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Sample records for lysholm positive displacement

  1. Positive displacement cylinder measures corrosive liquid volume

    NASA Technical Reports Server (NTRS)

    Mariman, R. A.; Vendl, C. J.

    1966-01-01

    Positive displacement cylinder accurately measures volumetric flow rates of corrosive liquids. The cylinder is compatible with corrosive liquids and handles flow rates from zero to 75 gpm at pressures to 900 psig with an accuracy of 0.25 per cent.

  2. Wirelessly Interrogated Position or Displacement Sensors

    NASA Technical Reports Server (NTRS)

    Woodard, Stanley E.; Taylor, Bryant D.

    2007-01-01

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

  3. Axial flow positive displacement worm compressor

    NASA Technical Reports Server (NTRS)

    Murrow, Kurt David (Inventor); Giffin, Rollin George (Inventor); Fakunle, Oladapo (Inventor)

    2010-01-01

    An axial flow positive displacement compressor has an inlet axially spaced apart and upstream from an outlet. Inner and outer bodies have offset inner and outer axes extend from the inlet to the outlet through first and second sections of a compressor assembly in serial downstream flow relationship. At least one of the bodies is rotatable about its axis. The inner and outer bodies have intermeshed inner and outer helical blades wound about the inner and outer axes respectively. The inner and outer helical blades extend radially outwardly and inwardly respectively. The helical blades have first and second twist slopes in the first and second sections respectively. The first twist slopes are less than the second twist slopes. An engine including the compressor has in downstream serial flow relationship from the compressor a combustor and a high pressure turbine drivingly connected to the compressor by a high pressure shaft.

  4. Axial flow positive displacement worm gas generator

    NASA Technical Reports Server (NTRS)

    Murrow, Kurt David (Inventor); Giffin, Rollin George (Inventor); Fakunle, Oladapo (Inventor)

    2010-01-01

    An axial flow positive displacement engine has an inlet axially spaced apart and upstream from an outlet. Inner and outer bodies have offset inner and outer axes extend from the inlet to the outlet through first, second, and third sections of a core assembly in serial downstream flow relationship. At least one of the bodies is rotatable about its axis. The inner and outer bodies have intermeshed inner and outer helical blades wound about the inner and outer axes respectively. The inner and outer helical blades extend radially outwardly and inwardly respectively. The helical blades have first, second, and third twist slopes in the first, second, and third sections respectively. The first twist slopes are less than the second twist slopes and the third twist slopes are less than the second twist slopes. A combustor section extends axially downstream through at least a portion of the second section.

  5. Examples of oil cavitation erosion in positive displacement pumps

    NASA Technical Reports Server (NTRS)

    Halat, J. A.; Ellis, G. O.

    1974-01-01

    The effects of cavitation flow on piston type, positive displacement, hydraulic pumps are discussed. The operating principles of the pump and the components which are most subject to erosion effects are described. The mechanisms of cavitation phenomena are identified from photographic records. Curves are developed to show the solubility of air in water, oil-water emulsion, and industrial hydraulic oil.

  6. Positive displacement compounding of a heavy duty diesel engine

    NASA Technical Reports Server (NTRS)

    Sekar, R.; Kamo, R.

    1983-01-01

    A helical screw type positive displacement (PD) compressor and expander was considered as an alternative to the turbocharger and the power turbine in the Cummins advanced turbocompound engine. The Institute of Gas Technology (IGT) completed the design, layout, and performance prediction of the PD machines. The results indicate that a screw compressor-expander system is feasible up to at least 750 HP, dry operation of the rotors is feasible, cost and producibility are uncertain, and the system will yield about 4% improvement in brake specific fuel consumption (BSFC) over the advanced turbocompound engine.

  7. Open loop pneumatic control of a Lysholm engine or turbine exhaust pressure

    SciTech Connect

    Plonski, B.A.

    1981-07-17

    A Lysholm engine, or helical screw expander, is currently being evaluated at the University of California, Berkeley for staging with a conventional turbine in geothermal energy conversion. A pneumatic closed loop, proportional-integral control system was implemented to control the Lysholm engine's exhaust pressure for performance testing of the engine at constant inlet/outlet pressure ratios. The control system will also be used to control the exhaust pressure of the conventional turbine during future testing of the staged Lysholm-turbine system. Analytical modeling of the control system was performed and successful tuning was achieved by applying Ziegler-Nichol's tuning method. Stable control and quick response, of approximately 1 minute, was demonstrated for load and set point changes in desired exhaust pressures.

  8. An Overview of NASA Research on Positive Displacement Type General Aviation Engines

    NASA Technical Reports Server (NTRS)

    Kempke, E. E.; Willis, E. A.

    1979-01-01

    The general aviation positive displacement engine program encompassing conventional, lightweight diesel, and rotary combustion engines is described. Lean operation of current production type spark ignition engines and advanced alternative engine concepts are emphasized.

  9. A Novel Position Estimation Method Based on Displacement Correction in AIS

    PubMed Central

    Jiang, Yi; Zhang, Shufang; Yang, Dongkai

    2014-01-01

    A new position estimation method by using the signals from two automatic identification system (AIS) stations is proposed in this paper. The time of arrival (TOA) method is enhanced with the displacement correction, so that the vessel's position can be determined even for the situation where it can receive the signals from only two AIS base stations. Its implementation scheme based on the mathematical model is presented. Furthermore, performance analysis is carried out to illustrate the relation between the positioning errors and the displacement vector provided by auxiliary sensors. Finally, the positioning method is verified and its performance is evaluated by simulation. The results show that the positioning accuracy is acceptable. PMID:25232913

  10. FIELD TRIALS OF NEWLY DEVELOPED POSITIVE DISPLACEMENT SUBMERSIBLE PUMP

    SciTech Connect

    Rob Beard; Leland Traylor

    2002-12-01

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

  11. FIELD TRIALS OF NEWLY DEVELOPED POSITIVE DISPLACEMENT SUBMERSIBLE PUMP

    SciTech Connect

    Rob Beard

    2003-10-01

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

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

    PubMed Central

    Brunherotti, Marisa Afonso Andrade; Martinez, Francisco Eulógio

    2015-01-01

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

  13. 5 CFR 330.404 - Displacement of preference eligibles occupying restricted positions in contracting out situations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Displacement of preference eligibles occupying restricted positions in contracting out situations. 330.404 Section 330.404 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RECRUITMENT, SELECTION, AND...

  14. 5 CFR 330.404 - Displacement of preference eligibles occupying restricted positions in contracting out situations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Displacement of preference eligibles occupying restricted positions in contracting out situations. 330.404 Section 330.404 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS RECRUITMENT, SELECTION, AND...

  15. Electromagnetic Tracking of Intrafraction Prostate Displacement in Patients Externally Immobilized in the Prone Position

    SciTech Connect

    Bittner, Nathan; Wallner, Kent E.; Merrick, Gregory S.

    2010-06-01

    Purpose: To evaluate intrafraction prostate displacement among patients immobilized in the prone position using real-time monitoring of implanted radiofrequency transponders. Methods and Materials: The Calypso localization system was used to track prostate motion in patients receiving external beam radiation therapy (XRT) for prostate cancer. All patients were treated in the prone position and immobilized with a thermoplastic immobilization device. Real-time measurement of prostate displacement was recorded for each treatment fraction. These measurements were used to determine the duration and magnitude of displacement along the three directional axes. Results: The calculated centroid of the implanted transponders was offset from the treatment isocenter by >=2 mm, >=3 mm, and >=4 mm for 38.0%, 13.9%, and 4.5% of the time. In the lateral dimension, the centroid was offset from the treatment isocenter by >=2 mm, >=3 mm, and >=4 mm for 2.7%, 0.4%, and 0.06% of the time. In the superior-inferior dimension, the centroid was offset from the treatment isocenter by >=2 mm, >=3 mm, and >=4 mm for 16.1%, 4.7%, and 1.5% of the time, respectively. In the anterior-posterior dimension, the centroid was offset from the treatment isocenter by >=2 mm, >=3 mm, and >=4 mm for 13.4%, 3.0%, and 0.5% of the time. Conclusions: Intrafraction prostate displacement in the prone position is comparable to that in the supine position. For patients with large girth, in whom the supine position may preclude accurate detection of implanted radiofrequency transponders, treatment in the prone position is a suitable alternative.

  16. Engineering research on positive displacement gas expanders. Phase I technical report

    SciTech Connect

    Lord, R. E.

    1984-02-01

    A research, design, and development program related to positive displacement gas expanders is reported. The objective of this program is to develop and demonstrate a more cost effective gas expander for use in those waste heat recovery systems which utilize an Organic Rankine Cycle. To provide a lower cost machine, the gas expander uses a positive displacement concept, rather than a turbine as currently used. Several positive displacement machine concepts were examined, and various performance measures have been developed for each of the concepts. The machine concepts were: single and multiple cylinder reciprocators, radial piston, roller piston, sliding vane, trochoidal, helical screw, and lobed rotor. For each of the concepts, designs were generated for machines operating with three different sets of operating conditions. These designs were then used to develop measures of efficiency and cost, and to examine other characteristics of the machines, such as development risk and ability to operate with different flow, pressure, and temperature levels. Based upon an evaluation of these characteristics, a specific concept was selected for further development. This concept is a double acting, single cylinder reciprocating machine with crossheads and ceramic liners.

  17. Positioning dielectric sheets on an electrostatic induction sheet conveyor using a built-in displacement sensor.

    PubMed

    Modabberifar, M

    2013-06-01

    The present paper proposes a method for positioning and control of dielectric sheet displacement using a novel built-in position sensor for an electrostatic induction sheet conveyor (EISC) which is used for dielectric sheet conveying. The actuator utilizes electrostatic actuation technology based on induced charges and can be used in automated systems for conveying dielectric sheets. The proposed sensing system superimposes a high-frequency sensors signal onto a low-frequency driving signal and uses the actuator's electrodes for position sensing. The operational principle of the built-in sensor is similar to typical capacitance-type linear encoder. In this paper, details of the built-in position sensor based on the exact model of the actuator and feedback position control are reported. The experimental results confirmed that the sensor can work successfully by sharing the same electrodes with the driving operation.

  18. Atomic displacement in solids: analysis of the primary event and the collision cascade. Part I: Neutron and positive ion irradiation

    NASA Astrophysics Data System (ADS)

    de Almeida, P.; Räisänen, J.

    2005-05-01

    A modern, mathematical-physics introduction to the analytical problem of atomic displacement in solids which is both technically adequate and relevant to an introductory graduate students' curriculum in radiation damage theory is reported. The problematic of atomic displacement in solids is introduced didactically, deriving first the primary event (that is, the formation of the primary knock-on atom) and then building on that specific set of results in order to extend their basics to secondary, tertiary and higher-order progeny—the collision cascade—for both neutrons and positive ions, namely, their average damage functions, displacement cross-sections and energy spectra. A comparison of atomic displacement in solids under neutron and positive ion irradiation is discussed in terms of the physical concept of concentration of displaced atoms (or displacement dose).

  19. An overview of NASA research on positive displacement type general aviation engines

    NASA Technical Reports Server (NTRS)

    Kempke, E. E.; Willis, E. A.

    1979-01-01

    The paper surveys the current status of the aviation positive displacement engine programs underway at the NASA Lewis Research Center. The program encompasses conventional, lightweight diesel, and rotary combustion engines. Attention is given to topics such as current production type engine improvement, cooling drag reduction, fuel injection, and experimental and theoretical combustion studies. It is shown that the program's two major technical thrusts are directed toward lean operation of current production type spark ignition engines and advanced alternative engine concepts. Finally, an Otto cycle computer model is also covered.

  20. Comparison of positional surfactant isomers for displacement of rubisco protein from the air-water interface.

    PubMed

    He, Lizhong; Onaizi, Sagheer A; Dimitrijev-Dwyer, Mirjana; Malcolm, Andrew S; Shen, Hsin-Hui; Dong, Chuchuan; Holt, Stephen A; Thomas, Robert K; Middelberg, Anton P J

    2011-08-15

    Protein-surfactant interaction, which is a function of the protein and surfactant characteristics, is a common phenomenon in a wide range of industrial applications. In this work, we used rubisco, the most abundant protein in nature, as a model protein and sodium dodecylbenzenesulfonate (SDOBS), one of the most widely used commercial surfactants, with two positional isomers (SDOBS-2 and SDOBS-6), as a model surfactant. We first examined the surface tension and the mechanical properties of interfacial mixed rubisco-SDOBS films adsorbed at the air-water interface. The concentration of rubisco in solution was fixed at 0.1 mg mL(-1) while the SDOBS concentration varied from 0 to 150 μM. Both the surface tension and the mechanical strength of the interfacial film decreased with increasing SDOBS concentration. Overall, the surface tension of a rubisco-SDOBS-6 mixture is lower than that of rubisco-SDOBS-2, while the mechanical strength of both systems is similar. Neutron reflection data suggest that rubisco protein is likely denatured at the interface. The populations of rubisco and SDOBS of the mixed systems at the interface were determined by combining non-deuterated and deuterated SDOBS to provide contrast variation. At a low surfactant concentration, SDOBS-6 has a stronger ability to displace rubisco from the air-water interface than SDOBS-2. However, when surfactant concentration reaches 50 μM, SDOBS-2 has a higher population than SDOBS-6, with more rubisco displaced from the interface. The results presented in this work suggest that the extent of protein displacement from the air-water interface, and hence the nature of the protein-surfactant interactions at the interface, are strongly affected by the position of surfactant isomerisation, which might allow the design of formulations for efficient removal of protein stains.

  1. Disc and condylar head position in the temporomandibular joint with and without disc displacement.

    PubMed

    Badel, Tomislav; Pavicin, Ivana Savić; Jakovac, Marko; Kern, Josipa; Zadravec, Dijana

    2013-09-01

    The purpose of this study was to evaluate the difference between disc and condyle position between temporomandibular joints (TMJs) without disc displacement (DD) in asymptomatic volunteers, and patients who have DD in contralateral joints, respectively unilateral DD. Secondly, there were two TMJ groups which consisted of measurements from patients' symptomatic DD and volunteers with asymptomatic DD. The study included 79 TMJs of 40 patients with unilateral DD. In the group of 25 asymptomatic volunteers, 20 volunteers were without DD bilaterally (40 joints), while five had DD in at least one TMJ. All subjects were examined clinically and DD was confirmed by magnetic resonance imaging. Left and right TMJs were analysed independently for each participant based on their DD status (symptomatic, asymptomatic, and without DD). All asymptomatic TMJs did not have any clinical signs of TMJ functional abnormalities. There was a significant statistical difference between disc position among TMJs without DD in asymptomatic volunteers and TMJs without DD in patients (p = 0.016). Moreover, no significant differences were found between condyle position in the same groups of joints (p = 0.706). There were no significant differences in the DD position (p = 0.918) or condyle position (p = 0.453) between the group with asymptomatic volunteers' joints and the group with symptomatic patients' joints. There was a significant difference between patient and volunteers' joints without DD: the disc was positioned more anteriorly in patients' joints without DD than in joints of asymptomatic volunteers without DD.

  2. Analysis of vibration and pressure pulsation in positive displacement drilling motors

    SciTech Connect

    Hamlin, D.B.; Dreesen, D.S.

    1998-12-31

    Three, Moineau principle, positive displacement (drilling) motors were tested on a dynamometer using water, air/mist, and foam. In conjunction with a traditional motor performance test, data were collected at 5000 samples per second using an adapted seismic data acquisition system. Shaft speed, torque, pressure, and three-axis vibration data were processed using Seismic Analysis Code (SAC) to obtain energy density spectrums (EDSs). Cascade plots were generated by plotting the EDSs against shaft speed. The cascade plots revealed that pressure pulses and motor vibrations are closely related to the eccentric rotation of the rotor in the power section. Excessive no-load vibrations were not observed in the small motors and test apparatus used; increasing torque usually decreases the amplitude of vibrations observed. Motor vibration amplitudes were as a rule not increased when compressible fluids were substituted for water.

  3. Validation of a CFD methodology for positive displacement LVAD analysis using PIV data.

    PubMed

    Medvitz, Richard B; Reddy, Varun; Deutsch, Steve; Manning, Keefe B; Paterson, Eric G

    2009-11-01

    Computational fluid dynamics (CFD) is used to asses the hydrodynamic performance of a positive displacement left ventricular assist device. The computational model uses implicit large eddy simulation direct resolution of the chamber compression and modeled valve closure to reproduce the in vitro results. The computations are validated through comparisons with experimental particle image velocimetry (PIV) data. Qualitative comparisons of flow patterns, velocity fields, and wall-shear rates demonstrate a high level of agreement between the computations and experiments. Quantitatively, the PIV and CFD show similar probed velocity histories, closely matching jet velocities and comparable wall-strain rates. Overall, it has been shown that CFD can provide detailed flow field and wall-strain rate data, which is important in evaluating blood pump performance.

  4. Modeling shear-induced CHO cell damage in a rotary positive displacement pump.

    PubMed

    Kamaraju, Hari; Wetzel, Kenneth; Kelly, William J

    2010-01-01

    Rotary lobe pumps are commonly used in the biotechnology industry for a variety of purposes. Shear damage to animal cells within the rotary lobe pump can adversely affect the product yield or purity during, for example, cell concentration via cross-flow filtration. In this research, CHO cells grown in 20-L bioreactors were fed to a rotary lobe pump in both single pass and recycle experiments were conducted at different RPMs and "slip" conditions. The results indicate that the slip flow rate more severely impacts the viability of the CHO cells than the pump RPM. A novel mathematical modeling approach is presented that predicts shear rates in all of the positive displacement pump's slip regions, and then predicts cell death vs. operating conditions. This model accounts for the complex flow situation that results from changes to RPM, backpressure and pump geometry (i.e., clearances).

  5. Displacement measurement of the compliant positioning stage based on a computer micro-vision method

    NASA Astrophysics Data System (ADS)

    Wu, Heng; Zhang, Xianmin; Wang, Ruizhou; He, Zhenya

    2016-02-01

    We propose a practical computer micro-vision-based method for displacement measurements of the compliant positioning stage. The algorithm of the proposed method is based on a template matching approach composed of an integer-pixel search and a sub-pixel search. By combining with an optical microscopy, a high resolution CCD camera and the proposed algorithm, an extremely high measuring precision is achieved. Various simulations and experiments are conducted. The simulation results demonstrate that the matching precision can reach to 0.01 pixel when the noise interference is low. A laser interferometer measurement system (LIMS) is established for comparison. The experimental results indicate that the proposed method possesses the same performance as the LIMS but exhibits a greater flexibility and operability. The measuring precision can theoretically attain to 2.83 nm/pixel.

  6. Nozzle optimization for water jet propulsion with a positive displacement pump

    NASA Astrophysics Data System (ADS)

    Yang, You-sheng; Xie, Ying-chun; Nie, Song-lin

    2014-06-01

    In the water jet propulsion system with a positive displacement (PD) pump, the nozzle, which converts pressure energy into kinetic energy, is one of the key parts exerting great influence on the reactive thrust and the efficiency of the system due to its high working pressure and easily occurring cavitation characteristics. Based on the previous studies of the energy loss and the pressure distribution of different nozzles, a model of water jet reactive thrust, which fully takes the energy loss and the nozzle parameters into consideration, is developed to optimize the nozzle design. Experiments and simulations are carried out to investigate the reactive thrust and the conversion efficiency of cylindrical nozzles, conical nozzles and optimized nozzles. The results show that the optimized nozzles have the largest reactive thrust and the highest energy conversion efficiency under the same inlet conditions. The related methods and conclusions are extended to the study of other applications of the water jet, such as water jet cutting, water mist fire suppression, water injection molding.

  7. Coal-water slurry spray characteristics of a positive displacement fuel injection system

    SciTech Connect

    Seshadri, A.K.; Caton, J.A.; Kihm, K.D.

    1992-12-31

    Experiments have been completed to characterized coal-water slurry sprays from a modified positive displacement fuel injection system of a diesel engine. The injection system includes an injection jerk pump driven by an electric motor, a specially designed diaphragm to separate the abrasive coal from the pump, and a single-hole fuel nozzle. The sprays were injected into a pressurized chamber equipped with windows. High speed movies and instantaneous fuel line pressures were obtained. For injection pressures of order 30 MPa or higher, the sprays were similar for coal-water slurry, diesel fuel and water. The time until the center core of the spray broke-up (break-up time) was determined from both the movies and from a model using the fuel line pressures. Results from these two independent procedures were in good agreement. For the base conditions, the break-up time was 0.58 and 0.50 ms for coal-water slurry and diesel fuel, respectively. The break-up times increased with increasing nozzle orifice size and with decreasing chamber density. The break-up time was not a function of coal loading for coal loadings up to 53%. Cone angles of the sprays were dependent on the operating conditions and fluid, as well as on the time and location of the measurement. For one set of cases studied, the time-averaged cone angle was 15.9{degree} and 16.3{degree} for coal-water slurry and diesel fuel, respectively.

  8. Flow measurement of liquid hydrocarbons with positive displacement meters: the correction for slippage

    NASA Astrophysics Data System (ADS)

    García-Berrocal, Agustín; Montalvo, Cristina; Blázquez, Juan; Balbás, Miguel

    2013-05-01

    In the oil industry, the economical and fiscal impact of the measurements accuracy on the custody transfer operations implies fulfilling strict requirements of legal metrology. In this work, we focus on the positive displacement meters (PD meters) for refined liquid hydrocarbons. The state of the art of the lack of accuracy due to slippage flow in these meters is revised. The slippage flow due to the pressure drop across the device has been calculated analytically by applying the Navier-Stokes equation. No friction with any wall of the slippage channel has been neglected and a more accurate formula than the one found in the literature has been obtained. PD meters are calibrated against a bidirectional prover in order to obtain their meter factor which allows correction of their indications. Instead of the analytical model, an empirical one is proposed to explain the variation of the meter factor of the PD meters with flow rate and temperature for a certain hydrocarbon. The empirical model is based on the historical calibration data, of 9 years on average, of 25 m with four types of refined hydrocarbon. This model has been statistically validated by linear least-squares fitting. By using the model parameters, we can obtain the meter factor corresponding to different conditions of temperature and flow rate from the conditions in which the devices were calibrated. The flow parameter is such that a 10% flow rate variation implies a meter factor variation lower than 0.01%. A rule of thumb value for the temperature parameter is 0.005% per degree Celsius. The model residuals allow surveillance of the device drift and quantifying its contribution to the meter factor uncertainty. The observed drift is 0.09% at 95% confidence level in the analyzed population of meters.

  9. Computerized method for measurement of displacement vectors of target positions on EPID cine images in stereotactic radiotherapy

    NASA Astrophysics Data System (ADS)

    Arimura, Hidetaka; Anai, Shigeo; Yoshidome, Satoshi; Nakamura, Katsumasa; Shioyama, Yoshiyuki; Nomoto, Satoshi; Honda, Hiroshi; Onizuka, Yoshihiko; Terashima, Hiromi

    2007-03-01

    The purpose of this study was to develop a computerized method for measurement of displacement vectors of target position on electronic portal imaging device (EPID) cine images in a treatment without implanted markers. Our proposed method was based on a template matching technique with cross-correlation coefficient between a reference portal (RP) image and each consecutive portal (CP) image acquired by the EPID. EPID images with 512×384 pixels (pixel size:0.56 mm) were acquired in a cine mode at a sampling rate of 0.5 frame/sec by using an energy of 4, 6, or 10MV on linear accelerators. The displacement vector of the target on each cine image was determined from the position in which took the maximum cross-correlation value between the RP image and each CP image. We applied our method to EPID cine images of a lung phantom with a tumor model simulating respiratory motion, and 5 cases with a non-small cell lung cancer and one case of metastasis. For validation of our proposed method, displacement vectors of a target position calculated by our method were compared with those determined manually by two radiation oncologists. As a result, for lung phantom images, target displacements by our method correlated well with those by the oncologists (r=0.972 - 0.994). Correlation values for 4 cases ranged from 0.854 to 0.991, but the values for the other two cases were 0.609 and 0.644. This preliminary result suggested that our method may be useful for monitoring of displacement vectors of target positions without implanted markers in stereotactic radiotherapy.

  10. Adjusting and positioning method with high displacement resolution for large-load worktable based on the invariable restoring force

    NASA Astrophysics Data System (ADS)

    Huang, Jingzhi; Sun, Tao; Gu, Wei; Wen, Zhongpu; Guo, Tenghui

    2015-02-01

    With the fast development of the advanced equipment manufacturing toward precision and ultra-precision trend, especially with the continuously improving of the aviation engine's performance, the problem of high displacement resolution for the large-load two-dimension adjusting and positioning worktable used for the aeroengine assembling become evident. A method was proposed which is based on the invariable restoring force, and the adjusting and positioning physical model was established. The experiment results indicate that under the occasion of a load with 508 kilogram, the worktable has got a displacement resolution of 0.3μm after using the improved method compared to 1.4μm of the traditional method. The improved method could meet the requirements of aviation engine assembling worktable.

  11. Nanometric position and displacement measurement of the six degrees of freedom by means of a patterned surface element.

    PubMed

    Sandoz, Patrick

    2005-03-10

    A method is presented for position and displacement measurements of the six degrees of freedom by use of a patterned surface element observed by a static interferometric vision system. The surface element is made of a regular pattern of circular holes etched on a chromium layer deposited onto a flat glass plate. The in-plane coordinates (x, y, theta(z)) are reconstructed with a subpixel resolution by a vision method based on phase measurements. The out-of-plane coordinates (z, theta(x), theta(y)) are reconstructed by phase-shifting interferometry. Resolutions achieved by the proposed method are in the range of microradians for the measurement of angles and of nanometers for the position and displacement.

  12. Prone Positioning Causes the Heart To Be Displaced Anteriorly Within the Thorax: Implications for Breast Cancer Treatment

    SciTech Connect

    Chino, Junzo P. Marks, Lawrence B.

    2008-03-01

    Introduction: Prone positioning has been suggested as an alternative to the conventional supine position for patients receiving breast radiotherapy, but few data exist on how this may alter heart location. We herein quantitatively compare the intrathoracic location of the heart in the prone and supine positions in patients treated for breast cancer. Methods and Materials: In 16 patients treated with tangent photons for breast cancer, the computed tomography planning images (obtained in the supine position) and diagnostic magnetic resonance images (obtained in the prone position) were studied. For each case, the distance between the anterior pericardium and the anterior chest wall was measured at nine specific points; three points at each of three axial levels. The differences in the measurements between the prone and supine positions were compared with the Wilcoxon signed-rank test. Results: There is a systematic displacement of the lateral and superior aspect of the heart closer to the chest wall in the prone vs. supine position (mean displacement 19 mm (95% confidence interval 13.7-25.1 mm, p < 0.001); the medial and inferior aspects remain fixed. There was also a reduction in volume of lung interposed between the heart and chest wall when prone (mean decrease of 22 mL, p < 0.001 for difference). Conclusions: The superior and lateral aspects of the heart typically move anteriorly during prone positioning compared with the supine position. This may have negative consequences in situations in which the high-risk target tissues include the chest wall or deep breast.

  13. Eddy current position indicating apparatus for measuring displacements of core components of a liquid metal nuclear reactor

    DOEpatents

    Day, Clifford K.; Stringer, James L.

    1977-01-01

    Apparatus for measuring displacements of core components of a liquid metal fast breeder reactor by means of an eddy current probe. The active portion of the probe is located within a dry thimble which is supported on a stationary portion of the reactor core support structure. Split rings of metal, having a resistivity significantly different than sodium, are fixedly mounted on the core component to be monitored. The split rings are slidably positioned around, concentric with the probe and symmetrically situated along the axis of the probe so that motion of the ring along the axis of the probe produces a proportional change in the probes electrical output.

  14. Rotating and positive-displacement pumps for low-thrust rocket engines. Volume 2: Fabrication and testing

    NASA Technical Reports Server (NTRS)

    Csomor, A.

    1974-01-01

    Rotating and positive displacement pumps of various types were studied for pumping liquid fluorine for low thrust high performance rocket engines. Included in the analysis were: centrifugal, pitot, Barske, Tesla, drag, gear, vane, axial piston, radial piston, diaphragm and helirotor pump concepts. The centrifugal and gear pumps were carried through detail design and fabrication. After preliminary testing in Freon 12, the centrifugal pump was selected for further testing and development. It was tested in Freon 12 to obtain the hydrodynamic performance. Tests were also conducted in liquid fluorine to demonstrate chemical compatibility.

  15. The noncavitating performance and life of a small vane-type positive displacement pump in liquid hydrogen

    NASA Technical Reports Server (NTRS)

    Ulbricht, T. E.; Hemminger, J. A.

    1986-01-01

    The low flow rate and high head rise requirements of hydrogen/oxygen auxiliary propulsion systems make the application of centrifugal pumps difficult. Positive displacement pumps are well-suited for these flow conditions, but little is known about their performance and life characteristics in liquid hydrogen. An experimental and analytical investigation was conducted to determine the performance and life characteristics of a vane-type, positive displacement pump. In the experimental part of this effort, mass flow rate and shaft torque were determined as functions of shaft speed and pump pressure rise. Since liquid hydrogen offers little lubrication in a rubbing situation, pump life is an issue. During the life test, the pump was operated intermittently for 10 hr at the steady-state point of 0.074 lbm/sec (0.03 kg/sec) flow rate, 3000 psid (2.07 MPa) pressure rise, and 9000 rpm (938 rad/sec) shaft speed. Pump performance was monitored during the life test series and the results indicated no loss in performance. Material loss from the vanes was recorded and wear of the other components was documented. In the analytical part of this effort, a comprehensive pump performance analysis computer code, developed in-house, was used to predict pump performance. The results of the experimental investigation are presented and compared with the results of the analysis. Results of the life test are also presented.

  16. The noncavitating performance and life of a small vane-type positive displacement pump in liquid hydrogen

    NASA Technical Reports Server (NTRS)

    Ulbricht, T. E.; Hemminger, J. A.

    1986-01-01

    The low flow rate and high head rise requirements of hydrogen/oxygen auxiliary propulsion systems make the application of centrifugal pumps difficult. Positive displacement pumps are well-suited for these flow conditions, but little is known about their performance and life characteristics in liquid hydrogen. An experimental and analytical investigation was conducted to determine the performance and life characteristics of a vane-type, positive displacement pump. In the experimental part of this effort, mass flow rate and shaft torque were determined as functions of shaft speed and pump pressure rise. Since liquid hydrogen offers little lubrication in a rubbing situation, pump life is an issue. During the life test, the pump was operated intermittently for 10 hr at the steady-state point of 0.074 lbm/sec (0.03 kg/sec) flow rate, 3000 psid (2.07 MPa) pressure rise, and 8000 rpm (838 rad/sec) shaft speed. Pump performance was monitored during the life test series and the results indicated no loss in performance. Material loss from the vanes was recorded and wear of the other components was documented. In the analytical part of this effort, a comprehensive pump performance analysis computer code, developed in-house, was used to predict pump performance. The results of the experimental investigation are presented and compared with the results of the analysis. Results of the life test are also presented.

  17. Positively and negatively large Goos-Hänchen lateral displacements from a single negative layered structure.

    PubMed

    Talebzadeh, Robabeh; Namdar, Abdolrahman

    2012-09-20

    We study the electromagnetic beam reflection from layered structures that include the so-called ε-negative and the μ-negative materials, also called single negative materials. We predict that such structures can demonstrate a giant lateral Goos-Hänchen shift of the resonant excitation of surface waves at the interface between the conventional and single negative materials, as well as due to the excitation of leaky modes in the layered structures. Then we replace the conventional layer with a left-handed layer (a material with both ε<0 and μ<0). We show that the Goos-Hänchen shift can be positive and negative depending on the type of this layer (conventional or LH material), which can support TE or TM surface waves.

  18. Multiparameter double hole contrast detail phantom: Ability to detect image displacement due to off position anode stem

    SciTech Connect

    Pauzi, Nur Farahana; Majid, Zafri Azran Abdul; Sapuan, Abdul Halim; Junet, Laila Kalidah; Azemin, Mohd Zulfaezal Che

    2015-04-24

    Contrast Detail phantom is a quality control tool to analyze the performance of imaging devices. Currently, its function is solely to evaluate the contrast detail characteristic of imaging system. It consists of drilled hole which gives effect to the penetration of x-ray beam divergence to pass through the base of each hole. This effect will lead to false appearance of image from its original location but it does not being visualized in the radiograph. In this study, a new design of Contrast Detail phantom’s hole which consists of double hole construction has been developed. It can detect the image displacement which is due to off position of anode stem from its original location. The double hole differs from previous milled hole, whereby it consists of combination of different hole diameters. Small hole diameter (3 mm) is positioned on top of larger hole diameter (10 mm). The thickness of double hole acrylic blocks is 13 mm. Result revealed that Multiparameter Double Hole Contrast Detail phantom can visualize the shifted flaw image quality produced by x-ray machine due to improper position of the anode stem which is attached to rotor and stator. The effective focal spot of x-ray beam also has been shifted from the center of collimator as a result of off-position anode stem. As a conclusion, the new design of double hole Contrast Detail phantom able to measure those parameters in a well manner.

  19. Development of flexure based 6-degrees of freedom parallel nano-positioning system with large displacement.

    PubMed

    Kang, Dongwoo; Gweon, Daegab

    2012-03-01

    This paper details the development of a novel flexure jointed precision parallel nano-positioning system in combination with piezo-electric stepping motor for the application of precise optics alignment. The characteristics of the developed system are evaluated in this paper by the simulation and experiments. Based on the precision piezo-electric stepping motor and flexure joints, a high precision motion is obtained. Results of this paper include that of a translation resolution of 15 nm and a rotational resolution of 0.14 arc sec being achieved. In addition, the piezo-electric stepping motors provide a power-off hold characteristic to the system. Meanwhile, the parallel structure provides the high dynamic bandwidth of the lowest resonant frequency of 396.1 Hz. The symmetric structure is advantageous for thermal variation. To increase the motion range of the system, all of flexure joints are designed specially and the coupled workspace of ±2 mm × ±2 mm × ±2 mm × ±2° × ±2° × ±2° is achieved. The overall size of the designed system is Φ350 mm × 120 mm.

  20. An advanced CFD model to study the effect of non-condensable gas on cavitation in positive displacement pumps

    NASA Astrophysics Data System (ADS)

    Iannetti, Aldo; Stickland, Matthew T.; Dempster, William M.

    2015-09-01

    An advanced transient CFD model of a positive displacement reciprocating pump was created to study its behavior and performance in cavitating condition during the inlet stroke. The "full" cavitation model developed by Singhal et al. was utilized, and a sensitivity analysis test on two air mass fraction amounts (1.5 and 15 parts per million) was carried out to study the influence of the dissolved air content in water on the cavitation phenomenon. The model was equipped with user defined functions to introduce the liquid compressibility, which stabilizes the simulation, and to handle the two-way coupling between the pressure field and the inlet valve lift history. Estimation of the performance is also presented in both cases.

  1. BDS Precise Point Positioning for Seismic Displacements Monitoring: Benefit from the High-Rate Satellite Clock Corrections.

    PubMed

    Geng, Tao; Su, Xing; Fang, Rongxin; Xie, Xin; Zhao, Qile; Liu, Jingnan

    2016-12-20

    In order to satisfy the requirement of high-rate high-precision applications, 1 Hz BeiDou Navigation Satellite System (BDS) satellite clock corrections are generated based on precise orbit products, and the quality of the generated clock products is assessed by comparing with those from the other analysis centers. The comparisons show that the root mean square (RMS) of clock errors of geostationary Earth orbits (GEO) is about 0.63 ns, whereas those of inclined geosynchronous orbits (IGSO) and medium Earth orbits (MEO) are about 0.2-0.3 ns and 0.1 ns, respectively. Then, the 1 Hz clock products are used for BDS precise point positioning (PPP) to retrieve seismic displacements of the 2015 Mw 7.8 Gorkha, Nepal, earthquake. The derived seismic displacements from BDS PPP are consistent with those from the Global Positioning System (GPS) PPP, with RMS of 0.29, 0.38, and 1.08 cm in east, north, and vertical components, respectively. In addition, the BDS PPP solutions with different clock intervals of 1 s, 5 s, 30 s, and 300 s are processed and compared with each other. The results demonstrate that PPP with 300 s clock intervals is the worst and that with 1 s clock interval is the best. For the scenario of 5 s clock intervals, the precision of PPP solutions is almost the same to 1 s results. Considering the time consumption of clock estimates, we suggest that 5 s clock interval is competent for high-rate BDS solutions.

  2. Predicting positive mental health in internally displaced persons in Indonesia: the roles of economic improvement and exposure to violent conflict.

    PubMed

    Saragih Turnip, Sherly; Sörbom, Dag; Hauff, Edvard

    2016-01-01

    Positive mental health, rather than just the absence of mental illness, is rarely investigated among the internally displaced persons (IDPs) affected by violent conflict in low-income countries. The purpose of this study was to investigate a model that could explain the interrelationship between factors contributing to positive mental health in displaced populations. In a longitudinal study we examine poverty, exposure to traumatic events and the change of material well-being after one year. We collected data in two consecutive years (2005 and 2006) from a community-based sample of IDPs in Ambon, Indonesia, through face-to-face structured interviews with consenting adults. Participants of this study were IDPs lived in Ambon during the violent conflict period. We interviewed 471 IDPs in the first year and reinterviewed 399 (85%) of the same subjects in the second year. The IDPs possessed good sense of coherence and subjective well-being. Our final model, which was generated by the use of structural equation modeling, fits the data well (χ(2) = 52.51, df = 45, p = .21, CFI = .99, RMSEA = .019). Exposure to violent conflict had a negative impact on IDPs' mental health initially and better economic conditions improved it (r = -.30 and .29 respectively). Mental health status one year previously was a strong predictor of future mental health, followed by individual economic growth in the past year (r = .43 and .29 respectively). On a group level the IDPs were resilient and adaptive to survive in adverse living conditions after devastating violent conflict, and the economic improvement contributed to it.

  3. BDS Precise Point Positioning for Seismic Displacements Monitoring: Benefit from the High-Rate Satellite Clock Corrections

    PubMed Central

    Geng, Tao; Su, Xing; Fang, Rongxin; Xie, Xin; Zhao, Qile; Liu, Jingnan

    2016-01-01

    In order to satisfy the requirement of high-rate high-precision applications, 1 Hz BeiDou Navigation Satellite System (BDS) satellite clock corrections are generated based on precise orbit products, and the quality of the generated clock products is assessed by comparing with those from the other analysis centers. The comparisons show that the root mean square (RMS) of clock errors of geostationary Earth orbits (GEO) is about 0.63 ns, whereas those of inclined geosynchronous orbits (IGSO) and medium Earth orbits (MEO) are about 0.2–0.3 ns and 0.1 ns, respectively. Then, the 1 Hz clock products are used for BDS precise point positioning (PPP) to retrieve seismic displacements of the 2015 Mw 7.8 Gorkha, Nepal, earthquake. The derived seismic displacements from BDS PPP are consistent with those from the Global Positioning System (GPS) PPP, with RMS of 0.29, 0.38, and 1.08 cm in east, north, and vertical components, respectively. In addition, the BDS PPP solutions with different clock intervals of 1 s, 5 s, 30 s, and 300 s are processed and compared with each other. The results demonstrate that PPP with 300 s clock intervals is the worst and that with 1 s clock interval is the best. For the scenario of 5 s clock intervals, the precision of PPP solutions is almost the same to 1 s results. Considering the time consumption of clock estimates, we suggest that 5 s clock interval is competent for high-rate BDS solutions. PMID:27999384

  4. Lateral displacement and rotational displacement sensor

    DOEpatents

    Duden, Thomas

    2014-04-22

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

  5. Positive displacement rotary pump

    NASA Astrophysics Data System (ADS)

    Moody, Paul E.

    1994-04-01

    An eccentric drive rotates inside a ring that is hinged to a plate and an elastomeric curtain is wrapped around the ring and across an articulated plate. The curtain moves along a cylindrical wall inside the pump cavity to move fluid from an inlet to an outlet end of the chamber. Two or more chambers can be coupled in series or in parallel with one another.

  6. Positive displacement rotary pump

    NASA Astrophysics Data System (ADS)

    Moody, Paul E.

    1992-12-01

    An eccentric drive rotates inside a ring that is hinged to a plate, and an elastomeric curtain is wrapped around the ring and across an articulated plate. The curtain moves along a cylindrical wall inside the pump cavity to move fluid from an inlet to an outlet end of the chamber. Two or more chambers can be coupled in series or in parallel with one another.

  7. Simultaneous piston position and tilt angle sensing for large vertical displacement micromirrors by frequency detection inductive sensing

    NASA Astrophysics Data System (ADS)

    Tseng, V. F.-G.; Xie, H.

    2015-11-01

    This paper presents a frequency detection based inductive eddy current sensing mechanism to simultaneously sense the piston position and tilt angle of the mirror plate of large vertical displacement micromirrors that exhibit piston scan ranges above 100 μm. This is accomplished by sensing the inductance change, and thus resonant frequency shift, of two microfabricated sensing coils packaged underneath the mirror plate. For demonstration purpose, the coils were paired with discrete circuit components to oscillate at 11.9 MHz and 12.5 MHz, respectively. The piston position and tilt angle of the mirror plate could be simultaneously monitored over a 500 μm piston scan range, achieving a maximum piston sensitivity of 4.15 kHz/μm with a piston sensing resolution of 96 nm and a maximum tilt angle sensitivity of 60.5 kHz/° with a tilt angle sensing resolution of 0.0013°. Analytical modeling of the coil inductance change via image theory was also conducted, showing that the sensor sensitivity and resolution could be improved by increasing the coil oscillation frequency and decreasing the coil size.

  8. Efficacy of cardiopulmonary resuscitation in the supine position with manual displacement of the uterus vs lateral tilt using a firm wedge: a manikin study.

    PubMed

    Butcher, M; Ip, J; Bushby, D; Yentis, S M

    2014-08-01

    Prevention of aortocaval compression is essential for effective cardiopulmonary resuscitation in late pregnancy. This can be achieved by either lateral maternal tilt or lateral uterine displacement. Results from a previous manikin study show that a firm foam-rubber wedge allowed successful chest compressions whilst providing stable and reliable lateral tilt. However, it did not investigate resuscitation in the supine position with manual uterine displacement. The aim of this study was to compare the effectiveness of chest compressions in a manikin in the supine position vs lateral tilt using a foam-rubber wedge, both on the floor and on a typical patient bed. Overall, we found that compressions were easier to perform in the supine position (p = 0.007 (bed) and 0.048 (floor)), and with greater stability in the supine position on the floor (p = 0.011). The effectiveness of chest compressions was similar in both the supine/uterine displacement and the lateral tilt positions, suggesting that either method may be suitable for CPR.

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

  11. Precision displacement reference system

    DOEpatents

    Bieg, Lothar F.; Dubois, Robert R.; Strother, Jerry D.

    2000-02-22

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

  12. Rotating and positive-displacement pumps for low-thrust rocket engines. Volume 1: Pump Evaluation and design. [of centrifugal pumps

    NASA Technical Reports Server (NTRS)

    Macgregor, C.; Csomor, A.

    1974-01-01

    Rotating and positive displacement pumps of various types were studied for pumping liquid fluorine for low-thrust, high-performance rocket engines. Included in the analysis were: centrifugal, pitot, Barske, Tesla, drag, gear, vane, axial piston, radial piston, diaphragm, and helirotor pump concepts. The centrifugal pump and the gear pump were selected and these were carried through detailed design and fabrication. Mechanical difficulties were encountered with the gear pump during the preliminary tests in Freon-12. Further testing and development was therefore limited to the centrifugal pump. Tests on the centrifugal pump were conducted in Freon-12 to determine the hydrodynamic performance and in liquid fluorine to demonstrate chemical compatibility.

  13. Finite element analysis of maxillary incisor displacement during en-masse retraction according to orthodontic mini-implant position

    PubMed Central

    Song, Jae-Won; Lim, Joong-Ki; Lee, Kee-Joon; Sung, Sang-Jin; Chun, Youn-Sic

    2016-01-01

    Objective Orthodontic mini-implants (OMI) generate various horizontal and vertical force vectors and moments according to their insertion positions. This study aimed to help select ideal biomechanics during maxillary incisor retraction by varying the length in the anterior retraction hook (ARH) and OMI position. Methods Two extraction models were constructed to analyze the three-dimentional finite element: a first premolar extraction model (Model 1, M1) and a residual 1-mm space post-extraction model (Model 2, M2). The OMI position was set at a height of 8 mm from the arch wire between the second maxillary premolar and the first molar (low OMI traction) or at a 12-mm height in the mesial second maxillary premolar (high OMI traction). Retraction force vectors of 200 g from the ARH (-1, +1, +3, and +6 mm) at low or high OMI traction were resolved into X-, Y-, and Z-axis components. Results In M1 (low and high OMI traction) and M2 (low OMI traction), the maxillary incisor tip was extruded, but the apex was intruded, and the occlusal plane was rotated clockwise. Significant intrusion and counter-clockwise rotation in the occlusal plane were observed under high OMI traction and -1 mm ARH in M2. Conclusions This study observed orthodontic tooth movement according to the OMI position and ARH height, and M2 under high OMI traction with short ARH showed retraction with maxillary incisor intrusion. PMID:27478801

  14. Internal displacement in Colombia

    PubMed Central

    Shultz, James M; Ceballos, Ángela Milena Gómez; Espinel, Zelde; Oliveros, Sofia Rios; Fonseca, Maria Fernanda; Florez, Luis Jorge Hernandez

    2014-01-01

    This commentary aims to delineate the distinguishing features of conflict-induced internal displacement in the nation of Colombia, South America. Even as Colombia is currently implementing a spectrum of legal, social, economic, and health programs for “victims of armed conflict,” with particular focus on internally displaced persons (IDPs), the dynamics of forced migration on a mass scale within this country are little known beyond national borders.   The authors of this commentary are embarking on a global mental health research program in Bogota, Colombia to define best practices for reaching the displaced population and implementing sustainable, evidence-based screening and intervention for common mental disorders. Presenting the defining characteristics of internal displacement in Colombia provides the context for our work and, more importantly, conveys the compelling and complex nature of this humanitarian crisis. We attempt to demonstrate Colombia’s unique position within the global patterning of internal displacement. PMID:28228997

  15. Tactile suppression of displacement.

    PubMed

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

    2010-10-01

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

  16. Synthesis of finite displacements and displacements in continental margins

    NASA Technical Reports Server (NTRS)

    Speed, R. C.; Elison, M. W.; Heck, F. R.; Russo, R. M.

    1988-01-01

    The scope of the project is the analysis of displacement-rate fields in the transitional regions between cratonal and oceanic lithospheres over Phanerozoic time (last 700 ma). Associated goals are an improved understanding of range of widths of major displacement zones; the partition of displacement gradients and rotations with position and depth in such zones; the temporal characteristics of such zones-the steadiness, episodicity, and duration of uniform versus nonunifrom fields; and the mechanisms and controls of the establishment and kinematics of displacement zones. The objective is to provide a context of time-averaged kinematics of displacement zones. The initial phase is divided topically among the methodology of measurement and reduction of displacements in the lithosphere and the preliminary analysis from geologic and other data of actual displacement histories from the Cordillera, Appalachians, and southern North America.

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

    PubMed Central

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

    2017-01-01

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

  18. 18,000 displacement vectors and 44 positions surveys of RFID tracers show a normal diffusion of the bedload in a proglacial stream (Bossons glacier, France)

    NASA Astrophysics Data System (ADS)

    Guillon, Hervé; Mugnier, Jean-Louis; Buoncristiani, Jean-François

    2016-04-01

    Bedload transport is a stochastic process during which each particle hops for a random length then rests for a random duration. In recent years, this probabilistic approach was investigated by theoretical models, numerical simulations and laboratory experiments. These experiments are generally carried out on short time scales with sand, but underline the diffusive behaviour of the bedload. Conversely, marked pebbles in natural streams have mainly be used to infer about transport processes and transport time of the bedload. In this study, the stochastic characteristics of bedload transport are inferred from the radio-frequency identification (RFID) of pebbles. In particular, we provide insights for answering the following question : is the bedload transport sub-diffusive, normally diffusive or super-diffusive at the long time scale (i.e. global range)? Experiments designed to investigate the phenomenology of bedload transport have been carried out in the proglacial area of Bossons glacier. This 350 m long alluvial plain exhibits daily flood from the glacial system and is still redistributing material from catastrophic events pre-dating our investigations. From 2011 to 2014, the position of the ˜ 1000 RFID tracers have been measured by a mobile antenna and a differential GPS during 44 surveys providing ˜ 2500 tracer positions. Additionnaly, in 2014, 650 new tracers were seeded upstream from a static RFID antenna located at the outlet of the study area. For the 1 to 32 cm fraction surveyed, both mobile and static antenna results show no evidence for a significant export outside of the surveyed zone. Initial data have been maximized by using each possible campaign pairs leading to ˜700 campaign pairs and more than 18,000 displacement vectors. To our knowledge, this is one of the most extensive dataset of tracers positions measured in a natural stream using the RFID methodology. Using 152 campaigns pairs with at least 20 retrieved tracers,r standard probability

  19. A surface displacement analysis for Volcan Pacaya from October 2001 through March 2013 by means of 3-D modeling of precise position GPS data

    NASA Astrophysics Data System (ADS)

    Hetland, Brianna R.

    Volcan Pacaya is one of three currently active volcanoes in Guatemala. Volcanic activity originates from the local tectonic subduction of the Cocos plate beneath the Caribbean plate along the Pacific Guatemalan coast. Pacaya is characterized by generally strombolian type activity with occasional larger vulcanian type eruptions approximately every ten years. One particularly large eruption occurred on May 27, 2010. Using GPS data collected for approximately 8 years before this eruption and data from an additional three years of collection afterwards, surface movement covering the period of the eruption can be measured and used as a tool to help understand activity at the volcano. Initial positions were obtained from raw data using the Automatic Precise Positioning Service provided by the NASA Jet Propulsion Laboratory. Forward modeling of observed 3-D displacements for three time periods (before, covering and after the May 2010 eruption) revealed that a plausible source for deformation is related to a vertical dike or planar surface trending NNW-SSE through the cone. For three distinct time periods the best fitting models describe deformation of the volcano: 0.45 right lateral movement and 0.55 m tensile opening along the dike mentioned above from October 2001 through January 2009 (pre-eruption); 0.55 m left lateral slip along the dike mentioned above for the period from January 2009 and January 2011 (covering the eruption); -0.025 m dip slip along the dike for the period from January 2011 through March 2013 (post-eruption). In all bestfit models the dike is oriented with a 75° westward dip. These data have respective RMS misfit values of 5.49 cm, 12.38 cm and 6.90 cm for each modeled period. During the time period that includes the eruption the volcano most likely experienced a combination of slip and inflation below the edifice which created a large scar at the surface down the northern flank of the volcano. All models that a dipping dike may be experiencing a

  20. Water displacement mercury pump

    DOEpatents

    Nielsen, M.G.

    1984-04-20

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

  1. Water displacement mercury pump

    DOEpatents

    Nielsen, Marshall G.

    1985-01-01

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

  2. Changes in the feed intake, pH and osmolality of rumen fluid, and the position of the abomasum of eight dairy cows during a diet-induced left displacement of the abomasum.

    PubMed

    Van Winden, S C L; Brattinga, C R; Müller, K E; Schonewille, J Th; Noordhuizen, J P T M; Beynen, A C

    2004-04-17

    During the last six weeks of the dry period, eight Holstein-Friesian cows were fed a restricted amount of grass silage; after calving, a mixture of maize silage and concentrates was offered in a feeding regimen designed to induce a displacement of the abomasum. In the first month after calving, the cows were monitored for the following variables: feed intake and composition, milk production, the position of the abomasum, and the pH and osmolality of the rumen contents. In five of the eight cows, a left displacement of the abomasum occurred between four and 21 days after calving in the absence of other diseases. The displacement was temporary, lasting between five and 36 consecutive hours and one or two days in two of the cows (floaters), and for three or more days in the other three. Before these three cows developed the displacement, their abomasum was 4.3 to 7.9 cm higher, its contents had a higher mean osmolality (+19.2 mosmol/kg), and the ratio of roughage to concentrates in their feed was lower (-0.87) than in the three cows that did not develop clinical signs of a displaced abomasum. There were no significant differences in these variables between the floaters and the healthy cows.

  3. Base-Displaced Intercalated Conformation of the 2-Amino-3-methylimidazo[4,5-f]quinoline N(2)-dG DNA Adduct Positioned at the Nonreiterated G(1) in the NarI Restriction Site.

    PubMed

    Stavros, Kallie M; Hawkins, Edward K; Rizzo, Carmelo J; Stone, Michael P

    2015-07-20

    The conformation of an N(2)-dG adduct arising from the heterocyclic amine 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), a potent food mutagen, was determined in 5'-d(C(1)T(2)C(3)X(4)G(5)C(6)G(7)C(8)C(9)A(10)T(11)C(12))-3':5'-d(G(13)A(14)T(15)G(16)G(17)C(18)G(19)C(20)C(21)G(22)A(23)G(24))-3'; X = N(2)-dG-IQ, in which the modified nucleotide X(4) corresponds to G(1) in the 5'-d(G(1)G(2)CG(3)CC)-3' NarI restriction endonuclease site. Circular dichroism (CD) revealed blue shifts relative to the unmodified duplex, consistent with adduct-induced twisting, and a hypochromic effect for the IQ absorbance in the near UV region. NMR revealed that the N(2)-dG-IQ adduct adopted a base-displaced intercalated conformation in which the modified guanine remained in the anti conformation about the glycosidic bond, the IQ moiety intercalated into the duplex, and the complementary base C(21) was displaced into the major groove. The processing of the N(2)-dG-IQ lesion by hpol η is sequence-dependent; when placed at the reiterated G(3) position, but not at the G(1) position, this lesion exhibits a propensity for frameshift replication [Choi, J. Y., et al. (2006) J. Biol. Chem., 281, 25297-25306]. The structure of the N(2)-dG-IQ adduct at the nonreiterated G(1) position was compared to that of the same adduct placed at the G(3) position [Stavros, K. M., et al. (2014) Nucleic Acids Res., 42, 3450-3463]. CD indicted minimal spectral differences between the G(1) vs G(3) N(2)-dG-IQ adducts. NMR indicated that the N(2)-dG-IQ adduct exhibited similar base-displaced intercalated conformations at both the G(1) and G(3) positions. This result differed as compared to the corresponding C8-dG-IQ adducts placed at the same positions. The C8-dG-IQ adduct adopted a minor groove conformation when placed at position G(1) but a base-displaced intercalated conformation when placed at position G(3) in the NarI sequence. The present studies suggest that differences in lesion bypass by hpol η may be

  4. Base-Displaced Intercalated Conformation of the 2-Amino-3-methylimidazo[4,5-f]quinoline N2-dG DNA Adduct Positioned at the Nonreiterated G1 in the NarI Restriction Site

    PubMed Central

    2016-01-01

    The conformation of an N2-dG adduct arising from the heterocyclic amine 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), a potent food mutagen, was determined in 5′-d(C1T2C3X4G5C6G7C8C9A10T11C12)-3′:5′-d(G13A14T15G16G17C18G19C20C21G22A23G24)-3′; X = N2-dG-IQ, in which the modified nucleotide X4 corresponds to G1 in the 5′-d(G1G2CG3CC)-3′ NarI restriction endonuclease site. Circular dichroism (CD) revealed blue shifts relative to the unmodified duplex, consistent with adduct-induced twisting, and a hypochromic effect for the IQ absorbance in the near UV region. NMR revealed that the N2-dG-IQ adduct adopted a base-displaced intercalated conformation in which the modified guanine remained in the anti conformation about the glycosidic bond, the IQ moiety intercalated into the duplex, and the complementary base C21 was displaced into the major groove. The processing of the N2-dG-IQ lesion by hpol η is sequence-dependent; when placed at the reiterated G3 position, but not at the G1 position, this lesion exhibits a propensity for frameshift replication [Choi, J. Y., et al. (2006) J. Biol. Chem., 281, 25297–25306]. The structure of the N2-dG-IQ adduct at the nonreiterated G1 position was compared to that of the same adduct placed at the G3 position [Stavros, K. M., et al. (2014) Nucleic Acids Res., 42, 3450–3463]. CD indicted minimal spectral differences between the G1 vs G3N2-dG-IQ adducts. NMR indicated that the N2-dG-IQ adduct exhibited similar base-displaced intercalated conformations at both the G1 and G3 positions. This result differed as compared to the corresponding C8-dG-IQ adducts placed at the same positions. The C8-dG-IQ adduct adopted a minor groove conformation when placed at position G1 but a base-displaced intercalated conformation when placed at position G3 in the NarI sequence. The present studies suggest that differences in lesion bypass by hpol η may be mediated by differences in the 3′-flanking sequences, perhaps modulating the ability

  5. Positioning.

    ERIC Educational Resources Information Center

    Conone, Ruth M.

    The key to positioning is the creation of a clear benefit image in the consumer's mind. One positioning strategy is creating in the prospect's mind a position that takes into consideration the company's or agency's strengths and weaknesses as well as those of its competitors. Another strategy is to gain entry into a position ladder owned by…

  6. Variable displacement blower

    DOEpatents

    Bookout, Charles C.; Stotts, Robert E.; Waring, Douglass R.; Folsom, Lawrence R.

    1986-01-01

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

  7. Arthroscopic treatment of displaced tibial eminence fractures using a suspensory fixation

    PubMed Central

    Loriaut, Philippe; Moreau, Pierre-Emmanuel; Loriaut, Patrick; Boyer, Patrick

    2017-01-01

    Background: Avulsion fractures of the tibial intercondylar eminence are fairly common injuries requiring surgery for the optimal functional outcome. The purpose of this study was to assess the clinical and radiological outcomes of an arthroscopic treatment of displaced tibial intercondylar eminence fractures using a suspensory device. Material and Methods: Five patients with type 2 and 3 displaced tibial intercondylar eminence fractures who received an arthroscopically assisted fixation using a double button device were enrolled from 2011 to 2012. Clinical assessment included the patient demographics, cause of injury, the delay before surgery, time for surgery, time to return to work and sport, the International Knee Documentation Committee (IKDC) and Lysholm knee scores. Stability was measured with the KT-2000 arthrometer with a force of 134 N. A side to side difference on the KT-2000 examination superior to 3 mm was considered as a significant and abnormal increase in the anterior translation. Radiological examination consisted of anteroposterior and lateral radiographs, as well as computed tomography (CT) scan of the affected knee. Clinical and radiological followup was done at 1, 2, 3, 6, and 12 months postoperatively and at final followup. CT-scan was performed before surgery and at 3 months followup. Results: The median age of patients was 31 years. Mean followup was 27 ± 5.1 months. The average delay before surgery was 3 days. At final followup, the mean IKDC and Lysholm knee scores were, 93.9 and 94.5 respectively. All patients had a complete functional recovery and were able to return to work and to resume their sport activities. No secondary surgeries were required to remove hardware. No complication was noted. Bony union was achieved in all patients. Conclusion: The arthroscopic treatment of displaced tibial intercondylar eminence fractures using a suspensory system provided a satisfactory clinical and radiological outcome at a followup of 2 years.

  8. Kinematics of the upper cervical spine during high velocity-low amplitude manipulation. Analysis of intra- and inter-operator reliability for pre-manipulation positioning and impulse displacements.

    PubMed

    Dugailly, Pierre-Michel; Beyer, Benoît; Sobczak, Stéphane; Salvia, Patrick; Rooze, Marcel; Feipel, Véronique

    2014-10-01

    To date, kinematics data analyzing continuous 3D motion of upper cervical spine (UCS) manipulation is lacking. This in vitro study aims at investigating inter- and intra-operator reliability of kinematics during high velocity low amplitude manipulation of the UCS. Three fresh specimens were used. Restricted dissection was realized to attach technical clusters to each bone (skull to C2). Motion data was obtained using an optoelectronic system during manipulation. Kinematics data were integrated into specific-subject 3D models to provide anatomical motion representation during thrust manipulation. The reliability of manipulation kinematics was assessed for three practitioners performing two sessions of three repetitions on two separate days. For pre-manipulation positioning, average UCS ROM (SD) were 10° (5°), 22° (5°) and 14° (4°) for lateral bending, axial rotation and flexion-extension, respectively. For the impulse phase, average axial rotation magnitude ranged from 7° to 12°. Reliability analysis showed average RMS up to 8° for pre-manipulation positioning and up to 5° for the impulse phase. As compared to physiological ROM, this study supports the limited angular displacement during manipulation for UCS motion components, especially for axial rotation. Kinematics reliability confirms intra- and inter-operator consistency although pre-manipulation positioning reliability is slightly lower between practitioners and sessions.

  9. Positive Displacement Compressor Technology for Air Congitioners

    NASA Astrophysics Data System (ADS)

    Nagatomo, Shigemi

    Trends of compressor technologies for air conditioners are presented in this paper. HFC refrigerants such is R410A and R407C are promising candidates as an alternative for R22. Performance of rotary and scroll compressors in the operation with R410A and R407C are described. In addition, compressor technologies such as efficiency improvement, reliability and simulation methods are described in both cases of rotary and scroll compressors. Advanced compressor technologies developed for air conditioners are desired in the field of the global environment protection and the energy saving.

  10. Positive displacement electronic fuel injection pump

    SciTech Connect

    Schechter, M.M.

    1986-04-22

    A fuel injection pump is described of the plunger, spill port type, including a single plunger reciprocably and rotatably mounted in a plunger barrel, an engine driven camshaft having gear means and a number of camlobes thereon for reciprocating and rotating the plunger a number of times for each revolution of the camshaft through a number of pumping upstrokes and fuel intake downstrokes for injecting fuel sequentially into a number of engine cylinders. The plunger barrel defines a fuel fill-spill chamber at the end of the plunger connected to a solenoid valve controlled spill port for pressurization of the chamber during the upstroke of the plunger upon closure of the spill port by the valve, the plunger having a number of internal axially spaced passages connected to the chamber for filling the chamber with fuel on the fuel intake upstroke of the plunger or alternately directing fuel from the chamber to a fuel injection nozzle during pressurization of the chamber, means connecting one of the internal passages to a fuel supply passage and another passage to a fuel injection nozzle line past a check valve in the other passage. The passages are spaced such that rotation and reciprocation of the plunger through one stroke connects the chamber to one passage which disconnecting the chamber from the other passage, and vice-versa during the next successive stroke of the plunger, the other passage being connected successively one at a time to each injection line in the engine upon rotation of the camshaft, the engine having at least four cylinders, and the camshaft having four camlobes on a single cam, the lobes each being 90% in extent with a peak and an essentially long flat surface inbetween peaks providing a slower upstroke of the plunger than the downstroke thereby providing a longer time for injection than for fuel intake.

  11. Perceived displacement explains wolfpack effect

    PubMed Central

    Šimkovic, Matúš; Träuble, Birgit

    2014-01-01

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

  12. The effect of a trunk release maneuver on Peak Pressure Index, trunk displacement and perceived discomfort in older adults seated in a high Fowler’s position: a randomized controlled trial

    PubMed Central

    2012-01-01

    Background Pressure ulcers pose significant negative individual consequences and financial burden on the healthcare system. Prolonged sitting in High Fowler’s position (HF) is common clinical practice for older adults who spend extended periods of time in bed. While HF aids in digestion and respiration, being placed in a HF may increase perceived discomfort and risk of pressure ulcers due to increased pressure magnitude at the sacral and gluteal regions. It is likely that shearing forces could also contribute to risk of pressure ulcers in HF. The purpose of this study was to evaluate the effect of a low-tech and time-efficient Trunk Release Manuever (TRM) on sacral and gluteal pressure, trunk displacement and perceived discomfort in ambulatory older adults. Method A randomized controlled trial was used. We recruited community-living adults who were 60 years of age and older using posters, newspaper advertisements and word-of-mouth. Participants were randomly allocated to either the intervention or control group. The intervention group (n = 59) received the TRM, while the control group (n = 58) maintained the standard HF position. Results The TRM group had significantly lower mean (SD) PPI values post-intervention compared to the control group, 59.6 (30.7) mmHg and 79.9 (36.5) mmHg respectively (p = 0.002). There was also a significant difference in trunk displacement between the TRM and control groups, +3.2 mm and −5.8 mm respectively (p = 0.005). There were no significant differences in perceived discomfort between the groups. Conclusion The TRM was effective for reducing pressure in the sacral and gluteal regions and for releasing the trunk at the point of contact between the skin and the support surface, but did not have an effect on perceived discomfort. The TRM is a simple method of repositioning which may have important clinical application for the prevention of pressure ulcers that may occur as a result of HF. PMID:23157714

  13. Displacement data assimilation

    NASA Astrophysics Data System (ADS)

    Rosenthal, W. Steven; Venkataramani, Shankar; Mariano, Arthur J.; Restrepo, Juan M.

    2017-02-01

    We show that modifying a Bayesian data assimilation scheme by incorporating kinematically-consistent displacement corrections produces a scheme that is demonstrably better at estimating partially observed state vectors in a setting where feature information is important. While the displacement transformation is generic, here we implement it within an ensemble Kalman Filter framework and demonstrate its effectiveness in tracking stochastically perturbed vortices.

  14. Internal displacement in Colombia: Fifteen distinguishing features.

    PubMed

    Shultz, James M; Ceballos, Ángela Milena Gómez; Espinel, Zelde; Oliveros, Sofia Rios; Fonseca, Maria Fernanda; Florez, Luis Jorge Hernandez

    2014-01-01

    This commentary aims to delineate the distinguishing features of conflict-induced internal displacement in the nation of Colombia, South America. Even as Colombia is currently implementing a spectrum of legal, social, economic, and health programs for "victims of armed conflict," with particular focus on internally displaced persons (IDPs), the dynamics of forced migration on a mass scale within this country are little known beyond national borders.   The authors of this commentary are embarking on a global mental health research program in Bogota, Colombia to define best practices for reaching the displaced population and implementing sustainable, evidence-based screening and intervention for common mental disorders. Presenting the defining characteristics of internal displacement in Colombia provides the context for our work and, more importantly, conveys the compelling and complex nature of this humanitarian crisis. We attempt to demonstrate Colombia's unique position within the global patterning of internal displacement.

  15. Advanced Triangulation Displacement Sensors

    NASA Technical Reports Server (NTRS)

    Poteet, Wade M.; Cauthen, Harold K.

    1996-01-01

    Advanced optoelectronic triangulation displacement sensors undergoing development. Highly miniaturized, more stable, more accurate, and relatively easy to use. Incorporate wideband electronic circuits suitable for real-time monitoring and control of displacements. Measurements expected to be accurate to within nanometers. In principle, sensors mass-produced at relatively low unit cost. Potential applications numerous. Possible industrial application in measuring runout of rotating shaft or other moving part during fabrication in "zero-defect" manufacturing system, in which measured runout automatically corrected.

  16. Internal displacement in Burma.

    PubMed

    Lanjouw, S; Mortimer, G; Bamforth, V

    2000-09-01

    The internal displacement of populations in Burma is not a new phenomenon. Displacement is caused by numerous factors. Not all of it is due to outright violence, but much is a consequence of misguided social and economic development initiatives. Efforts to consolidate the state by assimilating populations in government-controlled areas by military authorities on the one hand, while brokering cease-fires with non-state actors on the other, has uprooted civilian populations throughout the country. Very few areas in which internally displaced persons (IDPs) are found are not facing social turmoil within a climate of impunity. Humanitarian access to IDP populations remains extremely problematic. While relatively little information has been collected, assistance has been focused on targeting accessible groups. International concern within Burma has couched the problems of displacement within general development modalities, while international attention along its borders has sought to contain displacement. With the exception of several recent initiatives, few approaches have gone beyond assistance and engaged in the prevention or protection of the displaced.

  17. Optical displacement sensor

    DOEpatents

    Carr, Dustin W.

    2008-04-08

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

  18. Displaced Homemakers: Unresolved Issues.

    ERIC Educational Resources Information Center

    Zawada, Mary Ann

    1980-01-01

    Problems of today's displaced homemakers overlap with those of women in the 1960s. Problems of women seeking employment are similar to those of minority groups, older workers and welfare recipients. Recent legislation has expanded to fulfill some of the needs of women returning to the labor force. (Author/BEF)

  19. RTV 21 Displacements

    SciTech Connect

    Kurita, C.H.; /Fermilab

    1987-02-04

    A seal is needed for the cover of the Nitrogen Test Vessel in order to prevent leakage of the N{sub 2} gas. This seal is to be molded out of RTV 21. In this experiment, the Modulus of Elasticity of the RTV was sought after, and the displacements of the RTV due to various stresses were measured to see if they were large enough to provide a tight seal between the vessel and its cover.

  20. The photoelectric displacement converter

    NASA Astrophysics Data System (ADS)

    Dragoner, Valeriu V.

    2005-02-01

    In the article are examined questions of constructing photoelectric displacement converter satisfying demands that are stated above. Converter has channels of approximate and precise readings. The approximate reading may be accomplished either by the method of reading from a code mask or by the method of the consecutive calculation of optical scale gaps number. Phase interpolator of mouar strips" gaps is determined as a precise measuring. It is shown mathematical model of converter that allow evaluating errors and operating speed of conversion.

  1. Tunable beam displacer

    SciTech Connect

    Salazar-Serrano, Luis José; Valencia, Alejandra; Torres, Juan P.

    2015-03-15

    We report the implementation of a tunable beam displacer, composed of a polarizing beam splitter (PBS) and two mirrors, that divides an initially polarized beam into two parallel beams whose separation can be continuously tuned. The two output beams are linearly polarized with either vertical or horizontal polarization and no optical path difference is introduced between them. The wavelength dependence of the device as well as the maximum separation between the beams achievable is limited mainly by the PBS characteristics.

  2. Variable displacement vane pump

    SciTech Connect

    Tschantz, J.S.; Bisson, B.J.

    1997-12-31

    What has been developed under this program is a pumping system which can vary the amount of fuel delivered according to engine needs, thereby reducing the temperature rise of the fuel to very low levels. This permits the elimination of the air/oil coolers and conserves the vital airflow through the fan. The variable displacement vane pump (VDVP) also permits a substantial simplification of the control system with the elimination of complex metering valves, offering a significant reduction in fuel system cost. This program was initiated to develop a technology that embodied the ruggedness of the gear pump with the efficiency and metering versatility of the variable displacement vane pump. Thick metal vanes emulate the teeth on pumping gears while the simple, elegant swing cam feature provides the variable displacement capability without the unwieldy multiple cam segments found in other concepts. The result is a pumping architecture which is rugged, light in weight and extremely versatile, having demonstrated superb heat management and controllability in extensive bench and engine testing. This paper will report the results that the pumps have achieved to date both in terms of durability and efficiency.

  3. Variable delivery, fixed displacement pump

    SciTech Connect

    Sommars, Mark F.

    2001-01-01

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

  4. An electromechanical displacement transducer

    NASA Astrophysics Data System (ADS)

    Villiers, Marius; Mahboob, Imran; Nishiguchi, Katsuhiko; Hatanaka, Daiki; Fujiwara, Akira; Yamaguchi, Hiroshi

    2016-08-01

    Two modes of an electromechanical resonator are coupled through the strain inside the structure with a cooperativity as high as 107, a state-of-the-art value for purely mechanical systems, which enables the observation of normal-mode splitting. This coupling is exploited to transduce the resonator’s fundamental mode into the bandwidth of the second flexural mode, which is 1.4 MHz higher in frequency. Thus, an all-mechanical heterodyne detection scheme is implemented that can be developed into a high-precision displacement sensor.

  5. Computing Displacements And Strains From Video Images

    NASA Technical Reports Server (NTRS)

    Russell, Samuel S.; Mcneill, Stephen R.; Lansing, Matthew D.

    1996-01-01

    Subpixel digital video image correlation (SDVIC) technique for measuring in-plane displacements on surfaces of objects under loads, without contact. Used for analyses of experimental research specimens or actual service structures of virtually any size or material. Only minimal preparation of test objects needed, and no need to isolate test objects from minor vibrations or fluctuating temperatures. Technique implemented by SDVIC software, producing color-graduated, full-field representations of in-plane displacements and partial derivatives with respect to position along both principal directions in each image plane. From representations, linear strains, shear strains, and rotation fields determined. Written in C language.

  6. Angular displacement measuring device

    NASA Technical Reports Server (NTRS)

    Seegmiller, H. Lee B. (Inventor)

    1992-01-01

    A system for measuring the angular displacement of a point of interest on a structure, such as aircraft model within a wind tunnel, includes a source of polarized light located at the point of interest. A remote detector arrangement detects the orientation of the plane of the polarized light received from the source and compares this orientation with the initial orientation to determine the amount or rate of angular displacement of the point of interest. The detector arrangement comprises a rotating polarizing filter and a dual filter and light detector unit. The latter unit comprises an inner aligned filter and photodetector assembly which is disposed relative to the periphery of the polarizer so as to receive polarized light passing the polarizing filter and an outer aligned filter and photodetector assembly which receives the polarized light directly, i.e., without passing through the polarizing filter. The purpose of the unit is to compensate for the effects of dust, fog and the like. A polarization preserving optical fiber conducts polarized light from a remote laser source to the point of interest.

  7. Angular displacement measuring device

    NASA Astrophysics Data System (ADS)

    Seegmiller, H. Lee B.

    1992-08-01

    A system for measuring the angular displacement of a point of interest on a structure, such as aircraft model within a wind tunnel, includes a source of polarized light located at the point of interest. A remote detector arrangement detects the orientation of the plane of the polarized light received from the source and compares this orientation with the initial orientation to determine the amount or rate of angular displacement of the point of interest. The detector arrangement comprises a rotating polarizing filter and a dual filter and light detector unit. The latter unit comprises an inner aligned filter and photodetector assembly which is disposed relative to the periphery of the polarizer so as to receive polarized light passing the polarizing filter and an outer aligned filter and photodetector assembly which receives the polarized light directly, i.e., without passing through the polarizing filter. The purpose of the unit is to compensate for the effects of dust, fog and the like. A polarization preserving optical fiber conducts polarized light from a remote laser source to the point of interest.

  8. Forced displacement and women's security in Colombia.

    PubMed

    Meertens, Donny

    2010-04-01

    In the protracted Colombian conflict, assistance to internally displaced persons has developed in the context of contradictory political processes. The Colombian government's launching of a transitional justice process in the midst of armed conflict has generated a complex situation displaying both conflict and post-conflict characteristics. The progressive Constitutional Court rulings on internal displacement, in particular the gender-sensitive Auto 092, constitute an attempt to bring together humanitarian interventions and transitional justice measures in a rights-based framework. However, the national government is reluctant to adopt them fully and local realities still hamper their integrated implementation. Displaced women, therefore, remain in an especially vulnerable position. This paper argues that gender-sensitive humanitarian interventions must take into account all of these complexities of scale and political process in order to make legal frameworks more effective at the local level. In these contexts, interventions should pay particular attention to strategies that contribute to transforming pre-existing gender regimes.

  9. Anterior condylar displacement: its diagnosis and treatment.

    PubMed

    Weinberg, L A

    1975-08-01

    A deflective slide in centric relation to centric occlusion does not necessarily mean anterior condylar displacement. Its diagnosis and treatment depend on the correlation of three factors: the direction and magnitude of the mandibular slide from centric relation to centric occlusion, the change in vertical dimension of occlusion during the slide, and the position of the condyles in the fossae when the teeth are in the maximum occlusion (centric occlusion). When the change in vertical dimension almost equals to amount of slide from the deflective contact in centric relation to maximum intercuspation, very little anterior condylar displacement would be expected. Conversely, with proportionately little change in vertical dimension, more anterior condylar translation is required for a given degree of anterior slide. Examples of each type of anterior slide were related to the TMJ radiographs of the condylar position. If the direction and magnitude of the deflective occlusal contact can be correlated with the TMJ radiographs, the centric relation is "functional,'' and the clinically retruded mandibular position should be used. When this correlation does not exist, the centric relation is "dysfunctional'' and the terminal hinge position (retruded mandibular position) should not be used for restorative or corrective procedures. Examples of anterior condylar displacement were given, including deviation, with a comparison of "before'' and "after'' TMJ radiographs.

  10. Fiber optic multimode displacement sensor

    NASA Astrophysics Data System (ADS)

    Fisher, Karl A.; Jarzynski, Jacek

    1996-04-01

    An underwater Optical Motion Sensor (OMS) based on a design first presented by W. B. Spillman, Schlieren multimode fiber-optic hydrophone, Applied Physics Letters 37(2), 15 July 1980, p. 145-146 is described. The displacement sensor uses the same acoustooptical intensity modulation mechanism as Spillman, however the sensing mechanism is isolated from the ambient fluid environment by a small cylindrical aluminum enclosure (1″ OD×3/4″). The enclosure contains an inertial mass and the fiber collimators. The inertial mass is suspended in the center of the enclosure by three small wires rigidly mounted to the walls. The mass and wires act as a cantilever beam system with a mechanical resonance near 100 Hz. The transduction mechanism consists of two opposed optical gratings aligned and positioned between the fiber collimators. One grating is mounted on the inertial mass while the other is mounted on the lower end cap of the enclosure. Relative motion between the gratings causes a modulation of the light transmitted through the gratings. The modulated beam is focused onto a photodetector and converted to electric current. The frequency response is flat from 200 Hz-9 kHz with a minimum detectable displacement of 0.002 A and the dynamic range is 136 dB. The small size and light weight give the sensor an effective density of 1.08 g/cm3 making it almost neutrally buoyant in water. This in conjunction with the performance characteristics make this sensor suitable for use in acoustical sensing applications.

  11. Displacement parameter inversion for a novel electromagnetic underground displacement sensor.

    PubMed

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

    2014-05-22

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

  12. Measuring vulnerability to disaster displacement

    NASA Astrophysics Data System (ADS)

    Brink, Susan A.; Khazai, Bijan; Power, Christopher; Wenzel, Friedemann

    2015-04-01

    Large scale disasters can cause devastating impacts in terms of population displacement. Between 2008 and 2013, on average 27 million people were displaced annually by disasters (Yonetani 2014). After large events such as hurricane Katrina or the Port-au-Prince earthquake, images of inadequate public shelter and concerns about large scale and often inequitable migration have been broadcast around the world. Population displacement can often be one of the most devastating and visible impacts of a natural disaster. Despite the importance of population displacement in disaster events, measures to understand the socio-economic vulnerability of a community often use broad metrics to estimate the total socio-economic risk of an event rather than focusing on the specific impacts that a community faces in a disaster. Population displacement is complex and multi-causal with the physical impact of a disaster interacting with vulnerability arising from the response, environmental issues (e.g., weather), cultural concerns (e.g., expectations of adequate shelter), and many individual factors (e.g., mobility, risk perception). In addition to the complexity of the causes, population displacement is difficult to measure because of the wide variety of different terms and definitions and its multi-dimensional nature. When we speak of severe population displacement, we may refer to a large number of displaced people, an extended length of displacement or associated difficulties such as poor shelter quality, risk of violence and crime in shelter communities, discrimination in aid, a lack of access to employment or other difficulties that can be associated with large scale population displacement. We have completed a thorough review of the literature on disaster population displacement. Research has been conducted on historic events to understand the types of negative impacts associated with population displacement and also the vulnerability of different groups to these impacts. We

  13. Factors affecting self-eruption of displaced permanent maxillary canines.

    PubMed

    Smailienė, Dalia; Sidlauskas, Antanas; Lopatienė, Kristina; Guzevičienė, Vesta; Juodžbalys, Gintaras

    2011-01-01

    The aim of this study was to examine the possibility of the spontaneous eruption of displaced unerupted maxillary canines after the extraction of the deciduous canine and dental arch expansion and to determine the impact of initial canine position on treatment success rate. Materials and METHODS. The study sample included 50 patients (mean age, 13.5 years [SD, 2.2]) with unilaterally displaced unerupted maxillary canines. Deciduous canines were extracted, and the space for displaced canine was created at the beginning of the study. The follow-up period for the spontaneous eruption was 12 months. The initial vertical, horizontal, labio-palatal position and angle of inclination to the midline of the displaced canine were assessed on panoramic radiographs. RESULTS. Only 42% of displaced canines erupted spontaneously within one-year period (52.9% of labially displaced canines and 36.4% of palatally displaced canines). A significant difference of inclination was determined between spontaneously erupted and unerupted teeth in the labially displaced canine group (P<0.01), with no difference in the palatally displaced canine group. The receiver operating characteristic curve analysis showed that the critical angle of inclination for the spontaneous eruption of the retained canine was 20º (sensitivity 0.759; specificity 0.571; P<0.05). The majority of unerupted canines (75.9%) were inclined more than 20º. The initial height of canine was crucial for spontaneous eruption (sensitivity 0.966; specificity 0.81; P<0.001). This was true for both palatal and labial cases. CONCLUSIONS. The initial vertical position of the labially and palatally displaced canines and the inclination of the labially displaced canines were the most important predictors for spontaneous eruption of the cuspid.

  14. Membrane position control

    NASA Technical Reports Server (NTRS)

    Su, Ji (Inventor); Harrison, Joycelyn S. (Inventor)

    2004-01-01

    A membrane structure includes at least one electroactive bending actuator fixed to a supporting base. Each electroactive bending actuator is operatively connected to the membrane for controlling membrane position. Any displacement of each electroactive bending actuator effects displacement of the membrane. More specifically, the operative connection is provided by a guiding wheel assembly and a track, wherein displacement of the bending actuator effects translation of the wheel assembly along the track, thereby imparting movement to the membrane.

  15. Isothermal Multiple Displacement Amplification

    PubMed Central

    Luthra, Rajyalakshmi; Medeiros, L. Jeffrey

    2004-01-01

    Isothermal multiple strand displacement amplification (IMDA) of the whole human genome is a promising method for procuring abundant DNA from valuable and often limited clinical specimens. However, whether DNA generated by this method is of high quality and a faithful replication of the DNA in the original specimen, allowing for subsequent molecular diagnostic testing, requires verification. In this study, we evaluated the suitability of IMDA-generated DNA (IMDA-DNA) for detecting antigen receptor gene rearrangements, chromosomal translocations, and gene mutations using Southern blot analysis, polymerase chain reaction (PCR) methods, or sequencing methods in 28 lymphoma and leukemia clinical specimens. Molecular testing before and after whole genome amplification of these specimens using the IMDA technique showed concordance in 27 of 28 (96%) specimens. Analysis of IMDA-DNA by Southern blot analysis detected restriction fragments >12 kilobases long. No amplification bias was observed at all loci tested demonstrating that this method can be useful in generating large amounts of unbiased, high molecular weight DNA from limited clinical specimens. PMID:15269301

  16. Laser optical displacement system

    NASA Astrophysics Data System (ADS)

    Starritt, Larry W.; Matthews, Larryl K.

    1995-04-01

    The current quality of our nations bridges is on a decline. There are roughly half a million highway bridges in the United States and out of the half a million more than 200,000 are deficient. With catastrophic failure of bridges causing the loss of life and property, the need for bridge inspection and maintenance is evident. When the Silver Bridge that crossed the Ohio River collapsed in December 1967, 46 people were killed. The failure to prevent the disaster was attributed to the poor inspection techniques used by the bridge inspectors. Current inspection techniques depend on humans being able to recognize structural imperfections without the aid of instrumentation. The Federal-Aid Highway Act of 1968 mandated both national bridge inspection standards and training for bridge inspectors. This act has encouraged the development of instruments that would allow inspectors to perform more complete inspections of bridges. To improve the quality of inspection and data, there is a great need for proven methods and instruments used to acquire data. The Laser Optical Displacement System (L.O.D.S.) developed at New Mexico State University by the Optical and Materials Science Lab is such a device. The L.O.D.S. has been tested and proven in both laboratory situations and in the field. This paper describes some of the methods that are now being used to measure deflections in bridges. Then, a description of the development and application of the L.O.D.S. unit is given.

  17. The displacement estimation error back-propagation (DEEP) method for a multiple structural displacement monitoring system

    NASA Astrophysics Data System (ADS)

    Jeon, H.; Shin, J. U.; Myung, H.

    2013-04-01

    Visually servoed paired structured light system (ViSP) has been found to be useful in estimating 6-DOF relative displacement. The system is composed of two screens facing each other, each with one or two lasers, a 2-DOF manipulator and a camera. The displacement between two sides is estimated by observing positions of the projected laser beams and rotation angles of the manipulators. To apply the system to massive structures, the whole area should be partitioned and each ViSP module is placed in each partition in a cascaded manner. The estimated displacement between adjoining ViSPs is combined with the next partition so that the entire movement of the structure can be estimated. The multiple ViSPs, however, have a major problem that the error is propagated through the partitions. Therefore, a displacement estimation error back-propagation (DEEP) method which uses Newton-Raphson or gradient descent formulation inspired by the error back-propagation algorithm is proposed. In this method, the estimated displacement from the ViSP is updated using the error back-propagated from a fixed position. To validate the performance of the proposed method, various simulations and experiments have been performed. The results show that the proposed method significantly reduces the propagation error throughout the multiple modules.

  18. Displacement behaviour regulates the experience of stress in men.

    PubMed

    Mohiyeddini, Changiz; Semple, Stuart

    2013-03-01

    Behavioural coping strategies represent a key means by which people regulate their stress levels. Attention has recently focused on the potential role in coping of 'displacement behaviour' - activities such as scratching, lip biting and face touching. Increased levels of displacement behaviour are associated with feelings of anxiety and stress; however, the extent to which displacement behaviour, as a short-term behavioural response to emotionally challenging stimuli, influences the subsequent experience of stress remains poorly understood. The aim of this study was to investigate the potential role of displacement behaviour in coping with stress. In a study population of 42 healthy adult men (mean age = 28.09 years, SD = 7.98), we quantified displacement behaviour during a Trier Social Stress Test (TSST), and used self-report questionnaires to assess trait and state anxiety before the TSST, and the experience of stress afterwards. We predicted displacement behaviour would diminish the negative impact of the stressful situation, and hence be associated with lower post-TSST stress levels. Furthermore, we predicted displacement behaviour would mediate the link between state and trait anxiety on the one hand and the experience of stress on the other. Results showed the rate of displacement behaviour was positively correlated with state anxiety but unrelated to trait anxiety, and negatively correlated with the self-reported experience of stress, in agreement with the idea that displacement behaviour has a crucial impact on regulation of stress. Moreover, serial mediation analyses using a bias-corrected bootstrapping approach indicated displacement behaviour mediated the relationship between state anxiety and the experience of stress, and that state anxiety and displacement behaviour - in combination, respectively - mediated the link between trait anxiety and experience of stress. These results shed important new light on the function of displacement behaviour, and

  19. Displacement, Substitution, Sublimation: A Bibliography.

    ERIC Educational Resources Information Center

    Pedrini, D. T.; Pedrini, Bonnie C.

    Sigmund Freund worked with the mechanisms of displacement, substitution, and sublimation. These mechanisms have many similarities and have been studied diagnostically and therapeutically. Displacement and substitution seem to fit in well with phobias, hysterias, somatiyations, prejudices, and scapegoating. Phobias, prejudices, and scapegoating…

  20. Insect Wing Displacement Measurement Using Digital Holography

    SciTech Connect

    Aguayo, Daniel D.; Mendoza Santoyo, Fernando; Torre I, Manuel H. de la; Caloca Mendez, Cristian I.

    2008-04-15

    Insects in flight have been studied with optical non destructive techniques with the purpose of using meaningful results in aerodynamics. With the availability of high resolution and large dynamic range CCD sensors the so called interferometric digital holographic technique was used to measure the surface displacement of in flight insect wings, such as butterflies. The wings were illuminated with a continuous wave Verdi laser at 532 nm, and observed with a CCD Pixelfly camera that acquire images at a rate of 11.5 frames per second at a resolution of 1392x1024 pixels and 12 Bit dynamic range. At this frame rate digital holograms of the wings were captured and processed in the usual manner, namely, each individual hologram is Fourier processed in order to find the amplitude and phase corresponding to the digital hologram. The wings displacement is obtained when subtraction between two digital holograms is performed for two different wings position, a feature applied to all consecutive frames recorded. The result of subtracting is seen as a wrapped phase fringe pattern directly related to the wing displacement. The experimental data for different butterfly flying conditions and exposure times are shown as wire mesh plots in a movie of the wings displacement.

  1. Programmable energy landscapes for kinetic control of DNA strand displacement.

    PubMed

    Machinek, Robert R F; Ouldridge, Thomas E; Haley, Natalie E C; Bath, Jonathan; Turberfield, Andrew J

    2014-11-10

    DNA is used to construct synthetic systems that sense, actuate, move and compute. The operation of many dynamic DNA devices depends on toehold-mediated strand displacement, by which one DNA strand displaces another from a duplex. Kinetic control of strand displacement is particularly important in autonomous molecular machinery and molecular computation, in which non-equilibrium systems are controlled through rates of competing processes. Here, we introduce a new method based on the creation of mismatched base pairs as kinetic barriers to strand displacement. Reaction rate constants can be tuned across three orders of magnitude by altering the position of such a defect without significantly changing the stabilities of reactants or products. By modelling reaction free-energy landscapes, we explore the mechanistic basis of this control mechanism. We also demonstrate that oxDNA, a coarse-grained model of DNA, is capable of accurately predicting and explaining the impact of mismatches on displacement kinetics.

  2. Regenerative rotary displacer Stirling engine

    SciTech Connect

    Isshiki, Naotsugu; Watanabe, Hiroichi; Raggi, L.; Isshiki, Seita; Hirata, Koichi

    1996-12-31

    A few rotary displacer Stirling engines in which the displacer has one gas pocket space at one side and rotates in a main enclosed cylinder, which is heated from one side and cooled from opposite side without any regenerator, have been studied for some time by the authors. The authors tried to improve this engine by equipping it with a regenerator, because without a regenerator, pressure oscillation and efficiency are too small. Here, several types of regenerative rotary displacer piston Stirling engines are proposed. One is the contra-rotating tandem two disc type displacer engine using axial heat conduction through side walls or by heat pipes and another is a single disc type with circulating fluid regenerator or heat pipes. Stirling engines of this new rotary displacer type are thought to attain high speed. Here, experimental results of the original rotary displacer Stirling engine without a regenerator, and one contra-rotating tandem displacer engine with side wall regenerator by axial heat conduction are reported accompanied with a discussion of the results.

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

    PubMed

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

    2014-05-01

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

  4. Wireless Measurement of Rotation and Displacement Rate

    NASA Technical Reports Server (NTRS)

    Woodard, Stanley E.; Taylor, Bryant D.

    2007-01-01

    A magnetic field response sensor is designed to measure displacement or rotation rate without a physical connection to a power source, microprocessor, data acquisition equipment, or electrical circuitry. The sensor works with the magnetic field response recorder, which was described in Magnetic-Field-Response Measurement-Acquisition System, NASA Tech Briefs, Vol. 30, No. 6 (June 2006), page 28. These sensors are wirelessly powered and interrogated, and the measurement acquisition system and sensors are extremely lightweight.The response recorder uses oscillating magnetic fields to power the sensors. Once powered, the sensors respond with their own magnetic field. For displacement/ rotation measurements, the response recorder uses the sensor s response amplitude, which is dependent on the distance from the antenna. The recorder s antenna orientation and position are kept fixed, and the sampling period is constant.

  5. Displacement sensing system and method

    DOEpatents

    VunKannon, Jr., Robert S

    2006-08-08

    A displacement sensing system and method addresses demanding requirements for high precision sensing of displacement of a shaft, for use typically in a linear electro-dynamic machine, having low failure rates over multi-year unattended operation in hostile environments. Applications include outer space travel by spacecraft having high-temperature, sealed environments without opportunity for servicing over many years of operation. The displacement sensing system uses a three coil sensor configuration, including a reference and sense coils, to provide a pair of ratio-metric signals, which are inputted into a synchronous comparison circuit, which is synchronously processed for a resultant displacement determination. The pair of ratio-metric signals are similarly affected by environmental conditions so that the comparison circuit is able to subtract or nullify environmental conditions that would otherwise cause changes in accuracy to occur.

  6. Lucky interferometry for displacement measurement

    NASA Astrophysics Data System (ADS)

    Ioniţă, Bogdan; Logofătu, Petre Cătălin; Apostol, Dan

    2009-11-01

    We extrapolated the lucky imaging technique, mostly used in astronomy, to the field of interferometry for displacement measurement. From the batch of interferograms generated by a Twyman-Green-type interferometer and acquired by a CCD camera, those with high overall contrast were selected and fitted to a sinusoidal function. The high-contrast interferograms showed a significantly lower dispersion and, consequently, a lower uncertainty of the measured displacement.

  7. Measurement of axial injection displacement with trim coil current unbalance

    SciTech Connect

    Covo, Michel Kireeff

    2014-08-15

    The Dee probe used for measuring internal radial beam intensity shows large losses inside the radius of 20 cm of the 88 in. cyclotron. The current of the top and bottom innermost trim coil 1 is unbalanced to study effects of the axial injection displacement. A beam profile monitor images the ion beam bunches, turn by turn. The experimental bunch center of mass position is compared with calculations of the magnetic mirror effect displacement and shows good agreement.

  8. Measurement of axial injection displacement with trim coil current unbalance

    NASA Astrophysics Data System (ADS)

    Covo, Michel Kireeff

    2014-08-01

    The Dee probe used for measuring internal radial beam intensity shows large losses inside the radius of 20 cm of the 88 in. cyclotron. The current of the top and bottom innermost trim coil 1 is unbalanced to study effects of the axial injection displacement. A beam profile monitor images the ion beam bunches, turn by turn. The experimental bunch center of mass position is compared with calculations of the magnetic mirror effect displacement and shows good agreement.

  9. International Monetary Fund and aid displacement.

    PubMed

    Stuckler, David; Basu, Sanjay; McKee, Martin

    2011-01-01

    Several recent papers find evidence that global health aid is being diverted to reserves, education, military, or other sectors, and is displacing government spending. This is suggested to occur because ministers of finance have competing, possibly corrupt, priorities and deprive the health sector of resources. Studies have found that development assistance for health routed to governments has a negative impact on health spending and that similar assistance routed to private nongovernmental organizations has a positive impact. An alternative hypothesis is that World Bank and IMF macro-economic policies, which specifically advise governments to divert aid to reserves to cope with aid volatility and keep government spending low, could be causing the displacement of health aid. This article evaluates whether aid displacement was greater when countries undertook a new borrowing program from the IMF between 1996 and 2006. As found in existing studies, for each $1 of development assistance for health, about $0.37 is added to the health system. However, evaluating IMF-borrowing versus non-IMF-borrowing countries reveals that non-borrowers add about $0.45 whereas borrowers add less than $0.01 to the health system. On average, health system spending grew at about half the speed when countries were exposed to the IMF than when they were not. It is important to take account of the political economy of global health finance when interpreting data on financial flows.

  10. Job Displacement Among Single Mothers:

    PubMed Central

    Brand, Jennie E.; Thomas, Juli Simon

    2015-01-01

    Given the recent era of economic upheaval, studying the effects of job displacement has seldom been so timely and consequential. Despite a large literature associating displacement with worker well-being, relatively few studies focus on the effects of parental displacement on child well-being, and fewer still focus on implications for children of single parent households. Moreover, notwithstanding a large literature on the relationship between single motherhood and children’s outcomes, research on intergenerational effects of involuntary employment separations among single mothers is limited. Using 30 years of nationally representative panel data and propensity score matching methods, we find significant negative effects of job displacement among single mothers on children’s educational attainment and social-psychological well-being in young adulthood. Effects are concentrated among older children and children whose mothers had a low likelihood of displacement, suggesting an important role for social stigma and relative deprivation in the effects of socioeconomic shocks on child well-being. PMID:25032267

  11. A positive regulatory domain in CCAAT/enhancer binding protein β (C/EBPΒ) is required for the glucocorticoid-mediated displacement of histone deacetylase 1 (HDAC1) from the C/ebpα promoter and maximum adipogenesis.

    PubMed

    Abdou, Houssein-Salem; Atlas, Ella; Haché, Robert J G

    2013-04-01

    Glucocorticoids promote adipogenesis and contribute to the metabolic syndrome through a number of mechanisms. One of the effectors of glucocorticoid action is the CCAAT/enhancer binding protein β (C/EBPβ). C/EBPβ is a basic leucine-zipper transcription factor involved in diverse processes including differentiation, cellular proliferation, and inflammation. C/EBPβ transcriptional activity is regulated, in part, by its acetylation profile resulting from its dynamic interaction with either acetylases general control nonrepressed protein 5/p300/CBP associated factor (GCN5/PCAF) or deacetylase complexes (mSin3A/histone deacetylase 1 [HDAC1]). Glucocorticoid treatment of preadipocytes promotes C/EBPβ acetylation, leading to mSin3A/HDAC1 dissociation from C/EBPβ and resulting in C/ebpα promoter activation at the onset of adipogenesis, thus increasing the differentiation rate. We recently showed that the regulatory domain 1 (RD1) of C/EBPβ contains four residues (153-156) required for its interaction with HDAC1, therefore supporting RD1 proposed inhibitory role. In an attempt to further elucidate the intrinsic regulatory property of RD1, we sought to characterize the regulatory potential of the N terminus region of RD1 (residues 141-149). In this study, we show that C/EBPβΔ141-149 transcriptional activity was compromised on the C/ebpα, but not on the Pparγ, promoter. Additionally, the ability of C/EBPβΔ141-149 to induce adipogenesis in NIH 3T3 cells was compromised when compared with C/EBPβwt owing to a delayed expression of C/ebpα at the onset of differentiation. Furthermore, the data suggest that the reduced expression of C/ebpα in cells expressing C/EBPβΔ141-149 was due to a persistent recruitment of HDAC1 to the C/ebpα promoter after glucocorticoid treatment. Together, these results suggest that amino acids 141-149 of C/EBPβ act as a positive regulatory domain required for maximum transcriptional activity.

  12. PROJECT-INDUCED DISPLACEMENT, SECONDARY STRESSORS, AND HEALTH

    PubMed Central

    Cao, Yue; Hwang, Sean-Shong; Xi, Juan

    2012-01-01

    It has been estimated that about 15 million people are displaced by development projects around the world each year. Despite the magnitude of people affected, research on the health and other impacts of project-induced displacement is rare. This study extends existing knowledge by exploring the short-term health impact of a large scale population displacement resulting from China’s Three Gorges Dam Project. The study is theoretically guided by the stress process model, but we supplement it with Cernea’s Impoverishment Risks and Reconstruction (IRR) model widely used in displacement literature. Our panel analysis indicates that the displacement is associated positively with relocatees’ depression level, and negatively with their self-rated health measured against a control group. In addition, a path analysis suggests that displacement also affects depression and self-rated health indirectly by changing social integration, socioeconomic status, and community resources. The importance of social integration as a protective mechanism, a factor that has been overlooked in past studies of population displacement, is highlighted in this study. PMID:22341203

  13. Particle displacement tracking for PIV

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.

    1990-01-01

    A new Particle Imaging Velocimetry (PIV) data acquisition and analysis system, which is an order of magnitude faster than any previously proposed system has been constructed and tested. The new Particle Displacement Tracing (PDT) system is an all electronic technique employing a video camera and a large memory buffer frame-grabber board. Using a simple encoding scheme, a time sequence of single exposure images are time coded into a single image and then processed to track particle displacements and determine velocity vectors. Application of the PDT technique to a counter-rotating vortex flow produced over 1100 velocity vectors in 110 seconds when processed on an 80386 PC.

  14. Rotor component displacement measurement system

    DOEpatents

    Mercer, Gary D.; Li, Ming C.; Baum, Charles R.

    2003-05-27

    A measuring system for measuring axial displacement of a tube relative to an axially stationary component in a rotating rotor assembly includes at least one displacement sensor adapted to be located normal to a longitudinal axis of the tube; an insulated cable system adapted for passage through the rotor assembly; a rotatable proximitor module located axially beyond the rotor assembly to which the cables are connected; and a telemetry system operatively connected to the proximitor module for sampling signals from the proximitor module and forwarding data to a ground station.

  15. Displacement measurements with resolution in the 15 pm range

    SciTech Connect

    Puppin, Ezio

    2005-10-15

    An approach to the measurement of mechanical displacements in the picometer range is proposed. The basic idea is to intercept a focused laser beam with a blade whose displacements induce a variation in the intensity of the transmitted light. The smallest detectable displacement depends on the beam diameter and on the resolution of the electronic chain. In our preliminary experiment the beam has been focused with a microscope objective down to a size of 3 {mu}m. Two different methods have been used for reducing noise in the electronic chain. In one case the output signal has been normalized to the laser intensity. In the other case the blade position has been modulated at low frequency. In both cases the smallest detectable displacement is in the order of 15 pm.

  16. Polybenzimidazoles Via Aromatic Nucleophilic Displacement

    NASA Technical Reports Server (NTRS)

    Connell, John W.; Hergenrother, Paul M.; Smith, Joseph G.

    1994-01-01

    Soluble polybenzimidazoles (PBI's) synthesized by nucleophilic displacement reaction of di(hydroxyphenyl)-benzimidazole monomers with activated aromatic difluoride compounds in presence of anhydrous potassium carbonate. These polymers exhibit good thermal, thermo-oxidative, and chemical stability, and high mechanical properties. Using benzimidazole monomers, more economical, and new PBI's processed more easily than commercial PBI, without loss of desirable physical properties.

  17. Retraining Displaced Workers. Policy Brief

    ERIC Educational Resources Information Center

    LaLonde, Robert; Sullivan, Daniel

    2010-01-01

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

  18. How to select and apply positive-displacement rotary pumps

    SciTech Connect

    Neerken, R.F.

    1980-04-07

    The advantages of rotary pumps for process applications are promoted by these practical guidelines concerning the types available, facts about their operation and performance, and the fluid systems in which they can be used. Basic types of rotary pumps discussed include internal gear, sliding vane, single-screw (progressing cavity), cam and piston, flexible tube, flexible liner, external gear, circumferential piston, twin screw, triple screw, single lobe, and 3 lobe. Factors which are examined to make pump selection include suction requirements, viscosity of fluids, temperature at which process fluid is handled, working and allowable pressures, pump capacity, pump horsepower, materials of construction, and intended applications.

  19. Computer-controlled positive displacement pump for physiological flow simulation.

    PubMed

    Holdsworth, D W; Rickey, D W; Drangova, M; Miller, D J; Fenster, A

    1991-11-01

    A computer-controlled pump for use both in the study of vascular haemodynamics and in the calibration of clinical devices which measure blood flow is designed. The novel design of this pump incorporates two rack-mounted pistons, driven into opposing cylinders by a micro-stepping motor. This approach allows the production of nearly uninterrupted steady flow, as well as a variety of pulsatile waveforms, including waveforms with reverse flow. The capabilities of this pump to produce steady flow from 0.1 to 60 ml s-1, as well as sinusoidal flow and physiological flow, such as that found in the common femoral and common carotid arteries are demonstrated. Cycle-to-cycle reproducibility is very good, with an average variation of 0.1 ml s-1 over thousands of cycles.

  20. Free displacer and Ringbom displacer for a Malone refrigerator

    SciTech Connect

    Swift, G.W.; Brown, A.O.

    1994-05-01

    Malone refrigeration uses a liquid near its critical point (instead of the customary gas) as the working fluid in a Stirling, Brayton, or similar regenerative or recuperative cycle. Thus far, we have focused on the Stirling cycle, to avoid the difficult construction of the high-pressure-difference counterflow recuperator required for a Brayton machine. Our first Malone refrigerator used liquid propylene (C{sub 3}H{sub 6}) in a double-acting 4-cylinder Stirling configuration. First measurements with a free displacer used in a liquid working fluid are presented. The displacer was operated both in harmonic mode and in Ringbom mode, in liquid carbon dioxide. The results are in reasonable agreement with expectations.

  1. Interplay between interstitial displacement and displacive lattice transformations

    NASA Astrophysics Data System (ADS)

    Zhang, Xie; Hickel, Tilmann; Rogal, Jutta; Neugebauer, Jörg

    2016-09-01

    Diffusionless displacive lattice rearrangements, which include martensitic transformations, are in real materials often accompanied by a displacive drag of interstitials. The interplay of both processes leads to a particular atomistic arrangement of the interstitials in the product phase, which is decisive for its performance. An archetype example is the martensitic transformation in Fe-C alloys. One of the puzzles for this system is that the deviation from the cubic symmetry (i.e., the tetragonality) in the martensite resulting from this interplay is lower than what thermodynamics dictates. In our ab initio approach, the relative motion of C in the transforming lattice is studied with the nudged elastic band method. We prove that an atomic shearlike shuffle mechanism of adjacent (11 2 ¯) Fe layers along the ±[111] bcc directions is essential to achieve a redistribution of C atoms during the fcc → bcc transition, which fully explains the abnormal behavior. Furthermore, the good agreement with experiment validates our method to treat a diffusionless redistribution of interstitials and a displacive rearrangement of the host lattice simultaneously.

  2. Atomic displacements in quantum crystals

    NASA Astrophysics Data System (ADS)

    Dusseault, Marisa; Boninsegni, Massimo

    2017-03-01

    Displacements of atoms and molecules away from lattice sites in helium and parahydrogen solids at low temperature have been studied by means of quantum Monte Carlo simulations. In the bcc phases of 3He and 4He, atomic displacements are largely quantum-mechanical in character, even at melting. The computed Lindemann ratio at melting is found to be in good agreement with experimental results for 4He. Unlike the case of helium, in solid parahydrogen there exists near melting a significant thermal contribution to molecular vibrations, accounting for roughly half of the total effect. Although the Lindemann ratio at melting is in quantitative agreement with experiment, computed molecular mean square fluctuations feature a clear temperature dependence, in disagreement with recent experimental observations.

  3. Wettability controls slow immiscible displacement through local interfacial instabilities

    NASA Astrophysics Data System (ADS)

    Jung, Michael; Brinkmann, Martin; Seemann, Ralf; Hiller, Thomas; Sanchez de La Lama, Marta; Herminghaus, Stephan

    2016-11-01

    Immiscible fluid displacement with average front velocities in the capillary-dominated regime is studied in a transparent Hele-Shaw cell with cylindrical posts. Employing various combinations of fluids and wall materials allows us to cover a range of advancing contact angles 46∘≤θa≤180∘ of the invading fluid in our experiments. In parallel, we study the displacement process in particle-based simulations that account for wall wettability. Considering the same arrangement of posts in experiments and simulation, we find a consistent crossover between stable interfacial displacement at θa≲80∘ and capillary fingering at high contact angles θa≳120∘ . The position of the crossover is quantified through the evolution of the interface length and the final saturation of the displaced fluid. A statistical analysis of the local displacement processes demonstrates that the shape evolution of the fluid front is governed by local instabilities as proposed by Cieplak and Robbins for a quasistatic interfacial displacement [Cieplak and Robbins, Phys. Rev. Lett. 60, 2042 (1988), 10.1103/PhysRevLett.60.2042]. The regime of stable front advances coincides with a corresponding region of contact angles where cooperative interfacial instabilities prevail. Capillary fingering, however, is observed only for large θa, where noncooperative instabilities dominate the invasion process.

  4. Pattern of dynamic displacements in a strike-slip earthquake

    NASA Astrophysics Data System (ADS)

    Saltogianni, V.; Gianniou, M.; Moschas, F.; Stiros, S.

    2016-07-01

    High-rate (1 Hz) records from GPS stations uniformly distributed along the fault ruptures of the 2014 Samothraki-Gökçeada Mw6.9 earthquake in the North Aegean Trough, at the extension of the North Anatolian Fault Zone, were analyzed using the Precise Point Positioning (PPP) technique. Computed dynamic displacements shed light to the pattern of dynamic displacements during shallow strike-slip earthquakes. The area of near-field static seismic displacements bounds ramp-type, long-period dynamic displacements (fling steps) in the sense of static displacements. Along-fault and normal to fault components of dynamic displacement follow typical attenuation laws, but attenuation is higher in the fault-parallel component hence confined to the area of static dislocations. Forward directivity and local, especially topography-controlled amplification effects, consistent with accelerometer evidence, were also observed. The overall pattern seems to characterize shallow strike-slip earthquakes and is expected to prove useful to explain or even predict the near-field damaging potential of strike-slip earthquakes.

  5. Rapid Sunspot Displacement Associated with Solar Eruptions

    NASA Astrophysics Data System (ADS)

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

    2010-05-01

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

  6. Polybenzimidazole via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

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

    1994-01-01

    Di(hydroxyphenyl)benzimidazole monomers were prepared from phenyl-4-hydroxybenzoate and aromatic bis(o-diamine)s. These monomers were used in the synthesis of soluble polybenzimidazoles. The reaction involved the aromatic nucleophilic displacement of various di(hydroxyphenyl)benzimidazole monomers with activated aromatic dihalides or activated aromatic dinitro compounds in the presence of an alkali metal base. These polymers exhibited lower glass transition temperatures, improved solubility, and better compression moldability over their commercial counterparts.

  7. Polyphenylquinoxalines via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

    Polyphenylquinoxalines are prepared by the nucleophilic displacement reaction of di(hydroxyphenyl)quinoxaline monomers with activated aromatic dihalides or dinitro compounds. The reactions are carried out in polar aprotic solvents using alkali metal bases at elevated temperatures under nitrogen. The di(hydroxyphenyl)quinoxaline monomers are prepared either by reacting stoichiometric quantities of aromatic bis(o-diamines) with a hydroxybenzil or by reacting o-phenylenediamine with a dihydroxybenzil or bis(hydroxyphenylglyoxylyl)benzene.

  8. Polyphenylquinoxalines via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

    Polyphenylquinoxalines are prepared by the nucleophilic displacement reaction of di(hydroxyphenyl)quinoxaline monomers with activated aromatic dihalides or dinitro compounds. The reactions are carried out in polar aprotic solvents during alkali metal bases at elevated temperatures under nitrogen. The di(hydroxyphenyl)quinoxaline monomers are prepared either by reacting stoichiometric quantities of aromatic bis(o-diamines) with a hydroxybenzil or by reacting o-phenylenediamine with a dihydroxybenzil or bis(hydroxyphenylglyoxylyl)benzene.

  9. Single-mode displacement sensor

    NASA Astrophysics Data System (ADS)

    Duivenvoorden, Kasper; Terhal, Barbara M.; Weigand, Daniel

    2017-01-01

    We show that one can determine both parameters of a displacement acting on an oscillator with an accuracy which scales inversely with the square root of the number of photons in the oscillator. Our results are obtained by using a grid state as a sensor state for detecting small translations in phase space (displacements). Grid states were first proposed [D. Gottesman et al., Phys. Rev. A 64, 012310 (2001), 10.1103/PhysRevA.64.012310] for encoding a qubit into an oscillator: an efficient preparation protocol of such states, using a coupling to a qubit, was later developed [B. M. Terhal and D. Weigand, Phys. Rev. A 93, 012315 (2016), 10.1103/PhysRevA.93.012315]. We compare the performance of the grid state with the quantum compass or cat code state and place our results in the context of the two-parameter quantum Cramér-Rao lower bound on the variances of the displacement parameters. We show that the accessible information about the displacement for a grid state increases with the number of photons in the state when we measure and prepare the state using a phase estimation protocol. This is in contrast with the accessible information in the quantum compass state which we show is always upper bounded by a constant, independent of the number of photons. We present numerical simulations of a phase estimation based preparation protocol of a grid state in the presence of photon loss, nonlinearities, and qubit measurement, using no post-selection, showing how the two effective squeezing parameters which characterize the grid state change during the preparation. The idea behind the phase estimation protocol is a simple maximal-information gain strategy.

  10. Software for determining the true displacement of faults

    NASA Astrophysics Data System (ADS)

    Nieto-Fuentes, R.; Nieto-Samaniego, Á. F.; Xu, S.-S.; Alaniz-Álvarez, S. A.

    2014-03-01

    One of the most important parameters of faults is the true (or net) displacement, which is measured by restoring two originally adjacent points, called “piercing points”, to their original positions. This measurement is not typically applicable because it is rare to observe piercing points in natural outcrops. Much more common is the measurement of the apparent displacement of a marker. Methods to calculate the true displacement of faults using descriptive geometry, trigonometry or vector algebra are common in the literature, and most of them solve a specific situation from a large amount of possible combinations of the fault parameters. True displacements are not routinely calculated because it is a tedious and tiring task, despite their importance and the relatively simple methodology. We believe that the solution is to develop software capable of performing this work. In a previous publication, our research group proposed a method to calculate the true displacement of faults by solving most combinations of fault parameters using simple trigonometric equations. The purpose of this contribution is to present a computer program for calculating the true displacement of faults. The input data are the dip of the fault; the pitch angles of the markers, slickenlines and observation lines; and the marker separation. To prevent the common difficulties involved in switching between operative systems, the software is developed using the Java programing language. The computer program could be used as a tool in education and will also be useful for the calculation of the true fault displacement in geological and engineering works. The application resolves the cases with known direction of net slip, which commonly is assumed parallel to the slickenlines. This assumption is not always valid and must be used with caution, because the slickenlines are formed during a step of the incremental displacement on the fault surface, whereas the net slip is related to the finite slip.

  11. NGO action on refugees and displaced people.

    PubMed

    1998-06-01

    This article summarizes some issues that emerged from a 1997 seminar on reproductive health among refugees. 90 delegates from 16 countries shared ideas about how to better lend support in emergencies and discussed the prevention and control of AIDS. The role was not clear for nongovernmental organizations (NGOs) that preferred constructing community-based institutions instead of satisfying the basic, urgent needs of displaced persons. The NGO sector recognizes its reliance on UN funding, but desires better UNHCR and UNAIDS guidelines and more positive support. NGOs were very reluctant to integrate HIV testing and counseling in already mistrustful settings, while ignoring the violence against women, which is closely tied to their vulnerability to AIDS. UNHCR solutions appeared to prolong the conflict and offer opportunities to channel energies into negative sexuality. Most refugees are women and children. There is wide inconsistency in beliefs and government responses to basic human rights issues. It was proposed that a deterrent to the spread of AIDS is an emphasis on self-respect and a concept of belonging. Management issues in resettled populations vary with essential needs and different phases of an emergency. Common HIV and refugee concerns include a balance between the needs of host and displaced persons; a balance between long- and short-term HIV emergency needs; and a reduction of violence among militarized refugees. Pressing concerns were advocacy, vulnerability, and research on gender and effects of militarization.

  12. Precision optical displacement measurements using biphotons

    NASA Astrophysics Data System (ADS)

    Lyons, Kevin; Pang, Shengshi; Kwiat, Paul G.; Jordan, Andrew N.

    2016-04-01

    We propose and examine the use of biphoton pairs, such as those created in parametric down-conversion or four-wave mixing, to enhance the precision and the resolution of measuring optical displacements by position-sensitive detection. We show that the precision of measuring a small optical beam displacement with this method can be significantly enhanced by the correlation between the two photons, given the same optical mode. The improvement is largest if the correlations between the photons are strong, and falls off as the biphoton correlation weakens. More surprisingly, we find that the smallest resolvable parameter of a simple split detector scales as the inverse of the number of biphotons for small biphoton number ("Heisenberg scaling"), because the Fisher information diverges as the parameter to be estimated decreases in value. One usually sees this scaling only for systems with many entangled degrees of freedom. We discuss the transition for the split-detection scheme to the standard quantum limit scaling for imperfect correlations as the biphoton number is increased. An analysis of an N -pixel detector is also given to investigate the benefit of using a higher resolution detector. The physical limit of these metrology schemes is determined by the uncertainty in the birth zone of the biphoton in the nonlinear crystal.

  13. Transient digitizer with displacement current samplers

    DOEpatents

    McEwan, Thomas E.

    1996-01-01

    A low component count, high speed sample gate, and digitizer architecture using the sample gates is based on use of a signal transmission line, a strobe transmission line and a plurality of sample gates connected to the sample transmission line at a plurality of positions. The sample gates include a strobe pickoff structure near the strobe transmission line which generates a charge displacement current in response to propagation of the strobe signal on the strobe transmission line sufficient to trigger the sample gate. The sample gate comprises a two-diode sampling bridge and is connected to a meandered signal transmission line at one end and to a charge-holding cap at the other. The common cathodes are reverse biased. A voltage step is propagated down the strobe transmission line. As the step propagates past a capacitive pickoff, displacement current i=c(dv/dT), flows into the cathodes, driving the bridge into conduction and thereby charging the charge-holding capacitor to a value related to the signal. A charge amplifier converts the charge on the charge-holding capacitor to an output voltage. The sampler is mounted on a printed circuit board, and the sample transmission line and strobe transmission line comprise coplanar microstrips formed on a surface of the substrate. Also, the strobe pickoff structure may comprise a planar pad adjacent the strobe transmission line on the printed circuit board.

  14. Transient digitizer with displacement current samplers

    DOEpatents

    McEwan, T.E.

    1996-05-21

    A low component count, high speed sample gate, and digitizer architecture using the sample gates is based on use of a signal transmission line, a strobe transmission line and a plurality of sample gates connected to the sample transmission line at a plurality of positions. The sample gates include a strobe pickoff structure near the strobe transmission line which generates a charge displacement current in response to propagation of the strobe signal on the strobe transmission line sufficient to trigger the sample gate. The sample gate comprises a two-diode sampling bridge and is connected to a meandered signal transmission line at one end and to a charge-holding cap at the other. The common cathodes are reverse biased. A voltage step is propagated down the strobe transmission line. As the step propagates past a capacitive pickoff, displacement current i=c(dv/dT), flows into the cathodes, driving the bridge into conduction and thereby charging the charge-holding capacitor to a value related to the signal. A charge amplifier converts the charge on the charge-holding capacitor to an output voltage. The sampler is mounted on a printed circuit board, and the sample transmission line and strobe transmission line comprise coplanar microstrips formed on a surface of the substrate. Also, the strobe pickoff structure may comprise a planar pad adjacent the strobe transmission line on the printed circuit board. 16 figs.

  15. Angular displacement perception modulated by force background.

    PubMed

    Lackner, James R; DiZio, Paul

    2009-05-01

    We had recumbent subjects (n = 7) indicate the amplitude of imposed, passive yaw-axis body rotations in the 0, 1, and 1.8 g background force levels generated during parabolic flight maneuvers. The blindfolded subject, restrained in a cradle, aligned a gravity-neutral pointer with the subjective vertical while in an initial position and then tried to keep it aligned with the same external direction during a body rotation, lasting less than 1.5 s about the z-axis 30 degrees, 60 degrees, or 120 degrees in amplitude. All the rotations were above semicircular threshold levels for eliciting perception of angular displacement under terrestrial test conditions. In 1 and 1.8 g test conditions, subjects were able to indicate both the subjective vertical and the amplitude of the body rotation reasonably accurately. By contrast in 0 g, when indicating the subjective vertical, they aligned the pointer with the body midline and kept it nearly aligned with their midline during the subsequent body tilts. They also reported feeling supine throughout the 0 g test periods. The attenuation of apparent self-displacement in 0 g is discussed in terms of (1) a possible failure of integration of semicircular canal velocity signals, (2) a contribution of somatosensory pressure and contact cues, and (3) gravicentric versus body-centric reference frames. The significance of the findings for predicting and preventing motion sickness and disorientation in orbital space flight and in rotating artificial gravity environments is discussed.

  16. Children's Spiritual Development in Forced Displacement: A Human Rights Perspective

    ERIC Educational Resources Information Center

    Ojalehto, Bethany; Wang, Qi

    2008-01-01

    This article provides a synthesis of current research and theories of spiritual development in forced displacement from a human rights perspective. Spirituality, understood as a cognitive-cultural construct, has shown positive impact on children's development through both collective and individual processes and across ecological domains of the…

  17. 5 CFR 351.701 - Assignment involving displacement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... REDUCTION IN FORCE Assignment Rights (Bump and Retreat) § 351.701 Assignment involving displacement. (a... this section and retreat to a position that: (1) Is held by another employee with lower retention... grade intervals or equivalent) of the employee's retreat right. The agency does not consider the...

  18. Fiber-Optic Differential Displacement Sensor

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping

    1996-01-01

    Dual fiber-optic sensor measures small relative displacements of two proximate objects along common surface. Dual sensor comprises two fiber-optic sensors in differential configuration increasing sensitivity to displacement while decreasing sensitivity to thermal expansion and contraction.

  19. The case for character displacement in plants

    PubMed Central

    Beans, Carolyn M

    2014-01-01

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

  20. The case for character displacement in plants.

    PubMed

    Beans, Carolyn M

    2014-03-01

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

  1. 40 CFR 205.153 - Engine displacement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Engine displacement. 205.153 Section... TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycles § 205.153 Engine displacement. (a) Engine displacement must be calculated using nominal engine values and rounded to the nearest whole cubic...

  2. 40 CFR 205.153 - Engine displacement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Engine displacement. 205.153 Section... TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycles § 205.153 Engine displacement. (a) Engine displacement must be calculated using nominal engine values and rounded to the nearest whole cubic...

  3. Displacement Compensation of Temperature Probe Data

    NASA Technical Reports Server (NTRS)

    Welch, Christopher S.; Hubert, James A.; Barber, Patrick G.

    1996-01-01

    Analysis of temperature data from a probe in a vertical Bridgman furnace growing germanium crystals revealed a displacement of the temperature profile due to conduction error. A theoretical analysis shows that the displacement compensation is independent of local temperature gradient. A displacement compensation value should become a standard characteristic of temperature probes used for temperature profile measurements.

  4. 25 CFR 700.59 - Displaced person.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 2 2010-04-01 2010-04-01 false Displaced person. 700.59 Section 700.59 Indians THE OFFICE OF NAVAJO AND HOPI INDIAN RELOCATION COMMISSION OPERATIONS AND RELOCATION PROCEDURES General Policies and Instructions Definitions § 700.59 Displaced person. Displaced person means a member of...

  5. Micromachined Tunneling Displacement Transducers for Physical Sensors

    NASA Technical Reports Server (NTRS)

    Kenny, T. W.; Kaiser, W. J.; Podosek, J. A.; Rockstad, H. K.; Reynolds, J. K.; Vote, E. C.

    1993-01-01

    We have designed and constructed a series of tunneling sensors which take advantage of the extreme position sensitivity of electron tunneling. In these sensors, a tunneling displacement transducer, based on scanning tunneling microscopy principles, is used to detect the signal-induced motion of a sensor element. Through the use of high-resonant frequency mechanical elements for the transducer, sensors may be constructed which offer wide bandwidth, and are robust and easily operated. Silicon micromachining may be used to fabricate the transducer elements, allowing integration of sensor and control electronics. Examples of tunneling accelerometers and infrared detectors will be discussed. In each case, the use of the tunneling transducer allows miniaturization of the sensor as well as enhancement of the sensor performance.

  6. Polyphenylquinoxalines via Aromatic Nucleophilic Displacement

    NASA Technical Reports Server (NTRS)

    Hergenrother, Paul M.; Connell, John W.

    1988-01-01

    Polyphenylquinoxalines are produced by an aromatic nucleophilic displacement reaction involving an activated aromatic dihalide with an appropriate quinoxaline monomer. Polyphenylquinoxalines are high temperature thermoplastics used as adhesives, coatings, films and composite matrices. The novelty of this invention is threefold: (1) some of the quinoxaline monomers are new compositions of matter; (2) the phenylquinoxaline polymers which are the end products of the invention are new compositions of matter; and (3) the method of forming the polymers is novel, replacing a more costly prior art process, which is also limited in the kinds of products prepared therefrom.

  7. Displacement Current and Surface Flashover

    SciTech Connect

    harris, J R; Caporaso, G J; Blackfield, D; Chen, Y J

    2007-07-17

    High-voltage vacuum insulator failure is generally due to surface flashover rather than insulator bulk breakdown. Vacuum surface flashover is widely believed to be initiated by a secondary electron emission avalanche along the vacuum-insulator interface. This process requires a physical mechanism to cause secondary electrons emitted from the insulator surface to return to that surface. Here, we show that when an insulator is subjected to a fast high-voltage pulse, the magnetic field due to displacement current through the insulator can provide this mechanism. This indicates the importance of the voltage pulse shape, especially the rise time, in the flashover initiation process.

  8. Digital system for dynamic turbine engine blade displacement measurements

    NASA Technical Reports Server (NTRS)

    Kiraly, L. J.

    1979-01-01

    An instrumentation concept for measuring blade tip displacements which employs optical probes and an array of micro-computers is presented. The system represents a hitherto unknown instrumentation capability for the acquisition and direct digitization of deflection data concurrently from all of the blade tips of an operational engine rotor undergoing flutter or forced vibration. System measurements are made using optical transducers which are fixed to the case. Measurements made in this way are the equivalent of those obtained by placing three surface-normal displacement transducers at three positions on each blade of an operational rotor.

  9. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, John

    1999-01-01

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

  10. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, J.

    1999-04-06

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

  11. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, John

    1995-01-01

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

  12. Interferometric fiber optic displacement sensor

    DOEpatents

    Farah, J.

    1995-05-30

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

  13. Detection of radial motion depends on spatial displacement.

    PubMed

    de la Malla, Cristina; López-Moliner, Joan

    2010-06-01

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

  14. Understanding interferometry for micro-cantilever displacement detection

    PubMed Central

    Nörenberg, Tobias; Temmen, Matthias; Reichling, Michael

    2016-01-01

    Summary Interferometric displacement detection in a cantilever-based non-contact atomic force microscope (NC-AFM) operated in ultra-high vacuum is demonstrated for the Michelson and Fabry–Pérot modes of operation. Each mode is addressed by appropriately adjusting the distance between the fiber end delivering and collecting light and a highly reflective micro-cantilever, both together forming the interferometric cavity. For a precise measurement of the cantilever displacement, the relative positioning of fiber and cantilever is of critical importance. We describe a systematic approach for accurate alignment as well as the implications of deficient fiber–cantilever configurations. In the Fabry–Pérot regime, the displacement noise spectral density strongly decreases with decreasing distance between the fiber-end and the cantilever, yielding a noise floor of 24 fm/Hz0.5 under optimum conditions. PMID:27547601

  15. Understanding interferometry for micro-cantilever displacement detection.

    PubMed

    von Schmidsfeld, Alexander; Nörenberg, Tobias; Temmen, Matthias; Reichling, Michael

    2016-01-01

    Interferometric displacement detection in a cantilever-based non-contact atomic force microscope (NC-AFM) operated in ultra-high vacuum is demonstrated for the Michelson and Fabry-Pérot modes of operation. Each mode is addressed by appropriately adjusting the distance between the fiber end delivering and collecting light and a highly reflective micro-cantilever, both together forming the interferometric cavity. For a precise measurement of the cantilever displacement, the relative positioning of fiber and cantilever is of critical importance. We describe a systematic approach for accurate alignment as well as the implications of deficient fiber-cantilever configurations. In the Fabry-Pérot regime, the displacement noise spectral density strongly decreases with decreasing distance between the fiber-end and the cantilever, yielding a noise floor of 24 fm/Hz(0.5) under optimum conditions.

  16. Displacement of squeezed propagating microwave states

    NASA Astrophysics Data System (ADS)

    Fedorov, Kirill G.; Zhong, Ling; Pogorzalek, Stefan; Eder, Peter; Fischer, Michael; Goetz, Jan; Wulschner, Friedrich; Xie, Edwar; Menzel, Edwin; Deppe, Frank; Marx, Achim; Gross, Rudolf

    Displacement of propagating squeezed states is a fundamental operation for quantum communications. It can be applied to fundamental studies of macroscopic quantum coherence and has an important role in quantum teleportation protocols with propagating microwaves. We generate propagating squeezed states using a Josephson parametric amplifier and implement displacement using a cryogenic directional coupler. We study single- and two-mode displacement regimes. For the single-mode displacement we find that the squeezing level of the displaced squeezed state does not depend on the displacement amplitude. Also, we observe that quantum entanglement between two spatially separated channels stays constant across 4 orders of displacement power. We acknowledge support by the German Research Foundation through SFB 631 and FE 1564/1-1, the EU project PROMISCE, and Elite Network of Bavaria through the program ExQM.

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

    PubMed

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

    2012-01-01

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

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

    PubMed Central

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

    2012-01-01

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

  19. Multiplexed displacement fiber sensor using thin core fiber exciter.

    PubMed

    Chen, Zhen; Hefferman, Gerald; Wei, Tao

    2015-06-01

    This letter reports a multiplexed optical displacement sensor using a thin core fiber (TCF) exciter. The TCF exciter is followed by a stripped single mode optical fiber. A small section of buffer is used as the movable component along the single mode fiber. Ultra-weak cladding mode reflection (< - 75 dB) was employed to probe the refractive index discontinuity between the air and buffer coating boundary. The position change of the movable buffer segment results in a delay change of the cladding mode reflection. Thus, it is a measure of the displacement of the buffer segment with respect to the glass fiber. The insertion loss of one sensor was measured to be less than 3 dB. A linear relationship was evaluated between the measurement position and absolute position of the moving actuator. Multiplexed capability was demonstrated and no cross talk was found between the sensors.

  20. Polyimidazoles via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  1. Polyimidazoles via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  2. Polybenzimidazoles via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

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

    1995-01-01

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

  3. Polybenzimidazoles Via Aromatic Nucleophilic Displacement

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

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

  4. Limb displacement and brightness seismology

    NASA Astrophysics Data System (ADS)

    Emilio, Marcelo; Cunnyngham, Ian; Kuhn, Jeff; Mehret, Leandro; Bush, Rock; Scholl, Isabelle

    2015-08-01

    The Helioseismic and Magnetic Imager (HMI) abord the Solar Dynamics Observatory (SDO) has been used to obtain the most sensitive spectrally resolved observation of individual p-modes at the extreme solar limb. Such oscillation observations of the limb displacement and brightness for some spatial and temporal regimes are even competitive in signal-to-noise to full-disk doppler measurements of the p-mode spectrum. Limb measurements of 5-min p-modes, while having many similarities to full-disk doppler observations, have significantly different sensitivities to the solar rotation and the 5-min mode solar atmospheric structure. These may provide information about the solar structure which is complementary to full-disk measurements. In this work we present results from Individual spherical harmonic p-modes that were detected around solar limb with amplitudes at the micro-arcsecond level.

  5. Displaced electrode process for welding

    DOEpatents

    Heichel, L.J.

    1975-08-26

    A method is described for the butt-welding of a relatively heavy mass to a relatively small mass such as a thin-wall tube. In butt-welding heat is normally applied at the joint between the two pieces which are butt-welded together. The application of heat at the joint results in overheating the tube which causes thinning of the tube walls and porosity in the tube material. This is eliminated by displacing the welding electrode away from the seam toward the heavier mass so that heat is applied to the heavy mass and not at the butt seam. Examples of the parameters used in welding fuel rods are given. The cladding and end plugs were made of Zircalloy. The electrode used was of 2 percent thoriated tungsten. (auth)

  6. Displaceable Gear Torque Controlled Driver

    NASA Technical Reports Server (NTRS)

    Cook, Joseph S., Jr. (Inventor)

    1997-01-01

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

  7. DISPLACEMENT BASED SEISMIC DESIGN CRITERIA

    SciTech Connect

    HOFMAYER,C.H.

    1999-03-29

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

  8. Hydraulic efficiency of a hydrostatic transmission with a variable displacement pump and motor

    NASA Astrophysics Data System (ADS)

    Coombs, Daniel

    Pumps and motors are commonly connected hydraulically to create hydrostatic drives, also known as hydrostatic transmissions. A typical hydrostatic transmission consists of a variable displacement pump and a fixed displacement motor. Maximum efficiency is typically created for the system when the motor operates at maximum volumetric displacement. The objective of this research is to determine if a hydrostatic transmission with a variable displacement motor can be more efficient than one with a fixed displacement motor. A work cycle for a Caterpillar 320D excavator was created and the efficiency of the hydrostatic drive system, controlling the swing circuit, with a fixed displacement motor was compared to the efficiency with a variable displacement motor. Both multiplicative and additive uncertainty analysis were performed to determine uncertainty models that could be used to analyze the robustness of the system with feedback control applied. A PID and an H∞ controller were designed for a position control model, as well as velocity control. It was found that while it may seem obvious to achieve maximum efficiency at maximum displacement, there are some cases where maximum efficiency is achieved at a lower displacement. It was also found that for the given work cycle, a hydrostatic transmission with a variable displacement motor can be more efficient.

  9. Has multivessel angioplasty displaced surgical revascularization?

    PubMed

    King, S B; Ivanhoe, R J

    1990-01-01

    Over the years, PTCA has been proved a safe and effective therapy for single-vessel CAD. Given the record of favorable results for single-vessel angioplasty, the extension of angioplasty to multivessel CAD soon followed. The successful application of PTCA to multivessel disease has been facilitated by developments in balloon, guidewire, and guide catheter technology. Success rates have been satisfactory, and complications have remained acceptable. Furthermore, as an outgrowth of an understanding of the mechanism and effect of PTCA, guidelines have been developed to aid case selection. As emphasized earlier, these guidelines should weigh heavily in deciding whether to select PTCA as a treatment modality. Presently, in our opinion, PTCA has not yet completely displaced surgery for multivessel CAD. Surgical standby is required for safe PTCA, because emergency surgery can be lifesaving and limit myocardial infarction after failed angioplasty. It is doubtful that surgery will ever relinquish its position as the treatment of choice for left main coronary artery disease. Nor will elective surgery find wide application in single-vessel disease. Whether one mode of revascularization will emerge as the most efficacious for multivessel disease related to long-term survival, limitation of cardiac events, and cost will be addressed in the analysis of the ongoing randomized trials of surgery versus angioplasty. Andreas Gruentzig established that it was possible to work within the coronary artery in an alert and comfortable patient. Interventional cardiology has experienced rapid technologic growth. Many patients formerly treated with bypass surgery can be managed effectively with angioplasty. If effective bail-out methods for acute closure are proven effective and restenosis is limited to a small percentage of patients, angioplasty in some form will further displace CABG. Until those ultimate goals are achieved, the value of angioplasty compared with bypass surgery must rest

  10. Modelling Toehold-Mediated RNA Strand Displacement

    PubMed Central

    Šulc, Petr; Ouldridge, Thomas E.; Romano, Flavio; Doye, Jonathan P.K.; Louis, Ard A.

    2015-01-01

    We study the thermodynamics and kinetics of an RNA toehold-mediated strand displacement reaction with a recently developed coarse-grained model of RNA. Strand displacement, during which a single strand displaces a different strand previously bound to a complementary substrate strand, is an essential mechanism in active nucleic acid nanotechnology and has also been hypothesized to occur in vivo. We study the rate of displacement reactions as a function of the length of the toehold and temperature and make two experimentally testable predictions: that the displacement is faster if the toehold is placed at the 5′ end of the substrate; and that the displacement slows down with increasing temperature for longer toeholds. PMID:25762335

  11. Modelling toehold-mediated RNA strand displacement.

    PubMed

    Šulc, Petr; Ouldridge, Thomas E; Romano, Flavio; Doye, Jonathan P K; Louis, Ard A

    2015-03-10

    We study the thermodynamics and kinetics of an RNA toehold-mediated strand displacement reaction with a recently developed coarse-grained model of RNA. Strand displacement, during which a single strand displaces a different strand previously bound to a complementary substrate strand, is an essential mechanism in active nucleic acid nanotechnology and has also been hypothesized to occur in vivo. We study the rate of displacement reactions as a function of the length of the toehold and temperature and make two experimentally testable predictions: that the displacement is faster if the toehold is placed at the 5' end of the substrate; and that the displacement slows down with increasing temperature for longer toeholds.

  12. Precise displacement measurement for a local surface.

    PubMed

    Yeh, Sheng Lih; Lin, Shyh Tsong; Chang, Yu Hsin

    2009-11-01

    An optical measurement method to get the in-plane and out-of-plane displacements of a local surface using a laser is proposed. The proposed method simultaneously derives the in-plane and out-of-plane displacements by measuring the shift of interference fringes formed by scattered beams. The average errors of the in-plane and out-of-plane displacement measurements are significantly smaller than 10 nm. Moreover, the proposed method uses only low-cost optical elements.

  13. Displacement speeds in turbulent premixed flame simulations

    SciTech Connect

    Day, Marcus S.; Shepherd, Ian G.; Bell, J.; Grcar, Joseph F.; Lijewski, Michael J.

    2007-07-01

    The theory of turbulent premixed flames is based on acharacterization of the flame as a discontinuous surface propagatingthrough the fluid. The displacement speed, defined as the local speed ofthe flame front normal to itself, relative to the unburned fluid,provides one characterization of the burning velocity. In this paper, weintroduce a geometric approach to computing displacement speed anddiscuss the efficacy of the displacement speed for characterizing aturbulent flame.

  14. Internal displacement and health among the Palestinian minority in Israel.

    PubMed

    Daoud, Nihaya; Shankardass, Ketan; O'Campo, Patricia; Anderson, Kim; Agbaria, Ayman K

    2012-04-01

    Long term health impacts of internal displacement (ID) resulting from political violence are not well documented or understood. One such case is the ID of 300,000-420,000 Palestinian citizens of Israel and their descendants during the Nakba of 1948 (Palestinian Catastrophe). We aim to document the long term health impacts of this ID. We draw on data collected in 2005 from a nationwide random sample of 902 individuals aged 30-70. Research participants were interviewed in person after being selected through a multistage sampling procedure. About 24% of participants reported that either they or their families had been internally displaced. Palestinian internally displaced persons (IDPs), that is, those who were forcibly displaced and dispossessed from their homes and lands during the Nakba and its aftermath, as well as their families and descendants, and who reside within the current borders of Israel, had an odds ratio of 1.45 (95% CI = 1.02-2.07) for poor self-rated health (SRH) compared to non-IDPs after controlling for demographic, socioeconomic and psychosocial factors. No difference was found between IDPs and non-IDPs in limiting longstanding illness following control for confounders. Low socioeconomic position and chronic stress were significantly related to ID and to SRH. Our findings suggest adverse long term health impacts of the Nakba on the IDPs when compared to non-IDPs. We propose that these disparities might stem from IDPs' unhealed post-traumatic scars from the Nakba, or from becoming a marginalized minority within their own society due to their displacement and loss of collective identity. Given these long term health consequences, we conclude that displacement should be addressed with health and social policies for IDPs.

  15. Cervicitis associated with lateral cervical displacement.

    PubMed

    Gjoni, Indira; Muneyyirci-Delale, Ozgul

    2012-01-01

    Lateral cervical displacement has been recognized as a sign of endometriosis; however, other causes of the finding have not been explored. In our experience, patients without endometriosis are presenting with lateral cervical displacement, mainly towards the left of midline. The common finding in these cases is the presence of cervicitis leading us to hypothesize the role of cervicitis in causing lateral displacement of the cervix. Future research into this area will provide us with a stronger understanding of the role that lateral cervical displacement plays in the development of pelvic pathology and the development of cervical cancer.

  16. Displacement of Propagating Squeezed Microwave States

    NASA Astrophysics Data System (ADS)

    Fedorov, Kirill G.; Zhong, L.; Pogorzalek, S.; Eder, P.; Fischer, M.; Goetz, J.; Xie, E.; Wulschner, F.; Inomata, K.; Yamamoto, T.; Nakamura, Y.; Di Candia, R.; Las Heras, U.; Sanz, M.; Solano, E.; Menzel, E. P.; Deppe, F.; Marx, A.; Gross, R.

    2016-07-01

    Displacement of propagating quantum states of light is a fundamental operation for quantum communication. It enables fundamental studies on macroscopic quantum coherence and plays an important role in quantum teleportation protocols with continuous variables. In our experiments, we have successfully implemented this operation for propagating squeezed microwave states. We demonstrate that, even for strong displacement amplitudes, there is no degradation of the squeezing level in the reconstructed quantum states. Furthermore, we confirm that path entanglement generated by using displaced squeezed states remains constant over a wide range of the displacement power.

  17. Polybenzoxazole via aromatic nucleophilic displacement

    NASA Technical Reports Server (NTRS)

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

    1993-01-01

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

  18. Transverse-displacement stabilizer for passive magnetic bearing systems

    DOEpatents

    Post, Richard F

    2017-03-07

    The invention provides a way re-center a rotor's central longitudinal rotational axis with a desired system longitudinal axis. A pair of planar semicircular permanent magnets are pieced together to form a circle. The flux from each magnet is pointed in in opposite directions that are both parallel with the rotational axis. A stationary shorted circular winding the plane of which is perpendicular to the system longitudinal axis and the center of curvature of the circular winding is positioned on the system longitudinal axis. Upon rotation of the rotor, when a transverse displacement of the rotational axis occurs relative to the system longitudinal axis, the winding will experience a time-varying magnetic flux such that an alternating current that is proportional to the displacement will flow in the winding. Such time-varying magnetic flux will provide a force that will bring the rotor back to its centered position about the desired axis.

  19. Effects of Fault Displacement on Emplacement Drifts

    SciTech Connect

    F. Duan

    2000-04-25

    The purpose of this analysis is to evaluate potential effects of fault displacement on emplacement drifts, including drip shields and waste packages emplaced in emplacement drifts. The output from this analysis not only provides data for the evaluation of long-term drift stability but also supports the Engineered Barrier System (EBS) process model report (PMR) and Disruptive Events Report currently under development. The primary scope of this analysis includes (1) examining fault displacement effects in terms of induced stresses and displacements in the rock mass surrounding an emplacement drift and (2 ) predicting fault displacement effects on the drip shield and waste package. The magnitude of the fault displacement analyzed in this analysis bounds the mean fault displacement corresponding to an annual frequency of exceedance of 10{sup -5} adopted for the preclosure period of the repository and also supports the postclosure performance assessment. This analysis is performed following the development plan prepared for analyzing effects of fault displacement on emplacement drifts (CRWMS M&O 2000). The analysis will begin with the identification and preparation of requirements, criteria, and inputs. A literature survey on accommodating fault displacements encountered in underground structures such as buried oil and gas pipelines will be conducted. For a given fault displacement, the least favorable scenario in term of the spatial relation of a fault to an emplacement drift is chosen, and the analysis is then performed analytically. Based on the analysis results, conclusions are made regarding the effects and consequences of fault displacement on emplacement drifts. Specifically, the analysis will discuss loads which can be induced by fault displacement on emplacement drifts, drip shield and/or waste packages during the time period of postclosure.

  20. Flow instabilities during annular displacement of one non-Newtonian fluid by another

    NASA Astrophysics Data System (ADS)

    Tehrani, M. A.; Bittleston, S. H.; Long, P. J. G.

    1993-02-01

    This paper describes an experimental setup for axial laminar flow of liquids in the annulus between two eccentered cylinders. The design uses a conductivity method for measuring peak axial velocities around the annulus, and for the determination of displacement efficiency when displacing one fluid by another (displacement efficiency being defined as the ratio of volume of displaced fluid removed from the annulus, to the volume of the annulus, after a given number of annular volumes have been pumped). In an eccentric annulus, lower axial velocity in the narrow side produces “channeling” of the displacing fluid in the wide side and reduces the displacement efficiency. A positive density contrast between the two fluids can increase the efficiency by promoting azimuthal flow of the (denser) displacing fluid towards the narrow side. In this paper we report that gravity driven azimuthal flow is prone to severe instabilities which accelerate the displacement process but may leave behind an immobile strip of the displaced fluid in the narrow side.

  1. Quantitative measurements of force and displacement using an optical trap.

    PubMed Central

    Simmons, R M; Finer, J T; Chu, S; Spudich, J A

    1996-01-01

    We combined a single-beam gradient optical trap with a high-resolution photodiode position detector to show that an optical trap can be used to make quantitative measurements of nanometer displacements and piconewton forces with millisecond resolution. When an external force is applied to a micron-sized bead held by an optical trap, the bead is displaced from the center of the trap by an amount proportional to the applied force. When the applied force is changed rapidly, the rise time of the displacement is on the millisecond time scale, and thus a trapped bead can be used as a force transducer. The performance can be enhanced by a feedback circuit so that the position of the trap moves by means of acousto-optic modulators to exert a force equal and opposite to the external force applied to the bead. In this case the position of the trap can be used to measure the applied force. We consider parameters of the trapped bead such as stiffness and response time as a function of bead diameter and laser beam power and compare the results with recent ray-optic calculations. PMID:8785341

  2. 40 CFR 205.153 - Engine displacement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Engine displacement. 205.153 Section 205.153 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycles § 205.153 Engine displacement. (a)...

  3. 40 CFR 205.153 - Engine displacement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Engine displacement. 205.153 Section 205.153 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycles § 205.153 Engine displacement. (a)...

  4. 40 CFR 205.153 - Engine displacement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Engine displacement. 205.153 Section 205.153 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) NOISE ABATEMENT PROGRAMS TRANSPORTATION EQUIPMENT NOISE EMISSION CONTROLS Motorcycles § 205.153 Engine displacement. (a)...

  5. Is Maxwell's Displacement Current a Current?

    ERIC Educational Resources Information Center

    French, A. P.

    2000-01-01

    Discusses in detail the claim that certain well-known physics experiments demonstrate the magnetic field produced by Maxwell's displacement current. Addresses the question of whether the displacement current acts as a source of magnetic field in the same way as a current in a wire would. (Contains 12 references.) (WRM)

  6. Worker Displacement in a Strong Labor Market.

    ERIC Educational Resources Information Center

    Helwig, Ryan T.

    2001-01-01

    As economic growth continued in 1997 and 1998, job losses declined and the displacement rate was the lowest of the 1990s. Many displaced workers were able to find new jobs with little or no change in weekly earnings. (Author/JOW)

  7. Video Games, Adolescents, and the Displacement Effect

    ERIC Educational Resources Information Center

    Fisher, Carla Christine

    2012-01-01

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

  8. Displaced Homemakers: Vo-Tech Workshop Guide.

    ERIC Educational Resources Information Center

    Peltier, Wanda Jo

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

  9. Multi-interferometric displacement measurement system with variable measurement mirrors.

    PubMed

    Chang, Chung-Ping; Tung, Pi-Cheng; Shyu, Lih-Horng; Wang, Yung-Cheng; Manske, Eberhard

    2013-06-10

    Laser interferometers have been widely implemented for the displacement sensing and positioning calibration of the precision mechanical industry, due to their excellent measuring features and direct traceability to the dimensional definition. Currently some kinds of modified Fabry-Perot interferometers with a planar mirror or a corner cube prism as the measurement mirror have been proposed. Each optical structure of both models has the individual particularity and performance for measuring applications. In this investigation, a multi-interferometric displacement system has been proposed whose measurement mirror can be quickly and conveniently altered with a planar mirror or a corner cube reflector depending on the measuring demand. Some experimental results and analyses about the interpolation error and displacement measurements with both reflectors have been demonstrated. According to the results, suggestions about the choice of a measuring reflector and interpolation model have been presented. With the measuring verifications, the developed system with a maximum standard deviation less than 0.2081 μm in measuring range of 300 mm would be a compact and robust tool for sensing or calibrating the linear displacement of mechanical equipment.

  10. Oscillatory electromyographic responses to limb displacement in Parkinsonism.

    PubMed

    Teräväinen, H

    1980-05-01

    Forty Parkinsonian patients and 26 normal subjects were instructed not to resist movements of a handle which they maintained in a specified position (1) during tonic activation of muscles against the force produced by a torque motor and (2) while no force was produced by the motor. Electromyographic responses to handle displacements were recorded in biceps muscle (pronating or supinating displacements) or in wrist extensor and flexor muscles (displacements which extended or flexed the wrist). Displacements involving changes of muscle length elicited (1) excitation and inhibition occurring at monosynaptic latency in muscles which were stretched and shortened, respectively; (2) a "silent period" following the initial excitation in the stretched muscle and excitation following the initial inhibition in the shortened muscle (shortening reaction); and (3) (in Parkinsonian patients) sustained oscillations at about 4 to 5 Hz (at rest) or about 6 to 8 Hz (during maintained posture). It was also observed that the initial muscle responses in both the stretched and shortened muscle could be reciprocal and biphasic, with the two peaks of excitation in the agonist occurring during reduced activity of antagonist muscles, and vice versa.

  11. Nonaffine displacements in crystalline solids in the harmonic limit.

    PubMed

    Ganguly, Saswati; Sengupta, Surajit; Sollich, Peter; Rao, Madan

    2013-04-01

    A systematic coarse graining of microscopic atomic displacements generates a local elastic deformation tensor D as well as a positive definite scalar χ measuring nonaffinity, i.e., the extent to which the displacements are not representable as affine deformations of a reference crystal. We perform an exact calculation of the statistics of χ and D and their spatial correlations for solids at low temperatures, within a harmonic approximation and in one and two dimensions. We obtain the joint distribution P(χ,D) and the two-point spatial correlation functions for χ and D. We show that nonaffine and affine deformations are coupled even in a harmonic solid, with a strength that depends on the size of the coarse-graining volume Ω and dimensionality. As a corollary to our work, we identify the field h(χ) conjugate to χ and show that this field may be tuned to produce a transition to a state where the ensemble average <χ> and the correlation length of χ diverge. Our work should be useful as a template for understanding nonaffine displacements in realistic systems with or without disorder and as a means for developing computational tools for studying the effects of nonaffine displacements in melting, plastic flow, and the glass transition.

  12. Crustal displacements due to continental water loading

    USGS Publications Warehouse

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

    2001-01-01

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

  13. Crustal Displacements Due to Continental Water Loading

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  14. Airbag roll marks & displaced rocks and soil

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Looking southwest from the lander, soil disturbances indicating the spacecraft rolled through the landing site are visible. Arriving from the east, the lander, still encased in its protective airbags, rolled up a slight rise and then rolled back down to its final position. The inset at left shows displaced rocks near the rock 'Flat Top.' Dark patches of disturbed soil indicate where the rocks had originally rested Both insets show rocks that were pushed into the soil from the weight of the lander, visible from the areas of raised rims of dark, disturbed soil around several rocks. The south summit of Twin Peaks is in the background, while a lander petal, deflated airbag, and rear rover deployment ramp are in the foreground.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is an operating division of the California Institute of Technology (Caltech).

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

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  16. Displacement of location in illusory line motion.

    PubMed

    Hubbard, Timothy L; Ruppel, Susan E

    2013-05-01

    Six experiments examined displacement in memory for the location of the line in illusory line motion (ILM; appearance or disappearance of a stationary cue is followed by appearance of a stationary line that is presented all at once, but the stationary line is perceived to "unfold" or "be drawn" from the end closest to the cue to the end most distant from the cue). If ILM was induced by having a single cue appear, then memory for the location of the line was displaced toward the cue, and displacement was larger if the line was closer to the cue. If ILM was induced by having one of two previously visible cues vanish, then memory for the location of the line was displaced away from the cue that vanished. In general, the magnitude of displacement increased and then decreased as retention interval increased from 50 to 250 ms and from 250 to 450 ms, respectively. Displacement of the line (a) is consistent with a combination of a spatial averaging of the locations of the cue and the line with a relatively weaker dynamic in the direction of illusory motion, (b) might be implemented in a spreading activation network similar to networks previously suggested to implement displacement resulting from implied or apparent motion, and (c) provides constraints and challenges for theories of ILM.

  17. Displacive disorder in three high-k bismuth oxide pyrochlores

    SciTech Connect

    Melot, B.; Rodriguez, E.; Proffen, Th.; Hayward, M.A.; Seshadri, R. . E-mail: seshadri@mrl.ucsb.edu

    2006-05-25

    We use time-of-flight neutron powder diffraction to examine static displacive disorder in three different pyrochlore A{sub 2}B{sub 2}O{sub 6}O' compounds with Bi on the A site. The compounds (Bi{sub 1.5}Zn{sub 0.5})(Nb{sub 1.5}Zn{sub 0.5})O{sub 6}O' (BZN) (Bi{sub 1.5}Zn{sub 0.5})(Ta{sub 1.5}Zn{sub 0.5})O{sub 6}O' (BZT), and (Bi{sub 1.5}Zn{sub 0.5})(Sb{sub 1.5}Zn{sub 0.5})O{sub 6}O' (BZS), are of interest - particularly BZN - for their high dielectric constants in the absence of any phase transition from the cubic high temperature phase. The local structures of the three compounds is characterized by displacive disorder from the ideal pyrochlore positions for both the A and O' sites, with the precise nature of the disorder being quite similar. However the extent of displacive disorder is different, despite the B-O networks being nearly identical in the three compounds. The reported dielectric constants of the three compounds are related to the extent of local displacement, and BZN, with the largest extent of local atomic displacement of A and O', is also reported to have the largest dielectric constant at 1 MHz. The dielectric constants are also related to the magnitudes of the thermal parameters of the different ions. The strongest correlation is found to involve the thermal parameter on the B site (Nb, Ta, or Sb)

  18. Variable displacement alpha-type Stirling engine

    NASA Astrophysics Data System (ADS)

    Homutescu, V. M.; Bălănescu, D. T.; Panaite, C. E.; Atanasiu, M. V.

    2016-08-01

    The basic design and construction of an alpha-type Stirling engine with on load variable displacement is presented. The variable displacement is obtained through a planar quadrilateral linkage with one on load movable ground link. The physico-mathematical model used for analyzing the variable displacement alpha-type Stirling engine behavior is an isothermal model that takes into account the real movement of the pistons. Performances and power adjustment capabilities of such alpha-type Stirling engine are calculated and analyzed. An exemplification through the use of the numerical simulation was performed in this regard.

  19. Displacement sensor based on plasmonic slot metamaterials

    NASA Astrophysics Data System (ADS)

    Wu, Wei; Ren, Mengxin; Pi, Biao; Cai, Wei; Xu, Jingjun

    2016-02-01

    In this paper, we demonstrate a plasmonic type displacement sensor based on slot metamaterials. The sensors are formed by arranging metamaterial arrays with different dimension parameters adjacently. Hence, the measured spectra would be modified as a result of moving the sensors across the detecting area of the spectrometer. From the spectral changes, the displacement amount could be retrieved. The sensor is demonstrated to be capable of recognizing a displacement of 200 nm, which is equal to the period of the metamaterial lattice, and the sensitivity is largely dependent on the shape and size of the acquisition area of the spectrometer used for spectra analysis.

  20. A Differential Monolithically Integrated Inductive Linear Displacement Measurement Microsystem

    PubMed Central

    Podhraški, Matija; Trontelj, Janez

    2016-01-01

    An inductive linear displacement measurement microsystem realized as a monolithic Application-Specific Integrated Circuit (ASIC) is presented. The system comprises integrated microtransformers as sensing elements, and analog front-end electronics for signal processing and demodulation, both jointly fabricated in a conventional commercially available four-metal 350-nm CMOS process. The key novelty of the presented system is its full integration, straightforward fabrication, and ease of application, requiring no external light or magnetic field source. Such systems therefore have the possibility of substituting certain conventional position encoder types. The microtransformers are excited by an AC signal in MHz range. The displacement information is modulated into the AC signal by a metal grating scale placed over the microsystem, employing a differential measurement principle. Homodyne mixing is used for the demodulation of the scale displacement information, returned by the ASIC as a DC signal in two quadrature channels allowing the determination of linear position of the target scale. The microsystem design, simulations, and characterization are presented. Various system operating conditions such as frequency, phase, target scale material and distance have been experimentally evaluated. The best results have been achieved at 4 MHz, demonstrating a linear resolution of 20 µm with steel and copper scale, having respective sensitivities of 0.71 V/mm and 0.99 V/mm. PMID:26999146

  1. PDT - PARTICLE DISPLACEMENT TRACKING SOFTWARE

    NASA Technical Reports Server (NTRS)

    Wernet, M. P.

    1994-01-01

    Particle Imaging Velocimetry (PIV) is a quantitative velocity measurement technique for measuring instantaneous planar cross sections of a flow field. The technique offers very high precision (1%) directionally resolved velocity vector estimates, but its use has been limited by high equipment costs and complexity of operation. Particle Displacement Tracking (PDT) is an all-electronic PIV data acquisition and reduction procedure which is simple, fast, and easily implemented. The procedure uses a low power, continuous wave laser and a Charged Coupled Device (CCD) camera to electronically record the particle images. A frame grabber board in a PC is used for data acquisition and reduction processing. PDT eliminates the need for photographic processing, system costs are moderately low, and reduced data are available within seconds of acquisition. The technique results in velocity estimate accuracies on the order of 5%. The software is fully menu-driven from the acquisition to the reduction and analysis of the data. Options are available to acquire a single image or 5- or 25-field series of images separated in time by multiples of 1/60 second. The user may process each image, specifying its boundaries to remove unwanted glare from the periphery and adjusting its background level to clearly resolve the particle images. Data reduction routines determine the particle image centroids and create time history files. PDT then identifies the velocity vectors which describe the particle movement in the flow field. Graphical data analysis routines are included which allow the user to graph the time history files and display the velocity vector maps, interpolated velocity vector grids, iso-velocity vector contours, and flow streamlines. The PDT data processing software is written in FORTRAN 77 and the data acquisition routine is written in C-Language for 80386-based IBM PC compatibles running MS-DOS v3.0 or higher. Machine requirements include 4 MB RAM (3 MB Extended), a single or

  2. Is perceived angular displacement the time integral of perceived angular velocity?

    PubMed

    Mergner, T; Rumberger, A; Becker, W

    1996-01-01

    Estimates of rotational self-displacement and self-velocity have been used interchangeably in vestibular psycho-physics to characterize vestibular ego-motion perception. However, the assumption underlying this indiscriminate use has never been tested. The assumption holds that the two estimates are equivalent, with the displacement estimates reflecting the time integral of the signal underlying the velocity estimate. We tested this hypothesis by directly comparing displacement and velocity estimates. Two groups of healthy young subjects (2 x n = 15) were presented with the same vestibular stimuli (horizontal whole body rotations in the dark in the form of velocity steps of 5, 10, 20, and 40 degrees/s with 1, 2, 4, 8, and 16 s duration, yielding position ramps of 5, 10, 20, 40, 80, 160, and 320 degrees total displacement). The first subject group estimated peak velocity, and the second group estimated total displacement, both groups using a comparable psychophysical procedure (Stevens' magnitude estimation). The experimentally obtained velocity estimates were used to predict the displacement estimates. To this end, the velocity signal was assumed to decay exponentially from the reported peak value (reflecting the dynamics of peripheral and early central vestibular mechanisms) and was mathematically integrated. Predicted and measured displacement estimates were similar when a time constant of 20 s was assumed, which is in good agreement with earlier studies. We conclude that vestibular displacement estimates can, indeed, be considered equivalent to vestibular velocity estimates, at least for the stimulus parameters used.

  3. Stepping Aside: Correlates of Displacement in Pedestrians.

    ERIC Educational Resources Information Center

    Willis, Frank N., Jr.; And Others

    1979-01-01

    Examines the effects of gender, age, race, group size, and other characteristics on spatial displacement in the general population. Considers the relative contributions of power, gallantry, and status in the determining of who yields to whom. (JMF)

  4. Displacement field measurement in the nanometer range

    NASA Astrophysics Data System (ADS)

    Surrel, Yves; Fournier, Nicolas

    1996-09-01

    The grid method is a classical tool for displacement measurement, which provides field data. This method has benefited very much from the phase-shifting technique in recent years. Two examples of applications of this method in the nanometer range are presented. The first one concerns the materials science: it is shown that microgrids observed by SEM can provide displacement field data with an accuracy of a few nanometers. The second one concerns the measurement of a rigid-body displacement. In this case, displacement data can be averaged over the whole field, drastically increasing the sensitivity. It is shown that a sensitivity of 7 nm can be achieved by using a coarse grid with 8 lines per mm. This sensitivity corresponds to 1/18000 of the grid pitch.

  5. Bucky gel actuator displacement: experiment and model

    NASA Astrophysics Data System (ADS)

    Ghamsari, A. K.; Jin, Y.; Zegeye, E.; Woldesenbet, E.

    2013-02-01

    Bucky gel actuator (BGA) is a dry electroactive nanocomposite which is driven with a few volts. BGA’s remarkable features make this tri-layered actuator a potential candidate for morphing applications. However, most of these applications would require a better understanding of the effective parameters that influence the BGA displacement. In this study, various sets of experiments were designed to investigate the effect of several parameters on the maximum lateral displacement of BGA. Two input parameters, voltage and frequency, and three material/design parameters, carbon nanotube type, thickness, and weight fraction of constituents were selected. A new thickness ratio term was also introduced to study the role of individual layers on BGA displacement. A model was established to predict BGA maximum displacement based on the effect of these parameters. This model showed good agreement with reported results from the literature. In addition, an important factor in the design of BGA-based devices, lifetime, was investigated.

  6. Buoyant miscible displacement flows in vertical pipe

    NASA Astrophysics Data System (ADS)

    Amiri, A.; Larachi, F.; Taghavi, S. M.

    2016-10-01

    The displacement flow of two miscible Newtonian fluids is investigated experimentally in a vertical pipe of long aspect ratio (δ-1 ≈ 210). The fluids have a small density difference and they have the same viscosity. The heavy displacing fluid is initially placed above the light displaced fluid. The displacement flow is downwards. The experiments cover a wide range of the two dimensionless parameters that largely describe the flow: the modified Reynolds number (0 ≤ Ret⪅800) and the densimetric Froude number (0 ≤ Fr ≤ 24). We report on the stabilizing effect of the imposed flow and uncover the existence of two main flow regimes at long times: a stable displacement flow and an unstable displacement flow. The transition between the two regimes occurs at a critical modified Reynolds number " separators=" R et | Critical , as a function of Fr. We study in depth the stable flow regime: First, a lubrication model combined with a simple initial acceleration formulation delivers a reasonable prediction to the time-dependent penetrating displacing front velocity. Second, we find two sub-regimes for stable displacements, namely, sustained-back-flows and no-sustained-back-flows. The transition between the two sub-regimes is a marginal stationary interface flow state, which is also well predicted by the lubrication model. The unstable regime is associated to instabilities and diffusive features of the flow. In addition, particular patterns such as front detachment phenomenon appear in the unstable flow regime, for which we quantify the regions of existence versus the dimensionless groups.

  7. Monolithically integrated interferometer for optical displacement measurement

    NASA Astrophysics Data System (ADS)

    Hofstetter, Daniel; Zappe, Hans P.

    1996-01-01

    We discuss the fabrication of a monolithically integrated optical displacement sensors using III-V semiconductor technology. The device is configured as a Michelson interferometer and consists of a distributed Bragg reflector laser, a photodetector and waveguides forming a directional coupler. Using this interferometer, displacements in the 100 nm range could be measured at distances of up to 45 cm. We present fabrication, device results and characterization of the completed interferometer, problems, limitations and future applications will also be discussed.

  8. Displacement sensor for indoor machine calibrations.

    PubMed

    Mudassar, Asloob Ahmad; Butt, Saira

    2013-05-20

    This paper presents a simple displacement sensor for indoor machine calibrations. The sensor, which is placed in the path of a diverging laser beam, consists of two plane mirror pieces laterally displaced with the line joining their centers initially held perpendicular to the optical axis of the beam during the displacement of the sensor with one of the mirrors always traveling along the optical axis of the laser beam. The optical signals from the two mirrors are combined and a simple detector at the interference plane counts the fringes during the sensor displacement. The sensor could be mounted on the moving head of any mechanical machine, e.g., the lathe machine for displacement calibration. The device has been tested over a range of 10 cm beyond a distance of 150 cm from a diverging laser source giving an accuracy of 1.1015 μm. Theoretical modeling, simulation, and experimental results are presented which establish that the proposed sensor can be used as a promising displacement measuring device.

  9. Development and evolution of character displacement.

    PubMed

    Pfennig, David W; Pfennig, Karin S

    2012-05-01

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

  10. Displacement of the anterior leaflet of the tricuspid valve: Rare variant of Ebstein's anomaly.

    PubMed

    Tsujii, Nobuyuki; Kurosaki, Kenichi; Yasuda, Kenji; Mizuno, Masanori; Sakaguchi, Heima; Hoashi, Takaya; Ichikawa, Hajime; Shiraishi, Isao

    2016-08-01

    In Ebstein's anomaly, the points of attachment, or hinges, of the septal and mural leaflets in the right ventricle are displaced away from the atrioventricular junction. In contrast, the junctional hinge of the anterior leaflet usually retains a normal position. Here, we report a case of giant right atrial aneurysm due to isolated displacement of the anterior leaflet of the tricuspid valve in an infant, a rare variant of Ebstein's anomaly. Enlargement of the right atrium, which was initially diagnosed during the fetal period, progressively and markedly dilated after birth and was successfully treated with surgical resection. Isolated displacement of the anterior leaflet should be recognized as a variant of Ebstein's anomaly.

  11. Nuclear core positioning system

    DOEpatents

    Garkisch, Hans D.; Yant, Howard W.; Patterson, John F.

    1979-01-01

    A structural support system for the core of a nuclear reactor which achieves relatively restricted clearances at operating conditions and yet allows sufficient clearance between fuel assemblies at refueling temperatures. Axially displaced spacer pads having variable between pad spacing and a temperature compensated radial restraint system are utilized to maintain clearances between the fuel elements. The core support plates are constructed of metals specially chosen such that differential thermal expansion produces positive restraint at operating temperatures.

  12. Action can amplify motion-induced illusory displacement

    PubMed Central

    Caniard, Franck; Bülthoff, Heinrich H.; Thornton, Ian M.

    2015-01-01

    Local motion is known to produce strong illusory displacement in the perceived position of globally static objects. For example, if a dot-cloud or grating drifts to the left within a stationary aperture, the perceived position of the whole aperture will also be shifted to the left. Previously, we used a simple tracking task to demonstrate that active control over the global position of an object did not eliminate this form of illusion. Here, we used a new iPad task to directly compare the magnitude of illusory displacement under active and passive conditions. In the active condition, participants guided a drifting Gabor patch along a virtual slalom course by using the tilt control of an iPad. The task was to position the patch so that it entered each gate at the direct center, and we used the left/right deviations from that point as our dependent measure. In the passive condition, participants watched playback of standardized trajectories along the same course. We systematically varied deviation from midpoint at gate entry, and participants made 2AFC left/right judgments. We fitted cumulative normal functions to individual distributions and extracted the point of subjective equality (PSE) as our dependent measure. To our surprise, the magnitude of displacement was consistently larger under active than under passive conditions. Importantly, control conditions ruled out the possibility that such amplification results from lack of motor control or differences in global trajectories as performance estimates were equivalent in the two conditions in the absence of local motion. Our results suggest that the illusion penetrates multiple levels of the perception-action cycle, indicating that one important direction for the future of perceptual illusions may be to more fully explore their influence during active vision. PMID:25628558

  13. Autonomous dynamic displacement estimation from data fusion of acceleration and intermittent displacement measurements

    NASA Astrophysics Data System (ADS)

    Kim, Junhee; Kim, Kiyoung; Sohn, Hoon

    2014-01-01

    Addressing the importance of displacement measurement of structural responses in the field of structural health monitoring, this paper presents an autonomous algorithm for dynamic displacement estimation from acceleration integration fused with displacement data intermittently measured. The presented acceleration integration algorithm of multi-rate Kalman filtering distinguishes itself from the past study in the literature by explicitly considering acceleration measurement bias. Furthermore, the algorithm is formulated by unique state definition of integration errors and error dynamics system modeling. To showcase performance of the algorithm, a series of laboratory dynamic experiments for measuring structural responses of acceleration and displacement are conducted. Improved results are demonstrated through comparison between the proposed and past study.

  14. Public self-consciousness moderates the link between displacement behaviour and experience of stress in women.

    PubMed

    Mohiyeddini, Changiz; Bauer, Stephanie; Semple, Stuart

    2013-07-01

    When stressed, people typically show elevated rates of displacement behaviour--activities such as scratching and face touching that seem irrelevant to the ongoing situation. Growing evidence indicates that displacement behaviour may play a role in regulating stress levels, and thus may represent an important component of the coping response. Recently, we found evidence that this stress-regulating effect of displacement behaviour is found in men but not in women. This sex difference may result from women's higher levels of public self-consciousness, which could inhibit expression of displacement behaviour due to the fear of projecting an inappropriate image. Here, we explored the link between public self-consciousness, displacement behaviour and stress among 62 healthy women (mean age = 26.59 years; SD = 3.61). We first assessed participants' public self-consciousness, and then quantified displacement behaviour, heart rate and cognitive performance during a Trier Social Stress Test (TSST) and used self-report questionnaires to assess the experience of stress afterwards. Public self-consciousness was negatively correlated with rate of displacement behaviour, and positively correlated with both the subjective experience of stress post-TSST and the number of mistakes in the cognitive task. Moderation analyses revealed that for women high in public self-consciousness, high levels of displacement behaviour were associated with higher reported levels of stress and poorer cognitive performance. For women low in public self-consciousness, stress levels and cognitive performance were unrelated to displacement behaviour. Our findings indicate that public self-consciousness is associated with both the expression of displacement behaviour and how such behaviour mediates responses to social stress.

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

    SciTech Connect

    Butler, Wayne M.; Morris, Mallory N.; Merrick, Gregory S.; Kurko, Brian S.; Murray, Brian C.

    2012-10-01

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

  16. Kinetics of DNA Strand Displacement Systems with Locked Nucleic Acids.

    PubMed

    Olson, Xiaoping; Kotani, Shohei; Yurke, Bernard; Graugnard, Elton; Hughes, William L

    2017-03-30

    Locked nucleic acids (LNAs) are conformationally restricted RNA nucleotides. Their increased thermal stability and selectivity toward their complements make them well-suited for diagnostic and therapeutic applications. Although the structural and thermodynamic properties of LNA-LNA, LNA-RNA, and LNA-DNA hybridizations are known, the kinetic effects of incorporating LNA nucleotides into DNA strand displacement systems are not. Here, we thoroughly studied the strand displacement kinetics as a function of the number and position of LNA nucleotides in DNA oligonucleotides. When compared to that of an all-DNA control, with an identical sequence, the leakage rate constant was reduced more than 50-fold, to an undetectable level, and the invasion rate was preserved for a hybrid DNA/LNA system. The total performance enhancement ratio also increased more than 70-fold when calculating the ratio of the invading rate to the leakage rate constants for a hybrid system. The rational substitution of LNA nucleotides for DNA nucleotides preserves sequence space while improving the signal-to-noise ratio of strand displacement systems. Hybrid DNA/LNA systems offer great potential for high-performance chemical reaction networks that include catalyzed hairpin assemblies, hairpin chain reactions, motors, walkers, and seesaw gates.

  17. A novel bio-sensor based on DNA strand displacement.

    PubMed

    Shi, Xiaolong; Wang, Zhiyu; Deng, Chenyan; Song, Tao; Pan, Linqiang; Chen, Zhihua

    2014-01-01

    DNA strand displacement technology performs well in sensing and programming DNA segments. In this work, we construct DNA molecular systems based on DNA strand displacement performing computation of logic gates. Specifically, a class of so-called "DNA neurons" are achieved, in which a "smart" way inspired by biological neurons encoding information is developed to encode and deliver information using DNA molecules. The "DNA neuron" is bistable, that is, it can sense DNA molecules as input signals, and release "negative" or "positive" signals DNA molecules. We design intelligent DNA molecular systems that are constructed by cascading some particularly organized "DNA neurons", which could perform logic computation, including AND, OR, XOR logic gates, automatically. Both simulation results using visual DSD (DNA strand displacement) software and experimental results are obtained, which shows that the proposed systems can detect DNA signals with high sensitivity and accretion; moreover, the systems can process input signals automatically with complex nonlinear logic. The method proposed in this work may provide a new way to construct a sensitive molecular signal detection system with neurons spiking behavior in vitro, and can be used to develop intelligent molecular processing systems in vivo.

  18. High speed displacement analysis using digital speckle correlation

    NASA Astrophysics Data System (ADS)

    Siebert, T.; Splitthof, K.; Becker, T.; Krupka, R.

    2006-06-01

    Digital speckle correlation techniques have already been successfully proven for accurate displacement analysis. With the use of two cameras, three dimensional measurements of contours and displacements can be carried out. The principle of this technique is pretty easy to understood and realized, opening a nearly unlimited range of applications. Rapid new developments in the field of digital imaging and computer technology, especially for very much dynamic applications, opens further applications for these measurement method up to high speed deformation and strain analysis, e.g. in the fields of, material testing, fracture mechanics, high speed testing, advanced materials and component testing. The dynamic range is combined with the capability to measure very large strains (up to more than 100%). The resolution of the deformation in space and time opens a wide range of applications for vibration analysis of objects. Since the system determines the absolute position and displacements of the object in space it is capable of measuring high amplitudes and even objects with rigid body movements, which is a big advantage against full field ESPI systems. The absolute resolution depends on the field of view and is scalable. Calibration of the optical setup is a crucial point which will be discussed in detail. Examples of the analysis of high speed harmonic vibration and transient events out of material research and industrial applications are presented. Results of measurement performed on a vibrating membrane and a tensile test sample are show typical features of the system.

  19. Ultra-Sensitive Magnetoresistive Displacement Sensing Device

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  20. Quantification of the vocal folds’ dynamic displacements

    NASA Astrophysics Data System (ADS)

    del Socorro Hernández-Montes, María; Muñoz, Silvino; De La Torre, Manuel; Flores, Mauricio; Pérez, Carlos; Mendoza-Santoyo, Fernando

    2016-05-01

    Fast dynamic data acquisition techniques are required to investigate the motional behavior of the vocal folds (VFs) when they are subjected to a steady air-flow through the trachea. High-speed digital holographic interferometry (DHI) is a non-invasive full-field-of-view technique that has proved its usefulness to study rapid and non-repetitive object movements. Hence it is an ideal technique used here to measure VF displacements and vibration patterns at 2000 fps. Analyses from a set of 200 displacement images showed that VFs’ vibration cycles are established along their width (y) and length (x). Furthermore, the maximum deformation for the right and left VFs’ area may be quantified from these images, which in itself represents an important result in the characterization of this structure. At a controlled air pressure, VF displacements fall within the range ~100-1740 nm, with a calculated precision and accuracy that yields a variation coefficient of 1.91%. High-speed acquisition of full-field images of VFs and their displacement quantification are on their own significant data in the study of their functional and physiological behavior since voice quality and production depend on how they vibrate, i.e. their displacement amplitude and frequency. Additionally, the use of high speed DHI avoids prolonged examinations and represents a significant scientific and technological alternative contribution in advancing the knowledge and working mechanisms of these tissues.

  1. Fingering phenomena during grain-grain displacement

    NASA Astrophysics Data System (ADS)

    Mello, Nathália M. P.; Paiva, Humberto A.; Combe, G.; Atman, A. P. F.

    2017-04-01

    Spontaneous formation of fingered patterns during the displacement of dense granular assemblies was experimentally reported few years ago, in a radial Hele-Shaw cell. Here, by means of discrete element simulations, we have recovered the experimental findings and extended the original study to explore the control parameters space. In particular, using assemblies of grains with different geometries (monodisperse, bidisperse, or polydisperse), we measured the macroscopic stress tensor in the samples in order to confirm some conjectures proposed in analogy with Saffman-Taylor viscous fingering phenomena for immiscible fluids. Considering an axial setup which allows to control the discharge of grains and to follow the trajectory and the pressure gradient along the displacing interface, we have applied the Darcy law for laminar flow in fluids in order to measure an "effective viscosity" for each assembly combination, in an attempt to mimic variation of the viscosity ratio between the injected/displaced fluids in the Saffman-Taylor experiment. The results corroborate the analogy with the viscous fluids displacement, with the bidisperse assembly corresponding to the less viscous geometry. But, differently to fluid case, granular fingers only develop for a specific combination of displaced/injected geometries, and we have demonstrated that it is always related with the formation of a force chain network along the finger direction.

  2. Centimeter Cosmo-Skymed Range Measurements for Monitoring Ground Displacements

    NASA Astrophysics Data System (ADS)

    Fratarcangeli, F.; Nascetti, A.; Capaldo, P.; Mazzoni, A.; Crespi, M.

    2016-06-01

    The SAR (Synthetic Aperture Radar) imagery are widely used in order to monitor displacements impacting the Earth surface and infrastructures. The main remote sensing technique to extract sub-centimeter information from SAR imagery is the Differential SAR Interferometry (DInSAR), based on the phase information only. However, it is well known that DInSAR technique may suffer for lack of coherence among the considered stack of images. New Earth observation SAR satellite sensors, as COSMO-SkyMed, TerraSAR-X, and the coming PAZ, can acquire imagery with high amplitude resolutions too, up to few decimeters. Thanks to this feature, and to the on board dual frequency GPS receivers, allowing orbits determination with an accuracy at few centimetres level, the it was proven by different groups that TerraSAR-X imagery offer the capability to achieve, in a global reference frame, 3D positioning accuracies in the decimeter range and even better just exploiting the slant-range measurements coming from the amplitude information, provided proper corrections of all the involved geophysical phenomena are carefully applied. The core of this work is to test this methodology on COSMO-SkyMed data acquired over the Corvara area (Bolzano - Northern Italy), where, currently, a landslide with relevant yearly displacements, up to decimeters, is monitored, using GPS survey and DInSAR technique. The leading idea is to measure the distance between the satellite and a well identifiable natural or artificial Persistent Scatterer (PS), taking in account the signal propagation delays through the troposphere and ionosphere and filtering out the known geophysical effects that induce periodic and secular ground displacements. The preliminary results here presented and discussed indicate that COSMO-SkyMed Himage imagery appear able to guarantee a displacements monitoring with an accuracy of few centimetres using only the amplitude data, provided few (at least one) stable PS's are available around the

  3. Propagation error minimization method for multiple structural displacement monitoring system

    NASA Astrophysics Data System (ADS)

    Jeon, Haemin; Shin, Jae-Uk; Myung, Hyun

    2013-04-01

    In the previous study, a visually servoed paired structured light system (ViSP) which is composed of two sides facing each other, each with one or two lasers, a 2-DOF manipulator, a camera, and a screen has been proposed. The lasers project their parallel beams to the screen on the opposite side and 6-DOF relative displacement between two sides is estimated by calculating positions of the projected laser beams and rotation angles of the manipulators. To apply the system to massive civil structures such as long-span bridges or high-rise buildings, the whole area should be divided into multiple partitions and each ViSP module is placed in each partition in a cascaded manner. In other words, the movement of the entire structure can be monitored by multiplying the estimated displacements from multiple ViSP modules. In the multiplication, however, there is a major problem that the displacement estimation error is propagated throughout the multiple modules. To solve the problem, propagation error minimization method (PEMM) which uses Newton-Raphson formulation inspired by the error back-propagation algorithm is proposed. In this method, a propagation error at the last module is calculated and then the estimated displacement from ViSP at each partition is updated in reverse order by using the proposed PEMM that minimizes the propagation error. To verify the performance of the proposed method, various simulations and experimental tests have been performed. The results show that the propagation error is significantly reduced after applying PEMM.

  4. Domain wall displacement by remote spin-current injection

    SciTech Connect

    Skirdkov, P. N.; Zvezdin, K. A.; Belanovsky, A. D.; Zvezdin, A. K.; Grollier, J.; Cros, V.

    2014-06-16

    We demonstrate numerically the ability to displace a magnetic domain wall (DW) by remote spin current injection. We consider a long and narrow magnetic nanostripe with a single DW. The spin-polarized current is injected perpendicularly to the film plane through a small nanocontact which is located at certain distance from the DW initial position. We show that the DW motion can be initiated not only by conventional spin-transfer torque but also by indirect spin-torque, created by remote spin-current injection and then transferred to the DW by the exchange-spring mechanism. An analytical description of this effect is proposed.

  5. Displacement Cascade Damage Production in Metals

    SciTech Connect

    Stoller, Roger E; Malerba, Lorenzo; Nordlund, Kai

    2015-01-01

    Radiation-induced changes in microstructure and mechanical properties in structural materials are the result of a complex set of physical processes initiated by the collision between an energetic particle (neutron or ion) and an atom in the lattice. This primary damage event is called an atomic displacement cascade. The simplest description of a displacement cascade is to view it as a series of many billiard-ball-like elastic collisions among the atoms in the material. This chapter describes the formation and evolution of this primary radiation damage mechanism to provide an overview of how stable defects are formed by displacement cascades, as well as the nature and morphology of the defects themselves. The impact of the relevant variables such as cascade energy and irradiation temperature is discussed, and defect formation in different materials is compared.

  6. Amorphization of Silicon Carbide by Carbon Displacement

    SciTech Connect

    Devanathan, Ram; Gao, Fei; Weber, William J.

    2004-05-10

    We have used molecular dynamics simulations to examine the possibility of amorphizing silicon carbide (SiC) by exclusively displacing C atoms. At a defect generation corresponding to 0.2 displacements per atom, the enthalpy surpasses the level of melt-quenched SiC, the density decreases by about 15%, and the radial distribution function shows a lack of long-range order. Prior to amorphization, the surviving defects are mainly C Frenkel pairs (67%), but Si Frenkel pairs (18%) and anti-site defects (15%) are also present. The results indicate that SiC can be amorphized by C sublattice displacements. Chemical short-range disorder, arising mainly from interstitial production, plays a significant role in the amorphization.

  7. Simple and sensitive strain gauge displacement transducer

    NASA Astrophysics Data System (ADS)

    Ramana, Y. V.; Sarma, L. P.

    1981-09-01

    We describe a simple and sensitive strain gauge displacement transducer. It is based on the linear movement of a shaft (with two cantilevers and four strain gauges) in a tapered chamber, resulting in a change in resistance proportional to the cantilever deformation. The transducer with its Wheatstone full bridge configuration is calibrated against a mechanical dial indicator of 0.002 mm accuracy for both ac and dc voltage excitations. Its output is linear for measurements of full range displacement up to 25 mm. It has a sensitivity of ±0.0082 mm for ac excitation with a strain indicator whose resolution is ±1 μɛ. It has a dc full range sensitivity of 1.5 mV/V for excitation levels up to 5 V. It can have varied field and laboratory applications wherever displacements are precisely read, recorded, or monitored.

  8. Miscible, porous media displacements with density stratification.

    PubMed

    Riaz, Amir; Meiburg, Eckart

    2004-11-01

    High accuracy, three-dimensional numerical simulations of miscible displacements with gravity override, in both homogeneous and heterogeneous porous media, are discussed for the quarter five-spot configuration. The influence of viscous and gravitational effects on the overall displacement dynamics is described in terms of the vorticity variable. Density differences influence the flow primarily by establishing a narrow gravity layer, in which the effective Peclet number is enhanced due to the higher flow rate. Although this effect plays a dominant role in homogeneous flows, it is suppressed to some extent in heterogeneous displacements. This is a result of coupling between the viscous and permeability vorticity fields. When the viscous wavelength is much larger than the permeability wavelength, gravity override becomes more effective because coupling between the viscous and permeability vorticity fields is less pronounced. Buoyancy forces of a certain magnitude can lead to a pinch-off of the gravity layer, thereby slowing it down.

  9. Magnetic Resonance Imaging (MRI) Evaluation for Anterior Disc Displacement of the Temporomandibular Joint

    PubMed Central

    Yang, Zhongjun; Wang, Mingguo; Ma, Yingwei; Lai, Qingguo; Tong, Dongdong; Zhang, Fenghe; Dong, Lili

    2017-01-01

    Background Magnetic resonance imaging (MRI) is the criterion standard imaging technique for visualization of the temporomandibular joint (TMJ) region, and is currently considered the optimum modality for comprehensive evaluation in patients with temporomandibular joint disorder (TMD). This study was aimed at finding the value of MRI in pre-clinical diagnosis of TMJ disc displacement. Material/Methods Patients primarily diagnosed as having anterior disc displacement by clinical symptoms and X-ray were selected in the present study. MRI was used to evaluate surrounding anatomical structures and position, as well as morphological and signal intensity change between patients and normal controls. Results Posterior band position was significantly different between the patient group and control group. At the maximum opened-mouth position, the location of disc intermediate zone returned to normal. At closed-mouth position, the thickness of anterior and middle, but not posterior, band increased. The motion range of the condyle in the anterior disc displacement without reduction (ADDWR) patient group was significantly less than the value in the anterior disc displacement with reduction (ADDR) patient group and the control group. Whether at closed-mouth position or maximum opened-mouth position, the exudate volume in the patient group was greater than in the normal group. Conclusions MRI can be successfully used to evaluate multiple morphological changes at different mouth positions of normal volunteers and patients. The disc-condyle relationship can serve as an important indicator in assessing anterior disc displacement, and can be used to distinguish disc displacement with or without reduction. PMID:28176754

  10. Frictional behavior of large displacement experimental faults

    USGS Publications Warehouse

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

    1996-01-01

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

  11. Atomistic Simulation of Displacement Cascades in Zircon

    SciTech Connect

    Devanathan, Ram; Weber, William J.; Corrales, Louis R.; BP McGrail and GA Cragnolino

    2002-05-06

    Low energy displacement cascades in zircon (ZrSiO4) initiated by a Zr primary knock-on atom have been investigated by molecular dynamics simulations using a Coulombic model for long-range interactions, Buckingham potential for short-range interactions and Ziegler-Biersack potentials for close pair interactions. Displacements were found to occur mainly in the O sublattice, and O replacements by a ring mechanism were predominant. Clusters containing Si interstitials bridged by O interstitials, vacancy clusters and anti-site defects were found to occur. This Si-O-Si bridging is considerable in quenched liquid ZrSiO4.

  12. Force based displacement measurement in micromechanical devices

    SciTech Connect

    O {close_quote}Shea, S. J.; Ng, C. K.; Tan, Y. Y.; Xu, Y.; Tay, E. H.; Chua, B. L.; Tien, N. C.; Tang, X. S.; Chen, W. T.

    2001-06-18

    We demonstrate how force detection methods based on atomic force microscopy can be used to measure displacement in micromechanical devices. We show the operation of a simple microfabricated accelerometer, the proof mass of which incorporates a tip which can be moved towards an opposing surface. Both noncontact operation using long range electrostatic forces and tapping mode operation are demonstrated. The displacement sensitivity of the present device using feedback to control the tip-surface separation is approximately 1 nm. {copyright} 2001 American Institute of Physics.

  13. Displacement sensors using soft magnetostrictive alloys

    NASA Astrophysics Data System (ADS)

    Hristoforou, E.; Reilly, R. E.

    1994-09-01

    We report results on the response of a family of displacement sensors, which are based on the magentostrictive delay line (MDL) technique, using current conductors orthogonal to the MDL. Such sensing technique is based on the change of the magnetic circuit at the acoustic stress point of origin due to the displacement of a soft magnetic material above it. Integrated arrays of sensors can be obtained due to the acoustic delay line technique and they can be used as tactile arrays, digitizers or devices for medical applications (gait analysis etc.), while absence of hysteresis and low cost of manufacturing make them competent in this sector of sensor market.

  14. Correlation between balance and gait according to pelvic displacement in stroke patients

    PubMed Central

    Kong, Seon Woong; Jeong, Yeon Woo; Kim, Jin Young

    2015-01-01

    [Purpose] The purpose of this study was to investigate the correlations of balance and gait according to pelvic displacement in stroke patients. [Subjects] The subjects of this study were 58 stroke patients who had been admitted to a hospital. [Methods] A Global Postural System was used to measure pelvic displacement. To measure the balance ability, a Tetrax balance system was used to measure the weight distribution index and stability index. Gait ability was measured during the 10-Meter Walking Test and Figure-of-8 Walk Test. [Results] The results of this study showed that was significant positive correlation between the anterior superior iliac spine height difference in pelvic displacement and the weight distribution index and significant positive correlation between the posterior superior iliac spine height difference and the stability index in the normal position with the eyes closed. Statistically significant positive correlation also was found between the anterior superior iliac spine height difference and the straight and curved gait ability. [Conclusion] The increased pelvic displacement in stroke patients results in a decrease in balance ability and gait speed. This suggests that control of pelvic displacement is necessary before functional training for patients with stroke. PMID:26311948

  15. The value of anterior displacement of the abdominal aorta in diagnosing neuroblastoma in children*

    PubMed Central

    Schiavon, Jose Luiz de Oliveira; Caran, Eliana Maria Monteiro; Odone Filho, Vicente; Lederman, Henrique Manoel

    2016-01-01

    Objective To determine the value of anterior displacement of the abdominal aorta, when present at any level or only at the level of the adrenal gland, contralateral to the mass, in diagnosing neuroblastoma on computed tomography or magnetic resonance imaging in children up to 7 years of age. Materials and Methods Imaging examinations of 66 patients were classified by consensus as for the presence of anterior aorta displacement and were compared with the pathology report. Results We found anterior abdominal aorta displacement in 26 (39.39%) of the 66 patients evaluated. Among those 26 patients, we identified neuroblastoma in 22 (84.62%), nephroblastoma in 3 (11.54%), and Burkitt lymphoma in 1 (3.85%). The positive predictive value was 84.62%, and the specificity was 88.24%. The displacement of the aorta was at the adrenal level, contralateral to the mass, in 14 cases, all of which were attributed to neuroblastoma. Conclusion When the abdominal aorta is displaced at the level of the adrenal gland, contralateral to the mass, it can be said that the diagnosis is neuroblastoma, whereas abdominal aorta displacement occurring at other abdominal levels has a positive predictive value for neuroblastoma of approximately 85%. PMID:28100931

  16. Determining Fault Geometries From Surface Displacements

    NASA Astrophysics Data System (ADS)

    Volkov, D.; Voisin, C.; Ionescu, I. R.

    2017-02-01

    We introduce a new algorithm for determining the geometry of active parts of faults. This algorithm uses surface measurements of displacement fields and local modeling of the Earth's crust as a half-space elastic medium. The numerical method relies on iterations alternating non-linear steps for recovering the geometry and linear steps for reconstructing slip fields. Our algorithm greatly improves upon past attempts at reconstructing fault profiles. We argue that these past attempts suffered from either the restrictive assumption that the geometry of faults can be derived using only uniformly constant slips or that they relied on arbitrary assumptions on the statistics of the reconstruction error. We test this algorithm on the 2006 Guerrero, Mexico, slow slip event (SSE) and on the 2009 SSE for the same region. These events occurred on a relatively well-known subduction zone, whose geometry was derived from seismicity and gravimetric techniques, see Kostoglodov et al. (Geophys Res Lett 23(23):3385-3388, 1996), Pardo and Suarez (J Geophys Res 100(B7):357-373, 1995), Singh and Pardo (Geophys Res Lett 20(14):1483-1486, 1993), so our results can be compared to known benchmarks. Our derived geometry is found to be consistent with these benchmarks regarding dip and strike angles and the positioning of the North American Trench. In addition, our derived slip distribution is also consistent with previous studies (all done with an assumed fixed geometry), see Larson et al. (Geophys Res Lett 34(13), 2007), Bekaert et al. (J Geophys Res: Solid Earth 120(2):1357-1375, 2015), Radiguet et al. (Geophys J Int 184(2):816-828, 2011, J Geophys Res 2012), Rivet et al. (Geophys Res Lett 38(8), 2011), Vergnolle et al. (J Geophys Res: Solid Earth 115(B8), 2010), Walpersdorf et al. Geophys Res Lett 38(15), 2011), to name a few. We believe that the new computational inverse method introduced in this paper holds great promise for applications to blind inversion cases, where both geometry and

  17. A Workshop Guide for Post-Secondary Displaced Homemaker Programs.

    ERIC Educational Resources Information Center

    Dahlberg, Maurine

    Based on a survey of displaced homemakers and displaced homemaker advisory committee members in Texas and on a literature review, this guide was developed to help leaders of displaced homemaker programs conduct workshops for their clients. Following an introduction which explains the rationale for conducting workshops for displaced homemakers, the…

  18. 24 CFR 882.810 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... section. (c) Relocation assistance for displaced persons. A “displaced person” (defined in paragraph (g... displaced person must be advised of his or her rights under the Fair Housing Act (42 U.S.C. 3601-19) and, if... qualifies as a displaced person, or the amount of relocation assistance for which the person is...

  19. 24 CFR 92.353 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... assistance for displaced persons—(1) General. A displaced person (defined in paragraph (c)(2) of this section... U.S.C. 4201-4655) and 49 CFR part 24. A “displaced person” must be advised of his or her rights..., safe, and sanitary replacement dwellings not located in such areas. (2) Displaced Person. (i)...

  20. 24 CFR 941.207 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... paragraph (b)(1) of this section. (c) Relocation assistance for displaced persons. A “displaced person... CFR part 24. A “displaced person” shall be advised of his/her rights under the Fair Housing Act (42 U... qualifies as a “displaced person,” or the amount of relocation assistance for which the person is...

  1. Do displacement activities help preschool children to inhibit a forbidden action?

    PubMed

    Pecora, Giulia; Addessi, Elsa; Schino, Gabriele; Bellagamba, Francesca

    2014-10-01

    Displacement activities are commonly recognized as behavioral patterns, mostly including self-directed actions (e.g., scratching, self-touching), that often occur in situations involving conflicting motivational tendencies. In ethology, several researchers have suggested that displacement activities could facilitate individuals in dealing with the stress experienced in a frustrating context. In child developmental research, some authors have assessed whether distraction strategies could help children to inhibit a dominant response during delay of gratification tasks. However, little is known about the displacement activities that young children may produce in such situations. This study was aimed at investigating whether displacement activities had an effect on preschool children's ability to postpone an immediate gratification (i.e., interacting with an attractive toy, a musical box), thereby functioning as regulators of their emotional state. To this end, we administered 143 2- to 4-year-olds with a delay maintenance task and related their performance with displacement activities they produced during the task and with actions with an external object. Children's latency to touch the musical box was positively related to their rate of displacement activities. However, the rate of displacement activities increased progressively as long as the children were able to inhibit the interaction with the musical box. In addition, the rate of displacement activities during the first 1 min of test did not predict the ability of children to inhibit the interaction with the box. These results suggest that displacement activities represented a functionless by-product of motivational conflict rather than a strategy that children used to inhibit their response to an attractive stimulus.

  2. Displacement Damage in Bipolar Linear Integrated Circuits

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

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

  3. Ko Displacement Theory for Structural Shape Predictions

    NASA Technical Reports Server (NTRS)

    Ko, William L.

    2010-01-01

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

  4. RECOVERY OF METAL USING ALUMINUM DISPLACEMENT

    EPA Science Inventory

    The removal of typical metals (Cu, Pb, Sn, Ni) from printed circuit and metal finishing waste streams was evaluated using displacement with aluminum. he metal is recovered as non-hazardous metal particles and can be recycled by smelting. n acceptable aluminum metal configuration ...

  5. Opening Doors for the Displaced Worker.

    ERIC Educational Resources Information Center

    Moore, Martha Norris

    2000-01-01

    Describes the many benefits now available to laid-off and displaced textile and apparel-related workers through the North American Free Trade Agreement's Transitional Adjustment Allowance (NAFTA-TAA), which allows them to attend college for the first time. Examines the effectiveness of the TAA program and concludes that there is room for…

  6. Retraining Displaced Workers--Barriers and Facilitators.

    ERIC Educational Resources Information Center

    Wolansky, William D.

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

  7. Job Displacement and the Rural Worker.

    ERIC Educational Resources Information Center

    Podgursky, Michael

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

  8. Effect of aileron displacement on wing characteristics

    NASA Technical Reports Server (NTRS)

    Heald, R H

    1933-01-01

    The effect of aileron displacement on wing characteristics has been investigated for the Clark Y and the U.S.A. 27 wing sections equipped with rectangular ailerons. The airfoils, rectangular in plan, and having a 10 inch chord and 60 inch span, were mounted on a model fuselage.

  9. A Personal Appearance Program for Displaced Homemakers.

    ERIC Educational Resources Information Center

    Fiore, Ann Marie; De Long, Marilyn Revell

    1990-01-01

    A career counseling program evaluated the self-esteem of 28 displaced homemakers, then presented 3 sessions on the importance of personal appearance in hiring practices, wardrobe management, nonverbal communication, professional image, and self-concept. Analysis of participant evaluations indicated improved levels of control and confidence and…

  10. The Income Losses of Displaced Workers

    ERIC Educational Resources Information Center

    Hijzen, Alexander; Upward, Richard; Wright, Peter W.

    2010-01-01

    We use a new, matched worker-firm dataset for the United Kingdom to estimate the income loss resulting from firm closure and mass layoffs. We track workers for up to nine years after the displacement event, and the availability of predisplacement characteristics allows us to implement difference-in-differences estimators using propensity score…

  11. Efficiency Improvements to the Displacement Based Multilevel Structural Optimization Algorithm

    NASA Technical Reports Server (NTRS)

    Plunkett, C. L.; Striz, A. G.; Sobieszczanski-Sobieski, J.

    2001-01-01

    Multilevel Structural Optimization (MSO) continues to be an area of research interest in engineering optimization. In the present project, the weight optimization of beams and trusses using Displacement based Multilevel Structural Optimization (DMSO), a member of the MSO set of methodologies, is investigated. In the DMSO approach, the optimization task is subdivided into a single system and multiple subsystems level optimizations. The system level optimization minimizes the load unbalance resulting from the use of displacement functions to approximate the structural displacements. The function coefficients are then the design variables. Alternately, the system level optimization can be solved using the displacements themselves as design variables, as was shown in previous research. Both approaches ensure that the calculated loads match the applied loads. In the subsystems level, the weight of the structure is minimized using the element dimensions as design variables. The approach is expected to be very efficient for large structures, since parallel computing can be utilized in the different levels of the problem. In this paper, the method is applied to a one-dimensional beam and a large three-dimensional truss. The beam was tested to study possible simplifications to the system level optimization. In previous research, polynomials were used to approximate the global nodal displacements. The number of coefficients of the polynomials equally matched the number of degrees of freedom of the problem. Here it was desired to see if it is possible to only match a subset of the degrees of freedom in the system level. This would lead to a simplification of the system level, with a resulting increase in overall efficiency. However, the methods tested for this type of system level simplification did not yield positive results. The large truss was utilized to test further improvements in the efficiency of DMSO. In previous work, parallel processing was applied to the

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

    PubMed Central

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

    2014-01-01

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

  13. Displacement interferometry with stabilization of wavelength in air.

    PubMed

    Lazar, Josef; Holá, Miroslava; Cíp, Ondřej; Cížek, Martin; Hrabina, Jan; Buchta, Zdeněk

    2012-12-03

    We present a concept of suppression of the influence of variations of the refractive index of air in displacement measuring interferometry. The principle is based on referencing of wavelength of the coherent laser source in atmospheric conditions instead of traditional stabilization of the optical frequency and indirect evaluation of the refractive index of air. The key advantage is in identical beam paths of the position measuring interferometers and the interferometer used for the wavelength stabilization. Design of the optical arrangement presented here to verify the concept is suitable for real interferometric position sensing in technical practice especially where a high resolution measurement within some limited range in atmospheric conditions is needed, e.g. in nanometrology.

  14. Weak Values from Displacement Currents in Multiterminal Electron Devices

    NASA Astrophysics Data System (ADS)

    Marian, D.; Zanghı, N.; Oriols, X.

    2016-03-01

    Weak values allow the measurement of observables associated with noncommuting operators. Up to now, position-momentum weak values have been mainly developed for (relativistic) photons. In this Letter, a proposal for the measurement of such weak values in typical electronic devices is presented. Inspired by the Ramo-Shockley-Pellegrini theorem that provides a relation between current and electron velocity, it is shown that the displacement current measured in multiterminal configurations can provide either a weak measurement of the momentum or strong measurement of position. This proposal opens new opportunities for fundamental and applied physics with state-of-the-art electronic technology. As an example, a setup for the measurement of the Bohmian velocity of (nonrelativistic) electrons is presented and tested with numerical experiments.

  15. The effect of feature displacement on face recognition.

    PubMed

    Haig, Nigel D

    2013-01-01

    Human beings possess a remarkable ability to recognise familiar faces quickly and without apparent effort. In spite of this facility, the mechanisms of visual recognition remain tantalisingly obscure. An experiment is reported in which image processing equipment was used to displace slightly the features of a set of original facial images to form groups of modified images. Observers were then required to indicate whether they were being shown the "original" or a "modified" face, when shown one face at a time on a TV monitor screen. Memory reinforcement was provided by displaying the original face at another screen position, between presentations. The data show, inter alia, the very high significance of the vertical positioning of the mouth, followed by eyes, and then the nose, as well as high sensitivity to close-set eyes, coupled with marked insensitivity to wide-set eyes. Implications of the results for the use of recognition aids such as Identikit and Photofit are briefly discussed.

  16. Online Image-based Monitoring of Soft-tissue Displacements for Radiation Therapy of the Prostate

    SciTech Connect

    Schlosser, Jeffrey; Salisbury, Kenneth; Hristov, Dimitre

    2012-08-01

    Purpose: Emerging prolonged, hypofractionated radiotherapy regimens rely on high-dose conformality to minimize toxicity and thus can benefit from image guidance systems that continuously monitor target position during beam delivery. To address this need we previously developed, as a potential add-on device for existing linear accelerators, a novel telerobotic ultrasound system capable of real-time, soft-tissue imaging. Expanding on this capability, the aim of this work was to develop and characterize an image-based technique for real-time detection of prostate displacements. Methods and Materials: Image processing techniques were implemented on spatially localized ultrasound images to generate two parameters representing prostate displacements in real time. In a phantom and five volunteers, soft-tissue targets were continuously imaged with a customized robotic manipulator while recording the two tissue displacement parameters (TDPs). Variations of the TDPs in the absence of tissue displacements were evaluated, as was the sensitivity of the TDPs to prostate translations and rotations. Robustness of the approach to probe force was also investigated. Results: With 95% confidence, the proposed method detected in vivo prostate displacements before they exceeded 2.3, 2.5, and 2.8 mm in anteroposterior, superoinferior, and mediolateral directions. Prostate pitch was detected before exceeding 4.7 Degree-Sign at 95% confidence. Total system time lag averaged 173 ms, mostly limited by ultrasound acquisition rate. False positives (FPs) (FP) in the absence of displacements did not exceed 1.5 FP events per 10 min of continuous in vivo imaging time. Conclusions: The feasibility of using telerobotic ultrasound for real-time, soft-tissue-based monitoring of target displacements was confirmed in vivo. Such monitoring has the potential to detect small clinically relevant intrafractional variations of the prostate position during beam delivery.

  17. Correlation Between Clinical Findings of Temporomandibular Disorders and MRI Characteristics of Disc Displacement

    PubMed Central

    Kumar, Raman; Pallagatti, Shambulingappa; Sheikh, Soheyl; Mittal, Amit; Gupta, Deepak; Gupta, Sonam

    2015-01-01

    Objectives : Temporomandibular joint (TMJ) dysfunction is a common condition that is best evaluated with magnetic resonance (MR) imaging. The first step in MR imaging of the TMJ is to evaluate the articular disk, or meniscus, in terms of its morphologic features and its location relative to the condyle in both closed- and open-mouth positions. Disk location is of prime importance because the presence of a displaced disk is a critical sign of TMJ dysfunction. However, disk displacement is also frequently seen in asymptomatic volunteers. It is important for the maxillofacial radiologist to detect early MR imaging signs of dysfunction, thereby avoiding the evolution of this condition to its advanced and irreversible phase which is characterized by osteoarthritic changes such as condylar flattening or osteophytes. Further the MR imaging techniques will allow a better understanding of the sources of TMJ pain and of any discrepancy between imaging findings and patient symptoms. Henceforth, the aim of the study was to evaluate whether MRI findings of various degrees of disk displacement could be correlated with the presence or absence of clinical signs and symptoms of temporomandibular disorders in symptomatic and asymptomatic subjects. Materials and Methods : In this clinical study, 44 patients (88 TMJs) were examined clinically and divided into two groups. Group 1 consisted of 22 patients with clinical signs and symptoms of TMDs either unilaterally or bilaterally and considered as study group. Group 2 consisted of 22 patients with no signs and symptoms of TMDs and considered as control group. MRI was done for both the TMJs of each patient. Displacement of the posterior band of articular disc in relation to the condyle was quantified as anterior disc displacement with reduction (ADDR), anterior disc displacement without reduction (ADDWR), posterior disc displacement (PDD). Results : Disk displacement was found in 18 (81.8%) patients of 22 symptomatic subjects in Group 1

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

    USGS Publications Warehouse

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

    2014-01-01

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

  19. Residual Seminal Vesicle Displacement in Marker-Based Image-Guided Radiotherapy for Prostate Cancer and the Impact on Margin Design

    SciTech Connect

    Smitsmans, Monique H.P.; Bois, Josien de; Sonke, Jan-Jakob; Catton, Charles N.; Jaffray, David A.; Lebesque, Joos V.; Herk, Marcel van

    2011-06-01

    Purpose: The objectives of this study were to quantify residual interfraction displacement of seminal vesicles (SV) and investigate the efficacy of rotation correction on SV displacement in marker-based prostate image-guided radiotherapy (IGRT). We also determined the effect of marker registration on the measured SV displacement and its impact on margin design. Methods and Materials: SV displacement was determined relative to marker registration by using 296 cone beam computed tomography scans of 13 prostate cancer patients with implanted markers. SV were individually registered in the transverse plane, based on gray-value information. The target registration error (TRE) for the SV due to marker registration inaccuracies was estimated. Correlations between prostate gland rotations and SV displacement and between individual SV displacements were determined. Results: The SV registration success rate was 99%. Displacement amounts of both SVs were comparable. Systematic and random residual SV displacements were 1.6 mm and 2.0 mm in the left-right direction, respectively, and 2.8 mm and 3.1 mm in the anteroposterior (AP) direction, respectively. Rotation correction did not reduce residual SV displacement. Prostate gland rotation around the left-right axis correlated with SV AP displacement (R{sup 2} = 42%); a correlation existed between both SVs for AP displacement (R{sup 2} = 62%); considerable correlation existed between random errors of SV displacement and TRE (R{sup 2} = 34%). Conclusions: Considerable residual SV displacement exists in marker-based IGRT. Rotation correction barely reduced SV displacement, rather, a larger SV displacement was shown relative to the prostate gland that was not captured by the marker position. Marker registration error partly explains SV displacement when correcting for rotations. Correcting for rotations, therefore, is not advisable when SV are part of the target volume. Margin design for SVs should take these uncertainties into

  20. Conflict, displacement and health in the Middle East.

    PubMed

    Mowafi, Hani

    2011-01-01

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

  1. Closed loop control of dielectric elastomer actuators based on self-sensing displacement feedback

    NASA Astrophysics Data System (ADS)

    Rizzello, G.; Naso, D.; York, A.; Seelecke, S.

    2016-03-01

    This paper describes a sensorless control algorithm for a positioning system based on a dielectric elastomer actuator (DEA). The voltage applied to the membrane and the resulting current can be measured during the actuation and used to estimate its displacement, i.e., to perform self-sensing. The estimated displacement can be then used as a feedback signal for a position control algorithm, which results in a compact device capable of operating in closed loop control without the need for additional electromechanical or optical transducers. In this work, a circular DEA preloaded with a bi-stable spring is used as a case of study to validate the proposed control architecture. A comparison of the closed loop performance achieved using an accurate laser displacement sensor for feedback is also provided to better assess the performance limitations of the overall sensorless scheme.

  2. Character displacement of Cercopithecini primate visual signals

    PubMed Central

    Allen, William L.; Stevens, Martin; Higham, James P.

    2014-01-01

    Animal visual signals have the potential to act as an isolating barrier to prevent interbreeding of populations through a role in species recognition. Within communities of competing species, species recognition signals are predicted to undergo character displacement, becoming more visually distinctive from each other, however this pattern has rarely been identified. Using computational face recognition algorithms to model primate face processing, we demonstrate that the face patterns of guenons (tribe: Cercopithecini) have evolved under selection to become more visually distinctive from those of other guenon species with whom they are sympatric. The relationship between the appearances of sympatric species suggests that distinguishing conspecifics from other guenon species has been a major driver of diversification in guenon face appearance. Visual signals that have undergone character displacement may have had an important role in the tribe’s radiation, keeping populations that became geographically separated reproductively isolated on secondary contact. PMID:24967517

  3. Charge-displacement analysis for excited states

    SciTech Connect

    Ronca, Enrico Tarantelli, Francesco; Pastore, Mariachiara Belpassi, Leonardo; De Angelis, Filippo; Angeli, Celestino; Cimiraglia, Renzo

    2014-02-07

    We extend the Charge-Displacement (CD) analysis, already successfully employed to describe the nature of intermolecular interactions [L. Belpassi et al., J. Am. Chem. Soc. 132, 13046 (2010)] and various types of controversial chemical bonds [L. Belpassi et al., J. Am. Chem. Soc. 130, 1048 (2008); N. Salvi et al., Chem. Eur. J. 16, 7231 (2010)], to study the charge fluxes accompanying electron excitations, and in particular the all-important charge-transfer (CT) phenomena. We demonstrate the usefulness of the new approach through applications to exemplary excitations in a series of molecules, encompassing various typical situations from valence, to Rydberg, to CT excitations. The CD functions defined along various spatial directions provide a detailed and insightful quantitative picture of the electron displacements taking place.

  4. Laser-speckle angular-displacement sensor: theoretical and experimental study.

    PubMed

    Rose, B; Imam, H; Hanson, S G; Yura, H T; Hansen, R S

    1998-04-10

    A novel, to our knowledge, method for the measurement of angular displacement for arbitrarily shaped objects is presented in which the angular displacement is perpendicular to the optical axis. The method is based on Fourier-transforming the scattered field from a single laser beam that illuminates the target. The angular distribution of the light field at the target is linearly mapped on a linear image sensor placed in the Fourier plane. Measuring this displacement facilitates the determination of the angular displacement of the target. It is demonstrated both theoretically and experimentally that the angular-displacement sensor is insensitive to object shape and target distance if the linear image sensor is placed in the Fourier plane. A straightforward procedure for positioning the image sensor in the Fourier plane is presented. Any transverse or longitudinal movement of the target will give rise to partial speckle decorrelation, but it will not affect the angular measurement. Furthermore, any change in the illuminating wavelength will not affect the angular measurements. Theoretically and experimentally it is shown that the method has a resolution of 0.3 mdeg ( approximately 5 murad) for small angular displacements, and methods for further improvement in resolution is discussed. No special surface treatment is required for surfaces giving rise to fully developed speckle. The effect of partially developed speckle is considered both theoretically and experimentally.

  5. Evaluation of temporomandibular joint disc displacement as a risk factor for osteoarthrosis.

    PubMed

    Dias, I M; Cordeiro, P C de F; Devito, K L; Tavares, M L F; Leite, I C G; Tesch, R de S

    2016-03-01

    Temporomandibular joint (TMJ) disc displacement is a clinical sign often found in patients with temporomandibular disorders (TMDs) and associated with TMJ osteoarthrosis. Osteoarthrosis is a degenerative joint disease that may be associated with pain and functional disability. The aim of this study was to evaluate the odds ratio (OR) of joints with disc displacement presenting osteoarthrosis via magnetic resonance imaging (MRI) analysis. In total, 224 TMJ images from patients with signs and symptoms of a TMD were evaluated. The OR, a measure of association, was used to calculate the likelihood of TMJ disc displacement (with or without reduction) with osteoarthrosis. Joints with anterior disc displacement with reduction (ADDwR) and anterior disc displacement without reduction (ADDwoR) were 2.73- and 8.25-times, respectively, more likely to have osteoarthrosis. A nine-times greater likelihood of osteophyte occurrence was observed in cases of ADDwoR, whereas a lower OR for their occurrence (OR 2.96) was observed in cases of ADDwR. The significant OR of joints with disc displacement presenting osteoarthrosis, particularly in cases of ADDwoR, emphasizes the importance of accurate assessment of changes in disc position, which may be associated with other painful and functional disorders of the TMJ.

  6. Laser-detected lateral muscle displacement is correlated with force fluctuations during voluntary contractions in humans.

    PubMed

    Yoshitake, Yasuhide; Masani, Kei; Shinohara, Minoru

    2008-08-30

    Fluctuations in muscle force during steady voluntary contractions result from the summation of twitch forces produced by asynchronous activation of multiple motor units. We hypothesized that oscillatory lateral muscle displacement, measured with a non-contact high-resolution laser displacement sensor, is correlated with force fluctuations during steady, voluntary contractions with a human muscle. Eight healthy young adults (20-33 yrs) performed steady isometric contractions with the first dorsal interosseus muscle. Contraction intensity ranged from 2.5% to 60% of the maximal voluntary contraction force. Oscillatory lateral displacement of the muscle surface was measured with a high-resolution laser displacement sensor (0.5 microm resolution), concurrently with abduction force of the index finger. In the time-domain analysis, there was a significant positive peak in the cross-correlation function between lateral muscle displacement and force fluctuations. In addition, the amplitude increased linearly with contraction intensity in both signals. In the frequency-domain analysis, frequency content was similar in both signals, and there was significant coherence between signals for the major frequency range of the signals (<5 Hz). In conclusion, laser-detected lateral displacement of a hand muscle is correlated with force fluctuations across a wide range of contraction intensity during steady voluntary contractions in humans.

  7. Loading effects in GPS vertical displacement time series

    NASA Astrophysics Data System (ADS)

    Memin, A.; Boy, J. P.; Santamaría-Gómez, A.; Watson, C.; Gravelle, M.; Tregoning, P.

    2015-12-01

    Surface deformations due to loading, with yet no comprehensive representation, account for a significant part of the variability in geodetic time series. We assess effects of loading in GPS vertical displacement time series at several frequency bands. We compare displacement derived from up-to-date loading models to two global sets of positioning time series, and investigate how they are reduced looking at interannual periods (> 2 months), intermediate periods (> 7 days) and the whole spectrum (> 1day). We assess the impact of interannual loading on estimating velocities. We compute atmospheric loading effects using surface pressure fields from the ECMWF. We use the inverted barometer (IB) hypothesis valid for periods exceeding a week to describe the ocean response to the pressure forcing. We used general circulation ocean model (ECCO and GLORYS) to account for wind, heat and fresh water flux. We separately use the Toulouse Unstructured Grid Ocean model (TUGO-m), forced by air pressure and winds, to represent the dynamics of the ocean response at high frequencies. The continental water storage is described using GLDAS/Noah and MERRA-land models. Non-hydrology loading reduces the variability of the observed vertical displacement differently according to the frequency band. The hydrology loading leads to a further reduction mostly at annual periods. ECMWF+TUGO-m better agrees with vertical surface motion than the ECMWF+IB model at all frequencies. The interannual deformation is time-correlated at most of the locations. It is adequately described by a power-law process of spectral index varying from -1.5 to -0.2. Depending on the power-law parameters, the predicted non-linear deformation due to mass loading variations leads to vertical velocity biases up to 0.7 mm/yr when estimated from 5 years of continuous observations. The maximum velocity bias can reach up to 1 mm/yr in regions around the southern Tropical band.

  8. Character displacement and the origins of diversity

    PubMed Central

    Pfennig, David W.; Pfennig, Karin S.

    2012-01-01

    In The Origin of Species, Darwin proposed his ‘principle of divergence of character’ (a process now termed ‘character displacement’) to explain how new species arise and why they differ from one other phenotypically. Darwin maintained that the origin of species, and the evolution of differences between them, is ultimately caused by divergent selection acting to minimize competitive interactions between initially similar individuals, populations, and species. Here, we examine the empirical support for the various claims that constitute Darwin’s principle, specifically that: (1) competition promotes divergent trait evolution; (2) the strength of competitively mediated divergent selection increases with increasing phenotypic similarity between competitors; (3) divergence can occur within species; and (4) competitively mediated divergence can trigger speciation. We also explore aspects that Darwin failed to consider. In particular, we describe how: (1) divergence can arise from selection acting to lessen reproductive interactions; (2) divergence is fueled by the intersection of character displacement and sexual selection; and (3) phenotypic plasticity may play a key role in promoting character displacement. Generally, character displacement is well supported empirically, and it remains a vital explanation for how new species arise and diversify. PMID:21043778

  9. Simultaneous muscle force and displacement transducer

    NASA Technical Reports Server (NTRS)

    Feldstein, C.; Lewis, G. W.; Culler, V. H. (Inventor)

    1980-01-01

    A myocardial transducer for simultaneously measuring force and displacement within a very small area of myocardium is disclosed. The transducer comprised of an elongated body forked at one end to form an inverted Y shaped beam with each branch of the beam constituting a low compliant tine for penetrating the myocardium to a predetermined depth. Bonded to one of the low compliance tines is a small piezoresistive element for converting a force acting on the beam into an electrical signal. A third high compliant tine of the transducer, which measures displacement of the myocardium in a direction in line with the two low compliant tines, is of a length that just pierces the surface membrane. A small piezoresistive element is bonded to the third tine at its upper end where its bending is greatest. Displacement of the myocardium causes a deformation in curvature of the third tine, and the second small piezoresistive element bonded to the surface of its curved end converts its deformation into an electrical signal.

  10. Contactless sub-millimeter displacement measurements

    NASA Astrophysics Data System (ADS)

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

    2008-07-01

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

  11. Character displacement promotes cooperation in bacterial biofilms.

    PubMed

    Brockhurst, Michael A; Hochberg, Michael E; Bell, Thomas; Buckling, Angus

    2006-10-24

    Resource competition within a group of cooperators is expected to decrease selection for cooperative behavior but can also result in diversifying selection for the use of different resources, which in turn could retard the breakdown of cooperation. Diverse groups are likely to be less susceptible to invasion by noncooperating social cheats: First, competition repression resulting from character displacement may provide less of a selective advantage to cheating; second, cheats may trade off the ability to exploit cooperators that specialize in one type of resource against cooperators that specialize in another ; third, diverse communities of any kind may have higher invasion resistance because there are fewer resources available for an invader to use . Furthermore, diverse groups are likely to be more productive than clonal groups if a wider range of total resources are being used . We addressed these issues by using the cooperative trait of biofilm formation in Pseudomonas fluorescens. Character displacement through resource competition evolved within biofilms; productivity increased with increasing character displacement, and diverse biofilms were less susceptible to invasion by cheats. These results demonstrate that diversification into different ecological niches can minimize selection against cooperation in the face of local resource competition.

  12. Comparing Teaching Approaches About Maxwell's Displacement Current

    NASA Astrophysics Data System (ADS)

    Karam, Ricardo; Coimbra, Debora; Pietrocola, Maurício

    2014-08-01

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

  13. Research of aerial camera focal pane micro-displacement measurement system based on Michelson interferometer

    NASA Astrophysics Data System (ADS)

    Wang, Shu-juan; Zhao, Yu-liang; Li, Shu-jun

    2014-09-01

    The aerial camera focal plane in the correct position is critical to the imaging quality. In order to adjust the aerial camera focal plane displacement caused in the process of maintenance, a new micro-displacement measuring system of aerial camera focal plane in view of the Michelson interferometer has been designed in this paper, which is based on the phase modulation principle, and uses the interference effect to realize the focal plane of the micro-displacement measurement. The system takes He-Ne laser as the light source, uses the Michelson interference mechanism to produce interference fringes, changes with the motion of the aerial camera focal plane interference fringes periodically, and records the periodicity of the change of the interference fringes to obtain the aerial camera plane displacement; Taking linear CCD and its driving system as the interference fringes picking up tool, relying on the frequency conversion and differentiating system, the system determines the moving direction of the focal plane. After data collecting, filtering, amplifying, threshold comparing, counting, CCD video signals of the interference fringes are sent into the computer processed automatically, and output the focal plane micro displacement results. As a result, the focal plane micro displacement can be measured automatically by this system. This system uses linear CCD as the interference fringes picking up tool, greatly improving the counting accuracy and eliminated the artificial counting error almost, improving the measurement accuracy of the system. The results of the experiments demonstrate that: the aerial camera focal plane displacement measurement accuracy is 0.2nm. While tests in the laboratory and flight show that aerial camera focal plane positioning is accurate and can satisfy the requirement of the aerial camera imaging.

  14. Curved Displacement Transfer Functions for Geometric Nonlinear Large Deformation Structure Shape Predictions

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Fleischer, Van Tran; Lung, Shun-Fat

    2017-01-01

    For shape predictions of structures under large geometrically nonlinear deformations, Curved Displacement Transfer Functions were formulated based on a curved displacement, traced by a material point from the undeformed position to deformed position. The embedded beam (depth-wise cross section of a structure along a surface strain-sensing line) was discretized into multiple small domains, with domain junctures matching the strain-sensing stations. Thus, the surface strain distribution could be described with a piecewise linear or a piecewise nonlinear function. The discretization approach enabled piecewise integrations of the embedded-beam curvature equations to yield the Curved Displacement Transfer Functions, expressed in terms of embedded beam geometrical parameters and surface strains. By entering the surface strain data into the Displacement Transfer Functions, deflections along each embedded beam can be calculated at multiple points for mapping the overall structural deformed shapes. Finite-element linear and nonlinear analyses of a tapered cantilever tubular beam were performed to generate linear and nonlinear surface strains and the associated deflections to be used for validation. The shape prediction accuracies were then determined by comparing the theoretical deflections with the finiteelement- generated deflections. The results show that the newly developed Curved Displacement Transfer Functions are very accurate for shape predictions of structures under large geometrically nonlinear deformations.

  15. Highly sensitive displacement measurement based on spectral interferometry and Vernier effect

    NASA Astrophysics Data System (ADS)

    Militky, J.; Kadulova, M.; Hlubina, P.

    2016-05-01

    A highly sensitive measurement of the displacement of an interferometer mirror based on spectral interferometry and Vernier effect is proposed and demonstrated. The displacement measurement employs two interferometers in tandem, an interferometer represented by a combination of a polarizer, a birefrigent quartz crystal and an analyzer, and a Michelson interferometer. In the setup the Vernier effect is generated and the resultant channeled spectrum is with the envelope which shifts with the displacement of the interferometer mirror. We analyze the new measurement method theoretically and show that the sensitivity of the displacement measurement based on the wavelength interrogation is substantially increased in comparison to a standard method with a Michelson interferometer. We also demonstrate the realization of the measurement setup in which the position of the interferometer mirror is controlled via a closed-loop piezo positioning system. Experimental results show that the displacement measurement can reach a sensitivity of 264 nm/μm, which is substantially increased in comparison to -34 nm/μm reached for a standard measurement.

  16. Differential displacement of the human soleus and medial gastrocnemius aponeuroses during isometric plantar flexor contractions in vivo.

    PubMed

    Bojsen-Møller, Jens; Hansen, Philip; Aagaard, Per; Svantesson, Ulla; Kjaer, Michael; Magnusson, S Peter

    2004-11-01

    The human triceps surae muscle-tendon complex is a unique structure with three separate muscle compartments that merge via their aponeuroses into the Achilles tendon. The mechanical function and properties of these structures during muscular contraction are not well understood. The purpose of the study was to investigate the extent to which differential displacement occurs between the aponeuroses of the medial gastrocnemius (MG) and soleus (Sol) muscles during plantar flexion. Eight subjects (mean +/- SD; age 30 +/- 7 yr, body mass 76.8 +/- 5.5 kg, height 1.83 +/- 0.06 m) performed maximal isometric ramp contractions with the plantar flexor muscles. The experiment was performed in two positions: position 1, in which the knee joint was maximally extended, and position 2, in which the knee joint was maximally flexed (125 degrees ). Plantarflexion moment was assessed with a strain gauge load cell, and the corresponding displacement of the MG and Sol aponeuroses was measured by ultrasonography. Differential shear displacement of the aponeurosis was quantified by subtracting displacement of Sol from that of MG. Maximal plantar flexion moment was 36% greater in position 1 than in position 2 (132 +/- 20 vs. 97 +/- 11 N.m). In position 1, the displacement of the MG aponeurosis at maximal force exceeded that of the Sol (12.6 +/- 1.7 vs. 8.9 +/- 1.5 mm), whereas in position 2 displacement of the Sol was greater than displacement of the MG (9.6 +/- 1.0 vs. 7.9 +/- 1.2 mm). The amount and "direction" of shear between the aponeuroses differed significantly between the two positions across the entire range of contraction, indicating that the Achilles tendon may be exposed to intratendinous shear and stress gradients during human locomotion.

  17. Tympanic displacement analysis in healthy volunteers after indomethacin administration.

    PubMed

    Walsted, Alice; Wagner, Niels; Andersen, Kim Møller

    2002-12-01

    The aim of this study was to investigate whether a tympanic displacement analyser could detect decreases in cerebral blood flow and intracranial pressure after administration of indomethacin in healthy volunteers. In a double-blind crossover study involving 14 healthy volunteers all subjects first underwent a test-retest evaluation to investigate reproducibility followed by tests performed in sitting and supine positions to confirm intracranial-cochlear pressure transfer. In two further sessions tests were performed before and 90 min after subjects were blindly administered a suppository containing either 100 mg of indomethacin or placebo. It was found that tympanic membrane analysis performed 90 min after administration of such a suppository did not mirror the induced reduction in cerebral blood flow after administration of active drug. After administration of indomethacin eight of the subjects experienced discomfort and dizziness; after placebo none experienced subjective symptoms. After administration of indomethacin a statistically significant decrease in heart rate was demonstrated. The exponential form of the intracranial pressure-volume curve may explain why a decrease in intracranial pressure was not detected using the tympanic membrane displacement method, because the measurements were made in subjects with normal intracranial pressure. More significant findings may be found in patients with elevated intracranial pressure.

  18. Effects of spatially displaced feedback on remote manipulation tasks

    NASA Technical Reports Server (NTRS)

    Manahan, Meera K.; Stuart, Mark A.; Bierschwale, John M.; Hwang, Ellen Y.; Legendre, A. J.

    1992-01-01

    Several studies have been performed to determine the effects on computer and direct manipulation task performance when viewing conditions are spatially displaced. Whether results from these studies can be directly applied to remote manipulation tasks is quenstionable. The objective of this evaluation was to determine the effects of reversed, inverted, and inverted/reversed views on remote manipulation task performance using two 3-Degree of Freedom (DOF) hand controllers and a replica position hand controller. Results showed that trials using the inverted viewing condition showed the worst performance, followed by the inverted/reversed view and the reversed view when using the 2x3 DOF. However, these differences were not significant. The inverted and inverted/reversed viewing conditions were significantly worse than the normal and reversed viewing conditions when using the Kraft Replica. A second evaluation was conducted in which additional trials were performed with each viewing condition to determine the long term effects of spatially displaced views on task performance for the hand controllers. Results of the second evaluation indicated that there was more of a difference in performance between the perturbed viewing conditions and the normal viewing condition with the Kraft Replica than with the 2x3 DOF.

  19. Are Children Really Inferior Goods? Evidence from Displacement-Driven Income Shocks

    ERIC Educational Resources Information Center

    Lindo, Jason M.

    2010-01-01

    This paper explores the causal link between income and fertility by analyzing women's fertility response to the large and permanent income shock generated by a husband's job displacement. I find that the shock reduces total fertility, suggesting that the causal effect of income on fertility is positive. A model that incorporates the time cost of…

  20. Break-In, Performance, and Endurance Tests Results on Fixed Displacement Hydraulic Fluid Power Vane Pumps.

    DTIC Science & Technology

    1982-07-15

    displacement and further, it is recommended that the stroking control be locked into a position for a given Target Value). 10.3.3 Record data per Chart 2...specified for levels A, B, or C. Each inc,)rrect material, method, or container shall constitute ,ne de’ect. 11I.. interior surfaces of the pivmps nDt

  1. Calculation of the Displacement Current Using the Integral Form of Ampere's Law.

    ERIC Educational Resources Information Center

    Dahm, A. J.

    1978-01-01

    Derives the magnetic field as a function of position between two capacitor plates during discharge with the use of the integral form of Ampere's law and real currents only. The displacement current must be included to obtain the same result for arbitrary choices of contours. (Author/GA)

  2. 24 CFR 882.810 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... racial, ethnic, gender, and disability status of displaced persons. (g) Definition of displaced person... between the owner and the HA. (Approved by the Office of Management and Budget under OMB control...

  3. 24 CFR 882.810 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... racial, ethnic, gender, and disability status of displaced persons. (g) Definition of displaced person... between the owner and the HA. (Approved by the Office of Management and Budget under OMB control...

  4. 7 CFR 1944.667 - Relocation and displacement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... permanent or temporary relocation of displaced persons for units repaired or rehabilitated or for individual... displaced persons. The applicant shall include in its statement of activities, a statement concerning...

  5. Introducing the Concept of Displacement Center in Statics.

    ERIC Educational Resources Information Center

    Jong, I. C.; Crook, C. W.

    1990-01-01

    The concept of displacement center for teaching the virtual work method in statistics is described. An analytical treatment of the displacement center is presented. An example which illustrates the essential elements of this concept is provided. (CW)

  6. Is competition needed for ecological character displacement? Does displacement decrease competition?

    PubMed

    Abrams, Peter A; Cortez, Michael H

    2015-12-01

    Interspecific competition for resources is generally considered to be the selective force driving ecological character displacement, and displacement is assumed to reduce competition. Skeptics of the prevalence of character displacement often cite lack of evidence of competition. The present article uses a simple model to examine whether competition is needed for character displacement and whether displacement reduces competition. It treats systems with competing resources, and considers cases when only one consumer evolves. It quantifies competition using several different measures. The analysis shows that selection for divergence of consumers occurs regardless of the level of between-resource competition or whether the indirect interaction between the consumers is competition (-,-), mutualism (+,+), or contramensalism (+,-). Also, divergent evolution always decreases the equilibrium population size of the evolving consumer. Whether divergence of one consumer reduces or increases the impact of a subsequent perturbation of the other consumer depends on the parameters and the method chosen for measuring competition. Divergence in mutualistic interactions may reduce beneficial effects of subsequent increases in the other consumer's population. The evolutionary response is driven by an increase in the relative abundance of the resource the consumer catches more rapidly. Such an increase can occur under several types of interaction.

  7. Optical knife-edge technique for nanomechanical displacement detection

    SciTech Connect

    Karabacak, D.; Kouh, T.; Huang, C.C.; Ekinci, K.L.

    2006-05-08

    We describe an optical knife-edge technique for nanomechanical displacement detection. Here, one carefully focuses a laser spot on a moving edge and monitors the reflected power as the edge is displaced sideways. To demonstrate nanomechanical displacement detection using the knife-edge technique, we have measured in-plane resonances of nanometer scale doubly clamped beams. The obtained displacement sensitivity is in the {approx}1 pm/{radical}(Hz) range--in close agreement with a simple analytical model.

  8. Model for Providing Displaced Workers' Services. Research Report.

    ERIC Educational Resources Information Center

    Anderson, B. Harold; Naylor, Mary Lou

    This handbook presents a model that helps vocational educators and other individuals, institutions, and agencies plan programs to maintain displaced workers' dignity and economic security. Section 1 discusses identification of displaced workers. Section 2 offers guidelines for developing a profile for a specific group of displaced workers. A list…

  9. From Word to Image: Displacement and Meaning in "Greed."

    ERIC Educational Resources Information Center

    Grindon, Leger

    1989-01-01

    Describes levels of displacement in Stroheim's film "Greed," including (1) the displacement of reason, pleasure, and life by the desire for gold; and (2) the displacement that points to a double movement in Stroheim's cinematic style. Argues that the film's sense of doom arises from the psychic nightmare operating through the mechanics…

  10. Implications of Research on Displaced Workers. ERIC Digest No. 80.

    ERIC Educational Resources Information Center

    Naylor, Michele

    Worker displacement is more closely related to structural features associated with firms than to the characteristics of the individuals who lost their jobs. Despite economic growth, large numbers of displaced workers continue to experience difficulty in making labor market adjustments. Programs to retrain and reemploy displaced workers exist at…

  11. Rhetorics of Displacement: Constructing Identities in Forced Relocations

    ERIC Educational Resources Information Center

    Powell, Katrina M.

    2012-01-01

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

  12. 20 CFR 218.30 - Separation, displacement or dismissal allowance.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true Separation, displacement or dismissal..., Spouse, or Divorced Spouse Annuity Beginning Date § 218.30 Separation, displacement or dismissal allowance. (a) General. When an employee receives a separation, displacement or dismissal allowance from...

  13. 20 CFR 218.30 - Separation, displacement or dismissal allowance.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 20 Employees' Benefits 1 2014-04-01 2012-04-01 true Separation, displacement or dismissal..., Spouse, or Divorced Spouse Annuity Beginning Date § 218.30 Separation, displacement or dismissal allowance. (a) General. When an employee receives a separation, displacement or dismissal allowance from...

  14. 20 CFR 218.30 - Separation, displacement or dismissal allowance.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 1 2012-04-01 2012-04-01 false Separation, displacement or dismissal..., Spouse, or Divorced Spouse Annuity Beginning Date § 218.30 Separation, displacement or dismissal allowance. (a) General. When an employee receives a separation, displacement or dismissal allowance from...

  15. 20 CFR 218.30 - Separation, displacement or dismissal allowance.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false Separation, displacement or dismissal..., Spouse, or Divorced Spouse Annuity Beginning Date § 218.30 Separation, displacement or dismissal allowance. (a) General. When an employee receives a separation, displacement or dismissal allowance from...

  16. 20 CFR 218.30 - Separation, displacement or dismissal allowance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false Separation, displacement or dismissal..., Spouse, or Divorced Spouse Annuity Beginning Date § 218.30 Separation, displacement or dismissal allowance. (a) General. When an employee receives a separation, displacement or dismissal allowance from...

  17. 24 CFR 886.338 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... persons. A “displaced person” (defined in paragraph (g) of this section) must be provided relocation... regulations at 49 CFR part 24. A “displaced person” shall be advised of his or her rights under the Fair... owner's determination concerning whether the person qualifies as a “displaced person,” or the amount...

  18. 24 CFR 583.310 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... persons. A displaced person (defined in paragraph (f) of this section) must be provided relocation... “displaced person,” or the amount of relocation assistance for which the person is eligible, may file a... to the HUD field office. (f) Definition of displaced person. (1) For purposes of this section,...

  19. 24 CFR 886.138 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... persons. A “displaced person” (as defined in paragraph (g) of this section) must be provided relocation... regulations at 49 CFR part 24. A “displaced person” shall be advised of his or her rights under the Fair... Owner's determination concerning whether the person qualifies as a “displaced person,” or the amount...

  20. Job Displacement and Labor Market Mobility. Final Report.

    ERIC Educational Resources Information Center

    Podgursky, Michael; Swaim, Paul

    A study examined the labor market mobility of displaced workers, using a new data file that matches the January 1984, 1986, and 1988 Displaced Worker Surveys (DWS) to the March Current Population Surveys in the same years. This large database provides information on displaced workers and their families and permits comparison of the geographic…

  1. Temperature insensitive measurements of displacement using fiber Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Yang, Shuang; Li, Jun; Xu, Shengming; Sun, Miao; Tang, Yuquan; Gao, Gang; Dong, Fengzhong

    2016-11-01

    Optical fiber Bragg grating (FBG) displacement sensors play an important role in various areas due to the high sensitivity to displacement. However, it becomes a serious problem of FBG cross-sensitivity of temperature and displacement in applications with FBG displacement sensing. This paper presents a method of temperature insensitive measurement of displacement via using an appropriate layout of the sensor. A displacement sensor is constructed with two FBGs mounted on the opposite surface of a cantilever beam. The wavelengths of the FBGs shift with a horizontal direction displacement acting on the cantilever beam. Displacement measurement can be achieved by demodulating the wavelengths difference of the two FBGs. In this case, the difference of the two FBGs' wavelengths can be taken in order to compensate for the temperature effects. Four cantilever beams with different shapes are designed and the FBG strain distribution is quite different from each other. The deformation and strain distribution of cantilever beams are simulated by using finite element analysis, which is used to optimize the layout of the FBG displacement sensor. Experimental results show that an obvious increase in the sensitivity of this change on the displacement is obtained while temperature dependence greatly reduced. A change in the wavelength can be found with the increase of displacement from 0 to 10mm for a cantilever beam. The physical size of the FBG displacement sensor head can be adjusted to meet the need of different applications, such as structure health monitoring, smart material sensing, aerospace, etc.

  2. Compact fiber optic dual-detection confocal displacement sensor.

    PubMed

    Lee, Dong-Ryoung; Jang, Suin; Lee, Min Woo; Yoo, Hongki

    2016-09-20

    We propose a dual-detection confocal displacement sensor (DDCDS) with a compact fiber-based optical probe. This all-fiber-optic sensor probe is simple and robust, since it only requires simple alignment of a gradient refractive index lens and a double-clad fiber (DCF). The DDCDS is composed of two point detectors, one coupled to a single mode fiber and the other coupled to a multimode fiber, which are used to measure the light intensity from a core and an inner clad of a DCF, respectively. The ratio of the axial response curves, measured by the two detectors, can be used to obtain a linear relationship between the axial position of the object plane and the ratio of the intensity signals. We demonstrate the performance of the proposed method by measuring micromovement and fast vibration.

  3. Correction of palatally displaced maxillary lateral incisors without brackets

    PubMed Central

    Choi, Kyung-Hee; Lee, Yoonjung; Kim, Minji

    2013-01-01

    This article describes the orthodontic treatment of a 25-year-old Korean female patient with anterior crowding, including palatally displaced lateral incisors. Her facial profile was satisfactory, but 3.5 mm of maxillary anterior crowding was observed. To correct this crowding, we decided to minimize the use of the conventional fixed orthodontic appliances and employed a less bulky and more aesthetic appliance for applying light continuous force. We determined the final positions of the maxillary teeth via a working model for diagnostic set up and achieved space gaining and alignment with simple Ni-Ti spring and stainless steel round tubes. Tooth alignment was achieved efficiently and aesthetically without the conventional brackets. PMID:24015390

  4. Galvanic displacement of metals on semiconductor nanocrystals

    NASA Astrophysics Data System (ADS)

    Johnson, Melanie; Kelly, Joel A.; Henderson, Eric J.; Veinot, Jonathan G. C.

    2009-11-01

    We report the galvanic displacement (GD) of germanium from germanium nanocrystals (Ge-NCs) with silver. The Ge-NCs are synthesized by reductive thermal processing of germanium suboxide sol-gel prepolymers. Thermal processing yields size-controlled oxide-embedded Ge-NCs, which are liberated by dissolution of the germanium oxide matrix in water. Subsequent exposure of the freestanding Ge-NCs to aqueous solutions of AgNO3 leads to deposition of silver nanostructures by GD. The resulting metal structures were analyzed by XRD, XPS, TEM and EDX, confirming deposition of elemental silver in a variety of shapes and sizes.

  5. Spectroscopy with Random and Displaced Random Ensembles

    NASA Astrophysics Data System (ADS)

    Velázquez, V.; Zuker, A. P.

    2002-02-01

    Because of the time reversal invariance of the angular momentum operator J2, the average energies and variances at fixed J for random two-body Hamiltonians exhibit odd-even- J staggering that may be especially strong for J = 0. It is shown that upon ensemble averaging over random runs, this behavior is reflected in the yrast states. Displaced (attractive) random ensembles lead to rotational spectra with strongly enhanced B(E2) transitions for a certain class of model spaces. It is explained how to generalize these results to other forms of collectivity.

  6. Dynamic model of the threshold displacement energy

    NASA Astrophysics Data System (ADS)

    Kupchishin, A. I.; Kupchishin, A. A.

    2017-01-01

    A dynamic (cascade-probability) model for calculating the threshold displacement energy of knocked-out atoms (Ed) was proposed taking into account the influence of the instability zone (spontaneous recombination). General expression was recorded for Ed depending on the formation energy of interstitial atoms Ef and vacancies Ei, on the energy transfer coefficient α and the number of interactions i needed to move the atom out of the instability zone. The parameters of primary particles were calculated. Comparison of calculations with experimental data gives a satisfactory agreement.

  7. Displacement separations by continuous annular chromatography

    SciTech Connect

    DeCarli, J.P. II; Carta, G. ); Byers, C.H. . Chemical Technology Div.)

    1988-01-01

    Continuous annular chromatography (CAC) has been introduced as an effective means of carrying out chromatographic separations in a truly continuous manner. Process applications have been demonstrated. In this work the authors demonstrate how CAC can be operated for displacement development separations. In this mode of operation of the apparatus separation and concentration of multicomponent mixtures can be obtained simultaneously and continuously. Experimental results and model simulations for this novel separation device are presented along with a comparison of different modes of operation and a discussion of industrial applications.

  8. Competitive displacement of DNA during surface hybridization.

    PubMed

    Bishop, J; Wilson, C; Chagovetz, A M; Blair, S

    2007-01-01

    Using real-time dual-color fluorescence detection, we have experimentally tracked individual target species during competitive DNA surface hybridization in a two-component sample. Our experimental results demonstrate displacement of the lower affinity species by the higher affinity species and corroborate recent theoretical models describing competitive DNA surface hybridization. Competition at probe sites complementary to one of the two DNA species was monitored in separate experiments for two different target pairs. Each pair differs in sequence by a single nucleotide polymorphism, and one pair includes a folding target. We propose a mechanistic interpretation of the differences between hybridization curves of targets in multi-component and single-component experiments.

  9. Uncovering deformation processes from surface displacements

    NASA Astrophysics Data System (ADS)

    Stramondo, Salvatore; Trasatti, Elisa; Albano, Matteo; Moro, Marco; Chini, Marco; Bignami, Christian; Polcari, Marco; Saroli, Michele

    2016-12-01

    Today, satellite remote sensing has reached a key role in Earth Sciences. In particular, Synthetic Aperture Radar (SAR) sensors and SAR Interferometry (InSAR) techniques are widely used for the study of dynamic processes occurring inside our living planet. Over the past 3 decades, InSAR has been applied for mapping topography and deformation at the Earth's surface. These maps are widely used in tectonics, seismology, geomorphology, and volcanology, in order to investigate the kinematics and dynamics of crustal faulting, the causes of postseismic and interseismic displacements, the dynamics of gravity driven slope failures, and the deformation associated with subsurface movement of water, hydrocarbons or magmatic fluids.

  10. Nanometer displacement measurement using Fresnel diffraction.

    PubMed

    Khorshad, Ali Akbar; Hassani, Khosrow; Tavassoly, Mohammad Taghi

    2012-07-20

    We introduce a relatively simple and efficient optical technique to measure nanoscale displacement based on visibility variations of the Fresnel diffraction fringes from a two-dimensional phase step. In this paper we use our technique to measure electromechanical expansions by a thin piezoelectric ceramic and also thermal changes in the diameter of a tungsten wire. Early results provide convincing evidence that sensitivity up to a few nanometers can be achieved, and our technique has the potential to be used as a nanodisplacement probe.

  11. Atomic displacement energy in amorphous compounds

    NASA Astrophysics Data System (ADS)

    Sanditov, D. S.; Mashanov, A. A.

    2016-12-01

    Atomic displacement energy Δɛe in multicomponent sheet and lead-silicate glasses is calculated from the free activation energy of a viscous flow. The value of Δɛe is shown to remain constant in a rather wide range of temperatures in the glass transition region. Satisfactory agreement with calculations of Δɛe using the current formula incorporating the glass transition temperature and the fluctuation volume fraction frozen at this temperature is obtained. The validity of the above formula not only at the glass transition temperature but also in the temperature region adjacent to it is confirmed.

  12. Measuring fast stochastic displacements of bio-membranes with dynamic optical displacement spectroscopy.

    PubMed

    Monzel, C; Schmidt, D; Kleusch, C; Kirchenbüchler, D; Seifert, U; Smith, A-S; Sengupta, K; Merkel, R

    2015-10-06

    Stochastic displacements or fluctuations of biological membranes are increasingly recognized as an important aspect of many physiological processes, but hitherto their precise quantification in living cells was limited due to a lack of tools to accurately record them. Here we introduce a novel technique--dynamic optical displacement spectroscopy (DODS), to measure stochastic displacements of membranes with unprecedented combined spatiotemporal resolution of 20 nm and 10 μs. The technique was validated by measuring bending fluctuations of model membranes. DODS was then used to explore the fluctuations in human red blood cells, which showed an ATP-induced enhancement of non-Gaussian behaviour. Plasma membrane fluctuations of human macrophages were quantified to this accuracy for the first time. Stimulation with a cytokine enhanced non-Gaussian contributions to these fluctuations. Simplicity of implementation, and high accuracy make DODS a promising tool for comprehensive understanding of stochastic membrane processes.

  13. Measuring fast stochastic displacements of bio-membranes with dynamic optical displacement spectroscopy

    NASA Astrophysics Data System (ADS)

    Monzel, C.; Schmidt, D.; Kleusch, C.; Kirchenbüchler, D.; Seifert, U.; Smith, A.-S.; Sengupta, K.; Merkel, R.

    2015-10-01

    Stochastic displacements or fluctuations of biological membranes are increasingly recognized as an important aspect of many physiological processes, but hitherto their precise quantification in living cells was limited due to a lack of tools to accurately record them. Here we introduce a novel technique--dynamic optical displacement spectroscopy (DODS), to measure stochastic displacements of membranes with unprecedented combined spatiotemporal resolution of 20 nm and 10 μs. The technique was validated by measuring bending fluctuations of model membranes. DODS was then used to explore the fluctuations in human red blood cells, which showed an ATP-induced enhancement of non-Gaussian behaviour. Plasma membrane fluctuations of human macrophages were quantified to this accuracy for the first time. Stimulation with a cytokine enhanced non-Gaussian contributions to these fluctuations. Simplicity of implementation, and high accuracy make DODS a promising tool for comprehensive understanding of stochastic membrane processes.

  14. Displaced and non-displaced Colombian children's evaluations of moral transgressions, retaliation, and reconciliation

    PubMed Central

    Ardila-Rey, Alicia; Killen, Melanie; Brenick, Alaina

    2015-01-01

    In order to assess the effects of displacement and exposure to violence on children's moral reasoning, Colombian children exposed to minimal violence (non-displaced or low-risk) (N = 99) and to extreme violence (displaced or high-risk) (N = 94), evenly divided by gender, at 6-, 9-, and 12 - years of age, were interviewed regarding their evaluation of peer-oriented moral transgressions (hitting and not sharing toys). The vast majority of children evaluated moral transgressions as wrong. Group and age differences were revealed, however, regarding provocation and retaliation. Children who were exposed to violence, in contrast to those with minimum exposure, judged it more legitimate to inflict harm or deny resources when provoked and judged it more okay to retaliate for reasons of retribution. Surprisingly, and somewhat hopefully, all children viewed reconciliation as feasible. The results are informative regarding theories of morality, culture, and the effects of violence on children's social development. PMID:25722543

  15. Accurate Feeding of Nanoantenna by Singular Optics for Nanoscale Translational and Rotational Displacement Sensing

    NASA Astrophysics Data System (ADS)

    Xi, Zheng; Wei, Lei; Adam, A. J. L.; Urbach, H. P.; Du, Luping

    2016-09-01

    Identifying subwavelength objects and displacements is of crucial importance in optical nanometrology. We show in this Letter that nanoantennas with subwavelength structures can be excited precisely by incident beams with singularity. This accurate feeding beyond the diffraction limit can lead to dynamic control of the unidirectional scattering in the far field. The combination of the field discontinuity of the incoming singular beam with the rapid phase variation near the antenna leads to remarkable sensitivity of the far-field scattering to the displacement at a scale much smaller than the wavelength. This Letter introduces a far-field deep subwavelength position detection method based on the interaction of singular optics with nanoantennas.

  16. Improving Students' Understanding of Waves by Plotting a Displacement-Time Graph in Class

    NASA Astrophysics Data System (ADS)

    Wei, Yajun

    2012-04-01

    The topic of waves is one that many high school physics students find difficult to understand. This is especially true when using some A-level textbooks1,2used in the U.K., where the concept of waves is introduced prior to the concept of simple harmonic oscillations. One of the challenges my students encounter is understanding the difference between displacement-time graphs and displacement-position graphs. Many students wonder why these two graphs have the same sinusoidal shape. Having the students use multimedia simulations allows them to see, in a hands-on fashion, the relationship between the two graphs.

  17. Performance characterization of an internsity-modulated fiber optic displacement sensor

    SciTech Connect

    Moro, Erik Allan; Todd, Michael D; Puckett, Santhony D

    2010-09-30

    A testbed simulating an intensity-modulated fiber optic displacement sensor is experimentally characterized, and the implications regarding sensor design are discussed. Of interest are the intensity distribution of the transmitted optical signal and the relationships between sensor architecture and performance. Particularly, an intensity-modulated sensor's sensitivity, linearity, displacement range, and resolution are functions of the relative positioning of its transmitting and receiving fibers. In this paper, sensor architectures with various combinations of these performance metrics are discussed. A sensor capable of micrometer resolution is reported, and it is concluded that this work could lead to an improved methodology for sensor design.

  18. Respiratory arrest following posteriorly displaced odontoid fractures. Case reports and review of the literature.

    PubMed

    Lewallen, R P; Morrey, B F; Cabanela, M E

    1984-09-01

    Posterior displacement of the odontoid after fracture occurs much less frequently than does anterior displacement. Experience with four patients suggests that anatomic reduction may not be possible and prolonged attempts to gain reduction are not advisable. Those cases should be managed with early application of a halo vest. A rotating frame should be avoided. The potential for respiratory arrest, at least in the older individual, is great and can be precipitated even by a change of position in the process of turning on the rotating frame. The mechanism of the respiratory failure is obscure.

  19. 5(6)-anti-Substituted-2-azabicyclo[2.1.1]hexanes. A Nucleophilic Displacement Route

    PubMed Central

    Krow, Grant R.; Edupuganti, Ram; Gandla, Deepa; Choudhary, Amit; Lin, Guoliang; Sonnet, Philip E.; DeBrosse, Charles; Ross, Charles W.; Cannon, Kevin C.; Raines, Ronald T.

    2012-01-01

    Nucleophilic displacements of 5(6)-anti-bromo substituents in 2-azabicyclo[2.1.1]hexanes (methanopyrrolidines) have been accomplished. These displacements have produced 5-anti-X-6-anti-Y-difunctionalized-2-azabicyclo[2.1.1]hexanes containing bromo, fluoro, acetoxy, hydroxy, azido, imidazole, thiophenyl, and iodo substituents. Such displacements of anti-bromide ions require an amine nitrogen and are a function of the solvent and the choice of metal salt. Reaction rates were faster and product yields were higher in DMSO when compared to DMF and with CsOAc compared to NaOAc. Sodium or lithium salts gave products, except with NaF, where silver fluoride in nitromethane was best for substitution by fluoride. The presence of electron-withdrawing F, OAc, N3, Br, or SPh substituents in the 6-anti-position slows bromide displacements at the 5-anti-position. PMID:19799411

  20. Competitive adsorption, displacement, and transport of organic matter on iron oxide: II. Displacement and transport

    SciTech Connect

    Gu, B; Mehlhorn, T.L.; Liang, Liyuan

    1996-08-01

    The competitive interactions between organic matter compounds and mineral surfaces are poorly understood, yet these interactions may play a significant role in the stability and co-transport of mineral colloids and/or environmental contaminants. In this study, the processes of competitive adsorption, displacement, and transport of Suwannee River natural organic matter (SR-NOM) are investigated with several model organic compounds in packed beds of iron oxide-coated quartz columns. Results demonstrated that strongly-binding organic compounds are competitively adsorbed and displace those weakly-bound organic compounds along the flow path. Among the four organic compounds studied, polyacrylic acid (PAA) appeared to be the most competitive, whereas SR-NOM was more competitive than phthalic and salicylic acids. A diffuse adsorption and sharp desorption front (giving an appearance of irreversible adsorption) of the SR-NOM breakthrough curves are explained as being a result of the competitive time-dependent adsorption and displacement processes between different organic components within the SR-NOM. The stability and transport of iron oxide colloids varied as one organic component competitively displaces another. Relatively large quantities of iron oxide colloids are transported when the more strongly-binding PAA competitively displaces the weakly-binding SR-NOM or when SR-NOM competitively displaces phthalic and salicylic acids. Results of this study suggest that the chemical composition and hence the functional behavior of NOM (e.g., in stabilizing mineral colloids and in complexing contaminants) can change along its flow path as a result of the dynamic competitive interactions between heterogeneous NOM subcomponents. Further studies are needed to better define and quantify these NOM components as well as their roles in contaminant partitioning and transport. 37 refs., 10 figs.

  1. Gender-based violence in conflict and displacement: qualitative findings from displaced women in Colombia

    PubMed Central

    2014-01-01

    Introduction Gender-based violence (GBV) is prevalent among, though not specific to, conflict affected populations and related to multifarious levels of vulnerability of conflict and displacement. Colombia has been marked with decades of conflict, with an estimated 5.2 million internally displaced persons (IDPs) and ongoing violence. We conducted qualitative research to understand the contexts of conflict, displacement and dynamics with GBV. This as part of a multi-phase, mixed method study, in collaboration with UNHCR, to develop a screening tool to confidentially identify cases of GBV for referral among IDP women who were survivors of GBV. Methods Qualitative research was used to identify the range of GBV, perpetrators, contexts in conflict and displacement, barriers to reporting and service uptake, as well as to understand experiences of service providers. Thirty-five female IDPs, aged 18 years and older, who self-identified as survivors of GBV were enrolled for in-depth interviews in San Jose de Guaviare and Quibdo, Colombia in June 2012. Thirty-one service providers participated in six focus group discussions and four interviews across these sites. Results Survivors described a range of GBV across conflict and displacement settings. Armed actors in conflict settings perpetrated threats of violence and harm to family members, child recruitment, and, to a lesser degree, rape and forced abortion. Opportunistic violence, including abduction, rape, and few accounts of trafficking were more commonly reported to occur in the displacement setting, often perpetrated by unknown individuals. Intrafamilial violence, intimate partner violence, including physical and sexual violence and reproductive control were salient across settings and may be exacerbated by conflict and displacement. Barriers to reporting and services seeking were reported by survivors and providers alike. Conclusions Findings highlight the need for early identification of GBV cases, with emphasis on

  2. Moral Reasoning in Violent Contexts: Displaced and Non-Displaced Colombian Children's Evaluations of Moral Transgressions, Retaliation, and Reconciliation

    ERIC Educational Resources Information Center

    Ardila-Rey, Alicia; Killen, Melanie; Brenick, Alaina

    2009-01-01

    In order to assess the effects of displacement and exposure to violence on children's moral reasoning, Colombian children exposed to minimal violence (non-displaced or low risk; N = 99) and to extreme violence (displaced or high risk; N = 94), evenly divided by gender at 6, 9, and 12 years of age, were interviewed regarding their evaluation of…

  3. Glacial Debutressing and Displacement History of the Driest Rockslide (Central Alps, Switzerland)

    NASA Astrophysics Data System (ADS)

    Vogler, Matthias; Loew, Simon; Glueer, Franziska; Grämiger, Lorenz

    2016-04-01

    Only few studies have been performed, where the physical interactions between a retreating valley glacier and rock slope movements have been recorded and analyzed in detail. The Driest landslide, situated at the current tongue of the Great Aletsch Glacier in the Swiss Alps, offers a unique case study, because the history of the Great Aletsch Glacier has been studied in great detail by various researchers and the Driest landslide displacements can be unraveled for similar time windows. In this paper we focus on the most recent observation period, i.e. the rockslide and glacier history since the Little Ice Age, when the entire Driest landslide was covered by the glacial ice. Our kinematic model of the Driest landslide, based on field mapping and photogrammetric analyses, was confirmed by displacement vector data from two robotic total stations recording daily displacements of 12 reflectors positioned within the instability. The rockslide basal rupture plane is a compound sliding surface composed of a steeply dipping head scarp, a presumably moderately steep central section, and an upward directed daylighting frontal section. This rupture plane geometry is structurally conditioned by a regional fault in the head scarp area and a rotating Alpine foliation in the toe area. The most recent displacement history of this old rotational rockslide has been unraveled by lichenometry (i.e. systematic mapping of greenish Rhizocarpon Geographicum diameters) in the deepest part of the head scarp, calibrated with dendrochronologic data. Depending on the lichen profile position within the head scarp area, different displacement time histories of the Driest landslide can be developed and correlated with glacial ice elevations as recorded by multiple aerial images and historical documents. Whereas displacement rates before 1991 were in the order of 1 cm/year, significantly higher displacement rates ranging between 7 and 13 cm/year are recorded in the head scarp area for the period

  4. 3D deterministic lateral displacement separation systems

    NASA Astrophysics Data System (ADS)

    Du, Siqi; Drazer, German

    2016-11-01

    We present a simple modification to enhance the separation ability of deterministic lateral displacement (DLD) systems by expanding the two-dimensional nature of these devices and driving the particles into size-dependent, fully three-dimensional trajectories. Specifically, we drive the particles through an array of long cylindrical posts, such that they not only move parallel to the basal plane of the posts as in traditional two-dimensional DLD systems (in-plane motion), but also along the axial direction of the solid posts (out-of-plane motion). We show that the (projected) in-plane motion of the particles is completely analogous to that observed in 2D-DLD systems and the observed trajectories can be predicted based on a model developed in the 2D case. More importantly, we analyze the particles out-of-plane motion and observe significant differences in the net displacement depending on particle size. Therefore, taking advantage of both the in-plane and out-of-plane motion of the particles, it is possible to achieve the simultaneous fractionation of a polydisperse suspension into multiple streams. We also discuss other modifications to the obstacle array and driving forces that could enhance separation in microfluidic devices.

  5. Do alternative energy sources displace fossil fuels?

    NASA Astrophysics Data System (ADS)

    York, Richard

    2012-06-01

    A fundamental, generally implicit, assumption of the Intergovernmental Panel on Climate Change reports and many energy analysts is that each unit of energy supplied by non-fossil-fuel sources takes the place of a unit of energy supplied by fossil-fuel sources. However, owing to the complexity of economic systems and human behaviour, it is often the case that changes aimed at reducing one type of resource consumption, either through improvements in efficiency of use or by developing substitutes, do not lead to the intended outcome when net effects are considered. Here, I show that the average pattern across most nations of the world over the past fifty years is one where each unit of total national energy use from non-fossil-fuel sources displaced less than one-quarter of a unit of fossil-fuel energy use and, focusing specifically on electricity, each unit of electricity generated by non-fossil-fuel sources displaced less than one-tenth of a unit of fossil-fuel-generated electricity. These results challenge conventional thinking in that they indicate that suppressing the use of fossil fuel will require changes other than simply technical ones such as expanding non-fossil-fuel energy production.

  6. An interferometric strain-displacement measurement system

    NASA Technical Reports Server (NTRS)

    Sharpe, William N., Jr.

    1989-01-01

    A system for measuring the relative in-plane displacement over a gage length as short as 100 micrometers is described. Two closely spaced indentations are placed in a reflective specimen surface with a Vickers microhardness tester. Interference fringes are generated when they are illuminated with a He-Ne laser. As the distance between the indentations expands or contracts with applied load, the fringes move. This motion is monitored with a minicomputer-controlled system using linear diode arrays as sensors. Characteristics of the system are: (1) gage length ranging from 50 to 500 micrometers, but 100 micrometers is typical; (2) least-count resolution of approximately 0.0025 micrometer; and (3) sampling rate of 13 points per second. In addition, the measurement technique is non-contacting and non-reinforcing. It is useful for strain measurements over small gage lengths and for crack opening displacement measurements near crack tips. This report is a detailed description of a new system recently installed in the Mechanisms of Materials Branch at the NASA Langley Research Center. The intent is to enable a prospective user to evaluate the applicability of the system to a particular problem and assemble one if needed.

  7. Regression models for estimating coseismic landslide displacement

    USGS Publications Warehouse

    Jibson, R.W.

    2007-01-01

    Newmark's sliding-block model is widely used to estimate coseismic slope performance. Early efforts to develop simple regression models to estimate Newmark displacement were based on analysis of the small number of strong-motion records then available. The current availability of a much larger set of strong-motion records dictates that these regression equations be updated. Regression equations were generated using data derived from a collection of 2270 strong-motion records from 30 worldwide earthquakes. The regression equations predict Newmark displacement in terms of (1) critical acceleration ratio, (2) critical acceleration ratio and earthquake magnitude, (3) Arias intensity and critical acceleration, and (4) Arias intensity and critical acceleration ratio. These equations are well constrained and fit the data well (71% < R2 < 88%), but they have standard deviations of about 0.5 log units, such that the range defined by the mean ?? one standard deviation spans about an order of magnitude. These regression models, therefore, are not recommended for use in site-specific design, but rather for regional-scale seismic landslide hazard mapping or for rapid preliminary screening of sites. ?? 2007 Elsevier B.V. All rights reserved.

  8. Grating Loaded Cantilevers for Displacement Measurements

    NASA Astrophysics Data System (ADS)

    Karademir, Ertugrul; Olcum, Selim; Atalar, Abdullah; Aydinli, Atilla

    2010-03-01

    A cantilever with a grating coupler engraved on its tip is used for measuring displacement. The coupled light in the cantilever is guided to a single mode optical waveguide defined at the base of the cantilever. The grating period is 550 nm and is fabricated on a SOI wafer using nanoimprint lithography. The waveguide and the cantilever are defined by an RIE and cantilevers released by KOH and HF solutions. Light with 1550 nm wavelength, is directed onto the grating coupler and detected at the cleaved end of the SOI waveguide. The angle of incidence is controlled by a motorized rotary stage. Light couples into the waveguide at a characteristic angle with a full width at half maximum of approximately 6.9 mrads translating into a Q factor of 87.5. The displacement sensitivity is measured by driving the cantilever with a frequency controlled piezoelectric element. The modulation of the light at the waveguide output is lock-in detected by a biased infrared detector. The resulting 43%mrad-1 sensitivity can be increased with further optimization.

  9. Estimating Hydrologic Processes from Subsurface Soil Displacements

    NASA Astrophysics Data System (ADS)

    Freeman, C. E.; Murdoch, L. C.; Germanovich, L.; MIller, S.

    2012-12-01

    Soil moisture and the processes that control it are important components of the hydrologic cycle, but measuring these processes remains challenging. We have developed a new measurement method that offers flexibility compared to existing technology. The approach is to measure small vertical displacements in the soil which responds proportionally to distributed surface load changes such as variation in the near-surface water content. The instrument may be installed at a depth of several meters to hundreds of meters below the surface. Because the measurement averaging region scales with the depth of the displacement measurements, this approach provides the means for estimating the soil moisture time series over tens of square meters to tens of thousands of square meters. The instrument developed for this application is called a Sand-X, which is short for Sand Extensometer. It is designed for applications in unconsolidated material, ranging from clay to sand. The instrument is simple and relatively inexpensive, and it can be installed in a boring made with a hand auger or with a small drill rig. Studies at the field scale are ongoing at a field site near Clemson, SC. The site is underlain by saprolite weathered primarily from biotite gneiss. Several Sand-X devices are installed at a field site that is instrumented for validating soil moisture, precipitation, and evapotranspiration estimates. These instruments are emplaced at a depth of 6 m and respond to the weight of a vehicle out to 18 m from the well. Calibration is performed by comparing precipitation measurements to the soil displacement response. For example, the coefficient for one installation is roughly 185 nm soil displacement/mm water content change. The resolution of the instrument is approximately 10 nm, so the Sand-X is capable of detecting changes of soil moisture on the order of tenths of one mm in compliant soils like saprolite. A typical soil displacement time series shows alternating periods of

  10. Pitch change thresholds as influenced by angular rate and duration of the apparent horizon's displacement

    NASA Technical Reports Server (NTRS)

    Haines, R. F.

    1985-01-01

    The displacement threshold (DT) during voluntary visual tracking of a line and during fixation of a stable spot located at the initial stimulus position was determined to help in the modeling pilot manual dynamics during the nose-up 'flare' maneuver. Forty-six observers made paired comparison, forced choice judgments of the maximal downward displacements of a horizontal line moving at various speeds for the durations of 0.25, 0.50, and 1.00 sec. The results indicated that the DT is significantly lower, the confidence is higher, and the number of errors and guesses is smaller when a fixation dot is present; moreover, increasing both the stimulus velocity and duration significantly improves the accuracy of displacement discrimination and increases mean confidence.

  11. Differences between vehicle lateral displacement on the road and in a fixed-base simulator.

    PubMed

    Blana, Evi; Golias, John

    2002-01-01

    This work investigates differences in lateral displacement when driving on curved and straight road sections in real-road and simulator conditions. We observed 100 licensed drivers on a rural road and 100 in a fixed-base simulator. Speed and lateral position on the real road were measured using videocameras. The analysis indicates that the mean vehicle lateral displacement is in general higher on the real road than in the simulator. However, these differences decrease for higher speeds at curved sections and for lower speeds at straight sections. It was also found that the standard deviation of the vehicle lateral displacement is significantly lower on the real road than the corresponding values in the simulator, at either curved or straight sections. Actual or potential applications of this research are related to a more realistic assessment of driving behavior scenarios derived on the basis of simulation experiment results.

  12. Feynman's Proof and Non-Elastic Displacement Fields: Relationship Between Magnetic Field and Defects Field

    NASA Astrophysics Data System (ADS)

    Nakamura, Nozomu; Yamasaki, Kazuhito

    2016-12-01

    We consider the relationship between the magnetic field and the non-elastic displacement field including defects, from the viewpoints of non-commutativity of the positions and non-commutativity of the derivatives. The former non-commutativity is related to the magnetic field by Feynman's proof (1948), and the latter is related to the defect fields by the continuum theory of defects. We introduce the concept of differential geometry to the non-elastic displacement field and derive an extended relation that includes basic equations, such as Gauss's law for magnetism and the conservation law for dislocation density. The relation derived in this paper also extends the first Bianchi identity in linear approximation to include the effect of magnetism. These findings suggest that Feynman's approach with a non-elastic displacement field is useful for understanding the relationship between magnetism and non-elastic mechanics.

  13. Do Kirschner wires maintain reduction of displaced Colles' fractures?

    PubMed

    Barton, Tristan; Chambers, Charles; Lane, Emma; Bannister, Gordon

    2005-12-01

    Fifty-three patients underwent closed reduction and longitudinal k-wiring of displaced Colles' fractures and were reviewed after a mean of 26 months. Radiographs taken at the time of injury, after reduction and k-wiring, and at fracture union were compared for radial shortening and dorsal angulation. Manipulation significantly improved fracture position (P<0.001). Dorsal angulation was successfully corrected by manipulation in 98%, and this position was maintained to fracture union in all cases. Seventy-three percentage of fractures manipulated for radial shortening >2 mm were adequately reduced, but 41% of these fractures subsequently lost position to malunite. In this group of patients, the mean radial shortening between reduction and fracture union was 1.6 mm. This did not correlate with Frykman Class or radial shortening at injury. Closed reduction and k-wire stabilisation is an attractive technique because it is relatively non-invasive compared with plating or external fixation. However, a degree of radial shortening between reduction and fracture union must be anticipated. Fractures reduced inadequately to allow for this loss of radial length, are more likely to malunite. This may compromise functional outcome.

  14. Attenuation of Scalar Fluxes Measured with Spatially-displaced Sensors

    NASA Astrophysics Data System (ADS)

    Horst, T. W.; Lenschow, D. H.

    2009-02-01

    Observations from the Horizontal Array Turbulence Study (HATS) field program are used to examine the attenuation of measured scalar fluxes caused by spatial separation between the vertical velocity and scalar sensors. The HATS data show that flux attenuation for streamwise, crosswind, and vertical sensor displacements are each a function of a dimensionless, stability-dependent parameter n m multiplied by the ratio of sensor displacement to measurement height. The scalar flux decays more rapidly with crosswind displacements than for streamwise displacements and decays more rapidly for stable stratification than for unstable stratification. The cospectral flux attenuation model of Kristensen et al. agrees well with the HATS data for streamwise sensor displacements, although it is necessary to include a neglected quadrature spectrum term to explain the observation that flux attenuation is often less with the scalar sensor downwind of the anemometer than for the opposite configuration. A simpler exponential decay model provides good estimates for crosswind sensor displacements, as well as for streamwise sensor displacements with stable stratification. A model similar to that of Lee and Black correctly predicts flux attenuation for a combination of streamwise and crosswind displacements, i.e. as a function of wind direction relative to the sensor displacement. The HATS data for vertical sensor displacements extend the near-neutral results of Kristensen et al. to diabatic stratification and confirm their finding that flux attenuation is less with the scalar sensor located below the anemometer than if the scalar sensor is displaced an equal distance either horizontally or above the anemometer.

  15. Interfacial jumps and pressure bursts during fluid displacement in interacting irregular capillaries.

    PubMed

    Moebius, Franziska; Or, Dani

    2012-07-01

    The macroscopically regular motion of fluid displacement fronts in porous media often results from numerous pore scale interfacial jumps and associated pressure fluctuations. Such rapid pore scale dynamics defy postulated slow viscous energy dissipation and may shape phase entrapment and subsequent macroscopic transport properties. Certain displacement characteristics are predictable from percolation theory; however, insights into rapid interfacial dynamics require mechanistic models for hydraulically interacting pores such as found along fluid displacement fronts. A model for hydraulically coupled sinusoidal capillaries was used to analyze stick-jump interfacial motions with a significant inertial component absent in Darcy-based description of fluid front displacement. High-speed camera provided measurements of rapid interfacial dynamics in sintered glass beads cell during drainage. Interfacial velocities exceeding 50 times mean front velocity were observed in good agreement with model predictions for a pair of sinusoidal capillaries. In addition to characteristic pinning-jumping behavior, interfacial dynamics were sensitive to initial positions within pores at the onset of a jump. Even for a pair of sinusoidal capillaries, minute variations in pore geometry and boundary conditions yield rich behavior of motions, highlighting challenges and potential new insights offered by consideration of pore scale mechanisms in macroscopic description of fluid displacement fronts in porous media.

  16. Mortality displacement as a function of heat event strength in 7 US cities.

    PubMed

    Saha, Michael V; Davis, Robert E; Hondula, David M

    2014-02-15

    Mortality rates increase immediately after periods of high air temperature. In the days and weeks after heat events, time series may exhibit mortality displacement-periods of lower than expected mortality. We examined all-cause mortality and meteorological data from 1980 to 2009 in the cities of Atlanta, Georgia; Boston, Massachusetts; Minneapolis-St. Paul, Minnesota; Philadelphia, Pennsylvania; Phoenix, Arizona; Seattle, Washington; and St. Louis, Missouri. We modeled baseline mortality using a generalized additive model. Heat waves were defined as periods of 3 or more consecutive days in which the apparent temperature exceeded a variable percentile. For each heat wave, we calculated the sum of excess and deficit mortality. Mortality displacement, which is the ratio of grand sum deficit to grand sum excess mortality, decreased as a function of event strength in all cities. Displacement was close to 1.00 for the weakest events. At the highest temperatures, displacement varied from 0.35 (95% confidence interval: 0.21, 0.55) to 0.75 (95% confidence interval: 0.54, 0.97). We found strong evidence of acclimatization across cities. Without consideration of displacement effects, the net impacts of heat-wave mortality are likely to be significant overestimations. A statistically significant positive relationship between the onset temperature of nondisplaced heat mortality and mean warm-season temperature (R(2) = 0.78, P < 0.01) suggests that heat mortality thresholds may be predictable across cities.

  17. Respiratory Displacement of the Thoracic Aorta: Physiological Phenomenon With Potential Implications for Thoracic Endovascular Repair

    SciTech Connect

    Weber, Tim Frederik; Tetzlaff, Ralf; Rengier, Fabian; Geisbuesch, Philipp; Kopp-Schneider, Annette; Boeckler, Dittmar; Eichinger, Monika; Kauczor, Hans-Ulrich; Tengg-Kobligk, Hendrik von

    2009-07-15

    The purpose of this study was to assess the magnitude and direction of respiratory displacement of the ascending and descending thoracic aorta during breathing maneuvers. In 11 healthy nonsmokers, dynamic magnetic resonance imaging was performed in transverse orientation at the tracheal bifurcation during maximum expiration and inspiration as well as tidal breathing. The magnitude and direction of aortic displacement was determined relatively to resting respiratory position for the ascending (AA) and descending (DA) aorta. To estimate a respiratory threshold for occurrence of distinct respiratory aortic motion, the latter was related to the underlying change in anterior-posterior thorax diameter. Compound displacement between maximum expiration and inspiration was 24.3 {+-} 6.0 mm for the AA in the left anterior direction and 18.2 {+-} 5.5 mm for the DA in the right anterior direction. The mean respiratory thorax excursion during tidal breathing was 8.9 {+-} 2.8 mm. The respiratory threshold, i.e., the increase in thorax diameter necessary to result in respiratory aortic displacement, was estimated to be 15.7 mm. The data suggest that after a threshold of respiratory thorax excursion is exceeded, respiration is accompanied by significant displacement of the thoracic aorta. Although this threshold may not be reached during tidal breathing in the majority of individuals, segmental differences during forced respiration impact on aortic geometry, may result in additional extrinsic forces on the aortic wall, and may be of significance for aortic prostheses designed for thoracic endovascular aortic repair.

  18. Optical Coherence Tomographic Features and Prognosis of Pneumatic Displacement for Submacular Hemorrhage

    PubMed Central

    Bae, Kunho; Cho, Ga Eun; Yoon, Je Moon; Kang, Se Woong

    2016-01-01

    Purpose To identify prognostic factors, including optical coherence tomographic features, of visual outcome in exudative age-related macular degeneration with submacular hemorrhage treated with pneumatic displacement. Methods This retrospective interventional case series included 37 eyes with exudative age-related macular degeneration and submacular hemorrhage, all of which underwent pneumatic displacement. The best-corrected visual acuity (BCVA) was measured at diagnosis and at 3 and 6 months after treatment. In addition to demographic and funduscopic parameters, tomographic features such as reflectance of the submacular hemorrhage were analyzed with regard to BCVA at 6 months. Results After pneumatic displacement and a subsequent treatment such as laser or anti-vascular endothelial growth factor therapy, the BCVA at 3 and 6 months improved significantly (P < 0.001, respectively). Higher baseline BCVA (P < 0.001), shorter symptom duration (P = 0.007), and younger age (P = 0.014) were significant positive prognostic factors on regression analysis. Among optical coherence tomography characteristics, reflectance of the submacular hemorrhage, the shortest radius of the submacular hemorrhage centered on the fovea, and defects in the ellipsoid zone, and external limiting membrane affected the BCVA at 6 months (P < 0.05). Conclusion A favorable visual outcome was demonstrated after initial pneumatic displacement and subsequent treatment for submacular hemorrhage. The submacular hemorrhages exhibiting lower reflectance on optical coherence tomography and a smaller shortest radius from the foveal center were found to be good candidates for pneumatic displacement. PMID:27992524

  19. Automatic Alignment of Displacement-Measuring Interferometer

    NASA Technical Reports Server (NTRS)

    Halverson, Peter; Regehr, Martin; Spero, Robert; Alvarez-Salazar, Oscar; Loya, Frank; Logan, Jennifer

    2006-01-01

    A control system strives to maintain the correct alignment of a laser beam in an interferometer dedicated to measuring the displacement or distance between two fiducial corner-cube reflectors. The correct alignment of the laser beam is parallel to the line between the corner points of the corner-cube reflectors: Any deviation from parallelism changes the length of the optical path between the reflectors, thereby introducing a displacement or distance measurement error. On the basis of the geometrical optics of corner-cube reflectors, the length of the optical path can be shown to be L = L(sub 0)cos theta, where L(sub 0) is the distance between the corner points and theta is the misalignment angle. Therefore, the measurement error is given by DeltaL = L(sub 0)(cos theta - 1). In the usual case in which the misalignment is small, this error can be approximated as DeltaL approximately equal to -L(sub 0)theta sup 2/2. The control system (see figure) is implemented partly in hardware and partly in software. The control system includes three piezoelectric actuators for rapid, fine adjustment of the direction of the laser beam. The voltages applied to the piezoelectric actuators include components designed to scan the beam in a circular pattern so that the beam traces out a narrow cone (60 microradians wide in the initial application) about the direction in which it is nominally aimed. This scan is performed at a frequency (2.5 Hz in the initial application) well below the resonance frequency of any vibration of the interferometer. The laser beam makes a round trip to both corner-cube reflectors and then interferes with the launched beam. The interference is detected on a photodiode. The length of the optical path is measured by a heterodyne technique: A 100- kHz frequency shift between the launched beam and a reference beam imposes, on the detected signal, an interferometric phase shift proportional to the length of the optical path. A phase meter comprising analog

  20. Nursing Positions

    MedlinePlus

    ... breast with your other hand. The Clutch or Football Hold This is also a good position for ... same time may also choose this position. The football hold allows babies to take milk more easily — ...

  1. The Quantum State as Spatial Displacement

    NASA Astrophysics Data System (ADS)

    Holland, Peter

    We give a simple demonstration that the Schrödinger equation of wave mechanics may be recast as a self-contained second-order Newtonian law for a congruence of spacetime trajectories. This implies that a pictorial representation of the quantum state as a displacement function is implicit in the quantum description, complementary to and independent of the wave function. Quantum evolution is described by the deterministic unfolding of a continuous coordinate transformation. Introducing gauge potentials for the density and current density it is shown that the wave-mechanical and trajectory pictures are connected by a canonical transformation. The canonical trajectory theory is shown to provide an alternative basis for the quantum operator calculus and the observability of the quantum state is examined within this context. The construction illuminates some of the problems involved in connecting the quantum and classical descriptions.

  2. Mirror displacement energies and neutron skins

    NASA Astrophysics Data System (ADS)

    Duflo, J.; Zuker, A. P.

    2002-11-01

    A gross estimate of the neutron skin [0.80(5)(N-Z)/A fm] is extracted from experimental proton radii, represented by a four parameter fit, and observed mirror displacement energies (CDE). The calculation of the latter relies on an accurately derived Coulomb energy and smooth averages of the charge symmetry breaking potentials constrained to state of the art values. The only free parameter is the neutron skin itself. The Nolen Schiffer anomaly is reduced to small deviations (rms=127 keV) that exhibit a secular trend. It is argued that with state of the art shell model calculations the anomaly should disappear. Highly accurate fits to proton radii emerge as a fringe benefit.

  3. Inertia and scaling in deterministic lateral displacement.

    PubMed

    Bowman, Timothy J; Drazer, German; Frechette, Joelle

    2013-01-01

    The ability to separate and analyze chemical species with high resolution, sensitivity, and throughput is central to the development of microfluidics systems. Deterministic lateral displacement (DLD) is a continuous separation method based on the transport of species through an array of obstacles. In the case of force-driven DLD (f-DLD), size-based separation can be modelled effectively using a simple particle-obstacle collision model. We use a macroscopic model to study f-DLD and demonstrate, via a simple scaling, that the method is indeed predominantly a size-based phenomenon at low Reynolds numbers. More importantly, we demonstrate that inertia effects provide the additional capability to separate same size particles but of different densities and could enhance separation at high throughput conditions. We also show that a direct conversion of macroscopic results to microfluidic settings is possible with a simple scaling based on the size of the obstacles that results in a universal curve.

  4. Dynamics of liquid-liquid displacement.

    PubMed

    Fetzer, Renate; Ramiasa, Melanie; Ralston, John

    2009-07-21

    Capillary driven liquid-liquid displacement in a system with two immiscible liquids of comparable viscosity was investigated by means of optical high speed video microscopy. For the first time, the impact of substrate wettability on contact line dynamics in liquid-liquid systems was studied. On all substrates, qualitatively different dynamics, in two distinct velocity regimes, were found. Hydrodynamic models apply to the fast stage of initial spreading, while nonhydrodynamic dissipation dominates contact line motion in a final stage at low speed, where the molecular kinetic theory (MKT) successfully captured the dynamics. The MKT model parameter values showed no systematic dependence on substrate wettability. This unexpected result is interpreted in terms of local contact line pinning.

  5. [Control of tuberculosis in refugees and displaced].

    PubMed

    Kessler, C; Connolly, M; Levy, M; Chaulet, P

    1997-10-01

    As a result of national and international conflicts, the number of refugees and displaced persons in various countries of the world is increasing. The complex and protracted nature of these conflicts often forces refugees to remain away from their countries for long periods, living in refugee camps. Many refugees come from countries where tuberculosis is endemic and, once the immediate problems of establishing a camp are overcome, this disease becomes the principal problem affecting refugee camps. In order to advise the persons in charge of refugee camps on how to set up tuberculosis control programs, this document details the general requirements and specific recommendations of WHO for the implementation of such programs, as well as guidelines for their evaluation and monitoring, including criteria that would justify camp closure.

  6. Superconducting inductive displacement detection of a microcantilever

    SciTech Connect

    Vinante, A.

    2014-07-21

    We demonstrate a superconducting inductive technique to measure the displacement of a micromechanical resonator. In our scheme, a type I superconducting microsphere is attached to the free end of a microcantilever and approached to the loop of a dc Superconducting Quantum Interference Device (SQUID) microsusceptometer. A local magnetic field as low as 100 μT, generated by a field coil concentric to the SQUID, enables detection of the cantilever thermomechanical noise at 4.2 K. The magnetomechanical coupling and the magnetic spring are in good agreement with image method calculations assuming pure Meissner effect. These measurements are relevant to recent proposals of quantum magnetomechanics experiments based on levitating superconducting microparticles.

  7. Searching for displaced Higgs boson decays

    NASA Astrophysics Data System (ADS)

    Csáki, Csaba; Kuflik, Eric; Lombardo, Salvator; Slone, Oren

    2015-10-01

    We study a simplified model of the Standard Model (SM) Higgs boson decaying to a degenerate pair of scalars which travel a macroscopic distance before decaying to SM particles. This is the leading signal for many well-motivated solutions to the hierarchy problem that do not propose additional light colored particles. Bounds for displaced Higgs boson decays below 10 cm are found by recasting existing tracker searches from Run I. New tracker search strategies, sensitive to the characteristics of these models and similar decays, are proposed with sensitivities projected for Run II at √{s }=13 TeV . With 20 fb-1 of data, we find that Higgs branching ratios down to 2 ×1 0-4 can be probed for centimeter decay lengths.

  8. Optical inverse-square displacement sensor

    DOEpatents

    Howe, Robert D.; Kychakoff, George

    1989-01-01

    This invention comprises an optical displacement sensor that uses the inverse-square attenuation of light reflected from a diffused surface to calculate the distance from the sensor to the reflecting surface. Light emerging from an optical fiber or the like is directed onto the surface whose distance is to be measured. The intensity I of reflected light is angle dependent, but within a sufficiently small solid angle it falls off as the inverse square of the distance from the surface. At least a pair of optical detectors are mounted to detect the reflected light within the small solid angle, their ends being at different distances R and R+.DELTA.R from the surface. The distance R can then be found in terms of the ratio of the intensity measurements and the separation length as ##EQU1##

  9. Optical inverse-square displacement sensor

    DOEpatents

    Howe, R.D.; Kychakoff, G.

    1989-09-12

    This invention comprises an optical displacement sensor that uses the inverse-square attenuation of light reflected from a diffused surface to calculate the distance from the sensor to the reflecting surface. Light emerging from an optical fiber or the like is directed onto the surface whose distance is to be measured. The intensity I of reflected light is angle dependent, but within a sufficiently small solid angle it falls off as the inverse square of the distance from the surface. At least a pair of optical detectors are mounted to detect the reflected light within the small solid angle, their ends being at different distances R and R + [Delta]R from the surface. The distance R can then be found in terms of the ratio of the intensity measurements and the separation length as given in an equation. 10 figs.

  10. DNA strand displacement system running logic programs.

    PubMed

    Rodríguez-Patón, Alfonso; Sainz de Murieta, Iñaki; Sosík, Petr

    2014-01-01

    The paper presents a DNA-based computing model which is enzyme-free and autonomous, not requiring a human intervention during the computation. The model is able to perform iterated resolution steps with logical formulae in conjunctive normal form. The implementation is based on the technique of DNA strand displacement, with each clause encoded in a separate DNA molecule. Propositions are encoded assigning a strand to each proposition p, and its complementary strand to the proposition ¬p; clauses are encoded comprising different propositions in the same strand. The model allows to run logic programs composed of Horn clauses by cascading resolution steps. The potential of the model is demonstrated also by its theoretical capability of solving SAT. The resulting SAT algorithm has a linear time complexity in the number of resolution steps, whereas its spatial complexity is exponential in the number of variables of the formula.

  11. Can Monkeys (Macaca mulatta) Represent Invisible Displacement?

    NASA Technical Reports Server (NTRS)

    Filion, Christine M.; Washburn, David A.; Gulledge, Jonathan P.

    1996-01-01

    Four experiments were conducted to assess whether or not rhesus macaques (Macaca mulatta) could represent the unperceived movements of a stimulus. Subjects were tested on 2 computerized tasks, HOLE (monkeys) and LASER (humans and monkeys), in which subjects needed to chase or shoot at, respectively, a moving target that either remained visible or became invisible for a portion of its path of movement. Response patterns were analyzed and compared between target-visible and target-invisible conditions. Results of Experiments 1, 2, and 3 demonstrated that the monkeys are capable of extrapolating movement. That this extrapolation involved internal representation of the target's invisible movement was suggested but not confirmed. Experiment 4, however, demonstrated that the monkeys are capable of representing the invisible displacements of a stimulus.

  12. Experiments on chemically enhanced immiscible fluid displacements

    NASA Astrophysics Data System (ADS)

    Soori, Tejaswi; Ward, Thomas

    2016-11-01

    This talk focuses on experiments conducted by displacing a vegetable oil within a capillary tube (diameter < 1 mm) using an aqueous alkali solution. Estimates of the residual film were measured as a function of Reynolds (Re), viscous Atwood (At) and capillary (Ca) numbers. The pendant drop method was used to measure surface tension of the aqueous alkali solutions. We observed a decrease in surface tension for an increase in alkali concentration, which beyond a critical concentration forms a stable micro-emulsion. We estimate the shear viscosity of the emulsion as a function of alkali and aqueous/oil concentrations. Separately we attempt to measure the average bulk diffusion coefficient of the emulsion in both phases which is necessary to estimate the Péclet number (Pé) and subsequent mass transport phenomena. American Chemical Society Petroleum Research Fund.

  13. Positive Psychology

    ERIC Educational Resources Information Center

    Peterson, Christopher

    2009-01-01

    Positive psychology is a deliberate correction to the focus of psychology on problems. Positive psychology does not deny the difficulties that people may experience but does suggest that sole attention to disorder leads to an incomplete view of the human condition. Positive psychologists concern themselves with four major topics: (1) positive…

  14. Relativistic Lagrangian displacement field and tensor perturbations

    NASA Astrophysics Data System (ADS)

    Rampf, Cornelius; Wiegand, Alexander

    2014-12-01

    We investigate the purely spatial Lagrangian coordinate transformation from the Lagrangian to the basic Eulerian frame. We demonstrate three techniques for extracting the relativistic displacement field from a given solution in the Lagrangian frame. These techniques are (a) from defining a local set of Eulerian coordinates embedded into the Lagrangian frame; (b) from performing a specific gauge transformation; and (c) from a fully nonperturbative approach based on the Arnowitt-Deser-Misner (ADM) split. The latter approach shows that this decomposition is not tied to a specific perturbative formulation for the solution of the Einstein equations. Rather, it can be defined at the level of the nonperturbative coordinate change from the Lagrangian to the Eulerian description. Studying such different techniques is useful because it allows us to compare and develop further the various approximation techniques available in the Lagrangian formulation. We find that one has to solve the gravitational wave equation in the relativistic analysis, otherwise the corresponding Newtonian limit will necessarily contain spurious nonpropagating tensor artifacts at second order in the Eulerian frame. We also derive the magnetic part of the Weyl tensor in the Lagrangian frame, and find that it is not only excited by gravitational waves but also by tensor perturbations which are induced through the nonlinear frame dragging. We apply our findings to calculate for the first time the relativistic displacement field, up to second order, for a Λ CDM Universe in the presence of a local primordial non-Gaussian component. Finally, we also comment on recent claims about whether mass conservation in the Lagrangian frame is violated.

  15. Dealing with the Effects of Sensor Displacement in Wearable Activity Recognition

    PubMed Central

    Banos, Oresti; Toth, Mate Attila; Damas, Miguel; Pomares, Hector; Rojas, Ignacio

    2014-01-01

    Most wearable activity recognition systems assume a predefined sensor deployment that remains unchanged during runtime. However, this assumption does not reflect real-life conditions. During the normal use of such systems, users may place the sensors in a position different from the predefined sensor placement. Also, sensors may move from their original location to a different one, due to a loose attachment. Activity recognition systems trained on activity patterns characteristic of a given sensor deployment may likely fail due to sensor displacements. In this work, we innovatively explore the effects of sensor displacement induced by both the intentional misplacement of sensors and self-placement by the user. The effects of sensor displacement are analyzed for standard activity recognition techniques, as well as for an alternate robust sensor fusion method proposed in a previous work. While classical recognition models show little tolerance to sensor displacement, the proposed method is proven to have notable capabilities to assimilate the changes introduced in the sensor position due to self-placement and provides considerable improvements for large misplacements. PMID:24915181

  16. Lyapunov stable displacement-mode haptic manipulation of hydraulic actuators: theory and experiment

    NASA Astrophysics Data System (ADS)

    Zarei-nia, Kurosh; Sepehri, Nariman

    2012-09-01

    In this article, a stable control scheme is designed and experimentally evaluated for haptic-enabled teleoperated control of hydraulic actuators. At the actuator (slave) side, the controller allows the hydraulic actuator to have a stable position tracking. At the master side, the haptic device provides a kind of 'feel' of telepresence to the operator by creating a force that acts like a virtual spring, coupling the displacement of the haptic device to the displacement of the hydraulic actuator. In free motion, this virtual spring restricts the operator's hand to move fast when the slave manipulator is behind/ahead in terms of tracking the master manipulator's displacement. On the other hand, when interacting with the environment, the constrained force imposed on the hydraulic actuator is indirectly reflected through this virtual spring force. Extension of Lyapunov's stability theory to non-smooth systems is first employed to prove the stability of the resulting control system. Effectiveness of the controller is then validated via experimental studies. It is shown that the control scheme performs well in terms of both positioning the hydraulic actuator and providing a haptic feel to the operator. The control scheme is easy to implement since very little knowledge about system parameters is needed and the required on-line measurements are actuator's supply and line pressures and displacement.

  17. Analysis of Landslides Based on Displacements of Lines

    NASA Astrophysics Data System (ADS)

    Mozas-Calvache, A. T.; Pérez-García, J. L.; Fernández-del Castillo, T.; Gómez-López, J. M.; Colomo-Jiménez, C.

    2016-06-01

    Nowadays, the development of UAS has allowed the obtaining of high resolution and accurate cartographic products, such as DSMs and orthoimages. These products can be used in studies of the evolution of landslides. The stability of slopes is a main issue because, among others, it can suppose a serious risk to infrastructures. Until this moment, some studies for analysing slope movements have been carried out using the comparison of positions of well-defined points or comparing two surfaces obtained from two DSMs. In this paper we present a methodology for analysing landslides based on some linear elements located on the terrain. More specifically, we analyse some lines of road sections which are located on an unstable slope, checking the movements of the landslide and their effect on the infrastructure. The methodology includes the obtaining of high resolution orthoimages and DSMs which correspond to two or more epochs of the same landslide, the 3D digitizing of common linear elements, and the computing of the displacements of matched lines (from two epochs) using positional control methods based on lines. The proposed methodology has been tested using two DSMs and two orthoimages (corresponding to two epochs) obtained from two photogrammetric projects developed with an UAS. This real case was applied to an unstable slope with landslides which affected several sections of a road. The results have demonstrated the viability of the proposed methodology in analysing the behaviour of the landslide and more specifically, the effects on these infrastructures.

  18. Spectral characteristics of speech with fixed jaw displacements

    NASA Astrophysics Data System (ADS)

    Solomon, Nancy P.; Makashay, Matthew J.; Munson, Benjamin

    2004-05-01

    During speech, movements of the mandible and the tongue are interdependent. For some research purposes, the mandible may be constrained to ensure independent tongue motion. To examine specific spectral characteristics of speech with different jaw positions, ten normal adults produced sentences with multiple instances of /t/, /s/, /squflg/, /i/, /ai/, and /squflgi/. Talkers produced stimuli with the jaw free to vary, and while gently biting on 2- and 5-mm bite blocks unilaterally. Spectral moments of /s/ and /squflg/ frication and /t/ bursts differed such that mean spectral energy decreased, and diffuseness and skewness increased with bite blocks. The specific size of the bite block had minimal effect on these results, which were most consistent for /s/. Formant analysis for the vocoids revealed lower F2 frequency in /i/ and at the end of the transition in /ai/ when bite blocks were used; F2 slope for diphthongs was not sensitive to differences in jaw position. Two potential explanations for these results involve the physical presence of the bite blocks in the lateral oral cavity, and the oromotor system's ability to compensate for fixed jaw displacements. [Work supported by NIDCD R03-DC06096.

  19. Migratory Reed Warblers Need Intact Trigeminal Nerves to Correct for a 1,000 km Eastward Displacement

    PubMed Central

    Heyers, Dominik; Mouritsen, Henrik

    2013-01-01

    Several studies have shown that experienced night-migratory songbirds can determine their position, but it has remained a mystery which cues and sensory mechanisms they use, in particular, those used to determine longitude (east–west position). One potential solution would be to use a magnetic map or signpost mechanism like the one documented in sea turtles. Night-migratory songbirds have a magnetic compass in their eyes and a second magnetic sense with unknown biological function involving the ophthalmic branch of the trigeminal nerve (V1). Could V1 be involved in determining east–west position? We displaced 57 Eurasian reed warblers (Acrocephalus scirpaceus) with or without sectioned V1. Sham operated birds corrected their orientation towards the breeding area after displacement like the untreated controls did. In contrast, V1-sectioned birds did not correct for the displacement. They oriented in the same direction after the displacement as they had done at the capture site. Thus, an intact ophthalmic branch of the trigeminal nerve is necessary for detecting the 1,000 km eastward displacement in this night-migratory songbird. Our results suggest that V1 carries map-related information used in a large-scale map or signpost sense that the reed warblers needed to determine their approximate geographical position and/or an east–west coordinate. PMID:23840374

  20. Magnetic beam position monitor

    SciTech Connect

    Varfolomeev, A.A.; Ivanchenkov, S.N.; Khlebnikov, A.S.

    1995-12-31

    Many nondestructive beam position monitors are known. However, these devices can not be used for DC particle beam diagnostics. We investigated a method of beam diagnostics applicable for the operative control of DC high power e-beam inside closed waveguide. A design of the detector for determination of{open_quote} center of mass {close_quote} position of DC particle beam was developed. It was shown that the monitor can be used as a nondestructive method for the beam position control in resonators. Magnetic field of the particle beam outside a resonator is used. The detector consists of the steel yokes and magnetic field sensors. The sensors measure magnetic fluxes in the steel yokes fixed outside the resonator. When the particle beam changes its position, these magnetic fluxes also change. Beam displacement sensitivity of the monitor depends on the steel yoke dimensions. The detector sensitivity is equal to 1 Gauss/mm for the conditions adequate to the FOM-FEM project.

  1. Position sense asymmetry.

    PubMed

    Adamo, Diane E; Martin, Bernard J

    2009-01-01

    Asymmetries in upper limb position sense have been explained in the context of a left limb advantage derived from differences in hemispheric specialization in the processing of kinesthetic information. However, it is not clearly understood how the comparison of perceptual information associated with passive limb displacement and the corresponding matching movement resulting from the execution of a motor command contributes to these differences. In the present study, upper limb position sense was investigated in 12 right-hand-dominant young adults performing wrist position matching tasks which varied in terms of interhemispheric transfer, memory retrieval and whether the reference position was provided by the same or opposite limb. Right and left hand absolute matching errors were similar when the reference and matching positions were produced by the same hand but were 36% greater when matching the reference position with the opposite hand. When examining the constant errors generated from matching movements made with the same hand that provided the reference, the right and left hand matching errors (approximately 3 degrees) were similar. However, when matching with the opposite limb, a large overshoot (P < 0.05) characterized the error when the right hand matched the left hand reference while a large undershoot (P < 0.05) characterized the error when the left hand matched the right hand reference. The overshoot and undershoot were of similar magnitude (approximately 4 degrees). Although asymmetries in the central processing of proprioceptive information such as interhemispheric transfer may exist, the present study suggests that asymmetries in position sense predominantly result from a difference in the "gain of the respective proprioceptive sensory-motor loops". This new hypothesis is strongly supported by a dual-linear model representing the right and left hand sensory-motor systems as well as morphological and physiological data.

  2. Computer Simulation of Displacement Damage in Silicon Carbide

    SciTech Connect

    Devanathan, Ram; Gao, Fei; Weber, William J.; M. Chipara, D. L. Edwards, S. Phillips, and R. Benson

    2005-07-01

    We have performed molecular dynamics simulation of displacement events on silicon and carbon sublattices in silicon carbide for displacement doses ranging from 0.005 to 0.5 displacements per atom. Our results indicate that the displacement threshold energy is about 21 eV for C and 35 eV for Si, and amorphization can occur by accumulation of displacement damage regardless of whether Si or C is displaced. In addition, we have simulated defect production in high-energy cascades as a function of the primary knock-on atom energy and observed features that are different from the case of damage accumulation in Si. These systematic studies shed light on the phenomenon of non-ionizing energy loss that is relevant to understanding space radiation effects in semiconductor devices.

  3. Daily CT measurement of needle applicator displacement during multifractionated high-dose-rate interstitial brachytherapy for postoperative recurrent uterine cancer.

    PubMed

    Yoshida, Ken; Ueda, Mari; Takenaka, Tadashi; Yamazaki, Hideya; Kotsuma, Tadayuki; Aramoto, Kazumasa; Miyake, Shunsuke; Koretsune, Yukihiro; Ban, Chiaki; Tanaka, Eiichi

    2012-01-01

    We investigated daily needle applicator displacement during multifractionated high-dose-rate interstitial brachytherapy (HDR-ISBT) for postoperative recurrent uterine cancer. Eight patients with postoperative recurrent uterine cancer received HDR-ISBT with or without external beam radiotherapy using our unique ambulatory technique. To analyze displacement, we obtained daily computed tomography (CT) images for 122 flexible needle applicators at 21, 45, 69, and 93 hours after implantation. Displacement was defined as the length between the center of gravity of titanium markers and the needle applicator tips along the daily CT axis. For cases in which displacement was not corrected, we also calculated the dose that covered 90% of the clinical target volume (D90(CTV)) using a dose-volume histogram (DVH). Median caudal needle applicator displacement at 21, 45, 69, and 93 hours was 3, 2, 4, and 5 mm, respectively. More than 15 mm displacement was observed for 2% (2 of 122) and 17% (10 of 60) of needle applicators at 21 and 93 hours, respectively. Cases in which dwell positions were not changed to correct the treatment plan, 2 of 8 patients showed more than 10% reduction in D90(CTV) values compared with the initial treatment plan. Correction of dwell positions of the treatment source improves treatment DVH for multifractionated HDR-ISBT.

  4. Interferometric measurement of displacements and displacement velocities for nondestructive quality control

    NASA Astrophysics Data System (ADS)

    Shpeĭzman, V. V.; Peschanskaya, N. N.

    2007-07-01

    It is shown that the interferometric measurement of small displacements and small-displacement velocities can be used to determine internal stresses or the stresses induced by an applied load in solids and to control structural changes in them. The interferometric method based on the measurement of the reaction of a solid to a small perturbation in its state of stress is applied to determine stresses from the deviation of the reaction to perturbations from that in the standard stress-free case. For structural control, this method is employed to study the specific features of the characteristics of microplastic deformation that appear after material treatment or operation and manifest themselves in the temperature and force dependences of the rate of a small inelastic strain.

  5. Inter-application displacement of brachytherapy dose received by the bladder and rectum of the patients with inoperable cervical cancer

    PubMed Central

    Marosevic, Goran; Ljuca, Dzenita; Osmic, Hasan; Fazlic, Semir; Arsovski, Oliver; Mileusnic, Dusan

    2014-01-01

    Background The aim of the study was to examine on the CT basis the inter-application displacement of the positions D0.1cc, D1cc and D2cc of the brachytherapy dose applied to the bladder and rectum of the patients with inoperable cervical cancer. Patients and methods This prospective study included 30 patients with cervical cancer who were treated by concomitant chemo-radiotherapy. HDR intracavitary brachytherapy was made by the applicators type Fletcher tandem and ovoids. For each brachytherapy application the position D0.1cc was determined of the bladder and rectum that receive a brachytherapty dose. Then, based on the X, Y, and Z axis displacement, inter-application mean X, Y, and Z axis displacements were calculated as well as their displacement vectors (R). It has been analyzed whether there is statistically significant difference in inter-application displacement of the position of the brachytherapy dose D0.1cc, D1cc and D2cc of the bladder and rectum. The ANOVA test and post-hoc analysis by Tukey method were used for testing statistical importance of differences among the groups analyzed. The difference among the groups analyzed was considered significant if p < 0.05. Results There are significant inter-application displacements of the position of the brachytherapy dose D0,1cc, D1cc and D2cc of the bladder and rectum. Conclusions When we calculate the cumulative brachytherapy dose by summing up D0,1cc, D1cc and D2cc of the organs at risk for all the applications, we must bear in mind their inter-application displacement, and the fact that it is less likely that the worst scenario would indeed happen. PMID:24991211

  6. Displacement of lower third molar into the lateral pharyngeal space in a case of mandibular angle fracture: An unusual complication.

    PubMed

    Kasatwar, Akash; Bhola, Nitin; Borle, Rajiv; Rajanikanth, K

    2016-01-01

    Fracture of the angle of the mandible accounts for nearly one-third of all fractures involved. The presence of lower third molar increases the risk of fracture in angle region. The third molar acts as an area of weakness leading to fracture lines passing medially, distally, and occasionally through it. Angle fracture leads to the mobility of the third molar and sometimes its displacement. Third molars maintain its position in favorable fracture and can be displaced in unfavorable fractures. Displacement of lower third molar in lateral pharyngeal space due to mandibular fracture is not seen commonly. To our knowledge, this is the first reported incidence of displacement of the third molar into lateral pharyngeal space in a case of mandibular fracture.

  7. Does Aid to Families with Dependent Children Displace Familial Assistance?

    DTIC Science & Technology

    1996-07-01

    RAND Does Aid to Families with Dependent Children Displace Familial Assistance? Robert F. Schoeni July 1996 ■ved id ßuclie releasaj DRU-1453-RC...cite this Working paper without permission of the author. OTIC QUALITY JQSSEEGiaa 1 DOES AID TO FAMILIES WITH DEPENDENT CHILDREN DISPLACE FAMILIAL...Public Affairs at Syracuse University for valuable comments. DOES AID TO FAMTTJES WITH DEPENDENT CHILDREN DISPLACE FAMILIAL ASSISTANCE? Abstract

  8. Water displacement during sparging under perched water-table conditions

    SciTech Connect

    DiGiulio, D.C.

    1995-12-31

    The feasibility of using sparging to purposefully displace perched water in silt loam soils was evaluated at a field site in northwestern Oklahoma. Soils and groundwater are contaminated with petroleum hydrocarbons, trichloroethene (TCE), and vinyl chloride. During sparging, a transient response in water level measurements was observed in observation wells which is attributed to water displacement. Evidence of water displacement was manifested by water-table collapse upon the cessation of sparging.

  9. CVN 68 Class Displacement Concerns; Dealing with the Differences between the Modeled and Actual Displacements

    DTIC Science & Technology

    2009-09-01

    Paperwork Reduction Project (0704-0188) Washington DC 20503. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE September 2009 3. REPORT TYPE AND...CVN 68 class aircraft carriers are actually exceeding displacement limits based on NAVSEA projections . The NAVSEA projections are based on...values collected from all commissioned CVN 68 class aircraft carriers. Analysis reveals that the NAVSEA projections are predicting the carrier’s

  10. Fiber-Optic Lateral-Displacement Sensor

    NASA Technical Reports Server (NTRS)

    Roschak, Edmund J.

    1987-01-01

    Proposed fiber-optic sensor monitors axial position of shaft or bearing in turbomachine. Device senses position of non-magnetic as well as magnetic material and calibrates before assembly in machine. More compact. Concept extends to measure rotational speed of shaft.

  11. Access to medicines among internally displaced and non-displaced people in urban areas in Colombia.

    PubMed

    Ruiz-Rodríguez, Myriam; Wirtz, Veronika J; Idrovo, Alvaro J; Angulo, Mary Lupe

    2012-12-01

    This study analyzes access to medicines among displaced and non-displaced populations in urban areas in Bucaramanga, Colombia. A household survey was carried out to study access to medicines for self-reported and medically diagnosed health conditions. Multiple Poisson regression with robust variance was used to determine factors associated with access to medicines. Two thousand and sixty individuals from 514 families participated. Only 29.1% (95%CI: 22.04-37.08) of the individuals in the sample with prescriptions and 44.3% (95%CI: 40.42-48.25) with self-reported needs for pharmacotherapy were taking medicines. Greater access was associated with the perceived severity of the illness, higher income, having a health center nearby and not perceiving barriers in accessing services. Social security affiliation and being displaced were not related. Social security coverage alone does not have an effect on access to medicines because it does not include essential medicines that correspond to the health needs of this population. Resolving administrative and geographical barriers is likely to improve access to medicines.

  12. Does condylar height decrease more in temporomandibular joint nonreducing disc displacement than reducing disc displacement?

    PubMed Central

    Hu, Ying-Kai; Yang, Chi; Cai, Xie-Yi; Xie, Qian-Yang

    2016-01-01

    Abstract The aim of the study was to compare condylar height changes of anterior disc displacement with reduction (ADDwR) and anterior disc displacement without reduction (ADDwoR) in temporomandibular joint (TMJ) quantitatively, to get a better understanding of the changes in condylar height of patients with anterior disc displacement who had received no treatment, and to provide useful information for treatment protocol. This longitudinal retrospective study enrolled 206 joints in 156 patients, which were divided into ADDWR group and ADDwoR group based on magnetic resonance imaging examination. The joints were assessed quantitatively for condylar height at initial and follow-up visits. Also, both groups were further divided into 3 subgroups according to age: <15 years group, 15 to 21 years group, and 22 to 35 years group. Paired t test and independent t test were used to assess intra- and intergroup differences. The average age of the ADDwR group was 19.65 years with a mean of 9.47 months’ follow-up. The follow-up interval of the patients with ADDwoR was 7.96 months, with a mean age of 18.51 years. Condylar height in ADDwoR tended to decrease more than those in ADDwR, especially during the pubertal growth spurt and with the presence of osteoarthrosis, meaning ADDwoR could cause a severe disturbance in mandibular development. Thus, an early disc repositioning was suggested to avoid decrease in condylar height. PMID:27583909

  13. Severe hip displacement reduces health-related quality of life in children with cerebral palsy

    PubMed Central

    Ramstad, Kjersti; Jahnsen, Reidun B; Terjesen, Terje

    2017-01-01

    Background and purpose Hip displacement is common in children with severe cerebral palsy (CP) and can cause problems such as pain, contractures, and nursing difficulties. Caregiver priorities and child health index of life with disabilities (CPCHILD) is a recently developed measure of health-related quality of life (HRQL) in children with severe CP. The associations between CPCHILD scores and hip displacement have not been investigated. We explored the effect of hip displacement on HRQL. Patients and methods 67 children were recruited from the population-based Norwegian CP register. Mean age was 9 (7–12) years. There were 40 boys. Gross motor function classification system (GMFCS) distribution was 12 level III, 17 level IV, and 38 level V. Hip displacement was assessed by radiographic migration percentage (MP). The criterion for hip displacement was MP of the worst hip of ≥40%. Primary caregivers responded to 5 of the 6 domains of the CPCHILD questionnaire. Results Hip displacement was found in 18 children and it was significantly associated with lower scores on the CPCHILD domains 3 (Comfort and Emotions) and 5 (Health), but not with domains 1 (Activities of Daily Living/Personal Care), 2 (Positioning, Transfer, and Mobility), and 6 (Overall Quality of Life). GMFCS level V was a significant predictor of low scores in all the domains. Interpretation For the assessment of HRQL in children with severe CP and hip problems, we propose a modified and simplified version of the CPCHILD consisting of 14 of 37 questions. This would reduce the responders’ burden and probably increase the response rate in clinical studies without losing important information. PMID:27892753

  14. Severe hip displacement reduces health-related quality of life in children with cerebral palsy.

    PubMed

    Ramstad, Kjersti; Jahnsen, Reidun B; Terjesen, Terje

    2017-04-01

    Background and purpose - Hip displacement is common in children with severe cerebral palsy (CP) and can cause problems such as pain, contractures, and nursing difficulties. Caregiver priorities and child health index of life with disabilities (CPCHILD) is a recently developed measure of health-related quality of life (HRQL) in children with severe CP. The associations between CPCHILD scores and hip displacement have not been investigated. We explored the effect of hip displacement on HRQL. Patients and methods - 67 children were recruited from the population-based Norwegian CP register. Mean age was 9 (7-12) years. There were 40 boys. Gross motor function classification system (GMFCS) distribution was 12 level III, 17 level IV, and 38 level V. Hip displacement was assessed by radiographic migration percentage (MP). The criterion for hip displacement was MP of the worst hip of ≥40%. Primary caregivers responded to 5 of the 6 domains of the CPCHILD questionnaire. Results - Hip displacement was found in 18 children and it was significantly associated with lower scores on the CPCHILD domains 3 (Comfort and Emotions) and 5 (Health), but not with domains 1 (Activities of Daily Living/Personal Care), 2 (Positioning, Transfer, and Mobility), and 6 (Overall Quality of Life). GMFCS level V was a significant predictor of low scores in all the domains. Interpretation - For the assessment of HRQL in children with severe CP and hip problems, we propose a modified and simplified version of the CPCHILD consisting of 14 of 37 questions. This would reduce the responders' burden and probably increase the response rate in clinical studies without losing important information.

  15. Development of Displacement Gages Exposed to Solid Rocket Motor Internal Environments

    NASA Technical Reports Server (NTRS)

    Bolton, D. E.; Cook, D. J.

    2003-01-01

    The Space Shuttle Reusable Solid Rocket Motor (RSRM) has three non-vented segment-to-segment case field joints. These joints use an interference fit J-joint that is bonded at assembly with a Pressure Sensitive Adhesive (PSA) inboard of redundant O-ring seals. Full-scale motor and sub-scale test article experience has shown that the ability to preclude gas leakage past the J-joint is a function of PSA type, joint moisture from pre-assembly humidity exposure, and the magnitude of joint displacement during motor operation. To more accurately determine the axial displacements at the J-joints, two thermally durable displacement gages (one mechanical and one electrical) were designed and developed. The mechanical displacement gage concept was generated first as a non-electrical, self-contained gage to capture the maximum magnitude of the J-joint motion. When it became feasible, the electrical displacement gage concept was generated second as a real-time linear displacement gage. Both of these gages were refined in development testing that included hot internal solid rocket motor environments and simulated vibration environments. As a result of this gage development effort, joint motions have been measured in static fired RSRM J-joints where intentional venting was produced (Flight Support Motor #8, FSM-8) and nominal non-vented behavior occurred (FSM-9 and FSM-10). This data gives new insight into the nominal characteristics of the three case J-joint positions (forward, center and aft) and characteristics of some case J-joints that became vented during motor operation. The data supports previous structural model predictions. These gages will also be useful in evaluating J-joint motion differences in a five-segment Space Shuttle solid rocket motor.

  16. On the Morphological Description of Tracheal and Esophageal Displacement and Its Phylogenetic Distribution in Avialae

    PubMed Central

    Klingler, Jeremy J.

    2016-01-01

    This research examines the evolution and phylogenetic distribution of a peculiar and often overlooked character seen in birds, herein called tracheal and esophageal displacement. Tracheal and esophageal displacement refers to an asymmetrically situated trachea and/or esophagus along the length of the neck. This contrasts with what would be perceived as the “normal” (midsagittal) placement of these organs, wherein the two organs are situated along the ventral midline of the neck with no deviation. A total of forty-two bird species were examined (thirty-six of which came from dissections whereas six came from comments from previous literature or personal observations), as well as turtles, lizards, crocodylians, and mammals. This study found that essentially all birds have a laterally displaced trachea and/or esophagus. Lizards and mammals were seen to have normal, midsagittally placed tracheae and esophagi. Crocodylians were interesting in that alligators were defined by a normally situated trachea and esophagus whereas some crocodiles were characterized by displacement. In birds, the displacement may occur gradually along the neck, or it may happen immediately upon exiting the oropharynx. Displacement of these organs in birds is the result of a heavily modified neck wherein muscles that restrict mobility of the trachea and esophagus in lizards, alligators, and mammals (e.g., m. episternocleidomastoideus, m. omohyoideus, and m. sternohyoideus) no longer substantially restrict positions of the trachea and esophagus in birds. Rather, these muscles are modified in ways which may assist with making tracheal movements. The implications of this study may provide interesting insights for future comparisons in extinct taxa. PMID:27648952

  17. Solar cell angular position transducer

    NASA Technical Reports Server (NTRS)

    Sandford, M. C.; Gray, D. L. (Inventor)

    1980-01-01

    An angular position transducer utilizing photocells and a light source is disclosed. The device uses a fully rotatable baffle which is connected via an actuator shaft to the body whose rotational displacement is to be measured. The baffle blocks the light path between the light source and the photocells so that a constant semicircular beam of light reaches the photocells. The current produced by the photocells is fed through a resistor, a differential amplifier measures the voltage drop across the resistor which indicates the angular position of the actuator shaft and hence of the object.

  18. Low noise optical position sensor

    DOEpatents

    Spear, J.D.

    1999-03-09

    A novel optical position sensor is described that uses two component photodiodes electrically connected in parallel, with opposing polarities. A lens provides optical gain and restricts the acceptance angle of the detector. The response of the device to displacements of an optical spot is similar to that of a conventional bi-cell type position sensitive detector. However, the component photodiode design enables simpler electronic amplification with inherently less electrical noise than the bi-cell. Measurements by the sensor of the pointing noise of a focused helium-neon laser as a function of frequency demonstrate high sensitivity and suitability for optical probe beam deflection experiments. 14 figs.

  19. Low noise optical position sensor

    DOEpatents

    Spear, Jonathan David

    1999-01-01

    A novel optical position sensor is described that uses two component photodiodes electrically connected in parallel, with opposing polarities. A lens provides optical gain and restricts the acceptance angle of the detector. The response of the device to displacements of an optical spot is similar to that of a conventional bi-cell type position sensitive detector. However, the component photodiode design enables simpler electronic amplification with inherently less electrical noise than the bi-cell. Measurements by the sensor of the pointing noise of a focused helium-neon laser as a function of frequency demonstrate high sensitivity and suitability for optical probe beam deflection experiments.

  20. Comparative clinical efficacy evaluation of three gingival displacement systems

    PubMed Central

    Shrivastava, Kirti Jajoo; Bhoyar, Anjali; Agarwal, Surendra; Shrivastava, Saurabh; Parlani, Swapnil; Murthy, Varsha

    2015-01-01

    Aim: We compared the clinical efficacy of three gingival displacement systems to accurately record intra-crevicular margins of tooth preparation. Materials and Methods: One mechanical (magic foam cord) and two chemico-mechanical (expasyl paste and retraction cord impregnated with 15% aluminum chloride) gingival displacement systems were used. This study was conducted on the maxillary central incisors of 20 patients (20-60 years old) requiring full coverage restoration. All the three gingival displacement systems were tested in three sessions at an interval of 14 days in same order. The casts were sectioned and viewed under an optical microscope, followed by quantitative measurements of the width of the pre and postretracted sulci. Results: All the three displacement systems produced highly significant horizontal gingival displacement. Retraction cord soaked in 15% aluminum chloride produced maximum displacement (0.74 mm), followed by expasyl paste (0.48 mm) whereas magic foam cord produced the least displacement (0.41 mm). Conclusions: Gingival displacement shown by each displacement system was found to be more than the accepted value necessary for elastomeric impression accuracy (0.2 mm) to record intra-crevicular margins of tooth preparation. PMID:26604620

  1. Molecular dynamics simulation of threshold displacement energies in zircon

    SciTech Connect

    Moreira, Pedro A.; Devanathan, Ramaswami; Yu, Jianguo; Weber, William J.

    2009-10-15

    Molecular-dynamics simulations were used to examine the displacement threshold energy (Ed) surface for Zr, Si and O in zircon using two different interatomic potentials. For each sublattice, the simulation was repeated from different initial conditions to estimate the uncertainty in the calculated value of Ed. The displacement threshold energies vary considerably with crystallographic direction and sublattice. The average displacement energy calculated with a recently developed transferable potential is about 120 and 60 eV for cations and anions, respectively. The oxygen displacement energy shows good agreement with experimental estimates in ceramics.

  2. Job Displacement, Reemployment, and Earnings Loss: Evidence from the January 1984 Displaced Worker Survey. Research Report Series RR-86-18.

    ERIC Educational Resources Information Center

    Podgursky, Michael; Swaim, Paul

    Job displacement represents a serious labor market problem affecting a broad spectrum of the labor force. A study used data from the January 1984 Displaced Worker Survey, a supplement to the Current Population Survey, which analyzed patterns of job displacement, the post-displacement reemployment, and earnings experience of displaced workers. The…

  3. Positive Psychotherapy

    ERIC Educational Resources Information Center

    Seligman, Martin E. P.; Rashid, Tayyab; Parks, Acacia C.

    2006-01-01

    Positive psychotherapy (PPT) contrasts with standard interventions for depression by increasing positive emotion, engagement, and meaning rather than directly targeting depressive symptoms. The authors have tested the effects of these interventions in a variety of settings. In informal student and clinical settings, people not uncommonly reported…

  4. Motional displacements in proteins incorporating dynamical diversity

    NASA Astrophysics Data System (ADS)

    Vural, Derya; Smith, Jeremy; Glyde, Henry

    The average mean square displacement (MSD), , of hydrogen H in proteins is measured using incoherent neutron scattering methods. The observed MSD shows a marked increase in magnitude at a temperature TD ~= 240 K. This is widely interpreted as a dynamical transition to large MSDs which make function possible in proteins. However, when the data is interpreted in terms of a single averaged MSD, the extracted depends on the neutron momentum transfer, ℏQ , used in the measurement. We have shown recently that this apparent dependence on Q arises because the dynamical diversity of the H in the protein is neglected[2]. We present models of the dynamical diversity of H in Lysosyme that when used in the analysis of simulated neutron data lead to consistent, Q independent values for the average MSD and for the diversity model.2. D. Vural and L. Hong, J. C. Smith and H. R. Glyde. Phys. Rev. E 91, 052705 (2015). Supported in part by Office of Basic Energy Sciences, USDOE, ER46680.

  5. Gage for measuring displacements in rock samples

    DOEpatents

    Holcomb, D.J.; McNamee, M.J.

    1985-07-18

    A gage for measuring diametral displacement within a rock sample for use in a rock mechanics laboratory and in the field, comprises a support ring housing a linear variable differential transformer (LVDT), a mounting screw, and a leaf spring. The mounting screw is adjustable and defines a first point of contact with the rock sample. The leaf spring has opposite ends fixed to the inner periphery of the mounting ring. An intermediate portion of the leaf spring projecting radially inward from the ring is formed with a dimple defining a second point of contact with the sample. The first and second points of contact are diametrically opposed to each other. The LVDT is mounted in the ring with its axis parallel to the line of measurement and its core rod received in the dimple of the leaf spring. Any change in the length of the line between the first and second support points is directly communicated to the LVDT. The leaf spring is rigid to completely support lateral forces so that the LVDT is free of all load for improved precision.

  6. Gage for measuring displacements in rock samples

    DOEpatents

    Holcomb, David J.; McNamee, Michael J.

    1986-01-01

    A gage for measuring diametral displacement within a rock sample for use in a rock mechanics laboratory and in the field, comprises a support ring housing a linear variable differential transformer, a mounting screw, and a leaf spring. The mounting screw is adjustable and defines a first point of contact with the rock sample. The leaf spring has opposite ends fixed to the inner periphery of the mounting ring. An intermediate portion of the leaf spring projecting radially inward from the ring is formed with a dimple defining a second point of contact with the sample. The first and second points of contact are diametrically opposed to each other. The LVDT is mounted in the ring with its axis parallel to the line of measurement and its core rod received in the dimple of the leaf spring. Any change in the length of the line between the first and second support points is directly communicated to the LVDT. The leaf spring is rigid to completely support lateral forces so that the LVDT is free of all load for improved precision.

  7. Particle displacement tracking applied to air flows

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.

    1991-01-01

    Electronic Particle Image Velocimeter (PIV) techniques offer many advantages over conventional photographic PIV methods such as fast turn around times and simplified data reduction. A new all electronic PIV technique was developed which can measure high speed gas velocities. The Particle Displacement Tracking (PDT) technique employs a single cw laser, small seed particles (1 micron), and a single intensified, gated CCD array frame camera to provide a simple and fast method of obtaining two-dimensional velocity vector maps with unambiguous direction determination. Use of a single CCD camera eliminates registration difficulties encountered when multiple cameras are used to obtain velocity magnitude and direction information. An 80386 PC equipped with a large memory buffer frame-grabber board provides all of the data acquisition and data reduction operations. No array processors of other numerical processing hardware are required. Full video resolution (640x480 pixel) is maintained in the acquired images, providing high resolution video frames of the recorded particle images. The time between data acquisition to display of the velocity vector map is less than 40 sec. The new electronic PDT technique is demonstrated on an air nozzle flow with velocities less than 150 m/s.

  8. Rupture models with dynamically determined breakdown displacement

    USGS Publications Warehouse

    Andrews, D.J.

    2004-01-01

    The critical breakdown displacement, Dc, in which friction drops to its sliding value, can be made dependent on event size by specifying friction to be a function of variables other than slip. Two such friction laws are examined here. The first is designed to achieve accuracy and smoothness in discrete numerical calculations. Consistent resolution throughout an evolving rupture is achieved by specifying friction as a function of elapsed time after peak stress is reached. Such a time-weakening model produces Dc and fracture energy proportional to the square root of distance rupture has propagated in the case of uniform stress drop. The second friction law is more physically motivated. Energy loss in a damage zone outside the slip zone has the effect of increasing Dc and limiting peak slip velocity (Andrews, 1976). This article demonstrates a converse effect, that artificially limiting slip velocity on a fault in an elastic medium has a toughening effect, increasing fracture energy and Dc proportionally to rupture propagation distance in the case of uniform stress drop. Both the time-weakening and the velocity-toughening models can be used in calculations with heterogeneous stress drop.

  9. Displacement of the ventricular fold following cordectomy.

    PubMed

    Fukuda, H; Tsuji, D H; Kawasaki, Y; Kawaida, M; Sakou, T

    1990-01-01

    In order to avoid radiation and its undesirable side effects, we have employed surgical techniques for treatment of early glottic cancer when the lesion is confined to one membranous cord (Fukuda, Saito, Sato, and Kitahara: J. Jpn. Bronchoesophagol. Soc. 30: 7-14, 1979; Fukuda and Saito: Otologica 26: 434-436, 1980; Fukuda, Kawaida, Ohki, Kawasaki, Kita, and Tatehara: J. Jpn. Bronchoesophagaol. Soc. 39: 139-144, 1988). Laser is one of the most popular techniques and it has been accepted as the first choice by many authors (Annyas, Overbeek, Escajadillo, and Hoeksema: Laryngoscope 94: 836-838, 1984; Mcguirt and Koufman: Arch. Otolaryngol. Head Neck Surg. 113: 501-505, 1987; Tsuji, Fukuda, Kawaskai, Kawaida, and Kanzaki: Keio J. Med. 38: 413-418, 1989). However, some cases are difficult to approach by direct laryngoscopy, requiring an external way to expose the lesion. In these cases, cordectomy by laryngofissure is the method of choice, but the function of the glottis could be improved by replacing the excised cord displacing the ventricular fold. This technique, designed by the authors, was carried out in 22 patients and the results from the viewpoint of phonodynamics, voice quality, and cure rate are discussed in this study. The results are encouraging and we believe that this method is a very reasonable alternative to the laser when such equipment is not available. We also believe that late side effects and oncogenic problems associated with radiation are important points to be considered, especially in patients of relatively younger age.

  10. Mode-locking external-cavity laser-diode sensor for displacement measurements of technical surfaces

    SciTech Connect

    Czarske, Juergen; Moebius, Jasper; Moldenhauer, Karsten

    2005-09-01

    A novel laser sensor for position measurements of technical solid-state surfaces is proposed. An external Fabry-Perot laser cavity is assembled by use of an antireflection-coated laser diode together with the technical surface. Mode locking results from pumping the laser diode synchronously to the mode spacing of the cavity. The laser cavity length, i.e., the distance to the measurement object, is determined by evaluation of the modulation transfer function of the cavity by means of a phase-locked loop. The mode-locking external-cavity laser sensor incorporates a resonance effect that results in highly resolving position and displacement measurements. More than a factor-of-10 higher resolution than with conventional nonresonant sensing principles is achieved. Results of the displacement measurements of various technical surfaces are reported. Experimental and theoretical investigations are in good agreement.

  11. GNSS-derived Coseismic Displacement of the Gökçeada Earthquake (2014, Mw:6.9) based on 1 Hz GNSS Data

    NASA Astrophysics Data System (ADS)

    Özer Yiğit, Cemal; Tiryakioğlu, Ibrahim; Halis Saka, M.; Metin Alkan, Reha

    2015-04-01

    GNSS technology has been extensively used to measure crustal deformation and widely used to construct displacement waveforms. GNSS seismology uses GNSS receiver as displacement seismometer for earthquake studies. In other words, it can sense large dynamic displacement without saturation. In GNSS, relative positioning method requires a reference station with no-motion whereas Precise Point Positioning (PPP) method does not need any reference station. However, PPP method, unlike relative positioning method, requires readily precise GNSS satellite orbit and clock product calculated beforehand to perform absolute positioning using a single GNSS receiver data. In case of large earthquake, it may be crucial to select stable reference for relative positioning. Therefore, in order to monitor ground motion pattern caused by the earthquake, PPP method is advantageous because it provides absolute coseismic displacements with respect to a global reference frame. In this study, we investigate the pattern of coseismic displacement and velocity of the Gokceada (Turkey) earthquake (United States Geological Survey M=6.9, May 24, 2014 - 09:25:02 UTC). One hertz of 8 continuous GNSS stations, part of CORS-TR network, were processed using PPP and relative positioning techniques to estimate epoch-by-epoch positions of the sites. The epicenter distance of GNSS stations are ranging from 90 km to 250 km. CSRS-PPP and GAMIT-Track tool software were used for PPP and relative positioning solution, respectively. We analyze the ground motion characteristic of GNSS-derived displacement and velocity. Results show that the travelling time of earthquake wave for each station increased with respect to epicentral distance. Results also demonstrate that the shaking amplitude generated by the earthquake decreased while epicentral distance increased. Peak to peak displacement of the closest station to epicenter is around 10 cm and 5 cm for north and east component, respectively. For selected farthest

  12. Radiomagnetotelluric two-dimensional forward and inverse modelling accounting for displacement currents

    NASA Astrophysics Data System (ADS)

    Kalscheuer, Thomas; Pedersen, Laust B.; Siripunvaraporn, Weerachai

    2008-11-01

    conductive block and a spurious conductive layer is imaged at the surface. High-frequency RMT field data from Ävrö, Sweden, are re-interpreted using the newly developed 2-D inversion scheme that includes displacement currents. In contrast to previous quasi-static modelling, the new inverse models have electrical resistivity values comparable to a normal-resistivity borehole log and boundaries between resistive and conductive structures, which correlate with the positions of seismic reflectors.

  13. Quantifying the Interfractional Displacement of the Gastroesophageal Junction During Radiation Therapy for Esophageal Cancer

    SciTech Connect

    Wang Jingya; Lin, Steven H.; Dong Lei; Balter, Peter; Mohan, Radhe; Komaki, Ritsuko; Cox, James D.; Starkschall, George

    2012-06-01

    patient positioning. Because systematic displacement in the SI direction had dosimetric impact and correlated with tidal volume, better accounting for depth of breathing is needed to reduce interfractional variability.

  14. Coseismic Gravity and Displacement Signatures Induced by the 2013 Okhotsk Mw8.3 Earthquake

    PubMed Central

    Zhang, Guoqing; Shen, Wenbin; Xu, Changyi; Zhu, Yiqing

    2016-01-01

    In this study, Gravity Recovery and Climate Experiment (GRACE) RL05 data from January 2003 to October 2014 were used to extract the coseismic gravity changes induced by the 24 May 2013 Okhotsk Mw8.3 deep-focus earthquake using the difference and least square fitting methods. The gravity changes obtained from GRACE data agreed well with those from dislocation theory in both magnitude and spatial pattern. Positive and negative gravity changes appeared on both sides of the epicenter. The positive signature appeared on the western side, and the peak value was approximately 0.4 microgal (1 microgal = 10−8 m/s2), whereas on the eastern side, the gravity signature was negative, and the peak value was approximately −1.1 microgal. It demonstrates that deep-focus earthquakes Mw ≤ 8.5 are detectable by GRACE observations. Moreover, the coseismic displacements of 20 Global Positioning System (GPS) stations on the Earth’s surface were simulated using an elastic dislocation theory in a spherical earth model, and the results are consistent with the GPS results, especially the near-field results. We also estimated the gravity contributions from the coseismic vertical displacements and density changes, analyzed the proportion of these two gravity change factors (based on an elastic dislocation theory in a spherical earth model) in this deep-focus earthquake. The gravity effect from vertical displacement is four times larger than that caused by density redistribution. PMID:27598158

  15. Hyoid Displacement in Post-Treatment Cancer Patients: Preliminary Findings

    ERIC Educational Resources Information Center

    Zu, Yihe; Yang, Zhenyu; Perlman, Adrienne L.

    2011-01-01

    Purpose: Dysphagia after head and neck cancer treatment is a health care issue; in some cases, the cause of death is not cancer but, rather, the passage of food or liquid into the lungs. Hyoid displacement is known to be important to safe swallowing function. The purpose of this study was to evaluate hyoid displacement after cancer treatment.…

  16. Strain-Based Displacement Estimation For Precision Spacecraft Structures

    DTIC Science & Technology

    2005-12-01

    Model , Bragg gratings 15. NUMBER OF PAGES 49 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18. SECURITY CLASSIFICATION OF...deflection at successive nodes was computed and compared to a Nastran simulation of the truss displacements. vi...Experimental Implementation ........10 C. BUILDING THE ANALYTICAL MODEL .....................13 III. STRAIN-DISPLACEMENT MAPPING

  17. 24 CFR 236.1001 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... reasonable steps to minimize the displacement of persons (households, businesses, nonprofit organizations... temporarily to permit rehabilitation or other work for the assisted project. Such tenants must be provided: (1... shall maintain data on the race, ethnic, gender, and disability status of displaced persons....

  18. The successive displacement process: Oil recovery during blowdown

    SciTech Connect

    Irwin, D.D.; Batychy, J.P.

    1996-12-31

    Much of Western Canada`s conventional crude oil occurs in vertically-continuous reefal carbonate structures. A common strategy has been to support oil production through downward vertical gas displacement. The gravity stable displacement yields excellent conformance and high oil recoveries with typical residual levels of 20% pore volume. Once the oil zone has been depleted leaving only a sandwich loss, the pools enter a blowdown phase to produce the gas cap from the top of structure. During the blowdown phase, if there is an underlying aquifer, the oil sandwich is displaced upwards into the previously gas-displaced oil zone, trapping gas. Due to the presence of the trapped gas saturation and the low connate water saturation (typical of carbonate reefs), the remaining oil saturation in this zone, as it is displaced by the underlying water is reduced to near miscible levels (10 - 15% PV), mobilizing incremental oil equal to 5 - 10% PV. Whether or not there an aquifer is present, bottom water injection can be applied to ensure displacement through the entire gas-displacement oil zone. The Successive Displacement (SDP), as this tertiary waterflood concept has been named, has been confirmed with full-diameter reservoir-condition core tests on carbonate cores in the laboratory. Observation from the initial stages of a full-field SDP application in Imperial Oil`s Bonnie Glen reservoir after about four years of operation provide further encouragement with performance indicating a reduction in the residual of 5-6% PV.

  19. 46 CFR 153.966 - Discharge by liquid displacement.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Discharge by liquid displacement. 153.966 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer Procedures § 153.966 Discharge by liquid displacement. The person in charge of cargo transfer...

  20. 46 CFR 153.966 - Discharge by liquid displacement.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Discharge by liquid displacement. 153.966 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer Procedures § 153.966 Discharge by liquid displacement. The person in charge of cargo transfer...

  1. 46 CFR 153.966 - Discharge by liquid displacement.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Discharge by liquid displacement. 153.966 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer Procedures § 153.966 Discharge by liquid displacement. The person in charge of cargo transfer...

  2. 46 CFR 153.966 - Discharge by liquid displacement.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Discharge by liquid displacement. 153.966 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer Procedures § 153.966 Discharge by liquid displacement. The person in charge of cargo transfer...

  3. 46 CFR 153.966 - Discharge by liquid displacement.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Discharge by liquid displacement. 153.966 Section 153... SHIPS CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Cargo Transfer Procedures § 153.966 Discharge by liquid displacement. The person in charge of cargo transfer...

  4. 5 CFR 351.701 - Assignment involving displacement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Assignment involving displacement. 351... REDUCTION IN FORCE Assignment Rights (Bump and Retreat) § 351.701 Assignment involving displacement. (a... lease possible reduction, in representative rate. The employee must be qualified for the...

  5. Changes in the Age and Education Profile of Displaced Workers.

    ERIC Educational Resources Information Center

    Rodriguez, Daniel; Zavodny, Madeline

    2003-01-01

    Analysis of Displaced Workers Surveys suggests that between 1983-97, the likelihood of job loss declined among most age groups but rose for middle-aged/older workers relative to younger workers. Changes in educational attainment and industry shifts were contributing factors. Probability of displacement increased significantly for service workers.…

  6. Gender Differences in Displacement Cost: Evidence and Implications.

    ERIC Educational Resources Information Center

    Crossley, Thomas F.; And Others

    1994-01-01

    Canadian displaced worker data show that predisplacement wages rise at about the same rate, but women lose more from displacement than men and loss increases with tenure. Results do not support the hypothesis that women accumulate less job-specific human capital; gender differences in job search may be a cause. (SK)

  7. 24 CFR 42.350 - Relocation assistance for displaced persons.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Housing and Urban Development DISPLACEMENT, RELOCATION ASSISTANCE, AND REAL PROPERTY ACQUISITION FOR HUD... displacement, including moving expenses and increased housing costs, if: (1) The person must relocate... shall be discounted at the rate of interest paid on passbook savings deposits by a federally...

  8. Assisting Workers Displaced by Structural Change. An International Perspective.

    ERIC Educational Resources Information Center

    Leigh, Duane E.

    This monograph takes the perspective that increased awareness of how active labor market programs operate in other nations can substantially improve the way in which the United States deals with worker displacement. Chapter 1 considers the costs of worker displacement and how government programs designed to reduce these costs are evaluated.…

  9. Accurate measurement of gas volumes by liquid displacement

    NASA Technical Reports Server (NTRS)

    Christian, J. D.

    1972-01-01

    Mariotte bottle as liquid displacement device was used to measure gas volumes at flow rates that are far below threshold of wet test gas meters. Study of factors affecting amount of liquid displaced by gas flow was completed, and equations were derived which relate different variables.

  10. Regulation of DNA Strand Displacement Using Allosteric DNA Toehold.

    PubMed

    Yang, Xiaolong; Tang, Yanan; Traynor, Sarah M; Li, Feng

    2016-10-05

    Toehold-mediated DNA strand displacement is the fundamental basis for the construction and operation of diverse DNA devices, including circuits, machines, sensors, and reconfigurable structures. Controllable activation and regulation of toeholds are critical to construct devices with multistep, autonomous, and complex behaviors. A handful of unique toehold activation mechanisms, including toehold-exchange, associative toehold, and remote toehold, have been developed and are often combined to achieve desired strand displacement behaviors and functions. Here we report an allosteric DNA toehold (A-toehold) design that allows the flexible regulation of DNA strand displacement by splitting an input strand into an A-toehold and branch migration domain. Because of its simplicity, the A-toehold mechanism can be a useful addition to the current toolbox of DNA strand displacement techniques. We demonstrated that A-toehold enabled a number of interesting functions that were previously shown using more sophisticated DNA strand displacement systems, including 1) continuously tuning the rate of strand displacement, 2) dynamic control of strand displacement reactions, and 3) selective activation of multiple strand displacement reactions. Moreover, by combining A-toehold and toehold-exchange mechanisms, we have successfully constructed a non-covalent DNA catalysis network that resembles an allosteric enzyme.

  11. The effect of bone displacement operations on facial soft tissues.

    PubMed

    Habib, Ali; Hisham, Ahmed

    2013-01-01

    A novel biomechanical model for face soft tissue (skin, mucosa, and muscles) is introduced to investigate the effect of mandible and chin bone displacement on the overall appearance of the patient's face. Nonlinear FE analysis is applied to the model and the results obtained are used to help surgeons to decide the amount of displacement required.

  12. Nursing Positions

    MedlinePlus

    ... and actually needs to feed. Getting Comfortable With Breastfeeding Nursing can be one of the most challenging ... a mother. As you become more used to breastfeeding your baby, you can try different positions or ...

  13. Positive Proof.

    ERIC Educational Resources Information Center

    Auty, Geoffrey

    1988-01-01

    Presents experiments which show that in electrostatics there are logical reasons for describing charged materials as positive or negative. Indicates that static and current electricity are not separate areas of physics. Diagrams of experiments and circuits are included. (RT)

  14. Simulation of foam displacement in porous media

    SciTech Connect

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

    1993-08-01

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

  15. Displacement of soil pore water by trichloroethylene

    USGS Publications Warehouse

    Wershaw, R. L.; Aiken, G.R.; Imbrigiotta, T.E.; Goldberg, M.C.

    1994-01-01

    Dense nonaqueous phase liquids (DNAPLS) are important pollutants because of their widespread use as chemical and industrial solvents. An example of the pollution caused by the discharge of DNAPLs is found at the Picatinny Arsenal, New Jersey, where trichloroethylene (TCE) has been discharged directly into the unsaturated zone. This discharge has resulted in the formation of a plume of TCE-contaminated water in the aquifer downgradient of the discharge. A zone of dark-colored groundwater containing a high dissolved organic C content has been found near the point of discharge of the TCE. The colored-water plume extends from the point of discharge at least 30 m (100 feet) downgradient. Fulvic acids isolated from the colored-waters plume, from water from a background well that has not been affected by the discharge of chlorinated solvents, and from soil pore water collected in a lysimeter installed at an uncontaminated site upgradient of the study area have been compared. Nuclear magnetic resonance spectra of the fulvic acids from the colored waters and from the lysimeter are very similar, but are markedly different from the nuclear magnetic resonance spectrum of the fulvic acid from the background well. The three-dimensional fluorescence spectrum and the DOC fractionation profile of the colored groundwater and the soil pore water are very similar to each other, but quite different from those of the background water. It is proposed from these observations that this colored water is soil pore water that has been displaced by a separate DNAPL liquid phase downward to the saturated zone.

  16. Displacement of soil pore water by trichloroethylene

    SciTech Connect

    Wershaw, R.L.; Aiken, G.R.; Imbrigiotta, T.E.

    1994-07-01

    Dense nonaqueous phase liquids (DNAPLS) are important pollutants because of their widespread use as chemical and industrial solvents. An example of the pollution caused by the discharge of DNAPLs is found at the Picatinny Arsenal, New Jersey, where trichloroethylene (TCE) has been discharged directly into the unsaturated zone. This discharge has resulted in the formation of a plume of TCE-contaminated water in the aquifer downgradient of the discharge. A zone of dark-colored groundwater containing a high dissolved organic C content has been found near the point of discharge of the TCE. The colored-water plume extends from the point of discharge at least 30 m (100 feet) downgradient. Fulvic acids isolated from the colored-waters plume, from water from a background well that has not been affected by the discharge of chlorinated solvents, and from soil pore water collected in a lysimeter installed at an uncontaminated site upgradient of the study area have been compared. Nuclear magnetic resonance spectra of the fulvic acids from the colored waters and from the lysimeter am very similar, but are markedly different from the nuclear magnetic resonance spectrum of the fulvic acid from the background well. The three-dimensional fluorescence spectrum and the DOC fractionation profile of the colored groundwater and the soil pore water are very similar to each other, but quite different from those of the background water. It is proposed from these observations that this colored water is soil pore water that has been displaced by a separate DNAPL liquid phase downward to the saturated zone. 15 refs., 6 figs., 4 tabs.

  17. [Vestibularly displaced flap with bone augmentation].

    PubMed

    Bakalian, V L

    2009-01-01

    The aim of this study is to achieve esthetic gingival contours with the help of less traumatic mucogingival surgeries. 9 Patients were operated with horizontal deficiencies in 9 edentulous sites, planned to be restored with fixed partial dentures. In all cases there was lack of keratinized tissues. Temporary bridges were fabricated to all patients. Before surgery the bridges were removed and the abutment teeth were additionally cleaned with ultrasonic device. A horizontal incision was made from lingual (palatal) side between the abutment teeth, which was connected with two vertical releasing incisions to the mucogingival junction from the vestibular side. The horizontal incision was made on a distance 6-10 mm from the crest of the alveolar ridge. A partial thickness flap in the beginning 3-5 mm, then a full thickness flap up to the mucogingival junction, then a partial thickness flap was made. The flap was mobilized and displaced vestibularly. In the apical part the cortical bone was perforated, graft material was put and the flap was sutured. In all 9 cases the horizontal defect was partially or fully eliminated. The width of the keratinized tissues was also augmented in all cases. The postoperative healing was without complications, discomfort and painless. The donor sites also healed without complications. The application of Solcoseryl Dental Adhesive Paste 3 times a day for 7-10 days helped for painless healing of the donor site. The offered method of soft tissue and bone augmentation is effective in the treatment of horizontal defects of edentulous alveolar ridges of not big sizes. It makes possible to achieve esthetic results without traumatizing an additional donor-site.

  18. The effect of transient eddy on interannual meridional displacement of summer East Asian subtropical jet

    NASA Astrophysics Data System (ADS)

    Xiang, Yang; Yang, Xiuqun

    2012-05-01

    Using ERA-40 reanalysis daily data for the period 1958-2002, this study investigated the effect of transient eddy (TE) on the interannual meridional displacement of summer East Asian subtropical jet (EASJ) by conducting a detailed dynamical diagnosis. The summer EASJ axis features a significant interannual coherent meridional displacement. Associated with such a meridional displacement, the TE vorticity forcing anomalies are characterized by a meridional dipole pattern asymmetric about the climatological EASJ axis. The TE vorticity forcing anomalies yield barotropic zonal wind tendencies with a phase meridionally leading the zonal wind anomalies, suggesting that they act to reinforce further meridional displacement of the EASJ and favor a positive feedback in the TE and time-mean flow interaction. However, The TE thermal forcing anomalies induce baroclinic zonal wind tendencies that reduce the vertical shear of zonal wind and atmospheric baroclinicity and eventually suppress the TE activity, favoring a negative feedback in the TE and time-mean flow interaction. Although the two types of TE forcing tend to have opposite feedback roles, the TE vorticity forcing appears to be dominant in the TE effect on the time-mean flow.

  19. Displacement of D1, HP1 and topoisomerase II from satellite heterochromatin by a specific polyamide.

    PubMed

    Blattes, Roxane; Monod, Caroline; Susbielle, Guillaume; Cuvier, Olivier; Wu, Jian-hong; Hsieh, Tao-shih; Laemmli, Ulrich K; Käs, Emmanuel

    2006-06-07

    The functions of DNA satellites of centric heterochromatin are difficult to assess with classical molecular biology tools. Using a chemical approach, we demonstrate that synthetic polyamides that specifically target AT-rich satellite repeats of Drosophila melanogaster can be used to study the function of these sequences. The P9 polyamide, which binds the X-chromosome 1.688 g/cm3 satellite III (SAT III), displaces the D1 protein. This displacement in turn results in a selective loss of HP1 and topoisomerase II from SAT III, while these proteins remain bound to the adjacent rDNA repeats and to other regions not targeted by P9. Conversely, targeting of (AAGAG)n satellite V repeats by the P31 polyamide results in the displacement of HP1 from these sequences, indicating that HP1 interactions with chromatin are sensitive to DNA-binding ligands. P9 fed to larvae suppresses the position-effect variegation phenotype of white-mottled adult flies. We propose that this effect is due to displacement of the heterochromatin proteins D1, HP1 and topoisomerase II from SAT III, hence resulting in stochastic chromatin opening and desilencing of the nearby white gene.

  20. Criteria for design of the Yucca Mountain structures, systems and components for fault displacement

    SciTech Connect

    Stepp, C.; Hossain, Q.; Nesbit, S.; Hardy, M.

    1995-12-31

    The DOE intends to design the Yucca Mountain high-level waste facility structures, systems and components (SSCs) for fault displacements to provide reasonable assurance that they will meet the preclosure safety performance objectives established by 10 CFR Part 60. To the extent achievable, fault displacement design of the facility will follow guidance provided in the NRC Staff Technical Position. Fault avoidance will be the primary design criterion, especially for spatially compact or clustered SSCs. When fault avoidance is not reasonably achievable, expected to be the case for most spatially extended SSCs, engineering design procedures and criteria or repair and rehabilitation actions, depending on the SSC`s importance to safety, are provided. SSCs that have radiological safety importance will be designed for fault displacements that correspond to the hazard exceedance frequency equal to their established seismic safety performance goals. Fault displacement loads are generally localized and may cause local inelastic response of SSCs. For this reason, the DOE intends to use strain-based design acceptance criteria similar to the strain-based criteria used to design nuclear plant SSCs for impact and impulsive loads.

  1. Stress analysis in human temporomandibular joint affected by anterior disc displacement during prolonged clenching.

    PubMed

    Abe, S; Kawano, F; Kohge, K; Kawaoka, T; Ueda, K; Hattori-Hara, E; Mori, H; Kuroda, S; Tanaka, E

    2013-04-01

    Parafunctional habits, such as prolonged clenching and bruxism, have been associated with dysfunctional overloading in the temporomandibular joint (TMJ). In this study, stress distributions in the TMJ were analysed during prolonged clenching, using three-dimensional finite element (FE) models of the TMJ with and without disc displacement. The aim of this study was to investigate stress distribution of the cartilaginous tissues in the TMJ with and without disc displacement. Finite element models were developed on the basis of magnetic resonance images from two subjects with and without anterior disc displacement. Condylar movements recorded during a 5-min clenching were used as the loading condition for stress analysis. In the asymptomatic model, the highest von Mises stresses were located in the lateral area (4·91 MPa) of the disc surfaces, and after 5-min clenching, the higher stresses were still located at the lateral area (3·65 MPa). In all the cartilaginous tissues, 30-50% of stress reduction occurred during 5-min clenching. In contrast, the von Mises stress in the cartilaginous tissues of the symptomatic model with disc displacement was markedly lower, compared with the asymptomatic model. However, in the condylar cartilage, stress relaxation during clenching was not recognised. Furthermore, relatively high stresses were observed in the retrodiscal tissues throughout clenching. The present results indicate that disc position could be involved in the stress distribution of the TMJ components during prolonged clenching.

  2. An interferometric radar for displacement measurement and its application in civil engineering structures

    NASA Astrophysics Data System (ADS)

    Su, D.; Nagayama, T.; Sun, Z.; Fujino, Y.

    2012-04-01

    Recent progress in radar techniques and systems has led to the development of a microwave interferometer, potentially suitable for non-contact displacement monitoring of civil engineering structures. This paper describes a new interferometric radar system, named IBIS-S, which is possible to measure the static or dynamic displacement at multiple points of structures simultaneously with high accuracy. In this paper, the technical characteristics and specification of the radar system is described. Subsequently, the actual displacement sensitivity of the equipment is illustrated using the laboratory tests with random motion upon a shake table. Finally the applications of the radar system to the measurement on a cable-stayed bridge and a prestressed concrete bridge are presented and discussed. Results show that the new system is an accurate and effective method to measure displacements of multiple targets of structures. It should be noted that the current system can only measure the vibration of the target position along the sensor's line of sight. Hence, proper caution should be taken when designing the sensor posture and prior knowledge of the direction of motion is necessary.

  3. Blade Displacement Measurement Technique Applied to a Full-Scale Rotor Test

    NASA Technical Reports Server (NTRS)

    Abrego, Anita I.; Olson, Lawrence E.; Romander, Ethan A.; Barrows, Danny A.; Burner, Alpheus W.

    2012-01-01

    Blade displacement measurements using multi-camera photogrammetry were acquired during the full-scale wind tunnel test of the UH-60A Airloads rotor, conducted in the National Full-Scale Aerodynamics Complex 40- by 80-Foot Wind Tunnel. The objectives were to measure the blade displacement and deformation of the four rotor blades as they rotated through the entire rotor azimuth. These measurements are expected to provide a unique dataset to aid in the development and validation of rotorcraft prediction techniques. They are used to resolve the blade shape and position, including pitch, flap, lag and elastic deformation. Photogrammetric data encompass advance ratios from 0.15 to slowed rotor simulations of 1.0, thrust coefficient to rotor solidity ratios from 0.01 to 0.13, and rotor shaft angles from -10.0 to 8.0 degrees. An overview of the blade displacement measurement methodology and system development, descriptions of image processing, uncertainty considerations, preliminary results covering static and moderate advance ratio test conditions and future considerations are presented. Comparisons of experimental and computational results for a moderate advance ratio forward flight condition show good trend agreements, but also indicate significant mean discrepancies in lag and elastic twist. Blade displacement pitch measurements agree well with both the wind tunnel commanded and measured values.

  4. Synthetic-wavelength self-mixing interferometry for displacement measurement

    NASA Astrophysics Data System (ADS)

    Chen, Junbao; Zhu, Hongbin; Xia, Wei; Guo, Dongmei; Hao, Hui; Wang, Ming

    2016-06-01

    A simple synthetic-wavelength self-mixing interferometer is proposed for precision displacement measurement. Choosing the frequency difference of the orthogonally polarized dual frequency He-Ne laser appropriately, we introduce synthetic wavelength theory into self-mixing interference principle and demonstrate a feasible optical configuration by simply adjusting the optical design of self-mixing interferometer. The phase difference between the two orthogonally polarized feedback fringes is observed, and the tiny displacement of the object can be measured through the phase change of the synthetic signal. Since the virtual synthetic wavelength is 106 times larger than the operating wavelength, sub-nanometer displacement of the object can be obtained in millimeter criterion measurement without modulation, demodulation and complicated electrical circuits. Experimental results verifies the synthetic wavelength self-mixing interferometer's ability of measuring nanoscale displacement, which provides a potential approach for contactless precision displacement measurement in a number of scientific and industrial applications.

  5. Displacement of maxillary third molar into the lateral pharyngeal space.

    PubMed

    Lee, Doksa; Ishii, Syoichiro; Yakushiji, Noboru

    2013-10-01

    Iatrogenic tooth displacement is a rare complication during extraction of impacted molars, but displacement of a maxillary third molar into the maxillary sinus, infratemporal fossa, buccal space, pterygomandibular space, and lateral pharyngeal space has been reported. Currently, 6 published reports describe third molar displacement into the lateral pharyngeal space, only 1 of which involved the loss of a maxillary third molar into this area, which occurred after an attempted self-extraction by the patient. There have been no reported cases of iatrogenic displacement of the maxillary third molar during an extraction procedure. This article describes the recovery, under general anesthesia, of a maxillary third molar from the lateral pharyngeal space after an iatrogenic displacement.

  6. Pointwise fiber Bragg grating displacement sensor system for dynamic measurements.

    PubMed

    Chuang, Kuo-Chih; Ma, Chien-Ching

    2008-07-10

    A method for setting up a fiber Bragg grating (FBG) sensor which can measure the pointwise, out-of-plane or in-plane dynamic displacement is proposed. The proposed FBG sensor is reusable. A multiplexing demodulation system based on a single long-period fiber grating is used in this study. The experimental results of the steady-state motion for a multilayer piezoelectric actuator and the dynamic response of a cantilever beam subjected to impact loadings are presented. These results indicate that the proposed displacement sensor has the ability to measure the out-of-plane dynamic displacement with high sensitivity. Measurements for a piezoceramic plate excited by high frequency show that the proposed displacement sensor also has the ability to provide the in-plane dynamic displacement up to 20 kHz.

  7. Apes Communicate about Absent and Displaced Objects: Methodology Matters

    PubMed Central

    Lyn, Heidi; Russell, Jamie L.; Leavens, David A.; Bard, Kim A.; Boysen, Sarah T.; Schaeffer, Jennifer A.; Hopkins, William D.

    2013-01-01

    Displaced reference is the ability to refer to an item that has been moved (displaced) in space and/or time, and has been called one of the true hallmarks of referential communication. Several studies suggest that nonhuman primates have this capability, but a recent experiment concluded that in a specific situation (absent entities) human infants display displaced reference but chimpanzees do not. Here we show that chimpanzees and bonobos of diverse rearing histories are capable of displaced reference to absent and displaced objects. It is likely that some of the conflicting findings from animal cognition studies are due to relatively minor methodological differences, but are compounded by interpretation errors. Comparative studies are of great importance in elucidating the evolution of human cognition, however, greater care must be taken with methodology and interpretation for these studies to accurately reflect species differences. PMID:23681052

  8. Salt-independent hydrophobic displacement chromatography for antibody purification using cyclodextrin as supermolecular displacer.

    PubMed

    Ren, Jun; Yao, Peng; Chen, Jingjing; Jia, Lingyun

    2014-11-21

    Hydrophobic interaction chromatography (HIC) offers an orthogonal selectivity to ion exchange chromatography and the combination of the two processes can provide a potential cost-effective alternative to protein A chromatography in industrial antibody purification. However, the application of HIC is limited by its close dependence on high concentrations of kosmotropic salts to achieve desired separation. These salts can cause antibody precipitation and induce the corrosion of manufacturing facilities. Here, we report a new strategy of salt-independent HIC, which can capture antibody at the physiological salt concentration and allow the recovery of bound proteins through cyclodextrin (CD)-based displacement elution. Hydrophobicity-intensified HIC media with different coupling amount of phenyl ligands were prepared and assessed for their antibody binding capacity and selectivity. β-CD was investigated for its supermolecular interaction with phenyl ligands and elution capacity as a displacer. The results clarified a nearly linear correlation between binding capacity of human immunoglobulin G (IgG) and phenyl coupling density in the range of 44-159 μmol/mL. The host-guest interaction between β-CD and the phenyl ligands revealed a modest binding strength (Ka=4.1×10(3) M(-1)), and 15 mM β-CD solution showed a general effectiveness as displacement eluent for these HIC media, with IgG recovery varying with the ligand density. This strategy allowed the direct purification of human IgG from serum with satisfactory purity. The whole procedure of this method, including loading and elution, can be performed under physiological conditions. We expect such a salt-independent mode of HIC could be used as a capture or intermediate step in industrial antibody purification.

  9. High-resolution diffraction grating interferometric transducer of linear displacements

    NASA Astrophysics Data System (ADS)

    Shang, Ping; Xia, Haojie; Fei, Yetai

    2016-01-01

    A high-resolution transducer of linear displacements is presented. The system is based on semiconductor laser illumination and a diffraction grating applied as a length master. The theory of the optical method is formulated using Doppler description. The relationship model among the interference strips, measurement errors, grating deflection around the X, Y and Z axes and translation along the Z axis is built. The grating interference strips' direction and space is not changed with movement along the X (direction of grating movement), Y (direction of grating line), Z axis, and the direction and space has a great effect when rotating around the X axis. Moreover the space is little affected by deflection around the Z axis however the direction is changed dramatically. In addition, the strips' position shifted rightward or downwards respectively for deflection around the X or Y axis. Because the emitted beams are separated on the grating plane, the tilt around the X axis error of the stage during motion will lead to the optical path difference of the two beams resulting in phase shift. This study investigates the influence of the tilt around the X axis error. Experiments show that after yaw error compensation, the high-resolution diffraction grating interferometric transducer readings can be significantly improved. The error can be reduced from +/-80 nm to +/-30 nm in maximum.

  10. Phase Change Effects on Immiscible Flow Displacements in Radial Injection

    NASA Astrophysics Data System (ADS)

    Ahmadlouydarab, Majid; Azaiez, Jalel; Chen, Zhangxin

    2014-11-01

    We report a systematic simulation of immiscible fluid-fluid displacements in radial injection in the presence of phase change. Due to the presence of two fluid-fluid interfaces in the system, a special treatment has been adopted. To track the leading interface position, two highly accurate methods including Level Set and Immersed Interface Method were used, while for locating the trailing interface an energy equation was adopted assuming the existence of a constant thin condensate layer. Dimensional analysis led to three important dimensionless groups including capillary number (Ca), Jacob number (Ja) and viscosity ratios (M) of the three fluids. Simulation results indicate significant influences of these parameters on the development of the instability and the interfacial morphology of fingers. Increasing Ca or M tends to amplify the interfacial instability, fingertip splitting, and results in longer fingers. In contrast, increasing Ja has stabilizing effects due to an increase of the thickness of the condensate layer. On the other hand at lower viscosity ratios as well as lower Ca, because of compensation effects of the phase change, both leading and trailing interfaces are found to be less unstable. Moreover accumulated condensate and oil saturation depletion curves show increasing and decreasing trends, respectively, when the Ca increases. Although viscosity ratio and Ja have similar effects on the accumulated condensate, they do not show any effect on the oil depletion saturation.

  11. Charge displacement by adhesion and spreading of a cell.

    PubMed

    Svetlicić, V; Ivosević, N; Kovac, S; Zutić, V

    2001-01-01

    The potentiostatic control of surface charge density and interfacial tension of an electrode immersed in an aqueous electrolyte solution offers a possibility for direct studies of non-specific interactions in cell adhesion. Unicellular marine alga, Dunaliella tertiolecta (Chlorophyceae) of micrometer size and flexible cell envelope was used as a model cell and 0.1 M NaCl as supporting electrolyte. The dropping mercury electrode acted as in situ adhesion sensor and the electrochemical technique of chronoamperometry allowed measurement of the spread cell-electrode interface area and the distance of the closest approach of a cell. The adhesion and spreading of a single cell at the mercury electrode causes a displacement of counter-ions from the electrical double layer over a broad range of the positive and negative surface charge densities (from +16.0 to -8.2 microC/cm2). The flow of compensating current reflects the dynamics of adhesive contact formation and subsequent spreading of a cell. The adhesion and spreading rates are enhanced by the hydrodynamic regime of electrode's growing fluid interface. The distance of the closest approach of an adherent cell is smaller or equal to the distance of the outer Helmholz plane within the electrical double layer, i.e. 0.3-0.5 nm. There is a clear evidence of cell rupture for the potentials of maximum attraction as the area of the contact interface exceeded up to 100 times the cross-section area of a free cell.

  12. Competitive displacement among post-Paleozoic cyclostome and cheilostome bryozoans

    NASA Technical Reports Server (NTRS)

    Sepkoski, J. J. Jr; McKinney, F. K.; Lidgard, S.; Sepkoski JJ, J. r. (Principal Investigator)

    2000-01-01

    Encrusting bryozoans provide one of the few systems in the fossil record in which ecological competition can be observed directly at local scales. The macroevolutionary history of diversity of cyclostome and cheilostome bryozoans is consistent with a coupled-logistic model of clade displacement predicated on species within clades interacting competitively. The model matches observed diversity history if the model is perturbed by a mass extinction with a position and magnitude analogous to the Cretaceous/Tertiary boundary event, Although it is difficult to measure all parameters in the model from fossil data, critical factors are intrinsic rates of extinction, which can be measured. Cyclostomes maintained a rather low rate of extinction, and the model solutions predict that they would lose diversity only slowly as competitively superior species of cheilostomes diversified into their environment. Thus, the microecological record of preserved competitive interactions between cyclostome and cheilostome bryozoans and the macroevolutionary record of global diversity are consistent in regard to competition as a significant influence on diversity histories of post-Paleozoic bryozoans.

  13. Nucleic-acid structural deformability deduced from anisotropic displacement parameters.

    PubMed

    Peckham, Heather E; Olson, Wilma K

    2011-04-01

    The growing numbers of very well resolved nucleic-acid crystal structures with anisotropic displacement parameters provide an unprecedented opportunity to learn about the natural motions of DNA and RNA. Here we report a new Monte-Carlo approach that takes direct account of this information to extract the distortions of covalent structure, base pairing, and dinucleotide geometry intrinsic to regularly organized double-helical molecules. We present new methods to test the validity of the anisotropic parameters and examine the apparent deformability of a variety of structures, including several A, B, and Z DNA duplexes, an AB helical intermediate, an RNA, a ligand-DNA complex, and an enzyme-bound DNA. The rigid-body parameters characterizing the positions of the bases in the structures mirror the mean parameters found when atomic motion is taken into account. The base-pair fluctuations intrinsic to a single structure, however, differ from those extracted from collections of nucleic-acid structures, although selected base-pair steps undergo conformational excursions along routes suggested by the ensembles. The computations reveal surprising new molecular insights, such as the stiffening of DNA and concomitant separation of motions of contacted nucleotides on opposite strands by the binding of Escherichia coli endonuclease VIII, which suggest how the protein may direct enzymatic action.

  14. Therapeutic outcome assessment in permanent temporomandibular joint disc displacement.

    PubMed

    Kropmans, T J; Dijkstra, P U; Stegenga, B; de Bont, L G

    1999-05-01

    In permanent temporomandibular disc displacement (TMJ-DD) outcome studies many authors claim positive effects of arthroscopic surgery, arthrocentesis and physical therapy. This literature review was undertaken to analyse whether the claimed effects are based on acceptable methodology. The recorded papers were analysed by two independent observers according to (1) method of investigation, (2) therapeutic intervention studied, (3) therapeutic outcome variables used, and (4) claimed effectiveness of the intervention. Agreement between observers was calculated. Twenty-four papers were found in which therapeutic outcome of interventions on temporomandibular disorders were studied. Six studies applied a true experimental design. Each of these six studies compared a different set of interventions. Twenty-two papers used maximal mouth opening (MMO) as an outcome variable, nine studied pain intensity on a visual analogue scale, one paper assessed the mandibular function impairment questionnaire. Kappa for overall agreement concerning the reviewing criteria was 0.82 (P < or = 0.001). No distinguishing effects on MMO, pain or function impairment were reported between arthroscopic surgery, arthrocentesis and physical therapy. Results of methodological sound outcome studies evaluating the effects of arthroscopic surgery, arthrocentesis and physical therapy are needed.

  15. Gantry and isocenter displacements of a linear accelerator caused by an add-on micromultileaf collimator

    SciTech Connect

    Riis, Hans L.; Zimmermann, Sune J.; Hjelm-Hansen, Mogens

    2013-03-15

    Purpose: The delivery of high quality stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) treatments to the patient requires knowledge of the position of the isocenter to submillimeter accuracy. To meet the requirements the deviation between the radiation and mechanical isocenters must be less than 1 mm. The use of add-on micromultileaf collimators ({mu}MLCs) in SRS and SRT is an additional challenge to the anticipated high-level geometric and dosimetric accuracy of the treatment. The aim of this work was to quantify the gantry excursions during rotation with and without an add-on {mu}MLC attached to the gantry head. In addition, the shift in the position of the isocenter and its correlation to the kV beam center of the cone-beam CT system was included in the study. Methods: The quantification of the gantry rotational performance was done using a pointer supported by an in-house made rigid holder attached to the gantry head of the accelerator. The pointer positions were measured using a digital theodolite. To quantify the effect of an {mu}MLC of 50 kg, the measurements were repeated with the {mu}MLC attached to the gantry head. The displacement of the isocenter due to an add-on {mu}MLC of 50 kg was also investigated. In case of the pointer measurement the {mu}MLC was simulated by weights attached to the gantry head. A method of least squares was applied to determine the position and displacement of the mechanical isocenter. Additionally, the displacement of the radiation isocenter was measured using a ball-bearing phantom and the electronic portal image device system. These measurements were based on 8 MV photon beams irradiated onto the ball from the four cardinal angles and two opposed collimator angles. The measurements and analysis of the data were carried out automatically using software delivered by the manufacturer. Results: The displacement of the mechanical isocenter caused by a 50 kg heavy {mu}MLC was found to be (-0.01 {+-} 0.05, -0

  16. Evaluation of the Role of Displacement Surgery in the Management of Congenital Nystagmus

    PubMed Central

    Wagdy, Faried Mohammed; Ismael, Mohammed Eid; Sarhan, Abd Elrahman Elsebaey

    2017-01-01

    Introduction The aim of this study was to assess the effectiveness of displacement surgery in damping of ocular oscillation and management of compensatory head posture in patients of congenital nystagmus. Methods This study was carried out in 2014. The participants were 50 patients with congenital nystagmus that dampens in a certain direction of gaze with or without abnormal head posture and with or without strabismus. Patients underwent the augmented modified Kestenbaum (augmented parks) procedure. Data were analyzed by SPSS version 15, using Chi-square text, exact test, and Mann Whitney U test. Results In this study, 12 patients (80%) were noticed clinically to have damping of nystagmus while 3 patients (20%) had no damping of nystagmus. Twelve patients (80.0%) had no post-operative abnormal head position, while 3 patients (20.0%) had residual abnormal head position. There was a statistically significant difference between the pre-operative BCVA in primary position and post-operative BCVA in primary position (p = 0.001 for both right and left eyes). Conclusion The displacement surgeries (e.g. Kestenbaum procedure) for the treatment of patients with congenital nystagmus is an effective procedure for correction of abnormal head posture, improving the visual acuity in the primary position and damping of nystagmus in patients with congenital nystagmus who have null points away from the primary position. PMID:28243423

  17. An overview of NASA research on positive displacement general-aviation engines

    NASA Technical Reports Server (NTRS)

    Kempke, E. E., Jr.

    1980-01-01

    The research and technology program related to improved and advanced general aviation engines is described. Current research is directed at the near-term improvement of conventional air-cooled spark-ignition piston engines and at future alternative engine systems based on all-new spark-ignition piston engines, lightweight diesels, and rotary combustion engines that show potential for meeting program goals in the midterm and long-term future. The conventional piston engine activities involve efforts on applying existing technology to improve fuel economy, investigation of key processes to permit leaner operation and reduce drag, and the development of cost effective technology to permit flight at high-altitudes where fuel economy and safety are improved. The advanced engine concepts activities include engine conceptual design studies and enabling technology efforts on the critical or key technology items.

  18. Positive displacement type general-aviation engines: Summary and concluding remarks

    NASA Technical Reports Server (NTRS)

    Kempke, E. E., Jr.

    1980-01-01

    The activities of programs investigating various aspects of aircraft internal combustion engines are briefly described including developments in fuel injection technology, cooling systems and drag reduction, turbocharger technology, and stratified-charge rotary engines.

  19. Counter-Rotatable Fan Gas Turbine Engine with Axial Flow Positive Displacement Worm Gas Generator

    NASA Technical Reports Server (NTRS)

    Giffin, Rollin George (Inventor); Murrow, Kurt David (Inventor); Fakunle, Oladapo (Inventor)

    2014-01-01

    A counter-rotatable fan turbine engine includes a counter-rotatable fan section, a worm gas generator, and a low pressure turbine to power the counter-rotatable fan section. The low pressure turbine maybe counter-rotatable or have a single direction of rotation in which case it powers the counter-rotatable fan section through a gearbox. The gas generator has inner and outer bodies having offset inner and outer axes extending through first, second, and third sections of a core assembly. At least one of the bodies is rotatable about its axis. The inner and outer bodies have intermeshed inner and outer helical blades wound about the inner and outer axes and extending radially outwardly and inwardly respectively. The helical blades have first, second, and third twist slopes in the first, second, and third sections respectively. A combustor section extends through at least a portion of the second section.

  20. Lower Bound on the Mean Square Displacement of Particles in the Hard Disk Model

    NASA Astrophysics Data System (ADS)

    Richthammer, Thomas

    2016-08-01

    The hard disk model is a 2D Gibbsian process of particles interacting via pure hard core repulsion. At high particle density the model is believed to show orientational order, however, it is known not to exhibit positional order. Here we investigate to what extent particle positions may fluctuate. We consider a finite volume version of the model in a box of dimensions 2 n × 2 n with arbitrary boundary configuration, and we show that the mean square displacement of particles near the center of the box is bounded from below by c log n. The result generalizes to a large class of models with fairly arbitrary interaction.

  1. Measurement of craniocaudal catheter displacement between fractions in computed tomography-based high dose rate brachytherapy of prostate cancer.

    PubMed

    Kim, Yongbok; Hsu, I-Chow J; Pouliot, Jean

    2007-09-17

    The objective of this work is to measure the cranio-caudal displacement of catheters occurring between consecutive fractions of transrectal ultrasound (TRUS) guided high dose rate (HDR) prostate brachytherapy. Ten consecutive patients were treated with 2 fractions of 9.5 Gy TRUS guided HDR brachytherapy using dental putty for the fixation of catheters. For each patient, a CT scan with 3 mm slice thickness was acquired before each of the two fractions. Two different references were employed to measure the catheter displacement between fractions: the ischial bone as a bony marker (BM) and the center of two gold markers (COGM) implanted in the prostate. The catheter displacement was calculated by multiplying the thickness of CT slice with the difference in number of CT slices between the reference slice and the slice containing the tip of a catheter. The average (range) magnitude of caudal catheter displacement was 2.7 mm (-6.0 to 13.5 mm) for BM method and 5.4 mm (-3.75 to 18.0 mm) for COGM method, respectively. The measurement data obtained from BM and COGM methods verified that both prostate movement and catheter displacement occurred independently between fractions. The most anterior and medial two catheters (catheter position 8 and 12) had the greatest tendency to be displaced in the caudal direction because they were located at the most distant position from the fulcrum, susceptible to the rotation of the dental putty in lateral plane due to the movement of patient legs between fractions. In conclusion, the use of both BM and COGM methods can demonstrate the prostate and catheter movement relative to the BM between fractions. We found a pattern of catheter displacement using our technique. Based on our finding further improvement of our results may be possible by modification of our current technique.

  2. A Vision-Based Sensor for Noncontact Structural Displacement Measurement.

    PubMed

    Feng, Dongming; Feng, Maria Q; Ozer, Ekin; Fukuda, Yoshio

    2015-07-09

    Conventional displacement sensors have limitations in practical applications. This paper develops a vision sensor system for remote measurement of structural displacements. An advanced template matching algorithm, referred to as the upsampled cross correlation, is adopted and further developed into a software package for real-time displacement extraction from video images. By simply adjusting the upsampling factor, better subpixel resolution can be easily achieved to improve the measurement accuracy. The performance of the vision sensor is first evaluated through a laboratory shaking table test of a frame structure, in which the displacements at all the floors are measured by using one camera to track either high-contrast artificial targets or low-contrast natural targets on the structural surface such as bolts and nuts. Satisfactory agreements are observed between the displacements measured by the single camera and those measured by high-performance laser displacement sensors. Then field tests are carried out on a railway bridge and a pedestrian bridge, through which the accuracy of the vision sensor in both time and frequency domains is further confirmed in realistic field environments. Significant advantages of the noncontact vision sensor include its low cost, ease of operation, and flexibility to extract structural displacement at any point from a single measurement.

  3. A Vision-Based Sensor for Noncontact Structural Displacement Measurement

    PubMed Central

    Feng, Dongming; Feng, Maria Q.; Ozer, Ekin; Fukuda, Yoshio

    2015-01-01

    Conventional displacement sensors have limitations in practical applications. This paper develops a vision sensor system for remote measurement of structural displacements. An advanced template matching algorithm, referred to as the upsampled cross correlation, is adopted and further developed into a software package for real-time displacement extraction from video images. By simply adjusting the upsampling factor, better subpixel resolution can be easily achieved to improve the measurement accuracy. The performance of the vision sensor is first evaluated through a laboratory shaking table test of a frame structure, in which the displacements at all the floors are measured by using one camera to track either high-contrast artificial targets or low-contrast natural targets on the structural surface such as bolts and nuts. Satisfactory agreements are observed between the displacements measured by the single camera and those measured by high-performance laser displacement sensors. Then field tests are carried out on a railway bridge and a pedestrian bridge, through which the accuracy of the vision sensor in both time and frequency domains is further confirmed in realistic field environments. Significant advantages of the noncontact vision sensor include its low cost, ease of operation, and flexibility to extract structural displacement at any point from a single measurement. PMID:26184197

  4. Wide-range displacement expressions for standard fracture mechanics specimens

    NASA Technical Reports Server (NTRS)

    Kapp, J. A.; Gross, B.; Leger, G. S.

    1985-01-01

    Wide-range algebraic expressions for the displacement of cracked fracture mechanics specimens are developed. For each specimen two equations are given: one for the displacement as a function of crack length, the other for crack length as a function of displacement. All the specimens that appear in ASTM Test for Plane-Strain Fracture Toughness of Metallic Materials (E 399) are represented in addition to the crack mouth displacement for a pure bending specimen. For the compact tension sample and the disk-shaped compact tension sample, the displacement at the crack mouth and at the load line are both considered. Only the crack mouth displacements for the arc-shaped tension samples are presented. The agreement between the displacements or crack lengths predicted by the various equations and the corresponding numerical data from which they were developed are nominally about 3 percent or better. These expressions should be useful in all types of fracture testing including fracture toughness, K-resistance, and fatigue crack growth.

  5. The role of environmental degradation in population displacement.

    PubMed

    Lonergan, S

    1998-01-01

    This article answers a series of questions about the role of environmental degradation in population displacement, refugee movement, and migration. The environment tends not to be included in the reasons for migration. Roger's indicators of migration potential include population growth, economic restructuring, increased economic disparities, and increased refugee flows. Myers (1993) estimated that international displacement and internal displacement may amount to about 25 million and may rise to 150 million by 2050. The role of the environment in displacement must be examined in the broader political and cultural context. Definitions of environmental refugees are ambiguous and inconsistent, and research has not answered why people continue to move to Mexico City and Chongqing, China, which both have very high levels of pollution. El-Hinnawi (1985) defined 3 groups of environmental refugees: those displaced due to natural disasters; those displaced due to permanent habitat changes; and those displaced who migrated from areas that cannot support their basic needs and who desire an improved quality of life. Lonergan (1994) identified environmental stresses as natural disasters, cumulative or slow-onset changes, accidental disruptions or industrial accidents, development projects, and conflict and warfare. These 5 causes must be treated separately and not lumped together as environmental degradation. Shoreline erosion, coastal flooding, and agricultural disruption associated with climate change may increase migration. Global measures must address world poverty and promote sustainable development.

  6. The Effect of Basepair Mismatch on DNA Strand Displacement.

    PubMed

    Broadwater, D W Bo; Kim, Harold D

    2016-04-12

    DNA strand displacement is a key reaction in DNA homologous recombination and DNA mismatch repair and is also heavily utilized in DNA-based computation and locomotion. Despite its ubiquity in science and engineering, sequence-dependent effects of displacement kinetics have not been extensively characterized. Here, we measured toehold-mediated strand displacement kinetics using single-molecule fluorescence in the presence of a single basepair mismatch. The apparent displacement rate varied significantly when the mismatch was introduced in the invading DNA strand. The rate generally decreased as the mismatch in the invader was encountered earlier in displacement. Our data indicate that a single base pair mismatch in the invader stalls branch migration and displacement occurs via direct dissociation of the destabilized incumbent strand from the substrate strand. We combined both branch migration and direct dissociation into a model, which we term the concurrent displacement model, and used the first passage time approach to quantitatively explain the salient features of the observed relationship. We also introduce the concept of splitting probabilities to justify that the concurrent model can be simplified into a three-step sequential model in the presence of an invader mismatch. We expect our model to become a powerful tool to design DNA-based reaction schemes with broad functionality.

  7. Measurement of chest wall displacement based on terahertz wave

    NASA Astrophysics Data System (ADS)

    Li, Hui; Lv, Hao; Jiao, Teng; Lu, Guohua; Li, Sheng; Li, Zhao; Liu, Miao; Jing, Xijing; Wang, Jianqi

    2015-02-01

    Measurement of chest wall displacement is an important approach for measuring mechanics of chest wall, which has considerable significance for assessing respiratory system and diagnosing pulmonary diseases. However, existing optical methods for measuring chest wall displacement are inconvenient for some specific patients such as the female patients and the patients with bandaged chest. In this letter, we proposed a method for measuring chest wall displacement based on terahertz wave and established corresponding mathematic model and set up a terahertz measurement system. The main advantages of this method are that it can measure the chest wall displacement of the subjects without taking off clothes or arranging any markers. To validate this method and assess the performance of the terahertz system, in vitro, the displacement of a water module driven by a linear guide rail was measured by the terahertz system and compared with the actual displacement of the water module. The results showed that the waveforms measured with two methods have a good agreement, and the relative error is less than 5% and sufficiently good for measurement demands. In vivo, the synchronous experiment was performed on five human volunteers with the terahertz system and a respiratory belt transducer. The results demonstrate that this method has good performance and promising prospects for measuring chest wall displacement.

  8. Static atomic displacements in crystalline solid solution alloys

    SciTech Connect

    Ice, G.; Sparks, C.; Robertson, J.L.; Epperson, J.E.; Jiang, Xiaogang

    1996-06-01

    Atomic size differences induce static displacements from an average alloy lattice and play an important role in controlling alloy phase stability and properties. Details of this, however, are difficult to study, as chemical order and displacements are strongly interrelated and static displacements are hard to measure. Diffuse x-ray scattering with tunable-synchrotron radiation can now measure element- specific static displacements with an accuracy of {+-}0.1 pm and can simultaneously measure local chemical order out to 20 shells or more. Ideal alloys for this are those that have previously been the most intractable: alloys with small Z contrast, alloys with only local order and alloys with small size differences. The combination of precise characterization of local chemical order and precise measurement of static displacement provides new information that challenges existing alloy models. This paper reports on an ongoing systematic study of static displacements in the Fe/Ni/Cr alloys and compares the observed static displacements to these predicted by current theories. Availability of more brilliant 3rd generation hard x-ray sources will greatly enhance these measurements.

  9. Development of a Wireless Displacement Measurement System Using Acceleration Responses

    PubMed Central

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

    2013-01-01

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

  10. Low-Cost GNSS Receivers for Local Monitoring: Experimental Simulation, and Analysis of Displacements.

    PubMed

    Biagi, Ludovico; Grec, Florin Cătălin; Negretti, Marco

    2016-12-15

    The geodetic monitoring of local displacements and deformations is often needed for civil engineering structures and natural phenomena like, for example, landslides. A local permanent GNSS (Global Navigation Satellite Systems) network can be installed: receiver positions in the interest area are estimated and monitored with respect to reference stations. Usually, GNSS geodetic receivers are adopted and provide results with accuracies at the millimeter level: however, they are very expensive and the initial cost and the risk of damage and loss can discourage this approach. In this paper the accuracy and the reliability of low-cost u-blox GNSS receivers are experimentally investigated for local monitoring. Two experiments are analyzed. In the first, a baseline (65 m long) between one geodetic reference receiver and one u-blox is continuously observed for one week: the data are processed by hourly sessions and the results provide comparisons between two processing packages and a preliminary accuracy assessment. Then, a network composed of one geodetic and two u-blox receivers is set up. One u-blox is installed on a device (slide) that allows to apply controlled displacements. The geodetic and the other u-blox (at about 130 m) act as references. The experiment lasts about two weeks. The data are again processed by hourly sessions. The estimated displacements of the u-blox on the slide are analyzed and compared with the imposed displacements. All of the results are encouraging: in the first experiment the standard deviations of the residuals are smaller than 5 mm both in the horizontal and vertical; in the second, they are slightly worse but still satisfactory (5 mm in the horizontal and 13 mm in vertical) and the imposed displacements are almost correctly identified.

  11. A combined approach to cartographic displacement for buildings based on skeleton and improved elastic beam algorithm.

    PubMed

    Liu, Yuangang; Guo, Qingsheng; Sun, Yageng; Ma, Xiaoya

    2014-01-01

    Scale reduction from source to target maps inevitably leads to conflicts of map symbols in cartography and geographic information systems (GIS). Displacement is one of the most important map generalization operators and it can be used to resolve the problems that arise from conflict among two or more map objects. In this paper, we propose a combined approach based on constraint Delaunay triangulation (CDT) skeleton and improved elastic beam algorithm for automated building displacement. In this approach, map data sets are first partitioned. Then the displacement operation is conducted in each partition as a cyclic and iterative process of conflict detection and resolution. In the iteration, the skeleton of the gap spaces is extracted using CDT. It then serves as an enhanced data model to detect conflicts and construct the proximity graph. Then, the proximity graph is adjusted using local grouping information. Under the action of forces derived from the detected conflicts, the proximity graph is deformed using the improved elastic beam algorithm. In this way, buildings are displaced to find an optimal compromise between related cartographic constraints. To validate this approach, two topographic map data sets (i.e., urban and suburban areas) were tested. The results were reasonable with respect to each constraint when the density of the map was not extremely high. In summary, the improvements include (1) an automated parameter-setting method for elastic beams, (2) explicit enforcement regarding the positional accuracy constraint, added by introducing drag forces, (3) preservation of local building groups through displacement over an adjusted proximity graph, and (4) an iterative strategy that is more likely to resolve the proximity conflicts than the one used in the existing elastic beam algorithm.

  12. Robustness of IPSA optimized high-dose-rate prostate brachytherapy treatment plans to catheter displacements

    PubMed Central

    Whitaker, May

    2016-01-01

    Purpose Inverse planning simulated annealing (IPSA) optimized brachytherapy treatment plans are characterized with large isolated dwell times at the first or last dwell position of each catheter. The potential of catheter shifts relative to the target and organs at risk in these plans may lead to a more significant change in delivered dose to the volumes of interest relative to plans with more uniform dwell times. Material and methods This study aims to determine if the Nucletron Oncentra dwell time deviation constraint (DTDC) parameter can be optimized to improve the robustness of high-dose-rate (HDR) prostate brachytherapy plans to catheter displacements. A set of 10 clinically acceptable prostate plans were re-optimized with a DTDC parameter of 0 and 0.4. For each plan, catheter displacements of 3, 7, and 14 mm were retrospectively applied and the change in dose volume histogram (DVH) indices and conformity indices analyzed. Results The robustness of clinically acceptable prostate plans to catheter displacements in the caudal direction was found to be dependent on the DTDC parameter. A DTDC value of 0 improves the robustness of planning target volume (PTV) coverage to catheter displacements, whereas a DTDC value of 0.4 improves the robustness of the plans to changes in hotspots. Conclusions The results indicate that if used in conjunction with a pre-treatment catheter displacement correction protocol and a tolerance of 3 mm, a DTDC value of 0.4 may produce clinically superior plans. However, the effect of the DTDC parameter in plan robustness was not observed to be as strong as initially suspected. PMID:27504129

  13. A Combined Approach to Cartographic Displacement for Buildings Based on Skeleton and Improved Elastic Beam Algorithm

    PubMed Central

    Liu, Yuangang; Guo, Qingsheng; Sun, Yageng; Ma, Xiaoya

    2014-01-01

    Scale reduction from source to target maps inevitably leads to conflicts of map symbols in cartography and geographic information systems (GIS). Displacement is one of the most important map generalization operators and it can be used to resolve the problems that arise from conflict among two or more map objects. In this paper, we propose a combined approach based on constraint Delaunay triangulation (CDT) skeleton and improved elastic beam algorithm for automated building displacement. In this approach, map data sets are first partitioned. Then the displacement operation is conducted in each partition as a cyclic and iterative process of conflict detection and resolution. In the iteration, the skeleton of the gap spaces is extracted using CDT. It then serves as an enhanced data model to detect conflicts and construct the proximity graph. Then, the proximity graph is adjusted using local grouping information. Under the action of forces derived from the detected conflicts, the proximity graph is deformed using the improved elastic beam algorithm. In this way, buildings are displaced to find an optimal compromise between related cartographic constraints. To validate this approach, two topographic map data sets (i.e., urban and suburban areas) were tested. The results were reasonable with respect to each constraint when the density of the map was not extremely high. In summary, the improvements include (1) an automated parameter-setting method for elastic beams, (2) explicit enforcement regarding the positional accuracy constraint, added by introducing drag forces, (3) preservation of local building groups through displacement over an adjusted proximity graph, and (4) an iterative strategy that is more likely to resolve the proximity conflicts than the one used in the existing elastic beam algorithm. PMID:25470727

  14. Low-Cost GNSS Receivers for Local Monitoring: Experimental Simulation, and Analysis of Displacements

    PubMed Central

    Biagi, Ludovico; Grec, Florin Cătălin; Negretti, Marco

    2016-01-01

    The geodetic monitoring of local displacements and deformations is often needed for civil engineering structures and natural phenomena like, for example, landslides. A local permanent GNSS (Global Navigation Satellite Systems) network can be installed: receiver positions in the interest area are estimated and monitored with respect to reference stations. Usually, GNSS geodetic receivers are adopted and provide results with accuracies at the millimeter level: however, they are very expensive and the initial cost and the risk of damage and loss can discourage this approach. In this paper the accuracy and the reliability of low-cost u-blox GNSS receivers are experimentally investigated for local monitoring. Two experiments are analyzed. In the first, a baseline (65 m long) between one geodetic reference receiver and one u-blox is continuously observed for one week: the data are processed by hourly sessions and the results provide comparisons between two processing packages and a preliminary accuracy assessment. Then, a network composed of one geodetic and two u-blox receivers is set up. One u-blox is installed on a device (slide) that allows to apply controlled displacements. The geodetic and the other u-blox (at about 130 m) act as references. The experiment lasts about two weeks. The data are again processed by hourly sessions. The estimated displacements of the u-blox on the slide are analyzed and compared with the imposed displacements. All of the results are encouraging: in the first experiment the standard deviations of the residuals are smaller than 5 mm both in the horizontal and vertical; in the second, they are slightly worse but still satisfactory (5 mm in the horizontal and 13 mm in vertical) and the imposed displacements are almost correctly identified. PMID:27983707

  15. Positive psychotherapy.

    PubMed

    Seligman, Martin E P; Rashid, Tayyab; Parks, Acacia C

    2006-11-01

    Positive psychotherapy (PPT) contrasts with standard interventions for depression by increasing positive emotion, engagement, and meaning rather than directly targeting depressive symptoms. The authors have tested the effects of these interventions in a variety of settings. In informal student and clinical settings, people not uncommonly reported them to be "life-changing." Delivered on the Web, positive psychology exercises relieved depressive symptoms for at least 6 months compared with placebo interventions, the effects of which lasted less than a week. In severe depression, the effects of these Web exercises were particularly striking. This address reports two preliminary studies: In the first, PPT delivered to groups significantly decreased levels of mild-to-moderate depression through 1-year follow-up. In the second, PPT delivered to individuals produced higher remission rates than did treatment as usual and treatment as usual plus medication among outpatients with major depressive disorder. Together, these studies suggest that treatments for depression may usefully be supplemented by exercises that explicitly increase positive emotion, engagement, and meaning. ((c) 2006 APA, all rights reserved).

  16. High-level context effects on spatial displacement: the effects of body orientation and language on memory

    PubMed Central

    Vinson, David W.; Abney, Drew H.; Dale, Rick; Matlock, Teenie

    2014-01-01

    Three decades of research suggests that cognitive simulation of motion is involved in the comprehension of object location, bodily configuration, and linguistic meaning. For example, the remembered location of an object associated with actual or implied motion is typically displaced in the direction of motion. In this paper, two experiments explore context effects in spatial displacement. They provide a novel approach to estimating the remembered location of an implied motion image by employing a cursor-positioning task. Both experiments examine how the remembered spatial location of a person is influenced by subtle differences in implied motion, specifically, by shifting the orientation of the person’s body to face upward or downward, and by pairing the image with motion language that differed on intentionality, fell versus jumped. The results of Experiment 1, a survey-based experiment, suggest that language and body orientation influenced vertical spatial displacement. Results of Experiment 2, a task that used Adobe Flash and Amazon Mechanical Turk, showed consistent effects of body orientation on vertical spatial displacement but no effect of language. Our findings are in line with previous work on spatial displacement that uses a cursor-positioning task with implied motion stimuli. We discuss how different ways of simulating motion can influence spatial memory. PMID:25071628

  17. Active suppression of a beam under a moving mass using a pointwise fiber Bragg grating displacement sensing system.

    PubMed

    Chuang, Kuo-Chih; Ma, Chien-Ching; Wu, Rong-Hua

    2012-10-01

    This paper investigates active vibration control of a beam under a moving mass using a pointwise fiber Bragg grating (FBG) displacement sensing system. Dynamic responses of the proposed FBG displacement sensor are demodulated with an FBG filter and verified with measurement results obtained from a noncontact fiber-optic displacement sensor. System identification of the beam is first performed with a piezoceramic actuator and positive position feedback (PPF) controllers are designed based on the identified results. Then, transient responses of the beam under a moving mass with different moving conditions are measured using the FBG displacement sensor. A high-speed camera is used to detect the speed of the moving mass for further discussions about its influence on the transient response. Finally, active vibration control of the beam under the moving mass is performed and fast Fourier transform (FFT) as well as short-time Fourier transform (STFT) are employed to demonstrate control performances. For the case in which a rolling steel ball is directed from a slide to the beam to generate the moving mass, reductions of the vibration up to 50% and 60% are achieved in the frequency domain for the first and second modes of the beam, respectively. Based on the control experiments on the smallscale beam, results in this work show that the proposed FBG displacement sensing system can be used in research on the moving mass problem.

  18. Doppler displacements in kink MHD waves in solar flux tubes

    NASA Astrophysics Data System (ADS)

    Goossens, Marcel; Van Doorsselaere, Tom; Terradas, Jaume; Verth, Gary; Soler, Roberto

    Doppler displacements in kink MHD waves in solar flux tubes Presenting author: M. Goossens Co-authors: R. Soler, J. Terradas, T. Van Doorsselaere, G. Verth The standard interpretation of the transverse MHD waves observed in the solar atmosphere is that they are non-axisymmetric kink m=1) waves on magnetic flux tubes. This interpretation is based on the fact that axisymmetric and non-axisymmetric fluting waves do not displace the axis of the loop and the loop as a whole while kink waves indeed do so. A uniform transverse motion produces a Doppler displacement that is constant across the magnetic flux tube. A recent development is the observation of Doppler displacements that vary across the loop. The aim of the present contribution is to show that spatial variations of the Doppler displacements across the loop can be caused by kink waves. The motion associated with a kink wave is purely transverse only when the flux tube is uniform and sufficiently thin. Only in that case do the radial and azimuthal components of displacement have the same amplitude and is the azimuthal component a quarter of a period ahead of the radial component. This results in a unidirectional or transverse displacement. When the flux tube is non-uniform and has a non-zero radius the conditions for the generation of a purely transverse motion are not any longer met. In that case the motion in a kink wave is the sum of a transverse motion and a non-axisymmetric rotational motion that depends on the azimuthal angle. It can produce complicated variations of the Doppler displacement across the loop. I shall discuss the various cases of possible Doppler displacenents that can occur depending on the relative sizes of the amplitudes of the radial and azimuthal components of the displacement in the kink wave and on the orientation of the line of sight.

  19. Combined Effects of Mass and Velocity on Forward Displacement and Phenomenological Ratings: A Functional Measurement Approach to the Momentum Metaphor

    ERIC Educational Resources Information Center

    De Sa Teixeira, Nuno; Oliveira, Armando Monica; Amorim, Michel-Ange

    2010-01-01

    Representational Momentum (RepMo) refers to the phenomenon that the vanishing position of a moving target is perceived as displaced ahead in the direction of movement. Originally taken to reflect a strict internalization of physical momentum, the finding that the target implied mass did not have an effect led to its subsequent reinterpretation as…

  20. Vertical displacement threshold sensitivity along the horizontal meridian as a function of stimulus rate, duration, and length.

    PubMed

    Haines, R F; Kiefel, S M

    1988-04-01

    Vertical displacement thresholds (DT) were quantified in 24 observers at the fovea and each of 8 retinal positions out to 80 degrees along the horizontal meridian during binocular viewing. Stimulus length was increased with eccentricity angle in accordance with the cortical magnification factor (21); a 1 degree arc long stimulus served as a control at each position. Three movement durations (from 0.25 to 4 s) and three angular rates (from 0.04 to 0.42 degrees arc.s-1) were also quantified at each position to determine whether peripheral DT is mediated predominantly by an image displacement- or rate-sensitive mechanism. It was found that 1) DT is mediated predominantly by a constant rate-sensitive mechanism at each position when stimulus length is increased in proportion to the cortical magnification factor; 2) mean percent correct displacement judgments decrease significantly into the periphery for both stimulus lengths, however, increasing stimulus length yields significantly higher accuracy; and 3) at 10 and 30 degrees eccentricity, increasing rate and duration significantly improve displacement judgment accuracy, but beyond 40 degrees only lengthening the stimulus improves accuracy. The findings are related to the design optimization of dynamic attitude displays and symbology for aircraft.

  1. Scanning Twyman interferometer for measuring small angular displacement

    NASA Astrophysics Data System (ADS)

    Ma, Jianguo; Tong, Yue

    2010-12-01

    We present a simple but effective method for measuring small angular displacement based on a scanning Twyman interferometer ,in which, one of the two mirrors is mounted on the piezoelectric ceramic (PZT) droved by saw-tooth voltage, the status of interference fringes changes from static to dynamic. A photoelectric detector detects this dynamic photo-signal and changes into electronic signal. The signal is inputted into an oscillograph. The oscillogram will present interference crests. The method for measuring small angular displacement is based on the linear relation between the angular displacement and the crest shift on the oscillogram.

  2. Scanning Twyman interferometer for measuring small angular displacement

    NASA Astrophysics Data System (ADS)

    Ma, Jianguo; Tong, Yue

    2011-05-01

    We present a simple but effective method for measuring small angular displacement based on a scanning Twyman interferometer ,in which, one of the two mirrors is mounted on the piezoelectric ceramic (PZT) droved by saw-tooth voltage, the status of interference fringes changes from static to dynamic. A photoelectric detector detects this dynamic photo-signal and changes into electronic signal. The signal is inputted into an oscillograph. The oscillogram will present interference crests. The method for measuring small angular displacement is based on the linear relation between the angular displacement and the crest shift on the oscillogram.

  3. Optical method of measuring angular displacement using a diffraction pattern.

    PubMed

    Ami, M; Sato, K; Yamamoto, S; Kamada, O; Shibanuma, H

    1987-10-01

    We investigate a method of measuring the angular displacement of an aperture when the diffraction pattern rotates. The data that are on a rectangular coordinate are transformed into the data on a polar coordinate. We calculate a cross-correlation function between the diffraction pattern that is rotated and the reference pattern. When the angular displacement is within +/-5 degrees , the error is <0.050. Then, we calculated the angular displacement of the pattern on a spherical coordinate system by personal computer simulation. Consequently, when the azimuth and the elevation of its rotation axis are within +/-6 degrees , the error is <0.1 degrees .

  4. Method of making self-calibrated displacement measurements

    DOEpatents

    Pedersen, Herbert N.

    1977-01-01

    A method for monitoring the displacement of an object having an acoustically reflective surface at least partially submerged in an acoustically conductive medium. The reflective surface is designed to have a stepped interface responsive to an incident acoustic pulse to provide separate discrete reflected pulses to a receiving transducer. The difference in the time of flight of the reflected acoustic signals corresponds to the known step height and the time of travel of the signals to the receiving transducer provides a measure of the displacement of the object. Accordingly, the reference step length enables simultaneous calibration of each displacement measurement.

  5. An amplitude modulated laser system for distance and displacement measurement

    NASA Technical Reports Server (NTRS)

    Rogowski, Robert S.; Heyman, Joseph S.; Holben, Milford S., Jr.

    1986-01-01

    A laser distance and displacement measurement system is being developed to monitor small displacements in large space structures for strain analysis and structural control. The reflected laser beam is focused on a detector and the detected signal is mixed with the reference. Small displacements are indicated by a change in modulation frequency which is adjusted to maintain quadrature between the received signal and the reference signal from the voltage-controlled oscillator in a phase-locked loop. Measurement of absolute distance is accomplished by sweeping the modulation frequency from a quadrature lock point to an adjacent lock point.

  6. Sternal force-displacement relationship during cardiopulmonary resuscitation.

    PubMed

    Gruben, K G; Guerci, A D; Halperin, H R; Popel, A S; Tsitlik, J E

    1993-05-01

    A viscoelastic model is presented to describe the dynamic response of the human chest to cyclic loading during manual cardiopulmonary resuscitation (CPR). Sternal force and displacement were measured during 16 clinical resuscitation attempts and during compressions on five CPR training manikins. The model was developed to describe the clinical data and consists of the parallel combination of a spring and dashpot. The human chests' elastic and damping properties were both augmented with increasing displacement. The manikins' elastic properties were stiffer and both elastic and damping properties were less dependent on displacement than the humans'.

  7. Investigation of Creep Properties in RAINBOW High Displacement Actuators

    NASA Technical Reports Server (NTRS)

    Haertling, Gene; Furman, Eugene; Li, Guang; Barron, Bret; Moon, Youngwoo

    1997-01-01

    Results from this study on fatigue in Rainbow and Cerambow actuators show that these high displacement actuators have definite fatigue rates and lifetimes depending upon (1) the amount of displacement generated, (2) how hard they are driven electrically, and (3) the microstructure (grain size) of the ceramic material. Lifetimes for some actuators were on the order of 10(exp 7) cycles at near dc (1 Hz) frequencies while others still retained up to 74% of their displacement at 2.1 x 10(exp 7) Hz.

  8. Inhomogeneous phase shifting: an algorithm for nonconstant phase displacements

    SciTech Connect

    Tellez-Quinones, Alejandro; Malacara-Doblado, Daniel

    2010-11-10

    In this work, we have developed a different algorithm than the classical one on phase-shifting interferometry. These algorithms typically use constant or homogeneous phase displacements and they can be quite accurate and insensitive to detuning, taking appropriate weight factors in the formula to recover the wrapped phase. However, these algorithms have not been considered with variable or inhomogeneous displacements. We have generalized these formulas and obtained some expressions for an implementation with variable displacements and ways to get partially insensitive algorithms with respect to these arbitrary error shifts.

  9. The first derivative of the carotid displacement pulse.

    NASA Technical Reports Server (NTRS)

    Khan, A. H.; Spodick, D. H.

    1972-01-01

    The amplitude and time relationships of the carotid derivative in normal individuals and unselected cardiac patients is investigated together with the effects of different contraction strengths in patients with pulsus alternans and subjects challenged with isoproterenol and propranolol. Data regarding the relationship between the preejection period (PEP) and the ratio of peak to total amplitude of the carotid displacement pulse derivative are presented. It is found that cardiac abnormality tends to reduce the rate of rise of the carotid displacement pulse. The results obtained show that the PEP is a somewhat more sensitive index of the changes studied than the carotid displacement derivative.

  10. Effects of joint rate and displacement constraints on stability regions

    NASA Technical Reports Server (NTRS)

    Shrivastava, P. C.

    1987-01-01

    A block diagram showing plant dynamics in normal mode coordinates, a linear feedback controller with command limits, and actuator dynamics with rate and displacement limits is given. The objective is to examine the effects of joint rate and displacement saturation limits on the stability regions. An unstable short period dynamic model is transformed into normal mode coordinates and is augmented with actuator dynamics. A linear feedback controller is used to provide closed-loop stability. The stability with constrained actuator rate limits under varying bandwidth, displacement and command limits is examined.

  11. Helium vs. Proton Induced Displacement Damage in Electronic Materials

    NASA Technical Reports Server (NTRS)

    Ringo, Sawnese; Barghouty, A. F.

    2010-01-01

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

  12. Cockpit Window Edge Proximity Effects on Judgements of Horizon Vertical Displacement

    NASA Technical Reports Server (NTRS)

    Haines, R. F.

    1984-01-01

    To quantify the influence of a spatially fixed edge on vertical displacement threshold, twenty-four males (12 pilots, 12 non-pilots) were presented a series of forced choice, paired comparison trials in which a 32 deg arc wide, thin, luminous horizontal stimulus line moved smoothly downward through five angles from a common starting position within a three second-long period. The five angles were 1.4, 1.7, 2, 2.3, and 2.6 deg. Each angle was presented paired with itself and the other four angles in all combinations in random order. For each pair of trials the observer had to choose which trial possessed the largest displacement. A confidence response also was made. The independent variable was the angular separation between the lower edge of a stable 'window' aperture through which the stimulus was seen to move and the lowest position attained by the stimulus. It was found that vertical displacement accuracy is inversely related to the angle separating the stimulus and the fixed window edge (p = .05). In addition, there is a strong tendency for pilot confidence to be lower than that of non-pilots for each of the three angular separations. These results are discussed in erms of selected cockpit features and as they relate to how pilots judge changes in aircraft pitch attitude.

  13. Palatally displaced maxillary canines: factors influencing duration and cost of treatment.

    PubMed

    Bazargani, Farhan; Magnuson, Anders; Dolati, Ali; Lennartsson, Bertil

    2013-06-01

    The purpose of this retrospective study was to assess the relationship between the initial position of palatally displaced canines (PDCs) on panoramic radiographs and the duration of the orthodontic treatment and further to estimate the costs of the treatment. Data from panoramic radiographs and patient records of 66 consecutive patients (mean age 14.9 ± 1.7 years) with PDC were analysed. The initial position of the canine, the distance between the canine cusp tip and the occlusal plane, and the inclination of the canine were significantly associated with treatment duration both unadjusted and adjusted for background characteristics. The average estimated cost of the treatment of PDC was €3200 per case. The total annual cost for treatment of PDC in Sweden may therefore be estimated at €600,0000. In this study, duration of treatment averaged 17 months for canines displaced in impaction zone 1 or 2, 2.6 [95% confidence interval (CI) -1.0 to 6.2] months longer for those in impaction zone 3, and 7.6 (95% CI 4.1-11.1) months longer for canines displaced in impaction zone 4 or 5. This information makes it easier, through study of the panoramic radiograph, to estimate the duration of treatment and to give patients more precise information about the expected length of their treatment.

  14. Curvature in Arabidopsis inflorescence stems is limited to the region of amyloplast displacement.

    PubMed

    Weise, S E; Kuznetsov, O A; Hasenstein, K H; Kiss, J Z

    2000-06-01

    Gravitropic sensing in stems and stem-like organs is hypothesized to occur in the endodermis. However, since the endodermis runs the entire length of the stem, the precise site of gravisensing has been difficult to define. In this investigation of gravisensitivity in inflorescence stems of Arabidopsis, we positioned stems in a high gradient magnetic field (HGMF) on a rotating clinostat. Approximately 40% of the young, wild-type (WT) inflorescences, for all positions tested, curved toward the HGMF in the vicinity of the stem exposed to the field. In contrast, when the wedge was placed in the basal region of older inflorescence stems, no curvature was observed. As a control, the HGMF was applied to a starchless mutant, and 5% of the stems curved toward the field. Microscopy of the endodermis in the WT showed amyloplast displacement in the vicinity of the HGMF. Additional structural studies demonstrated that the basal region of WT stems experienced amyloplast displacement and, therefore, suggest this region is capable of gravity perception. However, increased lignification likely prevented curvature in the basal region. The lack of apical curvature after basal amyloplast displacement indicates that gravity perception in the base is not transmitted to the apex. Thus, these results provide evidence that the signal (and thus, response) resulting from perception in Arabidopsis inflorescence stems is spatially restricted.

  15. Curvature in Arabidopsis inflorescence stems is limited to the region of amyloplast displacement

    NASA Technical Reports Server (NTRS)

    Weise, S. E.; Kuznetsov, O. A.; Hasenstein, K. H.; Kiss, J. Z.

    2000-01-01

    Gravitropic sensing in stems and stem-like organs is hypothesized to occur in the endodermis. However, since the endodermis runs the entire length of the stem, the precise site of gravisensing has been difficult to define. In this investigation of gravisensitivity in inflorescence stems of Arabidopsis, we positioned stems in a high gradient magnetic field (HGMF) on a rotating clinostat. Approximately 40% of the young, wild-type (WT) inflorescences, for all positions tested, curved toward the HGMF in the vicinity of the stem exposed to the field. In contrast, when the wedge was placed in the basal region of older inflorescence stems, no curvature was observed. As a control, the HGMF was applied to a starchless mutant, and 5% of the stems curved toward the field. Microscopy of the endodermis in the WT showed amyloplast displacement in the vicinity of the HGMF. Additional structural studies demonstrated that the basal region of WT stems experienced amyloplast displacement and, therefore, suggest this region is capable of gravity perception. However, increased lignification likely prevented curvature in the basal region. The lack of apical curvature after basal amyloplast displacement indicates that gravity perception in the base is not transmitted to the apex. Thus, these results provide evidence that the signal (and thus, response) resulting from perception in Arabidopsis inflorescence stems is spatially restricted.

  16. Interfraction Displacement of Primary Tumor and Involved Lymph Nodes Relative to Anatomic Landmarks in Image Guided Radiation Therapy of Locally Advanced Lung Cancer

    SciTech Connect

    Jan, Nuzhat; Balik, Salim; Hugo, Geoffrey D.; Mukhopadhyay, Nitai; Weiss, Elisabeth

    2014-01-01

    Purpose: To analyze primary tumor (PT) and lymph node (LN) position changes relative to each other and relative to anatomic landmarks during conventionally fractionated radiation therapy for patients with locally advanced lung cancer. Methods and Materials: In 12 patients with locally advanced non-small cell lung cancer PT, LN, carina, and 1 thoracic vertebra were manually contoured on weekly 4-dimensional fan-beam CT scans. Systematic and random interfraction displacements of all contoured structures were identified in the 3 cardinal directions, and resulting setup margins were calculated. Time trends and the effect of volume changes on displacements were analyzed. Results: Three-dimensional displacement vectors and systematic/random interfraction displacements were smaller for carina than for vertebra both for PT and LN. For PT, mean (SD) 3-dimensional displacement vectors with carina-based alignment were 7 (4) mm versus 9 (5) mm with bony anatomy (P<.0001). For LN, smaller displacements were found with carina- (5 [3] mm, P<.0001) and vertebra-based (6 [3] mm, P=.002) alignment compared with using PT for setup (8 [5] mm). Primary tumor and LN displacements relative to bone and carina were independent (P>.05). Displacements between PT and bone (P=.04) and between PT and LN (P=.01) were significantly correlated with PT volume regression. Displacements between LN and carina were correlated with LN volume change (P=.03). Conclusions: Carina-based setup results in a more reproducible PT and LN alignment than bony anatomy setup. Considering the independence of PT and LN displacement and the impact of volume regression on displacements over time, repeated CT imaging even with PT-based alignment is recommended in locally advanced disease.

  17. Uncovering deformation processes from surface displacements

    NASA Astrophysics Data System (ADS)

    Stramondo, Salvatore

    2013-04-01

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

  18. Micro-displacement sensor with multimode fused coupler and concave mirror

    NASA Astrophysics Data System (ADS)

    Harun, S. W.; Yasin, M.; Ahmad, H.

    2011-04-01

    Fiber optic displacement sensor is demonstrated using a multimode fused coupler probe and a concave mirror target. It is observed that a focal length of the concave mirror make a significant influence to the displacement response, which illustrates three linear slopes with the second slope peaks at the position that is in vicinity of two times of the focal length. The highest sensitivity of 0.56 mV/mm is obtained with an infinity focal length and it is decreased as the focal length of the concave mirror decreases. The widest linear range of approximately 3.3 mm is observed in the third slope region with focal length of 6.0 mm. The highest linear range obtained with the use of 50:50 coupler.

  19. Application of Blue Laser Triangulation Sensors for Displacement Measurement Through Fire.

    PubMed

    Hoehler, Matthew S; Smith, Christopher M

    2016-11-01

    This paper explores the use of blue laser triangulation sensors to measure displacement of a target located behind or in the close proximity of natural gas diffusion flames. This measurement is critical for providing high-quality data in structural fire tests. The position of the laser relative to the flame envelope can significantly affect the measurement scatter, but has little influence on the mean values. We observe that the measurement scatter is normally distributed and increases linearly with the distance of the target from the flame along the beam path. Based on these observations, we demonstrate how time-averaging can be used to achieve a standard uncertainty associated with the displacement error of less than 0.1 mm, which is typically sufficient for structural fire testing applications. Measurements with the investigated blue laser sensors were not impeded by the thermal radiation emitted from the flame or the soot generated from the relatively clean-burning natural gas.

  20. Kicking the (barking) dog effect: the moderating role of target attributes on triggered displaced aggression.

    PubMed

    Pedersen, William C; Bushman, Brad J; Vasquez, Eduardo A; Miller, Norman

    2008-10-01

    Sometimes aggression is displaced onto a target who is not totally innocent but emits a mildly irritating behavior called a triggering event. In three experiments, the authors examine stable personal attributes of targets that can impact such triggered displaced aggression (TDA). Lower levels of TDA were directed to targets whose attitudes were similar as compared to dissimilar to those of the actor (Experiment 1) and to targets who were ingroup as compared to out-group members (Experiment 2). Conceptually replicating the findings of Experiments 1 and 2, the manipulated valence of the target (viz., liked, neutral, and disliked) functioned in a similar manner, with positive valence serving a buffering function against a triggering action that followed an initial provocation (Experiment 3). The results from all three experiments are consistent with cognitive neoassociationist theory.

  1. The effects of gamma irradiation on neutron displacement sensitivity of lateral PNP bipolar transistors

    NASA Astrophysics Data System (ADS)

    Wang, Chenhui; Chen, Wei; Liu, Yan; Jin, Xiaoming; Yang, Shanchao; Qi, Chao

    2016-09-01

    The effects of gamma irradiation on neutron displacement sensitivity of four types of lateral PNP bipolar transistors (LPNPs) with different neutral base widths, emitter widths and the doping concentrations of the epitaxial base region are studied. The physical mechanisms of the effects are explored by defect analysis using deep level transient spectroscopy (DLTS) techniques and numerical simulations of recombination process in the base region of the lateral PNP bipolar transistors, and are verified by the experiments on gate-controlled lateral PNP bipolar transistors (GCLPNPs) manufactured in the identical commercial bipolar process with different gate bias voltage. The results indicate that gamma irradiation increases neutron displacement damage sensitivity of lateral PNP bipolar transistors and the mechanism of this phenomenon is that positive charge induced by gamma irradiation enhances the recombination process in the defects induced by neutrons in the base region, leading to larger recombination component of base current and greater gain degradation.

  2. The use of a prosthetic tissue expander to displace bowel from a brachytherapy implant site

    SciTech Connect

    Armstrong, J.G.; Harrison, L.B.; Dattoli, M.; Concepcion, R.; Minsky, B.D.; Fortner, J. )

    1990-12-01

    We describe the use of a prosthetic maneuver to displace bowel from an implant site. The patient presented with a recurrent low grade fibrosarcoma which was grossly excised with positive microscopic margins in the right paravertebral area. For this reason we performed an Iridium-192 implant using afterloading catheters. Because of several dense adhesions, it was not possible to mobilize an omental sling over the implant site. To prevent the small bowel from lying on the catheters, we inserted a prosthetic breast tissue expander. This was expanded with saline and bacitracin solution and placed in the tumor bed overlying the catheters, thereby displacing the small bowel away from the sources. A postoperative CT scan with gastrograffin demonstrated that this procedure was effective. There were no complications. We conclude that such devices are suitable for use under these circumstances and can achieve the objective of decreasing the dose of radiation to the small bowel.

  3. Application of blue laser triangulation sensors for displacement measurement through fire

    NASA Astrophysics Data System (ADS)

    Hoehler, Matthew S.; Smith, Christopher M.

    2016-11-01

    This paper explores the use of blue laser triangulation sensors to measure displacement of a target located behind or in the close proximity of natural gas diffusion flames. This measurement is critical for providing high-quality data in structural fire tests. The position of the laser relative to the flame envelope can significantly affect the measurement scatter, but has little influence on the mean values. We observe that the measurement scatter is normally distributed and increases linearly with the distance of the target from the flame along the beam path. Based on these observations, we demonstrate how time-averaging can be used to achieve a standard uncertainty associated with the displacement error of less than 0.1 mm, which is typically sufficient for structural fire testing applications. Measurements with the investigated blue laser sensors were not impeded by the thermal radiation emitted from the flame or the soot generated from the relatively clean-burning natural gas.

  4. Bedrock displacements in Greenland manifest ice mass variations, climate cycles and climate change

    PubMed Central

    Bevis, Michael; Wahr, John; Khan, Shfaqat A.; Madsen, Finn Bo; Brown, Abel; Willis, Michael; Kendrick, Eric; Knudsen, Per; Box, Jason E.; van Dam, Tonie; Caccamise, Dana J.; Johns, Bjorn; Nylen, Thomas; Abbott, Robin; White, Seth; Miner, Jeremy; Forsberg, Rene; Zhou, Hao; Wang, Jian; Wilson, Terry; Bromwich, David; Francis, Olivier

    2012-01-01

    The Greenland GPS Network (GNET) uses the Global Positioning System (GPS) to measure the displacement of bedrock exposed near the margins of the Greenland ice sheet. The entire network is uplifting in response to past and present-day changes in ice mass. Crustal displacement is largely accounted for by an annual oscillation superimposed on a sustained trend. The oscillation is driven by earth’s elastic response to seasonal variations in ice mass and air mass (i.e., atmospheric pressure). Observed vertical velocities are higher and often much higher than predicted rates of postglacial rebound (PGR), implying that uplift is usually dominated by the solid earth’s instantaneous elastic response to contemporary losses in ice mass rather than PGR. Superimposed on longer-term trends, an anomalous ‘pulse’ of uplift accumulated at many GNET stations during an approximate six-month period in 2010. This anomalous uplift is spatially correlated with the 2010 melting day anomaly. PMID:22786931

  5. Long-delayed bright dancing sprite with large horizontal displacement from its parent flash

    NASA Astrophysics Data System (ADS)

    Yang, J.; Lu, G.; Lee, L. J.; Feng, G.

    2015-12-01

    A long-delayed very bright dancing sprite with large horizontal displacement from its parent flash was observed. The dancing sprite lasted only 60 ms, and the morphology consisted of three fields with two slim dim sprite elements in the first two fields and a very bright large sprite element in the third field, different from other observations. The bright sprite displaced at least 38 km from its parent flash and occurred over comparatively higher cloud top region. The parent flash was positive, with only one return stroke (~24 kA) and obvious continuing current process, and the charge moment change of the stroke was small (roughly the threshold for sprite production). All of the sprite elements occurred during the continuing current period, and the bright sprite induced considerable current. The sprite dancing features may be linked to parent storm electrical structure, dynamics and microphysics, and the parent CG discharge process which was consistent with VHF observations.

  6. 24 CFR 574.630 - Displacement, relocation and real property acquisition.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... under this part. (b) Relocation assistance for displaced persons. A displaced person (defined in... displaced person. (1) For purposes of this section, the term “displaced person” means a person (family... not qualify as a “displaced person” (and is not eligible for relocation assistance under the URA...

  7. Positive Psychologists on Positive Constructs

    ERIC Educational Resources Information Center

    Lyubomirsky, Sonja

    2012-01-01

    Comments on the original article by McNulty and Fincham (see record 2011-15476-001). In their article, the authors offered compelling evidence that constructs such as forgiveness and optimism can have both beneficial and adverse consequences, depending on the context. Their caution about labeling particular psychological processes as "positive" is…

  8. Characterization of displaced bipolar cells in the tiger salamander retina.

    PubMed

    Maple, Bruce R; Zhang, Jian; Pang, Ji-Jie; Gao, Fan; Wu, Samuel M

    2005-03-01

    In immunocytochemical studies of the tiger salamander retina, 17% of neurons in the outer nuclear layer did not label for recoverin, a photoreceptor marker. Lucifer yellow injection showed a population of cells in the ONL to be displaced bipolar cells, with axon terminals that stratified exclusively in the OFF sublamina of the inner plexiform layer (IPL), and predominately within the cone-dominated region of the OFF sublamina. Glutamate generated a dendritic cationic conductance increase in all displaced bipolar cells tested, and typical cone-dominated bipolar cell light responses were observed among displaced cells that stratified in the central IPL. We conclude that displaced bipolar cells in the tiger salamander retina are entirely OFF-center cells, and predominately cone-dominated cells.

  9. Electron-Induced Displacement Damage Effects in CCDs

    NASA Technical Reports Server (NTRS)

    Becker, Heidi N.; Elliott, Tom; Alexander, James W.

    2006-01-01

    We compare differences in parametric degradation for CCDs irradiated to the same displacement damage dose with 10-MeV and 50-MeV electrons. Charge transfer efficiency degradation was observed to not scale with NIEL for small signals.

  10. Analysis of variance of an underdetermined geodetic displacement problem

    SciTech Connect

    Darby, D.

    1982-06-01

    It has been suggested recently that point displacements in a free geodetic network traversing a strike-slip fault may be estimated from repeated surveys by minimizing only those displacement components normal to the strike. It is desirable to justify this procedure. We construct, from estimable quantities, a deformation parameter which is an F-statistic of the type occurring in the analysis of variance of linear models not of full rank. A test of its significance provides the criterion to justify the displacement solution. It is also interesting to study its behaviour as one varies the supposed strike of the fault. Justification of a displacement solution using data from a strike-slip fault is found, but not for data from a rift valley. The technique can be generalized to more complex patterns of deformation such as those expected near the end-zone of a fault in a dislocation model.

  11. 24 CFR 886.338 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... owner shall maintain data on the race, ethnic, gender, and handicap status of displaced persons. (g... Payments Contract. (Approved by the Office of Management and Budget under OMB Control Number 2506-0121)...

  12. 24 CFR 886.338 - Displacement, relocation, and acquisition.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... owner shall maintain data on the race, ethnic, gender, and handicap status of displaced persons. (g... Payments Contract. (Approved by the Office of Management and Budget under OMB Control Number 2506-0121)...

  13. Detection and magnification of bridge displacements using video images

    NASA Astrophysics Data System (ADS)

    Terán, Leticia; Ordóñez, Celestino; García-Cortés, Silverio; Menéndez, Agustín.

    2016-11-01

    Monitoring displacements on some structures such as large bridges is essential to study their structural performance in order to avoid severe damage or even their collapse. In this work, we use images obtained with digital video cameras to estimate the displacements of a metallic bridge by means of cross-correlation. Thus, it was possible to detect millimetric displacements for distances between the camera and the bridge upper ten meters. In order to obtain a better representation of the structural displacements along the bridge and its modal shapes, a technique of video magnification was also applied. The results obtained show that the combination of both techniques can provide relevant information for a structural analysis of the bridge.

  14. Do chimpanzees (Pan troglodytes) understand single invisible displacement?

    PubMed

    Collier-Baker, Emma; Davis, Joanne M; Nielsen, Mark; Suddendorf, Thomas

    2006-01-01

    Previous research suggests that chimpanzees understand single invisible displacement. However, this Piagetian task may be solvable through the use of simple search strategies rather than through mentally representing the past trajectory of an object. Four control conditions were thus administered to two chimpanzees in order to separate associative search strategies from performance based on mental representation. Strategies involving experimenter cue-use, search at the last or first box visited by the displacement device, and search at boxes adjacent to the displacement device were systematically controlled for. Chimpanzees showed no indications of utilizing these simple strategies, suggesting that their capacity to mentally represent single invisible displacements is comparable to that of 18-24-month-old children.

  15. Potential displacement of petroleum imports by solar energy technologies

    NASA Astrophysics Data System (ADS)

    Deleon, P.; Jackson, B. L.; McNown, R. F.; Mahrenholz, G. J.

    1980-05-01

    The United States currently imports close to half of its petroleum requirements. The economic, social, and political costs of a foreign oil dependency are discussed. Development of alternative, domestic energy sources, such as solar energy technologies, which can displace foreign petroleum is discussed. It is estimated that by the year 2000, solar energy technologies can displace 3.6 quads of petroleum. This figure includes solar energy applications in utilities, industrial and agricultural process heat, and transportation. The estimate can be treated as a lower bound; if the United States were to achieve the proposed goal of 20 quads by 2000, the amount of displaced oil probably would be greater. Although all the displaced oil would not be imported, the reduction in imported petroleum would relieve many of the conditions that increase the present cost of foreign oil to the American consumer.

  16. Health outcomes of crisis driven urban displacement: A conceptual framework

    PubMed Central

    Deola, Claudio; Patel, Ronak B

    2014-01-01

    With urbanisation, cities are increasingly home to greater proportions of the world's population. As this transition has significant implications on human health, the epidemiology of diseases among relatively stable urban populations is growing. As humanitarian crises increasingly drive people to urban centers rather than traditional refugee camps, however, rapid and massive urban displacements will increase in frequency. This paper explores the idea that such urban displacements combine epidemiological features of forced migration, slum conditions and humanitarian disaster contexts. This paper highlights the lack of primary data and the consequent paucity of solid epidemiological literature in the aftermath of rapid massive urban displacements. A framework of health outcomes in urban displacement drawing from the above 3 phenomenon is presented and avenues for improved epidemiologic work described. PMID:28229003

  17. Research and development of novel wireless digital capacitive displacement sensor

    NASA Astrophysics Data System (ADS)

    Cui, Junning; He, Zhangqiang; Sun, Tao; Bian, Xingyuan; Han, Lu

    2015-02-01

    In order to solve the problem of noncontact, wireless and nonmagnetic displacement sensing with nanometer resolution within critical limited space for ultraprecision displacement monitoring in the Joule balance device, a novel wireless digital capacitive displacement sensor (WDCDS) is proposed. The WDCDS is fabricated with brass and other nonmagnetic material and powered with a small battery inside, a small integrated circuit is assembled inside for converting and processing of capacitive signal, and low power Bluetooth is used for wireless signal transmission and communication. Experimental results show that the WDCDS proposed has a resolution of better than 1nm and a nonlinearity of 0.077%, therefore it is a delicate design for ultraprecision noncontact displacement monitoring in the Joule balance device, meeting the demand for properties of wireless, nonmagnetic and miniaturized size.

  18. Investigation of nonradiative recombination in semiconductors by photothermal displacement spectroscopy

    SciTech Connect

    Dersch, H.; Amer, N.M.

    1985-06-01

    The dynamics of nonradiative recombination processes are investigated by measuring the thermal expansion and subsequent displacement of a sample surface caused by the absorption of a modulated laser beam. 6 refs., 3 figs.

  19. Transducer senses displacements of panels subjected to vibration

    NASA Technical Reports Server (NTRS)

    Pea, R. O.

    1965-01-01

    Inductive vibration sensor measures the surface displacement of nonferrous metal panels subjected to vibration or flutter. This transducer does not make any physical contact with the test panel when measuring.

  20. Conventional and Microwave Joining of Silicon Carbide Using Displacement Reactions

    NASA Technical Reports Server (NTRS)

    Kingsley, J.; Yiin, T.; Barmatz, M.

    1995-01-01

    Microwave heating was used to join Silicon Carbide rods using a thin TiC /Si tape interlayer . Microwaves quickly heated the rods and tape to temperatures where solid-state displacement reactions between TiC and Si occurred.