonics is not finished.

  12. Intermittent plate tectonics?

    Science.gov (United States)

    Silver, Paul G; Behn, Mark D

    2008-01-04

    Although it is commonly assumed that subduction has operated continuously on Earth without interruption, subduction zones are routinely terminated by ocean closure and supercontinent assembly. Under certain circumstances, this could lead to a dramatic loss of subduction, globally. Closure of a Pacific-type basin, for example, would eliminate most subduction, unless this loss were compensated for by comparable subduction initiation elsewhere. Given the evidence for Pacific-type closure in Earth's past, the absence of a direct mechanism for termination/initiation compensation, and recent data supporting a minimum in subduction flux in the Mesoproterozoic, we hypothesize that dramatic reductions or temporary cessations of subduction have occurred in Earth's history. Such deviations in the continuity of plate tectonics have important consequences for Earth's thermal and continental evolution.

  13. VISAS AND GREEN PLATES

    CERN Multimedia

    2000-01-01

    From 3 April 2000, all questions relating to visa requests for Switzerland, France, or Russia for a member of the personnel must be addressed to Ms. Agnita Querrou (telephone 72838, office 5-2-019, e-mail Agnita.Querrou@cern.ch).The Users' Office continues to deal with requests for letters of invitation and questions concerning visas for users in EP Division.Questions relating to removals, requests for green plates, to privileges of members of the personnel and to the importation of vehicles are still dealt with by Ms Zuzana Miller (telephone 79257, office 33-1-017, e-mail Zuzana.Muller@cern.ch) and Ms Joëlle Belleman (telephone 73962, office 33-1-019, e-mail Joelle.Belleman@cern.ch).

  14. Random vibrations of composite beams and plates

    Science.gov (United States)

    Abdelnaser, Ahmad Shehadeh

    In this study, a generalized modal approach is presented to solve more general vibration problems of composite beams and plates. The coupled systems of partial differential equations, representing the equations of motion, are uncoupled into modal equations by utilizing the eigenfunctions of the system and its adjoint. A method is presented to obtain these eigenfunctions for beams with arbitrary boundary conditions and for plates with Levy-type boundary conditions. The forced vibration solutions obtained by this method are then used to calculate the random response characteristics of beams and plates subjected to spatially and temporally correlated random loads. In the analysis of beams, both symmetric cross-ply and angle-ply configurations have been considered. In the symmetric cross-ply configuration with no torsional loads, of course, the warping effects are absent. The angle-ply case, however, includes torsion-warping effects and coupled bending-torsion motions. A simple displacement field is introduced to reflect warping in the third-order shear deformation theory. In the analysis of plates two configurations of the laminates have also been considered: symmetric cross-ply and antisymmetric angle-ply. At this time, these are the only two configurations which can be solved by the closed-form modal analysis approach for the Levy-type boundary conditions. In both cases of the beams and plates, the numerical results with and without shear deformations are obtained and compared. The result for no shear deformation theory are obtained with the classical lamination theory. The results have also been obtained for the first-order shear deformation theory with a somewhat simpler displacement field which has been commonly used in the past. The numerical results are obtained for the global response quantities such as frequencies, displacements, and crossing rates as well as for the local response quantities such as normal and shear stresses across a cross section. The

  15. Plate osteosynthesis of simple forearm fractures : LCP versus DC plates

    NARCIS (Netherlands)

    Stevens, Charles Tjerk; Ten Duis, Henk Jan

    2008-01-01

    The aim of this study was to compare the time to radiological bony union of simple A-type fractures of the forearm, treated with either a locking compression plate (LCP) or a dynamic compression plate (DCP). For each fracture, the relation between the use of compression and radiological healing time

  16. Plate osteosynthesis of simple forearm fractures : LCP versus DC plates

    NARCIS (Netherlands)

    Stevens, Charles Tjerk; Ten Duis, Henk Jan

    The aim of this study was to compare the time to radiological bony union of simple A-type fractures of the forearm, treated with either a locking compression plate (LCP) or a dynamic compression plate (DCP). For each fracture, the relation between the use of compression and radiological healing time

  17. Weak Force

    CERN Multimedia

    Without the weak force, the sun wouldn't shine. The weak force causes beta decay, a form of radioactivity that triggers nuclear fusion in the heart of the sun. The weak force is unlike other forces: it is characterised by disintegration. In beta decay, a down quark transforms into an up quark and an electron is emitted. Some materials are more radioactive than others because the delicate balance between the strong force and the weak force varies depending on the number of particles in the atomic nucleus. We live in the midst of a natural radioactive background that varies from region to region. For example, in Cornwall where there is a lot of granite, levels of background radiation are much higher than in the Geneva region. Text for the interactive: Move the Geiger counter to find out which samples are radioactive - you may be surprised. It is the weak force that is responsible for the Beta radioactivity here. The electrons emitted do not cross the plastic cover. Why do you think there is some detected radioa...

  18. Heterotrophic plate count methodology in the United States.

    Science.gov (United States)

    Reasoner, Donald J

    2004-05-01

    In the United States (US), the history of bacterial plate counting (BPC) methods used for water can be traced largely through Standard Methods for the Examination of Water and Wastewater (Standard Methods). The bacterial count method has evolved from the original Standard Methods (1st edition, 1905) plate count which used nutrient gelatin and incubation at 20 degrees C for 48 h, to the HPC method options in the latest edition of Standard Methods that provide greater flexibility of application, depending on the data needs of the water analyst. The use of agar-agar as a gelling agent, replacing gelatin, allowed the use of higher incubation temperatures and resulted in the "body temperature count" (37 degrees C) found in the 3rd through the 8th edition of Standard Methods. The change from 37 degrees C incubation to 35+/-0.5 degrees C accommodated laboratories that did both milk and water analyses. By using a single temperature, fewer incubators were needed. The term "standard plate count" (SPC) first appeared in 1960 (11th edition) along with plate count agar. Incubation at 20 degrees C for the plate count was dropped from the 13th to 15th editions and few changes were made in the SPC method from the 11th edition through the 13th editions. Plate count analysis of bottled waters was included in the 14th edition (1975), calling for incubation at 35+/-0.5 degrees C for 72+/-4 h. Perhaps the most significant changes in plate count methods occurred with the 16th edition (1985). The term heterotrophic plate count replaced the standard plate count, and the spread plate (SP) and membrane filter (MF) methods were added along with new media for pour and spread plates (R2A agar and NWRI agar, both low nutrient) and for the membrane filter method (mHPC medium). The use of low nutrient media, lower incubation temperature, and longer incubation times, results in higher plate count results for most water samples. The options currently available, including low and high nutrient media

  19. Eastern Indian Ocean microcontinent formation driven by plate motion changes

    Science.gov (United States)

    Whittaker, J. M.; Williams, S. E.; Halpin, J. A.; Wild, T. J.; Stilwell, J. D.; Jourdan, F.; Daczko, N. R.

    2016-11-01

    The roles of plate tectonic or mantle dynamic forces in rupturing continental lithosphere remain controversial. Particularly enigmatic is the rifting of microcontinents from mature continental rifted margins, with plume-driven thermal weakening commonly inferred to facilitate calving. However, a role for plate tectonic reorganisations has also been suggested. Here, we show that a combination of plate tectonic reorganisation and plume-driven thermal weakening were required to calve the Batavia and Gulden Draak microcontinents in the Cretaceous Indian Ocean. We reconstruct the evolution of these two microcontinents using constraints from new paleontological samples, 40Ar/39Ar ages, and geophysical data. Calving from India occurred at 101-104 Ma, coinciding with the onset of a dramatic change in Indian plate motion. Critically, Kerguelen plume volcanism does not appear to have directly triggered calving. Rather, it is likely that plume-related thermal weakening of the Indian passive margin preconditioned it for microcontinent formation but calving was triggered by changes in plate tectonic boundary forces.

  20. Being “on the alert” and “a forced volunteer”: a qualitative study of the invisible care provided by the next of kin of patients with chronic heart failure

    Directory of Open Access Journals (Sweden)

    Strøm A

    2015-06-01

    Full Text Available Anita Strøm,1 Kirsti Lauvli Andersen,2 Kari Korneliussen,3 May Solveig Fagermoen4 1Department of Masters and Continuing Education, Lovisenberg Diaconal University College, Oslo, Norway; 2Faculty of Health and Social Work Studies, Østfold University College, Halden, Norway; 3Heart Failure Clinic, Vestfold Hospital Trust, Tønsberg, Norway; 4Institute of Health and Society, University of Oslo, Oslo, Norway Background: Relatives’ support is an important factor in how well people with chronic heart failure (CHF manage their illness and everyday life. Deepening professionals' understanding of the content of relatives’ invisible care activities, often characterized as care burden, is necessary to strengthen support services. Objective: To explore the next of kin’s experiences of invisible care and the inherent responsibilities in caring for a relative with CHF. Design, setting, and methods: Relatives were recruited from CHF outpatient clinics and home care services. Seventeen women and two men were interviewed, age range 45–83 years; 12 were partners, and seven were daughters. The qualitative interviews were taped and transcribed and thematic cross-case analyses were performed. Results: Two main themes were revealed. The first, “being on the alert”, refers to a perceived need, real or assumed, to be aware day and night, whether present with the patient or not, that occupies the mind, emotions, and body. The second theme, “being a forced volunteer”, refers to two different dimensions: relatives'’ own perceptions of responsibility with regard to the patient's needs; and voiced or silent expectations from the patient, family members, and health personnel that the relative will help the patient. Both findings appeared to have positive and negative impacts on the relationship with the patient. Conclusion: The identified themes reflect how challenging being a next of kin of CHF patients can be. The results may deepen professionals

  1. Force transmission in epithelial tissues.

    Science.gov (United States)

    Vasquez, Claudia G; Martin, Adam C

    2016-03-01

    In epithelial tissues, cells constantly generate and transmit forces between each other. Forces generated by the actomyosin cytoskeleton regulate tissue shape and structure and also provide signals that influence cells' decisions to divide, die, or differentiate. Forces are transmitted across epithelia because cells are mechanically linked through junctional complexes, and forces can propagate through the cell cytoplasm. Here, we review some of the molecular mechanisms responsible for force generation, with a specific focus on the actomyosin cortex and adherens junctions. We then discuss evidence for how these mechanisms promote cell shape changes and force transmission in tissues.

  2. Development and validation of system for measuring poling forces during Nordic walking

    Directory of Open Access Journals (Sweden)

    Jakub Krejčí

    2013-09-01

    Full Text Available BACKGROUND: Recently, the popularity of Nordic walking (NW has been rising steadily. Many scientific studies researched the promising and beneficial effects of this form of physical activity. However, only a few studies provided data about the forces acting on the poles. We did not find a commercially available system that enables the measurement of the poling forces. OBJECTIVE: The objective of this paper was to develop and validate a system for measuring the poling forces during NW. METHODS: Strain gauge force tranducers were mounted below the grips of standard NW poles. The transducer signals were amplified and converted to digital form for transmitting to a personal computer. Special software was developed for processing the measured data and the calculation method of output variables was described. Validation of the system was performed using a Kistler force plate. Poling cycles with peak force of about 150 N were imitated by pressing the pole over a force plate. RESULTS: A function sample of the measurement system was constructed. Validation yielded the mean absolute error of 1.1 N in case of poling cycles without pole impacts or 3.0 N in case of poling cycles with impacts. CONCLUSIONS: The validation result of our system is comparable to the results of similar systems used for measurements during cross-country skiing. The system enables independent measurement of the poling forces on both poles and the duration of measurement can be up to one hour. The system provides a tool that can be used to answer a number of questions that researches raise about NW. Understanding of the biomechanical and physiological aspects of poling action can constitute a scientific basis for promoting, teaching and training of NW.

  3. Observation of the thermal Casimir force

    CERN Document Server

    Sushkov, A O; Dalvit, D A R; Lamoreaux, S K

    2010-01-01

    Quantum theory predicts the existence of the Casimir force between macroscopic bodies, due to the zero-point energy of electromagnetic field modes around them. This quantum fluctuation-induced force has been experimentally observed for metallic and semiconducting bodies, although the measurements to date have been unable to clearly settle the question of the correct low-frequency form of the dielectric constant dispersion (the Drude model or the plasma model) to be used for calculating the Casimir forces. At finite temperature a thermal Casimir force, due to thermal, rather than quantum, fluctuations of the electromagnetic field, has been theoretically predicted long ago. Here we report the experimental observation of the thermal Casimir force between two gold plates. We measured the attractive force between a flat and a spherical plate for separations between 0.7 $\\mu$m and 7 $\\mu$m. An electrostatic force caused by potential patches on the plates' surfaces is included in the analysis. The experimental resul...

  4. Faulting within the Pacific plate at the Mariana Trench: Implications for plate interface coupling and subduction of hydrous minerals

    Science.gov (United States)

    Emry, Erica L.; Wiens, Douglas A.; Garcia-Castellanos, Daniel

    2014-04-01

    We investigate faulting within the incoming Pacific plate at the Mariana subduction trench to understand stresses within the bending plate, regional stresses acting upon the plate interface, and the extent of possible faulting-induced mantle serpentinization. We determine accurate depths by inverting teleseismic P and SH waveforms for earthquakes occurring during 1990-2011 with Global Centroid Moment Tensor (GCMT) solutions. For earthquakes with Mw 5.0+, we determine centroid depths and source time functions and refine the fault parameters. Results from Central Mariana indicate that all earthquakes are extensional and occur at centroid depths down to 11 km below the Moho. At the Southern Mariana Trench, extensional earthquakes continue to 5 km below the Moho. One compressional earthquake at 34 km below the seafloor suggests stronger plate interface coupling here. In addition, we model the stress distribution within the Pacific plate along two bathymetric profiles extending seaward from the Mariana subduction trench axis to better understand whether our earthquake depth solutions match modeled scenarios for plate bending under applied external forces. Results from our flexure models match the locations of extensional and compressional earthquakes and suggest that the Pacific plate at Southern Mariana is experiencing larger, compressional stresses, possibly due to greater interplate coupling. Additionally, we conclude that if extensional faulting promotes the infiltration of water into the subducting plate mantle, then the top 5-15 km of the Pacific plate mantle are partially serpentinized, and a higher percentage of serpentinization is located near the Central Mariana trench where extensional events extend deeper.

  5. PEM fuel cell bipolar plate material requirements for transportation applications

    Energy Technology Data Exchange (ETDEWEB)

    Borup, R.L.; Stroh, K.R.; Vanderborgh, N.E. [Los Alamos National Lab., NM (United States)] [and others

    1996-04-01

    Cost effective bipolar plates are currently under development to help make proton exchange membrane (PEM) fuel cells commercially viable. Bipolar plates separate individual cells of the fuel cell stack, and thus must supply strength, be electrically conductive, provide for thermal control of the fuel stack, be a non-porous materials separating hydrogen and oxygen feed streams, be corrosion resistant, provide gas distribution for the feed streams and meet fuel stack cost targets. Candidate materials include conductive polymers and metal plates with corrosion resistant coatings. Possible metals include aluminium, titanium, iron/stainless steel and nickel.

  6. Asymptotic Behavior of a Structure Made by a Plate and a Straight Rod

    Institute of Scientific and Technical Information of China (English)

    Dominique BLANCHARD; Georges GRISO

    2013-01-01

    This paper is devoted to describing the asymptotic behavior of a structure made by a thin plate and a thin perpendicular rod in the framework of nonlinear elasticity.The authors scale the applied forces in such a way that the level of the total elastic energy leads to the Von-Kármán's equations (or the linear model for smaller forces) in the plate and to a one-dimensional rod-model at the limit.The junction conditions include in particular the continuity of the bending in the plate and the stretching in the rod at the junction.

  7. LOW VELOCITY RESPONSE CHARACTERISTICS OF COMPOSITE PLATE WITH EMBEDDED SHAPE MEMORY ALLOY

    Institute of Scientific and Technical Information of China (English)

    WuYongdong; ZhongWeifang; LiangYide

    2004-01-01

    This paper analyzes the characteristics of utilizing shape memory effect (SME) of shape memory alloy (SMA) in improving the low velocity impact resistance performance of composite plate by using finite element method. The constitutive relation for SMA hybrid composite plates is presented. The analytic model of finite element for SMA composite plate subjected to low velocity impact is established. The modified Hertz's contact law is used to determine the impact contact force. The computing procedures for solving the finite element equation using Newmark direct integration method are given. The numerical modelling results show that the SMA can effectively improve the low velocity impact resistance performance of composite plate.

  8. Characterization and Scaling of Heave Plates for Ocean Wave Energy Converters

    Science.gov (United States)

    Rosenberg, Brian; Mundon, Timothy

    2016-11-01

    Ocean waves present a tremendous, untapped source of renewable energy, capable of providing half of global electricity demand by 2040. Devices developed to extract this energy are known as wave energy converters (WECs) and encompass a wide range of designs. A somewhat common archetype is a two-body point-absorber, in which a surface float reacts against a submerged "heave" plate to extract energy. Newer WEC's are using increasingly complex geometries for the submerged plate and an emerging challenge in creating low-order models lies in accurately determining the hydrodynamic coefficients (added mass and drag) in the corresponding oscillatory flow regime. Here we present experiments in which a laboratory-scale heave plate is sinusoidally forced in translation (heave) and rotation (pitch) to characterize the hydrodynamic coefficients as functions of the two governing nondimensional parameters, Keulegan-Carpenter number (amplitude) and Reynolds number. Comparisons against CFD simulations are offered. As laboratory-scale physical model tests remain the standard for testing wave energy devices, effects and implications of scaling (with respect to a full-scale device) are also investigated.

  9. The Golosiiv on-line plate archive database, management and maintenance

    Science.gov (United States)

    Pakuliak, L.; Sergeeva, T.

    2007-08-01

    We intend to create online version of the database of the MAO NASU plate archive as VO-compatible structures in accordance with principles, developed by the International Virtual Observatory Alliance in order to make them available for world astronomical community. The online version of the log-book database is constructed by means of MySQL+PHP. Data management system provides a user with user interface, gives a capability of detailed traditional form-filling radial search of plates, obtaining some auxiliary sampling, the listing of each collection and permits to browse the detail descriptions of collections. The administrative tool allows database administrator the data correction, enhancement with new data sets and control of the integrity and consistence of the database as a whole. The VO-compatible database is currently constructing under the demands and in the accordance with principles of international data archives and has to be strongly generalized in order to provide a possibility of data mining by means of standard interfaces and to be the best fitted to the demands of WFPDB Group for databases of the plate catalogues. On-going enhancements of database toward the WFPDB bring the problem of the verification of data to the forefront, as it demands the high degree of data reliability. The process of data verification is practically endless and inseparable from data management owing to a diversity of data errors nature, that means to a variety of ploys of their identification and fixing. The current status of MAO NASU glass archive forces the activity in both directions simultaneously: the enhancement of log-book database with new sets of observational data as well as generalized database creation and the cross-identification between them. The VO-compatible version of the database is supplying with digitized data of plates obtained with MicroTek ScanMaker 9800 XL TMA. The scanning procedure is not total but is conducted selectively in the frames of special

  10. 78 FR 31577 - Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan

    Science.gov (United States)

    2013-05-24

    ...)] Diffusion-Annealed, Nickel-Plated Flat-Rolled Steel Products From Japan Determination On the basis of the... reason of imports from Japan of diffusion-annealed, nickel-plated flat-rolled steel products, provided... diffusion-annealed, nickel-plated flat-rolled steel products from Japan. Accordingly, effective March...

  11. Casimir Effect for Dielectric Plates

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    We generalize Kupisewska method to the three-dimensional system and another derivation of the Casimir effect between two dielectric plates is presented based on the explicit quantization of the electromagnetic field in the presence of dielectrics, where the physical meaning of "evanescent mode" is discussed. The Lifshitz's formula is rederived perfect metallic plates will the evanescent modes become unimportant.

  12. Gold plating on spectacle frames.

    Science.gov (United States)

    Kenny, I; Mitchell, J W; Walsh, G

    1997-05-01

    An investigation was carried out into the thickness and standard of application of the plating and lacquer coatings applied to three metal spectacle frames. All conform to BS 6625 (1991) for plating thickness, but there was considerable variation in regularity and porosity.

  13. Imaging with straight-edge phase plates in the TEM.

    Science.gov (United States)

    Edgcombe, C J

    2017-06-22

    The image of a simple phase object produced by a round lens with a Foucault or Hilbert phase plate can be determined with Abbe imaging theory and a 2D transform expressed in cylindrical coordinates. The contributions to the image amplitude from a uniform disc object and an azimuthally varying plate can then be distinguished and their phases relative to the incident wave can be compared. It appears that the usual choice of added phase for a Hilbert plate causes the image of a weak disc object to vanish as the plate edge approaches the axis, but a different choice of plate thickness can enable a weak phase object to provide a linear contribution to image intensity. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Reaction-induced rheological weakening enables oceanic plate subduction

    Science.gov (United States)

    Hirauchi, Ken-Ichi; Fukushima, Kumi; Kido, Masanori; Muto, Jun; Okamoto, Atsushi

    2016-08-01

    Earth is the only terrestrial planet in our solar system where an oceanic plate subducts beneath an overriding plate. Although the initiation of plate subduction requires extremely weak boundaries between strong plates, the way in which oceanic mantle rheologically weakens remains unknown. Here we show that shear-enhanced hydration reactions contribute to the generation and maintenance of weak mantle shear zones at mid-lithospheric depths. High-pressure friction experiments on peridotite gouge reveal that in the presence of hydrothermal water, increasing strain and reactions lead to an order-of-magnitude reduction in strength. The rate of deformation is controlled by pressure-solution-accommodated frictional sliding on weak hydrous phyllosilicate (talc), providing a mechanism for the `cutoff' of the high peak strength at the brittle-plastic transition. Our findings suggest that infiltration of seawater into transform faults with long lengths and low slip rates is an important controlling factor on the initiation of plate tectonics on terrestrial planets.

  15. Synovial fistula after tension band plating for genu valgum correction.

    Science.gov (United States)

    Momaya, Amit; Ray, Peter; Khoury, Joseph

    2015-01-01

    Tension band plating is a commonly performed procedure to address angular deformities about the knee in children. We present a case of a synovial fistula formation after tension band plate removal, an unreported complication in the literature. An 11-year-old girl underwent tension band plating for genu valgum. After removal of the plate, she developed a synovial fistula that was confirmed by magnetic resonance imaging. Her knee was immobilized in extension, which allowed the synovial fistula to heal. The unique capsular anatomy in the knee provides a possible etiology. Physicians performing tension band plating should be aware of this complication and consider a brief period of immobilization of 3 to 5 days after hardware removal to allow the capsular rent to heal.

  16. One-way successive plate cross wedge rolling machine

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In our last paper(Sci China Ser E-Tech Sci,2009,52(11):3117-3121) we designed the precision forming machine with rolling plate CWR(cross wedge rolling).This kind of machine colligates the advantages of high rigidity and small floor space for roller CWR machine and those of simple die manufacture and high precision for plate CWR machine.At the same time,it abandons the shortcomings of complex die manufacture and poor precision for roller CWR machine,and those of poor rigidity and large floor space for plate CWR machine.During rolling,the upper and lower rolling plates of the machine make reciprocating slide toward or away from each other,so the inertial forces should be overcome,which will cause great energy loss,besides,large floor space is needed when the rolled workpiece is large.In order to solve the above problems,this paper presents the one-way successive plate CWR machine,whose rolling plates need not make reciprocating slide.Hence,it has high energy utilization efficiency and production efficiency.Furthermore,the roll scale can be removed automatically.In particular,the machine can produce large axisymmetrical workpieces.

  17. Biomechanical analysis of limited-contact plate used for osteosynthesis.

    Science.gov (United States)

    Pochrząst, Magdalena; Basiaga, Marcin; Marciniak, Jan; Kaczmarek, Marcin

    2014-01-01

    This paper presents the results of numerical analysis aimed at determining the state of stresses and displacements of compression plate used in osteosynthesis of tibia, carried out by applying finite element method using the ANSYS program. The analysis took into account two variants of the osteosynthesis. Variant I included the osteosynthesis in which plate was attached directly to the bone, in variant II, the plate was moved away from the bones by about 5 mm. Biomechanical characteristics of the corrective osteotomy plate-tibia was determined for implants made of Ti-6Al-4V alloy. The boundary conditions adopted for the analysis reflect phenomena occurring in a real system. Based on the results of the analysis relative displacements and reduced stresses in various components were determined as a function of the applied load within the range of F = 500-1500 N. The maximum forces, both variant I and variant II determined during analysis, ensure that the generated stress does not exceed yield strength of the material and compressive strength of the bone, and do not exceed safety movement in the fracture gap. In addition, it was found that the locking of the compressive plate to the bone has a little effect on the distribution of displacements and stresses on the plate-tibia system in the case of a simple fracture.

  18. Fluid stiction modeling for quickly separating plates considering the liquid tensile strength

    DEFF Research Database (Denmark)

    Roemer, Daniel Beck; Johansen, Per; Pedersen, Henrik C.;

    2015-01-01

    separation speed and low plate distance are present. In the case of small initial plate separation, fluid tension is known to develop and the stiction force may exceed the maximum stiction force calculated by assuming strictly positive pressures in the fluid film. In this paper, a model for simulating......Fluid stiction may significantly influence the dynamic behavior when attempting to quickly separate two plates in close contact. The liquid fluid film, filling the gap between the plates, experiences a pressure drop resulting from an increasing distance, and cavitation may appear if sufficient...... the need for finite element/volume methods. The considered geometry is two long parallel plates submerged in liquid, as present in many valve applications. The model is compared to experimental measurements, and it is found that the model is able to predict the stiction effect with reasonable accuracy...

  19. Plate shell structures of glass

    DEFF Research Database (Denmark)

    Bagger, Anne

    . This modelling technique is used to model a plate shell structure with a span of 11.5 meters in the FE software \\textsc{Abaqus}. The structure is analyzed with six different connection details with varying stiffness characteristics, to investigate the influence of these characteristics on the structural effects...... University, a script has been developed for an automated generation of a given plate shell geometry and a corresponding finite element (FE) model. A suitable FE modelling technique is proposed, suggesting a relatively simple method of modelling the connection detail's stiffness characteristics....... Based on these investigations, and FE analysis of other plate shell models, the structural behaviour is described. Possible methods of estimating the stresses in a given plate shell structure are proposed. The non-linear behaviour of a plate shell structure is investigated for varying parameters...

  20. Distributed Surface Force

    Science.gov (United States)

    2014-06-01

    proposed SSC. 1. Definition and Planning The definition and planning phase is appropriate when utilizing any problem- solving algorithm . Before any... MONKEY 149 AGENDA · Background · Scenario · Assumptions · Mission, Commander’s Intent, and Org. Chart · Naval and Air forces . Concept of...forces provide support to Coal ition partners during the execution of Operation Mute Monkey in the South China Sea. · End-state: Deter Chinese