Science.gov

Sample records for air motion measurement

  1. Calibration of NASA Turbulent Air Motion Measurement System

    NASA Technical Reports Server (NTRS)

    Barrick, John D. W.; Ritter, John A.; Watson, Catherine E.; Wynkoop, Mark W.; Quinn, John K.; Norfolk, Daniel R.

    1996-01-01

    A turbulent air motion measurement system (TAMMS) was integrated onboard the Lockheed 188 Electra airplane (designated NASA 429) based at the Wallops Flight Facility in support of the NASA role in global tropospheric research. The system provides air motion and turbulence measurements from an airborne platform which is capable of sampling tropospheric and planetary boundary-layer conditions. TAMMS consists of a gust probe with free-rotating vanes mounted on a 3.7-m epoxy-graphite composite nose boom, a high-resolution inertial navigation system (INS), and data acquisition system. A variation of the tower flyby method augmented with radar tracking was implemented for the calibration of static pressure position error and air temperature probe. Additional flight calibration maneuvers were performed remote from the tower in homogeneous atmospheric conditions. System hardware and instrumentation are described and the calibration procedures discussed. Calibration and flight results are presented to illustrate the overall ability of the system to determine the three-component ambient wind fields during straight and level flight conditions.

  2. Comparison of computed and measured air motion in circular and square piston cups

    SciTech Connect

    McKinley, T.L.; Primus, R.J.; O'Rourke, P.J.; Butler, T.D

    1988-01-01

    A multi-dimensional flow code was used to predict the motoring air motion in an engine with both circular and square piston cups. The program solved the Navier-Stokes equations, supplemented with a /kappa/-e turbulence model. The computational results were compared to recently published cycle-resolved LDV measurements for the same engine geometry. It was found that the predicted means radial and tangential velocity distributions agreed well with the measurements. The predicted and measured turbulence intensities were also in good agreement prior to TDC. However, during the expansion stroke the computed turbulence intensities were much higher than the experimental values. These differences were related to reverse squish effects shortly after TDC. The response of the model to the change from circular to square piston geometries was also in agreement with the experimental data.

  3. The development of an air motion measurement system for NASA's Electra aircraft

    NASA Technical Reports Server (NTRS)

    Ritter, J.; Beck, S.; Hedgepeth, R.; Barrick, J.; Butler, C.

    1987-01-01

    The development of the Turbulent Air Motion Measurement System (TAMMS), which is to measure dynamical and photochemical processes over a wide range of spatial and temporal scales, is examined. The composition and operation of the TAMMS subsystems, which include (1) fast-response meteorological sensors; (2) a boom/inertial navigation system; (3) baseline meteorological sensors; (4) an analog/digital interface; (5) control and data acquisition; and (6) data/reduction and spectral analysis software, are described. The planned flight testing and calibration of the TAMMS are discussed. The TAMMS platform wil be able to estimate the turbulent fluxes of heat, moisture, momentum, and any chemical species for which fast-response instrumentation is available.

  4. Measuring mandibular motions

    NASA Technical Reports Server (NTRS)

    Dimeff, J.; Rositano, S.; Taylor, R. C.

    1977-01-01

    Mandibular motion along three axes is measured by three motion transducers on floating yoke that rests against mandible. System includes electronics to provide variety of outputs for data display and processing. Head frame is strapped to test subject's skull to provide fixed point of reference for transducers.

  5. On helical vortex motions of moist air

    NASA Astrophysics Data System (ADS)

    Kurgansky, M. V.

    2013-09-01

    Two results that are fundamentally different from what takes place in a dry atmosphere have been obtained for adiabatic motions of unsaturated moist air: (1) the steady helical motion of moist air with collinear velocity and vorticity vectors everywhere is dynamically impossible; (2) the spontaneous amplification (generation) of helicity in a moist air due to baroclinicity is dynamically and thermodynamically feasible. In the absence of helicity flux through the boundary of the domain occupied by air flows, the difference between the values of integral helicity H at time instant t delaying at a small time interval from the initial instant t 0 (at which the instantaneous state of air motion is isomorphic either to a steady Beltrami flow or to an irrotational flow) and the initial value of H increases proportionally to ( t - t 0)4. The nonzero value of the proportionality factor is ensured by the difference in values of the Poisson ratio for dry air and water vapor, respectively.

  6. Theory and operation of the Gould 32/27 programs ABLE-2A and EBLE for the tropospheric air motion measurement system

    NASA Technical Reports Server (NTRS)

    Butler, C.

    1986-01-01

    Software development for the Trospheric Air Motion Measurement Systems (TAMMS) is documented. In July/August the TAMMS was flown on the NASA/Goddard Flight Center Electra aircraft for 19 mission for the ABLE-2A (Amazon Boundary Layer Experiment) in Brazil. In December 1985, several flights were performed to assess the contamination and boundary layer of the Electra. Position data, flow angles, pressure transducer measurements were recorded. The programs written for the ABLE-2A were modified due to timing considerations for this particular program. The 3-step programs written for EBLE (Electra Boundary Layer Experiment) are described. Power up and log-on procedures are discussed. A few editing techniques are described for modification of the programs.

  7. Motion of Air Bubbles in Water Subjected to Microgravity Accelerations

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard; Kelly, Eric M.; Hrovat, Kenneth; Nelson, Emily S.; Pettit, Donald R.

    2006-01-01

    The International Space Station (ISS) serves as a platform for microgravity research for the foreseeable future. A microgravity environment is one in which the effects of gravity are drastically reduced which then allows physical experiments to be conducted without the over powering effects of gravity. During his 6-month stay on the ISS, astronaut Donald R. Pettit performed many informal/impromptu science experiments with available equipment. One such experiment focused on the motion of air bubbles in a rectangular container nearly filled with de-ionized water. Bubbles were introduced by shaking and then the container was secured in place for several hours while motion of the bubbles was recorded using time-lapse photography. This paper shows correlation between bubble motion and quasi-steady acceleration levels during one such experiment operation. The quasi-steady acceleration vectors were measured by the Microgravity Acceleration Measurement System (MAMS). Essentially linear motion was observed in the condition considered here. Dr. Pettit also created other conditions which produced linear and circulating motion, which are the subjects of further study. Initial observations of this bubble motion agree with calculations from many microgravity physical science experiments conducted on shuttle microgravity science missions. Many crystal-growth furnaces involve heavy metals and high temperatures in which undesired acceleration-driven convection during solidification can adversely affect the crystal. Presented in this paper will be results showing correlation between bubble motion and the quasi-steady acceleration vector.

  8. Motion of Air Bubbles in Water Subjected to Microgravity Accelerations

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard; Kelly, Eric M.; Hrovar, Kenneth; Nelson, Emily S.; Pettit, Donald R.

    2004-01-01

    The International Space Station (ISS) serves as a platform for microgravity research for the foreseeable future. A microgravity environment is one in which the effects of gravity are drastically reduced which then allows physical experiments to be conducted without the overpowering effects of gravity. During his six month stay on the ISS, astronaut Donald R Pettit performed many informal/impromptu science experiments with available equipment. One such experiment focused on the motion of air bubbles in a rectangular container nearly filled with de-ionized water. Bubbles were introduced by shaking and the container was secured in place for several hours while motion of the bubbles were recorded using time-lapse photography. This paper shows correlation between bubble motion and quasi-steady acceleration levels during one such experiment operation. The quasi-steady acceleration vectors were measured by the Microgravity Acceleration Measurement System. Essentially linear motion was observed in the condition considered here. Dr. Pettit also created other conditions which produced linear and circulating motion, which are the subjects of further study. Initial observations of this bubble motion agree with calculations from many microgravity physical science experiments conducted on Shuttle microgravity science missions. Many crystal-growth furnaces involve heavy metals and high temperatures in which undesired acceleration-driven convection during solidification can adversely affect the crystal. Presented in this paper will be results showing correlation between bubble motion and the quasi-steady acceleration vector.

  9. Interferometric measurement of angular motion

    NASA Astrophysics Data System (ADS)

    Peña Arellano, Fabián Erasmo; Panjwani, Hasnain; Carbone, Ludovico; Speake, Clive C.

    2013-04-01

    This paper describes the design and realization of a homodyne polarization interferometer for measuring angular motion. The optical layout incorporates carefully designed cat's eye retroreflectors that maximize the measurable range of angular motion and facilitate initial alignment. The retroreflectors are optimized and numerically characterized in terms of defocus and spherical aberrations using Zemax software for optical design. The linearity of the measurement is then calculated in terms of the aberrations. The actual physical interferometer is realized as a compact device with optical components from stock and without relying on adjustable holders. Evaluation of its performance using a commercial autocollimator confirmed a reproducibility within 0.1%, a non-linearity of less than 1 ppm with respect to the autocollimator, an upper limit to its sensitivity of about 5 × 10-11 rad/sqrt{textrm {Hz}} from audioband down to 100 mHz and an angular measurement range of more than ±1°.

  10. Air motion determination by tracking humidity patterns in isentropic layers

    NASA Technical Reports Server (NTRS)

    Mancuso, R. L.; Hall, D. J.

    1975-01-01

    Determining air motions by tracking humidity patterns in isentropic layers was investigated. Upper-air rawinsonde data from the NSSL network and from the AVE-II pilot experiment were used to simulate temperature and humidity profile data that will eventually be available from geosynchronous satellites. Polynomial surfaces that move with time were fitted to the mixing-ratio values of the different isentropic layers. The velocity components of the polynomial surfaces are part of the coefficients that are determined in order to give an optimum fitting of the data. In the mid-troposphere, the derived humidity motions were in good agreement with the winds measured by rawinsondes so long as there were few or no clouds and the lapse rate was relatively stable. In the lower troposphere, the humidity motions were unreliable primarily because of nonadiabatic processes and unstable lapse rates. In the upper troposphere, the humidity amounts were too low to be measured with sufficient accuracy to give reliable results. However, it appears that humidity motions could be used to provide mid-tropospheric wind data over large regions of the globe.

  11. Characteristics of vertical air motion in isolated convective clouds

    NASA Astrophysics Data System (ADS)

    Yang, Jing; Wang, Zhien; Heymsfield, Andrew J.; French, Jeffrey R.

    2016-08-01

    The vertical velocity and air mass flux in isolated convective clouds are statistically analyzed using aircraft in situ data collected from three field campaigns: High-Plains Cumulus (HiCu) conducted over the midlatitude High Plains, COnvective Precipitation Experiment (COPE) conducted in a midlatitude coastal area, and Ice in Clouds Experiment-Tropical (ICE-T) conducted over a tropical ocean. The results show that small-scale updrafts and downdrafts (< 500 m in diameter) are frequently observed in the three field campaigns, and they make important contributions to the total air mass flux. The probability density functions (PDFs) and profiles of the observed vertical velocity are provided. The PDFs are exponentially distributed. The updrafts generally strengthen with height. Relatively strong updrafts (> 20 m s-1) were sampled in COPE and ICE-T. The observed downdrafts are stronger in HiCu and COPE than in ICE-T. The PDFs of the air mass flux are exponentially distributed as well. The observed maximum air mass flux in updrafts is of the order 104 kg m-1 s-1. The observed air mass flux in the downdrafts is typically a few times smaller in magnitude than that in the updrafts. Since this study only deals with isolated convective clouds, and there are many limitations and sampling issues in aircraft in situ measurements, more observations are needed to better explore the vertical air motion in convective clouds.

  12. Remote air pollution measurement

    NASA Technical Reports Server (NTRS)

    Byer, R. L.

    1975-01-01

    This paper presents a discussion and comparison of the Raman method, the resonance and fluorescence backscatter method, long path absorption methods and the differential absorption method for remote air pollution measurement. A comparison of the above remote detection methods shows that the absorption methods offer the most sensitivity at the least required transmitted energy. Topographical absorption provides the advantage of a single ended measurement, and differential absorption offers the additional advantage of a fully depth resolved absorption measurement. Recent experimental results confirming the range and sensitivity of the methods are presented.

  13. Nocturnal wave-like air motion in forests

    NASA Astrophysics Data System (ADS)

    Hu, Xinzhang

    2001-09-01

    Although the wave-like air motion has been frequently observed near the treetops on clear nights, its flow structure and the nixing property remain largely unknown. A through knowledge of this type of motion will be beneficial to the measurement of the forest-atmosphere exchange of gases. The objectives of this dissertation are (1) to investigate the two-dimensional wave structure by analyzing the field observation; (2) to investigate the effect of the canopy drag on the wave dynamics with a two-layered linear wave model and a two-dimensional numerical wave model. The time-height analysis of the field observation illustrates that the wave-like motion bears resemblance to a Kelvin-Helmholtz (KH) wave. The temperature field and the polarization relation between the fluctuating velocities are similar to those of a KH wave at its growing and saturated stages. During the wave events, erratic flux-gradient relations have been found, sometimes associated with the statically unstable structure in the overturning waves. It is postulated that the wave-like motion has certain mixing ability. However, this mixing cannot be satisfactorily quantified by the current instrument setup. The two-layered linear model has been developed to investigate the effect of the canopy drag. It shows that, by modifying the growth rate, the canopy drag can either stabilize or destabilize the flow. A new type of instability has been found solely because of introducing the canopy drag to the otherwise stable background flow. Contrary to the common wisdom that the canopy drag will damp out any types of motion, the model indicates that forest canopies are actually favorable to the occurrence of the wave-like motion. Furthermore, the two-dimensional flow structure of the wave-like motion has been reproduced with a numerical model. With a simple turbulence closure scheme, the growth of a small disturbance to a finite-amplitude wave in a prescribed background has been computed. The computed flow

  14. Sensing Movement: Microsensors for Body Motion Measurement

    PubMed Central

    Zeng, Hansong; Zhao, Yi

    2011-01-01

    Recognition of body posture and motion is an important physiological function that can keep the body in balance. Man-made motion sensors have also been widely applied for a broad array of biomedical applications including diagnosis of balance disorders and evaluation of energy expenditure. This paper reviews the state-of-the-art sensing components utilized for body motion measurement. The anatomy and working principles of a natural body motion sensor, the human vestibular system, are first described. Various man-made inertial sensors are then elaborated based on their distinctive sensing mechanisms. In particular, both the conventional solid-state motion sensors and the emerging non solid-state motion sensors are depicted. With their lower cost and increased intelligence, man-made motion sensors are expected to play an increasingly important role in biomedical systems for basic research as well as clinical diagnostics. PMID:22346595

  15. Sensing movement: microsensors for body motion measurement.

    PubMed

    Zeng, Hansong; Zhao, Yi

    2011-01-01

    Recognition of body posture and motion is an important physiological function that can keep the body in balance. Man-made motion sensors have also been widely applied for a broad array of biomedical applications including diagnosis of balance disorders and evaluation of energy expenditure. This paper reviews the state-of-the-art sensing components utilized for body motion measurement. The anatomy and working principles of a natural body motion sensor, the human vestibular system, are first described. Various man-made inertial sensors are then elaborated based on their distinctive sensing mechanisms. In particular, both the conventional solid-state motion sensors and the emerging non solid-state motion sensors are depicted. With their lower cost and increased intelligence, man-made motion sensors are expected to play an increasingly important role in biomedical systems for basic research as well as clinical diagnostics. PMID:22346595

  16. Comparison of Motion Blur Measurement Methods

    NASA Technical Reports Server (NTRS)

    Watson, Andrew B.

    2008-01-01

    Motion blur is a significant display property for which accurate, valid measurement methods are needed. Recent measurements of a set of eight displays by a set of six measurement devices provide an opportunity to evaluate techniques of measurement and of the analysis of those measurements.

  17. Flight Simulator Platform Motion and Air Transport Pilot Training

    NASA Technical Reports Server (NTRS)

    Lee, Alfred T.; Bussolari, Steven R.

    1989-01-01

    The influence of flight simulator platform motion on pilot training and performance was examined In two studies utilizing a B-727-200 aircraft simulator. The simulator, located at Ames Research Center, Is certified by the FAA for upgrade and transition training in air carrier operations. Subjective ratings and objective performance of experienced B-727 pilots did not reveal any reliable effects of wide variations In platform motion de- sign. Motion platform variations did, however, affect the acquisition of control skill by pilots with no prior heavy aircraft flying experience. The effect was limited to pitch attitude control inputs during the early phase of landing training. Implications for the definition of platform motion requirements in air transport pilot training are discussed.

  18. Seismic switch for strong motion measurement

    DOEpatents

    Harben, P.E.; Rodgers, P.W.; Ewert, D.W.

    1995-05-30

    A seismic switching device is described that has an input signal from an existing microseismic station seismometer and a signal from a strong motion measuring instrument. The seismic switch monitors the signal level of the strong motion instrument and passes the seismometer signal to the station data telemetry and recording systems. When the strong motion instrument signal level exceeds a user set threshold level, the seismometer signal is switched out and the strong motion signal is passed to the telemetry system. The amount of time the strong motion signal is passed before switching back to the seismometer signal is user controlled between 1 and 15 seconds. If the threshold level is exceeded during a switch time period, the length of time is extended from that instant by one user set time period. 11 figs.

  19. Seismic switch for strong motion measurement

    DOEpatents

    Harben, Philip E.; Rodgers, Peter W.; Ewert, Daniel W.

    1995-01-01

    A seismic switching device that has an input signal from an existing microseismic station seismometer and a signal from a strong motion measuring instrument. The seismic switch monitors the signal level of the strong motion instrument and passes the seismometer signal to the station data telemetry and recording systems. When the strong motion instrument signal level exceeds a user set threshold level, the seismometer signal is switched out and the strong motion signal is passed to the telemetry system. The amount of time the strong motion signal is passed before switching back to the seismometer signal is user controlled between 1 and 15 seconds. If the threshold level is exceeded during a switch time period, the length of time is extended from that instant by one user set time period.

  20. Simulation study of plane motion of air cushion vehicle

    NASA Astrophysics Data System (ADS)

    Zhao, Shu-Qin; Shi, Xiao-Cheng; Shi, Yi-Long; Bian, Xin-Qian

    2003-12-01

    This research is on horizontal plane motion equations of Air Cushion Vehicle (ACV) and its simulation. To investigate this, a lot of simulation study including ACV’s voyage and turning performance has been done. It was found that the voyage simulation results were accorded with ACV own characteristic and turning simulation results were accorded with USA ACV’s movement characteristic basically.

  1. Orientation-independent measures of ground motion

    USGS Publications Warehouse

    Boore, D.M.; Watson-Lamprey, Jennie; Abrahamson, N.A.

    2006-01-01

    The geometric mean of the response spectra for two orthogonal horizontal components of motion, commonly used as the response variable in predictions of strong ground motion, depends on the orientation of the sensors as installed in the field. This means that the measure of ground-motion intensity could differ for the same actual ground motion. This dependence on sensor orientation is most pronounced for strongly correlated motion (the extreme example being linearly polarized motion), such as often occurs at periods of 1 sec or longer. We propose two new measures of the geometric mean, GMRotDpp, and GMRotIpp, that are independent of the sensor orientations. Both are based on a set of geometric means computed from the as-recorded orthogonal horizontal motions rotated through all possible non-redundant rotation angles. GMRotDpp is determined as the ppth percentile of the set of geometric means for a given oscillator period. For example, GMRotDOO, GMRotD50, and GMRotD100 correspond to the minimum, median, and maximum values, respectively. The rotations that lead to GMRotDpp depend on period, whereas a single-period-independent rotation is used for GMRotIpp, the angle being chosen to minimize the spread of the rotation-dependent geometric mean (normalized by GMRotDpp) over the usable range of oscillator periods. GMRotI50 is the ground-motion intensity measure being used in the development of new ground-motion prediction equations by the Pacific Earthquake Engineering Center Next Generation Attenuation project. Comparisons with as-recorded geometric means for a large dataset show that the new measures are systematically larger than the geometric-mean response spectra using the as-recorded values of ground acceleration, but only by a small amount (less than 3%). The theoretical advantage of the new measures is that they remove sensor orientation as a contributor to aleatory uncertainty. Whether the reduction is of practical significance awaits detailed studies of large

  2. Continuous Quantitative Measurements on a Linear Air Track

    ERIC Educational Resources Information Center

    Vogel, Eric

    1973-01-01

    Describes the construction and operational procedures of a spark-timing apparatus which is designed to record the back and forth motion of one or two carts on linear air tracks. Applications to measurements of velocity, acceleration, simple harmonic motion, and collision problems are illustrated. (CC)

  3. Nonlinear optomechanical measurement of mechanical motion.

    PubMed

    Brawley, G A; Vanner, M R; Larsen, P E; Schmid, S; Boisen, A; Bowen, W P

    2016-01-01

    Precision measurement of nonlinear observables is an important goal in all facets of quantum optics. This allows measurement-based non-classical state preparation, which has been applied to great success in various physical systems, and provides a route for quantum information processing with otherwise linear interactions. In cavity optomechanics much progress has been made using linear interactions and measurement, but observation of nonlinear mechanical degrees-of-freedom remains outstanding. Here we report the observation of displacement-squared thermal motion of a micro-mechanical resonator by exploiting the intrinsic nonlinearity of the radiation-pressure interaction. Using this measurement we generate bimodal mechanical states of motion with separations and feature sizes well below 100 pm. Future improvements to this approach will allow the preparation of quantum superposition states, which can be used to experimentally explore collapse models of the wavefunction and the potential for mechanical-resonator-based quantum information and metrology applications. PMID:26996234

  4. Nonlinear optomechanical measurement of mechanical motion

    PubMed Central

    Brawley, G. A.; Vanner, M. R.; Larsen, P. E.; Schmid, S.; Boisen, A.; Bowen, W. P.

    2016-01-01

    Precision measurement of nonlinear observables is an important goal in all facets of quantum optics. This allows measurement-based non-classical state preparation, which has been applied to great success in various physical systems, and provides a route for quantum information processing with otherwise linear interactions. In cavity optomechanics much progress has been made using linear interactions and measurement, but observation of nonlinear mechanical degrees-of-freedom remains outstanding. Here we report the observation of displacement-squared thermal motion of a micro-mechanical resonator by exploiting the intrinsic nonlinearity of the radiation-pressure interaction. Using this measurement we generate bimodal mechanical states of motion with separations and feature sizes well below 100 pm. Future improvements to this approach will allow the preparation of quantum superposition states, which can be used to experimentally explore collapse models of the wavefunction and the potential for mechanical-resonator-based quantum information and metrology applications. PMID:26996234

  5. On the motion of air through the stratospheric polar vortex

    NASA Technical Reports Server (NTRS)

    Manney, G. L.; Zurek, R. W.; O'Neill, A.; Swinbank, R.

    1994-01-01

    Trajectory calculations using horizontal winds from the U.K. Meteorological Office data assimilation system and vertical velocities from a radiation calculation are used to simulate the three-dimensional motion of air through the stratospheric polar vortex for Northern Hemisphere (NH) and Southern Hemisphere (SH) winters since the launch of the Upper Atmosphere Research Satellite (UARS). Throughout the winter, air from the upper stratosphere moves poleward and descends into the middle stratosphere. In the SH lower to middle stratosphere, strongest descent occurs near the edge of the polar vortex, with that edge defined by mixing characteristics. The NH shows a similar pattern in late winter, but in early winter strongest descent is near the center of the vortex, except when wave activity is particularly strong. Strong barriers to latitudinal mixing exist above about 420 K throughout the winter. Below this, the polar night jet is weak in early winter, so air descending below that level mixes between polar and middle latitudes. In late winter, parcels descend less and the polar night jet moves downward, so there is less latitudinal mixing. The degree of mixing in the lower stratosphere thus depends strongly on the position and evolution of the polar night jet and on the amount of descent experienced by the air parcels; these characteristics show considerable interannual variability in both hemispheres. The computed trajectories provide a three-dimensional picture of air motion during the final warming. Large tongues of air are drawn off the vortex and stretched into increasingly long and narrow tongues extending into low latitudes. This vortex erosion process proceeds more rapidly in the NH than in he SH. In the lower stratosphere, the majority of air parcels remain confined within a lingering region of strong potential vorticity gradients into December in the SH and April in the NH, well after the vortex breaks up in the midstratosphere.

  6. Measuring mechanical motion with a single spin

    NASA Astrophysics Data System (ADS)

    Bennett, S. D.; Kolkowitz, S.; Unterreithmeier, Q. P.; Rabl, P.; Bleszynski Jayich, A. C.; Harris, J. G. E.; Lukin, M. D.

    2012-12-01

    We study theoretically the measurement of a mechanical oscillator using a single two-level system as a detector. In a recent experiment, we used a single electronic spin associated with a nitrogen-vacancy center in diamond to probe the thermal motion of a magnetized cantilever at room temperature (Kolkowitz et al 2012 Science 335 1603). Here, we present a detailed analysis of the sensitivity limits of this technique, as well as the possibility to measure the zero-point motion of the oscillator. Further, we discuss the issue of measurement backaction in sequential measurements and find that although backaction heating can occur, it does not prohibit the detection of zero-point motion. Throughout the paper, we focus on the experimental implementation of a nitrogen-vacancy center coupled to a magnetic cantilever; however, our results are applicable to a wide class of spin-oscillator systems. The implications for the preparation of nonclassical states of a mechanical oscillator are also discussed.

  7. The integrated motion measurement simulation for SOFIA

    NASA Astrophysics Data System (ADS)

    Kaswekar, Prashant; Greiner, Benjamin; Wagner, Jörg

    2014-07-01

    The Stratospheric Observatory for Infrared Astronomy SOFIA consists of a B747-SP aircraft, which carries aloft a 2.7-meter reflecting telescope. The image stability goal for SOFIA is 0:2 arc-seconds rms. The performance of the telescope structure is affected by elastic vibrations induced by aeroacoustic and suspension disturbances. Active compensation of such disturbances requires a fast way of estimating the structural motion. Integrated navigation systems are examples of such estimation systems. However they employ a rigid body assumption. A possible extension of these systems to an elastic structure is shown by different authors for one dimensional beam structures taking into account the eigenmodes of the structural system. The rigid body motion as well as the flexible modes of the telescope assembly, however, are coupled among the three axes. Extending a special mathematical approach to three dimensional structures, the aspect of a modal observer based on integrated motion measurement is simulated for SOFIA. It is in general a fusion of different measurement methods by using their benefits and blinding out their disadvantages. There are no mass and stillness properties needed directly in this approach. However, the knowledge of modal properties of the structure is necessary for the implementation of this method. A finite-element model is chosen as a basis to extract the modal properties of the structure.

  8. Measuring Proper Motion of Barnard's Star

    NASA Astrophysics Data System (ADS)

    Wiechmann, Katrina; Michalik, Tom

    2009-03-01

    Stars of the night sky are generally considered to be fixed points, not changing noticeably over generations of observations. While most stars seem to appear in the same place year after year, some change location noticeably, the best example being Barnard's Star. Barnard's star is closer to Earth than any other star except Proxima Centauri. It also appears to move across the sky faster than any other star. This change in apparent location is caused by the movements of our Solar System and the motion of the star in question, and is known as proper motion. Using the astrometric capabilities of the MIRA software along with precise positional information for reference stars from the Tycho satellite star catalogue, the position of Barnard's star is computed relative to the reference stars. We calibrate a series of images of Barnard's Star taken in the Randolph College Observatory between 2001 and 2008 in order to independently determine the coordinates of Barnard's Star, revealing how these change over time. By measuring changes in the celestial coordinates, Right Ascension and Declination, we determine the proper motion of Barnard's star and compare this measurement to the accepted value of 10.25'' per year.

  9. Motion Measurement for Synthetic Aperture Radar.

    SciTech Connect

    Doerry, Armin W.

    2015-01-01

    Synthetic Aperture Radar (SAR) measures radar soundings from a set of locations typically along the flight path of a radar platform vehicle. Optimal focusing requires precise knowledge of the sounding source locations in 3 - D space with respect to the target scene. Even data driven focusing techniques (i.e. autofocus) requires some degree of initial fidelity in the measurements of the motion of the radar. These requirements may be quite stringent especially for fine resolution, long ranges, and low velocities. The principal instrument for measuring motion is typically an Inertial Measurement Unit (IMU), but these instruments have inherent limi ted precision and accuracy. The question is %22How good does an IMU need to be for a SAR across its performance space?%22 This report analytically relates IMU specifications to parametric requirements for SAR. - 4 - Acknowledgements Th e preparation of this report is the result of a n unfunded research and development activity . Although this report is an independent effort, it draws heavily from limited - release documentation generated under a CRADA with General Atomics - Aeronautical System, Inc. (GA - ASI), and under the Joint DoD/DOE Munitions Program Memorandum of Understanding. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of En ergy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.

  10. Measurement, characterization, and prediction of strong ground motion

    USGS Publications Warehouse

    Joyner, William; Boore, David M.

    1988-01-01

    A number of predictive relationships derived from regression analysis of strong-motion data are available for horizontal peak acceleration, velocity, and response spectral values. Theoretical prediction of ground motion calls for stochastic source models because source heterogeneities control the amplitude of ground motion at most, if not all, frequencies of engineering interest. Theoretical methods have been developed for estimation of ground-motion parameters and simulation of ground-motion time series. These methods are particularly helpful for regions such, as eastern North America where strong-motion data are sparse. The authors survey the field, first reviewing developments in ground-motion measurement and data processing. The authors then consider the choice of parameters for characterizing strong ground motion and describe the wave-types involved in strong ground motion and the factors affecting ground-motion amplitudes. They conclude by describing methods for predicting ground motion.

  11. Vertical air motions derived from a descending radiosonde using a lightweight hard ball as the parachute

    NASA Astrophysics Data System (ADS)

    Chen, H.; Zhu, Y.; Zhang, J.; Xuan, Y.

    2013-09-01

    Knowledge of vertical air motions in the atmosphere is important for meteorological and climate studies due to its impact on clouds, precipitation and the vertical transport of air masses, heat, momentum, and composition. It is among the most difficult quantities to measure because of its small magnitude. In this study, a descending radiosonde technique has been developed to detect the vertical wind speed (VW) in the atmosphere. The system is composed of a radiosonde and a 0.5-m diameter hard ball made of plastic foam that acts as a parachute. The radiosonde hangs under the hard ball by a string which is then cut when the instrument is elevated into the upper troposphere by a balloon. The VW is derived from the difference between the observed radiosonde descent rate and the calculated radiosonde descent rate in still air based on fluid dynamics. Deduction of the appropriate drag coefficient for the radiosonde is facilitated by the symmetrical shape of the parachute. An intensive radiosonde launch experiment was held in northern China during the summer seasons of 2010 to 2012. This study uses radiosonde data collected during the campaign to retrieve the vertical air velocity within the radiosonde altitude-detecting range. In general, the VW ranges from -1 to 1 m s-1. Strong vertical air motion (~2 m s-1) is seen in a few radiosonde measurements. Although considerable uncertainties exist in measuring weak vertical air motions, a case study shows that there is reasonable agreement between retrievals of VW in the lower atmosphere from the radiosonde and a wind profiler radar located at the launch site.

  12. Fluctuations of total ozone and their relationship to stratospheric air motions

    NASA Technical Reports Server (NTRS)

    Salby, Murry L.; Callaghan, Patrick F.

    1993-01-01

    The origin of fluctuations of total ozone and the interactions that take place between the distribution of total ozone and the circulation of the troposphere are investigated on the basis of observations of total ozone from Nimbus 7 TOMS together with contemporaneous analyses of the circulation. It is shown that a sizable component of total ozone variability is explained by the quasi-columnar motion of air in the lower stratosphere. The development also suggests that in combination with isentropic analyses, total ozone measurements can provide a detailed picture of air motions in the lower stratosphere. Distributions of ozone column abundance and pressure on the 375-K isentropic surface for the Northern and Southern Hemispheres are illustrated.

  13. Ultrasonic bistatic Doppler sonar in air for personnel motion detection

    NASA Astrophysics Data System (ADS)

    Ekimov, Alexander; Hickey, Craig J.

    2012-06-01

    The National Center for Physical Acoustics (NCPA) at the University of Mississippi is working on the application of ultrasonic Doppler sonars in air for personnel motion detection. Two traditional Doppler sonar configurations, a monostatic and a bistatic, are being studied. In the monostatic configuration, the distance between the transmitter and the receiver is small. The proximity of the source to the receiver places a limitation on the system associated with the overloading of the receivers' input due to acoustic energy leakage from the transmitters' output. The maximum range of detection is therefore limited by the dynamic range of the acquisition system. In a bistatic Doppler ultrasonic sonar, the source and receiver are spaced apart and the acoustic energy along the direct path does not constrain the maximum acoustic power level output of the transmitter. In a monostatic configuration the acoustic signal suffers from beam spreading and natural absorption during propagation from the transmitter to the target and from the target back to the receiver. In a bistatic configuration the acoustic propagation is in one direction only and theoretically the detection distance can be twice the monostatic distance. For comparison the experiments of a human walking in a building hallway using the bistatic and monostaic Doppler sonars in air were conducted. The experimental results for human signatures from these Doppler sonars are presented and discussed.

  14. Air pollution measurements from satellites

    NASA Technical Reports Server (NTRS)

    Ludwig, C. B.; Griggs, M.; Malkmus, W.; Bartle, E. R.

    1973-01-01

    A study is presented on the remote sensing of gaseous and particulate air pollutants which is an extension of a previous report. Pollutants can be observed by either active or passive remote sensing systems. Calculations discussed herein indicate that tropospheric CO, CO2, SO2, NO2, NH3, HCHO, and CH4 can be measured by means of nadir looking passive systems. Additional species such as NO, HNO3, O3, and H2O may be measured in the stratosphere through a horizon experiment. A brief theoretical overview of resonance Raman scattering and resonance fluorescence is given. It is found that radiance measurements are most promising for general global applications, and that stratospheric aerosols may be measured using a sun occultation technique. The instrumentation requirements for both active and passive systems are examined and various instruments now under development are described.

  15. Evaluation of Three Sensor Types for Particle Motion Measurement.

    PubMed

    Martin, Bruce; Zeddies, David G; Gaudet, Briand; Richard, Joel

    2016-01-01

    All fish sense acoustic particle motion; some species also sense pressure. Concern over the effects of anthropogenic sounds is increasing the need to monitor acoustic particle motion. Particle motion can be measured directly using vector sensors or calculated from pressure gradients. This article compares three devices that measure particle motion: a three-axis accelerometer, a three-axis velocity sensor, and two 4-element hydrophone arrays. A series of sounds (constant-wave tones, white noise, and Ricker wavelets) were played from a fixed-position projector. The particle motion of sounds from imploding light bulbs was also measured. PMID:26611019

  16. Motion measurement of acoustically levitated object

    NASA Technical Reports Server (NTRS)

    Watkins, John L. (Inventor); Barmatz, Martin B. (Inventor)

    1993-01-01

    A system is described for determining motion of an object that is acoustically positioned in a standing wave field in a chamber. Sonic energy in the chamber is sensed, and variation in the amplitude of the sonic energy is detected, which is caused by linear motion, rotational motion, or drop shape oscillation of the object. Apparatus for detecting object motion can include a microphone coupled to the chamber and a low pass filter connected to the output of the microphone, which passes only frequencies below the frequency of sound produced by a transducer that maintains the acoustic standing wave field. Knowledge about object motion can be useful by itself, can be useful to determine surface tension, viscosity, and other information about the object, and can be useful to determine the pressure and other characteristics of the acoustic field.

  17. Motion capture for human motion measuring by using single camera with triangle markers

    NASA Astrophysics Data System (ADS)

    Takahashi, Hidenori; Tanaka, Takayuki; Kaneko, Shun'ichi

    2005-12-01

    This study aims to realize a motion capture for measuring 3D human motions by using single camera. Although motion capture by using multiple cameras is widely used in sports field, medical field, engineering field and so on, optical motion capture method with one camera is not established. In this paper, the authors achieved a 3D motion capture by using one camera, named as Mono-MoCap (MMC), on the basis of two calibration methods and triangle markers which each length of side is given. The camera calibration methods made 3D coordinates transformation parameter and a lens distortion parameter with Modified DLT method. The triangle markers enabled to calculate a coordinate value of a depth direction on a camera coordinate. Experiments of 3D position measurement by using the MMC on a measurement space of cubic 2 m on each side show an average error of measurement of a center of gravity of a triangle marker was less than 2 mm. As compared with conventional motion capture method by using multiple cameras, the MMC has enough accuracy for 3D measurement. Also, by putting a triangle marker on each human joint, the MMC was able to capture a walking motion, a standing-up motion and a bending and stretching motion. In addition, a method using a triangle marker together with conventional spherical markers was proposed. Finally, a method to estimate a position of a marker by measuring the velocity of the marker was proposed in order to improve the accuracy of MMC.

  18. Pen-Based Interface Using Hand Motions in the Air

    NASA Astrophysics Data System (ADS)

    Suzuki, Yu; Misue, Kazuo; Tanaka, Jiro

    A system which employs a stylus as an input device is suitable for creative activities like writing and painting. However, such a system does not always provide the user with a GUI that is easy to operate using the stylus. In addition, system usability is diminished because the stylus is not always integrated into the system in a way that takes into consideration the features of a pen. The purpose of our research is to improve the usability of a system which uses a stylus as an input device. We propose shortcut actions, which are interaction techniques for operation with a stylus that are controlled through a user's hand motions made in the air. We developed the Context Sensitive Stylus as a device to implement the shortcut actions. The Context Sensitive Stylus consists of an accelerometer and a conventional stylus. We also developed application programs to which we applied the shortcut actions; e.g., a drawing tool, a scroll supporting tool, and so on. Results from our evaluation of the shortcut actions indicate that users can concentrate better on their work when using the shortcut actions than when using conventional menu operations.

  19. Some Effects of Yaw Damping on Airplane Motions and Vertical-Tail Loads in Turbulent Air

    NASA Technical Reports Server (NTRS)

    Funk, Jack; Cooney, T. V.

    1959-01-01

    Results of analytical and flight studies are presented to indicate the effect of yaw damping on the airplane motions and the vertical-tail loads in rough air. The analytical studied indicate a rapid reduction in loads on the vertical tail as the damping is increased up to the point of damping the lateral motions to 1/2 amplitude in one cycle. Little reduction in load is obtained by increasing the lateral damping beyond that point. Flight measurements made in rough air at 5,000 and 35,000 feet on a large swept-wing bomber equipped with a yaw damper show that the yaw damper decreased the loads on the vertical tail by about 50 percent at 35,000 feet. The reduction in load at 5,000 feet was not nearly as great. Measurements of the pilot's ability to damp the lateral motions showed that the pilot could provide a significant amount of damping but that manual control was not as effective as a yaw damper in reducing the loads.

  20. Micro air vehicle motion tracking and aerodynamic modeling

    NASA Astrophysics Data System (ADS)

    Uhlig, Daniel V.

    Aerodynamic performance of small-scale fixed-wing flight is not well understood, and flight data are needed to gain a better understanding of the aerodynamics of micro air vehicles (MAVs) flying at Reynolds numbers between 10,000 and 30,000. Experimental studies have shown the aerodynamic effects of low Reynolds number flow on wings and airfoils, but the amount of work that has been conducted is not extensive and mostly limited to tests in wind and water tunnels. In addition to wind and water tunnel testing, flight characteristics of aircraft can be gathered through flight testing. The small size and low weight of MAVs prevent the use of conventional on-board instrumentation systems, but motion tracking systems that use off-board triangulation can capture flight trajectories (position and attitude) of MAVs with minimal onboard instrumentation. Because captured motion trajectories include minute noise that depends on the aircraft size, the trajectory results were verified in this work using repeatability tests. From the captured glide trajectories, the aerodynamic characteristics of five unpowered aircraft were determined. Test results for the five MAVs showed the forces and moments acting on the aircraft throughout the test flights. In addition, the airspeed, angle of attack, and sideslip angle were also determined from the trajectories. Results for low angles of attack (less than approximately 20 deg) showed the lift, drag, and moment coefficients during nominal gliding flight. For the lift curve, the results showed a linear curve until stall that was generally less than finite wing predictions. The drag curve was well described by a polar. The moment coefficients during the gliding flights were used to determine longitudinal and lateral stability derivatives. The neutral point, weather-vane stability and the dihedral effect showed some variation with different trim speeds (different angles of attack). In the gliding flights, the aerodynamic characteristics

  1. Air brake-dynamometer accurately measures torque

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Air brake-dynamometer assembly combines the principles of the air turbine and the air pump to apply braking torque. The assembly absorbs and measures power outputs of rotating machinery over a wide range of shaft speeds. It can also be used as an air turbine.

  2. Measuring Air Resistance in a Computerized Laboratory.

    ERIC Educational Resources Information Center

    Takahashi, Ken; Thompson, D.

    1999-01-01

    Presents an activity that involves dropping spherical party balloons onto a sonic motion sensor to show that the force associated with the air resistance is proportional to both the square of the velocity and the cross-sectional area of the balloon. (Author/WRM)

  3. Thermal Characteristics of Air in the Problem of Hypersonic Motion of Bodies in the Earth's Atmosphere

    NASA Astrophysics Data System (ADS)

    Alhussan, K.; Morozov, D. O.; Stankevich, Yu. A.; Stanchits, L. K.; Stepanov, K. L.

    2014-07-01

    The thermal properties of hot air needed for describing the hypersonic motion of bodies in the Earth's atmosphere have been considered. Such motion, as is known, is accompanied by the propagation of strong shock waves analogous to waves generated by powerful explosions. Calculations have been made and data banks have been created for the equations of state and thermal characteristics of air in the temperature and density ranges corresponding to velocities of motion of bodies of up to 10 km/s at altitudes of 0-100 km. The formulation of the problem of hypersonic motion in the absence of thermodynamic equilibrium is discussed.

  4. Development of magnetically preloaded air bearings for a linear slide: active compensation of three degrees of freedom motion errors.

    PubMed

    Ro, Seung-Kook; Kim, Soohyun; Kwak, Yoonkeun; Park, Chun-Hong

    2008-03-01

    This article describes a linear air-bearing stage that uses active control to compensate for its motion errors. The active control is based on preloads generated by magnetic actuators, which were designed to generate nominal preloads for the air bearings using permanent magnets to maintain the desired stiffness while changing the air-bearing clearance by varying the magnetic flux generated by the current in electromagnetic coils. A single-axis linear stage with a linear motor and 240 mm of travel range was built to verify this design concept and used to test its performance. The motion of the table in three directions was controlled with four magnetic actuators driven by current amplifiers and a DSP (Digital Signal Processor)-based digital controller. The motion errors were measured using a laser interferometer combined with a two-probe method, and had 0.085 microm of repeatability for the straightness error. As a result of feed-forward active compensation, the errors were reduced from 1.09 to 0.11 microm for the vertical motion, from 9.42 to 0.18 arcsec for the pitch motion, and from 2.42 to 0.18 arcsec for the roll motion. PMID:18377049

  5. Development of magnetically preloaded air bearings for a linear slide: Active compensation of three degrees of freedom motion errors

    NASA Astrophysics Data System (ADS)

    Ro, Seung-Kook; Kim, Soohyun; Kwak, Yoonkeun; Park, Chun-Hong

    2008-03-01

    This article describes a linear air-bearing stage that uses active control to compensate for its motion errors. The active control is based on preloads generated by magnetic actuators, which were designed to generate nominal preloads for the air bearings using permanent magnets to maintain the desired stiffness while changing the air-bearing clearance by varying the magnetic flux generated by the current in electromagnetic coils. A single-axis linear stage with a linear motor and 240mm of travel range was built to verify this design concept and used to test its performance. The motion of the table in three directions was controlled with four magnetic actuators driven by current amplifiers and a DSP (Digital Signal Processor)-based digital controller. The motion errors were measured using a laser interferometer combined with a two-probe method, and had 0.085μm of repeatability for the straightness error. As a result of feed-forward active compensation, the errors were reduced from 1.09to0.11μm for the vertical motion, from 9.42to0.18arcsec for the pitch motion, and from 2.42to0.18arcsec for the roll motion.

  6. Vertical air motions over the Tropical Western Pacific for validating cloud resolving and regional models

    SciTech Connect

    Williams, Christopher R.

    2015-03-16

    The objective of this project was to estimate the vertical air motion using Doppler velocity spectra from two side-by-side vertically pointing radars. The retrieval technique was applied to two different sets of radars. This first set was 50- and 920-MHz vertically pointing radars near Darwin, Australia. The second set was 449-MHz and 2.8-GHz vertically pointing radars deployed at SGP for MC3E. The retrieval technique uses the longer wavelength radar (50 or 449 MHz) to observe both the vertical air motion and precipitation motion while the shorter wavelength radar (920 MHz or 2.8 GHz) observes just the precipitation motion. By analyzing their Doppler velocity spectra, the precipitation signal in the 920 MHz or 2.8 GHz radar is used to mask-out the precipitation signal in the 50 or 449 MHz radar spectra, leaving just the vertical air motion signal.

  7. The influence of scales of atmospheric motion on air pollution over Portugal

    NASA Astrophysics Data System (ADS)

    Russo, Ana; Trigo, Ricardo; Mendes, Manuel; Jerez, Sonia; Gouveia, Célia Marina

    2014-05-01

    Air pollution is determined by the combination of different factors, namely, emissions, physical constrains, meteorology and chemical processes [1,2,3]. The relative importance of such factors is influenced by their interaction on diverse scales of atmospheric motion. Each scale depicts different meteorological conditions, which, when combined with the different air pollution sources and photochemistry, result in varying ambient concentrations [2]. Identifying the dominant scales of atmospheric motion over a given airshed can be of great importance for many applications such as air pollution and pollen dispersion or wind energy management [2]. Portugal has been affected by numerous air pollution episodes during the last decade. These episodes are often related to peak emissions from local industry or transport, but can also be associated to regional transport from other urban areas or to exceptional emission events, such as forest fires. This research aims to identify the scales of atmospheric motion which contribute to an increase of air pollution. A method is proposed for differentiating between the scales of atmospheric motion that can be applied on a daily basis from data collected at several wind-measuring sites in a given airshed and to reanalysis datasets. The method is based on the daily mean wind recirculation and the mean and standard deviation between sites. The determination of the thresholds between scales is performed empirically following the approach of Levy et al. [2] and also through a automatic statistical approach computed taking into account the tails of the distributions (e.g. 95% and 99% percentile) of the different wind samples. A comparison is made with two objective approaches: 1) daily synoptic classification for the same period over the region [4] and 2) a 3-D backward trajectory approach [5,6] for specific episodes. Furthermore, the outcomes are expected to support the Portuguese authorities on the implementation of strategies for a

  8. Unbiased measures of interocular transfer of motion adaptation.

    PubMed

    Vilidaité, Greta; Baker, Daniel H

    2015-01-01

    Numerous studies have measured the extent to which motion aftereffects transfer interocularly. However, many have done so using bias-prone methods, and studies rarely compare different types of motion directly. Here, we use a technique designed to reduce bias (Morgan, 2013, Journal of Vision, 13(8):26, 1-11) to estimate interocular transfer (IOT) for five types of motion: simple translational motion, expansion/contraction, rotation, spiral, and complex translational motion. We used both static and dynamic targets with subjects making binary judgments of perceived speed. Overall, the average IOT was 65%, consistent with previous studies (mean over 17 studies of 67% transfer). There was a main effect of motion type, with translational motion producing stronger IOT (mean: 86%) overall than any of the more complex varieties of motion (mean: 51%). This is inconsistent with the notion that IOT should be strongest for motion processed in extrastriate regions that are fully binocular. We conclude that adaptation is a complex phenomenon too poorly understood to make firm inferences about the binocular structure of motion systems. PMID:26422902

  9. Effect of plateout, air motion and dust removal on radon decay product concentration in a simulated residence.

    PubMed

    Rudnick, S N; Hinds, W C; Maher, E F; First, M W

    1983-08-01

    The effectiveness of increased air motion and dust removal in reducing radon decay product concentration in residences subject to radon intrusion was evaluated in a 78-m3 room under steady-state conditions for air infiltration rates between 0.2 and 0.9 air changes per hour. Room-size, portable electrostatic precipitators and high-efficiency fibrous filters were tested as typical residential air cleaning devices; a portable box fan and a ceiling fan were employed as typical residential air movers. Reductions in working levels of 40-90% were found. The fate of radon decay products, with and without mixing fans, was determined by direct measurement. When mixing fans were used, most of the nonairborne potential alpha-energy was plated out on the room surfaces; less than 10% was deposited on the fan blades or housing. Results were compared to a mathematical model based on well-mixed room air, and good agreement was obtained. PMID:6885451

  10. INCORPORATING MEASUREMENT UNCERTAINTY INTO AIR QUALITY EVALUATIONS

    EPA Science Inventory

    Decisions on air quality problems must often be made on the basis of existing ambient air quality data. One consideration in such situations is how to accomodate the uncertainty associated with these measurements. Measurement error is often stated in terms of a single measurement...

  11. Effects of yaw and pitch motion on model attitude measurements

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Tripp, John S.; Finley, Tom D.

    1995-01-01

    This report presents a theoretical analysis of the dynamic effects of angular motion in yaw and pitch on model attitude measurements in which inertial sensors were used during wind tunnel tests. A technique is developed to reduce the error caused by these effects. The analysis shows that a 20-to-1 reduction in model attitude measurement error caused by angular motion is possible with this technique.

  12. Use of HART-II Measured Motion in CFD

    NASA Technical Reports Server (NTRS)

    Boyd, D. Douglas, Jr.

    2008-01-01

    This presentation examines the use of HART-II measured rotor blade motion in computational fluid dynamics (CFD). Historically, comprehensive analyses were used for input to acoustic calculations. These analyses focused on lifting line aerodynamics and beam models. However, there is a a need to evolve lifting line aerodynamics to first principles, notably the use of CFD instead of lifting line. The current analysis focuses on CFD and computational structural dynamics (CSD) coupling. Beam models are still very good (CSD is typically from comprehensive analysis), but generally CFD replaced aerodynamics in comprehensive analysis. This presentation examines both CFD and CSD individually and includes predictions using measured motion as well as predictions using measured motion versus coupled motion and calculations of "correct" airloads, noise and vibration.

  13. Ground Motion Prediction Equations Empowered by Stress Drop Measurement

    NASA Astrophysics Data System (ADS)

    Miyake, H.; Oth, A.

    2015-12-01

    Significant variation of stress drop is a crucial issue for ground motion prediction equations and probabilistic seismic hazard assessment, since only a few ground motion prediction equations take into account stress drop. In addition to average and sigma studies of stress drop and ground motion prediction equations (e.g., Cotton et al., 2013; Baltay and Hanks, 2014), we explore 1-to-1 relationship for each earthquake between stress drop and between-event residual of a ground motion prediction equation. We used the stress drop dataset of Oth (2013) for Japanese crustal earthquakes ranging 0.1 to 100 MPa and K-NET/KiK-net ground motion dataset against for several ground motion prediction equations with volcanic front treatment. Between-event residuals for ground accelerations and velocities are generally coincident with stress drop, as investigated by seismic intensity measures of Oth et al. (2015). Moreover, we found faster attenuation of ground acceleration and velocities for large stress drop events for the similar fault distance range and focal depth. It may suggest an alternative parameterization of stress drop to control attenuation distance rate for ground motion prediction equations. We also investigate 1-to-1 relationship and sigma for regional/national-scale stress drop variation and current national-scale ground motion equations.

  14. Measuring nanometer, three-dimensional motions with light microscopy

    NASA Astrophysics Data System (ADS)

    Davis, Charles Quentin

    Computational motion analysis of images from a light microscope is used to explore mechanics in the microscopic worlds of cells and man-made micromachines. Images of a moving target are taken using a strobe light and a CCD camera attached to a microscope. Temporal sequences of stop-action images are recorded at multiple planes of focus to characterize three-dimensional motions. We demonstrate that motion resolution is limited by the motion detection algorithm. The largest source of error in gradient-based and matching algorithms is statistical bias. We present a new algorithm with errors that are typically smaller than 0.02 pixels. With this algorithm and our video microscopy system, we can measure motions of submicrometer targets with nanometer accuracy. The system has been used to study both hearing structures and man-made micromachines. Analysis of electrically- induced motions of a microfabricated accelerometer and a microfabricated angular velocity sensor allow visualization and quantification of complex modes of motion that limit the performance of these sensors. Pilot studies demonstrate that the system can also measure sound-induced motions of the human stapes, where it can resolve complex modes of motion thought to be important for loud sounds and for certain middle-ear pathologies. The system has also been used to measure mechanical deformations in the mouse tectorial membrane, a gelatinous inner-ear structure that has previously been a difficult target of study. Our major application has been the study of sound-induced motions of sensory cells and accessory structures in the ear of a lizard. Our results, while still preliminary, are the first direct measurements of sound-induced motions of hair bundles and their overlying tectorial membrane. They indicate that the tectorial membrane does not move as a rigid body but has significant shear throughout its thickness. Therefore, the relative motion between the tectorial membrane and the reticular lamina is

  15. Earth rotation and polar motion - Measurements and implications

    NASA Technical Reports Server (NTRS)

    Dickey, J. O.; Eubanks, T. M.

    1985-01-01

    Several methods used to measure earth rotation and polar motion are discussed. The development of techniques for combining smoothing, and intercomparing geodetic measurements is described. Emphasis is given to measurements obtained since 1980 using VLBI, lunar laser ranging (LLR) and satellite laser ranging (SLR) techniques. The calculation of atmospheric angular momentum (AAM) excitation functions is outlined, and a comparison of AAM excitation functions with variations in the length of day (LOD) and polar motion data is presented. The geophysical implications of geodetic measurements are addressed.

  16. Measurements of Load Train Motion on a Stratospheric Balloon Flight

    NASA Technical Reports Server (NTRS)

    Gruner, Timothy D.; Olney, David J.; Russo, Angela M.

    2005-01-01

    Attitude measurements using gyros and magnetometers placed on a stratospheric balloon during a non-pointed test flight were used to observe the natural azimuth and elevation motions of a balloon/load train/gondola at an altitude of 36 km over a total flight time of 400 minutes. Time traces of the entire flight are presented. This flight, conducted under nominal atmospheric conditions, had significant motion about the azimuth. Some discussion on balloon disturbances is also included.

  17. Air Quality Measurements for Science and Policy

    EPA Science Inventory

    Air quality measurements and the methods used to conduct them are vital to advancing our knowledge of the source-to-receptor-to-health effects continuum1-3. This information then forms the basis for evaluating and managing air quality to protect human health and welfa...

  18. Measurement of Air Pollutants in the Troposphere

    ERIC Educational Resources Information Center

    Clemitshaw, Kevin C.

    2011-01-01

    This article describes the principles, applications and performances of methods to measure gas-phase air pollutants that either utilise passive or active sampling with subsequent laboratory analysis or involve automated "in situ" sampling and analysis. It focuses on air pollutants that have adverse impacts on human health (nitrogen dioxide, carbon…

  19. A precision translation stage for reproducing measured target volume motions.

    PubMed

    Litzenberg, Dale W; Hadley, Scott W; Lam, Kwok L; Balter, James M

    2007-01-01

    The development of 4D imaging, treatment planning and treatment delivery methods for radiation therapy require the use of a high-precision translation stage for testing and validation. These technologies may require spatial resolutions of 1 mm, and temporal resolutions of 2-30 Hz for CT imaging, electromagnetic tracking, and fluoroscopic imaging. A 1D programmable translation stage capable of reproducing idealized and measured anatomic motions common to the thorax has been design and built to meet these spatial and temporal resolution requirement with phantoms weighing up to 27 kg. The stage consists of a polycarbonate base and table, driven by an AC servo motor with encoder feedback by means of a belt-coupled precision screw. Complex motions are possible through a programmable motion controller that is capable of running multiple independent control and monitoring programs concurrently. Programmable input and output ports allow motion to be synchronized with beam delivery and other imaging and treatment delivery devices to within 2.0 ms. Average deviations from the programmed positions are typically 0.2 mm or less, while the average typical maximum positional errors are typically 0.5 mm for an indefinite number of idealized breathing motion cycles and while reproducing measured target volume motions for several minutes. PMID:17712294

  20. Experimental measurements of motion cue effects on STOL approach tasks

    NASA Technical Reports Server (NTRS)

    Ringland, R. F.; Stapleford, R. L.

    1972-01-01

    An experimental program to investigate the effects of motion cues on STOL approach is presented. The simulator used was the Six-Degrees-of-Freedom Motion Simulator (S.01) at Ames Research Center of NASA which has ?2.7 m travel longitudinally and laterally and ?2.5 m travel vertically. Three major experiments, characterized as tracking tasks, were conducted under fixed and moving base conditions: (1) A simulated IFR approach of the Augmentor Wing Jet STOL Research Aircraft (AWJSRA), (2) a simulated VFR task with the same aircraft, and (3) a single-axis task having only linear acceleration as the motion cue. Tracking performance was measured in terms of the variances of several motion variables, pilot vehicle describing functions, and pilot commentary.

  1. Super-Sharp Radio "Vision" Measures Galaxy's Motion in Space

    NASA Astrophysics Data System (ADS)

    2005-03-01

    Astronomers using the National Science Foundation's Very Long Baseline Array (VLBA) have measured the motion across the sky of a galaxy nearly 2.4 million light-years from Earth. While scientists have been measuring the motion of galaxies directly toward or away from Earth for decades, this is the first time that the transverse motion (called proper motion by astronomers) has been measured for a galaxy that is not a satellite of our own Milky Way Galaxy. M33 Radio/Optical Image of M33 CREDIT: NRAO/AUI/NSF, NOAO/AURA/NSF (Click on image for more files) An international scientific team analyzed VLBA observations made over two and a half years to detect minuscule shifts in the sky position of the spiral galaxy M33. Combined with previous measurements of the galaxy's motion toward Earth, the new data allowed the astronomers to calculate M33's movement in three dimensions for the first time. "A snail crawling on Mars would appear to be moving across the surface more than 100 times faster than the motion we measured for this galaxy," said Mark Reid, of the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA. M33 is a satellite of the larger galaxy M31, the well-known Andromeda Galaxy that is the most distant object visible to the naked eye. Both are part of the Local Group of galaxies that includes the Milky Way. In addition to measuring the motion of M33 as a whole, the astronomers also were able to make a direct measurement of the spiral galaxy's rotation. Both measurements were made by observing the changes in position of giant clouds of molecules inside the galaxy. The water vapor in these clouds acts as a natural maser, strengthening, or amplifying, radio emission the same way that lasers amplify light emission. The natural masers acted as bright radio beacons whose movement could be tracked by the ultra-sharp radio "vision" of the VLBA. Reid and his colleagues plan to continue measuring M33's motion and also to make similar measurements of M31's motion

  2. An automated motion measurement system for clinical gait analysis.

    PubMed

    Taylor, K D; Mottier, F M; Simmons, D W; Cohen, W; Pavlak, R; Cornell, D P; Hankins, G B

    1982-01-01

    An automated motion measurement system using a television camera interfaced to a computer was constructed and evaluated to determine its applicability to clinical gait analysis. Experimental data indicate that the motion measurement system has a resolution of 1 part in 2000 and a static accuracy of 1 part in 1000 with a worst case dynamic error of 1 part in 300. The study has also shown that this system can reliably track multiple passive markers on a human illuminated with infrared light emitting diodes. This approach minimizes patient distraction, since the illumination is not visible, and reduces patient discomfort since a marker telemetry back pack system, to control active markers, is not needed. Further, the motion measurement system has been successfully demonstrated under conditions similar to those expected in a clinical environment. PMID:7130206

  3. Vision System Measures Motions of Robot and External Objects

    NASA Technical Reports Server (NTRS)

    Talukder, Ashit; Matthies, Larry

    2008-01-01

    A prototype of an advanced robotic vision system both (1) measures its own motion with respect to a stationary background and (2) detects other moving objects and estimates their motions, all by use of visual cues. Like some prior robotic and other optoelectronic vision systems, this system is based partly on concepts of optical flow and visual odometry. Whereas prior optoelectronic visual-odometry systems have been limited to frame rates of no more than 1 Hz, a visual-odometry subsystem that is part of this system operates at a frame rate of 60 to 200 Hz, given optical-flow estimates. The overall system operates at an effective frame rate of 12 Hz. Moreover, unlike prior machine-vision systems for detecting motions of external objects, this system need not remain stationary: it can detect such motions while it is moving (even vibrating). The system includes a stereoscopic pair of cameras mounted on a moving robot. The outputs of the cameras are digitized, then processed to extract positions and velocities. The initial image-data-processing functions of this system are the same as those of some prior systems: Stereoscopy is used to compute three-dimensional (3D) positions for all pixels in the camera images. For each pixel of each image, optical flow between successive image frames is used to compute the two-dimensional (2D) apparent relative translational motion of the point transverse to the line of sight of the camera. The challenge in designing this system was to provide for utilization of the 3D information from stereoscopy in conjunction with the 2D information from optical flow to distinguish between motion of the camera pair and motions of external objects, compute the motion of the camera pair in all six degrees of translational and rotational freedom, and robustly estimate the motions of external objects, all in real time. To meet this challenge, the system is designed to perform the following image-data-processing functions: The visual-odometry subsystem

  4. Measuring Air Density in the Introductory Lab

    NASA Astrophysics Data System (ADS)

    Calzà, G.; Gratton, L. M.; López-Arias, T.; Oss, S.

    2010-03-01

    The measurement of the mass, or the density, of air can easily be done with very simple materials and offers many interesting phenomena for discussion—buoyancy and its effects being the most obvious but not the only one. Many interesting considerations can be done regarding the behavior of gases, the effect of the external conditions in the measurement, and the reason for the choice of the procedure, among others. One of the most widespread approaches makes use of rubber balloons. Such an approach can be misleading if attention is not paid to the effect of the buoyant force on the balloon, exerted by the surrounding air. Air is weightless in an environment full of it. While this fact can usually be neglected in daily, nontechnical weight measurements, it is not the case when we are interested in the weight of air itself. A sketch such as the one depicted in Fig. 1 is often presented in elementary science textbooks, as a demonstration that air has weight. A search of the Internet will reveal that this misleading approach is often presented as the simplest one for this kind of measurement at an elementary level and represents one among other common misconceptions that can be found in K-6 science textbooks as discussed, for instance, in Ref. 2. For a more detailed description of the flaws inherent to the measurement of air's weight with a rubber balloon, see Ref. 3. In this paper we will describe two procedures to measure the density of air: weighing a PET bottle and a vacuum rigid container. There are other interesting ways to estimate the weight of air; see, for instance, the experiment of Zhu and Se-yuen using carbon dioxide and Archimedes' principle.4 We emphasize the experimental implications and the physical reasons for the accuracy and conceptual correctness of each method. It is important not to undervalue the importance of both simplicity and reliability for any experimental measurement made in a didactic context.

  5. Air volume measurement of 'Braeburn' apple fruit.

    PubMed

    Drazeta, Lazar; Lang, Alexander; Hall, Alistair J; Volz, Richard K; Jameson, Paula E

    2004-05-01

    The radial disposition of air in the flesh of fruit of Malus domestica Borkh., cv 'Braeburn' was investigated using a gravimetric technique based on Archimedes' principle. Intercellular air volume was measured by weighing a small tissue sample under water before and after vacuum infiltration to remove the air. In a separate procedure, the volume of the same sample was measured by recording the buoyant upthrust experienced by it when fully immersed in water. The method underestimates tissue air volume due to a slight invasion of the intercellular air spaces around the edges of the sample when it is immersed in water. To correct for this error, an adjustment factor was made based upon an analysis of a series of measurements of air volume in samples of different dimensions. In 'Braeburn' there is a gradient of declining air content from just beneath the skin to the centre of the fruit with a sharp discontinuity at the core line. Cell shape and cell packing were observed in the surface layers of freshly excised and stained flesh samples using a dissecting microscope coupled to a video camera and a PC running proprietary software. Tissue organization changed with distance below the skin. It is speculated that reduced internal gas movement, due to the tightly packed tissue of 'Braeburn' and to the potential diffusion barrier at the core line between the cortex and the pith, may increase susceptibility of the flesh to disorders associated with tissue browning and breakdown. PMID:15047764

  6. Measurements of ground motion and magnet vibrations at the APS

    SciTech Connect

    Shiltsev, V.

    1996-09-01

    This article presents results of ground motion and magnet vibrations measurements at the Advanced Photon Source. The experiments were done over a wide, frequency range (0-05-100 Hz) with the use of SM-3KV-type seismic probes from the Budker Institute of Nuclear Physics (Russia). Spectral power densities of vertical and horizontal motions of the APS hall floor and quadrupoles on regular supports were obtained. Also investigated were magnet vibrations induced by designed cooling water flow and spectral characteristics of spatial correlation of the quadrupole vibrations at different sectors of the ring. The influence of personnel activity in the hall and traffic under the ring on the slow motion of storage ring elements were observed. Amplitudes of vibrations at the APS are compared with results of seismic measurements at some other accelerators.

  7. Super-Sharp Radio "Vision" Measures Galaxy's Motion in Space

    NASA Astrophysics Data System (ADS)

    2005-03-01

    Astronomers using the National Science Foundation's Very Long Baseline Array (VLBA) have measured the motion across the sky of a galaxy nearly 2.4 million light-years from Earth. While scientists have been measuring the motion of galaxies directly toward or away from Earth for decades, this is the first time that the transverse motion (called proper motion by astronomers) has been measured for a galaxy that is not a satellite of our own Milky Way Galaxy. M33 Radio/Optical Image of M33 CREDIT: NRAO/AUI/NSF, NOAO/AURA/NSF (Click on image for more files) An international scientific team analyzed VLBA observations made over two and a half years to detect minuscule shifts in the sky position of the spiral galaxy M33. Combined with previous measurements of the galaxy's motion toward Earth, the new data allowed the astronomers to calculate M33's movement in three dimensions for the first time. "A snail crawling on Mars would appear to be moving across the surface more than 100 times faster than the motion we measured for this galaxy," said Mark Reid, of the Harvard-Smithsonian Center for Astrophysics in Cambridge, MA. M33 is a satellite of the larger galaxy M31, the well-known Andromeda Galaxy that is the most distant object visible to the naked eye. Both are part of the Local Group of galaxies that includes the Milky Way. In addition to measuring the motion of M33 as a whole, the astronomers also were able to make a direct measurement of the spiral galaxy's rotation. Both measurements were made by observing the changes in position of giant clouds of molecules inside the galaxy. The water vapor in these clouds acts as a natural maser, strengthening, or amplifying, radio emission the same way that lasers amplify light emission. The natural masers acted as bright radio beacons whose movement could be tracked by the ultra-sharp radio "vision" of the VLBA. Reid and his colleagues plan to continue measuring M33's motion and also to make similar measurements of M31's motion

  8. Trajectories of air parcel motions in Mars' atmosphere computed using HYSPLIT.

    NASA Astrophysics Data System (ADS)

    Bruggeman, D.; Bridger, A. F. C.

    2014-12-01

    The HYSPLIT model has been adapted to compute trajectories of air and dust particle motions in the Martian atmosphere. We use winds generated by the NASA-Ames Mars General Circulation Model as input to HYSPLIT. Trajectories of air parcels emanating from the Hellas region during the MY25 dust storm will be examined in an effort to "follow the dust". Later we will examine backward trajectories to estimate the origins of surface dust at high latitudes.

  9. A head motion measurement system suitable for emission computed tomography.

    PubMed

    Goldstein, S R; Daube-Witherspoon, M E; Green, M V; Eidsath, A

    1997-02-01

    Subject motion during brain imaging studies can adversely affect the images through loss of resolution and other artifacts related to movement. We have developed and tested a device to measure head motion externally in real-time during emission computed tomographic (ECT) brain imaging studies, to be used eventually to correct ECT data for that motion. The system is based on optical triangulation of three miniature lights affixed to the patient's head and viewed by two position-sensitive detectors. The computer-controlled device converts the three sets of lamp positions into rotational and translational coordinates every 0.7 seconds. When compared against a mechanical test fixture, the optical system was found to be linear and accurate with minimal crosstalk between the coordinates. In a study of two subjects, comparing the angular motions measured by the optical device and a commercially available electromagnetic motion detector, the two systems agreed well, with an root mean square (rms) difference of less than 0.6 degree for all rotations. PMID:9050405

  10. The Measurement of Air Speed in Airplanes

    NASA Technical Reports Server (NTRS)

    Thompson, F L

    1937-01-01

    Various methods of measuring the air speed of airplanes are described. Particular emphasis is placed on the procedure required to obtain precise measurements of speed by the use of the suspended Pitot-static head or the suspended static head. Typical calibration curves for service installations of Pitot-static heads are shown and the relation between errors in air speed and corresponding errors in observed altitude for such installations is discussed. There is included a brief discussion of various speed-course methods of measuring speed.

  11. Anisotropic orientational motion of molecular adsorbates at the air-water interface

    SciTech Connect

    Zimdars, D.; Dadap, J.I.; Eisenthal, K.B.; Heinz, T.F.

    1999-04-29

    The ultrafast orientational motions of coumarin 314 (C314) adsorbed at the air/water interface were investigated by time-resolved surface second harmonic generation (TRSHG). The theory and method of using TRSHG to detect both out-of-plane and in-plane orientational motions are discussed. The interfacial solute motions were found to be anisotropic, with differing out-of-plane and in-plane reorientation time constants. This report presents the first direct observation of in-plane orientational motion of a molecule (C314) at the air/water interface using TRSHG. The in-plane reorientation time constant is 600 {+-} 40 ps. The out-of-plane reorientation time constant is 350 {+-} 20 ps. The out-of-plane orientational motion of C314 is similar to the previous results on rhodamine 6G at the air/water interface which indicated increased interfacial friction compared with bulk aqueous solution. The surface reorientation times are 2--3 times slower than the bulk isotropic orientational diffusion time.

  12. Effects from measured ground motions at the SSC

    SciTech Connect

    Ng, King-Yuen ); Peterson, J.M. )

    1990-12-01

    The separation of the two beams in the SSC caused by ground motion produced by railroad and highway traffic crossing over the ring and by nearby quarry blasts were estimated from measured amplitude spectra using a complete optical model of the accelerator lattice, but a simplified model of the ground structure. The beam separation expected from the largest ground motion recorded from train crossings is only a few percent of the rms beam width at the beam-crossing points. However, the beam separation caused by quarry blasts are larger and can momentarily produce significant loss in luminosity. 6 refs., 15 figs., 3 tabs.

  13. REPRESENTATION OF ATMOSPHERIC MOTION IN MODELS OF REGIONAL-SCALE AIR POLLUTION

    EPA Science Inventory

    A method is developed for generating ensembles of wind fields for use in regional scale (1000 km) models of transport and diffusion. The underlying objective is a methodology for representing atmospheric motion in applied air pollution models that permits explicit treatment of th...

  14. GPS Measurements Of The Relative Motion Between India And Sundaland

    NASA Astrophysics Data System (ADS)

    Socquet, A.; Vigny, C.; Pubellier, M.; Chamot-Rooke, N.; Rangin, C.

    GPS measurements acquired in the framework of the GEODYSSEA project have pro- vided significant new information on the present day plate tectonics in South East Asia. In order to further investigate the relative motion between India and South East Asia, we have performed a combined processing the THAICA, APRGP, MYANMAR, GEODYSSEA and RTSD data (10 GPS campaigns from 1994 to 2000) including 90 stations in South East Asia. Global plate motion model Nuvel-1A [DeMets et al., 1994] predicts a relative motion of India with respect to Eurasia of about 5.5 cm/yr oriented around N20rE on the east- ern border of the Indian plate in Myanmar. Our geodetic results allow us to confirm That India motion is actually slower than this value in agreement with the results ob- tained by Paul et al., 2001. In addition, since the block along which India is sliding is not stable Eurasia but rather the Sundaland block [Michel et al., 2001], the relative motion expected between India and Sundaland on the Myanmar boundary reduces to about 4.5 cm/yr and rotates towards North. The local Myanmar velocity field [Vigny et al.,2001] show that, out of the 4.5 cm/yr of India versus Sundaland rate, only 3 cm/yr are accommodated in Myanmar, distributed between 2 cm/yr on the Sagaing fault and 1 cm/yr in the Myanmar Central Basins. Therefore, 1.5 cm/yr have to be taken elsewhere. Our results indicate that about 0.5 cm/yr can be accommodated in a large shear zone in Indochina, the remaining motion being accommodated in the Andaman trench. DeMets, C., R. G. Gordon, D. Argus, and S. Stein, Effect of recent revisions to the geomagnetic reversal time scale on estimates of current plate motions, Geophys. Res. Letters., 21, 2191-2194, 1994. Michel, G., Y. Yu, S. Zhu, C. Reigber, M. Becker, E. Reinhart, W. Simons, B. Am- brosius, C. Vigny, N. Chamot-Rooke, X. LePichon, P. Morgan, and S. Matheussen, Crustal motion and block behavior in SE-Asia from GPS measurements,.Earth and Physics Science letters, 187, 289

  15. High-Resolution, Single-Molecule Measurements of Biomolecular Motion

    PubMed Central

    Greenleaf, William J.; Woodside, Michael T.; Block, Steven M.

    2007-01-01

    Many biologically important macromolecules undergo motions that are essential to their function. Biophysical techniques can now resolve the motions of single molecules down to the nanometer scale or even below, providing new insights into the mechanisms that drive molecular movements. This review outlines the principal approaches that have been used for high-resolution measurements of single-molecule motion, including centroid tracking, fluorescence resonance energy transfer, magnetic tweezers, atomic force microscopy, and optical traps. For each technique, the principles of operation are outlined, the capabilities and typical applications are examined, and various practical issues for implementation are considered. Extensions to these methods are also discussed, with an eye toward future application to outstanding biological problems. PMID:17328679

  16. Comparisons between measurement and analysis of fluid motion in internal combustion engines

    SciTech Connect

    Witze, P.O.

    1981-10-01

    The Engine Combustion Technology Project was created for the purpose of promoting the development of advanced piston engine concepts by the development of techniques to measure, analyze, and understand the combustion process. The technologies emphasized in the project include laser-based measurement techniques and large-scale computer simulations. Considerable progress has already been achieved by project participants in modeling engine air motion, fuel sprays, and engine combustion phenomena. This milestone report covers one part of that progress, summarizing the current capabilities of multi-dimensional computer codes being developed by the project to predict the behavior of turbulent air motion in an engine environment. Computed results are compared directly with experimental data in six different areas of importance to internal combustion engines: (1) Induction-generated ring-vortex structures; (2) Piston-induced vortex roll-up; (3) Behavior of turbulence during compression; (4) Decay of swirling flow during compression; (5) Decay of swirling flow in a constant volume engine simulator; (6) Exhaust-pipe flow. The computational procedures used include vortex dynamics, rapid distortion theory, and finite difference models employing two-equation and subgrid-scale turbulence models. Although the capability does not yet exist to predict the air motion in an engine from its geometric configuration alone, the results presented show that many flowfield sub-processes can be predicted given well-specified initial and boundary conditions.

  17. Ground motion measurements from the demolition of steel towers

    SciTech Connect

    Joshi, J.R.; Lee, R.C.

    1998-12-31

    Steel towers from a decommissioned heavy water plant were to be demolished. Ground motions due to the proposed felling were estimated in order to assess the structural integrity of neighboring buildings and piping systems. The extraction towers were 125 feet (38.1 m) high in two sizes: 6.5 and 11 feet (1.98 and 3.35 m) inside diameters weighing 215 X 10{sup 3} and 470 X 10{sup 3} lb (956 X 10{sup 3} and 2.1 X 10{sup 6} N). The total potential energy of the tower collapse was about 15 X 10{sup 6} and 32 X 10{sup 6} ft-lb (20.3 X 10{sup 6} and 43.4 X 10{sup 6} Nm) for the small and large towers, respectively. The ground motion predictions were based on a credible theoretical relationship with constants estimated from data available for a different location at the site for dynamic compaction with an energy input an order of magnitude less than that for the towers. Due to the uncertainty of prediction of ground motions a coefficient of variation of 2.0 was used in the structural assessment. Ground motion from the collapse of the extraction towers were monitored by several 3- and 6-components seismographs. Recorded measurements indicated that the ground motion was less than the predicted values. Peak radial motions were approximately equal to the vertical ones. Video tapes of the demolition suggested significant internal energy losses. The measurements suggested that the tower potential energy conversion to dynamic impact energy was about 25 percent. 7 figs.

  18. Measurement of formaldehyde in clean air

    SciTech Connect

    Neitzert, V.; Seiler, W.

    1981-01-01

    A method for the measurement of small amounts of formaldehyde in air has been developed. The method is based on the derivatization of HCHO with 2.4-Denetrophenylhydragine, forming 2.4-Dentrophylhydragine, measured with GC-ECD-technique. HCHO is preconcentrated using a cryogenic sampling technique. The detection limit is 0.05 ppbv for a sampling volume of 200 liter. The method has been applied for measurements in continental and marine air masses showing HCHO mixing ratios of 0.4--5.0 ppbv and 0.2--1.0 ppbv, respectively. HCHO mixing ratios show diurnal variations with maximum values during the early afternoon and minimum values during the early morning. In continental air, HCHO mixing ratios are positively correlated with CO and SO/sub 2/, indicating anthropogenic HCHO sources which are estimated to be 6--11 x 10/sup 12/g/year/sup -1/ on a global scale.

  19. Measuring the force of drag on air sheared sessile drops

    NASA Astrophysics Data System (ADS)

    Milne, Andrew J. B.; Fleck, Brian; Amirfazli, Alidad

    2012-11-01

    To blow a drop along or off of a surface (i.e. to shed the drop), the drag force on the drop (based on flow conditions, drop shape, and fluid properties) must overcome the adhesion force between the drop and the surface (based on surface tension, drop shape, and contact angle). While the shedding of sessile drops by shear flow has been studied [Milne, A. J. B. & Amirfazli, A. Langmuir 25, 14155 (2009).], no independent measurements of the drag or adhesion forces have been made. Likewise, analytic predictions are limited to hemispherical drops and low air velocities. We present, therefore, measurements of the drag force on sessile drops at air velocities up to the point of incipient motion. Measurements were made using a modified floating element shear sensor in a laminar low speed wind tunnel to record drag force over the surface with the drop absent, and over the combined system of the surface and drop partially immersed in the boundary layer. Surfaces of different wettabilities were used to study the effects of drop shape and contact angles, with drop volume ranged between approximately 10 and 100 microlitres. The drag force for incipient motion (which by definition equals the maximum of the adhesion force) is compared to simplified models for drop adhesion such as that of Furmidge

  20. Abdominal organ motion measured using 4D CT

    SciTech Connect

    Brandner, Edward D.; Wu, Andrew . E-mail: andrew.wu@jefferson.edu; Chen, Hungcheng; Heron, Dwight; Kalnicki, Shalom; Komanduri, Krishna; Gerszten, Kristina; Burton, Steve; Ahmed, Irfan; Shou, Zhenyu

    2006-06-01

    Purpose: To measure respiration-induced abdominal organ motion using four-dimensional computed tomography (4D CT) scanning and to examine the organ paths. Methods and Materials: During 4D CT scanning, consecutive CT images are acquired of the patient at each couch position. Simultaneously, the patient's respiratory pattern is recorded using an external marker block taped to the patient's abdomen. This pattern is used to retrospectively organize the CT images into multiple three-dimensional images, each representing one breathing phase. These images are analyzed to measure organ motion between each phase. The displacement from end expiration is compared to a displacement limit that represents acceptable dosimetric results (5 mm). Results: The organs measured in 13 patients were the liver, spleen, and left and right kidneys. Their average superior to inferior absolute displacements were 1.3 cm for the liver, 1.3 cm for the spleen, 1.1 cm for the left kidney, and 1.3 cm for the right kidney. Although the organ paths varied among patients, 5 mm of superior to inferior displacement from end expiration resulted in less than 5 mm of displacement in the other directions for 41 of 43 organs measured. Conclusions: Four-dimensional CT scanning can accurately measure abdominal organ motion throughout respiration. This information may result in greater organ sparing and planning target volume coverage.

  1. Improving optical bench radius measurements using stage error motion data

    SciTech Connect

    Schmitz, Tony L.; Gardner, Neil; Vaughn, Matthew; Medicus, Kate; Davies, Angela

    2008-12-20

    We describe the application of a vector-based radius approach to optical bench radius measurements in the presence of imperfect stage motions. In this approach, the radius is defined using a vector equation and homogeneous transformation matrix formulism. This is in contrast to the typical technique, where the displacement between the confocal and cat's eye null positions alone is used to determine the test optic radius. An important aspect of the vector-based radius definition is the intrinsic correction for measurement biases, such as straightness errors in the stage motion and cosine misalignment between the stage and displacement gauge axis, which lead to an artificially small radius value if the traditional approach is employed. Measurement techniques and results are provided for the stage error motions, which are then combined with the setup geometry through the analysis to determine the radius of curvature for a spherical artifact. Comparisons are shown between the new vector-based radius calculation, traditional radius computation, and a low uncertainty mechanical measurement. Additionally, the measurement uncertainty for the vector-based approach is determined using Monte Carlo simulation and compared to experimental results.

  2. Solving the aerodynamics of fungal flight: how air viscosity slows spore motion.

    PubMed

    Fischer, Mark W F; Stolze-Rybczynski, Jessica L; Davis, Diana J; Cui, Yunluan; Money, Nicholas P

    2010-01-01

    Viscous drag causes the rapid deceleration of fungal spores after high-speed launches and limits discharge distance. Stokes' law posits a linear relationship between drag force and velocity. It provides an excellent fit to experimental measurements of the terminal velocity of free-falling spores and other instances of low Reynolds number motion (Re<1). More complex, non-linear drag models have been devised for movements characterized by higher Re, but their effectiveness for modeling the launch of fast-moving fungal spores has not been tested. In this paper, we use data on spore discharge processes obtained from ultra-high-speed video recordings to evaluate the effects of air viscosity predicted by Stokes' law and a commonly used non-linear drag model. We find that discharge distances predicted from launch speeds by Stokes' model provide a much better match to measured distances than estimates from the more complex drag model. Stokes' model works better over a wide range projectile sizes, launch speeds, and discharge distances, from microscopic mushroom ballistospores discharged at <1 m s(-1) over a distance of <0.1mm (Re<1.0), to macroscopic sporangia of Pilobolus that are launched at >10 m s(-1) and travel as far as 2.5m (Re>100). PMID:21036338

  3. Solving the aerodynamics of fungal flight: How air viscosity slows spore motion

    PubMed Central

    Fischer, Mark W. F.; Stolze-Rybczynski, Jessica L.; Davis, Diana J.; Cui, Yunluan; Money, Nicholas P.

    2010-01-01

    Viscous drag causes the rapid deceleration of fungal spores after high-speed launches and limits discharge distance. Stokes' law posits a linear relationship between drag force and velocity. It provides an excellent fit to experimental measurements of the terminal velocity of free-falling spores and other instances of low Reynolds number motion (Re<1). More complex, non-linear drag models have been devised for movements characterized by higher Re, but their effectiveness for modeling the launch of fast-moving fungal spores has not been tested. In this paper, we use data on spore discharge processes obtained from ultra-high-speed video recordings to evaluate the effects of air viscosity predicted by Stokes' law and a commonly used non-linear drag model. We find that discharge distances predicted from launch speeds by Stokes' model provide a much better match to measured distances than estimates from the more complex drag model. Stokes' model works better over a wide range projectile sizes, launch speeds, and discharge distances, from microscopic mushroom ballistospores discharged at <1 m/s over a distance of <0.1 mm (Re<1.0), to macroscopic sporangia of Pilobolus that are launched at >10 m/s and travel as far as 2.5 m (Re>100). PMID:21036338

  4. Air-coupled ultrasonic measurements in composites

    NASA Astrophysics Data System (ADS)

    Kommareddy, Vamshi; Peters, John J.; Hsu, David K.

    2005-04-01

    Air-coupled ultrasound is a non-contact technique and has clear advantages over water-coupled testing. This work aims at gaining quantitative understanding of the principles underlining air-coupled ultrasonic measurement. The transmission of air-coupled ultrasonic energy through a plate is measured experimentally; model calculation of the transmission coefficient, taking into account the real transducer characteristics, is compared with the experimental results. The occurrence of "Poisson bright spot" in the flaw images of thin laminates and honeycomb composites were investigated; A qualitative comparison with a model based on the Fresnel's wave theory of light is discussed. Through transmission C-scans at 120 and 400 kHz using focused transmitter and receiver were studied.

  5. Dimensional coordinate measurements: application in characterizing cervical spine motion

    NASA Astrophysics Data System (ADS)

    Zheng, Weilong; Li, Linan; Wang, Shibin; Wang, Zhiyong; Shi, Nianke; Xue, Yuan

    2014-06-01

    Cervical spine as a complicated part in the human body, the form of its movement is diverse. The movements of the segments of vertebrae are three-dimensional, and it is reflected in the changes of the angle between two joint and the displacement in different directions. Under normal conditions, cervical can flex, extend, lateral flex and rotate. For there is no relative motion between measuring marks fixed on one segment of cervical vertebra, the cervical vertebrae with three marked points can be seen as a body. Body's motion in space can be decomposed into translational movement and rotational movement around a base point .This study concerns the calculation of dimensional coordinate of the marked points pasted to the human body's cervical spine by an optical method. Afterward, these measures will allow the calculation of motion parameters for every spine segment. For this study, we choose a three-dimensional measurement method based on binocular stereo vision. The object with marked points is placed in front of the CCD camera. Through each shot, we will get there two parallax images taken from different cameras. According to the principle of binocular vision we can be realized three-dimensional measurements. Cameras are erected parallelly. This paper describes the layout of experimental system and a mathematical model to get the coordinates.

  6. Integrated motion measurement illustrated by a cantilever beam

    NASA Astrophysics Data System (ADS)

    Örtel, T.; Wagner, J. F.; Saupe, F.

    2013-01-01

    The combination of inertial sensors and satellite navigation receivers like those of GPS (Global Positioning System) represents a very typical integrated navigation system. Integrated navigation is the most common example of integrated motion measurement determining the translational and angular position, velocity, and acceleration of a vehicle. Traditionally, this object is assumed to be a rigid body and the signals of its closely spaced sensors are referenced to a single point of the structure. During periods of low vehicle dynamics such common navigation systems typically show stability problems due to a loss of observability of some of the motion variables. The range of applications for integrated navigation systems can be expanded due to the continuously increasing performance of data processing and cheap sensors. Further, it can be shown that the stability of such a navigation system (i. e. of the motion observer employed for the system, typically a Kalman filter) can be sustained by distributing appropriately additional sensors over the vehicle structures at distinct locations. This comprises the compensation of drift effects of the system by adding sensors that are drift-free and the guarantee of the observability of all estimated motion components. Large structures like airplanes, space stations, skyscrapers, and tower cranes with distributed sensors, however, have to take the flexibility of the structure into account. This includes an appropriate kinematical model of the structure. In this case, the theory of integrated systems has to be expanded to flexible structures. On the other hand, the additional system information obtained can be used not only for vehicle guidance but also for structural control. Within this work individual kinematical models especially of a cantilever beam, idealizing e.g. the wing of an airplane, are developed and investigated with regard to the observability of the motion variables to guarantee a stable integrated system

  7. Air Pressure Controlled Mass Measurement System

    NASA Astrophysics Data System (ADS)

    Zhong, Ruilin; Wang, Jian; Cai, Changqing; Yao, Hong; Ding, Jin'an; Zhang, Yue; Wang, Xiaolei

    Mass measurement is influenced by air pressure, temperature, humidity and other facts. In order to reduce the influence, mass laboratory of National Institute of Metrology, China has developed an air pressure controlled mass measurement system. In this system, an automatic mass comparator is installed in an airtight chamber. The Chamber is equipped with a pressure controller and associate valves, thus the air pressure can be changed and stabilized to the pre-set value, the preferred pressure range is from 200 hPa to 1100 hPa. In order to keep the environment inside the chamber stable, the display and control part of the mass comparator are moved outside the chamber, and connected to the mass comparator by feed-throughs. Also a lifting device is designed for this system which can easily lift up the upper part of the chamber, thus weights can be easily put inside the mass comparator. The whole system is put on a marble platform, and the temperature and humidity of the laboratory is very stable. The temperature, humidity, and carbon dioxide content inside the chamber are measured in real time and can be used to get air density. Mass measurement cycle from 1100 hPa to 200 hPa and back to 1100 hPa shows the effective of the system.

  8. Measuring Air Density in the Introductory Lab

    ERIC Educational Resources Information Center

    Calza, G.; Gratton, L. M.; Lopez-Arias, T.; Oss, S.

    2010-01-01

    The measurement of the mass, or the density, of air can easily be done with very simple materials and offers many interesting phenomena for discussion--buoyancy and its effects being the most obvious but not the only one. Many interesting considerations can be done regarding the behavior of gases, the effect of the external conditions in the…

  9. Measure Guideline: Guide to Attic Air Sealing

    SciTech Connect

    Lstiburek, J.

    2014-09-01

    The Guide to Attic Air Sealing was completed in 2010 and although not in the standard Measure Guideline format, is intended to be a Measure Guideline on Attic Air Sealing. The guide was reviewed during two industry stakeholders meetings held on December 18th, 2009 and January 15th, 2010, and modified based on the comments received. Please do not make comments on the Building America format of this document. The purpose of the Guide to Attic Air Sealing is to provide information and recommendations for the preparation work necessary prior to adding attic insulation. Even though the purpose of this guide is to save energy - health, safety and durability should not be compromised by energy efficiency. Accordingly, combustion safety and ventilation for indoor air quality are addressed first. Durability and attic ventilation then follow. Finally, to maximize energy savings, air sealing is completed prior to insulating. The guide is intended for home remodelers, builders, insulation contractors, mechanical contractors, general contractors who have previously done remodeling and homeowners as a guide to the work that needs to be done.

  10. Measured quantum probability distribution functions for Brownian motion

    SciTech Connect

    Ford, G. W.; O'Connell, R. F.

    2007-10-15

    The quantum analog of the joint probability distributions describing a classical stochastic process is introduced. A prescription is given for constructing the quantum distribution associated with a sequence of measurements. For the case of quantum Brownian motion this prescription is illustrated with a number of explicit examples. In particular, it is shown how the prescription can be extended in the form of a general formula for the Wigner function of a Brownian particle entangled with a heat bath.

  11. Review of air flow measurement techniques

    SciTech Connect

    McWilliams, Jennifer

    2002-12-01

    Airflow measurement techniques are necessary to determine the most basic of indoor air quality questions: ''Is there enough fresh air to provide a healthy environment for the occupants of the building?'' This paper outlines airflow measurement techniques, but it does not make recommendations for techniques that should be used. The airflows that will be discussed are those within a room or zone, those between rooms or zones, such as through doorways (open or closed) or passive vents, those between the building and outdoors, and those through mechanical air distribution systems. Techniques that are highlighted include particle streak velocimetry, hot wire anemometry, fan pressurization (measuring flow at a given pressure), tracer gas, acoustic methods for leak size determination, the Delta Q test to determine duct leakage flows, and flow hood measurements. Because tracer gas techniques are widely used to measure airflow, this topic is broken down into sections as follows: decay, pulse injection, constant injection, constant concentration, passive sampling, and single and multiple gas measurements for multiple zones.

  12. Laser photoacoustic sensor for air toxicity measurements

    NASA Astrophysics Data System (ADS)

    Prasad, Coorg R.; Lei, Jie; Shi, Wenhui; Li, Guangkun; Dunayevskiy, Ilya; Patel, C. Kumar N.

    2012-06-01

    US EPA's Clean Air Act lists 187 hazardous air pollutants (HAP) or airborne toxics that are considered especially harmful to health, and hence the measurement of their concentration is of great importance. Numerous sensor systems have been reported for measuring these toxic gases and vapors. However, most of these sensors are specific to a single gas or able to measure only a few of them. Thus a sensor capable of measuring many of the toxic gases simultaneously is desirable. Laser photoacoustic spectroscopy (LPAS) sensors have the potential for true broadband measurement when used in conjunction with one or more widely tunable laser sources. An LPAS gas analyzer equipped with a continuous wave, room temperature IR Quantum Cascade Laser tunable over the wavelength range of 9.4 μm to 9.7 μm was used for continuous real-time measurements of multiple gases/chemical components. An external cavity grating tuner was used to generate several (75) narrow line output wavelengths to conduct photoacoustic absorption measurements of gas mixtures. We have measured various HAPs such as Benzene, Formaldehyde, and Acetaldehyde in the presence of atmospheric interferents water vapor, and carbon dioxide. Using the preliminary spectral pattern recognition algorithm, we have shown our ability to measure all these chemical compounds simultaneously in under 3 minutes. Sensitivity levels of a few part-per-billion (ppb) were achieved with several of the measured compounds with the preliminary laboratory system.

  13. Measure Guideline: Guide to Attic Air Sealing

    SciTech Connect

    Lstiburek, Joseph

    2014-09-01

    The purpose of this measure guideline is to provide information and recommendations for the preparation work necessary prior to adding attic insulation. Even though the purpose of this guide is to save energy, health, safety, and durability should not be compromised by energy efficiency. Accordingly, combustion safety and ventilation for indoor air quality are addressed first. Durability and attic ventilation then follow. Finally, to maximize energy savings, air sealing is completed prior to insulating. The guide is intended for home remodelers, builders, insulation contractors, mechanical contractors, general contractors who have previously done remodeling and homeowners as a guide to the work that needs to be done.

  14. Velocity measurements by laser resonance fluorescence. [single atom diffusional motion

    NASA Technical Reports Server (NTRS)

    She, C. Y.; Fairbank, W. M., Jr.

    1980-01-01

    The photonburst correlation method was used to detect single atoms in a buffer gas. Real time flow velocity measurements with laser induced resonance fluorescence from single or multiple atoms was demonstrated and this method was investigated as a tool for wind tunnel flow measurement. Investigations show that single atoms and their real time diffusional motion on a buffer gas can be measured by resonance fluorescence. By averaging over many atoms, flow velocities up to 88 m/s were measured in a time of 0.5 sec. It is expected that higher flow speeds can be measured and that the measurement time can be reduced by a factor of 10 or more by careful experimental design. The method is clearly not ready for incorporation in high speed wind tunnels because it is not yet known whether the stray light level will be higher or lower, and it is not known what detection efficiency can be obtained in a wind tunnel situation.

  15. 40 CFR 91.416 - Intake air flow measurement specifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Intake air flow measurement... Procedures § 91.416 Intake air flow measurement specifications. (a) If used, the engine intake air flow measurement method used must have a range large enough to accurately measure the air flow over the...

  16. DCShake: Measuring Variations in Earthquake Ground Motions in Washington, DC

    NASA Astrophysics Data System (ADS)

    Pratt, T. L.; Horton, J. W., Jr.; Hough, S. E.; Munoz, J.; Chapman, M. C.; Olgun, G.; Beale, J.

    2015-12-01

    During the 2011 Mw5.8 Mineral, VA earthquake, many buildings in Washington DC, including national landmarks like the Washington National Cathedral, the Smithsonian "Castle," and the Washington Monument, sustained damage despite being 130 km from the epicenter. The surprisingly large amount of damage from weak bedrock ground motions raises questions of whether and how the local geologic materials beneath the city amplify ground motions. In particular, how much and at what frequencies do the southeast-thickening sedimentary strata of the Atlantic Coastal Plain (ACP) strata, sitting on crystalline bedrock, amplify and possibly trap energy? Between November 2014 and August 2015, we used 27 seismometers to measure ground motions across the city during teleseismic and regional earthquakes. Four sites on Piedmont crystalline rocks in NW Washington served as bedrock reference sites, and 23 sites were on ACP strata between 11 m and 200 m thick. Recordings of teleseisms and regional earthquakes provide data with sufficiently high signal-to-noise for computing spectral ratios of the horizontal ground shaking relative to the average of the 4 bedrock sites. Preliminary results are consistent with the primary influence on the amplitudes of ground motions coming from the ACP strata. At frequencies below 1 Hz most sites showed little difference in amplification relative to bedrock, suggesting that basement rocks beneath the ACP strata exert little influence on ground shaking. Strong spectral amplifications of a factor or 10 or greater at frequencies of 1 Hz and above are interpreted as being caused by the ACP strata, with the largest amplitudes at frequencies near the fundamental resonance frequency. A gradual decrease in amplification with higher frequencies above the fundamental peak is consistent with harmonics and resonances from within ACP strata. Results indicate significant amplification of ground motions in the DC area, the frequencies of which will be compared to the

  17. A disk-type capacitive sensor for five-dimensional motion measurements

    NASA Astrophysics Data System (ADS)

    Ahn, Hyeong-Joon; Park, Jung-Ho; Um, Chang-Yong; Han, Dong-Chul

    2008-04-01

    This paper presents a disk-type capacitive sensor for the simultaneous measurement of five-dimensional motions of a target. The sensor detects both air gap and mutual area changes for these five-dimensional motions. In addition, the sensor is manufactured with a printed circuit board (PCB), which reduces manufacturing costs. The sensor is optimally designed through both an error analysis of possible mechanical errors and a finite element analysis of the parasitic capacitances. Furthermore, the sensor can correct measurement errors due to the initial misalignment between the sensor and the target. A prototype PCB sensor, electronics and a test rig were built, and the effectiveness of the developed sensor was proved through experiments.

  18. 40 CFR 89.326 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine intake air humidity measurement... Test Equipment Provisions § 89.326 Engine intake air humidity measurement. (a) Humidity conditioned air supply. Air that has had its absolute humidity altered is considered humidity- conditioned air. For...

  19. 40 CFR 89.326 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine intake air humidity measurement... Test Equipment Provisions § 89.326 Engine intake air humidity measurement. (a) Humidity conditioned air supply. Air that has had its absolute humidity altered is considered humidity- conditioned air. For...

  20. 40 CFR 89.326 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine intake air humidity measurement... Test Equipment Provisions § 89.326 Engine intake air humidity measurement. (a) Humidity conditioned air supply. Air that has had its absolute humidity altered is considered humidity- conditioned air. For...

  1. 40 CFR 89.326 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine intake air humidity measurement... Test Equipment Provisions § 89.326 Engine intake air humidity measurement. (a) Humidity conditioned air supply. Air that has had its absolute humidity altered is considered humidity- conditioned air. For...

  2. 40 CFR 89.326 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air humidity measurement... Test Equipment Provisions § 89.326 Engine intake air humidity measurement. (a) Humidity conditioned air supply. Air that has had its absolute humidity altered is considered humidity- conditioned air. For...

  3. Surface deposition of 222Rn decay products with and without enhanced air motion.

    PubMed

    Rudnick, S N; Maher, E F

    1986-09-01

    The effectiveness of fan-induced air motion in reducing airborne activities of short-lived 222Rn decay products was evaluated in a 78.5-m3 chamber. Observed reductions were as high as 50% for 218Po (RaA), 79% for 214Pb (RaB), and 86% for 214Bi (RaC). Activity measurements of these nuclides on chamber and fan surfaces, along with airborne activities, were used to calculate material balances. Greater than about 90% of deposited activity was found on chamber surfaces, although areal activity densities were higher on fan surfaces. Deposition velocities for decay products not attached to particles were 2.3 mm s-1 when no fans were in operation and 9.2 to 13 mm s-1 when fans were used. Mean boundary layer thicknesses for unattached decay products were estimated to be about four times the recoil distance of a 214Pb atom when no fans were used and about equal to the recoil distance when fans were used. PMID:3744829

  4. Surface deposition of 222Rn decay products with and without enhanced air motion

    SciTech Connect

    Rudnick, S.N.; Maher, E.F.

    1986-09-01

    The effectiveness of fan-induced air motion in reducing airborne activities of short-lived /sup 222/Rn decay products was evaluated in a 78.5-m3 chamber. Observed reductions were as high as 50% for 218Po (RaA), 79% for /sup 214/Pb (RaB), and 86% for /sup 214/Bi (RaC). Activity measurements of these nuclides on chamber and fan surfaces, along with airborne activities, were used to calculate material balances. Greater than about 90% of deposited activity was found on chamber surfaces, although areal activity densities were higher on fan surfaces. Deposition velocities for decay products not attached to particles were 2.3 mm s-1 when no fans were in operation and 9.2 to 13 mm s-1 when fans were used. Mean boundary layer thicknesses for unattached decay products were estimated to be about four times the recoil distance of a /sup 214/Pb atom when no fans were used and about equal to the recoil distance when fans were used.

  5. Amine Measurements in Boreal Forest Air

    NASA Astrophysics Data System (ADS)

    Hemmilä, Marja; Hellén, Heidi; Makkonen, Ulla; Hakola, Hannele

    2015-04-01

    Amines are reactive, volatile bases in the air with a general formula of RNH2, R2NH or R3N. Especially small amines can stabilize sulphuric acid clusters and hence affect nucleation. Amines react rapidly with hydroxyl radical (OH˙) thus affecting oxidative capacity of the atmosphere. The amine concentrations are higher in forest air than in urban air (Hellén et al., 2014), but the sources are not known. In order to get more information concerning amine sources, we conducted a measurement campaign in a boreal forest. At SMEAR II station at Hyytiälä, Southern Finland (61°510'N, 24°170'E, 180 m a.s.l.) The measurements cover seven months, from June to December 2014. For sampling and measuring we used MARGA (The instrument for Measuring AeRosols and Gases in Ambient air) which is an on-line ion chromatograph (IC) connected to a sampling system. The IC component of the MARGA system was coupled to an electrospray ionization quadrupole mass spectrometer (MS) to improve sensitivity of amine measurements. This new set-up enabled amine concentration measurements in ambient air both in aerosol and gas phases with a time resolution of only 1 hour. With MARGA-MS we analysed 7 different amines: monomethylamine (MMA), dimethylamine (DMA), trimethylamine (TMA), ethylamine (EA), diethylamine (DEA), propylamine (PA) and butylamine (BA). In preliminary data-analysis we found out, that in June and July most of the measured amines were in gas phase, and particle phase amine concentrations were mostly under detection limits (<1.7 pptv). In June the gaseous amine concentrations were higher than in July. The measured concentrations of gaseous amines followed temperature variation, which could indicate that amines are produced and emitted from the environment or re-emitted from the surfaces as temperature rises after deposition during night-time. All measured amines had similar diurnal variation with maxima during afternoon and minima during night. Results from other months will also

  6. On modeling animal movements using Brownian motion with measurement error.

    PubMed

    Pozdnyakov, Vladimir; Meyer, Thomas; Wang, Yu-Bo; Yan, Jun

    2014-02-01

    Modeling animal movements with Brownian motion (or more generally by a Gaussian process) has a long tradition in ecological studies. The recent Brownian bridge movement model (BBMM), which incorporates measurement errors, has been quickly adopted by ecologists because of its simplicity and tractability. We discuss some nontrivial properties of the discrete-time stochastic process that results from observing a Brownian motion with added normal noise at discrete times. In particular, we demonstrate that the observed sequence of random variables is not Markov. Consequently the expected occupation time between two successively observed locations does not depend on just those two observations; the whole path must be taken into account. Nonetheless, the exact likelihood function of the observed time series remains tractable; it requires only sparse matrix computations. The likelihood-based estimation procedure is described in detail and compared to the BBMM estimation. PMID:24669719

  7. Simplified motional heating rate measurements of trapped ions

    SciTech Connect

    Epstein, R. J.; Seidelin, S.; Leibfried, D.; Wesenberg, J. H.; Bollinger, J. J.; Amini, J. M.; Blakestad, R. B.; Britton, J.; Home, J. P.; Itano, W. M.; Jost, J. D.; Knill, E.; Langer, C.; Ozeri, R.; Shiga, N.; Wineland, D. J.

    2007-09-15

    We have measured motional heating rates of trapped atomic ions, a factor that can influence multi-ion quantum logic gate fidelities. Two simplified techniques were developed for this purpose: one relies on Raman sideband detection implemented with a single laser source, while the second is even simpler and is based on time-resolved fluorescence detection during Doppler recooling. We applied these methods to determine heating rates in a microfrabricated surface-electrode trap made of gold on fused quartz, which traps ions 40 {mu}m above its surface. Heating rates obtained from the two techniques were found to be in reasonable agreement. In addition, the trap gives rise to a heating rate of 300{+-}30 s{sup -1} for a motional frequency of 5.25 MHz, substantially below the trend observed in other traps.

  8. Exposure measurement for air-pollution epidemiology

    SciTech Connect

    Ferris, B.G.; Ware, J.H.; Spengler, J.D.

    1988-08-01

    The chapter describes the evolution of air-pollution epidemiology over a period when changes in pollution technologies have both lowered total exposures and dispersed them over vastly greater areas. Since personal exposure and microenvironmental measurements are expensive, studies oriented toward measurements of total exposure will be smaller and more intensive. The shift in emphasis to total human exposure also will affect health risk assessment and raise difficult issues in the regulatory domain. Considering that outdoor exposures (for which EPA has a regulatory mandate) occur in the context of exposures from other sources, the potential effect of regulatory action would probably be small. The regulatory issues are even more difficult for particulate air pollution since cigarette smoking is the strongest determinant of indoor levels but the EPA lacks regulatory responsibility for cigarette smoke.

  9. 40 CFR 89.414 - Air flow measurement specifications.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Air flow measurement specifications. 89.414 Section 89.414 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Emission Test Procedures § 89.414 Air flow measurement specifications. (a) The air flow measurement...

  10. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  11. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  12. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  13. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  14. 40 CFR 91.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine intake air temperature... Provisions § 91.309 Engine intake air temperature measurement. (a) Engine intake air temperature measurement... the supply system or in the air stream entering the engine. (b) The temperature measurements must...

  15. 40 CFR 89.414 - Air flow measurement specifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Air flow measurement specifications. 89.414 Section 89.414 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Emission Test Procedures § 89.414 Air flow measurement specifications. (a) The air flow measurement...

  16. 40 CFR 91.310 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine intake air humidity measurement... Provisions § 91.310 Engine intake air humidity measurement. This section refers to engines which are supplied... air, the ambient testcell humidity measurement may be used. (a) Humidity conditioned air supply....

  17. 40 CFR 91.310 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine intake air humidity measurement... Provisions § 91.310 Engine intake air humidity measurement. This section refers to engines which are supplied... air, the ambient testcell humidity measurement may be used. (a) Humidity conditioned air supply....

  18. 40 CFR 91.310 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air humidity measurement... Provisions § 91.310 Engine intake air humidity measurement. This section refers to engines which are supplied... air, the ambient testcell humidity measurement may be used. (a) Humidity conditioned air supply....

  19. 40 CFR 91.310 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine intake air humidity measurement... Provisions § 91.310 Engine intake air humidity measurement. This section refers to engines which are supplied... air, the ambient testcell humidity measurement may be used. (a) Humidity conditioned air supply....

  20. 40 CFR 91.310 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine intake air humidity measurement... Provisions § 91.310 Engine intake air humidity measurement. This section refers to engines which are supplied... air, the ambient testcell humidity measurement may be used. (a) Humidity conditioned air supply....

  1. Methodological aspects of EEG and body dynamics measurements during motion

    PubMed Central

    Reis, Pedro M. R.; Hebenstreit, Felix; Gabsteiger, Florian; von Tscharner, Vinzenz; Lochmann, Matthias

    2014-01-01

    EEG involves the recording, analysis, and interpretation of voltages recorded on the human scalp which originate from brain gray matter. EEG is one of the most popular methods of studying and understanding the processes that underlie behavior. This is so, because EEG is relatively cheap, easy to wear, light weight and has high temporal resolution. In terms of behavior, this encompasses actions, such as movements that are performed in response to the environment. However, there are methodological difficulties which can occur when recording EEG during movement such as movement artifacts. Thus, most studies about the human brain have examined activations during static conditions. This article attempts to compile and describe relevant methodological solutions that emerged in order to measure body and brain dynamics during motion. These descriptions cover suggestions on how to avoid and reduce motion artifacts, hardware, software and techniques for synchronously recording EEG, EMG, kinematics, kinetics, and eye movements during motion. Additionally, we present various recording systems, EEG electrodes, caps and methods for determinating real/custom electrode positions. In the end we will conclude that it is possible to record and analyze synchronized brain and body dynamics related to movement or exercise tasks. PMID:24715858

  2. Methodological aspects of EEG and body dynamics measurements during motion.

    PubMed

    Reis, Pedro M R; Hebenstreit, Felix; Gabsteiger, Florian; von Tscharner, Vinzenz; Lochmann, Matthias

    2014-01-01

    EEG involves the recording, analysis, and interpretation of voltages recorded on the human scalp which originate from brain gray matter. EEG is one of the most popular methods of studying and understanding the processes that underlie behavior. This is so, because EEG is relatively cheap, easy to wear, light weight and has high temporal resolution. In terms of behavior, this encompasses actions, such as movements that are performed in response to the environment. However, there are methodological difficulties which can occur when recording EEG during movement such as movement artifacts. Thus, most studies about the human brain have examined activations during static conditions. This article attempts to compile and describe relevant methodological solutions that emerged in order to measure body and brain dynamics during motion. These descriptions cover suggestions on how to avoid and reduce motion artifacts, hardware, software and techniques for synchronously recording EEG, EMG, kinematics, kinetics, and eye movements during motion. Additionally, we present various recording systems, EEG electrodes, caps and methods for determinating real/custom electrode positions. In the end we will conclude that it is possible to record and analyze synchronized brain and body dynamics related to movement or exercise tasks. PMID:24715858

  3. Sea ice motion measurements from Seasat SAR images

    NASA Technical Reports Server (NTRS)

    Leberl, F.; Raggam, J.; Elachi, C.; Campbell, W. J.

    1983-01-01

    Data from the Seasat synthetic aperture radar (SAR) experiment are analyzed in order to determine the accuracy of this information for mapping the distribution of sea ice and its motion. Data from observations of sea ice in the Beaufort Sea from seven sequential orbits of the satellite were selected to study the capabilities and limitations of spaceborne radar application to sea-ice mapping. Results show that there is no difficulty in identifying homologue ice features on sequential radar images and the accuracy is entirely controlled by the accuracy of the orbit data and the geometric calibration of the sensor. Conventional radargrammetric methods are found to serve well for satellite radar ice mapping, while ground control points can be used to calibrate the ice location and motion measurements in the cases where orbit data and sensor calibration are lacking. The ice motion was determined to be approximately 6.4 + or - 0.5 km/day. In addition, the accuracy of pixel location was found over land areas. The use of one control point in 10,000 sq km produced an accuracy of about + or 150 m, while with a higher density of control points (7 in 1000 sq km) the location accuracy improves to the image resolution of + or - 25 m. This is found to be applicable for both optical and digital data.

  4. Turbulence measurements in axisymmetric jets of air and helium

    NASA Astrophysics Data System (ADS)

    Panchapakesan, N. R.

    Turbulent axisymmetric jets of air helium with the same nozzle momentum flux were studied experimentally using hot-wire probes. An X-wire hot-wire probe was used in the air jet and a composite probe consisting of an X-wire and an interference probe of the Way-Libby type was used in the helium jet to measure the helium concentration and two velocity components. Moments of turbulent fluctuations, up to fourth order, were calculated to characterize turbulent transport in the jet and to evaluate current models for triple moments that occur in the Reynolds stress equation. In the air jet, the momentum flux across the jet was found to be within +/- 5 percent of the nozzle input and the integral of the radial diffusive flux of the turbulent kinetic energy across the jet was found to be close to zero indicating consistency of measurements with the equations of motion. The fourth moments were very well described in terms of the second moments by the quasi-Gaussian approximation across the entire jet. Profiles of third moments were found to be significantly different from earlier measurements - (u(v exp 2)) (u(w exp 2)) and ((u exp 2)v) were found to be negative near the axis of the jet. The measurements in the helium jet were in the intermediate region between the non-buoyant jet and the plume regions. The helium mass flux across the jet was found to be within +/- 0 percent of the nozzle input. The far field behavior was in accord with the expected plume scalings. The near field behavior of the mean velocity along the axis of the jet follows the scaling expressed by the effective diameter but the mean concentration decay has a different density ratio dependence. The radical profiles of mean velocity and concentration indicate a turbulent Schmidt number of 0.7, the same as for passive scalars in round jets. Turbulent intensity of axial velocity fluctuations was significantly higher than that observed in the air jet while the radial and azimuthal intensities are virtually

  5. Measurement of air entrainment in plasma jets

    SciTech Connect

    Fincke, J.R.; Rodriquez, R.; Pentecost, C.G.

    1990-01-01

    The concentration and temperature of air entrained into argon and helium plasma jets has been measured using coherent anti-Stokes Raman spectroscopy (CARS). The argon plasma flow field is characterized by a short region of well behaved laminar flow near the nozzle exit followed by an abrupt transition to turbulence. Once the transition of turbulence occurs, air is rapidly mixed into the jet core. The location of the transition region is determined by the rapid cooling of the jet and the resulting increase in Reynolds number. In contrast, the helium plasma flow field never exceeds a Reynolds number of 200 and remains laminar. The entrainment process in this case is controlled by molecular diffusion rather than turbulent mixing. 9 refs., 5 figs., 1 tab.

  6. Measurement of air entrainment in plasma jets

    NASA Astrophysics Data System (ADS)

    Fincke, J. R.; Rodriquez, R.; Pentecost, C. G.

    The concentration and temperature of air entrained into argon and helium plasma jets has been measured using coherent anti-Stokes Raman spectroscopy (CARS). The argon plasma flow field is characterized by a short region of well behaved laminar flow near the nozzle exit followed by an abrupt transition to turbulence. Once the transition of turbulence occurs, air is rapidly mixed into the jet core. The location of the transition region is determined by the rapid cooling of the jet and the resulting increase in Reynolds number. In contrast, the helium plasma flow field never exceeds a Reynolds number of 200 and remains laminar. The entrainment process in this case is controlled by molecular diffusion rather than turbulent mixing.

  7. Kerbside DOAS measurements of air pollutants

    NASA Astrophysics Data System (ADS)

    Schäfer, Klaus; Ling, Hong; Legelli, Stefan; Münkel, Christoph; Emeis, Stefan

    2014-10-01

    Emission sources as well as wind speed and direction and MLH are important factors which influence high air pollutant concentrations. This is generally known (Schäfer et al., 2006) but the detailed understanding of processes directing certain air pollutant concentrations like HCHO is not complete. To study these processes a long-term campaign in Augsburg, Germany, was performed since March 2012. The concentrations of NO, NO2, O3 and HCHO, which were measured with a DOAS from OPSIS across a main traffic road and a nearby park area, are analysed. A ceilometer CL31 from Vaisala which is an eye-safe commercial mini-lidar system is applied to detect layering of the lower atmosphere continuously. Special software for this ceilometer with MATLAB provides routine retrievals of lower atmosphere layering from vertical profiles of laser backscatter data. Meteorological data were measured by a ground-based weather station at the measurement site as well as taken from monitoring data archives of the German National Meteorological Service (DWD), which are measured by radiosondes (Oberschleißheim). Correlation analyses are applied to show the coupling of temporal variations of NO, NO2, O3 and HCHO concentrations with temperature, mixing layer height and wind speed. HCHO which is emitted from both anthropogenic and biogenic sources is studied especially.

  8. Correlated Protein Motion Measurements of Dihydrofolate Reductase Crystals

    NASA Astrophysics Data System (ADS)

    Xu, Mengyang; Niessen, Katherine; Pace, James; Cody, Vivian; Markelz, Andrea

    2014-03-01

    We report the first direct measurements of the long range structural vibrational modes in dihydrofolate reductase (DHFR). DHFR is a universal housekeeping enzyme that catalyzes the reduction of 7,8-dihydrofolate to 5,6,7,8-tetra-hydrofolate, with the aid of coenzyme nicotinamide adenine dinucleotide phosphate (NADPH). This crucial enzymatic role as the target for anti-cancer [methotrexate (MTX)], and other clinically useful drugs, has made DHFR a long-standing target of enzymological studies. The terahertz (THz) frequency range (5-100 cm-1), corresponds to global correlated protein motions. In our lab we have developed Crystal Anisotropy Terahertz Microscopy (CATM), which directly measures these large scale intra-molecular protein vibrations, by removing the relaxational background of the solvent and residue side chain librational motions. We demonstrate narrowband features in the anisotropic absorbance for mouse DHFR with the ligand binding of NADPH and MTX single crystals as well as Escherichia coli DHFR with the ligand binding of NADPH and MTX single crystals. This work is supported by NSF grant MRI2 grant DBI2959989.

  9. Measurement Performance of a Computer Assisted Vertebral Motion Analysis System

    PubMed Central

    Davis, Reginald J.; Lee, David C.; Cheng, Boyle

    2015-01-01

    Background Segmental instability of the lumbar spine is a significant cost within the US health care system; however current thresholds for indication of radiographic instability are not well defined. Purpose To determine the performance measurements of sagittal lumbar intervertebral measurements using computerassisted measurements of the lumbar spine using motion sequences from a video-fluoroscopic technique. Study design Sensitivity, specificity, predictive values, prevalence, and test-retest reliability evaluation of digitized manual versus computer-assisted measurements of the lumbar spine. Patient sample A total of 2239 intervertebral levels from 509 symptomatic patients, and 287 intervertebral levels from 73 asymptomatic participants were retrospectively evaluated. Outcome measures Specificity, sensitivity, negative predictive value (NPV), diagnostic accuracy, and prevalence between the two measurement techniques; Measurements of Coefficient of repeatability (CR), limits of agreement (LOA), intraclass correlation coefficient (ICC; type 3,1), and standard error of measurement for both measurement techniques. Methods Asymptomatic individuals and symptomatic patients were all evaluated using both the Vertebral Motion Analysis (VMA) system and fluoroscopic flexion extension static radiographs (FE). The analysis was compared to known thresholds of 15% intervertebral translation (IVT, equivalent to 5.3mm assuming a 35mm vertebral body depth) and 25° intervertebral rotation (IVR). Results The VMA measurements demonstrated greater specificity, % change in sensitivity, NPV, prevalence, and reliability compared with FE for radiographic evidence of instability. Specificity was 99.4% and 99.1% in the VMA compared to 98.3% and 98.2% in the FE for IVR and IVT, respectively. Sensitivity in this study was 41.2% and 44.6% greater in the VMA compared to the FE for IVR and IVT, respectively. NPV was 91% and 88% in the VMA compared to 62% and 66% in the FE for IVR and IVT

  10. 40 CFR 92.108 - Intake and cooling air measurements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Intake and cooling air measurements. 92.108 Section 92.108 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.108 Intake and cooling air measurements....

  11. 40 CFR 92.108 - Intake and cooling air measurements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... practice J244 (incorporated by reference at § 92.5) are allowed. (b) Humidity and temperature measurements. (1) Air that has had its absolute humidity altered is considered humidity-conditioned air. For this type of intake air supply, the humidity measurements must be made within the intake air supply...

  12. 40 CFR 92.108 - Intake and cooling air measurements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... recommended practice J244 (incorporated by reference at § 92.5) are allowed. (b) Humidity and temperature measurements. (1) Air that has had its absolute humidity altered is considered humidity-conditioned air. For this type of intake air supply, the humidity measurements must be made within the intake air...

  13. 40 CFR 92.108 - Intake and cooling air measurements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... recommended practice J244 (incorporated by reference at § 92.5) are allowed. (b) Humidity and temperature measurements. (1) Air that has had its absolute humidity altered is considered humidity-conditioned air. For this type of intake air supply, the humidity measurements must be made within the intake air...

  14. Mobile VLBI and GPS measurement of vertical crustal motion

    NASA Technical Reports Server (NTRS)

    Kroger, P. M.; Davidson, J. M.; Gardner, E. C.

    1985-01-01

    Mobile Very Long Base Interferometry (VLBI) and Global Positioning System (GPS) geodetic measurements have many error sources in common. Calibration of the effects of water vapor on signal transmission through the atmosphere, however, remains the primary limitation to the accuracy of vertical crustal motion measurements made by either technique. The two primary methods of water vapor calibration currently in use for mobile VLBI baseline measurements were evaluated: radiometric measurements of the sky brightness near the 22 GHz emission line of free water molecules and surface meteorological measurements used as input to an atmospheric model. Based upon a limited set of 9 baselines, it is shown that calibrating VLBI data with water vapor radiometer measurements provides a significantly better fit to the theoretical decay model than calibrating the same data with surface meteorological measurements. The effect of estimating a systematic error in the surface meteorological calibration is shown to improve the consistency of the vertical baseline components obtained by the two calibration methods. A detailed error model for the vertical baseline components obtained indicates current mobile VLBI technology should allow accuracies of order 3 cm with WVR calibration and 10 cm when surface meteorological calibration is used.

  15. Investigation of the motion and heat transfer of water droplets in the swirling air flow in weightlessness

    NASA Astrophysics Data System (ADS)

    Gubaidullin, D. A.; Fedyaev, V. L.; Morenko, I. V.; Snigerev, B. A.; Galimov, E. R.

    2016-06-01

    The motion and heat transfer of water droplets with a swirling air flow is investigated. Flow was considered in a cylindrical chamber in the absence of gravity. We created a mathematical model of this problem and made appropriate calculations. The features of the air flow at a tangential feeding it into the chamber, and the motion of the drops, their thermal behaviour are founded. We presented the recommendations for the rational choice of parameters of the apparatus and rational operation regime.

  16. 40 CFR 89.414 - Air flow measurement specifications.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Air flow measurement specifications. 89... Test Procedures § 89.414 Air flow measurement specifications. (a) The air flow measurement method used... during the test. Overall measurement accuracy must be ± 2 percent of the maximum engine value for...

  17. 40 CFR 89.414 - Air flow measurement specifications.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Air flow measurement specifications... Emission Test Procedures § 89.414 Air flow measurement specifications. (a) The air flow measurement method... during the test. Overall measurement accuracy must be ± 2 percent of the maximum engine value for...

  18. 40 CFR 89.414 - Air flow measurement specifications.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Air flow measurement specifications... Emission Test Procedures § 89.414 Air flow measurement specifications. (a) The air flow measurement method... during the test. Overall measurement accuracy must be ± 2 percent of the maximum engine value for...

  19. 40 CFR 90.416 - Intake air flow measurement specifications.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Intake air flow measurement... Gaseous Exhaust Test Procedures § 90.416 Intake air flow measurement specifications. (a) If used, the engine intake air flow measurement method used must have a range large enough to accurately measure...

  20. Motion observation and SPR measurements of kinesin motility on microtubules

    NASA Astrophysics Data System (ADS)

    Sikora, A.; Oliveira, D.; Kim, K.; Liao, A. L.; Umetsu, M.; Adschiri, T.; Hwang, W.; Teizer, W.

    2012-02-01

    Motor proteins convert chemical energy directly into mechanical work with high efficiency (˜50%). One of these proteins, kinesin, is used in the cell to transport organelles. It ``walks'' along biopolymer tracks called microtubules and, depending on the type, can reach speeds of a few micrometers per second. Kinesin can carry intracellular cargo over long distances against several piconewtons of loads and is barely limited by the cargo size. Motion of streptavidin-coated quantum dots carried by kinesin on microtubules will be presented. We have expressed biotinylated Kinesin-1 using Escherichia coli. Attachment to quantum dots was performed using the strong binding affinity between streptavidin and biotin. Microtubules, labeled with rhodamine, allow visualization by fluorescence microscopy. The measured speed of our kinesin fits well with results found in the literature. Surface Plasmon Resonance (SPR) measurements allow the identification and strength evaluation of bonding. Using this technique, we will present results on the binding between our expressed kinesin and microtubule.

  1. Laser filamentation induced air-flow motion in a diffusion cloud chamber.

    PubMed

    Sun, Haiyi; Liu, Jiansheng; Wang, Cheng; Ju, Jingjing; Wang, Zhanxin; Wang, Wentao; Ge, Xiaochun; Li, Chuang; Chin, See Leang; Li, Ruxin; Xu, Zhizhan

    2013-04-22

    We numerically simulated the air-flow motion in a diffusion cloud chamber induced by femtosecond laser filaments for different chopping rates. A two dimensional model was employed, where the laser filaments were treated as a heat flux source. The simulated patterns of flow fields and maximum velocity of updraft compare well with the experimental results for the chopping rates of 1, 5, 15 and 150 Hz. A quantitative inconsistency appears between simulated and experimental maximum velocity of updraft for 1 kHz repetition rate although a similar pattern of flow field is obtained, and the possible reasons were analyzed. Based on the present simulated results, the experimental observation of more water condensation/snow at higher chopping rate can be explained. These results indicate that the specific way of laser filament heating plays a significant role in the laser-induced motion of air flow, and at the same time, our previous conclusion of air flow having an important effect on water condensation/snow is confirmed. PMID:23609636

  2. Hydrogen-isotope motion in scandium studied by ultrasonic measurements

    SciTech Connect

    Leisure, R.G. ); Schwarz, R.B.; Migliori, A. ); Torgeson, D.R. ); Svare, I. )

    1993-07-01

    Resonant ultrasound spectroscopy has been used to investigate ultrasonic attenuation in single crystals of Sc, ScH[sub 0.25], and ScD[sub 0.18] over the temperature range of 10--300 K for frequencies near 1 MHz. Ultrasonic-attenuation peaks were observed in the samples containing H or D with the maximum attenuation occurring near 25 K for ScH[sub 0.25] and near 50 K for ScD[sub 0.18]. The general features of the data suggest that the motion reflected in the ultrasonic attenuation is closely related to the low-temperature motion seen in nulcear-magnetic-resonance spin-lattice-relaxation measurements. The ultrasonic results were fit with a two-level-system (TLS) model involving tunneling between highly asymmetric sites. The relaxation of the TLS was found to consist of two parts: a weakly temperature-dependent part, probably due to coupling to electrons; and a much more strongly temperature-dependent part, attributed to multiple-phonon processes. The strongly temperature-dependent part was almost two orders of magnitude faster in ScH[sub 0.25] than in ScD[sub 0.18], in accordance with the idea that tunneling is involved in the motion. Surprisingly, the weakly temperature-dependent part was found to be about the same for the two isotopes. The asymmetries primarily responsible for coupling the TLS to the ultrasound are attributed to interactions between hydrogen ions that lie on adjacent [ital c] axes. The results are consistent with an isotope-independent strength for the coupling of the TLS to the ultrasound.

  3. Motion.

    ERIC Educational Resources Information Center

    Gerhart, James B.; Nussbaum, Rudi H.

    This monograph was written for the Conference on the New Instructional Materials in Physics held at the University of Washington in summer, 1965. It is intended for use in an introductory course in college physics. It consists of an extensive qualitative discussion of motion followed by a detailed development of the quantitative methods needed to…

  4. Motion.

    ERIC Educational Resources Information Center

    Brand, Judith, Ed.

    2002-01-01

    This issue of Exploratorium Magazine focuses on the topic of motion. Contents include: (1) "First Word" (Zach Tobias); (2) "Cosmic Collisions" (Robert Irion); (3) "The Mobile Cell" (Karen E. Kalumuck); (4) "The Paths of Paths" (Steven Vogel); (5) "Fragments" (Pearl Tesler); (6) "Moving Pictures" (Amy Snyder); (7) "Plants on the Go" (Katharine…

  5. Patient motion tracking in the presence of measurement errors.

    PubMed

    Haidegger, Tamás; Benyó, Zoltán; Kazanzides, Peter

    2009-01-01

    The primary aim of computer-integrated surgical systems is to provide physicians with superior surgical tools for better patient outcome. Robotic technology is capable of both minimally invasive surgery and microsurgery, offering remarkable advantages for the surgeon and the patient. Current systems allow for sub-millimeter intraoperative spatial positioning, however certain limitations still remain. Measurement noise and unintended changes in the operating room environment can result in major errors. Positioning errors are a significant danger to patients in procedures involving robots and other automated devices. We have developed a new robotic system at the Johns Hopkins University to support cranial drilling in neurosurgery procedures. The robot provides advanced visualization and safety features. The generic algorithm described in this paper allows for automated compensation of patient motion through optical tracking and Kalman filtering. When applied to the neurosurgery setup, preliminary results show that it is possible to identify patient motion within 700 ms, and apply the appropriate compensation with an average of 1.24 mm positioning error after 2 s of setup time. PMID:19964394

  6. Regular oscillations and random motion of glass microspheres levitated by a single optical beam in air

    DOE PAGESBeta

    Moore, Jeremy; Martin, Leopoldo L.; Maayani, Shai; Kim, Kyu Hyun; Chandrahalim, Hengky; Eichenfield, Matt; Martin, Inocencio R.; Carmon, Tal

    2016-02-03

    We experimentally reporton optical binding of many glass particles in air that levitate in a single optical beam. A diversity of particle sizes and shapes interact at long range in a single Gaussian beam. Our system dynamics span from oscillatory to random and dimensionality ranges from 1 to 3D. In conclusion, the low loss for the center of mass motion of the beads could allow this system to serve as a standard many body testbed, similar to what is done today with atoms, but at the mesoscopic scale.

  7. Direct measurement of clarinet air column oscillations

    NASA Astrophysics Data System (ADS)

    Jones, Jesse; Rogers, Chris; French, Chris

    2003-10-01

    The internal oscillation of a clarinet air column has been directly measured through the implementation of hot-wire anemometry. By taking a series of measurements down the centerline of the bore, velocity and pressure modal shapes of individual harmonics are separated, measured, and plotted. Finally, composite averaged power spectra of the internal oscillation are presented and compared to acoustic measurements acquired outside the clarinet. In many cases, the even harmonics of the internal oscillation dominate over the power found in the odd harmonics. This contradicts the classic model of the clarinet as a cylindrical pipe closed at one end and open at the other (where only odd harmonics are produced). Further, the data from the direct velocity measurements also contradict the externally acquired acoustic data, where odd harmonics generally dominate for the lowest 5-9 harmonics. Thus the clarinet, in theory and practice, is generally considered incapable of generating strong even harmonics. In this research, however, it is seen that dominate even harmonics are generated, but the energy for these frequencies is largely trapped inside the clarinet, whereas the energy associated with the odd harmonics is released to the ambient. [This research was conducted with the support of Selmer Musical Instruments.

  8. 40 CFR 89.325 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air temperature... Test Equipment Provisions § 89.325 Engine intake air temperature measurement. (a) Engine intake air temperature measurement must be made within 122 cm of the engine. The measurement location must be made...

  9. 40 CFR 89.325 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine intake air temperature... Test Equipment Provisions § 89.325 Engine intake air temperature measurement. (a) Engine intake air temperature measurement must be made within 122 cm of the engine. The measurement location must be made...

  10. 40 CFR 89.325 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine intake air temperature... Test Equipment Provisions § 89.325 Engine intake air temperature measurement. (a) Engine intake air temperature measurement must be made within 122 cm of the engine. The measurement location must be made...

  11. 40 CFR 89.325 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine intake air temperature... Test Equipment Provisions § 89.325 Engine intake air temperature measurement. (a) Engine intake air temperature measurement must be made within 122 cm of the engine. The measurement location must be made...

  12. 40 CFR 89.325 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine intake air temperature... Test Equipment Provisions § 89.325 Engine intake air temperature measurement. (a) Engine intake air temperature measurement must be made within 122 cm of the engine. The measurement location must be made...

  13. 40 CFR 90.310 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine intake air humidity measurement... Emission Test Equipment Provisions § 90.310 Engine intake air humidity measurement. This section refers to... for the engine intake air, the ambient test cell humidity measurement may be used. (a)...

  14. 40 CFR 90.310 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air humidity measurement... Emission Test Equipment Provisions § 90.310 Engine intake air humidity measurement. This section refers to... for the engine intake air, the ambient test cell humidity measurement may be used. (a)...

  15. 40 CFR 90.310 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine intake air humidity measurement... Emission Test Equipment Provisions § 90.310 Engine intake air humidity measurement. This section refers to... for the engine intake air, the ambient test cell humidity measurement may be used. (a)...

  16. 40 CFR 90.310 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine intake air humidity measurement... Emission Test Equipment Provisions § 90.310 Engine intake air humidity measurement. This section refers to... for the engine intake air, the ambient test cell humidity measurement may be used. (a)...

  17. 40 CFR 90.310 - Engine intake air humidity measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine intake air humidity measurement... Emission Test Equipment Provisions § 90.310 Engine intake air humidity measurement. This section refers to... for the engine intake air, the ambient test cell humidity measurement may be used. (a)...

  18. Deuterium motion in yttrium studied by ultrasonic measurements

    SciTech Connect

    Leisure, R.G. ); Schwarz, R.B.; Migliori, A. ); Torgeson, D.R. ); Svare, I. ); Anderson, I.S. )

    1993-07-01

    Ultrasonic-attenuation measurements in YD[sub 0.10] reveal broad, asymmetric attenuation peaks that are interpreted in terms of rapid motion of deuterium among interstitial sites in the Y metal lattice. The results are well described with a model involving tunneling among highly asymmetric sites. A weakly temperature-dependent relaxation rate, compatible with coupling of the sites to electrons, accounts for the relaxation up to about 70 K. At higher temperatures a strongly temperature-dependent relaxation rate becomes dominant. The major asymmetries that are responsible for the coupling of the tunneling centers to the ultrasound are attributed to the interaction between D atoms that lie on [ital different] [ital c] axes.

  19. Spectrally resolved motional Stark effect measurements on ASDEX Upgrade

    SciTech Connect

    Reimer, R.; Dinklage, A.; Wolf, R.; Fischer, R.; Hobirk, J.; Löbhard, T.; Mlynek, A.; Reich, M.; Sawyer, L.; Collaboration: ASDEX Upgrade

    2013-11-15

    A spectrally resolved Motional Stark Effect (MSE) diagnostic has been installed at ASDEX Upgrade. The MSE data have been fitted by a forward model providing access to information about the magnetic field in the plasma interior [R. Reimer, A. Dinklage, J. Geiger et al., Contrib. Plasma Phys. 50, 731–735 (2010)]. The forward model for the beam emission spectra comprises also the fast ion D{sub α} signal [W. W. Heidbrink and G. J. Sadler, Nucl. Fusion 34, 535–615 (1994)] and the smearing on the CCD-chip. The calculated magnetic field data as well as the revealed (dia)magnetic effects are consistent with the results from equilibrium reconstruction solver. Measurements of the direction of the magnetic field are affected by unknown and varying polarization effects in the observation.

  20. Protein rotational motion in solution measured by polarized fluorescence depletion.

    PubMed Central

    Yoshida, T M; Barisas, B G

    1986-01-01

    A microscope-based system is described for directly measuring protein rotational motion in viscous environments such as cell membranes by polarized fluorescence depletion (PFD). Proteins labeled with fluorophores having a high quantum yield for triplet formation, such as eosin isothiocyanate (EITC), are examined anaerobically in a fluorescence microscope. An acousto-optic modulator generates a several-microsecond pulse of linearly polarized light which produces an orientationally-asymmetric depletion of ground state fluorescence in the sample. When the sample is then probed with light polarized parallel to the excitation pulse, fluorescence recovers over 0-1,000 microseconds as the sum of two exponentials. One exponential corresponds to triplet decay and the other to the rotational relaxation. An exciting pulse perpendicular to the probe beam is then applied. Fluorescence recovery following this pulse is the difference of the same two exponentials. Equations for fluorescence recovery kinetics to be expected in various experimentally significant cases are derived. Least-squares analysis using these equations then permits the triplet lifetime and rotational correlation time to be determined directly from PFD data. Instrumentation for PFD measurements is discussed that permits photobleaching recovery measurements of lateral diffusion coefficients using the same microscope system. With this apparatus, both rotational and translational diffusion coefficients (Dr, Dt) were measured for EITC-labeled bovine serum albumin in glycerol solutions. Values obtained for Dr and Dt are discussed in light of both the PFD models and the experimental system. PMID:3730506

  1. Simulation and Experimental Analysis of Arc Motion Characteristics in Air Circuit Breaker

    NASA Astrophysics Data System (ADS)

    Niu, Chunping; Ding, Juwen; Wu, Yi; Yang, Fei; Dong, Delong; Fan, Xingyu; Rong, Mingzhe

    2016-03-01

    In this paper, to simulate the arc motion in an air circuit breaker (ACB), a three-dimensional magneto-hydrodynamic (MHD) model is developed, considering the influence of thermal radiation, the change of physical parameters of arc plasma and the nonlinear characteristic of ferromagnetic material. The distributions of pressure, temperature, gas flow and current density of arc plasma in the arc region are calculated. The simulation results show some phenomena which discourage arc interruption, such as back commutation and arc burning at the back of the splitter plate. To verify the simulation model, the arc motion is studied experimentally. The influences of the material and position of the innermost barrier plate are analyzed mainly. It proved that the model developed in this paper can efficiently simulate the arc motion. The results indicate that the insulation barrier plate close to the top of the splitter plate is conducive to the arc splitting, which leads to the significant increase of the arc voltage, so it is better for arc interruption. The research can provide methods and references to the optimization of ACB design. supported by National Key Basic Research Program of China (973 Program) (Nos. 2015CB251002, 6132620303), National Natural Science Foundation of China (Nos. 51221005, 51377128, 51577144), and the Fundamental Research Funds for the Central Universities, China

  2. Measuring intracellular motion in cancer cell using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Zam, Azhar; Kolios, Michael C.

    2016-03-01

    In this study, we demonstrate that OCT speckle decorrelation techniques can be used to probe intracellular motion in cancer cells. Spheroids and cell pellets were used as a model to probe intracellular motion. ZnCl2 was used to inhibit mitochondrial motion within the cells. The results reveal the changes in intracellular motion during the spheroid growth phase. Moreover, to modify the motion of mitochondria, cell pellet were exposed to ZnCl2, and agent known to o impair cellular energy production through inhibition of mitochondrial function. The speckle decorrelation time during the growth phase of spheroids decreased by 35 ms over 21 days and 25 ms during inhibition of mitochondrial motion 10 minutes after exposure to ZnCl2.

  3. Measurement of vertical velocity using clear-air Doppler radars

    NASA Technical Reports Server (NTRS)

    Vanzandt, T. E.; Green, J. L.; Nastrom, G. D.; Gage, K. S.; Clark, W. L.; Warnock, J. M.

    1989-01-01

    A new clear air Doppler radar was constructed, called the Flatland radar, in very flat terrain near Champaign-Urbana, Illinois. The radar wavelength is 6.02 m. The radar has been measuring vertical velocity every 153 s with a range resolution of 750 m almost continuously since March 2, 1987. The variance of vertical velocity at Flatland is usually quite small, comparable to the variance at radars located near rough terrain during periods of small background wind. The absence of orographic effects over very flat terrain suggests that clear air Doppler radars can be used to study vertical velocities due to other processes, including synoptic scale motions and propagating gravity waves. For example, near rough terrain the shape of frequency spectra changes drastically as the background wind increases. But at Flatland the shape at periods shorter than a few hours changes only slowly, consistent with the changes predicted by Doppler shifting of gravity wave spectra. Thus it appears that the short period fluctuations of vertical velocity at Flatland are alsmost entirely due to the propagating gravity waves.

  4. HUMAN EXPOSURE MEASUREMENTS OF AIR TOXICS

    EPA Science Inventory

    EPA's air toxics program is moving toward a risk-based focus. The framework for such a focus was laid out in the National Air Toxics Program: Integrated Urban Strategy which included the requirement for EPA to conduct a National-Scale Air Toxics Assessment (NATA) of human expos...

  5. Oscillatory motion based measurement method and sensor for measuring wall shear stress due to fluid flow

    DOEpatents

    Armstrong, William D.; Naughton, Jonathan; Lindberg, William R.

    2008-09-02

    A shear stress sensor for measuring fluid wall shear stress on a test surface is provided. The wall shear stress sensor is comprised of an active sensing surface and a sensor body. An elastic mechanism mounted between the active sensing surface and the sensor body allows movement between the active sensing surface and the sensor body. A driving mechanism forces the shear stress sensor to oscillate. A measuring mechanism measures displacement of the active sensing surface relative to the sensor body. The sensor may be operated under periodic excitation where changes in the nature of the fluid properties or the fluid flow over the sensor measurably changes the amplitude or phase of the motion of the active sensing surface, or changes the force and power required from a control system in order to maintain constant motion. The device may be operated under non-periodic excitation where changes in the nature of the fluid properties or the fluid flow over the sensor change the transient motion of the active sensor surface or change the force and power required from a control system to maintain a specified transient motion of the active sensor surface.

  6. Measuring Concentrations of Particulate 140La in the Air.

    PubMed

    Okada, Colin E; Kernan, Warnick; Keillor, Martin; Kirkham, Randy; Sorom, Rich D; Van Etten, Don M

    2016-05-01

    Air sampling systems were deployed to measure the concentration of radioactive material in the air during the Full-Scale Radiological Dispersal Device Field Trials. The air samplers were positioned 100-600 m downwind of the release point. The filters were collected immediately and analyzed in a field laboratory. Quantities for total activity collected on the air filters are reported along with additional information to compute the average or integrated air concentrations. PMID:27023029

  7. Quantitative viscoelastic parameters measured by harmonic motion imaging.

    PubMed

    Vappou, Jonathan; Maleke, Caroline; Konofagou, Elisa E

    2009-06-01

    Quantifying the mechanical properties of soft tissues remains a challenging objective in the field of elasticity imaging. In this work, we propose an ultrasound-based method for quantitatively estimating viscoelastic properties, using the amplitude-modulated harmonic motion imaging (HMI) technique. In HMI, an oscillating acoustic radiation force is generated inside the medium by using focused ultrasound and the resulting displacements are measured using an imaging transducer. The proposed approach is a two-step method that uses both the properties of the propagating shear wave and the phase shift between the applied stress and the measured strain in order to infer to the shear storage (G') and shear loss modulus (G''), which refer to the underlying tissue elasticity and viscosity, respectively. The proposed method was first evaluated on numerical phantoms generated by finite-element simulations, where a very good agreement was found between the input and the measured values of G' and G''. Experiments were then performed on three soft tissue-mimicking gel phantoms. HMI measurements were compared to rotational rheometry (dynamic mechanical analysis), and very good agreement was found at the only overlapping frequency (10 Hz) in the estimate of the shear storage modulus G' (14% relative error, averaged p-value of 0.34), whereas poorer agreement was found in G'' (55% relative error, averaged p-value of 0.0007), most likely due to the significantly lower values of G'' of the gel phantoms, posing thus a greater challenge in the sensitivity of the method. Nevertheless, this work proposes an original model-independent ultrasound-based elasticity imaging method that allows for direct, quantitative estimation of tissue viscoelastic properties, together with a validation against mechanical testing. PMID:19454785

  8. Air density measurement with a falling A4 sheet

    NASA Astrophysics Data System (ADS)

    Oladyshkin, Ivan V.; Oladyshkina, Anastasia A.

    2016-09-01

    We propose a simple experiment on the air density measurement which does not require any special equipment: just an A4 sheet of paper, a stopwatch and a ruler. The discussed method uses the most basic air resistance model.

  9. A two-axis in-plane motion measurement system based on optical beam deflection

    NASA Astrophysics Data System (ADS)

    Sriramshankar, R.; Mrinalini, R. Sri Muthu; Jayanth, G. R.

    2013-10-01

    Measurement of in-plane motion with high resolution and large bandwidth enables model-identification and real-time control of motion-stages. This paper presents an optical beam deflection based system for measurement of in-plane motion of both macro- and micro-scale motion stages. A curved reflector is integrated with the motion stage to achieve sensitivity to in-plane translational motion along two axes. Under optimal settings, the measurement system is shown to theoretically achieve sub-angstrom measurement resolution over a bandwidth in excess of 1 kHz and negligible cross-sensitivity to linear motion. Subsequently, the proposed technique is experimentally demonstrated by measuring the in-plane motion of a piezo flexure stage and a scanning probe microcantilever. For the former case, reflective spherical balls of different radii are employed to measure the in-plane motion and the measured sensitivities are shown to agree with theoretical values, on average, to within 8.3%. For the latter case, a prototype polydimethylsiloxane micro-reflector is integrated with the microcantilever. The measured in-plane motion of the microcantilever probe is used to identify nonlinearities and the transient dynamics of the piezo-stage upon which the probe is mounted. These are subsequently compensated by means of feedback control.

  10. A two-axis in-plane motion measurement system based on optical beam deflection

    SciTech Connect

    Sriramshankar, R.; Mrinalini, R. Sri Muthu; Jayanth, G. R.

    2013-10-15

    Measurement of in-plane motion with high resolution and large bandwidth enables model-identification and real-time control of motion-stages. This paper presents an optical beam deflection based system for measurement of in-plane motion of both macro- and micro-scale motion stages. A curved reflector is integrated with the motion stage to achieve sensitivity to in-plane translational motion along two axes. Under optimal settings, the measurement system is shown to theoretically achieve sub-angstrom measurement resolution over a bandwidth in excess of 1 kHz and negligible cross-sensitivity to linear motion. Subsequently, the proposed technique is experimentally demonstrated by measuring the in-plane motion of a piezo flexure stage and a scanning probe microcantilever. For the former case, reflective spherical balls of different radii are employed to measure the in-plane motion and the measured sensitivities are shown to agree with theoretical values, on average, to within 8.3%. For the latter case, a prototype polydimethylsiloxane micro-reflector is integrated with the microcantilever. The measured in-plane motion of the microcantilever probe is used to identify nonlinearities and the transient dynamics of the piezo-stage upon which the probe is mounted. These are subsequently compensated by means of feedback control.

  11. Acoustic method for measuring air temperature and humidity in rooms

    NASA Astrophysics Data System (ADS)

    Kanev, N. G.

    2014-05-01

    A method is proposed to determine air temperature and humidity in rooms with a system of sound sources and receivers, making it possible to find the sound velocity and reverberation time. Nomograms for determining the air temperature and relative air humidity are constructed from the found sound velocity and time reverberation values. The required accuracy of measuring these parameters is estimated.

  12. 40 CFR 92.108 - Intake and cooling air measurements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... during the test. Overall measurement accuracy must be ±2 percent of full-scale value of the measurement... full-scale value. The Administrator must be advised of the method used prior to testing. (2... measurements. (1) Air that has had its absolute humidity altered is considered humidity-conditioned air....

  13. 40 CFR 90.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Engine intake air temperature... Emission Test Equipment Provisions § 90.309 Engine intake air temperature measurement. (a) The measurement...) The temperature measurements must be accurate to within ±2 °C....

  14. 40 CFR 90.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Engine intake air temperature... Emission Test Equipment Provisions § 90.309 Engine intake air temperature measurement. (a) The measurement...) The temperature measurements must be accurate to within ±2 °C....

  15. 40 CFR 90.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Engine intake air temperature... Emission Test Equipment Provisions § 90.309 Engine intake air temperature measurement. (a) The measurement...) The temperature measurements must be accurate to within ±2 °C....

  16. 40 CFR 90.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine intake air temperature... Emission Test Equipment Provisions § 90.309 Engine intake air temperature measurement. (a) The measurement...) The temperature measurements must be accurate to within ±2 °C....

  17. 40 CFR 90.309 - Engine intake air temperature measurement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Engine intake air temperature... Emission Test Equipment Provisions § 90.309 Engine intake air temperature measurement. (a) The measurement...) The temperature measurements must be accurate to within ±2 °C....

  18. Equipment for Measuring Air Flow, Air Temperature, Relative Humidity, and Carbon Dioxide in Schools. Technical Bulletin.

    ERIC Educational Resources Information Center

    Jacobs, Bruce W.

    Information on equipment and techniques that school facility personnel may use to evaluate IAQ conditions are discussed. Focus is placed on the IAQ parameters of air flow, air temperature, relative humidity, as well as carbon dioxide and the equipment used to measure these factors. Reasons for measurement and for when the measurement of these…

  19. Effects of motion sickness on thermoregulatory responses in a thermoneutral air environment.

    PubMed

    Nobel, Gerard; Tribukait, Arne; Mekjavic, Igor B; Eiken, Ola

    2012-05-01

    Motion sickness (MS) has been identified as a non-thermal factor that can moderate autonomic thermoregulatory responses. It has been shown that MS exaggerates core cooling during immersion in cold (15 °C) and luke-warm (28 °C) water by attenuating cold-induced vasoconstriction. The aim of the present study was to investigate whether MS affects thermal balance in a thermoneutral air environment. Eleven subjects were exposed to rotation in two conditions, control (CN) and MS. In the CN condition subjects refrained from head movements, whereas in the MS condition they performed a sequence of maximal head movements (left, right, up, down) at 15-s intervals until they were very nauseous. Sweating rate, rectal temperature (T(re)), the difference in temperature between the right forearm and tip of the second finger (T(ff)) as an index of cutaneous vasomotor tone, perceived MS, thermal comfort and temperature perception were recorded before and during rotation, and during 90-min post-rotation. During the post-rotation period, T(re) dropped and sweating rate increased in the MS but not in the CN condition. The T(ff) response suggests that MS-induced peripheral vasodilatation which, together with the sweating resulted in increased heat loss. During rotation, subjects perceived temperature to be uncomfortably high, suggesting that MS may also affect thermoregulatory behaviour. It thus appears that also in a thermoneutral air environment MS may substantially affect thermal balance. PMID:21892631

  20. Measurement of Radon in Indoor Air.

    ERIC Educational Resources Information Center

    Downey, Daniel M.; Simolunas, Glenn

    1988-01-01

    Describes a laboratory experiment to teach the principles of air sampling, gamma ray spectroscopy, nuclear decay, and radioactive equilibrium. Analyzes radon by carbon adsorption and gamma ray counting. Provides methodology and rate of decay equations. (MVL)

  1. Characteristics of horizontal ground motion measures along principal directions

    NASA Astrophysics Data System (ADS)

    Hong, H. P.; Goda, K.

    2010-03-01

    Ground motion records are often used to develop ground motion prediction equations (GMPEs) for a randomly oriented horizontal component, and to assess the principal directions of ground motions based on the Arias intensity tensor or the orientation of the major response axis. The former is needed for seismic hazard assessment, whereas the latter can be important for assessing structural responses under multi-directional excitations. However, a comprehensive investigation of the pseudo-spectral acceleration (PSA) and of GMPEs conditioned on different axes is currently lacking. This study investigates the principal directions of strong ground motions and their relation to the orientation of the major response axis, statistics of the PSA along the principal directions on the horizontal plane, and correlation of the PSA along the principal directions on the horizontal plane. For these, three sets of strong ground motion records, including intraplate California earthquakes, inslab Mexican earthquakes, and interface Mexican earthquakes, are used. The results indicate that one of the principal directions could be considered as quasi-vertical. By focusing on seismic excitations on the horizontal plane, the statistics of the angles between the major response axis and the major principal axis are obtained; GMPEs along the principal axes are provided and compared with those obtained for a randomly oriented horizontal component; and statistical analysis of residuals associated with GMPEs along the principal directions is carried out.

  2. Improving Pulse Rate Measurements during Random Motion Using a Wearable Multichannel Reflectance Photoplethysmograph.

    PubMed

    Warren, Kristen M; Harvey, Joshua R; Chon, Ki H; Mendelson, Yitzhak

    2016-01-01

    Photoplethysmographic (PPG) waveforms are used to acquire pulse rate (PR) measurements from pulsatile arterial blood volume. PPG waveforms are highly susceptible to motion artifacts (MA), limiting the implementation of PR measurements in mobile physiological monitoring devices. Previous studies have shown that multichannel photoplethysmograms can successfully acquire diverse signal information during simple, repetitive motion, leading to differences in motion tolerance across channels. In this paper, we investigate the performance of a custom-built multichannel forehead-mounted photoplethysmographic sensor under a variety of intense motion artifacts. We introduce an advanced multichannel template-matching algorithm that chooses the channel with the least motion artifact to calculate PR for each time instant. We show that for a wide variety of random motion, channels respond differently to motion artifacts, and the multichannel estimate outperforms single-channel estimates in terms of motion tolerance, signal quality, and PR errors. We have acquired 31 data sets consisting of PPG waveforms corrupted by random motion and show that the accuracy of PR measurements achieved was increased by up to 2.7 bpm when the multichannel-switching algorithm was compared to individual channels. The percentage of PR measurements with error ≤ 5 bpm during motion increased by 18.9% when the multichannel switching algorithm was compared to the mean PR from all channels. Moreover, our algorithm enables automatic selection of the best signal fidelity channel at each time point among the multichannel PPG data. PMID:26959034

  3. Improving Pulse Rate Measurements during Random Motion Using a Wearable Multichannel Reflectance Photoplethysmograph

    PubMed Central

    Warren, Kristen M.; Harvey, Joshua R.; Chon, Ki H.; Mendelson, Yitzhak

    2016-01-01

    Photoplethysmographic (PPG) waveforms are used to acquire pulse rate (PR) measurements from pulsatile arterial blood volume. PPG waveforms are highly susceptible to motion artifacts (MA), limiting the implementation of PR measurements in mobile physiological monitoring devices. Previous studies have shown that multichannel photoplethysmograms can successfully acquire diverse signal information during simple, repetitive motion, leading to differences in motion tolerance across channels. In this paper, we investigate the performance of a custom-built multichannel forehead-mounted photoplethysmographic sensor under a variety of intense motion artifacts. We introduce an advanced multichannel template-matching algorithm that chooses the channel with the least motion artifact to calculate PR for each time instant. We show that for a wide variety of random motion, channels respond differently to motion artifacts, and the multichannel estimate outperforms single-channel estimates in terms of motion tolerance, signal quality, and PR errors. We have acquired 31 data sets consisting of PPG waveforms corrupted by random motion and show that the accuracy of PR measurements achieved was increased by up to 2.7 bpm when the multichannel-switching algorithm was compared to individual channels. The percentage of PR measurements with error ≤ 5 bpm during motion increased by 18.9% when the multichannel switching algorithm was compared to the mean PR from all channels. Moreover, our algorithm enables automatic selection of the best signal fidelity channel at each time point among the multichannel PPG data. PMID:26959034

  4. Air quality measurements from the Fresno Supersite.

    PubMed

    Watson, J G; Chow, J C; Bowen, J L; Lowenthal, D H; Hering, S; Ouchida, P; Oslund, W

    2000-08-01

    The Fresno Supersite intends to 1) evaluate non-routine monitoring methods, establishing their comparability with existing methods and their applicability to air quality planning, exposure assessment, and health effects studies; 2) provide a better understanding of aerosol characteristics, behavior, and sources to assist regulatory agencies in developing standards and strategies that protect public health; and 3) support studies that evaluate relationships between aerosol properties, co-factors, and observed health end-points. Supersite observables include in-situ, continuous, short-duration measurements of 1) PM2.5, PM10, and coarse (PM10 minus PM2.5) mass; 2) PM2.5 SO4(-2), NO3-, carbon, light absorption, and light extinction; 3) numbers of particles in discrete size bins ranging from 0.01 to approximately 10 microns; 4) criteria pollutant gases (O3, CO, NOx); 5) reactive gases (NO2, NOy, HNO3, peroxyacetyl nitrate [PAN], NH3); and 6) single particle characterization by time-of-flight mass spectrometry. Field sampling and laboratory analysis are applied for gaseous and particulate organic compounds (light hydrocarbons, heavy hydrocarbons, carbonyls, polycyclic aromatic hydrocarbons [PAH], and other semi-volatiles), and PM2.5 mass, elements, ions, and carbon. Observables common to other Supersites are 1) daily PM2.5 24-hr average mass with Federal Reference Method (FRM) samplers; 2) continuous hourly and 5-min average PM2.5 and PM10 mass with beta attenuation monitors (BAM) and tapered element oscillating microbalances (TEOM); 3) PM2.5 chemical speciation with a U.S. Environmental Protection Agency (EPA) speciation monitor and protocol; 4) coarse particle mass by dichotomous sampler and difference between PM10 and PM2.5 BAM and TEOM measurements; 5) coarse particle chemical composition; and 6) high sensitivity and time resolution scalar and vector wind speed, wind direction, temperature, relative humidity, barometric pressure, and solar radiation. The Fresno

  5. Cervical Coupling Motion Characteristics in Healthy People Using a Wireless Inertial Measurement Unit

    PubMed Central

    Kim, Jeong-Kyun; Park, Young-Jae; Oh, Hwan-Sup; Park, Young-Bae

    2013-01-01

    Objective. The objectives were to show the feasibility of a wireless microelectromechanical system inertial measurement unit (MEMS-IMU) to assess the time-domain characteristics of cervical motion that are clinically useful to evaluate cervical spine movement. Methods. Cervical spine movements were measured in 18 subjects with wireless IMUs. All rotation data are presented in the Euler angle system. Amount of coupling motions was evaluated by calculating the average angle ratio and the maximum angle ratio of the coupling motion to the primary motion. Reliability is presented with intraclass correlation coefficients (ICC). Results. Entire time-domain characteristics of cervical motion were measured with developed MEMS-IMU system. Cervical range of motion (CROM) and coupling motion range were measured with high ICCs. The acquired data and calculated parameters had similar tendency with the previous studies. Conclusions. We evaluated cervical motion with economic system using a wireless IMU of high reliability. We could directly measure the three-dimensional cervical motion in degrees in realtime. The characteristics measured by this system may provide a diagnostic basis for structural or functional dysfunction of cervical spine. This system is also useful to demonstrate the effectiveness of any intervention such as conventional medical treatment, and Korean medical treatment, exercise therapy. PMID:23935668

  6. Image motion-blur-based object's speed measurement using an interlaced scan image

    NASA Astrophysics Data System (ADS)

    Ting-Fa, Xu; Peng, Zhao

    2010-07-01

    In motion-blur-based speed measurement, a key step is the calculation of the horizontal blur extent. To perform this calculation robustly and accurately when both a defocus blur and a motion blur occur, and for a moving object with irregular shape edges, we propose a novel scheme using the image matting and transparency map. This scheme can isolate the defocus blur from the motion blur effectively, and can also calculate the horizontal blur extent accurately, regardless of the object's shape. Moreover, our novel scheme can also perform speed measurement for an object with uniformly accelerated/retarded motion (i.e. a rigid body linear motion with a constant acceleration) by using one interlaced scan CCD image. Simulation and real experiments prove that our scheme not only outperforms the current scan-line algorithm for blur extent computation, but can also perform speed measurement accurately for uniformly accelerated/retarded motion.

  7. Particle motion measured at an operational wind turbine in relation to hearing sensitivity in fish.

    PubMed

    Sigray, Peter; Andersson, Mathias H

    2011-07-01

    The effect of sound pressure on the hearing of fish has been extensively investigated in laboratory studies as well as in field trials in contrast to particle motion where few studies have been carried out. To improve this dearth of knowledge, an instrument for measuring particle motion was developed and used in a field trial. The particle motion is measured using a neutrally buoyant sphere, which co-oscillates with the fluid motion. The unit was deployed in close vicinity to a wind turbine foundation at Utgrunden wind farm in the Baltic Sea. Measurements of particle motion were undertaken at different distances from the turbine as well as at varying wind speeds. Levels of particle motion were compared to audiograms for cod (Gadus morhua L.) and plaice (Pleuronectes platessa L.). PMID:21786890

  8. Drift motion of the magnetic monopole of Poljakov-'t Hooft in the air and the ball-lightning phenomenon

    SciTech Connect

    Korshunov, V.K. )

    1990-08-30

    In this paper by virtue of theoretical investigations of V. Rubakov on nucleons and nuclei decay with monopole-nucleon interaction, a qualitative analysis of the drift motion of the mon in the air is conducted. The physical picture obtained coincided in detail with the descriptions of the ball-lightning, for which reason ball- lightning is considered evidence for the magnetic monopole.

  9. Calibration of a system for measuring low air flow velocity in a wind tunnel

    NASA Astrophysics Data System (ADS)

    Krach, Andrzej; Kruczkowski, Janusz

    2016-08-01

    This article presents the calibration of a system for measuring air flow velocity in a wind tunnel with a multiple-hole orifice. The comparative method was applied for the calibration. The method consists in equalising the air flow velocity in a test section of the tunnel with that of the hot-wire anemometer probe which should then read zero value. The hot-wire anemometer probe moves reciprocally in the tunnel test section with a constant velocity, aligned and opposite to the air velocity. Air velocity in the tunnel test section is adjusted so that the minimum values of a periodic hot-wire anemometer signal displayed on an oscilloscope screen reach the lowest position (the minimum method). A sinusoidal component can be superimposed to the probe constant velocity. Then, the air flow velocity in the tunnel test section is adjusted so that, when the probe moves in the direction of air flow, only the second harmonic of the periodically variable velocity superimposed on the constant velocity (second harmonic method) remains at the output of the low-pass filter to which the hot-wire anemometer signal, displayed on the oscilloscope screen, is supplied. The velocity of the uniform motion of the hot-wire anemometer probe is measured with a magnetic linear encoder. The calibration of the system for the measurement of low air velocities in the wind tunnel was performed in the following steps: 1. Calibration of the linear encoder for the measurement of the uniform motion velocity of the hot-wire anemometer probe in the test section of the tunnel. 2. Calibration of the system for measurement of low air velocities with a multiple-hole orifice for the velocities of 0.1 and 0.25 m s‑1: - (a) measurement of the probe movement velocity setting; - (b) measurement of air velocity in the tunnel test section with comparison according to the second harmonic method; - (c) measurement of air velocity in the tunnel with comparison according to the minimum method. The calibration

  10. A simple 5-DoF MR-compatible motion signal measurement system.

    PubMed

    Chung, Soon-Cheol; Kim, Hyung-Sik; Yang, Jae-Woong; Lee, Su-Jeong; Choi, Mi-Hyun; Kim, Ji-Hye; Yeon, Hong-Won; Park, Jang-Yeon; Yi, Jeong-Han; Tack, Gye-Rae

    2011-09-01

    The purpose of this study was to develop a simple motion measurement system with magnetic resonance (MR) compatibility and safety. The motion measurement system proposed here can measure 5-DoF motion signals without deteriorating the MR images, and it has no effect on the intense and homogeneous main magnetic field, the temporal-gradient magnetic field (which varies rapidly with time), the transceiver radio frequency (RF) coil, and the RF pulse during MR data acquisition. A three-axis accelerometer and a two-axis gyroscope were used to measure 5-DoF motion signals, and Velcro was used to attach a sensor module to a finger or wrist. To minimize the interference between the MR imaging system and the motion measurement system, nonmagnetic materials were used for all electric circuit components in an MR shield room. To remove the effect of RF pulse, an amplifier, modulation circuit, and power supply were located in a shielded case, which was made of copper and aluminum. The motion signal was modulated to an optic signal using pulse width modulation, and the modulated optic signal was transmitted outside the MR shield room using a high-intensity light-emitting diode and an optic cable. The motion signal was recorded on a PC by demodulating the transmitted optic signal into an electric signal. Various kinematic variables, such as angle, acceleration, velocity, and jerk, can be measured or calculated by using the motion measurement system developed here. This system also enables motion tracking by extracting the position information from the motion signals. It was verified that MR images and motion signals could reliably be measured simultaneously. PMID:21487903

  11. Technique for Measuring Speed and Visual Motion Sensitivity in Lizards

    ERIC Educational Resources Information Center

    Woo, Kevin L.; Burke, Darren

    2008-01-01

    Testing sensory characteristics on herpetological species has been difficult due to a range of properties related to physiology, responsiveness, performance ability, and the type of reinforcer used. Using the Jacky lizard as a model, we outline a successfully established procedure in which to test the visual sensitivity to motion characteristics.…

  12. Evaluation of structure from motion for soil microtopography measurement

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Recent developments in low cost structure from motion (SFM) technologies offer new opportunities for geoscientists to acquire high resolution soil microtopography data at a fraction of the cost of conventional techniques. However, these new methodologies often lack easily accessible error metrics an...

  13. Measurement of storage ring motion at the advanced light source

    SciTech Connect

    Krebs, G.F.

    1997-05-01

    The mechanical stability of the Advanced Light Source storage ring is examined over a period of 1.5 years from the point of view of floor motion. The storage ring beam position monitor stability is examined under various operating conditions.

  14. Precise Measurement of Velocity Dependent Friction in Rotational Motion

    ERIC Educational Resources Information Center

    Alam, Junaid; Hassan, Hafsa; Shamim, Sohaib; Mahmood, Waqas; Anwar, Muhammad Sabieh

    2011-01-01

    Frictional losses are experimentally determined for a uniform circular disc exhibiting rotational motion. The clockwise and anticlockwise rotations of the disc, that result when a hanger tied to a thread is released from a certain height, give rise to vertical oscillations of the hanger as the thread winds and unwinds over a pulley attached to the…

  15. Perfluorocarbon tracer method for air-infiltration measurements

    DOEpatents

    Dietz, R.N.

    1982-09-23

    A method of measuring air infiltration rates suitable for use in rooms of homes and buildings comprises the steps of emitting perfluorocarbons in the room to be measured, sampling the air containing the emitted perfluorocarbons over a period of time, and analyzing the samples at a laboratory or other facility.

  16. Novel Assessment of Renal Motion in Children as Measured via Four-Dimensional Computed Tomography

    SciTech Connect

    Pai Panandiker, Atmaram S.; Sharma, Shelly; Naik, Mihir H.; Wu, Shengjie; Hua, Chiaho; Beltran, Chris; Krasin, Matthew J.; Merchant, Thomas E.

    2012-04-01

    Objectives: Abdominal intensity-modulated radiation therapy and proton therapy require quantification of target and organ motion to optimize localization and treatment. Although addressed in adults, there is no available literature on this issue in pediatric patients. We assessed physiologic renal motion in pediatric patients. Methods and Materials: Twenty free-breathing pediatric patients at a median age of 8 years (range, 2-18 years) with intra-abdominal tumors underwent computed tomography simulation and four-dimensional computed tomography acquisition (slice thickness, 3 mm). Kidneys and diaphragms were contoured during eight phases of respiration to estimate center-of-mass motion. We quantified center of kidney mass mobility vectors in three dimensions: anteroposterior (AP), mediolateral (ML), and superoinferior (SI). Results: Kidney motion decreases linearly with decreasing age and height. The 95% confidence interval for the averaged minima and maxima of renal motion in children younger than 9 years was 5-9 mm in the ML direction, 4-11 mm in the AP direction, and 12-25 mm in the SI dimension for both kidneys. In children older than 9 years, the same confidence interval reveals a widening range of motion that was 5-16 mm in the ML direction, 6-17 mm in the AP direction, and 21-52 mm in the SI direction. Although not statistically significant, renal motion correlated with diaphragm motion in older patients. The correlation between diaphragm motion and body mass index was borderline (r = 0.52, p = 0.0816) in younger patients. Conclusions: Renal motion is age and height dependent. Measuring diaphragmatic motion alone does not reliably quantify pediatric renal motion. Renal motion in young children ranges from 5 to 25 mm in orientation-specific directions. The vectors of motion range from 5 to 52 mm in older children. These preliminary data represent novel analyses of pediatric intra-abdominal organ motion.

  17. GAS CHROMATOGRAPHIC TECHNIQUES FOR THE MEASUREMENT OF ISOPRENE IN AIR

    EPA Science Inventory

    The chapter discusses gas chromatographic techniques for measuring isoprene in air. Such measurement basically consists of three parts: (1) collection of sufficient sample volume for representative and accurate quantitation, (2) separation (if necessary) of isoprene from interfer...

  18. Next-generation air measurement technologies

    EPA Science Inventory

    This is a presentation at a workshop in Chicago on emerging air monitoring technologies, hosted by a local nonprofit. The audience is composed of a mixture of technical backgrounds. This presentation will be part of an opening panel and the goal is to give an overview of the st...

  19. Uncertainties in the measurement of the atmospheric velocity due to balloon-gondola pendulum-like motions

    NASA Astrophysics Data System (ADS)

    Alexander, P.; de la Torre, A.

    2011-02-01

    Balloons lead to the highest vertical resolution of air velocity data actually attainable from atmospheric soundings. However, the pendulum-like motion of the balloon-gondola system may significantly affect these measurements if the distance between balloon and gondola is large. This may prevent the study of the highest vertical resolution range obtained. Also, if not appropriately discriminated, these fluctuations could be confused with small scale or turbulent oscillations of the atmosphere. It is shown from simple energy considerations that horizontal and vertical wind velocity perturbations introduced in the observations by the pendulum motion may usually be comparable to typical measurements. Vertical velocity data that were obtained with an instrumented gondola in a zero pressure balloon, which typically reach the lower stratosphere, are analyzed and found to be in agreement with the above statements. The pendulum-like behavior in this sounding seems to be stimulated by the buoyant oscillation of the atmosphere.

  20. Determination of the linear equations of position-sensing detectors for small motion measurement systems.

    PubMed

    Liu, Chien-Sheng; Lin, Psang Dain

    2010-11-01

    Small motion measurement systems are widely used in industry measurement fields to measure small positional/angular motions. These systems usually consist of two parts: a measuring assembly and a reference assembly. The position-sensing detectors (PSDs) are embedded in either measuring assembly or reference assembly to sense the variations of laser light incidence points when there are any small positional/angular motions. To use these systems, it is necessary to determine the linear equations of PSD readings, which relate the six-degrees-of-freedom small positional/angular motions and PSD readings. The purpose of this paper is to derive these equations based on the paraxial raytracing method. Two measurement systems are used as illustrative examples to validate the proposed methodology. The methodology of this study will be useful for system design of PSD-based measurement systems and their applications. PMID:21045913

  1. Crowdsourcing urban air temperature measurements using smartphones

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2013-10-01

    Crowdsourced data from cell phone battery temperature sensors could be used to contribute to improved real-time, high-resolution air temperature estimates in urban areas, a new study shows. Temperature observations in cities are in some cases currently limited to a few weather stations, but there are millions of smartphone users in many cities. The batteries in cell phones have temperature sensors to avoid damage to the phone.

  2. New Focus: method for measuring vinyl chloride in air

    SciTech Connect

    Not Available

    1987-05-01

    This note discusses a recently released standard entitled Method for the Measurement of Vinyl Chloride in Air (CAN3-Z223.25-M86). It is one in a series of Canadian Standard Association standards on the measurement of pollutants in air. This unique document provides a standardized method of sampling and analysis that may be used for the measurement of vinyl chloride in air over a concentration range of 0.01 to 2600 mg/mT under standard atmospheric conditions. The methodology includes calibration requirements, sampling procedures (the collection of samples in a gas bag or a sorbent tube), quantitative gas chromatographic analysis, and series of calculations. It is the first published document that standardizes the method of measurement of vinyl chloride in air and specifies a concentration range that applies to industrial hygiene and ambient air applications.

  3. Measurements of three-dimensional shape and sound-induced motion of the chinchilla tympanic membrane

    PubMed Central

    Rosowski, John J; Dobrev, Ivo; Khaleghi, Morteza; Lu, Weina; Cheng, Jeffrey Tao; Harrington, Ellery; Furlong, Cosme

    2013-01-01

    Opto-electronic computer holographic measurements were made of the tympanic membrane (TM) in cadaveric chinchillas. Measurements with two laser wavelengths were used to compute the 3D-shape of the TM. Single laser wavelength measurements locked to eight distinct phases of a tonal stimulus were used to determine the magnitude and the relative phase of the surface displacements. These measurements were made at over 250,000 points on the TM surface. The measured motions contained spatial phase variations consistent with relatively low-order (large spatial frequency) modal motions and smaller magnitude higher-order (smaller spatial frequency) motions that appear to travel, but may also be explained by losses within the membrane. The measurement of shape and thin shell theory allowed us to separate the measured motions into those components orthogonal to the plane of the tympanic ring, and those components within the plane of the tympanic ring based on the 3D-shape. The predicted in-plane motion components are generally smaller than the out-of-plane perpendicular component of motion. Since the derivation of in-plane and out-of plane depended primarily on the membrane shape, the relative sizes of the predicted motion components did not vary with frequency. PMID:23247058

  4. The effect of motion on IMRT - looking at interplay with 3D measurements

    NASA Astrophysics Data System (ADS)

    Thomas, A.; Yan, H.; Oldham, M.; Juang, T.; Adamovics, J.; Yin, F. F.

    2013-06-01

    Clinical recommendations to address tumor motion management have been derived from studies dealing with simulations and 2D measurements. 3D measurements may provide more insight and possibly alter the current motion management guidelines. This study provides an initial look at true 3D measurements involving leaf motion deliveries by use of a motion phantom and the PRESAGE/DLOS dosimetry system. An IMRT and VMAT plan were delivered to the phantom and analyzed by means of DVHs to determine whether the expansion of treatment volumes based on known imaging motion adequately cover the target. DVHs confirmed that for these deliveries the expansion volumes were adequate to treat the intended target although further studies should be conducted to allow for differences in parameters that could alter the results, such as delivery dose and breathe rate.

  5. Measure Guideline: Air Sealing Attics in Multifamily Buildings

    SciTech Connect

    Otis, C.; Maxwell, S.

    2012-06-01

    This Building America Measure Guideline is intended for owners, builders, contractors, homeowners, and other stakeholders in the multifamily building industry, and focuses on challenges found in existing buildings for a variety of housing types. It explains why air sealing is desirable, explores related health and safety issues, and identifies common air leakage points in multifamily building attics. In addition, it also gives an overview of materials and techniques typically used to perform air sealing work.

  6. Measure Guideline. Air Sealing Attics in Multifamily Buildings

    SciTech Connect

    Otis, Casey; Maxwell, Sean

    2012-06-01

    This Building America Measure Guideline is intended for owners, builders, contractors, homeowners, and other stakeholders in the multifamily building industry, and focuses on challenges found in existing buildings for a variety of housing types. It explains why air sealing is desirable, explores related health and safety issues, and identifies common air leakage points in multifamily building attics. In addition, it also gives an overview of materials and techniques typically used to perform air sealing work.

  7. Direct Measurement of Helical Cell Motion of the Spirochete Leptospira

    PubMed Central

    Nakamura, Shuichi; Leshansky, Alexander; Magariyama, Yukio; Namba, Keiichi; Kudo, Seishi

    2014-01-01

    Leptospira are spirochete bacteria distinguished by a short-pitch coiled body and intracellular flagella. Leptospira cells swim in liquid with an asymmetric morphology of the cell body; the anterior end has a long-pitch spiral shape (S-end) and the posterior end is hook-shaped (H-end). Although the S-end and the coiled cell body called the protoplasmic cylinder are thought to be responsible for propulsion together, most observations on the motion mechanism have remained qualitative. In this study, we analyzed the swimming speed and rotation rate of the S-end, protoplasmic cylinder, and H-end of individual Leptospira cells by one-sided dark-field microscopy. At various viscosities of media containing different concentrations of Ficoll, the rotation rate of the S-end and protoplasmic cylinder showed a clear correlation with the swimming speed, suggesting that these two helical parts play a central role in the motion of Leptospira. In contrast, the H-end rotation rate was unstable and showed much less correlation with the swimming speed. Forces produced by the rotation of the S-end and protoplasmic cylinder showed that these two helical parts contribute to propulsion at nearly equal magnitude. Torque generated by each part, also obtained from experimental motion parameters, indicated that the flagellar motor can generate torque >4000 pN nm, twice as large as that of Escherichia coli. Furthermore, the S-end torque was found to show a markedly larger fluctuation than the protoplasmic cylinder torque, suggesting that the unstable H-end rotation might be mechanically related to changes in the S-end rotation rate for torque balance of the entire cell. Variations in torque at the anterior and posterior ends of the Leptospira cell body could be transmitted from one end to the other through the cell body to coordinate the morphological transformations of the two ends for a rapid change in the swimming direction. PMID:24411236

  8. Doppler shift and ambiguity velocity caused by relative motion in quantum-enhanced measurement.

    PubMed

    Shen, Yanghe; Xu, Luping; Zhang, Hua; Yang, Peng

    2015-07-13

    We study the effect of relative motion on a frequency-entangled-based ranging scheme. Two major puzzles arise, i.e., Doppler shift and ambiguity velocity. During condition of rapid relative motion, Doppler shift invalidates the measurement result of this scheme; while during condition of slow relative motion, the ambiguity velocity turns into a major limitation. If relative speed between targets and measurement platform exceeds the ambiguity velocity, an accumulated profile obtained by the coincidence measurement will be distorted, which causes a lower ranging accuracy. Theoretical analysis shows a time-varying delay can be introduced to solve the two major puzzles. PMID:26191903

  9. Proton dose calculation based on in-air fluence measurements.

    PubMed

    Schaffner, Barbara

    2008-03-21

    Proton dose calculation algorithms--as well as photon and electron algorithms--are usually based on configuration measurements taken in a water phantom. The exceptions to this are proton dose calculation algorithms for modulated scanning beams. There, it is usual to measure the spot profiles in air. We use the concept of in-air configuration measurements also for scattering and uniform scanning (wobbling) proton delivery techniques. The dose calculation includes a separate step for the calculation of the in-air fluence distribution per energy layer. The in-air fluence calculation is specific to the technique and-to a lesser extent-design of the treatment machine. The actual dose calculation uses the in-air fluence as input and is generic for all proton machine designs and techniques. PMID:18367787

  10. Proton dose calculation based on in-air fluence measurements

    NASA Astrophysics Data System (ADS)

    Schaffner, Barbara

    2008-03-01

    Proton dose calculation algorithms—as well as photon and electron algorithms—are usually based on configuration measurements taken in a water phantom. The exceptions to this are proton dose calculation algorithms for modulated scanning beams. There, it is usual to measure the spot profiles in air. We use the concept of in-air configuration measurements also for scattering and uniform scanning (wobbling) proton delivery techniques. The dose calculation includes a separate step for the calculation of the in-air fluence distribution per energy layer. The in-air fluence calculation is specific to the technique and—to a lesser extent—design of the treatment machine. The actual dose calculation uses the in-air fluence as input and is generic for all proton machine designs and techniques.

  11. Spindle error motion measurement using concentric circle grating and phase modulation interferometers

    NASA Astrophysics Data System (ADS)

    Aketagawa, M.; Madden, M.; Uesugi, S.; Kumagai, T.; Maeda, Y.; Okuyama, E.

    2012-11-01

    In the conventional methods to measure radial, axial and angular motions of spindles, complicated artifacts with relative large volume (such as two balls linked with a cylinder) are required. Small volume artifact is favorable from the viewpoint of the accurate and practical measurement of the spindle motion. This paper describes a concurrent measurement of spindle radial, axial and angular motions using concentric circle grating and phase modulation interferometers. In the measurement, the concentric circle grating with fine pitch is installed on top of the spindle of interest. The grating is a reference artifact in the method. Three optical sensors are fixed over the concentric circle grating, and observe the proper positions of the grating. The optical sensor consists of a frequency modulated laser diode as a light source, and two interferometers. One interferometer observes an interference fringe between reflected light form a fixed mirror and 0-th order diffraction light from the grating to measure the axial motion. Another interferometer observes an interference fringe between +/-2nd diffraction lights from the grating to measure the radial motion. Using three optical sensors, three radial displacements and three axial displacements of the proper observed position of the grating can be measured. From these measured displacements, radial, axial and angular motions of the spindle can be calculated concurrently. In the paper, a measurement instrument, a novel fringe interpolation technique by sinusoidal phase modulation and experimental results are discussed.

  12. AMBIENT MEASUREMENT METHODS AND PROPERTIES OF THE 189 CLEAN AIR ACT HAZARDOUS AIR POLLUTANTS

    EPA Science Inventory

    Measurement methods for the 189 Hazardous Air Pollutants (HAPS) designated in Title III of the 1990 Clean Air Act Amendments are either identified or suggested for all but 10 of the compounds. n extensive list of chemical and physical properties are developed for all compounds. u...

  13. Optical Air Flow Measurements in Flight

    NASA Technical Reports Server (NTRS)

    Bogue, Rodney K.; Jentink, Henk W.

    2004-01-01

    This document has been written to assist the flight-test engineer and researcher in using optical flow measurements in flight applications. The emphasis is on describing tradeoffs in system design to provide desired measurement performance as currently understood. Optical system components are discussed with examples that illustrate the issues. The document concludes with descriptions of optical measurement systems designed for a variety of applications including aeronautics research, airspeed measurement, and turbulence hazard detection. Theoretical discussion is minimized, but numerous references are provided to supply ample opportunity for the reader to understand the theoretical underpinning of optical concepts.

  14. Measuring the Effects of Lift and Drag on Projectile Motion

    ERIC Educational Resources Information Center

    Cross, Rod

    2012-01-01

    The trajectory of a projectile through the air is affected both by gravity and by aerodynamic forces. The latter forces can conveniently be ignored in many situations, even when they are comparatively large. For example, if a 145-g, 74-mm diameter baseball is pitched at 40 ms[superscript -1] (89.5 mph), it experiences a drag force of about 1.5 N.…

  15. Relationship of area postrema to three putative measures of motion sickness

    NASA Technical Reports Server (NTRS)

    Sutton, R.; Fox, Robert A.; Daunton, Nancy G.

    1991-01-01

    Although the rat has an incomplete emetic reflex, several species-specific responses to motion were proposed as measures of 'motion sickness' in rats. The purpose was to determine the dependence of these responses on one of several neural structures known to be essential to motion-induced vomiting in species with a complete emetic reflex. The Area Postrema (AP) was shown to play an important role in the production of motion sickness in vomiting species. The effects of thermo-cautery ablations of the AP on three different responses supposedly reflecting motion sickness in the rat were compared: conditioned taste aversion (CTA); drinking suppression; and fecal boli. Efficacy of the ablations was determined by subjecting ablated, sham-operated, and unoperated control animals to a CTA test which is known to require a functional AP. Animals with AP ablations failed to form CTA when 0.15 M LiCl was paired with a 10 percent sucrose solution, while sham-operated control subjects conditioned as well as the unoperated control subjects. The extent of the ablations was evaluated histologically at the end of the experiment. To determine the effects of the ablations on the measures of motion sickness, all animals were subjected to rotation for 30 min or 90 min on a platform displaced 20 deg from earth horizontal. Results indicate that ablation of AP in the rat has no effect on the formation of CTA to a 4 percent solution of cider paired with motion, on the suppression of drinking immediately after exposure to motion, or on the frequency of fecal boli during exposure to motion. This failure of AP ablations to eliminate the effects of motion on any of these responses discourages their use as equivalents of motion-induced vomiting. The appropriateness of other suggested measures, e.g., pica, remains untested but the dependence of such measures on stimulation more severe than commonly used in motion sickness research and the absence of a demonstration of their dependence on neural

  16. Operation Ivy. Project 6. 2. Report to the Scientific Director. Blast-wave mass-motion measurements

    SciTech Connect

    Seacord, D.F.

    1985-09-01

    OPERATION IVY was instrumented for the mass-motion method of pressure measurement in a manner similar to that used on OPERATIONS BUSTER-JANGLE and TUMBLER-SNAPPER. Low-altitude pyrotechnic mortar bursts and high-altitude gun bursts (on Mike only) labeled the air for photographic recording. The methods of instrumentation are described, the method of data analysis is outlined and derived data on time of arrival, peak material velocity, peak shock velocity, and peak overpressure are presented in tabular and graphical form. Appendixes present meteorological and ballistic data and calculations. An outstanding conclusion of the experiment is the lowness of peak overpressures near the surface compared with the peak overpressures at altitudes up to 25,000 feet because of the effect of atmospheric inhomogeneity at long ranges. The mass-motion technique offers a useful diagnostic tool for the determination of total hydrodynamic yield.

  17. Intrinsic feature-based pose measurement for imaging motion compensation

    SciTech Connect

    Baba, Justin S.; Goddard, Jr., James Samuel

    2014-08-19

    Systems and methods for generating motion corrected tomographic images are provided. A method includes obtaining first images of a region of interest (ROI) to be imaged and associated with a first time, where the first images are associated with different positions and orientations with respect to the ROI. The method also includes defining an active region in the each of the first images and selecting intrinsic features in each of the first images based on the active region. Second, identifying a portion of the intrinsic features temporally and spatially matching intrinsic features in corresponding ones of second images of the ROI associated with a second time prior to the first time and computing three-dimensional (3D) coordinates for the portion of the intrinsic features. Finally, the method includes computing a relative pose for the first images based on the 3D coordinates.

  18. Bronchoscopy guidance system based on bronchoscope-motion measurements

    NASA Astrophysics Data System (ADS)

    Cornish, Duane C.; Higgins, William E.

    2012-02-01

    Bronchoscopy-guidance systems assist physicians during bronchoscope navigation. However, these systems require an attending technician and fail to continuously track the bronchoscope. We propose a real-time technicianfree bronchoscopy-guidance system that employs continuous tracking. For guidance, our system presents directions on virtual views that are generated from the bronchoscope's tracked location. The system achieves bronchoscope tracking using a strategy that is based on a recently proposed method for sensor-based bronchoscope-motion tracking.1 Furthermore, a graphical indicator notifies the physician when he/she has maneuvered the bronchoscope to an incorrect branch. Our proposed system uses the sensor data to generate virtual views through multiple candidate routes and employs image matching in a Bayesian framework to determine the most probable bronchoscope pose. Tests based on laboratory phantoms validate the potential of the system.

  19. Quantitative measurement of body motion using Schottky barrier silicon photodiode.

    PubMed

    Yoo, J H; Suh, I H; Wallace, S; Hankla, J W; Wauters, K A

    1979-11-01

    A new motion detection system has been developed using a laser beam and a Schottky barrier silicon photodiode. The system broadens the scope of gravitational center stabilography by facilitating the quantitative assessment of tremors of body appendages such as the hands and even the head. The system also eliminates cumbersome platforms and wire attachments previously used in gravitational center stabilography. The subject is asked to aim the beam at the photodiode. A quantitative off-center variation parameter, ARDS (Average Radial Distance Squared multiplied by time), was utilized in units of cm2 sec. A preliminary evaluation of the system shows that it is suitable for rapidly screening large numbers of subjects for localised neuromuscular control. PMID:526517

  20. Wireless Measurement of Contact and Motion Between Contact Surfaces

    NASA Technical Reports Server (NTRS)

    Woodard, Stanley E.; Taylor, Bryant D.

    2007-01-01

    This method uses a magnetic-field- response contact sensor that is designed to identify surface contact and motion between contact locations. The sensor has three components: (1) a capacitor-inductor circuit with two sets of electrical contact pads, (2) a capacitor with a set of electrical contact pads, and (3) an inductor with a set of electrical contact pads. A unique feature of this sensor is that it is inherently multifunctional. Information can be derived from analyzing such sensor response attributes as amplitude, frequency, and bandwidth. A change in one attribute can be due to a change in a physical property of a system. A change in another attribute can be due to another physical property, which has no relationship to the first one.

  1. Crystal motion measurement by means of satellite techniques

    NASA Technical Reports Server (NTRS)

    Siry, J. W.

    1973-01-01

    A system for monitoring precursory crustal motions is presented. It involves a set of automated corner reflector stations tracked by means of a laser operating in the Geopause satellite. It is possible to range some three times during every Geopause pass to each of the sites in such an ensemble, weather permitting. One centimeter range data gathered during a quarter of a year can yield position component accuracies of the order of a couple of centimeters. A laser beam of a tenth of a milliradian in diameter would, illuminate a single station in such an array. A broader beam would generate reflections from several sites, yielding overlapping data. A chain or pattern of such overlapping regions can strengthen the solution for site positions. Pressure, temperature and humidity gauges can provide refraction correction data. Turnaround transponders interrogated by the Geopause radio tracking system can furnish corresponding data in excessively cloudy regions.

  2. Vehicles in Motion Parameters Measurement Pre-Selection System

    NASA Astrophysics Data System (ADS)

    Mitas, Andrzej; Konior, Witold

    2012-03-01

    Heavy goods vehicles moving on public roads are driven by people belonging to all walks of society, including those, who for the price paid by others are ready to multiply their own profits. This problem is discussed in the article, in particular in terms of overloading car's. There is pointed out on the technical implications of such actions. Later in the paper are presented the basic assumptions of lorries pre-selection weighting, which could be treated as a potential reason to the implementation of time-consuming exact weighting procedure. The discussion of hardware-software solution of pre-selection weighing systems was related to practical applications in national conditions. The article highlighted the problem of dynamic effects, significantly influencing the process of weighting in motion.

  3. AIR INFILTRATION MEASUREMENTS USING TRACER GASES: A LITERATURE REVIEW

    EPA Science Inventory

    The report gives results of a literature review of air filtration measurements using tracer gases, including sulfur hexafluoride, hydrogen, carbon monoxide, carbon dioxide, nitrous oxide, and radioactive argon and krypton. Sulfur hexafluoride is the commonest tracer gas of choice...

  4. Note: A resonating reflector-based optical system for motion measurement in micro-cantilever arrays

    SciTech Connect

    Sathishkumar, P.; Punyabrahma, P.; Sri Muthu Mrinalini, R.; Jayanth, G. R.

    2015-09-15

    A robust, compact optical measurement unit for motion measurement in micro-cantilever arrays enables development of portable micro-cantilever sensors. This paper reports on an optical beam deflection-based system to measure the deflection of micro-cantilevers in an array that employs a single laser source, a single detector, and a resonating reflector to scan the measurement laser across the array. A strategy is also proposed to extract the deflection of individual cantilevers from the acquired data. The proposed system and measurement strategy are experimentally evaluated and demonstrated to measure motion of multiple cantilevers in an array.

  5. Note: A resonating reflector-based optical system for motion measurement in micro-cantilever arrays.

    PubMed

    Sathishkumar, P; Punyabrahma, P; Mrinalini, R Sri Muthu; Jayanth, G R

    2015-09-01

    A robust, compact optical measurement unit for motion measurement in micro-cantilever arrays enables development of portable micro-cantilever sensors. This paper reports on an optical beam deflection-based system to measure the deflection of micro-cantilevers in an array that employs a single laser source, a single detector, and a resonating reflector to scan the measurement laser across the array. A strategy is also proposed to extract the deflection of individual cantilevers from the acquired data. The proposed system and measurement strategy are experimentally evaluated and demonstrated to measure motion of multiple cantilevers in an array. PMID:26429493

  6. Note: A resonating reflector-based optical system for motion measurement in micro-cantilever arrays

    NASA Astrophysics Data System (ADS)

    Sathishkumar, P.; Punyabrahma, P.; Sri Muthu Mrinalini, R.; Jayanth, G. R.

    2015-09-01

    A robust, compact optical measurement unit for motion measurement in micro-cantilever arrays enables development of portable micro-cantilever sensors. This paper reports on an optical beam deflection-based system to measure the deflection of micro-cantilevers in an array that employs a single laser source, a single detector, and a resonating reflector to scan the measurement laser across the array. A strategy is also proposed to extract the deflection of individual cantilevers from the acquired data. The proposed system and measurement strategy are experimentally evaluated and demonstrated to measure motion of multiple cantilevers in an array.

  7. Determination of Foton M-2 satellite attitude motion by the data of microacceleration measurements

    NASA Astrophysics Data System (ADS)

    Beuselinck, T.; van Bavinchove, C.; Sazonov, V. V.; Chebukov, S. Yu.

    2009-12-01

    The results of reconstruction of uncontrolled attitude motion of the Foton M-2 satellite using measurements with the accelerometer TAS-3 are presented. The attitude motion of this satellite has been previously determined by the measurement data of the Earth’s magnetic field and the angular velocity. The TAS-3 data for this purpose are used for the first time. These data contain a well-pronounced additional component which made impossible their direct employment for the reconstruction of the attitude motion and whose origin was unknown several years ago. Later it has become known that the additional component is caused by the influence of the Earth’s magnetic field. The disclosure of this fact allowed us to take into account a necessary correction in processing of TAS-3 data and to use them for the reconstruction of the attitude motion of Foton M-2. Here, a modified method of processing TAS-3 data is described, as well as results of its testing and employing. The testing consisted in the direct comparison of the motion reconstructed by the new method with the motion constructed by the magnetic measurements. The new method allowed us to find the actual motion of Foton M-2 in the period June 9, 2005-June 14, 2005, when no magnetic measurements were carried out.

  8. Method and Apparatus for Measuring Surface Air Pressure

    NASA Technical Reports Server (NTRS)

    Lin, Bing (Inventor); Hu, Yongxiang (Inventor)

    2014-01-01

    The present invention is directed to an apparatus and method for remotely measuring surface air pressure. In one embodiment, the method of the present invention utilizes the steps of transmitting a signal having multiple frequencies into the atmosphere, measuring the transmitted/reflected signal to determine the relative received power level of each frequency and then determining the surface air pressure based upon the attenuation of the transmitted frequencies.

  9. Feasibility of Measuring Mean Vertical Motion for Estimating Advection. Chapter 6

    NASA Technical Reports Server (NTRS)

    Vickers, Dean; Mahrt, L.

    2005-01-01

    Numerous recent studies calculate horizontal and vertical advection terms for budget studies of net ecosystem exchange of carbon. One potential uncertainty in such studies is the estimate of mean vertical motion. This work addresses the reliability of vertical advection estimates by contrasting the vertical motion obtained from the standard practise of measuring the vertical velocity and applying a tilt correction, to the vertical motion calculated from measurements of the horizontal divergence of the flow using a network of towers. Results are compared for three different tilt correction methods. Estimates of mean vertical motion are sensitive to the choice of tilt correction method. The short-term mean (10 to 60 minutes) vertical motion based on the horizontal divergence is more realistic compared to the estimates derived from the standard practise. The divergence shows long-term mean (days to months) sinking motion at the site, apparently due to the surface roughness change. Because all the tilt correction methods rely on the assumption that the long-term mean vertical motion is zero for a given wind direction, they fail to reproduce the vertical motion based on the divergence.

  10. Measuring In-Air and Underwater Hearing in Seabirds.

    PubMed

    Crowell, Sara C

    2016-01-01

    Electrophysiological methods were used to measure the in-air hearing of 10 species of seabirds. There are currently no measures of the underwater hearing abilities of diving birds. In preparation for constructing a behavioral audiogram both in-air and underwater hearing, several species of diving ducks were raised. Because there is a considerable amount of literature on bird hearing in air, the technical setup and training methods were modeled on similar studies, with modifications to address the nature of the underwater sound field and the difficulty of the task for the birds. PMID:26611081

  11. 3D Measurement of Forearm and Upper Arm during Throwing Motion using Body Mounted Sensor

    NASA Astrophysics Data System (ADS)

    Koda, Hideharu; Sagawa, Koichi; Kuroshima, Kouta; Tsukamoto, Toshiaki; Urita, Kazutaka; Ishibashi, Yasuyuki

    The aim of this study is to propose the measurement method of three-dimensional (3D) movement of forearm and upper arm during pitching motion of baseball using inertial sensors without serious consideration of sensor installation. Although high accuracy measurement of sports motion is achieved by using optical motion capture system at present, it has some disadvantages such as the calibration of cameras and limitation of measurement place. Whereas the proposed method for 3D measurement of pitching motion using body mounted sensors provides trajectory and orientation of upper arm by the integration of acceleration and angular velocity measured on upper limb. The trajectory of forearm is derived so that the elbow joint axis of forearm corresponds to that of upper arm. Spatial relation between upper limb and sensor system is obtained by performing predetermined movements of upper limb and utilizing angular velocity and gravitational acceleration. The integration error is modified so that the estimated final position, velocity and posture of upper limb agree with the actual ones. The experimental results of the measurement of pitching motion show that trajectories of shoulder, elbow and wrist estimated by the proposed method are highly correlated to those from the motion capture system within the estimation error of about 10 [%].

  12. Optical Air Flow Measurements for Flight Tests and Flight Testing Optical Air Flow Meters

    NASA Technical Reports Server (NTRS)

    Jentink, Henk W.; Bogue, Rodney K.

    2005-01-01

    Optical air flow measurements can support the testing of aircraft and can be instrumental to in-flight investigations of the atmosphere or atmospheric phenomena. Furthermore, optical air flow meters potentially contribute as avionics systems to flight safety and as air data systems. The qualification of these instruments for the flight environment is where we encounter the systems in flight testing. An overview is presented of different optical air flow measurement techniques applied in flight and what can be achieved with the techniques for flight test purposes is reviewed. All in-flight optical airflow velocity measurements use light scattering. Light is scattered on both air molecules and aerosols entrained in the air. Basic principles of making optical measurements in flight, some basic optical concepts, electronic concepts, optoelectronic interfaces, and some atmospheric processes associated with natural aerosols are reviewed. Safety aspects in applying the technique are shortly addressed. The different applications of the technique are listed and some typical examples are presented. Recently NASA acquired new data on mountain rotors, mountain induced turbulence, with the ACLAIM system. Rotor position was identified using the lidar system and the potentially hazardous air flow profile was monitored by the ACLAIM system.

  13. Modeling and measurement of the motion of the DIII-D vacuum vessel during vertical instabilities

    SciTech Connect

    Reis, E.; Blevins, R.D.; Jensen, T.H.; Luxon, J.L.; Petersen, P.I.; Strait, E.J.

    1991-11-01

    The motions of the D3-D vacuum vessel during vertical instabilities of elongated plasmas have been measured and studied over the past five years. The currents flowing in the vessel wall and the plasma scrapeoff layer were also measured and correlated to a physics model. These results provide a time history load distribution on the vessel which were input to a dynamic analysis for correlation to the measured motions. The structural model of the vessel using the loads developed from the measured vessel currents showed that the calculated displacement history correlated well with the measured values. The dynamic analysis provides a good estimate of the stresses and the maximum allowable deflection of the vessel. In addition, the vessel motions produce acoustic emissions at 21 Hertz that are sufficiently loud to be felt as well as heard by the D3-D operators. Time history measurements of the sounds were correlated to the vessel displacements. An analytical model of an oscillating sphere provided a reasonable correlation to the amplitude of the measured sounds. The correlation of the theoretical and measured vessel currents, the dynamic measurements and analysis, and the acoustic measurements and analysis show that: (1) The physics model can predict vessel forces for selected values of plasma resistivity. The model also predicts poloidal and toroidal wall currents which agree with measured values; (2) The force-time history from the above model, used in conjunction with an axisymmetric structural model of the vessel, predicts vessel motions which agree well with measured values; (3) The above results, input to a simple acoustic model predicts the magnitude of sounds emitted from the vessel during disruptions which agree with acoustic measurements; (4) Correlation of measured vessel motions with structural analysis shows that a maximum vertical motion of the vessel up to 0.24 in will not overstress the vessel or its supports. 11 refs., 10 figs., 1 tab.

  14. Measures and Relative Motions of Some Mostly F. G. W. Struve Doubles

    NASA Astrophysics Data System (ADS)

    Wiley, E. O.

    2012-04-01

    Measures of 59 pairs of double stars with long observational histories using "lucky imaging" techniques are reported. Relative motions of 59 pairs are investigated using histories of observation, scatter plots of relative motion, ordinary least-squares (OLS) and total proper motion analyses performed in "R," an open source programming language. A scatter plot of the coefficient of determinations derived from the OLS y|epoch and OLS x|epoch clearly separates common proper motion pairs from optical pairs and what are termed "long-period binary candidates." Differences in proper motion separate optical pairs from long-term binary candidates. An Appendix is provided that details how to use known rectilinear pairs as calibration pairs for the program REDUC.

  15. Motion measurement of SAR antenna based on high frame rate camera

    NASA Astrophysics Data System (ADS)

    Li, Q.; Cao, R.; Feng, H.; Xu, Z.

    2015-03-01

    Synthetic Aperture Radar (SAR) is currently in the marine, agriculture, geology and other fields are widely used, while the SAR antenna is one of the most important subsystems. Performance of antenna has a significant impact on the SAR sensitivity, azimuth resolution, image blur degree and other parameter. To improve SAR resolution, SAR antenna is designed and fabricated according to flexible expandable style. However, the movement of flexible antenna will have a greater impact on accuracy of SAR systems, so the motion measurement of the flexible antenna is an urgent problem. This paper studied motion measurements method based on high frame rate camera, designed and completed a flexible antenna motion measurement experiment. In the experiment the main IMU and the sub IMU were placed at both ends of the cantilever, which is simulation of flexible antenna, the high frame rate camera was placed above the main IMU, and the imaging target was set on side of the sub IMU. When the cantilever motion occurs, IMU acquired spatial coordinates of cantilever movement in real-time, and high frame rate camera captured a series of target images, and then the images was input into JTC to obtain the cantilever motion coordinates. Through the contrast and analysis of measurement results, the measurement accuracy of flexible antenna motion is verified.

  16. Utilization of lasers for air data measurements

    NASA Astrophysics Data System (ADS)

    Hammer, J.

    1991-05-01

    The operating principles of the ALEV3 three axis laser Doppler anemometer, which was designed for flight tests with the A-320 and A-340 aircraft, are depicted. If mounted on the aircraft center of gravity, the ALEV-3 allows true flight velocity in three directions and angles of attack and sideslip to be directly measured with a very good accuracy, in particular flight areas such as limit buffeting, stall, high Mach numbers, or sideslip flights. Aircraft parameter estimation, calculation, and calibration results are presented. The accuracies of velocity, static pressure and aerodynamic angle measurements were compared with classical anemometers precisions. Flight tests results of the ALEV-1 one axis laser anemometer for A-320 are given as a reference.

  17. Measuring the Effects of Lift and Drag on Projectile Motion

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2012-02-01

    The trajectory of a projectile through the air is affected both by gravity and by aerodynamic forces. The latter forces can conveniently be ignored in many situations, even when they are comparatively large. For example, if a 145-g, 74-mm diameter baseball is pitched at 40 ms-1 (89.5 mph), it experiences a drag force of about 1.5 N. The gravitational force on the ball 1.42 N. Nevertheless, the trajectory of a baseball pitched without spin is not strongly affected by the drag force. Because the ball is relatively heavy and the flight distance is relatively small (about 60 ft), the drag force reduces the ball speed by only about 10% by the time it reaches the batter. As a result, the time taken for the ball to reach the batter is only about 5% longer than in a vacuum, and the actual trajectory is also very similar.2

  18. Subtle in-scanner motion biases automated measurement of brain anatomy from in vivo MRI.

    PubMed

    Alexander-Bloch, Aaron; Clasen, Liv; Stockman, Michael; Ronan, Lisa; Lalonde, Francois; Giedd, Jay; Raznahan, Armin

    2016-07-01

    While the potential for small amounts of motion in functional magnetic resonance imaging (fMRI) scans to bias the results of functional neuroimaging studies is well appreciated, the impact of in-scanner motion on morphological analysis of structural MRI is relatively under-studied. Even among "good quality" structural scans, there may be systematic effects of motion on measures of brain morphometry. In the present study, the subjects' tendency to move during fMRI scans, acquired in the same scanning sessions as their structural scans, yielded a reliable, continuous estimate of in-scanner motion. Using this approach within a sample of 127 children, adolescents, and young adults, significant relationships were found between this measure and estimates of cortical gray matter volume and mean curvature, as well as trend-level relationships with cortical thickness. Specifically, cortical volume and thickness decreased with greater motion, and mean curvature increased. These effects of subtle motion were anatomically heterogeneous, were present across different automated imaging pipelines, showed convergent validity with effects of frank motion assessed in a separate sample of 274 scans, and could be demonstrated in both pediatric and adult populations. Thus, using different motion assays in two large non-overlapping sets of structural MRI scans, convergent evidence showed that in-scanner motion-even at levels which do not manifest in visible motion artifact-can lead to systematic and regionally specific biases in anatomical estimation. These findings have special relevance to structural neuroimaging in developmental and clinical datasets, and inform ongoing efforts to optimize neuroanatomical analysis of existing and future structural MRI datasets in non-sedated humans. Hum Brain Mapp 37:2385-2397, 2016. © 2016 Wiley Periodicals, Inc. PMID:27004471

  19. Direct and indirect measures of speech articulator motions using low power EM sensors

    SciTech Connect

    Barnes, T; Burnett, G; Gable, T; Holzrichter, J F; Ng, L

    1999-05-12

    Low power Electromagnetic (EM) Wave sensors can measure general properties of human speech articulator motions, as speech is produced. See Holzrichter, Burnett, Ng, and Lea, J.Acoust.Soc.Am. 103 (1) 622 (1998). Experiments have demonstrated extremely accurate pitch measurements (< 1 Hz per pitch cycle) and accurate onset of voiced speech. Recent measurements of pressure-induced tracheal motions enable very good spectra and amplitude estimates of a voiced excitation function. The use of the measured excitation functions and pitch synchronous processing enable the determination of each pitch cycle of an accurate transfer function and, indirectly, of the corresponding articulator motions. In addition, direct measurements have been made of EM wave reflections from articulator interfaces, including jaw, tongue, and palate, simultaneously with acoustic and glottal open/close signals. While several types of EM sensors are suitable for speech articulator measurements, the homodyne sensor has been found to provide good spatial and temporal resolution for several applications.

  20. Identification and influence of spatial outliers in air quality measurements

    NASA Astrophysics Data System (ADS)

    O'Leary, B. F.; Lemke, L. D.

    2015-12-01

    The heterogeneous nature of urban air complicates the analysis of spatial and temporal variability in air quality measurements. Evaluation of potentially inaccurate measurements (i.e., outliers) poses particularly difficult challenges in extensive air quality datasets with multiple measurements distributed in time and space. This study investigated the identification and impact of outliers in measurements of NO­2, BTEX, PM2.5, and PM10 in the contiguous Detroit, Michigan, USA and Windsor, Ontario, Canada international airshed. Measurements were taken at 100 locations during September 2008 and June 2009 and modeled at a 300m by 300m scale resolution. The objective was to determine if outliers were present and, if so, to quantify the magnitude of their impact on modeled spatial pollution distributions. The study built upon previous investigations by the Geospatial Determinants of Health Outcomes Consortium that examined relationships between air pollutant distributions and asthma exacerbations in the Detroit and Windsor airshed. Four independent approaches were initially employed to identify potential outliers: boxplots, variogram clouds, difference maps, and the Local Moran's I statistic. Potential outliers were subsequently reevaluated for consistency among methods and individually assessed to select a final set of outliers. The impact of excluding individual outliers was subsequently determined by revising the spatially variable air pollution models and recalculating associations between air contaminant concentrations and asthma exacerbations in Detroit and Windsor in 2008. For the pollutants examined, revised associations revealed weaker correlations with spatial outliers removed. Nevertheless, the approach employed improves the model integrity by increasing our understanding of the spatial variability of air pollution in the built environment and providing additional insights into the association between acute asthma exacerbations and air pollution.

  1. Measurement of transient force produced by a propagating arc magnetohydrodynamic plasma actuator in quiescent atmospheric air

    NASA Astrophysics Data System (ADS)

    Choi, Young Joon; Sirohi, Jayant; Raja, Laxminarayan L.

    2015-10-01

    An experimental study was conducted on a magnetohydrodynamic plasma actuator consisting of two parallel, six inch long, copper electrodes flush mounted on an insulating ceramic plate. An electrical arc is generated by a  ∼1 kA current pulse at  ∼100 V across the electrodes. A self-induced Lorentz force drives the arc along the electrodes. The motion of the arc induces flow in the surrounding air through compression as well as entrainment, and generates a transient force, about  ∼4 ms in duration. Experiments were performed on a prototype actuator in quiescent atmospheric air to characterize the motion of the arc and the momentum transferred to the surrounding air. Measurements included transient force and total impulse generated by the actuator as well as the armature voltage and current. The arc shape and transit velocity were determined by high-speed imaging. A peak force of 0.4 N imparting an impulse of 0.68 mN-s was measured for a peak current of 1.2 kA. The force scaled with the square of the armature current and the impulse scaled linearly with the spent capacitor energy. The results provide insight into the mechanisms of body force generation and momentum transfer of a magnetohydrodynamic plasma actuator.

  2. Accurate and portable weigh-in-motion system for manifesting air cargo

    SciTech Connect

    Nodine, R.N.; Scudiere, M.B.; Jordan, J.K.

    1995-12-01

    An automated and portable weigh-in-motion system has been developed at Oak Ridge National Laboratory for the purpose of manifesting cargo onto aircraft. The system has an accuracv range of {plus_minus} 3.0% to {plus_minus} 6.0% measuring gross vehicle weight and locating the center of balance of moving vehicles at speeds of 1 to 5 mph. This paper reviews the control/user interface system and weight determination algorithm developed to acquire, process, and interpret multiple sensor inputs. The development effort resulted in a self-zeroing, user-friendly system capable of weighing a wide range of vehicles in any random order. The control system is based on the STANDARD (STD) bus and incorporates custom-designed data acquisition and sensor fusion hardware controlled by a personal computer (PC) based single-board computer. The user interface is written in the ``C`` language to display number of axles, axle weight, axle spacing, gross weight, and center of balance. The weighing algorithm developed will function with any linear weight sensor and a set of four axle switches per sensor.

  3. Measurements of ground motion and SSC dipole vibrations

    SciTech Connect

    Parkhomchuk, V.V.; Shiltsev, V.D.; Weaver, H.J.

    1993-06-01

    The results of seismic ground measurements at the Superconducting Super Collider (SSC) site and investigations of vibrational properties of superconducting dipoles for the SSC are presented. Spectral analysis of the data obtained in the large frequency band from 0.05 Hz to 2000 Hz is done. Resonant behavior and the dipole-to-ground transform ratio are investigated. The influence of measured vibrations on SSC operations is considered.

  4. An out-of-plane linear motion measurement system based on optical beam deflection

    NASA Astrophysics Data System (ADS)

    Piyush, P.; Jayanth, G. R.

    2016-02-01

    Measurement of out-of-plane linear motion with high precision and bandwidth is indispensable for development of precision motion stages and for dynamic characterization of mechanical structures. This paper presents an optical beam deflection (OBD) based system for measurement of out-of-plane linear motion for fully reflective samples. The system also achieves nearly zero cross-sensitivity to angular motion, and a large working distance. The sensitivities to linear and angular motion are analytically obtained and employed to optimize the system design. The optimal shot-noise limited resolution is shown to be less than one angstrom over a bandwidth in excess of 1 kHz. Subsequently, the system is experimentally realized and the sensitivities to out-of-plane motions are calibrated using a novel strategy. The linear sensitivity is found to be in agreement with theory. The angular sensitivity is shown to be over 7.5-times smaller than that of conventional OBD. Finally, the measurement system is employed to measure the transient response of a piezo-positioner, and, with the aid of an open-loop controller, reduce the settling time by about 90%. It is also employed to operate the positioner in closed-loop and demonstrate significant minimization of hysteresis and positioning error.

  5. Motion data classification on the basis of dynamic time warping with a cloud point distance measure

    NASA Astrophysics Data System (ADS)

    Switonski, Adam; Josinski, Henryk; Zghidi, Hafedh; Wojciechowski, Konrad

    2016-06-01

    The paper deals with the problem of classification of model free motion data. The nearest neighbors classifier which is based on comparison performed by Dynamic Time Warping transform with cloud point distance measure is proposed. The classification utilizes both specific gait features reflected by a movements of subsequent skeleton joints and anthropometric data. To validate proposed approach human gait identification challenge problem is taken into consideration. The motion capture database containing data of 30 different humans collected in Human Motion Laboratory of Polish-Japanese Academy of Information Technology is used. The achieved results are satisfactory, the obtained accuracy of human recognition exceeds 90%. What is more, the applied cloud point distance measure does not depend on calibration process of motion capture system which results in reliable validation.

  6. Measurement results obtained from air quality monitoring system

    SciTech Connect

    Turzanski, P.K.; Beres, R.

    1995-12-31

    An automatic system of air pollution monitoring operates in Cracow since 1991. The organization, assembling and start-up of the network is a result of joint efforts of the US Environmental Protection Agency and the Cracow environmental protection service. At present the automatic monitoring network is operated by the Provincial Inspection of Environmental Protection. There are in total seven stationary stations situated in Cracow to measure air pollution. These stations are supported continuously by one semi-mobile (transportable) station. It allows to modify periodically the area under investigation and therefore the 3-dimensional picture of creation and distribution of air pollutants within Cracow area could be more intelligible.

  7. MEASUREMENT OF LOW LEVEL AIR TOXICS WITH MODIFIED UV DOAS

    EPA Science Inventory

    To further understand near source impacts, EPA is working to develop open-path optical techniques for spatiotemporal-resolved measurement of air pollutants. Of particular interest is near real time quantification of mobile-source generated CO, Nox and hydrocarbons measured in cl...

  8. Turbulence measurements in axisymmetric jets of air and helium. I - Air jet. II - Helium jet

    NASA Astrophysics Data System (ADS)

    Panchapakesan, N. R.; Lumley, J. L.

    1993-01-01

    Results are presented of measurements on turbulent round jets of air and of helium of the same nozzle momentum efflux, using, for the air jets, x-wire hot-wire probes mounted on a moving shuttle and, for He jets, a composite probe consisting of an interference probe of the Way-Libby type and an x-probe. Current models for scalar triple moments were evaluated. It was found that the performance of the model termed the Full model, which includes all terms except advection, was very good for both the air and the He jets.

  9. The Aeroflex: A Bicycle for Mobile Air Quality Measurements

    PubMed Central

    Elen, Bart; Peters, Jan; Van Poppel, Martine; Bleux, Nico; Theunis, Jan; Reggente, Matteo; Standaert, Arnout

    2013-01-01

    Fixed air quality stations have limitations when used to assess people's real life exposure to air pollutants. Their spatial coverage is too limited to capture the spatial variability in, e.g., an urban or industrial environment. Complementary mobile air quality measurements can be used as an additional tool to fill this void. In this publication we present the Aeroflex, a bicycle for mobile air quality monitoring. The Aeroflex is equipped with compact air quality measurement devices to monitor ultrafine particle number counts, particulate mass and black carbon concentrations at a high resolution (up to 1 second). Each measurement is automatically linked to its geographical location and time of acquisition using GPS and Internet time. Furthermore, the Aeroflex is equipped with automated data transmission, data pre-processing and data visualization. The Aeroflex is designed with adaptability, reliability and user friendliness in mind. Over the past years, the Aeroflex has been successfully used for high resolution air quality mapping, exposure assessment and hot spot identification. PMID:23262484

  10. The Aeroflex: a bicycle for mobile air quality measurements.

    PubMed

    Elen, Bart; Peters, Jan; Poppel, Martine Van; Bleux, Nico; Theunis, Jan; Reggente, Matteo; Standaert, Arnout

    2013-01-01

    Fixed air quality stations have limitations when used to assess people's real life exposure to air pollutants. Their spatial coverage is too limited to capture the spatial variability in, e.g., an urban or industrial environment. Complementary mobile air quality measurements can be used as an additional tool to fill this void. In this publication we present the Aeroflex, a bicycle for mobile air quality monitoring. The Aeroflex is equipped with compact air quality measurement devices to monitor ultrafine particle number counts, particulate mass and black carbon concentrations at a high resolution (up to 1 second). Each measurement is automatically linked to its geographical location and time of acquisition using GPS and Internet time. Furthermore, the Aeroflex is equipped with automated data transmission, data pre-processing and data visualization. The Aeroflex is designed with adaptability, reliability and user friendliness in mind. Over the past years, the Aeroflex has been successfully used for high resolution air quality mapping, exposure assessment and hot spot identification.  PMID:23262484

  11. Measuring the Surface Motion of Fast-Moving Glaciers with Expendable, Low-Cost GPS (Invited)

    NASA Astrophysics Data System (ADS)

    Howat, I. M.; Behar, A. E.; Brown, A. K.

    2009-12-01

    The recent retreats and acceleration in flow speeds of marine-terminating glaciers around the globe have raised concern over the potential for rapid loss of ice and increased rates of sea level rise. The dynamics of these glaciers are poorly understood, partly due to the difficulty in obtaining observations of ice flow speed that can be compared to potentially important forcing variables, such as air and ocean temperatures or calving rates. The high flow speeds (often >10 m/day) and large strain rates the near the fronts of these glaciers result in extreme crevassing, making surface travel for instrument deployment impossible. Due to this impassibility, measurements of surface motion have come predominantly from optical surveying or repeat satellite or photographic imaging. Remote sensing methods are limited in spatial and temporal resolution and optical surveys require manual operation in the field and have limited range. In contrast, Global Positioning System (GPS ) receivers offer very high resolution and, once deployed, collect data autonomously. GPS has been used to measure glacier surface motion for over a decade. Dual-frequency systems can yield post-processed displacements with accuracies of 1 cm or less, with a temporal resolution of minutes. These observations have been critical for resolving the stick-slip motion of Antarctic ice streams and the controls on glacial “icequakes” in Greenland. These systems have been combined with satellite-based data telemetry systems to provide near real-time position data to any location. These systems, however, typically cost several thousands of dollars, preventing their deployment in situations with low or no probability of recovery. The few field programs that have deployed dual-frequency receivers on fast-moving glaciers retrieved the systems after only a few days to prevent loss. While some investigators may be able to absorb the cost of loss of these systems, large-scale deployments will require a more cost

  12. Measuring contemporary crustal motions; NASA’s Crustal Dynamics Project

    USGS Publications Warehouse

    Frey, H. V.; Bosworth, J. M.

    1988-01-01

    In this article we describe briefly the two space geodetic techniques and how they are used by the Crustal Dynamics Project, show some of the very exciting results that have emerged at the halfway point in the project's life, describe the availability and utilization of the data being collected, and consider what the future may hold when measurement accuracies eventually exceed even those now available and when other international groups become more heavily involved.   

  13. Influence of detector motion in entanglement measurements with photons

    SciTech Connect

    Landulfo, Andre G. S.; Matsas, George E. A.; Torres, Adriano C.

    2010-04-15

    We investigate how the polarization correlations of entangled photons described by wave packets are modified when measured by moving detectors. For this purpose, we analyze the Clauser-Horne-Shimony-Holt Bell inequality as a function of the apparatus velocity. Our analysis is motivated by future experiments with entangled photons designed to use satellites. This is a first step toward the implementation of quantum information protocols in a global scale.

  14. Polarized radio emission from extensive air showers measured with LOFAR

    SciTech Connect

    Schellart, P.; Buitink, S.; Corstanje, A.; Enriquez, J.E.; Falcke, H.; Hörandel, J.R.; Krause, M.; Nelles, A.; Rachen, J.P.; Veen, S. ter; Thoudam, S.

    2014-10-01

    We present LOFAR measurements of radio emission from extensive air showers. We find that this emission is strongly polarized, with a median degree of polarization of nearly 99%, and that the angle between the polarization direction of the electric field and the Lorentz force acting on the particles, depends on the observer location in the shower plane. This can be understood as a superposition of the radially polarized charge-excess emission mechanism, first proposed by Askaryan and the geomagnetic emission mechanism proposed by Kahn and Lerche. We calculate the relative strengths of both contributions, as quantified by the charge-excess fraction, for 163 individual air showers. We find that the measured charge-excess fraction is higher for air showers arriving from closer to the zenith. Furthermore, the measured charge-excess fraction also increases with increasing observer distance from the air shower symmetry axis. The measured values range from (3.3± 1.0)% for very inclined air showers at 25 m to (20.3± 1.3)% for almost vertical showers at 225 m. Both dependencies are in qualitative agreement with theoretical predictions.

  15. Measurement of time delays in gated radiotherapy for realistic respiratory motions

    SciTech Connect

    Chugh, Brige P.; Quirk, Sarah; Conroy, Leigh; Smith, Wendy L.

    2014-09-15

    Purpose: Gated radiotherapy is used to reduce internal motion margins, escalate target dose, and limit normal tissue dose; however, its temporal accuracy is limited. Beam-on and beam-off time delays can lead to treatment inefficiencies and/or geographic misses; therefore, AAPM Task Group 142 recommends verifying the temporal accuracy of gating systems. Many groups use sinusoidal phantom motion for this, under the tacit assumption that use of sinusoidal motion for determining time delays produces negligible error. The authors test this assumption by measuring gating time delays for several realistic motion shapes with increasing degrees of irregularity. Methods: Time delays were measured on a linear accelerator with a real-time position management system (Varian TrueBeam with RPM system version 1.7.5) for seven motion shapes: regular sinusoidal; regular realistic-shape; large (40%) and small (10%) variations in amplitude; large (40%) variations in period; small (10%) variations in both amplitude and period; and baseline drift (30%). Film streaks of radiation exposure were generated for each motion shape using a programmable motion phantom. Beam-on and beam-off time delays were determined from the difference between the expected and observed streak length. Results: For the system investigated, all sine, regular realistic-shape, and slightly irregular amplitude variation motions had beam-off and beam-on time delays within the AAPM recommended limit of less than 100 ms. In phase-based gating, even small variations in period resulted in some time delays greater than 100 ms. Considerable time delays over 1 s were observed with highly irregular motion. Conclusions: Sinusoidal motion shapes can be considered a reasonable approximation to the more complex and slightly irregular shapes of realistic motion. When using phase-based gating with predictive filters even small variations in period can result in time delays over 100 ms. Clinical use of these systems for patients

  16. Introduction of New Motion Measurement Equipment into Virtual Walk System

    NASA Astrophysics Data System (ADS)

    Furukawa, Tatsuya; Itoh, Hideaki; Hori, Toshiyuki; Fukumoto, Hisao; Wakuya, Hiroshi; Ohchi, Masashi

    The “Virtual Walk System” has been developed to support rehabilitation therapy in homes. In the system, a user has been able to perform walking-like exercise on a fitness machine called a stepper. In front of the user, a projected image of a vast virtual reality space is generated by 3-dimensional computer graphics (3DCG). The user's movement is measured and the projected image changes just like the user is walking in the virtual space. Viewing the changing image, the user can enjoy the exercise. In this study, we have decomposed the virtual walk system into two modules (the measurement and control module operated by a microcomputer board and the 3DCG module operated by a personal computer) to facilitate rapid development. Then we have introduced two kinds of new equipment, i.e., a bicycle for cycling exercise and a treadmill for walking exercise. We have also developed a treadmill control system by which a user can easily change the walking speed during exercise.

  17. Low-frequency sound absorption measurements in air

    NASA Technical Reports Server (NTRS)

    Zuckerwar, A. J.; Meredith, R. W.

    1984-01-01

    Thirty sets of sound absorption measurements in air at a pressure of 1 atmosphere are presented at temperatures from 10 C to 50 C, relative humidities from 0 to 100 percent, and frequencies from 10 to 2500 Hz. The measurements were conducted by the method of free decay in a resonant tube having a length of 18.261 m and bore diameter of 0.152 m. Background measurements in a gas consisting of 89.5 percent N2 and 10.5 percent Ar, a mixture which has the same sound velocity as air, permitted the wall and structural losses of the tube to be separated from the constituent absorption, consisting of classical rotational and vibrational absorption, in the air samples. The data were used to evaluate the vibrational relaxation frequencies of N2 and/or O2 for each of the 30 sets of meteorological parameters. Over the full range of humidity, the measured relaxation frequencies of N2 in air lie between those specified by ANSI Standard S1.26-1978 and those measured earlier in binary N2H2O mixtures. The measured relaxation frequencies could be determined only at very low values of humidity, reveal a significant trend away from the ANSI standard, in agreement with a prior investigation.

  18. Measuring Outdoor Air Intake Rates into Existing Building

    SciTech Connect

    Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

    2009-04-16

    Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10 percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15 percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100 percent, and were often greater than 25 percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

  19. Indoor air quality. [Health hazards due to energy conservation measures

    SciTech Connect

    Hollowell, C.D.

    1981-06-01

    Rising energy prices, among other factors, have generated an incentive to reduce ventilation rates and thereby reduce the cost of heating and cooling buildings. Reduced ventilation in buildings may significantly increase exposure to indoor air pollution and perhaps have adverse effects on occupant health and comfort. Preliminary findings suggest that reduced ventilation may adversely affect indoor air quality unless appropriate control strategies are undertaken. The strategies used to control indoor air pollution depend on the specific pollutant or class of pollutants encountered, and differ somewhat depending on whether the application is to an existing building or a new building under design and construction. Whenever possible, the first course of action is prevention or reduction of pollutant emissions at the source. In most buildings, control measures involve a combination of prevention, removal, and suppression. Common sources of indoor air pollution in buildings, the specific pollutants emitted by each source, the potential health effects, and possible control techniques are discussed.

  20. Drop size distribution and air velocity measurements in air assist swirl atomizer sprays

    NASA Astrophysics Data System (ADS)

    Mao, C.-P.; Oechsle, V.; Chigier, N.

    1987-03-01

    Detailed measurements of mean drop size (SMD) and size distribution parameters have been made using a Fraunhofer diffraction particle sizing instrument in a series of sprays generated by an air assist swirl atomizer. Thirty-six different combinations of fuel and air mass flow rates were examined with liquid flow rates up to 14 lbm/hr and atomizing air flow rates up to 10 lbm/hr. Linear relationships were found between SMD and liquid to air mass flow rate ratios. SMD increased with distance downstream along the center line and also with radial distance from the axis. Increase in obscuration with distance downstream was due to an increase in number density of particles as the result of deceleration of drops and an increase in the exposed path length of the laser beam. Velocity components of the atomizing air flow field measured by a laser anemometer show swirling jet air flow fields with solid body rotation in the core and free vortex flow in the outer regions.

  1. Drop size distribution and air velocity measurements in air assist swirl atomizer sprays

    NASA Technical Reports Server (NTRS)

    Mao, C.-P.; Oechsle, V.; Chigier, N.

    1987-01-01

    Detailed measurements of mean drop size (SMD) and size distribution parameters have been made using a Fraunhofer diffraction particle sizing instrument in a series of sprays generated by an air assist swirl atomizer. Thirty-six different combinations of fuel and air mass flow rates were examined with liquid flow rates up to 14 lbm/hr and atomizing air flow rates up to 10 lbm/hr. Linear relationships were found between SMD and liquid to air mass flow rate ratios. SMD increased with distance downstream along the center line and also with radial distance from the axis. Increase in obscuration with distance downstream was due to an increase in number density of particles as the result of deceleration of drops and an increase in the exposed path length of the laser beam. Velocity components of the atomizing air flow field measured by a laser anemometer show swirling jet air flow fields with solid body rotation in the core and free vortex flow in the outer regions.

  2. New Measurements of the Motion of the Zodiacal Dust

    NASA Astrophysics Data System (ADS)

    Reynolds, R. J.; Madsen, G. J.; Moseley, S. H.

    2004-09-01

    Using the Wisconsin Hα Mapper (WHAM), we have measured at high spectral resolution and high signal-to-noise ratio the profile of the scattered solar Mg I λ5184 Fraunhofer line in the zodiacal light. The observations were carried out toward 49 directions that sampled the ecliptic equator from solar elongations of 48° (evening sky) to 334° (morning sky) plus observations near +47° and +90° ecliptic latitude. The spectra show a clear prograde kinematic signature that is inconsistent with dust confined to the ecliptic plane and in circular orbits influenced only by the Sun's gravity. In particular, the broadened widths of the profiles, together with large amplitude variations in the centroid velocity with elongation angle, indicate that a significant population of dust is on eccentric orbits. In addition, the wide, flat-bottomed line profile toward the ecliptic pole indicates a broad distribution of orbital inclinations extending up to about 30°-40° with respect to the ecliptic plane. The absence of pronounced asymmetries in the shape of the profiles limits the retrograde population to less than 10% of the prograde population, and also places constraints on the scattering phase function of the particles. These results do not show the radial outflow or evening-morning velocity amplitude asymmetry reported in some earlier investigations. The reduction of the spectra included the discovery and removal of extremely faint, unidentified terrestrial emission lines that contaminate and distort the underlying Mg I profile. This atmospheric emission is too weak to have been seen in earlier, lower signal-to-noise ratio observations, but it probably affected the line centroid measurements of previous investigations.

  3. QUALITY ASSURANCE HANDBOOK FOR AIR POLLUTION MEASUREMENT SYSTEMS: VOLUME IV - METEOROLOGICAL MEASUREMENTS (REVISED - AUGUST 1994)

    EPA Science Inventory

    Procedures on installing, acceptance testing, operating, maintaining and quality assuring three types of ground-based, upper air meteorological measurement systems are described. he limitations and uncertainties in precision and accuracy measurements associated with these systems...

  4. Analysis of tissue changes, measurement system effects, and motion artifacts in echo decorrelation imaging

    PubMed Central

    Hooi, Fong Ming; Nagle, Anna; Subramanian, Swetha; Douglas Mast, T.

    2015-01-01

    Echo decorrelation imaging, a method for mapping ablation-induced ultrasound echo changes, is analyzed. Local echo decorrelation is shown to approximate the decoherence spectrum of tissue reflectivity. Effects of the ultrasound measurement system, echo signal windowing, electronic noise, and tissue motion on echo decorrelation images are determined theoretically, leading to a method for reduction of motion and noise artifacts. Theoretical analysis is validated by simulations and experiments. Simulated decoherence of the scattering medium was recovered with root-mean-square error less than 10% with accuracy dependent on the correlation window size. Motion-induced decorrelation measured in an ex vivo pubovisceral muscle model showed similar trends to theoretical motion-induced decorrelation for a 2.1 MHz curvilinear array with decorrelation approaching unity for 3–4 mm elevational displacement or 1–1.6 mm range displacement. For in vivo imaging of porcine liver by a 7 MHz linear array, theoretical decorrelation computed using image-based motion estimates correlated significantly with measured decorrelation (r = 0.931, N = 10). Echo decorrelation artifacts incurred during in vivo radiofrequency ablation in the same porcine liver were effectively compensated based on the theoretical echo decorrelation model and measured pre-treatment decorrelation. These results demonstrate the potential of echo decorrelation imaging for quantification of heat-induced changes to the scattering tissue medium during thermal ablation. PMID:25697993

  5. Task Specific Frequencies of Neck Motion Measured in Healthy Young Adults over a 5 Day Period

    PubMed Central

    Cobian, Daniel G.; Sterling, Andrew C.; Anderson, Paul A.; Heiderscheit, Bryan C.

    2010-01-01

    Study Design Observational cohort design. Objective To quantify the frequencies and magnitudes of neck motion during daily activities in healthy subjects. Summary of Background Data Previous studies have measured the maximum excursions during re-created ADLs in lab settings, but there is a lack of information available on frequencies and excursions of neck motion with ADLs in non-artificial settings. Methods Ten healthy young adults were fitted with a portable motion measurement device that recorded movement about each primary axis. Participants were instructed to wear the unit continuously over a 5-day period and record their daily activities with corresponding times. After the collection period, subjects' activity logs were analyzed and data were partitioned into five categories which provided the most primary representation of ADLs: athletics, work, travel, sleep, and miscellaneous. Each category was further divided into increasingly specific activities (e.g. running and walking). Frequency of motions within 5° increments was determined and an hourly rate was calculated for each activity. Median motion about each axis for each activity was also determined. Results The total number of movements per hour for all axes, regardless of amplitude, was highest during athletic activity and lowest during sleeping. The majority of movements (92% of athletic activity, 90% of work) required less than 25° of lateral bending, while greater range of movement requirements were observed for flexion-extension and axial rotation. The median range of motion along all axes was highest for athletic activity and lowest for sleeping. Conclusions The results of this study provide a baseline of the frequency and magnitude of neck motion during normal ADLs for the specified population. These findings can assist physicians and physical therapists in determining the extent of disability and identifying activities that will likely be problematic for patients with limited cervical motion

  6. FMPS measurement of nanoparticle pollutant in office air

    NASA Astrophysics Data System (ADS)

    Yin, Zhaoqin; Lin, Jianzhong; Yu, Mingzhou

    2010-08-01

    Fast Mobility Particle Sizer (FMPS) is an electrical mobility instrument used to measure the nanoparticle number concentration and size distribution in an office environment. Actual measurements indicate the distributions of ultrafine particle number and size in office air are inhomogeneous in space. The nonaparticle size is bimodal and log-normally distribution in an office environment when only people activities are considered. The traffic pollutant in the outdoor including the automobile tail gas and the dust will change the particles size distribution and enhance the particle number concentration those of indoor air. It can also be seen from the results that the laser printer releases a large number of nanoparticles, especially around 80nm in diameter in the printing process. The laser printer may be the mainly ultrafine particle source in the office air.

  7. Mathematical analysis of errors resulting from choice of reference frame coordinates in measuring human joint motion

    SciTech Connect

    Hollerbach, K.; Hollister, A.

    1995-02-01

    Measurements of human joint motion frequently involve the use of opto-electronic and other motion analysis systems where some type of makers are used to establish joint motion within a global reference coordinate frame. Typically, this global reference coordinate frame is chosen to be most convenient for the person carrying out the experiment in which the joint motion is measured, and Euler angles are chosen as the measure of joint motion. Results, however, may be quite arbitrary and therefore rendered meaningless if the reference frame is not properly chosen with respect to the physical joint axis. In order to make a proper choice of coordinate axes in the reference frame, one must take into consideration both the location and the orientation of die physical joint axis relative to the reference frame`s axes. In nature, joint axes can exist at any orientation and location relative to an arbitrarily chosen global reference frame. An axis that is not properly aligned with the global reference frame is therefore called an arbitrary axis. We demonstrate that errors result when measurements and calculations are made in a global reference frame that is arbitrarily placed and oriented, with little regard for the physical axis. Slight offsets of global reference frame produce significant errors in recording rotations about the joint axis. We conclude that, in order to be able to reach valid conclusions from joint motion measurements, the reference frame with respect to which all are taken must be brought to the physical axis; furthermore, one of the reference axes must be aligned with the physical axis. Any other choice of reference axes will result in misleading an often erroneous results.

  8. TECHNIQUE FOR MEASURING REDUCED FORMS OF SULFUR IN AMBIENT AIR

    EPA Science Inventory

    A new technique for measuring low concentrations of volatile sulfur compounds in ambient air is discussed. The technique consists of preconcentration of sulfur compounds by chemisorption on gold metal coated sand or gold foil surface followed by thermal desorption, separation, an...

  9. METHOD FOR MEASURING AIR-IMMISCIBLE LIQUID PARTITION COEFFICIENTS

    EPA Science Inventory

    The principal objective of this work was to measure nonaqueous phase liquid-air partition coefficients for various gas tracer compounds. Known amounts of trichloroethene (TCE) and tracer, as neat compounds, were introduced into glass vials and allowed to equilibrate. The TCE and ...

  10. Measured Air Distribution Effectiveness for Residential Mechanical Ventilation Systems

    SciTech Connect

    Sherman, Max; Sherman, Max H.; Walker, Iain S.

    2008-05-01

    The purpose of ventilation is dilute or remove indoor contaminants that an occupant is exposed to. In a multi-zone environment such as a house, there will be different dilution rates and different source strengths in every zone. Most US homes have central HVAC systems, which tend to mix the air thus the indoor conditions between zones. Different types of ventilation systems will provide different amounts of exposure depending on the effectiveness of their air distribution systems and the location of sources and occupants. This paper will report on field measurements using a unique multi-tracer measurement system that has the capacity to measure not only the flow of outdoor air to each zone, but zone-to-zone transport. The paper will derive seven different metrics for the evaluation of air distribution. Measured data from two homes with different levels of natural infiltration will be used to evaluate these metrics for three different ASHRAE Standard 62.2 compliant ventilation systems. Such information can be used to determine the effectiveness of different systems so that appropriate adjustments can be made in residential ventilation standards such as ASHRAE Standard 62.2.

  11. Measurement of inter and intra fraction organ motion in radiotherapy using cone beam CT projection images

    NASA Astrophysics Data System (ADS)

    Marchant, T. E.; Amer, A. M.; Moore, C. J.

    2008-02-01

    A method is presented for extraction of intra and inter fraction motion of seeds/markers within the patient from cone beam CT (CBCT) projection images. The position of the marker is determined on each projection image and fitted to a function describing the projection of a fixed point onto the imaging panel at different gantry angles. The fitted parameters provide the mean marker position with respect to the isocentre. Differences between the theoretical function and the actual projected marker positions are used to estimate the range of intra fraction motion and the principal motion axis in the transverse plane. The method was validated using CBCT projection images of a static marker at known locations and of a marker moving with known amplitude. The mean difference between actual and measured motion range was less than 1 mm in all directions, although errors of up to 5 mm were observed when large amplitude motion was present in an orthogonal direction. In these cases it was possible to calculate the range of motion magnitudes consistent with the observed marker trajectory. The method was shown to be feasible using clinical CBCT projections of a pancreas cancer patient.

  12. Global Ammonia Concentrations Seen by the 13-years AIRS Measurements

    NASA Astrophysics Data System (ADS)

    Warner, Juying; Wei, Zigang; Larrabee Strow, L.; Dickerson, Russell; Nowak, John; Wang, Yuxuan

    2016-04-01

    Ammonia is an integral part of the nitrogen cycle and is projected to be the largest single contributor to each of acidification, eutrophication and secondary particulate matter in Europe by 2020 (Sutton et al., 2008). The impacts of NH3 also include: aerosol production affecting global radiative forcing, increases in emissions of the greenhouse gases nitrous oxide (N2O) and methane (CH4), and modification of the transport and deposition patterns of SO2 and NOx. Therefore, monitoring NH3 global distribution of sources is vitally important to human health with respect to both air and water quality and climate change. We have developed new daily and global ammonia (NH3) products from AIRS hyperspectral measurements. These products add value to AIRS's existing products that have made significant contributions to weather forecasts, climate studies, and air quality monitoring. With longer than 13 years of data records, these measurements have been used not only for daily monitoring purposes but also for inter-annual variability and short-term trend studies. We will discuss the global NH3 emission sources from biogenic and anthropogenic activities over many emission regions captured by AIRS. We will focus their variability in the last 13 years.

  13. CARS Temperature and Species Measurements For Air Vehicle Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Gord, James R.; Grisch, Frederic; Klimenko, Dmitry; Clauss, Walter

    2005-01-01

    The coherent anti-Stokes Raman spectroscopy (CARS) method has recently been used in the United States and Europe to probe several different types of propulsion systems for air vehicles. At NASA Langley Research Center in the United States, CARS has been used to simultaneously measure temperature and the mole fractions of N2, O2 and H2 in a supersonic combustor, representative of a scramjet engine. At Wright- Patterson Air Force Base in the United States, CARS has been used to simultaneously measure temperature and mole fractions of N2, O2 and CO2, in the exhaust stream of a liquid-fueled, gas-turbine combustor. At ONERA in France and the DLR in Germany researchers have used CARS to measure temperature and species concentrations in cryogenic LOX-H2 rocket combustion chambers. The primary aim of these measurements has been to provide detailed flowfield information for computational fluid dynamics (CFD) code validation.

  14. AMBIENT AIR MEASUREMENTS OF HYDROGEN PEROXIDE IN THE CALIFORNIA SOUTH COAST AIR BASIN

    EPA Science Inventory

    Hydrogen peroxide (H2O2) concentrations have been measured at two locations (Claremont and Riverside) in the California South Coast Air Basin during the months of July and August 1977. Three different analytical methods were employed: a chemiluminescent method and two colorimetri...

  15. Measurement of Glottal Flow across Scaled Up Dynamic Vocal Fold Motion

    NASA Astrophysics Data System (ADS)

    Sherman, Erica; Krane, Michael; Zhang, Lucy; Wei, Timothy

    2009-11-01

    An experiment to provide DPIV measurements of dynamic human vocal folds motion is presented. The experiment is run in a free-stream water tunnel using a 10x scaled-up model of the human vocal folds and vocal tract. The vocal fold model is a new design that incorporates both the rocking as well as the oscillatory open/close motions characteristic of vocal fold motions The Reynolds number and Strouhal number have been matched to human physiologic conditions. Flow measurements show the start-up jet, vortex dynamics and ultimate jet pinch-off as the model progresses through a cycle. The effects of asymmetries associated with disease will be discussed.

  16. Laser vibrometer analysis of sensor loading effects in underwater measurements of compliant surface motion

    SciTech Connect

    Caspall, J.J.; Gray, M.D.; Caille, G.W.; Jarzynski, J.; Rogers, P.H.; McCall, G.S. II

    1996-04-01

    The application of contact motion sensors, such as accelerometers, in the measurement of the vibration of compliant surfaces underwater may lead to errors in the evaluation of certain types of surface motion. An underwater scanning laser Doppler vibrometer (USLDV) was used to measure the scattered velocity field due to a mock sensor (rigid, neutrally buoyant cylindrical body) on a compliant surface (the outer surface of a thin cylindrical shell coated with a layer of soft rubber). Axially propagating waves were launched in the shell by a ring of 10 uniformly distributed shakers located near one end of the shell and driven with a short pulse. The outer surface of the coating was scanned over a short line segment in the axial direction with and without the mock sensor attached. The extracted scattered field, consisted of high wavenumber fluid-solid interface waves accompanied by rotational motion of the mock sensor. [Work supported by ONR] {copyright} {ital 1996 American Institute of Physics.}

  17. Measurement of forces due to liquid motion in a propellant tank

    NASA Technical Reports Server (NTRS)

    Tegart, J. R.; Berry, R. L.; Demchak, L. J.; Craig, M. K.

    1981-01-01

    This paper presents the results of a study to develop an analytical model capable of predicting the forces acting on a tank caused by large-amplitude propellant motion. This effort contributed to an analysis of the influence of propellant dynamics on separation of the External Tank from the space shuttle orbiter. This paper is concerned with an experimental investigation that aided in development and verification of the analytical model. A scaling approach was developed that allowed the liquid motion to be simulated in subscale tanks. Liquid reorientation forces were measured using two test systems. One operated in the low-gravity environment produced in a drop tower and the second operated aboard the KC-135 'zero-g' test aircraft. The manner of liquid motion, influence of various factors, and the measured forces are discussed.

  18. Measurement of wind profiles by motion-stabilised ship-borne Doppler lidar

    NASA Astrophysics Data System (ADS)

    Achtert, P.; Brooks, I. M.; Brooks, B. J.; Moat, B. I.; Prytherch, J.; Persson, P. O. G.; Tjernström, M.

    2015-09-01

    Three months of Doppler lidar wind measurements were obtained during the Arctic Cloud Summer Experiment on the icebreaker Oden during the summer of 2014. Such ship-borne measurements require active stabilisation to remove the effects of ship motion. We demonstrate that the combination of a commercial Doppler lidar with a custom-made motion-stabilisation platform enables the retrieval of wind profiles in the Arctic boundary layer during both cruising and ice-breaking with statistical uncertainties comparable to land-based measurements. This holds particularly within the planetary boundary layer even though the overall aerosol load was very low. Motion stabilisation was successful for high wind speeds in open water and the resulting wave conditions. It allows for the retrieval of winds with a random error below 0.2 m s-1, comparable to the measurement error of standard radiosondes. The combination of a motion-stabilised platform with a low-maintenance autonomous Doppler lidar has the potential to enable continuous long-term high-resolution ship-based wind profile measurements over the oceans.

  19. Measurement of wind profiles by motion-stabilised ship-borne Doppler lidar

    NASA Astrophysics Data System (ADS)

    Achtert, P.; Brooks, I. M.; Brooks, B. J.; Moat, B. I.; Prytherch, J.; Persson, P. O. G.; Tjernström, M.

    2015-11-01

    Three months of Doppler lidar wind measurements were obtained during the Arctic Cloud Summer Experiment on the icebreaker Oden during the summer of 2014. Such ship-borne Doppler measurements require active stabilisation to remove the effects of ship motion. We demonstrate that the combination of a commercial Doppler lidar with a custom-made motion-stabilisation platform enables the retrieval of wind profiles in the Arctic atmospheric boundary layer during both cruising and ice-breaking with statistical uncertainties comparable to land-based measurements. This held true particularly within the atmospheric boundary layer even though the overall aerosol load was very low. Motion stabilisation was successful for high wind speeds in open water and the resulting wave conditions. It allows for the retrieval of vertical winds with a random error below 0.2 m s-1. The comparison of lidar-measured wind and radio soundings gives a mean bias of 0.3 m s-1 (2°) and a mean standard deviation of 1.1 m s-1 (12°) for wind speed (wind direction). The agreement for wind direction degrades with height. The combination of a motion-stabilised platform with a low-maintenance autonomous Doppler lidar has the potential to enable continuous long-term high-resolution ship-based wind profile measurements over the oceans.

  20. Assessment of tissue Doppler imaging measurements of arterial wall motion using a tissue mimicking test rig.

    PubMed

    Thrush, Abigail J; Brewin, Mark P; Birch, Malcolm J

    2008-03-01

    The aim of this in vitro study is to assess the accuracy of the tissue Doppler imaging arterial wall motion (TDI AWM) technique in measuring dilation over a range of distances and velocities. A test rig, consisting of two parallel blocks of tissue mimicking material (TMM), has been developed to generate known wall motion. One block remains stationary while the other moves in a cyclical motion. A calibrated laser range finder was used to measure the TMM motion. The TDI AWM measurements were found to underestimate the dilation by 21% +/- 4.7% when using the recommended scanner parameters. The size of the error was found to increase with a decrease in ultrasound output power. Results suggested that errors in the TDI AWM dilation measurements relate to underestimates in the velocity measured by the TDI technique. The error demonstrated in this study indicates a limitation in the value of TDI AWM result obtained in vivo. (E-mail: abigail.thrush@bartsandthelondon.nhs.uk). PMID:17964065

  1. Front surface thermal property measurements of air plasma spray coatings

    SciTech Connect

    Bennett, Ted; Kakuda, Tyler; Kulkarni, Anand

    2009-04-15

    A front-surface measurement for determining the thermal properties of thermal barrier coatings has been applied to air plasma spray coatings. The measurement is used to determine all independent thermal properties of the coating simultaneously. Furthermore, with minimal requirements placed on the sample and zero sample preparation, measurements can be made under previously impossible conditions, such as on serviceable engine parts. Previous application of this technique was limited to relatively thin coatings, where a one-dimensional heat transfer model is applied. In this paper, the influence of heat spreading on the measurement of thicker coatings is investigated with the development of a two-dimensional heat transfer model.

  2. Real-time weigh-in-motion measurement using fiber Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Huang, Ying; Palek, Leonard; Strommen, Robert; Worel, Ben; Chen, Genda

    2014-03-01

    Overloading truck loads have long been one of the key reasons for accelerating road damage, especially in rural regions where the design loads are expected to be small and in the cold regions where the wet-and-dry cycle places a significant role. To control the designed traffic loads and further guide the road design in future, periodical weight stations have been implemented for double check of the truck loads. The weight stations give chances for missing measurement of overloaded vehicles, slow down the traffic, and require additional labors. Infrastructure weight-in-motion sensors, on the other hand, keep consistent traffic flow and monitor all types of vehicles on roads. However, traditional electrical weight-in-motion sensors showed high electromagnetic interference (EMI), high dependence on environmental conditions such as moisture, and relatively short life cycle, which are unreliable for long-term weigh-inmotion measurements. Fiber Bragg grating (FBG) sensors, with unique advantages of compactness, immune to EMI and moisture, capability of quasi-distributed sensing, and long life cycle, will be a perfect candidate for long-term weigh-in-motion measurements. However, the FBG sensors also surfer from their frangible nature of glass materials for a good survive rate during sensor installation. In this study, the FBG based weight-in-motion sensors were packaged by fiber reinforced polymer (FRP) materials and further validated at MnROAD facility, Minnesota DOT (MnDOT). The design and layout of the FRP-FBG weight-in-motion sensors, their field test setup, data acquisition, and data analysis will be presented. Upon validation, the FRP-FBG sensors can be applied weigh-in-motion measurement to assistant road managements.

  3. Definition of air quality measurements for monitoring space shuttle launches

    NASA Technical Reports Server (NTRS)

    Thorpe, R. D.

    1978-01-01

    A description of a recommended air quality monitoring network to characterize the impact on ambient air quality in the Kennedy Space Center (KSC) (area) of space shuttle launch operations is given. Analysis of ground cloud processes and prevalent meteorological conditions indicates that transient HCl depositions can be a cause for concern. The system designed to monitor HCl employs an extensive network of inexpensive detectors combined with a central analysis device. An acid rain network is also recommended. A quantitative measure of projected minimal long-term impact involves the limited monitoring of NOx and particulates. All recommended monitoring is confined ti KSC property.

  4. Measurement of the Three-Dimensional Vibration Motion of the Ossicular Chain in the Living Gerbil

    NASA Astrophysics Data System (ADS)

    Decraemer, Willem F.; de La Rochefoucauld, Ombeline; Olson, Elizabeth S.

    2011-11-01

    In previous studies 3D motion of the middle-ear ossicles in cat and human temporal bone were explored but models for hearing research has shifted in the last decades to smaller mammals and gerbil in particular has become a hearing model of first choice. In the present study we have measured with an optical interferometer the 3D motion of the malleus and incus in anesthetized gerbil for sound of moderate intensity (90 dB SPL) in a broad frequency range. To access the malleus and incus the pars flaccida was completely removed exposing the neck and head of the malleus and the incus from the malleus-incus joint to the long process of the incus and the plate of the lenticular process. In a previous study an approach through a hole in the bullar wall was used to study the stapes motion so that we now have a complete picture of the middle ear motion. In both approaches vibration measurements were done at 6 to 7 points per ossicle while the angle of observation was varied over approximately 30 degrees to enable calculation of the 3D velocity components. Knowledge of middle ear motion is of great importance in understanding how the middle ear transforms the acoustical input from the ear canal to the cochlea.

  5. Measurement of six degree-of-freedom ground motion by using eight accelerometers

    NASA Astrophysics Data System (ADS)

    Yang, Zhenyu; Shen, Yi; Liu, Zhiyan

    2005-12-01

    A new integrated measuring system with eight force-balance accelerometers is proposed to obtain a direct measurement of six degree-of freedom (DOF) ground motions, including three rotational and three actual translational acceleration components without gyroscopes. In the proposed measuring system, the relationship between the output from eight force-balance accelerometer and the six DOF motion of the measuring system under an earthquake are described by differential equations. These equations are derived from the positions and directions of the eight force-balance accelerometers in the measuring system. The third-order Runge-Kutta algorithm is used to guarantee the accuracy of the numerical calculation. All the algorithms used to compute the six DOF components of the ground motion are implemented in a real-time in Digital Signal Processor (DSP). The distortion of the measured results caused by position and direction errors of the accelerometers in the measuring system are reduced by multiplying a compensation coefficient C to the output and subtracting static zero drift from the measured results, respectively.

  6. Wave motion on the surface of the human tympanic membrane: Holographic measurement and modeling analysis

    PubMed Central

    Cheng, Jeffrey Tao; Hamade, Mohamad; Merchant, Saumil N.; Rosowski, John J.; Harrington, Ellery; Furlong, Cosme

    2013-01-01

    Sound-induced motions of the surface of the tympanic membrane (TM) were measured using stroboscopic holography in cadaveric human temporal bones at frequencies between 0.2 and 18 kHz. The results are consistent with the combination of standing-wave-like modal motions and traveling-wave-like motions on the TM surface. The holographic techniques also quantified sound-induced displacements of the umbo of the malleus, as well as volume velocity of the TM. These measurements were combined with sound-pressure measurements near the TM to compute middle-ear input impedance and power reflectance at the TM. The results are generally consistent with other published data. A phenomenological model that behaved qualitatively like the data was used to quantify the relative magnitude and spatial frequencies of the modal and traveling-wave-like displacement components on the TM surface. This model suggests the modal magnitudes are generally larger than those of the putative traveling waves, and the computed wave speeds are much slower than wave speeds predicted by estimates of middle-ear delay. While the data are inconsistent with simple modal displacements of the TM, an alternate model based on the combination of modal motions in a lossy membrane can also explain these measurements without invoking traveling waves. PMID:23363110

  7. Suggested Courseware for the Non-Calculus Physics Student: Measurement, Vectors, and One-Dimensional Motion.

    ERIC Educational Resources Information Center

    Mahoney, Joyce; And Others

    1988-01-01

    Evaluates 16 commercially available courseware packages covering topics for introductory physics. Discusses the price, sub-topics, program type, interaction, time, calculus required, graphics, and comments of each program. Recommends two packages in measurement and vectors, and one-dimensional motion respectively. (YP)

  8. Wave motion on the surface of the human tympanic membrane: holographic measurement and modeling analysis.

    PubMed

    Cheng, Jeffrey Tao; Hamade, Mohamad; Merchant, Saumil N; Rosowski, John J; Harrington, Ellery; Furlong, Cosme

    2013-02-01

    Sound-induced motions of the surface of the tympanic membrane (TM) were measured using stroboscopic holography in cadaveric human temporal bones at frequencies between 0.2 and 18 kHz. The results are consistent with the combination of standing-wave-like modal motions and traveling-wave-like motions on the TM surface. The holographic techniques also quantified sound-induced displacements of the umbo of the malleus, as well as volume velocity of the TM. These measurements were combined with sound-pressure measurements near the TM to compute middle-ear input impedance and power reflectance at the TM. The results are generally consistent with other published data. A phenomenological model that behaved qualitatively like the data was used to quantify the relative magnitude and spatial frequencies of the modal and traveling-wave-like displacement components on the TM surface. This model suggests the modal magnitudes are generally larger than those of the putative traveling waves, and the computed wave speeds are much slower than wave speeds predicted by estimates of middle-ear delay. While the data are inconsistent with simple modal displacements of the TM, an alternate model based on the combination of modal motions in a lossy membrane can also explain these measurements without invoking traveling waves. PMID:23363110

  9. Constraining the Mass of the Local Group through Proper Motion Measurements of Local Group Galaxies

    NASA Astrophysics Data System (ADS)

    Sohn, S. Tony; van der Marel, R.; Anderson, J.

    2012-01-01

    The Local Group and its two dominant spiral galaxies have been the benchmark for testing many aspects of cosmological and galaxy formation theories. This includes, e.g., dark halo profiles and shapes, substructure and the "missing satellite" problem, and the minimum mass for galaxy formation. But despite the extensive work in all of these areas, our knowledge of the mass of the Milky Way and M31, and thus the total mass of the Local Group remains one of the most poorly established astronomical parameters (uncertain by a factor of 4). One important reason for this problem is the lack of information in tangential motions of galaxies, which can be only obtained through proper motion measurements. In this study, we introduce our projects for measuring absolute proper motions of (1) the dwarf spheroidal galaxy Leo I, (2) M31, and (3) the 4 dwarf galaxies near the edge of the Local Group (Cetus, Leo A, Tucana, and Sag DIG). Results from these three independent measurements will provide important clues to the mass of the Milky Way, M31, and the Local Group as a whole, respectively. We also present our proper motion measurement technique that uses compact background galaxies as astrometric reference sources.

  10. ISAR motion compensation using the burst derivative measure as a focal quality indicator

    NASA Astrophysics Data System (ADS)

    Bocker, Richard P.; Jones, Scott A.

    1993-04-01

    Inverse synthetic aperture radar (ISAR) is an imaging technique that shows great promise in classifying airborne targets in realtime, under all weather conditions. The success of classifying targets using ISAR is predicated upon forming highly focused radar images of these targets. Efforts to develop highly focused imaging computer software have been challenging, mainly because the imaging depends on and is affected by the motion of the target. Computationally intensive motion compensation algorithms have been developed to remove the unwanted degrading effects of target motion. Those particular motion compensation algorithms which require the use of a space-domain focal quality indicator, e.g., entropy, to determine image sharpness as processing proceeds pay a severe computational penalty due to the large number of two-dimensional fast Fourier transforms (2D-FFT's) which must be computed. This is due to the fact that the actual processing of ISAR data is primarily done in the spatial frequency domain and not in the space-domain where the final ISAR image is displayed. If a focal quality indicator could be developed to measure image sharpness in the spatial frequency domain, then the computational burden introduced by the numerous 2D-FFT's could be greatly relaxed. This paper describes the use of a new focal quality indicator called the burst derivative measure for determining ISAR image sharpness in the spatial frequency domain. Tests have been performed on simulated as well as actual ISAR data using both the burst derivative measure and the entropy measure.

  11. Designed microtremor array based actual measurement and analysis of strong ground motion at Palu city, Indonesia

    NASA Astrophysics Data System (ADS)

    Thein, Pyi Soe; Pramumijoyo, Subagyo; Brotopuspito, Kirbani Sri; Wilopo, Wahyu; Kiyono, Junji; Setianto, Agung; Putra, Rusnardi Rahmat

    2015-04-01

    In this study, we investigated the strong ground motion characteristics under Palu City, Indonesia. The shear wave velocity structures evaluated by eight microtremors measurement are the most applicable to determine the thickness of sediments and average shear wave velocity with Vs ≤ 300 m/s. Based on subsurface underground structure models identified, earthquake ground motion was estimated in the future Palu-Koro earthquake by using statistical green's function method. The seismic microzonation parameters were carried out by considering several significant controlling factors on ground response at January 23, 2005 earthquake.

  12. Designed microtremor array based actual measurement and analysis of strong ground motion at Palu city, Indonesia

    SciTech Connect

    Thein, Pyi Soe; Pramumijoyo, Subagyo; Wilopo, Wahyu; Setianto, Agung; Brotopuspito, Kirbani Sri; Kiyono, Junji; Putra, Rusnardi Rahmat

    2015-04-24

    In this study, we investigated the strong ground motion characteristics under Palu City, Indonesia. The shear wave velocity structures evaluated by eight microtremors measurement are the most applicable to determine the thickness of sediments and average shear wave velocity with Vs ≤ 300 m/s. Based on subsurface underground structure models identified, earthquake ground motion was estimated in the future Palu-Koro earthquake by using statistical green’s function method. The seismic microzonation parameters were carried out by considering several significant controlling factors on ground response at January 23, 2005 earthquake.

  13. Crustal motion in the Antarctic interior from a decade of Global Positioning System measurements

    NASA Astrophysics Data System (ADS)

    Willis, Michael J.

    A decade of Global Positioning System (GPS) data have been collected at bedrock sites in southern Victoria Land, Antarctica. Measured motions of the crust have been examined to determine if ongoing tectonic deformation occurs within the study area, across the structural boundary between East and West Antarctica. Crustal motions are used to test for activity over the offshore Terror Rift, where young faulting is documented, and to assess locally whether the active Erebus volcano deforms the crust. Bedrock motions caused by large scale ice-mass changes that have occurred in the area since the Last Glacial Maximum are also a major focus of the study. The horizontal GPS motions record Antarctic plate motion of ˜15 mm/yr to the southeast. No deformation is observed over the Transantarctic Mountains Front Zone. Very small amounts of deformation are observed along the Terror Rift, however the recorded direction of motions may be the result of Glacial Isostatic Adjustment (GIA), rather than active tectonics. Recorded motions observed to the south of Ross Island suggest that the Terror Rift continues beneath the Ross Ice Shelf. No volcanic loading signal is observed. Vertical crustal motions exhibit a down-to-the-east tilt over the study area. A suite of earth models, including more than three hundred different mantle viscosity profiles, three different lithospheric thicknesses and three different ice histories, were used to model uplift due to Glacial Isostatic Adjustment driven by ice mass change. None replicate the observed tilt. Two Relative Sea Level curves for the region also could not be replicated by GIA models examined. Comparison of GPS vertical velocities and our GIA models produce well-constrained earth models for the study area, but suggest that current ice history models for the region must be revised to replicate measured crustal motions. We compare the output of our GPS-constrained models with published crustal uplift rates used in modern ice mass balance

  14. Noncontact ballistic motion measurement using a fiber-optic confocal sensor

    NASA Astrophysics Data System (ADS)

    Shafir, E.; Berkovic, G.; Horovitz, Y.; Appelbaum, G.; Moshe, E.; Horovitz, E.; Skutelski, A.; Werdiger, M.; Perelmutter, L.; Sudai, M.

    2007-05-01

    A fiber-optic confocal sensor for noncontact ballistic measurements is described. Determination of motion at velocities of 1.7 km/s with an uncertainty as small as ±0.3% is demonstrated for both a projectile and a free-surface target. The fibers detect the passage of the object at their conjugate image points created by low F/# optics. This results in an output signal comprising a train of sharp pulses each precisely identifying when the ballistic object traverses an image point. Since the ballistic object does not contact the sensor at the time of imaging, the measurements do not perturb the motion, enabling multi-fragment measurement, as well as repetitive measurements of the same object point.

  15. Measuring accurate body parameters of dressed humans with large-scale motion using a Kinect sensor.

    PubMed

    Xu, Huanghao; Yu, Yao; Zhou, Yu; Li, Yang; Du, Sidan

    2013-01-01

    Non-contact human body measurement plays an important role in surveillance, physical healthcare, on-line business and virtual fitting. Current methods for measuring the human body without physical contact usually cannot handle humans wearing clothes, which limits their applicability in public environments. In this paper, we propose an effective solution that can measure accurate parameters of the human body with large-scale motion from a Kinect sensor, assuming that the people are wearing clothes. Because motion can drive clothes attached to the human body loosely or tightly, we adopt a space-time analysis to mine the information across the posture variations. Using this information, we recover the human body, regardless of the effect of clothes, and measure the human body parameters accurately. Experimental results show that our system can perform more accurate parameter estimation on the human body than state-of-the-art methods. PMID:24064597

  16. Measurement of structure motion by means of a moving light sheet

    NASA Technical Reports Server (NTRS)

    Tcheng, Ping; Jordan, Thomas; Franke, John; Cate, Kenneth

    1990-01-01

    The elaboration of an optical system which measures the displacement and velocity of large flexible space structures is reviewed. The motion-measuring system, comprised of a laser, optics, motorized mirror, two photodiodes and electronics, is designed to allow feedback for configuration control of flexible structures. A motor or scanner is employed to sweep the light sheet. The range of motion was shown to be 2 inches, and information was received at a rate of 30 Hz. The uncertainty in displacement measurement was better than +0.01 inch from a distance of 16 feet. The results are considered to be very good for two scanning light sheet systems. Higher sample rates and a more constant speed would improve the rotating mirror option, and the accuracy and range of the scanning mirror option could be upgraded as well. Both setups are shown to be viable noncontact measuring methods for the displacement and velocity of large space structures.

  17. Air shower measurements with the LOPES radio antenna array

    NASA Astrophysics Data System (ADS)

    Lopes Collaboration; Haungs, A.; Apel, W. D.; Arteaga, J. C.; Asch, T.; Auffenberg, J.; Badea, F.; Bähren, L.; Bekk, K.; Bertaina, M.; Biermann, P. L.; Blümer, J.; Bozdog, H.; Brancus, I. M.; Brüggemann, M.; Buchholz, P.; Buitink, S.; Cantoni, E.; Chiavassa, A.; Cossavella, F.; Daumiller, K.; de Souza, V.; di Pierro, F.; Doll, P.; Engel, R.; Falcke, H.; Finger, M.; Fuhrmann, D.; Gemmeke, H.; Ghia, P. L.; Glasstetter, R.; Grupen, C.; Heck, D.; Hörandel, J. R.; Horneffer, A.; Huege, T.; Isar, P. G.; Kampert, K.-H.; Kang, D.; Kickelbick, D.; Kolotaev, Y.; Krömer, O.; Kuijpers, J.; Lafebre, S.; Łuczak, P.; Mathes, H. J.; Mayer, H. J.; Milke, J.; Mitrica, B.; Morello, C.; Navarra, G.; Nehls, S.; Nigl, A.; Oehlschläger, J.; Over, S.; Petcu, M.; Pierog, T.; Rautenberg, J.; Rebel, H.; Roth, M.; Saftoiu, A.; Schieler, H.; Schmidt, A.; Schröder, F.; Sima, O.; Singh, K.; Stümpert, M.; Toma, G.; Trinchero, G. C.; Ulrich, H.; Walkowiak, W.; Weindl, A.; Wochele, J.; Wommer, M.; Zabierowski, J.; Zensus, J. A.; LOPES Collaboration

    2009-06-01

    LOPES is set up at the location of the KASCADE-Grande extensive air shower experiment in Karlsruhe, Germany and aims to measure and investigate radio pulses from extensive air showers. Since radio waves suffer very little attenuation, radio measurements allow the detection of very distant or highly inclined showers. These waves can be recorded day and night, and provide a bolometric measure of the leptonic shower component. LOPES is designed as a digital radio interferometer using high bandwidths and fast data processing and profits from the reconstructed air shower observables of KASCADE-Grande. The LOPES antennas are absolutely amplitude calibrated allowing to reconstruct the electric field strength which can be compared with predictions from detailed Monte-Carlo simulations. We report about the analysis of correlations present in the radio signals measured by the LOPES 30 antenna array. Additionally, LOPES operates antennas of a different type (LOPESSTAR) which are optimized for an application at the Pierre Auger Observatory. Status, recent results of the data analysis and further perspectives of LOPES and the possible large scale application of this new detection technique are discussed.

  18. Air quality measurements in urban green areas - a case study

    NASA Astrophysics Data System (ADS)

    Kuttler, W.; Strassburger, A.

    The influence of traffic-induced pollutants (e.g. CO, NO, NO 2 and O 3) on the air quality of urban areas was investigated in the city of Essen, North Rhine-Westphalia (NRW), Germany. Twelve air hygiene profile measuring trips were made to analyse the trace gas distribution in the urban area with high spatial resolution and to compare the air hygiene situation of urban green areas with the overall situation of urban pollution. Seventeen measurements were made to determine the diurnal concentration courses within urban parks (summer conditions: 13 measurements, 530 30 min mean values, winter conditions: 4 measurements, 128 30 min mean values). The measurements were carried out during mainly calm wind and cloudless conditions between February 1995 and March 1996. It was possible to establish highly differentiated spatial concentration patterns within the urban area. These patterns were correlated with five general types of land use (motorway, main road, secondary road, residential area, green area) which were influenced to varying degrees by traffic emissions. Urban parks downwind from the main emission sources show the following typical temporal concentration courses: In summer rush-hour-dependent CO, NO and NO 2 maxima only occurred in the morning. A high NO 2/NO ratio was established during weather conditions with high global radiation intensities ( K>800 W m -2), which may result in a high O 3 formation potential. Some of the values measured found in one of the parks investigated (Gruga Park, Essen, area: 0.7 km 2), which were as high as 275 μg m -3 O 3 (30-min mean value) were significantly higher than the German air quality standard of 120 μg m -3 (30-min mean value, VDI Guideline 2310, 1996) which currently applies in Germany and about 20% above the maximum values measured on the same day by the network of the North Rhine-Westphalian State Environment Agency. In winter high CO and NO concentrations occur in the morning and during the afternoon rush-hour. The

  19. Role of the area postrema in three putative measures of motion sickness in the rat

    NASA Technical Reports Server (NTRS)

    Sutton, Richard L.; Fox, Robert A.; Daunton, Nancy G.

    1991-01-01

    After thermal cauterization of the area postrema in rats, the absence of conditioned taste aversion of sucrose paired with lithium chloride (0.15M, 3.3 ml/kg) was used as a pharmacologic/behavioral index of area postrema damage. In a subsequent experiment the effects of area postrema lesions on three measures proposed as species-relevant measures of motion sickness were studied, using off-vertical rotation at 150 deg/s for either 30 or 90 min. Lesions of area postrema did not alter postrotational suppression of drinking or amount of defecation during motion. The initial acquisition of conditioned taste aversion to a novel cider vinegar solution paired with motion was not affected by lesioning of the area postrema, but these taste aversions extinguished more slowly in lesioned rats than in sham-operates or intact controls. Results are discussed in terms of proposed humoral factors which may induce motion sickness and in light of recent data on the role of the area postrema in similar measures in species possessing the complete emetic reflex.

  20. Feasibility of using respiratory correlated mega voltage cone beam computed tomography to measure tumor motion.

    PubMed

    Chen, Mingqing; Siochi, R Alfredo

    2011-01-01

    The purpose of this study was to test the feasibility of using respiratory correlated mega voltage cone-beam computed tomography (MVCBCT), taken during patient localization, to quantify the size and motion of lung tumors. An imaging phantom was constructed of a basswood frame embedded with six different-sized spherical pieces of paraffin wax. The Quasar respiratory motion phantom was programmed to move the imaging phantom using typical respiratory motion. The moving imaging phantom was scanned using various MVCBCT imaging parameters, including two beam line types, two protocols with different ranges of rotation and different imaging doses. A static phantom was also imaged as a control. For all the 3D volumetric images, the contours of the six spherical inserts were measured manually. Compared with the nominal sphere diameter, the average relative error in the size of the respiratory correlated MVCBCT spheres ranged from 5.3% to 12.6% for the four largest spheres, ranging in size from 3.6 cc to 29 cc. Larger errors were recorded for the two smallest inserts. The average relative error in motion was 5.1% smaller than the programmed amplitude of 3.0 cm. We are able to conclude that it is feasible to use respiratory correlated MVCBCT to quantify tumor motion for lung cancer patients. PMID:21587196

  1. Nanomechanical motion measured with an imprecision below the standard quantum limit

    NASA Astrophysics Data System (ADS)

    Donner, Tobias

    2010-03-01

    Observing quantum behavior of mechanical motion is challenging because it is difficult both to prepare pure quantum states of motion and to detect those states with high enough precision. We present displacement measurements of a nanomechanical oscillator with an imprecision below that at the standard quantum limit [1]. To achieve this, we couple the motion of the oscillator to the microwave field in a high-Q superconducting resonant circuit. The oscillator's displacement imprints a phase modulation on the microwave signal. We attain the low imprecision by reading out the modulation with a Josephson Parametric Amplifier, realizing a microwave interferometer that operates near the shot-noise limit. The apparent motion of the mechanical oscillator due the interferometer's noise is now substantially less than its zero-point motion, making future detection of quantum states feasible. In addition, the phase sensitivity of the demonstrated interferometer is 30 times higher than previous microwave interferometers, providing a critical piece of technology for many experiments investigating quantum information encoded in microwave fields. [4pt] [1] J. D. Teufel, T. Donner, M. A. Castellanos-Beltran, J. W. Harlow, K. W. Lehnert, Nature Nanotechnology, doi:10.1038/nnano.2009.343, (2009).

  2. Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun.

    PubMed

    Amenomori, M; Ayabe, S; Cui, S W; Danzengluobu; Ding, L K; Ding, X H; Feng, C F; Feng, Z Y; Gao, X Y; Geng, Q X; Guo, H W; He, H H; He, M; Hibino, K; Hotta, N; Hu, Haibing; Hu, H B; Huang, J; Huang, Q; Jia, H Y; Kajino, F; Kasahara, K; Katayose, Y; Kato, C; Kawata, K; Labaciren; Le, G M; Li, J Y; Lu, H; Lu, S L; Meng, X R; Mizutani, K; Mori, S; Mu, J; Munakata, K; Nanjo, H; Nishizawa, M; Ohnishi, M; Ohta, I; Onuma, H; Ouchi, T; Ozawa, S; Ren, J R; Saito, T; Sakata, M; Sasaki, T; Shibata, M; Shiomi, A; Shirai, T; Sugimoto, H; Takita, M; Tan, Y H; Tateyama, N; Torii, S; Tsuchiya, H; Udo, S; Utsugi, T; Wang, B S; Wang, H; Wang, X; Wang, Y G; Wu, H R; Xue, L; Yamamoto, Y; Yan, C T; Yang, X C; Yasue, S; Ye, Z H; Yu, G C; Yuan, A F; Yuda, T; Zhang, H M; Zhang, J L; Zhang, N J; Zhang, X Y; Zhang, Y; Zhaxisangzhu; Zhou, X X

    2004-08-01

    We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made. PMID:15323615

  3. Angle-independent measure of motion for image-based gating in 3D coronary angiography

    SciTech Connect

    Lehmann, Glen C.; Holdsworth, David W.; Drangova, Maria

    2006-05-15

    The role of three-dimensional (3D) image guidance for interventional procedures and minimally invasive surgeries is increasing for the treatment of vascular disease. Currently, most interventional procedures are guided by two-dimensional x-ray angiography, but computed rotational angiography has the potential to provide 3D geometric information about the coronary arteries. The creation of 3D angiographic images of the coronary arteries requires synchronization of data acquisition with respect to the cardiac cycle, in order to minimize motion artifacts. This can be achieved by inferring the extent of motion from a patient's electrocardiogram (ECG) signal. However, a direct measurement of motion (from the 2D angiograms) has the potential to improve the 3D angiographic images by ensuring that only projections acquired during periods of minimal motion are included in the reconstruction. This paper presents an image-based metric for measuring the extent of motion in 2D x-ray angiographic images. Adaptive histogram equalization was applied to projection images to increase the sharpness of coronary arteries and the superior-inferior component of the weighted centroid (SIC) was measured. The SIC constitutes an image-based metric that can be used to track vessel motion, independent of apparent motion induced by the rotational acquisition. To evaluate the technique, six consecutive patients scheduled for routine coronary angiography procedures were studied. We compared the end of the SIC rest period ({rho}) to R-waves (R) detected in the patient's ECG and found a mean difference of 14{+-}80 ms. Two simultaneous angular positions were acquired and {rho} was detected for each position. There was no statistically significant difference (P=0.79) between {rho} in the two simultaneously acquired angular positions. Thus we have shown the SIC to be independent of view angle, which is critical for rotational angiography. A preliminary image-based gating strategy that employed the SIC

  4. Simulation of Arc Motion in Air Switching Devices Taking Ferromagnetic Material into Accout

    NASA Astrophysics Data System (ADS)

    Li, Xingwen; Tusongjiang, Kari; Chen, Degui; Sun, Haitao; Xie, Ensheng

    2009-04-01

    FLUENT and ANSYS codes are used to solve the magnethydrodynamics (MHD) equations and electromagnetic field equations, respectively. An interface code is developed to implement the bi-direction transfer of calculation data between FLUENT and ANSYS. Then a 2-D MHD arc model is built up with the consideration of the nonlinear ferromagnetic material. The arc shape, gas flow velocity and magnetic field distribution are presented at a current of 200 A. The influence of the number of splitter plates on arc motion is also analyzed.

  5. Measuring Density Of Air By Ultraviolet Rayleigh Scattering

    NASA Technical Reports Server (NTRS)

    Mckenzie, Robert L.

    1992-01-01

    Report presents theoretical and experimental studies directed toward development of optoelectronic instrument to measure density of air at altitudes from 50 to 90 km and possibly beyond. Instrument mounted in Space Shuttle orbiter and operated during reentry into atmosphere. Data gathered by instrument needed because density of upper atmosphere highly variable in space and time and this variability affects aerodynamic behavior and trajectory of reentering Shuttle. Variations in density also meteorologically significant.

  6. Measuring the speed of sound in air using smartphone applications

    NASA Astrophysics Data System (ADS)

    Yavuz, A.

    2015-05-01

    This study presents a revised version of an old experiment available in many textbooks for measuring the speed of sound in air. A signal-generator application in a smartphone is used to produce the desired sound frequency. Nodes of sound waves in a glass pipe, of which one end is immersed in water, are more easily detected, so results can be obtained more quickly than from traditional acoustic experiments using tuning forks.

  7. Advances in Fast Response Acoustically Derived Air Temperature Measurements

    NASA Astrophysics Data System (ADS)

    Bogoev, Ivan; Jacobsen, Larry; Horst, Thomas; Conrad, Benjamin

    2016-04-01

    Fast-response accurate air-temperature measurements are required when estimating turbulent fluxes of heat, water and carbon dioxide by open-path eddy-covariance technique. In comparison with contact thermometers like thermocouples, ultra-sonic thermometers do not suffer from solar radiation loading, water vapor condensation and evaporative cooling effects. Consequently they have the potential to provide more accurate true air temperature measurements. The absolute accuracy of the ultrasonic thermometer is limited by the following parameters: the distance between the transducer pairs, transducer delays associated with the electrical-acoustic signal conversion that vary with temperature, components of the wind vector that are normal to the ultrasonic paths, and humidity. The distance between the transducer pairs is commonly obtained by coordinate measuring machine. Improved accuracy demonstrated in this study results from increased stiffness in the anemometer head to better maintain the ultrasonic path-length distances. To further improve accuracy and account for changes in transducer delays and distance as a function of temperature, these parameters are characterized in a zero-wind chamber over the entire operating temperature range. When the sonic anemometer is combined with a co-located fast-response water vapor analyzer, like in the IRGASON instrument, speed of sound can be compensated for humidity effects on a point-by-point basis resulting in a true fast-response air temperature measurement. Laboratory test results show that when the above steps are implemented in the calibration of the ultrasonic thermometer air-temperature accuracy better than ±0.5 degrees Celsius can be achieved over the entire operating range. The approach is also validated in a field inter-comparison with an aspirated thermistor probe mounted in a radiation shield.

  8. Experimental measurement of human head motion for high-resolution computed tomography system design

    NASA Astrophysics Data System (ADS)

    Li, Liang; Chen, Zhiqiang; Jin, Xin; Yu, Hengyong; Wang, Ge

    2010-06-01

    Human head motion has been experimentally measured for high-resolution computed tomography (CT) design using a Canon digital camera. Our goal is to identify the minimal movements of the human head under ideal conditions without rigid fixation. In our experiments, all the 19 healthy volunteers were lying down with strict self-control. All of them were asked to be calm without pressures. Our results showed that the mean absolute value of the measured translation excursion was about 0.35 mm, which was much less than the measurements on real patients. Furthermore, the head motions in different directions were correlated. These results are useful for the design of the new instant CT system for in vivo high-resolution imaging (about 40 μm).

  9. The error analysis and online measurement of linear slide motion error in machine tools

    NASA Astrophysics Data System (ADS)

    Su, H.; Hong, M. S.; Li, Z. J.; Wei, Y. L.; Xiong, S. B.

    2002-06-01

    A new accurate two-probe time domain method is put forward to measure the straight-going component motion error in machine tools. The characteristics of non-periodic and non-closing in the straightness profile error are liable to bring about higher-order harmonic component distortion in the measurement results. However, this distortion can be avoided by the new accurate two-probe time domain method through the symmetry continuation algorithm, uniformity and least squares method. The harmonic suppression is analysed in detail through modern control theory. Both the straight-going component motion error in machine tools and the profile error in a workpiece that is manufactured on this machine can be measured at the same time. All of this information is available to diagnose the origin of faults in machine tools. The analysis result is proved to be correct through experiment.

  10. Measurement of ion motional heating rates over a range of trap frequencies and temperatures

    NASA Astrophysics Data System (ADS)

    Bruzewicz, C. D.; Sage, J. M.; Chiaverini, J.

    2015-04-01

    We present measurements of the motional heating rate of a trapped ion at different trap frequencies and temperatures between ˜0.6 and 1.5 MHz and ˜4 and 295 K. Additionally, we examine the possible effect of adsorbed surface contaminants with boiling points below ˜105 ∘C by measuring the ion heating rate before and after locally baking our ion trap chip under ultrahigh vacuum conditions. We compare the heating rates presented here to those calculated from available electric-field noise models. We can tightly constrain a subset of these models based on their expected frequency and temperature scaling interdependence. Discrepancies between the measured results and predicted values point to the need for refinement of theoretical noise models in order to more fully understand the mechanisms behind motional trapped-ion heating.

  11. A FIRST MEASUREMENT OF THE PROPER MOTION OF THE LEO II DWARF SPHEROIDAL GALAXY

    SciTech Connect

    Lepine, Sebastien; Koch, Andreas; Rich, R. Michael; Kuijken, Konrad

    2011-11-10

    We use 14 year baseline images obtained with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope (HST) to derive a proper motion for one of the Milky Way's most distant dwarf spheroidal companions, Leo II, relative to an extragalactic background reference frame. Astrometric measurements are performed in the effective point-spread function formalism using our own developed code. An astrometric reference grid is defined using 3224 stars that are members of Leo II and brighter than a magnitude of 25 in the F814W band. We identify 17 compact extragalactic sources, for which we measure a systemic proper motion relative to this stellar reference grid. We derive a proper motion [{mu}{sub {alpha},{mu}{delta}}] = [+104 {+-}113,-33 {+-} 151] {mu}as yr{sup -1} for Leo II in the heliocentric reference frame. Though marginally detected, the proper motion yields constraints on the orbit of Leo II. Given a distance of d {approx_equal} 230 kpc and a heliocentric radial velocity v{sub r} = +79 km s{sup -1}, and after subtraction of the solar motion, our measurement indicates a total orbital motion v{sub G} = 266.1 {+-} 128.7 km s{sup -1} in the Galactocentric reference frame, with a radial component v{sub r{sub G}}=21.5{+-}4.3 km s{sup -1} and tangential component v{sub t{sub G}} = 265.2 {+-} 129.4 km s{sup -1}. The small radial component indicates that Leo II either has a low-eccentricity orbit or is currently close to perigalacticon or apogalacticon distance. We see evidence for systematic errors in the astrometry of the extragalactic sources which, while close to being point sources, are slightly resolved in the HST images. We argue that more extensive observations at later epochs will be necessary to better constrain the proper motion of Leo II. We provide a detailed catalog of the stellar and extragalactic sources identified in the HST data which should provide a solid early-epoch reference for future astrometric measurements.

  12. MRI-based measurements of respiratory motion variability and assessment of imaging strategies for radiotherapy planning

    NASA Astrophysics Data System (ADS)

    Blackall, J. M.; Ahmad, S.; Miquel, M. E.; McClelland, J. R.; Landau, D. B.; Hawkes, D. J.

    2006-09-01

    Respiratory organ motion has a significant impact on the planning and delivery of radiotherapy (RT) treatment for lung cancer. Currently widespread techniques, such as 4D-computed tomography (4DCT), cannot be used to measure variability of this motion from one cycle to the next. In this paper, we describe the use of fast magnetic resonance imaging (MRI) techniques to investigate the intra- and inter-cycle reproducibility of respiratory motion and also to estimate the level of errors that may be introduced into treatment delivery by using various breath-hold imaging strategies during lung RT planning. A reference model of respiratory motion is formed to enable comparison of different breathing cycles at any arbitrary position in the respiratory cycle. This is constructed by using free-breathing images from the inhale phase of a single breathing cycle, then co-registering the images, and thereby tracking landmarks. This reference model is then compared to alternative models constructed from images acquired during the exhale phase of the same cycle and the inhale phase of a subsequent cycle, to assess intra- and inter-cycle variability ('hysteresis' and 'reproducibility') of organ motion. The reference model is also compared to a series of models formed from breath-hold data at exhale and inhale. Evaluation of these models is carried out on data from ten healthy volunteers and five lung cancer patients. Free-breathing models show good levels of intra- and inter-cycle reproducibility across the tidal breathing range. Mean intra-cycle errors in the position of organ surface landmarks of 1.5(1.4)-3.5(3.3) mm for volunteers and 2.8(1.8)-5.2(5.2) mm for patients. Equivalent measures of inter-cycle variability across this range are 1.7(1.0)-3.9(3.3) mm for volunteers and 2.8(1.8)-3.3(2.2) mm for patients. As expected, models based on breath-hold sequences do not represent normal tidal motion as well as those based on free-breathing data, with mean errors of 4

  13. MEASURING THE UNDETECTABLE: PROPER MOTIONS AND PARALLAXES OF VERY FAINT SOURCES

    SciTech Connect

    Lang, Dustin; Hogg, David W.; Jester, Sebastian; Rix, Hans-Walter

    2009-05-15

    The near future of astrophysics involves many large solid-angle, multi-epoch, multiband imaging surveys. These surveys will, at their faint limits, have data on a large number of sources that are too faint to be detected at any individual epoch. Here, we show that it is possible to measure in multi-epoch data not only the fluxes and positions, but also the parallaxes and proper motions of sources that are too faint to be detected at any individual epoch. The method involves fitting a model of a moving point source simultaneously to all imaging, taking account of the noise and point-spread function (PSF) in each image. By this method it is possible to measure the proper motion of a point source with an uncertainty close to the minimum possible uncertainty given the information in the data, which is limited by the PSF, the distribution of observation times (epochs), and the total signal-to-noise in the combined data. We demonstrate our technique on multi-epoch Sloan Digital Sky Survey (SDSS) imaging of the SDSS Southern Stripe (SDSSSS). We show that with our new technique we can use proper motions to distinguish very red brown dwarfs from very high-redshift quasars in these SDSS data, for objects that are inaccessible to traditional techniques, and with better fidelity than by multiband imaging alone. We rediscover all 10 known brown dwarfs in our sample and present nine new candidate brown dwarfs, identified on the basis of significant proper motion.

  14. Horizontal crustal motion in the central and eastern Mediterranean inferred from Satellite Laser Ranging measurements

    NASA Technical Reports Server (NTRS)

    Smith, David E.; Kolenkiewicz, Ron; Robbins, John W.; Dunn, Peter J.; Torrence, Mark H.

    1994-01-01

    Four campaigns to acquire Satellite Laser Ranging (SLR) measurements at sites in the Mediterranean region have been completed. These measurements to the LAGEOS satellite, made largely by mobile systems, cover a time span beginning in November 1985 and ending in June 1993. The range data from 18 sites in the central and eastern Mediterranean have been simultaneously analyzed with data acquired by the remainder of the global laser tracking network. Estimates of horizontal motion were placed into a regional, northern Europe-fixed, kinematic reference frame. Uncertainties are on the order of 5 mm/yr for sites having at least four occupations by mobile systems and approach 1 mm/yr for permanently located sites with long histories of tracking. The resulting relative motion between sites in the Aegean exhibit characteristics of broadly distributed pattern of radial extension, but at rates that are about 50% larger than those implied from studies of seismic strain rates based on seismicity of magnitude 6 or greater or across the region. The motion estimated for sites in Turkey exhibit velocity components associated with the westward motion of the Anatolian Block relative to Eurasia. These results provide a present-day 'snapshot' of ongoing deformational processes as experienced by the locations occupied by SLR systems.

  15. Direct Measurement of Lung Motion Using Hyperpolarized Helium-3 MR Tagging

    SciTech Connect

    Cai Jing; Miller, G. Wilson; Altes, Talissa A.; Read, Paul W.; Benedict, Stanley H.; Lange, Eduard E. de; Cates, Gordon D.; Brookeman, James R.; Mugler, John P.; Sheng Ke . E-mail: ks2mc@virginia.edu

    2007-07-01

    Purpose: To measure lung motion between end-inhalation and end-exhalation using a hyperpolarized helium-3 (HP {sup 3}He) magnetic resonance (MR) tagging technique. Methods and Materials: Three healthy volunteers underwent MR tagging studies after inhalation of 1 L HP {sup 3}He gas diluted with nitrogen. Multiple-slice two-dimensional and volumetric three-dimensional MR tagged images of the lungs were obtained at end-inhalation and end-exhalation, and displacement vector maps were computed. Results: The grids of tag lines in the HP {sup 3}He MR images were well defined at end-inhalation and remained evident at end-exhalation. Displacement vector maps clearly demonstrated the regional lung motion and deformation that occurred during exhalation. Discontinuity and differences in motion pattern between two adjacent lung lobes were readily resolved. Conclusions: Hyperpolarized helium-3 MR tagging technique can be used for direct in vivo measurement of respiratory lung motion on a regional basis. This technique may lend new insights into the regional pulmonary biomechanics and thus provide valuable information for the deformable registration of lung.

  16. Improved Pose Measurement and Tracking System for Motion Correction of Awake, Unrestrained Small Animal SPECT Imaging

    SciTech Connect

    Goddard Jr, James Samuel; Baba, Justin S; Weisenberger, A G; Smith, M F

    2007-01-01

    An improved optical landmark-based pose measurement and tracking system has been developed to provide 3D animal pose data for a single photon emission computed tomography (SPECT) imaging system for awake, unanesthetized, unrestrained laboratory animals. The six degree of freedom animal position and orientation measurement data are time synchronized with the SPECT list mode data to provide for motion correction after the scan and before reconstruction. The tracking system employs infrared (IR) markers placed on the animal's head along with synchronized, strobed IR LEDs to illuminate the reflectors and freeze motion while minimizing reflections. A new design trinocular stereo image acquisition system using IEEE 1394 CMOS cameras acquires images of the animal with markers contained within a transparent enclosure. The trinocular configuration provides improved accuracy, range of motion, and robustness over the binocular stereo used previously. Enhanced software detects obstructions, automatically segments the markers, rejects reflections, performs marker correspondence, and calculates the 3D pose of the animal's head using image data from three cameras. The new hardware design provides more compact camera positioning with enhanced animal viewing through the 360 degree SPECT scan. This system has been implemented on a commercial scanner and tested using live mice and has been shown to be more reliable with higher accuracy than the previous system. Experimental results showing the improved motion tracking results are given.

  17. PAH Measurements in Air in the Athabasca Oil Sands Region.

    PubMed

    Hsu, Yu-Mei; Harner, Tom; Li, Henrik; Fellin, Phil

    2015-05-01

    Polycyclic aromatic hydrocarbon (PAH) measurements were conducted by Wood Buffalo Environmental Association (WBEA) at four community ambient Air quality Monitoring Stations (AMS) in the Athabasca Oil Sands Region (AOSR) in Northeastern Alberta, Canada. The 2012 and 2013 mean concentrations of a subset of the 22 PAH species were 9.5, 8.4, 8.8, and 32 ng m(-3) at AMS 1 (Fort McKay), AMS 6 (residential Fort McMurray), AMS 7 (downtown Fort McMurray), and AMS 14 (Anzac), respectively. The average PAH concentrations in Fort McKay and Fort McMurray were in the range of rural and semirural areas, but peak values reflect an industrial emission influence. At these stations, PAHs were generally associated with NO, NO2, PM2.5, and SO2, indicating the emissions were from the combustion sources such as industrial stacks, vehicles, residential heating, and forest fires, whereas the PAH concentrations at AMS 14 (∼35 km south of Fort McMurray) were more characteristic of urban areas with a unique pattern: eight of the lower molecular weight PAHs exhibited strong seasonality with higher levels during the warmer months. Enthalpies calculated from Clausius-Clapeyron plots for these eight PAHs suggest that atmospheric emissions were dominated by temperature-dependent processes such as volatilization at warm temperatures. These findings point to the potential importance of localized water-air and/or surface-air transfer on observed PAH concentrations in air. PMID:25844542

  18. Ambulatory measurement of knee motion and physical activity: preliminary evaluation of a smart activity monitor

    PubMed Central

    Huddleston, James; Alaiti, Amer; Goldvasser, Dov; Scarborough, Donna; Freiberg, Andrew; Rubash, Harry; Malchau, Henrik; Harris, William; Krebs, David

    2006-01-01

    Background There is currently a paucity of devices available for continuous, long-term monitoring of human joint motion. Non-invasive, inexpensive devices capable of recording human activity and joint motion have many applications for medical research. Such a device could be used to quantify range of motion outside the gait laboratory. The purpose of this study was to test the accuracy of the modified Intelligent Device for Energy Expenditure and Activity (IDEEA) in measuring knee flexion angles, to detect different physical activities, and to quantify how often healthy subjects use deep knee flexion in the ambulatory setting. Methods We compared Biomotion Laboratory (BML) "gold standard" data to simultaneous IDEEA measures of knee motion and gait, step up/down, and stair descent in 5 healthy subjects. In addition, we used a series of choreographed physical activities outside the BML to confirm the IDEEA's ability to accurately measure 7 commonly-performed physical activities. Subjects then continued data collection during ordinary activities outside the gait laboratory. Results Pooled correlations between the BML and IDEEA knee flexion angles were .97 +/- .03 for step up/down, .98 +/- .02 for stair descent, and .98 +/- .01 for gait. In the BML protocol, the IDEEA accurately identified gait, but was less accurate in identifying step up/down and stair descent. During sampling outside the BML, the IDEEA accurately detected walking, running, stair ascent, stair descent, standing, lying, and sitting. On average, subjects flexed their knees >120° for 0.17% of their data collection periods outside the BML. Conclusion The modified IDEEA system is a useful clinical tool for evaluating knee motion and multiple physical activities in the ambulatory setting. These five healthy subjects rarely flexed their knees >120°. PMID:16970818

  19. Use of Oriented Spray Nozzles to Set the Vapor-Air Flow in Rotary Motion in the Superspray Space of the Evaporative Chimney-Type Tower

    NASA Astrophysics Data System (ADS)

    Dobrego, K. V.; Davydenko, V. F.; Koznacheev, I. A.

    2016-01-01

    The present paper considers the problem of upgrading the thermal efficiency of chimney-type evaporative cooling towers due to the rotary motion of the vapor-air flow in the superspray space. To set the vapor-air flow in rotary motion, we propose to use the momentum of the sprayed water. It has been shown that the existing parameters of spray nozzles permit setting up to 30% of the water flow momentum in translatory motion, which is enough for changing considerably the aerodynamics of the vapor-air flow in the superspray space and improving the operation of the cooling tower. The optimal angle of axial inclination of the spray cone has been estimated. Recommendations are given and problems have been posed for engineering realization of the proposed technologies in a chimney-type cooling tower.

  20. Versatile radar measurement of the electron loss rate in air

    SciTech Connect

    Dogariu, Arthur; Shneider, Mikhail N.; Miles, Richard B.

    2013-11-25

    We present an experimental method that makes possible in-situ measurements of the electron loss rate in arbitrary gas mixtures. A weakly ionized plasma is induced via resonant multiphoton ionization of trace amounts of nitric oxide seeded into the gas, and homodyne microwave scattering detection is used to study the dynamics of the electron loss mechanisms. Using this approach, the attachment rate for electrons to molecular oxygen in room temperature, atmospheric pressure air is determined. The measured 0.76 × 10{sup 8} s{sup −1} attachment rate is in very good agreement with predictions based on literature data.

  1. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  2. Measurements of Intense Femtosecond Laser Pulse Propagation in Air

    NASA Astrophysics Data System (ADS)

    Ting, Antonio

    2004-11-01

    Intense femtosecond pulses generated from chirped pulse amplification (CPA) lasers can deliver laser powers many times above the critical power for self-focusing in air. Catastrophic collapse of the laser pulse is usually prevented by the defocusing of the plasma column formed when the laser intensity gets above the threshold for multiphoton ionization. The resultant laser/plasma filament can extend many meters as the laser pulse propagates in the atmosphere. We have carried out a series of experiments both for understanding the formation mechanisms of the filaments and the nonlinear effects such as white light and harmonics generation associated with them. Many applications of these filaments such as remote atmospheric breakdown, laser induced electrical discharge and femtosecond laser material interactions require direct measurements of their characteristics. Direct measurements of these filaments had been difficult because the high laser intensity ( ˜10^13 W/cm^2) can damage practically any optical diagnostics. A novel technique was invented to obtain the first absolute measurements of laser energy, transverse profile, fluence and spectral content of the filaments. We are investigating a ``remote atmospheric breakdown'' concept of remotely sensing chemical and biological compounds. A short intense laser pulse can be generated at a remote position by using the group velocity dispersion (GVD) of the air to compress an initially long, frequency negatively chirped laser pulse to generate the air breakdown and filaments. We have observed that nonlinear contributions to the laser spectrum through self-phase modulation can lead to modification of the linear GVD compression. We have also observed the generation of ultraviolet (UV) radiations from these filaments in air and the induced fluorescence by the UV radiation of a surrogate biological agent. These and other results such as laser induced electrical discharges will be presented.

  3. Bias in air sampling techniques used to measure inhalation exposure.

    PubMed

    Cohen, B S; Harley, N H; Lippmann, M

    1984-03-01

    Factors have been evaluated which contribute to the lack of agreement between inhalation exposure estimates obtained by time-weighted averaging of samples taken with mini hi-volume samplers, and those measured by time integrating, low-volume, lapel mounted, personal monitors. Measurements made with real-time aerosol monitors on workers at a Be-Cu production furnace show that part of the discrepancy results from variability of the aerosol concentration within the breathing zone. Field studies of sampler inlet bias, the influences of the electrostatic fields around polystyrene filter holders, and resuspension of dust from work clothing, were done in three areas of a Be plant. No significant differences were found in Be air concentrations measured simultaneously by open and closed face cassettes, and "mini hi-volume" samplers mounted on a test stand. No significant influence on Be collection was detected between either positively or negatively charged monitors and charge neutralized control monitors. The effect of contaminated work clothing on dust collection by lapel mounted monitors is most important. Beryllium release from the fabrics affected air concentrations measured by fabric mounted monitors more than it affected concentrations measured by monitors positioned above the fabrics. The latter were placed 16 cm from the vertically mounted fabrics, to simulate the position of the nose or mouth. We conclude that dust resuspended from work clothing is the major source of the observed discrepancy between exposures estimated from lapel mounted samplers and time-weighted averages. PMID:6720582

  4. Bias in air sampling techniques used to measure inhalation exposure

    SciTech Connect

    Cohen, B.S.; Harley, N.H.; Lippmann, M.

    1984-03-01

    Factors have been evaluated which contribute to the lack of agreement between inhalation exposure estimates obtained by time-weighted averaging of samples taken with mini hi-volume samplers, and those measured by time integrating, low-volume, lapel mounted, personal monitors. Measurements made with real-time aerosol monitors on workers at a Be-Cu production furnace show that part of the discrepancy results from variability of the aerosol concentration within the breathing zone. Field studies of sampler inlet bias, the influences of the electrostatic fields around polystyrene filter holders, and resuspension of dust from work clothing, were done in three areas of a Be plant. No significant differences were found in Be air concentrations measured simultaneously by open and closed face cassettes, and mini hi-volume samplers mounted on a test stand. No significant influence on Be collection was detected between either positively or negatively charged monitors and charge neutralized control monitors. The effect of contaminated work clothing on dust collection by lapel mounted monitors is most important. Beryllium release from the fabrics affected air concentrations measured by fabric mounted monitors more than it affected concentrations measured by monitors positioned above the fabrics. The latter were placed 16 cm from the vertically mounted fabrics, to simulate the position of the nose or mouth. The authors conclude that dust resuspended from work clothing is the major source of the observed discrepancy between exposures estimated from lapel mounted samplers and time-weighted averages.

  5. Prototype Systems for Measuring Outdoor Air Intake Rates in Rooftop Air Handlers

    SciTech Connect

    Fisk, William J.; Chan, Wanyu R.; Hotchi, Toshifumi

    2015-01-01

    The widespread absence of systems for real-time measurement and feedback control, of minimum outdoor air intake rates in HVAC systems contributes to the poor control of ventilation rates in commercial buildings. Ventilation rates affect building energy consumption and influence occupant health. The project designed fabricated and tested four prototypes of systems for measuring rates of outdoor air intake into roof top air handlers. All prototypes met the ±20% accuracy target at low wind speeds, with all prototypes accurate within approximately ±10% after application of calibration equations. One prototype met the accuracy target without a calibration. With two of four prototype measurement systems, there was no evidence that wind speed or direction affected accuracy; however, winds speeds were generally below usually 3.5 m s-1 (12.6 km h-1) and further testing is desirable. The airflow resistance of the prototypes was generally less than 35 Pa at maximum RTU air flow rates. A pressure drop of this magnitude will increase fan energy consumption by approximately 4%. The project did not have resources necessary to estimate costs of mass produced systems. The retail cost of components and materials used to construct prototypes ranged from approximately $1,200 to $1,700. The test data indicate that the basic designs developed in this project, particularly the designs of two of the prototypes, have considerable merit. Further design refinement, testing, and cost analysis would be necessary to fully assess commercial potential. The designs and test results will be communicated to the HVAC manufacturing community.

  6. Integrated Assessment of Air Pollution Control Measures for Megacities

    NASA Astrophysics Data System (ADS)

    Friedrich, R.; Theloke, J.; Denier-van-der-Gon, H.; Kugler, U.; Kampffmeyer, T.; Roos, J.; Torras, S.

    2012-04-01

    Air pollution in large cities is still a matter of concern. Especially the concentration of fine particles (PM10 and PM2.5) is largest in large cities leading to severe health impacts. Furthermore the PM10 thresholds of the EU Air Quality Directive are frequently exceeded. Thus the question arises, whether the initiated policies and measures for mitigating air pollution are sufficient to meet the air quality targets and - if not - which efficient further pollution mitigation measures exist. These questions have been addressed in the EU research project MEGAPOLI for the four European megacities respectively agglomerations London, Paris, Rhine-Ruhr area and Po valley. Firstly, a reference scenario of future activities and emissions has been compiled for the megacities for the years 2020, 2030 and 2050 for all relevant air pollutants (CO, NH3, NMVOC, NOx, PM10, PM2.5 and SO2) and greenhouse gases (CO2, CH4 and N2O). The reference scenario takes into account as well population changes as technical progress and economic growth. As pollution flowing in from outside the city is about as important as pollution caused by emissions in the city, the analysis covers the whole of Europe and not only the city area. Emissions are then transformed into concentrations using atmospheric models. The higher concentrations in cities were estimated with a newly developed 'urban increment' model. Results show, that in the megacities the limits of the Air Quality Directive (2008/50/EC) will be exceeded. Thus additional efforts are necessary to reduce emissions further. Thus, a number of further measures (not implemented in current legislation) were selected and assessed. These included mitigation options for road transport, other mobile sources, large combustion plants, small and medium combustion plants and industry. For each measure and in addition for various bundles of measures a cost-benefit analysis has been carried out. Benefits (avoided health risks and climate change risks) have

  7. The use of 2D ultrasound elastography for measuring tendon motion and strain.

    PubMed

    Chernak Slane, Laura; Thelen, Darryl G

    2014-02-01

    The goal of the current study was to investigate the fidelity of a 2D ultrasound elastography method for the measurement of tendon motion and strain. Ultrasound phantoms and ex vivo porcine flexor tendons were cyclically stretched to 4% strain while cine ultrasound radiofrequency (RF) data and video data were simultaneously collected. 2D ultrasound elastography was used to estimate tissue motion and strain from RF data, and surface tissue motion and strain were separately estimated using digital image correlation (DIC). There were strong correlations (R(2)>0.97) between DIC and RF measurements of phantom displacement and strain, and good agreement in estimates of peak phantom strain (DIC: 3.5±0.2%; RF: 3.7±0.1%). For tendon, elastographic estimates of displacement profiles also correlated well with DIC measurements (R(2)>0.92), and exhibited similar estimated peak tendon strain (DIC: 2.6±1.4%; RF: 2.2±1.3%). Elastographic tracking with B-Mode images tended to under-predict peak strain for both the phantom and tendon. This study demonstrates the capacity to use quantitative elastographic techniques to measure tendon displacement and strain within an ultrasound image window. The approach may be extendible to in vivo use on humans, which would allow for the non-invasive analysis of tendon deformation in both normal and pathological states. PMID:24388164

  8. Angular Motion Estimation Using Dynamic Models in a Gyro-Free Inertial Measurement Unit

    PubMed Central

    Edwan, Ezzaldeen; Knedlik, Stefan; Loffeld, Otmar

    2012-01-01

    In this paper, we summarize the results of using dynamic models borrowed from tracking theory in describing the time evolution of the state vector to have an estimate of the angular motion in a gyro-free inertial measurement unit (GF-IMU). The GF-IMU is a special type inertial measurement unit (IMU) that uses only a set of accelerometers in inferring the angular motion. Using distributed accelerometers, we get an angular information vector (AIV) composed of angular acceleration and quadratic angular velocity terms. We use a Kalman filter approach to estimate the angular velocity vector since it is not expressed explicitly within the AIV. The bias parameters inherent in the accelerometers measurements' produce a biased AIV and hence the AIV bias parameters are estimated within an augmented state vector. Using dynamic models, the appended bias parameters of the AIV become observable and hence we can have unbiased angular motion estimate. Moreover, a good model is required to extract the maximum amount of information from the observation. Observability analysis is done to determine the conditions for having an observable state space model. For higher grades of accelerometers and under relatively higher sampling frequency, the error of accelerometer measurements is dominated by the noise error. Consequently, simulations are conducted on two models, one has bias parameters appended in the state space model and the other is a reduced model without bias parameters. PMID:22778586

  9. The Use of 2D Ultrasound Elastography for Measuring Tendon Motion and Strain

    PubMed Central

    Slane, Laura Chernak; Thelen, Darryl G.

    2014-01-01

    The goal of the current study was to investigate the fidelity of a 2D ultrasound elastography method for the measurement of tendon motion and strain. Ultrasound phantoms and ex vivo porcine flexor tendons were cyclically stretched to 4% strain while cine ultrasound radiofrequency (RF) data and video data were simultaneously collected. 2D ultrasound elastography was used to estimate tissue motion and strain from RF data, and surface tissue motion and strain were separately estimated using digital image correlation (DIC). There were strong correlations (R2 > 0.97) between DIC and RF measurements of phantom displacement and strain, and good agreement in estimates of peak phantom strain (DIC: 3.5 ± 0.2%; RF: 3.7 ± 0.1%). For tendon, elastographic estimates of displacement profiles also correlated well with DIC measurements (R2 > 0.92), and exhibited similar estimated peak tendon strain (DIC: 2.6 ± 1.4%; RF: 2.2 ± 1.3%). Elastographic tracking with B-Mode images tended to under-predict peak strain for both the phantom and tendon. This study demonstrates the capacity to use quantitative elastographic techniques to measure tendon displacement and strain within an ultrasound image window. The approach may be extendible to in vivo use on humans, which would allow for the non-invasive analysis of tendon deformation in both normal and pathological states. PMID:24388164

  10. Air Quality Science and Regulatory Efforts Require Geostationary Satellite Measurements

    NASA Technical Reports Server (NTRS)

    Pickering, Kenneth E.; Allen, D. J.; Stehr, J. W.

    2006-01-01

    Air quality scientists and regulatory agencies would benefit from the high spatial and temporal resolution trace gas and aerosol data that could be provided by instruments on a geostationary platform. More detailed time-resolved data from a geostationary platform could be used in tracking regional transport and in evaluating mesoscale air quality model performance in terms of photochemical evolution throughout the day. The diurnal cycle of photochemical pollutants is currently missing from the data provided by the current generation of atmospheric chemistry satellites which provide only one measurement per day. Often peak surface ozone mixing ratios are reached much earlier in the day during major regional pollution episodes than during local episodes due to downward mixing of ozone that had been transported above the boundary layer overnight. The regional air quality models often do not simulate this downward mixing well enough and underestimate surface ozone in regional episodes. Having high time-resolution geostationary data will make it possible to determine the magnitude of this lower-and mid-tropospheric transport that contributes to peak eight-hour average ozone and 24-hour average PM2.5 concentrations. We will show ozone and PM(sub 2.5) episodes from the CMAQ model and suggest ways in which geostationary satellite data would improve air quality forecasting. Current regulatory modeling is typically being performed at 12 km horizontal resolution. State and regional air quality regulators in regions with complex topography and/or land-sea breezes are anxious to move to 4-km or finer resolution simulations. Geostationary data at these or finer resolutions will be useful in evaluating such models.

  11. Photoinduced Directional Motions of Microparticles at Air-Liquid-Crystal Interfaces of Azobenzene-Doped Liquid-Crystal Films with Homeotropic or Homogeneous Alignment Structures

    NASA Astrophysics Data System (ADS)

    Yamamoto, Takahiro; Yoshida, Masaru

    2012-10-01

    We investigated the effects of liquid-crystal (LC) alignments on photoinduced motions of microparticles at air-LC interfaces of azobenzene-doped LC films. In homeotropically aligned LC films, the lattice spacings of pseudo-hexagonal structures of microparticles site-selectively exhibited reversible expansion or contraction on alternating irradiation with ultraviolet and visible light. The particle motions were probably driven by photochemical deformation of LC surfaces. In homogeneously aligned films, alternating irradiation induced macroscopic convective flows followed by rapid gathering or dispersion of linear chains of microparticles. Particle motions were significantly influenced by LC alignments as well as the light wavelength.

  12. SCANNING VOLTA POTENTIALS MEASUREMENTS OF METALS IN IRRADIATED AIR.

    SciTech Connect

    ISAACS, H.S.; ADZIC, G.; AND ENERGY SCIENCES AND TECHNOLOGY DEPARTMENT; JEFFCOATE, C.S.

    2000-10-22

    A method for direct dc measurement of the Volta potential is presented. High intensity synchrotron x-ray beams were used to locally irradiate the atmosphere adjacent to the metal surface and produce a conducting path between a sample and a reference probe. The direct measurements of potential in the ionized air could be made at probe heights of around 1 mm compared to less than 0.1 mm for the Kelvin probe. The measurements were similar to traditional Kelvin probe measurements, but had a poorer spatial resolution. In contrast to the Kelvin probe methods, the approach described allows observation of the current as a function of impressed voltage. Methods to improve the special resolution of the technique and applications to corrosion under coating will be presented.

  13. 13c Measurements On Air of Small Ice Samples

    NASA Astrophysics Data System (ADS)

    Eyer, M.; Leuenberger, M.

    We have developed a new method for 13C analysis for very small air amounts of less than 0.5 cc STP, corresponding to less than 10 gram of ice. It is based on the needle-crasher technique, which we routinely use for CO2 concentration measurements by infrared laser absorption. The extracted air is slowly expanded into a large volume through a water trap held at ­100°C. This sampled air is then carried by a high helium flux through a modified Precon system of Thermo-Finnigan to separate CO2 from the air and to inject the pure CO2 gas in a low helium stream via an open split device to a Delta Plus XL mass spectrometer. The overall precision based on replicates of standard air is significantly better than 0.1 for a single analysis and is further improved by a triplicate measurement of the same sample through a specially designed gas splitter. We have used this new method for investigations on polar ice cores. The 13C measurements are important for climate reconstructions, e.g. to reconstruct the evolution and its variability in the terrestrial and oceanic carbon sinks and to identify natural variations in the marine carbon cycle. During the industrialization atmospheric 13C decreased by about -2, mainly due to the anthropogenic release of biogenic CO2 by fossil fuel burning. Reconstructions of carbon and oxygen cycles of Joos at al. [1999] using a double deconvolution method show that between 1930 and 1950 the net terrestrial release is changing to a net terrestrial uptake of CO2. A highly resolved 13C dataset of this time window would replenish the documentation of this behaviour. Further, it would be interesting to compare such data with O2/N2 measurements, known as an other partitioning tool for carbon sources and sinks. At the EGS 2002 we will present a highly resolved 13C record from Antarctic ice covering this time period.

  14. Seine estuary modelling and AirSWOT measurements validation

    NASA Astrophysics Data System (ADS)

    Chevalier, Laetitia; Lyard, Florent; Laignel, Benoit

    2013-04-01

    In the context of global climate change, knowing water fluxes and storage, from the global scale to the local scale, is a crucial issue. The future satellite SWOT (Surface Water and Ocean Topography) mission, dedicated to the surface water observation, is proposed to meet this challenge. SWOT main payload will be a Ka-band Radar Interferometer (KaRIn). To validate this new kind of measurements, preparatory airborne campaigns (called AirSWOT) are currently being designed. AirSWOT will carry an interferometer similar to Karin: Kaspar-Ka-band SWOT Phenomenology Airborne Radar. Some campaigns are planned in France in 2014. During these campaigns, the plane will fly over the Seine River basin, especially to observe its estuary, the upstream river main channel (to quantify river-aquifer exchange) and some wetlands. The present work objective is to validate the ability of AirSWOT and SWOT, using a Seine estuary hydrodynamic modelling. In this context, field measurements will be collected by different teams such as GIP (Public Interest Group) Seine Aval, the GPMR (Rouen Seaport), SHOM (Hydrographic and Oceanographic Service of the Navy), the IFREMER (French Research Institute for Sea Exploitation), Mercator-Ocean, LEGOS (Laboratory of Space Study in Geophysics and Oceanography), ADES (Data Access Groundwater) ... . These datasets will be used first to validate locally AirSWOT measurements, and then to improve a hydrodynamic simulations (using tidal boundary conditions, river and groundwater inflows ...) for AirSWOT data 2D validation. This modelling will also be used to estimate the benefit of the future SWOT mission for mid-latitude river hydrology. To do this modelling,the TUGOm barotropic model (Toulouse Unstructured Grid Ocean model 2D) is used. Preliminary simulations have been performed by first modelling and then combining to different regions: first the Seine River and its estuarine area and secondly the English Channel. These two simulations h are currently being

  15. Measurement of Temporal Awareness in Air Traffic Control

    NASA Technical Reports Server (NTRS)

    Rantanen, E.M.

    2009-01-01

    Temporal awareness, or level 3 situation awareness, is critical to successful control of air traffic, yet the construct remains ill-defined and difficult to measure. This research sought evidence for air traffic controllers awareness of temporal characteristics of their tasks in data from a high-fidelity system evaluation simulation. Five teams of controllers worked on four scenarios with different traffic load. Several temporal parameters were defined for each task controllers performed during a simulation run and their actions on the tasks were timed relative to them. Controllers showed a strong tendency to prioritize tasks according to a first come, first served principle. This trend persisted as task load increased. Also evident was awareness of the urgency of tasks, as tasks with impending closing of a window of opportunity were performed before tasks that had longer time available before closing of the window.

  16. Ambient air measurements of monoterpenes, oxygenated terpenes, and sesquiterpenes

    NASA Astrophysics Data System (ADS)

    Bouvier-Brown, N. C.; Goldstein, A. H.

    2007-12-01

    Chemical ozone loss within the forest canopy and the presence of biogenic VOC (BVOC) oxidation products in and above the canopy indirectly suggest the presence of very reactive BVOCs at Blodgett Forest. As a part of the 2007 BEARPEX campaign at this coniferous forest in the Sierra Nevada Mountains of California (1300 m elevation, 38.90° N, 120.63° W,), we quantified ambient concentrations of terpenes using a modified in-situ gas chromatograph with a mass spectrometer and a flame ionization detector (GC-MS-FID). The range of terpenes observed in ambient air matched enclosure based measurements of branch level emissions. To our knowledge, these observations represent the first quantification of the oxygenated monoterpene methyl chavicol and various sesquiterpenes in ambient air. Details of the instrument modifications, diurnal profiles of the terpenes, and comparison to branch level emissions will be presented.

  17. Development of a differential column image motion light detection and ranging for measuring turbulence profiles.

    PubMed

    Jing, Xu; Hou, Zaihong; Wu, Yi; Qin, Lai'an; He, Feng; Tan, Fengfu

    2013-09-01

    We have developed a differential column image motion (DCIM) lidar for measuring real-time vertical profiles of Fried's transverse coherence length (r0) and testing it against a differential image motion (DIM) lidar and a DIM monitor by observing stars throughout a range of turbulent conditions. With the DCIM lidar system parameters elaborately designed and the detector installed with an angle corresponding to the receiving telescope axis, the focal position of the laser guide star from a range of altitudes that coincide with the CCD's receiving area, r0 of different altitudes can be obtained simultaneously. The experiment results support the DCIM lidar and confirm that a high temporal and spatial resolution r0 profile can be measured with this method. PMID:23988980

  18. A measurement approach based on micro-Doppler maps for signature and motion analysis

    NASA Astrophysics Data System (ADS)

    Ricci, R.; Sona, A.

    2013-05-01

    In this paper, a novel and comprehensive measurement approach is proposed for the detection and analysis of human motion signature. The approach combines theoretical concepts and tools of micro-Doppler theory, image processing, and human modeling, in a original way. The attention is primarily focused on the description of the most meaningful parameters influencing the accuracy of the obtained signature. The ultimate purpose is to provide a framework through which organizing, comparing, and merging future research activities, ideas and results in the field of human motion signature analysis for security, health and disaster recovery purposes. Some simulation and experimental results underlying the feasibility and effectiveness of the measurement approach are also summarized and analyzed.

  19. A neural network learned information measures for heart motion abnormality detection

    NASA Astrophysics Data System (ADS)

    Nambakhsh, M. S.; Punithakumar, Kumaradevan; Ben Ayed, Ismail; Goela, Aashish; Islam, Ali; Peters, Terry; Li, Shuo

    2011-03-01

    In this study, we propose an information theoretic neural network for normal/abnormal left ventricular motion classification which outperforms significantly other recent methods in the literature. The proposed framework consists of a supervised 3-layer artificial neural network (ANN) which uses hyperbolic tangent sigmoid and linear transfer functions for hidden and output layers, respectively. The ANN is fed by information theoretic measures of left ventricular wall motion such as Shannon's differential entropy (SDE), Rényi entropy and Fisher information, which measure global information of subjects distribution. Using 395×20 segmented LV cavities of short-axis magnetic resonance images (MRI) acquired from 48 subjects, the experimental results show that the proposed method outperforms Support Vector Machine (SVM) and thresholding based information theoretic classifiers. It yields a specificity equal to 90%, a sensitivity of 91%, and a remarkable Area Under Curve (AUC) for Receiver Operating Characteristic (ROC), equal to 93.2%.

  20. A New Position Measurement System Using a Motion-Capture Camera for Wind Tunnel Tests

    PubMed Central

    Park, Hyo Seon; Kim, Ji Young; Kim, Jin Gi; Choi, Se Woon; Kim, Yousok

    2013-01-01

    Considering the characteristics of wind tunnel tests, a position measurement system that can minimize the effects on the flow of simulated wind must be established. In this study, a motion-capture camera was used to measure the displacement responses of structures in a wind tunnel test, and the applicability of the system was tested. A motion-capture system (MCS) could output 3D coordinates using two-dimensional image coordinates obtained from the camera. Furthermore, this remote sensing system had some flexibility regarding lab installation because of its ability to measure at relatively long distances from the target structures. In this study, we performed wind tunnel tests on a pylon specimen and compared the measured responses of the MCS with the displacements measured with a laser displacement sensor (LDS). The results of the comparison revealed that the time-history displacement measurements from the MCS slightly exceeded those of the LDS. In addition, we confirmed the measuring reliability of the MCS by identifying the dynamic properties (natural frequency, damping ratio, and mode shape) of the test specimen using system identification methods (frequency domain decomposition, FDD). By comparing the mode shape obtained using the aforementioned methods with that obtained using the LDS, we also confirmed that the MCS could construct a more accurate mode shape (bending-deflection mode shape) with the 3D measurements. PMID:24064600

  1. Development and Validation of a Method to Measure Lumbosacral Motion Using Ultrasound Imaging.

    PubMed

    van den Hoorn, Wolbert; Coppieters, Michel W; van Dieën, Jaap H; Hodges, Paul W

    2016-05-01

    The study aim was to validate an ultrasound imaging technique to measure sagittal plane lumbosacral motion. Direct and indirect measures of lumbosacral angle change were developed and validated. Lumbosacral angle was estimated by the angle between lines through two landmarks on the sacrum and lowest lumbar vertebrae. Distance measure was made between the sacrum and lumbar vertebrae, and angle was estimated after distance was calibrated to angle. This method was tested in an in vitro spine and an in vivo porcine spine and validated to video and fluoroscopy measures, respectively. R(2), regression coefficients and mean absolute differences between ultrasound measures and validation measures were, respectively: 0.77, 0.982, 0.67° (in vitro, angle); 0.97, 0.992, 0.82° (in vitro, distance); 0.94, 0.995, 2.1° (in vivo, angle); and 0.95, 0.997, 1.7° (in vivo, distance). Lumbosacral motion can be accurately measured with ultrasound. This provides a basis to develop measurements for use in humans. PMID:26895754

  2. Ambient measurement methods and properties of the 189 Clean Air Act hazardous air pollutants. Final report

    SciTech Connect

    Kelly, T.J.; Mukund, R.; Gordon, S.M.; Hays, M.J.

    1994-03-01

    Measurement methods for the 189 Hazardous Air Pollutants (HAPs) designated in Title III of the 1990 Clean Air Act Amendments are either identified or suggested for all but 10 of the compounds. An extensive list of chemical and physical properties are provided for all compounds. Suggestions for methods development of compounds with no written references are based on the similarity of these chemical and physical properties to other of the HAPs. For 126 of the HAPs, established and documented methods were found; for 53 other HAPs, methods were identified having need for further development; and for 10 HAPs, either no methods or methods requiring extensive development were found. The primary recommendation of the study is that method development be focussed on the 53 HAPs for which additional development is expected to result in reliable methods.

  3. Continuous measurement of gaseous pollutants in Buenos Aires city

    NASA Astrophysics Data System (ADS)

    Bogo, Horacio; Martín Negri, R.; San Román, Enrique

    Data on CO, NO, NO 2 and O 3 concentrations measured in Buenos Aires city using a continuous monitoring station are reported. This is the first systematic study of this kind carried out in the city, which is, together with its surroundings, the third more populated in Latin America. Measurements were performed during 12 months in one of the principal avenues near downtown. Results indicate that vehicular traffic is the principal source of CO and NO x. The concentration of O 3 is generally quite low and results from the mixing of clean air masses with exhaust gases containing high amounts of NO. The monthly averages of CO and NO decrease from Winter to Summer in correlation with the increase of the mean wind speed and average temperature. These results are compared with previous measurements on the spatial distribution of NO 2 in the whole city using passive diffusion tubes and with the concentration of CO, which is being continuously registered since several years in the downtown area. Measurements performed at a green, windy, low traffic area beneath the La Plata river are also shown.

  4. Measurement of motion detection of wireless capsule endoscope inside large intestine.

    PubMed

    Zhou, Mingda; Bao, Guanqun; Pahlavan, Kaveh

    2014-01-01

    Wireless Capsule Endoscope (WCE) provides a noninvasive way to inspect the entire Gastrointestinal (GI) tract, including large intestine, where intestinal diseases most likely occur. As a critical component of capsule endoscopic examination, physicians need to know the precise position of the endoscopic capsule in order to identify the position of detected intestinal diseases. Knowing how the capsule moves inside the large intestine would greatly complement the existing wireless localization systems by providing the motion information. Since the most recently released WCE can take up to 6 frames per second, it's possible to estimate the movement of the capsule by processing the successive image sequence. In this paper, a computer vision based approach without utilizing any external device is proposed to estimate the motion of WCE inside the large intestine. The proposed approach estimate the displacement and rotation of the capsule by calculating entropy and mutual information between frames using Fibonacci method. The obtained results of this approach show its stability and better performance over other existing approaches of motion measurements. Meanwhile, findings of this paper lay a foundation for motion pattern of WCEs inside the large intestine, which will benefit other medical applications. PMID:25571262

  5. A comparison of lung motion measured using implanted electromagnetic transponders and motion algorithmically predicted using external surrogates as an alternative to respiratory correlated CT imaging

    NASA Astrophysics Data System (ADS)

    Lechleiter, Kristen M.; Low, Daniel A.; Chaudhari, Amir; Lu, Wei; Hubenschmidt, James P.; Mayse, Martin L.; Dimmer, Steven C.; Bradley, Jeffrey D.; Parikh, Parag J.

    2007-03-01

    Three-dimensional volumetric imaging correlated with respiration (4DCT) typically utilizes external breathing surrogates and phase-based models to determine lung tissue motion. However, 4DCT requires time consuming post-processing and the relationship between external breathing surrogates and lung tissue motion is not clearly defined. This study compares algorithms using external respiratory motion surrogates as predictors of internal lung motion tracked in real-time by electromagnetic transponders (Calypso® Medical Technologies) implanted in a canine model. Simultaneous spirometry, bellows, and transponder positions measurements were acquired during free breathing and variable ventilation respiratory patterns. Functions of phase, amplitude, tidal volume, and airflow were examined by least-squares regression analysis to determine which algorithm provided the best estimate of internal motion. The cosine phase model performed the worst of all models analyzed (R2 = 31.6%, free breathing, and R2 = 14.9%, variable ventilation). All algorithms performed better during free breathing than during variable ventilation measurements. The 5D model of tidal volume and airflow predicted transponder location better than amplitude or either of the two phasebased models analyzed, with correlation coefficients of 66.1% and 64.4% for free breathing and variable ventilation respectively. Real-time implanted transponder based measurements provide a direct method for determining lung tissue location. Current phase-based or amplitude-based respiratory motion algorithms cannot as accurately predict lung tissue motion in an irregularly breathing subject as a model including tidal volume and airflow. Further work is necessary to quantify the long term stability of prediction capabilities using amplitude and phase based algorithms for multiple lung tumor positions over time.

  6. Measurement of Shoulder Range of Motion in Patients with Adhesive Capsulitis Using a Kinect

    PubMed Central

    Chung, Sun Gun; Kim, Hee Chan; Kwak, Youngbin; Park, Hee-won; Kim, Keewon

    2015-01-01

    Range of motion (ROM) measurements are essential for the evaluation for and diagnosis of adhesive capsulitis of the shoulder (AC). However, taking these measurements using a goniometer is inconvenient and sometimes unreliable. The Kinect (Microsoft, Seattle, WA, USA) is gaining attention as a new motion detecting device that is nonintrusive and easy to implement. This study aimed to apply Kinect to measure shoulder ROM in AC; we evaluated its validity by calculating the agreement of the measurements obtained using Kinect with those obtained using goniometer and assessed its utility for the diagnosis of AC. Both shoulders of 15 healthy volunteers and affected shoulders of 12 patients with AC were included in the study. The passive and active ROM of each were measured with a goniometer for flexion, abduction, and external rotation. Their active shoulder motions for each direction were again captured using Kinect and the ROM values were calculated. The agreement between the two measurements was tested with the intraclass correlation coefficient (ICC). Diagnostic performance using the Kinect ROM was evaluated with Cohen’s kappa value. The cutoff values of the limited ROM were determined in the following ways: the same as passive ROM values, reflecting the mean difference, and based on receiver operating characteristic curves. The ICC for flexion/abduction/external rotation between goniometric passive ROM and the Kinect ROM were 0.906/0.942/0.911, while those between active ROMs and the Kinect ROMs were 0.864/0.932/0.925. Cohen’s kappa values were 0.88, 0.88, and 1.0 with the cutoff values in the order above. Measurements of the shoulder ROM using Kinect show excellent agreement with those taken using a goniometer. These results indicate that the Kinect can be used to measure shoulder ROM and to diagnose AC as an alternative to goniometer. PMID:26107943

  7. Trajectories of air parcel motions in Mars' atmosphere computed using HYSPLIT

    NASA Astrophysics Data System (ADS)

    Bruggeman, David

    An analysis of the advection of air parcels in the Martian atmosphere during the 2001 global dust storm through the use of three-dimensional trajectories is presented. The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, well-known for trajectory, dispersion, and deposition modeling, and originally developed for Earth was modified for Mars to provide forward and backward trajectories. The custom HYSPLIT for Mars uses meteorological input generated by the NASA Ames Mars General Circulation Model (MGCM). The 2001 global dust storm was the earliest on record (Ls ˜ 180°) and originated from local dust storms around the Hellas basin as the storm expanded asymmetrically to the east. Trajectories near Hellas and Claritas Fossae correspond with dust transport detected using satellite imagery. Forward trajectories at Ls = 184° from Hellas show flow to the south, transporting dust around the south polar cap, while after Ls = 188° there is an eastward shift in propagation. Air parcel trajectories intersecting the surface during the dust storm may indicate the processes involved with global dust storms contributing to dust layers in the polar regions. Backward trajectories from Claritas Fossae reveal the dust activity in this region was the result of local dust storm activity instead of the propagation of dust eastward from the Hellas region.

  8. Recoil of the Stellar Remnant from the Puppis A Supernova: Proper-Motion Measurement from Chandra

    NASA Technical Reports Server (NTRS)

    Petre, Robert; Winkler, P. F.

    2006-01-01

    A sequence of three Chandra X-ray Observatory High Resolution Camera images taken over a span of five years reveals arc-second-scale displacement of RX-J0822--4300, the stellar remnant near the center of the Puppis A supernova remnant. We measure its proper motion to be 0.16+/-0.02 arcsec/yr toward the west-southwest. At a distance of 2 kpc, this corresponds to a transverse space velocity of approx. 1500 km/s. This is the first case of a compact X-ray source with a directly measured proper motion. The space velocity is consistent with the explosion center inferred from proper motions of the oxygen-rich optical filaments, and confirms the idea that Puppis A resulted from an asymmetric explosion accompanied by a kick that imparted on the order of 3 x 10(exp 49) ergs of kinetic energy (some 3 percent of the supernova kinetic energy) to the stellar remnant. We will summarize this measurement and discuss possible mechanisms for producing such a violent kick. This research has been supported by NASA grant G04-5062X.

  9. Ozone measurement system for NASA global air sampling program

    NASA Technical Reports Server (NTRS)

    Tiefermann, M. W.

    1979-01-01

    The ozone measurement system used in the NASA Global Air Sampling Program is described. The system uses a commercially available ozone concentration monitor that was modified and repackaged so as to operate unattended in an aircraft environment. The modifications required for aircraft use are described along with the calibration techniques, the measurement of ozone loss in the sample lines, and the operating procedures that were developed for use in the program. Based on calibrations with JPL's 5-meter ultraviolet photometer, all previously published GASP ozone data are biased high by 9 percent. A system error analysis showed that the total system measurement random error is from 3 to 8 percent of reading (depending on the pump diaphragm material) or 3 ppbv, whichever are greater.

  10. The influence of bowl offset on air motion in a direct injection diesel engine

    SciTech Connect

    McKinley, T.L.; Primus, R.J

    1988-01-01

    The influence of bowl offset on motored mean flow and turbulence in a direct injection diesel engine has been examined with the aid of a multi-dimensional flow code. Results are presented for three piston geometries. The bowl geometry of each piston was the same, while the offset between the bowl and the cylinder axis was varied from 0.0 to 9.6% of the bore. The swirl ratio at intake valve closing was also varied from 2.60 to 4.27. It was found that the angular momentum of the air at TDC was decreased by less than 8% when the bowl was offset. Nevertheless, the mean (squish and swirl) flows were strongly affected by the offset. In addition, the distribution of turbulent kinetic energy (predicted by the /delta/-e model) was modified. Moderate increases (10% or less) in mass averaged turbulence intensity at TDC with offset were observed.

  11. Investigation on Plasma Jet Flow Phenomena During DC Air Arc Motion in Bridge-Type Contacts

    NASA Astrophysics Data System (ADS)

    Zhai, Guofu; Bo, Kai; Chen, Mo; Zhou, Xue; Qiao, Xinlei

    2016-05-01

    Arc plasma jet flow in the air was investigated under a bridge-type contacts in a DC 270 V resistive circuit. We characterized the arc plasma jet flow appearance at different currents by using high-speed photography, and two polished contacts were used to search for the relationship between roughness and plasma jet flow. Then, to make the nature of arc plasma jet flow phenomena clear, a simplified model based on magnetohydrodynamic (MHD) theory was established and calculated. The simulated DC arc plasma was presented with the temperature distribution and the current density distribution. Furthermore, the calculated arc flow velocity field showed that the circular vortex was an embodiment of the arc plasma jet flow progress. The combined action of volume force and contact surface was the main reason of the arc jet flow. supported by National Natural Science Foundation of China (Nos. 51307030, 51277038)

  12. Air-Sea Interaction Measurements from R/P FLIP

    NASA Astrophysics Data System (ADS)

    Friehe, C. A.

    2002-12-01

    Soon after its inception, R/P FLIP was used to study the interaction of the atmosphere and ocean due to its unique stability and low flow distortion. A number of campaigns have been conducted to measure the surface fluxes of heat, water vapor and horizontal momentum of the wind with instrumentation as used over land, supported by the Office of Naval Research and the National Science Foundation. The size of FLIP allows for simultaneous ocean wave and mixed-layer measurements as well. Air-sea interaction was a prime component of BOMEX in 1968, where FLIP transited the Panama Canal. The methods used were similar to the over-land "Kansas" experiment of AFCRL in 1968. BOMEX was followed by many experiments in the north Pacific off San Diego, northern California, and Hawaii. Diverse results from FLIP include identification of the mechanism that causes erroneous fluctuating temperature measurements in the salt-aerosol-laden marine atmosphere, the role of humidity on optical refractive index fluctuations, and identification of Miles' critical layer in the air flow over waves.

  13. Evaluation of a hybrid system for three-dimensional measurement of trunk posture in motion.

    PubMed

    Plamondon, A; Delisle, A; Larue, C; Brouillette, D; McFadden, D; Desjardins, P; Larivière, C

    2007-11-01

    Ambulatory assessment of trunk posture is important in improving our understanding of the risk of low back injury. Recently, small inertial sensors combining accelerometers, gyroscopes and magnetometers were developed and appear to be promising for measuring human movement. However, the validity of such sensors for assessing three-dimensional (3D) trunk posture in motion has not been documented. The purpose of this study was to evaluate a hybrid system (HS) composed of two inertial sensors for the 3D measurement of trunk posture. A secondary purpose was to explore the utility of adding another source of information, a potentiometer, to measure the relative rotation between both sensors in order to improve the validity of the system. The first sensor was placed over the sacrum and the second on the upper part of the thorax. Both sensors were linked by a flexible rod with a potentiometer. A complementary quaternion filter algorithm was used to estimate trunk orientation by taking advantage of the nine components of each sensor and the potentiometer. The HS's orientations were compared to those obtained from a 3D optoelectronic system. Validation of the HS was performed in three steps in which six subjects had to perform manual handling tasks in: (1) static postures; (2) dynamic motions of short duration (30s); and (3) dynamic motions of long duration (30min). The results showed that the root mean square (RMS) error of the HS was generally below 3 degrees for the flexion and lateral bending axes, and less than 6 degrees for the torsion axis, and that this error was lower for the short-duration tests compared to the long-duration one. The potentiometer proved to be an essential addition, particularly when the magnetometer signals were corrupted and only the gyroscope and accelerometer could be combined. It is concluded that the HS can be a useful tool for quantifying 3D trunk posture in motion. PMID:17382283

  14. The influence of forward speed on ship motions in abnormal waves: Experimental measurements and numerical predictions

    NASA Astrophysics Data System (ADS)

    Bennett, S. S.; Hudson, D. A.; Temarel, P.

    2013-05-01

    Ship encounters with abnormal waves are increasingly well documented and it is therefore important to be able to model such encounters in order to assess the risks involved and whether there is a requirement for more stringent design rules.This paper presents the results of an experimental investigation into the influence of abnormal waves on a vessel travelling with forward speed in irregular seas. The vessel studied in this case is a naval frigate travelling at a range of speeds. To put the motions measured in abnormal waves into context comparisons are made to those in random seas with a variety of significant wave heights, both non-severe and severe. A further objective is to compare experimental measurements with motion predictions from both a two-dimensional linear strip theory and a three-dimensional partly nonlinear seakeeping model.Results demonstrate that abnormal waves may not necessarily be the worst conditions that a ship can encounter. However, accelerations derived from the rigid body motions appear to be in excess of rules values. This has implications for design due to the unexpected nature of abnormal wave occurrence and the consequent likelihood of encountering such a wave at a higher speed (hence in a more severe operating condition) than a random sea of an equivalent height.The three-dimensional partly nonlinear model demonstrates improved agreement with experimental measurements of rigid body motions, compared to the two-dimensional strip theory. It is therefore considered to have greater potential as a design tool for abnormal wave encounters. Further validation with a wide range of sea states and vessel types is required.

  15. Measuring both Rotational and Translational Ground-Motions from Explosions and Local Earthquakes in Taiwan

    NASA Astrophysics Data System (ADS)

    Huang, B.; Lee, W.; Lin, C.; Liu, C.; Shin, T.; Teng, T.; Wu, C.

    2008-12-01

    Since rotational motions can "contaminate" translational ground-motion measurements due to the induced perturbation of the Earth's gravitational field, we started a program to measure rotational ground motions near Hualien (Taiwan) in December, 2000. However, no useful data were obtained after 3 years, until a rotational sensor of much higher sensitivity was deployed at the HGSD station in eastern Taiwan in December, 2004. Rotational and translational seismograms were obtained from several hundred local earthquakes. As noted by several authors before, we found a linear relationship between peak rotational rate (PRR in mrad/s) and peak ground acceleration (PGA in m/s2) from local earthquakes in Taiwan: PRR = 0.002 + 1.301 PGA, with a correlation coefficient of 0.988. Taking advantage of two large explosions of the TAIGER Active Seismic Experiment, we deployed 13 accelerometers and 8 rotational sensors within 600 m from the N3 shot points and obtained some interesting results, which will be presented by Langston et al. in this Session. In December, 2007, we began an instrument array deployment along the Meishan fault in southwestern Taiwan, where a major earthquake occurred in 1906 with surface rupture of more than 12 km long. The deployed instruments are: (1) a 32-element seismic array in free-field, (2) a 32-element accelerometer array in a building, (3) a six-channel unit with a low-gain broadband seismometer and an accelerometer, and (4) two six-channel units with an accelerometer and an external rotational senor. We have 8 rotational sensors now deployed in Taiwan and seven new rotational sensors are scheduled for deployment soon in a program to assess the effect of ground rotation on traditional measurements of translational strong ground motions.

  16. Autocorrelation spectra of an air-fluidized granular system measured by NMR

    NASA Astrophysics Data System (ADS)

    Lasic, S.; Stepisnik, J.; Mohoric, A.; Sersa, I.; Planinsic, G.

    2006-09-01

    A novel insight into the dynamics of a fluidized granular system is given by a nuclear magnetic resonance method that yields the spin-echo attenuation proportional to the spectrum of the grain positional fluctuation. Measurements of the air-fluidized oil-filled spheres and mustard seeds at different degrees of fluidization and grain volume fractions provide the velocity autocorrelation that differs from the commonly anticipated exponential Enskog decay. An empiric formula, which corresponds to the model of grain caging at collisions with adjacent beads, fits well to the experimental data. Its parameters are the characteristic collision time, the free path between collisions and the cage-breaking rate or the diffusion-like constant, which decreases with increasing grain volume fraction. Mean-squared displacements calculated from the correlation spectrum clearly show transitions from ballistic, through sub-diffusion and into diffusion regimes of grain motion.

  17. Repeatability of kinematic and electromyographical measures during standing and trunk motion: how many trials are sufficient?

    PubMed

    Schinkel-Ivy, Alison; DiMonte, Stephen; Drake, Janessa D M

    2015-04-01

    Previous studies have recommended a minimum of five trials to produce repeatable kinematic and electromyography (EMG) measures during target postures or contraction levels. This study aimed to evaluate the repeatability and reliability of kinematic and EMG measures that are of primary interest in the investigation of trunk movement, and to determine the number of trials required to achieve repeatability and reliability for these measures. Thirty participants performed ten trials of upright standing and maximum trunk ranges-of-motion. Mean (upright standing) and maximum (movement tasks) kinematic and EMG measures were assessed using intraclass correlation coefficients and standard error of measurement, which were used to identify the minimum number of trials for each measure. The repeatability and reliability of the measures were generally high, with 64%, 77%, 85%, and 92% of measures producing repeatable and reliable values with two, three, four, and five trials, respectively. Ten trials were not sufficient for several upright standing angle measures and maximum twist lumbar angles. Further, several abdominal muscles during maximum flexion, as well as the left lower-thoracic erector spinae during maximum twist, required as many as five trials. These measures were typically those with very small amounts of motion, or muscles that did not act in the role of prime mover. These results suggest that as few as two trials may be sufficient for many of the kinematic and EMG measures of primary interest in the investigation of trunk movement, while the collection of four trials should produce repeatable and reliable values for over 80% of measures. These recommendations are intended to provide an acceptable trade-off between repeatable and reliable values and feasibility of the collection protocol. PMID:25661241

  18. The impact of European measures to reduce air pollutants on air quality, human health and climate

    NASA Astrophysics Data System (ADS)

    Turnock, S.; Butt, E. W.; Richardson, T.; Mann, G.; Forster, P.; Haywood, J. M.; Crippa, M.; Janssens-Maenhout, G. G. A.; Johnson, C.; Bellouin, N.; Spracklen, D. V.; Carslaw, K. S.; Reddington, C.

    2015-12-01

    European air quality legislation has reduced emissions of air pollutants across Europe since the 1970s, resulting in improved air quality and benefits to human health but also an unintended impact on regional climate. Here we used a coupled chemistry-climate model and a new policy relevant emission scenario to determine the impact of air pollutant emission reductions over Europe. The emission scenario shows that a combination of technological improvements and end-of-pipe abatement measures in the energy, industrial and road transport sectors reduced European emissions of sulphur dioxide, black carbon and organic carbon by 53%, 59% and 32% respectively. We estimate that these emission reductions decreased European annual mean concentrations of fine particulate matter (PM2.5) by 35%, sulphate by 44%, black carbon (BC) by 56% and particulate organic matter (POM) by 23%. The reduction in PM2.5 concentrations is calculated to have prevented 107,000 (40,000-172,000, 5-95% confidence intervals) premature deaths annually from cardiopulmonary disease and lung cancer across the EU member states. The decrease in aerosol concentrations caused a positive all-sky aerosol radiative forcing at the top of atmosphere over Europe of 2.3±0.06 W m-2 and a positive clear-sky forcing of 1.7±0.05 W m-2. Additionally, the amount of solar radiation incident at the surface over Europe increased by 3.3±0.07 W m-2 under all-sky and by 2.7±0.05 W m-2 under clear-sky conditions. Reductions in BC concentrations caused a 1 Wm-2 reduction in atmospheric absorption. We use an energy budget approximation to show that the aerosol induced radiative changes caused both temperature and precipitation to increase globally and over Europe. Our results show that the implementation of European legislation to reduce the emission of air pollutants has improved air quality and human health over Europe, as well as altered the regional radiative balance and climate.

  19. Climatology of Vertical Air Motion During Rainfall in Niamey, Niger and Black Forest, Germany using an Innovative Cloud Radar Retrieval Technique

    NASA Astrophysics Data System (ADS)

    Luke, E. P.; Giangrande, S. E.; Kollias, P.

    2008-12-01

    In recent years, the DOE Atmospheric Radiation Measurement (ARM) program has deployed its ARM Mobile Facility (AMF) to collect continuous measurements in several climatologically distinct locations, including a year-long stay in Niamey, Niger and eight months in Germany's Black Forest. The AMF includes a vertically pointing 95 GHz cloud radar, a tool of choice for profiling non-precipitating clouds at high spatial and temporal resolutions, but commonly considered poorly suited to the quantitative study of precipitation, due in large part to attenuation. However, an innovative technique first explored by Lhermitte in the late 1980s, and subsequently by others, sidesteps much of the quantitative uncertainty imposed by attenuation by exploiting non-Rayleigh resonance effects of scattering from raindrops at 95 GHz. Given a modest range of suitable drop sizes, non-Rayleigh resonances appear as distinct peaks and valleys in Doppler spectra, which once identified, can be directly mapped to known drop sizes by Mie theory. Although attenuation in rain at 95 GHz is substantial, key to the technique is that all non-Rayleigh peaks and valleys in a given Doppler spectrum are affected equally, preserving their relative positions and magnitudes (barring feature extinction). Vertical air motion is retrieved very accurately by taking the difference between the measured Doppler velocity of a resonance feature (usually the first valley) and the known terminal velocity of its associated drop size. We have achieved promising retrieval accuracies at spatial and temporal resolutions of 30 meters and 2 seconds. Here we present lessons learned when the retrieval technique is automated and applied to measurements taken in rain over the full durations of the Niamey and Black Forest AMF deployments, comparing vertical air velocity patterns of monsoonal precipitation over the African desert with those of the orographically influenced precipitation in Germany's mountains.

  20. Analysis of visual acuity and motion resolvability as measures for optimal visual perception of the workspace.

    PubMed

    Janabi-Sharifi, Farrokh; Vakanski, Aleksandar

    2011-03-01

    For working tasks with high visual demand, ergonomic design of the working stations requires defining criteria for comparative evaluation and analysis of the visual perceptibility in different regions of the workspace. This paper provides kinematic models of visual acuity and motion resolvability as adopted measures of visual perceptibility of the workspace. The proposed models have been examined through two sets of experiments. The first experiment is designed to compare the models outputs with those from experiments. Time measurements of the participants' response to visual events are employed for calculation of the perceptibility measures. The overall comparison results show similar patterns and moderate statistical errors of the measured and kinematically modeled values of the parameters. In the second experiment, the proposed set of visual perceptibility measures are examined for a simulated industrial task of inserting electronic chips into slots of a working table, resembling a fine assembly line of transponders manufacturing. The results from ANOVA tests for the visual acuity and the motion resolvability justify the postures adopted by the participants using visual perceptibility measures for completing the insertion tasks. PMID:20947063

  1. Gage cookbook: Tools and techniques to measure stresses and motions on explosive experiments

    SciTech Connect

    Smith, C.W.

    1996-01-01

    Tools and techniques developed to measure stresses and motions on underground nuclear and high explosive tests in the tuff geologies at the Nevada Test Site are described in this document. The thrust of the measurements was to understand containment phenomenology. The authors concentrate on the fluid-coupled ytterbium gage; it was fielded to measure dynamic stress in the 0.2 to 20 kilobar range and the subsequent, low amplitude residual stress. Also described are accelerometer packages; their traces were integrated to obtain particle motion. Various cable survival techniques were investigated with field measurements for they wished to extend the measurements to late-time. Field measurements were also made to address the gage inclusion problem. Work to date suggests that the problem is a minimum when the stress level is above the yield strength of the host rock and grout. Below the yield level stress amplitudes in the grouted hole can range from 60 to 200% of the stress in the host rock.

  2. Measuring the proper motions of the Large and Small Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Ellingsen, Simon; Macquart, Jean-Pierre; Bignall, Hayley; Breen, Shari; Reynolds, Cormac; Imai, Hiroshi; Keller, Stefan; Bekki, Kenji; Krishnan, Vasaant; Cioni, Maria-Rosa

    2013-10-01

    Interactions between galaxies are known to play a key role in their evolution throughout cosmic history. Studies of past and current interactions between Local Group galaxies provide us with a unique opportunity to investigate the key factors and effects of such interactions at high resolution and sensitivity. Our understanding of the interaction of the Large and Small Magellanic Clouds (LMC & SMC) with each other and with the Milky Way (MW) have changed dramatically in the last decade due to the determination of the proper motions of the LMC and SMC from optical studies. The derived proper motions predict a history of interaction for the Clouds that is at odds with the leading and trailing arms of Magellanic Stream gas. This proposal is a companion to an LBA project to measure the proper motions of both the Large and Small Magellanic Clouds. Observations to measure the flux density of the potential maser targets a few weeks prior to an LBA observation will enable us to tailor the observing strategy to maximise the observational sensitivity and hence the astrometric accuracy.

  3. Measuring the proper motions of the Large and Small Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Ellingsen, Simon; Macquart, Jean-Pierre; Bignall, Hayley; Breen, Shari; Reynolds, Cormac; Imai, Hiroshi; Keller, Stefan; Bekki, Kenji; Krishnan, Vasaant; Cioni, Maria-Rosa

    2013-04-01

    Interactions between galaxies are known to play a key role in their evolution throughout cosmic history. Studies of past and current interactions between Local Group galaxies provide us with a unique opportunity to investigate the key factors and effects of such interactions at high resolution and sensitivity. Our understanding of the interaction of the Large and Small Magellanic Clouds (LMC & SMC) with each other and with the Milky Way (MW) have changed dramatically in the last decade due to the determination of the proper motions of the LMC and SMC from optical studies. The derived proper motions predict a history of interaction for the Clouds that is at odds with the leading and trailing arms of Magellanic Stream gas. This proposal is a companion to an LBA project to measure the proper motions of both the Large and Small Magellanic Clouds. Observations to measure the flux density of the potential maser targets a few weeks prior to an LBA observation will enable us to tailor the observing strategy to maximise the observational sensitivity and hence the astrometric accuracy.

  4. Measuring the proper motions of the Large and Small Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Ellingsen, Simon; Macquart, Jean-Pierre; Bignall, Hayley; Beasley, Tony; Breen, Shari; Reynolds, Cormac; Imai, Hiroshi; Keller, Stefan; Bekki, Kenji; Krishnan, Vasaant; Cioni, Maria-Rosa

    2014-04-01

    Interactions between galaxies are known to play a key role in their evolution throughout cosmic history. Studies of past and current interactions between Local Group galaxies provide us with a unique opportunity to investigate the key factors and effects of such interactions at high resolution and sensitivity. Our understanding of the interaction of the Large and Small Magellanic Clouds (LMC & SMC) with each other and with the Milky Way (MW) have changed dramatically in the last decade due to the determination of the proper motions of the LMC and SMC from optical studies. The derived proper motions predict a history of interaction for the Clouds that is at odds with the leading and trailing arms of Magellanic Stream gas. This proposal is a companion to an LBA project to measure the proper motions of both the Large and Small Magellanic Clouds. Observations to measure the flux density of the potential maser targets a few weeks prior to an LBA observation will enable us to tailor the observing strategy to maximise the observational sensitivity and hence the astrometric accuracy.

  5. Performance Evaluation of Smartphone Inertial Sensors Measurement for Range of Motion.

    PubMed

    Mourcou, Quentin; Fleury, Anthony; Franco, Céline; Klopcic, Frédéric; Vuillerme, Nicolas

    2015-01-01

    Over the years, smartphones have become tools for scientific and clinical research. They can, for instance, be used to assess range of motion and joint angle measurement. In this paper, our aim was to determine if smartphones are reliable and accurate enough for clinical motion research. This work proposes an evaluation of different smartphone sensors performance and different manufacturer algorithm performances with the comparison to the gold standard, an industrial robotic arm with an actual standard use inertial motion unit in clinical measurement, an Xsens product. Both dynamic and static protocols were used to perform these comparisons. Root Mean Square (RMS) mean values results for static protocol are under 0.3° for the different smartphones. RMS mean values results for dynamic protocol are more prone to bias induced by Euler angle representation. Statistical results prove that there are no filter effect on results for both protocols and no hardware effect. Smartphones performance can be compared to the Xsens gold standard for clinical research. PMID:26389900

  6. Two modes of motion of the alligator lizard cochlea: Measurements and model predictions

    NASA Astrophysics Data System (ADS)

    Aranyosi, A. J.; Freeman, Dennis M.

    2005-09-01

    Measurements of motion of an in vitro preparation of the alligator lizard basilar papilla in response to sound demonstrate elliptical trajectories. These trajectories are consistent with the presence of both a translational and rotational mode of motion. The translational mode is independent of frequency, and the rotational mode has a displacement peak near 5 kHz. These measurements can be explained by a simple mechanical system in which the basilar papilla is supported asymmetrically on the basilar membrane. In a quantitative model, the translational admittance is compliant while the rotational admittance is second order. Best-fit model parameters are consistent with estimates based on anatomy and predict that fluid flow across hair bundles is a primary source of viscous damping. The model predicts that the rotational mode contributes to the high-frequency slopes of auditory nerve fiber tuning curves, providing a physical explanation for a low-pass filter required in models of this cochlea. The combination of modes makes the sensitivity of hair bundles more uniform with radial position than that which would result from pure rotation. A mechanical analogy with the organ of Corti suggests that these two modes of motion may also be present in the mammalian cochlea.

  7. Performance Evaluation of Smartphone Inertial Sensors Measurement for Range of Motion

    PubMed Central

    Mourcou, Quentin; Fleury, Anthony; Franco, Céline; Klopcic, Frédéric; Vuillerme, Nicolas

    2015-01-01

    Over the years, smartphones have become tools for scientific and clinical research. They can, for instance, be used to assess range of motion and joint angle measurement. In this paper, our aim was to determine if smartphones are reliable and accurate enough for clinical motion research. This work proposes an evaluation of different smartphone sensors performance and different manufacturer algorithm performances with the comparison to the gold standard, an industrial robotic arm with an actual standard use inertial motion unit in clinical measurement, an Xsens product. Both dynamic and static protocols were used to perform these comparisons. Root Mean Square (RMS) mean values results for static protocol are under 0.3° for the different smartphones. RMS mean values results for dynamic protocol are more prone to bias induced by Euler angle representation. Statistical results prove that there are no filter effect on results for both protocols and no hardware effect. Smartphones performance can be compared to the Xsens gold standard for clinical research. PMID:26389900

  8. Direct measurements of magnetic interaction-induced cross-correlations of two microparticles in Brownian motion

    PubMed Central

    Romodina, Maria N.; Khokhlova, Maria D.; Lyubin, Evgeny V.; Fedyanin, Andrey A.

    2015-01-01

    The effect of magnetic interactions on the Brownian motion of two magnetic microparticles is investigated. The cross-correlations of the thermal fluctuations of the two magnetic microbeads are directly measured using double-trap optical tweezers. It is experimentally demonstrated that the cross-correlation function is governed by the gradient of the magnetic force between the microparticles. The magnetic forces are measured with femtonewton precision, and the magnetic dipole moments of individual microparticles are determined within an accuracy on the order of fA-m2. PMID:26035153

  9. Correction of motion measurement errors beyond the range resolution of a synthetic aperture radar

    SciTech Connect

    Doerry, Armin W.; Heard, Freddie E.; Cordaro, J. Thomas

    2008-06-24

    Motion measurement errors that extend beyond the range resolution of a synthetic aperture radar (SAR) can be corrected by effectively decreasing the range resolution of the SAR in order to permit measurement of the error. Range profiles can be compared across the slow-time dimension of the input data in order to estimate the error. Once the error has been determined, appropriate frequency and phase correction can be applied to the uncompressed input data, after which range and azimuth compression can be performed to produce a desired SAR image.

  10. Measurements of reduced corkscrew motion on the ETA-II linear induction accelerator

    SciTech Connect

    Allen, S.L.; Brand, H.R.; Chambers, F.W.; Chen, Y.J.; Coffield, F.E.; Deadrick, F.J.; Griffith, L.V.; Lager, D.L.; Mauer, W.J.; Nexsen, W.E.; Paul, A.C.; Sampayan, S.; Turner, W.C.

    1991-05-01

    The ETA-II linear induction accelerator is used to drive a microwave free electron laser (FEL). Corkscrew motion, which previously limited performance, has been reduced by: (1) an improved pulse distribution system which reduces energy sweep, (2) improved magnetic alignment achieved with a stretched wire alignment technique (SWAT) and (3) a unique magnetic tuning algorithm. Experiments have been carried out on a 20-cell version of ETA-II operating at 1500 A and 2.7 MeV. The measured transverse beam motion is less than 0.5 mm for 40 ns of the pulse, an improvement of a factor of 2 to 3 over previous results. Details of the computerized tuning procedure, estimates of the corkscrew phase, and relevance of these results to future FEL experiments are presented. 11 refs.

  11. Error motion compensating tracking interferometer for the position measurement of objects with rotational degree of freedom

    NASA Astrophysics Data System (ADS)

    Holler, Mirko; Raabe, Jörg

    2015-05-01

    The nonaxial interferometric position measurement of rotating objects can be performed by imaging the laser beam of the interferometer to a rotating mirror which can be a sphere or a cylinder. This, however, requires such rotating mirrors to be centered on the axis of rotation as a wobble would result in loss of the interference signal. We present a tracking-type interferometer that performs such measurement in a general case where the rotating mirror may wobble on the axis of rotation, or even where the axis of rotation may be translating in space. Aside from tracking, meaning to measure and follow the position of the rotating mirror, the interferometric measurement errors induced by the tracking motion of the interferometer itself are optically compensated, preserving nanometric measurement accuracy. As an example, we show the application of this interferometer in a scanning x-ray tomography instrument.

  12. Acoustic levitator for contactless motion and merging of large droplets in air

    NASA Astrophysics Data System (ADS)

    Bjelobrk, Nada; Nabavi, Majid; Poulikakos, Dimos

    2012-09-01

    Large droplet transport in a line-focussed acoustic manipulator in terms of maximum droplet size is achieved by employing a driving voltage control mechanism. The maximum volume of the transported droplets in the order of few microliters is thereby increased by three orders of magnitude compared to the constant voltage case, widening the application field of this method significantly. A drop-on-demand droplet generator is used to supply the liquid droplets into the system. The ejected sequence of picoliter-size droplets is guided along trajectories by the acoustic field and accumulates at the selected pressure node, merging into a single large droplet. Droplet movement is achieved by varying the reflector height. This also changes the intensity of the radiation pressure during droplet movement, which in turn could atomise the droplet. The acoustic force is adjusted by regulating the driving voltage of the actuator to keep the liquid droplet suspended in air and to prevent atomisation. In the herein presented levitation concept, liquids with a wide range of surface tension (water and tetradecane were tested) can be transported over distances of several mm. The aspect ratio of the droplet in the acoustic field is shown to be a good indicator for radiation pressure intensity and is kept between 1.1 and 1.4 during droplet transport. Despite certain limitations with volatile liquids, the presented acoustic levitator concept has the potential to expand the range of analytical characterisation and manipulation methods in applications ranging from chemistry and biology.

  13. Inertial sensors as measurement tools of elbow range of motion in gerontology

    PubMed Central

    Sacco, G; Turpin, JM; Marteu, A; Sakarovitch, C; Teboul, B; Boscher, L; Brocker, P; Robert, P; Guerin, O

    2015-01-01

    Background and purpose Musculoskeletal system deterioration among the aging is a major reason for loss of autonomy and directly affects the quality of life of the elderly. Articular evaluation is part of physiotherapeutic assessment and helps in establishing a precise diagnosis and deciding appropriate therapy. Reference instruments are valid but not easy to use for some joints. The main goal of our study was to determine reliability and intertester reproducibility of the MP-BV, an inertial sensor (the MotionPod® [MP]) combined with specific software (BioVal [BV]), for elbow passive range-of-motion measurements in geriatrics. Methods This open, monocentric, randomized study compared inertial sensor to inclinometer in patients hospitalized in an acute, post-acute, and long-term-care gerontology unit. Results Seventy-seven patients (mean age 83.5±6.4 years, sex ratio 1.08 [male/female]) were analyzed. The MP-BV was reliable for each of the three measurements (flexion, pronation, and supination) for 24.3% (CI 95% 13.9–32.8) of the patients. Separately, the percentages of reliable measures were 59.7% (49.2–70.5) for flexion, 68.8% (58.4–79.5) for pronation, and 62.3% (51.2–73.1) for supination. The intraclass correlation coefficients were 0.15 (0.07–0.73), 0.46 (0.27–0.98), and 0.50 (0.31–40 0.98) for flexion, pronation, and supination, respectively. Conclusion This study shows the convenience of the MP-BV in terms of ease of use and of export of measured data. However, this instrument seems less reliable and valuable compared to the reference instruments used to measure elbow range of motion in gerontology. PMID:25759568

  14. Measurement of Intervertebral Cervical Motion by Means of Dynamic X-Ray Image Processing and Data Interpolation

    PubMed Central

    Bifulco, Paolo; Cesarelli, Mario; Romano, Maria; Sansone, Mario

    2013-01-01

    Accurate measurement of intervertebral kinematics of the cervical spine can support the diagnosis of widespread diseases related to neck pain, such as chronic whiplash dysfunction, arthritis, and segmental degeneration. The natural inaccessibility of the spine, its complex anatomy, and the small range of motion only permit concise measurement in vivo. Low dose X-ray fluoroscopy allows time-continuous screening of cervical spine during patient's spontaneous motion. To obtain accurate motion measurements, each vertebra was tracked by means of image processing along a sequence of radiographic images. To obtain a time-continuous representation of motion and to reduce noise in the experimental data, smoothing spline interpolation was used. Estimation of intervertebral motion for cervical segments was obtained by processing patient's fluoroscopic sequence; intervertebral angle and displacement and the instantaneous centre of rotation were computed. The RMS value of fitting errors resulted in about 0.2 degree for rotation and 0.2 mm for displacements. PMID:24288523

  15. A guide for upper-air reference measurements

    NASA Astrophysics Data System (ADS)

    Immler, F.; Dykema, J.; Gardiner, T.; Whiteman, D. N.; Thorne, P. W.; Vömel, H.

    2010-04-01

    The accurate monitoring of climate change imposes strict requirements upon observing systems, in particular regarding measurement accuracy and long-term stability. Currently available data records of the essential climate variables (temperature-T, geopotential-p, humidity-RH, wind, and cloud properties) in the upper-air generally fail to fulfill such requirements. This raises serious issues about the ability to detect, quantify and understand recent climate changes and their causes. GCOS is currently implementing a Reference Upper-Air Network (GRUAN) in order to fill this major void within the global observing system. As part of the GRUAN implementation plan we provide herein fundamental guidelines for establishing and maintaining reference quality atmospheric observations which are based on principal concepts of metrology, in particular traceability. It is argued that the detailed analysis of the uncertainty budget of a measurement technique is the critical step for achieving this goal. As we will demonstrate with an example, detailed knowledge of the calibration procedures and data processing algorithms are required for determining the uncertainty of each individual data point. Of particular importance is the careful assessment of the uncertainties introduced by correction schemes adjusting for systematic effects.

  16. Projection Moire Interferometry Measurements of Micro Air Vehicle Wings

    NASA Technical Reports Server (NTRS)

    Fleming, Gary A.; Bartram, Scott M.; Waszak, Martin R.; Jenkins, Luther N.

    2001-01-01

    Projection Moire Interferometry (PMI) has been used to measure the structural deformation of micro air vehicle (MAV) wings during a series of wind tunnel tests. The MAV wings had a highly flexible wing structure, generically reminiscent of a bat s wing, which resulted in significant changes in wing shape as a function of MAV angle-of-attack and simulated flight speed. This flow-adaptable wing deformation is thought to provide enhanced vehicle stability and wind gust alleviation compared to rigid wing designs. Investigation of the potential aerodynamic benefits of a flexible MAV wing required measurement of the wing shape under aerodynamic loads. PMI was used to quantify the aerodynamically induced changes in wing shape for three MAV wings having different structural designs and stiffness characteristics. This paper describes the PMI technique, its application to MAV testing, and presents a portion of the PMI data acquired for the three different MAV wings tested.

  17. Projection moire interferometry measurements of micro air vehicle wings

    NASA Astrophysics Data System (ADS)

    Fleming, Gary A.; Bartram, Scott M.; Waszak, Martin R.; Jenkins, Luther N.

    2001-11-01

    Projection Moire Interferometry (PMI) has been used to measure the structural deformation of micro air vehicle (MAV) wings during a series of wind tunnel tests. The MAV wings had a highly flexible wing structure, generically reminiscent of a bat's wing, which resulted in significant changes in wing shape as a function of MAV angle-of-attack and simulated flight speed. This flow-adaptable wing deformation is thought to provide enhanced vehicle stability and wind gust alleviation compared to rigid wing designs. Investigation of the potential aerodynamic benefits of a flexible MAV wing required measurement of the wing shape under aerodynamic loads. PMI was used to quantify the aerodynamically induced changes in wing shape for three MAV wings having different structural designs and stiffness characteristics. This paper describes the PMI technique, its application to MAV testing, and presents a portion of the PMI data acquired for the three different MAV wings tested.

  18. High performance target measurement flights from Vandenberg Air Force Base

    NASA Astrophysics Data System (ADS)

    Chalfant, C. P.; Rosen, H.; Jerger, J. H.

    A description is presented of a new launch facility which is being prepared for the High Performance Target Measurement (HPTEM) booster at Vandenberg Air Force Base (VAFB). A deactivated Atlas launch complex is currently being modified to allow the rocket to be launched from a semisilo. The underground launch operations building will contain a new control center and instrumentation room. Attention is given to the Multi-Spectral Measurement Program (MSMP), details concerning the launch facility, and a target and flight safety trajectory analysis. Construction and modification of the facility is scheduled to be completed in mid-1983. The first HPTEM launch is planned to occur in April 1984. The HPTEM launch facility can also be utilized to launch Aries I (single stage) and Aries II (two-stage) probes with minor modification.

  19. Air toxics being measured more accurately, controlled more effectively

    SciTech Connect

    1995-04-01

    In response to the directives of the Clean Air Act Amendments, Argonne National Laboratory is developing new or improved pollutant control technologies for industries that burn fossil fuels. This research continues Argonne`s traditional support for the US DOE Flue Gas Cleanup Program. Research is underway to measure process emissions and identify new and improved control measures. Argonne`s emission control research has ranged from experiments in the basic chemistry of pollution-control systems, through laboratory-scale process development and testing to pilot-scale field tests of several technologies. Whenever appropriate, the work has emphasized integrated or combined control systems as the best approach to technologies that offer low cost and good operating characteristics.

  20. A New Ground Motion Intensity Measure, Peak Filtered Acceleration (PFA), to Estimate Collapse Vulnerability of Buildings in Earthquakes

    NASA Astrophysics Data System (ADS)

    Song, Shiyan

    In this thesis, we develop an efficient collapse prediction model, the PFA (Peak Filtered Acceleration) model, for buildings subjected to different types of ground motions. For the structural system, the PFA model covers modern steel and reinforced concrete moment-resisting frame buildings (potentially reinforced concrete shear wall buildings). For ground motions, the PFA model covers ramp-pulse-like ground motions, long-period ground motions, and short-period ground motions. To predict whether a building will collapse in response to a given ground motion, we first extract long-period components from the ground motion using a Butterworth low-pass filter with suggested order and cutoff frequency. The order depends on the type of ground motion, and the cutoff frequency depends on the building's natural frequency and ductility. We then compare the filtered acceleration time history with the capacity of the building. The capacity of the building is a constant for 2-dimentional buildings and a limit domain for 3-dimentional buildings. If the filtered acceleration exceeds the building's capacity, the building is predicted to collapse. Otherwise, it is expected to survive the ground motion. The parameters used in PFA model, which include fundamental period, global ductility and lateral capacity, can be obtained either from numerical analysis or interpolation based on the reference building system proposed in this thesis. The PFA collapse prediction model greatly reduces computational complexity while archiving good accuracy. It is verified by FEM simulations of 13 frame building models and 150 ground motion records. Based on the developed collapse prediction model, we propose to use PFA (Peak Filtered Acceleration) as a new ground motion intensity measure for collapse prediction. We compare PFA with traditional intensity measures PGA, PGV, PGD, and Sa in collapse prediction and find that PFA has the best performance among all the intensity measures. We also provide a

  1. Validation of Attitude and Heading Reference System and Microsoft Kinect for Continuous Measurement of Cervical Range of Motion Compared to the Optical Motion Capture System

    PubMed Central

    2016-01-01

    Objective To compare optical motion capture system (MoCap), attitude and heading reference system (AHRS) sensor, and Microsoft Kinect for the continuous measurement of cervical range of motion (ROM). Methods Fifteen healthy adult subjects were asked to sit in front of the Kinect camera with optical markers and AHRS sensors attached to the body in a room equipped with optical motion capture camera. Subjects were instructed to independently perform axial rotation followed by flexion/extension and lateral bending. Each movement was repeated 5 times while being measured simultaneously with 3 devices. Using the MoCap system as the gold standard, the validity of AHRS and Kinect for measurement of cervical ROM was assessed by calculating correlation coefficient and Bland–Altman plot with 95% limits of agreement (LoA). Results MoCap and ARHS showed fair agreement (95% LoA<10°), while MoCap and Kinect showed less favorable agreement (95% LoA>10°) for measuring ROM in all directions. Intraclass correlation coefficient (ICC) values between MoCap and AHRS in –40° to 40° range were excellent for flexion/extension and lateral bending (ICC>0.9). ICC values were also fair for axial rotation (ICC>0.8). ICC values between MoCap and Kinect system in –40° to 40° range were fair for all motions. Conclusion Our study showed feasibility of using AHRS to measure cervical ROM during continuous motion with an acceptable range of error. AHRS and Kinect system can also be used for continuous monitoring of flexion/extension and lateral bending in ordinary range. PMID:27606262

  2. Mobile Air Monitoring: Measuring Change in Air Quality in the City of Hamilton, 2005-2010

    ERIC Educational Resources Information Center

    Adams, Matthew D.; DeLuca, Patrick F.; Corr, Denis; Kanaroglou, Pavlos S.

    2012-01-01

    This paper examines the change in air pollutant concentrations between 2005 and 2010 occurring in the City of Hamilton, Ontario, Canada. After analysis of stationary air pollutant concentration data, we analyze mobile air pollutant concentration data. Air pollutants included in the analysis are CO, PM[subscript 2.5], SO[subscript 2], NO,…

  3. Measuring Sea-Ice Motion in the Arctic with Real Time Photogrammetry

    NASA Astrophysics Data System (ADS)

    Brozena, J. M.; Hagen, R. A.; Peters, M. F.; Liang, R.; Ball, D.

    2014-12-01

    The U.S. Naval Research Laboratory, in coordination with other groups, has been collecting sea-ice data in the Arctic off the north coast of Alaska with an airborne system employing a radar altimeter, LiDAR and a photogrammetric camera in an effort to obtain wide swaths of measurements coincident with Cryosat-2 footprints. Because the satellite tracks traverse areas of moving pack ice, precise real-time estimates of the ice motion are needed to fly a survey grid that will yield complete data coverage. This requirement led us to develop a method to find the ice motion from the aircraft during the survey. With the advent of real-time orthographic photogrammetric systems, we developed a system that measures the sea ice motion in-flight, and also permits post-process modeling of sea ice velocities to correct the positioning of radar and LiDAR data. For the 2013 and 2014 field seasons, we used this Real Time Ice Motion Estimation (RTIME) system to determine ice motion using Applanix's Inflight Ortho software with an Applanix DSS439 system. Operationally, a series of photos were taken in the survey area. The aircraft then turned around and took more photos along the same line several minutes later. Orthophotos were generated within minutes of collection and evaluated by custom software to find photo footprints and potential overlap. Overlapping photos were passed to the correlation software, which selects a series of "chips" in the first photo and looks for the best matches in the second photo. The correlation results are then passed to a density-based clustering algorithm to determine the offset of the photo pair. To investigate any systematic errors in the photogrammetry, we flew several flight lines over a fixed point on various headings, over an area of non-moving ice in 2013. The orthophotos were run through the correlation software to find any residual offsets, and run through additional software to measure chip positions and offsets relative to the aircraft

  4. Gas and liquid measurements in air-water bubbly flows

    SciTech Connect

    Zhou, X.; Doup, B.; Sun, X.

    2012-07-01

    Local measurements of gas- and liquid-phase flow parameters are conducted in an air-water two-phase flow loop. The test section is a vertical pipe with an inner diameter of 50 mm and a height of 3.2 m. The measurements are performed at z/D = 10. The gas-phase measurements are performed using a four-sensor conductivity probe. The data taken from this probe are processed using a signal processing program to yield radial profiles of the void fraction, bubble velocity, and interfacial area concentration. The velocity measurements of the liquid-phase are performed using a state-of-the-art Particle Image Velocimetry (PIV) system. The raw PIV images are acquired using fluorescent particles and an optical filtration device. Image processing is used to remove noise in the raw PIV images. The statistical cross correlation is introduced to determine the axial velocity field and turbulence intensity of the liquid-phase. Measurements are currently being performed at z/D = 32 to provide a more complete data set. These data can be used for computational fluid dynamic model development and validation. (authors)

  5. Vesicle Motion during Sustained Exocytosis in Chromaffin Cells: Numerical Model Based on Amperometric Measurements

    PubMed Central

    Jarukanont, Daungruthai; Bonifas Arredondo, Imelda; Femat, Ricardo; Garcia, Martin E.

    2015-01-01

    Chromaffin cells release catecholamines by exocytosis, a process that includes vesicle docking, priming and fusion. Although all these steps have been intensively studied, some aspects of their mechanisms, particularly those regarding vesicle transport to the active sites situated at the membrane, are still unclear. In this work, we show that it is possible to extract information on vesicle motion in Chromaffin cells from the combination of Langevin simulations and amperometric measurements. We developed a numerical model based on Langevin simulations of vesicle motion towards the cell membrane and on the statistical analysis of vesicle arrival times. We also performed amperometric experiments in bovine-adrenal Chromaffin cells under Ba2+ stimulation to capture neurotransmitter releases during sustained exocytosis. In the sustained phase, each amperometric peak can be related to a single release from a new vesicle arriving at the active site. The amperometric signal can then be mapped into a spike-series of release events. We normalized the spike-series resulting from the current peaks using a time-rescaling transformation, thus making signals coming from different cells comparable. We discuss why the obtained spike-series may contain information about the motion of all vesicles leading to release of catecholamines. We show that the release statistics in our experiments considerably deviate from Poisson processes. Moreover, the interspike-time probability is reasonably well described by two-parameter gamma distributions. In order to interpret this result we computed the vesicles’ arrival statistics from our Langevin simulations. As expected, assuming purely diffusive vesicle motion we obtain Poisson statistics. However, if we assume that all vesicles are guided toward the membrane by an attractive harmonic potential, simulations also lead to gamma distributions of the interspike-time probability, in remarkably good agreement with experiment. We also show that

  6. Effects of line-of-sight motion on hyperspectral Fourier transform measurements

    NASA Astrophysics Data System (ADS)

    Miecznik, Grzegorz; Johnson, Brian R.

    2015-01-01

    Atmospheric spectra reconstructed from interferometric measurements are susceptible to scene motion, which can be caused by changing environment or instrument jitter. This leads to a coupling between the time series of the modulated scene radiance and the interferogram collected as a function of time. Spectral artifacts are generated when this occurs and appear as both narrow, isolated spikes in the measurement wavelength band as well as broad, out-of-band features. Here, we derive an analytical relationship that depends on jitter frequency, amplitude and phase, and the scene gradient. The observed radiance is expressed as a spatially weighted mixture of radiance originating from various points within the scene. Spectral artifacts created by relative scene motion are shown to be proportional to the radiometric scene difference within the instrument field of view (FOV) and jitter amplitude, and vary significantly with the jitter frequency. The analytical solution can be useful in various applications, where image instability is expected to have an effect on measurements in question, ranging from spectroscopy of turbine plumes, through airborne measurements of smoke density and chemical composition in natural fire or volcanic events, to atmospheric sounding from space.

  7. Appearance and disappearance of motional sideband asymmetry in measurement-based control of a mechanical oscillator

    NASA Astrophysics Data System (ADS)

    Sudhir, Vivishek; Wilson, Dalziel; Schilling, Ryan; Schuetz, Hendrik; Nunnenkamp, Andreas; Kippenberg, Tobias

    Measurement-based feedback provides an avenue to study the delicate interplay between the quantum correlations established during the process of measurement, and their progressive obfuscation when exposed to uncorrelated noise in the form of fundamental quantum fluctuations in the feedback path. Here we demonstrate this tradeoff using a feedback strategy whose objective is to cool a nano-mechanical oscillator close to its ground state. The correlations established due to the measurement are revealed in the appearance of motional sideband asymmetry. The latter, faithfully measured using an optical heterodyne interferometer with an imprecision ~17 dB below that at the standard quantum limit, increases to 6% as the oscillator is feedback cooled to an occupation of 15 phonons. Further increase in the gain of the feedback loop leads to a decrease in the asymmetry. This is due to the addition of unavoidable quantum fluctuations in a feedback amplifier - photon shot-noise amplified by a homodyne detector in our case.

  8. Vertical Crustal Motion Derived from Satellite Altimetry and Tide Gauges, and Comparisons with DORIS Measurements

    NASA Technical Reports Server (NTRS)

    Ray, R. D.; Beckley, B. D.; Lemoine, F. G.

    2010-01-01

    A somewhat unorthodox method for determining vertical crustal motion at a tide-gauge location is to difference the sea level time series with an equivalent time series determined from satellite altimetry, To the extent that both instruments measure an identical ocean signal, the difference will be dominated by vertical land motion at the gauge. We revisit this technique by analyzing sea level signals at 28 tide gauges that are colocated with DORIS geodetic stations. Comparisons of altimeter-gauge vertical rates with DORIS rates yield a median difference of 1.8 mm/yr and a weighted root-mean-square difference of2.7 mm/yr. The latter suggests that our uncertainty estimates, which are primarily based on an assumed AR(l) noise process in all time series, underestimates the true errors. Several sources of additional error are discussed, including possible scale errors in the terrestrial reference frame to which altimeter-gauge rates are mostly insensitive, One of our stations, Male, Maldives, which has been the subject of some uninformed arguments about sea-level rise, is found to have almost no vertical motion, and thus is vulnerable to rising sea levels. Published by Elsevier Ltd. on behalf of COSPAR.

  9. Structure-specific scalar intensity measures for near-source and ordinary earthquake ground motions

    USGS Publications Warehouse

    Luco, N.; Cornell, C.A.

    2007-01-01

    Introduced in this paper are several alternative ground-motion intensity measures (IMs) that are intended for use in assessing the seismic performance of a structure at a site susceptible to near-source and/or ordinary ground motions. A comparison of such IMs is facilitated by defining the "efficiency" and "sufficiency" of an IM, both of which are criteria necessary for ensuring the accuracy of the structural performance assessment. The efficiency and sufficiency of each alternative IM, which are quantified via (i) nonlinear dynamic analyses of the structure under a suite of earthquake records and (ii) linear regression analysis, are demonstrated for the drift response of three different moderate- to long-period buildings subjected to suites of ordinary and of near-source earthquake records. One of the alternative IMs in particular is found to be relatively efficient and sufficient for the range of buildings considered and for both the near-source and ordinary ground motions. ?? 2007, Earthquake Engineering Research Institute.

  10. Differential Proper-Motion Measurements of The Cygnus Egg Nebula; The Presence of Fast Equatorial Outflows

    NASA Astrophysics Data System (ADS)

    Tomasino, Rachael; Ueta, T.; Ferguson, B. A.

    2013-01-01

    We present the results of differential proper-motion analyses of the dust shell structure in the Egg Nebula (RAFGL 2688, V1610 Cyg), based on the archived two-epoch imaging-polarimetric data in the optical taken with the Hubble Space Telescope. We measured the amount of motion of local structures and the signature concentric arcs in the nebula by determining their relative shifts over an interval of 7.25 yr. We discovered that the optical polarization characteristics of the Egg Nebula was influenced by the marginal optical thickness of the circumstellar shell and the illumination of the nebula was done in two-step mechanism - most of the nebula is illuminated by the secondary/dust-scattered starlight emanating from the bipolar lobes themselves due to the central concentration of dust grains of more than 10^3 AU diameter that regulates the seepage of the starlight from the central region. Nevertheless, based on two types of differential proper-motion analyses we revealed interesting dynamics of the lobes and concentric arcs, which should provide solid constraints on the subsequent theoretical/numerical investigations.

  11. Differential Proper-Motion Measurements of The Cygnus Egg Nebula; The Presence of Fast Equatorial Outflows

    NASA Astrophysics Data System (ADS)

    Tomasino, Rachael; Ueta, Toshiya; Ferguson, Brian

    2012-10-01

    We present the results of differential proper-motion analyses of the dust shell structure in the Egg Nebula (RAFGL 2688, V1610 Cyg), based on the archived two-epoch imaging-polarimetric data in the optical taken with the Hubble Space Telescope. We measured the amount of motion of local structures and the signature concentric arcs in the nebula by determining their relative shifts over an interval of 7.25 yr. We discovered that the optical polarization characteristics of the Egg Nebula was influenced by the marginal optical thickness of the circumstellar shell and the illumination of the nebula was done in two-step mechanism - most of the nebula is illuminated by the secondary/dust-scattered starlight emanating from the bipolar lobes themselves due to the central concentration of dust grains of more than 10^3 AU diameter that regulates the seepage of the starlight from the central region. Nevertheless, based on two types of differential proper-motion analyses we revealed interesting dynamics of the lobes and concentric arcs, which should provide solid constraints on the subsequent theoretical/numerical investigations.

  12. SU-C-210-04: Considerable Pancreatic Tumor Motion During Breath-Hold Measured Using Intratumoral Fiducials On Fluoroscopic Movies

    SciTech Connect

    Lens, E; Horst, A van der; Versteijne, E; Tienhoven, G van; Bel, A

    2015-06-15

    Purpose: Using a breath hold (BH) technique during radiotherapy of pancreatic tumors is expected to reduce intra-fractional motion. The aim of this study was to evaluate the tumor motion during BH. Methods: In this pilot study, we included 8 consecutive pancreatic cancer patients. All had 2– 4 intratumoral gold fiducials. Patients were asked to perform 3 consecutive 30-second end-inhale BHs on day 5, 10 and 15 of their three-week treatment. During BH, airflow through a mouthpiece was measured using a spirometer. Any inadvertent flow of air during BH was monitored for all patients. We measured tumor motion on lateral fluoroscopic movies (57 in total) made during BH. In each movie the fiducials as a group were tracked over time in superior-inferior (SI) and anterior-posterior (AP) direction using 2-D image correlation between consecutive frames. We determined for each patient the range of intra-BH motion over all movies; we also determined the absolute means and standard deviations (SDs) for the entire patient group. Additionally, we investigated the relation between inadvertent airflow during BH and the intra-BH motion. Results: We found intra-BH tumor motion of up to 12.5 mm (range, 1.0–12.5 mm) in SI direction and up to 8.0 mm (range, 1.0–8.0 mm) in AP direction. The absolute mean motion over the patient population was 4.7 (SD: 3.0) mm and 2.8 (SD: 1.2) mm in the SI and AP direction, respectively. Patients were able to perform stable consecutive BHs; during only 20% of the movies we found very small airflows (≤ 65 ml). These were mostly stepwise in nature and could not explain the continuous tumor motions we observed. Conclusion: We found substantial (up to 12.5 mm) pancreatic tumor motion during BHs. We found minimal inadvertent airflow, seen only during a minority of BHs, and this did not explain the obtained results. This work was supported by the foundation Bergh in het Zadel through the Dutch Cancer Society (KWF Kankerbestrijding) project No. UVA 2011-5271.

  13. Thickness and air gap measurement of assembled IR objectives

    NASA Astrophysics Data System (ADS)

    Lueerss, B.; Langehanenberg, P.

    2015-10-01

    A growing number of applications like surveillance, thermography, or automotive demand for infrared imaging systems. Their imaging performance is significantly influenced by the alignment of the individual lenses. Besides the lateral orientation of lenses, the air spacing between the lenses is a crucial parameter. Because of restricted mechanical accessibility within an assembled objective, a non-contact technique is required for the testing of these parameters. So far, commercial measurement systems were not available for testing of IR objectives since most materials used for infrared imaging are non-transparent at wavelengths below 2 μm. We herewith present a time-domain low coherent interferometer capable of measuring any kind of infrared material (e.g., Ge, Si, etc.) as well as VIS materials. The set-up is based on a Michelson interferometer in which the light from a broadband superluminescent diode is split into a reference arm with a variable optical delay and a measurement arm where the sample is placed. On a detector, the reflected signals from both arms are superimposed and recorded as a function of the variable optical path. Whenever the group delay difference is zero, a coherence peak occurs and the relative distances of the lens surfaces are derived from the optical delay. In order to penetrate IR materials, the instrument operates at 2.2 μm. Together with an LWIR autocollimator, this technique allows for the determination of centering errors, lens thicknesses and air spacings of assembled IR objective lenses with a micron accuracy. It is therefore a tool for precision manufacturing and quality control.

  14. Thickness and air gap measurement of assembled IR objectives

    NASA Astrophysics Data System (ADS)

    Lueerss, B.; Langehanenberg, P.

    2015-05-01

    A growing number of applications like surveillance, thermography, or automotive demand for infrared imaging systems. Their imaging performance is significantly influenced by the alignment of the individual lens elements. Besides the lateral orientation of lenses, the air spacing between the lenses is a crucial parameter. Because of restricted mechanical accessibility within an assembled objective, a non-contact technique is required for the testing of these parameters. So far commercial measurement systems were not available for testing of IR objectives since many materials used for infrared imaging are non-transparent at wavelengths below 2 μm. We herewith present a time-domain low coherent interferometer capable of measuring any kind of infrared material (e.g., Ge, Si, etc.) as well as VIS materials. The fiber-optic set-up is based on a Michelson-Interferometer in which the light from a broadband super-luminescent diode is split into a reference arm with a variable optical delay and a measurement arm where the sample is placed. On a photo detector, the reflected signals from both arms are superimposed and recorded as a function of the variable optical path. Whenever the group delay difference is zero, a coherence peak occurs and the relative lens' surface distances are derived from the optical delay. In order to penetrate IR materials, the instrument operates at 2.2 μm. The set-up allows the contactless determination of thicknesses and air gaps inside of assembled infrared objective lenses with accuracy in the micron range. It therefore is a tool for the precise manufacturing or quality control.

  15. Internal models of target motion: expected dynamics overrides measured kinematics in timing manual interceptions.

    PubMed

    Zago, Myrka; Bosco, Gianfranco; Maffei, Vincenzo; Iosa, Marco; Ivanenko, Yuri P; Lacquaniti, Francesco

    2004-04-01

    Prevailing views on how we time the interception of a moving object assume that the visual inputs are informationally sufficient to estimate the time-to-contact from the object's kinematics. Here we present evidence in favor of a different view: the brain makes the best estimate about target motion based on measured kinematics and an a priori guess about the causes of motion. According to this theory, a predictive model is used to extrapolate time-to-contact from expected dynamics (kinetics). We projected a virtual target moving vertically downward on a wide screen with different randomized laws of motion. In the first series of experiments, subjects were asked to intercept this target by punching a real ball that fell hidden behind the screen and arrived in synchrony with the visual target. Subjects systematically timed their motor responses consistent with the assumption of gravity effects on an object's mass, even when the visual target did not accelerate. With training, the gravity model was not switched off but adapted to nonaccelerating targets by shifting the time of motor activation. In the second series of experiments, there was no real ball falling behind the screen. Instead the subjects were required to intercept the visual target by clicking a mousebutton. In this case, subjects timed their responses consistent with the assumption of uniform motion in the absence of forces, even when the target actually accelerated. Overall, the results are in accord with the theory that motor responses evoked by visual kinematics are modulated by a prior of the target dynamics. The prior appears surprisingly resistant to modifications based on performance errors. PMID:14627663

  16. Measuring important parameters for air-sea heat exchange

    NASA Astrophysics Data System (ADS)

    Garbe, Christoph; Schimpf, Uwe; Jaehne, Bernd

    2002-03-01

    The heat transfer between the ocean and the atmosphere is one of the most important parameters governing the global climate. Important parameters include the heat transfer velocity and the net heat flux as well as parameters of the underlying transport model. However, the net heat flux is hard to measure since processes take place in the thermal boundary layer, that is the topmost layer of the ocean less than 1 mm thick. Current techniques rely on three independent measurements of the constituent fluxes, the sensible heat flux, latent heat flux and radiative flux. They depend on indirect measurements of meteorological parameters and rely on a combination of data from different sensors using a number of heuristic assumptions. High relative errors and the need for long temporal averaging reduce the practicability of these techniques. In this paper a novel technique is presented that circumvents these drawbacks by directly measuring the net heat flux across the air-water interface with a single low-NETD infrared camera. A newly developed digital image processing technique allows to simultaneously estimating the surface velocity field and parameters of the temporal temperature change. In particular, this technique allows estimating the total derivative of the temperature with respect to time from a sequence of infrared images, together with error bounds on the estimates. This derivative can be used to compute the heat flux density and the heat transfer velocity, as well as the probability density function of the underlying surface renewal model. It is also possible to estimate the bulk-skin temperature difference given rise to by the net heat flux. Our technique has been successfully used in both laboratory measurements in the Heidelberg Aeolotron, as well as in field measurements in the equatorial pacific during the NOAA GasExII experiment this spring. The data show that heat flux measurements to an accuracy of better than 5% on a time scale of seconds are feasible.

  17. INVESTIGATION OF THE ERRORS IN SLOAN DIGITAL SKY SURVEY PROPER-MOTION MEASUREMENTS USING SAMPLES OF QUASARS

    SciTech Connect

    Dong Ruobing; Gunn, James; Knapp, Gillian; Rockosi, Constance

    2011-10-15

    We investigate in detail the probability distribution function (pdf) of the proper-motion measurement errors in the SDSS+USNO-B proper-motion catalog of Munn et al. using clean quasar samples. The pdf of the errors is well represented by a Gaussian core with extended wings, plus a very small fraction (<0.1%) of 'outliers'. We find that while formally the pdf could be well fit by a five-parameter fitting function, for many purposes it is also adequate to represent the pdf with a one-parameter approximation to this function. We apply this pdf to the calculation of the confidence intervals on the true proper motion for an SDSS+USNO-B proper-motion measurement, and discuss several scientific applications of the SDSS proper-motion catalog. Our results have various applications in studies of the galactic structure and stellar kinematics. Specifically, they are crucial for searching hyper-velocity stars in the Galaxy.

  18. Simultaneous measurement of calcium transients and motion in cultured heart cells.

    PubMed

    Peeters, G A; Hlady, V; Bridge, J H; Barry, W H

    1987-12-01

    The fluorescent Ca2+ probe indo-1 is a new intracellular Ca2+ concentration [( Ca2+]i) indicator that may be suitable for measurement of [Ca2+]i transients in intact heart cells. We exposed spontaneously contracting cultured chick embryo ventricular cells (37 degrees C) to the membrane-permeable indo-1-acetoxymethyl ester (indo-1 AM). Indo-1 loading was associated with a decrease in the amplitude of contraction measured with a video motion detector, but contractility returned to control levels during a subsequent 30-min wash. Analysis of emission spectra of dye obtained by digitonin permeabilization of cells loaded in indo-1 AM showed that the active intracellular dye was not pure indo-1 but probably includes partially deesterified molecules. With the use of an inverted X40 objective epifluorescence system, washed cells containing indo-1 were excited at 360 nm, and fluorescence intensity was measured at 410 nm (increases with increasing [Ca2+]) and 480 nm (decreases with increasing [Ca2+]). Calibration of the [Ca2+]i signals, reflected by the ratio of 410 to 480 nm fluorescence, was achieved by use of ethylen-glycol-bis(beta-aminoethylether)-N,N'-tetraacetic acid (EGTA)-Ca2+ buffered solutions containing the nonfluorescent Ca2+ ionophore Bromo-A23187. Average end-diastolic and peak-systolic [Ca2+]i were 328 +/- 32 and 813 +/- 72 nM (means +/- SE, n = 8). The onset of the [Ca2+]i transient preceded motion by 27 +/- 5 ms (means +/- SE, n = 4), but generally resembled the motion signals in contour. These findings indicate that indo-1 may be used to detect [Ca2+]i transients in isolated ventricular cells without causing significant alterations in mechanical performance. PMID:3122589

  19. Air quality performed with satellite measurement within the QUITSAT project

    NASA Astrophysics Data System (ADS)

    Masieri, Samuele; Petritoli, Andrea; Premuda, Margarita; Kostadinov, Ivan; Bortoli, Daniele; Ravegnani, Fabrizio; Giovanelli, Giorgio

    Ground pollutants monitoring, using satellite observation, represents an interesting and high potential approach to air quality that could be inserted into Global monitoring systems. The QUITSAT Italian pilot project (air QUality with Integration of ground based and SAtellite measurements and chemical Transport and multiphase model), funded by the Italian Space Agency (ASI), proposes a new approach producing some interesting results in this frame. The approach focuses in the integration of the satellite observations (ENVISAT/SCIAMACHY and AURA/OMI) with the outputs of the GAMES (Gas Aerosol Modelling Evaluation System) chemical transport model, to provide the evaluation of the tropospheric profiles of some atmo-spheric compounds such as NO2 , O3 , HCHO and SO2 . This activity appears to be very useful to retrieve the surface concentration of trace gases from tropospheric columns of atmospheric compounds obtained with satellite instrumentation. The comparison with the in situ analyzer network over the Po' Valley shows a good correlation between the two data set. The corre-spondence can be improved taking into account also concentration gradients between different stations, classifying the ground base stations according to their rural or urban characteristics and considering the general orography of the ground. Results and methodology are presented and discussed.

  20. Indoor air quality measurements in 38 Pacific Northwest commercial buildings

    SciTech Connect

    Turk, B.H.; Brown, J.T.; Geisling-Sobotka, K.; Froehlich, D.A.; Grimsrud, D.T.; Harrison, J.; Revzan, K.L.

    1986-06-01

    A Bonneville Power Administration-funded study monitored ventilation rates and a variety of indoor air pollutants in 38 Pacific Northwest commercial buildings. The buildings ranged in age from 6 months to 90 years, in size from 864 to 34,280 m/sup 2/, and occupancy from 25 to 2500 people. Building average formaldehyde (HCHO) concentrations were below the 20 ppB detection limit in 48% of the buildings. Nitrogen dioxide (NO/sub 2/) concentration averages ranged from 5 ppB to 43 ppB and were lower than outdoor concentrations in 8 of 13 buildings. At only one site, an elementary school classroom, did carbon dioxide (CO/sub 2/) exceed 1000 ppM. Radon (Rn) levels were elevated in one building with an average concentration of 7.4 pCiL/sup -1/. Respirable particles (RSP) concentrations in smoking areas in 32 buildings had a geometric mean of 44 ..mu..g m/sup -3/ and ranged up to 308 ..mu..g m/sup -3/ at one site. In non-smoking areas the geometric mean RSP was 15 ..mu..g m/sup -3/. Outside air ventilation rates did not appear to be the single dominant parameter in determining indoor pollutant concentrations. Measured pollutant concentrations in 2 ''complaint'' buildings were below accepted guidelines. The cause of the complaints was not identified.

  1. Linewidth-modulated motional Stark effect measurements of internal field structure in low-field configurations

    NASA Astrophysics Data System (ADS)

    Reinecke, E. A.; Fonck, R. J.; Thorson, T. A.

    2001-01-01

    Motional Stark effect measurements of internal field structure in low-field magnetic confinement configurations are considered for both magnitude and direction of the local magnetic field. The amplitude and phase delay of an oscillating spectral linewidth driven by a rotating polarizer provides a means of determining the magnitude and direction of the total field simultaneously while avoiding difficulties of neutral beam energy drift. Photon-noise limit estimates for a diagnostic beam on the low-field PEGASUS toroidal experiment indicate sensitivities of roughly 20 G and 0.2° for the magnitude and direction angle. These values are sufficient to provide significant constraints on magnetic equilibrium reconstructions.

  2. Monitoring motion and measuring relative position of the Chang'E-3 rover

    NASA Astrophysics Data System (ADS)

    Liu, Qinghui; Zheng, Xin; Huang, Yong; Li, Peijia; He, Qingbao; Wu, Yajun; Guo, Li; Tang, Mingle

    2014-11-01

    Same-beam very long baseline interferometry observations were performed between the rover and the lander of Chang'E-3 and differential phase delay data were obtained with the minimum random error of about 0.03 ps. These data were used to monitor the rover motions, as small as several centimeters, including movement, turning, and attitude adjustment. The relative position between the rover and the lander was precisely measured with an accuracy of 1 m, which is an improvement of 10 times compared with that of the Apollo project.

  3. VLBI Water Maser Proper Motion Measurements in Star-Forming Regions

    NASA Astrophysics Data System (ADS)

    Torrelles, J. M.; Patel, N.; Gómez, J. F.; Anglada, G.; Uscanga, L.

    We review some of the recent water maser proper motion measurements in star-forming regions performed through VLBI multi-epoch observations. These observations are starting to reveal exciting perspectives, providing the full kinematics of the gas within the outflows/circumstellar disks around YSOs at scales of AUs, discovering new phenomena (e.g., isotropic mass ejections, watermaser "micro-structures" exhibiting remarkable coherent and well ordered spatio-kinematical behavior at AU scale), and opening new, puzzling questions related to the early stellar evolution.

  4. Vlbi Water Maser Proper Motion Measurements in Star-Forming Regions

    NASA Astrophysics Data System (ADS)

    Torrelles, J. M.; Patel, N.; Gómez, J. F.; Anglada, G.; Uscanga, L.

    2005-01-01

    We review some of the recent water maser proper motion measurements in star-forming regions performed through VLBI multi-epoch observations. These observations are starting to reveal exciting perspectives, providing the full kinematics of the gas within the outflows/circumstellar disks around YSOs at scales of AUs, discovering new phenomena (e.g., isotropic mass ejections, water maser "micro-structures" exhibiting remarkable coherent and well ordered spatio-kinematical behavior at AU scale), and opening new, puzzling questions related to the early stellar evolution.

  5. Linewidth-modulated motional Stark effect measurements of internal field structure in low-field configurations

    SciTech Connect

    Reinecke, E. A.; Fonck, R. J.; Thorson, T. A.

    2001-01-01

    Motional Stark effect measurements of internal field structure in low-field magnetic confinement configurations are considered for both magnitude and direction of the local magnetic field. The amplitude and phase delay of an oscillating spectral linewidth driven by a rotating polarizer provides a means of determining the magnitude and direction of the total field simultaneously while avoiding difficulties of neutral beam energy drift. Photon-noise limit estimates for a diagnostic beam on the low-field PEGASUS toroidal experiment indicate sensitivities of roughly 20 G and 0.2{sup o} for the magnitude and direction angle. These values are sufficient to provide significant constraints on magnetic equilibrium reconstructions.

  6. Measurements of the Motion of Plasma Filaments in a Plasma Ball

    SciTech Connect

    Campanell, M.; Laird, J.; Provost, T.; Vasquez, S.; Zweben, S. J.

    2010-01-26

    Measurements were made of the motion of the filamentary structures in a plasma ball using high speed cameras and other optical detectors. These filaments traverse the ball radially at ~106 cm/sec at the driving frequency of ~26 kHz, and drift upward through the ball at ~1 cm/sec. Varying the applied high voltage and frequency caused the number, length, and diameter of the filaments to change. A custom plasma ball was constructed to observe the effects of varying gas pressure and species on the filament structures.

  7. Inertial Measures of Motion for Clinical Biomechanics: Comparative Assessment of Accuracy under Controlled Conditions - Effect of Velocity

    PubMed Central

    Lebel, Karina; Boissy, Patrick; Hamel, Mathieu; Duval, Christian

    2013-01-01

    Background Inertial measurement of motion with Attitude and Heading Reference Systems (AHRS) is emerging as an alternative to 3D motion capture systems in biomechanics. The objectives of this study are: 1) to describe the absolute and relative accuracy of multiple units of commercially available AHRS under various types of motion; and 2) to evaluate the effect of motion velocity on the accuracy of these measurements. Methods The criterion validity of accuracy was established under controlled conditions using an instrumented Gimbal table. AHRS modules were carefully attached to the center plate of the Gimbal table and put through experimental static and dynamic conditions. Static and absolute accuracy was assessed by comparing the AHRS orientation measurement to those obtained using an optical gold standard. Relative accuracy was assessed by measuring the variation in relative orientation between modules during trials. Findings Evaluated AHRS systems demonstrated good absolute static accuracy (mean error < 0.5o) and clinically acceptable absolute accuracy under condition of slow motions (mean error between 0.5o and 3.1o). In slow motions, relative accuracy varied from 2o to 7o depending on the type of AHRS and the type of rotation. Absolute and relative accuracy were significantly affected (p<0.05) by velocity during sustained motions. The extent of that effect varied across AHRS. Interpretation Absolute and relative accuracy of AHRS are affected by environmental magnetic perturbations and conditions of motions. Relative accuracy of AHRS is mostly affected by the ability of all modules to locate the same global reference coordinate system at all time. Conclusions Existing AHRS systems can be considered for use in clinical biomechanics under constrained conditions of use. While their individual capacity to track absolute motion is relatively consistent, the use of multiple AHRS modules to compute relative motion between rigid bodies needs to be optimized according to

  8. Methodology to apportion ambient air measurements to investigate potential effects on air quality near waste incinerators

    SciTech Connect

    Mukerjee, S.; Fox, D.L.; Stevens, R.K.; Shy, C.M.; Vescio, N.

    1993-01-01

    Ambient air samples at four sites located near two incinerators (a biomedical waste and a municipal incinerator) in the vicinity of Charlotte, North Carolina were acquired as part of a health effects study that is examining potential, short-term, lung dysfunctions associated with incinerator and other source emissions. Ambient monitoring was performed for one month intervals at a treatment and control community site for each of the two incinerator locations. Twelve-hour ambient samples were acquired by means of a Versatile Air Pollution Sampler (VAPS) which enabled sampling for fine (< 2.5 micrometers) and coarse (2.5 - 10 micrometers) particulate matter, acid-gases by diffusion sampling and fine carbon sampling on quartz filters. X-ray Fluorescence Spectroscopy (XRF) was used on the coarse and fine particulate filters to measure metals while Ion Chromatography (IC) analyzed acid gases. The Chemical Mass Balance Receptor Model (CMB) was then used on the average ambient data from each wind vector to apportion the contribution of ambient pollutants which were attributable to the sources of interest from a given wind direction.

  9. Use of power-line interference for adaptive motion artifact removal in biopotential measurements.

    PubMed

    Xu, Lin; Rooijakkers, Michael J; Rabotti, Chiara; Peuscher, Jan; Mischi, Massimo

    2016-01-01

    Motion artifacts (MA) have long been a problem in biopotential measurements. Adaptive filtering is widely used for optimal noise removal in many biomedical applications. However, the existing adaptive filtering methods involve the use of additional sensors, limiting the applicability of adaptive filtering for MA reduction. In the present study, a novel adaptive filtering method without need for additional sensors is proposed. In biopotential measurements, movement of the electrodes and their leads may cause variations not only in the skin and half-cell potential (motion artifacts), but also in the electrode-skin impedance. Such impedance variations may also cause power-line interference modulation (PLIM), resulting in additional spectral components around the power-line interference (PLI) in the frequency domain. Demodulation of the PLI may reflect the movement-induced electrode-skin impedance variation, and can therefore represent a reference signal for the adaptive filter. Preliminary validation on ECG measurements with seven volunteers showed a high correlation coefficient (R  =  0.97) between MA and PLIM, and excellent MA removal by the proposed adaptive filter, possibly leading to improved analysis of biopotential signals. PMID:26641265

  10. ARM - Midlatitude Continental Convective Clouds Experiment (MC3E): Multi-Frequency Profilers, Vertical Air Motion (williams-vertair)

    DOE Data Explorer

    Williams, Christopher; Jensen, Mike

    2012-11-06

    This data was collected by the NOAA 449-MHz and 2.8-GHz profilers in support of the Department of Energy (DOE) and NASA sponsored Mid-latitude Continental Convective Cloud Experiment (MC3E). The profiling radars were deployed in Northern Oklahoma at the DOE Atmospheric Radiation Mission (ARM) Southern Great Plans (SGP) Central Facility from 22 April through 6 June 2011. NOAA deployed three instruments: a Parsivel disdrometer, a 2.8-GHz profiler, and a 449-MHz profiler. The parasivel provided surface estimates of the raindrop size distribution and is the reference used to absolutely calibrate the 2.8 GHz profiler. The 2.8-GHz profiler provided unattenuated reflectivity profiles of the precipitation. The 449-MHz profiler provided estimates of the vertical air motion during precipitation from near the surface to just below the freezing level. By using the combination of 2.8-GHz and 449-MHz profiler observations, vertical profiles of raindrop size distributions can be retrieved. The profilers are often reference by their frequency band: the 2.8-GHz profiler operates in the S-band and the 449-MHz profiler operates in the UHF band. The raw observations are available as well as calibrated spectra and moments. This document describes how the instruments were deployed, how the data was collected, and the format of the archived data.

  11. Species measurements in a hypersonic, hydrogen-air, combustion wake

    NASA Technical Reports Server (NTRS)

    Skinner, K. A.; Stalker, R. J.

    1995-01-01

    A continuously sampling, time-of-flight mass spectrometer has been used to measure relative species concentrations in a two-dimensional, hydrogen-air combustion wake at mainstream Mach numbers exceeding 5. The experiments, which were conducted in a free piston shock tunnel, yielded distributions of hydrogen, oxygen, nitrogen, water and nitric oxide at stagnation enthalpies ranging from 5.6 MJ kg(exp -1) to 1.2 MJ kg(exp -1) and at a distance of approximately 100 times the thickness of the initial hydrogen jet. The amount of hydrogen that was mixed in stoichiometric proportions was approximately independent of the stagnation enthalpy, in spite of the fact that the proportion of hydrogen in the wake increased with stagnation enthalpy. Roughly 50 percent of the mixed hydrogen underwent combustion at the highest enthalpy. The proportion of hydrogen reacting to water could be approximately predicted using reaction rates based on mainstream temperatures.

  12. Species measurements in a hypersonic, hydrogen-air, combustion wake

    SciTech Connect

    Skinner, K.A.; Stalker, R.J.

    1996-09-01

    A continuously sampling, time-of-flight mass spectrometer has been used to measure relative species concentrations in a two-dimensional, hydrogen-air combustion wake at mainstream Mach numbers exceeding 5. The experiments, in a free piston shock tunnel, yielded distributions of hydrogen, oxygen, nitrogen, water, and nitric oxide at stagnation enthalpies ranging from 5.6 MJ/kg to 12.2 MJ/kg and at a distance of approximately 100s times the thickness of the initial hydrogen jet. The amount of hydrogen mixed in stoichiometric proportions was approximately independent of the stagnation enthalpy, despite the fact that the proportion of hydrogen in the wake was increased with stagnation enthalpy. Roughly 50% of the mixed hydrogen underwent combustion at the highest enthalpy. The proportion of hydrogen reacting to water could be approximately predicted using reaction rates based on mainstream temperatures.

  13. q-profile measurements with motional stark effect in DIII-D

    SciTech Connect

    Rice, B.W.

    1996-07-01

    Motional Stark Effect (MSE) has emerged as the most reliable technique for the measurement of q profiles in tokamaks equipped with neutral beams. On DIII-D, two separate 8-channel MSE instruments are utilized, giving 16 radial measurements. The viewing geometry for each instrument is designed to optimize radial resolution (1.5 cm < {delta}R < 6 cm) over the measurement range. Dual-frequency polarization modulators combined with lock-in detection provides maximum signal-to-noise with a time response of {approximately}1 ms. Special consideration has gone into the design of the collection optics to minimize undesirable polarization effects on reflectors and Faraday rotation in lenses. Examples of data from negative central magnetic shear, VH-mode, and sawtoothing discharges highlight the capabilities of the DIII-D MSE diagnostic.

  14. Measurement of the atmospheric primary aberrations by a 4-aperture differential image motion monitor

    NASA Astrophysics Data System (ADS)

    Shomali, Ramin; Nasiri, Sadollah; Darudi, Ahmad

    2011-05-01

    The present paper investigates and discusses the ability of the Hartmann test with a 4-aperture differential image motion monitor (DIMM) to measure the atmospheric primary aberrations which, in turn, can be used for the calculation of the atmospheric coherence time. Through performing numerical simulations, we show that the 4-aperture DIMM is able to measure the defocus and astigmatism terms correctly whereas its results are not reliable for the coma. The most important limitations in the measurement of the primary aberrations by the 4-aperture DIMM are the centroid displacements of the spots which are caused by the higher order aberrations. This effect is negligible in the calculation of the defocus and astigmatisms, whereas it cannot be ignored in the calculation of the coma.

  15. Measurement of four-degree-of-freedom error motions based on non-diffracting beam

    NASA Astrophysics Data System (ADS)

    Zhai, Zhongsheng; Lv, Qinghua; Wang, Xuanze; Shang, Yiyuan; Yang, Liangen; Kuang, Zheng; Bennett, Peter

    2016-05-01

    A measuring method for the determination of error motions of linear stages based on non-diffracting beams (NDB) is presented. A right-angle prism and a beam splitter are adopted as the measuring head, which is fixed on the moving stage in order to sense the straightness and angular errors. Two CCDs are used to capture the NDB patterns that are carrying the errors. Four different types error s, the vertical straightness error and three rotational errors (the pitch, roll and yaw errors), can be separated and distinguished through theoretical analysis of the shift in the centre positions in the two cameras. Simulation results show that the proposed method using NDB can measure four-degrees-of-freedom errors for the linear stage.

  16. Synoptic Mapping of Chemical Composition, Thermal Structure, and Air Motion from UARS Observations

    NASA Technical Reports Server (NTRS)

    Salby, Murry L.

    1999-01-01

    An operational mapping algorithm was developed to process measurements of individual species observed by different satellite instruments on board UARS. Based on Fast Fourier Synoptic Mapping (FFSM), the algorithm accounts for the precessing orbit of UARS, the error of individual instruments, and gaps associated with instrument duty cycle and the satellite yaw maneuver. It provides synoptic structure and evolution on periods as short as 1 day, derived collectively from all observations of an individual species. The algorithm was applied to synoptically map temperature, thickness, and several chemical constituents observed by the instruments: MLS, CLAES, ISAMS, and HALOE. Each field variable observed by these instruments was mapped twice-daily in continuous global time series several months long. Mapped behavior produced via FFSM was compared against standard archived products generated via Kalman filtering. The standard map products reveal similar behavior, but are limited to features of larger scale. Tracer structure that develops through flow deformation and attending transport is therefore represented in those products more coarsely, eventually being sheared down to scales that are no longer represented properly. The synoptic time series also reveal a diurnal cycle for several of the constituents, one that emerges clearly in their space-time spectra. The zonal and meridional structure of diurnal variability was mapped by filtering the space-time spectrum, an intermediate product of FFSM, to those scales resolved by the UARS sampling. Geographical variations of the diurnal cycle have also been evaluated in its seasonal-mean structure by compositing distributions at individual local times. Both were compared to diurnal variations in chemical models and in dynamical models that account for transport by the diurnal tide. Diurnal variations were found to introduce spurious behavior into the archived products generated via Kalman filtering, behavior that is

  17. Measurement of total reduced sulfur compounds in ambient air

    SciTech Connect

    McQuaker, N.R.; Rajala, G.E.; Pengilly, D.

    1986-05-01

    Methods for the determination of total reduced sulfur (TRS) compounds in the ambient air based on coulometric detection (Philips Model PW 9700 analyzer) and thermal oxidation followed by detection using pulsed fluorescence (Teco Model 43 analyzer) have been evaluated. Analytical response factors, relative to H/sub 2/S, were determined for both the individual TRS compounds and compounds such as terpenes and carbonyl sulfide that may be a potential source of interference. The results for COS and terpenes indicate that in a typical monitoring situation normally encountered concentrations of these compounds are not expected to cause significant measurement bias. The results for the individual TRS compounds indicate that while variations in TRS composition are not a factor in assessing measurement bias for the thermal oxidation/pulsed fluorescence method, they are a factor for the Philips coulometric method; i.e., increasing positive measurement bias maybe introduced as the TRS composition shifts toward relatively less H/sub 2/S. Philips-Teco comparison data collected at a single site in the vicinity of three operating kraft pupil mills are compatible with these expectations. 8 references, 1 figure, 3 tables.

  18. A Non-Contact Measurement System for the Range of Motion of the Hand

    PubMed Central

    Pham, Trieu; Pathirana, Pubudu N.; Trinh, Hieu; Fay, Pearse

    2015-01-01

    An accurate and standardised tool to measure the active range of motion (ROM) of the hand is essential to any progressive assessment scenario in hand therapy practice. Goniometers are widely used in clinical settings for measuring the ROM of the hand. However, such measurements have limitations with regard to inter-rater and intra-rater reliability and involve direct physical contact with the hand, possibly increasing the risk of transmitting infections. The system proposed in this paper is the first non-contact measurement system utilising Intel Perceptual Technology and a Senz3D Camera for measuring phalangeal joint angles. To enhance the accuracy of the system, we developed a new approach to achieve the total active movement without measuring three joint angles individually. An equation between the actual spacial position and measurement value of the proximal inter-phalangeal joint was established through the measurement values of the total active movement, so that its actual position can be inferred. Verified by computer simulations, experimental results demonstrated a significant improvement in the calculation of the total active movement and successfully recovered the actual position of the proximal inter-phalangeal joint angles. A trial that was conducted to examine the clinical applicability of the system involving 40 healthy subjects confirmed the practicability and consistency in the proposed system. The time efficiency conveyed a stronger argument for this system to replace the current practice of using goniometers. PMID:26225976

  19. Impacts of climate change on secular and seasonal ground motion in Iceland as measured by CGPS

    NASA Astrophysics Data System (ADS)

    Compton, K. C.; Bennett, R. A.; Hreinsdottir, S.

    2014-12-01

    Rapid melting of ice in Iceland results in uplift rates exceeding 25 mm/yr in central Iceland and uplift accelerations of nearly 2 mm/yr2, but the relative contributions of the lithosphere's elastic and viscoelastic responses to uplift acceleration is currently not well understood. We analyzed data from 62 continuous GPS (CGPS) stations throughout Iceland to investigate the uplift signal and its relationship to ice melting. We find that sites in central and southern Iceland, closest to the major ice caps, which measure the largest velocities and accelerations, also display the largest annual vertical variations. Velocity and acceleration estimates are positively correlated with the amplitude of annual site motion with calculated correlation coefficients of 0.8027 and 0.4664 respectively (r95 = 0.2489, n = 62). Since seasonal snow load on the Icelandic glaciers account for a significant proportion of the annual signal measured by GPS, these observations suggest that variability of snow and ice mass loads result in a similar spatial pattern of crustal motion on both annual and decadal time scales, presumably controlled by the current locations of the ice caps and driven by weather and climate, respectively. Simple admittance analysis indicates that annual differences in ice cap mass balance translate to contemporaneous vertical position differences, with model results within 10 mm of observations. We are also able to reproduce observed velocities and accelerations by calculating the response to unloading over a viscous half-space. Both models, however, require an accelerating ice melt rate. We aim to include variations in the seasonal component of CPGS site motion in Iceland as a way to improve our models. We build upon previous work (Grapenthin et al., 2006) and take into account the changing global climate and a documented lengthening of the Arctic melt season in an attempt to better constrain the elastic contribution to observed uplift.

  20. Motion capture measures variability in laryngoscopic movement during endotracheal intubation: A preliminary report

    PubMed Central

    Carlson, Jestin N; Das, Samarjit; De la Torre, Fernando; Callaway, Clifton W; Phrampus, Paul E; Hodgins, Jessica

    2012-01-01

    Background Success rates with emergent endotracheal intubation (ETI) improve with increasing provider experience. Few objective metrics exist to quantify differences in ETI technique between providers of various skill levels. We tested the feasibility of using motion capture videography to quantify variability in the motions of the left hand and the laryngoscope in providers with various experience. Methods Three providers with varying levels of experience (attending physician (experienced), Emergency Medicine resident (intermediate), and post doctoral student with no previous ETI experience (novice)) each performed ETI four times on a mannequin. A Vicon, 16-camera system tracked the 3D orientation and movement of markers on the providers, handle of the laryngoscope, and mannequin. Attempt duration, path length of the left hand and the inclination of the plane of the laryngoscope handle (mean squared angular deviation from vertical) were calculated for each laryngoscopy attempt. We compared inter-attempt and inter-provider variability of each measure Results All ETI attempts were successful. Mean (SD) duration of laryngoscopy attempts in seconds differed between experienced 5.50 (0.68), intermediate 6.32 (1.13) and novice 12.38 (1.06) providers (p=0.021). Mean path length of the left hand did not differ between providers (p=0.37). Variability of the plane of the laryngoscope (degrees2) differed between providers: 8.3 (experienced), 28.7 (intermediate) and 54.5 (novice). Conclusion Motion analysis can detect inter-provider differences in hand and laryngoscope movements during ETI which may be related to provider experience. This technology has potential to objectively measure training and skill in ETI. PMID:22801254

  1. Air-Sea Interaction Measurements from the Controlled Towed Vehicle

    NASA Astrophysics Data System (ADS)

    Khelif, D.; Bluth, R. T.; Jonsson, H.; Barge, J.

    2014-12-01

    The Controlled Towed Vehicle (CTV) uses improved towed drone technology to actively maintain via a radar altimeter and controllable wing a user-set height that can be as low as the canonical reference height of 10 m above the sea surface. After take-off, the drone is released from the tow aircraft on a ~700-m stainless steel cable. We have instrumented the 0.23 m diameter and 2.13 m long drone with high fidelity instruments to measure the means and turbulent fluctuations of 3-D wind vector, temperature, humidity, pressure, CO2 and IR sea surface temperature. Data are recorded internally at 40 Hz and simultaneously transmitted to the tow aircraft via dedicated wireless Ethernet link. The CTV accommodates 40 kg of instrument payload and provides it with 250 W of continuous power through a ram air propeller-driven generator. Therefore its endurance is only limited by that of the tow aircraft.We will discuss the CTV development, the engineering challenges and solutions that have been successfully implemented to overcome them. We present results from recent flights as low as 9 m over the coastal ocean and comparisons of profiles and turbulent fluxes from the CTV and the tow aircraft. Manned aircraft operation at low-level boundary-layer flights is very limited. Dropsondes and UAS (Unmanned Aerial Systems) and UAS are alternates for measurements near the ocean surface. However, dropsondes have limited sensor capability and do not measure fluxes, and most present UAS vehicles do not have the payload and power capacity nor the low-flying ability in high winds over the oceans. The CTV therefore, fills a needed gap between the dropsondes, in situ aircraft, and UAS. The payload, capacity and power of the CTV makes it suitable for a variety of atmospheric research measurements. Other sensors to measure aerosol, chemistry, radiation, etc., could be readily accommodated in the CTV.

  2. High resolution measurement of striation patterns and sarcomere motions in cardiac muscle cells.

    PubMed Central

    Krueger, J W; Denton, A

    1992-01-01

    We describe an extension of the method of Myers et al. (1982) to measure with high precision the uniformity of contractile motions that occur between sarcomeres in the isolated cardiac muscle cell (guinea pig and rat). The image of the striations, observed with modulation contrast microscopy, was detected by a linear array of photodiodes. Sarcomere length was measured greater than 500/s from the frequency of the array's video signal at two selectable regions of the cell. A precision test grating demonstrated that method resolves known differences in the spacing between two contiguous striations to +/- 0.01 micron and that the effects of image translation and microscopic resolution are minor. The distribution of striation spacing appears to be discrete in isolated segments of the cell, and patches of fairly uniform length can be identified that are laterally contiguous. When electrically triggered, contraction is synchronous and the sarcomeres shorten and relengthen smoothly. The contrast between the striations is transiently enhanced during relengthening, an indication that the contracting cell can not be treated as a simple grating. Pauses that occur during late in relengthening (and transient contractile alternans) are characterized by very synchronized activity. These forms of irregular contractile behavior are not explained by desynchronization of a mechanism of release of intracellular calcium. A companion article describes application of the technique to study the nonuniform motions that occur between sarcomeres. Images FIGURE 1 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 PMID:1540686

  3. Quantum noise in the position measurement of a cavity mirror undergoing Brownian motion

    NASA Astrophysics Data System (ADS)

    Jacobs, K.; Tittonen, I.; Wiseman, H. M.; Schiller, S.

    1999-07-01

    We perform a quantum theoretical calculation of the noise power spectrum for a phase measurement of the light output from a coherently driven optical cavity with a freely moving rear mirror. We examine how the noise resulting from the quantum back action appears among the various contributions from other noise sources. We do not assume an ideal (homodyne) phase measurement, but rather consider phase-modulation detection, which we show has a different shot noise level. We also take into account the effects of thermal damping of the mirror, losses within the cavity, and classical laser noise. We relate our theoretical results to experimental parameters, so as to make direct comparisons with current experiments simple. We also show that in this situation, the standard Brownian motion master equation is inadequate for describing the thermal damping of the mirror, as it produces a spurious term in the steady-state phase-fluctuation spectrum. The corrected Brownian motion master equation [L. Diosi, Europhys. Lett. 22, 1 (1993)] rectifies this inadequacy.

  4. Developments in hot-film anemometry measurements of hydroacoustic particle motion

    NASA Astrophysics Data System (ADS)

    Dubbelday, Pieter S.; Apostolico, Virgil V.; Diebel, Dean L.

    1988-08-01

    Hot film anemometry may be used to measure particle motion in hydroacoustic fields. Since the cylindrical sensors used thus far are very fragile, the method is little suited for use outside the laboratory. The measurement of the response of a more rugged conical sensor is reported here. Another way of protecting the sensor consists of packaging the sensor in a rubber liquid filled boot. This also prevents fouling and bubble formation on the heated film. The response shows a resonance at low frequency, ascribed to the liquid filled boot, which may be used for enhanced response in a limited frequency region. The response of a hot film anemometer to vertical hydroacoustic particle motion is influenced by free convection, which acts as a bias flow. The output was shown to be proportional to particle displacement for a wide range of parameters. It was expected that an imposed bias flow would increase the output and remove the dependence on the direction of gravity. Therefore, a hot-film sensor (diameter d) was subjected to an underwater jet from a nozzle. The output showed a transition from being proportional to particle speed, to being proportional to particle displacement, depending on the angular frequency omega and imposed flow speed omega. The transition takes place when a dimensionless number omega, defined as omega = omega/nu is of order 1.

  5. Adaptation of the S-5-S pendulum seismometer for measurement of rotational ground motion

    NASA Astrophysics Data System (ADS)

    Knejzlík, Jaromír; Kaláb, Zdeněk; Rambouský, Zdeněk

    2012-10-01

    The Russian electrodynamic seismometer model S-5-S has been adapted for the measurement of rotational ground motion. The mechanical system of the original S-5-S seismometer consists of electrodynamic sensing and damping transducer coils mounted on an asymmetrical double-arm pendulum. This pendulum is suspended on a footing using two pairs of crossed flat springs, which operate as the axis of rotation. The pendulum is stabilised by an additional spring. The S-5-S can be used either as a vertical or as a horizontal sensor. The adaptation of the S-5-S seismometer described below involves removal of the additional spring and installation of an additional mass on the damping arm. Strain gauge angle sensors are installed on one pair of the crossed flat springs. The main dynamic parameters of the rotational seismometer created in this way, i.e. the natural period and damping, are controlled electronically by feedback currents proportional to the angular displacement and angular velocity, both fed to the damping transducer coil. This new seismometer, named the S-5-SR, enables measurement of the rotational component of ground motion around the horizontal or the vertical axes. The output signal from this S-5-SR seismometer can be proportional either to rotational displacement or rotational velocity.

  6. Dynamic adhesive force measurements under vertical and horizontal motions of interacting rough surfaces.

    PubMed

    Yeo, Chang-Dong; Lee, Sung-Chang; Polycarpou, Andreas A

    2008-01-01

    An instrument to measure dynamic adhesive forces between interacting rough surfaces has been developed. It consists of four parts, namely, main instrument body, vertical positioning system with both micrometer and nanometer positioning accuracies, horizontal positioning system with nanometer positioning accuracy, and custom-built high-resolution, and high dynamic bandwidth capacitive force transducer. The vertical piezoelectric actuator (PZT) controls the vertical (approaching and retracting) motion of the upper specimen, while the horizontal PZT controls the horizontal (reciprocal) motion of the lower specimen. The force transducer is placed in line with the upper specimen and vertical PZT, and directly measures the adhesive forces with a root-mean-square load resolution of 1.7 microN and a dynamic bandwidth of 1.7 kHz. The newly developed instrument enables reliable measurements of near-contact and contact adhesive forces for microscale devices under different dynamic conditions. Using the developed instrument, dynamic pull-in and pull-off force measurements were performed between an aluminum-titanium-carbide sphere and a 10 nm thick carbon film disk sample. Three different levels of contact force were investigated; where for each contact force level the vertical velocity of the upper sample was varied from 0.074 to 5.922 microms, while the lower sample was stationary. It was found that slower approaching and retracting velocities result in higher pull-in and pull-off forces. The noncontact attractive force was also measured during horizontal movement of the lower sample, and it was found that the periodic movements of the lower disk sample also affect the noncontact surface interactions. PMID:18248070

  7. Measurement-while-drilling (MWD) development for air drilling

    SciTech Connect

    Rubin, L.A.; Harrison, W.H.

    1992-01-01

    The objective of this program is to tool-harden and make commercially available an existing wireless MWD tool to reliably operate in an air, air-mist, or air-foam environment during Appalachian Basin oil and gas directional drilling operations in conjunction with downhole motors and/or (other) bottom-hole assemblies. The application of this technology is required for drilling high angle (holes) and horizontal well drilling in low-pressure, water sensitive, tight gas formations that require air, air-mist, and foam drilling fluids. The basic approach to accomplishing this objective was to modify GEC's existing electromagnetic (e-m) CABLELESS''{trademark} MWD tool to improve its reliability in air drilling by increasing its tolerance to higher vibration and shock levels (hardening). Another important aim of the program is to provide for continuing availability of the resultant tool for use on DOE-sponsored, and other, air-drilling programs.

  8. Measurement-while-drilling (MWD) development for air drilling

    SciTech Connect

    Rubin, L.A.; Harrison, W.H.

    1992-06-01

    The objective of this program is to tool-harden and make commercially available an existing wireless MWD tool to reliably operate in an air, air-mist, or air-foam environment during Appalachian Basin oil and gas directional drilling operations in conjunction with downhole motors and/or (other) bottom-hole assemblies. The application of this technology is required for drilling high angle (holes) and horizontal well drilling in low-pressure, water sensitive, tight gas formations that require air, air-mist, and foam drilling fluids. The basic approach to accomplishing this objective was to modify GEC`s existing electromagnetic (e-m) ``CABLELESS``{trademark} MWD tool to improve its reliability in air drilling by increasing its tolerance to higher vibration and shock levels (hardening). Another important aim of the program is to provide for continuing availability of the resultant tool for use on DOE-sponsored, and other, air-drilling programs.

  9. Measurement-while-drilling (MWD) development for air drilling

    SciTech Connect

    Harrison, W.H.; Rubin, L.A.

    1992-05-01

    The objective of this program is to tool-harden and make commercially available an existing wireless MWD tool to reliably operate in an air, air-mist, or air-foam environment during Appalachian Basin oil and gas directional drilling operations in conjunction with downhole motors and/or (other) bottom-hole assemblies. The application of this technology is required for drilling high angle (holes) and horizontal well drilling in low- pressure, water sensitive, tight gas formations that require air, air-mist, and foam drilling fluids. The basic approach to accomplishing this objective was to modify GEC`s existing electromagnetic (e-m) {open_quotes}Cableless{close_quotes} MWD tool to improve its reliability in air drilling by increasing its tolerance to higher vibration and shock levels (hardening). Another important aim of the program is to provide for continuing availability of the resultant tool for use on DOE-sponsored, and other, air-drilling programs.

  10. Density fluctuation measurement using motional Stark effect optics in JT-60U

    SciTech Connect

    Suzuki, T.; Fujita, T.; Oyama, N.; Isayama, A.; Matsunaga, G.; Oikawa, T.; Asakura, N.; Takechi, M.

    2006-10-15

    The multichannel motional Stark effect (MSE) diagnostic system in JT-60U has been upgraded to measure density fluctuation profile. A 16-channel fast-sampling digitizer has been added in order to measure photomultiplier-tube signals at measurement frequency of 0.5-1 MHz. The new system works as a MSE and beam emission spectroscopy diagnostic. Spatially resolved electron density fluctuation profile measurement in various operation regimes is presented. In the core plasma, density fluctuation induced by rotation of tearing mode islands was observed. Temporal evolution of the fluctuation frequency agrees with that measured by Mirnov coils (poloidal and toroidal mode numbers: 2 and 1, respectively). The phases of the fluctuations on either side of the q=2 surface are inverted, which is consistent with electron cyclotron emission. These measurements show that the density fluctuation is caused by a rotating magnetic island structure induced by the tearing mode. In the scrape-off layer of a H-mode plasma with edge-localized-mode (ELM), i. e., ELMy H-mode outward propagation of strong intermittent emission corresponding to ELM crash was also observed. The propagation velocity is 0.69-2.2 km/s along the MSE measurement points, the time lag and distance between adjacent channels being 67{+-}35 {mu}s and 70 mm, respectively.

  11. Mobile very long baseline interferometry and Global Positioning System measurement of vertical crustal motion

    NASA Technical Reports Server (NTRS)

    Kroger, Peter M.; Davidson, John M.; Gardner, Elaine C.

    1986-01-01

    Mobile Very Long Base Interferometry (VLBI) and Global Positioning System (GPS) geodetic measurements have many error sources in common. Calibration of the effects of water vapor on signal transmission through the atmosphere, however, remains the primary limitation to the accuracy of vertical crustal motion measurements made by either technique. The two primary methods of water vapor calibration currently in use for mobile VLBI baseline measurements were evaluated: radiometric measurements of the sky brightness near the 22 GHz emission line of free water molecules and surface meteorological measurements used as input to an atmospheric model. Based upon a limited set of 9 baselines, it is shown that calibrating VLBI data with water vapor radiometer measurements provides a significantly better fit to the theoretical decay model than calibrating the same data with surface meteorological measurements. The effect of estimating a systematic error in the surface meteorological calibration is shown to improve the consistency of the vertical baseline components obtained by the two calibration methods. A detailed error model for the vertical baseline components obtained indicates current mobile VLBI technology should allow accuracies of order 3 cm with WVR calibration and 10 cm when surface meteorological calibration is used.

  12. Density fluctuation measurement using motional Stark effect optics in JT-60U

    NASA Astrophysics Data System (ADS)

    Suzuki, T.; Fujita, T.; Oyama, N.; Isayama, A.; Matsunaga, G.; Oikawa, T.; Asakura, N.; Takechi, M.

    2006-10-01

    The multichannel motional Stark effect (MSE) diagnostic system in JT-60U has been upgraded to measure density fluctuation profile. A 16-channel fast-sampling digitizer has been added in order to measure photomultiplier-tube signals at measurement frequency of 0.5-1MHz. The new system works as a MSE and beam emission spectroscopy diagnostic. Spatially resolved electron density fluctuation profile measurement in various operation regimes is presented. In the core plasma, density fluctuation induced by rotation of tearing mode islands was observed. Temporal evolution of the fluctuation frequency agrees with that measured by Mirnov coils (poloidal and toroidal mode numbers: 2 and 1, respectively). The phases of the fluctuations on either side of the q =2 surface are inverted, which is consistent with electron cyclotron emission. These measurements show that the density fluctuation is caused by a rotating magnetic island structure induced by the tearing mode. In the scrape-off layer of a H-mode plasma with edge-localized-mode (ELM), i. e., ELMy H-mode outward propagation of strong intermittent emission corresponding to ELM crash was also observed. The propagation velocity is 0.69-2.2km/s along the MSE measurement points, the time lag and distance between adjacent channels being 67±35μs and 70mm, respectively.

  13. Relation of motion sickness susceptibility to vestibular and behavioral measures of orientation

    NASA Technical Reports Server (NTRS)

    Peterka, Robert J.

    1995-01-01

    The objective is to determine the relationship of motion sickness susceptibility to vestibulo-ocular reflexes (VOR), motion perception, and behavioral utilization of sensory orientation cues for the control of postural equilibrium. The work is focused on reflexes and motion perception associated with pitch and roll movements that stimulate the vertical semicircular canals and otolith organs of the inner ear. This work is relevant to the space motion sickness problem since 0 g related sensory conflicts between vertical canal and otolith motion cues are a likely cause of space motion sickness.

  14. Flammability measurements of difluoromethane in air at 100 C

    SciTech Connect

    Grosshandler, W.L.; Donnelly, M.K.; Womeldorf, C.

    1999-07-01

    Difluoromethane (CH{sub 2}F{sub 2}, or R-32) is a candidate to replace currently used ozone-depleting chlorofluorocarbon refrigerants. Because CH{sub 2}F{sub 2} is flammable, it is necessary to assess the hazard posed by a leak in a refrigeration machine. The currently accepted method for determining flammability, ASTM E 681, has difficulty discerning the flammability boundary for weak fuels such as CH{sub 2}F{sub 2}. This paper describes an alternative approach to identify the limits of flammability, using a twin, premixed counter-flow flame. By using the extinction of an already established flame, the point dividing flammable from non-flammable becomes unambiguous. The limiting extinction mixture changes with stretch rate, so it is convenient to report the flammability limit as the value extrapolated to a zero stretch condition. In the burner, contoured nozzles with outlet diameters of 12 mm are aligned counter to each other and spaced 12 mm apart. The lean flammability limit of CH{sub 2}F{sub 2} in dry air at room temperature was previously reported by the authors to be a mole fraction of 0.14, using the twin counter-flow flame method. In the current study, relative humidity was not found to affect the lean limit. Increasing the temperature of the premixed fuel and air to 100 C is shown to extend the flammability limit in the lean direction to 0.13. The rich limit of CH{sub 2}F{sub 2} found using the counter-flow method is around 0.27. The uncertainties of the measurements are presented and the results compared to data in the literature.

  15. Measurements and analysis of air quality in Islamabad, Pakistan

    NASA Astrophysics Data System (ADS)

    Rasheed, Anjum; Aneja, Viney P.; Aiyyer, Anantha; Rafique, Uzaira

    2014-06-01

    Ambient air quality of Islamabad, Pakistan, reveals that annual average mass concentration of particulate matter (PM2.5) (˜45 to ˜95 µg m-3) and nitric oxide (NO) (˜41 to ˜120 µg m-3) exceeds the Pakistan's National Environmental Quality Standards (NEQS). The annual ozone (O3) concentration is within the permissible limits; however, some of the hourly concentration exceeds the NEQS mostly during the summer months. Correlation studies suggest that carbon monoxide (CO) has a significant (p-value ≤ 0.01) positive correlation with NO and NOy'; whereas, with O3, a significant (p-value ≤ 0.01) negative correlation is observed. The regression analysis estimates the background CO concentration to be ˜300 to ˜600 ppbv in Islamabad. The higher ratio of CO/NO (˜10) suggests that mobile sources are the major contributor to NO concentration. On the other hand, the ratio analysis of sulfur dioxide (SO2)/NO for Islamabad (˜0.011) indicates that the point sources are contributing to SO2 in the city. NO and SO2 correlation indicates contribution of direct sulfur emission sources. Ratios of [CO] to [NO] and [SO2] to [NO], based on ambient air quality measurements, provide a test for emission inventories. The ratios of these pollutants in the available Islamabad emission inventories are consistent with ambient values for these pollutants. The correlation of PM2.5 and NO suggests that a fraction of secondary PM2.5 is produced by chemical conversion of NO into nitrates. The regional background O3 concentration for Islamabad has been determined to be ˜31 ppbv. This study suggests that there is an increase in O3 concentration with increases in photochemical conversion of NO to reservoir NOy' species.

  16. Hazard Assessment of Chemical Air Contaminants Measured in Residences

    SciTech Connect

    Logue, J.M.; McKone, T.E.; Sherman, M. H.; Singer, B.C.

    2010-05-10

    Identifying air pollutants that pose a potential hazard indoors can facilitate exposure mitigation. In this study, we compiled summary results from 77 published studies reporting measurements of chemical pollutants in residences in the United States and in countries with similar lifestyles. These data were used to calculate representative mid-range and upper bound concentrations relevant to chronic exposures for 267 pollutants and representative peak concentrations relevant to acute exposures for 5 activity-associated pollutants. Representative concentrations are compared to available chronic and acute health standards for 97 pollutants. Fifteen pollutants appear to exceed chronic health standards in a large fraction of homes. Nine other pollutants are identified as potential chronic health hazards in a substantial minority of homes and an additional nine are identified as potential hazards in a very small percentage of homes. Nine pollutants are identified as priority hazards based on the robustness of measured concentration data and the fraction of residences that appear to be impacted: acetaldehyde; acrolein; benzene; 1,3-butadiene; 1,4-dichlorobenzene; formaldehyde; naphthalene; nitrogen dioxide; and PM{sub 2.5}. Activity-based emissions are shown to pose potential acute health hazards for PM{sub 2.5}, formaldehyde, CO, chloroform, and NO{sub 2}.

  17. Mobile system for on-road measurements of air pollutants

    NASA Astrophysics Data System (ADS)

    Katulski, Ryszard J.; Namieśnik, Jacek; Sadowski, Jarosław; Stefański, Jacek; Szymańska, Krystyna; Wardencki, Waldemar

    2010-04-01

    The paper presents a prototype of a mobile monitoring system for measuring the levels of the main traffic air pollutants (C6H6, NO2, NOx, CO, and CO2,) in cities. The novelty of the proposed system lies in the fact that it can be utilized to monitor emissions from urban traffic along roads and areas where traditional monitoring stations cannot be placed. In the proposed system, the monitoring device can be mounted on any moving vehicle (such as a car, bus, or truck) rather than be attached to a dedicated van, as most systems of this kind found in literature are. Analyzers used in this system are small portable structures that contain an electronic instrument to measure, record, and transmit relevant data on concentrations of the pollutants to a website. The model outcome for carbon monoxide obtained in functional tests in real conditions is also presented here. Data on temporal changes of carbon monoxide concentration are compared against meteorological parameters and speed of the vehicle. Spatial interpolation techniques are applied to obtain a nonplanar visualization of carbon monoxide and benzene concentrations in the main arteries of a city.

  18. Air shower arrival directions measured at Buckland Park

    NASA Technical Reports Server (NTRS)

    Gerhardy, P. R.; Prescott, J. R.; Protheroe, R. J.; Clay, R. W.; Patterson, J. R.; Gregory, A. G.

    1985-01-01

    The Buckland Park air shower array was operated for 3 years from 1979 to 1981 particularly for the study of anisotropies in the region of the knee of the size spectrum. The array which has been described in detail elsewhere was situated at a latitude of 35 S and had an effective size threshold of approx 3 x 10 to the 5th power particles (approx 3 x 10 to the 15th power Ev for vertical showers). A number of results from this experiment have already been published including anisotropy analyses (Gerhardy and Clay, 1983) and searches for very high energy gamma ray sources. The final distribution of measured shower arrival directions are presented here. These 1.3 x 10 to the 5th power events were selected as indicated in detail in Gerhardy and Clay (1983) and were essentially those events with well measured arrival directions. They are the same data set used in the above reference but no complete sky map has previously been presented.

  19. Analytical evaluation of the effects of inconsistent anthropometric measurements on joint kinematics in motion capturing.

    PubMed

    Krumm, Dominik; Cockcroft, John; Zaumseil, Falk; Odenwald, Stephan; Milani, Thomas L; Louw, Quinette

    2016-05-01

    Clinical decisions based on gait data obtained by optoelectronic motion capturing require profound knowledge about the repeatability of the used measurement systems and methods. The purpose of this study was to evaluate the effects of inconsistent anthropometric measurements on joint kinematics calculated with the Plug-in Gait model. Therefore, a sensitivity study was conducted to ascertain how joint kinematics output is affected to different anthropometric data input. One previously examined gait session of a healthy male subject and his anthropometric data that were assessed by two experienced examiners served as a basis for this analytical evaluation. This sensitivity study yielded a maximum difference in joint kinematics by the two sets of anthropometrics of up to 1.2°. In conclusion, this study has shown that the reliability of subjects' anthropometrics assessed by experienced examiners has no considerable effects on joint kinematics. PMID:27131168

  20. First mirror contamination studies for polarimetry motional Stark effect measurements for ITER

    SciTech Connect

    Kuldkepp, M.; Rachlew, E.; Hawkes, N.C.; Schunke, B.

    2004-10-01

    The motional Stark effect (MSE) diagnostic on the International Thermonuclear Experimental Reactor will need to guide the light through a labyrinth of mirrors to provide neutron shielding. Knowledge of how the mirrors change the polarization is essential for accurate determination of the q profile. The optical properties of the plasma facing mirror are also expected to change with time due to deposition/erosion. For the purpose of examining this experimentally a detector system, identical to the JET MSE system, using twin photoelastic modulators was constructed. Measurements have been performed on freshly prepared mirrors, on mirrors after exposure to plasmas in Tore Supra, and labyrinth designs. The result shows a significant effect on the optical properties and demonstrate the need for in situ monitoring. The measured properties of the labyrinth closely follow the Mueller matrix formalism. With a correct choice of material the angle change introduced by the four mirrors furthest away from the plasma will be below 1 deg.

  1. Note: Compact and light displacement sensor for a precision measurement system in large motion

    SciTech Connect

    Lee, Sang Heon

    2015-08-15

    We developed a compact and light displacement sensor applicable to systems that require wide range motions of its sensing device. The proposed sensor utilized the optical pickup unit of the optical disk drive, which has been used applied to atomic force microscopy (AFM) because of its compactness and lightness as well as its high performance. We modified the structure of optical pickup unit and made the compact sensor driver attachable to a probe head of AFM to make large rotation. The feasibilities of the developed sensor for a general probe-moving measurement device and for probe-rotating AFM were verified. Moreover, a simple and precise measurement of alignment between centers of rotator and probe tip in probe-rotation AFM was experimentally demonstrated using the developed sensor.

  2. A METHOD OF ASSESSING AIR TOXICS CONCENTRATIONS IN URBAN AREAS USING MOBILE PLATFORM MEASUREMENTS

    EPA Science Inventory

    The objective of this paper is to demonstrate an approach to characterize the spatial variability in ambient air concentrations using mobile platform measurements. This approach may be useful for air toxic assessments in Environmental Justice applications, epidemiological studies...

  3. Next Generation Air Measurements for Fugitive, Area Source, and Fence Line Applications

    EPA Science Inventory

    Next generation air measurements (NGAM) is an EPA term for the advancing field of air pollutant sensor technologies, data integration concepts, and geospatial modeling strategies. Ranging from personal sensors to satellite remote sensing, NGAM systems may provide revolutionary n...

  4. Within-day reliability of shoulder range of motion measurement with a smartphone.

    PubMed

    Shin, Seung Han; Ro, Du Hyun; Lee, O-Sung; Oh, Joo Han; Kim, Sae Hoon

    2012-08-01

    Measuring range of motion (ROM) is the first step of a physical examination and functional evaluation of the shoulder joint. Digital inclinometers are available on the market; however, they are expensive, and hence will not come into wide use. In this study, we present a new method for the shoulder ROM measurement using the inclinometer application on a smartphone. We hypothesized that the method would demonstrate acceptable reliability and reproducibility. Three observers performed goniometric and smartphone inclinometric measurements of various shoulder movements, including both active and passive ROM for forward flexion, abduction, external rotation while the arms are at the sides, external rotation at 90° abduction, and internal rotation at 90° abduction. Measurements were performed in the affected shoulders of 41 patients. All measurements were taken twice to assess the intra-observer reliability. Inter- and intra-observer reliabilities were evaluated using the intraclass correlation coefficient (ICC). Reliability between two measurements was also assessed in terms of the ICC. Both the goniometric and inclinometric measurements showed satisfactory inter-observer reliability except for internal rotation at 90° abduction for which the ICC value was <0.7 (range, 0.63-0.68). Intra-observer reliability was excellent with an ICC value>0.9, except for some movements. Within-day inclinometric measurements with a smartphone showed acceptable reliability compared to the classical goniometric measurements of movements and the correlation between the two measurements was fairly high. Considering convenience and cost-effectiveness, this new method could be widely used for measuring the shoulder ROM, although the between-day reliability needs to be established first. PMID:22421186

  5. THE PROPER MOTION OF PSR J1550-5418 MEASURED WITH VLBI: A SECOND MAGNETAR VELOCITY MEASUREMENT

    SciTech Connect

    Deller, A. T.; Camilo, F.; Halpern, J. P.; Reynolds, J. E.

    2012-03-20

    The formation mechanism of neutron stars with extremely large magnetic field strengths (magnetars) remains unclear. Some formation scenarios predict that magnetars should be born with extremely high space velocities, >1000 km s{sup -1}. Using the Long Baseline Array in Australia, we have measured the proper motion of the intermittently radio-bright magnetar PSR J1550-5418 (1E 1547.0-5408): {mu} = 9.2 {+-} 0.6 mas yr{sup -1}. For a likely distance of 6 {+-} 2 kpc, the implied transverse velocity is 280{sup +130}{sub -120} km s{sup -1} after correcting for Galactic rotation. Along with the Almost-Equal-To 200 km s{sup -1} transverse velocity measured for the magnetar XTE J1810-197, this result suggests that formation pathways producing large magnetic fields do not require very large birth kicks.

  6. A novel approach for the extraction of cloud motion vectors using airglow imager measurements

    NASA Astrophysics Data System (ADS)

    Satheesh Kumar, S.; Narayana Rao, T.; Taori, A.

    2015-09-01

    The paper explores the possibility of implementing an advanced photogrammetric technique, generally employed for satellite measurements, on airglow imager, a ground-based remote sensing instrument primarily used for upper atmospheric studies, measurements of clouds for the extraction of cloud motion vectors (CMVs). The major steps involved in the algorithm remain the same, including image processing for better visualization of target elements and noise removal, identification of target cloud, setting a proper search window for target cloud tracking, estimation of cloud height, and employing 2-D cross-correlation to estimate the CMVs. Nevertheless, the implementation strategy at each step differs from that of satellite, mainly to suit airglow imager measurements. For instance, climatology of horizontal winds at the measured site has been used to fix the search window for target cloud tracking. The cloud height is estimated very accurately, as required by the algorithm, using simultaneous collocated lidar measurements. High-resolution, both in space and time (4 min), cloud imageries are employed to minimize the errors in retrieved CMVs. The derived winds are evaluated against MST radar-derived winds by considering it as a reference. A very good correspondence is seen between these two wind measurements, both showing similar wind variation. The agreement is also found to be good in both the zonal and meridional wind velocities with RMSEs < 2.4 m s-1. Finally, the strengths and limitations of the algorithm are discussed, with possible solutions, wherever required.

  7. Use of fluidic oscillator to measure fuel-air ratios of combustion gases

    NASA Technical Reports Server (NTRS)

    Riddlebaugh, S. M.

    1974-01-01

    A fluidic oscillator was investigated for use in measuring fuel-air ratios in hydrocarbon combustion processes. The oscillator was operated with dry exhaust gas from an experimental combustor burning ASTM A-1 fuel. Tests were conducted with fuel-air ratios between 0.015 and 0.031. Fuel-air ratios determined by oscillator frequency were within 0.001 of the values computed from separate flow measurements of the air and fuel.

  8. The Effective Mass of a Ball in the Air

    ERIC Educational Resources Information Center

    Messer, J.; Pantaleone, J.

    2010-01-01

    The air surrounding a projectile affects the projectile's motion in three very different ways: the drag force, the buoyant force, and the added mass. The added mass is an increase in the projectile's inertia from the motion of the air around it. Here we experimentally measure the added mass of a spherical projectile in air. The results agree well…

  9. MEASUREMENT OF HYDROPEROXIDES DURING THE TEXAS 2000 AIR QUALITY STUDY.

    SciTech Connect

    ZHENG,J.; ALAOUIE,A.; WEINSTEIN-LLOYD,J.B.; SPRINGSTON,S.R.; NUNNERMACKER,L.J.; LEE,Y.N.; BRECHTEL,F.; KLEINMAN,L.; DAUM,P.

    2002-01-17

    Hydroperoxides are important atmospheric oxidants. They are responsible for most of the oxidation of aqueous-phase SO{sub 2} to sulfate in the northeastern United States, resulting in the formation of acid precipitation and visibility-reducing sulfate aerosol (Penkett et al., 1979; Lind et al., 1987; Madronich and Calvert, 1990; Tanner and Schorran, 1995). Atmospheric hydrogen peroxide (H{sub 2}O{sub 2} or HP) is produced by the self-reaction of hydroperoxyl radicals (HO{sub 2}); higher organic peroxides are produced by reaction of HO{sub 2} with alkylperoxyl radicals (RO{sub 2}). Peroxyl radicals, along with OH, are chain carriers in the complex photochemical process that produces tropospheric ozone. Thus, concentrations of peroxides and their free radical precursors depend on solar intensity and ambient concentrations of water vapor, ozone, NO{sub x} (NO + NO{sub 2}), and VOCs (volatile organic compounds). Several investigators have demonstrated that HP and hydroxymethyl hydroperoxide (HOCH2 OOH or HMHP) also may be formed when ozone reacts with alkenes in moist air (Becker et al., 1990; Hewitt and Kok, 1991; Gaeb et al., 1995). Peroxides are the expected sink for peroxyl radicals when concentrations of NO are low. Otherwise, these radicals react with NO to form NO{sub 2}. Under high NO{sub x} conditions, NO{sub z} (oxidation products of NO and NO{sub 2}) becomes the principal radical sink. Therefore, formation rates of peroxides relative to NO{sub z} provide information about the history of an air mass and the expected sensitivity of ozone production to reduced emissions (Kleinman et al., 1997; Sillman, 1995; 1997). Through photolysis and reaction with OH, peroxides also act as a radical source; thus, reliable peroxide measurements are necessary for calculating ozone production rates. In this paper, we will summarize peroxide observations at the Williams Tower, and aboard the U.S. Department of Energy G-1 research aircraft in Houston, TX, during August and

  10. Laboratory Evaluation of Air Flow Measurement Methods for Residential HVAC Returns

    SciTech Connect

    Walker, Iain; Stratton, Chris

    2015-07-01

    This project improved the accuracy of air flow measurements used in commissioning California heating and air conditioning systems in Title 24 (Building and Appliance Efficiency Standards), thereby improving system performance and efficiency of California residences. The research team at Lawrence Berkeley National Laboratory addressed the issue that typical tools used by contractors in the field to test air flows may not be accurate enough to measure return flows used in Title 24 applications. The team developed guidance on performance of current diagnostics as well as a draft test method for use in future evaluations. The series of tests performed measured air flow using a range of techniques and devices. The measured air flows were compared to reference air flow measurements using inline air flow meters built into the test apparatus. The experimental results showed that some devices had reasonable results (typical errors of 5 percent or less) but others had much bigger errors (up to 25 percent).

  11. Multi-temporal InSAR measurement of interseimic motion on the eastern Tibet border

    NASA Astrophysics Data System (ADS)

    Doin, M. P.; Lasserre, C.; He, P.; de Sigoyer, J.

    2014-12-01

    We use here SAR interferometry using archived Envisat data to map the interseismic deformation of eastern Tibet. The area under study starts just South of the Haiyuan fault, crosses the eastern termination of the Kunlun fault and the bend on the XianShuiHe fault to the South. It includes the Longriba fault system, an active structure located 150 km west of the Longmen Shan front (Xu et al., 2008, Ren et al., 2013). GPS data suggest that it may accommodate a large part of the present-day relative movement (6-8 mm/yr) between the Aba block and the south China block (Thatcher, 2007, Shen et al 2005). The Longriba and the Longmen Shan faults might be linked at depth by a decollement zone or by ductile shear in the crust (Shu et al., 2008). We process three adjacent Envisat 1000 km long swaths crossing this mountainous and vegetated terrain using a small baseline strategy. The interferograms show numerous phase perturbations that mask the interseismic motion due to : (1) coherence loss, (2) stratified atmospheric delays, (3) DEM error contribution, (4) the 2008 Sichuan earthquake. We will show how we tackle these limitations and display the effect of successive corrections. Focus will first be brought to the corrections applied before filtering and unwrapping, that increase phase spatial continuity. We estimate empirically stratified atmospheric delay polynomial relationship, depending on azimuth and elevation, on wrapped interferograms. We then estimate the local DEM error for each pixel. Multi-looking and filtering are based on various measures of pixel reliability in order to increase the signal to noise ratio of filtered interferograms. Finally, unwrapping is obtained by a region growing algorithm, from the most reliable areas to the least, avoiding to cross layover areas. Time series of phase delay maps in the Longriba area are dominated by a side lobe of the May 2008 Sichuan earthquake. After its extraction and correction, principal component analysis clearly

  12. Measurement of basilar membrane motion in the turtle with laser-feedback interferometry

    NASA Astrophysics Data System (ADS)

    O'Neill, Michael P.; Bearden, Alan J.

    1993-09-01

    In mammalian hearing, the frequency-dependent spatial pattern of movement in the basilar membrane (BM) forms the basis of frequency discrimination (tuning). This is not necessarily the case in lower vertebrates; the turtle, for example, has an electrical resonance mechanism in its auditory receptor cells that varies in best frequency from cell-to-cell along the underlying BM. But how much, if any, of the frequency separation by this reptile is done mechanically by its BM? In other animals, vibrational analyses were indirect in that they required the placement of nonphysiological objects on the BM (e.g., the radioactive source of the Mossbaurer technique or the mirror of traditional laser interferometry). Our attempt to find an alternative approach led to the rediscovery of laser-feedback interferometry (LFI), here applied for the first time to vibration analysis in a biological system. LFI is an ideal method to directly measure the nanometer motion (amplitude and phase) of diffuse scattering surfaces such as the BM because of its simple geometry, ease of alignment, and its ability to respond to surfaces with a broad range of reflectances (10-6 to 1). Preliminary LFI investigations of BM motion in the turtle reveal that its BM is broadly tuned and mainly reflects middle ear filter characteristics. No evidence for frequency-selective spatial BM mechanical tuning was found.

  13. Kinematics differences between the flat, kick, and slice serves measured using a markerless motion capture method.

    PubMed

    Sheets, Alison L; Abrams, Geoffrey D; Corazza, Stefano; Safran, Marc R; Andriacchi, Thomas P

    2011-12-01

    Tennis injuries have been associated with serving mechanics, but quantitative kinematic measurements in realistic environments are limited by current motion capture technologies. This study tested for kinematic differences at the lower back, shoulder, elbow, wrist, and racquet between the flat, kick, and slice serves using a markerless motion capture (MMC) system. Seven male NCAA Division 1 players were tested on an outdoor court in daylight conditions. Peak racquet and joint center speeds occurred sequentially and increased from proximal (back) to distal (racquet). Racquet speeds at ball impact were not significantly different between serve types. However, there were significant differences in the direction of the racquet velocity vector between serves: the kick serve had the largest lateral and smallest forward racquet velocity components, while the flat serve had the smallest vertical component (p < 0.01). The slice serve had lateral velocity, like the kick, and large forward velocity, like the flat. Additionally, the racquet in the kick serve was positioned 8.7 cm more posterior and 21.1 cm more medial than the shoulder compared with the flat, which could suggest an increased risk of shoulder and back injury associated with the kick serve. This study demonstrated the potential for MMC for testing sports performance under natural conditions. PMID:21984513

  14. "New Proper Motion Measurements of the Superluminal Velocities in the M87 Optical Jet with HST"

    NASA Astrophysics Data System (ADS)

    Meyer, Eileen T.; Sparks, W. B.; Biretta, J. A.; Sohn, S.; Anderson, J.; Van Der Marel, R. P.; Norman, C. A.; Nakamura, M.

    2014-01-01

    Using over 13 years of archival HST observations of the relativistic jet in the archetypal radio galaxy M87, we have produced astrometric speed measurements of the optically bright synchrotron emitting plasma components in the jet with unprecedented accuracy. Building on previous work showing the superluminal nature of the jet in the optical, we have found that the jet motion is incredibly complex, with both transverse motions and flux variations which can be seen very clearly by eye in the timeseries of deep exposures. These observations of M87 provide us with a unique dataset with which to refine theoretical models of the largescale jet structure, potentially addressing open questions such as the jet collimation mechanism, bulk acceleration and deceleration in the jet, and the presence of a helical structure. I will also present very recent results using data from the HST archive on the optical counterjet and nuclear regions of M87 and discuss the larger implications of these detailed studies of one of the most nearby AGN jets.

  15. OPTICAL PROPER MOTION MEASUREMENTS OF THE M87 JET: NEW RESULTS FROM THE HUBBLE SPACE TELESCOPE

    SciTech Connect

    Meyer, Eileen T.; Sparks, W. B.; Biretta, J. A.; Anderson, Jay; Sohn, Sangmo Tony; Van der Marel, Roeland P.; Norman, Colin; Nakamura, Masanori

    2013-09-10

    We report new results from a Hubble Space Telescope archival program to study proper motions in the optical jet of the nearby radio galaxy M87. Using over 13 yr of archival imaging, we reach accuracies below 0.1c in measuring the apparent velocities of individual knots in the jet. We confirm previous findings of speeds up to 4.5c in the inner 6'' of the jet, and report new speeds for optical components in the outer part of the jet. We find evidence of significant motion transverse to the jet axis on the order of 0.6c in the inner jet features, and superluminal velocities parallel and transverse to the jet in the outer knot components, with an apparent ordering of velocity vectors possibly consistent with a helical jet pattern. Previous results suggested a global deceleration over the length of the jet in the form of decreasing maximum speeds of knot components from HST-1 outward, but our results suggest that superluminal speeds persist out to knot C, with large differentials in very nearby features all along the jet. We find significant apparent accelerations in directions parallel and transverse to the jet axis, along with evidence for stationary features in knots D, E, and I. These results are expected to place important constraints on detailed models of kiloparsec-scale relativistic jets.

  16. MOTION AND DISORDER IN CRYSTAL STRUCTURE ANALYSIS: Measuring and Distinguishing Them

    NASA Astrophysics Data System (ADS)

    Burgi, H. B.

    2000-10-01

    Dynamic processes in crystalline solids are reflected in the atomic displacement amplitudes determined, together with the atomic coordinates, by crystal structure analysis. The interpretation of such amplitudes poses two severe problems: (a) The relative phases of the atomic displacements are lost; and (b) the amplitudes may reflect disorder in the structure and systematic error in the diffraction experiment in addition to motion, but the three contributions cannot be separated on the basis of measurements at a single temperature. Several approximate ways to solve these problems, e.g. rigid-body and segmented-rigid-body analysis, are reviewed together with their limitations. A more recent approach that represents a significant advance with respect to both difficulties is also described: Crystal structures are determined over a range of temperatures; the mean square amplitude quantities are interpreted by taking explicit account of their temperature dependence, i.e. by exploiting the difference in behavior of a microscopic oscillator in the low-temperature, quantum regime and in the high-temperature, classical regime. A distinction between low-frequency and high-frequency motion, disorder, and systematic error becomes possible with this model; this is illustrated with the help of case studies.

  17. Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. 3; Measurement for URSA Minor

    NASA Technical Reports Server (NTRS)

    Piatek, Slawomir; Pryor, Carlton; Bristow, Paul; Olszewski, Edward W.; Harris, Hugh C.; Mateo, Mario; Minniti, Dante; Tinney, Christopher G.

    2005-01-01

    This article presents a measurement of the proper motion of the Ursa Minor dwarf spheroidal galaxy determined from images taken with the Hubble Space Telescope in two distinct fields. Each field contains a quasi-stellar object that serves as the "reference point". Integrating the motion of Ursa Minor in a realistic potential for the Milky Way produces orbital elements. The perigalacticon and apogalacticon are 40 (10, 76) and 89 (78, 160) kpc, respectively, where the values in the parentheses represent the 95% confidence intervals derived from Monte Carlo experiments. The eccentricity of the orbit is 0.39 (0.09, 0.79), and the orbital period is 1.5 (1.1, 2.7) Gyr. The orbit is retrograde and inclined by 124 degrees (94 deg, 36 deg ) to the Galactic plane. Ursa Minor is not a likely member of a proposed stream of galaxies on similar orbits around the Milky Way, nor is the plane of its orbit coincident with a recently proposed planar alignment of galaxies around the Milky Way. Comparing the orbits of Ursa Minor and Carina shows no reason for the different star formation histories of these two galaxies. Ursa Minor must contain dark matter to have a high probability of having survived disruption by the Galactic tidal force until the present.

  18. In vivo motion and force measurement of surgical needle intervention during prostate brachytherapy

    SciTech Connect

    Podder, Tarun; Clark, Douglas; Sherman, Jason; Fuller, Dave; Messing, Edward; Rubens, Deborah; Strang, John; Brasacchio, Ralph; Liao, Lydia; Ng, W.-S.; Yu Yan

    2006-08-15

    In this paper, we present needle insertion forces and motion trajectories measured during actual brachytherapy needle insertion while implanting radioactive seeds in the prostate glands of 20 different patients. The needle motion was captured using ultrasound images and a 6 degree-of-freedom electromagnetic-based position sensor. Needle velocity was computed from the position information and the corresponding time stamps. From in vivo data we found the maximum needle insertion forces to be about 15.6 and 8.9 N for 17 gauge (1.47 mm) and 18 gauge (1.27 mm) needles, respectively. Part of this difference in insertion forces is due to the needle size difference (17G and 18G) and the other part is due to the difference in tissue properties that are specific to the individual patient. Some transverse forces were observed, which are attributed to several factors such as tissue heterogeneity, organ movement, human factors in surgery, and the interaction between the template and the needle. However, theses insertion forces are significantly responsible for needle deviation from the desired trajectory and target movement. Therefore, a proper selection of needle and modulated velocity (translational and rotational) may reduce the tissue deformation and target movement by reducing insertion forces and thereby improve the seed delivery accuracy. The knowledge gleaned from this study promises to be useful for not only designing mechanical/robotic systems but also developing a predictive deformation model of the prostate and real-time adaptive controlling of the needle.

  19. Simultaneous Measurement of Fluid and Particle Motion in Shear Induced Erosion

    NASA Astrophysics Data System (ADS)

    Krueger, Paul S.; An, Zhongfeng

    2015-11-01

    Fluid particle interaction is fundamental to shear induced particle erosion, but experimental measurements of this interaction are challenging due to differing optical characteristics of the fluid and particles and because of the high particle volume fraction in the particle bed. To address these challenges, monodisperse glass beads were used with a refractive-index matched aqueous solution of NaI flowing horizontally over the particle bed. Two cameras separately imaged the fluid and particle phase motion using optical filters to isolate the emission bands of the fluorescent fluid tracer particles and dye added to the fluid for the fluid and particle phase cameras, respectively. Then digital particle image velocimetry and particle tracking were used to obtain the full-field, time-varying evolution of the fluid and particle motion simultaneously. The results showed rapid, fluctuating particle transport near flow initiation for sufficiently high fluid flow rates. Increased slip in mean particle velocities was observed above from the particle bed surface and an approximately linear relationship was observed between particle and fluid velocity fluctuations. This material is based on work supported by the National Science Foundation under grant no. 1000908.

  20. Motion artifact removal algorithm by ICA for e-bra: a women ECG measurement system

    NASA Astrophysics Data System (ADS)

    Kwon, Hyeokjun; Oh, Sechang; Varadan, Vijay K.

    2013-04-01

    Wearable ECG(ElectroCardioGram) measurement systems have increasingly been developing for people who suffer from CVD(CardioVascular Disease) and have very active lifestyles. Especially, in the case of female CVD patients, several abnormal CVD symptoms are accompanied with CVDs. Therefore, monitoring women's ECG signal is a significant diagnostic method to prevent from sudden heart attack. The E-bra ECG measurement system from our previous work provides more convenient option for women than Holter monitor system. The e-bra system was developed with a motion artifact removal algorithm by using an adaptive filter with LMS(least mean square) and a wandering noise baseline detection algorithm. In this paper, ICA(independent component analysis) algorithms are suggested to remove motion artifact factor for the e-bra system. Firstly, the ICA algorithms are developed with two kinds of statistical theories: Kurtosis, Endropy and evaluated by performing simulations with a ECG signal created by sgolayfilt function of MATLAB, a noise signal including 0.4Hz, 1.1Hz and 1.9Hz, and a weighed vector W estimated by kurtosis or entropy. A correlation value is shown as the degree of similarity between the created ECG signal and the estimated new ECG signal. In the real time E-Bra system, two pseudo signals are extracted by multiplying with a random weighted vector W, the measured ECG signal from E-bra system, and the noise component signal by noise extraction algorithm from our previous work. The suggested ICA algorithm basing on kurtosis or entropy is used to estimate the new ECG signal Y without noise component.

  1. Measuring vibrational motion in the presence of speckle using off-axis holography.

    PubMed

    Redding, Brandon; Davis, Allen; Kirkendall, Clay; Dandridge, Anthony

    2016-02-20

    We present a holographic laser vibrometer designed to mitigate the effects of speckle noise when measuring the vibrational motion of a rough object. We show that multiplexing the interferometric measurement across 105 pixels provides a 50 dB reduction in the incoherent noise. Using a high-speed camera, this enables a displacement sensitivity of 50  fm/√Hz with a bandwidth of 12.5 kHz when measuring rough objects, representing a 20 dB improvement compared with a commercially available single-detector-based laser vibrometer. Finally, we show that the holographic vibrometer system is capable of stand-off acoustic sensing by measuring the acoustic-induced vibrations of a piece of paper with sensitivity as low as 10 dB (re 20 μPa). The ability to sensitively and noninvasively measure the vibrations of arbitrary rough surfaces could enable new applications in laser vibrometry. PMID:26906594

  2. Motion as a perturbation: Measurement-guided dose estimates to moving patient voxels during modulated arc deliveries

    SciTech Connect

    Feygelman, Vladimir; Zhang, Geoffrey; Hunt, Dylan; Opp, Daniel; Stambaugh, Cassandra; Wolf, Theresa K.; Nelms, Benjamin E.

    2013-02-15

    Purpose: To present a framework for measurement-guided VMAT dose reconstruction to moving patient voxels from a known motion kernel and the static phantom data, and to validate this perturbation-based approach with the proof-of-principle experiments. Methods: As described previously, the VMAT 3D dose to a static patient can be estimated by applying a phantom measurement-guided perturbation to the treatment planning system (TPS)-calculated dose grid. The fraction dose to any voxel in the presence of motion, assuming the motion kernel is known, can be derived in a similar fashion by applying a measurement-guided motion perturbation. The dose to the diodes in a helical phantom is recorded at 50 ms intervals and is transformed into a series of time-resolved high-density volumetric dose grids. A moving voxel is propagated through this 4D dose space and the fraction dose to that voxel in the phantom is accumulated. The ratio of this motion-perturbed, reconstructed dose to the TPS dose in the phantom serves as a perturbation factor, applied to the TPS fraction dose to the similarly situated voxel in the patient. This approach was validated by the ion chamber and film measurements on four phantoms of different shape and structure: homogeneous and inhomogeneous cylinders, a homogeneous cube, and an anthropomorphic thoracic phantom. A 2D motion stage was used to simulate the motion. The stage position was synchronized with the beam start time with the respiratory gating simulator. The motion patterns were designed such that the motion speed was in the upper range of the expected tumor motion (1-1.4 cm/s) and the range exceeded the normally observed limits (up to 5.7 cm). The conformal arc plans for X or Y motion (in the IEC 61217 coordinate system) consisted of manually created narrow (3 cm) rectangular strips moving in-phase (tracking) or phase-shifted by 90 Degree-Sign (crossing) with respect to the phantom motion. The XY motion was tested with the computer-derived VMAT

  3. Research on Air Flow Measurement and Optimization of Control Algorithm in Air Disinfection System

    NASA Astrophysics Data System (ADS)

    Bing-jie, Li; Jia-hong, Zhao; Xu, Wang; Amuer, Mohamode; Zhi-liang, Wang

    2013-01-01

    As the air flow control system has the characteristics of delay and uncertainty, this research designed and achieved a practical air flow control system by using the hydrodynamic theory and the modern control theory. Firstly, the mathematical model of the air flow distribution of the system is analyzed from the hydrodynamics perspective. Then the model of the system is transformed into a lumped parameter state space expression by using the Galerkin method. Finally, the air flow is distributed more evenly through the estimation of the system state and optimal control. The simulation results show that this algorithm has good robustness and anti-interference ability

  4. Six Degrees-of-Freedom Prostate and Lung Tumor Motion Measurements Using Kilovoltage Intrafraction Monitoring

    SciTech Connect

    Huang, Chen-Yu; Tehrani, Joubin Nasehi; Ng, Jin Aun; Booth, Jeremy; Keall, Paul

    2015-02-01

    Purpose: Tumor positional uncertainty has been identified as a major issue that deteriorates the efficacy of radiation therapy. Tumor rotational movement, which is not well understood, can result in significant geometric and dosimetric inaccuracies. The objective of this study was to measure 6 degrees-of-freedom (6 DoF) prostate and lung tumor motion, focusing on the more novel rotation, using kilovoltage intrafraction monitoring (KIM). Methods and Materials: Continuous kilovoltage (kV) projections of tumors with gold fiducial markers were acquired during radiation therapy for 267 fractions from 10 prostate cancer patients and immediately before or after radiation therapy for 50 fractions from 3 lung cancer patients. The 6 DoF motion measurements were determined from the individual 3-dimensional (3D) marker positions, after using methods to reject spurious and smooth noisy data, using an iterative closest point algorithm. Results: There were large variations in the magnitude of the tumor rotation among different fractions and patients. Various rotational patterns were observed. The average prostate rotation angles around the left-right (LR), superior-inferior (SI), and anterior-posterior (AP) axes were 1.0 ± 5.0°, 0.6 ± 3.3°, and 0.3 ± 2.0°, respectively. For 35% of the time, the prostate rotated more than 5° about the LR axis, indicating the need for intrafractional adaptation during radiation delivery. For lung patients, the average LR, SI, and AP rotation angles were 0.8 ± 4.2°, −0.8 ± 4.5°, and 1.7 ± 3.1°, respectively. For about 30% of the time, the lung tumors rotated more than 5° around the SI axis. Respiration-induced rotation was detected in 2 of the 3 lung patients. Conclusions: The prostate and lung tumors were found to undergo rotations of more than 5° for about a third of the time. The lung tumor data represent the first 6 DoF tumor motion measured by kV images. The 6 DoF KIM method can enable rotational and translational

  5. Using motionally-induced electric signals to indirectly measure ocean velocity: Instrumental and theoretical developments

    NASA Astrophysics Data System (ADS)

    Szuts, Zoltan B.

    2012-04-01

    The motion of conductive sea water through the earth’s magnetic field generates electromagnetic (EM) fields through a process called motional induction. Direct measurements of oceanic electric fields can be easily converted to water velocities by application of a first order theory. This technique has been shown to obtain high quality velocities through instrumental advances and an accumulation of experience during the past decades. EM instruments have unique operational considerations and observe, for instance, vertically-averaged horizontal velocity (from stationary sensors) or vertical profiles of horizontal velocity (from expendable probes or autonomous profiling floats). The first order theory describes the dominant electromagnetic response, in which vertically-averaged and vertically-varying horizontal velocities are proportional to electric fields and electric currents, respectively. After discussions of the first order theory and deployment practices, operational capabilities are shown through recently published projects that describe stream-coordinate velocity structure of the Antarctic Circumpolar Current, quickly-evolving overflow events in the Denmark Strait, and time-development of momentum input into the ocean from a hurricane. A detailed analysis of the Gulf Stream at its separation point from the continental slope serves as a case study for interpreting EM measurements, including the incorporation of geophysical knowledge of the sediment. In addition, the first order approximation is tested by the many features at this location that contradict the approximation’s underlying assumptions: sharp horizontal velocity gradients, steep topography, and thick and inhomogeneous sediments. Numerical modeling of this location shows that the first order assumption is accurate to a few percent (a few cm s-1) in almost all cases. The errors in depth-varying velocity are <3% (1-3 cm s-1), are substantiated by the direct observations, and can be corrected by

  6. Comparisons of Air Radiation Model with Shock Tube Measurements

    NASA Technical Reports Server (NTRS)

    Bose, Deepak; McCorkle, Evan; Bogdanoff, David W.; Allen, Gary A., Jr.

    2009-01-01

    This paper presents an assessment of the predictive capability of shock layer radiation model appropriate for NASA s Orion Crew Exploration Vehicle lunar return entry. A detailed set of spectrally resolved radiation intensity comparisons are made with recently conducted tests in the Electric Arc Shock Tube (EAST) facility at NASA Ames Research Center. The spectral range spanned from vacuum ultraviolet wavelength of 115 nm to infrared wavelength of 1400 nm. The analysis is done for 9.5-10.5 km/s shock passing through room temperature synthetic air at 0.2, 0.3 and 0.7 Torr. The comparisons between model and measurements show discrepancies in the level of background continuum radiation and intensities of atomic lines. Impurities in the EAST facility in the form of carbon bearing species are also modeled to estimate the level of contaminants and their impact on the comparisons. The discrepancies, although large is some cases, exhibit order and consistency. A set of tests and analyses improvements are proposed as forward work plan in order to confirm or reject various proposed reasons for the observed discrepancies.

  7. Demonstrations of Magnetic Phenomena: Measuring the Air Permeability Using Tablets

    ERIC Educational Resources Information Center

    Lara, V. O. M.; Amaral, D. F.; Faria, D.; Vieira, L. P.

    2014-01-01

    We use a tablet to experimentally determine the dependencies of the magnetic field (B) on the electrical current and the axial distance from a coil (z). Our data shows good precision on the inverse cubic dependence of the magnetic field on the axial distance, B?z[superscript -3]. We obtain the value of air permeability µ[subscript air] with good…

  8. Combination of Insar and GPS to Measure Ground Motions and Atmospheric Signals

    NASA Astrophysics Data System (ADS)

    Zerbini, S.; Prati, C.; Errico, M.; Ferri, S.; Novali, F.; Scirpoli, S.; Tiberi, L.

    2010-12-01

    The combination of different techniques such as InSAR and GPS is characterized by the added value of taking advantage of their complementary strengths and of minimizing their respective weaknesses, thus allowing for the full exploitation of the complementary aspects by overcoming the limitations inherent in the use of each technique alone. Another important aspect of the GPS/InSAR integration regards the fact that today’s application of interferometric SAR techniques is limited by the knowledge of the wet tropospheric path delay in microwave observations. GPS-based estimates of tropospheric delays may help in obtaining better corrections which will enhance the coherence and will allow the application of InSAR in a wider range of applications. The area selected for the InSAR/GPS comparison/integration is in northeastern Italy and includes the town of Bologna, and two nearby sites Medicina (agricultural area) and Loiano (a small city on the Apennines) where a small network of permanent GPS stations is operated by the University of Bologna. The InSAR data used are the COSMO-SkyMed (CSK) images made available by the Italian Space Agency (ASI) in the framework of the research contract AO-1140. The Permanent Scatterers (PS) technique will be applied to a number of repeated CSK strip map SAR images acquired over a 40x40 square km area encompassing the towns mentioned above. Ultimately this work will contribute demonstrating the CSK capabilities to operate in a repeated interferometric survey mode for measuring ground deformation with millimeter accuracy in different environments. A PS is a target whose radar signature is stable with time. Such targets can be identified by means of multiple SAR observations and they can be exploited for jointly estimating their relative motion and the atmospheric artifacts on a grid that can be quite dense in space but not in time (depending on the SAR revisiting time interval). On the contrary the GPS can provide very frequent time

  9. Measurement of velocity and vorticity fields in the wake of an airfoil in periodic pitching motion

    NASA Technical Reports Server (NTRS)

    Booth, Earl R., Jr.

    1987-01-01

    The velocity field created by the wake of an airfoil undergoing a prescribed pitching motion was sampled using hot wire anemometry. Data analysis methods concerning resolution of velocity components from cross wire data, computation of vorticity from velocity time history data, and calculation of vortex circulation from vorticity field data are discussed. These data analysis methods are applied to a flow field relevant to a two dimensional blade-vortex interaction study. Velocity time history data were differentiated to yield vorticity field data which are used to characterize the wake of the pitching airfoil. Measurement of vortex strength in sinusoidal and nonsinusoidal wakes show vortices in the sinusoidal wake have stronger circulation and more concentrated vorticity distributions than the tailored nonsinusoidal wake.

  10. 3-dimentional measurement of cable configuration being based on feature tracking motion stereo

    NASA Astrophysics Data System (ADS)

    Domae, Yukiyasu; Okuda, Haruhisa; Takauji, Hidenori; Kaneko, Shun'ichi; Tanaka, Takayuki

    2007-10-01

    We propose a novel three-Dimensional measurement approach of flexible cables for factory automation appliations, such as cable handling, connecter insertion without conflicts with cables by using robotic arms. The approach is based on motion stereo with a vision sensor. Laser slit beams are irradiated and make landmalks on the cables to solve stereo correspondence problem efficiently. These landmark points and interpolated points having rich texture are tracked in a image sequence, and reconstructed as the cable shape. For stable feature point tracking, a robust texture matching method which is Orientation Code Matching and tracking stability analysis are applied. In our experiments, arch-like cables have been reconstructed with an uncertainty of 1.5 % by this method.

  11. Large band high sensitivity motion measurement and control of spacecrafts and satellites

    NASA Astrophysics Data System (ADS)

    Barone, F.; Giordano, G.; Acernese, F.; Romano, R.

    2016-04-01

    In this paper we describe the characteristics and performances of mono-axial monolithic sensors aimed to low frequency motion measurement and control of spacecrafts and satellites. The mechanical part of these sensors is based on the UNISA Folded Pendulum, a mechanical architecture developed for ground-based applications. The unique features of the UNISA class of folded pendulum sensors (compactness, lightness, scalability, low resonance frequency and high quality factor) are based on the action of the gravitational force on the the moving part of the sensor. In this paper we show how to extend the application of ground-based folded pendulum also to space, in absence of gravity, still keeping all their peculiar features and characteristics. Tests on a prototype confirm the feasibility of this application, demonstrating also that interesting performances can be relatively easily obtained.

  12. Validation of the flux loop diagnostic for the measurement of launch package motion during electromagnetic launch

    NASA Astrophysics Data System (ADS)

    Koops, M.

    1992-07-01

    The development of diagnostics for studying the behavior and performance of armatures and rail accelerators is one of the subjects covered by the section EML-research of the PML-Pulse Physics Laboratory. Within that framework the development of data analysis software is in progress. This report describes a new data reduction technique to resolve armature motion from the measurement of the voltage induced in a flux loop diagnostic and the load current through the rail-armature circuit and/or its time derivative. Velocity and position of the armature as a function of time are calculated by the computer code developed. The recent improvements in data reduction are exemplified by the results of experiments performed with a 1m, 15mm square bore dipole rail accelerator. Validation of the flux loop diagnostic, in terms of accuracy, precision, range of operation, resolution, sensitivity and prospects is carried out. Suggestions to reduce the influence of the disadvantages observed are given.

  13. Using Brownian motion to measure shape asymmetry in mesoscopic matter using optical tweezers.

    PubMed

    Roy, Basudev; Mondal, Argha; Bera, Sudipta K; Banerjee, Ayan

    2016-06-21

    We propose a new method for quantifying shape asymmetry on the mesoscopic scale. The method takes advantage of the intrinsic coupling between rotational and translational Brownian motion (RBM and TBM, respectively) which happens in the case of asymmetric particles. We determine the coupling by measuring different correlation functions of the RBM and TBM for single, morphologically different, weakly trapped red blood cells in optical tweezers. The cells have different degrees of asymmetry that are controllably produced by varying the hypertonicity of their aqueous environment. We demonstrate a clear difference in the nature of the correlation functions both qualitatively and quantitatively for three types of cells having a varying degree of asymmetry. This method can have a variety of applications ranging from early stage disease diagnosis to quality control in microfabrication. PMID:27198612

  14. Airborne Measurements of Trace Gases and Aerosols in Northern China: EAST-AIRE IOP 2005

    NASA Astrophysics Data System (ADS)

    Li, C.; Dickerson, R. R.; Li, Z.; Stehr, J. W.; Chen, H.; Marufu, L. T.

    2005-12-01

    To characterize the emission, transport and removal of pollutants and aerosols emitted from East Asia, a US-China joint field campaign was conducted from February to April in China under the EAST-AIRE project. Surface and airborne measurements of trace gases and aerosols were made at different locations in northern China. In early April, eight research flights were conducted around Shenyang, an industrialized city with a population of about 6 million, 600 km northeast of Beijing. Parameters measured include SO2, CO, O3, aerosol size distribution, aerosol scattering and absorption coefficients. During 4 of the 8 flights, the research aircraft made spirals over two suburban locations (~50 km south and north of the downtown area of Shenyang) to determine the detailed vertical distribution of trace gases and aerosols. Various weather patterns were encountered, allowing an examination of the roles of atmospheric circulation in transporting local pollutants to much larger areas. For example, the flights made ahead of the cold front showed fairly high concentrations of pollutants above the planetary boundary layer, probably lifted by the upward motion associated with the approaching cold fronts. On the other hand, much lower pollutant levels were found for the flights made behind the cold front. Also observed in one cold-sector flight is a level (~3000 m) with enhanced aerosol scattering but almost undetectable SO2. Back trajectory analysis using NOAA-HYSPLIT model suggests possible dust transport from source regions.

  15. Color structured light system of chest wall motion measurement for respiratory volume evaluation

    NASA Astrophysics Data System (ADS)

    Chen, Huijun; Cheng, Yuan; Liu, Dongdong; Zhang, Xiaodong; Zhang, Jue; Que, Chengli; Wang, Guangfa; Fang, Jing

    2010-03-01

    We present a structured light system to dynamically measure human chest wall motion for respiratory volume estimation. Based on a projection of an encoded color pattern and a few active markers attached to the trunk, respiratory volumes are obtained by evaluating the 3-D topographic changes of the chest wall in an anatomically consistent measuring region during respiration. Three measuring setups are established: a single-sided illuminating-recording setup for standing posture, an inclined single-sided setup for supine posture, and a double-sided setup for standing posture. Results are compared with the pneumotachography and show good agreement in volume estimations [correlation coefficient: R>0.99 (P<0.001) for all setups]. The isovolume tests present small variations of the obtained volume during the isovolume maneuver (standard deviation<0.085 L for all setups). After validation by the isovolume test, an investigation of a patient with pleural effusion using the proposed method shows pulmonary functional differences between the diseased and the contralateral sides of the thorax, and subsequent improvement of this imbalance after drainage. These results demonstrate the proposed optical method is capable of not only whole respiratory volume evaluation with high accuracy, but also regional pulmonary function assessment in different chest wall behaviors, with the advantage of whole-field measurement.

  16. Ground motion measurement in the lake Mead (Nevada, USA) area by temporal analysis of multiple interferograms.

    NASA Astrophysics Data System (ADS)

    Cavalie, O.; Doin, M.; Lasserre, C.; Briole, P.

    2004-12-01

    SAR interferometry has proven to be a reliable method for detecting small displacements due to ground subsidence. In this study, we propose to measure ground motion around the lake Mead (Nevada, USA) using InSAR. This artificial lake has been filled with water in 1935. An earlier studie, based on levelling measurements, has shown that the lake impoundement has induced a subsidence of 17 centimeters (Kaufmann et al., 2000). This relaxation process is analogous to the postglacial rebound, but at a smaller scale. To quantify the deformation and constrain the crust and mantle rheological parameters in the lake area, we have analysed multiple interferograms (245) based on 45 ERS images between 1992 and 2001. The interferometric phase contains information about deformation occurring between two satellite passes, as well as satellite orbits errors, topographic, and atmospheric artefacts. The topographic signature is removed using the 3-arc seconds SRTM data. To correct for orbital errors, we remove a best fitting linear ramp. Atmospheric artefact, in our interferograms, are mainly due to the variation of water vapor vertical stratification between the two passes. This results in a interferometric phase correlation with altitude which we remove by minimization. These corrections are then refined through an iterative procedure and validated using data from global atmospheric models. Corrected interferograms are then inverted to solve for deformation using a method based on the large spatial coverage of coherent pixels, allowing to strengthen the signal to noise ratio (Schmidt and Burgmann, 2003). This data inversion provides a time series of the expected deformation in the lake Mead area. The analysis of the deformation evolution during the period covered by the ERS satellites (1992-2001) shows a correlation between the vertical motion and the water level changes. So, we observe a subsidence of up to 1.5 cm between 1996 and 1998, followed by an uplift due to the drop of the

  17. Current Arabian Plate Motion From Campaign GPS Measurements in Saudi Arabia: Preliminary Results

    NASA Astrophysics Data System (ADS)

    Almuslmani, B.; Teferle, F. N.; Bingley, R. M.; Moore, T.

    2007-12-01

    Current investigations of the motions of the Arabian and its neighboring plates are primarily based on GPS measurements obtained in the surrounding areas of the Arabian plate, with few stations actually located on the Arabian plate itself in the Kingdom of Saudi Arabia. In order to advance the knowledge of the dynamics of the Arabian plate and its intra-plate deformations, the General Directorate of Military Survey (GDMS), through collaboration with the Institute of Engineering Surveying and Space Geodesy (IESSG), densified the GPS network in Saudi Arabia, covering nearly two thirds of the tectonic plate. Since July 2002, a network of 32 GPS stations has been established at locations of the Saudi Arabia geodetic network. At all of these GPS stations a concrete pillar has been used as the monument and the locations have been selected in order to give the broadest distribution of observing sites. During 2005, 27 additional GPS stations in the Hejaz and Asser Mountains, and the Farasan Islands, all in south-western Saudi Arabia, have been established, for which the past and future campaign GPS measurements will provide valuable data for investigations of crustal deformations close to the plate boundaries between the Nubia, Somalian and Arabian plates. In this presentation we will show results in the form of velocity field and plate motion estimates based on data from at least three campaigns occupying the initial 32 GDMS GPS network stations, but also from a number of IGS stations in the region. Our reference frame is aligned to ITRF2005 and uses approximately 40 IGS reference frame stations located on all major tectonic plates, e.g. Nubia and Somalia, surrounding the Arabian plate. Furthermore, we apply absolute satellite and receiver antenna phase center models together with newly available GPS products from a recent global re-processing effort.

  18. Motional induction voltage measurements in estuarine environments: the Ria de Aveiro Lagoon (Portugal)

    NASA Astrophysics Data System (ADS)

    Nolasco, Rita; Soares, António; Dias, João M.; Monteiro Santos, Fernando A.; Palshin, N. A.; Represas, Patricia; Vaz, Nuno

    2006-07-01

    Electromagnetic fluctuations in the ocean have external sources like ionospheric-magnetospheric current systems, and purely internal oceanic sources associated with interaction between water velocity fields and the geomagnetic field, that is, the motionally induced voltage (MIV). During the last decade techniques based on MIV have proven to provide reliable information when applied to the flow monitoring at large oceanic channels. In this paper analysis of data resulting from the implementation of these techniques in a small-scale system, that is, the Ria de Aveiro lagoon (Portugal), is presented. A submarine cable crossing the channel at the entrance of the lagoon (Barra channel) allows the measurement of the potential difference between two electrodes located on both sides of the channel. Spectral analysis of these data reveals that measured voltages are dominated by semidiurnal M2, S2/K2 frequencies. Comparison between the sum of the four main constituents determined by harmonic analysis and the sea surface elevation measured at a tide gauge located at the lagoon mouth reveal that the measured potential difference is proportional to the water flow. To estimate the water flow in this location from the MIV measurements the data collected using this methodology were compared with numerical results obtained from a previously calibrated hydrodynamic model. A value of 720 m3 s-1 mV-1 was estimated for the coefficient relating voltage and water transport at Barra. Taking this value into account a sediment layer of about 20 m is estimated, at Barra. The results show that it is possible to indirectly measure the water transport (by tidal and residual flows) through the channel by measuring the differences of electrical potential. This demonstrates the applicability of the MIV method to a small-scale system.

  19. X-ray radiographic measurements of radiation-driven shock and interface motion in solid density material

    SciTech Connect

    Hammel, B.A.; Griswold, D.; Landen, O.L.; Perry, T.S.; Remington, B.A.; Miller, P.L.; Peyser, T.A.; Kilkenny, J.D. )

    1993-07-01

    Time resolved x-ray radiographic measurements at high photon energy ([similar to]7 keV) are used to observe radiation-driven shock propagation and interface motion in solid density plastic samples, produced by indirect drive on the Nova laser. Measurements of x-ray transmission through the shock compressed material are used to infer a density of approximately three times solid. In addition, by doping a section of a sample with high-[ital Z] material (Br) for radiographic contrast, the shocked particle velocity was measured by observing the motion of the interface between the doped and nondoped materials resulting from acceleration by a shock.

  20. THE M31 VELOCITY VECTOR. I. HUBBLE SPACE TELESCOPE PROPER-MOTION MEASUREMENTS

    SciTech Connect

    Sohn, Sangmo Tony; Anderson, Jay; Van der Marel, Roeland P.

    2012-07-01

    We present the first proper-motion (PM) measurements for the galaxy M31. We obtained new V-band imaging data with the Hubble Space Telescope ACS/WFC and the WFC3/UVIS instruments of three fields: a spheroid field near the minor axis, an outer disk field along the major axis, and a field on the Giant Southern Stream. The data provide five to seven year time baselines with respect to pre-existing deep first-epoch observations of the same fields. We measure the positions of thousands of M31 stars and hundreds of compact background galaxies in each field. High accuracy and robustness is achieved by building and fitting a unique template for each individual object. The average PM for each field is obtained from the average motion of the M31 stars between the epochs with respect to the background galaxies. For the three fields, the observed PMs ({mu}{sub W}, {mu}{sub N}) are, in units of mas yr{sup -1}, (- 0.0458, -0.0376) {+-} (0.0165, 0.0154), (- 0.0533, -0.0104) {+-} (0.0246, 0.0244), and (- 0.0179, -0.0357) {+-} (0.0278, 0.0272), respectively. The ability to average over large numbers of objects and over the three fields yields a final displacement accuracy of a few thousandths of a pixel, corresponding to only 12 {mu}as yr{sup -1}. This is comparable to what has been achieved for other Local Group galaxies using Very Long Baseline Array observations of water masers. Potential systematic errors are controlled by an analysis strategy that corrects for detector charge transfer inefficiency, spatially and time-dependent geometric distortion, and point-spread function variations. The robustness of the PM measurements and uncertainties are supported by the fact that data from different instruments, taken at different times and with different telescope orientations, as well as measurements of different fields, all yield statistically consistent results. Papers II and III of this series explore the implications of the new measurements for our understanding of the history

  1. Development of a 6-DoF motion system for realizing a linear datum for geometric measurements.

    PubMed

    Wang, Shaokai; Cui, Jiwen; Tan, Jiubin; Liu, Yongmeng

    2016-08-01

    In order to further improve the linear datum based geometric measurement accuracy and expand the measurement range, a 6-DoF motion system is developed for realizing a linear datum in the form of motion trajectory of the contact point (CP) of an absolute displacement measurement probe. This linear datum is established based on the concept of coordinate measurement and it does not contain straightness error in theory. The 6-DoF motion system consists of a 6-DoF fine stage and a 1-DoF coarse stage. The probe is moved by the 6-DoF fine stage which is magnetically noncontact supported and parallelly noncontact actuated. A CP-centred 6-DoF metrology model and a CP-centred 6-DoF motion model are established for elimination of Abbe error and on-line compensation of motion error of CP, respectively. 1-DoF coarse stage is controlled with relative position between two stages to extend the limited motion range of 6-DoF fine stage along the linear datum. Effectiveness of the metrology and motion models is verified through experiment. Straightness error of a 91.5 mm long line of an optical flat is measured by the proposed system and a commercial Fizeau interferometer. Comparison shows a consistency with standard deviation of 11 nm. Another experiment indicates that the proposed system could be used to realize a linear datum within a range of 220 mm with a repeatability of standard deviation of 7 nm. PMID:27587168

  2. Real-Time Aerodynamic Parameter Estimation without Air Flow Angle Measurements

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    2010-01-01

    A technique for estimating aerodynamic parameters in real time from flight data without air flow angle measurements is described and demonstrated. The method is applied to simulated F-16 data, and to flight data from a subscale jet transport aircraft. Modeling results obtained with the new approach using flight data without air flow angle measurements were compared to modeling results computed conventionally using flight data that included air flow angle measurements. Comparisons demonstrated that the new technique can provide accurate aerodynamic modeling results without air flow angle measurements, which are often difficult and expensive to obtain. Implications for efficient flight testing and flight safety are discussed.

  3. Optical coherence-based techniques for motional Stark effect measurements of magnetic field pitch angle

    NASA Astrophysics Data System (ADS)

    Howard, John

    1999-02-01

    The motional Stark effect measurement of magnetic field pitch angle in tokamaks is a mature and powerful technique for estimating plasma current density in tokamaks. However, its range of applicability is limited by the requirement that 0741-3335/41/2/012/img3 and 0741-3335/41/2/012/img4 manifolds are spectrally sufficiently well separated (high magnetic fields, high beam energies) to ensure adequate net polarization for a successful measurement. This paper proposes alternative schemes based on the optical coherence properties of the Stark multiplet that are somewhat more versatile than the standard method and better suited to measurements on low-field toroidal confinement devices. An interference filter is used to transmit the Stark multiplet to a polarimeter (which uses a single photoelastic plate) that modulates the light temporal coherence and/or its first spectral moment. This light is subsequently processed using a novel electro-optically modulated solid-state interferometer that is sensitive to low-order spectral moments. The modulation of these quantities conveys information about the orientation of the light polarization and hence the magnetic field pitch angle.

  4. Measurement of basilar membrane motion during round window stimulation in guinea pigs.

    PubMed

    Chen, Yongzheng; Guan, Xiying; Zhang, Tianyu; Gan, Rong Z

    2014-12-01

    Driving the cochlea in reverse via the round window membrane (RWM) is an alternative treatment option for the hearing rehabilitation of a nonfunctional or malformed middle ear. However, cochlear stimulation from the RWM side is not a normal sound transmission pathway. The basilar membrane (BM) motion elicited by mechanical stimulation of the RWM is unknown. In this study, the BM movement at the basal turn was investigated in both reverse via RWM drive and acoustic stimulation in the ear canal or forward drive in postmortem isolated temporal bone preparations of guinea pigs. During reverse drive, a magnet-coil was coupled on RWM, and the BM vibration at the basal turn and the movement of the incus tip were measured with laser Doppler vibrometry. During forward drive, the vibration of the incus tip induced by sound pressure in the ear canal resulted in BM vibration and the BM movement at the same location as that in the reverse stimulation was measured. The displacement ratio of the BM to RWM in reverse drive and the ratio of the BM to incus in forward drive were compared. The results demonstrated that the BM response measured in both situations was similar in nature between forward and reverse drives. This study provides new knowledge for an understanding of BM movement induced by reverse drive via the RWM stimulation. PMID:25080894

  5. Estimation of uncertainty in tracer gas measurement of air change rates.

    PubMed

    Iizuka, Atsushi; Okuizumi, Yumiko; Yanagisawa, Yukio

    2010-12-01

    Simple and economical measurement of air change rates can be achieved with a passive-type tracer gas doser and sampler. However, this is made more complex by the fact many buildings are not a single fully mixed zone. This means many measurements are required to obtain information on ventilation conditions. In this study, we evaluated the uncertainty of tracer gas measurement of air change rate in n completely mixed zones. A single measurement with one tracer gas could be used to simply estimate the air change rate when n = 2. Accurate air change rates could not be obtained for n ≥ 2 due to a lack of information. However, the proposed method can be used to estimate an air change rate with an accuracy of <33%. Using this method, overestimation of air change rate can be avoided. The proposed estimation method will be useful in practical ventilation measurements. PMID:21318005

  6. Air Traffic Complexity Measurement Environment (ACME): Software User's Guide

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A user's guide for the Air Traffic Complexity Measurement Environment (ACME) software is presented. The ACME consists of two major components, a complexity analysis tool and user interface. The Complexity Analysis Tool (CAT) analyzes complexity off-line, producing data files which may be examined interactively via the Complexity Data Analysis Tool (CDAT). The Complexity Analysis Tool is composed of three independently executing processes that communicate via PVM (Parallel Virtual Machine) and Unix sockets. The Runtime Data Management and Control process (RUNDMC) extracts flight plan and track information from a SAR input file, and sends the information to GARP (Generate Aircraft Routes Process) and CAT (Complexity Analysis Task). GARP in turn generates aircraft trajectories, which are utilized by CAT to calculate sector complexity. CAT writes flight plan, track and complexity data to an output file, which can be examined interactively. The Complexity Data Analysis Tool (CDAT) provides an interactive graphic environment for examining the complexity data produced by the Complexity Analysis Tool (CAT). CDAT can also play back track data extracted from System Analysis Recording (SAR) tapes. The CDAT user interface consists of a primary window, a controls window, and miscellaneous pop-ups. Aircraft track and position data is displayed in the main viewing area of the primary window. The controls window contains miscellaneous control and display items. Complexity data is displayed in pop-up windows. CDAT plays back sector complexity and aircraft track and position data as a function of time. Controls are provided to start and stop playback, adjust the playback rate, and reposition the display to a specified time.

  7. A Conductivity Device for Measuring Sulfur Dioxide in the Air

    ERIC Educational Resources Information Center

    Craig, James C.

    1972-01-01

    Described is a general electroconductivity device enabling students to determine sulfur dioxide concentration in a particular location, hopefully leading to a deeper understanding of the problem of air pollution. (DF)

  8. Effect of air on energy and rise-time spectra measured by proportional gas counter

    SciTech Connect

    Kawano, T.; Tanaka, M.; Isozumi, S.; Isozumi, Y.; Tosaki, M.; Sugiyama, T.

    2015-03-15

    Air exerts a negative effect on radiation detection using a gas counter because oxygen contained in air has a high electron attachment coefficient and can trap electrons from electron-ion pairs created by ionization from incident radiation in counting gas. This reduces radiation counts. The present study examined the influence of air on energy and rise-time spectra measurements using a proportional gas counter. In addition, a decompression procedure method was proposed to reduce the influence of air and its effectiveness was investigated. For the decompression procedure, the counting gas inside the gas counter was decompressed below atmospheric pressure before radiation detection. For the spectrum measurement, methane as well as various methane and air mixtures were used as the counting gas to determine the effect of air on energy and rise-time spectra. Results showed that the decompression procedure was effective for reducing or eliminating the influence of air on spectra measurement using a proportional gas counter. (authors)

  9. Application of a dry-gas meter for measuring air sample volumes in an ambient air monitoring network

    SciTech Connect

    Fritz, Brad G.

    2009-05-24

    Ambient air monitoring for non-research applications (e.g. compliance) occurs at locations throughout the world. Often, the air sampling systems employed for these purposes employee simple yet robust equipment capable of handling the rigors of demanding sampling schedules. At the Hanford Site (near Richland, Washington) concentrations of radionuclides in ambient air are monitored continuously at 44 locations. In 2004, mechanical dry-gas meters were incorporated into the Hanford Site ambient air sample collection system to allow the direct measurement of sample volumes. These meters replaced a portable airflow measurement system that required two manual flow measurements and a sample duration measurement to determine sample volume. A six-month evaluation of the dry-gas meters compared sample volumes calculated using the original flow rate method to the direct sample volume measurement (new method). The results of the evaluation indicate that use of the dry-gas meters result in accurate sample volume measurements and provide greater confidence in the measured sample volumes. In several years of in-network use, the meters have proven to be reliable and have resulted in an improved sampling system.

  10. The far distance to G7.47+0.06 from proper motion measurement of H2O masers

    NASA Astrophysics Data System (ADS)

    Yamauchi, Aya; Yamashita, Kazuyoshi; Honma, Mareki; Sunada, Kazuyoshi; Nakagawa, Akiharu; Ueno, Yuji

    2016-08-01

    We report on a distance measurement of 22 GHz H2O maser features associated with an ultra-compact H II region G7.47+0.06 using VERA (VLBI Exploration of Radio Astrometry). Since the source is located farther away than 10 kpc, it turned out to be difficult to derive the distance from annual parallax measurement. Meanwhile, we clearly detected the source's proper motion parallel to the Galactic plane. The proper motion is μ = -5.03 ± 0.07 mas yr-1 and is approaching the Galactic center. We applied a new method to determine the source distance based on absolute proper motions. Considering uncertainties of the Galactic rotation curve and the solar peculiar motion, the detected proper motion leads to a source distance of D = 20 ± 2 kpc, demonstrating that astrometric observation can provide an accurate distance measurement at a 10% level even for sources too distant to measure the annual parallax. Lastly, we scale the physical parameters of the H II region estimated in a previous paper to be 20 kpc, and show that the H2O maser features are associated with a massive star-forming region corresponding to the spectral type of O5.5.

  11. The far distance to G7.47+0.06 from proper motion measurement of H2O masers

    NASA Astrophysics Data System (ADS)

    Yamauchi, Aya; Yamashita, Kazuyoshi; Honma, Mareki; Sunada, Kazuyoshi; Nakagawa, Akiharu; Ueno, Yuji

    2016-06-01

    We report on a distance measurement of 22 GHz H2O maser features associated with an ultra-compact H II region G7.47+0.06 using VERA (VLBI Exploration of Radio Astrometry). Since the source is located farther away than 10 kpc, it turned out to be difficult to derive the distance from annual parallax measurement. Meanwhile, we clearly detected the source's proper motion parallel to the Galactic plane. The proper motion is μ = -5.03 ± 0.07 mas yr-1 and is approaching the Galactic center. We applied a new method to determine the source distance based on absolute proper motions. Considering uncertainties of the Galactic rotation curve and the solar peculiar motion, the detected proper motion leads to a source distance of D = 20 ± 2 kpc, demonstrating that astrometric observation can provide an accurate distance measurement at a 10% level even for sources too distant to measure the annual parallax. Lastly, we scale the physical parameters of the H II region estimated in a previous paper to be 20 kpc, and show that the H2O maser features are associated with a massive star-forming region corresponding to the spectral type of O5.5.

  12. HST Astrometry in the 30 Doradus Region: Measuring Proper Motions of Individual Stars in the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Platais, Imants; van der Marel, Roeland P.; Lennon, Daniel J.; Anderson, Jay; Bellini, Andrea; Sabbi, Elena; Sana, Hugues; Bedin, Luigi R.

    2015-09-01

    We present measurements of positions and relative proper motions in the 30 Doradus region of the LMC. We detail the construction of a single-epoch astrometric reference frame, based on specially designed observations obtained with the two main imaging instruments Advanced Camera for Surveys/Wide Field Channel and Wide Field Camera 3/UVIS on board the Hubble Space Telescope (HST). Internal comparisons indicate a sub milliarcsecond (mas) precision in the positions and the presence of semi-periodic systematics with a mean amplitude of ˜0.8 mas. We combined these observations with numerous archival images taken with Wide Field Planetary Camera 2 and spanning 17 years. The precision of the resulting proper motions for well-measured stars around the massive cluster Radcliffe 136 (R136) can be as good as ˜20 μas yr-1, although the true accuracy of proper motions is generally lower due to the residual systematic errors. The observed proper-motion dispersion for our highest-quality measurements is ˜0.1 mas yr-1. Our catalog of positions and proper motions contains 86,590 stars down to V ˜ 25 and over a total area of ˜70 square arcmin. We examined the proper motions of 105 relatively bright stars and identified a total of six candidate runaway stars. We are able to tentatively confirm the runaway status of star VFTS 285, consistent with the findings from line of sight velocities, and to show that this star has likely been ejected from R136. This study demonstrates that with HST it is now possible to reliably measure proper motions of individual stars in the nearest dwarf galaxies such as the LMC.

  13. DIFFERENTIAL PROPER-MOTION MEASUREMENTS OF THE CYGNUS EGG NEBULA: THE PRESENCE OF EQUATORIAL OUTFLOWS

    SciTech Connect

    Ueta, Toshiya; Tomasino, Rachael L.; Ferguson, Brian A.

    2013-08-01

    We present the results of differential proper-motion analyses of the Egg Nebula (RAFGL 2688, V1610 Cyg) based on the archived two-epoch optical data taken with the Hubble Space Telescope. First, we determined that the polarization characteristics of the Egg Nebula are influenced by the higher optical depth of the central regions of the nebula (i.e., the 'dustsphere' of {approx}10{sup 3} AU radius), causing the nebula to illuminate in two steps-the direct starlight is first channeled into bipolar cavities and then scattered off to the rest of the nebula. We then measured the amount of motion of local structures and the signature concentric arcs by determining their relative shifts over the 7.25 yr interval. Based on our analysis, which does not rely on the single-scattering assumption, we concluded that the lobes have been excavated by a linear expansion along the bipolar axis for the past {approx}400 yr, while the concentric arcs have been generated continuously and moving out radially at about 10 km s{sup -1} for the past {approx}5500 yr, and there appears to be a colatitudinally increasing trend in the radial expansion velocity field of the concentric arcs. Numerical investigations into the mass-loss modulation by the central binary system exist, which predict such a colatitudinally increasing expansion velocity field in the spiral-shock trails of the mass-loss ejecta. Therefore, the Egg Nebula may represent a rare edge-on case of the binary-modulated circumstellar environs, corroborating the previous theoretical predictions.

  14. The First X-Ray Proper-Motion Measurements of the Forward Shock in the Northeastern Limb of Sn 1006

    NASA Technical Reports Server (NTRS)

    Katsuda, Satoru; Petre, Robert; Long, Knox S.; Reynolds, Stephen P.; Winkler, P. Frank; Mori, Koji; Tsunemi, Hiroshi

    2009-01-01

    We report on the first X-ray proper-motion measurements of the nonthermally-dominated forward shock in the northeastern limb of SN 1006, based on two Chandra observations taken in 2000 and 2008. We find that the proper motion of the forward shock is about 0.48"/yr and does not vary around the rim within the approx.10% measurement uncertainties. The proper motion measured is consistent with that determined by the previous radio observations. The mean expansion index of the forward shock is calculated to be approx..0.54 which matches the value expected based on an evolutionary model of a Type Ia supernova with either a power-law or an exponential ejecta density profile. Assuming pressure equilibrium around the periphery from the thermally-dominated northwestern rim to the nonthermally-dominated northeastern rim, we estimate the ambient density to the northeast of SN 1006 to be approx..0.085/cu cm.

  15. Indirect measurement of machine tool motion axis error with single laser tracker

    NASA Astrophysics Data System (ADS)

    Wu, Zhaoyong; Li, Liangliang; Du, Zhengchun

    2015-02-01

    For high-precision machining, a convenient and accurate detection of motion error for machine tools is significant. Among common detection methods such as the ball-bar method, the laser tracker approach has received much more attention. As a high-accuracy measurement device, laser tracker is capable of long-distance and dynamic measurement, which increases much flexibility during the measurement process. However, existing methods are not so satisfactory in measurement cost, operability or applicability. Currently, a plausible method is called the single-station and time-sharing method, but it needs a large working area all around the machine tool, thus leaving itself not suitable for the machine tools surrounded by a protective cover. In this paper, a novel and convenient positioning error measurement approach by utilizing a single laser tracker is proposed, followed by two corresponding mathematical models including a laser-tracker base-point-coordinate model and a target-mirror-coordinates model. Also, an auxiliary apparatus for target mirrors to be placed on is designed, for which sensitivity analysis and Monte-Carlo simulation are conducted to optimize the dimension. Based on the method proposed, a real experiment using single API TRACKER 3 assisted by the auxiliary apparatus is carried out and a verification experiment using a traditional RENISHAW XL-80 interferometer is conducted under the same condition for comparison. Both results demonstrate a great increase in the Y-axis positioning error of machine tool. Theoretical and experimental studies together verify the feasibility of this method which has a more convenient operation and wider application in various kinds of machine tools.

  16. Development of a miniaturized position sensing system for measuring brain motion during impact - biomed 2013.

    PubMed

    Wing, I D; Merkle, A C; Armiger, R S; Carkhuff, B G; Roberts, J C

    2013-01-01

    Since 2000, the Department of Defense has documented more than 253,000 cases of Traumatic Brain Injury (TBI). A significant portion of these injuries were attributed to explosive events, yet ninety-eight percent were non-penetrating. Understanding the response of the brain to blast events is critical, yet the mechanisms of brain injury from explosive trauma are poorly understood. This knowledge gap has led to an increased research focus on devices capable of investigating human brain response to non-penetrating, blast-induced loading. Furthermore, traumatic brain injury is a major issue for the civilian population as well with over 1.7 million cases of TBI per year in the US, primarily from falls and motor vehicle accidents. Current head surrogates and instrumentation are incapable of directly measuring critical parameters associated with TBI, such as brain motion, during dynamic loading. To this end, a novel sensor system for measuring brain motion inside of a human head surrogate was conceptualized and developed. The positioning system is comprised of a set of three fixed “generator” coils and a plurality of mobile, miniaturized “receiver” coil triads. Each generator coil transmits a sinusoidal electromagnetic signal at a unique frequency, and groups of three orthogonally arranged “receiver” coils detect these signals. Because of the oscillatory nature of these signals, the magnetic flux through the coil is always changing, allowing the application of Faraday’s Law of Induction and the point dipole model of an electric field to model the strength and direction of the field vector at any given point. Thus, the strength of the signal measured by a particular receiver coil depends on its position and orientation relative to the fixed position of the generators. These predictable changes are used to determine the six degrees of freedom (6-DOF) motion of the receiver. To calibrate and validate the system, a receiver coil was moved about in a controlled manner

  17. Flexural Stiffness of Myosin Va Subdomains as Measured from Tethered Particle Motion.

    PubMed

    Michalek, Arthur J; Kennedy, Guy G; Warshaw, David M; Ali, M Yusuf

    2015-01-01

    Myosin Va (MyoVa) is a processive molecular motor involved in intracellular cargo transport on the actin cytoskeleton. The motor's processivity and ability to navigate actin intersections are believed to be governed by the stiffness of various parts of the motor's structure. Specifically, changes in calcium may regulate motor processivity by altering the motor's lever arm stiffness and thus its interhead communication. In order to measure the flexural stiffness of MyoVa subdomains, we use tethered particle microscopy, which relates the Brownian motion of fluorescent quantum dots, which are attached to various single- and double-headed MyoVa constructs bound to actin in rigor, to the motor's flexural stiffness. Based on these measurements, the MyoVa lever arm and coiled-coil rod domain have comparable flexural stiffness (0.034 pN/nm). Upon addition of calcium, the lever arm stiffness is reduced 40% as a result of calmodulins potentially dissociating from the lever arm. In addition, the flexural stiffness of the full-length MyoVa construct is an order of magnitude less stiff than both a single lever arm and the coiled-coil rod. This suggests that the MyoVa lever arm-rod junction provides a flexible hinge that would allow the motor to maneuver cargo through the complex intracellular actin network. PMID:26770194

  18. Flexural Stiffness of Myosin Va Subdomains as Measured from Tethered Particle Motion

    PubMed Central

    Michalek, Arthur J.; Kennedy, Guy G.; Warshaw, David M.; Ali, M. Yusuf

    2015-01-01

    Myosin Va (MyoVa) is a processive molecular motor involved in intracellular cargo transport on the actin cytoskeleton. The motor's processivity and ability to navigate actin intersections are believed to be governed by the stiffness of various parts of the motor's structure. Specifically, changes in calcium may regulate motor processivity by altering the motor's lever arm stiffness and thus its interhead communication. In order to measure the flexural stiffness of MyoVa subdomains, we use tethered particle microscopy, which relates the Brownian motion of fluorescent quantum dots, which are attached to various single- and double-headed MyoVa constructs bound to actin in rigor, to the motor's flexural stiffness. Based on these measurements, the MyoVa lever arm and coiled-coil rod domain have comparable flexural stiffness (0.034 pN/nm). Upon addition of calcium, the lever arm stiffness is reduced 40% as a result of calmodulins potentially dissociating from the lever arm. In addition, the flexural stiffness of the full-length MyoVa construct is an order of magnitude less stiff than both a single lever arm and the coiled-coil rod. This suggests that the MyoVa lever arm-rod junction provides a flexible hinge that would allow the motor to maneuver cargo through the complex intracellular actin network. PMID:26770194

  19. Wearable motion sensors to continuously measure real-world physical activities

    PubMed Central

    Dobkin, Bruce H.

    2014-01-01

    Purpose of review Rehabilitation for sensorimotor impairments aims to improve daily activities, walking, exercise, and motor skills. Monitoring of practice and measuring outcomes, however, is usually restricted to laboratory-based procedures and self-reports. Mobile health devices may reverse these confounders of daily care and research trials. Recent findings Wearable, wireless motion sensor data, analyzed by activity pattern-recognition algorithms, can describe the type, quantity, and quality of mobility-related activities in the community. Data transmission from sensors to the cell phone and Internet enable continuous monitoring. Remote access to laboratory-quality data about walking speed, duration and distance, gait asymmetry and smoothness of movements, as well as cycling, exercise, and skills practice, opens new opportunities to engage patients in progressive, personalized therapies with feedback about performance. Clinical trial designs will be able to include remote verification of the integrity of complex physical interventions and compliance with practice, as well as capture repeated, ecologically sound, ratio-scale outcome measures. Summary Given the progressively falling cost of miniaturized wearable gyroscopes, accelerometers, and other physiologic sensors, as well as inexpensive data transmission, sensing systems may become as ubiquitous as cell phones for health care. Neurorehabilitation can develop these mobile health platforms for daily care and clinical trials to improve exercise and fitness, skills learning, and physical functioning. PMID:24136126

  20. Measurement of the motional sidebands of a nanogram-scale oscillator in the quantum regime

    NASA Astrophysics Data System (ADS)

    Underwood, M.; Mason, D.; Lee, D.; Xu, H.; Jiang, L.; Shkarin, A. B.; Børkje, K.; Girvin, S. M.; Harris, J. G. E.

    2015-12-01

    We describe measurements of the motional sidebands produced by a mechanical oscillator (with effective mass 43 ng and resonant frequency 705 kHz) that is placed in an optical cavity and cooled close to its quantum ground state. The red and blue sidebands (corresponding to Stokes and anti-Stokes scattering) from a single laser beam are recorded simultaneously via a heterodyne measurement. The oscillator's mean phonon number n ¯ is inferred from the ratio of the sidebands, and reaches a minimum value of 0.84 ±0.22 (corresponding to a mode temperature T =28 ±7 μ K ). We also infer n ¯ from the calibrated area of each of the two sidebands, and from the oscillator's total damping. The values of n ¯ inferred from these four methods are in close agreement. The behavior of the sidebands as a function of the oscillator's temperature agrees well with theory that includes the quantum fluctuations of both the cavity field and the mechanical oscillator.