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Sample records for high-resolution velocity measurements

  1. Laser-strophometry high-resolution technique for velocity gradient measurements in fluid flows

    CERN Document Server

    Staude, Wilfried

    2001-01-01

    This book describes techniques that allow the measurement of arbitrary velocity gradient components in fluids with high spatial and temporal resolution, e.g. turbulent fluids. The techniques are based on the properties of scattered laser light. The book gives a detailed and rigorous treatment of the physical and mathematical background in a pedagogical presentation accessible to students in physics and engineering. From both the theoretical and experimental points of view, four different schemes are discussed in detail; the schemes differ in the way the velocity of the moving pattern of the scattered laser light is measured.

  2. High-resolution spectroscopy diagnostics for measuring impurity ion temperature and velocity on the COMPASS tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Weinzettl, Vladimir, E-mail: vwei@ipp.cas.cz [Institute of Plasma Physics ASCR, Prague (Czech Republic); Shukla, Gaurav [Institute of Plasma Physics ASCR, Prague (Czech Republic); Department of Applied Physics, Ghent University, Ghent (Belgium); Faculty of Mathematics and Physics, Charles University in Prague, Prague (Czech Republic); Ghosh, Joydeep [Institute for Plasma Research, Bhat, Gandhinagar (India); Melich, Radek; Panek, Radomir [Institute of Plasma Physics ASCR, Prague (Czech Republic); Tomes, Matej; Imrisek, Martin; Naydenkova, Diana [Institute of Plasma Physics ASCR, Prague (Czech Republic); Faculty of Mathematics and Physics, Charles University in Prague, Prague (Czech Republic); Varju, Josef [Institute of Plasma Physics ASCR, Prague (Czech Republic); Pereira, Tiago [Instituto de Plasmas e Fusão Nuclear, Lisboa (Portugal); Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); Gomes, Rui [Instituto de Plasmas e Fusão Nuclear, Lisboa (Portugal); Abramovic, Ivana; Jaspers, Roger [Eindhoven University of Technology, Eindhoven (Netherlands); Pisarik, Michael [SQS Vlaknova optika a.s., Nova Paka (Czech Republic); Department of Electromagnetic Field, Faculty of Electrical Engineering, Czech Technical University in Prague (Czech Republic); Odstrcil, Tomas [Max-Planck-Institut fur Plasmaphysik, Garching (Germany); Van Oost, Guido [Department of Applied Physics, Ghent University, Ghent (Belgium)

    2015-10-15

    Highlights: • We built a new diagnostic of poloidal plasma rotation on the COMPASS tokamak. • Improvements in throughput via toroidal integration and fiber optimizations shown. • Poloidal rotation and ion temperature measured in L- and H-mode and during RMP. • Design and parameters of a new CXRS diagnostic for COMPASS are introduced. - Abstract: High-resolution spectroscopy is a powerful tool for the measurement of plasma rotation as well as ion temperature using the Doppler shift of the emitted spectral lines and their Doppler broadening, respectively. Both passive and active diagnostic variants for the COMPASS tokamak are introduced. The passive diagnostic focused on the C III lines at about 465 nm is utilized for the observation of the poloidal plasma rotation. The current set-up of the measuring system is described, including the intended high-throughput optics upgrade. Different options to increase the fiber collection area are mentioned, including a flower-like fiber bundle, and the use of micro-lenses or tapered fibers. Recent measurements of poloidal plasma rotation of the order of 0–6 km/s are shown. The design of the new active diagnostic using a deuterium heating beam and based on charge exchange recombination spectroscopy (C VI line at 529 nm) is introduced. The tool will provide both space (0.5–5 cm) and time (10 ms) resolved toroidal plasma rotation and ion temperature profiles. The results of the Simulation of Spectra code used to examine the feasibility of charge exchange measurements on COMPASS are shown and connected with a selection of the spectrometer coupled with the CCD camera.

  3. In vivo measurement of changes in venous blood-oxygenation with high resolution functional MRI at 0.95 tesla by measuring changes in susceptibility and velocity.

    Science.gov (United States)

    Hoogenraad, F G; Reichenbach, J R; Haacke, E M; Lai, S; Kuppusamy, K; Sprenger, M

    1998-01-01

    High-resolution functional imaging experiments at 0.95 Tesla have been performed to determine the changes in oxygen saturation in pial veins during motor activation by measuring both flow and susceptibility changes in the blood. Averaging across subjects, mean values for the change of the oxygenation level, deltaY = 0.16 +/- 0.08 (n = 7) and deltaY = 0.13 +/- 0.09 (n = 4), were obtained from the susceptibility sensitive and the flow sensitive acquisitions, respectively. The results suggest that the increase in blood flow is largely uncoupled from the oxygen consumption. The quoted errors reflect mainly the intersubject variability. In addition, low-resolution echo planar imaging (EPI) measurements were performed on the same volunteers to quantify signal intensity changes. Using the measured change in oxygenation, the observed signal changes in the EPI experiments can be attributed to a 5% venous blood volume.

  4. Measurement of Rayleigh wave Z/H ratio and joint inversion for a high-resolution S wave velocity model beneath the Gulf of Mexico passive margin

    Science.gov (United States)

    Miao, W.; Li, G.; Niu, F.

    2016-12-01

    Knowledge on the 3D sediment structure beneath the Gulf of Mexico passive margin is not only important to explore the oil and gas resources in the area, but also essential to decipher the deep crust and mantle structure beneath the margin with teleseismic data. In this study, we conduct a joint inversion of Rayleigh wave ellipticity and phase velocity at 6-40 s to construct a 3-D S wave velocity model in a rectangular area of 100°-87° west and 28°-37° north. We use ambient noise data from a total of 215 stations of the Transportable Array deployed under the Earthscope project. Rayleigh wave ellipticity, or Rayleigh wave Z/H (vertical to horizontal) amplitude ratio is mostly sensitive to shallow sediment structure, while the dispersion data are expected to have reasonably good resolution to uppermost mantle depths. The Z/H ratios measured from stations inside the Gulf Coastal Plain are distinctly lower in comparison with those measured from the inland stations. We also measured the phase velocity dispersion from the same ambient noise dataset. Our preliminary 3-D model is featured by strong low-velocity anomalies at shallow depth, which are spatially well correlated with Gulf Cost, East Texas, and the Lower Mississippi basins. We will discuss other features of the 3-D models once the model is finalized.

  5. High Resolution Measurement of the Glycolytic Rate

    Science.gov (United States)

    Bittner, Carla X.; Loaiza, Anitsi; Ruminot, Iván; Larenas, Valeria; Sotelo-Hitschfeld, Tamara; Gutiérrez, Robin; Córdova, Alex; Valdebenito, Rocío; Frommer, Wolf B.; Barros, L. Felipe

    2010-01-01

    The glycolytic rate is sensitive to physiological activity, hormones, stress, aging, and malignant transformation. Standard techniques to measure the glycolytic rate are based on radioactive isotopes, are not able to resolve single cells and have poor temporal resolution, limitations that hamper the study of energy metabolism in the brain and other organs. A new method is described in this article, which makes use of a recently developed FRET glucose nanosensor to measure the rate of glycolysis in single cells with high temporal resolution. Used in cultured astrocytes, the method showed for the first time that glycolysis can be activated within seconds by a combination of glutamate and K+, supporting a role for astrocytes in neurometabolic and neurovascular coupling in the brain. It was also possible to make a direct comparison of metabolism in neurons and astrocytes lying in close proximity, paving the way to a high-resolution characterization of brain energy metabolism. Single-cell glycolytic rates were also measured in fibroblasts, adipocytes, myoblasts, and tumor cells, showing higher rates for undifferentiated cells and significant metabolic heterogeneity within cell types. This method should facilitate the investigation of tissue metabolism at the single-cell level and is readily adaptable for high-throughput analysis. PMID:20890447

  6. High resolution measurement of the glycolytic rate

    Directory of Open Access Journals (Sweden)

    Carla X Bittner

    2010-09-01

    Full Text Available The glycolytic rate is sensitive to physiological activity, hormones, stress, aging and malignant transformation. Standard techniques to measure the glycolytic rate are based on radioactive isotopes, are not able to resolve single cells and have poor temporal resolution, limitations that hamper the study of energy metabolism in the brain and other organs. A new method is described in this article, which makes use of a recently-developed FRET glucose nanosensor to measure the rate of glycolysis in single cells with high temporal resolution. Used in cultured astrocytes, the method showed for the first time that glycolysis can be activated within seconds by a combination of glutamate and K+, supporting a role for astrocytes in neurometabolic and neurovascular coupling in the brain. It was also possible to make a direct comparison of metabolism in neurons and astrocytes lying in close proximity, paving the way to a high-resolution characterization of brain energy metabolism. Single-cell glycolytic rates were also measured in fibroblasts, adipocytes, myoblasts and tumor cells, showing higher rates for undifferentiated cells and significant metabolic heterogeneity within cell types. This method should facilitate the investigation of tissue metabolism at the single-cell level and is readily adaptable for high-throughput analysis.

  7. High Resolution Radar Measurements of Snow Avalanches

    Science.gov (United States)

    McElwaine, Jim; Sovilla, Betty; Vriend, Nathalie; Brennan, Paul; Ash, Matt; Keylock, Chris

    2013-04-01

    Geophysical mass flows, such as snow avalanches, are a major hazard in mountainous areas and have a significant impact on the infrastructure, economy and tourism of such regions. Obtaining a thorough understanding of the dynamics of snow avalanches is crucial for risk assessment and the design of defensive structures. However, because the underlying physics is poorly understood there are significant uncertainties concerning current models, which are poorly validated due to a lack of high resolution data. Direct observations of the denser core of a large avalanche are particularly difficult, since it is frequently obscured by the dilute powder cloud. We have developed and installed a phased array FMCW radar system that penetrates the powder cloud and directly images the dense core with a resolution of around 1 m at 50 Hz over the entire slope. We present data from recent avalanches at Vallee de la Sionne that show a wealth of internal structure and allow the tracking of individual fronts, roll waves and surges down the slope for the first time. We also show good agreement between the radar results and existing measurement systems that record data at particular points on the avalanche track.

  8. High Resolution Velocity Map Imaging Photoelectron Spectroscopy of the Beryllium Oxide Anion, BeO-

    Science.gov (United States)

    Dermer, Amanda Reed; Mascaritolo, Kyle; Heaven, Michael

    2016-06-01

    The photodetachment spectrum of BeO- has been studied using high resolution velocity map imaging photoelectron spectroscopy. The vibrational contours were imaged and compared with Franck-Condon simulations for the ground and excited states of the neutral. The electron affinity of BeO was measured for the first time, and anisotropies of several transitions were determined. Experimental findings are compared to high level ab initio calculations.

  9. High resolution temperature measurement technique for measuring marine heat flow

    Institute of Scientific and Technical Information of China (English)

    QIN; YangYang; YANG; XiaoQiu; WU; BaoZhen; SUN; ZhaoHua; SHI; XiaoBin

    2013-01-01

    High resolution temperature measurement technique is one of the key techniques for measuring marine heat flow. Basing on Pt1000 platinum resistance which has the characteristics of high accuracy and good stability, we designed a bridge reversal excitation circuit for high resolution temperature measurement. And the deep ocean floor in-situ test results show that: (1) temperature deviation and peak-to-peak resolution of the first version circuit board (V1) are 1.960-1.990 mK and 0.980-0.995 m Kat 1.2-2.7°C, respectively; and temperature deviation and peak-to-peak resolution of the second circuit board (V2) are 2.260mK and 1.130 mK at 1.2-1.3°C, respectively; (2) During the 2012NSFC-IndOcean cruise, seafloor geothermal gradient at Ind2012HF03,-07 and-12 stations (water depth ranges from 3841 to 4541 m) were successfully measured, the values are 59.1,75.1 and 71.6°C/km, respectively. And the measurement errors of geothermal gradient at these three stations are less than 3.0% in terms of the peak-to-peak resolution. These indicate that the high resolution temperature measurement technique based on Pt1000 platinum resistance in this paper can be applied to marine heat flow measurement to obtain high precision geothermal parameters.

  10. High resolution pollutant measurements in complex urban ...

    Science.gov (United States)

    Measuring air pollution in real-time using an instrumented vehicle platform has been an emerging strategy to resolve air pollution trends at a very fine spatial scale (10s of meters). Achieving second-by-second data representative of urban air quality trends requires advanced instrumentation, such as a quantum cascade laser utilized to resolve carbon monoxide and real-time optical detection of black carbon. An equally challenging area of development is processing and visualization of complex geospatial air monitoring data to decipher key trends of interest. EPA’s Office of Research and Development staff have applied air monitoring to evaluate community air quality in a variety of environments, including assessing air quality surrounding rail yards, evaluating noise wall or tree stand effects on roadside and on-road air quality, and surveying of traffic-related exposure zones for comparison with land-use regression estimates. ORD has ongoing efforts to improve mobile monitoring data collection and interpretation, including instrumentation testing, evaluating the effect of post-processing algorithms on derived trends, and developing a web-based tool called Real-Time Geospatial Data Viewer (RETIGO) allowing for a simple plug-and-play of mobile monitoring data. Example findings from mobile data sets include an estimated 50% in roadside ultrafine particle levels when immediately downwind of a noise barrier, increases in neighborhood-wide black carbon levels (3

  11. A Super High Resolution Distance Measurement Method Based on Phase Comparison

    Institute of Scientific and Technical Information of China (English)

    LI Zhi-Qi; ZHOU Wei; MIAO Miao; ZHOU Hui; ZHENG Sheng-Feng

    2008-01-01

    @@ Phase comparison method can enhance the measurement resolution to 10-13/τ in time domain. This method can also be used in distance measurement in the navigation and positioning. We propose a super high-resolution distance measurement based on linear phase comparison method. A high resolution scheme is put forward on the basis of the research of major factors concerning the phase comparison in the distance measurement. Conversion of a high-linearity phase difference to voltage and high-resolution voltage meter make it possible to obtain a very high phase measurement resolution. When the purpose is to measure distance, the phase noise of frequency source used in the measurement can be reduced partly. Thus this method is favourable for high resolution distance measurement. The precision of the distance measurement can reach 0.1c ps with c being the velocity of light in vacuum.

  12. High resolution spectroscopy of bright subdwarf B stars - I. Radial velocity variables

    CERN Document Server

    Edelmann, H; Altmann, M; Karl, C; Lisker, T

    2005-01-01

    Radial velocity curves for 15 bright subdwarf B binary systems have been measured using high precision radial velocity measurements from high S/N optical high-resolution spectra. In addition, two bright sdB stars are discovered to be radial velocity variable but the period could not yet be determined. The companions for all systems are unseen. The periods range from about 0.18 days up to more than ten days. The radial velocity semi amplitudes are found to lie between 15 and 130 km/s. Using the mass functions, the masses of the unseen companions have been constrained to lower limits of 0.03 up to 0.55 M_sun, and most probable values of 0.03 up to 0.81 M_sun. The invisible companions for three of our program stars are undoubtedly white dwarfs. In the other cases they could be either white dwarfs or main sequence stars. For two stars the secondaries could possibly be brown dwarfs. As expected, the orbits are circular for most of the systems. However, for one third of the program stars we find slightly eccentric ...

  13. Detecting non-maxwellian electron velocity distributions at JET by high resolution Thomson scattering.

    Science.gov (United States)

    Beausang, K V; Prunty, S L; Scannell, R; Beurskens, M N; Walsh, M J; de la Luna, E

    2011-03-01

    The present work is motivated by a long standing discrepancy between the electron temperature measurements of Thomson scattering (TS) and electron cyclotron emission (ECE) diagnostics for plasmas with strong auxiliary heating observed at both JET and TFTR above 6–7 keV, where in some cases the ECE electron temperature measurements can be 15%–20% higher than the TS measurements. Recent analysis based on ECE results at JET has shown evidence of distortions to the Maxwellian electron velocity distribution and a correlation with the TS and ECE discrepancies has been suggested. In this paper, a technique to determine the presence of non-Maxwellian behavior using TS diagnostics is outlined. The difficulties and limitations of modern TS system designs to determine the electron velocity distribution are also discussed. It is demonstrated that small deviations such as those suggested by previous ECE analysis could be potentially detected, depending on the spectral layout of the TS polychromators. The spectral layout of the JET high resolution Thomson scattering system is such that it could be used to determine these deviations between 1 and 6 keV, and the results presented here indicate that no evidence of non-Maxwellian behavior is observed in this range. In this paper, a modification to the current polychromator design is proposed, allowing non-Maxwellian distortions to be detected up to at least 10 keV.

  14. Detecting non-Maxwellian electron velocity distributions at JET by high resolution Thomson scattering

    Science.gov (United States)

    Beausang, K. V.; Prunty, S. L.; Scannell, R.; Beurskens, M. N.; Walsh, M. J.; de La Luna, E.; Jet Efda Contributors

    2011-03-01

    The present work is motivated by a long standing discrepancy between the electron temperature measurements of Thomson scattering (TS) and electron cyclotron emission (ECE) diagnostics for plasmas with strong auxiliary heating observed at both JET and TFTR above 6-7 keV, where in some cases the ECE electron temperature measurements can be 15%-20% higher than the TS measurements. Recent analysis based on ECE results at JET has shown evidence of distortions to the Maxwellian electron velocity distribution and a correlation with the TS and ECE discrepancies has been suggested. In this paper, a technique to determine the presence of non-Maxwellian behavior using TS diagnostics is outlined. The difficulties and limitations of modern TS system designs to determine the electron velocity distribution are also discussed. It is demonstrated that small deviations such as those suggested by previous ECE analysis could be potentially detected, depending on the spectral layout of the TS polychromators. The spectral layout of the JET high resolution Thomson scattering system is such that it could be used to determine these deviations between 1 and 6 keV, and the results presented here indicate that no evidence of non-Maxwellian behavior is observed in this range. In this paper, a modification to the current polychromator design is proposed, allowing non-Maxwellian distortions to be detected up to at least 10 keV

  15. High-Resolution Seismic Velocity and Attenuation Models of the Caucasus-Caspian Region

    Science.gov (United States)

    2010-03-20

    bottom). complicated tectonics . Lg appears to propagate well in the Arabian plate but is dramatically attenuated in the Lesser Caucasus. This may be...AFRL-RV-HA-TR-2010-1022 High-Resolution Seismic Velocity and Attenuation Models of the Caucasus-Caspian Region Robert J. Mellors...Resolution Seismic Velocity and Attenuation Models of the Caucasus-Caspian Region 5a. CONTRACT NUMBER FA8718-07-C-0007 5b. GRANT NUMBER 5c

  16. High-Resolution Wind Measurements for Offshore Wind Energy Development

    Science.gov (United States)

    Nghiem, Son V.; Neumann, Gregory

    2011-01-01

    A mathematical transform, called the Rosette Transform, together with a new method, called the Dense Sampling Method, have been developed. The Rosette Transform is invented to apply to both the mean part and the fluctuating part of a targeted radar signature using the Dense Sampling Method to construct the data in a high-resolution grid at 1-km posting for wind measurements over water surfaces such as oceans or lakes.

  17. High resolution resonant recombination measurements using evaporative cooling technique

    Energy Technology Data Exchange (ETDEWEB)

    Beilmann, C; Lopez-Urrutia, J R Crespo; Mokler, P H; Ullrich, J, E-mail: christian.beilmann@mpi-hd.mpg.d [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)

    2010-09-15

    We report on a method significantly improving the energy resolution of dielectronic recombination (DR) measurements in electron beam ion traps (EBITs). The line width of DR resonances can be reduced to values distinctly smaller than the corresponding space charge width of the uncompensated electron beam. The experimental technique based on forced evaporative cooling is presented together with test measurements demonstrating its high efficiency. The principle for resolution improvement is elucidated and the limiting factors are discussed. This method opens access to high resolution DR measurements at high ion-electron collision energies required for innermost shell DR in highly charged ions (HCI).

  18. Multifractal analysis of high resolution solar wind proton density measurements

    Science.gov (United States)

    Sorriso-Valvo, Luca; Carbone, Francesco; Leonardis, Ersilia; Chen, Christopher H. K.; Šafránková, Jana; Němeček, Zdenek

    2017-03-01

    The solar wind is a highly turbulent medium, with a high level of field fluctuations throughout a broad range of scales. These include an inertial range where a turbulent cascade is assumed to be active. The solar wind cascade shows intermittency, which however may depend on the wind conditions. Recent observations have shown that ion-scale magnetic turbulence is almost self-similar, rather than intermittent. A similar result was observed for the high resolution measurements of proton density provided by the spacecraft Spektr-R. Intermittency may be interpreted as the result of the multifractal properties of the turbulent cascade. In this perspective, this paper is devoted to the description of the multifractal properties of the high resolution density measurements. In particular, we have used the standard coarse-graining technique to evaluate the generalized dimensions Dq , and from these the multifractal spectrum f (α) , in two ranges of scale. A fit with the p-model for intermittency provided a quantitative measure of multifractality. Such indicator was then compared with alternative measures: the width of the multifractal spectrum, the peak of the kurtosis, and its scaling exponent. The results indicate that the small-scale fluctuations are multifractal, and suggest that different measures of intermittency are required to fully understand the small scale cascade.

  19. Velocity-space observation regions of high-resolution two-step reaction gamma-ray spectroscopy

    DEFF Research Database (Denmark)

    Salewski, Mirko; Nocente, M.; Gorini, G.

    2015-01-01

    High-resolution γ-ray spectroscopy (GRS) measurements resolve spectral shapes of Dopplerbroadened γ-rays. We calculate weight functions describing velocity-space sensitivities of any two-step reaction GRS measurements in magnetized plasmas using the resonant nuclear reaction 9Be(α, nγ)12C as an e...... given alpha-particle velocity-space region contributes to the measurements in each γ-ray energy bin.......High-resolution γ-ray spectroscopy (GRS) measurements resolve spectral shapes of Dopplerbroadened γ-rays. We calculate weight functions describing velocity-space sensitivities of any two-step reaction GRS measurements in magnetized plasmas using the resonant nuclear reaction 9Be(α, nγ)12C...... as an example. The energy-dependent cross sections of this reaction suggest that GRS is sensitive to alpha particles above about 1.7 MeV and highly sensitive to alpha particles at the resonance energies of the reaction. Here we demonstrate that highresolution two-step reaction GRS measurements are not only...

  20. Improving estimation of microseismic focal mechanisms using a high-resolution velocity model

    Science.gov (United States)

    Chen, T.; Chen, Y.; Lin, Y.; Huang, L.

    2015-12-01

    Injection and migration of CO2 during the geological carbon sequestration change the pore pressure and stress distribution in the reservoir. The change in stress may induce brittle failure on fractures, causing microseismic events. Focal mechanisms of induced microseismic events are useful for understanding stress evolution in the reservoir. An accurate estimation of microseismic focal mechanism depends on the accuracy of velocity models. In this work, we study the improvement on estimation of microseismic focal mechanisms using a high-resolution velocity model. We obtain the velocity model using a velocity inversion algorithm with a modified total-variation scheme rather than the commonly used Tikhonov regularization technique. We demonstrate with synthetic microseismic data that the velocity inversion method with a modified total-variation regularization scheme improves velocity inversion, and the improved velocity models enhance the accuracy of estimated focal mechanisms of microseismic events. We apply the new methodology to microseismic data acquired at a CO2-EOR (enhanced oil recovery) site at Aneth, Utah.

  1. Velocity and abundance precisions for future high-resolution spectroscopic surveys: a study for 4MOST

    CERN Document Server

    Caffau, E; Sbordone, L; Sartoretti, P; Hansen, C J; Royer, F; Leclerc, N; Bonifacio, P; Christlieb, N; Ludwig, H G; Grebel, E K; de Jong, R S; Chiappini, C; Walcher, J; Mignot, S; Feltzing, S; Cohen, M; Minchev, I; Helmi, A; Piffl, T; Depagne, E; Schnurr, O

    2012-01-01

    In preparation for future, large-scale, multi-object, high-resolution spectroscopic surveys of the Galaxy, we present a series of tests of the precision in radial velocity and chemical abundances that any such project can achieve at a 4m class telescope. We briefly discuss a number of science cases that aim at studying the chemo-dynamical history of the major Galactic components (bulge, thin and thick disks, and halo) - either as a follow-up to the Gaia mission or on their own merits. Based on a large grid of synthetic spectra that cover the full range in stellar parameters of typical survey targets, we devise an optimal wavelength range and argue for a moderately high-resolution spectrograph. As a result, the kinematic precision is not limited by any of these factors, but will practically only suffer from systematic effects, easily reaching uncertainties <1 km/s. Under realistic survey conditions (namely, considering stars brighter than r=16 mag with reasonable exposure times) we prefer an ideal resolving...

  2. High resolution velocity structure beneath Mount Vesuvius from seismic array data

    Science.gov (United States)

    Scarpa, Roberto; Tronca, Fabrizio; Bianco, Francesca; Del Pezzo, Edoardo

    2002-11-01

    A high resolution P-wave image of Mt. Vesuvius edifice has been derived from simultaneous inversion of travel times and hypocentral parameters of local earthquakes, land based shots and small aperture array data. The results give details down to 300-500 m. The relocated local seismicity appears to extend down to 5 km below the central crater, distributed in a major cluster, centered at 3 km below the central crater and in a minor group, with diffuse hypocenters inside the volcanic edifice. The two clusters are separated by an anomalously high Vp region at around 1 km depth. A zone with high Vp/Vs in the upper layers is interpreted as produced by the presence of intense fluid circulation. The highest energy quakes (up to M = 3.6) are located in the deeper cluster, in a high P-wave velocity zone. Our results favor an interpretation in terms of absence of shallow magma reservoirs.

  3. Velocity gap mode of capillary electrophoresis developed for high-resolution chiral separations.

    Science.gov (United States)

    Li, Xue; Li, Youxin; Zhao, Lumeng; Shen, Jianguo; Zhang, Yong; Bao, James J

    2014-10-01

    A new CE method based on velocity gap (VG) theory has been developed for high-resolution chiral separations. In VG, two consecutive electric fields are adopted to drive analytes passing through two capillaries, which are linked together through a joint. The joint is immersed inside another buffer vial which has conductivity communication with the buffer inside the capillary. By adjusting the field strengths onto the two capillaries, it is possible to observe different velocities of an analyte when it passes through those two capillaries and there would be a net velocity change (NVC) for the same analyte. Different analytes may have different NVC which may be specifically meaningful for enantioseparations because enantiomers are usually hard to resolve. By taking advantage of this NVC, it is possible to enhance the resolution of a chiral separation if a proper voltage program is applied. The feasibility of using NVC to enhance chiral separation was demonstrated in the separations of three pairs of enantiomers: terbutaline, chlorpheniramine, and promethazine. All separations started with partial separation in a conventional CE and were significantly improved under the same experimental conditions. The results indicated that VG has the potential to be used to improve the resolving power of CE in chiral separations.

  4. Measurement of Fluid Flow in Pipe and Porous Media by High-Resolution Magnetic Resonance Imaging

    Institute of Scientific and Technical Information of China (English)

    JIANG Lan-lan; SONG Yong-chen; LIU Yu; DOU Bin-lin; ZHU Ning-jun; ZHAO Jia-fei; BULITI Abudula

    2012-01-01

    The objective of this study is to understand the process of fluid flow in pipe and porous media with different pore structures.High-resolution Magnetic Resonance Imaging (MRI) technique was used to visualize the pore structure and measure fluid flow.The porous media was formed by packed bed of glass beads.Flow measurement was carried out by a modified spin echo sequence.The results show that the velocity distribution in pipe is annular and the linear relation between MRI velocity and actual velocity is found in pipe flow measurement.The flow distribution in porous media is rather heterogeneous,and it is consistent with heterogeneous pore structure.The flow through pores with the high volume flow rate is determined largely by geometrical effects such as pore size and cross-sectional area.

  5. The PRL Stabilized High Resolution Echelle Fiber-fed Spectrograph: Instrument Description & First Radial Velocity Results

    CERN Document Server

    Chakraborty, Abhijit; Roy, Arpita; Dixit, Vaibhav; Richardson, Eric Harvey; Dongre, Varun; Pathan, F M; Chaturvedi, Priyanka; Shah, Vishal; Ubale, Girish P; Anandarao, B G

    2013-01-01

    We present spectrograph design details and initial radial velocity results from the PRL optical fiber-fed high-resolution cross-dispersed echelle spectrograph (PARAS), which has recently been commissioned at the Mt Abu 1.2 m telescope, in India. Data obtained as part of the post-commissioning tests with PARAS show velocity precision better than 2m/s over a period of several months on bright RV standard stars. For observations of sigma-Dra we report 1.7m/s precision for a period of seven months and 2.1m/s for HD 9407 over a period of 2 months. PARAS is capable of a single-shot spectral coverage of 3800A - 9500A at a resolution of about 67,000. The RV results were obtained between 3800A and 6900A using simultaneous wavelength calibration with a Thorium-Argon (ThAr) hollow cathode lamp. The spectrograph is maintained under stable conditions of temperature with a precision of 0.01 - 0.02C (rms) at 25.55C, and enclosed in a vacuum vessel at pressure of 0.1 +/-0.03 mbar. The blaze peak efficiency of the spectrograp...

  6. High-resolution measurements of humidity and temperature with lidar

    Science.gov (United States)

    Behrendt, Andreas; Wulfmeyer, Volker; Spaeth, Florian; Hammann, Eva; Muppa, Shravan Kumar; Metzendorf, Simon; Riede, Andrea

    2015-04-01

    3-dimensional thermodynamic fields of temperature and moisture including their turbulent fluctuations have been observed with the two scanning lidar systems of University of Hohenheim in three field campaigns in 2013 and 2014. In this contribution, we will introduce these two self-developed instruments and illustrate their performance with measurement examples. Finally, an outlook to envisioned future research activities with the new data sets of the instruments is given. Our temperature lidar is based on the rotational Raman technique. The scanning rotational Raman lidar (RRL) uses a seeded frequency-doubled Nd:YAG laser at a wavelength of 355 nm. A two-mirror scanner with a 40-cm telescope collects the atmospheric backscatter signals. Humidity measurements are made with a scanning water vapor differential absorption lidar (DIAL) which uses a titanium sapphire laser at 820 nm as transmitter. This laser is pumped with a frequency-doubled Nd:YAG laser and injection-seeded for switching between the online and offline wavelengths. The DIAL receiver consists of a scanning 80-cm telescope. The measured temperature and humidity profiles of both instruments have typical resolutions of only a few seconds and 100 m in the atmospheric boundary layer both in day- and night-time. Recent field experiments with the RRL and the DIAL of University of Hohenheim were (1) the HD(CP)2 Prototype Experiment (HOPE) in spring 2013 in western Germany - this activity is embedded in the project HD(CP)2 (High-definition clouds and precipitation for advancing climate prediction); (2) a measurement campaign in Hohenheim in autumn 2013; (3) the campaign SABLE (Surface Atmospheric Boundary Layer Exchange) in south-western Germany in summer 2014. The collected moisture and temperature data will serve as initial thermodynamic fields for forecast experiments related to the formation of clouds and precipitation. Due to their high resolution and high precision, the systems are capable of resolving

  7. High Resolution Shear Profile Measurements in Entangled Polymers

    KAUST Repository

    Hayes, Keesha A.

    2008-11-17

    We use confocal microscopy and particle image velocimetry to visualize motion of 250-300 nm. fluorescent tracer particles in entangled polymers subject to a rectilinear shear flow. Our results show linear velocity profiles in polymer solutions spanning a wide range of molecular weights and number of entanglements (8≤Z≤56), but reveal large differences between the imposed and measured shear rates. These findings disagree with recent reports that shear banding is a characteristic flow response of entangled polymers, and instead point to interfacial slip as an important source of strain loss. © 2008 The American Physical Society.

  8. High-resolution seismic velocities and shallow structure of the San Andreas fault zone at Middle Mountain, Parkfield, California

    Science.gov (United States)

    Catchings, R.D.; Rymer, M.J.; Goldman, M.R.; Hole, J.A.; Huggins, R.; Lippus, C.

    2002-01-01

    A 5-km-long, high-resolution seismic imaging survey across the San Andreas fault (SAF) zone and the proposed San Andreas Fault Observatory at Depth (SAFOD) drill site near Parkfield, California, shows that velocities vary both laterally and vertically. Velocities range from 4.0 km/sec) probably correspond to granitic rock of the Salinian block, which is exposed a few kilometers southwest of the SAF. The depth to the top of probable granitic rock varies laterally along the seismic profile but is about 600 m below the surface at the proposed SAFOD site. We observe a prominent, lateral low-velocity zone (LVZ) beneath and southwest of the surface trace of the SAF. The LVZ is about 1.5 km wide at 300-m depth but tapers to about 600 m wide at 750-m depth. At the maximum depth of the velocity model (750 m), the LVZ is centered approximately 400 m southwest of the surface trace of the SAF. Similar velocities and velocity gradients are observed at comparable depths on both sides of the LVZ, suggesting that the LVZ is anomalous relative to rocks on either side of it. Velocities within the LVZ are lower than those of San Andreas fault gouge, and the LVZ is also anomalous with respect to gravity, magnetic, and resistivity measurements. Because of its proximity to the surface trace of the SAF, it is tempting to suggest that the LVZ represents a zone of fractured crystalline rocks at depth. However, the LVZ instead probably represents a tectonic sliver of sedimentary rock that now rests adjacent to or encompasses the SAF. Such a sliver of sedimentary rock implies fault strands on both sides and possibly within the sliver, suggesting a zone of fault strands at least 1.5 km wide at a depth of 300 m, tapering to about 600 m wide at 750-m depth. Fluids within the sedimentary sliver are probably responsible for observed low-resistivity values.

  9. High-resolution HI and CO observations of high-latitude intermediate-velocity clouds

    CERN Document Server

    Röhser, T; Bekhti, N Ben; Winkel, B

    2016-01-01

    Intermediate-velocity clouds (IVCs) are HI halo clouds that are likely related to a Galactic fountain process. In-falling IVCs are candidates for the re-accretion of matter onto the Milky Way. We study the evolution of IVCs at the disk-halo interface, focussing on the transition from atomic to molecular IVCs. We compare an atomic IVC to a molecular IVC and characterise their structural differences in order to investigate how molecular IVCs form high above the Galactic plane. With high-resolution HI observations of the Westerbork Synthesis Radio Telescope and 12CO(1-0) and 13CO(1-0) observations with the IRAM 30m telescope, we analyse the small-scale structures within the two clouds. By correlating HI and far-infrared (FIR) dust continuum emission from the Planck satellite, the distribution of molecular hydrogen (H2) is estimated. We conduct a detailed comparison of the HI, FIR, and CO data and study variations of the $X_\\rm{CO}$ conversion factor. The atomic IVC does not disclose detectable CO emission. The a...

  10. Studying Vortex Dynamics of Rotating Convection with High-resolution PIV Measurement

    Science.gov (United States)

    Fu, Hao; Sun, Shiwei; Wang, Yu; Zhou, Bowen; Wang, Yuan

    2016-11-01

    A novel experimental setup for studying vortex dynamics in rotating Rayleigh-Benard convection has been made in School of Atmospheric Sciences, Nanjing University. With water as the working fluid, three lasers with different frequencies and the corresponding three CCDs have been placed to complete 2D2C (two dimensions, two components) PIV measurement. The lasers are fixed on two crossing guiding ways and can move up and down to scan the flow field. An algorithm has been made to reconstruct 3D velocity field based on multiple 2D2C PIV data. This time, we are going to present the details of this new machine and algorithm, as well as some scientific understanding of vortex dynamics owing to this high-resolution velocity measurement system. This work was supported by "LMSWE Lab Funding No. 14380001".

  11. Measurement of Two Phase Flow in Porous Medium Using High-resolution Magnetic Resonance Imaging

    Institute of Scientific and Technical Information of China (English)

    JIANG Lanlan; SONG Yongchen; LIU Yu; YANG Mingjun; ZHU Ningjun; WANG Xiaojing; DOU Binlin

    2013-01-01

    Measurement of two phase flow in porous medium for sequestration was carried out using high-resolution magnetic resonance imaging (MRI) technique.The porous medium was a packed bed of glass beads.Spin echo multi sequence was used to measure the distribution of CO2 and water in the porous medium.The intensity images show that the fluid distribution is non-uniform due to its viscosity and pore structure of porous medium.The velocity distribution of fluids is calculated from the saturation of water and porosity of porous medium.The experimental results show that fluid velocities vary with time and position.The capillary dispersion rate donated the effects of capillary,which was largest at water saturations of 0.45.The displacement process is different between in BZ-02 and BZ-2.The final water residual saturation depends on permeability and porosity.

  12. Localized corrosion information using high resolution measurement devices

    DEFF Research Database (Denmark)

    Ambat, Rajan

    2005-01-01

    to control the solution flow at the tip. Through addition of reference and counter electrodes, the pipette system becomes a microscopic electrochemical cell, which can then be used with high precision to determine the electrochemical characteristics of the microstructural region of interest. The capability...... of the technique could be further enhanced by adding new features such as high resolution video visualization systems, fretting/tribo-corroson attachments, and also by integrating it with stress corrosion testing, corrosion investigation of concrete for a few to name with. The corrosion group in MPT, Technical...

  13. Numerical simulation for accuracy of velocity analysis in small-scale high-resolution marine multichannel seismic technology

    Science.gov (United States)

    Luo, Di; Cai, Feng; Wu, Zhiqiang

    2017-06-01

    When used with large energy sparkers, marine multichannel small-scale high-resolution seismic detection technology has a high resolution, high-detection precision, a wide applicable range, and is very flexible. Positive results have been achieved in submarine geological research, particularly in the investigation of marine gas hydrates. However, the amount of traveltime difference information is reduced for the velocity analysis under conditions of a shorter spread length, thus leading to poorer focusing of the velocity spectrum energy group and a lower accuracy of the velocity analysis. It is thus currently debatable whether the velocity analysis accuracy of short-arrangement multichannel seismic detection technology is able to meet the requirements of practical application in natural gas hydrate exploration. Therefore, in this study the bottom boundary of gas hydrates (Bottom Simulating Reflector, BSR) is used to conduct numerical simulation to discuss the accuracy of the velocity analysis related to such technology. Results show that a higher dominant frequency and smaller sampling interval are not only able to improve the seismic resolution, but they also compensate for the defects of the short-arrangement, thereby improving the accuracy of the velocity analysis. In conclusion, the accuracy of the velocity analysis in this small-scale, high-resolution, multi-channel seismic detection technology meets the requirements of natural gas hydrate exploration.

  14. High-resolution spectroscopy of RGB stars in the Sagittarius Streams. I. Radial velocities and chemical abundances

    CERN Document Server

    Monaco, L; Bonifacio, P; Buzzoni, A; Ferraro, F R; Marconi, G; Sbordone, L; Zaggia, S

    2006-01-01

    Aims. The Sagittarius (Sgr) dwarf spheroidal galaxy is currently disrupting under the strain of the Milky Way. A reliable reconstructions of Sgr star formation history can only be obtained joining core and stream informations. We present radial velocities for 67 stars belonging to the Sgr Stream. For 12 stars in the sample we also present iron (Fe) and $\\alpha$-element (Mg, Ca) abundances. Methods. Spectra were secured using different high resolution facilities: UVES@VLT, HARPS@3.6m and SARG@TNG. Radial velocities are obtained through cross correlation with a template spectra. Concerning chemical analysis, for the various elements, selected line equivalent widths (EWs) were measured and abundances computed using the WIDTH code and ATLAS model atmospheres. Results. The velocity dispersion of the trailing tail is found to be $\\sigma$=8.3$\\pm$0.9 km s$^{-1}, i.e. significantly lower than in the core of the Sgr galaxy and marginally lower than previous estimates in the same portion of the stream. Stream stars fol...

  15. High-resolution spectroscopy of RGB stars in the Sagittarius streams. I. Radial velocities and chemical abundances

    Science.gov (United States)

    Monaco, L.; Bellazzini, M.; Bonifacio, P.; Buzzoni, A.; Ferraro, F. R.; Marconi, G.; Sbordone, L.; Zaggia, S.

    2007-03-01

    Context: The Sagittarius (Sgr) dwarf spheroidal galaxy is currently being disrupted under the strain of the Milky Way. A reliable reconstruction of Sgr star formation history can only be obtained by combining core and stream information. Aims: We present radial velocities for 67 stars belonging to the Sgr Stream. For 12 stars in the sample we also present iron (Fe) and α-element (Mg, Ca) abundances. Methods: Spectra were secured using different high resolution facilities: UVES@VLT, HARPS@3.6 m, and SARG@TNG. Radial velocities are obtained through cross correlation with a template spectra. Concerning chemical analysis, for the various elements, selected line equivalent widths were measured and abundances computed using the WIDTH code and ATLAS model atmospheres. Results: The velocity dispersion of the trailing tail is found to be σ = 8.3 ± 0.9 km s-1, i.e., significantly lower than in the core of the Sgr galaxy and marginally lower than previous estimates in the same portion of the stream. Stream stars follow the same trend as Sgr main body stars in the [ α/Fe] vs. [Fe/H] plane. However, stars are, on average, more metal poor in the stream than in the main body. This effect is slightly stronger in stars belonging to more ancient wraps of the stream, according to currently accepted models of Sgr disruption. Based on observations taken at ESO VLT Kueyen telescope (Cerro Paranal, Chile, program: 075.B-0127(A)) and 3.6 m telescope (La Silla, Chile). Also based on spectroscopic observations taken at the Telescopio Nazionale Galileo, operated by the Fundación G. Galilei of INAF at the Spanish Observatorio del Roque de los Muchachos of the IAC (La Palma, Spain). Appendix A and Table [see full text] are only available in electronic form at http://www.aanda.org

  16. High-resolution spectroscopy of RGB stars in the Sagittarius Streams. I. Radial velocities and chemical abundances

    OpenAIRE

    Monaco, L.; Bellazzini, M; Bonifacio, P.; A. Buzzoni; Ferraro, F. R.; Marconi, G; Sbordone, L.; S. Zaggia

    2006-01-01

    Context. The Sagittarius (Sgr) dwarf spheroidal galaxy is currently being disrupted under the strain of the Milky Way. A reliable reconstruction of Sgr star formation history can only be obtained by combining core and stream information. Aims. We present radial velocities for 67 stars belonging to the Sgr Stream. For 12 stars in the sample we also present iron (Fe) and $\\alpha$-element (Mg, Ca) abundances. Methods. Spectra were secured using different high resolution facilities: UVES@VLT, HAR...

  17. Automated High Resolution Measurement of Heliostat Slope Errors

    OpenAIRE

    Ulmer, Steffen; März, Tobias; Reinalter, Wolfgang; Belhomme, Boris

    2010-01-01

    A new optical measurement method that simplifies and optimizes the mounting and canting of heliostats and helps to assure their optical quality before commissioning of the solar field was developed. This method is based on the reflection of regular patterns in the mirror surface and their distortions due to mirror surface errors. The measurement has a resolution of about one million points per heliostat with a measurement uncertainty of less than 0.2 mrad and a measurement time of about one m...

  18. AUTOMATED HIGH RESOLUTION MEASUREMENT OF HELIOSTAT SLOPE ERRORS

    OpenAIRE

    Ulmer, Steffen; März, Tobias; Prahl, Christoph; Reinalter, Wolfgang; Belhomme, Boris

    2009-01-01

    A new optical measurement method that simplifies and optimizes the mounting and canting of heliostats and helps to assure their optical quality before commissioning of the solar field was developed. This method is based on the reflection of regular patterns in the mirror surface and their distortions due to mirror surface errors. The measurement has a resolution of about one million points per heliostat with a measurement uncertainty of less than 0.2 mrad and a measurement time of about one m...

  19. High-Resolution Correlated Fission Product Measurements of 235U (nth , f) with SPIDER

    Science.gov (United States)

    Shields, Dan; Spider Team

    2015-10-01

    The SPIDER detector (SPectrometer for Ion DEtermination in fission Research) has obtained high-resolution, moderate-efficiency, correlated fission product data needed for many applications including the modeling of next generation nuclear reactors, stockpile stewardship, and the fundamental understanding of the fission process. SPIDER simultaneously measures velocity and energy of both fission products to calculate fission product yields (FPYs), neutron multiplicity (ν), and total kinetic energy (TKE). These data will be some of the first of their kind available to nuclear data evaluations. An overview of the SPIDER detector, analytical method, and preliminary results for 235U (nth , f) will be presented. LA-UR-15-20130 This work benefited from the use of the LANSCE accelerator facility and was performed under the auspices of the US Department of Energy by Los Alamos Security, LLC under Contract DE-AC52-06NA25396.

  20. High resolution applications of seismic tomography: low velocity anomalies and static corrections using wave-equation datuming

    Science.gov (United States)

    Flecha, I.; Marti, D.; Escuder, J.; Perez-Estaun, A.; Carbonell, R.

    2003-04-01

    A detailed characterization of the internal structure and physical properties of shallow surface can be obtained using high-resolution seismic tomography. Two applications of high resolution seismic tomography are presented in this study. Several synthetics simulations have been carried out to asses the resolving power of this methodology in different cases. The first studied case is the detection of low velocity anomalies in the shallow subsoil. Underground cavities (mines), water flows (formation wich loose sand), etc., are geological features present in the shallow subsurface characterized by low seismic velocities, and are targets of considerable social interest. We have considered a 400m×50m two dimensional velocity model consisting of a background velocity gradient in depth from 3 to 4 Km/s which included a rectangular low velocity anomaly (300 m/s). This anomaly was placed between 10m and 30m in depth and between 180m and 220m in length. The inversions schemes provided estimates of the velocity, however the tomograms and the ray tracing diagrams indicated a low resolution for the anomaly. In the second case we have applied wave-equation datuming to pre-stack layer replacement. The standard seismic data processing applies a vertical time shift to the data traces. However, it is not a good option when we are dealing with rugged topography or bathymetry, and when the media presents a high heterogeneity. Wave-equation datuming extrapolates seismic time data to some level datum keeping consistency between raypaths and wavefield propagation. It improves considerably seismic reflectors imaging. In order to implement this technique a velocity model is required, and usually a constant velocity is used to propagate the wavefield; instead of it we have used seismic tomography to provide an accurate velocity model.

  1. High resolution climatological wind measurements for wind energy applications

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, H. [Uppsala Univ. (Sweden). Dept. of Meteorology

    1996-12-01

    Measurements with a combined cup anemometer/wind vane instrument, developed at the Department of Meteorology in Uppsala, is presented. The instrument has a frequency response of about 1 Hz, making it suitable not only for mean wind measurements, but also for studies of atmospheric turbulence. It is robust enough to be used for climatological purposes. Comparisons with data from a hot-film anemometer show good agreement, both as regards standard deviations and the spectral decomposition of the turbulent wind signal. The cup anemometer/wind vane instrument is currently used at three sites within the Swedish wind energy research programme. These measurements are shortly described, and a few examples of the results are given. 1 ref, 10 figs

  2. High resolution wind measurements for offshore wind energy development

    Science.gov (United States)

    Nghiem, Son Van (Inventor); Neumann, Gregory (Inventor)

    2013-01-01

    A method, apparatus, system, article of manufacture, and computer readable storage medium provide the ability to measure wind. Data at a first resolution (i.e., low resolution data) is collected by a satellite scatterometer. Thin slices of the data are determined. A collocation of the data slices are determined at each grid cell center to obtain ensembles of collocated data slices. Each ensemble of collocated data slices is decomposed into a mean part and a fluctuating part. The data is reconstructed at a second resolution from the mean part and a residue of the fluctuating part. A wind measurement is determined from the data at the second resolution using a wind model function. A description of the wind measurement is output.

  3. High-resolution kinetic energy distributions via doppler shift measurements

    Science.gov (United States)

    Xu, Z.; Koplitz, B.; Buelow, S.; Baugh, D.; Wittig, C.

    1986-07-01

    In photolysis/probe experiments using pulsed sources, time delay produces both spatial and directional bias in the fragment distributions, thus enabling well-resolved kinetic energy distributions to be obtained from Doppler shift measurements. Data are presented for H-atoms detected using two-photon ionization, and high S/N and laser-limited kinetic energy resolution are demonstrated.

  4. High resolution DNA content measurements of mammalian sperm

    Energy Technology Data Exchange (ETDEWEB)

    Pinkel, D.; Lake, S.; Gledhill, B.L.; Van Dilla, M.A.; Stephenson, D.; Watchmaker, G.

    1982-01-01

    The high condensation and flat shape of the mammalian sperm nucleus present unique difficulties to flow cytometric measurement of DNA content. Chromatin compactness makes quantitative fluorescent staining for DNA difficult and causes a high index of refraction. The refractive index makes optical measurements sensitive to sperm head orientation. We demonstrate that the optical problems can be overcome using the commercial ICP22 epiillumination flow cytometer (Ortho Instruments, Westwood, MA) or a specially built cell orientating flow cytometer (OFCM). The design and operation of the OFCM are described. Measurements of the angular dependence of fluorescence from acriflavine stained rabbit sperm show that it is capable of orienting flat sperm with a tolerance of +-7/sup 0/. Differences in the angular dependence for the similarly shaped bull and rabbit sperm allow discrimination of these cells. We show that DNA staining with 4-6 diamidino-2-phenylindole (DAPI) or an ethidium bromide mithramycin combination allows resolution of the X and Y populations in mouse sperm. They have also been successful with sperm from the bull, ram, rabbit, and boar. Reliable results with human sperm are not obtained. The accuracy of the staining and measurement techniques are verified by the correct determination of the relative content of these two populations in sperm from normal mice and those with the Cattanach (7 to X) translocation. Among the potential uses of these techniques are measurement of DNA content errors induced in sperm due to mutagen exposure, and assessment of the fractions of X and Y sperm in semen that may have one population artifically enriched.

  5. High Resolution Viscosity Measurement by Thermal Noise Detection

    Directory of Open Access Journals (Sweden)

    Felipe Aguilar Sandoval

    2015-11-01

    Full Text Available An interferometric method is implemented in order to accurately assess the thermal fluctuations of a micro-cantilever sensor in liquid environments. The power spectrum density (PSD of thermal fluctuations together with Sader’s model of the cantilever allow for the indirect measurement of the liquid viscosity with good accuracy. The good quality of the deflection signal and the characteristic low noise of the instrument allow for the detection and corrections of drawbacks due to both the cantilever shape irregularities and the uncertainties on the position of the laser spot at the fluctuating end of the cantilever. Variation of viscosity below 0.03 mPa·s was detected with the alternative to achieve measurements with a volume as low as 50 µL.

  6. High-resolution observations of the spatial and velocity distribution of cometary hydrogen

    Science.gov (United States)

    Brown, Michael E.; Spinrad, Hyron

    1992-01-01

    We have obtained high velocity and spatial resolution long-slit H alpha spectra of comets Austin (1989c1) and Levy (1990c). Spectra of both comets clearly show the existence of a low velocity thermalized component of hydrogen gas. The amount of slow hydrogen is estimated for comet Austin. The Levy spectrum shows an unusual high-velocity spatially-confined blob of hydrogen emission of unknown origin.

  7. Measuring Large-Scale Social Networks with High Resolution

    DEFF Research Database (Denmark)

    Stopczynski, Arkadiusz; Sekara, Vedran; Sapiezynski, Piotr

    2014-01-01

    , telecommunication, social networks, location, and background information (personality, demographics, health, politics) for a densely connected population of 1 000 individuals, using state-of-the-art smartphones as social sensors. Here we provide an overview of the related work and describe the motivation......This paper describes the deployment of a large-scale study designed to measure human interactions across a variety of communication channels, with high temporal resolution and spanning multiple years-the Copenhagen Networks Study. Specifically, we collect data on face-to-face interactions...

  8. High-Resolution Measurements of Low-Energy Conversion Electrons

    CERN Multimedia

    Gizon, A; Putaux, J

    2002-01-01

    Measurements of low-energy internal conversion electrons have been performed with high energy resolution in some N = 105 odd and odd-odd nuclei using a semi-circular spectrograph associated to a specific tape transport system. These experiments aimed to answer the following questions~: \\begin{itemize} \\item Do M3 isomeric transitions exist in $^{183}$Pt and $^{181}$Os, isotones of $^{184}$Au~? \\item Are the neutron configurations proposed to describe the isomeric and ground states of $^{184}$Au right or wrong~? \\item Does it exist an isomeric state in $^{182}$Ir, isotone of $^{181}$Os, $^{183}$Pt and $^{184}$Au~? \\item What are the spin and parity values of the excited states of $^{182}$Ir~? \\end{itemize} In $^{183}$Pt, the 35.0 keV M3 isomeric transition has been clearly observed and the reduced transition probability has been determined. The deduced hindrance factor is close to that observed in the neighbouring odd-odd $^{184}$Au nucleus. This confirms the neutron configurations previously proposed for the ...

  9. High-Resolution Seismic Velocity and Attenuation Models of Eastern Tibet and Adjacent Regions (Post Print)

    Science.gov (United States)

    2012-06-04

    mantle in this region. Similarly, a high velocity and high Q block in southeastern Tibet around eastern Bangong-Nujiang Suture and Eastern Himalaya ...Similarly, a high velocity and high Q block in southeastern Tibet around eastern Bangong-Nujiang Suture and Eastern Himalaya Syntaxis correlates well...underthrusting Indian plate. Azimuthal fast directions are consistent at all depths up to approximately 200 km, which suggests a vertical coherent

  10. High-Resolution Radial Velocity Mapping of Optical Filaments in Evolved Supernova Remnants

    Science.gov (United States)

    Greidanus, H.; Strom, R. G.

    The authors report on observations of the kinematical structure of optical filaments in evolved supernova remnants, using an imaging Fabry-Perot interferometer. The radial velocity characteristics as seen in [O III] λ5007 emission in one area in the Cygnus Loop are described, where four kinematically different components contributing to the emission can be recognized.

  11. A multi-plate velocity-map imaging design for high-resolution photoelectron spectroscopy

    Science.gov (United States)

    Kregel, Steven J.; Thurston, Glen K.; Zhou, Jia; Garand, Etienne

    2017-09-01

    A velocity map imaging (VMI) setup consisting of multiple electrodes with three adjustable voltage parameters, designed for slow electron velocity map imaging applications, is presented. The motivations for this design are discussed in terms of parameters that influence the VMI resolution and functionality. Particularly, this VMI has two tunable potentials used to adjust for optimal focus, yielding good VMI focus across a relatively large energy range. It also allows for larger interaction volumes without significant sacrifice to the resolution via a smaller electric gradient at the interaction region. All the electrodes in this VMI have the same dimensions for practicality and flexibility, allowing for relatively easy modifications to suit different experimental needs. We have coupled this VMI to a cryogenic ion trap mass spectrometer that has a flexible source design. The performance is demonstrated with the photoelectron spectra of S- and CS2 -. The latter has a long vibrational progression in the ground state, and the temperature dependence of the vibronic features is probed by changing the temperature of the ion trap.

  12. Combination of comprehensive geophysical measurements and conventional soil sampling for high resolution soil mapping

    Science.gov (United States)

    Werban, U.; Nuesch, A.; Vienken, T.; Dietrich, P.; Behrens, T.

    2010-12-01

    consistently by a - in iSOIL developed - sampling protocol with conventional soil sampling methods with regard to texture, organic matter content, etc. - Out of these sampling points selected points are chosen for further detailed measurements. Around a single point a small area of 30 x 70 meters is placed to accomplish geophysical high resolution measurements. Besides EMI and gamma-spectrometry also magnetics, seismics and GPR are applied. The line distance is only one meter and also the towing-velocity is slow. The combination and common interpretation of different methods require several prerequisites to a single method. The measurements need to be comparable within several fields and over time. As a representative we show results of a comparability study with the EMI instrument EM38DD.

  13. High-resolution absorption measurements of NH3 at high temperatures: 500–2100cm−1

    DEFF Research Database (Denmark)

    Barton, Emma J.; Yurchenko, Sergei N.; Tennyson, Jonathan

    2015-01-01

    High-resolution absorption spectra of NH3 in the region 500–2100 cm -1 at temperatures up to1027 1C and approximately atmospheric pressure (1013±20 mbar) are measured. NH3 concentrations of 1000 ppm,0.5% and 1% in volume fraction were used in the measurements. Spectra are recorded in high...... temperature gas flow cells using a FourierTransform Infrared (FTIR) spectrometer at a nominal resolution of 0.09cm-1. Measurements at 22.7 °C are compared to high-resolution cross sections available from thePacific Northwest National Laboratory (PNNL). The higher temperature spectra are analysed by comparison...

  14. Retrieval of Precise Radial Velocities from Near-Infrared High Resolution Spectra of Low Mass Stars

    CERN Document Server

    Gao, Peter; Gagné, Jonathan; Furlan, Elise; Bottom, Michael; Anglada-Escudé, Guillem; White, Russel; Davison, Cassy; Beichman, Charles; Brinkworth, Carolyn; Johnson, John; Ciardi, David; Wallace, James; Mennesson, Bertrand; von Braun, Kaspar; Vasisht, Gautam; Prato, Lisa; Kane, Stephen; Tanner, Angelle; Crawford, Timothy; Latham, David; Rougeot, Raphaël; Geneser, Claire; Catanzarite, Joseph

    2016-01-01

    Given that low-mass stars have intrinsically low luminosities at optical wavelengths and a propensity for stellar activity, it is advantageous for radial velocity (RV) surveys of these objects to use near-infrared (NIR) wavelengths. In this work we describe and test a novel RV extraction pipeline dedicated to retrieving RVs from low mass stars using NIR spectra taken by the CSHELL spectrograph at the NASA Infrared Telescope Facility, where a methane isotopologue gas cell is used for wavelength calibration. The pipeline minimizes the residuals between the observations and a spectral model composed of templates for the target star, the gas cell, and atmospheric telluric absorption; models of the line spread function, continuum curvature, and sinusoidal fringing; and a parameterization of the wavelength solution. The stellar template is derived iteratively from the science observations themselves without a need for separate observations dedicated to retrieving it. Despite limitations from CSHELL's narrow wavelen...

  15. The precision radial velocity error budget for the Gemini High-resolution Optical SpecTrograph (GHOST)

    Science.gov (United States)

    Ireland, Michael J.; Artigau, Étienne; Burley, Greg; Edgar, Michael; Margheim, Steve; Robertson, Gordon; Pazder, John; McDermid, Richard; Zhelem, Ross

    2016-08-01

    The Gemini High-resolution Optical SpecTrograph (GHOST) is a fiber fed spectrograph primarily designed for high efficiency and broad wavelength coverage (363 -1000nm), with an anticipated commissioning early in 2018. The primary scientific goal of the Precision Radial Velocity (PRV) mode will be follow-up of relatively faint (R>12) transiting exoplanet targets, especially from the TESS mission. In the PRV mode, the 1.2 arcsec diameter stellar image will be split 19 ways, combined in a single slit with a simultaneous Th/Xe reference source, dispersed at a resolving power of 80,000 and imaged onto two detectors. The spectrograph will be thermally stabilized in the Gemini pier laboratory, and modal noise will be reduced below other sources through the use of a fiber agitator. Unlike other precision high resolution spectrographs, GHOST will not be pressure controlled (although pressure will be monitored precisely), and there will be no double scrambler or shaped (e.g. octagonal) fibers. Instead, GHOST will have to rely on simultaneous two-color imaging of the slit and the simultaneous Th/Xe fiber to correct for variable fiber illumination and focal-ratio degradation. This configuration presents unique challenges in estimating a PRV error budget.

  16. High resolution rainfall – runoff measurement setup for green roof experiments in a tropical environment

    Directory of Open Access Journals (Sweden)

    T. Vergroesen

    2010-12-01

    Full Text Available This article describes the measurement setup that is used for green roof experiments in a tropical environment, the required data treatment to obtain reliable values of rainfall, runoff and evapotranspiration, and how to deal with external disturbances that can influence the experiment results. High resolution rainfall runoff measurements to identify, understand and properly model the relevant runoff processes in a green roof require both tailored equipment and data treatment. A tipping bucket rain gauge is calibrated for and installed to measure minute based rain intensities. A runoff measuring setup is developed that can accurately quantify the runoff up to 6 l/min, and has a high resolution in both time and volume. Two different measuring setups are used to verify the evapotranspiration that is derived from the rainfall and runoff measurements.

  17. Performance of high-resolution X-band radar for rainfall measurement in The Netherlands

    Directory of Open Access Journals (Sweden)

    C. Z. van de Beek

    2010-02-01

    Full Text Available This study presents an analysis of 195 rainfall events gathered with the X-band weather radar SOLIDAR and a tipping bucket rain gauge network near Delft, The Netherlands, between May 1993 and April 1994. The aim of this paper is to present a thorough analysis of a climatological dataset using a high spatial (120 m and temporal (16 s resolution X-band radar. This makes it a study of the potential for high-resolution rainfall measurements with non-polarimetric X-band radar over flat terrain. An appropriate radar reflectivity – rain rate relation is derived from measurements of raindrop size distributions and compared with radar – rain gauge data. The radar calibration is assessed using a long-term comparison of rain gauge measurements with corresponding radar reflectivities as well as by analyzing the evolution of the stability of ground clutter areas over time. Three different methods for ground clutter correction as well as the effectiveness of forward and backward attenuation correction algorithms have been studied. Five individual rainfall events are discussed in detail to illustrate the strengths and weaknesses of high-resolution X-band radar and the effectiveness of the presented correction methods. X-band radar is found to be able to measure the space-time variation of rainfall at high resolution, far greater than what can be achieved by rain gauge networks or a typical operational C-band weather radar. On the other hand, SOLIDAR can suffer from receiver saturation, wet radome attenuation as well as signal loss along the path. During very strong convective situations the signal can even be lost completely. In combination with several rain gauges for quality control, high resolution X-band radar is considered to be suitable for rainfall monitoring over relatively small (urban catchments. These results offer great prospects for the new high resolution polarimetric doppler X-band radar IDRA.

  18. Performance of high-resolution X-band radar for rainfall measurement in The Netherlands

    Directory of Open Access Journals (Sweden)

    C. Z. van de Beek

    2009-09-01

    Full Text Available This study presents an analysis of 195 rainfall events gathered with the X-band weather radar SOLIDAR and a tipping bucket rain gauge network near Delft, The Netherlands, between May 1993 and April 1994. The high spatial (120 m and temporal (16 s resolution of the radar combined with the extent of the database make this study a climatological analysis of the potential for high-resolution rainfall measurement with non-polarimetric X-band radar over completely flat terrain. An appropriate radar reflectivity – rain rate relation is derived from measurements of raindrop size distributions and compared with radar – rain gauge data. The radar calibration is assessed using a long-term comparison of rain gauge measurements with corresponding radar reflectivities as well as by analyzing the evolution of the stability of ground clutter areas over time. Three different methods for ground clutter correction as well as the effectiveness of forward and backward attenuation correction algorithms have been studied. Five individual rainfall events are discussed in detail to illustrate the strengths and weaknesses of high-resolution X-band radar and the effectiveness of the presented correction methods. X-band radar is found to be able to measure the space-time variation of rainfall at high resolution, far greater than can be achieved by rain gauge networks or a typical operational C-band weather radar. On the other hand, SOLIDAR can suffer from receiver saturation, wet radome attenuation as well as signal loss along the path. During very strong convective situations the signal can even be lost completely. In combination with several rain gauges for quality control, high resolution X-band radar is considered to be suitable for rainfall monitoring over relatively small (urban catchments. These results offer great prospects for the new high resolution polarimetric doppler X-band radar IDRA.

  19. To assess the intimal thickness, flow velocities, and luminal diameter of carotid arteries using high-resolution B-mode ultrasound doppler imaging

    Science.gov (United States)

    Vemuru, Madhuri; Jabbar, Afzal; Chandra, Suman

    2004-04-01

    Carotid imaging is a Gold Standard test that provides useful information about the structure and functions of carotid arteries. Spectral imaging helps to evaluate the vessel and hemodynamic changes. High resolution B-mode imaging has emerged as one of the methods of choice for determining the anatomic extent of atherosclerosis and its progression and for assessing cardiovascular risks. The measurements made with Doppler correlate well with pathologic measurements. Recent prospective studies have clearly demonstrated that these measurements of carotid intimal thickness are potent predictors of Myocardial Infarction and Stroke. This method appears very attractive as it is non-invasive, extremely safe, well accepted by the patient and relatively inexpensive. It can be performed serially and has the advantage of visualizing the arterial wall in contrast to angiographic techniques which provide only an outline of the arterial lumen. Recently, there has been an interest in the clinical use of this technique in making difficult clinical decisions like deciding on preventive therapies. 30 subjects aged 21-60 years and 30 subjects aged 61-85 years of both sexes are selected after doing a baseline study to exclude Hypertension, Diabetes, Obesity and Hyperlipidemia. The carotid arteries were examined for intimal thickening, blood flow velocities and luminal diameter. With aging there is a narrowing of the carotid vessels and significant increase in intimal thickening with a consequent increase in the blood flow velocities. Inter-observer, intra-observer and instrument variations are seen and there is no significant change in the values when the distal flow pattern is considered for measurements. Aging produces major cardiovascular changes including decreased elasticity and compliance of great arteries leading to structural and functional alterations in heart and vessels. With aging there is increased intimal thickness and increased pulse wave velocity which is clearly

  20. Two-Phase Flow Modelling Perspectives Based on Novel High-Resolution Acoustic Measurements of Uniform Steady Sheet-Flow

    Science.gov (United States)

    Chauchat, J.; Revil-Baudard, T.; Hurther, D.

    2014-12-01

    Sheet flow is believed to be a major process for morphological evolution of natural systems. An important research effort has been dedicated to laboratory and numerical studies of sheet flow regime that have allowed to make some progress in the understanding of the underlying physical processes. Recent advances made in high resolution measurement techniques allows to give new insights into the small scale physical processes. In this contribution, a novel uniform and steady sheet flow dataset based on an Acoustic Concentration and Velocity Profiler (ACVP) is presented. Profile of colocated velocities (streamwise and wall-normal) and sediment concentration has been measured at high-resolution (3 mm ; 78 Hz for the velocities and 4.9 Hz for the concentration). The measured profiles extend over the whole water column, from the free surface down to the fixed bed and an ensemble averaging over eleven realisations of the same experimental conditions has been used to obtain mean profiles of streamwise velocity, concentration, sediment flux and turbulent shear stress. The present experiment corresponds to a Shields number of θ=0.44 and a suspension number of ws/u*=1.1 corresponding to the lower limit of the no-suspension sheet flow regime. The analysis of the mixing length profile allows to identify two layers, a dilute suspension layer dominated by turbulence and a dense moving bed layer dominated by granular interactions. Our measurements show that the Von Karman parameter is reduced by a factor of more than two and that the Schmidt number is almost constant with a mean value of σs=0.44. Frictional and collisional interactions are encountered in the bed layer. Frictional interactions dominate close to the fixed bed interface whereas collisional interactions seems to control the flow at the transition between the dense and dilute layers. The relevancy of different constitutive laws for two-phase flow models are discussed.

  1. High-resolution setup for measuring wavelength sensitivity of photoyellowing of translucent materials

    Energy Technology Data Exchange (ETDEWEB)

    Vaskuri, Anna, E-mail: anna.vaskuri@aalto.fi; Kärhä, Petri [Metrology Research Institute, Aalto University, P.O. Box 13000, FI-00076 Aalto (Finland); Heikkilä, Anu [R& D/Climate Research, Finnish Meteorological Institute, P.O. Box 503, FI-00101 Helsinki (Finland); Ikonen, Erkki [Metrology Research Institute, Aalto University, P.O. Box 13000, FI-00076 Aalto (Finland); MIKES Metrology, VTT Technical Research Centre of Finland Ltd., P.O. Box 1000, FI-02044 VTT (Finland)

    2015-10-15

    Polystyrene and many other materials turn yellow when exposed to ultraviolet (UV) radiation. All photodegradation mechanisms including photoyellowing are functions of the exposure wavelength, which can be described with an action spectrum. In this work, a new high-resolution transmittance measurement setup based on lasers has been developed for measuring color changes, such as the photoyellowing of translucent materials aged with a spectrograph. The measurement setup includes 14 power-stabilized laser lines between 325 nm and 933 nm wavelengths, of which one at a time is directed on to the aged sample. The power transmitted through the sample is measured with a silicon detector utilizing an integrating sphere. The sample is mounted on a high-resolution XY translation stage. Measurement at various locations aged with different wavelengths of exposure radiation gives the transmittance data required for acquiring the action spectrum. The combination of a UV spectrograph and the new high-resolution transmittance measurement setup enables a novel method for studying the UV-induced ageing of translucent materials with a spectral resolution of 3–8 nm, limited by the adjustable spectral bandwidth range of the spectrograph. These achievements form a significant improvement over earlier methods.

  2. High-resolution compact shear stress sensor for direct measurement of skin friction in fluid flow

    Science.gov (United States)

    Xu, Muchen; Kim, Chang-Jin ``Cj''

    2015-11-01

    The high-resolution measurement of skin friction in complex flows has long been of great interest but also a challenge in fluid mechanics. Compared with indirect measurement methods (e.g., laser Doppler velocimetry), direct measurement methods (e.g., floating element) do not involve any analogy and assumption but tend to suffer from instrumentation challenges, such as low sensing resolution or misalignments. Recently, silicon micromachined floating plates showed good resolution and perfect alignment but were too small for general purposes and too fragile to attach other surface samples repeatedly. In this work, we report a skin friction sensor consisting of a monolithic floating plate and a high-resolution optical encoder to measure its displacement. The key for the high resolution is in the suspension beams, which are very narrow (e.g., 0.25 mm) to sense small frictions along the flow direction but thick (e.g., 5 mm) to be robust along all other directions. This compact, low profile, and complete sensor is easy to use and allows repeated attachment and detachment of surface samples. The sheer-stress sensor has been tested in water tunnel and towing tank at different flow conditions, showing high sensing resolution for skin friction measurement. Supported by National Science Foundation (NSF) (No. 1336966) and Defense Advanced Research Projects Agency (DARPA) (No. HR0011-15-2-0021).

  3. Comparative Analysis of two Methods for High-Resolution Differential Conductance Measurement

    Science.gov (United States)

    Cusick, David; Naito, Michio; Ramos, Roberto

    We compare two methods of differential conductance measurement. The first is a traditional method in which current and voltage data is acquired via four-wire measurement, then averaged and differentiated numerically. The second method calculates dI / dV in real time by superimposing a small DC signal dI on the input step function, alternating between addition and subtraction of the signal with each step, then averaging the small signal voltage response over three steps to obtain dV . This requires two instruments: a DC current source and a high-resolution voltmeter. Keithley Instruments has commercially promoted the Keithley 622x current source and 2182A nanovoltmeter as means to achieve this measurement; we therefore refer to it as the Keithley method. We compare the two methods by performing high-resolution measurements of the energy gap of MgB2 thin film Josephson junctions. We show that the Keithley method has advantages of cleaner data, easier implementation, and overall faster data collection, but may lack the traditional method's high resolution. R.C.R. acknowledges support from National Science Foundation Grant # DMR-1555775.

  4. Experimental validation of a 2D overland flow model using high resolution water depth and velocity data

    Science.gov (United States)

    Cea, L.; Legout, C.; Darboux, F.; Esteves, M.; Nord, G.

    2014-05-01

    This paper presents a validation of a two-dimensional overland flow model using empirical laboratory data. Unlike previous publications in which model performance is evaluated as the ability to predict an outlet hydrograph, we use high resolution 2D water depth and velocity data to analyze to what degree the model is able to reproduce the spatial distribution of these variables. Several overland flow conditions over two impervious surfaces of the order of one square meter with different micro and macro-roughness characteristics are studied. The first surface is a simplified representation of a sinusoidal terrain with three crests and furrows, while the second one is a mould of a real agricultural seedbed terrain. We analyze four different bed friction parameterizations and we show that the performance of formulations which consider the transition between laminar, smooth turbulent and rough turbulent flow do not improve the results obtained with Manning or Keulegan formulas for rough turbulent flow. The simulations performed show that using Keulegan formula with a physically-based definition of the bed roughness coefficient, a two-dimensional shallow water model is able to reproduce satisfactorily the flow hydrodynamics. It is shown that, even if the resolution of the topography data and numerical mesh are high enough to include all the small scale features of the bed surface, the roughness coefficient must account for the macro-roughness characteristics of the terrain in order to correctly reproduce the flow hydrodynamics.

  5. Applications of High Resolution Mid-Infrared Spectroscopy for Atmospheric and Environmental Measurements

    Science.gov (United States)

    Roscioli, Joseph R.; McManus, J. Barry; Nelson, David; Zahniser, Mark; Herndon, Scott C.; Shorter, Joanne; Yacovitch, Tara I.; Jervis, Dylan; Dyroff, Christoph; Kolb, Charles E.

    2016-06-01

    For the past 20 years, high resolution infrared spectroscopy has served as a valuable tool to measure gas-phase concentrations of ambient gas samples. We review recent advances in atmospheric sampling using direct absorption high resolution mid-infrared spectroscopy from the perspective of light sources, detectors, and optical designs. Developments in diode, quantum cascade and interband cascade laser technology have led to thermoelectrically-cooled single-mode laser sources capable of operation between 800 wn and 3100 wn, with 10 mW power. Advances in detector and preamplifier technology have yielded thermoelectriocally-cooled sensors capable of room-temperature operation with extremely high detectivities. Finally, novel spectrometer optical designs have led to robust multipass absorption cells capable of >400 m effective pathlength in a compact package. In combination with accurate spectroscopic databases, these developments have afforded dramatic improvements in measurement sensitivity, accuracy, precision, and selectivity. We will present several examples of the applications of high resolution mid-IR spectrometers in real-world field measurements at sampling towers and aboard mobile platforms such as vehicles and airplanes.

  6. High resolution magnetostriction measurements in pulsed magnetic fields using fiber Bragg gratings.

    Science.gov (United States)

    Daou, Ramzy; Weickert, Franziska; Nicklas, Michael; Steglich, Frank; Haase, Ariane; Doerr, Mathias

    2010-03-01

    We report on a new high resolution apparatus for measuring magnetostriction suitable for use at cryogenic temperatures in pulsed high magnetic fields which we have developed at the Hochfeld-Magnetlabor Dresden. Optical fiber strain gauges based on fiber Bragg gratings are used to measure the strain in small (approximately 1 mm) samples. We describe the implementation of a fast measurement system capable of resolving strains in the order of 10(-7) with a full bandwidth of 47 kHz, and demonstrate its use on single crystal samples of GdSb and GdSi.

  7. The high-resolution extraterrestrial solar spectrum (QASUMEFTS determined from ground-based solar irradiance measurements

    Directory of Open Access Journals (Sweden)

    J. Gröbner

    2017-09-01

    Full Text Available A high-resolution extraterrestrial solar spectrum has been determined from ground-based measurements of direct solar spectral irradiance (SSI over the wavelength range from 300 to 500 nm using the Langley-plot technique. The measurements were obtained at the Izaña Atmospheric Research Centre from the Agencia Estatal de Meteorología, Tenerife, Spain, during the period 12 to 24 September 2016. This solar spectrum (QASUMEFTS was combined from medium-resolution (bandpass of 0.86 nm measurements of the QASUME (Quality Assurance of Spectral Ultraviolet Measurements in Europe spectroradiometer in the wavelength range from 300 to 500 nm and high-resolution measurements (0.025 nm from a Fourier transform spectroradiometer (FTS over the wavelength range from 305 to 380 nm. The Kitt Peak solar flux atlas was used to extend this high-resolution solar spectrum to 500 nm. The expanded uncertainties of this solar spectrum are 2 % between 310 and 500 nm and 4 % at 300 nm. The comparison of this solar spectrum with solar spectra measured in space (top of the atmosphere gave very good agreements in some cases, while in some other cases discrepancies of up to 5 % were observed. The QASUMEFTS solar spectrum represents a benchmark dataset with uncertainties lower than anything previously published. The metrological traceability of the measurements to the International System of Units (SI is assured by an unbroken chain of calibrations leading to the primary spectral irradiance standard of the Physikalisch-Technische Bundesanstalt in Germany.

  8. Sulphur Dioxide: High Resolution Ultra-Violet Photoabsorption Cross Section Measurements at 200K.

    Science.gov (United States)

    Blackie, D.; Blackwell-Whitehead, R.; Stark, G.; Pickering, J. C.; Rufus, J.; Thorne, A.; Smith, P. L.

    2007-12-01

    Sulphur Dioxide plays an important role not only within the Earth's atmosphere but also within the complex chemistry of both the upper atmosphere of Venus and the volcanically active Jovian moon Io. The lack of high resolution laboratory studies has prevented the full, accurate determination of absorption cross sections which are the basis for reliable photochemical models. High resolution laboratory measurements of SO2 are essential to resolve the complex SO2 spectrum and yield accurate photoabsorption cross sections. Using the Imperial College UV Fourier Transform Spectrometer new high resolution (λ/δλ ~ 450,000) measurements have been recorded over a range of temperatures and pressures. As part of an on-going series of measurements, current laboratory work focused on photoabsorption cross sections of SO2 at 200K across the wavelength range 220 → 325 nm. These measurements not only compliment previous room temperature measurements obtained at Imperial College in the 190 → 220 nm and 220 → 328 nm ranges (Stark et al., JGR Planets 104, 16, 585 (1999) and Rufus et al.,( JGR Planets 108, 2, 5 (2003)), but also coincide with the wavelength regions being recorded by the Venus Express mission through the UV-IR spectrometer SPICAV (ESA-SCI(2001)6). Our new measurements will allow accurate analysis of the chemical processes in the upper atmosphere of Venus. These absorption cross section measurements are the first to be acquired at this resolution, temperature and pressure. Results will be presented. This work was supported in part by NASA Grant NNG05GA03G, PPARC (UK), and the Leverhulme Trust.

  9. Using High-Resolution Field Measurements to Model Dune Kinematics in a Large Elongate Meander Bend.

    Science.gov (United States)

    Konsoer, K. M.; Rhoads, B. L.; Best, J.; Frias, C. E.; Abad, J. D.; Langendoen, E. J.

    2014-12-01

    Due to recent advances in hydroacoustic technology, such as the development of multibeam echo sounders, it is now possible to obtain highly accurate and detailed bathymetric data for river channels. These data provide the basis for detailed characterizations of bed form morphology ranging from individual ripples to composite dune fields. Theoretical models suggest that bed forms reach an equilibrium morphology based on hydraulic conditions during steady flow. However, at the scale of individual meander bends, bed form morphology will vary according to the local flow structure as influenced by overall bed morphology and planform curvature. Thus, the coevolution of flow structure, bed form morphology, and sediment transport should vary throughout a meander bend. This paper examines spatial variation in bed form characteristics and rates of bed form migration, and thus bed material transport, within a large, actively migrating, elongate meander loop. During a May 2013 flood event on Maier Bend, Wabash River (IL-IN, USA), repeat multibeam echo sounding surveys were conducted ~4 hours apart, providing estimates of dune celerity and volumetric rates of sediment transport at different locations around the bend. Three-dimensional velocity measurements, obtained using an acoustic Doppler current profiler, provide hydraulic data for evaluating interactions between flow structure and bed form morphology. Results show that bed form morphology is highly variable within the bend, ranging from barchans dunes on the upstream limb, 2D ripples across the point bar, and 3D composite dunes with wavelength of ~20 meters near the bend apex. Rates of dune celerity varied from 0.3 m/hr to 0.7 m/hr and were dependent on bed form geometry and local hydraulic conditions. The high-resolution data on flow and form are used to calibrate a 2D numerical model of sediment transport through the bend. Simulations using the calibrated model are used to evaluate the fluvial processes underlying

  10. High-resolution absorption measurements of NH3 at high temperatures: 2100–5500 cm−1

    DEFF Research Database (Denmark)

    Barton, Emma J.; Yurchenko, Sergei N.; Tennyson, Jonathan

    2017-01-01

    High-resolution absorption spectra of NH3 in the region 2100–5500 cm−1 at 1027 °C and approximately atmospheric pressure (1045±3 mbar) are measured. An NH3 concentration of 10% in volume fraction is used in the measurements. Spectra are recorded in a high-temperature gas-flow cell using a Fourier...... Transform Infrared (FTIR) spectrometer at a nominal resolution of 0.09 cm−1. The spectra are analysed by comparison to a variational line list, BYTe, and experimental energy levels determined using the MARVEL procedure. 2308 lines have been assigned to 45 different bands, of which 1755 and 15 have been...

  11. High Resolution and High Sensitivity Measurement of Methane at 1.51 μm

    Institute of Scientific and Technical Information of China (English)

    DENG Lun-Hua; GAO Xiao-Ming; CAO Zhen-Song; ZHAO Wei-Xiong; ZHANG Wei-Jun

    2006-01-01

    @@ The high-resolution absorption spectrum of CH4 at 1.51 μm is observed by direct absorption spectroscopy technique with a White absorption cell. Multi-peak fitting technique is adopted to reveal line positions and line intensities of CH4 from 6608 cm-1 to 6625 cm-1. Special attention is paid on the determination of the line positions, and the accuracy is better than ±0.002 cm-1. A minimum measurable absorption of 2.1 × 10-s (3σr) has been achieved based on the measured direct absorption spectroscopy.

  12. Super-High Resolution Time Interval Measurement Method Based on Time-Space Relationships

    Institute of Scientific and Technical Information of China (English)

    DU Bao-Qiang; ZHOU Wei

    2009-01-01

    Based on the principle of quantized delay-time, a super-high resolution time interval measurement method is proposed based on time-space relationships.Using the delay-time stability that time and frequency signal travel in a specific medium, the measured time interval can be quantized.Combined with the phase coincidence detection technique, the measurement of time can be changed into the measurement of space length.The resolution and the stability of the measurement system are easily improved.Experimental results show that the measurement resolution of the measured time interval depends on the length difference of the double delay-time unit.When the length difference is set up on millimeter level or sub-millimeter level, super-high measurement resolution from hundreds of picosecond to tens of picosecond can be obtained.

  13. High-Resolution Group Quantization Phase Processing Method in Radio Frequency Measurement Range.

    Science.gov (United States)

    Du, Baoqing; Feng, Dazheng; Tang, Yaohua; Geng, Xin; Zhang, Duo; Cai, Chaofeng; Wan, Maoquan; Yang, Zhigang

    2016-07-08

    Aiming at the more complex frequency translation, the longer response time and the limited measurement precision in the traditional phase processing, a high-resolution phase processing method by group quantization higher than 100 fs level is proposed in radio frequency measurement range. First, the phase quantization is used as a step value to quantize every phase difference in a group by using the fixed phase relationships between different frequencies signals. The group quantization is formed by the results of the quantized phase difference. In the light of frequency drift mainly caused by phase noise of measurement device, a regular phase shift of the group quantization is produced, which results in the phase coincidence of two comparing signals which obtain high-resolution measurement. Second, in order to achieve the best coincidences pulse, a subtle delay is initiatively used to reduce the width of the coincidences fuzzy area according to the transmission characteristics of the coincidences in the specific medium. Third, a series of feature coincidences pulses of fuzzy area can be captured by logic gate to achieve the best phase coincidences information for the improvement of the measurement precision. The method provides a novel way to precise time and frequency measurement.

  14. Instantaneous frequency measurement based on transversal microwave filters with high resolution

    Institute of Scientific and Technical Information of China (English)

    Jiaji Dong; Yuan Yu; Xinliang Zhang; Dexiu Huang

    2011-01-01

    We propose a novel photonic technique for microwave frequency measurement based on transversal microwave filters with high resolution. Two parallel microwave filters with sine and cosine frequency responses are obtained by cross gain modulation in a single semiconductor optical amplifier, which introduces two different frequency responses to achieve an amplitude comparison function. We also demonstrate a proofof-concept experiment. The measurement error is less than ±0.04 GHz for the first band range of 0-3.45 GHz and less than ±0.03 GHz for the second band range of 3.45-5.8 GHz. Our scheme is found to be capable of being extended for larger frequency range measurements using a shorter fiber length.%@@ We propose a novel photonic technique for microwave frequency measurement based on transversal microwave filters with high resolution.Two parallel microwave filters with sine and cosine frequency responses are obtained by cross gain modulation in a single semiconductor optical amplifier, which introduces two different frequency responses to achieve an amplitude comparison function.We also demonstrate a proofof-concept experiment.

  15. Real-time, high-resolution x-ray diffraction measurements on shocked crystals at a synchrotron facility.

    Science.gov (United States)

    Gupta, Y M; Turneaure, Stefan J; Perkins, K; Zimmerman, K; Arganbright, N; Shen, G; Chow, P

    2012-12-01

    The Advanced Photon Source (APS) at Argonne National Laboratory was used to obtain real-time, high-resolution x-ray diffraction measurements to determine the microscopic response of shock-compressed single crystals. Disk shaped samples were subjected to plane shock wave compression by impacting them with half-inch diameter, flat-faced projectiles. The projectiles were accelerated to velocities ranging between 300 and 1200 m/s using a compact powder gun designed specifically for use at a synchrotron facility. The experiments were designed to keep the sample probed volume under uniaxial strain and constant stress for a duration longer than the 153.4 ns spacing between x-ray bunches. X-rays from a single pulse (crystals at the APS are presented. Analytic developments to determine the effects of crystal substructure and non-ideal geometry on the diffraction pattern position and shape are presented. Representative real-time x-ray diffraction data, indicating shock-induced microstructural changes, are presented for a shock-compressed Al(111) sample. The experimental developments presented here provided, in part, the impetus for the Dynamic Compression Sector (DCS) currently under development at the APS. Both the synchronization∕x-ray detection methods and the analysis equations for high-resolution single crystal x-ray diffraction can be used at the DCS.

  16. Turbulence Fine Structure, Intermittency, and Large-Scale Interactions in the Stable Boundary Layer and Residual Layer: Correlative High-Resolution Measurements and Direct Numerical Simulations

    Science.gov (United States)

    2014-12-06

    SECURITY CLASSIFICATION OF: The research employed stable boundary layer measurements using the DataHawk UAV and high-resolution direct numerical...simulations ( DNS ) to examine the interactions and instabilities occurring in multi-scale flows that drive intermittent turbulence events in the stable...atmosphere. Both measurements and the DNS revealed the occurrence and persistence of sheet-and-layer structures in the temperature and velocity fields that

  17. Marvel Analysis of the Measured High-resolution Rovibronic Spectra of TiO

    Science.gov (United States)

    McKemmish, Laura K.; Masseron, Thomas; Sheppard, Samuel; Sandeman, Elizabeth; Schofield, Zak; Furtenbacher, Tibor; Császár, Attila G.; Tennyson, Jonathan; Sousa-Silva, Clara

    2017-02-01

    Accurate, experimental rovibronic energy levels, with associated labels and uncertainties, are reported for 11 low-lying electronic states of the diatomic {}48{{Ti}}16{{O}} molecule, determined using the Marvel (Measured Active Rotational-Vibrational Energy Levels) algorithm. All levels are based on lines corresponding to critically reviewed and validated high-resolution experimental spectra taken from 24 literature sources. The transition data are in the 2-22,160 cm-1 region. Out of the 49,679 measured transitions, 43,885 are triplet-triplet, 5710 are singlet-singlet, and 84 are triplet-singlet transitions. A careful analysis of the resulting experimental spectroscopic network (SN) allows 48,590 transitions to be validated. The transitions determine 93 vibrational band origins of {}48{{Ti}}16{{O}}, including 71 triplet and 22 singlet ones. There are 276 (73) triplet-triplet (singlet-singlet) band-heads derived from Marvel experimental energies, 123(38) of which have never been assigned in low- or high-resolution experiments. The highest J value, where J stands for the total angular momentum, for which an energy level is validated is 163. The number of experimentally derived triplet and singlet {}48{{Ti}}16{{O}} rovibrational energy levels is 8682 and 1882, respectively. The lists of validated lines and levels for {}48{{Ti}}16{{O}} are deposited in the supporting information to this paper.

  18. High-resolution, continuous method for measurement of acidity in ice cores.

    Science.gov (United States)

    Pasteris, Daniel R; McConnell, Joseph R; Edwards, Ross

    2012-02-07

    The acid content of ice core samples provides information regarding the history of volcanism, biogenic activity, windblown dust, forest fires, and pollution-induced acid rain. A continuous ice core analysis allows for collection of high-resolution data in a very efficient manner, but this technique has not been readily applied to the measurement of pH and acidity in ice cores. The difficulty arises because the sample is highly undersaturated with respect to carbon dioxide (CO(2)) immediately after melting, making it difficult to maintain stable concentrations of dissolved carbon dioxide and carbonic acid (H(2)CO(3)). Here, we present a solution to this problem in the form of a small flow-through bubbling chamber that is supplied with a known concentration of CO(2). The bubbling action allows for quick equilibration while the small size of the chamber limits sample mixing in order to maintain high resolution. Thorough error analysis provides a measurement uncertainty of ±0.20 μM or ±5% of the acidity value, whichever is greater, and the T95 signal response time is determined to be 1.25 min. The performance of the technique is further evaluated with data from a 63-year ice core from northwest Greenland for which all major ion species were also measured. The measured acidity closely matches the acidity derived from a charge balance calculation, indicating that all of the analytes were measured accurately. The performance specifications that we provide are applicable to ice cores with low concentrations of alkaline dust (ice cores that are collected. To date, the method has not been evaluated with samples containing high alkaline dust concentrations, such as Greenland cores from the last glacial period, where measurement could be made difficult by memory effects as particles coat the internal surfaces of the sample stream.

  19. A high-resolution x-ray spectrometer for a kaon mass measurement

    Science.gov (United States)

    Phelan, Kevin; Suzuki, Ken; Zmeskal, Johann; Tortorella, Daniele; Bühler, Matthias; Hertrich, Theo

    2017-02-01

    The ASPECT consortium (Adaptable Spectrometer Enabled by Cryogenic Technology) is currently constructing a generalised cryogenic platform for cryogenic detector work which will be able to accommodate a wide range of sensors. The cryogenics system is based on a small mechanical cooler with a further adiabatic demagnetisation stage and will work with cryogenic detectors at sub-Kelvin temperatures. The commercial aim of the consortium is to produce a compact, user-friendly device with an emphasis on reliability and portability which can easily be transported for specialised on-site work, such as beam-lines or telescope facilities. The cryogenic detector platform will accommodate a specially developed cryogenic sensor, either a metallic magnetic calorimeter or a magnetic penetration-depth thermometer. The detectors will be designed to work in various temperatures regions with an emphasis on optimising the various detector resolutions for specific temperatures. One resolution target is of about 10 eV at the energies range typically created in kaonic atoms experiments (soft x-ray energies). A following step will see the introduction of continuous, high-power, sub-Kelvin cooling which will bring the cryogenic basis for a high resolution spectrometer system to the market. The scientific goal of the project will produce an experimental set-up optimised for kaon-mass measurements performing high-resolution x-ray spectroscopy on a beam-line provided foreseeably by the J-PARC (Tokai, Japan) or DAΦNE (Frascati, Italy) facilities.

  20. The high resolution spectrum of methyltrioxorhenium reinvestigated with new infrared and millimeter-wave measurements

    CERN Document Server

    Asselin, Pierre; Huet, Thérèse; Margulès, Laurent; Motiyenko, Roman; Hendricks, Richard; Tarbutt, Michael; Tokunaga, Sean; Darquié, Benoît

    2016-01-01

    Following our first paper about high resolution spectroscopy of methyltrioxorhenium (MTO) [Stoeffler et al. PCCP, 13, 854, (2011)], the present study reports a deeper investigation of the ground state, and Re=O antisymmetric (nu\\_as) and symmetric (nu\\_s) stretching excited states of both CH3(187Re)O3 and CH3(185Re)O3 isotopologues, thanks to new devices implemented within our consortium. We carry out high resolution millimeter-wave (MMW) and infrared (IR) spectroscopy in room temperature absorption cells, in a pulsed supersonic jet and in a cryogenic buffer gas cell. This collection of sensitive spectrometers enables us to probe both levels of a vibrational transition in low and room temperature gaseous environments. We thus report a new series of measurements providing particularly accurate rotational and rovibrational data for such a large and heavy organometallic molecule that is solid at room temperature.The combination of the new MMW and IR data leads to an improvement of the rovibrational model of MTO:...

  1. High-resolution in situ measurement of nitrate in runoff from the Greenland Ice Sheet.

    Science.gov (United States)

    Beaton, Alexander David; Wadham, Jemma L; Hawkings, Jon; Bagshaw, Elizabeth A; Lamarche-Gagnon, Guillaume; Mowlem, Matthew C; Tranter, Martyn

    2017-09-27

    We report the first in situ high-resolution nitrate time series from two proglacial meltwater rivers draining the Greenland Ice Sheet, using a recently developed submersible analyser based on lab-on-chip (LOC) technology. The low sample volume (320 μL) required by the LOC analyser meant that low concentration (few to sub μM), highly turbid subglacial meltwater could be filtered and colourimetrically analysed in situ. These data are linked to an unparalleled, multi-component data set. Nitrate concentrations in rivers draining Leverett Glacier in South-West Greenland and Kiattuut Sermiat in Southern Greenland exhibited a clear diurnal signal and a gradual decline at the commencement of the melt season, displaying trends would not be discernible using traditional daily manual sampling. Nitrate concentrations varied by 4.4 μM (+/- 0.2 μM) over a 10-day period at Kiattuut Sermiat and 3.0 μM (+/- 0.2 μM) over a 14 day period at Leverett Glacier. Marked changes in nitrate concentrations were observed when discharge began to increase. High resolution in situ measurements such as these have the potential to significantly advance the understanding of nutrient cycling in remote systems, where the dynamics of nutrient release are complex but are important for downstream biogeochemical cycles.

  2. Fall speed measurement and high-resolution multi-angle photography of hydrometeors in free fall

    Directory of Open Access Journals (Sweden)

    T. J. Garrett

    2012-11-01

    Full Text Available We describe here a new instrument for imaging hydrometeors in free fall. The Multi-Angle Snowflake Camera (MASC captures high-resolution photographs of hydrometeors from three angles while simultaneously measuring their fall speed. Based on the stereoscopic photographs captured over the two months of continuous measurements obtained at a high altitude location within the Wasatch Front in Utah, we derive statistics for fall speed, hydrometeor size, shape, orientation and aspect ratio. From a selection of the photographed hydrometeors, an illustration is provided for how the instrument might be used for making improved microwave scattering calculations. Complex, aggregated snowflake shapes appear to be more strongly forward scattering, at the expense of reduced back-scatter, than heavily rimed graupel particles of similar size.

  3. Dual Wavelength Laser Writing and Measurement Methodology for High Resolution Bimetallic Grayscale Photomasks

    Science.gov (United States)

    Qarehbaghi, Reza

    Grayscale bimetallic photomasks consist of bi-layer thermal resists (Bismuth-on-Indium or Tin-on-Indium) which become controllably transparent when exposed to a focused laser beam as a function of the absorbed power changing from ~3OD (unexposed) to writing. This thesis investigates using two wavelength beams for mask writing (514.5nm) and OD measurement (457.9nm) separated from a multi-line Argon ion laser source: a Dual Wavelength Writing and Measurement System. The writing laser profile was modified to a top-hat using a beam shaper. Several mask patterns tested the creation of high resolution grayscale masks. Finally, for creation of 3D structures in photoresist, the mask transparency to resist thickness requirements was formulated and linear slope patterns were successfully created.

  4. High-resolution absorption measurements of NH3 at high temperatures: 2100-5500 cm-1

    Science.gov (United States)

    Barton, Emma J.; Yurchenko, Sergei N.; Tennyson, Jonathan; Clausen, Sønnik; Fateev, Alexander

    2017-03-01

    High-resolution absorption spectra of NH3 in the region 2100-5500 cm-1 at 1027 °C and approximately atmospheric pressure (1045±3 mbar) are measured. An NH3 concentration of 10% in volume fraction is used in the measurements. Spectra are recorded in a high-temperature gas-flow cell using a Fourier Transform Infrared (FTIR) spectrometer at a nominal resolution of 0.09 cm-1. The spectra are analysed by comparison to a variational line list, BYTe, and experimental energy levels determined using the MARVEL procedure. 2308 lines have been assigned to 45 different bands, of which 1755 and 15 have been assigned or observed for the first time in this work.

  5. MARVEL analysis of the measured high-resolution spectra of 14NH3

    Science.gov (United States)

    Al Derzi, Afaf R.; Furtenbacher, Tibor; Tennyson, Jonathan; Yurchenko, Sergei N.; Császár, Attila G.

    2015-08-01

    Accurate, experimental rotational-vibrational energy levels and line positions, with associated labels and uncertainties, are reported for the ground electronic state of the symmetric-top 14NH3 molecule. All levels and lines are based on critically reviewed and validated high-resolution experimental spectra taken from 56 literature sources. The transition data are in the 0.7-17 000 cm-1 region, with a large gap between 7000 and 15 000 cm-1. The MARVEL (Measured Active Rotational-Vibrational Energy Levels) algorithm is used to determine the energy levels. Out of the 29 450 measured transitions 10 041 and 18 947 belong to ortho- and para-14NH3, respectively. A careful analysis of the related experimental spectroscopic network (SN) allows 28 530 of the measured transitions to be validated, 18 178 of these are unique, while 462 transitions belong to floating components. Despite the large number of spectroscopic measurements published over the last 80 years, the transitions determine only 30 vibrational band origins of 14NH3, 8 for ortho- and 22 for para-14NH3. The highest J value, where J stands for the rotational quantum number, for which an energy level is validated is 31. The number of experimental-quality ortho- and para-14NH3 rovibrational energy levels is 1724 and 3237, respectively. The MARVEL energy levels are checked against ones in the BYTe first-principles database, determined previously. The lists of validated lines and levels for 14NH3 are deposited in the Supporting Information to this paper. Combination of the MARVEL energy levels with first-principles absorption intensities yields a huge number of experimental-quality rovibrational lines, which should prove to be useful for the understanding of future complex high-resolution spectroscopy on 14NH3; these lines are also deposited in the Supporting Information to this paper.

  6. Retrieving mesospheric winds and gravity waves using high resolution radar measurements of polar mesospheric summer echoes with MAARSY

    Science.gov (United States)

    Stober, G.; Sommer, S.; Schult, C.; Chau, J. L.; Latteck, R.

    2013-12-01

    The Middle Atmosphere Alomar Radar System (MAARSY) located at the northern Norwegian island of Andøya (69.3 ° N, 16° E) observes polar mesosphere summer echoes (PMSE) on a regular basis. This backscatter turned out to be an ideal tracer of atmospheric dynamics and to investigate the wind field at the mesosphere/lower thermosphere (MLT) at high spatial and temporal scales. MAARSY is dedicated to explore the polar mesosphere at such high resolution and employs an active phased array antenna with the capability to steer the beam on a pulse-to-pulse basis, which permits to perform systematic scanning of PMSE and to investigate the horizontal structure of the backscatter. The radar also uses a 16 channel receiver system for interferometric applications e.g. mean angle of arrival analysis or coherent radar imaging. Here we present measurements using these features of MAARSY to study the wind field at the MLT applying sophisticated wind analysis algorithms such as velocity azimuth display or volume velocity processing to derive gravity wave parameters such as horizontal wave length, phase speed and propagation direction. Further, we compare the interferometrically corrected and uncorrected wind measurements to emphasize the importance to account for likely edge effects using PMSE as tracer of the dynamics. The observations indicate huge deviations from the nominal beam pointing direction at the upper and lower edges of the PMSE altering the wind analysis.

  7. Double seismic zone of the Nazca plate in northern Chile: High-resolution velocity structure, petrological implications, and thermomechanical modeling

    Science.gov (United States)

    Dorbath, Catherine; Gerbault, Muriel; Carlier, Gabriel; Guiraud, Michel

    2008-07-01

    This paper presents an interdisciplinary study of the northern Chile double seismic zone. First, a high-resolution velocity structure of the subducting Nazca plate has been obtained by the tomoDD double-difference tomography method. The double seismic zone (DSZ) is observed between 80 and 140 km depth, and the two seismic planes is 20 km apart. Then, the chemical and petrologic characteristics of the oceanic lithosphere associated with this DSZ are deduced by using current thermal-petrological-seismological models and are compared to pressure-temperature conditions provided by a numerical thermomechanical model. Our results agree with the common hypothesis that seismicity in both upper and lower planes is related to fluid releases associated with metamorphic dehydration reactions. In the seismic upper plane located within the upper crust, these reactions would affect material of basaltic (MORB) composition and document different metamorphic reactions occurring within high-P (>2.4 GPa) and low-T (130 km), lawsonite-amphibole eclogite conditions. The lower plane lying in the oceanic mantle can be associated with serpentinite dehydration reactions. The Vp and Vs characteristics of the region in between both planes are consistent with a partially (˜25-30 vol % antigorite, ˜0-10% vol % brucite, and ˜4-10 vol % chlorite) hydrated harzburgitic material. Discrepancies persist that we attribute to complexities inherent to heterogeneous structural compositions. While various geophysical indicators evidence particularly cold conditions in both the descending Nazca plate and the continental fore arc, thermomechanical models indicate that both seismic planes delimit the inner slab compressional zone around the 400°C (±50°C) isotherm. Lower plane earthquakes are predicted to occur in the slab's flexural neutral plane, where fluids released from surrounding metamorphic reactions could accumulate and trigger seismicity. Fluids migrating upward from the tensile zone below

  8. Potassium Stable Isotopic Compositions Measured by High-Resolution MC-ICP-MS

    Science.gov (United States)

    Morgan, Leah E.; Lloyd, Nicholas S.; Ellam, Robert M.; Simon, Justin I.

    2012-01-01

    Potassium isotopic (K-41/K-39) compositions are notoriously difficult to measure. TIMS measurements are hindered by variable fractionation patterns throughout individual runs and too few isotopes to apply an internal spike method for instrumental mass fractionation corrections. Internal fractionation corrections via the K-40/K-39 ratio can provide precise values but assume identical K-40/K-39 ratios (e.g. 0.05% (1sigma) in [1]); this is appropriate in some cases (e.g. identifying excess K-41) but not others (e.g., determining mass fractionation effects and metrologically traceable isotopic abundances). SIMS analyses have yielded measurements with 0.25% precisions (1sigma) [2]. ICP-MS analyses are significantly affected by interferences from molecular species such as Ar-38H(+) and Ar-40H(+) and instrument mass bias. Single collector ICP-MS instruments in "cold plasma" mode have yielded uncertainties as low as 2% (1sigma, e.g. [3]). Although these precisions may be acceptable for some concentration determinations, they do not resolve isotopic variation in terrestrial materials. Here we present data from a series of measurements made on the Thermo Scientific NEPTUNE Plus multi-collector ICP-MS that demonstrate the ability to make K-41/K-39 ratio measurements with 0.07% precisions (1sigma). These data, collected on NIST K standards, indicate the potential for MC-ICP-MS measurements to look for K isotopic variations at the sub-permil level. The NEPTUNE Plus can sufficiently resolve 39K and 41K from the interfering 38ArH+ and 40ArH+ peaks in wet cold plasma and high-resolution mode. Measurements were made on small but flat, interference-free, plateaus (ca. 50 ppm by mass width for K-41). Although ICP-MS does not yield accurate K-41/K-39 values due to significant instrumental mass fractionation (ca. 6%), this bias can be sufficiently stable over the time required for several measurements so that relative K-41/K-39 values can be precisely determined via sample

  9. Reference-free, high-resolution measurement method of timing jitter spectra of optical frequency combs

    Science.gov (United States)

    Kwon, Dohyeon; Jeon, Chan-Gi; Shin, Junho; Heo, Myoung-Sun; Park, Sang Eon; Song, Youjian; Kim, Jungwon

    2017-01-01

    Timing jitter is one of the most important properties of femtosecond mode-locked lasers and optical frequency combs. Accurate measurement of timing jitter power spectral density (PSD) is a critical prerequisite for optimizing overall noise performance and further advancing comb applications both in the time and frequency domains. Commonly used jitter measurement methods require a reference mode-locked laser with timing jitter similar to or lower than that of the laser-under-test, which is a demanding requirement for many laser laboratories, and/or have limited measurement resolution. Here we show a high-resolution and reference-source-free measurement method of timing jitter spectra of optical frequency combs using an optical fibre delay line and optical carrier interference. The demonstrated method works well for both mode-locked oscillators and supercontinua, with 2 × 10−9 fs2/Hz (equivalent to −174 dBc/Hz at 10-GHz carrier frequency) measurement noise floor. The demonstrated method can serve as a simple and powerful characterization tool for timing jitter PSDs of various comb sources including mode-locked oscillators, supercontinua and recently emerging Kerr-frequency combs; the jitter measurement results enabled by our method will provide new insights for understanding and optimizing timing noise in such comb sources. PMID:28102352

  10. Void measurement using high-resolution gamma-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Bieberle, Andre, E-mail: a.bieberle@hzdr.de [Institute of Safety Research, Helmholz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden (Germany); Hoppe, Dietrich; Schleicher, Eckhard; Hampel, Uwe [Institute of Safety Research, Helmholz-Zentrum Dresden-Rossendorf, Bautzner Landstrasse 400, 01328 Dresden (Germany)

    2011-06-15

    Highlights: > We present a CT system determining void distributions in thermo hydraulic facilities. > The system has been carefully designed for harsh operating conditions. > To increase measurement accuracy a scattered correction algorithm was developed. > First results of laboratory measurements on a bundle mock-up are presented. - Abstract: We present a high-resolution gamma-ray computed tomography (CT) measurement system for the determination of cross-sectional time-averaged void distributions in thermo hydraulic facilities. The system has been carefully designed for harsh operating conditions, such as varying temperature fields and strong magnetic fields, typically produced by thermal hydraulic test loops with direct electric bundle heating. Measurements are non invasive, thus the two-phase flow in the test section is not influenced. The gamma-ray CT system consists of a collimated {sup 137}Cs isotopic source, a gamma radiation detector arc including 320 single elements, a pulse processing unit and a thermal stabilisation unit. The spatial resolution of the CT system is about 2 mm in plane. Recently, the thermal design of the detector arc is improved to secure maintenance of constant temperature of thermally sensitive components under changing environmental conditions. This turned out to be a key issue for achieving accurate quantitative measurements. First results of laboratory measurements on a bundle mock-up with this improved system are presented.

  11. The effect of pattern overlap on the accuracy of high resolution electron backscatter diffraction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Vivian, E-mail: v.tong13@imperial.ac.uk [Department of Materials, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom); Jiang, Jun [Department of Materials, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom); Wilkinson, Angus J. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Britton, T. Ben [Department of Materials, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom)

    2015-08-15

    High resolution, cross-correlation-based, electron backscatter diffraction (EBSD) measures the variation of elastic strains and lattice rotations from a reference state. Regions near grain boundaries are often of interest but overlap of patterns from the two grains could reduce accuracy of the cross-correlation analysis. To explore this concern, patterns from the interior of two grains have been mixed to simulate the interaction volume crossing a grain boundary so that the effect on the accuracy of the cross correlation results can be tested. It was found that the accuracy of HR-EBSD strain measurements performed in a FEG-SEM on zirconium remains good until the incident beam is less than 18 nm from a grain boundary. A simulated microstructure was used to measure how often pattern overlap occurs at any given EBSD step size, and a simple relation was found linking the probability of overlap with step size. - Highlights: • Pattern overlap occurs at grain boundaries and reduces HR-EBSD accuracy. • A test is devised to measure the accuracy of HR-EBSD in the presence of overlap. • High pass filters can sometimes, but not generally, improve HR-EBSD measurements. • Accuracy of HR-EBSD remains high until the reference pattern intensity is <72%. • 9% of points near a grain boundary will have significant error for 200nm step size in Zircaloy-4.

  12. Validation of meter-scale surface faulting offset measurements from high-resolution topographic data

    Science.gov (United States)

    Salisbury, Barrett; Haddad, D.E.; Rockwell, T.K.; Arrowsmith, R.; Madugo, C.; Zielke, O.; Scharer, Katherine M.

    2015-01-01

    Studies of active fault zones have flourished with the availability of high-resolution topographic data, particularly where airborne light detection and ranging (lidar) and structure from motion (SfM) data sets provide a means to remotely analyze submeter-scale fault geomorphology. To determine surface offset at a point along a strike-slip earthquake rupture, geomorphic features (e.g., stream channels) are measured days to centuries after the event. Analysis of these and cumulatively offset features produces offset distributions for successive earthquakes that are used to understand earthquake rupture behavior. As researchers expand studies to more varied terrain types, climates, and vegetation regimes, there is an increasing need to standardize and uniformly validate measurements of tectonically displaced geomorphic features. A recently compiled catalog of nearly 5000 earthquake offsets across a range of measurement and reporting styles provides insight into quality rating and uncertainty trends from which we formulate best-practice and reporting recommendations for remote studies. In addition, a series of public and beginner-level studies validate the remote methodology for a number of tools and emphasize considerations to enhance measurement accuracy and precision for beginners and professionals. Our investigation revealed that (1) standardizing remote measurement methods and reporting quality rating schemes is essential for the utility and repeatability of fault-offset measurements; (2) measurement discrepancies often involve misinterpretation of the offset geomorphic feature and are a function of the investigator’s experience; (3) comparison of measurements made by a single investigator in different climatic regions reveals systematic differences in measurement uncertainties attributable to variation in feature preservation; (4) measuring more components of a displaced geomorphic landform produces more consistently repeatable estimates of offset; and (5

  13. Validation of meter-scale surface faulting offset measurements from high-resolution topographic data

    KAUST Repository

    Salisbury, J. Barrett

    2015-10-24

    Studies of active fault zones have flourished with the availability of high-resolution topographic data, particularly where airborne light detection and ranging (lidar) and structure from motion (SfM) data sets provide a means to remotely analyze submeter- scale fault geomorphology. To determine surface offset at a point along a strike-slip earthquake rupture, geomorphic features (e.g., stream channels) are measured days to centuries after the event. Analysis of these and cumulatively offset features produces offset distributions for successive earthquakes that are used to understand earthquake rupture behavior. As researchers expand studies to more varied terrain types, climates, and vegetation regimes, there is an increasing need to standardize and uniformly validate measurements of tectonically displaced geomorphic features. A recently compiled catalog of nearly 5000 earthquake offsets across a range of measurement and reporting styles provides insight into quality rating and uncertainty trends from which we formulate best-practice and reporting recommendations for remote studies. In addition, a series of public and beginner-level studies validate the remote methodology for a number of tools and emphasize considerations to enhance measurement accuracy and precision for beginners and professionals. Our investigation revealed that (1) standardizing remote measurement methods and reporting quality rating schemes is essential for the utility and repeatability of fault-offset measurements; (2) measurement discrepancies often involve misinterpretation of the offset geomorphic feature and are a function of the investigator\\'s experience; (3) comparison of measurements made by a single investigator in different climatic regions reveals systematic differences in measurement uncertainties attributable to variation in feature preservation; (4) measuring more components of a displaced geomorphic landform produces more consistently repeatable estimates of offset; and (5

  14. High-resolution gamma ray attenuation density measurements on mining exploration drill cores, including cut cores

    Science.gov (United States)

    Ross, P.-S.; Bourke, A.

    2017-01-01

    Physical property measurements are increasingly important in mining exploration. For density determinations on rocks, one method applicable on exploration drill cores relies on gamma ray attenuation. This non-destructive method is ideal because each measurement takes only 10 s, making it suitable for high-resolution logging. However calibration has been problematic. In this paper we present new empirical, site-specific correction equations for whole NQ and BQ cores. The corrections force back the gamma densities to the "true" values established by the immersion method. For the NQ core caliber, the density range extends to high values (massive pyrite, 5 g/cm3) and the correction is thought to be very robust. We also present additional empirical correction factors for cut cores which take into account the missing material. These "cut core correction factors", which are not site-specific, were established by making gamma density measurements on truncated aluminum cylinders of various residual thicknesses. Finally we show two examples of application for the Abitibi Greenstone Belt in Canada. The gamma ray attenuation measurement system is part of a multi-sensor core logger which also determines magnetic susceptibility, geochemistry and mineralogy on rock cores, and performs line-scan imaging.

  15. A compact and miniaturized high resolution capacitance dilatometer for measuring thermal expansion and magnetostriction.

    Science.gov (United States)

    Küchler, R; Bauer, T; Brando, M; Steglich, F

    2012-09-01

    We describe the design, construction, calibration, and two different applications of a miniature capacitance dilatometer. The device is suitable for thermal expansion and magnetostriction measurements from 300 K down to about 25 mK, with a resolution of 0.02 Å at low temperatures. The main body of the dilatometer is fabricated from a single block of a Be-Cu alloy by electrical discharge milling. This creates an extremely compact high-resolution measuring cell. We have successfully tested and operated dilatometers of this new type with the commonly used physical property measurement system by quantum design, as well as with several other cryogenic refrigeration systems down to 25 mK and in magnetic fields up to 20 T. Here, the capacitance is measured with a commercially available capacitance bridge. Using a piezoelectric rotator from Attocube Systems, the cell can be rotated at T = 25 mK inside of an inner vacuum chamber of 40 mm diameter. The miniaturized design for the one-axis rotation setup allows a rotation of 360°.

  16. A modified high-resolution TEM for thermoelectric properties measurements of nanowires and nanotubes

    Science.gov (United States)

    Dames, C.; Chen, S.; Harris, C. T.; Huang, J. Y.; Ren, Z. F.; Dresselhaus, M. S.; Chen, G.

    2006-10-01

    Nanowires are interesting candidates for thermoelectric applications because of their potentially low thermal conductivity and high power factor. However, measurements at the single-wire level are challenging and tend to lack detailed information about the atomic-level structure of the sample and contacts. We are modifying a high-resolution transmission electron microscope (HRTEM) with integrated scanning tunneling microscope (STM) for in-situ measurements of the thermoelectric properties of individual nanowires and nanotubes. A slender hot-wire probe is used to make electrical and thermal contact to the free end of a nanowire or nanotube. The electrical conductance of the nanowire/nanotube can be measured with the usual STM mode of operation. The Seebeck coefficient can be extracted from the transient response to a step change in the joule heating of the hot-wire probe. The thermal conductance can be calculated from the temperature and heat leakage of the hot-wire probe. These measurements are combined with detailed HRTEM observations.

  17. High resolution acoustic measurement system and beam pattern reconstruction method for bat echolocation emissions.

    Science.gov (United States)

    Gaudette, Jason E; Kloepper, Laura N; Warnecke, Michaela; Simmons, James A

    2014-01-01

    Measurements of the transmit beam patterns emitted by echolocating bats have previously been limited to cross-sectional planes or averaged over multiple signals using sparse microphone arrays. To date, no high-resolution measurements of individual bat transmit beams have been reported in the literature. Recent studies indicate that bats may change the time-frequency structure of their calls depending on the task, and suggest that their beam patterns are more dynamic than previously thought. To investigate beam pattern dynamics in a variety of bat species, a high-density reconfigurable microphone array was designed and constructed using low-cost ultrasonic microphones and custom electronic circuitry. The planar array is 1.83 m wide by 1.42 m tall with microphones positioned on a 2.54 cm square grid. The system can capture up to 228 channels simultaneously at a 500 kHz sampling rate. Beam patterns are reconstructed in azimuth, elevation, and frequency for visualization and further analysis. Validation of the array measurement system and post-processing functions is shown by reconstructing the beam pattern of a transducer with a fixed circular aperture and comparing the result with a theoretical model. To demonstrate the system in use, transmit beam patterns of the big brown bat, Eptesicus fuscus, are shown.

  18. Method for local temperature measurement in a nanoreactor for in situ high-resolution electron microscopy.

    Science.gov (United States)

    Vendelbo, S B; Kooyman, P J; Creemer, J F; Morana, B; Mele, L; Dona, P; Nelissen, B J; Helveg, S

    2013-10-01

    In situ high-resolution transmission electron microscopy (TEM) of solids under reactive gas conditions can be facilitated by microelectromechanical system devices called nanoreactors. These nanoreactors are windowed cells containing nanoliter volumes of gas at ambient pressures and elevated temperatures. However, due to the high spatial confinement of the reaction environment, traditional methods for measuring process parameters, such as the local temperature, are difficult to apply. To address this issue, we devise an electron energy loss spectroscopy (EELS) method that probes the local temperature of the reaction volume under inspection by the electron beam. The local gas density, as measured using quantitative EELS, is combined with the inherent relation between gas density and temperature, as described by the ideal gas law, to obtain the local temperature. Using this method we determined the temperature gradient in a nanoreactor in situ, while the average, global temperature was monitored by a traditional measurement of the electrical resistivity of the heater. The local gas temperatures had a maximum of 56 °C deviation from the global heater values under the applied conditions. The local temperatures, obtained with the proposed method, are in good agreement with predictions from an analytical model. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Single CMOS sensor system for high resolution double volume measurement applied to membrane distillation system

    Science.gov (United States)

    Lorenz, M. G.; Izquierdo-Gil, M. A.; Sanchez-Reillo, R.; Fernandez-Pineda, C.

    2007-01-01

    Membrane distillation (MD) [1] is a relatively new process that is being investigated world-wide as a low cost, energy saving alternative to conventional separation processes such as distillation and reverse osmosis (RO). This process offers some advantages compared to other more popular separation processes, such as working at room conditions (pressure and temperature); low-grade, waste and/or alternative energy sources such as solar and geothermal energy may be used; a very high level of rejection with inorganic solutions; small equipment can be employed, etc. The driving force in MD processes is the vapor pressure difference across the membrane. A temperature difference is imposed across the membrane, which results in a vapor pressure difference. The principal problem in this kind of system is the accurate measurement of the recipient volume change, especially at very low flows. A cathetometer, with up to 0,05 mm resolution, is the instrument used to take these measurements, but the necessary human intervention makes this instrument not suitable for automated systems. In order to overcome this lack, a high resolution system is proposed, that makes automatic measurements of the volume of both recipients, cold and hot, at a rate of up to 10 times per second.

  20. High-resolution photoabsorption cross section measurements of sulfur dioxide between 198 nm and 325 nm

    Science.gov (United States)

    Stark, Glenn; Smith, Peter; Blackie, Douglas; Blackwell-Whitehead, Richard; Pickering, Juliet; Rufus, James; Thorne, Anne

    Accurate photoabsorption cross section data at a range of temperatures are required for the incorporation of sulfur dioxide into atmospheric photochemical models. In addition to its role in the terrestrial atmosphere, sulfur dioxide is observed in significant concentrations in the atmospheres of Venus and Io. Our laboratory measurement program focuses on the very congested SO2 spectrum in the ultraviolet. Using the Imperial College UV Fourier transform spectrometer, we have recorded high-resolution (resolving power (λ/∆λ) = 450,000) absorption spectra in the 198 to 325 nm region over a range of temperatures from 160 K to 295 K. This high resolving power allows resolutions approaching those required to fully resolve the Doppler profile of SO2 in the UV. We have reported absolute photoabsorption cross sections at 295 K [Stark et al., JGR Planets 104, 16585 (1999); Rufus et al. JGR Planets 108, doi:10.1029/2002JE001931,(2003)]. Further measurements, at 160 K in the 198 to 200 nm region and at 195 K in the 220 to 325 nm region, have been recorded and analyzed. We present an overview of our new measured cross sections at temperatures and pressures comparable to those found in planetary atmospheres. This work was supported in part by NASA Grant NNG05GA03G, PPARC (UK), and the Leverhulme Trust.

  1. UDECON: deconvolution optimization software for restoring high-resolution records from pass-through paleomagnetic measurements

    Science.gov (United States)

    Xuan, Chuang; Oda, Hirokuni

    2015-11-01

    The rapid accumulation of continuous paleomagnetic and rock magnetic records acquired from pass-through measurements on superconducting rock magnetometers (SRM) has greatly contributed to our understanding of the paleomagnetic field and paleo-environment. Pass-through measurements are inevitably smoothed and altered by the convolution effect of SRM sensor response, and deconvolution is needed to restore high-resolution paleomagnetic and environmental signals. Although various deconvolution algorithms have been developed, the lack of easy-to-use software has hindered the practical application of deconvolution. Here, we present standalone graphical software UDECON as a convenient tool to perform optimized deconvolution for pass-through paleomagnetic measurements using the algorithm recently developed by Oda and Xuan (Geochem Geophys Geosyst 15:3907-3924, 2014). With the preparation of a format file, UDECON can directly read pass-through paleomagnetic measurement files collected at different laboratories. After the SRM sensor response is determined and loaded to the software, optimized deconvolution can be conducted using two different approaches (i.e., "Grid search" and "Simplex method") with adjustable initial values or ranges for smoothness, corrections of sample length, and shifts in measurement position. UDECON provides a suite of tools to view conveniently and check various types of original measurement and deconvolution data. Multiple steps of measurement and/or deconvolution data can be compared simultaneously to check the consistency and to guide further deconvolution optimization. Deconvolved data together with the loaded original measurement and SRM sensor response data can be saved and reloaded for further treatment in UDECON. Users can also export the optimized deconvolution data to a text file for analysis in other software.

  2. Measuring stellar magnetic fields from high resolution spectroscopy of near-infrared lines

    Science.gov (United States)

    Leone, F.; Vacca, W. D.; Stift, M. J.

    2003-10-01

    Zeeman splitting of otherwise degenerate levels provides a straight-forward method of measuring stellar magnetic fields. In the optical, the relative displacements of the Zeeman components are quite small compared to the rotational line broadening, and therefore observations of Zeeman splitting are usually possible only for rather strong magnetic fields in very slowly rotating stars. However, the magnitude of the Zeeman splitting is proportional to the square of the wavelength, whereas rotational line broadening mechanisms are linear in wavelength; therefore, there is a clear advantage in using near-infrared spectral lines to measure surface stellar magnetic fields. We have obtained high resolution (R >= 25 000) spectra in the 15 625-15 665 Å region for two magnetic chemically peculiar stars, viz. HD 176232 and HD 201601, and for the suspected magnetic chemically peculiar star HD 180583, as part of a pilot study aimed at determining the accuracy with which we can measure stellar magnetic fields using the Zeeman splitting of near-infrared lines. We confirm that in principle the magnetic field strength can be estimated from the magnetic intensification of spectral lines, i.e. the increase in equivalent width of a line over the zero-field value. However, due to line blending as well as the dependence of this intensification on abundance and field geometry, accurate estimates of the magnetic field strengths can be obtained only by modelling the line profiles by means of spectral synthesis techniques. Using this approach, we find a 1.4 kG magnetic field modulus in HD 176132 and an upper limit of 0.2 kG in HD 180583. The very weak infrared lines in the spectrum of HD 201601 are consistent with a 3.9 kG field modulus estimated from the splitting of the Fe II 6149.258 Å line seen in an optical spectrum. Finally, we would like to draw attention to the fact that there are no sufficiently detailed and reliable atomic line lists available for the near-infrared region that

  3. The investigation of active Martian dune fields using very high resolution photogrammetric measurements

    Science.gov (United States)

    Kim, Jungrack; Kim, Younghwi; Park, Minseong

    2016-10-01

    At the present time, arguments continue regarding the migration speeds of Martian dune fields and their correlation with atmospheric circulation. However, precisely measuring the spatial translation of Martian dunes has succeeded only a very few times—for example, in the Nili Patera study (Bridges et al. 2012) using change-detection algorithms and orbital imagery. Therefore, in this study, we developed a generic procedure to precisely measure the migration of dune fields with recently introduced 25-cm resolution orbital imagery specifically using a high-accuracy photogrammetric processor. The processor was designed to trace estimated dune migration, albeit slight, over the Martian surface by 1) the introduction of very high resolution ortho images and stereo analysis based on hierarchical geodetic control for better initial point settings; 2) positioning error removal throughout the sensor model refinement with a non-rigorous bundle block adjustment, which makes possible the co-alignment of all images in a time series; and 3) improved sub-pixel co-registration algorithms using optical flow with a refinement stage conducted on a pyramidal grid processor and a blunder classifier. Moreover, volumetric changes of Martian dunes were additionally traced by means of stereo analysis and photoclinometry. The established algorithms have been tested using high-resolution HIRISE time-series images over several Martian dune fields. Dune migrations were iteratively processed both spatially and volumetrically, and the results were integrated to be compared to the Martian climate model. Migrations over well-known crater dune fields appeared to be almost static for the considerable temporal periods and were weakly correlated with wind directions estimated by the Mars Climate Database (Millour et al. 2015). As a result, a number of measurements over dune fields in the Mars Global Dune Database (Hayward et al. 2014) covering polar areas and mid-latitude will be demonstrated

  4. High resolution measurement of light in terrestrial ecosystems using photodegrading dyes.

    Science.gov (United States)

    Roales, Javier; Durán, Jorge; Bechtold, Heather A; Groffman, Peter M; Rosi-Marshall, Emma J

    2013-01-01

    Incoming solar radiation is the main determinant of terrestrial ecosystem processes, such as primary production, litter decomposition, or soil mineralization rates. Light in terrestrial ecosystems is spatially and temporally heterogeneous due to the interaction among sunlight angle, cloud cover and tree-canopy structure. To integrate this variability and to know light distribution over time and space, a high number of measurements are needed, but tools to do this are usually expensive and limited. An easy-to-use and inexpensive method that can be used to measure light over time and space is needed. We used two photodegrading fluorescent organic dyes, rhodamine WT (RWT) and fluorescein, for the quantification of light. We measured dye photodegradation as the decrease in fluorescence across an irradiance gradient from full sunlight to deep shade. Then, we correlated it to accumulated light measured with PAR quantum sensors and obtained a model for this behavior. Rhodamine WT and fluorescein photodegradation followed an exponential decay curve with respect to accumulated light. Rhodamine WT degraded slower than fluorescein and remained unaltered after exposure to temperature changes. Under controlled conditions, fluorescence of both dyes decreased when temperatures increased, but returned to its initial values after cooling to the pre-heating temperature, indicating no degradation. RWT and fluorescein can be used to measure light under a varying range of light conditions in terrestrial ecosystems. This method is particularly useful to integrate solar radiation over time and to measure light simultaneously at different locations, and might be a better alternative to the expensive and time consuming traditional light measurement methods. The accuracy, low price and ease of this method make it a powerful tool for intensive sampling of large areas and for developing high resolution maps of light in an ecosystem.

  5. High resolution measurement of light in terrestrial ecosystems using photodegrading dyes.

    Directory of Open Access Journals (Sweden)

    Javier Roales

    Full Text Available Incoming solar radiation is the main determinant of terrestrial ecosystem processes, such as primary production, litter decomposition, or soil mineralization rates. Light in terrestrial ecosystems is spatially and temporally heterogeneous due to the interaction among sunlight angle, cloud cover and tree-canopy structure. To integrate this variability and to know light distribution over time and space, a high number of measurements are needed, but tools to do this are usually expensive and limited. An easy-to-use and inexpensive method that can be used to measure light over time and space is needed. We used two photodegrading fluorescent organic dyes, rhodamine WT (RWT and fluorescein, for the quantification of light. We measured dye photodegradation as the decrease in fluorescence across an irradiance gradient from full sunlight to deep shade. Then, we correlated it to accumulated light measured with PAR quantum sensors and obtained a model for this behavior. Rhodamine WT and fluorescein photodegradation followed an exponential decay curve with respect to accumulated light. Rhodamine WT degraded slower than fluorescein and remained unaltered after exposure to temperature changes. Under controlled conditions, fluorescence of both dyes decreased when temperatures increased, but returned to its initial values after cooling to the pre-heating temperature, indicating no degradation. RWT and fluorescein can be used to measure light under a varying range of light conditions in terrestrial ecosystems. This method is particularly useful to integrate solar radiation over time and to measure light simultaneously at different locations, and might be a better alternative to the expensive and time consuming traditional light measurement methods. The accuracy, low price and ease of this method make it a powerful tool for intensive sampling of large areas and for developing high resolution maps of light in an ecosystem.

  6. The design and construction of a high-resolution velocity-map imaging apparatus for photoelectron spectroscopy studies of size-selected clusters

    Science.gov (United States)

    León, Iker; Yang, Zheng; Liu, Hong-Tao; Wang, Lai-Sheng

    2014-08-01

    A new velocity-map imaging apparatus equipped with a laser-vaporization supersonic cluster source and a time-of-flight mass spectrometer is described for high-resolution photoelectron spectroscopy studies of size-selected cluster anions. Vibrationally cold anion clusters are produced using a laser-vaporization supersonic cluster source, size-selected by a time-of-flight mass spectrometer, and then focused co-linearly into the interaction zone of the high-resolution velocity-map imaging (VMI) system. The multilens VMI system is optimized via systematic simulations and can reach a resolution of 1.2 cm-1 (FWHM) for near threshold electrons while maintaining photoelectron kinetic energy resolutions (ΔKE/KE) of ˜0.53% for higher energy electrons. The new VMI lens has superior focusing power over a large energy range, yielding highly circular images with distortions no larger than 1.0025 between the long and short radii. The detailed design, simulation, construction, testing, and performance of the high-resolution VMI apparatus are presented.

  7. The design and construction of a high-resolution velocity-map imaging apparatus for photoelectron spectroscopy studies of size-selected clusters

    Energy Technology Data Exchange (ETDEWEB)

    León, Iker; Yang, Zheng; Liu, Hong-Tao; Wang, Lai-Sheng, E-mail: Lai-Sheng-Wang@brown.edu [Department of Chemistry, Brown University, Providence, Rhode Island 02912 (United States)

    2014-08-15

    A new velocity-map imaging apparatus equipped with a laser-vaporization supersonic cluster source and a time-of-flight mass spectrometer is described for high-resolution photoelectron spectroscopy studies of size-selected cluster anions. Vibrationally cold anion clusters are produced using a laser-vaporization supersonic cluster source, size-selected by a time-of-flight mass spectrometer, and then focused co-linearly into the interaction zone of the high-resolution velocity-map imaging (VMI) system. The multilens VMI system is optimized via systematic simulations and can reach a resolution of 1.2 cm{sup −1} (FWHM) for near threshold electrons while maintaining photoelectron kinetic energy resolutions (ΔKE/KE) of ∼0.53% for higher energy electrons. The new VMI lens has superior focusing power over a large energy range, yielding highly circular images with distortions no larger than 1.0025 between the long and short radii. The detailed design, simulation, construction, testing, and performance of the high-resolution VMI apparatus are presented.

  8. Clinically relevant human temporal bone measurements using novel high-resolution cone-beam CT

    Directory of Open Access Journals (Sweden)

    Jing Zou

    2017-03-01

    Conclusion: This novel high-resolution CBCT system has potentially broad applications in the diagnosis of inner ear disease and in monitoring associated pathological changes, surgical planning, navigation for the ear surgery, and temporal bone training.

  9. A High Resolution Fourier-Transform Spectrometer for the Measurement of Atmospheric Column Abundances

    Science.gov (United States)

    Cageao, R.; Sander, S.; Blavier, J.; Jiang, Y.; Nemtchinov, V.

    2000-01-01

    A compact, high resolution Fourier-transform spectrometer for atmospheric near ultraviolet spectroscopy has been installed at the Jet Propulsion Laboratory's Table Mountain Facility (34.4N, 117.7 W, elevation 2290m).

  10. Simultaneous high-resolution measurement of mitochondrial respiration and hydrogen peroxide production.

    Science.gov (United States)

    Krumschnabel, Gerhard; Fontana-Ayoub, Mona; Sumbalova, Zuzana; Heidler, Juliana; Gauper, Kathrin; Fasching, Mario; Gnaiger, Erich

    2015-01-01

    Mitochondrial respiration is associated with the formation of reactive oxygen species, primarily in the form of superoxide (O2 (•-)) and particularly hydrogen peroxide (H2O2). Since H2O2 plays important roles in physiology and pathology, measurement of hydrogen peroxide has received considerable attention over many years. Here we describe how the well-established Amplex Red assay can be used to detect H2O2 production in combination with the simultaneous assessment of mitochondrial bioenergetics by high-resolution respirometry. Fundamental instrumental and methodological parameters were optimized for analysis of the effects of various substrate, uncoupler, and inhibitor titrations (SUIT) on respiration versus H2O2 production. The sensitivity of the H2O2 assay was strongly influenced by compounds contained in different mitochondrial respiration media, which also exerted significant effects on chemical background fluorescence changes. Near linearity of the fluorescence signal was restricted to narrow ranges of accumulating resorufin concentrations independent of the nature of mitochondrial respiration media. Finally, we show an application example using isolated mouse brain mitochondria as an experimental model for the simultaneous measurement of mitochondrial respiration and H2O2 production in SUIT protocols.

  11. High-resolution electron beam length measuring equipment; Kobunkaino denshisen sokucho sochi

    Energy Technology Data Exchange (ETDEWEB)

    Otaka, T.; Sasada, K.; Ezumi, M.; Maeda, T. [Hitachi, Ltd., Tokyo (Japan)

    1997-10-01

    Regarding the manufacture of semiconductor devices, the 16-megabit DRAM mass production system has been established, 64-megabit DRAM mass production has begun, and research and assessment are under way for the mass production of 256-megabit to 1-gigabit DRAMs. For the handling of devices so advanced in their microstructural feature and integration, sophisticated evaluation technologies are indispensable for the high-resolution observation of product geometry and for the high-precision management of product dimensions. Hitachi, Ltd., aiming to satisfy such needs, has introduced commercially its S-8820 series electron beam length measuring equipment based on the scanning electron microscope technology. This time, the corporation has developed S-8840 electron beam length measuring equipment, which can deal with the next-generation manufacturing processes. This equipment incorporates into itself an innovative signal detecting function for observing the bottom of, for example, a contact hole whose aspect ratio is quite high. The S-8840 type, furthermore, can process wafers at a rate approximately 50% higher than the conventional equipment for enhanced cost/performance. 3 refs., 8 figs., 1 tab.

  12. High-resolution threshold photoelectron study of the propargyl radical by the vacuum ultraviolet laser velocity-map imaging method

    Science.gov (United States)

    Gao, Hong; Xu, Yuntao; Yang, Lei; Lam, Chow-Shing; Wang, Hailing; Zhou, Jingang; Ng, C. Y.

    2011-12-01

    By employing the vacuum ultraviolet (VUV) laser velocity-map imaging (VMI) photoelectron scheme to discriminate energetic photoelectrons, we have measured the VUV-VMI-threshold photoelectrons (VUV-VMI-TPE) spectra of propargyl radical [C3H3({tilde X}{}^2B_1)] near its ionization threshold at photoelectron energy bandwidths of 3 and 7 cm-1 (full-width at half-maximum, FWHM). The simulation of the VUV-VMI-TPE spectra thus obtained, along with the Stark shift correction, has allowed the determination of a precise value 70 156 ± 4 cm-1 (8.6982 ± 0.0005 eV) for the ionization energy (IE) of C3H3. In the present VMI-TPE experiment, the Stark shift correction is determined by comparing the VUV-VMI-TPE and VUV laser pulsed field ionization-photoelectron (VUV-PFI-PE) spectra for the origin band of the photoelectron spectrum of the {tilde X}^ + {- tilde X} transition of chlorobenzene. The fact that the FWHMs for this origin band observed using the VUV-VMI-TPE and VUV-PFI-PE methods are nearly the same indicates that the energy resolutions achieved in the VUV-VMI-TPE and VUV-PFI-PE measurements are comparable. The IE(C3H3) value obtained based on the VUV-VMI-TPE measurement is consistent with the value determined by the VUV laser PIE spectrum of supersonically cooled C3H3({tilde X}{}^2B_1) radicals, which is also reported in this article.

  13. Patterning pallet arrays for cell selection based on high-resolution measurements of fluorescent biosensors.

    Science.gov (United States)

    Shadpour, Hamed; Zawistowski, Jon S; Herman, Annadele; Hahn, Klaus; Allbritton, Nancy L

    2011-06-24

    Pallet arrays enable cells to be separated while they remain adherent to a surface and provide a much greater range of cell selection criteria relative to that of current technologies. However there remains a need to further broaden cell selection criteria to include dynamic intracellular signaling events. To demonstrate the feasibility of measuring cellular protein behavior on the arrays using high resolution microscopy, the surfaces of individual pallets were modified to minimize the impact of scattered light at the pallet edges. The surfaces of the three-dimensional pallets on an array were patterned with a coating such as fibronectin using a customized stamping tool. Micropatterns of varying shape and size were printed in designated regions on the pallets in single or multiple steps to demonstrate the reliability and precision of patterning molecules on the pallet surface. Use of a fibronectin matrix stamped at the center of each pallet permitted the localization of H1299 and mouse embryonic fibroblast (MEF) cells to the pallet centers and away from the edges. Compared to pallet arrays with fibronectin coating the entire top surface, arrays with a central fibronectin pattern increased the percentage of cells localized to the pallet center by 3-4-fold. Localization of cells to the pallet center also enabled the physical separation of cells from optical artifacts created by the rough pallet side walls. To demonstrate the measurement of dynamic intracellular signaling on the arrays, fluorescence measurements of high spatial resolution were performed using a RhoA GTPase biosensor. This biosensor utilized fluorescence resonance energy transfer (FRET) between cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP) to measure localized RhoA activity in cellular ruffles at the cell periphery. These results demonstrated the ability to perform spatially resolved measurements of fluorescence-based sensors on the pallet arrays. Thus, the patterned pallet arrays

  14. New method for measuring myocardial blood flow by high resolution scintigraphy in the excised dog heart.

    Science.gov (United States)

    Hung, C Y; Burow, R D; Scherlag, B J; Basmadjian, G P; Lazzara, R

    1986-10-01

    The standard method for measuring myocardial blood flow (MBF) with radioactive microspheres requires processing of selected tissue samples usually from the excised heart, and consequent loss of exact relation to myocardial morphology. A computer-based image processing method was developed by using [99mTc]microspheres (mean particle size 20 microns) for quantitative analysis of MBF in 25 dogs. A computer-controlled gamma camera was used to obtain the images of radioactive microsphere distribution in transaxial slices of the ex vivo heart. Any portion of these slice images could be quantitated by using a computer program based on modification of the formula for determining MBF by the standard microsphere method. Regional myocardial perfusion calculated by this technique correlated well with values obtained with reference microspheres (r = 0.96) over a broad range of MBF. The results show that our new method, accurately and with high resolution, delineated zones of differing MBF and confirmed the increase of MBF in surviving myocardium with healing.

  15. New method for measuring myocardial blood flow by high resolution scintigraphy in the excised dog heart

    Energy Technology Data Exchange (ETDEWEB)

    Hung, C.Y.; Burow, R.D.; Scherlag, B.J.; Basmadjian, G.P.; Lazzara, R.

    1986-10-01

    The standard method for measuring myocardial blood flow (MBF) with radioactive microspheres requires processing of selected tissue samples usually from the excised heart, and consequent loss of exact relation to myocardial morphology. A computer-based image processing method was developed by using (99mTc)microspheres (mean particle size 20 microns) for quantitative analysis of MBF in 25 dogs. A computer-controlled gamma camera was used to obtain the images of radioactive microsphere distribution in transaxial slices of the ex vivo heart. Any portion of these slice images could be quantitated by using a computer program based on modification of the formula for determining MBF by the standard microsphere method. Regional myocardial perfusion calculated by this technique correlated well with values obtained with reference microspheres (r = 0.96) over a broad range of MBF. The results show that our new method, accurately and with high resolution, delineated zones of differing MBF and confirmed the increase of MBF in surviving myocardium with healing.

  16. Measurement of ciliary beat frequency using ultra-high resolution optical coherence tomography

    Science.gov (United States)

    Chen, Jason J.; Jing, Joseph C.; Su, Erica; Badger, Christopher; Coughlan, Carolyn A.; Chen, Zhongping; Wong, Brian J. F.

    2016-02-01

    Ciliated epithelial cells populate up to 80% of the surface area of the human airway and are responsible for mucociliary transport, which is the key protective mechanism that provides the first line of defense in the respiratory tract. Cilia beat in a rhythmic pattern and may be easily affected by allergens, pollutants, and pathogens, altering ciliary beat frequency (CBF) subsequently. Diseases including cystic fibrosis, chronic obstructive pulmonary disease, and primary ciliary dyskinesia may also decrease CBF. CBF is therefore a critical component of respiratory health. The current clinical method of measuring CBF is phase-contrast microscopy, which involves a tissue biopsy obtained via brushing of the nasal cavity. While this method is minimally invasive, the tissue sample must be oriented to display its profile view, making the visualization of a single layer of cilia challenging. In addition, the conventional method requires subjective analysis of CBF, e.g., manually counting by visual inspection. On the contrary, optical coherence tomography (OCT) has been used to study the retina in ophthalmology as well as vasculature in cardiology, and offers higher resolution than conventional computed tomography and magnetic resonance imaging. Based on this technology, our lab specifically developed an ultra-high resolution OCT system to image the microstructure of the ciliated epithelial cells. Doppler analysis was also performed to determine CBF. Lastly, we also developed a program that utilizes fast Fourier transform to determine CBF under phase-contrast microscopy, providing a more objective method compared to the current method.

  17. Spatial variability of the Black Sea surface temperature from high resolution modeling and satellite measurements

    Science.gov (United States)

    Mizyuk, Artem; Senderov, Maxim; Korotaev, Gennady

    2016-04-01

    Large number of numerical ocean models were implemented for the Black Sea basin during last two decades. They reproduce rather similar structure of synoptical variability of the circulation. Since 00-s numerical studies of the mesoscale structure are carried out using high performance computing (HPC). With the growing capacity of computing resources it is now possible to reconstruct the Black Sea currents with spatial resolution of several hundreds meters. However, how realistic these results can be? In the proposed study an attempt is made to understand which spatial scales are reproduced by ocean model in the Black Sea. Simulations are made using parallel version of NEMO (Nucleus for European Modelling of the Ocean). A two regional configurations with spatial resolutions 5 km and 2.5 km are described. Comparison of the SST from simulations with two spatial resolutions shows rather qualitative difference of the spatial structures. Results of high resolution simulation are compared also with satellite observations and observation-based products from Copernicus using spatial correlation and spectral analysis. Spatial scales of correlations functions for simulated and observed SST are rather close and differs much from satellite SST reanalysis. Evolution of spectral density for modelled SST and reanalysis showed agreed time periods of small scales intensification. Using of the spectral analysis for satellite measurements is complicated due to gaps. The research leading to this results has received funding from Russian Science Foundation (project № 15-17-20020)

  18. An autonomous spectrophotometric system for high resolution measurement of seawater pH

    Science.gov (United States)

    Reggiani, E. R.; Bellerby, R. G. J.

    2012-04-01

    The increase in carbon dioxide (CO2) concentration in the ocean is a growing concern and is undergoing considerable research. A comprehensive monitoring of the carbonate system in seawater is essential to understand ocean acidification and modification to oceanic carbon transport and the ocean's atmospheric CO2 uptake. Providing calibration and drift-free measurements, spectrophotometric detection of pH, with the monitoring of one of the other "major" carbonate variables (pCO2, total alkalnity, dissolved inorganic carbon) allows the determination of the entire carbonate system speciation with the uncertainty required to detect long-term oceanic acidification. Stability, reliability and robustness are the critical features when in-situ long-term deployment is required. We have developed a method that makes use of a high-resolution low noise miniature spectrophotometer and a combined low power LED source, an optimal absorbance detection is achieved in a custom designed bubble-free cuvette with a sample volume of 6 ml, limiting indicator perturbations within the on-line precision of the instrument, currently evaluated at 0,0005 pH units and achieving the adequate uncertainty for systematic shifts evaluation. The system operates unattended with a sampling frequency up to 2 samples per minute and the actual temperature of the sample is monitored, not controlled, thus reducing power consumption. With its portability, the system is ideally suitable for both underway operation on ships of opportunity and for discrete sample analysis in remote research campaigns.

  19. A high-resolution spectropolarimetric survey of Herbig Ae/Be stars - I. Observations and measurements

    CERN Document Server

    Alecian, E; Catala, C; Grunhut, J H; Landstreet, J D; Bagnulo, S; Böhm, T; Folsom, C P; Marsden, S; Waite, I

    2012-01-01

    This is the first in a series of papers in which we describe and report the analysis of a large survey of Herbig Ae/Be stars in circular spectropolarimetry. Using the ESPaDOnS and Narval high-resolution spectropolarimeters at the Canada-France-Hawaii and Bernard Lyot Telescopes, respectively, we have acquired 132 circularly-polarised spectra of 70 Herbig Ae/Be stars and Herbig candidates. The large majority of these spectra are characterised by a resolving power of about 65,000, and a spectral coverage from about 3700 ang to 1 micron. The peak SNR per CCD pixel ranges from below 100 (for the faintest targets) to over 1000 (for the brightest). The observations were acquired with the primary aim of searching for magnetic fields in these objects. However, our spectra are suitable for a variety of other important measurements, including rotational properties, variability, binarity, chemical abundances, circumstellar environment conditions and structure, etc. In this first paper, we describe the sample selection, ...

  20. High resolution measurement of neutron inelastic scattering cross-sections for 23Na

    Science.gov (United States)

    Rouki, C.; Archier, P.; Borcea, C.; De Saint Jean, C.; Drohé, J. C.; Kopecky, S.; Moens, A.; Nankov, N.; Negret, A.; Noguère, G.; Plompen, A. J. M.; Stanoiu, M.

    2012-04-01

    The neutron inelastic scattering cross-section of 23Na has been measured in response to the relevant request of the OECD-NEA High Priority Request List, which requires a target uncertainty of 4% in the energy range up to 1.35 MeV for the development of sodium-cooled fast reactors. The measurement was performed at the GELINA facility with the Gamma Array for Inelastic Neutron Scattering (GAINS), featuring eight high purity germanium detectors. The setup is installed at a 200 m flight path from the neutron source and provides high resolution measurements using the (n,n'γ)-technique. The sample was an 80 mm diameter metallic sodium disk prepared at IRMM. Transitions up to the seventh excited state were observed and the differential gamma cross-sections at 110° and 150° were measured, showing mostly isotropic gamma emission. From these the gamma production, level and inelastic cross-sections were determined for neutron energies up to 3838.9 keV. The results agree well with the existing data and the evaluated nuclear data libraries in the low energies, and provide new experimental points in the little studied region above 2 MeV. Following a detailed review of the methodology used for the gamma efficiency calibrations and flux normalization of GAINS data, an estimated total uncertainty of 2.2% was achieved for the inelastic cross-section integrals over the energy ranges 0.498-1.35 MeV and 1.35-2.23 MeV, meeting the required targets.

  1. High-resolution hot-film measurement of surface heat flux to an impinging jet

    Science.gov (United States)

    O'Donovan, T. S.; Persoons, T.; Murray, D. B.

    2011-10-01

    To investigate the complex coupling between surface heat transfer and local fluid velocity in convective heat transfer, advanced techniques are required to measure the surface heat flux at high spatial and temporal resolution. Several established flow velocity techniques such as laser Doppler anemometry, particle image velocimetry and hot wire anemometry can measure fluid velocities at high spatial resolution (µm) and have a high-frequency response (up to 100 kHz) characteristic. Equivalent advanced surface heat transfer measurement techniques, however, are not available; even the latest advances in high speed thermal imaging do not offer equivalent data capture rates. The current research presents a method of measuring point surface heat flux with a hot film that is flush mounted on a heated flat surface. The film works in conjunction with a constant temperature anemometer which has a bandwidth of 100 kHz. The bandwidth of this technique therefore is likely to be in excess of more established surface heat flux measurement techniques. Although the frequency response of the sensor is not reported here, it is expected to be significantly less than 100 kHz due to its physical size and capacitance. To demonstrate the efficacy of the technique, a cooling impinging air jet is directed at the heated surface, and the power required to maintain the hot-film temperature is related to the local heat flux to the fluid air flow. The technique is validated experimentally using a more established surface heat flux measurement technique. The thermal performance of the sensor is also investigated numerically. It has been shown that, with some limitations, the measurement technique accurately measures the surface heat transfer to an impinging air jet with improved spatial resolution for a wide range of experimental parameters.

  2. High resolution seismic velocity structure around the Yamasaki fault zone of southwest Japan as revealed from travel-time tomography

    Science.gov (United States)

    Nugraha, Andri Dian; Ohmi, Shiro; Mori, Jim; Shibutani, Takuo

    2013-08-01

    The Yamasaki fault zone in southwestern Japan currently has a high potential for producing a large damaging earthquake. We carried out a seismic tomographic study to determine detailed crustal structures for the region. The velocity model clearly images a low-velocity and high V p / V s (high Poisson's ratio) anomaly in the lower crust beneath the Yamasaki fault zone at a depth of ~15-20 km. This anomaly may be associated with the existence of partially-melted minerals. The existence of this anomaly below the fault zone may contribute to changing the long-term stress concentration in the seismogenic zone.

  3. Exploiting High Resolution Multi-Seasonal Textural Measures and Spectral Information for Reedbed Mapping

    Directory of Open Access Journals (Sweden)

    Alex Okiemute Onojeghuo

    2016-02-01

    Full Text Available Reedbeds across the UK are amongst the most important habitats for rare and endangered birds, wildlife and organisms. However, over the past century, this valued wetland habitat has experienced a drastic reduction in quality and spatial coverage due to pressures from human related activities. To this end, conservation organisations across the UK have been charged with the task of conserving and expanding this threatened habitat. With this backdrop, the study aimed to develop a methodology for accurate reedbed mapping through the combined use of multi-seasonal texture measures and spectral information contained in high resolution QuickBird satellite imagery. The key objectives were to determine the most effective single-date (autumn or summer and multi-seasonal QuickBird imagery suitable for reedbed mapping over the study area; to evaluate the effectiveness of combining multi-seasonal texture measures and spectral information for reedbed mapping using a variety of combinations; and to evaluate the most suitable classification technique for reedbed mapping from three selected classification techniques, namely maximum likelihood classifier, spectral angular mapper and artificial neural network. Using two selected grey-level co-occurrence textural measures (entropy and angular second moment, a series of experiments were conducted using varied combinations of single-date and multi-seasonal QuickBird imagery. Overall, the results indicate the multi-seasonal pansharpened multispectral bands (eight layers combined with all eight grey level co-occurrence matrix texture measures (entropy and angular second moment computed using windows 3 × 3 and 7 × 7 produced the optimal reedbed (76.5% and overall classification (78.1% accuracies using the maximum likelihood classifier technique. Using the optimal 16 layer multi-seasonal pansharpened multispectral and texture combined image dataset, a total reedbed area of 9.8 hectares was successfully mapped over the

  4. Ambient Aerosol in Southeast Asia: High Resolution Aerosol Mass Spectrometer Measurements Over Oil Palm (Elaeis guineensis)

    Science.gov (United States)

    Phillips, G.; Dimarco, C.; Misztal, P.; Nemitz, E.; Farmer, D.; Kimmel, J.; Jimenez, J.

    2008-12-01

    The emission of organic compounds in the troposphere is important factor in the formation of secondary organic aerosol (SOA). A very large proportion of organic material emitted globally is estimated to arise from biogenic sources, with almost half coming from tropical and sub-tropical forests. Preliminary analyses of leave cuvette emission studies suggest that oil palm (Elaeis guineensis) is a significantly larger source of isoprene than tropical forest. Much larger sources of isoprene over oil palm allied with a larger anthropogenic component of local emissions contrast greatly with the remote tropical forest environment and therefore the character of SOA formed may differ significantly. These issues, allied with the high price of palm oil on international markets leading to increased use of land for oil palm production, could give rise to rapidly changing chemical and aerosol regimes in the tropics. It is therefore important to understand the current emissions and composition of organic aerosol over all important land-uses in the tropical environment. This in turn will lead to a greater understanding of the present, and to an improvement in predictive capacity for the future system. To help address these issues, a high resolution time of flight aerosol mass spectrometer (HR-ToF-AMS) was deployed in the Sabahmas (PPB OIL) oil palm plantation near Lahad Datu, in Eastern Sabah, as part of the field component of the Aerosol Coupling in the Earth System (ACES) project, part of the UK NERC APPRAISE program. This project was allied closely with measurements made of similar chemical species and aerosol components at a forest site in the Danum Valley as part of the UK Oxidant and Particle Photochemical Processes above a Southeast Asian tropical rainforest (OP3) project. Measurements of submicron non- refractory aerosol composition are presented along with some preliminary analysis of chemically resolved aerosol fluxes made with a new eddy covariance system, based on the

  5. Depth of interaction resolution measurements for a high resolution PET detector using position sensitive avalanche photodiodes.

    Science.gov (United States)

    Yang, Yongfeng; Dokhale, Purushottam A; Silverman, Robert W; Shah, Kanai S; McClish, Mickel A; Farrell, Richard; Entine, Gerald; Cherry, Simon R

    2006-05-07

    We explore dual-ended read out of LSO arrays with two position sensitive avalanche photodiodes (PSAPDs) as a high resolution, high efficiency depth-encoding detector for PET applications. Flood histograms, energy resolution and depth of interaction (DOI) resolution were measured for unpolished LSO arrays with individual crystal sizes of 1.0, 1.3 and 1.5 mm, and for a polished LSO array with 1.3 mm pixels. The thickness of the crystal arrays was 20 mm. Good flood histograms were obtained for all four arrays, and crystals in all four arrays can be clearly resolved. Although the amplitude of each PSAPD signal decreases as the interaction depth moves further from the PSAPD, the sum of the two PSAPD signals is essentially constant with irradiation depth for all four arrays. The energy resolutions were similar for all four arrays, ranging from 14.7% to 15.4%. A DOI resolution of 3-4 mm (including the width of the irradiation band which is approximately 2 mm) was obtained for all the unpolished arrays. The best DOI resolution was achieved with the unpolished 1 mm array (average 3.5 mm). The DOI resolution for the 1.3 mm and 1.5 mm unpolished arrays was 3.7 and 4.0 mm respectively. For the polished array, the DOI resolution was only 16.5 mm. Summing the DOI profiles across all crystals for the 1 mm array only degraded the DOI resolution from 3.5 mm to 3.9 mm, indicating that it may not be necessary to calibrate the DOI response separately for each crystal within an array. The DOI response of individual crystals in the array confirms this finding. These results provide a detailed characterization of the DOI response of these PSAPD-based PET detectors which will be important in the design and calibration of a PET scanner making use of this detector approach.

  6. Analysis and high resolution modelling of black carbon vertical profiles measured over three Italian valleys

    Science.gov (United States)

    Gandolfi, Ilaria; Curci, Gabriele; Falasca, Serena; Ferrero, Luca

    2017-04-01

    Analysis and high resolution modelling of black carbon vertical profiles measured over three Italian valleys Ilaria Gandolfi1,2, Gabriele Curci1,2, Serena Falasca1,2, Luca Ferrero3 1 Department of Physical and Chemical Sciences, University of L'Aquila, L'Aquila, Italy 2 Center of Excellence CETEMPS, University of L'Aquila, L'Aquila, Italy 3 POLARIS Research Centre, Department of Earth and Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milan, Italy Last decades were characterized by a growing interest in aerosols: mainly for their effect on human health and on the energy balance of solar and planetary radiation, thus their role in climate change. In this study, we analyze the evolution of vertical profile of black carbon (BC) through tethered balloon observations and chemistry-transport modelling. Black carbon is regarded as the second most important anthropogenic climate forcing agent and its concentration varies significantly depending on the altitude and the sources on the territory. In winter of 2010 University Of Milan Bicocca conducted three intensive measurements campaigns over three Italian basin valleys (Terni, Po Valley, Passiria Valley). The choice of the valleys was made taking into consideration the orography and the river basin structure. The measurement campaign was based on a helium-filled tethered balloon, on which the instrumentation for the analysis has been mounted; the instrumentation consisted on a meteorological station, an OPC, a cascade impactor and a micro-Aethalometer. Subsequently, at University of L'Aquila simulations were produced to help interpretation of these vertical aerosol profiles (mass, composition and distribution) and related optical properties (scattering, absorption) using a chemistry-transport model (WRF-CHIMERE) at high horizontal resolution (1 km). The analysis focused primarily on the calculation of the heating rate and of the Direct Radiative Effect (DRE), and on the analysis of the

  7. Emerging Trends on the Volatile Chemistry in Comets as Measured with High-Resolution Infrared Spectroscopy

    Science.gov (United States)

    Dello Russo, Neil; Kawakita, Hideyo; Vervack, Ronald J., Jr.; Weaver, Harold A.

    2016-10-01

    A systematic analysis of the mixing ratios with respect to H2O for eight species (CH3OH, HCN, NH3, H2CO, C2H2, C2H6, CH4, and CO) measured with high-resolution infrared spectroscopy is presented. Some trends are beginning to emerge when mixing ratios in individual comets are compared to average mixing ratios obtained for all species within the population. The variation in mixing ratios for all measured species is at least an order of magnitude. Overall, Jupiter-family comets are depleted in volatile species with respect to H2O compared to long-period Oort cloud comets, with the most volatile species showing the greatest relative depletion. There is a high positive correlation between the mixing ratios of HCN, C2H6, and CH4, whereas NH3, H2CO, and C2H2 are moderately correlated with each other but generally uncorrelated or show only weak correlation with other species. CO is generally uncorrelated with the other measured species possibly because it has the highest volatility and is therefore more susceptible to thermal evolutionary effects. Molecular mixing ratios for CH3OH, HCN, C2H6, and CH4 show an expected behavior with heliocentric distance suggesting a dominant ice source, whereas there is emerging evidence that the mixing ratios of NH3, H2CO, and C2H2 may increase at small heliocentric distances, suggesting the possibility of additional sources related to the thermal decomposition of organic dust. Although this provides information on the composition of the most volatile grains in comets, it presents an additional difficulty in classifying comet chemistry because most comets within this dataset were only observed over a limited range of heliocentric distance. Optical and infrared comparisons indicate that mixing ratios of daughter species and potential parents from cometary ices are sometimes but not always consistent with one another. This suggests that in many comets there are significant sources of C2 and/or CN from grains, and that the importance of these

  8. A high resolution 3D velocity model beneath the Tokyo Metropolitan area by MeSO-net

    Science.gov (United States)

    Nakagawa, S.; Sakai, S.; Honda, R.; Kimura, H.; Hirata, N.

    2015-12-01

    Beneath the Tokyo metropolitan area, the Philippine Sea Plate (PSP) subducts and causes devastating mega-thrust earthquakes, such as the 1703 Genroku earthquake (M8.0) and the 1923 Kanto earthquake (M7.9). An M7 or greater (M7+) earthquake in this area at present has high potential to produce devastating serious loss of life and property with even greater global economic repercussions. The Central Disaster Management Council of Japan estimates that an M7+ earthquake will cause 23,000 fatalities and 95 trillion yen (about 1 trillion US$) economic loss. We have launched the Special Project for Reducing Vulnerability for Urban Mega Earthquake Disasters in collaboration with scientists, engineers, and social-scientists in nationwide institutions since 2012. We analyze data from the dense seismic array called Metropolitan Seismic Observation network (MeSO-net), which has 296 seismic stations with spacing of 5 km (Sakai and Hirata, 2009; Kasahara et al., 2009). We applied the double-difference tomography method (Zhang and Thurber, 2003) and estimated the velocity structure and the upper boundary of PSP (Nakagawa et al., 2010). The 2011 Tohoku-oki earthquake (M9.0) has activated seismicity also in Kanto region, providing better coverage of ray paths for tomographic analysis. We obtain much higher resolution velocity models from whole dataset observed by MeSO-net between 2008 and 2015. A detailed image of tomograms shows that PSP contacts Pacific plate at a depth of 50 km beneath northern Tokyo bay. A variation of velocity along the oceanic crust suggests dehydration reaction to produce seismicity in a slab, which may related to the M7+ earthquake. Acknowledgement: This study was supported by the Special Project for Reducing Vulnerability for Urban Mega Earthquake Disasters of MEXT, Japan and the Earthquake Research Institute cooperative research program.

  9. Estimation of the Vertical Velocity Leading to the Formation of Cirrus Using Ultra-High Resolution Global Simulations

    Science.gov (United States)

    Barahona, D.; Molod, A.; Putman, W.; Suarez, M.

    2014-12-01

    Cirrus clouds significantly impact the radiative and transport processes of the upper troposphere and the lower stratosphere. State-of-the-art global models parameterize the formation of cirrus explicitly linking ice nucleation events to the aerosol properties and the cloud-scale dynamics. However most GCMs cannot resolve the scale at which cloud formation occurs. Thus subgrid scale dynamics is typically parameterized by relating the vertical velocity variance, σw, to grid-scale fields. These parameterizations are typically validated against field campaign data for specific locations. However an assessment of the global spatial distribution of σw is lacking, limiting the ability of GCMs to describe cirrus formation. Here the non-hydrostatic version of the NASA Goddard Earth Observing System model (GEOS-5) is used to estimate the variance of vertical velocity in GCMs. GEOS-5 was run at cloud-resolving resolutions (~7 km), allowing the explicit calculation of σw. Our results indicate that σw is determined by orographic drag and local convection, and higher over the continents than over the ocean. A recently developed parameterization of σw is also evaluated. Compared to the model results the parameterization is able to reproduce the global distribution of σw for warm cirrus clouds but tends to overestimate σw near the tropopause. Our work provides for the first time an assessment of the global variability in the subgrid scale dynamics leading to the formation of cirrus.

  10. High-resolution wind speed measurements using actively heated fiber optics

    Science.gov (United States)

    Sayde, Chadi; Thomas, Christoph K.; Wagner, James; Selker, John

    2015-11-01

    We present a novel technique to simultaneously measure wind speed (U) at thousands of locations continuously in time based on measurement of velocity-dependent heat transfer from a heated surface. Measuring temperature differences between paired passive and actively heated fiber-optic (AHFO) cables with a distributed temperature sensing system allowed estimation of U at over 2000 sections along the 230 m transect (resolution of 0.375 m and 5.5 s). The underlying concept is similar to that of a hot wire anemometer extended in space. The correlation coefficient between U measured by two colocated sonic anemometers and the AHFO were 0.91 during the day and 0.87 at night. The combination of classical passive and novel AHFO provides unprecedented dynamic observations of both air temperature and wind speed spanning 4 orders of magnitude in spatial scale (0.1-1000 m) while resolving individual turbulent motions, opening new opportunities for testing basic theories for near-surface geophysical flows.

  11. An ML-Based Radial Velocity Estimation Algorithm for Moving Targets in Spaceborne High-Resolution and Wide-Swath SAR Systems

    Directory of Open Access Journals (Sweden)

    Tingting Jin

    2017-04-01

    Full Text Available Multichannel synthetic aperture radar (SAR is a significant breakthrough to the inherent limitation between high-resolution and wide-swath (HRWS compared with conventional SAR. Moving target indication (MTI is an important application of spaceborne HRWS SAR systems. In contrast to previous studies of SAR MTI, the HRWS SAR mainly faces the problem of under-sampled data of each channel, causing single-channel imaging and processing to be infeasible. In this study, the estimation of velocity is equivalent to the estimation of the cone angle according to their relationship. The maximum likelihood (ML based algorithm is proposed to estimate the radial velocity in the existence of Doppler ambiguities. After that, the signal reconstruction and compensation for the phase offset caused by radial velocity are processed for a moving target. Finally, the traditional imaging algorithm is applied to obtain a focused moving target image. Experiments are conducted to evaluate the accuracy and effectiveness of the estimator under different signal-to-noise ratios (SNR. Furthermore, the performance is analyzed with respect to the motion ship that experiences interference due to different distributions of sea clutter. The results verify that the proposed algorithm is accurate and efficient with low computational complexity. This paper aims at providing a solution to the velocity estimation problem in the future HRWS SAR systems with multiple receive channels.

  12. Retrieval of Precise Radial Velocities from Near-infrared High-resolution Spectra of Low-mass Stars

    Science.gov (United States)

    Gao, Peter; Plavchan, P.; Gagné, J.; Furlan, E.; Bottom, M.; Anglada-Escudé, G.; White, R.; Davison, C. L.; Beichman, C.; Brinkworth, C.; Johnson, J.; Ciardi, D.; Wallace, K.; Mennesson, B.; von Braun, K.; Vasisht, G.; Prato, L.; Kane, S. R.; Tanner, A.; Crawford, T. J.; Latham, D.; Rougeot, R.; Geneser, C. S.; Catanzarite, J.

    2016-10-01

    Given that low-mass stars have intrinsically low luminosities at optical wavelengths and a propensity for stellar activity, it is advantageous for radial velocity (RV) surveys of these objects to use near-infrared (NIR) wavelengths. In this work, we describe and test a novel RV extraction pipeline dedicated to retrieving RVs from low-mass stars using NIR spectra taken by the CSHELL spectrograph at the NASA Infrared Telescope Facility, where a methane isotopologue gas cell is used for wavelength calibration. The pipeline minimizes the residuals between the observations and a spectral model composed of templates for the target star, the gas cell, and atmospheric telluric absorption; models of the line-spread function, continuum curvature, and sinusoidal fringing; and a parameterization of the wavelength solution. The stellar template is derived iteratively from the science observations themselves without a need for separate observations dedicated to retrieving it. Despite limitations from CSHELL’s narrow wavelength range and instrumental systematics, we are able to (1) obtain an RV precision of 35 m s-1 for the RV standard star GJ 15 A over a time baseline of 817 days, reaching the photon noise limit for our attained signal-to-noise ratio; (2) achieve ˜3 m s-1 RV precision for the M giant SV Peg over a baseline of several days and confirm its long-term RV trend due to stellar pulsations, as well as obtain nightly noise floors of ˜2-6 m s-1 and (3) show that our data are consistent with the known masses, periods, and orbital eccentricities of the two most massive planets orbiting GJ 876. Future applications of our pipeline to RV surveys using the next generation of NIR spectrographs, such as iSHELL, will enable the potential detection of super-Earths and mini-Neptunes in the habitable zones of M dwarfs.

  13. Eddy covariance measurements with high-resolution time-of-flight aerosol mass spectrometry: a new approach to chemically-resolved aerosol fluxes

    Directory of Open Access Journals (Sweden)

    D. K. Farmer

    2010-12-01

    Full Text Available Although laboratory studies show that biogenic volatile organic compounds (VOCs yield substantial secondary organic aerosol (SOA, production of biogenic SOA as indicated by upward fluxes has not been conclusively observed over forests. Further, while aerosols are known to deposit to surfaces, few techniques exist to provide chemically-resolved particle deposition fluxes. To better constrain aerosol sources and sinks, we have developed a new technique to directly measure fluxes of chemically-resolved submicron aerosols using the high-resolution time-of-flight aerosol mass spectrometer (HR-AMS in a new, fast eddy covariance mode. This approach takes advantage of the instrument's ability to quantitatively identify both organic and inorganic components, including ammonium, sulphate and nitrate, at a temporal resolution of several Hz. The new approach has been successfully deployed over a temperate ponderosa pine plantation in California during the BEARPEX-2007 campaign, providing both total and chemically resolved non-refractory (NR PM1 fluxes. Average deposition velocity for total NR-PM1 aerosol at noon was 2.05 ± 0.04 mm/s. Using a high resolution measurement of the NH2+ and NH3+ fragments, we demonstrate the first eddy covariance flux measurements of particulate ammonium, which show a noon-time deposition velocity of 1.9 ± 0.7 mm/s and are dominated by deposition of ammonium sulphate.

  14. High-resolution real-time 3D shape measurement on a portable device

    Science.gov (United States)

    Karpinsky, Nikolaus; Hoke, Morgan; Chen, Vincent; Zhang, Song

    2013-09-01

    Recent advances in technology have enabled the acquisition of high-resolution 3D models in real-time though the use of structured light scanning techniques. While these advances are impressive, they require large amounts of computing power, thus being limited to using large desktop computers with high end CPUs and sometimes GPUs. This is undesirable in making high-resolution real-time 3D scanners ubiquitous in our mobile lives. To address this issue, this work describes and demonstrates a real-time 3D scanning system that is realized on a mobile device, namely a laptop computer, which can achieve speeds of 20fps 3D at a resolution of 640x480 per frame. By utilizing a graphics processing unit (GPU) as a multipurpose parallel processor, along with a parallel phase shifting technique, we are able to realize the entire 3D processing pipeline in parallel. To mitigate high speed camera transfer problems, which typically require a dedicated frame grabber, we make use of USB 3.0 along with direct memory access (DMA) to transfer camera images to the GPU. To demonstrate the effectiveness of the technique, we experiment with the scanner on both static geometry of a statue and dynamic geometry of a deforming material sample in front of the system.

  15. The relation between gas density and velocity power spectra in galaxy clusters: high-resolution hydrodynamic simulations and the role of conduction

    CERN Document Server

    Gaspari, M; Nagai, D; Lau, E T; Zhuravleva, I

    2014-01-01

    Exploring the ICM power spectrum can help us to probe the physics of galaxy clusters. Using high-resolution 3D plasma simulations, we study the statistics of the velocity field and its relation with the thermodynamic perturbations. The normalization of the ICM spectrum (density, entropy, or pressure) is linearly tied to the level of large-scale motions, which excite both gravity and sound waves due to stratification. For low 3D Mach number M~0.25, gravity waves mainly drive entropy perturbations, traced by preferentially tangential turbulence. For M>0.5, sound waves start to significantly contribute, passing the leading role to compressive pressure fluctuations, associated with isotropic turbulence (or a slight radial bias). Density and temperature fluctuations are then characterized by the dominant process: isobaric (low M), adiabatic (high M), or isothermal (strong conduction). Most clusters reside in the intermediate regime, showing a mixture of gravity and sound waves, hence drifting towards isotropic vel...

  16. Isolation of Intact Mitochondria from Skeletal Muscle by Differential Centrifugation for High-resolution Respirometry Measurements.

    Science.gov (United States)

    Djafarzadeh, Siamak; Jakob, Stephan Mathias

    2017-03-08

    Mitochondria are involved in cellular energy metabolism and use oxygen to produce energy in the form of adenosine triphosphate (ATP). Differential centrifugation at low- and high-speed is commonly used to isolate mitochondria from tissues and cultured cells. Crude mitochondrial fractions obtained by differential centrifugation are used for respirometry measurements. The differential centrifugation technique is based on the separation of organelles according to their size and sedimentation velocity. The isolation of mitochondria is performed immediately after tissue harvesting. The tissue is immersed in an ice-cold homogenization medium, minced using scissors and homogenized in a glass homogenizer with a loose-fitting pestle. The differential centrifugation technique is efficient, fast and inexpensive and the mitochondria obtained by differential centrifugation are pure enough for respirometry assays. Some of the limitations and disadvantages of isolated mitochondria, based on differential centrifugation, are that the mitochondria can be damaged during the homogenization and isolation procedure and that large amounts of the tissue biopsy or cultured cells are required for the mitochondrial isolation.

  17. A Proposed Method for Measurement of Absolute Air Fluorescence Yield based on High Resolution Optical Emission Spectroscopy

    CERN Document Server

    Gika, V; Maltezos, S

    2016-01-01

    In this work, we present a method for absolute measurement of air fluorescence yield based on high resolution optical emission spectroscopy. The absolute measurement of the air fluorescence yield is feasible using the Cherenkov light, emitted by an electron beam simultaneously with the fluorescence light, as a "standard candle". The separation of these two radiations can be accomplished exploiting the "dark" spectral regions of the emission band systems of the molecular spectrum of nitrogen. In these "dark" regions the net Cherenkov light can be recorded experimentally and be compared with the calculated one. The instrumentation for obtaining the nitrogen molecular spectra in high resolution and the noninvasive method for monitoring the rotational temperature of the emission process are also described. For the experimental evaluation of the molecular spectra analysis we used DC normal glow discharges in air performed in an appropriate spectral lamp considered as an air-fluorescence light emulator. The propose...

  18. Extended-range grazing-incidence spectrometer for high-resolution extreme ultraviolet measurements on an electron beam ion trap

    Energy Technology Data Exchange (ETDEWEB)

    Beiersdorfer, P.; Magee, E. W.; Brown, G. V.; Träbert, E.; Widmann, K. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Hell, N. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Dr. Remeis-Sternwarte and ECAP, Universität Erlangen-Nürnberg, 96049 Bamberg (Germany)

    2014-11-15

    A high-resolution grazing-incidence grating spectrometer has been implemented on the Livermore electron beam ion traps for performing very high-resolution measurements in the soft x-ray and extreme ultraviolet region spanning from below 10 Å to above 300 Å. The instrument operates without an entrance slit and focuses the light emitted by highly charged ions located in the roughly 50 μm wide electron beam onto a cryogenically cooled back-illuminated charge-coupled device detector. The measured line widths are below 0.025 Å above 100 Å, and the resolving power appears to be limited by the source size and Doppler broadening of the trapped ions. Comparisons with spectra obtained with existing grating spectrometers show an order of magnitude improvement in spectral resolution.

  19. The optimization of super-high resolution frequency measurement techniques based on phase quantization regularities between any frequencies.

    Science.gov (United States)

    Li, Zhiqi; Zhou, Wei; Zhou, Hui; Zhang, Xueping; Zhao, Jie

    2013-02-01

    Step phase quantization regularity between different nominal frequency signals is introduced in this paper. Based on this regularity, an optimized high resolution frequency measurement technique is presented. The key features and issues of phase quantization characteristics and measurements are described. Based on the relationship between the same or multiple nominal signals with a certain differences, the resolution of frequency measurements is developed and the range is widened. Several measurement results are provided to support the concepts with experimental evidence. The resolution of frequency measurement can reach 10(-12) (s(-1)) over a wide range or higher for specific frequency signals.

  20. Model validation: Issues regarding comparisons of point measurements and high-resolution modeling results

    Science.gov (United States)

    Sandvik, Anne D.; Skagseth, Øystein; Skogen, Morten D.

    2016-10-01

    In this study we compare a high resolution model of waters on the Norwegian Shelf with hydrographic observations obtained during 2009 at Ingøy, a fixed coastal station off northwestern Norway operated by the Institute of Marine Research. The observations comprise snapshots from Ingøy every two weeks, whereas the model represents an average over a certain volume and is continuous in time. We suggest that bias is the best way to compare the modeled and observed times series, while acknowledging the short-term variability (within a day) it is recommended to use the modeled range to estimate an acceptable deviation between single points in the series. Using the suggested method we conclude that an acceptable deviation between the modeled and observed surface temperatures at Ingøy is 0.6 °C. With such an acceptance level the model is correct in 27 out of 33 points for the time series considered.

  1. Gemini Planet Imager Observational Calibrations III: Empirical Measurement Methods and Applications of High-Resolution Microlens PSFs

    OpenAIRE

    Ingraham, Patrick; Ruffio, Jean-Baptiste; Perrin, Marshall D.; Wolff, Schuyler G.; Draper, Zachary H.; Maire, Jerome; Marchis, Franck; Fesquet, Vincent

    2014-01-01

    The newly commissioned Gemini Planet Imager (GPI) combines extreme adaptive optics, an advanced coronagraph, precision wavefront control and a lenslet-based integral field spectrograph (IFS) to measure the spectra of young extrasolar giant planets between 0.9-2.5 um. Each GPI detector image, when in spectral model, consists of ~37,000 microspectra which are under or critically sampled in the spatial direction. This paper demonstrates how to obtain high-resolution microlens PSFs and discusses ...

  2. Measurement of pyrethroid, organophosphorus, and carbamate insecticides in human plasma using isotope dilution gas chromatography-high resolution mass spectrometry.

    Science.gov (United States)

    Pérez, José J; Williams, Megan K; Weerasekera, Gayanga; Smith, Kimberly; Whyatt, Robin M; Needham, Larry L; Barr, Dana Boyd

    2010-10-01

    We have developed a gas chromatography-high resolution mass spectrometry method for measuring pyrethroid, organophosphorus, carbamate and fipronil pesticides and the synergist piperonyl butoxide in human plasma. Plasma samples were extracted using solid phase extraction and were then concentrated for injection and analysis using isotope dilution gas chromatography-high resolution mass spectrometry. The limits of detection ranged from 10 to 158 pg/mL with relative recoveries at concentrations near the LODs (e.g., 25 or 250 pg/mL) ranging from 87% to 156% (9 of the 16 compounds were within ±15% of 100%). The extraction recoveries ranged from 20% to 98% and the overall method relative standard deviations were typically less than 20% with some exceptions. Analytical characteristics were determined at 25, 250, and 1000 pg/mL.

  3. High resolution measurements of the electron scattering for applications in electron microscopy and Monte-Carlo simulations of electron scattering

    CERN Document Server

    Berger, D

    2000-01-01

    scanning electron microscope is examined. By means of the scattering at mono-crystalline samples the influence of channeling (anomalous absorption and transmission) on backscattered electron spectra is shown. Captions are given in English language. This work presents high resolution measurements of the energy and complete angular distribution of the scattering of 20 keV electrons (energy resolution 0.55%). The examinations include take-off angles close to the target surface and non-perpendicular incidences of electrons partly for the first time. The results are of interest for the understanding of fundamental scattering processes, the interpretation of signals and new detector systems in electron microscopy and electron spectroscopy. Furthermore, they are used for the verification of electron scattering models and simulations. The applied compact electrostatic spectrometers with spherical and toroidal geometries are characterized and compared. High resolution spectra are obtained by deconvolution of the measu...

  4. Very high resolution measurement of the penetration depth of superconductors by a novel single-coil inductance technique

    Science.gov (United States)

    Gauzzi, A.; Le Cochec, J.; Lamura, G.; Jönsson, B. J.; Gasparov, V. A.; Ladan, F. R.; Plaçais, B.; Probst, P. A.; Pavuna, D.; Bok, J.

    2000-05-01

    We describe a novel single-coil mutual inductance technique for measuring the magnetic penetration depth λ of superconductors at 2-4 MHz as a function of temperature in the 4-100 K range. We combine a single-coil configuration with a high-stability marginal oscillator; this enables us to measure the absolute value of λ on both bulk samples and thin films with very high resolution (δλ=10 pm) and a precision of 30 nm. As example of application, we report measurements on NbTi bulk samples and Nb films. This contactless technique is suited for probing the superconducting properties of samples over large surfaces.

  5. A computational method to help identify and measure metal lines in high resolution QSO spectra

    Institute of Scientific and Technical Information of China (English)

    Xi-Heng Shi; David Tytler; Jin-Liang Hou; David Kirkman; Jeffery Lee; Benjamin Ou

    2011-01-01

    A computational code is developed to help identify metal absorption lines in high resolution QSO spectra,especially in the Lyα forest.The input to the code includes a list of line central wavelengths,column densities and Doppler widths.The code then searches for candidate metal absorption systems and assesses the probability that each system could be real.The framework of the strategy we employ is described in detail and we discuss how to estimate the errors in line profile fitting that are essential to identification.A series of artificial spectra is constructed to calibrate the performance of the code.Due to the effects of blending and noise on Voigt profile fitting,the completeness of the identification depends on the column density of absorbers.For intermediate and strong artificial metal absorbers,more than 90% could be confirmed by the code.The results of applying the code to the real spectra of QSOs HS0757+5218 and Q0100+1300 are also presented.

  6. High-Resolution THz Measurements of BrO Generated in AN Inductively Coupled Plasma

    Science.gov (United States)

    Nemchick, Deacon J.; Drouin, Brian

    2017-06-01

    Building upon the foundation provided by previous work, the X_{1}^{2}Π_{3/2} and X_{2}^{2}Π_{1/2} states of the transient radical, BrO, were interrogated in previously unprobed spectral regions (0.5 to 1.7 THz) by employing JPL developed high-resolution cascaded frequency multiplier sources. Like other members of the halogen monoxides (XO), this species has been the target of several recent atmospheric remote sensing studies and is a known participant in a catalytic ozone degradation cycle. For the current work, BrO is generated in an inductively coupled plasma under dynamic flow conditions and rotational lines are observed directly at their Doppler-limited resolution. New spectral transitions including those owing to both the ground (ν=0) and excited (ν=1 and 2) vibrational states of isotopologues composed of permutations of natural abundance ^{16}O, ^{18}O, ^{79}Br, and ^{81}Br are fit to a global Hamiltonian containing both fine and hyperfine terms. In addition to further refining existing spectroscopic parameters, new observations will be made available to remote detection communities through addition to the JPL catalog. New findings will be discussed along with future plans to extend these studies to other halogen monoxides (X=Cl and I) and the more massive halogen dioxides (OXO & XOO).

  7. Using high-resolution phosphorus data to investigate mitigation measures in headwater river catchments

    Directory of Open Access Journals (Sweden)

    J. M. Campbell

    2014-09-01

    Full Text Available This study reports the use of high resolution water quality monitoring to assess the influence of changes in landuse management on total phosphorus (TP transfers in two 5 km2 agricultural sub-catchments. Specifically, the work investigates the "wicked problem" of agricultural soil P management and subsequent diffuse transfers at high river flows over a five year timescale. The work also investigates the phenomenon of low flow P pollution from septic tank systems (STS and mitigation efforts – here termed the "filthy issue" of rural catchment management. Results showed an inconsistent response to soil P management over five years with one catchment showing a convergence to optimum P concentrations and the other an overall increase. Both catchments indicated an overall increase in P concentration in defined high flow ranges. Low flow P concentration showed little change or higher P concentrations in defined low flow ranges despite replacement of defective systems and this is possibly due to a number of confounding reasons including increased housing densities due to new-builds. The work indicates fractured responses to catchment management advice and mitigation and that the short to medium term may be an insufficient time to expect the full implementation of policies (here defined as convergence to optimum soil P concentration and mitigation of STS and also to gauge their effectiveness.

  8. Is the type and extent of hippocampal sclerosis measurable on high-resolution MRI?

    Energy Technology Data Exchange (ETDEWEB)

    Urbach, H; Schwarzwald, R [Medical Center University of Freiburg, Dept. of Neuroradiology, Freiburg (Germany); Huppertz, H.J. [Swiss Epilepsy Center, Zurich (Switzerland); Becker, A.J. [Medical Center University of Bonn, Department of Neuropathology, Bonn (Germany); Wagner, J. [Medical Center University of Bonn, Department of Epileptology, Bonn (Germany); Bahri, M. Delsous; Tschampa, H.J. [Medical Center University of Bonn, Department of Radiology/Neuroradiology, Bonn (Germany)

    2014-09-15

    The purpose of this study is to relate hippocampal volume and FLAIR signal intensity to Wyler grading of hippocampal sclerosis (HS). Of 100 consecutive patients with temporal lobe epilepsy and HS as histopathological diagnosis, 32 had high-resolution 3 Tesla MRI and anatomically well-preserved hippocampi following amygdalo-hippocampectomy. Hippocampal volume on 3D T1-weighted gradient echo and signal intensity on coronal FLAIR sequences were determined using FreeSurfer and SPM tools and related to Wyler grading. Seizure outcome was determined after 1 year. Histopathology showed four Wyler II, 19 Wyler III, and 9 Wyler IV HS. Hippocampal volumes were 3.08 ml for Wyler II (Wyler II/contralateral side: p > 0.05), 2.19 ml for Wyler III (p < 0.01), 2.62 ml for Wyler IV (p = 0.01), and 3.08 ml for the contralateral side. Normalized FLAIR signals were 1,354 (p = 0.0004), 1,408 (p < 0.0001), 1,371 (p < 0.04), and 1,296, respectively. Wyler II hippocampi were visually normal. Two of four (50 %) Wyler II, 16/19 (84 %) Wyler III, and 6/9 (66 %) Wyler IV patients achieved Engel I outcome. Combined volumetry and quantitative FLAIR signal analysis clearly identifies Wyler III and IV HS. Quantitative FLAIR signal analysis may be helpful to identify Wyler II HS. (orig.)

  9. Using high-resolution phosphorus data to investigate mitigation measures in headwater river catchments

    Science.gov (United States)

    Campbell, J. M.; Jordan, P.; Arnscheidt, J.

    2014-09-01

    This study reports the use of high resolution water quality monitoring to assess the influence of changes in landuse management on total phosphorus (TP) transfers in two 5 km2 agricultural sub-catchments. Specifically, the work investigates the "wicked problem" of agricultural soil P management and subsequent diffuse transfers at high river flows over a five year timescale. The work also investigates the phenomenon of low flow P pollution from septic tank systems (STS) and mitigation efforts - here termed the "filthy issue" of rural catchment management. Results showed an inconsistent response to soil P management over five years with one catchment showing a convergence to optimum P concentrations and the other an overall increase. Both catchments indicated an overall increase in P concentration in defined high flow ranges. Low flow P concentration showed little change or higher P concentrations in defined low flow ranges despite replacement of defective systems and this is possibly due to a number of confounding reasons including increased housing densities due to new-builds. The work indicates fractured responses to catchment management advice and mitigation and that the short to medium term may be an insufficient time to expect the full implementation of policies (here defined as convergence to optimum soil P concentration and mitigation of STS) and also to gauge their effectiveness.

  10. High-resolution isotope measurements resolve rapid ecohydrological dynamics at the soil-plant interface.

    Science.gov (United States)

    Volkmann, Till H M; Haberer, Kristine; Gessler, Arthur; Weiler, Markus

    2016-05-01

    Plants rely primarily on rainfall infiltrating their root zones - a supply that is inherently variable, and fluctuations are predicted to increase on most of the Earth's surface. Yet, interrelationships between water availability and plant use on short timescales are difficult to quantify and remain poorly understood. To overcome previous methodological limitations, we coupled high-resolution in situ observations of stable isotopes in soil and transpiration water. We applied the approach along with Bayesian mixing modeling to track the fate of (2) H-labeled rain pulses following drought through soil and plants of deciduous tree ecosystems. We resolve how rainwater infiltrates the root zones in a nonequilibrium process and show that tree species differ in their ability to quickly acquire the newly available source. Sessile oak (Quercus petraea) adjusted root uptake to vertical water availability patterns under drought, but readjustment toward the rewetted topsoil was delayed. By contrast, European beech (Fagus sylvatica) readily utilized water from all soil depths independent of water depletion, enabling faster uptake of rainwater. Our results demonstrate that species-specific plasticity and responses to water supply fluctuations on short timescales can now be identified and must be considered to predict vegetation functional dynamics and water cycling under current and future climatic conditions.

  11. The apogee red-clump catalog: Precise distances, velocities, and high-resolution elemental abundances over a large area of the Milky Way's disk

    Energy Technology Data Exchange (ETDEWEB)

    Bovy, Jo [Institute for Advanced Study, Einstein Drive, Princeton, NJ 08540 (United States); Nidever, David L. [Department of Astronomy, University of Michigan, Ann Arbor, MI 48109 (United States); Rix, Hans-Walter [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Girardi, Léo; Rodrigues, Thaíse S. [Osservatorio Astronomico di Padova-INAF, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy); Zasowski, Gail [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Chojnowski, S. Drew; Majewski, Steven R. [Department of Astronomy, University of Virginia, Charlottesville, VA, 22904 (United States); Holtzman, Jon; Hayden, Michael R. [New Mexico State University, Las Cruces, NM 88003 (United States); Epstein, Courtney; Johnson, Jennifer A.; Pinsonneault, Marc H.; Andrews, Brett [Department of Astronomy, The Ohio State University, Columbus, OH 43210 (United States); Frinchaboy, Peter M. [Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX 76129 (United States); Stello, Dennis [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Allende Prieto, Carlos [Instituto de Astrofísica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain); Basu, Sarbani [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520-8101 (United States); Beers, Timothy C. [National Optical Astronomy Observatory, Tucson, AZ 85719 (United States); Bizyaev, Dmitry, E-mail: bovy@ias.edu [Apache Point Observatory and New Mexico State University, P.O. Box 59, Sunspot, NM, 88349-0059 (United States); and others

    2014-08-01

    The Sloan Digital Sky Survey III's Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a high-resolution near-infrared spectroscopic survey covering all of the major components of the Galaxy, including the dust-obscured regions of the inner Milky Way disk and bulge. Here we present a sample of 10,341 likely red-clump stars (RC) from the first two years of APOGEE operations, selected based on their position in color-metallicity-surface-gravity-effective-temperature space using a new method calibrated using stellar evolution models and high-quality asteroseismology data. The narrowness of the RC locus in color-metallicity-luminosity space allows us to assign distances to the stars with an accuracy of 5%-10%. The sample extends to typical distances of about 3 kpc from the Sun, with some stars out to 8 kpc, and spans a volume of approximately 100 kpc{sup 3} over 5 kpc ≲ R ≲ 14 kpc, |Z| ≲ 2 kpc, and –15° ≲ Galactocentric azimuth ≲ 30°. The APOGEE red-clump (APOGEE-RC) catalog contains photometry from the Two Micron All Sky Survey, reddening estimates, distances, line-of-sight velocities, stellar parameters and elemental abundances determined from the high-resolution APOGEE spectra, and matches to major proper motion catalogs. We determine the survey selection function for this data set and discuss how the RC selection samples the underlying stellar populations. We use this sample to limit any azimuthal variations in the median metallicity within the ≈45° azimuthal region covered by the current sample to be ≤0.02 dex, which is more than an order of magnitude smaller than the radial metallicity gradient. This result constrains coherent non-axisymmetric flows within a few kiloparsecs from the Sun.

  12. New turbidity current model based on high-resolution monitoring of the longest flow ever measured

    Science.gov (United States)

    Azpiroz, Maria; Cartigny, Matthieu; Talling, Peter; Parsons, Daniel; Simmons, Steve; Clare, Michael; Sumner, Esther; Pope, Ed

    2016-04-01

    Turbidity currents transport large amounts of sediment from shallow waters towards deep ocean basins. Little is known about these flows, despite their potential hazard for damaging expensive and strategically important seafloor infrastructure. So far turbidity currents have been profiled in only 6 deep ocean locations worldwide. Our current knowledge of these flows is therefore mainly based on scaled-down experimental and computationally-limited numerical modelling. Here we present results from the monitoring of a one-week long turbidity current in the Congo Canyon that had a discharge close to that of the Mississippi River. Measurements taken every 5 seconds give the most detailed image yet of a turbidity current deep-water over an unprecedented duration. Our analysis reveals a different flow structure than that presented in previous models. Classical models display a thick front of the flow followed by a thinner and faster flow, which gives way to a short and quasi-steady body. Instead, we observe a thin frontal cell that outruns a thicker (~80 m), long and slower quasi-steady flow. In contrast to the previous model, where the thinner faster flow feeds sediment into the head, the Congo Canyon turbidity current shows a frontal cell that feeds sediment into, and at the same time outruns, the succeeding quasi-steady flow. As a result of the faster moving frontal cell, the flow should continuously stretch and grow in length while propagating down the system. Within the quasi-steady body, the flow switches between what appears to be two stable flow modes. One mode exhibits a fast and thin velocity profile whose maximum is a low distance from the seabed and resembles Froude-supercritical flow conditions, while the other mode is similar to Froude-subcritical flow conditions as the flow is thicker and slower. These first observations provide new insights into the behaviour of deep water long duration flows that differ from traditional models and provide an exciting

  13. High-resolution recombination patterns in a region of human chromosome 21 measured by sperm typing.

    Directory of Open Access Journals (Sweden)

    Irene Tiemann-Boege

    2006-05-01

    Full Text Available For decades, classical crossover studies and linkage disequilibrium (LD analysis of genomic regions suggested that human meiotic crossovers may not be randomly distributed along chromosomes but are focused instead in "hot spots." Recent sperm typing studies provided data at very high resolution and accuracy that defined the physical limits of a number of hot spots. The data were also used to test whether patterns of LD can predict hot spot locations. These sperm typing studies focused on several small regions of the genome already known or suspected of containing a hot spot based on the presence of LD breakdown or previous experimental evidence of hot spot activity. Comparable data on target regions not specifically chosen using these two criteria is lacking but is needed to make an unbiased test of whether LD data alone can accurately predict active hot spots. We used sperm typing to estimate recombination in 17 almost contiguous ~5 kb intervals spanning 103 kb of human Chromosome 21. We found two intervals that contained new hot spots. The comparison of our data with recombination rates predicted by statistical analyses of LD showed that, overall, the two datasets corresponded well, except for one predicted hot spot that showed little crossing over. This study doubles the experimental data on recombination in men at the highest resolution and accuracy and supports the emerging genome-wide picture that recombination is localized in small regions separated by cold areas. Detailed study of one of the new hot spots revealed a sperm donor with a decrease in recombination intensity at the canonical recombination site but an increase in crossover activity nearby. This unique finding suggests that the position and intensity of hot spots may evolve by means of a concerted mechanism that maintains the overall recombination intensity in the region.

  14. Surface structure of imidazolium-based ionic liquids: Quantitative comparison between simulations and high-resolution RBS measurements

    Science.gov (United States)

    Nakajima, Kaoru; Nakanishi, Shunto; Lísal, Martin; Kimura, Kenji

    2016-03-01

    Elemental depth profiles of 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([CnMIM][TFSI], n = 4, 6, 8) are measured using high-resolution Rutherford backscattering spectroscopy (HRBS). The profiles are compared with the results of molecular dynamics (MD) simulations. Both MD simulations and HRBS measurements show that the depth profiles deviate from the uniform stoichiometric composition in the surface region, showing preferential orientations of ions at the surface. The MD simulations qualitatively reproduce the observed HRBS profiles but the agreement is not satisfactory. The observed discrepancy is ascribed to the capillary waves. By taking account of the surface roughness induced by the capillary waves, the agreement becomes almost perfect.

  15. Application of high-resolution spectral absorbance measurements to determine dissolved organic carbon concentration in remote areas

    Science.gov (United States)

    Avagyan, Armine; Runkle, Benjamin R. K.; Kutzbach, Lars

    2014-09-01

    Accurate quantification of dissolved organic carbon (DOC) in surface and soil pore waters is crucial for understanding changes in water resources under the influence of climate and land use changes. Sampling and laboratory analysis of DOC content at a sufficient temporal frequency are especially difficult to achieve for natural DOC sources like the extensive boreal and arctic mire landscapes due to their remoteness. Therefore, the goals of this paper are (1) to investigate the performance of a portable, high-resolution ultraviolet-visible light spectroscopic method for determining the DOC content of surface and soil pore water samples from a boreal mire complex and (2) to compare the spectroscopic method with other DOC measurement techniques, e.g., the wet heated persulfate oxidation method and a laboratory, expulsion-based spectrophotometric method and (3) to assess different multivariate models that relate absorbance measurements with DOC contents. The study indicates that high-resolution spectroscopic measurements provide a simple, robust and non-destructive method for measuring DOC content. These measurements are of short duration (<1 min) and the sample analysis is portable, rendering this method particularly advantageous for in situ investigations at remote field locations. The study also demonstrates that if absorbances at specific wavelengths are used as proxies for DOC concentration, it is recommended to create site-specific calibration models that include more than one wavelength to achieve the optimal accuracy of the proxy-based DOC quantification.

  16. Eddy covariance measurements with high-resolution time-of-flight aerosol mass spectrometry: a new approach to chemically resolved aerosol fluxes

    Directory of Open Access Journals (Sweden)

    D. K. Farmer

    2011-06-01

    Full Text Available Although laboratory studies show that biogenic volatile organic compounds (VOCs yield substantial secondary organic aerosol (SOA, production of biogenic SOA as indicated by upward fluxes has not been conclusively observed over forests. Further, while aerosols are known to deposit to surfaces, few techniques exist to provide chemically-resolved particle deposition fluxes. To better constrain aerosol sources and sinks, we have developed a new technique to directly measure fluxes of chemically-resolved submicron aerosols using the high-resolution time-of-flight aerosol mass spectrometer (HR-AMS in a new, fast eddy covariance mode. This approach takes advantage of the instrument's ability to quantitatively identify both organic and inorganic components, including ammonium, sulphate and nitrate, at a temporal resolution of several Hz. The new approach has been successfully deployed over a temperate ponderosa pine plantation in California during the BEARPEX-2007 campaign, providing both total and chemically resolved non-refractory (NR PM1 fluxes. Average deposition velocities for total NR-PM1 aerosol at noon were 2.05 ± 0.04 mm s−1. Using a high resolution measurement of the NH2+ and NH3+ fragments, we demonstrate the first eddy covariance flux measurements of particulate ammonium, which show a noon-time deposition velocity of 1.9 ± 0.7 mm s−1 and are dominated by deposition of ammonium sulphate.

  17. Scientific system for high-resolution measurement of the circumsolar radiation

    Energy Technology Data Exchange (ETDEWEB)

    Schrott, Simeon, E-mail: thomas.schmidt@ise.fraunhofer.de; Schmidt, Thomas, E-mail: thomas.schmidt@ise.fraunhofer.de; Hornung, Thorsten, E-mail: thomas.schmidt@ise.fraunhofer.de; Nitz, Peter, E-mail: thomas.schmidt@ise.fraunhofer.de [Fraunhofer Institute for Solar Energy Systems ISE, Freiburg (Germany)

    2014-09-26

    We developed a camera based system for measurements of the circumsolar radiation with a high angular resolution of 0.1 mrad. Subsequent measurements may be taken at intervals as short as 15 s. In this publication we describe the optical system in detail and discuss some aspects of the measurement method. First results from two days of measurement at Freiburg i. Br., Germany, are presented and compared to data from literature. The good results encourage us to perform longer measurement campaigns in future to better understand the influence of circumsolar radiation on the power yield of concentrating photovoltaic systems.

  18. The RINGS Survey: High-Resolution H-alpha Velocity Fields of Nearby Spiral Galaxies with the SALT Fabry-Perot

    CERN Document Server

    Mitchell, Carl J; Williams, T B; Spekkens, Kristine; Lee-Waddell, K; de Naray, Rachel Kuzio

    2015-01-01

    We have obtained high-spatial-resolution spectrophotometric data on several nearby spiral galaxies with the Southern African Large Telescope (SALT) Fabry-P\\'erot interferometer on the Robert Stobie Spectrograph (RSS) as a part of the RSS Imaging spectroscopy Nearby Galaxy Survey (RINGS). We have successfully reduced two tracks of Fabry-P\\'erot data for the galaxy NGC 2280 to produce a velocity field of the H-alpha line of excited hydrogen. We have modeled these data with the DiskFit modeling software and found these models to be in excellent agreement both with previous measurements in the literature and with our lower-resolution HI velocity field of the same galaxy. Despite this good agreement, small regions exist where the difference between the H-alpha and HI velocities is larger than would be expected from typical dispersions. We investigate these regions of high velocity difference and offer possible explanations for their existence.

  19. Power Measurement and Data Logger with High-Resolution for Industrial DC-Grid Application

    Directory of Open Access Journals (Sweden)

    Apse-Apsitis Peteris

    2015-12-01

    Full Text Available Power and energy measurement and monitoring is a key factor for many industries in terms of energy and cost efficiency evaluation. Due to trends of Smart Grid concept application in industrial environment, including decentralized DC-Grid implementation, for precise evaluation – faster and low-cost measurement equipment is needed. Manufacturing industry widely uses industrial robots that have dynamic load characteristics for which faster measurement equipment is needed.

  20. High-resolution CT of transplanted teeth: imaging technique and measurement accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Gahleitner, Andre [Medical University of Vienna, Department of Radiology/Osteology and MR, Vienna (Austria); Medical University Vienna, Department of Radiology, Vienna (Austria); Kuchler, Ulrike; Heschl, Janina; Watzek, Georg [Medical University of Vienna, Department of Oral Surgery, Vienna (Austria); Homolka, Peter [Medical University of Vienna, Center for Biomedical Engineering and Physics, Vienna (Austria); Imhof, Herwig [Medical University of Vienna, Department of Radiology/Osteology and MR, Vienna (Austria)

    2008-12-15

    The aim of this study was to determine the accuracy of crown diameter measurements by dental CT as a tool for preoperative diagnosis before tooth transplantations. Fifty-eight patients underwent clinically indicated dental CT. The diameter of the crowns were measured by CT using a standard protocol (1.5-mm slice thickness, 1-mm table feed, 120 kV, 25-75 mA/s, 2-s scan time/slice, 512 matrix) and a standard dental software package. Postoperatively, the same distances were clinically measured using a sliding gauge. The degree of the deviation between CT measurements and clinical measurements was in the sub-millimeter range. According to the regression analysis, the correlation coefficient equals 0.98 and 0.97, indicating a strong relationship between the CT and the manual measurement of the crown diameter in the bucco-lingual and the mesio-distal direction. The mean deviation of CT measurements with regard to the bucco-lingual diameter of the crown was +0.08 mm (SD: {+-}0.38 mm). For the mesio-distal diameter, the mean deviation of CT measurements was -0.24 mm (SD: {+-}0.53 mm). These results demonstrate that dental CT promises to be a valuable tool for the evaluation of the potential and optimal size and site for tooth transplantations. (orig.)

  1. High Resolution Temperature Measurement of Liquid Stainless Steel Using Hyperspectral Imaging

    Science.gov (United States)

    Devesse, Wim; De Baere, Dieter; Guillaume, Patrick

    2017-01-01

    A contactless temperature measurement system is presented based on a hyperspectral line camera that captures the spectra in the visible and near infrared (VNIR) region of a large set of closely spaced points. The measured spectra are used in a nonlinear least squares optimization routine to calculate a one-dimensional temperature profile with high spatial resolution. Measurements of a liquid melt pool of AISI 316L stainless steel show that the system is able to determine the absolute temperatures with an accuracy of 10%. The measurements are made with a spatial resolution of 12 µm/pixel, justifying its use in applications where high temperature measurements with high spatial detail are desired, such as in the laser material processing and additive manufacturing fields. PMID:28067764

  2. High Resolution Temperature Measurement of Liquid Stainless Steel Using Hyperspectral Imaging

    Directory of Open Access Journals (Sweden)

    Wim Devesse

    2017-01-01

    Full Text Available A contactless temperature measurement system is presented based on a hyperspectral line camera that captures the spectra in the visible and near infrared (VNIR region of a large set of closely spaced points. The measured spectra are used in a nonlinear least squares optimization routine to calculate a one-dimensional temperature profile with high spatial resolution. Measurements of a liquid melt pool of AISI 316L stainless steel show that the system is able to determine the absolute temperatures with an accuracy of 10%. The measurements are made with a spatial resolution of 12 µm/pixel, justifying its use in applications where high temperature measurements with high spatial detail are desired, such as in the laser material processing and additive manufacturing fields.

  3. Application of image cross-correlation to the measurement of glacier velocity using satellite image data

    Science.gov (United States)

    Scambos, Theodore A.; Dutkiewicz, Melanie J.; Wison, Jeremy C.; Bindschadler, Robert A.

    1992-01-01

    A high-resolution map of the velocity field of the central portion of Ice Stream E in West Antarctica, generated by the displacement-measuring technique, is presented. The use of cross-correlation software is found to be a significant improvement over previous manually based photogrammetric methods for velocity measurement, and is far more cost-effective than in situ methods in remote polar areas. A hue-intensity-saturation image of Ice Stream E and its velocity field is shown.

  4. A high-resolution optical measurement system for rapid acquisition of radiation flux density maps

    Science.gov (United States)

    Thelen, Martin; Raeder, Christian; Willsch, Christian; Dibowski, Gerd

    2017-06-01

    To identify the power and flux density of concentrated solar radiation the Institute of Solar Research at the German Aerospace Center (DLR - Deutsches Zentrum für Luft-und Raumfahrt e. V.) has used the camera-based measurement system FATMES (Flux and Temperature Measurement System) since 1995. The disadvantages of low resolution, difficult handling and poor computing power required a revision of the existing measurement system. The measurement system FMAS (Flux Mapping Acquisition system) is equipped with state-of-the-art-hardware, is compatible with computers off-the-shelf and is programmed in LabView. The expenditure of time for an image evaluation is reduced by the factor 60 compared to FATMES. The new measurement system is no longer associated with the facilities Solar Furnace and High Flux Solar Simulator at the DLR in Cologne but is also applicable as a mobile system. The data and the algorithms are transparent throughout the complete process. The measurement accuracy of FMAS is determined to at most ±3 % until now. The error of measurement of FATMES is at least 2 % higher according to the conducted comparison tests.

  5. High-Resolution Energy and Intensity Measurements with CVD Diamond at REX-ISOLDE

    CERN Document Server

    Griesmayer, E; Dobos, D; Wenander, F; Bergoz, J; Bayle, H; Frais-Kölbl, H; Leinweber, J; Aumeyr, T; CERN. Geneva. BE Department

    2009-01-01

    A novel beam instrumentation device for the HIE-REX (High In-tensity and Energy REX) upgrade has been developed and tested at the On-Line Isotope Mass Separator ISOLDE, located at the European Laboratory for Particle Physics (CERN). This device is based on CVD diamond detector technology and is used for measuring the beam intensity, particle counting and measuring the energy spectrum of the beam. An energy resolution of 0.6% was measured at a carbon ion energy of 22.8 MeV. This corresponds to an energy spread of ± 140 keV.

  6. A simple technique for high resolution time domain phase noise measurement

    Science.gov (United States)

    Reinhardt, V. S.; Donahoe, T.

    1977-01-01

    A new time domain phase comparator is described. The device uses a novel technique to allow time domain phase measurements to be made with period and time interval counters without the use of offset reference oscillators. The device uses a single reference oscillator and allows measurements with a phase resolution greater than the noise floor of the reference. Data is presented showing a phase resolution of 0.02ps at 5 MHz with a crystal reference. The device has application in measuring the phase stability of systems where approximate phase quadrature can be maintained.

  7. A Compact Remote Sensing Lidar for High Resolution Measurements of Methane Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ? Develop the technology for a compact, space-qualifiable laser transmitter for a lidar operating at 1.65 5 to enable Earth observation CH4 measurements. ? Reduce...

  8. Reconstruction of high-resolution time series from slow-response atmospheric measurements by deconvolution

    Science.gov (United States)

    Ehrlich, André; Wendisch, Manfred

    2017-04-01

    Measurements of high temporal resolution are often needed to study the spatial or temporal variation of atmospheric parameters. An efficient method to enhance the temporal resolution of slow-response measurements is introduced. It is based on the deconvolution theorem of Fourier transform to restore amplitude and phase shift of high frequent fluctuations. It is shown that the quality of reconstruction depends on the instrument noise, the sensor response time and the frequency of the oscillations. The method is demonstrated by application to measurements of broadband terrestrial irradiance using pyrgeometer and temperature and humidity measurements by drop sondes. Using a CGR-4 pyrgeometer with response time of 3 s, the method is tested in laboratory measurements for synthetic time series including a boxcar function and periodic oscillations. The originally slow-response pyrgeometer data were reconstructed to higher resolution and compared to the predefined synthetic time series. The reconstruction of the time series worked up to oscillations of 0.5 Hz frequency and 2 W m-2 amplitude if the sampling frequency of the data acquisition is 16 kHz or higher. For oscillations faster than 2 Hz, the instrument noise exceeded the reduced amplitude of the oscillations in the measurements and the reconstruction failed. The method was applied to airborne measurements of upward terrestrial irradiance and drop sonde profiles from the VERDI (Vertical Distribution of Ice in Arctic Clouds) field campaign. Pyrgeometer data above open leads in sea ice and a broken cloud field were reconstructed and compared to KT19 infrared thermometer data. The reconstruction of amplitude and phase shift of the deconvoluted data improved the agreement with the KT19 data and removed biases for the maximum and minimum values. By application to temperature and humidity profiles measured by drop sonde profiles, the resolution of the cloud top inversion cloud be improved.

  9. Ice Fog and Light Snow Measurements Using a High-Resolution Camera System

    Science.gov (United States)

    Kuhn, Thomas; Gultepe, Ismail

    2016-09-01

    Ice fog, diamond dust, and light snow usually form over extremely cold weather conditions, and they affect both visibility and Earth's radiative energy budget. Prediction of these hydrometeors using models is difficult because of limited knowledge of the microphysical properties at the small size ranges due to measurement issues. These phenomena need to be better represented in forecast and climate models; therefore, in addition to remote sensing accurate measurements using ground-based instrumentation are required. An imaging instrument, aimed at measuring ice fog and light snow particles, has been built and is presented here. The ice crystal imaging (ICI) probe samples ice particles into a vertical, tapered inlet with an inlet flow rate of 11 L min-1. A laser beam across the vertical air flow containing the ice crystals allows for their detection by a photodetector collecting the scattered light. Detected particles are then imaged with high optical resolution. An illuminating LED flash and image capturing are triggered by the photodetector. In this work, ICI measurements collected during the fog remote sensing and modeling (FRAM) project, which took place during Winter of 2010-2011 in Yellowknife, NWT, Canada, are summarized and challenges related to measuring small ice particles are described. The majority of ice particles during the 2-month-long campaign had sizes between 300 and 800 μm. During ice fog events the size distribution measured had a lower mode diameter of 300 μm compared to the overall campaign average with mode at 500 μm.

  10. High-speed high-resolution fine wire diameter measurement system

    Science.gov (United States)

    Guimaraes, Marcelo F.; Doiron, Theodore D.

    1993-10-01

    A fine wire diameter measurement system, for on-line monitoring, has been proposed by using a Machine Vision System and a visible diode laser. The system uses the Fraunhofer diffraction principle. The diffraction pattern, generated by a small wire exposed to a collimated laser beam, is acquired by a CCD industrial camera that is connected to a processing board inside a PC computer. Two different methods of measuring the diameters, static and dynamic, have been proposed in order to get high precision and high measurement rate. Wires with diameter from 10 to 350 micrometers have been measured by this system with 0.06% resolution. The accuracy is less than +/- 0.5% over a range of 90 - 350 micrometers diameter. For thinner wires, the measurement system should be calibrated to eliminate the systematic errors. The estimate random errors are +/- 0.25%. The instrument can measure the wire diameter at a 1000 Hz rate and allows it to move laterally in a 1 mm square window, maintaining the above accuracy. The system is compact and there are no moving parts.

  11. The Kinect as a low cost high resolution small scale LiDAR for water surface and shallow subsurface measurements

    Science.gov (United States)

    Mankoff, K. D.; Russo, T. A.

    2012-04-01

    The Microsoft Kinect, a video game input device designed for the Xbox system, can be used by earth scientists as a low cost high resolution LiDAR sensor. The device can see through at least 1 m of clear still water, or image the surface of opaque water. When observing through water the measurement is distorted by the refraction at the air/water interface. We present initial results of a calibration for sub-aqueous measurements, and describe a method for measuring sub-aqueous features and water height. When waves exist on the surface the signal is further convoluted and both the waves and subsurface are captured in the signal. We discuss signal deconvolution and techniques for capturing the relative and/or absolute values of surface waves and subsurface features.

  12. Results of the High Resolution OTR Measurements at KEK and comparison with simulations

    CERN Document Server

    Bolzon, B; Mazzoni, S; Welsch, C P; Karataev, P; Kruchinin, K; Aryshev, A

    2013-01-01

    Optical Transition Radiation (OTR) is emitted when a charged particle crosses the interface between two media with different dielectric properties. It has become a standard tool for beam imaging and transverse beam size measurements. At the KEK Accelerator Test Facility 2 (ATF2), OTR is used at the beginning of the final focus system to measure micrometre beam size using the visibility of the OTR Point Spread Function (PSF). In order to study in detail the PSF and improve the resolution of the monitor, a novel simulation tool has been developed. Based on the physical optic propagation mode of ZEMAX, the propagation of the OTR electric field can be simulated very precisely up to the image plane, taking into account aberrations and diffraction. This contribution presents the comparison between Zemax simulations and measurements performed at ATF2.

  13. Automated multimode phase speed measurements for high-resolution regional-scale tomography: application to North America

    Science.gov (United States)

    Yoshizawa, K.; Ekström, Göran

    2010-12-01

    A fully automated method for obtaining multimode phase speed measurements from a single seismogram has been developed and applied to a large data set of three-component long-period seismograms in North America, constructing high-resolution phase speed maps on a continental scale. The method of our phase speed estimation is based on a fully non-linear waveform inversion by Yoshizawa & Kennett working with a global search method (the Neighbourhood Algorithm). The entire process of waveform fitting and the evaluation of the estimated phase speed have been fully automated employing several empirical quantitative measures, assessing the quality of waveform fit and the relative contributions of each mode in a chosen time window. The measured phase speed data undergo automatic screening for quality control, comprising the threshold evaluation of their reliability and outlier detection and removal. This new automated method has been applied to a large data set recorded at North American stations, including the latest transportable stations of USArray. Using long-period three-component seismograms recorded during the past eight years, we have successfully retrieved large numbers of regional surface wave paths, including over 20000 paths for the fundamental-mode Rayleigh waves over a wide range of frequencies, and over 10000 paths for the higher mode Rayleigh as well as the fundamental-mode Love waves. The consistent results of the automated measurement procedure suggest that the method works well at regional distances, allowing us to perform a high-resolution mapping of multimode phase speeds in North America. The results of the automated waveform analysis also indicate some intrinsic limitations in the higher mode phase speed measurements from a single seismogram particularly in the short period range, mainly due to the overlapping of higher mode arrivals as well as coupling between mode branches. Despite such an innate difficulty in the higher mode dispersion measurements

  14. High resolution kilometric range optical telemetry in air by radio frequency phase measurement

    Energy Technology Data Exchange (ETDEWEB)

    Guillory, Joffray; García-Márquez, Jorge; Truong, Daniel; Wallerand, Jean-Pierre [Laboratoire Commun de Métrologie LNE-Cnam (LCM), LNE, 1 rue Gaston Boissier, 75015 Paris (France); Šmíd, Radek [Laboratoire Commun de Métrologie LNE-Cnam (LCM), LNE, 1 rue Gaston Boissier, 75015 Paris (France); Institute of Scientific Instruments of the CAS, Kralovopolska 147, 612 64 Brno (Czech Republic); Alexandre, Christophe [Centre d’Études et de Recherche en Informatique et Communications (CEDRIC), Cnam, 292 rue St-Martin, 75003 Paris (France)

    2016-07-15

    We have developed an optical Absolute Distance Meter (ADM) based on the measurement of the phase accumulated by a Radio Frequency wave during its propagation in the air by a laser beam. In this article, the ADM principle will be described and the main results will be presented. In particular, we will emphasize how the choice of an appropriate photodetector can significantly improve the telemeter performances by minimizing the amplitude to phase conversion. Our prototype, tested in the field, has proven its efficiency with a resolution better than 15 μm for a measurement time of 10 ms and distances up to 1.2 km.

  15. High resolution kilometric range optical telemetry in air by radio frequency phase measurement

    Science.gov (United States)

    Guillory, Joffray; Šmíd, Radek; García-Márquez, Jorge; Truong, Daniel; Alexandre, Christophe; Wallerand, Jean-Pierre

    2016-07-01

    We have developed an optical Absolute Distance Meter (ADM) based on the measurement of the phase accumulated by a Radio Frequency wave during its propagation in the air by a laser beam. In this article, the ADM principle will be described and the main results will be presented. In particular, we will emphasize how the choice of an appropriate photodetector can significantly improve the telemeter performances by minimizing the amplitude to phase conversion. Our prototype, tested in the field, has proven its efficiency with a resolution better than 15 μm for a measurement time of 10 ms and distances up to 1.2 km.

  16. A high-resolution, multi-parameter, β-γ coincidence, μ-γ anticoincidence system for radioxenon measurement

    Science.gov (United States)

    Schroettner, T.; Schraick, I.; Furch, T.; Kindl, P.

    2010-09-01

    A high-resolution β-γ coincidence measurement system has been developed by combining a high-purity broad energy germanium and a silicon surface barrier detector. The system is intended for calibration of reference spikes and re-measurement of CTBT samples, by detection of coincident β-γ or conversion electron and X-ray radiation of the four radioxenon isotopes 131mXe, 133mXe, 133Xe and 135Xe. The use of a high-resolution, list-mode, multi-parameter data acquisition system allows off-line setup and optimization of the (anti)coincidence. A 166mHo β-γ source has been produced and validated for energy calibration and system check. The β-γ coincidence has been further enhanced by a cosmic muon veto based on six plastic scintillation detectors. The μ-γ anticoincidence has been implemented using a 50 ns resolution real-time clock for time spectroscopy. This method has been verified by running conventional TAC-ADC (combined time-amplitude and analog-digital converter) based time spectroscopy in parallel. The whole measurement system has been characterized, by measuring various radioxenon spikes and backgrounds with and without (anti)coincidence. Peak efficiencies and minimum detectable activities (MDA) for the main radioxenon isotopes have been determined. Application of μ-γ anticoincidence reduced the MDA by about a factor of two for all four radioxenon isotopes. Complementary adoption of β-γ coincidence further reduced the MDA for the metastable isotopes by more than an order of magnitude. The MDA for 135Xe reaches about 6 mBq after 1 day of measurement. For 131mXe, 133Xe and 133mXe a MDA of about 2 mBq is obtained after one week measurement.

  17. A High-Resolution Antenna Diagnostics Technique for Spherical Nesr-Field Measurements

    DEFF Research Database (Denmark)

    Cappellin, Cecilia; Breinbjerg, Olav; Frandsen, Aksel

    2005-01-01

    A new diagnostics technique for spherical near-field antenna measurements, that can provide a high spatial resolution of the reconstructed aperture field, is presented. This technique is realized by transforming the spherical wave expansion (SWE) of the radiated field into the corresponding plane...

  18. High resolution pollutant measurements in complex urban environments using mobile monitoring

    Science.gov (United States)

    Measuring air pollution in real-time using an instrumented vehicle platform has been an emerging strategy to resolve air pollution trends at a very fine spatial scale (10s of meters). Achieving second-by-second data representative of urban air quality trends requires advanced in...

  19. Deconvolution of differential OTF (dOTF) to measure high-resolution wavefront structure

    Science.gov (United States)

    Knight, Justin M.; Rodack, Alexander T.; Codona, Johanan L.; Miller, Kelsey L.; Guyon, Olivier

    2015-09-01

    Differential OTF uses two images taken with a telescope pupil modification between them to measure the complex field over most of the pupil. If the pupil modification involves a non-negligible region of the pupil, the dOTF field is blurred by convolution with the complex conjugate of the pupil field change. In some cases, the convolution kernel, or difference field, can cause significant blurring. We explore using deconvolution to recover a highresolution measurement of the complex pupil field. In particular, by assuming we know something about the area and nature of the difference field, we can construct a Wiener filter that increases the resolution of the complex pupil field estimate in the presence of noise. By introducing a controllable pupil modification, such as actuating a telescope primary mirror segment in piston-tip-tilt to make the measurement, we explain added features to the difference field which can be used to increase the signal-to-noise ratio for information in arbitrary ranges of spatial frequency. We will present theory and numerical simulations to discuss key features of the difference field which lead to its utility for deconvolution of dOTF measurements.

  20. High-resolution Sonographic Measurements of Lower Extremity Bursae in Chinese Healthy Young Men

    Directory of Open Access Journals (Sweden)

    Yong-Yan Gao

    2016-01-01

    Conclusions: Using HR-US imaging, we were able to analyze lower extremity bursae with high detection rates in healthy young men. The normal ranges of lower extremity bursa dimensions in healthy young men measured by HR-US in this study could be used as reference values for evaluation of bursa abnormalities in the lower extremity.

  1. Open-path, quantum cascade laser-based sensor for high resolution atmospheric ammonia measurements

    Directory of Open Access Journals (Sweden)

    D. J. Miller

    2013-07-01

    Full Text Available We demonstrate a compact, open-path, quantum cascade laser-based atmospheric ammonia sensor operating at 9.06 μm for high sensitivity, high temporal resolution, ground-based measurements. Atmospheric ammonia (NH3 is a gas-phase precursor to fine particulate matter, with implications for air quality and climate change. Currently, NH3 sensing challenges have led to a lack of widespread in-situ measurements. Our open-path sensor configuration avoids sampling artifacts associated with NH3 surface adsorption onto inlet tubing and reduced pressure sampling cells, as well as condensed-phase partitioning ambiguities. Multi-harmonic wavelength modulation spectroscopy allows for selective and sensitive detection of atmospheric-pressure broadened absorption features. An in-line ethylene reference cell provides real-time calibration (±20% accuracy and normalization for instrument drift under rapidly changing field conditions. The sensor has a sensitivity and minimum detection limit of 0.15 ppbv NH3 at 10 Hz, a mass of ~ 5 kg and consumes ~ 50 W of electrical power. In-situ field performance of this open-path NH3 sensor is demonstrated, with 10 Hz time resolution and a large dynamic response for in-situ NH3 measurements. This sensor provides the capabilities for improved in-situ gas phase NH3 sensing relevant for emission source characterization and flux measurements.

  2. High resolution steady-state measurements of thermal contact resistance across thermal interface material junctions

    Science.gov (United States)

    Warzoha, Ronald J.; Donovan, Brian F.

    2017-09-01

    Thermal interface materials (TIMs) are meant to reduce the interfacial thermal resistance (RT) across bare metal contacts in commercial electronics packaging systems. However, there is little scientific consensus governing material design for optimized thermal performance. This is principally due to the inability to separate the effects of the intrinsic material thermal properties from the magnitude of heat flow crossing the TIM-substrate junction (RC). To date, efforts to isolate these effects using standard thermal interface material characterization techniques have not been successful. In this work, we develop an infrared thermography-based steady-state heat meter bar apparatus with a novel in situ thickness measurement system having 0.5 nm sensitivity. These in situ thickness measurements allow us to simultaneously determine RT and RC independently across current state-of-the-art TIMs with ±5% uncertainty. In this work, thermal pastes with bond line thicknesses ranging between 5 and 50 μ m are used to illustrate the capability of the apparatus to measure extremely thin materials that are expected to achieve relatively low values of RT. Results suggest that the contribution of the thermal contact resistance to the total thermal resistance can range from 5% to 80% for these materials. This finding highlights the need for appropriate metrology and independent measurements of RC and RT to better optimize thermal interface materials for a number of important electronics applications.

  3. High Resolution Flicker-Noise-Free Frequency Measurements of Weak Microwave Signals

    CERN Document Server

    Creedon, Daniel L; Ivanov, Eugene N; Hartnett, John G

    2011-01-01

    Amplification is usually necessary when measuring the frequency instability of microwave signals. In this work, we develop a flicker noise free frequency measurement system based on a common or shared amplifier. First, we show that correlated flicker phase noise can be cancelled in such a system. Then we compare the new system with the conventional by simultaneously measuring the beat frequency from two cryogenic sapphire oscillators with parts in 10^15 fractional frequency instability. We determine for low power, below -80 dBm, the measurements were not limited by correlated noise processes but by thermal noise of the readout amplifier. In this regime, we show that the new readout system performs as expected and at the same level as the standard system but with only half the number of amplifiers. We also show that, using a standard readout system, the next generation of cryogenic sapphire oscillators could be flicker phase noise limited when instability reaches parts in 10^16 or better

  4. High resolution isotope shifts and hyperfine structure measurements of tungsten by laser induced fluorescence spectroscopy

    CERN Document Server

    Lee, Jeongwon; Leanhardt, Aaron

    2012-01-01

    Isotope shifts and hyperfine structure of tungsten were studied in the near UV range. We have used laser induced fluorescence spectroscopy on a pulsed supersonic beam to probe the 5D0 -> 5F1 transition at 384.9 nm, 7S3 -> 7P4 transition at 400.9 nm, and 7S3 -> 7P3 transition at 407.4 nm. Three new magnetic hyperfine constants are reported for 7P3,7P4, and 5F1 states. The isotope shifts of the 384.9 nm transition are presented for the first time, and the isotope shifts of 400.9 nm and 407.4 nm transition are measured with an order of magnitude higher precision compared to the previous measurements. As a result, the nuclear parameters lambda and lambda_{rel} are extracted from the isotope shifts with an improved precision.

  5. Kerr effect measurements in the high temperature superconductor LBCO using high resolution Sagnac interferometry

    Science.gov (United States)

    Karapetyan, Hovnatan; Kapitulnik, Aharon; Hucker, Markus; Gu, Genda; Tranquada, John

    2012-02-01

    Polar Kerr effect in LBCO high-Tc superconductor system was measured at zero magnetic field with high precision using a cryogenic Sagnac fiber interferometer with zero-area. We observed non-zero Kerr rotations of order ˜10 μrad appearing in charge ordered phase of LBCO-1/8. In this talk we will review our work on La1.875Ba0.125CuO4. In particular, we observe an emergence of Kerr signal that appears at temperature ˜ 54K, which is near charge ordering phase transition in this system. The signal peaks to 10 μrad at temperatures 30K to 40K and drops to a saturated value of ˜5 μrad at 5K. In addition, we we will present magnetic field training data of the Kerr signal. Through birefringence measurement, we also observe the first order structural phase transition in this system at ˜55K.

  6. An improved continuous flow analysis system for high-resolution field measurements on ice cores.

    Science.gov (United States)

    Kaufmann, Patrik R; Federer, Urs; Hutterli, Manuel A; Bigler, Matthias; Schüpbach, Simon; Ruth, Urs; Schmitt, Jochen; Stocker, Thomas F

    2008-11-01

    Continuous flow analysis (CFA) is a well-established method to obtain information about impurity contents in ice cores as indicators of past changes in the climate system. A section of an ice core is continuously melted on a melter head supplying a sample water flow which is analyzed online. This provides high depth and time resolution of the ice core records and very efficient sample decontamination as only the inner part of the ice sample is analyzed. Here we present an improved CFA system which has been totally redesigned in view of a significantly enhanced overall efficiency and flexibility, signal quality, compactness, and ease of use. These are critical requirements especially for operations of CFA during field campaigns, e.g., in Antarctica or Greenland. Furthermore, a novel deviceto measure the total air content in the ice was developed. Subsequently, the air bubbles are now extracted continuously from the sample water flow for subsequent gas measurements.

  7. Higgs boson measurements in high resolution channels with CMS arXiv

    CERN Document Server

    Tao, Junquan

    The latest measurements of the Higgs boson properties in both the $\\mathrm{H}\\rightarrow\\gamma\\gamma$ decay channel and the $\\mathrm{H}\\rightarrow{\\rm Z}{\\rm Z}\\rightarrow4\\ell$ ($\\ell={\\rm e},\\mu$) decay channel using the proton-proton collision data corresponding to an integrated luminosity of 35.9 $\\mathrm{fb}^{-1}$ at $\\sqrt{s}=13$ $TeV$, including the signal strength relative to the standard model prediction, signal strength modifiers for different Higgs production modes, coupling modifiers to fermions and bosons, and effective coupling modifiers to photons and gluons, are presented. In addition, dedicated measurements of the Higgs boson's mass, width, total and differential fiducial cross sections have been summarized. All results are consistent, within their uncertainties, with the expectations for the SM Higgs boson.

  8. High-resolution, real-time simultaneous 3D surface geometry and temperature measurement.

    Science.gov (United States)

    An, Yatong; Zhang, Song

    2016-06-27

    This paper presents a method to simultaneously measure three-dimensional (3D) surface geometry and temperature in real time. Specifically, we developed 1) a holistic approach to calibrate both a structured light system and a thermal camera under exactly the same world coordinate system even though these two sensors do not share the same wavelength; and 2) a computational framework to determine the sub-pixel corresponding temperature for each 3D point as well as discard those occluded points. Since the thermal 2D imaging and 3D visible imaging systems do not share the same spectrum of light, they can perform sensing simultaneously in real time: we developed a hardware system that can achieve real-time 3D geometry and temperature measurement at 26 Hz with 768 × 960 points per frame.

  9. A High Resolution Capacitive Sensing System for the Measurement of Water Content in Crude Oil

    Directory of Open Access Journals (Sweden)

    Muhammad Zubair Aslam

    2014-06-01

    Full Text Available This paper presents the design of a non-intrusive system to measure ultra-low water content in crude oil. The system is based on a capacitance to phase angle conversion method. Water content is measured with a capacitance sensor comprising two semi-cylindrical electrodes mounted on the outer side of a glass tube. The presence of water induces a capacitance change that in turn converts into a phase angle, with respect to a main oscillator. A differential sensing technique is adopted not only to ensure high immunity against temperature variation and background noise, but also to eliminate phase jitter and amplitude variation of the main oscillator that could destabilize the output. The complete capacitive sensing system was implemented in hardware and experiment results using crude oil samples demonstrated that a resolution of ±50 ppm of water content in crude oil was achieved by the proposed design.

  10. Measuring high-resolution sky luminance distributions with a CCD camera.

    Science.gov (United States)

    Tohsing, Korntip; Schrempf, Michael; Riechelmann, Stefan; Schilke, Holger; Seckmeyer, Gunther

    2013-03-10

    We describe how sky luminance can be derived from a newly developed hemispherical sky imager (HSI) system. The system contains a commercial compact charge coupled device (CCD) camera equipped with a fish-eye lens. The projection of the camera system has been found to be nearly equidistant. The luminance from the high dynamic range images has been calculated and then validated with luminance data measured by a CCD array spectroradiometer. The deviation between both datasets is less than 10% for cloudless and completely overcast skies, and differs by no more than 20% for all sky conditions. The global illuminance derived from the HSI pictures deviates by less than 5% and 20% under cloudless and cloudy skies for solar zenith angles less than 80°, respectively. This system is therefore capable of measuring sky luminance with the high spatial and temporal resolution of more than a million pixels and every 20 s respectively.

  11. High-resolution measurements of face-to-face contact patterns in a primary school.

    Directory of Open Access Journals (Sweden)

    Juliette Stehlé

    Full Text Available BACKGROUND: Little quantitative information is available on the mixing patterns of children in school environments. Describing and understanding contacts between children at school would help quantify the transmission opportunities of respiratory infections and identify situations within schools where the risk of transmission is higher. We report on measurements carried out in a French school (6-12 years children, where we collected data on the time-resolved face-to-face proximity of children and teachers using a proximity-sensing infrastructure based on radio frequency identification devices. METHODS AND FINDINGS: Data on face-to-face interactions were collected on Thursday, October 1(st and Friday, October 2(nd 2009. We recorded 77,602 contact events between 242 individuals (232 children and 10 teachers. In this setting, each child has on average 323 contacts per day with 47 other children, leading to an average daily interaction time of 176 minutes. Most contacts are brief, but long contacts are also observed. Contacts occur mostly within each class, and each child spends on average three times more time in contact with classmates than with children of other classes. We describe the temporal evolution of the contact network and the trajectories followed by the children in the school, which constrain the contact patterns. We determine an exposure matrix aimed at informing mathematical models. This matrix exhibits a class and age structure which is very different from the homogeneous mixing hypothesis. CONCLUSIONS: We report on important properties of the contact patterns between school children that are relevant for modeling the propagation of diseases and for evaluating control measures. We discuss public health implications related to the management of schools in case of epidemics and pandemics. Our results can help define a prioritization of control measures based on preventive measures, case isolation, classes and school closures, that

  12. High-Resolution ac Measurements of the Hall Effect in Organic Field-Effect Transistors

    Science.gov (United States)

    Chen, Y.; Yi, H. T.; Podzorov, V.

    2016-03-01

    We describe a high resolving power technique for Hall-effect measurements, efficient in determining Hall mobility and carrier density in organic field-effect transistors and other low-mobility systems. We utilize a small low-frequency ac magnetic field (Brmsphase-sensitive (lock-in) detection of Hall voltage, with the necessary corrections for Faraday induction. This method significantly enhances the signal-to-noise ratio and eliminates the necessity of using high magnetic fields in Hall-effect studies. With the help of this method, we are able to obtain the Hall mobility and carrier density in organic transistors with a mobility as low as μ ˜0.3 cm2 V-1 s-1 by using a compact desktop apparatus and low magnetic fields. We find a good agreement between Hall-effect and electric-field-effect measurements, indicating that, contrary to the common belief, certain organic semiconductors with mobilities below 1 cm2 V-1 s-1 can still exhibit a fully developed, band-semiconductor-like Hall effect, with the Hall mobility and carrier density matching those obtained in longitudinal transistor measurements. This suggests that, even when μ organic semiconductors can still behave as delocalized coherent carriers. This technique paves the way to ubiquitous Hall-effect studies in a wide range of low-mobility materials and devices, where it is typically very difficult to resolve the Hall effect even in very high dc magnetic fields.

  13. Implementation of Ultrasonic Sensing for High Resolution Measurement of Binary Gas Mixture Fractions

    CERN Document Server

    Bates, Richard; Berry, Stephane; Bitadze, Alexander; Bonneau, Pierre; Bousson, Nicolas; Boyd, George; Bozza, Gennaro; Crespo-Lopez, Olivier; Da Riva, Enrico; Degeorge, Cyril; Deterre, Cecile; DiGirolamo, Beniamino; Doubek, Martin; Favre, Gilles; Godlewski, Jan; Hallewell, Gregory; Hasib, Ahmed; Katunin, Sergey; Langevin, Nicolas; Lombard, Didier; Mathieu, Michel; McMahon, Stephen; Nagai, Koichi; Pearson, Benjamin; Robinson, David; Rossi, Cecilia; Rozanov, Alexandre; Strauss, Michael; Vitek, Michal; Vacek, Vaclav; Zwalinski, Lukasz

    2014-01-01

    We describe an ultrasonic instrument for continuous real-time analysis of the fractional mixture of a binary gas system. The instrument is particularly well suited to measurement of leaks of a high molecular weight gas into a system that is nominally composed of a single gas. Sensitivity < 5 ×10−5 is demonstrated to leaks of octaflouropropane (C3F8) coolant into nitrogen during a long duration (18 month) continuous study. The sensitivity of the described measurement system is shown to depend on the difference in molecular masses of the two gases in the mixture. The impact of temperature and pressure variances on the accuracy of the measurement is analysed. Practical considerations for the implementation and deployment of long term, in situ ultrasonic leak detection systems are also described. Although development of the described systems was motivated by the requirements of an evaporative fluorocarbon cooling system, the instrument is applicable to the detection of leaks of many other gases and to proce...

  14. Implementation of Ultrasonic Sensing for High Resolution Measurement of Binary Gas Mixture Fractions

    Directory of Open Access Journals (Sweden)

    Richard Bates

    2014-06-01

    Full Text Available We describe an ultrasonic instrument for continuous real-time analysis of the fractional mixture of a binary gas system. The instrument is particularly well suited to measurement of leaks of a high molecular weight gas into a system that is nominally composed of a single gas. Sensitivity < 5 × 10−5 is demonstrated to leaks of octaflouropropane (C3F8 coolant into nitrogen during a long duration (18 month continuous study. The sensitivity of the described measurement system is shown to depend on the difference in molecular masses of the two gases in the mixture. The impact of temperature and pressure variances on the accuracy of the measurement is analysed. Practical considerations for the implementation and deployment of long term, in situ ultrasonic leak detection systems are also described. Although development of the described systems was motivated by the requirements of an evaporative fluorocarbon cooling system, the instrument is applicable to the detection of leaks of many other gases and to processes requiring continuous knowledge of particular binary gas mixture fractions.

  15. Interrogating biology with force: single molecule high-resolution measurements with optical tweezers.

    Science.gov (United States)

    Capitanio, Marco; Pavone, Francesco S

    2013-09-17

    Single molecule force spectroscopy methods, such as optical and magnetic tweezers and atomic force microscopy, have opened up the possibility to study biological processes regulated by force, dynamics of structural conformations of proteins and nucleic acids, and load-dependent kinetics of molecular interactions. Among the various tools available today, optical tweezers have recently seen great progress in terms of spatial resolution, which now allows the measurement of atomic-scale conformational changes, and temporal resolution, which has reached the limit of the microsecond-scale relaxation times of biological molecules bound to a force probe. Here, we review different strategies and experimental configurations recently developed to apply and measure force using optical tweezers. We present the latest progress that has pushed optical tweezers' spatial and temporal resolution down to today's values, discussing the experimental variables and constraints that are influencing measurement resolution and how these can be optimized depending on the biological molecule under study. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  16. SU-E-I-40: New Method for Measurement of Task-Specific, High-Resolution Detector System Performance

    Energy Technology Data Exchange (ETDEWEB)

    Loughran, B; Singh, V; Jain, A; Bednarek, D; Rudin, S [University at Buffalo, Buffalo, NY (United States)

    2014-06-01

    Purpose: Although generalized linear system analytic metrics such as GMTF and GDQE can evaluate performance of the whole imaging system including detector, scatter and focal-spot, a simplified task-specific measured metric may help to better compare detector systems. Methods: Low quantum-noise images of a neuro-vascular stent with a modified ANSI head phantom were obtained from the average of many exposures taken with the high-resolution Micro-Angiographic Fluoroscope (MAF) and with a Flat Panel Detector (FPD). The square of the Fourier Transform of each averaged image, equivalent to the measured product of the system GMTF and the object function in spatial-frequency space, was then divided by the normalized noise power spectra (NNPS) for each respective system to obtain a task-specific generalized signal-to-noise ratio. A generalized measured relative object detectability (GM-ROD) was obtained by taking the ratio of the integral of the resulting expressions for each detector system to give an overall metric that enables a realistic systems comparison for the given detection task. Results: The GM-ROD provides comparison of relative performance of detector systems from actual measurements of the object function as imaged by those detector systems. This metric includes noise correlations and spatial frequencies relevant to the specific object. Additionally, the integration bounds for the GM-ROD can be selected to emphasis the higher frequency band of each detector if high-resolution image details are to be evaluated. Examples of this new metric are discussed with a comparison of the MAF to the FPD for neuro-vascular interventional imaging. Conclusion: The GM-ROD is a new direct-measured task-specific metric that can provide clinically relevant comparison of the relative performance of imaging systems. Supported by NIH Grant: 2R01EB002873 and an equipment grant from Toshiba Medical Systems Corporation.

  17. Day and Night Variability of CO2 Fluxes and Priming Effects under zea Mays Measured in High Resolution

    Science.gov (United States)

    Splettstoesser, Thomas; Pausch, Johanna

    2017-04-01

    Plant induced increase of soil organic matter turnover rates contribute to carbon emissions in agricultural land use systems. In order to better understand these rhizosphere priming effects, we conducted an experiment which enabled us to monitor CO2 fluxes under Zea mays plants in high resolution. The experiment was conducted in a climate chamber where the plants were grown in tightly sealed boxes for 40 days and CO2 efflux from soil was measured twice a day. Continuous 13C-CO2 label was used to allow differentiation between plant- and soil-derived CO2.This enabled us to monitor root respiration and soil organic matter turnover in the early stages of plant growth and to highlight changes in soil CO2 emissions and priming effects between day and night. The measurements were conducted with a PICARRO G2131-I C high-precision isotopic CO2 Analyzer (PICARRO INC.) utilizing an automated valve system governed by a CR1000 data logger (Campbell Scientific). After harvest roots and shoots were analyzed for 13C content. Microbial biomass, root length density and enzymatic activities in soil were measured and linked to soil organic matter turnover rates. Results show an increased soil CO2 efflux at day time periods and an overall increase with increasing plant biomass. No difference in chloroform fumigation extractable microbial biomass has been found but a strong negative priming effect was measured in the short experimental period, suggesting that the microbes shifted to the utilization of plant exudates without actual microbial growth triggered by the new labile C input. This is coherent with the observed shift in enzyme kinetics. With this experimental setup we show that measurement of priming effects in high resolution can be achieved.

  18. Measurement of Surface Displacement and Deformation of Mass Movements Using Least Squares Matching of Repeat High Resolution Satellite and Aerial Images

    Directory of Open Access Journals (Sweden)

    Misganu Debella-Gilo

    2012-01-01

    Full Text Available Displacement and deformation are fundamental measures of Earth surface mass movements such as glacier flow, rockglacier creep and rockslides. Ground-based methods of monitoring such mass movements can be costly, time consuming and limited in spatial and temporal coverage. Remote sensing techniques, here matching of repeat optical images, are increasingly used to obtain displacement and deformation fields. Strain rates are usually computed in a post-processing step based on the gradients of the measured velocity field. This study explores the potential of automatically and directly computing velocity, rotation and strain rates on Earth surface mass movements simultaneously from the matching positions and the parameters of the geometric transformation models using the least squares matching (LSM approach. The procedures are exemplified using bi-temporal high resolution satellite and aerial images of glacier flow, rockglacier creep and land sliding. The results show that LSM matches the images and computes longitudinal strain rates, transverse strain rates and shear strain rates reliably with mean absolute deviations in the order of 10−4 (one level of significance below the measured values as evaluated on stable grounds. The LSM also improves the accuracy of displacement estimation of the pixel-precision normalized cross-correlation by over 90% under ideal (simulated circumstances and by about 25% for real multi-temporal images of mass movements.

  19. Mid-Infrared OPO for High Resolution Measurements of Trace Gases in the Mars Atmosphere

    Science.gov (United States)

    Yu, Anthony W.; Numata,Kenji; Riris, haris; Abshire, James B.; Allan, Graham; Sun, Xiaoli; Krainak, Michael A.

    2008-01-01

    The Martian atmosphere is composed primarily (>95%) of CO2 and N2 gas, with CO, O2, CH4, and inert gases such as argon comprising most of the remainder. It is surprisingly dynamic with various processes driving changes in the distribution of CO2, dust, haze, clouds and water vapor on global scales in the meteorology of Mars atmosphere [I]. The trace gases and isotopic ratios in the atmosphere offer important but subtle clues as to the origins of the planet's atmosphere, hydrology, geology, and potential for biology. In the search for life on Mars, an important process is the ability of bacteria to metabolize inorganic substrates (H2, CO2 and rock) to derive energy and produce methane as a by-product of anaerobic metabolism. Trace gases have been measured in the Mars atmosphere from Earth, Mars orbit, and from the Mars surface. The concentration of water vapor and various carbon-based trace gases are observed in variable concentrations. Within the past decade multiple groups have reported detection of CH4, with concentrations in the 10's of ppb, using spectroscopic observations from Earth [2]. Passive spectrometers in the mid-infrared (MIR) are restricted to the sunlit side of the planet, generally in the mid latitudes, and have limited spectral and spatial resolution. To accurately map the global distribution and to locate areas of possibly higher concentrations of these gases such as plumes or vents requires an instrument with high sensitivity and fine spatial resolution that also has global coverage and can measure during both day and night. Our development goal is a new MIR lidar capable of measuring, on global scales, with sensitivity, resolution and precision needed to characterize the trace gases and isotopic ratios of the Martian atmosphere. An optical parametric oscillator operating in the MIR is well suited for this instrument. The sufficient wavelength tuning range of the OPO can extend the measurements to other organic molecules, CO2, atmospheric water

  20. High resolution hydrological modeling with measured precipitation data for the city of Amsterdam

    Science.gov (United States)

    van Vossen, Jojanneke; Schuurmans, Hanneke; Siemerink, Martijn; van Leeuwen, Elgard; Oudhuis, Richard

    2014-05-01

    Assessing measures to reduce flooding in densely populated urban areas require a high level of detail to properly analyse the hydrological response to precipitation events. This means detailed data (for example elevation and landuse) and fast models that can cope with this level of detail. This also indicates the value of having a similar level of detail in precipitation data. We present an approach in which Dutch National Rainfall Radar data are combined with a new approach to hydrological modeling called 3di. This is illustrated for a case in the city of Amsterdam to assess the effects of precipitation events and the possibilities for suitable measures in the public space to reduce the effects of flooding. Dutch National Rainfall Radar is a consortium of water authorities and the industry and scientific experts/universities/research centers to improve the available radar data in the Netherlands. This is achieved by making a composite of the radar stations in The Netherlands together with German and Belgian radar stations. In addition, the composite image is calibrated with local rainfall stations. 3Di is a novel approach to calculate the hydrological response of catchments as a function of properties, such as surface elevation and land use. Because of the ability of the model to take the detail of the elevation and land-use (both 0,5x0m5 meter) into the calculations, this model allows for a very detailed modeling of the hydrological response of urban areas to precipitation events. In addition, the model is extremely fast and allows for real-time and interactive changes in the geometry, making it a very powerful tool to assess the effects of measures in the public space for reducing flooding. We illustrate this approach for a case for the city of Amsterdam, a densely populated, low-lying city in The Netherlands. The obtained level of detail allows to study which houses are flooded, which roads remain available for emergency services etc. The model is used to show

  1. High resolution measurement of DUF1220 domain copy number from whole genome sequence data.

    Science.gov (United States)

    Astling, David P; Heft, Ilea E; Jones, Kenneth L; Sikela, James M

    2017-08-14

    DUF1220 protein domains found primarily in Neuroblastoma BreakPoint Family (NBPF) genes show the greatest human lineage-specific increase in copy number of any coding region in the genome. There are 302 haploid copies of DUF1220 in hg38 (~160 of which are human-specific) and the majority of these can be divided into 6 different subtypes (referred to as clades). Copy number changes of specific DUF1220 clades have been associated in a dose-dependent manner with brain size variation (both evolutionarily and within the human population), cognitive aptitude, autism severity, and schizophrenia severity. However, no published methods can directly measure copies of DUF1220 with high accuracy and no method can distinguish between domains within a clade. Here we describe a novel method for measuring copies of DUF1220 domains and the NBPF genes in which they are found from whole genome sequence data. We have characterized the effect that various sequencing and alignment parameters and strategies have on the accuracy and precision of the method and defined the parameters that lead to optimal DUF1220 copy number measurement and resolution. We show that copy number estimates obtained using our read depth approach are highly correlated with those generated by ddPCR for three representative DUF1220 clades. By simulation, we demonstrate that our method provides sufficient resolution to analyze DUF1220 copy number variation at three levels: (1) DUF1220 clade copy number within individual genes and groups of genes (gene-specific clade groups) (2) genome wide DUF1220 clade copies and (3) gene copy number for DUF1220-encoding genes. To our knowledge, this is the first method to accurately measure copies of all six DUF1220 clades and the first method to provide gene specific resolution of these clades. This allows one to discriminate among the ~300 haploid human DUF1220 copies to an extent not possible with any other method. The result is a greatly enhanced capability to analyze the

  2. Thickness measurement of GaN epilayer using high resolution X-ray diffraction technique

    Institute of Scientific and Technical Information of China (English)

    冯淦; 朱建军; 沈晓明; 张宝顺; 赵德刚; 王玉田; 杨辉; 梁骏吾

    2003-01-01

    In this paper we propose a new method for measuring the thickness of the GaN epilayer, by using the ratio of the integrated intensity of the GaN epilayer X-ray diffraction peaks to that of the sapphire substrate ones. This ratio shows a linear dependence on the GaN epilayer thickness up to 2 μm. The new method is more accurate and convenient than those of using the relationship between the integrated intensity of GaN epilayer diffraction peaks and the GaN thickness. Besides, it can eliminate the absorption effect of the GaN epilayer.

  3. Characterization of Fault Roughness at Various Scales: Implications of Three-Dimensional High Resolution Topography Measurements

    CERN Document Server

    Candela, Thibault; Bouchon, Michel; Marsan, David; Schmittbuhl, Jean; Voisin, Christophe

    2008-01-01

    Accurate description of the topography of active faults surfaces represents an important geophysical issue because this topography is strongly related to the stress distribution along fault planes, and therefore to processes implicated in earthquake nucleation, propagation, and arrest. With the recent development of Light Detection And Ranging (LIDAR) apparatus, it is now possible to measure accurately the 3D topography of rough surfaces with a comparable resolution in all directions, both at field and laboratory scales. In the present study, we have investigated the scaling properties including possible anisotropy properties of several outcrops of two natural fault surfaces (Vuache strike-slip fault, France, and Magnola normal fault, Italy) in limestones.

  4. High resolution measurements of dune movement in a scale model of the River Oder

    Science.gov (United States)

    Hüsener, Thorsten; Henning, Martin

    2010-05-01

    The paper presents the analysis of three dimensional river bed topographies of high spatial and temporal resolution, obtained from scale model experiments with movable bed. The use of a stereo photogrammetric system allowed for measuring the submerged river bed during the laboratory experiments. The system is based on three synchronized cameras and a bar code system for orientation and can be used in both dry and wet conditions. For bed surface elevation measurements, a grid is projected onto the channel bed, defining the bed surface via slide projection. When applied to subaqueous problems, the system provides reliable data and insight in the distribution and migration of bed forms and the impact of steady and unsteady discharges on bed topography. The presented data has been obtained from a hydraulic scale model with moveable bed, concerning an 8km long reach of the River Oder at the German-Polish border. The model has been set up in order to investigate the influence of river training measures on accessible water depths and on the development of river bed forms. To determine the movement of the dunes, a 3 x 3 m² area of the model, representing 90,000 m² in field scale, has been recorded over a time of 11 h, providing 4000 topographic data sets of about 10,000 data points each. To simulate nature like transport conditions, the natural bedload material was substituted by synthetic granules (polystyrene) with lesser density and coarser diameter. Due to the small density of polystyrene the dune migration was considerably faster than it would have been for the use of sand as bed load material. In theory, flow is often assumed to be steady and uniform. However, during sediment transport, bed topography changes continuously. The presented analysis of the data shows the wide spatial and temporal variety of occurring dunes and the correlation between dune dimen-sions and dune migration speed. Possible future analysis of the three-dimensional data will be discussed and

  5. Velocity Correction and Measurement Uncertainty Analysis of Light Screen Velocity Measuring Method

    Institute of Scientific and Technical Information of China (English)

    ZHENG Bin; ZUO Zhao-lu; HOU Wen

    2012-01-01

    Light screen velocity measuring method with unique advantages has been widely used in the velocity measurement of various moving bodies.For large air resistance and friction force which the big moving bodies are subjected to during the light screen velocity measuring,the principle of velocity correction was proposed and a velocity correction equation was derived.A light screen velocity measuring method was used to measure the velocity of big moving bodies which have complex velocity attenuation,and the better results were gained in practical tests.The measuring uncertainty after the velocity correction was calculated.

  6. High-resolution temperature sensor through measuring the frequency shift of single-frequency Erbium-doped fiber ring laser

    Science.gov (United States)

    Zhang, Haiwei; Shi, Wei; Duan, Liangcheng; Fu, Shijie; Sheng, Quan; Yao, Jianquan

    2017-02-01

    We propose a principle to achieve a high-resolution temperature sensor through measuring the central frequency shift in the single-frequency Erbium-doped fiber ring laser induced by the thermal drift via the optical heterodyne spectroscopy method. We achieve a temperature sensor with a sensitivity about 9.7 pm/°C and verify the detection accuracy through an experiment. Due to the narrow linewidth of the output singlefrequency signal and the high accuracy of the optical heterodyne spectroscopy method in measuring the frequency shift in the single-frequency ring laser, the temperature sensor can be employed to resolve a temperature drift up to 5.5×10-6 °C theoretically when the single-frequency ring laser has a linewidth of 1 kHz and 10-kHz frequency shift is achieved from the heterodyne spectra.

  7. Accurate correction of magnetic field instabilities for high-resolution isochronous mass measurements in storage rings

    CERN Document Server

    Shuai, P; Zhang, Y H; Litvinov, Yu A; Wang, M; Tu, X L; Blaum, K; Zhou, X H; Yuan, Y J; Audi, G; Yan, X L; Chen, X C; Xu, X; Zhang, W; Sun, B H; Yamaguchi, T; Chen, R J; Fu, C Y; Ge, Z; Huang, W J; Liu, D W; Xing, Y M; Zeng, Q

    2014-01-01

    Isochronous mass spectrometry (IMS) in storage rings is a successful technique for accurate mass measurements of short-lived nuclides with relative precision of about $10^{-5}-10^{-7}$. Instabilities of the magnetic fields in storage rings are one of the major contributions limiting the achievable mass resolving power, which is directly related to the precision of the obtained mass values. A new data analysis method is proposed allowing one to minimise the effect of such instabilities. The masses of the previously measured at the CSRe $^{41}$Ti, $^{43}$V, $^{47}$Mn, $^{49}$Fe, $^{53}$Ni and $^{55}$Cu nuclides were re-determined with this method. An improvement of the mass precision by a factor of $\\sim 1.7$ has been achieved for $^{41}$Ti and $^{43}$V. The method can be applied to any isochronous mass experiment irrespective of the accelerator facility. Furthermore, the method can be used as an on-line tool for checking the isochronous conditions of the storage ring.

  8. High-resolution nonlinear ellipse rotation measurements for 3D microscopy

    Science.gov (United States)

    Miguez, M. L.; Barbano, E. C.; Coura, J. A.; Zilio, S. C.; Misoguti, L.

    2015-03-01

    Nonlinear optical effects have been widely explored for microscopy due to the possibility of three-dimension (3D) image acquisition. Harmonic generation and nonlinear absorption, for instance, were used for this purpose. Each nonlinear effect has its own characteristic, complexity, type of contrast, advantage and disadvantage, etc. Recently, we developed a new simple and sensitive method for measuring nonlinear ellipse rotation (NER) using a dual-phase lock-in amplifier, which could be successfully applied for measuring local nonlinearity distribution on a sample and, consequently, the image acquisition. The NER is a particular refractive nonlinear effect which appears when strong elliptical polarized laser beam propagates along one nonlinear material. It is type of refractive Kerr nonlinearity similar to self-focalization responsible for the signal in the Z-scan technique. The self-focalization is one of the most important refractive effects, but it cannot be used for image acquisition. On the other hand, NER does. Furthermore, such refractive nonlinearities signal can be very strong and serves as a new contrast for nonlinear microscopy.

  9. Real-time high-resolution heterodyne-based measurements of spectral dynamics in fibre lasers

    Science.gov (United States)

    Sugavanam, Srikanth; Fabbri, Simon; Le, Son Thai; Lobach, Ivan; Kablukov, Sergey; Khorev, Serge; Churkin, Dmitry

    2016-03-01

    Conventional tools for measurement of laser spectra (e.g. optical spectrum analysers) capture data averaged over a considerable time period. However, the generation spectrum of many laser types may involve spectral dynamics whose relatively fast time scale is determined by their cavity round trip period, calling for instrumentation featuring both high temporal and spectral resolution. Such real-time spectral characterisation becomes particularly challenging if the laser pulses are long, or they have continuous or quasi-continuous wave radiation components. Here we combine optical heterodyning with a technique of spatio-temporal intensity measurements that allows the characterisation of such complex sources. Fast, round-trip-resolved spectral dynamics of cavity-based systems in real-time are obtained, with temporal resolution of one cavity round trip and frequency resolution defined by its inverse (85 ns and 24 MHz respectively are demonstrated). We also show how under certain conditions for quasi-continuous wave sources, the spectral resolution could be further increased by a factor of 100 by direct extraction of phase information from the heterodyned dynamics or by using double time scales within the spectrogram approach.

  10. Development of measurement apparatus for high resolution electrical surveys; Komitsudo denki tansa sokuteiki no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Moriuchi, H.; Matsuda, Y.; Shiokawa, Y. [Sumiko Consultants Co. Ltd., Tokyo (Japan); Uchino, Y. [Cosmic Co. Ltd., Tokyo (Japan)

    1996-05-01

    For the enforcement of the {rho}a-{rho}u survey method which is a type of high-density electrical survey, a multichannel resistivity measuring instrument has been developed. This instrument, in addition to the above, conducts resistivity tomography and various other kinds of high-density electrical survey. A potential produced by a low frequency rectangular current of 1Hz or lower outputted by the transmitter of this instrument is received and measured by the receiver connected to electrodes positioned at 100 or less locations. The receiver comprises a scanner that automatically switches from electrode to electrode, conditioner that processes signals, and controller. A transmitter of the standard design outputs a maximum voltage of 800V and maximum current of 2A, making a device suitable for probing 50 to several 100m-deep levels. The receiver is operated by a personal computer that the controller is provided with. The newly-developed apparatus succeeded in presenting high-precision images of the result of a {rho}a-{rho}u analysis for an apparent resistivity section and of the underground structure, verifying the high quality of the data collected by this apparatus. 10 refs., 5 figs., 1 tab.

  11. High-resolution Tangential AXUV Arrays for Radiated Power Density Measurements on NSTX-U

    Energy Technology Data Exchange (ETDEWEB)

    Delgado-Aparicio, L [PPPL; Bell, R E [PPPL; Faust, I [MIT; Tritz, K [The Johns Hopkins University, Baltimore, MD, 21209, USA; Diallo, A [PPPL; Gerhardt, S P [PPPL; Kozub, T A [PPPL; LeBlanc, B P [PPPL; Stratton, B C [PPPL

    2014-07-01

    Precise measurements of the local radiated power density and total radiated power are a matter of the uttermost importance for understanding the onset of impurity-induced instabilities and the study of particle and heat transport. Accounting of power balance is also needed for the understanding the physics of various divertor con gurations for present and future high-power fusion devices. Poloidal asymmetries in the impurity density can result from high Mach numbers and can impact the assessment of their flux-surface-average and hence vary the estimates of P[sub]rad (r, t) and (Z[sub]eff); the latter is used in the calculation of the neoclassical conductivity and the interpretation of non-inductive and inductive current fractions. To this end, the bolometric diagnostic in NSTX-U will be upgraded, enhancing the midplane coverage and radial resolution with two tangential views, and adding a new set of poloidally-viewing arrays to measure the 2D radiation distribution. These systems are designed to contribute to the near- and long-term highest priority research goals for NSTX-U which will integrate non-inductive operation at reduced collisionality, with high-pressure, long energy-confinement-times and a divertor solution with metal walls.

  12. First measurements with new high-resolution gadolinium-GEM neutron detectors

    Science.gov (United States)

    Pfeiffer, D.; Resnati, F.; Birch, J.; Etxegarai, M.; Hall-Wilton, R.; Höglund, C.; Hultman, L.; Llamas-Jansa, I.; Oliveri, E.; Oksanen, E.; Robinson, L.; Ropelewski, L.; Schmidt, S.; Streli, C.; Thuiner, P.

    2016-05-01

    European Spallation Source instruments like the macromolecular diffractometer (NMX) require an excellent neutron detection efficiency, high-rate capabilities, time resolution, and an unprecedented spatial resolution in the order of a few hundred micrometers over a wide angular range of the incoming neutrons. For these instruments solid converters in combination with Micro Pattern Gaseous Detectors (MPGDs) are a promising option. A GEM detector with gadolinium converter was tested on a cold neutron beam at the IFE research reactor in Norway. The μTPC analysis, proven to improve the spatial resolution in the case of 10B converters, is extended to gadolinium based detectors. For the first time, a Gd-GEM was successfully operated to detect neutrons with a measured efficiency of 11.8% at a wavelength of 2 Åand a position resolution better than 250 μm.

  13. Functional exploratory data analysis for high-resolution measurements of urban particulate matter.

    Science.gov (United States)

    Ranalli, M Giovanna; Rocco, Giorgia; Jona Lasinio, Giovanna; Moroni, Beatrice; Castellini, Silvia; Crocchianti, Stefano; Cappelletti, David

    2016-09-01

    In this work we propose the use of functional data analysis (FDA) to deal with a very large dataset of atmospheric aerosol size distribution resolved in both space and time. Data come from a mobile measurement platform in the town of Perugia (Central Italy). An OPC (Optical Particle Counter) is integrated on a cabin of the Minimetrò, an urban transportation system, that moves along a monorail on a line transect of the town. The OPC takes a sample of air every six seconds and counts the number of particles of urban aerosols with a diameter between 0.28 μm and 10 μm and classifies such particles into 21 size bins according to their diameter. Here, we adopt a 2D functional data representation for each of the 21 spatiotemporal series. In fact, space is unidimensional since it is measured as the distance on the monorail from the base station of the Minimetrò. FDA allows for a reduction of the dimensionality of each dataset and accounts for the high space-time resolution of the data. Functional cluster analysis is then performed to search for similarities among the 21 size channels in terms of their spatiotemporal pattern. Results provide a good classification of the 21 size bins into a relatively small number of groups (between three and four) according to the season of the year. Groups including coarser particles have more similar patterns, while those including finer particles show a more different behavior according to the period of the year. Such features are consistent with the physics of atmospheric aerosol and the highlighted patterns provide a very useful ground for prospective model-based studies.

  14. Membrane-based nanocalorimeter for high-resolution measurements of low-temperature specific heat

    CERN Document Server

    Tagliati, S; Rydh, A

    2012-01-01

    A differential, membrane-based nanocalorimeter for general specific heat studies of very small samples, ranging from 0.5 mg to sub-{\\mu}g in mass, is described. The calorimeter operates over the temperature range from above room temperature down to 0.5 K. It consists of a pair of cells, each of which is a stack of heaters and thermometer in the center of a silicon nitride membrane, in total giving a background heat capacity less than 100 nJ/K at 300 K, decreasing to 10 pJ/K at 1K. The device has several distinctive features: i) The resistive thermometer, made of a Ge_{1-x}Au_{x} alloy, displays a high dimensionless sensitivity |dlnR/dlnT | \\geq 1 over the entire temperature range. ii) The sample is placed in direct contact with the thermometer, which is allowed to self-heat. The thermometer can thus be operated at high dc current to increase the resolution. iii) Data are acquired with a set of eight synchronized lock-in amplifiers measuring dc, 1st and 2nd harmonic signals of heaters and thermometer. This giv...

  15. High-resolution measurement of the {sup 16}O({gamma},pn) reaction

    Energy Technology Data Exchange (ETDEWEB)

    Isaksson, L.

    1996-10-01

    The {sup 16}O({gamma},pn) reaction has been measured with a resolution high enough to resolve individual low-lying states in the residual {sup 14}N nucleus. Partial cross-sections, available to the acceptance of the detector system, have been extracted for the individual states, and compared to a recent calculation based on absorption on one-pion exchange currents and the {Delta} resonance current. The experiment was performed at the Maxlab accelerator laboratory in Lund, Sweden, using tagged photons at an energy of 67 - 76 MeV. The proton detector angular range was 60 - 100 deg and the corresponding for the neutron detector 81 - 103 deg. A missing energy resolution of 1.5 MeV was obtained. The relative population of the states in the residual {sup 14}N nucleus indicates that the reaction takes place predominantly on proton-neutron pairs coupled to (J{sup {pi}},T) = (1{sup +},0). The cross-section for absorption on (0{sup +},1) pairs is strongly suppressed. Furthermore, the relative population of the states indicates that both L=0 and L=2 pairs participate in the reaction. 45 refs.

  16. High-resolution measurements from the airborne Atmospheric Nitrogen Dioxide Imager (ANDI

    Directory of Open Access Journals (Sweden)

    J. P. Lawrence

    2015-06-01

    Full Text Available Nitrogen Dioxide is both a primary pollutant with direct health effects and a key precursor of the secondary pollutant ozone. This paper reports on the development, characterisation and test flight of the Atmospheric Nitrogen Dioxide Imager (ANDI remote sensing system. The ANDI system includes an imaging (UV-vis grating spectrometer able to capture scattered sunlight spectra for the determination of tropospheric nitrogen dioxide (NO2 concentrations by way of DOAS slant column density and vertical column density measurements. Results are shown for an ANDI test flight over Leicester City in the UK. Retrieved NO2 columns at a surface resolution of 80 m x 20 m revealed hot spots in a series of locations around Leicester City, including road junctions, the train station, major car parks, areas of heavy industry, a nearby airport (East Midlands and a power station (Ratcliffe-on-Soar. In the city centre the dominant source of NO2 emissions was identified as road traffic, contributing to a background concentration as well as producing localised hot spots. Quantitative analysis revealed a significant urban increment over the city centre which increased throughout the flight.

  17. Case study of wave breaking with high-resolution turbulence measurements with LITOS and WRF simulations

    Science.gov (United States)

    Schneider, Andreas; Söder, Jens; Gerding, Michael; Wagner, Johannes; Lübken, Franz-Josef

    2016-04-01

    Gravity waves in their final stage produce turbulence and dissipation. In the stratosphere only few studies of this phenomenon exist because the observation is technically challenging. In order to precisely infer energy dissipation rates, the viscous subrange has to be covered, which in the stratosphere lies at scales of centimetres and below. With our balloon-borne instrument LITOS (Leibniz-Institute Turbulence Observations in the Stratosphere), which has a vertical resolution below 1 mm, measurements were performed from Kiruna (68°N, 21°E) as well as from Kühlungsborn (54°N, 12°E). To characterise the atmospheric background conditions, WRF simulations driven by ECMWF reanalysis data were performed for the times of the flights. Averaged dissipation rates observed by LITOS are connected to wave signatures seen in the model. Particularly, larger dissipation rates correlate to larger amplitudes seen in the horizontal divergence or vertical winds in the model and vice versa. For one flight, a very pronounced maximum in dissipation is observed below the tropopause. It is connected to a wind reversal and dynamic instability. In the corresponding WRF simulation, turbulent kinetic energies (TKE) and amplitudes in horizontal divergence are enhanced in this region. For the other flights, no such pronounced maximum in dissipation but also no enhanced values of TKE outside of the boundary layer are observed. That means that low and moderate turbulence is not resolved in WRF, but is observed by LITOS throughout all altitudes.

  18. Hybrid Young interferometer for high resolution measurement of dynamic speckle using high birefringence liquid crystal

    Science.gov (United States)

    Bennis, N.; Holdynski, Z.; Merta, I.; Marc, P.; Kula, P.; Mazur, R.; Piecek, W.; Jaroszewicz, L. R.

    2015-08-01

    It is well known that the Young interference experiment is the fundamental setup to combine two beams and to construct the phase modulated light. Moreover, homodyne phase demodulator is based on signal decoding in back Fourier focal plane using bicell photodetector (B-PD). On the above base, we propose a novel experimental approach to the signals demodulation by using the optical interferometer which operates in homodyne mode, combined with liquid crystal spatial light modulators operating both phase as speckle modulator. Dynamic phase changes between the two beams can be controlled by monopixel liquid crystals cell placed in one branch of the interferometer. A phase modulation effect in a signal arm of interferometer is observed as a dynamic shift of the speckle pattern. Simple arithmetic combination of signals from B-PD placed in speckle pattern plane is only one necessary numerical manipulation to obtain exactly phase difference. Concept of signals demodulation in the Fourier focal plane can be only used for exactly defined geometrical (B-PD as well as Young interferometer) and physical parameters (polarization, wavelength). We optimize the setup geometry to obtain extremely high measurement resolution. In this paper we focus on the principles of operation of each part of the system as well as discussion their requirement in order to increase the signal to noise ratio.

  19. High-resolution measurements of face-to-face contact patterns in a primary school

    CERN Document Server

    Stehlé, J; Barrat, A; Cattuto, C; Isella, L; Pinton, J -F; Quaggiotto, M; Broeck, W Van den; Régis, C; Lina, B; Vanhems, P; 10.1371/journal.pone.0023176

    2011-01-01

    Little quantitative information is available on the mixing patterns of children in school environments. Describing and understanding contacts between children at school would help quantify the transmission opportunities of respiratory infections and identify situations within schools where the risk of transmission is higher. We report on measurements carried out in a French school (6-12 years children), where we collected data on the time-resolved face-to-face proximity of children and teachers using a proximity-sensing infrastructure based on radio frequency identification devices. Data on face-to-face interactions were collected on October 1st and 2nd, 2009. We recorded 77,602 contact events between 242 individuals. Each child has on average 323 contacts per day with 47 other children, leading to an average daily interaction time of 176 minutes. Most contacts are brief, but long contacts are also observed. Contacts occur mostly within each class, and each child spends on average three times more time in con...

  20. HIGH-RESOLUTION RADIO CONTINUUM MEASUREMENTS OF THE NUCLEAR DISKS OF Arp 220

    Energy Technology Data Exchange (ETDEWEB)

    Barcos-Muñoz, L.; Evans, A. S.; Privon, G. C.; Stierwalt, S. [Department of Astronomy, University of Virginia, 530 McCormick Road, Charlottesville, VA 22904 (United States); Leroy, A. K.; Condon, J.; Reichardt, A. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22904 (United States); Armus, L. [Spitzer Science Center, California Institute of Technology, MC 220-6, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Mazzarella, J. M.; Murphy, E. J. [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, Pasadena, CA 91125 (United States); Meier, D. S. [New Mexico Institute of Mining and Technology, 801 Leroy Place, Socorro, NM 87801 (United States); Momjian, E.; Ott, J. [National Radio Astronomy Observatory, P.O. Box O, 1003 Lopezville Road, Socorro, NM 87801 (United States); Sakamoto, K. [Academia Sinica, Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 10617, Taiwan (China); Sanders, D. B. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96816 (United States); Schinnerer, E.; Walter, F. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Surace, J. A. [Spitzer Science Center, MS 314-6, California Institute of Technology, Pasadena, CA 91125 (United States); Thompson, T. A., E-mail: ldb7et@virginia.edu [Department of Astronomy and Center for Cosmology and Astro-Particle Physics, The Ohio State University, Columbus, OH 43210 (United States)

    2015-01-20

    {sub ☉} yr{sup –1}kpc{sup –2}. These values, especially for the western nucleus are, to our knowledge, the highest luminosity surface densities and star formation rate surface densities measured for any star-forming system. Despite these high values, the nuclei appear to lie below the dusty Eddington limit in which radiation pressure is balanced only by self-gravity. The small measured sizes also imply that at wavelengths shorter than λ = 1 mm, dust absorption effects must play an important role in the observed light distribution while below 5 GHz free-free absorption contributes substantial opacity. According to these calculations, the nuclei of Arp 220 are only transparent in the frequency range ∼5-350 GHz. Our results offer no clear evidence that an active galactic nucleus dominates the emission from either nucleus at 33 GHz.

  1. Merging Field Measurements and High Resolution Modeling to Predict Possible Societal Impacts of Permafrost Degradation

    Science.gov (United States)

    Romanovsky, V. E.; Nicolsky, D.; Marchenko, S. S.; Cable, W.; Panda, S. K.

    2015-12-01

    A general warming trend in permafrost temperatures has triggered permafrost degradation in Alaska, especially at locations influenced by human activities. Various phenomena related to permafrost degradation are already commonly observed, including increased rates of coastal and riverbank erosion, increased occurrences of retrogressive thaw slumps and active layer detachment slides, and the disappearance of tundra lakes. The combination of thawing permafrost and erosion is damaging local community infrastructure such as buildings, roads, airports, pipelines, water and sanitation facilities, and communication systems. The potential scale of direct ecological and economical damage due to degrading permafrost has just begun to be recognized. While the projected changes in permafrost are generally available on global and regional scales, these projections cannot be effectively employed to estimate the societal impacts because of their coarse resolution. Intrinsic problems with the classical "spatial grid" approach in spatially distributed modeling applications preclude the use of this modeling approach to solve the above stated problem. Two types of models can be used to study permafrost dynamics in this case. One approach is a site-specific application of the GIPL2.0 permafrost model and another is a very high (tens to hundred meter) resolution spatially distributed version of the same model. The results of properly organized field measurements are also needed to calibrate and validate these models for specific locations and areas of interest. We are currently developing a "landscape unit" approach that allows practically unlimited spatial resolution of the modeling products. Classification of the study area into particular "landscape units" should be performed in accordance with the main factors controlling the expression of climate on permafrost in the study area, typically things such as vegetation, hydrology, soil properties, topography, etc. In areas with little

  2. Velocity Measurement Based on Laser Doppler Effect

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan-Yan; HUO Yu-Jing; HE Shu-Fang; GONG Ke

    2010-01-01

    @@ A novel method for velocity measurement is presented.In this scheme,a parallel-linear-polarization dualfrequency laser is incident on the target and senses the target velocity with both the frequencies,which can increase the maximum measurable velocity significantly.The theoretical analysis and verification experiment of the novel method are presented,which show that high-velocity measurement can be achieved with high precision using this method.

  3. A scanning, all-fiber Sagnac interferometer for high resolution magneto-optic measurements at 820 nm

    Energy Technology Data Exchange (ETDEWEB)

    Fried, Alexander [Department of Physics, Stanford University, Stanford, California 94305 (United States); Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States); Fejer, Martin [Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Ginzton Laboratory, Stanford University, Stanford, California 94305 (United States); Kapitulnik, Aharon [Department of Physics, Stanford University, Stanford, California 94305 (United States); Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305 (United States); Department of Applied Physics, Stanford University, Stanford, California 94305 (United States)

    2014-10-15

    The Sagnac Interferometer has historically been used for detecting non-reciprocal phenomena, such as rotation. We demonstrate an apparatus in which this technique is employed for high resolution measurements of the Magneto-Optical Polar Kerr effect—a direct indicator of magnetism. Previous designs have incorporated free-space components which are bulky and difficult to align. We improve upon this technique by using all fiber-optic coupled components and demonstrate operation at a new wavelength, 820 nm, with which we can achieve better than 1 μrad resolution. Mounting the system on a piezo-electric scanner allows us to acquire diffraction limited images with 1.5 μm spatial resolution. We also provide extensive discussion on the details and of the Sagnac Interferometer's construction.

  4. Interior channels in Martian valleys: Constraints on fluvial erosion by measurements of the Mars Express High Resolution Stereo Camera

    Science.gov (United States)

    Jaumann, R.; Reiss, D.; Frei, S.; Neukum, G.; Scholten, F.; Gwinner, K.; Roatsch, T.; Matz, K.-D.; Mertens, V.; Hauber, E.; Hoffmann, H.; Köhler, U.; Head, J. W.; Hiesinger, H.; Carr, M. H.

    2005-08-01

    In High Resolution Stereo Camera (HRSC) images of the Mars Express Mission a 130 km long interior channel is identified within a 400 km long valley network system located in the Lybia Montes. Ages of the valley floor and the surroundings as derived from crater counts define a period of ~350 Myrs during which the valley might have been formed. Based on HRSC stereo measurements the discharge of the interior channel is estimated at ~4800 m3/s, corresponding to a runoff production rate of ~1 cm/day. Mass balances indicate erosion rates of a few cm/year implying the erosion activity in the valley to a few thousand years for continuous flow, or one or more orders of magnitude longer time spans for more intermittent flows. Therefore, during the Hesperian, relatively brief but recurring episodes of erosion intervals are more likely than sustained flow.

  5. A Scanning, All-Fiber Sagnac Interferometer for High Resolution Magneto-Optic Measurements at 820 nm

    CERN Document Server

    Fried, Alexander; Kapitulnik, Aharon

    2014-01-01

    The Sagnac Interferometer has historically been used for detecting non-reciprocal phenomena, such as rotation. We demonstrate an apparatus in which this technique is employed for high resolution measurements of the Magneto-Optical Polar Kerr effect--a direct indicator of magnetism. Previous designs have incorporated free-space components which are bulky and difficult to align. We improve upon this technique by using all fiber-optic coupled components and demonstrate operation at a new wavelength, 820 nm, with which we can achieve better than 1 $\\mu$rad resolution. Mounting the system on a piezo-electric scanner allows us to acquire diffraction limited images with 1.5 $\\mu$m spatial resolution. We also provide extensive discussion on the details and of the Sagnac Interferometer's construction.

  6. High-resolution 3D surface displacements from 2004 - 2012 at Santorini volcano, Greece measured by LiDAR-differencing

    Science.gov (United States)

    Parks, M.; Pyle, D. M.; Nissen, E.; Mather, T. A.; Raptakis, C.; Nomikou, P.

    2012-12-01

    In January 2011 Santorini volcano entered a period of unrest characterised by earthquake swarms and caldera-wide uplift. Interferometric Synthetic Aperture Radar (InSAR) measurements indicate vertical motions of 8 - 14 cm across the central volcanic island of Nea Kameni since the onset of unrest. In April 2004, a NERC funded Airborne Research and Survey Facility (ARSF) flight acquired high-resolution (1m per pixel) light detection and ranging laser radar (LiDAR) data over the central volcanic islands of Nea Kameni and Palea Kameni. This survey was repeated in May 2012 to provide an updated digital elevation model (DEM). We apply a new method of differencing pre- and post- deformation LiDAR point clouds using the Iterative Closest Point (ICP) algorithm to produce a high-resolution grid of 3D surface displacements from 2004 - 2012. The 2004 ("source") and 2012 ("target") point clouds are first split into square subsets ("windows") and the displacement for each window is determined by iterating three steps: (1) identifying closest point pairs; (2) calculating the translation and rotation required that best aligns the paired points; (3) applying this transformation to the source cloud. The surface displacement map spans both a period of slow subsidence (from 2004 - 2010), and a subsequent period of inflation (from 2011 - 2012). We shall compare our results with those obtained from simple DEM elevation differencing and from InSAR. To our knowledge, this is the first application of the ICP technique to measuring volcanic deformation. This approach may be implemented at other volcanoes to monitor 3D surface displacements during periods of unrest.

  7. PHOENIX: a scoring function for affinity prediction derived using high-resolution crystal structures and calorimetry measurements.

    Science.gov (United States)

    Tang, Yat T; Marshall, Garland R

    2011-02-28

    Binding affinity prediction is one of the most critical components to computer-aided structure-based drug design. Despite advances in first-principle methods for predicting binding affinity, empirical scoring functions that are fast and only relatively accurate are still widely used in structure-based drug design. With the increasing availability of X-ray crystallographic structures in the Protein Data Bank and continuing application of biophysical methods such as isothermal titration calorimetry to measure thermodynamic parameters contributing to binding free energy, sufficient experimental data exists that scoring functions can now be derived by separating enthalpic (ΔH) and entropic (TΔS) contributions to binding free energy (ΔG). PHOENIX, a scoring function to predict binding affinities of protein-ligand complexes, utilizes the increasing availability of experimental data to improve binding affinity predictions by the following: model training and testing using high-resolution crystallographic data to minimize structural noise, independent models of enthalpic and entropic contributions fitted to thermodynamic parameters assumed to be thermodynamically biased to calculate binding free energy, use of shape and volume descriptors to better capture entropic contributions. A set of 42 descriptors and 112 protein-ligand complexes were used to derive functions using partial least-squares for change of enthalpy (ΔH) and change of entropy (TΔS) to calculate change of binding free energy (ΔG), resulting in a predictive r2 (r(pred)2) of 0.55 and a standard error (SE) of 1.34 kcal/mol. External validation using the 2009 version of the PDBbind "refined set" (n = 1612) resulted in a Pearson correlation coefficient (R(p)) of 0.575 and a mean error (ME) of 1.41 pK(d). Enthalpy and entropy predictions were of limited accuracy individually. However, their difference resulted in a relatively accurate binding free energy. While the development of an accurate and applicable

  8. Inexpensive Time-of-Flight Velocity Measurements.

    Science.gov (United States)

    Everett, Glen E.; Wild, R. L.

    1979-01-01

    Describes a circuit designed to measure time-of-flight velocity and shows how to use it to determine bullet velocity in connection with the ballistic pendulum demonstration of momentum conservation. (Author/GA)

  9. Using initial field campaigns for optimal placement of high resolution stable water isotope and water chemistry measurements

    Science.gov (United States)

    Sahraei, Amirhossein; Kraft, Philipp; Windhorst, David; Orlowski, Natalie; Bestian, Konrad; Holly, Hartmut; Breuer, Lutz

    2017-04-01

    Understanding hydrological processes and flow paths is of major importance for the management of catchment water resources. The power of stable isotopes as a tracer and to encoder environmental information provides the opportunity to assess hydrological flow paths, catchment residence times, landscape influences, and the origin of water resources in catchments. High resolution isotope sampling of multiple sources ensures detailed comprehension of hydrological and biogeochemical interactions within catchments. Technical advances over the last years have made it feasible to directly measure stable water isotope signatures of various sources online in a high temporal resolution during field campaigns. However, measuring long time series in a high temporal resolutions are still costly and can only be performed at few places in a study area. The identification of locations where measurements should be implemented is still challenging. Our study is conducted in the developed landscape of the Schwingbach catchment located in central Germany. A reconnaissance assessment of the spatial distribution of runoff generating areas was performed in a short time frame prior to the selection of the final sampling site. We used a combination of: water quality snapshot sampling to identify spatial differences and potential hot spots, event-based hydrograph separation to differentiate possible flow paths, consecutive runoff measurements by salt dilution to identify gaining and loosing reaches, field reconnaissance mapping of potentially variable source areas in the riparian zone, infrared imagery of stream surface temperatures to locate potential concentrated groundwater discharge to the stream, and groundwater table mapping to identify sites where different dominant processes (e.g., groundwater flow, groundwater-surface water interactions and runoff generation) can be expected. First results indicated that precipitation and stream water are significantly different in isotopic

  10. Ocean color measurements onboard a jet ski: consistency for calval exercise of high-resolution satellite imagery?

    Science.gov (United States)

    Martiny, Nadège; Dehouck, Aurélie; Froidefond, Jean-Marie; Sénéchal, Nadia

    2009-01-01

    An original data set has been acquired on the 5th of April 2008 during the international field experiment ECORS-Truc Vert 2008 (SW France) in the nearshore zone over a complex bathymetry and in moderate turbid waters (SPM RAMSES sensors which measure simultaneous atmospheric downwelling irradiances Ed and in-water upwelling radiances Lu in the 350-950nm range. Water samples have also been collected at different stages of the jet-ski trajectory (3-25m water depth) in order to assess the concentrations of the ocean constituents (SPM and Chl-a). In the current study we present a methodology to validate FORMOSAT-2 high-resolution ocean color data using "jetski" reflectance measurements, which first require a detailed analysis. The reflectance spectra measurements are shown to be consistent: (i) they are typical of the presence of mineral particles with light absorption at short wavelengths; (ii) their shape and magnitude depend on the depth and the water type (turbidity); (iii) some of them, especially in low turbid waters, are similar to other reflectance spectra measured northward from a ship (Gironde mouth). Thus, the use of "jet-ski" ocean color measurements appears to be adequate for remote sensing calval activities in shallow case-2 waters.

  11. A simple calculation algorithm to separate high-resolution CH4 flux measurements into ebullition and diffusion-derived components

    Science.gov (United States)

    Hoffmann, Mathias; Schulz-Hanke, Maximilian; Garcia Alba, Joana; Jurisch, Nicole; Hagemann, Ulrike; Sachs, Torsten; Sommer, Michael; Augustin, Jürgen

    2016-04-01

    Processes driving methane (CH4) emissions in wetland ecosystems are highly complex. Especially, the separation of CH4 emissions into ebullition and diffusion derived flux components, a perquisite for the mechanistic process understanding and identification of potential environmental driver is rather challenging. We present a simple calculation algorithm, based on an adaptive R-script, which separates open-water, closed chamber CH4 flux measurements into diffusion- and ebullition-derived components. Hence, flux component specific dynamics are revealed and potential environmental driver identified. Flux separation is based on a statistical approach, using ebullition related sudden concentration changes obtained during high resolution CH4 concentration measurements. By applying the lower and upper quartile ± the interquartile range (IQR) as a variable threshold, diffusion dominated periods of the flux measurement are filtered. Subsequently, flux calculation and separation is performed. The algorithm was verified in a laboratory experiment and tested under field conditions, using flux measurement data (July to September 2013) from a flooded, former fen grassland site. Erratic ebullition events contributed 46% to total CH4 emissions, which is comparable to values reported by literature. Additionally, a shift in the diurnal trend of diffusive fluxes throughout the measurement period, driven by the water temperature gradient, was revealed.

  12. Normalized velocity profiles of field-measured turbidity currents

    Science.gov (United States)

    Xu, Jingping

    2010-01-01

    Multiple turbidity currents were recorded in two submarine canyons with maximum speed as high as 280 cm/s. For each individual turbidity current measured at a fixed station, its depth-averaged velocity typically decreased over time while its thickness increased. Some turbidity currents gained in speed as they traveled downcanyon, suggesting a possible self-accelerating process. The measured velocity profiles, first in this high resolution, allowed normalizations with various schemes. Empirical functions, obtained from laboratory experiments whose spatial and time scales are two to three orders of magnitude smaller, were found to represent the field data fairly well. The best similarity collapse of the velocity profiles was achieved when the streamwise velocity and the elevation were normalized respectively by the depth-averaged velocity and the turbidity current thickness. This normalization scheme can be generalized to an empirical function Y = exp(–αXβ) for the jet region above the velocity maximum. Confirming theoretical arguments and laboratory results of other studies, the field turbidity currents are Froude-supercritical.

  13. In situ measurement of ions parameters of laser produced ion source using high resolution Thomson Parabola Spectrometer

    Science.gov (United States)

    Chaurasia, S.; Kaur, C.; Rastogi, V.; Poswal, A. K.; Munda, D. S.; Bhatia, R. K.; Nataraju, V.

    2016-08-01

    The laser produced plasma based heavy ion source has become an outstanding front end for heavy ion accelerators. Before being implemented in the heavy ion accelerators its detailed characterization is required. For this purpose, a high resolution and high dispersion Thomson parabola spectrometer comprising of Time-of-Flight diagnostics has been developed for the characterization of ions with energy in the range from 1 keV to 1 MeV/nucleon and incorporated in the Laser plasma experimental chamber. The ion spectrometer is optimized with graphite target. The carbon ions of charge states C1+ to C6+ are observed in the energy range from 3 keV to 300 keV, which has also been verified by Time-of-Flight measurement. Experimental results were matched with simulation done by SIMION 7.0 code which is used for the design of the spectrometer. We also developed data analysis software using Python language to measure in situ ion's parameters and the results are in better agreement to the experimental results than the commercially available software SIMION 7.0. The resolution of the spectrometer is ΔE/E = 0.026 @ 31 keV for charge state (C4+) of carbon.

  14. High-resolution elasticity maps and cytoskeletal dynamics of neurons measured by combined fluorescence and atomic force microscopy

    Science.gov (United States)

    Staii, Cristian

    2014-03-01

    Detailed knowledge of mechanical parameters such as cell elasticity, stiffness of the growth substrate, or traction stresses generated during axonal extensions is essential for understanding the mechanisms that control neuronal growth. Here I present results obtained in my research group, which combine Atomic Force Microscopy and Fluorescence Microscopy measurements to produce systematic, high-resolution elasticity maps for different types of live neuronal cells cultured on glass or biopolymer-based substrates. We measure how the stiffness of neurons changes both during neurite outgrowth and upon chemical modification (disruption of the cytoskeleton) of the cell. We find a reversible local stiffening of the cell during growth, and show that the increase in local elastic modulus is primarily due to the formation of microtubules in the cell soma. We also report a reversible shift in the elastic modulus of the cortical neurons cytoskeleton with temperature, from tubulin dominated regions at 37C to actin dominated regions at 25C. We demonstrate that the dominant mechanism by which the elasticity of the neuronal soma changes in response to temperature is the contractile stiffening of the actin component of the cytoskeleton induced by the activity of myosin II motors. We acknowledge financial support from NSF grant CBET 1067093.

  15. Feasibility study of high-resolution DCE-MRI for glomerular filtration rate (GFR) measurement in a routine clinical modal.

    Science.gov (United States)

    Zhang, Yu-Dong; Wu, Chen-Jiang; Zhang, Jing; Wang, Xiao-Ning; Liu, Xi-Sheng; Shi, Hai-Bin

    2015-10-01

    Dynamic contrast enhanced (DCE) MR renography has been identified as an interesting tool to determine single-kidney GFR. However, a fundamental issue for the applicability of MR-based estimate of single-kidney GFR is selecting a balance between spatial and temporal resolution of DCE-MRI data. The purpose is to assess the feasibility of GFR estimate from high-resolution (HR) dynamic contrast-enhanced (DCE) MRI in a routine clinical modal. Standard MR renography (2.4s/phase, total 4min; 4-ml Gd) and five-phase, HR-based imaging protocol (0, 30, 70, 120, and 240s; 0.05mmol/kg Gd) were prospectively performed in twelve volunteers who were scheduled for routine renal MRI. Data were plotted with Patlak, two-compartment modified Tofts model (2CTM), and two-compartment filtration model (2CFM) for GFR estimate. During all the measurements, only the signal intensities in the aorta and whole kidney parenchyma were considered. Standard 2CFM and 2CTM produced lower residuals over the fitted interval than HR-based measures (pGFR and higher residuals than that plots with 0-120s data points (pGFR with HR-based DCE-MRI and appreciate kinetic model. Patlak plots from 0, 30, 70, and 120s data points is better than plots from 0, 30, 70, 120, and 240s data points.

  16. High Resolution CH4 Emissions and Dissolved CH4 Measurements Elucidate Surface Gas Exchange Processes in Toolik Lake, Arctic Alaska

    Science.gov (United States)

    Del Sontro, T.; Sollberger, S.; Kling, G. W.; Shaver, G. R.; Eugster, W.

    2013-12-01

    Approximately 14% of the Alaskan North Slope is covered in lakes of various sizes and depths. Diffusive carbon emissions (CH4 and CO2) from these lakes offset the tundra sink by ~20 %, but the offset would substantially increase if ebullitive CH4 emissions were also considered. Ultimately, arctic lake CH4 emissions are not insignificant in the global CH4 budget and their contribution is bound to increase due to impacts from climate change. Here we present high resolution CH4 emission data as measured via eddy covariance and a Los Gatos gas analyzer during the ice free period from Toolik Lake, a deep (20 m) Arctic lake located on the Alaskan North Slope, over the last few summers. Emissions are relatively low (Gatos gas analyzer. Thus, having both the flux and the CH4 gradient across the air-water interface measured directly, we can calculate k and investigate the processes influencing CH4 gas exchange in this lake. Preliminary results indicate that there are two regimes in wind speed that impact k - one at low wind speeds up to ~5 m s-1 and another at higher wind speeds (max ~10 m s-1). The differential wind speeds during night and day may compound the effect of convective mixing and cause the diurnal variation in observed fluxes.

  17. Photodissociation in the atmosphere of Mars - Impact of high resolution, temperature-dependent CO2 cross-section measurements

    Science.gov (United States)

    Anbar, A. D.; Allen, M.; Nair, H. A.

    1993-01-01

    We have investigated the impact of high resolution, temperature-dependent CO2 cross-section measurements, reported by Lewis and Carver (1983), on calculations of photodissociation rate coefficients in the Martian atmosphere. We find that the adoption of 50 A intervals for the purpose of computational efficiency results in errors in the calculated values for photodissociation of CO2, H2O, and O2 which are generally not above 10 percent, but as large as 20 percent in some instances. These are acceptably small errors, especially considering the uncertainties introduced by the large temperature dependence of the CO2 cross section. The inclusion of temperature-dependent CO2 cross sections is shown to lead to a decrease in the diurnally averaged rate of CO2 photodissociation as large as 33 percent at some altitudes, and increases of as much as 950 percent and 80 percent in the photodissociation rate coefficients of H2O and O2, respectively. The actual magnitude of the changes depends on the assumptions used to model the CO2 absorption spectrum at temperatures lower than the available measurements, and at wavelengths longward of 1970 A.

  18. A new method for high-resolution methane measurements on polar ice cores using continuous flow analysis.

    Science.gov (United States)

    Schüpbach, Simon; Federer, Urs; Kaufmann, Patrik R; Hutterli, Manuel A; Buiron, Daphné; Blunier, Thomas; Fischer, Hubertus; Stocker, Thomas F

    2009-07-15

    Methane (CH4) is the second most important anthropogenic greenhouse gas in the atmosphere. Rapid variations of the CH4 concentration, as frequently registered, for example, during the last ice age, have been used as reliable time markers for the definition of a common time scale of polar ice cores. In addition, these variations indicate changes in the sources of methane primarily associated with the presence of wetlands. In order to determine the exact time evolution of such fast concentration changes, CH4 measurements of the highest resolution in the ice core archive are required. Here, we present a new, semicontinuous and field-deployable CH4 detection method, which was incorporated in a continuous flow analysis (CFA) system. In CFA, samples cut along the axis of an ice core are melted at a melt speed of typically 3.5 cm/min. The air from bubbles in the ice core is extracted continuously from the meltwater and forwarded to a gas chromatograph (GC) for high-resolution CH4 measurements. The GC performs a measurement every 3.5 min, hence, a depth resolution of 15 cm is achieved atthe chosen melt rate. An even higher resolution is not necessary due to the low pass filtering of air in ice cores caused by the slow bubble enclosure process and the diffusion of air in firn. Reproducibility of the new method is 3%, thus, for a typical CH4 concentration of 500 ppb during an ice age, this corresponds to an absolute precision of 15 ppb, comparable to traditional analyses on discrete samples. Results of CFA-CH4 measurements on the ice core from Talos Dome (Antarctica) illustrate the much higher temporal resolution of our method compared with established melt-refreeze CH4 measurements and demonstrate the feasibility of the new method.

  19. High-resolution magic angle spinning (1) H NMR measurement of ligand concentration in solvent-saturated chromatographic beads.

    Science.gov (United States)

    Elwinger, Fredrik; Furó, István

    2016-04-01

    A method based on (1) H high-resolution magic angle spinning NMR has been developed for measuring concentration accurately in heterogeneous materials like that of ligands in chromatography media. Ligand concentration is obtained by relating the peak integrals for a butyl ligand in the spectrum of a water-saturated chromatography medium to the integral of the added internal reference. The method is fast, with capacity of 10 min total sample preparation and analysis time per sample; precise, with a reproducibility expressed as 1.7% relative standard deviation; and accurate, as indicated by the excellent agreement of derived concentration with that obtained previously by (13) C single-pulse excitation MAS NMR. The effects of radiofrequency field inhomogeneity, spin rate, temperature increase due to spinning, and distribution and re-distribution of medium and reference solvent both inside the rotor during spinning and between bulk solvent and pore space are discussed in detail. © 2016 The Authors Magnetic Resonance in Chemistry published by John Wiley & Sons Ltd.

  20. Copper L X-ray spectra measured by a high resolution ion-induced X-ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ryohei; Hamaguchi, Dai; Kageyama, Hiroyoshi [Kyoto Inst. of Tech. (Japan)] [and others

    1997-03-01

    High resolution L X-ray emission spectra of Cu have been measured by 0.75 MeV/u H, He, and F, 0.73 MeV/u Ar, 0.64 MeV/u Si, and 0.073 MeV/u Si ion impacts with a crystal spectrometer. The X-ray transition energies in the Cu target for L{iota}, L{eta}, L{alpha}{sub 1,2}, L{beta}{sub 1}, and L{beta}{sub 3,4} diagram lines induced by light ion impacts are determined, which are in good agreement with those given in the reference. The difference in L X-ray emission spectra produced by H, He, F, Si, and Ar ions are considered and the L{alpha}{sub 1,2} and L{beta}{sub 1} emission spectra are compared with the calculated ones based on the multiconfiguration Dirac-Fock method. (author)

  1. Definition for Rheumatoid Arthritis Erosions Imaged with High Resolution Peripheral Quantitative Computed Tomography and Interreader Reliability for Detection and Measurement.

    Science.gov (United States)

    Barnabe, Cheryl; Toepfer, Dominique; Marotte, Hubert; Hauge, Ellen-Margrethe; Scharmga, Andrea; Kocijan, Roland; Kraus, Sebastian; Boutroy, Stephanie; Schett, Georg; Keller, Kresten Krarup; de Jong, Joost; Stok, Kathryn S; Finzel, Stephanie

    2016-10-01

    High-resolution peripheral quantitative computed tomography (HR-pQCT) sensitively detects erosions in rheumatoid arthritis (RA); however, nonpathological cortical bone disruptions are potentially misclassified as erosive. Our objectives were to set and test a definition for pathologic cortical bone disruptions in RA and to standardize reference landmarks for measuring erosion size. HR-pQCT images of metacarpophalangeal joints of RA and control subjects were used in an iterative process to achieve consensus on the definition and reference landmarks. Independent readers (n = 11) applied the definition to score 58 joints and measure pathologic erosions in 2 perpendicular multiplanar reformations for their maximum width and depth. Interreader reliability for erosion detection and variability in measurements between readers [root mean square coefficient of variation (RMSCV), intraclass correlation (ICC)] were calculated. Pathologic erosions were defined as cortical breaks extending over a minimum of 2 consecutive slices in perpendicular planes, with underlying trabecular bone loss and a nonlinear shape. Interreader agreement for classifying pathologic erosions was 90.2%, whereas variability for width and depth erosion assessment was observed (RMSCV perpendicular width 12.3%, axial width 20.6%, perpendicular depth 24.0%, axial depth 22.2%; ICC perpendicular width 0.206, axial width 0.665, axial depth 0.871, perpendicular depth 0.783). Mean erosion width was 1.84 mm (range 0.16-8.90) and mean depth was 1.86 mm (range 0.30-8.00). We propose a new definition for erosions visualized with HR-pQCT imaging. Interreader reliability for erosion detection is good, but further refinement of selection of landmarks for erosion size measurement, or automated volumetric methods, will be pursued.

  2. Usage of four-phase high-resolution rhinomanometry and measurement of nasal resistance in sleep-disordered breathing.

    Science.gov (United States)

    Toh, Song-Tar; Lin, Cheng-Hui; Guilleminault, Christian

    2012-10-01

    To investigate the ease of use of four-phase high-resolution rhinomanometry (HRR), a new way of measuring nasal resistance, in measuring change in nasal resistance from supine to inclined position in a clinical sleep laboratory setting, and to correlate findings with continuous positive airway pressure (CPAP) tolerance. Retrospective review of clinical charts. Forty successively seen Caucasian subjects diagnosed with sleep-disordered breathing (SDB) with complete charts were analyzed. Using four-phase HRR and acoustic rhinometry, nasal resistance and minimal cross-sectional area of the nasal cavity were objectively measured with the patient in the supine position and repeated in the inclined position (30° from the horizontal plane), respectively. From the supine to inclined position, reduction in total nasal resistance was observed in 87.5% (35 out of 40). There was a mean reduction of nasal resistance by 37.1 ± 21.6%. Five (12.5%) out of 40 subjects showed no change or mild increase in nasal resistance. Subjects with nasal resistance unresponsive to the inclined position change tended to have difficulty using nasal CPAP based on downloaded compliance card data. Four-phase HRR and acoustic rhinometry are tests that can be easily performed by sleep specialists to characterize nasal resistance in SDB patients and determine changes in resistance with positional changes. In this study, we found that patients who did not demonstrate a decrease in nasal resistance with inclined position were more likely to be noncompliant with nasal CPAP. These measurements may help us objectively identify patients who might have trouble tolerating nasal CPAP. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

  3. A new measure of Δα/α at redshift z = 1.84 from very high resolution spectra of Q 1101-264

    Science.gov (United States)

    Levshakov, S. A.; Molaro, P.; Lopez, S.; D'Odorico, S.; Centurión, M.; Bonifacio, P.; Agafonova, I. I.; Reimers, D.

    2007-05-01

    Aims:We probe the evolution of the fine-structure constant α with cosmic time. Methods: Accurate positions of the Fe II lines λ1608, λ2382, and λ2600 are measured in the z_abs = 1.84 absorption system from a high-resolution (FWHM ~ 3.8 km s-1) and high signal-to-noise (S/N ⪆ 100) spectrum of the quasar Q 1101-264 (z_em = 2.15, V = 16.0), integrated for 15.4 h. The Single Ion Differential α Measurement (SIDAM) procedure and the Δ χ2 method are used to set constraints on Δα/α. Results: We have found a relative radial velocity shift between the λ1608 and λλ2382,2600 lines of Δ v = -180 ± 85 m s-1 (both random and systematic errors are included), which, if real, would correspond to Δα/α = (5.4±2.5) × 10-6 (1σ C.L.). Considering the strong implications of a such variability, additional observations with comparable accuracy at redshift z ˜ 1.8 are required to confirm this result. Based on observations performed at the VLT Kueyen telescope (ESO, Paranal, Chile), the ESO programme No. 076.A-0463.

  4. Feasibility of High-Resolution Soil Erosion Measurements by Means of Rainfall Simulations and SfM Photogrammetry

    Directory of Open Access Journals (Sweden)

    Phoebe Hänsel

    2016-11-01

    Full Text Available The silty soils of the intensively used agricultural landscape of the Saxon loess province, eastern Germany, are very prone to soil erosion, mainly caused by water erosion. Rainfall simulations, and also increasingly structure-from-motion (SfM photogrammetry, are used as methods in soil erosion research not only to assess soil erosion by water, but also to quantify soil loss. This study aims to validate SfM photogrammetry determined soil loss estimations with rainfall simulations measurements. Rainfall simulations were performed at three agricultural sites in central Saxony. Besides the measured data runoff and soil loss by sampling (in mm, terrestrial images were taken from the plots with digital cameras before and after the rainfall simulation. Subsequently, SfM photogrammetry was used to reconstruct soil surface changes due to soil erosion in terms of high resolution digital elevation models (DEMs for the pre- and post-event (resolution 1 × 1 mm. By multi-temporal change detection, the digital elevation model of difference (DoD and an averaged soil loss (in mm is received, which was compared to the soil loss by sampling. Soil loss by DoD was higher than soil loss by sampling. The method of SfM photogrammetry-determined soil loss estimations also include a comparison of three different ground control point (GCP approaches, revealing that the most complex one delivers the most reliable soil loss by DoD. Additionally, soil bulk density changes and splash erosion beyond the plot were measured during the rainfall simulation experiments in order to separate these processes and associated surface changes from the soil loss by DoD. Furthermore, splash was negligibly small, whereas higher soil densities after the rainfall simulations indicated soil compaction. By means of calculated soil surface changes due to soil compaction, the soil loss by DoD achieved approximately the same value as the soil loss by rainfall simulation.

  5. A new method to measure bowen ratios using high resolution vertical dry and wet bulb temperature profiles

    Directory of Open Access Journals (Sweden)

    T. Euser

    2013-06-01

    Full Text Available The Bowen ratio surface energy balance method is a relatively simple method to determine the latent heat flux and the actual land surface evaporation. Despite its simplicity, the Bowen ratio method is generally considered to be unreliable due to the use of two-level sensors that are installed by default in operational Bowen ratio systems. In this paper we present the concept of a new measurement methodology to estimate the Bowen ratio from high resolution vertical dry and wet bulb temperature profiles. A short field experiment with Distributed Temperature Sensing (DTS in a fibre optic cable having 13 levels was undertaken. A dry and a wetted section of a fibre optic cable were suspended on a 6 m high tower installed over a sugar beet trial near Pietermaritzburg (South Africa. Using the DTS cable as a psychrometer, a near continuous observation of vapour pressure and temperature at 0.20 m intervals was established. These data allows the computation of the Bowen ratio with a high precision. By linking the Bowen ratio to net radiation and soil heat flux, the daytime latent heat flux was estimated. The latent heat flux derived from DTS-based Bowen ratio (BR-DTS showed consistent agreement (correlation coefficients between 0.97 and 0.98 with results derived from eddy covariance, surface layer scintillometer and surface renewal techniques. The latent heat from BR-DTS overestimated the latent heat derived with the eddy covariance by 4% and the latent heat derived with the surface layer scintillometer by 8%. Through this research, a new window is opened to engage on simplified, inexpensive and easy to interpret in situ measurement techniques for measuring evaporation.

  6. A new method using evaporation for high-resolution measurements of soil thermal conductivity at changing water contents

    Science.gov (United States)

    Markert, A.; Trinks, S.; Facklam, M.; Wessolek, G.

    2012-04-01

    The thermal conductivity of soils is a key parameter to know if their use as heat source or sink is planned. It is required to calculate the efficiency of ground-source heat pump systems in combination with soil heat exchangers. Apart from geothermal energy, soil thermal conductivity is essential to estimate the ampacity for buried power cables. The effective thermal conductivity of saturated and unsaturated soils, as a function of water transport, water vapour transport and heat conduction, mainly depends on the soil water content, its bulk density and texture. The major objectives of this study are (i) to describe the thermal conductivity of soil samples with a non-steady state measurement at changing water contents and for different bulk densities. Based on that it is (ii) tested if available soil thermal conductivity models are able to describe the measured data for the whole range of water contents. The new method allows a continuous measurement of thermal conductivity for soil from full water saturation to air-dryness. Thermal conductivity is measured with a thermal needle probe in predefined time intervals while the change of water content is controlled by evaporation. To relate the measured thermal conductivity to the current volumetric water content, the decrease in weight of the sample, due to evaporation, is logged with a lab scale. Soil texture of the 11 soil substrates tested in this study range between coarse sand and silty clay. To evaluate the impact of the bulk density on heat transport processes, thermal conductivity at 20°C was measured at 1.5g/cm3; 1.7g/cm3 and 1.9g/cm3 for each soil substrate. The results correspond well to literature values used to describe heat transport in soils. Due to the high-resolution and non-destructive measurements, the specific effects of the soil texture and bulk density on thermal conductivity could be proved. Decreasing water contents resulted in a non-linear decline of the thermal conductivity for all samples

  7. High-Resolution Measurement of the {sup 4}He({gamma},n) Reaction in the Giant Resonance Region

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Bjoern

    2003-03-01

    A comprehensive near-threshold {sup 4}He(gamma,n) absolute cross section measurement has been performed at the high-resolution tagged-photon facility MAX-lab located in Lund, Sweden. The 20 < Eg < 45 MeV tagged photons (covering the Giant Dipole Resonance energy region) were directed towards a liquid {sup 4}He target, and knocked-out neutrons were detected in a pair of 60 cm x 60 cm vetoed NE213A liquid scintillator arrays. The intense and varying charge-neutral experimental backgrounds were carefully quantified and removed from the data using a precision fitting procedure. Eight average laboratory angles (30, 45, 60, 75, 90, 105, 120, and 135 deg) were investigated for eight photon energy bins (25, 27, 29, 31, 35, 36, 39, and 41 MeV), resulting in 64 differential cross sections. These angular distributions were integrated to produce total cross sections as a function of photon energy. The resulting cross sections peak at 1.9 mb at a photon energy of 27 MeV, and fall off to a near-constant value of 1.1 mb by 36 MeV. Further, they are in excellent agreement with those measured by Sims et al. using tagged photons in the Quasi-Deuteron energy region. Overall, the results favor modern theoretical models which are based upon a charge-symmetric nucleon-nucleon force, in marked contrast to the recommendations made by Calarco et al. in 1983 based on the sparse {sup 4}He(gamma,n) data available at the time.

  8. Subsea Target Measurement Technique of High Resolution Multi-Beam Sonar System -A Case Study of Ocean Oil & Gas Production Platform and Pipeline Detection

    Science.gov (United States)

    Ding, J.; Tang, Q.; Zhou, X.

    2015-12-01

    Abstract: with fast development of modern science and technology, subsea pipeline detection means have been increasingly improved which have not only improved detection efficiency, but also extremely advanced the detection precision. The article has integrated the performance characteristics of high resolution multi-beam measurement system in recent years, which has introduced the relevant technique and detection achievement of subsea pipeline detecting (especially for exposed pipeline) by detection cases. The final detection result has been verified that high resolution multi-beam measurement system could accurately detect subsea minisize target object, which has provided the technical reference with popularization and application of new characteristics.

  9. Velocity structure and active fault of Yanyuan-Mabian seismic zone——The result of high-resolution seismic refraction experiment

    Institute of Scientific and Technical Information of China (English)

    WANG FuYun; XU XiWei; LIU BaoFeng; DUAN YongHong; YANG ZhuoXin; ZHANG ChengKe; ZHAO JinRen; ZHANG JianShi; ZHANG XianKang; LIU QiYuan; ZHU AiLan

    2008-01-01

    The authors processed the seismic retraction Pg-wave travel time data with finite difference tomography method and revealed velocity structure of the upper crust on active block boundaries and deep features of the active faults in western Sichuan Province.The following are the results of our investigation.The upper crust of Yanyuan basin and the Houlong Mountains consists of the superficial low-velocity layer and the deep uniform high-velocity layer, and between the two layers, there is a distinct, and gently west-dipping structural plane.Between model coordinates 180-240 km, P-wave velocity distribution features steeply inclined strip-like structure with strongly non-uniform high and low velocities alternately.Xichang Mesozoic basin between 240 and 300 km consists of a thick low-velocity upper layer and a high-velocity lower layer, where lateral and vertical velocity variations are very strong and the interface between the two layers fluctuates a lot.The Daliang Mountains to the east of the 300 km coordinate is a non-uniform high-velocity zone, with a superficial velocity of approximately 5 km/s.From 130 to 150 km and from 280 to 310 km, there are extremely distinct deep anomalous high-velocity bodies, which are supposed to be related with Permian magmatic activity.The Yanyuan nappe structure is composed of the superficial low-velocity nappe, the gently west-dipping detachment surface and the deep high-velocity basement, with Jinhe-Qinghe fault zone as the nappe front.Mopanshan fault is a west-dipping low-velocity zone, which extends to the top surface of the basement.Anninghe fault and Zemuhe fault are east-dipping, tabular-like, and low-velocity zones, which extend deep into the basement.At a great depth, Daliangshan fault separates into two segments, which are represented by drastic variation of velocity structures in a narrow strip: the west segment dips westward and the east segment dips eastward, both stretching into the basement.The east margin fault of

  10. Velocity structure and active fault of Yanyuan-Mabian seismic zone―The result of high-resolution seismic refraction experiment

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The authors processed the seismic refraction Pg-wave travel time data with finite difference tomography method and revealed velocity structure of the upper crust on active block boundaries and deep features of the active faults in western Sichuan Province. The following are the results of our investigation. The upper crust of Yanyuan basin and the Houlong Mountains consists of the superficial low-velocity layer and the deep uniform high-velocity layer, and between the two layers, there is a distinct, and gently west-dipping structural plane. Between model coordinates 180-240 km, P-wave velocity distribution features steeply inclined strip-like structure with strongly non-uniform high and low velocities alternately. Xichang Mesozoic basin between 240 and 300 km consists of a thick low-velocity upper layer and a high-velocity lower layer, where lateral and vertical velocity variations are very strong and the interface between the two layers fluctuates a lot. The Daliang Mountains to the east of the 300 km coordinate is a non-uniform high-velocity zone, with a superficial velocity of approximately 5 km/s. From 130 to 150 km and from 280 to 310 km, there are extremely distinct deep anomalous high-velocity bodies, which are supposed to be related with Permian magmatic activity. The Yanyuan nappe structure is composed of the superficial low-velocity nappe, the gently west-dipping detachment surface and the deep high-velocity basement, with Jinhe-Qinghe fault zone as the nappe front. Mopanshan fault is a west-dipping low-velocity zone, which extends to the top surface of the basement. Anninghe fault and Zemuhe fault are east-dipping, tabular-like, and low-velocity zones, which extend deep into the base-ment. At a great depth, Daliangshan fault separates into two segments, which are represented by drastic variation of velocity structures in a narrow strip: the west segment dips westward and the east segment dips eastward, both stretching into the basement. The east margin

  11. High-resolution measurements of atmospheric molecular hydrogen and its isotopic composition at the West African coast of Mauritania

    Directory of Open Access Journals (Sweden)

    S. Walter

    2013-05-01

    Full Text Available Oceans are a net source of molecular hydrogen (H2 to the atmosphere, where nitrogen (N2 fixation is assumed to be the main biological production pathway followed by photochemical production from organic material. The sources can be distinguished using isotope measurements because of clearly differing isotopic signatures of the produced hydrogen. Here we present the first ship-borne measurements of atmospheric molecular H2 mixing ratio and isotopic composition at the West African coast of Mauritania (16–25° W, 17–24° N. This area is one of the biologically most active regions of the world's oceans with seasonal upwelling events and characterized by strongly differing hydrographical/biological properties and phytoplankton community structures. The aim of this study was to identify areas of H2 production and distinguish H2 sources by isotopic signatures of atmospheric H2. For this more than 100 air samples were taken during two cruises in February 2007 and 2008. During both cruises a transect from the Cape Verde Islands towards the Mauritanian Coast was sampled to cover differing oceanic regions such as upwelling and oligotrophic regimes. In 2007, additionally, four days were sampled at high resolution of one sample per hour to investigate a possible diurnal cycle of atmospheric H2. Our results indicate the influence of local sources and suggest the Banc d'Arguin as a pool for precursors for photochemical H2 production, whereas oceanic N2 fixation could not be identified as a source for atmospheric H2 during these two cruises. The variability in diurnal cycles is probably influenced by released precursors for photochemical H2 production and also affected by a varying origin of air masses. This means for future investigations that only measuring the mixing ratio of H2 is insufficient to explain the variability of an atmospheric diurnal cycle and support is needed, e.g. by isotopic measurements. Nevertheless, measurements of atmospheric H2

  12. Low-Velocity Measurement in Water

    Science.gov (United States)

    Ellis, Christopher; Stefan, Heinz G.

    1986-09-01

    Water velocities in the centimeter per second range or less are measurable by only a few instruments. Experimental laboratory studies frequently require such measurements. A review of low water velocity measurement methods is presented. An inexpensive optical hydrogen bubble-tracing technique is described for velocity measurements in the range 0.5 to 8 cm/s. Modification to a thymol blue (pH) tracer method extends its applicability to the range 0.1 to 1.0 cm/s. Design and operational characteristics of the hydrogen bubble/thymol blue current meter are described.

  13. Relationship between vessel diameter and depth measurements within the limbus using ultra-high resolution optical coherence tomography.

    Science.gov (United States)

    Alabi, Emmanuel; Hutchings, Natalie; Bizheva, Kostadinka; Simpson, Trefford

    2017-06-16

    To establish a relationship between the diameter and depth position of vessels in the superior and inferior corneo-scleral limbus using ultra-high resolution optical coherence tomography (UHR-OCT). Volumetric OCT images of the superior and inferior limbus were acquired from 14 healthy subjects with a research-grade UHR-OCT system. Differences in vessel diameter and depth between superior and inferior limbus were analyzed using repeated measured ANOVA in SPSS and R. The mean (± SD) superior and inferior diameters were 29±18μm and 24±18μm respectively, and the mean (± SD) superior and inferior depths were 177±109μm and 207±132μm respectively. The superior limbal vessels were larger than the inferior ones (RM-ANOVA, p=0.004), and the inferior limbal vessels were deeper than the superior vessels (RM-ANOVA, p=0.041). There was a positive linear association between limbal vessel depth and size within the superior and inferior limbus with Pearson correlation coefficients of 0.803 and 0.754, respectively. This study demonstrated that the UHR-OCT was capable of imaging morphometric characteristics such as the size and depth of vessels in the limbus. The results of this study suggest a difference in the size and depth of vessels across different positions of the limbus, which may be indicative of adaptations to chronic hypoxia caused by the covering of the superior limbus by the upper eyelid. UHR-OCT may be a useful tool to evaluate the effect of contact lenses on the microvascular properties within the limbus. Copyright © 2017 Spanish General Council of Optometry. All rights reserved.

  14. High Resolution Measurement of Rhizosphere Priming Effects and Temporal Variability of CO2 Fluxes under Zea Mays

    Science.gov (United States)

    Splettstößer, T.; Pausch, J.

    2016-12-01

    Plant induced increase of soil organic matter turnover rates contribute to carbon emissions in agricultural land use systems. In order to better understand these rhizosphere priming effects, we conducted an experiment, which enabled us to monitor CO2 fluxes under zea mays plants with high resolution. The experiment was conducted in a climate chamber where the plants were grown in thin, tightly sealed boxes for 40 days and CO2 efflux from soil was measured twice a day. 13C-CO2 was introduced to allow differentiation between plant and soil derived CO2.This enabled us to monitor root respiration and soil organic matter turnover in the early stages of plant growth and to highlight changes in soil CO2 emissions and priming effects between day and night. The measurements were conducted with a PICARRO G2131-I δ13C high-precision isotopic CO2 Analyzer (PICARRO INC.) utilizing an automated valve system governed by a CR1000 data logger (Campbell Scientific). After harvest roots and shoots were analyzed for 13C content. Microbial biomass, root length density and enzymatic activities in soil were measured and linked to soil organic matter turnover rates. In order to visualize the spatial distribution of carbon allocation to the root system a few plants were additionally labeled with 14C and 14C distribution was monitored by 14C imaging of the root systems over 4 days. Based on the 14C distribution a grid was chosen and the soil was sampled from each square of the grid to investigate the impact of carbon allocation hotspots on enzymatic activities and microbial biomass. First initial results show an increase of soil CO2 efflux in the night periods, whereby the contribution of priming is not fully analyzed yet. Additionally, root tips were identified as hotspots of short term carbon allocation via 14C imaging and an in increase in microbial biomass could be measured in this regions. The full results will be shown at AGU 2016.

  15. High resolution imaging Fourier transform spectrometer with no moving components for the measurement of atmospheric trace gases

    Science.gov (United States)

    Mortimer, H.

    2014-12-01

    A high resolution Static Imaging Fourier Transform Spectrometer, SIFTS, with no moving parts has been developed for the detection of atmospheric gases. The instrument has been shown to have high spectral resolution (4 cm-1) and temporal resolution (10kHz) resolution in both the mid and near infrared and moderate spectral resolution (14cm-1) in the visible. This instrument has been developed for the remote sensing and in-situ measurements of atmospheric gases. It has been identified that due to the low mass and compact size of the instrument system, that the SIFTS could be deployed as a remote sensing instrument onboard a Earth Observation satellite or Unmanned Aerial Vehicle (UAV), or conversely as a radiosonde instrument for in-situ measurements of atmospheric gases. The technique is based on a static optical configuration whereby light is split into two paths and made to recombine along a focal plane producing an interference pattern. The spectral information is returned using a detector array to digitally capture the interferogram which can then be processed into a spectrum by applying a Fourier transform. As there are no moving components, the speed of measurement is determined by the frame rate of the detector array. Thus, this instrument has a temporal advantage over common Michelson FTIR instruments. Using a high speed Toshiba CCD line array, sensitive over the spectral region of 400 - 1100nm, spectra have been recorded at a rate of one every 100 microseconds. Using an uncooled microbolometer infrared detector array, sensitive over the spectral region of 2 to 15μm, the gases NH3, O3 and CH4 have been used to demonstrate the sensitivity of the SIFTS instrument. It has been shown that the Signal to Noise of the SIFTSMIR is >1200 using an integration time of 77msec. The novel optical design has reduced the optics to only 3 optical components, and the detector array, to generate and measure the interferogram. The experimental performance of the SIFTS instrument

  16. Position and velocity estimation through acceleration measurements

    OpenAIRE

    Estrada, Antonio; Efimov, Denis; Perruquetti, Wilfrid

    2014-01-01

    International audience; This paper proposes a solution to the problem of velocity and position estimation for a class of oscillating systems whose position, velocity and acceleration are zero mean signals. The proposed scheme considers that the dynamic model of the system is unknown and only noisy acceleration measurements are available.

  17. Factor analysis of combined organic and inorganic aerosol mass spectra from high resolution aerosol mass spectrometer measurements

    Directory of Open Access Journals (Sweden)

    Y. L. Sun

    2012-05-01

    Full Text Available The high resolution mass spectra of organic and inorganic aerosols from aerosol mass spectrometer (AMS measurements were first combined into positive matrix factorization (PMF analysis to investigate the sources and evolution processes of atmospheric aerosols. The new approach is able to study the mixing of organic aerosols (OA and inorganic species, the acidity of OA factors, and the fragment ion patterns related to photochemical processing. In this study, PMF analysis of the unified AMS spectral matrices resolved 8 factors for the submicron aerosols measured at Queens College in New York City in summer 2009. The hydrocarbon-like OA (HOA and cooking OA (COA contain very minor inorganic species, indicating the different sources and mixing characteristics between primary OA and secondary species. The two factors that are primarily ammonium sulfate (SO4-OA and ammonium nitrate (NO3-OA, respectively, are overall neutralized, of which the OA in SO4-OA shows the highest oxidation state (O/C = 0.69 among OA factors. The semi-volatile oxygenated OA comprises two components, i.e., a less oxidized (LO-OOA and a more oxidized (MO-OOA. The MO-OOA represents a local photochemical product with the diurnal profile exhibiting a pronounced noon peak, consistent with those of formaldehyde (HCHO and Ox (= O3+NO2. The much higher NO+/NO2+ fragment ion ratio in MO-OOA than that from ammonium nitrate alone provides evidence for the formation of organic nitrates. The amine-related nitrogen-enriched OA (NOA contains ~25% of acidic inorganic salts, elucidating the formation of secondary OA from amines in acidic environments. The size distributions derived from 3-dimensional size-resolved mass spectra show distinct diurnal evolving behaviors for different OA factors, but overall a progressing evolution from smaller to larger particle mode as a function of oxidation states

  18. Fast Airborne Aerosol Size and Chemistry Measurements with the High Resolution Aerosol Mass Spectrometer during the MILAGRO Campaign

    Science.gov (United States)

    DeCarlo, P. F.; Dunlea, E. J.; Kimmel, J. R.; Aiken, A. C.; Sueper, D.; Crounse, J.; Wennberg, P. O.; Emmons, L.; Shinozuka, Y.; Clarke, A.; Zhou, J.; Tomlinson, J.; Collins,D. R.; Knapp, D.; Weinheimer, A. J.; Montzka,D. D.; Campos,T.; Jimenez, J. L.

    2007-01-01

    The concentration, size, and composition of non-refractory submicron aerosol (NR-PM(sub l)) was measured over Mexico City and central Mexico with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) onboard the NSF/NCAR C-130 aircraft as part of the MILAGRO field campaign. This was the first aircraft deployment of the HR-ToF-AMS. During the campaign the instrument performed very well, and provided 12 s data. The aerosol mass from the AMS correlates strongly with other aerosol measurements on board the aircraft. Organic aerosol (OA) species dominate the NR-PM(sub l) mass. OA correlates strongly with CO and HCN indicating that pollution (mostly secondary OA, SOA) and biomass burning (BB) are the main OA sources. The OA to CO ratio indicates a typical value for aged air of around 80 microg/cubic m (STP) ppm(exp -1). This is within the range observed in outflow from the Northeastern US, which could be due to a compensating effect between higher BB but lower biogenic VOC emissions during this study. The O/C atomic ratio for OA is calculated from the HR mass spectra and shows a clear increase with photochemical age, as SOA forms rapidly and quickly overwhelms primary urban OA, consistent with Volkamer et al. (2006) and Kleinman et al. (2008). The stability of the OA/CO while O/C increases with photochemical age implies a net loss of carbon from the OA. BB OA is marked by signals at m/z 60 and 73, and also by a signal enhancement at large m/z indicative of larger molecules or more resistance to fragmentation. The main inorganic components show different spatial patterns and size distributions. Sulfate is regional in nature with clear volcanic and petrochemical/power plant sources, while the urban area is not a major regional source for this species. Nitrate is enhanced significantly in the urban area and immediate outflow, and is strongly correlated with CO indicating a strong urban source. The importance of nitrate decreases with distance from the city

  19. Fast airborne aerosol size and chemistry measurements with the high resolution aerosol mass spectrometer during the MILAGRO Campaign

    Science.gov (United States)

    Decarlo, P. F.; Dunlea, E. J.; Kimmel, J. R.; Aiken, A. C.; Sueper, D.; Crounse, J.; Wennberg, P. O.; Emmons, L.; Shinozuka, Y.; Clarke, A.; Zhou, J.; Tomlinson, J.; Collins, D. R.; Knapp, D.; Weinheimer, A. J.; Montzka, D. D.; Campos, T.; Jimenez, J. L.

    2007-12-01

    The concentration, size, and composition of non-refractory submicron aerosol (NR-PM1) was measured over Mexico City and central Mexico with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) onboard the NSF/NCAR C-130 aircraft as part of the MILAGRO field campaign. This was the first aircraft deployment of the HR-ToF-AMS, in which the instrument performed very well, and provided 12 s data. The aerosol mass from the AMS correlates strongly with other aerosol measurements on board the aircraft. Organic aerosol (OA) species dominate the NR-PM1 mass. OA correlates strongly with CO and HCN indicating that pollution (mostly secondary OA, SOA) and biomass burning (BB) are the main OA sources. The OA to CO ratio indicates a typical value for aged air of around 80 μg m-3 (STP) ppm-1. This is within the range observed in outflow from the Northeastern US, which could be due to a compensating effect between higher BB but lower biogenic VOC emissions during this study. The O/C atomic ratio for OA is calculated from the HR mass spectra and shows a clear increase with photochemical age, as SOA forms rapidly and quickly overwhelms primary urban OA, consistent with Volkamer et al. (2006) and Kleinman et al. (2007b). BB OA is marked by signals at m/z 60 and 73, and also by a signal enhancement at large m/z indicative of larger molecules or more resistance to fragmentation. The main inorganic components show different spatial patterns and size distributions. Sulfate is regional in nature with clear volcanic and petrochemical/power plant sources, while the urban area is not a major source for this species. Nitrate is enhanced significantly in the urban area and immediate outflow, and is strongly correlated with CO indicating a strong urban source. The importance of nitrate decreases with distance from the city likely due to evaporation. BB does not appear to be a strong source of nitrate despite its high emissions of nitrogen oxides, presumably due to low ammonia

  20. Fast airborne aerosol size and chemistry measurements with the high resolution aerosol mass spectrometer during the MILAGRO Campaign

    Directory of Open Access Journals (Sweden)

    P. F. DeCarlo

    2007-12-01

    Full Text Available The concentration, size, and composition of non-refractory submicron aerosol (NR-PM1 was measured over Mexico City and central Mexico with a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS onboard the NSF/NCAR C-130 aircraft as part of the MILAGRO field campaign. This was the first aircraft deployment of the HR-ToF-AMS, in which the instrument performed very well, and provided 12 s data. The aerosol mass from the AMS correlates strongly with other aerosol measurements on board the aircraft. Organic aerosol (OA species dominate the NR-PM1 mass. OA correlates strongly with CO and HCN indicating that pollution (mostly secondary OA, SOA and biomass burning (BB are the main OA sources. The OA to CO ratio indicates a typical value for aged air of around 80 μg m−3 (STP ppm−1. This is within the range observed in outflow from the Northeastern US, which could be due to a compensating effect between higher BB but lower biogenic VOC emissions during this study. The O/C atomic ratio for OA is calculated from the HR mass spectra and shows a clear increase with photochemical age, as SOA forms rapidly and quickly overwhelms primary urban OA, consistent with Volkamer et al. (2006 and Kleinman et al. (2007b. BB OA is marked by signals at m/z 60 and 73, and also by a signal enhancement at large m/z indicative of larger molecules or more resistance to fragmentation. The main inorganic components show different spatial patterns and size distributions. Sulfate is regional in nature with clear volcanic and petrochemical/power plant sources, while the urban area is not a major source for this species. Nitrate is enhanced significantly in the urban area and immediate outflow, and is strongly correlated with CO indicating a strong urban source. The importance of nitrate decreases with distance from the city likely due to evaporation. BB does not appear to be a strong source of nitrate

  1. Marker-referred movement measurement with grey-scale coordinate extraction for high-resolution real-time 3D at 100 Hz

    NARCIS (Netherlands)

    Furnée, E.H.; Jobbá, A.; Sabel, J.C.; Veenendaal, H.L.J. van; Martin, F.; Andriessen, D.C.W.G.

    1997-01-01

    A review of early history in photography highlights the origin of cinefilm as a scientific tool for image-based measurement of human and animal motion. The paper is concerned with scanned-area video sensors (CCD) and a computer interface for the real-time, high-resolution extraction of image coordin

  2. Measuring Bullet Velocity with a PC Soundcard

    CERN Document Server

    Courtney, M; Courtney, Michael; Edwards, Brian

    2006-01-01

    This article describes a simple method for using a PC soundcard to accurately measure bullet velocity. The method involves placing the microphone within a foot of the muzzle and firing at a steel target between 50 and 100 yards away. The time of flight for the bullet is simply the recorded time between muzzle blast and sound of the bullet hitting the target minus the time it takes the sound to return from the target to the microphone. The average bullet velocity is simply the distance from the muzzle to the target divided by the time of flight of the bullet. This method can also be applied to measurement of paintball velocities.

  3. The APOGEE red-clump catalog: Precise distances, velocities, and high-resolution elemental abundances over a large area of the Milky Way's disk

    CERN Document Server

    Bovy, Jo; Rix, Hans-Walter; Girardi, Léo; Zasowski, Gail; Chojnowski, S Drew; Holtzman, Jon; Epstein, Courtney; Frinchaboy, Peter M; Hayden, Michael R; Rodrigues, Thaíse S; Majewski, Steven R; Johnson, Jennifer A; Pinsonneault, Marc H; Stello, Dennis; Prieto, Carlos Allende; Andrews, Brett; Basu, Sarbani; Beers, Timothy C; Bizyaev, Dmitry; Burton, Adam; Chaplin, William J; Cunha, Katia; Elsworth, Yvonne; García, Rafael A; García-Herńandez, Domingo A; Pérez, Ana E García; Hearty, Fred R; Hekker, Saskia; Kallinger, Thomas; Kinemuchi, Karen; Koesterke, Lars; Mészáros, Szabolcs; Mosser, Benoît; O'Connell, Robert W; Oravetz, Daniel; Pan, Kaike; Robin, Annie C; Schiavon, Ricardo P; Schneider, Donald P; Schultheis, Mathias; Serenelli, Aldo; Shetrone, Matthew; Aguirre, Victor Silva; Simmons, Audrey; Skrutskie, Michael; Smith, Verne V; Stassun, Keivan; Weinberg, David H; Wilson, John C; Zamora, Olga

    2014-01-01

    The Sloan Digital Sky Survey III's Apache Point Observatory Galactic Evolution Experiment (APOGEE) is a high-resolution near-infrared spectroscopic survey covering all of the major components of the Galaxy, including the dust-obscured regions of the inner Milky Way disk and bulge. Here we present a sample of 10,352 likely red-clump stars (RC) from the first two years of APOGEE operations, selected based on their position in color-metallicity-surface-gravity-effective-temperature space using a new method calibrated using stellar-evolution models and high-quality asteroseismology data. The narrowness of the RC locus in color-metallicity-luminosity space allows us to assign distances to the stars with an accuracy of 5 to 10%. The sample extends to typical distances of about 3 kpc from the Sun, with some stars out to 8 kpc, and spans a volume of approximately 100 kpc^3 over 5 kpc <~ R <~ 14 kpc, |Z| <~ 2 kpc, and -15 deg <~ Galactocentric azimuth <~ 30 deg. The APOGEE red-clump (APOGEE-RC) catalog ...

  4. Acoustic measurement of potato cannon velocity

    CERN Document Server

    Courtney, M; Courtney, Amy; Courtney, Michael

    2006-01-01

    This article describes measurement of potato cannon velocity with a digitized microphone signal. A microphone is attached to the potato cannon muzzle and a potato is fired at an aluminum target about 10 m away. The potato's flight time can be determined from the acoustic waveform by subtracting the time in the barrel and time for sound to return from the target. The potato velocity is simply the flight distance divided by the flight time.

  5. High Resolution Elevation Contours

    Data.gov (United States)

    Minnesota Department of Natural Resources — This dataset contains contours generated from high resolution data sources such as LiDAR. Generally speaking this data is 2 foot or less contour interval.

  6. 2D/3D velocity model for the high resolution 2D and 3D seismic data from the CO2SINK Ketzin Project

    Science.gov (United States)

    Ivanova, A.; Asch, G.; Lueth, S.; Goetz, J.

    2009-04-01

    Seismic traveltime inversion, traveltime tomography and seismic reflection techniques have been applied for two dimensional (2D) and three dimensional (3D) data acquired in conjunction with characterization and monitoring aspects at a carbon dioxide (CO2) geological storage site at Ketzin, Germany (the CO2SINK project) (S.Yordkayhun, 2008). A seismic source comparison from the 2D pilot study regarding acquisition parameters have been tested at the side has shown the weight drop source is suitable concerning the signal penetration, frequency content of the data and minimizing time and costs for the 3D data acquisition. For the Ketzin seismic data, the ability to obtain an accurate 2D/3D interval velocity model is limited by the acquisition geometry, source-generated noise and time shifts due to the near-surface effects producing severe distortions in the data. Moreover, these time shifts are comparable to the dominant periods of the reflections and to the size of structures to be imaged. Therefore, a combination of seismic refraction and state-of-the-art processing techniques, including careful static corrections and more accurate velocity analysis, has resulted in key improvements of the images and has allowed new information about the 2D/3D interval velocities. The results from these studies together with borehole information, hydrogeologic models and seismic modeling will be combined into an integrated 2D/3D velocity model. After that a careful 2D/3D depth migration is to be provided. It can be used as a database for the future monitoring program at the site.

  7. Velocity-selective EIT measurement of potassium Rydberg states

    CERN Document Server

    Xu, Wenchao

    2016-01-01

    We demonstrate a velocity selection scheme that mitigates suppression of electromagnetically induced transparency (EIT) by Doppler shifts for low--high EIT probe--coupling wavelength ordering. An optical pumping beam counter-propagating with the EIT probe beam transfers atoms between hyperfine states in a velocity selective fashion. Measurement of the transmitted probe beam synchronous with chopping of the optical pumping beam enables a Doppler-free EIT signal to be detected. Transition frequencies between 5P$_{1/2}$ and $n$S$_{1/2}$ states for $n=$26, 27, and 28 in $^{39}$K are obtained via EIT spectroscopy in a heated vapor cell with a probe beam stabilized to the 4S$_{1/2}\\rightarrow$5P$_{1/2}$ transition. Using previous high-resolution measurements of the 4S$_{1/2}\\rightarrow$nS$_{1/2}$ transitions, we make a determination of the absolute frequency of the 4S$_{1/2}\\rightarrow$5P$_{1/2}$ transition. Our measurement is shifted by 560 MHz from the currently accepted value with a two-fold improvement in uncer...

  8. High-resolution, terrestrial radar velocity observations and model results reveal a strong bed at stable, tidewater Rink Isbræ, West Greenland

    Science.gov (United States)

    Bartholomaus, T. C.; Walker, R. T.; Stearns, L. A.; Fahnestock, M. A.; Cassotto, R.; Catania, G. A.; Felikson, D.; Fried, M.; Sutherland, D.; Nash, J. D.; Shroyer, E.

    2015-12-01

    At tidewater Rink Isbræ, on the central west coast of Greenland, satellite observations reveal that glacier velocities and terminus positions have remained stable, while the lowest 25 km have thinned 30 m since 1985. Over this same time period, other tidewater glaciers in central west Greenland have retreated, thinned and accelerated. Here we present field observations and model results to show that the flow of Rink Isbræ is resisted by unusually high basal shear stresses. Terrestrial radar interferometry (TRI) observations over 9 days in summer 2014 demonstrate weak velocity response to 4 km wide, full thickness calving events. Velocities at the terminus change by +/- 10% in response to rising and falling tides within a partial-width, 2.5-km-long floating ice tongue; however these tidal perturbations damp out within 2 km of the grounding line. Inversions for basal shear stress and force balance analyses together show that basal shear stresses in excess of 300 kPa support the majority of the driving stress at thick, steep Rink Isbræ. These observational and modeling results tell a consistent story in which a strong bed may limit the unstable tidewater glacier retreats observed elsewhere. Rink Isbræ has an erosion resistant quartzite bed with low fracture density. We hypothesize that this geology may play a major role in the bed strength.

  9. Wideband high-resolution direction of arrival estimation method based on the pressure-velocity combined processing using the acoustic vector sensor array

    Institute of Scientific and Technical Information of China (English)

    BAI Xingyu; YANG Desen; ZHAO Chunhui

    2007-01-01

    In order to solve the problem of DOA (Direction of Arrival) estimation of underwater distant wideband targets, a novel coherent signal-subspace method based on the cross spectral matrix of pressure and particle velocity using the Acoustic Vector Sensor Array (AVSA)is proposed in this paper. The proposed method is different from existing AVSA based DOA estimation methods in using particle velocity information of Acoustic Vector Sensor (AVS) as an independent array element. It is entirely based on the combined information processing of pressure and particle velocity, namely, the P-V cross spectrum, has better DOA estimation performance than existing methods in isotropic noise field. By theoretical analysis, both focusing principle and eigendecomposition theory based on the P-V cross spectral matrix are given.At the same time, the corresponding criteria for source number detection is also presented.Computer simulations with data from lake trials demonstrate that the proposed method is effective and obviously outperforms existing methods in resolution and accuracy in the case of low Signal-to-Noise Ratio (SNR).

  10. VLA observations of the OH emission from Comet Wilson (1986) - The value of high resolution in both spatial and velocity coordinates

    Science.gov (United States)

    Palmer, Patrick; De Pater, Imke; Snyder, Lewis E.

    1989-01-01

    In comparison with Comet Halley, the radio OH emission from Comet Wilson behaved very erratically, changing rapidly in position as well as in velocity, while the emission and brightness distribution from Comet Halley displayed apparent stability. A few months later, nearer perihelion, just the opposite behavior was observed at UV wavelengths. Another difference between the two comets is that the OH emission from Comet Halley seemed confined to a region a few times 100.000 km in size, while the emission from Comet Wilson showed up in sporadic blobs, with variable intensities and velocities, at distances as far as 10 to the 6th km from the nucleus. This behavior in Comet Wilson may be associated with the disintegration of the outer frosting associated with new comets and possibly with the fragmentation and ejection of cometesimals from the nucleus. As part of the data analysis, it is demonstrated that lengthening the integration time and lowering the velocity resolution affects the symmetry of the OH images and spectral-line profiles. As a consequence, asymmetric cometary OH line profiles may be more common than previously thought.

  11. High-resolution measurement and mapping of tungstate in waters, soils and sediments using the low-disturbance DGT sampling technique

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Dong-Xing [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China); Williams, Paul N. [Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast BT9 7BL (United Kingdom); Xu, Hua-Cheng [State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008 (China); Li, Gang [Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021 (China); Luo, Jun, E-mail: esluojun@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China); Ma, Lena Q. [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023 (China); Soil and Water Science Department, University of Florida, Gainesville, FL 32611 (United States)

    2016-10-05

    Highlights: • Two high-resolution diffusive gradients in thin-films samplers were characterized. • For the first time DGT was applied to study the bioavailability of W in soils. • 1D and 2D high resolution profiling of W fluxes across the SWI were obtained. • The apparent diffusion W fluxes across two micro-interfaces were calculated. - Abstract: Increasing tungsten (W) use for industrial and military applications has resulted in greater W discharge into natural waters, soils and sediments. Risk modeling of W transport and fate in the environment relies on measurement of the release/mobilization flux of W in the bulk media and the interfaces between matrix compartments. Diffusive gradients in thin-films (DGT) is a promising passive sampling technique to acquire such information. DGT devices equipped with the newly developed high-resolution binding gels (precipitated zirconia, PZ, or ferrihydrite, PF, gels) or classic/conventional ferrihydrite slurry gel were comprehensively assessed for measuring W in waters. {sup Ferrihydrite}DGT can measure W at various ionic strengths (0.001–0.5 mol L{sup −1} NaNO{sub 3}) and pH (4–8), while {sup PZ}DGT can operate across slightly wider environmental conditions. The three DGT configurations gave comparable results for soil W measurement, showing that typically W resupply is relatively poorly sustained. 1D and 2D high-resolution W profiling across sediment—water and hotspot—bulk media interfaces from Lake Taihu were obtained using {sup PZ}DGT coupled with laser ablation ICP–MS measurement, and the apparent diffusion fluxes across the interfaces were calculated using a numerical model.

  12. Antarctica: measuring glacier velocity from satellite images.

    Science.gov (United States)

    Lucchitta, B K; Ferguson, H M

    1986-11-28

    Many Landsat images of Antarctica show distinctive flow and crevasse features in the floating part of ice streams and outlet glaciers immediately below their grounding zones. Some of the features, which move with the glacier or ice stream, remain visible over many years and thus allow time-lapse measurements of ice velocities. Measurements taken from Landsat images of features on Byrd Glacier agree well with detailed ground and aerial observations. The satellite-image technique thus offers a rapid and cost-effective method of obtaining average velocities, to a first order of accuracy, of many ice streams and outlet glaciers near their termini.

  13. Comparison of Methods to Map and Measure River Terraces using High-Resolution Airborne LiDAR Data

    Science.gov (United States)

    Hopkins, A. J.; Snyder, N. P.

    2013-12-01

    Fluvial terraces are important recorders of land-use, climate, and tectonic history that form in both erosional and depositional landscapes and consist of a flat surface bounded by valley walls and a steep-sloping scarp adjacent to the river channel. Combining these defining characteristics with high-resolution digital elevation models (DEMs) derived from airborne light detection and ranging (lidar) surveys, several methods have been developed to identify and map terraces. The goals of this research are to compare some of these existing techniques and develop an objective approach to map terraces over entire watersheds using lidar DEMs. Additionally, we aim to quantify the thickness and volume of fill terrace deposits. Our preliminary application is to the Sheepscot River watershed, Maine, where strath and fill terraces are present and record Pleistocene deglaciation, Holocene eustatic forcing, and Anthropocene land-use change. We identify terraces along the longitudinal profile using an algorithm developed by Finnegan and Balco (2013), that computes the elevation frequency distribution at regularly spaced cross-sections normal to the channel. Next, we delineate terrace spatial extent using three separate methodologies: (1) image processing using Matlab, (2) feature classification algorithms developed by Wood (1996), and (3) image interpretation using manually placed points on known terraces to construct interpolated surfaces (Walter and Merritts, 2008). Lastly, we determine the thickness and volume of fill terrace sediments by subtracting an interpolated, adjacent water surface elevation from the defined terrace points. We compare our LiDAR-based results with field mapping, stratigraphic columns of terrace landforms, and ground penetrating radar over terrace surfaces. These findings suggest powerful new ways to rapidly analyze landscape history over large regions using high-resolution lidar DEMs, with less reliance on detailed and costly field data collection.

  14. Improving Measurement of Forest Structural Parameters by Co-Registering of High Resolution Aerial Imagery and Low Density LiDAR Data

    OpenAIRE

    Huang, Huabing; Gong, Peng; CHENG, XIAO; Clinton, Nick; Li, Zengyuan

    2009-01-01

    Forest structural parameters, such as tree height and crown width, are indispensable for evaluating forest biomass or forest volume. LiDAR is a revolutionary technology for measurement of forest structural parameters, however, the accuracy of crown width extraction is not satisfactory when using a low density LiDAR, especially in high canopy cover forest. We used high resolution aerial imagery with a low density LiDAR system to overcome this shortcoming. A morphological filtering was used to ...

  15. Absolute velocity measurements in the solar transition region and corona

    Science.gov (United States)

    Hassler, D. M.; Rottman, G. J.; Orrall, F. Q.

    An experimental technique is presented to measure absolute velocities of minor ions formed in the solar transition region and corona. A sounding rocket experiment July 27 1987 obtained high resolution EUV spectra along a solar diameter with spatial resolution of 20 x 20 arcsec. The wavelengths of the 1533 Si II, 1548 C IV, and 770 Ne VIII emission lines were directly compared with wavelengths of known platinum lines generated by an inflight calibration lamp. On the assumption that horisontal motions cancel statistically so that the line-of-sight velocity approaches zero at the limb, a net radial downflow of approximately 7.5 + or - 1.0 km/s was found for C IV and upper limits were found on the radial flow for Si II and Ne VIII. This assumption was tested by direct comparison to the on-board wavelength reference using recently published laboratory rest wavelengths of the solar emission lines. Agreement was found within the published uncertainties of the laboratory wavelengths + or - 2 km/s in the case of C IV. It is suggested that improved laboratory wavelength measurements (+ or - 1 km/s) in conjunction with inflight wavelength calibration would improve constraints on models of transition region and coronal dynamics.

  16. Device for measuring mechanical drilling velocity

    Energy Technology Data Exchange (ETDEWEB)

    Turchaninov, Y.N.; Ippolitova, L.G.; Khizgilov, A.I.; Rolik, V.A.

    1980-12-17

    A device is proposed for measuring the mechanical drilling velocity which includes a primary drilling tool supply transformer, control block, trigger, range switch; control block, block for determining motion direction, time counter and measurement instrument. In order to guarantee continuous measurement of the mechanical velocity and to improve the accuracy of measuring the average mechanical velocity during drilling at sea, it is equipped with a block for multiplying the number of pulses, four I circuits, supply counter, supply recorder, primary neutral transformer, two controllable frequency dividers, first frequency divider, generator of prime pulses consisting of a generatror of reference frequencies and second frequency divider, time recorder, counter and velocity recorder, time recorder and digital-analog transformer. In this case the outlet of the primary transformer for drilling tool supply is connected through a in-series connected block for determining the movement direction, block for multiplying the number of pulses, first circuit I and supply counter to one of the inlets of the supply counter. Its second inlet is connected through a block of control to the primary neutral transformer and one of the inlets of the time recorder. Its second inlet is connected through a in-series connected time counter, fourth I circuit, second frequency divider, generator of reference frequency, first frequency divider, third circuit I, second controllable frequency divider, counter and velocity recorder and digital-analog transformer of the measurement instrument. The outlet of the supply recorder is connected to one of the inlets of the first controllable divider. Its second inlet is connected to the second I circuit to the outlet of the first frequency divider, and the outlet is connected to one of the trigger inlets.

  17. Placido disk-based topography versus high-resolution rotating Scheimpflug camera for corneal power measurements in keratoconic and post-LASIK eyes: reliability and agreement

    Science.gov (United States)

    Penna, Rachele R.; de Sanctis, Ugo; Catalano, Martina; Brusasco, Luca; Grignolo, Federico M.

    2017-01-01

    AIM To compare the repeatability/reproducibility of measurement by high-resolution Placido disk-based topography with that of a high-resolution rotating Scheimpflug camera and assess the agreement between the two instruments in measuring corneal power in eyes with keratoconus and post-laser in situ keratomileusis (LASIK). METHODS One eye each of 36 keratoconic patients and 20 subjects who had undergone LASIK was included in this prospective observational study. Two independent examiners worked in a random order to take three measurements of each eye with both instruments. Four parameters were measured on the anterior cornea: steep keratometry (Ks), flat keratometry (Kf), mean keratometry (Km), and astigmatism (Ks-Kf). Intra-examiner repeatability and inter-examiner reproducibility were evaluated by calculating the within-subject standard deviation (Sw) the coefficient of repeatability (R), the coefficient of variation (CoV), and the intraclass correlation coefficient (ICC). Agreement between instruments was tested with the Bland-Altman method by calculating the 95% limits of agreement (95% LoA). RESULTS In keratoconic eyes, the intra-examiner and inter-examiner ICC were >0.95. As compared with measurement by high-resolution Placido disk-based topography, the intra-examiner R of the high-resolution rotating Scheimpflug camera was lower for Kf (0.32 vs 0.88), Ks (0.61 vs 0.88), and Km (0.32 vs 0.84) but higher for Ks-Kf (0.70 vs 0.57). Inter-examiner R values were lower for all parameters measured using the high-resolution rotating Scheimpflug camera. The 95% LoA were -1.28 to +0.55 for Kf, -1.36 to +0.99 for Ks, -1.08 to +0.50 for Km, and -1.11 to +1.48 for Ks-Kf. In the post-LASIK eyes, the intra-examiner and inter-examiner ICC were >0.87 for all parameters. The intra-examiner and inter-examiner R were lower for all parameters measured using the high-resolution rotating Scheimpflug camera. The intra-examiner R was 0.17 vs 0.88 for Kf, 0.21 vs 0.88 for Ks, 0.17 vs 0

  18. X-RAY HIGH-RESOLUTION SPECTROSCOPY REVEALS FEEDBACK IN A SEYFERT GALAXY FROM AN ULTRA-FAST WIND WITH COMPLEX IONIZATION AND VELOCITY STRUCTURE

    Energy Technology Data Exchange (ETDEWEB)

    Longinotti, A. L. [Catedrática CONACYT—Instituto Nacional de Astrofísica, Óptica y Electrónica, Luis E. Erro 1, Tonantzintla, Puebla, C.P. 72840, México (Mexico); Krongold, Y. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Apartado Postal 70264, 04510 Mexico D.F. (Mexico); Guainazzi, M.; Santos-Lleo, M.; Rodriguez-Pascual, P. [ESAC, P.O. Box, 78 E-28691 Villanueva de la Cañada, Madrid (Spain); Giroletti, M. [INAF Osservatorio di Radioastronomia, via Gobetti 101, I-40129 Bologna (Italy); Panessa, F. [INAF—Istituto di Astrofisica e Planetologia Spaziali di Roma (IAPS), Via del Fosso del Cavaliere 100, I-00133 Roma (Italy); Costantini, E. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands)

    2015-11-10

    Winds outflowing from active galactic nuclei (AGNs) may carry significant amounts of mass and energy out to their host galaxies. In this paper we report the detection of a sub-relativistic outflow observed in the narrow line Seyfert 1 galaxy IRAS 17020+4544 as a series of absorption lines corresponding to at least five absorption components with an unprecedented wide range of associated column densities and ionization levels and velocities in the range of 23,000–33,000 km s{sup −1}, detected at X-ray high spectral resolution (E/ΔE ∼ 1000) with the ESA's observatory XMM-Newton. The charge states of the material constituting the wind clearly indicate a range of low to moderate ionization states in the outflowing gas and column densities that are significantly lower than observed in highly ionized ultra-fast outflows. We estimate that at least one of the outflow components may carry sufficient energy to substantially suppress star formation and heat the gas in the host galaxy. IRAS 17020+4544 therefore provides an interesting example of feedback by a moderately luminous AGN that is hosted in a spiral galaxy, a case barely envisaged in most evolution models, which often predict that feedback processes take place in massive elliptical galaxies hosting luminous quasars in a post-merger phase.

  19. X-ray high-resolution spectroscopy reveals feedback in a Seyfert galaxy from an ultra fast wind with complex ionization and velocity structure

    CERN Document Server

    Longinotti, Anna Lia; Guainazzi, Matteo; Giroletti, Marcello; Panessa, Francesca; Costantini, Elisa; Lleo, Maria Santos; Rodriguez-Pascual, Pedro

    2015-01-01

    Winds outflowing from Active Galactic Nuclei (AGNs) may carry significant amount of mass and energy out to their host galaxies. In this paper we report the detection of a sub-relativistic outflow observed in the Narrow Line Seyfert 1 Galaxy IRAS17020+4544 as a series of absorption lines corresponding to at least 5 absorption components with an unprecedented wide range of associated column densities and ionization levels and velocities in the range of 23,000-33,000 km/s, detected at X-ray high spectral resolution (E/Delta E ~1000) with the ESA's observatory XMM-Newton. The charge states of the material constituting the wind clearly indicate a range of low to moderate ionization states in the outflowing gas and column densities significantly lower than observed in highly ionized ultra fast outflows. We estimate that at least one of the outflow components may carry sufficient energy to substantially suppress star formation, and heat the gas in the host galaxy. IRAS17020+4544 provides therefore an interesting exa...

  20. High-resolution headlamp

    Science.gov (United States)

    Gut, Carsten; Cristea, Iulia; Neumann, Cornelius

    2016-04-01

    The following article shall describe how human vision by night can be influenced. At first, front lighting systems that are already available on the market will be described, followed by their analysis with respect to the positive effects on traffic safety. Furthermore, how traffic safety by night can be increased since the introduction of high resolution headlamps shall be discussed.

  1. High Resolution Formaldehyde Photochemistry

    Science.gov (United States)

    Ernest, C. T.; Bauer, D.; Hynes, A. J.

    2010-12-01

    Formaldehyde (HCHO) is the most abundant and most important organic carbonyl compound in the atmosphere. The sources of formaldehyde are the oxidation of methane, isoprene, acetone, and other volatile organic compounds (VOCs); fossil fuel combustion; and biomass burning. The dominant loss mechanism for formaldehyde is photolysis which occurs via two pathways: (R1) HCHO + hv → HCO + H (R2) HCHO + hv → H2 + CO The first pathway (R1) is referred to as the radical channel, while the second pathway (R2) is referred to as the molecular channel. The products of both pathways play a significant role in atmospheric chemistry. The CO that is produced in the molecular channel undergoes further oxidation to produce CO2. Under atmospheric conditions, the H atom and formyl radical that are produced in the radical channel undergo rapid reactions with O2 to produce the hydroperoxyl radical (HO2) via (R3) and (R4). (R3) HCO + O2 → HO2 + CO (R4) H + O2 → HO2 Thus, for every photon absorbed, the photolysis of formaldehyde can contribute one CO2 molecule to the global greenhouse budget or two HO2 radicals to the tropospheric HOx (OH + HO2) cycle. The HO2 radicals produced during formaldehyde photolysis have also been implicated in the formation of photochemical smog. The HO2 radicals act as radical chain carriers and convert NO to NO2, which ultimately results in the catalytic production of O3. Constraining the yield of HO2 produced via HCHO photolysis is essential for improving tropospheric chemistry models. In this study, both the absorption cross section and the quantum yield of the radical channel (R1) were measured at high resolution over the tropospherically relevant wavelength range 304-330 nm. For the cross section measurements a narrow linewidth Nd:YAG pumped dye laser was used with a multi-pass cell. Partial pressures of HCHO were kept below 0.3 torr. Simultaneous measurement of OH LIF in a flame allowed absolute calibration of the wavelength scale. Pressure

  2. High-resolution ionospheric observations and modeling over Belgium during the solar eclipse of 20 March 2015 including first results of ionospheric tilt and plasma drift measurements

    Science.gov (United States)

    Verhulst, Tobias G. W.; Sapundjiev, Danislav; Stankov, Stanimir M.

    2016-06-01

    The ionospheric behavior over Belgium during the partial solar eclipse of 20 March 2015 is analyzed based on high-resolution solar radio flux, vertical incidence sounding, and GPS TEC measurements. First results of ionosonde-based ionospheric plasma drift and tilt observations are presented and analyzed, including some traveling ionospheric disturbances caused by the eclipse. Also, collocated ionosonde and GPS measurements are used to reconstruct the time evolution of the vertical electron density distribution using the Royal Meteorological Institute (RMI) ionospheric specification system, called Local Ionospheric Electron Density profile Reconstruction (LIEDR).

  3. High-Resolution Seismic Velocity and Attenuation Structure of the Sichuan-Yunnan Region, Southwest China, Using Seismic Catalog and Waveform Data

    Science.gov (United States)

    2007-07-13

    in Lees and Lindley (1994), for Loma Prieta , and Rietbrock (2001), for Kobe. Our approach will follow that of Rietbrock (2001). Briefly, the set of...are also important in discriminating between earthquakes and explosions. For example, the Lg/Pg ratio has been shown to be an effective ...close; however, the measured differential t* values from spectral ratios are free from station effects and are not affected by the source model

  4. Water erosion as a cause for agricultural soil loss: modeling of dynamic processes using high-resolution ground based LiDAR measurements

    Science.gov (United States)

    Oz, Imri; Filin, Sagi; Assouline, Shmuel; Shtain, Zachi; Furman, Alexander

    2016-04-01

    Soil erosion by rainfall and water flow is a frequent natural geomorphic process shaping the earth's surface at various scales. Conventional agrotechnical methods enhance soil erosion at the field scale and are at the origin of the reduction of the upper soil layer depth. This reduction is expressed in two aspects: decrease of soil depth, mainly due to erosion, and the diminution of soil quality, mainly due to the loss of fine material, nutrients and organic matter. Rain events, not even the most extremes, cause detachment and transport of fertile soil rich in organic matter and nutrients away from the fields, filling and plugging drainage channels, blocking infrastructure and contaminating water sources. Empirical, semi-empirical and mechanistic models are available to estimate soil erosion by water flow and sediment transport (e.g. WEPP, KINEROSS, EUROSEM). Calibration of these models requires data measured at high spatial and temporal resolutions. Development of high-resolution measurement tools (for both spatial and temporal aspects) should improve the calibration of functions related to particles detachment and transport from the soil surface. In addition, despite the great impact of different tillage systems on the soil erosion process, the vast majority of the models ignore this fundamental factor. The objective of this study is to apply high-resolution ground-based LiDAR measurements to different tillage schemes and scales to improve the ability of models to accurately describe the process of soil erosion induced by rainfall and overland flow. Ground-based laser scans provide high resolution accurate and subtle geomorphic changes, as well as larger-scale deformations. As such, it allows frequent monitoring, so that even the effect of a single storm can be measured, thus improving the calibration of the erosion models. Preliminary results for scans made in the field show the potential and limitations of ground-based LiDAR, and at this point qualitatively can

  5. Technical Note: Skin thickness measurements using high-resolution flat-panel cone-beam dedicated breast CT

    Energy Technology Data Exchange (ETDEWEB)

    Shi Linxi; Vedantham, Srinivasan; Karellas, Andrew [Department of Radiology, University of Massachusetts Medical School, Worcester, Massachusetts 01655 (United States); O' Connell, Avice M. [Department of Radiology, University of Rochester Medical Center, Rochester, New York 14642 (United States)

    2013-03-15

    Purpose: To determine the mean and range of location-averaged breast skin thickness using high-resolution dedicated breast CT for use in Monte Carlo-based estimation of normalized glandular dose coefficients. Methods: This study retrospectively analyzed image data from a clinical study investigating dedicated breast CT. An algorithm similar to that described by Huang et al.['The effect of skin thickness determined using breast CT on mammographic dosimetry,' Med. Phys. 35(4), 1199-1206 (2008)] was used to determine the skin thickness in 137 dedicated breast CT volumes from 136 women. The location-averaged mean breast skin thickness for each breast was estimated and the study population mean and range were determined. Pathology results were available for 132 women, and were used to investigate if the distribution of location-averaged mean breast skin thickness varied with pathology. The effect of surface fitting to account for breast curvature was also studied. Results: The study mean ({+-} interbreast SD) for breast skin thickness was 1.44 {+-} 0.25 mm (range: 0.87-2.34 mm), which was in excellent agreement with Huang et al. Based on pathology, pair-wise statistical analysis (Mann-Whitney test) indicated that at the 0.05 significance level, there were no significant difference in the location-averaged mean breast skin thickness distributions between the groups: benign vs malignant (p= 0.223), benign vs hyperplasia (p= 0.651), hyperplasia vs malignant (p= 0.229), and malignant vs nonmalignant (p= 0.172). Conclusions: Considering this study used a different clinical prototype system, and the study participants were from a different geographical location, the observed agreement between the two studies suggests that the choice of 1.45 mm thick skin layer comprising the epidermis and the dermis for breast dosimetry is appropriate. While some benign and malignant conditions could cause skin thickening, in this study cohort the location-averaged mean breast skin

  6. High-resolution measurement and mapping of tungstate in waters, soils and sediments using the low-disturbance DGT sampling technique.

    Science.gov (United States)

    Guan, Dong-Xing; Williams, Paul N; Xu, Hua-Cheng; Li, Gang; Luo, Jun; Ma, Lena Q

    2016-10-05

    Increasing tungsten (W) use for industrial and military applications has resulted in greater W discharge into natural waters, soils and sediments. Risk modeling of W transport and fate in the environment relies on measurement of the release/mobilization flux of W in the bulk media and the interfaces between matrix compartments. Diffusive gradients in thin-films (DGT) is a promising passive sampling technique to acquire such information. DGT devices equipped with the newly developed high-resolution binding gels (precipitated zirconia, PZ, or ferrihydrite, PF, gels) or classic/conventional ferrihydrite slurry gel were comprehensively assessed for measuring W in waters. (Ferrihydrite)DGT can measure W at various ionic strengths (0.001-0.5molL(-1) NaNO3) and pH (4-8), while (PZ)DGT can operate across slightly wider environmental conditions. The three DGT configurations gave comparable results for soil W measurement, showing that typically W resupply is relatively poorly sustained. 1D and 2D high-resolution W profiling across sediment-water and hotspot-bulk media interfaces from Lake Taihu were obtained using (PZ)DGT coupled with laser ablation ICP-MS measurement, and the apparent diffusion fluxes across the interfaces were calculated using a numerical model. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Ultra high resolution tomography

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, W.S.

    1994-11-15

    Recent work and results on ultra high resolution three dimensional imaging with soft x-rays will be presented. This work is aimed at determining microscopic three dimensional structure of biological and material specimens. Three dimensional reconstructed images of a microscopic test object will be presented; the reconstruction has a resolution on the order of 1000 A in all three dimensions. Preliminary work with biological samples will also be shown, and the experimental and numerical methods used will be discussed.

  8. High Resolution Acoustical Imaging

    Science.gov (United States)

    1989-05-01

    1028 (September 1982). 26 G. Arfken , Mathematical Methods for Physicists (Academic Press, New York, 1971), 2nd printing, pp.662-666. 27 W. R. Hahn...difference in the approach used by the two methods , as noted in the previous paragraph, forming a direct mathematical com- parison may be impossible...examines high resolution methods which use a linear array to locate stationary objects which have scattered the fressure waves. Several;- new methods

  9. Measurement of the velocity of a quantum object: A role of phase and group velocities

    Science.gov (United States)

    Lapinski, Mikaila; Rostovtsev, Yuri V.

    2017-08-01

    We consider the motion of a quantum particle in a free space. Introducing an explicit measurement procedure for velocity, we demonstrate that the measured velocity is related to the group and phase velocities of the corresponding matter waves. We show that for long distances the measured velocity coincides with the matter wave group velocity. We discuss the possibilities to demonstrate these effects for the optical pulses in coherently driven media or for radiation propagating in waveguides.

  10. SAFE for PTSD: noncontact psychophysiological measure based on high-resolution thermal imaging to aid in PTSD diagnosis and assessment of treatment

    Science.gov (United States)

    Familoni, Babajide O.; Ma, Lein; Hutchinson, J. Andrew; Morgan, C. Andrew, III; Rasmusson, Ann; O'Kane, Barbara L.

    2012-06-01

    Post Traumatic Stress Disorder (PTSD) sometimes develops following exposure to very stressful or traumatic events such as motor vehicle accidents, rape, and war. It is arguably the signature injury of the conflicts in Iraq and Afghanistan. Previous studies have demonstrated that PTSD sufferers exhibit autonomic hyper-responsiveness to both neutral and trauma-related stimuli. In this study, we propose using high resolution thermal imaging of sweat-pores to obtain a noncontact, remote, and quantifiable measure of the sympathetic autonomic nervous reactivity to guide diagnosis, assess response to treatment, and tease out important cues to suicidality as a PTSD comorbidity.

  11. Using high-resolution fiber-optic distributed temperature sensing to measure spatially resolved speed and temperature of airflows in a shallow gully

    Science.gov (United States)

    Thomas, Christoph; Sayde, Chadi; Selker, John

    2015-04-01

    the cold-air pool was displaced from the gully by intermittently strong external wind forcing. Even gentle surface heterogeneity can have dramatic impacts on the structure of the near-surface flow, turbulence, and heat transport, which calls for spatial observations to quantify and compensate for the location bias of traditional single-point flow and flux measurements. The novel approach, which allows studying the spatial structure of the surface layer on scales spanning four orders of magnitude (0.1 - 1000m), opens up many important opportunities for testing fundamental assumptions and concepts in micrometeorology including, but not limited to turbulent length scales, the validity of Taylors hypothesis and ergodicity, surface heterogeneity, and internal boundary layers. References: Thomas, C.K., Kennedy, A.M., Selker, J.S., Moretti, A., Schroth, M.H., Smoot, A.R., Tufillaro, N.B., Zeeman, M.J., 2012. High-resolution fibre-optic temperature sensing: A new tool to study the two-dimensional structure of atmospheric surface layer flow. Boundary-Layer Meteorol. 142, 177-192. DOI: 10.1007/s10546-011-9672-7 Zeeman MJ, Selker JS, Thomas CK. Near-surface motion in the nocturnal, stable boundary layer observed with fibre-optic distributed temperature sensing. Boundary- Layer Meterology. 2014:online first. doi:10.1007/s10546-014-9972-9.

  12. Use of high-resolution ultrasound to measure changes in plantar fascia thickness resulting from tissue creep in runners and walkers.

    Science.gov (United States)

    Welk, Aaron B; Haun, Daniel W; Clark, Thomas B; Kettner, Norman W

    2015-01-01

    This study sought to use high-resolution ultrasound to measure changes in plantar fascia thickness as a result of tissue creep generated by walking and running. Independent samples of participants were obtained. Thirty-six walkers and 25 runners walked on a treadmill for 10 minutes or ran for 30 minutes, respectively. Standardized measures of the thickness of the plantar fascia were obtained in both groups using high-resolution ultrasound. The mean thickness of the plantar fascia was measured immediately before and after participation. The mean plantar fascia thickness was decreased by 0.06 ± 0.33 mm SD after running and 0.03 ± 0.22 mm SD after walking. The difference between groups was not significant. Although the parameters of this study did not produce significant changes in the plantar fascia thickness, a slightly higher change in the mean thickness of the plantar fascia in the running group deserves further investigation. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

  13. Developing and testing a low cost method for high resolution measurements of volcanic water vapour emissions at Vulcano and Mt. Etna

    Science.gov (United States)

    Pering, Tom D.; McGonigle, Andrew J. S.; Tamburello, Giancarlo; Aiuppa, Alessandro; Bitetto, Marcello; Rubino, Cosimo

    2015-04-01

    The most voluminous of emissions from volcanoes are from water vapour (H2O) (Carroll and Holloway, 1994), however, measurements of this species receive little focus due to the difficulty of independent measurement, largely a result of high atmospheric background concentrations which often undergo rapid fluctuations. A feasible method of measuring H2O emissions at high temporal and spatial resolutions would therefore be highly valuable. We describe a new and low-cost method combining modified web cameras (i.e. with infrared filters removed) with measurements of temperature and relative humidity to produce high resolution measurements (≈ 0.25 Hz) of H2O emissions. The cameras are affixed with near-infrared filters at points where water vapour absorbs (940 nm) and doesn't absorb (850 nm) incident light. Absorption of H2O is then determined by using Lambert-Beer's law on a pixel by pixel basis, producing a high spatial resolution image. The system is then calibrated by placing a Multi-GAS unit within the gas source and camera field-of-view, which measures; SO2, CO2, H2S and relative humidity. By combining the point measurements of the Multi-GAS unit with pixel values for absorption, first correcting for the width of the gas source (generally a Gaussian distribution), a calibration curve is produced which allows the conversion of absorption values to mass of water within a pixel. In combination with relative humidity measurements made outside of the plume it is then possible to subtract the non-volcanic background H2O concentration to produce a high resolution calibrated volcanic H2O flux. This technique is demonstrated in detail at the active fumarolic system on Vulcano (Aeolian Islands, Italy). Data processing and image acquisition was completed in Matlab® using a purpose built code. The technique is also demonstrated for the plume of the North-East Crater of Mt. Etna (Sicily, Italy). Here, contemporaneously acquired measurements of SO2 using a UV camera, combined

  14. Tomographic Particle Localization and Velocity Measurement

    Science.gov (United States)

    Kirner, S.; Forster, G.; Schein, J.

    2015-01-01

    Wire arc spraying is one of the most common and elementary thermal spray processes. Due to its easy handling, high deposition rate, and relative low process costs, it is a frequently used coating technology for the production of wear and corrosion resistant coatings. In order to produce reliable and reproducible coatings, it is necessary to be able to control the coating process. This can be achieved by analyzing the parameters of the particles deposited. Essential for the coating quality are, for example, the velocity, the size, and the temperature of the particles. In this work, an innovative diagnostic for particle velocity and location determination is presented. By the use of several synchronized CMOS-Cameras positioned around the particle jet, a series of images from different directions is simultaneously taken. The images contain the information that is necessary to calculate the 3D-location-vector of the particles and finally with the help of the exposure time the trajectory can be determined. In this work, the experimental setup of the tomographic diagnostic is presented, the mathematical method of the reconstruction is explained, and first measured velocity distributions are shown.

  15. Seasonal variabilty of surface velocities and ice discharge of Columbia Glacier, Alaska using high-resolution TanDEM-X satellite time series and NASA IceBridge data

    Science.gov (United States)

    Vijay, Saurabh; Braun, Matthias

    2014-05-01

    Columbia Glacier is a grounded tidewater glacier located on the south coast of Alaska. It has lost half of its volume during 1957-2007, more rapidly after 1980. It is now split into two branches, known as Main/East and West branch due to the dramatic retreat of ~ 23 km and calving of iceberg from its terminus in past few decades. In Alaska, a majority of the mass loss from glaciers is due to rapid ice flow and calving icebergs into tidewater and lacustrine environments. In addition, submarine melting and change in the frontal position can accelerate the ice flow and calving rate. We use time series of high-resolution TanDEM-X stripmap satellite imagery during 2011-2013. The active image of the bistatic TanDEM-X acquisitions, acquired over 11 or 22 day repeat intervals, are utilized to derive surface velocity fields using SAR intensity offset tracking. Due to the short temporal baselines, the precise orbit control and the high-resolution of the data, the accuracies of the velocity products are high. We observe a pronounce seasonal signal in flow velocities close to the glacier front of East/Main branch of Columbia Glacier. Maximum values at the glacier front reach up to 14 m/day were recorded in May 2012 and 12 m/day in June 2013. Minimum velocities at the glacier front are generally observed in September and October with lowest values below 2 m/day in October 2012. Months in between those dates show corresponding increase or deceleration resulting a kind of sinusoidal annual course of the surface velocity at the glacier front. The seasonal signal is consistently decreasing with the distance from the glacier front. At a distance of 17.5 km from the ice front, velocities are reduced to 2 m/day and almost no seasonal variability can be observed. We attribute these temporal and spatial variability to changes in the basal hydrology and lubrification of the glacier bed. Closure of the basal drainage system in early winter leads to maximum speeds while during a fully

  16. High-resolution transmission measurements of CO2 at high temperatures for industrial applications

    DEFF Research Database (Denmark)

    Evseev, Vadim; Fateev, Alexander; Clausen, Sønnik

    2012-01-01

    . The spectra have been recorded in a high-temperature flow gas cell and using a Fourier transform infrared (FTIR) spectrometer at a nominal resolution of 0.125 cm-1. The volume fractions of CO2 in the measurements were 1,10 and 100%. The measurements have been validated by comparison with medium...

  17. Assessment of climatic and seismic cycles in southern chile from high resolution XRF and magnetic susceptibility measurements of historic lake sediments.

    Science.gov (United States)

    Boes, X.; Hubert-Ferrari, A.; Fagel, N.

    2006-12-01

    The high-resolution sedimentological studies performed on the sediment cores collected in the oceans or in the lakes constitutes the basis for inter-comparison of past climate variability. Among the new high-resolution approaches, the X-Ray Fluorescence (XRF) analysis of varved marine and lacustrine cores represents some of the best resolution. These data are particularly useful for tracking short-term climate changes expressed with calibrated time scales. However, the XRF results obtain on the fresh cores surface may be of low resolution because the core material is wet and unconsolidated. One particularly attractive method to solve this problem consists of impregnating the sediment cores with polymers in order to polish the core surface for XRF analyses. This step is essential for being able to get significant XRF and Magnetic Susceptibility (MS) results in the muddy cores. Since the 1960s, the evolution of sediment impregnation methods has been strongly linked to the development of innovative techniques (e.g., sampling devices, cryogenic and vacuum technologies, polymers, etc.). In this communication, we first propose a revised method that may be applied to prepare sediment cores for high-resolution XRF and MS data acquisition. Then we show an example of XRF and MS results obtain on laminated lake sediments from South America (Lago Puyehue, 40°S). As this area is very sensitive in terms of precipitation change (i.e., Southern Westerlies); the XRF data are compared with the regional instrumental precipitation database. The results are discussed in terms of climate and sismo- tectonic impacts over historic times. Our results shows that, in order to better interpret XRF tool over long sequences, the measurements should be first "calibrated" according to instrumental data such as precipitation, temperatures, and earthquake magnitudes.

  18. Obtaining biophysical measurements of woody vegetation from high resolution digital aerial photography in tropical and arid environments: Northern Territory, Australia

    Science.gov (United States)

    Staben, G. W.; Lucieer, A.; Evans, K. G.; Scarth, P.; Cook, G. D.

    2016-10-01

    Biophysical parameters obtained from woody vegetation are commonly measured using field based techniques which require significant investment in resources. Quantitative measurements of woody vegetation provide important information for ecological studies investigating landscape change. The fine spatial resolution of aerial photography enables identification of features such as trees and shrubs. Improvements in spatial and spectral resolution of digital aerial photographic sensors have increased the possibility of using these data in quantitative remote sensing. Obtaining biophysical measurements from aerial photography has the potential to enable it to be used as a surrogate for the collection of field data. In this study quantitative measurements obtained from digital aerial photography captured at ground sampling distance (GSD) of 15 cm (n = 50) and 30 cm (n = 52) were compared to woody biophysical parameters measured from 1 ha field plots. Supervised classification of the aerial photography using object based image analysis was used to quantify woody and non-woody vegetation components in the imagery. There was a high correlation (r ≥ 0.92) between all field measured woody canopy parameters and aerial derived green woody cover measurements, however only foliage projective cover (FPC) was found to be statistically significant (paired t-test; α = 0.01). There was no significant difference between measurements derived from imagery captured at either GSD of 15 cm and 30 cm over the same field site (n = 20). Live stand basal area (SBA) (m2 ha-1) was predicted from the aerial photographs by applying an allometric equation developed between field-measured live SBA and woody FPC. The results show that there was very little difference between live SBA predicted from FPC measured in the field or from aerial photography. The results of this study show that accurate woody biophysical parameters can be obtained from aerial photography from a range of woody vegetation

  19. Saturn's rings - high resolution

    Science.gov (United States)

    1981-01-01

    Voyager 2 obtained this high-resolution picture of Saturn's rings Aug. 22, when the spacecraft was 4 million kilometers (2.5 million miles) away. Evident here are the numerous 'spoke' features, in the B-ring; their very sharp, narrow appearance suggests short formation times. Scientists think electromagnetic forces are responsible in some way for these features, but no detailed theory has been worked out. Pictures such as this and analyses of Voyager 2's spoke movies may reveal more clues about the origins of these complex structures. The Voyager project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

  20. Rapid, high-resolution measurement of leaf area and leaf orientation using terrestrial LiDAR scanning data

    Science.gov (United States)

    Bailey, Brian N.; Mahaffee, Walter F.

    2017-06-01

    The rapid evolution of high performance computing technology has allowed for the development of extremely detailed models of the urban and natural environment. Although models can now represent sub-meter-scale variability in environmental geometry, model users are often unable to specify the geometry of real domains at this scale given available measurements. An emerging technology in this field has been the use of terrestrial LiDAR scanning data to rapidly measure the three-dimensional geometry of trees, such as the distribution of leaf area. However, current LiDAR methods suffer from the limitation that they require detailed knowledge of leaf orientation in order to translate projected leaf area into actual leaf area. Common methods for measuring leaf orientation are often tedious or inaccurate, which places constraints on the LiDAR measurement technique. This work presents a new method to simultaneously measure leaf orientation and leaf area within an arbitrarily defined volume using terrestrial LiDAR data. The novelty of the method lies in the direct measurement of the fraction of projected leaf area G from the LiDAR data which is required to relate projected leaf area to total leaf area, and in the new way in which radiation transfer theory is used to calculate leaf area from the LiDAR data. The method was validated by comparing LiDAR-measured leaf area to (1) ‘synthetic’ or computer-generated LiDAR data where the exact area was known, and (2) direct measurements of leaf area in the field using destructive sampling. Overall, agreement between the LiDAR and reference measurements was very good, showing a normalized root-mean-squared-error of about 15% for the synthetic tests, and 13% in the field.

  1. High-resolution measurements of morphodynamics in rapidly changing PROglacial Systems of the Alps - results from the PROSA project

    Science.gov (United States)

    Hilger, Ludwig; Dusik, Jana-Marie; Heckmann, Tobias; Haas, Florian; Näher, Martin; Philipp, Rumohr; Philipp, Glira; Lucas, Vehling; Michael, Becht

    2016-04-01

    In June 2012, the PROSA-project was initiated with the goal to construct a sediment budget of the Upper Kaunertal Valley, Ötztal Alps, Austria. A unique feature of the project being the dedicated usage of study-area wide multi-volume LiDAR survey data of relatively high density on a meso-scale catchment resulting in a data base of over 4 billion LiDAR measurement points. A high effort was undertaken to produce classified point data as a methodological backbone of the project. Both ALS and georeferenced TLS data as well as other remote sensing and mapping products were used in addition to extensive fieldwork as basis for a regionalization of monitoring-site based measurements to arrive at basin-wide sediment production rates and identification of sediment pathways. Results can now be presented for: Rock fall (plot-based measurement and subsequent model-based regionalization), debris flows (study area-wide direct measurement from LiDAR and analysis of historical orthophotos), rock glaciers (feature-tracking and direct differencing), hillslope channels (plot-based measurements and model-based regionalization) and avalanches (sample site measurement, mapping and extrapolation). Sediment budgets were subsequently constructed for different representative subsystems within the 62.5 km2 catchment. Although also glacier and main channel transport was looked into by the PROSA-project, the presentation will focus on the processes mentioned above.

  2. High Frequency Transducer Dedicated to the High-resolution in Situ Measurement of the Distance between Two Nuclear Fuel Plates

    Science.gov (United States)

    Zaz, G.; Dekkious, A.; Meignen, P. A.; Calzavara, Y.; Le Clézio, E.; Despaux, G.

    Most high flux reactors for research purposes have fuel elements composed of plates and not pencils. The measure of inter-plate distance of a fuel element is tricky since a resolution of a micron is searched to measure plate swellings of about ten microns while the dimension between the plates is close to the millimeter. This measure should provide information about the fuel and particularly its history of irradiation. That is the reason why a solution has been considered: a robust device based upon high frequency ultrasonic probes adapted to the high radiation environment and thinned to 1 mm to be inserted into a 1.8 mm width water channel between two fuel plates. To achieve the expected resolution, the system is excited with frequencies up to 150 MHz. Thanks to a specific signal processing, this device allows the distance measurement through an ultrasonic wave's time of flight. The feasibility of such challenging distance measurement has already been proved with success on a full size irradiated fuel element of the RHF.

  3. High resolution x-ray Thomson scattering measurements from cryogenic hydrogen jets using the linac coherent light source.

    Science.gov (United States)

    Fletcher, L B; Zastrau, U; Galtier, E; Gamboa, E J; Goede, S; Schumaker, W; Ravasio, A; Gauthier, M; MacDonald, M J; Chen, Z; Granados, E; Lee, H J; Fry, A; Kim, J B; Roedel, C; Mishra, R; Pelka, A; Kraus, D; Barbrel, B; Döppner, T; Glenzer, S H

    2016-11-01

    We present the first spectrally resolved measurements of x-rays scattered from cryogenic hydrogen jets in the single photon counting limit. The 120 Hz capabilities of the LCLS, together with a novel hydrogen jet design [J. B. Kim et al., Rev. Sci. Instrum. (these proceedings)], allow for the ability to record a near background free spectrum. Such high-dynamic-range x-ray scattering measurements enable a platform to study ultra-fast, laser-driven, heating dynamics of hydrogen plasmas. This measurement has been achieved using two highly annealed pyrolytic graphite crystal spectrometers to spectrally resolve 5.5 keV x-rays elastically and inelastically scattered from cryogenic hydrogen and focused on Cornell-SLAC pixel array detectors [S. Herrmann et al., Nucl. Instrum. Methods Phys. Res., Sect. A 718, 550 (2013)].

  4. High resolution x-ray Thomson scattering measurements from cryogenic hydrogen jets using the linac coherent light source

    Science.gov (United States)

    Fletcher, L. B.; Zastrau, U.; Galtier, E.; Gamboa, E. J.; Goede, S.; Schumaker, W.; Ravasio, A.; Gauthier, M.; MacDonald, M. J.; Chen, Z.; Granados, E.; Lee, H. J.; Fry, A.; Kim, J. B.; Roedel, C.; Mishra, R.; Pelka, A.; Kraus, D.; Barbrel, B.; Döppner, T.; Glenzer, S. H.

    2016-11-01

    We present the first spectrally resolved measurements of x-rays scattered from cryogenic hydrogen jets in the single photon counting limit. The 120 Hz capabilities of the LCLS, together with a novel hydrogen jet design [J. B. Kim et al., Rev. Sci. Instrum. (these proceedings)], allow for the ability to record a near background free spectrum. Such high-dynamic-range x-ray scattering measurements enable a platform to study ultra-fast, laser-driven, heating dynamics of hydrogen plasmas. This measurement has been achieved using two highly annealed pyrolytic graphite crystal spectrometers to spectrally resolve 5.5 keV x-rays elastically and inelastically scattered from cryogenic hydrogen and focused on Cornell-SLAC pixel array detectors [S. Herrmann et al., Nucl. Instrum. Methods Phys. Res., Sect. A 718, 550 (2013)].

  5. Assignment of resonances in dissociative recombination of HD+ ions: high-resolution measurements compared with accurate computations

    CERN Document Server

    Tamo, F O Waffeu; Motapon, O; Altevogt, S; Andrianarijaona, V M; Grieser, M; Lammich, L; Lestinsky, M; Motsch, M; Nevo, I; Novotny, S; Orlov, D A; Pedersen, H B; Schwalm, D; Sprenger, F; Urbain, X; Weigel, U; Wolf, A; Schneider, I F

    2011-01-01

    The collision-energy resolved rate coefficient for dissociative recombination of HD+ ions in the vibrational ground state is measured using the photocathode electron target at the heavy-ion storage ring TSR. Rydberg resonances associated with ro-vibrational excitation of the HD+ core are scanned as a function of the electron collision energy with an instrumental broadening below 1 meV in the low-energy limit. The measurement is compared to calculations using multichannel quantum defect theory, accounting for rotational structure and interactions and considering the six lowest rotational energy levels as initial ionic states. Using thermal equilibrium level populations at 300 K to approximate the experimental conditions, close correspondence between calculated and measured structures is found up to the first vibrational excitation threshold of the cations near 0.24 eV. Detailed assignments, including naturally broadened and overlapping Rydberg resonances, are performed for all structures up to 0.024 eV. Resona...

  6. High resolution x-ray Thomson scattering measurements from cryogenic hydrogen jets using the linac coherent light source

    Energy Technology Data Exchange (ETDEWEB)

    Fletcher, L. B., E-mail: lbfletch@slac.stanford.edu; Galtier, E.; Gamboa, E. J.; Schumaker, W.; Gauthier, M.; Granados, E.; Lee, H. J.; Fry, A.; Kim, J. B.; Roedel, C.; Mishra, R.; Glenzer, S. H. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Zastrau, U. [European XFEL, Schenefeld (Germany); Goede, S. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); European XFEL, Schenefeld (Germany); Ravasio, A. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Laboratoire pour l’Utilisation des Lasers Intenses, Palaiseau Cedex (France); MacDonald, M. J. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); University of Michigan, Ann Arbor, Michigan 48109 (United States); Chen, Z. [SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); University of Alberta, Edmonton, Alberta T6G 2R3 (Canada); Pelka, A. [Helmholtz Zentrum Dresden-Rossendorf, Dresden (Germany); Kraus, D. [Helmholtz Zentrum Dresden-Rossendorf, Dresden (Germany); Department of Physics, University of California Berkeley, Berkeley, California 94720 (United States); Barbrel, B. [Department of Physics, University of California Berkeley, Berkeley, California 94720 (United States); and others

    2016-11-15

    We present the first spectrally resolved measurements of x-rays scattered from cryogenic hydrogen jets in the single photon counting limit. The 120 Hz capabilities of the LCLS, together with a novel hydrogen jet design [J. B. Kim et al., Rev. Sci. Instrum. (these proceedings)], allow for the ability to record a near background free spectrum. Such high-dynamic-range x-ray scattering measurements enable a platform to study ultra-fast, laser-driven, heating dynamics of hydrogen plasmas. This measurement has been achieved using two highly annealed pyrolytic graphite crystal spectrometers to spectrally resolve 5.5 keV x-rays elastically and inelastically scattered from cryogenic hydrogen and focused on Cornell-SLAC pixel array detectors [S. Herrmann et al., Nucl. Instrum. Methods Phys. Res., Sect. A 718, 550 (2013)].

  7. Revisiting spin-lattice relaxation time measurements for dilute spins in high-resolution solid-state NMR spectroscopy

    Science.gov (United States)

    Fu, Riqiang; Li, Jun; Cui, Jingyu; Peng, Xinhua

    2016-07-01

    Numerous nuclear magnetic resonance (NMR) measurements of spin-lattice relaxation times (T1S) for dilute spins such as 13C have led to investigations of the motional dynamics of individual functional groups in solid materials. In this work, we revisit the Solomon equations and analyze how the heteronuclear cross relaxation between the dilute S (e.g. 13C) and abundant I (e.g. 1H) spins affects the measured T1S values in solid-state NMR in the absence of 1H saturation during the recovery time. It is found theoretically that at the beginning of the S spin magnetization recovery, the existence of non-equilibrium I magnetization introduces the heteronuclear cross relaxation effect onto the recovery of the S spin magnetization and confirmed experimentally that such a heteronuclear cross relaxation effect results in the recovery overshoot phenomena for the dilute spins when T1S is on the same order of T1H, leading to inaccurate measurements of the T1S values. Even when T1S is ten times larger than T1H, the heteronuclear cross relaxation effect on the measured T1S values is still noticeable. Furthermore, this cross relaxation effect on recovery trajectory of the S spins can be manipulated and even suppressed by preparing the initial I and S magnetization, so as to obtain the accurate T1S values. A sample of natural abundance L-isoleucine powder has been used to demonstrate the T1S measurements and their corresponding measured T1C values under various experimental conditions.

  8. Reconstruction of high resolution time series from slow-response broadband solar and terrestrial irradiance measurements by deconvolution

    Directory of Open Access Journals (Sweden)

    A. Ehrlich

    2015-05-01

    Full Text Available Broadband solar and terrestrial irradiance measurements of high temporal resolution are needed to study inhomogeneous clouds or surfaces and to derive vertical profiles of heating/cooling rates at cloud top. An efficient method to enhance the temporal resolution of slow-response measurements of broadband irradiance using pyranometer or pyrgeometer is introduced. It is based on the deconvolution theorem of Fourier transform to restore amplitude and phase shift of high frequent fluctuations. It is shown that the quality of reconstruction depends on the instrument noise, the pyrgeometer response time and the frequency of the oscillations. The method is tested in laboratory measurements for synthetic time series including a boxcar function and periodic oscillations using a CGR-4 pyrgeometer with response time of 3 s. The originally slow-response pyrgeometer data were reconstructed to higher resolution and compared to the predefined synthetic time series. The reconstruction of the time series worked up to oscillations of 0.5 Hz frequency and 2 W m−2 amplitude if the sampling frequency of the data acquisition is 16 kHz or higher. For oscillations faster than 2 Hz the instrument noise exceeded the reduced amplitude of the oscillations in the measurements and the reconstruction failed. The method was applied to airborne measurements of upward terrestrial irradiance from the VERDI (Vertical Distribution of Ice in Arctic Clouds field campaign. Pyrgeometer data above open leads in sea ice and a broken cloud field were reconstructed and compared to KT19 infrared thermometer data. The reconstruction of amplitude and phase shift of the deconvoluted data improved the agreement with the KT19 data. Cloud top temperatures were improved by up to 1 K above broken clouds while an underestimation of 2.5 W m−2 was found for the upward irradiance over small leads when using the slow-response data. The limitations of the method with respect to instrument noise and

  9. Development of a novel precision instrument for high-resolution simultaneous normal and shear force measurements between small planar samples

    Science.gov (United States)

    Lundstrom, Troy; Clark, William; Jalili, Nader

    2017-05-01

    In the design and development of end effector pads for silicon wafer handling robots, it is imperative that the static friction/adhesion force properties of the pads with respect to a variety of planar surfaces be characterized. In this work, the overall design, calibration, and data acquisition procedure of an instrument developed for performing these measurements on small (nano/micro- and macroscales; however, this device allows for the consistent measurement of these same types of forces on components with surface dimensions ranging from 0.1 mm to 10 mm.

  10. Microfabricated thermal conductivity sensor: a high resolution tool for quantitative thermal property measurement of biomaterials and solutions.

    Science.gov (United States)

    Liang, Xin M; Ding, Weiping; Chen, Hsiu-hung; Shu, Zhiquan; Zhao, Gang; Zhang, Hai-feng; Gao, Dayong

    2011-10-01

    Obtaining accurate thermal properties of biomaterials plays an important role in the field of cryobiology. Currently, thermal needle, which is constructed by enclosing a manually winded thin metal wire with an insulation coating in a metallic sheath, is the only available device that is capable of measuring thermal conductivity of biomaterials. Major drawbacks, such as macroscale sensor size, lack of versatile format to accommodate samples with various shapes and sizes, neglected effects of heat transfer inside the probe and thermal contact resistance between the sensing element and the probe body, difficult to mass produce, poor data repeatability and reliability and labor-intense sensor calibration, have significantly reduced their potential to be an essential measurement tool to provide key thermal property information of biological specimens. In this study, we describe the development of an approach to measure thermal conductivity of liquids and soft bio-tissues using a proof-of-concept MEMS based thermal probe. By employing a microfabricated closely-packed gold wire to function as the heater and the thermistor, the presented thermal sensor can be used to measure thermal conductivities of fluids and natural soft biomaterials (particularly, the sensor may be directly inserted into soft tissues in living animal/plant bodies or into tissues isolated from the animal/plant bodies), where other more standard approaches cannot be used. Thermal standard materials have been used to calibrate two randomly selected thermal probes at room temperature. Variation between the obtained system calibration constants is less than 10%. By incorporating the previously obtained system calibration constant, three randomly selected thermal probes have been successfully utilized to measure the thermal conductivities of various solutions and tissue samples under different temperatures. Overall, the measurements are in agreement with the recommended values (percentage error less than 5

  11. Long-term and high resolution measurements of bed level changes in a temperate, microtidal coastal lagoon

    DEFF Research Database (Denmark)

    Andersen, Thorbjørn J.; Pejrup, Morten; Nielsen, Allan Aasbjerg

    2006-01-01

    This study presents the results of a long-term monitoring program of bed level changes measured during 8 yr at an intertidal mudflat in a microtidal, temperate coastal lagoon. Additionally, bed level measurements obtained at a 10-min temporal resolution at the same tidal flat and at the bed of a ...... are not seriously threatened by the expected sea level rise in the 21st century.......This study presents the results of a long-term monitoring program of bed level changes measured during 8 yr at an intertidal mudflat in a microtidal, temperate coastal lagoon. Additionally, bed level measurements obtained at a 10-min temporal resolution at the same tidal flat and at the bed...... of a nearby tidal channel are presented. Short-term changes in bed level are one or two orders of magnitude larger than the annual net-deposition rate, which shows that the environment is highly dynamic with respect to erosion, transport and deposition of fine-grained sediment. Some seasonality in the bed...

  12. Rapid, high-resolution measurement of leaf area and leaf orientation using terrestrial LiDAR scanning data

    Science.gov (United States)

    Leaf orientation plays a fundamental role in many transport processes in plant canopies. At the plant or stand level, leaf orientation is often highly anisotropic and heterogeneous, yet most analyses neglect such complexity. In many cases, this is due to the difficulty in measuring the spatial varia...

  13. A simple calculation algorithm to separate high-resolution CH4 flux measurements into ebullition- and diffusion-derived components

    Science.gov (United States)

    Hoffmann, Mathias; Schulz-Hanke, Maximilian; Garcia Alba, Juana; Jurisch, Nicole; Hagemann, Ulrike; Sachs, Torsten; Sommer, Michael; Augustin, Jürgen

    2017-01-01

    Processes driving the production, transformation and transport of methane (CH4) in wetland ecosystems are highly complex. We present a simple calculation algorithm to separate open-water CH4 fluxes measured with automatic chambers into diffusion- and ebullition-derived components. This helps to reveal underlying dynamics, to identify potential environmental drivers and, thus, to calculate reliable CH4 emission estimates. The flux separation is based on identification of ebullition-related sudden concentration changes during single measurements. Therefore, a variable ebullition filter is applied, using the lower and upper quartile and the interquartile range (IQR). Automation of data processing is achieved by using an established R script, adjusted for the purpose of CH4 flux calculation. The algorithm was validated by performing a laboratory experiment and tested using flux measurement data (July to September 2013) from a former fen grassland site, which converted into a shallow lake as a result of rewetting. Ebullition and diffusion contributed equally (46 and 55 %) to total CH4 emissions, which is comparable to ratios given in the literature. Moreover, the separation algorithm revealed a concealed shift in the diurnal trend of diffusive fluxes throughout the measurement period. The water temperature gradient was identified as one of the major drivers of diffusive CH4 emissions, whereas no significant driver was found in the case of erratic CH4 ebullition events.

  14. Reconstruction of high-resolution 3D dose from matrix measurements : error detection capability of the COMPASS correction kernel method

    NARCIS (Netherlands)

    Godart, J.; Korevaar, E. W.; Visser, R.; Wauben, D. J. L.; van t Veld, Aart

    2011-01-01

    TheCOMPASS system (IBADosimetry) is a quality assurance (QA) tool which reconstructs 3D doses inside a phantom or a patient CT. The dose is predicted according to the RT plan with a correction derived from 2D measurements of a matrix detector. This correction method is necessary since a direct recon

  15. High-resolution measurements of atmospheric molecular hydrogen and its isotopic composition at the West African coast of Mauritania

    NARCIS (Netherlands)

    Walter, S.; Kock, A; Röckmann, T.

    2013-01-01

    Oceans are a net source of molecular hydrogen (H2) to the atmosphere, where nitrogen (N2) fixation is assumed to be the main biological production pathway followed by photochemical production from organic material. The sources can be distinguished using isotope measurements because of clearly

  16. Measuring the Gap Between Car and Transit Accessibility : Estimating Access Using a High-Resolution Transit Network Geographic Information System

    NARCIS (Netherlands)

    Benenson, I.; Martens, C.J.C.M.; Rofé, Y.

    2010-01-01

    Accessibility is increasingly identified in the academic literature and in planning practice as a key criterion to assess transport policies and urban land use development. This paper contributes in two respects to the growing body of literature on accessibility and accessibility measurement. First,

  17. Performance of high-resolution SEM/EDX systems equipped with transmission mode (TSEM) for imaging and measurement of size and size distribution of spherical nanoparticles.

    Science.gov (United States)

    Hodoroaba, Vasile-Dan; Motzkus, Charles; Macé, Tatiana; Vaslin-Reimann, Sophie

    2014-04-01

    The analytical performance of high-resolution scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) for accurate determination of the size, size distribution, qualitative elemental analysis of nanoparticles (NPs) was systematically investigated. It is demonstrated how powerful high-resolution SEM is by using both mono- and bi-modal distributions of SiO2 airborne NPs collected on appropriate substrates after their generation from colloidal suspension. The transmission mode of the SEM (TSEM) is systematically employed for NPs prepared on thin film substrates such as transmission electron microscopy grids. Measurements in the transmission mode were performed by using a "single-unit" TSEM transmission setup as manufactured and patented by Zeiss. This alternative to the "conventional" STEM detector consists of a special sample holder that is used in conjunction with the in-place Everhart-Thornley detector. In addition, the EDX capabilities for imaging NPs, highlighting the promising potential with respect to exploitation of the sensitivity of the new large area silicon drift detector energy dispersive X-ray spectrometers were also investigated. The work was carried out in the frame of a large prenormative VAMAS (Versailles Project on Advanced Materials and Standards) project, dedicated to finding appropriate methods and procedures for traceable characterization of NP size and size distribution.

  18. Reconstruction of high-resolution time series from slow-response broadband terrestrial irradiance measurements by deconvolution

    Directory of Open Access Journals (Sweden)

    A. Ehrlich

    2015-09-01

    Full Text Available Broadband solar and terrestrial irradiance measurements of high temporal resolution are needed to study inhomogeneous clouds or surfaces and to derive vertical profiles of heating/cooling rates at cloud top. An efficient method to enhance the temporal resolution of slow-response measurements of broadband terrestrial irradiance using pyrgeometer is introduced. It is based on the deconvolution theorem of Fourier transform to restore amplitude and phase shift of high frequent fluctuations. It is shown that the quality of reconstruction depends on the instrument noise, the pyrgeometer response time and the frequency of the oscillations. The method is tested in laboratory measurements for synthetic time series including a boxcar function and periodic oscillations using a CGR-4 pyrgeometer with response time of 3 s. The originally slow-response pyrgeometer data were reconstructed to higher resolution and compared to the predefined synthetic time series. The reconstruction of the time series worked up to oscillations of 0.5 Hz frequency and 2 W m−2 amplitude if the sampling frequency of the data acquisition is 16 kHz or higher. For oscillations faster than 2 Hz, the instrument noise exceeded the reduced amplitude of the oscillations in the measurements and the reconstruction failed. The method was applied to airborne measurements of upward terrestrial irradiance from the VERDI (Vertical Distribution of Ice in Arctic Clouds field campaign. Pyrgeometer data above open leads in sea ice and a broken cloud field were reconstructed and compared to KT19 infrared thermometer data. The reconstruction of amplitude and phase shift of the deconvoluted data improved the agreement with the KT19 data. Cloud top temperatures were improved by up to 1 K above broken clouds of 80–800 m size (1–10 s flight time while an underestimation of 2.5 W m−2 was found for the upward irradiance over small leads of about 600 m diameter (10 s flight time when using the slow

  19. High resolution 3D laser scanner measurements of a strike-slip fault quantify its morphological anisotropy at all scales

    CERN Document Server

    Renard, Francois; Marsan, Davd; Schmittbuhl, Jean

    2008-01-01

    The surface roughness of a recently exhumed strikeslip fault plane has been measured by three independent 3D portable laser scanners. Digital elevation models of several fault surface areas, from 1 m2 to 600 m2, have been measured at a resolution ranging from 5 mm to 80 mm. Out of plane height fluctuations are described by non-Gaussian distribution with exponential long range tails. Statistical scaling analyses show that the striated fault surface exhibits self-affine scaling invariance with a small but significant directional morphological anisotropy that can be described by two scaling roughness exponents, H1 = 0.7 in the direction of slip and H2 = 0.8 perpendicular to the direction of slip.

  20. Kalman-filtered compressive sensing for high resolution estimation of anthropogenic greenhouse gas emissions from sparse measurements.

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Jaideep; Lee, Jina; Lefantzi, Sophia; Yadav, Vineet; Michalak, Anna M.; van Bloemen Waanders, Bart Gustaaf; McKenna, Sean Andrew

    2013-09-01

    The estimation of fossil-fuel CO2 emissions (ffCO2) from limited ground-based and satellite measurements of CO2 concentrations will form a key component of the monitoring of treaties aimed at the abatement of greenhouse gas emissions. The limited nature of the measured data leads to a severely-underdetermined estimation problem. If the estimation is performed at fine spatial resolutions, it can also be computationally expensive. In order to enable such estimations, advances are needed in the spatial representation of ffCO2 emissions, scalable inversion algorithms and the identification of observables to measure. To that end, we investigate parsimonious spatial parameterizations of ffCO2 emissions which can be used in atmospheric inversions. We devise and test three random field models, based on wavelets, Gaussian kernels and covariance structures derived from easily-observed proxies of human activity. In doing so, we constructed a novel inversion algorithm, based on compressive sensing and sparse reconstruction, to perform the estimation. We also address scalable ensemble Kalman filters as an inversion mechanism and quantify the impact of Gaussian assumptions inherent in them. We find that the assumption does not impact the estimates of mean ffCO2 source strengths appreciably, but a comparison with Markov chain Monte Carlo estimates show significant differences in the variance of the source strengths. Finally, we study if the very different spatial natures of biogenic and ffCO2 emissions can be used to estimate them, in a disaggregated fashion, solely from CO2 concentration measurements, without extra information from products of incomplete combustion e.g., CO. We find that this is possible during the winter months, though the errors can be as large as 50%.

  1. High resolution imaging of 2D distribution of lithium in thin samples measured with multipixel detectors in sandwich geometry

    Science.gov (United States)

    Tomandl, I.; Vacík, J.; Mora Sierra, Y.; Granja, C.; Kraus, V.

    2017-02-01

    A method that enables visualization of lateral distribution of Li in thin films is described. The method is based on the simultaneous detection of the reaction products of the 6Li(n,α)t nuclear reaction with thermal neutrons measured with two multipixel detectors in a sandwich geometry with a sample. Here, the principle and basic methodological parameters of the method, including tests with thin polymers with known Li microstructure, are discussed.

  2. Low-power, open-path mobile sensing platform for high-resolution measurements of greenhouse gases and air pollutants

    Science.gov (United States)

    Tao, Lei; Sun, Kang; Miller, David J.; Pan, Dan; Golston, Levi M.; Zondlo, Mark A.

    2015-04-01

    A low-power mobile sensing platform has been developed with multiple open-path gas sensors to measure the ambient concentrations of greenhouse gases and air pollutants with high temporal and spatial resolutions over extensive spatial domains. The sensing system consists of four trace gas sensors including two custom quantum cascade laser-based open-path sensors and two LICOR open-path sensors to measure CO2, CO, CH4, N2O, NH3, and H2O mixing ratios simultaneously at 10 Hz. In addition, sensors for meteorological and geolocation data are incorporated into the system. The system is powered by car batteries with a low total power consumption (~200 W) and is easily transportable due to its low total mass (35 kg). Multiple measures have been taken to ensure robust performance of the custom, open-path sensors located on top of the vehicle where the optics are exposed to the harsh on-road environment. The mobile sensing system has been integrated and installed on top of common passenger vehicles and participated in extensive field campaigns (>400 h on-road time with >18,000 km total distance) in both the USA and China. The simultaneous detection of multiple trace gas species makes the mobile sensing platform a unique and powerful tool to identify and quantify different emission sources through mobile mapping.

  3. High-resolution measurements of the exited states (n,pn), (n,dn) C-12 cross sections

    Science.gov (United States)

    Pillon, M.; Angelone, M.; Belloni, F.; Geerts, W.; Loreti, S.; Milocco, A.; Plompen, A. J. M.

    2017-09-01

    Measurements of C12 cross sections for the excited states (n,p0) up to (n,p4) and (n,d0), (n,d1) have been carried out. The Van de Graaff neutron generator of the EC-JRC-IRMM laboratory has been used for these measurements. A very thin tritiated target (263 μg/cm2) was employed with deuteron beams energies impinging on the target in the range 2.5-4.0 MeV. Neutrons in the range 18.9-20.7 MeV were produced with an intrinsic energy spread of 0.2-0.25% FWHM. With such narrow neutron energy spread, using a high energy resolution device such as a single crystal diamond detector, several peaks from the outgoing charged particles produced by the (n,pn), (n,dn) and also (n,α0) reactions appear in the pulse height spectrum. The peaks can be identified using the reaction Q-values. The diamond detector used for these measurements has shown an intrinsic energy resolution lower than 0.9% FWHM. The analysis of the peaks has permitted to derive the partial carbon reaction cross sections for several excited states. The results are presented in this paper with the associated uncertainties and they are compared with different versions of TENDL compilation when these data are available (e.g. versions 2009, 2010, 2011 and 2015) and also with experimental results available in the EXFOR database.

  4. Missing SO2 oxidant in the coastal atmosphere? – Evidence from high resolution measurements of OH and atmospheric sulfur compounds

    Directory of Open Access Journals (Sweden)

    H. Berresheim

    2014-01-01

    Full Text Available Diurnal and seasonal variations of gaseous sulfuric acid (H2SO4 and methane sulfonic acid (MSA were measured in N.E. Atlantic air at the Mace Head atmospheric research station during the years 2010 and 2011. The measurements utilized selected ion/chemical ionization mass spectrometry (SI/CIMS with a detection limit for both compounds of 4.3 × 10 4 cm−3 at 5 min signal integration. The H2SO4 and MSA gas-phase concentrations were analysed in conjunction with the condensational sink for both compounds derived from 3 nm–10 μm (diameter aerosol size distributions. Accommodation coefficients of 1.0 for H2SO4 and 0.12 for MSA were assumed leading to estimated atmospheric lifetimes of the order of 7 min and 25 min, respectively. With the SI/CIMS instrument in OH measurement mode alternating between OH signal and background (non-OH signal evidence was obtained for the presence of one or more unknown oxidants of SO2 in addition to OH. Depending on the nature of the oxidant(s their ambient concentration may be enhanced in the CIMS inlet system by additional production. The apparent unknown SO2 oxidant was additionally confirmed by direct measurements of SO2 in conjunction with calculated H2SO4 concentrations. The calculated concentrations were consistently lower than the measured concentrations by a factor 4.8 ± 3.4 when considering the oxidation of SO2 by OH as the only source of H2SO4. Both the OH and the background signal were also observed to increase significantly during daytime aerosol nucleation events, independent of the ozone photolysis frequency, J(O1D, and were followed by peaks in both H2SO4 and MSA concentrations. This suggests a strong relation between the unknown oxidant(s, OH chemistry, and the atmospheric photo-oxidation of biogenic iodine compounds. As to the identity of the oxidant(s, we have been able to exclude ClO, BrO, IO, and OIO as possible candidates based on ab initio calculations. Stabilized Criegee intermediates (s

  5. Simultaneous Measurement of Leaf and Whole-Canopy Solar-Induced Fluorescence using Very-High-Resolution Imaging Spectroscopy

    Science.gov (United States)

    Silva, C. E.; Cushman, K. C.; Wiseman, S. M.; Yang, X.; Kellner, J. R.

    2015-12-01

    Incoming solar radiation absorbed by chlorophyll molecules drives the light-dependent reactions of photosynthesis. However, a portion of the radiation absorbed by chlorophyll is dissipated as heat or emitted as fluorescence. Therefore, solar-induced fluorescence (SIF) is mechanistically linked with the instantaneous rate of photosynthesis at the molecular level. Recent studies have shown SIF is correlated with gross primary production (GPP) at the level of individual leaves as well as plant canopies, indicating SIF measurements via satellite and airborne remote sensing may improve estimates of terrestrial GPP. However, accurate inference of canopy GPP from SIF measurements requires resolving several challenges. One challenge is the contribution from leaves in the canopy interior to total canopy SIF. Remotely observed canopy SIF is dominated by the upper canopy, because photons fluoresced within the canopy interior are re-absorbed by other leaves. However, the contribution of interior canopy leaves to total canopy GPP is non-negligible. Models indicate that leaf-level GPP plateaus with increasing SIF, whereas the relationship between whole-canopy GPP and SIF does not saturate. Here we use hourly SIF measurements from a VNIR imaging spectrometer mounted on a canopy tower to quantify within-canopy variation in SIF. We examine leaf-level SIF at < 1 cm spatial resolution in directly illuminated leaves versus leaves in the canopy interior at different canopy heights over the course of several days. The within-canopy variation in SIF demonstrates how the leaf-level contribution to total canopy photosynthesis likely varies throughout the canopy volume. Our results can help inform SIF-derived GPP estimates, which are crucial to quantifying the response of terrestrial ecosystems to climate change.

  6. High-resolution continuous flow analysis setup for water isotopic measurement from ice cores using laser spectroscopy

    Science.gov (United States)

    Emanuelsson, B. D.; Baisden, W. T.; Bertler, N. A. N.; Keller, E. D.; Gkinis, V.

    2014-12-01

    Here we present an experimental setup for water stable isotopes (δ18O and δD) continuous flow measurements. It is the first continuous flow laser spectroscopy system that is using Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS; analyzer manufactured by Los Gatos Research - LGR) in combination with an evaporation unit to continuously analyze sample from an ice core. A Water Vapor Isotopic Standard Source (WVISS) calibration unit, manufactured by LGR, was modified to: (1) increase the temporal resolution by reducing the response time (2) enable measurements on several water standards, and (3) to reduce the influence from memory effects. While this setup was designed for the Continuous Flow Analysis (CFA) of ice cores, it can also continuously analyze other liquid or vapor sources. The modified setup provides a shorter response time (~54 and 18 s for 2013 and 2014 setup, respectively) compared to the original WVISS unit (~62 s), which is an improvement in measurement resolution. Another improvement compared to the original WVISS is that the modified setup has a reduced memory effect. Stability tests comparing the modified WVISS and WVISS setups were performed and Allan deviations (σAllan) were calculated to determine precision at different averaging times. For the 2013 modified setup the precision after integration times of 103 s are 0.060 and 0.070‰ for δ18O and δD, respectively. For the WVISS setup the corresponding σAllan values are 0.030, 0.060 and 0.043‰ for δ18O, δD and δ17O, respectively. For the WVISS setup the precision is 0.035, 0.070 and 0.042‰ after 103 s for δ18O, δD and δ17O, respectively. Both the modified setups and WVISS setup are influenced by instrumental drift with δ18O being more drift sensitive than δD. The σAllan values for δ18O of 0.30 and 0.18‰ for the modified (2013) and WVISS setup, respectively after averaging times of 104 s (2.78 h). The Isotopic Water Analyzer (IWA)-modified WVISS setup used during the

  7. High-resolution continuous flow analysis setup for water isotopic measurement from ice cores using laser spectroscopy

    Directory of Open Access Journals (Sweden)

    B. D. Emanuelsson

    2014-12-01

    Full Text Available Here we present an experimental setup for water stable isotopes (δ18O and δD continuous flow measurements. It is the first continuous flow laser spectroscopy system that is using Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS; analyzer manufactured by Los Gatos Research – LGR in combination with an evaporation unit to continuously analyze sample from an ice core. A Water Vapor Isotopic Standard Source (WVISS calibration unit, manufactured by LGR, was modified to: (1 increase the temporal resolution by reducing the response time (2 enable measurements on several water standards, and (3 to reduce the influence from memory effects. While this setup was designed for the Continuous Flow Analysis (CFA of ice cores, it can also continuously analyze other liquid or vapor sources. The modified setup provides a shorter response time (~54 and 18 s for 2013 and 2014 setup, respectively compared to the original WVISS unit (~62 s, which is an improvement in measurement resolution. Another improvement compared to the original WVISS is that the modified setup has a reduced memory effect. Stability tests comparing the modified WVISS and WVISS setups were performed and Allan deviations (σAllan were calculated to determine precision at different averaging times. For the 2013 modified setup the precision after integration times of 103 s are 0.060 and 0.070‰ for δ18O and δD, respectively. For the WVISS setup the corresponding σAllan values are 0.030, 0.060 and 0.043‰ for δ18O, δD and δ17O, respectively. For the WVISS setup the precision is 0.035, 0.070 and 0.042‰ after 103 s for δ18O, δD and δ17O, respectively. Both the modified setups and WVISS setup are influenced by instrumental drift with δ18O being more drift sensitive than δD. The σAllan values for δ18O of 0.30 and 0.18‰ for the modified (2013 and WVISS setup, respectively after averaging times of 104 s (2.78 h. The Isotopic Water Analyzer (IWA-modified WVISS setup used

  8. High-resolution wave number spectrum using multi-point measurements in space – the Multi-point Signal Resonator (MSR technique

    Directory of Open Access Journals (Sweden)

    Y. Narita

    2011-02-01

    Full Text Available A new analysis method is presented that provides a high-resolution power spectrum in a broad wave number domain based on multi-point measurements. The analysis technique is referred to as the Multi-point Signal Resonator (MSR and it benefits from Capon's minimum variance method for obtaining the proper power spectral density of the signal as well as the MUSIC algorithm (Multiple Signal Classification for considerably reducing the noise part in the spectrum. The mathematical foundation of the analysis method is presented and it is applied to synthetic data as well as Cluster observations of the interplanetary magnetic field. Using the MSR technique for Cluster data we find a wave in the solar wind propagating parallel to the mean magnetic field with relatively small amplitude, which is not identified by the Capon spectrum. The Cluster data analysis shows the potential of the MSR technique for studying waves and turbulence using multi-point measurements.

  9. Validation of high-resolution WRF-ARW model runs against airborne measurements over complex terrain in central Italy

    Science.gov (United States)

    Carotenuto, Federico; Gioli, Beniamino; Toscano, Piero; Gualtieri, Giovanni; Miglietta, Franco; Wohlfahrt, Georg

    2015-04-01

    An intensive aerial campaign was flown in the context of the CARBIUS project (Maselli et al., 2010) between July 2004 and December 2005. The flights covered, over more than 240 Km, a target area in central Italy (between the regions of Lazio and Tuscany) characterized by various land uses and topography, ranging from coastal zones to mountainous landscapes (Colline Metallifere, Tuscany). The aerial vector (Sky Arrow 650 ERA) was equipped for high frequency (50 Hz) measurements of the three components of mean wind and turbulence, as well as air temperature, CO2 and H2O concentrations. While the aim of the CARBIUS campaign was focused on GHG fluxes, the dataset is used in the present work as a benchmark to assess the capability of mesoscale models to correctly simulate transport fields. A first assessment has been done by comparing the dataset to a coupled WRF-NMM-CALMET system (Gioli et al., 2014), but the aim of the present work is to expand on those foundations by comparing the data to higher resolution WRF-ARW simulations. WRF-ARW outputs are, in fact, frequently used as inputs to multiple dispersion models and any misrepresentation of the "real" situation is therefore propagated through the modelling chain. Our aim is to assess these potential errors keeping into account different topographic situations and seasons thanks to the existent aerial dataset. Moreover the sensitivity of the WRF-ARW model to different initial and boundary conditions (ECMWF vs. CFSR) is explored, since also the initial forcing may influence the representation of the transport field. Results show that the model is generally capable of reproducing the main features of the mean wind field independently from the choice of the initial forcing. Terrain features still show an impact on the model outputs (especially on wind directions), moreover the performance of the model is also influenced by seasonal effects. Gioli B., Gualtieri G., Busillo C., Calastrini F., Gozzini B., Miglietta F. (2014

  10. Selective measurement of digital nerve conduction velocity.

    Science.gov (United States)

    Terai, Y; Senda, M; Hashizume, H; Nagashima, H; Inoue, H

    2001-01-01

    We developed a new method to measure the nerve conduction velocity of a single digital nerve. In 27 volunteers (27 hands), we separately stimulated each digital nerve on the radial and ulnar sides of the middle and ring fingers. A double-peaked potential was recorded above the median nerve at the wrist joint when either the radial-side nerve or the ulnar-side nerve of the middle finger was stimulated. The first peak of this potential had disappeared after the digital nerve was blocked under the stimulating electrodes, and the peak appeared again coinciding with the decrease of anesthesia. Shifting the stimulating electrodes on the digital nerve resulted in no significant difference in the peak conduction velocity. It is possible that each peak of the potential was attributable to conduction of an action potential along one of the two digital nerves. This new method allows the assessment of a single digital nerve, and may be clinically useful for assessing the rupture of a digital nerve and the sensory nerve action potentials in carpal tunnel syndrome.

  11. Velocity Gradient Maps Directly Measured by PLF

    Science.gov (United States)

    Quintella, Cristina M.; Gonçalves, Cristiane C.; Lima, Angelo Mv; Pepe, Iuri M.

    2000-11-01

    Flows are macroscopically classified as laminar or turbulent due to their velocity distributions, nevertheless most chemical and biological phenomena are yield or enhanced by intermolecular orientation and microscopic turbulence. Here was studied a 100micra liquid sheet produced by a slit nozzle, both flowing freely into air and over a borosilicate surface (roughness bellow 5nm), ranging from 17 to 36Re (143 to 297cm/s, similar to muscles and brain blood flow). Mono ethylene glycol was used either pure, or with sodium alkyl benzene sulfated (ABS) surfactant (24.5mol/L, submicellar), or with poly(ethylene oxide) (PEO) (1409ppm, 4millions aw). Velocity gradients were directly measured by 514nm polarized laser induced fluorescence (PLF) with R6G as probe. Intermolecular alignment (IA) maps were obtained all over the flow (about 1,950 points, 0.02mm2 precision). The free jet average IA has increased 57% when flowing over borosilicate. With ABS, the IA increased, suggesting wall drag reduction. With PEO the IA decreases due to solvent intermolecular forces attenuation, generating wider turbulent areas. PLF proved to be an excellent method to evaluate IA within liquid thin flows. Chosen solute additions permits IA control over wide regions.

  12. Kerr effect measurements in the pseudo-gap regime of LBCO and Pb-BSCO using high resolution Sagnac

    Science.gov (United States)

    Karapetyan, Hovnatan; Nathan, Vikram; He, Ruihua; Hashimoto, Makoto; Shen, Zhi-Xun; Kapitulnik, Aharon; Eisaki, Hiroshi; Koralek, Jake; Hinton, Jamie; Orenstein, Joe; Tranquada, John; Gu, Genda; Huecker, Markus

    2011-03-01

    Polar Kerr effect in several high-Tc superconductors systems was measured at zero magnetic field with high precision using a cryogenic Sagnac fiber interferometer with zero-area. We observed non-zero Kerr rotations of order ~ 1 μ rad appearing near the pseudogap temperature T* , and marking what appears to be a true phase transition. In this talk we will review our work on YBa2Cu3 O 6 + x , La1.875Ba0.125CuO4 and Pb0.55Bi1.5Sr1.6La0.4CuO6 + δ . In particular, in Pb-BSCO we observe an emergence of Kerr signal that coincides with ARPES data showing an abrupt change at T* from a relatively simple one- band metal into a state with profoundly-altered electronic structure.

  13. Validation of high-resolution aerosol optical thickness simulated by a global non-hydrostatic model against remote sensing measurements

    Science.gov (United States)

    Goto, Daisuke; Sato, Yousuke; Yashiro, Hisashi; Suzuki, Kentaroh; Nakajima, Teruyuki

    2017-02-01

    A high-performance computing resource allows us to conduct numerical simulations with a horizontal grid spacing that is sufficiently high to resolve cloud systems. The cutting-edge computational capability, which was provided by the K computer at RIKEN in Japan, enabled the authors to perform long-term, global simulations of air pollutions and clouds with unprecedentedly high horizontal resolutions. In this study, a next generation model capable of simulating global air pollutions with O(10 km) grid spacing by coupling an atmospheric chemistry model to the Non-hydrostatic Icosahedral Atmospheric Model (NICAM) was performed. Using the newly developed model, month-long simulations for July were conducted with 14 km grid spacing on the K computer. Regarding the global distributions of aerosol optical thickness (AOT), it was found that the correlation coefficient (CC) between the simulation and AERONET measurements was approximately 0.7, and the normalized mean bias was -10%. The simulated AOT was also compared with satellite-retrieved values; the CC was approximately 0.6. The radiative effects due to each chemical species (dust, sea salt, organics, and sulfate) were also calculated and compared with multiple measurements. As a result, the simulated fluxes of upward shortwave radiation at the top of atmosphere and the surface compared well with the observed values, whereas those of downward shortwave radiation at the surface were underestimated, even if all aerosol components were considered. However, the aerosol radiative effects on the downward shortwave flux at the surface were found to be as high as 10 W/m2 in a global scale; thus, simulated aerosol distributions can strongly affect the simulated air temperature and dynamic circulation.

  14. UAS and DTS: Using Drones and Fiber Optics to Measure High Resolution Temperature of the Atmospheric Boundary Layer

    Science.gov (United States)

    Predosa, R. A.; Darricau, B.; Higgins, C. W.

    2015-12-01

    The atmospheric boundary layer (ABL) is the lowest part of the atmosphere that directly interacts with the planet's surface. The development of the ABL plays a vital role, as it affects the transport of atmospheric constituents such as air pollutants, water vapor, and greenhouse gases. Measurements of the processes in the ABL have been difficult due to the limitations in the spatial and temporal resolutions of the equipment as well as the height of the traditional flux tower. Recent advances in the unmanned aerial vehicle (UAV) and distributed temperature sensing (DTS) technologies have provided us with new tools to study the complex processes in ABL. We conducted a series of pioneering experiments in Eastern Oregon using a platform that combines UAV and DTS to collect data during morning and evening transitions in the ABL. The major components of this platform consists of a quad-copter, a DTS computer unit, and a set of customized fiber optic cables. A total of 75 flights were completed to investigate: (1) the capability of a duplexed fiber optic cable to reduce noise in the high spatial and temporal temperature measurements taken during the morning transition; (2) the possibility of using fiber optic cable as "wet bulb" thermometer to calculate relative humidity in the ABL at high spatial and temporal resolution. The preliminary results showed that using a fiber optic cable in a duplexed configuration with the UAV-DTS platform can effectively reduce noise level during the morning transition data collection. The customized "wet bulb" fiber optic cable is capable of providing information for the calculation of relative humidity in the ABL at unprecedented spatial and temporal resolutions. From this study, the UAV-DTS platform demonstrated great potential in collecting temperature data in the ABL and with the development of atmospheric sensor technologies, it will have more applications in the future.

  15. Background dust emission following grassland fire: a snapshot across the particle-size spectrum highlights how high-resolution measurements enhance detection

    Energy Technology Data Exchange (ETDEWEB)

    Whicker, Jeffrey J [Los Alamos National Laboratory; Martin, Luis M [UNIV OF ARIZONA; Field, Jason P [UNIV OF ARIZONA; Villegas, Juan C [UNIV OF ARIZONA; Brehsears, David D [UNIV OF ARIZONA; Law, Darin J [UNIV OF ARIZONA; Urgeghe, Anna M [UNIV OF ARIZONA

    2009-01-01

    Dust emission rates vary temporally and with particle size. Many studies of dust emission focus on a particular temporal scale and the portion of the particle-size spectrum associated with a single instrument; fewer studies have assessed dust emission across the particle-size spectrum and associated temporal scales using multiple instruments. Particularly lacking are measurements following disturbances such as fire that are high-resolution and focused on finer particles - those with direct implications for human health and potential for long-distance biogeochemical transport - during less windy but more commonly occurring background conditions. We measured dust emissions in unburned and burned semiarid grassland using four different instruments spanning different combinations of temporal resolution and particle-size spectrum: Big Springs Number Eight (BSNE) and Sensit instruments for larger saltating particles, DustTrak instruments for smaller suspended particles, and Total Suspended Particulate (TSP) samplers for measuring the entire range of particle sizes. Unburned and burned sites differed in vegetation cover and aerodynamic roughness, yet surprisingly differences in dust emission rates were only detectable for saltation using BSNE and for smaller aerosols using DustTrak. Our results, surprising in the lack of consistently detected differences, indicate that high-resolution DustTrak measurements offered the greatest promise for detecting differences in background emission rates and that BSNE samplers, which integrate across height, were effective for longer intervals. More generally, our results suggest that interplay between particle size, temporal resolution, and integration across time and height can be complex and may need to be considered more explicitly for effective sampling for background dust emissions.

  16. High Resolution Laboratory Spectroscopy

    CERN Document Server

    Brünken, Sandra

    2016-01-01

    In this short review we will highlight some of the recent advancements in the field of high-resolution laboratory spectroscopy that meet the needs dictated by the advent of highly sensitive and broadband telescopes like ALMA and SOFIA. Among these is the development of broadband techniques for the study of complex organic molecules, like fast scanning conventional absorption spectroscopy based on multiplier chains, chirped pulse instrumentation, or the use of synchrotron facilities. Of similar importance is the extension of the accessible frequency range to THz frequencies, where many light hydrides have their ground state rotational transitions. Another key experimental challenge is the production of sufficiently high number densities of refractory and transient species in the laboratory, where discharges have proven to be efficient sources that can also be coupled to molecular jets. For ionic molecular species sensitive action spectroscopic schemes have recently been developed to overcome some of the limita...

  17. Exploiting artificial intelligence for in-situ analysis of high-resolution radio emission measurements on a CubeSat

    Science.gov (United States)

    Isham, Brett; Bergman, Jan; Krause, Linda; Rincon-Charris, Amilcar; Bruhn, Fredrik; Funk, Peter; Stramkals, Arturs

    2016-07-01

    CubeSat missions are intentionally constrained by the limitations of their small platform. Mission payloads designed for low volume, mass, and power, may however be disproportionally limited by available telemetry allocations. In many cases, it is the data delivered to the ground which determines the value of the mission. However, transmitting more data does not necessarily guarantee high value, since the value also depends on data quality. By exploiting fast on-board computing and efficient artificial intelligence (AI) algorithms for analysis and data selection, the usage of the telemetry link can be optimized and value added to the mission. This concept is being implemented on the Puerto Rico CubeSat, which will make measurements of ambient ionospheric radio waves and ion irregularities and turbulence. Principle project goals include providing aerospace and systems engineering experiences to students. Science objectives include the study of natural space plasma processes to aid in better understanding of space weather and the Sun to Earth connection, and in-situ diagnostics of ionospheric modification experiments using high-power ground-based radio transmitters. We hope that this project might point the way to the productive use of AI in space and other remote, low-data-bandwidth environments.

  18. A New Automated Way to Measure Polyethylene Wear in THA Using a High Resolution CT Scanner: Method and Analysis

    Directory of Open Access Journals (Sweden)

    Gerald Q. Maguire Jr.

    2014-01-01

    Full Text Available As the most advantageous total hip arthroplasty (THA operation is the first, timely replacement of only the liner is socially and economically important because the utilization of THA is increasing as younger and more active patients are receiving implants and they are living longer. Automatic algorithms were developed to infer liner wear by estimating the separation between the acetabular cup and femoral component head given a computed tomography (CT volume. Two series of CT volumes of a hip phantom were acquired with the femoral component head placed at 14 different positions relative to the acetabular cup. The mean and standard deviation (SD of the diameter of the acetabular cup and femoral component head, in addition to the range of error in the expected wear values and the repeatability of all the measurements, were calculated. The algorithms resulted in a mean (±SD for the diameter of the acetabular cup of 54.21 (±0.011 mm and for the femoral component head of 22.09 (±0.02 mm. The wear error was ±0.1 mm and the repeatability was 0.077 mm. This approach is applicable clinically as it utilizes readily available computed tomography imaging systems and requires only five minutes of human interaction.

  19. Optimization of metallic magnetic calorimeters for high resolution measurement of the {sup 163}Ho electron capture spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Haehnle, Sebastian [Kirchhoff-Institute for Physics, Heidelberg University (Germany); Collaboration: ECHo-Collaboration

    2015-07-01

    The absolute scale of the neutrino mass eigenstates is one of the puzzles in modern particle physics. One method to investigate the value of the electron neutrino mass is to analyse the high energy region of the {sup 163}Ho electron capture spectrum. In the ECHo experiment low temperature metallic magnetic calorimeters (MMCs) are used for the calorimetric measurements of the EC spectrum of {sup 163}Ho. To ensure 100% quantum efficiency, the {sup 163}Ho ions are implanted into the gold absorber. Experiments carried out with a first detector prototype have demonstrated that MMC-based detectors fulfill the requirements in terms of energy resolution, rise-time and energy calibration. We discuss methods to further optimize the performance of MMCs with implanted {sup 163}Ho. Our aim is to achieve an energy resolution Δ E{sub FWHM} < 5 eV and a signal rise-time τ < 100 ns. An important aspect of this optimization is to define the maximum activity per pixel. This will result from a compromise between allowed unresolved pile-up fraction, additional heat capacity in the absorber due to Ho ions in the absorber material and minimization of the pixel number. We discuss experimental approaches for the determination of the optimal activity per pixel.

  20. High-resolution positron Q-value measurements and nuclear-structure studies far from the stability line. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Avignone, F.T. III.

    1981-02-28

    Extensive data analysis and theoretical analysis has been done to complete the extensive decay scheme investigation of /sup 206/ /sup 208/Fr and the level structures of /sup 206/ /sup 208/Rn. A final version of a journal article is presented in preprint form. Extensive Monte Carlo calculations have been made to correct the end point energies of positron spectra taken with intrinsic Ge detectors for annihilation radiation interferences. These calculations were tested using the decay of /sup 82/Sr which has previously measured positron branches. This technique was applied to the positron spectra collected at the on-line UNISOR isotope separator. The reactions used were /sup 60/Ni(/sup 20/Ne;p2n)/sup 77/Rb and /sup 60/Ni(/sup 20/Ne;pn)/sup 78/Rb. Values for 5, ..gamma..-..beta../sup +/ coincidence positron end point energies are given for the decay of /sup 77/Rb. The implied Q-value is 5.075 +- 0.010 MeV. A complete paper on the calculated corrections is presented. A flow chart of a more complete program which accounts for positrons scattering out of the detector and for bremsstralung radiation is also presented. End-point energies of four ..beta../sup +/ branches in /sup 77/Rb are given as well as a proposed energy level scheme of /sup 75/Kr based on ..gamma..-..gamma.. coincidence data taken at UNISOR.

  1. Imaging crystal spectrometer for high-resolution x-ray measurements on electron beam ion traps and tokamaks

    Science.gov (United States)

    Beiersdorfer, P.; Magee, E. W.; Hell, N.; Brown, G. V.

    2016-11-01

    We describe a crystal spectrometer implemented on the Livermore electron beam ion traps that employ two spherically bent quartz crystals and a cryogenically cooled back-illuminated charge-coupled device detector to measure x rays with a nominal resolving power of λ/Δλ ≥ 10 000. Its focusing properties allow us to record x rays either with the plane of dispersion perpendicular or parallel to the electron beam and, thus, to preferentially select one of the two linear x-ray polarization components. Moreover, by choice of dispersion plane and focussing conditions, we use the instrument either to image the distribution of the ions within the 2 cm long trap region, or to concentrate x rays of a given energy to a point on the detector, which optimizes the signal-to-noise ratio. We demonstrate the operation and utility of the new instrument by presenting spectra of Mo34+, which prepares the instrument for use as a core impurity diagnostic on the NSTX-U spherical torus and other magnetic fusion devices that employ molybdenum as plasma facing components.

  2. A statistical look at turbulence from high-resolution temperature measurements above a deep-ocean sloping seafloor.

    Science.gov (United States)

    Cimatoribus, Andrea; van Haren, Hans

    2016-04-01

    A detailed analysis of the statistics of temperature in an oceanographic observational dataset is presented. The data is collected using a moored array of 144 thermistors, 100m tall, deployed above the slopes of a seamount in the North Eastern Atlantic Ocean from April to August 2013. The thermistors are built in-house at the Royal Netherlands Institute for Sea Research, and provide a precision better than 10-3 K and very low noise levels. The thermistors measure temperature every second, synchronised throughout the moored array. The thermistor array ends 5m above the bottom, and no bottom mixed layer is visible in the data, indicating that restratification is constantly occurring and that a mixed layer is either absent or very thin. Intense turbulence is observed, and a strong dependence of turbulence parameters on the phase of the semidiurnal tidal wave (the dominant frequency in the power spectrum) is also evident. We present an overview of the results obtained form this dataset, exploiting the unprecedent detail of the observations. We compute the statistical moments (generalised structure functions) of order up to 10 of the distributions of temperature increments. Strong intermittency is observed, in particular, during the downslope phase of the tide, and farther from the seafloor. In the lower half of the mooring during the upslope phase, the temperature statistics are consistent with those of a passive scalar. In the upper half of the mooring, the temperature statistics deviate from those of a passive scalar, and evidence of turbulent convective activity is found. The downslope phase is generally thought to be more shear-dominated, but our results suggest on the other hand that convective activity is present. High-order moments also show that the turbulence scaling behaviour breaks at a well-defined scale (of the order of the buoyancy length scale), which is however dependent on the flow state (tidal phase, height above the bottom). At larger scales, wave

  3. Reconstruction of ocean velocities from the synergy between SSH and SST measurements

    Science.gov (United States)

    Isern-Fontanet, Jordi; Turiel, Antonio

    2013-04-01

    Recent advances in our understanding of the dynamics in the upper layers of the ocean have allowed us to develop methodologies to recover high resolution velocities from surface measurements such as Sea Surface Heights (SSH) and Sea Surface Temperatures (SST). These methods are based on the combined use of advanced signal processing techniques, such as wavelet analysis and singularity analysis, with dynamical approaches such as the Surface Quasi-Geostrophic (SQG) equations. Within the SQG framework, SSH and SST are closely related, which can be exploited to develop a synergetic approach that combines existing satellite measurements of these fields that can be used to recover subsurface buoyancy anomaly, surface and subsurface horizontal velocities and vertical velocities in the upper 300-500 m. Sentinel-3 satellite will follow its predecessors, ERS-1/2 and Envisat, and will provide simultaneous measurements of SST (SLSTR instrument) and SSH (SRAL and auxiliary instruments) that can be combined to produce high resolution surface currents. To test the feasibility of this approach for Sentinel-3 satellites we have reconstructed surface currents from AATSR and RA data provided by Envisat and compared results against independent SSH measurements provided Jason-1/2 platforms.

  4. Quantification of ultrasound correlation-based flow velocity mapping and edge velocity gradient measurement.

    Science.gov (United States)

    Park, Dae Woo; Kruger, Grant H; Rubin, Jonathan M; Hamilton, James; Gottschalk, Paul; Dodde, Robert E; Shih, Albert J; Weitzel, William F

    2013-10-01

    This study investigated the use of ultrasound speckle decorrelation- and correlation-based lateral speckle-tracking methods for transverse and longitudinal blood velocity profile measurement, respectively. By studying the blood velocity gradient at the vessel wall, vascular wall shear stress, which is important in vascular physiology as well as the pathophysiologic mechanisms of vascular diseases, can be obtained. Decorrelation-based blood velocity profile measurement transverse to the flow direction is a novel approach, which provides advantages for vascular wall shear stress measurement over longitudinal blood velocity measurement methods. Blood flow velocity profiles are obtained from measurements of frame-to-frame decorrelation. In this research, both decorrelation and lateral speckle-tracking flow estimation methods were compared with Poiseuille theory over physiologic flows ranging from 50 to 1000 mm/s. The decorrelation flow velocity measurement method demonstrated more accurate prediction of the flow velocity gradient at the wall edge than the correlation-based lateral speckle-tracking method. The novelty of this study is that speckle decorrelation-based flow velocity measurements determine the blood velocity across a vessel. In addition, speckle decorrelation-based flow velocity measurements have higher axial spatial resolution than Doppler ultrasound measurements to enable more accurate measurement of blood velocity near a vessel wall and determine the physiologically important wall shear.

  5. Application of the Minkowski functionals in 3D to high-resolution MR images of trabecular bone: prediction of the biomechanical strength by nonlinear topological measures

    Science.gov (United States)

    Boehm, Holger F.; Link, Thomas M.; Monetti, Roberto A.; Mueller, Dirk; Rummeny, Ernst J.; Newitt, David; Majumdar, Sharmila; Raeth, Christoph W.

    2004-05-01

    Multi-dimensional convex objects can be characterized with respect to shape, structure, and the connectivity of their components using a set of morphological descriptors known as the Minkowski functionals. In a 3D Euclidian space, these correspond to volume, surface area, mean integral curvature, and the Euler-Poincaré characteristic. We introduce the Minkowski functionals to medical image processing for the morphological analysis of trabecular bone tissue. In the context of osteoporosis-a metabolic disorder leading to a weakening of bone due to deterioration of micro-architecture-the structure of bone increasingly gains attention in the quantification of bone quality. The trabecular architecture of healthy cancellous bone consists of a complex 3D system of inter-connected mineralised elements whereas in osteoporosis the micro-structure is dominated by gaps and disconnections. At present, the standard parameter for diagnosis and assessment of fracture risk in osteoporosis is the bone mineral density (BMD) - a bulk measure of mineralisation irrespective of structural texture characteristics. With the development of modern imaging modalities (high resolution MRI, micro-CT) with spatial resolutions allowing to depict individual trabeculae bone micro-architecture has successfully been analysed using linear, 2- dimensional structural measures adopted from standard histo-morphometry. The preliminary results of our study demonstrate that due to the complex - i.e. the non-linear - network of trabecular bone structures non-linear measures in 3D are superior to linear ones in predicting mechanical properties of trabecular bone from structural information extracted from high resolution MR image data.

  6. Absence of an energy gap in measurements of Cu-O superconductors with high-resolution electron-energy-loss spectroscopy

    Science.gov (United States)

    Phelps, R. B.; Akavoor, P.; Kesmodel, L. L.; Barr, A. L.; Markert, J. T.; Ma, J.; Kelley, R. J.; Onellion, M.

    1994-09-01

    We report extensive measurements of Bi2Sr2CaCu2O8 (Bi 2:2:1:2) and YBa2Cu3O7 (Y 1:2:3) single crystals with high-resolution electron-energy-loss spectroscopy (HREELS). Both as-grown and oxygen-annealed Bi 2:2:1:2 samples were studied. In all cases, peaks due to surface optical phonons were observed at loss energies from 24 to 80 meV. We see no evidence for the weak feature near 60 meV which has been previously reported and attributed to the superconducting energy gap. Our results demonstrate that the optical conductivity of high-temperature superconductors deduced from HREELS, like that deduced from infrared spectroscopy, does not exhibit the gaplike structure expected for a BCS superconductor.

  7. Absence of an energy gap in measurements of Cu-O superconductors with high-resolution electron-energy-loss spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Phelps, R.B.; Akavoor, P.; Kesmodel, L.L. (Physics Department and Materials Research Institute, Indiana University, Bloomington, Indiana 47405 (United States)); Barr, A.L.; Markert, J.T. (Department of Physics, University of Texas, Austin, Texas 78712 (United States)); Ma, J.; Kelley, R.J.; Onellion, M. (Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States))

    1994-09-01

    We report extensive measurements of Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub 8] (Bi 2:2:1:2) and YBa[sub 2]Cu[sub 3]O[sub 7] (Y 1:2:3) single crystals with high-resolution electron-energy-loss spectroscopy (HREELS). Both as-grown and oxygen-annealed Bi 2:2:1:2 samples were studied. In all cases, peaks due to surface optical phonons were observed at loss energies from 24 to 80 meV. We see no evidence for the weak feature near 60 meV which has been previously reported and attributed to the superconducting energy gap. Our results demonstrate that the optical conductivity of high-temperature superconductors deduced from HREELS, like that deduced from infrared spectroscopy, does not exhibit the gaplike structure expected for a BCS superconductor.

  8. A simple measuring technique of surface flow velocity to analyze the behavior of velocity fields in hydraulic engineering applications.

    Science.gov (United States)

    Tellez, Jackson; Gomez, Manuel; Russo, Beniamino; Redondo, Jose M.

    2015-04-01

    An important achievement in hydraulic engineering is the proposal and development of new techniques for the measurement of field velocities in hydraulic problems. The technological advances in digital cameras with high resolution and high speed found in the market, and the advances in digital image processing techniques now provides a tremendous potential to measure and study the behavior of the water surface flows. This technique was applied at the Laboratory of Hydraulics at the Technical University of Catalonia - Barcelona Tech to study the 2D velocity fields in the vicinity of a grate inlet. We used a platform to test grate inlets capacity with dimensions of 5.5 m long and 4 m wide allowing a zone of useful study of 5.5m x 3m, where the width is similar of the urban road lane. The platform allows you to modify the longitudinal slopes from 0% to 10% and transversal slope from 0% to 4%. Flow rates can arrive to 200 l/s. In addition a high resolution camera with 1280 x 1024 pixels resolution with maximum speed of 488 frames per second was used. A novel technique using particle image velocimetry to measure surface flow velocities has been developed and validated with the experimental data from the grate inlets capacity. In this case, the proposed methodology can become a useful tools to understand the velocity fields of the flow approaching the inlet where the traditional measuring equipment have serious problems and limitations. References DigiFlow User Guide. (2012), (June). Russo, B., Gómez, M., & Tellez, J. (2013). Methodology to Estimate the Hydraulic Efficiency of Nontested Continuous Transverse Grates. Journal of Irrigation and Drainage Engineering, 139(10), 864-871. doi:10.1061/(ASCE)IR.1943-4774.0000625 Teresa Vila (1), Jackson Tellez (1), Jesus Maria Sanchez (2), Laura Sotillos (1), Margarita Diez (3, 1), and J., & (1), M. R. (2014). Diffusion in fractal wakes and convective thermoelectric flows. Geophysical Research Abstracts - EGU General Assembly 2014

  9. High resolution measurements of methane and carbon dioxide in surface waters over a natural seep reveal dynamics of dissolved phase air-sea flux.

    Science.gov (United States)

    Du, Mengran; Yvon-Lewis, Shari; Garcia-Tigreros, Fenix; Valentine, David L; Mendes, Stephanie D; Kessler, John D

    2014-09-01

    Marine hydrocarbon seeps are sources of methane and carbon dioxide to the ocean, and potentially to the atmosphere, though the magnitude of the fluxes and dynamics of these systems are poorly defined. To better constrain these variables in natural environments, we conducted the first high-resolution measurements of sea surface methane and carbon dioxide concentrations in the massive natural seep field near Coal Oil Point (COP), California. The corresponding high resolution fluxes were calculated, and the total dissolved phase air-sea fluxes over the surveyed plume area (∼363 km(2)) were 6.66 × 10(4) to 6.71 × 10(4) mol day(-1) with respect to CH4 and -6.01 × 10(5) to -5.99 × 10(5) mol day(-1) with respect to CO2. The mean and standard deviation of the dissolved phase air-sea fluxes of methane and carbon dioxide from the contour gridding analysis were estimated to be 0.18 ± 0.19 and -1.65 ± 1.23 mmol m(-2) day(-1), respectively. This methane flux is consistent with previous, lower-resolution estimates and was used, in part, to conservatively estimate the total area of the dissolved methane plume at 8400 km(2). The influx of carbon dioxide to the surface water refutes the hypothesis that COP seep methane appreciably influences carbon dioxide dynamics. Seeing that the COP seep field is one of the biggest natural seeps, a logical conclusion could be drawn that microbial oxidation of methane from natural seeps is of insufficient magnitude to change the resulting plume area from a sink of atmospheric carbon dioxide to a source.

  10. MISTiC Winds: A micro-satellite constellation approach to high resolution observations of the atmosphere using infrared sounding and 3D winds measurements

    Science.gov (United States)

    Maschhoff, K. R.; Polizotti, J. J.; Aumann, H. H.; Susskind, J.

    2016-09-01

    MISTiCTM Winds is an approach to improve short-term weather forecasting based on a miniature high resolution, wide field, thermal emission spectrometry instrument that will provide global tropospheric vertical profiles of atmospheric temperature and humidity at high (3-4 km) horizontal and vertical ( 1 km) spatial resolution. MISTiC's extraordinarily small size, payload mass of less than 15 kg, and minimal cooling requirements can be accommodated aboard a 27U-class CubeSat or an ESPA-Class micro-satellite. Low fabrication and launch costs enable a LEO sunsynchronous sounding constellation that would collectively provide frequent IR vertical profiles and vertically resolved atmospheric motion vector wind observations in the troposphere. These observations are highly complementary to present and emerging environmental observing systems, and would provide a combination of high vertical and horizontal resolution not provided by any other environmental observing system currently in operation. The spectral measurements that would be provided by MISTiC Winds are similar to those of NASA's AIRS that was built by BAE Systems and operates aboard the AQUA satellite. These new observations, when assimilated into high resolution numerical weather models, would revolutionize short-term and severe weather forecasting, save lives, and support key economic decisions in the energy, air transport, and agriculture arenas-at much lower cost than providing these observations from geostationary orbit. In addition, this observation capability would be a critical tool for the study of transport processes for water vapor, clouds, pollution, and aerosols. Key remaining technical risks are being reduced through laboratory and airborne testing under NASA's Instrument Incubator Program.

  11. MISTiC Winds, a Micro-Satellite Constellation Approach to High Resolution Observations of the Atmosphere using Infrared Sounding and 3D Winds Measurements

    Science.gov (United States)

    Maschhoff, K. R.; Polizotti, J. J.; Susskind, J.; Aumann, H. H.

    2015-12-01

    MISTiCTM Winds is an approach to improve short-term weather forecasting based on a miniature high resolution, wide field, thermal emission spectrometry instrument that will provide global tropospheric vertical profiles of atmospheric temperature and humidity at high (3-4 km) horizontal and vertical ( 1 km) spatial resolution. MISTiC's extraordinarily small size, payload mass of less than 15 kg, and minimal cooling requirements can be accommodated aboard a 27U-class CubeSat or an ESPA-Class micro-satellite. Low fabrication and launch costs enable a LEO sun-synchronous sounding constellation that would collectively provide frequent IR vertical profiles and vertically resolved atmospheric motion vector wind observations in the troposphere. These observations are highly complementary to present and emerging environmental observing systems, and would provide a combination of high vertical and horizontal resolution not provided by any other environmental observing system currently in operation. The spectral measurements that would be provided by MISTiC Winds are similar to those of NASA's Atmospheric Infrared Sounder that was built by BAE Systems and operates aboard the AQUA satellite. These new observations, when assimilated into high resolution numerical weather models, would revolutionize short-term and severe weather forecasting, save lives, and support key economic decisions in the energy, air transport, and agriculture arenas-at much lower cost than providing these observations from geostationary orbit. In addition, this observation capability would be a critical tool for the study of transport processes for water vapor, clouds, pollution, and aerosols. Key technical risks are being reduced through laboratory and airborne testing under NASA's Instrument Incubator Program.

  12. Mistic winds, a microsatellite constellation approach to high-resolution observations of the atmosphere using infrared sounding and 3d winds measurements

    Science.gov (United States)

    Maschhoff, K. R.; Polizotti, J. J.; Aumann, H. H.; Susskind, J.

    2016-10-01

    MISTiC Winds is an approach to improve short-term weather forecasting based on a miniature high resolution, wide field, thermal emission spectrometry instrument that will provide global tropospheric vertical profiles of atmospheric temperature and humidity at high (3-4 km) horizontal and vertical ( 1 km) spatial resolution. MISTiC's extraordinarily small size, payload mass of less than 15 kg, and minimal cooling requirements can be accommodated aboard a 27U-class CubeSat or an ESPA-Class micro-satellite. Low fabrication and launch costs enable a LEO sunsynchronous sounding constellation that would collectively provide frequent IR vertical profiles and vertically resolved atmospheric motion vector wind observations in the troposphere. These observations are highly complementary to present and emerging environmental observing systems, and would provide a combination of high vertical and horizontal resolution not provided by any other environmental observing system currently in operation. The spectral measurements that would be provided by MISTiC Winds are similar to those of NASA's AIRS that was built by BAE Systems and operates aboard the AQUA satellite. These new observations, when assimilated into high resolution numerical weather models, would revolutionize short-term and severe weather forecasting, save lives, and support key economic decisions in the energy, air transport, and agriculture arenas-at much lower cost than providing these observations from geostationary orbit. In addition, this observation capability would be a critical tool for the study of transport processes for water vapor, clouds, pollution, and aerosols. Key remaining technical risks are being reduced through laboratory and airborne testing under NASA's Instrument Incubator Program.

  13. Comparison of high-resolution peripheral quantitative computerized tomography with dual-energy X-ray absorptiometry for measuring bone mineral density.

    Science.gov (United States)

    Colt, E; Akram, M; Pi Sunyer, F X

    2017-06-01

    The objective of this study was to compare the measurement of areal bone mineral density (aBMD) by dual-energy X-ray absorptiometry (DXA) with the measurement of volumetric bone mineral density (vBMD) by high-resolution peripheral computerized tomography (HR-pQCT) in subjects with a wide range of body mass indices (BMI). We scanned the arms and legs of 49 premenopausal women, aged 21-45 years, with BMI from 18.5 to 46.5, by HR-pQCT and found that there was a nonsignificant change in vBMD associated with increased BMI, whereas aBMD (DXA) was associated with a positive significant increase. HR-pQCT scans a slice at the extremity of the tibia and radius, whereas DXA scans the entire leg and arm. The correlation coefficients (r) of BMD (DXA) of the legs with BMI were 0.552, PD100) of legs and arms measured by HR-pQCT with BMI, W and %fat were not significant. Although HR-pQCT and DXA scan different parts of the bone, the high r of BMD with BMI and low r of bone density measured by HR-pQCT with BMI suggest that BMD measured by DXA is artifactually increased in the presence of obesity.

  14. 高分辨率的频率空间域声波全波形速度反演-理论模型%High resolution acoustic wave full waveform velocity inversion in frequency space domain-theoretical model

    Institute of Scientific and Technical Information of China (English)

    廖建平; 刘和秀; 王华忠; 彭叶辉; 杨天春; 王齐仁

    2011-01-01

    使用最速下降法进行二维频率空间域声波波动方程全波形速度反演,讨论了如何快速实现高精度的二维频率空间域声波波动方程全波形速度反演.多尺度的思想耦合在反演框架中.把非线性问题化为逐步线性问题是我们关注的焦点,目的是把整个非线性反演的黑匣子转化成为每一步可控的过程,尽可能得到想要的反演解.仅仅使用3个离散的频率,每个频率迭代10次,对广角Marmousi模型进行地面地震声波全波形速度反演,反演得到高分辨率、高精度的速度,为全波形反演实际资料奠定了很好的基础.%We use the steepest descent method based on two-dimensional frequency space domain acoustic wave equation for full waveform velocity inversion, discuss how to quickly realize high precision two-dimensional frequency domain full waveform velocity inversion. Multi-scale criterial is coupling in the inversion framework. The nonlinear problem changes into gradually linear problem is our focus. The purpose is the whole nonlinear inverse black box into every step of controllable process as far as possible, getting an inversion solution we want. Use only three discrete frequencies, each frequency iterative ten times, we make surface seismic acoustic wave full waveform inversion on extended Marmousi and get a high resolution and high precision imaging of velocity. This gives a good foundation for full waveform inversion on real field data.

  15. Measuring Hg and MeHg fluxes from dynamic systems using high resolution in situ monitoring - case study: the Sacramento-San Joaquin Delta

    Science.gov (United States)

    Fleck, J. A.; Bergamaschi, B. A.; Downing, B. D.; Lionberger, M. A.; Schoellhamer, D.; Boss, E.; Heim, W.; Stephenson, M.

    2006-12-01

    Quantifying net loads in tidal systems is difficult, time consuming, and often very expensive. Owing to the relatively rapid nature of tidal exchange, numerous measurements are required in a brief amount of time to accurately quantify constituent fluxes between a tidal wetland and its surrounding waters. Further complicating matters, the differences in chemical concentrations of a constituent between the flood and ebb tides are often small, so that the net export of the constituent is orders of magnitude smaller than the bulk exchange in either direction over the tidal cycle. Thus, high-resolution sampling coupled with high-sensitivity instruments over an adequate amount of time is required to accurately determine a net flux. These complications are exacerbated for mercury species because of the difficulties related to clean sampling and trace-level analysis. The USGS currently is collecting data to determine the fluxes of total mercury (Hg) and methyl-Hg (MeHg) in dissolved and particulate phases at Browns Island in the San Francisco Bay-Delta, a tidally influenced estuarine system. Our field deployment package consists of an upward-looking current profiler to quantify water flux, and an array of other instruments measuring the following parameters: UV absorption, DO, pH, salinity, temperature, water depth, optical backscatter, fluorescence, and spectral attenuation. Measurements are collected at 30-minute intervals for seasonal, month-long deployments in the main slough of Brown's Island. We infer Hg and MeHg concentrations by using multivariate analysis of spectral absorbance and fluorescence properties of the continuous measurements, and comparing them to those of discrete samples taken hourly over a 25-hour tidal cycle for each deployment. Preliminary results indicate that in situ measurements can be used to predict MeHg concentrations in a tidal wetland slough in both the filtered (r2=0.96) and unfiltered (r2=0.95) fractions. Despite seasonal differences in

  16. Velocity and Vorticity Measurements of Jupiter's Great Red Spot Using Automated Cloud Feature Tracking

    CERN Document Server

    Choi, David S; Gierasch, Peter J; Showman, Adam P; 10.1016/j.icarus.2006.10.037

    2013-01-01

    We have produced mosaics of the Great Red Spot (GRS) using images taken by the Galileo spacecraft in May 2000, and have measured the winds of the GRS using an automated algorithm that does not require manual cloud tracking. Our technique yields a high-density, regular grid of wind velocity vectors that is advantageous over a limited number of scattered wind vectors that result from manual cloud tracking. The high-velocity collar of the GRS is clearly seen from our velocity vector map, and highest wind velocities are measured to be around 170 m/s. The high resolution of the mosaics have also enabled us to map turbulent eddies inside the chaotic central region of the GRS, similar to those mapped by Sada et al. (1996) and Vasavada et al. (1998). Using the wind velocity measurements, we computed particle trajectories around the GRS as well as maps of relative and absolute vorticities. We have discovered a narrow ring of cyclonic vorticity that surrounds the main anti-cyclonic high-velocity collar. This narrow rin...

  17. Conformational ordering of biomolecules in the gas phase: nitrogen collision cross sections measured on a prototype high resolution drift tube ion mobility-mass spectrometer.

    Science.gov (United States)

    May, Jody C; Goodwin, Cody R; Lareau, Nichole M; Leaptrot, Katrina L; Morris, Caleb B; Kurulugama, Ruwan T; Mordehai, Alex; Klein, Christian; Barry, William; Darland, Ed; Overney, Gregor; Imatani, Kenneth; Stafford, George C; Fjeldsted, John C; McLean, John A

    2014-02-18

    Ion mobility-mass spectrometry measurements which describe the gas-phase scaling of molecular size and mass are of both fundamental and pragmatic utility. Fundamentally, such measurements expand our understanding of intrinsic intramolecular folding forces in the absence of solvent. Practically, reproducible transport properties, such as gas-phase collision cross-section (CCS), are analytically useful metrics for identification and characterization purposes. Here, we report 594 CCS values obtained in nitrogen drift gas on an electrostatic drift tube ion mobility-mass spectrometry (IM-MS) instrument. The instrument platform is a newly developed prototype incorporating a uniform-field drift tube bracketed by electrodynamic ion funnels and coupled to a high resolution quadrupole time-of-flight mass spectrometer. The CCS values reported here are of high experimental precision (±0.5% or better) and represent four chemically distinct classes of molecules (quaternary ammonium salts, lipids, peptides, and carbohydrates), which enables structural comparisons to be made between molecules of different chemical compositions for the rapid "omni-omic" characterization of complex biological samples. Comparisons made between helium and nitrogen-derived CCS measurements demonstrate that nitrogen CCS values are systematically larger than helium values; however, general separation trends between chemical classes are retained regardless of the drift gas. These results underscore that, for the highest CCS accuracy, care must be exercised when utilizing helium-derived CCS values to calibrate measurements obtained in nitrogen, as is the common practice in the field.

  18. Measurement of toxaphene congeners in pooled human serum collected in three U.S. cities using high-resolution mass spectrometry.

    Science.gov (United States)

    Barr, John R; Woolfitt, Adrian R; Maggio, Vincent L; Patterson, Donald G

    2004-05-01

    Because human toxaphene exposure data are largely lacking, we surveyed human serum pools collected from U.S. residents to determine the feasibility of measuring toxaphene in human samples and to determine whether additional analytical requirements were needed for routine measurement of toxaphene. We report a method for quantification of toxaphene congeners in human serum using a mixed-bed gradient solid-phase extraction and analysis using gas chromatography-high-resolution mass spectrometry with electron-impact ionization. In this method, we monitored low-mass fragment ions that were common to all 22 congeners. To verify the specific congeners detected, we further analyzed the extract using negative methane chemical ionization. We used this method to measure two specific congeners, Parlar 26 and 50, at concentrations ranging from about 3 to 30 pg/ml (0.7-7 ng/g lipid) in pooled human serum collected in Atlanta, Chicago, and Cincinnati. We identified several analytical parameters that must be strengthened to routinely measure toxaphene congeners in human samples.

  19. High resolution grazing-incidence in-plane x-ray diffraction for measuring the strain of a Si thin layer.

    Science.gov (United States)

    Omote, Kazuhiko

    2010-12-01

    We have measured the strain of a thin Si layer deposited on a SiGe layer using a high resolution x-ray diffraction system. The Si layer was deposited on the SiGe layer in order to introduce a tensile strain to the Si layer. To measure the in-plane lattice constant accurately, we have employed so-called grazing-incidence in-plane diffraction. For this measurement, we have made a new five-axis x-ray goniometer which has four ordinal circles (ω, 2θ, χ, φ) plus a counter-χ-axis for selecting the exit angle of the diffracted x-rays. In grazing-incidence geometry, an incident x-ray is focused on the sample surface in order to obtain good diffraction intensity even though the layer thickness is less than 5 nm. Because diffracted x-rays are detected through analyzer crystals, the diffraction angle can be determined with an accuracy of ± 0.0003°. This indicates that the strain sensitivity is about 10( - 5) when we measure in-plane Si 220 diffraction. Use of x-ray diffraction could be the best standard metrology method for determining strain in thin layers. Furthermore, we have demonstrated that incident/exit angle selected in-plane diffraction is very useful for height/depth selective strain determination.

  20. Plasma flow velocity measurements using a modulated Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J. [Australian National Univ., Canberra, ACT (Australia). Plasma Research Lab.; Meijer, F.G. [FOM-Instituut voor Plasmafysica `Rijnhuizen`, Association Euratom-FOM, PO Box 1207, 3430 BE Nieuwegein (Netherlands)]|[Physics Faculty, University of Amsterdam, Amsterdam (Netherlands)

    1997-03-01

    This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (orig.) 1 refs.

  1. Applications of High-Resolution Electrospray Ionization Mass Spectrometry to Measurements of Average Oxygen to Carbon Ratios in Secondary Organic Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Bateman, Adam P.; Laskin, Julia; Laskin, Alexander; Nizkorodov, Sergey

    2012-07-02

    The applicability of high resolution electrospray ionization mass spectrometry (HR ESI-MS) to measurements of the average oxygen to carbon ratio (O/C) in organic aerosols was investigated. Solutions with known average O/C containing up to 10 standard compounds representative of secondary organic aerosol (SOA) were analyzed and corresponding electrospray ionization efficiencies were quantified. The assumption of equal ionization efficiency commonly used in estimating O/C ratios of organic aerosols was found to be reasonably accurate. We found that the accuracy of the measured O/C ratios increases by averaging the values obtained from both (+) and (-) modes. A correlation was found between the ratio of the ionization efficiencies in the positive and negative ESI modes with the octanol-water partition constant, and more importantly, with the compound's O/C. To demonstrate the utility of this correlation for estimating average O/C values of unknown mixtures, we analyzed the ESI (+) and ESI (-) data for SOA produced by oxidation of limonene and isoprene and compared to online O/C measurements using an aerosol mass spectrometer (AMS). This work demonstrates that the accuracy of the HR ESI-MS methods is comparable to that of the AMS, with the added benefit of molecular identification of the aerosol constituents.

  2. Measuring slip in paleoearthquakes using high-resolution aerial lidar data: Combined analysis of the Wairau, Awatere, Clarence, and Hope faults, South Island, New Zealand

    Science.gov (United States)

    Zinke, R. W.; Dolan, J. F.; Hatem, A. E.; Van Dissen, R. J.; Langridge, R.; Grenader, J.; McGuire, C. P.; Rhodes, E. J.; Nicol, A., , Prof

    2016-12-01

    Analysis of a large new high-resolution aerial lidar microtopographic data set provides > 500 measured fault offsets from sections of the four primary right-lateral strike-slip faults of the Marlborough Fault System (MFS), in northern South Island, New Zealand. With a shot density of >12 shots/m2 (and locally up to 18 shots/m2) these high-quality data allow us to resolve topographically defined geomorphic offsets with decimeter precision along 250 km of combined fault length. The measured offsets range in size from 2 m to > 100 m, and allow us to constrain displacements in the past one to several surface ruptures along stretches of the Wairau, Awatere, Clarence, and Hope faults. Our results reveal a number of important details of the rupture history of these faults, including: (1) the amount of slip and spatial variability (along and across strike) of strain released in the most recent event along sections of each of the four faults; (2) the consistency of slip throughout the past several ruptures on specific faults; and (3) suggestions of potential linkages and segment boundaries along each fault. The lidar data also facilitate precise measurements of larger offsets that, when combined with age data collected as part of our broader collaborative analyses of incremental fault slip rates and paleoearthquake ages, help to constrain the broader spatial and temporal patterns of strain release across the MFS during Holocene and latest Pleistocene time.

  3. High-Resolution X-ray Spectroscopy of Hercules X-1 with the XMM-Newton RGS CNO Element Abundance Measurements and Density Diagnostics of a Photoionized Plasma

    CERN Document Server

    Jiménez-Garate, M A; Den Herder, J W A; Zane, S; Ramsay, G

    2002-01-01

    We analyze the high-resolution X-ray spectrum of Hercules X-1, an intermediate-mass X-ray binary, which was observed with the XMM-Newton Reflection Grating Spectrometer. We measure the elemental abundance ratios by use of spectral models, and we detect material processed through the CNO-cycle. The CNO abundances, and in particular the ratio N/O > 4.0 times solar, provide stringent constraints on the evolution of the binary system. The low and short-on flux states of Her X-1 exhibit narrow line emission from C VI, N VI, N VII, O VII, O VIII, Ne IX, and Ne X ions. The spectra show signatures of photoionization. We measure the electron temperature, quantify photoexcitation in the He alpha lines, and set limits on the location and density of the gas. The recombination lines may originate in the accretion disk atmosphere and corona, or on the X-ray illuminated face of the mass donor (HZ Her). The spectral variation over the course of the 35 d period provides additional evidence for the precession of the disk. Duri...

  4. Measuring Global Monopole Velocities, one by one

    CERN Document Server

    Lopez-Eiguren, Asier; Achúcarro, Ana

    2016-01-01

    We present an estimation of the average velocity of a network of global monopoles in a cosmological setting using large numerical simulations. In order to obtain the value of the velocity, we improve some already known methods, and present a new one. This new method estimates individual global monopole velocities in a network, by means of detecting each monopole position in the lattice and following the path described by each one of them. Using our new estimate we can settle an open question previously posed in the literature: velocity-dependent one-scale (VOS) models for global monopoles predict two branches of scaling solutions, one with monopoles moving at subluminal speeds and one with monopoles moving at luminal speeds. Previous attempts to estimate monopole velocities had large uncertainties and were not able to settle that question. Our simulations find no evidence of a luminal branch. We also estimate the values of the parameters of the VOS model. With our new method we can also study the microphysics...

  5. Measuring global monopole velocities, one by one

    Science.gov (United States)

    Lopez-Eiguren, Asier; Urrestilla, Jon; Achúcarro, Ana

    2017-01-01

    We present an estimation of the average velocity of a network of global monopoles in a cosmological setting using large numerical simulations. In order to obtain the value of the velocity, we improve some already known methods, and present a new one. This new method estimates individual global monopole velocities in a network, by means of detecting each monopole position in the lattice and following the path described by each one of them. Using our new estimate we can settle an open question previously posed in the literature: velocity-dependent one-scale (VOS) models for global monopoles predict two branches of scaling solutions, one with monopoles moving at subluminal speeds and one with monopoles moving at luminal speeds. Previous attempts to estimate monopole velocities had large uncertainties and were not able to settle that question. Our simulations find no evidence of a luminal branch. We also estimate the values of the parameters of the VOS model. With our new method we can also study the microphysics of the complicated dynamics of individual monopoles. Finally we use our large simulation volume to compare the results from the different estimator methods, as well as to asses the validity of the numerical approximations made.

  6. A New Filtering Algorithm Utilizing Radial Velocity Measurement

    Institute of Scientific and Technical Information of China (English)

    LIU Yan-feng; DU Zi-cheng; PAN Quan

    2005-01-01

    Pulse Doppler radar measurements consist of range, azimuth, elevation and radial velocity. Most of the radar tracking algorithms in engineering only utilize position measurement. The extended Kalman filter with radial velocity measureneut is presented, then a new filtering algorithm utilizing radial velocity measurement is proposed to improve tracking results and the theoretical analysis is also given. Simulation results of the new algorithm, converted measurement Kalman filter, extended Kalman filter are compared. The effectiveness of the new algorithm is verified by simulation results.

  7. Atmospheric Corrections Using MODTRAN for TOA and Surface BRDF Characteristics from High Resolution Spectroradiometric/Angular Measurements from a Helicopter Platform

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    High-resolution spectral radiance measurements were taken by a spectral radiometer on board a heli copter over the US Oklahoma Southern Great Plain near the Atmospheric Radiation Measurements (ARM) site during August 1998. The radiometer has a spectral range from 350 nm to 2500 nm at 1 nm resolution. The measurements covered several grass and cropland scene types at multiple solar zenith angles. Detailed atmospheric corrections using the Moderate Resolution Transmittance (MODTRAN) radiation model and in-situ sounding and aerosol measurements have been applied to the helicopter measurements in order to re trieve the surface and top of atmosphere (TOA) Bidirectional Reflectance Distribution Function (BRDF) characteristics. The atmospheric corrections are most significant in the visible wavelengths and in the strong water vapor absorption wavelengths in the near infrared region. Adjusting the BRDF to TOA requires a larger correction in the visible channels since Rayleigh scattering contributes significantly to the TOA reflectance. The opposite corrections to the visible and near infrarred wavelengths can alter the radiance dif ference and ratio that many remote sensing techniques are based on, such as the normalized difference vege tation index (NDVI). The data show that surface BRDFs and spectral albedos are highly sensitive to the veg etation type and solar zenith angle while BRDF at TOA depends more on atmospheric conditions and the vi ewing geometry. Comparison with the Clouds and the Earth's Radiant Energy System (CERES) derived clear sky Angular Distribution Model (ADM) for crop and grass scene type shows a standard deviation of 0.08 in broadband anisotropic function at 25° solar zenith angle and 0.15 at 50° solar zenith angle, respectively.

  8. Simultaneous observations of structure function parameter of refractive index using a high-resolution radar and the DataHawk small airborne measurement system

    Science.gov (United States)

    Scipión, Danny E.; Lawrence, Dale A.; Milla, Marco A.; Woodman, Ronald F.; Lume, Diego A.; Balsley, Ben B.

    2016-09-01

    The SOUSY (SOUnding SYstem) radar was relocated to the Jicamarca Radio Observatory (JRO) near Lima, Peru, in 2000, where the radar controller and acquisition system were upgraded with state-of-the-art parts to take full advantage of its potential for high-resolution atmospheric sounding. Due to its broad bandwidth (4 MHz), it is able to characterize clear-air backscattering with high range resolution (37.5 m). A campaign conducted at JRO in July 2014 aimed to characterize the lower troposphere with a high temporal resolution (8.1 Hz) using the DataHawk (DH) small unmanned aircraft system, which provides in situ atmospheric measurements at scales as small as 1 m in the lower troposphere and can be GPS-guided to obtain measurements within the beam of the radar. This was a unique opportunity to make coincident observations by both systems and to directly compare their in situ and remotely sensed parameters. Because SOUSY only points vertically, it is only possible to retrieve vertical radar profiles caused by changes in the refractive index within the resolution volume. Turbulent variations due to scattering are described by the structure function parameter of refractive index Cn2. Profiles of Cn2 from the DH are obtained by combining pressure, temperature, and relative humidity measurements along the helical trajectory and integrated at the same scale as the radar range resolution. Excellent agreement is observed between the Cn2 estimates obtained from the DH and SOUSY in the overlapping measurement regime from 1200 m up to 4200 m above sea level, and this correspondence provides the first accurate calibration of the SOUSY radar for measuring Cn2.

  9. Measuring melt and velocity of Alaskan mountain glaciers using phase-sensitive radar and differential GPS

    Science.gov (United States)

    Neuhaus, S.; Tulaczyk, S. M.

    2015-12-01

    Alaskan glaciers show some of the highest rates of retreat worldwide, contributing to sea level rise. This retreat is due to both increased velocity and increased melt. We seek to understand the role of glacial meltwater on velocity. Matanuska glacier, a land terminating glacier in Alaska, has been well-studied using traditional glaciological techniques, but new technology has emerged that allows us to measure melt and velocity more accurately. We employed high-resolution differential GPS to create surface velocity profiles across flow in the ablation zone during the summer of 2015. We also measured surface ablation using stakes and measured basal melt using phase-sensitive radar designed by the British Antarctic Survey. The positions acquired by differential GPS are obtained to a resolution of less than 0.5m, while feature tracking using time-lapse photography for the same time period yields positions with greater and more variable uncertainty. The phase-sensitive radar provides ice thinning rates. Phase-sensitive radar together with ground penetrating radar provides us with an understanding of the internal structure of the glacier. This suite of data allows us to determine the relative importance of surface melt, basal melt, and internal deformation on ice velocity in warm mountain glaciers.

  10. Comprehensive spatiotemporal glacier and ice sheet velocity measurements from Landsat 8

    Science.gov (United States)

    Moon, Twila; Fahnestock, Mark; Scambos, Ted; Klinger, Marin; Haran, Terry

    2015-04-01

    Combining newly developed software with Landsat 8 image returns, we are now producing broad-coverage ice velocity measurements on weekly to monthly scales across ice sheets and glaciers. Using new image-to-image cross correlation software, named PyCorr, we take advantage of the improved radiometric resolution of the Landsat 8 panchromatic band to create velocity maps with sub-pixel accuracy. Landsat 8's 12-bit radiometric resolution supports measurement of ice flow in uncrevassed regions based on persistent sastrugi patterns lasting weeks to a few months. We also leverage these improvements to allow for ice sheet surface roughness measurements. Landsat 8's 16-day repeat orbit and increased image acquisition across the Greenland and Antarctic ice sheets supports development of seasonal to annual ice sheet velocity mosaics with full coverage of coastal regions. We also create time series for examining sub-seasonal change with near real time processing in areas such as the Amundsen Sea Embayment and fast flowing Greenland outlet glaciers. In addition, excellent geolocation accuracy enables velocity mapping of smaller ice caps and glaciers, which we have already applied in Alaska and Patagonia. Finally, PyCorr can be used for velocity mapping with other remote sensing imagery, including high resolution WorldView satellite data.

  11. Tidal inundation (“Rob”) investigation using time series of high resolution satellite image data and from institu measurements along northern coast of Java (Pantura)

    Science.gov (United States)

    Andreas, Heri; Usriyah; Zainal Abidin, Hasanuddin; Anggreni Sarsito, Dina

    2017-06-01

    Tidal inundation (in Javanese they call it “Rob”) is now becoming a well known phenomenon along northern coast of Java Indonesia (Pantura). The occurrence of tidal inundation was recognized at least in the early 2000 and even earlier. In the recent years the tidal inundation comes not only at a high tide but even at the regular tide in some area across Pantura. In fact in location such as Pondok Bali, north of Blanakan, north of Pekalongan, north of Semarang and north west of Demak, seems those areas are sinking to the sea through times. Sea level rise and land subsidence are considered as main factors deriving the occurrence of this tidal inundation. We were using time series of high resolution satellite image data and insitu data measurements to mapping the tidal inundation along northern coast of Java. All available data from google data satellite archives (year 2000- recent years) and any available sources being analyze together with field surveys tagging and also from media information. As a result we can see the tidal inundation are taking place in Tanggerang, Jakarta, Bekasi, Cilamaya, Pondok Bali, Blanakan, Indramayu, Cirebon, Brebes, Tegal, Pemalang, Pekalongan, Kendal, Semarang, Demak, Gresik, Surabaya, Sidoarjo and Pasuruan.

  12. Time-Resolved Quantitative Measurement of OH HO2 and CH2O in Fuel Oxidation Reactions by High Resolution IR Absorption Spectroscopy.

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Haifeng; Rotavera, Brandon; Taatjes, Craig A.

    2014-08-01

    Combined with a Herriott-type multi-pass slow flow reactor, high-resolution differential direct absorption spectroscopy has been used to probe, in situ and quantitatively, hydroxyl (OH), hydroperoxy (HO 2 ) and formaldehyde (CH 2 O) molecules in fuel oxidation reactions in the reactor, with a time resolution of about 1 micro-second. While OH and CH 2 O are probed in the mid-infrared (MIR) region near 2870nm and 3574nm respectively, HO 2 can be probed in both regions: near-infrared (NIR) at 1509nm and MIR at 2870nm. Typical sensitivities are on the order of 10 10 - 10 11 molecule cm -3 for OH at 2870nm, 10 11 molecule cm -3 for HO 2 at 1509nm, and 10 11 molecule cm -3 for CH 2 O at 3574nm. Measurements of multiple important intermediates (OH and HO 2 ) and product (CH 2 O) facilitate to understand and further validate chemical mechanisms of fuel oxidation chemistry.

  13. Improving Measurement of Forest Structural Parameters by Co-Registering of High Resolution Aerial Imagery and Low Density LiDAR Data.

    Science.gov (United States)

    Huang, Huabing; Gong, Peng; Cheng, Xiao; Clinton, Nick; Li, Zengyuan

    2009-01-01

    Forest structural parameters, such as tree height and crown width, are indispensable for evaluating forest biomass or forest volume. LiDAR is a revolutionary technology for measurement of forest structural parameters, however, the accuracy of crown width extraction is not satisfactory when using a low density LiDAR, especially in high canopy cover forest. We used high resolution aerial imagery with a low density LiDAR system to overcome this shortcoming. A morphological filtering was used to generate a DEM (Digital Elevation Model) and a CHM (Canopy Height Model) from LiDAR data. The LiDAR camera image is matched to the aerial image with an automated keypoints search algorithm. As a result, a high registration accuracy of 0.5 pixels was obtained. A local maximum filter, watershed segmentation, and object-oriented image segmentation are used to obtain tree height and crown width. Results indicate that the camera data collected by the integrated LiDAR system plays an important role in registration with aerial imagery. The synthesis with aerial imagery increases the accuracy of forest structural parameter extraction when compared to only using the low density LiDAR data.

  14. Analysis of adhesive binding forces between laminin-1 and C2C12 muscle cell membranes measured via high resolution force spectroscopy

    Science.gov (United States)

    Gluck, George; Gilbert, Richard; Ortiz, Christine

    2002-03-01

    Laminins are a family of glycoproteins that regulate cell differentiation, shape, and motility through interactions with various cell surface receptors. Here, we have directly measured the biomolecular adhesive binding forces between a cantilever / probe tip that was covalently attached with laminin-1 and membrane receptors on C2C12 muscle cells using the technique of high-resolution force spectroscopy (HRFS). On retraction of the probe tip away from the membrane surface, discrete, long-range adhesive unbinding events were always observed. Statistical analysis of the data revealed an initial broad distribution of heterogeneous unbinding events (occurring at separation distances, D=0-2µm from the point of maximum compression) of magnitude 92.23±37.87pN followed by a narrow distribution of homogeneous unbinding events (occurring at D > 2µm) of magnitude 38.16±9.10pN, which is suggestive of an individual biomolecular adhesive interaction. On-going studies include loading rate dependence and effect of dystroglycan mutation.

  15. Vertical modeling of the nitrogen cycle in the eastern tropical South Pacific oxygen deficient zone using high-resolution concentration and isotope measurements

    Science.gov (United States)

    Peters, Brian D.; Babbin, Andrew R.; Lettmann, Karsten A.; Mordy, Calvin W.; Ulloa, Osvaldo; Ward, Bess B.; Casciotti, Karen L.

    2016-11-01

    Marine oxygen deficient zones (ODZs) have long been identified as sites of fixed nitrogen (N) loss. However, the mechanisms and rates of N loss have been debated, and traditional methods for measuring these rates are labor-intensive and may miss hot spots in spatially and temporally variable environments. Here we estimate rates of heterotrophic nitrate reduction, heterotrophic nitrite reduction (denitrification), nitrite oxidation, and anaerobic ammonium oxidation (anammox) at a coastal site in the eastern tropical South Pacific (ETSP) ODZ based on high-resolution concentration and natural abundance stable isotope measurements of nitrate (NO3-) and nitrite (NO2-). These measurements were used to estimate process rates using a two-step inverse modeling approach. The modeled rates were sensitive to assumed isotope effects for NO3- reduction and NO2- oxidation. Nevertheless, we addressed two questions surrounding the fates of NO2- in the ODZ: (1) Is NO2- being primarily reduced to N2 or oxidized to NO3- in the ODZ? and (2) what are the contributions of anammox and denitrification to NO2- removal? Depth-integrated rates from the model suggest that 72-88% of the NO2- produced in the ODZ was oxidized back to NO3-, while 12-28% of NO2- was reduced to N2. Furthermore, our model suggested that 36-74% of NO2- loss was due to anammox, with the remainder due to denitrification. These model results generally agreed with previously measured rates, though with a large range of uncertainty, and they provide a long-term integrated view that compliments incubation experiments to obtain a broader picture of N cycling in ODZs.

  16. High-resolution image analysis.

    Science.gov (United States)

    Preston, K

    1986-01-01

    In many departments of cytology, cytogenetics, hematology, and pathology, research projects using high-resolution computerized microscopy are now being mounted for computation of morphometric measurements on various structural components, as well as for determination of cellular DNA content. The majority of these measurements are made in a partially automated, computer-assisted mode, wherein there is strong interaction between the user and the computerized microscope. At the same time, full automation has been accomplished for both sample preparation and sample examination for clinical determination of the white blood cell differential count. At the time of writing, approximately 1,000 robot differential counting microscopes are in the field, analyzing images of human white blood cells, red blood cells, and platelets at the overall rate of about 100,000 slides per day. This mammoth through-put represents a major accomplishment in the application of machine vision to automated microscopy for hematology. In other areas of automated high-resolution microscopy, such as cytology and cytogenetics, no commercial instruments are available (although a few metaphase-finding machines are available and other new machines have been announced during the past year). This is a disappointing product, considering the nearly half century of research effort in these areas. This paper provides examples of the state of the art in automation of cell analysis for blood smears, cervical smears, and chromosome preparations. Also treated are new developments in multi-resolution automated microscopy, where images are now being generated and analyzed by a single machine over a range of 64:1 magnification and from 10,000 X 20,000 to 500 X 500 in total picture elements (pixels). Examples of images of human lymph node and liver tissue are presented. Semi-automated systems are not treated, although there is mention of recent research in the automation of tissue analysis.

  17. Accurate Sound Velocity Measurement in Ocean Near-Surface Layer

    Science.gov (United States)

    Lizarralde, D.; Xu, B. L.

    2015-12-01

    Accurate sound velocity measurement is essential in oceanography because sound is the only wave that can propagate in sea water. Due to its measuring difficulties, sound velocity is often not measured directly but instead calculated from water temperature, salinity, and depth, which are much easier to obtain. This research develops a new method to directly measure the sound velocity in the ocean's near-surface layer using multi-channel seismic (MCS) hydrophones. This system consists of a device to make a sound pulse and a long cable with hundreds of hydrophones to record the sound. The distance between the source and each receiver is the offset. The time it takes the pulse to arrive to each receiver is the travel time.The errors of measuring offset and travel time will affect the accuracy of sound velocity if we calculated with just one offset and one travel time. However, by analyzing the direct arrival signal from hundreds of receivers, the velocity can be determined as the slope of a straight line in the travel time-offset graph. The errors in distance and time measurement result in only an up or down shift of the line and do not affect the slope. This research uses MCS data of survey MGL1408 obtained from the Marine Geoscience Data System and processed with Seismic Unix. The sound velocity can be directly measured to an accuracy of less than 1m/s. The included graph shows the directly measured velocity verses the calculated velocity along 100km across the Mid-Atlantic continental margin. The directly measured velocity shows a good coherence to the velocity computed from temperature and salinity. In addition, the fine variations in the sound velocity can be observed, which is hardly seen from the calculated velocity. Using this methodology, both large area acquisition and fine resolution can be achieved. This directly measured sound velocity will be a new and powerful tool in oceanography.

  18. High-resolution measurement of nitrous oxide in the Elbe estuary under hypoxia: Hot-spots of biological N2O production

    Science.gov (United States)

    Brase, Lisa; Lendt, Ralf; Sanders, Tina; Dähnke, Kirstin

    2016-04-01

    Nitrous oxide (N2O) is one of the most important greenhouse gases. Its global warming potential exceeds that of CO2 by a factor of ˜300. Estuaries, being sites of intense biological N-turnover, are one of the major natural sources of N2O emissions. On two ship cruises in April and June 2015, concentrations of N2O were measured in the surface water using equilibrator laser based on-line measurements. Based on these high-resolution N2O profiles along the Elbe estuary, N2O saturation and N2O-fluxes between surface water and air were calculated. Additionally, DIN concentrations and dual stable isotopes of nitrate (δ15N and δ18O) were analyzed. Concentration and water-to-air fluxes of N2O were highest in the Hamburg port region and dropped quickly further downstream. Highest water-to-air fluxes were up to 800μM/m2/d and 1600μM/m2/d in April and in June, respectively. Downstream of the port region, an N2O oversaturation of 150-200% was estimated over the entire estuary, with saturation approaching equilibrium (96-100%) only in the North Sea region. N2O production was much higher in June than in April 2015, likely coupled to lower oxygen saturation in the water column in June. Based on these measurements, the port of Hamburg region was identified as a hot-spot of N2O production. High N2O concentration and depleted values of nitrate isotopes suggest that nitrification is a significant source of N2O in the estuary, especially at low oxygen concentration. In the Elbe estuary, hypoxia obviously drastically increased the emissions of the greenhouse gas N2O.

  19. Multi Point Velocity, Density and Temperature Measurements using LITA Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Laser induced thermal acoustics (LITA) is a nonintrusive, transient-grating optical technique that provides simultaneous high-accuracy measurements of velocity,...

  20. High-Resolution Autoradiography

    Science.gov (United States)

    1955-01-01

    measurements see appendix ehrbide containced 6.68 percent carbon while the alpha iron 13). Theii Oak Ridge National Laboratory analysis gave (,t(e matrix...the cementite phase leaving only a (5) The sample was fixed for a minute, washed in water for very small amount of activity in the alpha iron phase. a

  1. Experimental Measurement for Shock Velocity-Mass Velocity Relationship of Liquid Argon Up to 46 GPa

    Institute of Scientific and Technical Information of China (English)

    孟川民; 施尚春; 董石; 杨向东; 谭华; 经福谦

    2003-01-01

    Shock properties of liquid argon were measured in the shock pressure up to 46 GPa by employing the two-stage light gas gun. Liquid nitrogen was used as coolant liquid. The cryogenic target system has been improved to compare with the previous work. Shock velocities were measured with self-shorting electrical probes. Impactor velocities were measured with an electrical-magnetic induction system. Mass velocities were obtained by mean of shock impedance matching method. The experimental data shows that the slope of experimental Hugoniot curve of liquid argon begins to decrease above 30 GPa.

  2. High resolution differential thermometer

    Directory of Open Access Journals (Sweden)

    Gotra Z. Yu.

    2009-11-01

    Full Text Available Main schematic solutions of differential thermometers with measurement resolution about 0.001°C are considered. Differential temperature primary transducer realized on a transistor differential circuit in microampere mode. Analytic calculation and schematic mathematic simulation of primary transducer are fulfilled. Signal transducer is realized on a high precision Zero-Drift Single-Supply Rail-to-Rail operation amplifier AD8552 and 24-Bit S-D microconverter ADuC834.

  3. Accurate measurement of ultrasonic velocity by eliminating the diffraction effect

    Institute of Scientific and Technical Information of China (English)

    WEI Tingcun

    2003-01-01

    The accurate measurement method of ultrasonic velocity by the pulse interferencemethod with eliminating the diffraction effect has been investigated in VHF range experimen-tally. Two silicate glasses were taken as the specimens, their frequency dependences of longitu-dinal velocities were measured in the frequency range 50-350 MHz, and the phase advances ofultrasonic signals caused by diffraction effect were calculated using A. O. Williams' theoreticalexpression. For the frequency dependences of longitudinal velocities, the measurement resultswere in good agreement with the simulation ones in which the phase advances were included.It has been shown that the velocity error due to diffraction effect can be corrected very well bythis method.

  4. Validation of {sup 226}Ra, {sup 228}Ra and {sup 210}Pb measurements in soil and sediment samples through high resolution gamma ray spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Danila Carrijo da Silva; Silva, Nivaldo Carlos da; Bonifacio, Rodrigo Leandro; Guerrero, Eder Tadeu Zenun [Comissao Nacional de Energia Nuclear (LAPOC/CNEN-MG), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas

    2013-07-01

    Radionuclides found in ore extraction waste materials are a great source of concern regarding public health and environmental safety. One technique to determine the concentration of substances is high resolution gamma ray spectrometry using HPGe. Validating a measurement technique is essential to warrant high levels of quality to any scientific work. The Laboratory of Pocos de Caldas of the Brazilian Commission for Nuclear Energy partakes into a Quality Management System project, seeking Accreditation under ISO/IEC 17025 through the validation of techniques of chemical and radiometric analysis of environmental samples from water, soil and sediment. The focus of the Radon Laboratory at LAPOC is validation of Ra-226, Ra-228 and Pb-210 concentration determinations in soil and sediment through a gamma spectrometer system. The stages of this validation process included sample reception and preparation, detector calibration and sample analyses. Dried samples were sealed in metallic containers and analyzed after radioactive equilibrium between Ra-226 and daughters Pb-214 and Bi-214. Gamma spectrometry was performed using CANBERRA HPGe detector and gamma spectrum software Genie 2000. The photo peaks used for Ra-226 determination were 609 keV and 1020 keV of Bi-214 and 351 keV of Pb-214. For the Ra-228 determination a photopeak of 911 keV was used from its short half-life daughter Ac-228 (T1/2 = 6.12 h). For Pb-210, the photopeak of 46.5 keV was used, which, due to the low energy, self-absorption correction was needed. Parameters such as precision, bias/accuracy, linearity, detection limit and uncertainty were evaluated for that purpose. The results have pointed to satisfying results. (author)

  5. SPIDER Progress Towards High Resolution Correlated Fission Product Data

    Science.gov (United States)

    Shields, Dan; Meierbachtol, Krista; Tovesson, Fredrik; Arnold, Charles; Blackeley, Rick; Bredeweg, Todd; Devlin, Matt; Hecht, Adam; Jandel, Marian; Jorgenson, Justin; Nelson, Ron; White, Morgan; Spider Team

    2014-09-01

    The SPIDER detector (SPectrometer for Ion DEtermination in fission Research) is under development with the goal of obtaining high-resolution, high-efficiency, correlated fission product data needed for many applications including the modeling of next generation nuclear reactors, stockpile stewardship, and the fundamental understanding of the fission process. SPIDER simultaneously measures velocity and energy of both fission products to calculate fission product yields (FPYs), neutron multiplicity (ν), and total kinetic energy (TKE). A detailed description of the prototype SPIDER detector components will be presented. Characterization measurements with alpha and spontaneous fission sources will also be discussed. LA-UR-14-24875. The SPIDER detector (SPectrometer for Ion DEtermination in fission Research) is under development with the goal of obtaining high-resolution, high-efficiency, correlated fission product data needed for many applications including the modeling of next generation nuclear reactors, stockpile stewardship, and the fundamental understanding of the fission process. SPIDER simultaneously measures velocity and energy of both fission products to calculate fission product yields (FPYs), neutron multiplicity (ν), and total kinetic energy (TKE). A detailed description of the prototype SPIDER detector components will be presented. Characterization measurements with alpha and spontaneous fission sources will also be discussed. LA-UR-14-24875. This work is in part supported by LANL Laboratory Directed Research and Development Projects 20110037DR and 20120077DR.

  6. High resolution pipette

    Energy Technology Data Exchange (ETDEWEB)

    Beroz, Justin Douglas; Hart, Anastasios John

    2016-06-07

    A pipette includes a movable piston and a diaphragm that at least partly defines a fluid chamber enclosing a volume of working fluid. The piston displaces a volumetric amount of the working fluid in the chamber when moved. In response, the diaphragm displaces a smaller volumetric amount of fluid outside the chamber. A deamplification ratio is defined by the ratio of the volume displaced by the diaphragm to the volume displaced by the piston. The deamplification ratio is adjustable by adjusting or changing the diaphragm and/or by adjusting the size of the fluid chamber. The deamplifying pipette enables measuring and dispensing of very small volumes of liquid and is easily adapted to commercially available pipette components. Pipette components such as a pipette tip or adaptor may include a diaphragm to enable deamplification of the nominal volume capacity of a given pipette device.

  7. Fat mass measured by DXA varies with scan velocity

    DEFF Research Database (Denmark)

    Black, Eva; Petersen, Liselotte; Kreutzer, Martin

    2002-01-01

    To study the influence of scan velocities of DXA on the measured size of fat mass, lean body mass, bone mineral content and density, and total body weight.......To study the influence of scan velocities of DXA on the measured size of fat mass, lean body mass, bone mineral content and density, and total body weight....

  8. Velocity-space sensitivity of neutron spectrometry measurements

    DEFF Research Database (Denmark)

    Jacobsen, Asger Schou; Salewski, Mirko; Eriksson, J.;

    2015-01-01

    Neutron emission spectrometry (NES) measures the energies of neutrons produced in fusion reactions. Here we present velocity-space weight functions for NES and neutron yield measurements. Weight functions show the sensitivity as well as the accessible regions in velocity space for a given range...

  9. Inertial Measurements Based Velocity-free Attitude Stabilization

    CERN Document Server

    Tayebi, A; Benallegue, A

    2012-01-01

    The existing attitude controllers (without angular velocity measurements) involve explicitly the orientation (\\textit{e.g.,} the unit-quaternion) in the feedback. Unfortunately, there does not exist any sensor that directly measures the orientation of a rigid body, and hence, the attitude must be reconstructed using a set of inertial vector measurements as well as the angular velocity (which is assumed to be unavailable in velocity-free control schemes). To overcome this \\textit{circular reasoning}-like problem, we propose a velocity-free attitude stabilization control scheme relying solely on inertial vector measurements. The originality of this control strategy stems from the fact that the reconstruction of the attitude as well as the angular velocity measurements are not required at all. Moreover, as a byproduct of our design approach, the proposed controller does not lead to the unwinding phenomenon encountered in unit-quaternion based attitude controllers.

  10. Emerging trends and a comet taxonomy based on the volatile chemistry measured in thirty comets with high-resolution infrared spectroscopy between 1997 and 2013

    Science.gov (United States)

    Dello Russo, Neil; Kawakita, Hideyo; Vervack, Ronald J.; Weaver, Harold A.

    2016-11-01

    A systematic analysis of the mixing ratios with respect to H2O for eight species (CH3OH, HCN, NH3, H2CO, C2H2, C2H6, CH4, and CO) measured with high-resolution infrared spectroscopy in thirty comets between 1997 and 2013 is presented. Some trends are beginning to emerge when mixing ratios in individual comets are compared to average mixing ratios obtained for all species within the population. The variation in mixing ratios for all measured species is at least an order of magnitude. Overall, Jupiter-family comets are depleted in volatile species with respect to H2O compared to long-period Oort cloud comets, with the most volatile species showing the greatest relative depletion. There is a high positive correlation between the mixing ratios of HCN, C2H6, and CH4, whereas NH3, H2CO, and C2H2 are moderately correlated with each other but generally uncorrelated or show only weak correlation with other species. CO is generally uncorrelated with the other measured species possibly because it has the highest volatility and is therefore more susceptible to thermal evolutionary effects. Most of these correlations appear to be independent of dynamical class with a few possible exceptions. Molecular mixing ratios for CH3OH, HCN, C2H6, and CH4 show an expected behavior with heliocentric distance suggesting a dominant ice source, whereas there is emerging evidence that the mixing ratios of NH3, H2CO, C2H2, NH2, and CN may increase at small heliocentric distances, suggesting the possibility of additional sources related to the thermal decomposition of organic dust. Although this provides information on the composition of the most volatile grains in comets, it presents an additional difficulty in classifying comet chemistry because most comets within this dataset were only observed over a limited range of heliocentric distance. Although there is remarkable compositional diversity resulting in a unique chemical fingerprint for each comet, a hierarchical tree cluster analysis is

  11. Supersonic Relative Velocity Effect on the Baryonic Acoustic Oscillation Measurements

    CERN Document Server

    Yoo, Jaiyul; Seljak, Uros

    2011-01-01

    We investigate the effect of supersonic relative velocities between baryons and dark matter, recently shown to arise generically at high redshift, on baryonic acoustic oscillation (BAO) measurements at low redshift. The amplitude of the relative velocity effect at low redshift is model-dependent, but can be parameterized by using an unknown bias. We find that if unaccounted, the relative velocity effect can shift the BAO peak position and bias estimates of the dark energy equation-of-state due to its non-smooth, out-of-phase oscillation structure around the BAO scale. Fortunately, the relative velocity effect can be easily modeled in constraining cosmological parameters without substantially inflating the error budget. We also demonstrate that the presence of the relative velocity effect gives rise to a unique signature in the galaxy bispectrum, which can be utilized to isolate this effect. Future dark energy surveys can accurately measure the relative velocity effect and subtract it from the power spectrum a...

  12. Navigation Doppler Lidar Sensor for Precision Altitude and Vector Velocity Measurements Flight Test Results

    Science.gov (United States)

    Pierrottet, Diego F.; Lockhard, George; Amzajerdian, Farzin; Petway, Larry B.; Barnes, Bruce; Hines, Glenn D.

    2011-01-01

    An all fiber Navigation Doppler Lidar (NDL) system is under development at NASA Langley Research Center (LaRC) for precision descent and landing applications on planetary bodies. The sensor produces high resolution line of sight range, altitude above ground, ground relative attitude, and high precision velocity vector measurements. Previous helicopter flight test results demonstrated the NDL measurement concepts, including measurement precision, accuracies, and operational range. This paper discusses the results obtained from a recent campaign to test the improved sensor hardware, and various signal processing algorithms applicable to real-time processing. The NDL was mounted in an instrumentation pod aboard an Erickson Air-Crane helicopter and flown over vegetation free terrain. The sensor was one of several sensors tested in this field test by NASA?s Autonomous Landing and Hazard Avoidance Technology (ALHAT) project.

  13. High resolution 3D nonlinear integrated inversion

    Institute of Scientific and Technical Information of China (English)

    Li Yong; Wang Xuben; Li Zhirong; Li Qiong; Li Zhengwen

    2009-01-01

    The high resolution 3D nonlinear integrated inversion method is based on nonlinear theory. Under layer control, the log data from several wells (or all wells) in the study area and seismic trace data adjacent to the wells are input to a network with multiple inputs and outputs and are integratedly trained to obtain an adaptive weight function of the entire study area. Integrated nonlinear mapping relationships are built and updated by the lateral and vertical geologic variations of the reservoirs. Therefore, the inversion process and its inversion results can be constrained and controlled and a stable seismic inversion section with high resolution with velocity inversion, impedance inversion, and density inversion sections, can be gained. Good geologic effects have been obtained in model computation tests and real data processing, which verified that this method has high precision, good practicality, and can be used for quantitative reservoir analysis.

  14. A new method of measuring the peculiar velocity power spectrum

    CERN Document Server

    Zhang, P; Juszkiewicz, R; Feldman, H A; Zhang, Pengjie; Stebbins, Albert; Juszkiewicz, Roman; Feldman, Hume

    2004-01-01

    We show that by directly correlating the cluster kinetic Sunyaev Zeldovich (KSZ) flux, the cluster peculiar velocity power spectrum can be measured to $\\sim 10%$ accuracy by future large sky coverage KSZ surveys. This method is almost free of systemics entangled in the usual velocity inversion method. The direct correlation brings extra information of density and velocity clustering. We utilize these information to construct two indicators of the Hubble constant and comoving angular distance and propose a novel method to constrain cosmology.

  15. A comparison of measured and modeled velocity fields for a laminar flow in a porous medium

    Science.gov (United States)

    Wood, B. D.; Apte, S. V.; Liburdy, J. A.; Ziazi, R. M.; He, X.; Finn, J. R.; Patil, V. A.

    2015-11-01

    Obtaining highly-resolved velocity data from experimental measurements in porous media is a significant challenge. The goal of this work is to compare the velocity fields measured in a randomly-packed porous medium obtained from particle image velocimetry (PIV) with corresponding fields predicted from direct numerical simulation (DNS). Experimentally, the porous medium was comprised of 15 mm diameter spherical beads made of optical glass placed in a glass flow cell to create the packed bed. A solution of ammonium thiocyanate was refractive-index matched to the glass creating a medium that could be illuminated with a laser sheet without distortion. The bead center locations were quantified using the imaging system so that the geometry of the porous medium was known very accurately. Two-dimensional PIV data were collected and processed to provide high-resolution velocity fields at a single plane within the porous medium. A Cartesian-grid-based fictitious domain approach was adopted for the direct numerical simulation of flow through the same geometry as the experimental measurements and without any adjustable parameters. The uncertainties associated with characterization of the pore geometry, PIV measurements, and DNS predictions were all systematically quantified. Although uncertainties in bead position measurements led to minor discrepancies in the comparison of the velocity fields, the axial and normal velocity deviations exhibited normalized root mean squared deviations (NRMSD) of only 11.32% and 4.74%, respectively. The high fidelity of both the experimental and numerical methods have significant implications for understanding and even for engineering the micro-macro relationship in porous materials. The ability to measure and model sub-pore-scale flow features also has relevance to the development of upscaled models for flow in porous media, where physically reasonable closure models must be developed at the sub-pore scale. These results provide valuable data

  16. High-Resolution Mass Spectrometers

    Science.gov (United States)

    Marshall, Alan G.; Hendrickson, Christopher L.

    2008-07-01

    Over the past decade, mass spectrometry has been revolutionized by access to instruments of increasingly high mass-resolving power. For small molecules up to ˜400 Da (e.g., drugs, metabolites, and various natural organic mixtures ranging from foods to petroleum), it is possible to determine elemental compositions (CcHhNnOoSsPp…) of thousands of chemical components simultaneously from accurate mass measurements (the same can be done up to 1000 Da if additional information is included). At higher mass, it becomes possible to identify proteins (including posttranslational modifications) from proteolytic peptides, as well as lipids, glycoconjugates, and other biological components. At even higher mass (˜100,000 Da or higher), it is possible to characterize posttranslational modifications of intact proteins and to map the binding surfaces of large biomolecule complexes. Here we review the principles and techniques of the highest-resolution analytical mass spectrometers (time-of-flight and Fourier transform ion cyclotron resonance and orbitrap mass analyzers) and describe some representative high-resolution applications.

  17. Interferometric measurement of the angular velocity of moving humans

    Science.gov (United States)

    Nanzer, Jeffrey A.

    2012-06-01

    This paper presents an analysis of the measurement of the angular velocity of walking humans using a millimeter-wave correlation interferometer. Measurement of the angular velocity of moving objects is a desirable function in remote sensing applications. Doppler radar sensors are able to measure the signature of moving humans based on micro-Doppler analysis; however, a person moving with little to no radial velocity produces negligible Doppler returns. Measurement of the angular movement of humans can be done with traditional radar techniques, however the process involves either continuous tracking with narrow beamwidth or angle-of-arrival estimation algorithms. A new method of measuring the angular velocity of moving objects using interferometry has recently been developed which measures the angular velocity of an object without tracking or complex processing. The frequency of the interferometer signal response is proportional to the angular velocity of the object as it passes through the interferometer beam pattern. In this paper, the theory of the interferometric measurement of angular velocity is covered and simulations of the response of a walking human are presented. Simulations are produced using a model of a walking human to show the significant features associated with the interferometer response, which may be used in classification algorithms.

  18. Influence of speckle effect on doppler velocity measurement

    Science.gov (United States)

    Zheng, Zheng; Changming, Zhao; Haiyang, Zhang; Suhui, Yang; Dehua, Zhang; Xingyuan, Zheng; Hongzhi, Yang

    2016-06-01

    In a coherent Lidar system, velocity measurement of a target is achieved by measuring Doppler frequency shift between the echo and local oscillator (LO) signals. The measurement accuracy is proportional to the spectrum width of Doppler signal. Actually, the speckle effect caused by the scattering of laser from a target will broaden the Doppler signal's spectrum and bring uncertainty to the velocity measurement. In this paper, a theoretical model is proposed to predict the broadening of Doppler spectrum with respect to different target's surface and motion parameters. The velocity measurement uncertainty caused by the broadening of spectrum is analyzed. Based on the analysis, we design a coherent Lidar system to measure the velocity of the targets with different surface roughness and transverse velocities. The experimental results are in good agreement with theoretical analysis. It is found that the target's surface roughness and transverse velocity can significantly affect the spectrum width of Doppler signal. With the increase of surface roughness and transverse velocity, the measurement accuracy becomes worse. However, the influence of surface roughness becomes weaker when the spot size of laser beam on the target is smaller.

  19. Integrating high-resolution mapping of the seafloor with sediment-transport measurements to understand coastal erosion in northern South Carolina

    Science.gov (United States)

    Barnhardt, W.; Baldwin, W.; Denny, J.; Schwab, W.; Paul, G.; Driscoll, N.; Warner, J.; Voulgaris, G.

    2006-12-01

    Shoreline behavior along the coast of Long Bay, South Carolina is dictated by waves, tidal currents, and sediment supply that act within the overall constraints of the regional geologic setting. This study examined the influence of the geologic framework on coastal evolution through the interpretation of high-resolution geophysical data (swath bathymetry, sidescan-sonar imagery, seismic-reflection profiles), bottom samples and cores. Interpreted geophysical data were used to form conceptual models of sediment flux in the nearshore area, which are being tested by conducting site-specific sediment transport and oceanographic measurements and modeling. The inner shelf of Long Bay extends from the shoreface to about 10 km offshore (5-15 m water depth). It is underlain by coastal-plain strata of Cretaceous/Tertiary age that are incised by large fluvial channels formed during the Pliocene and Pleistocene. The indurated coastal-plain and channel-fill deposits are exposed as hardgrounds over large expanses of the inner shelf, and locally overlain by a discontinuous veneer of sandy Holocene sediment generally less than 1-m thick. A regional unconformity, thought to represent erosion during the most recent marine transgression, coincides with the seafloor in these areas of sparse sediment. Minor bathymetric highs occur where relatively thicker accumulations of Holocene sediment lie above the low- relief, transgressive unconformity. One of the thickest accumulations of Holocene sediment is contained within an anomalous, shore-oblique sand body that lies 3 km offshore of Myrtle Beach and is not associated with a modern tidal inlet. The lobate deposit is approximately 11-km long, 3-km wide, and up to 3-m thick. Cores show that the shoal is a marine deposit less than 5000 years old with a gravelly lag at the base representing the transgressive surface. It contains an estimated volume of 26 million m3 of sediment, largely consisting of fine to medium, well sorted quartz sand and

  20. Seagrass beds as ocean acidification refuges for mussels? High resolution measurements of pCO2 and O2 in a Zostera marina and Mytilus edulis mosaic habitat

    Science.gov (United States)

    Saderne, V.; Fietzek, P.; Aßmann, S.; Körtzinger, A.; Hiebenthal, C.

    2015-07-01

    It has been speculated that macrophytes beds might act as a refuge for calcifiers from ocean acidification. In the shallow nearshores of the western Kiel Bay (Baltic Sea), mussel and seagrass beds are interlacing, forming a mosaic habitat. Naturally, the diverse physiological activities of seagrasses and mussels are affected by seawater carbonate chemistry and they locally modify it in return. Calcification by shellfishes is sensitive to seawater acidity; therefore the photosynthetic activity of seagrasses in confined shallow waters creates favorable chemical conditions to calcification at daytime but turn the habitat less favorable or even corrosive to shells at night. In contrast, mussel respiration releases CO2, turning the environment more favorable for photosynthesis by adjacent seagrasses. At the end of summer, these dynamics are altered by the invasion of high pCO2/low O2 coming from the deep water of the Bay. However, it is in summer that mussel spats settle on the leaves of seagrasses until migrating to the permanent habitat where they will grow adult. These early life phases (larvae/spats) are considered as most sensitive with regard to seawater acidity. So far, the dynamics of CO2 have never been continuously measured during this key period of the year, mostly due to the technological limitations. In this project we used a combination of state-of-the-art technologies and discrete sampling to obtain high-resolution time-series of pCO2 and O2 at the interface between a seagrass and a mussel patch in Kiel Bay in August and September 2013. From these, we derive the entire carbonate chemistry using statistical models. We found the monthly average pCO2 more than 50 % (approx. 640 μatm for August and September) above atmospheric equilibrium right above the mussel patch together with large diel variations of pCO2 within 24 h: 887 ± 331 μatm in August and 742 ± 281 μatm in September (mean ± SD). We observed important daily corrosiveness for calcium

  1. Seagrass beds as ocean acidification refuges for mussels? High resolution measurements of pCO2 and O2 in a Zostera marina and Mytilus edulis mosaic habitat

    Directory of Open Access Journals (Sweden)

    V. Saderne

    2015-07-01

    Full Text Available It has been speculated that macrophytes beds might act as a refuge for calcifiers from ocean acidification. In the shallow nearshores of the western Kiel Bay (Baltic Sea, mussel and seagrass beds are interlacing, forming a mosaic habitat. Naturally, the diverse physiological activities of seagrasses and mussels are affected by seawater carbonate chemistry and they locally modify it in return. Calcification by shellfishes is sensitive to seawater acidity; therefore the photosynthetic activity of seagrasses in confined shallow waters creates favorable chemical conditions to calcification at daytime but turn the habitat less favorable or even corrosive to shells at night. In contrast, mussel respiration releases CO2, turning the environment more favorable for photosynthesis by adjacent seagrasses. At the end of summer, these dynamics are altered by the invasion of high pCO2/low O2 coming from the deep water of the Bay. However, it is in summer that mussel spats settle on the leaves of seagrasses until migrating to the permanent habitat where they will grow adult. These early life phases (larvae/spats are considered as most sensitive with regard to seawater acidity. So far, the dynamics of CO2 have never been continuously measured during this key period of the year, mostly due to the technological limitations. In this project we used a combination of state-of-the-art technologies and discrete sampling to obtain high-resolution time-series of pCO2 and O2 at the interface between a seagrass and a mussel patch in Kiel Bay in August and September 2013. From these, we derive the entire carbonate chemistry using statistical models. We found the monthly average pCO2 more than 50 % (approx. 640 μatm for August and September above atmospheric equilibrium right above the mussel patch together with large diel variations of pCO2 within 24 h: 887 ± 331 μatm in August and 742 ± 281 μatm in September (mean ± SD. We observed important daily corrosiveness for

  2. Simultaneous temperature and velocity Lagrangian measurements in turbulent thermal convection

    CERN Document Server

    Liot, O; Zonta, F; Chibbaro, S; Coudarchet, T; Gasteuil, Y; Pinton, J -F; Salort, J; Chillà, F

    2015-01-01

    We report joint Lagrangian velocity and temperature measurements in turbulent thermal convection. Measurements are performed using an improved version (extended autonomy) of the neutrally-buoyant instrumented particle that was used by to performed experiments in a parallelepipedic Rayleigh-Benard cell. The temperature signal is obtained from a RFtransmitter. Simultaneously, we determine particle's position and velocity with one camera, which grants access to the Lagrangian heat flux. Due to the extended autonomy of the present particle, we obtain well converged temperature and velocity statistics, as well as pseudo-eulerian maps of velocity and heat flux. Present experimental results have also been compared with the results obtained by a corresponding campaign of Direct Numerical Simulations and Lagrangian Tracking of massless tracers. The comparison between experimental and numerical results show the accuracy and reliability of our experimental measurements. Finally, the analysis of lagrangian velocity and t...

  3. Compressive sensing for high resolution radar imaging

    NARCIS (Netherlands)

    Anitori, L.; Otten, M.P.G.; Hoogeboom, P.

    2010-01-01

    In this paper we present some preliminary results on the application of Compressive Sensing (CS) to high resolution radar imaging. CS is a recently developed theory which allows reconstruction of sparse signals with a number of measurements much lower than what is required by the Shannon sampling th

  4. Measurement of gas flow velocities by laser-induced gratings

    Energy Technology Data Exchange (ETDEWEB)

    Hemmerling, B.; Stampanoni-Panariello, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Kozlov, A.D.N. [General Physics Institute, Moscow (Russian Federation)

    1999-08-01

    Time resolved light scattering from laser-induced electrostrictive gratings was used for the determination of flow velocities in air at room temperature. By measuring the velocity profile across the width of a slit nozzle we demonstrated the high spatial resolution (about 200 mm) of this novel technique. (author) 3 figs., 1 ref.

  5. Plasma flow velocity measurements using a modulated Michelson interferometer

    NARCIS (Netherlands)

    Howard, J.; Meijer, F. G.

    1997-01-01

    This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (C) 1997 Elsevier Science S.A.

  6. Electron drift velocity measurements in liquid krypton-methane mixtures

    CERN Document Server

    Folegani, M; Magri, M; Piemontese, L

    1999-01-01

    Electron drift velocities have been measured in liquid krypton, pure and mixed with methane at different concentrations (1-10% in volume) versus electric field strength, and a possible effect of methane on electron lifetime has been investigated. While no effect on lifetime could be detected, since lifetimes were in all cases longer than what measurable, a very large increase in drift velocity (up to a factor 6) has been measured.

  7. Measuring Oscillatory Velocity Fields Due to Swimming Algae

    CERN Document Server

    Guasto, Jeffrey S; Gollub, J P

    2010-01-01

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

  8. Laser Doppler anemometer measurements using nonorthogonal velocity components: error estimates.

    Science.gov (United States)

    Orloff, K L; Snyder, P K

    1982-01-15

    Laser Doppler anemometers (LDAs) that are arranged to measure nonorthogonal velocity components (from which orthogonal components are computed through transformation equations) are more susceptible to calibration and sampling errors than are systems with uncoupled channels. In this paper uncertainty methods and estimation theory are used to evaluate, respectively, the systematic and statistical errors that are present when such devices are applied to the measurement of mean velocities in turbulent flows. Statistical errors are estimated for two-channel LDA data that are either correlated or uncorrelated. For uncorrelated data the directional uncertainty of the measured velocity vector is considered for applications where mean streamline patterns are desired.

  9. Unsteady Pressure and Velocity Measurements in Pumps

    Science.gov (United States)

    2006-11-01

    to reproduce the data with controlled experiments . For example, the rotor exit flow measured by means of a stationary high response probe will be...Turbomachinery by Means of High-Frequency Pressure Transducers. ASME, J. of Turbomachinery, Vol. 114, pp. 100-107. [3] Castorph, D. (1975): Messung ...Dreiß, A.; Kosyna, G. (1997): Experimental Investigations of Cavitation-States in a Radial Pump Impeller. JSME CENTENNIAL GRAND CONGRESS Proceedings of

  10. Three Component Velocity and Acceleration Measurement Using FLEET

    Science.gov (United States)

    Danehy, Paul M.; Bathel, Brett F.; Calvert, Nathan; Dogariu, Arthur; Miles, Richard P.

    2014-01-01

    The femtosecond laser electronic excitation and tagging (FLEET) method has been used to measure three components of velocity and acceleration for the first time. A jet of pure N2 issuing into atmospheric pressure air was probed by the FLEET system. The femtosecond laser was focused down to a point to create a small measurement volume in the flow. The long-lived lifetime of this fluorescence was used to measure the location of the tagged particles at different times. Simultaneous images of the flow were taken from two orthogonal views using a mirror assembly and a single intensified CCD camera, allowing two components of velocity to be measured in each view. These different velocity components were combined to determine three orthogonal velocity components. The differences between subsequent velocity components could be used to measure the acceleration. Velocity accuracy and precision were roughly estimated to be +/-4 m/s and +/-10 m/s respectively. These errors were small compared to the approx. 100 m/s velocity of the subsonic jet studied.

  11. Sources and atmospheric processing of winter aerosols in Seoul, Korea: insights from real-time measurements using a high-resolution aerosol mass spectrometer

    Science.gov (United States)

    Kim, Hwajin; Zhang, Qi; Bae, Gwi-Nam; Kim, Jin Young; Bok Lee, Seung

    2017-02-01

    Highly time-resolved chemical characterization of nonrefractory submicrometer particulate matter (NR-PM1) was conducted in Seoul, the capital and largest metropolis of Korea, using an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS). The measurements were performed during winter, when elevated particulate matter (PM) pollution events are often observed. This is the first time that detailed real-time aerosol measurement results have been reported from Seoul, Korea, and they reveal valuable insights into the sources and atmospheric processes that contribute to PM pollution in this region. The average concentration of submicron aerosol (PM1 = NR-PM1+ black carbon (BC)) was 27.5 µg m-3, and the total mass was dominated by organics (44 %), followed by nitrate (24 %) and sulfate (10 %). The average atomic ratios of oxygen to carbon (O / C), hydrogen to carbon (H / C), and nitrogen to carbon (N / C) of organic aerosols (OA) were 0.37, 1.79, and 0.018, respectively, which result in an average organic mass-to-carbon (OM / OC) ratio of 1.67. The concentrations (2.6-90.7 µg m-3) and composition of PM1 varied dynamically during the measurement period due to the influences of different meteorological conditions, emission sources, and air mass origins. Five distinct sources of OA were identified via positive matrix factorization (PMF) analysis of the HR-ToF-AMS data: vehicle emissions represented by a hydrocarbon-like OA factor (HOA, O / C = 0.06), cooking activities represented by a cooking OA factor (COA, O / C = 0.14), wood combustion represented by a biomass burning OA factor (BBOA, O / C = 0.34), and secondary organic aerosol (SOA) represented by a semivolatile oxygenated OA factor (SV-OOA, O / C = 0.56) and a low-volatility oxygenated OA factor (LV-OOA, O / C = 0.68). On average, primary OA (POA = HOA + COA + BBOA) accounted for 59 % the OA mass, whereas SV-OOA and LV-OOA contributed 15 and 26 %, respectively. Our results indicate that air

  12. High-resolution slug testing.

    Science.gov (United States)

    Zemansky, G M; McElwee, C D

    2005-01-01

    The hydraulic conductivity (K) variation has important ramifications for ground water flow and the transport of contaminants in ground water. The delineation of the nature of that variation can be critical to complete characterization of a site and the planning of effective and efficient remedial measures. Site-specific features (such as high-conductivity zones) need to be quantified. Our alluvial field site in the Kansas River valley exhibits spatial variability, very high conductivities, and nonlinear behavior for slug tests in the sand and gravel aquifer. High-resolution, multilevel slug tests have been performed in a number of wells that are fully screened. A general nonlinear model based on the Navier-Stokes equation, nonlinear frictional loss, non-Darcian flow, acceleration effects, radius changes in the wellbore, and a Hvorslev model for the aquifer has been used to analyze the data, employing an automated processing system that runs within the Excel spreadsheet program. It is concluded that slug tests can provide the necessary data to identify the nature of both horizontal and vertical K variation in an aquifer and that improved delineation or higher resolution of K structure is possible with shorter test intervals. The gradation into zones of higher conductivity is sharper than seen previously, and the maximum conductivity observed is greater than previously measured. However, data from this project indicate that well development, the presence of fines, and the antecedent history of the well are important interrelated factors in regard to slug-test response and can prevent obtaining consistent results in some cases.

  13. Near-wall velocity profile measurement for nanofluids

    Science.gov (United States)

    Kanjirakat, Anoop; Sadr, Reza

    2016-01-01

    We perform near-wall velocity measurements of a SiO2-water nanofluid inside a microchannel. Nanoparticle image velocimetry measurements at three visible depths within 500 nm of the wall are conducted. We evaluate the optical properties of the nanofluid and their effect on the measurement technique. The results indicate that the small effect of the nanoparticles on the optical properties of the suspension have a negligible effect on the measurement technique. Our measurements show an increase in nanofluid velocity gradients near the walls, with no measurable slip, relative to the equivalent basefluid flow. We conjecture that particle migration induced by shear may have caused this increase. The effect of this increase in the measured near wall velocity gradient has implications on the viscosity measurement for these fluids.

  14. Near-wall velocity profile measurement for nanofluids

    Directory of Open Access Journals (Sweden)

    Anoop Kanjirakat

    2016-01-01

    Full Text Available We perform near-wall velocity measurements of a SiO2–water nanofluid inside a microchannel. Nanoparticle image velocimetry measurements at three visible depths within 500 nm of the wall are conducted. We evaluate the optical properties of the nanofluid and their effect on the measurement technique. The results indicate that the small effect of the nanoparticles on the optical properties of the suspension have a negligible effect on the measurement technique. Our measurements show an increase in nanofluid velocity gradients near the walls, with no measurable slip, relative to the equivalent basefluid flow. We conjecture that particle migration induced by shear may have caused this increase. The effect of this increase in the measured near wall velocity gradient has implications on the viscosity measurement for these fluids.

  15. Measuring surface flow velocity with smartphones: potential for citizen observatories

    Science.gov (United States)

    Weijs, Steven V.; Chen, Zichong; Brauchli, Tristan; Huwald, Hendrik

    2014-05-01

    Stream flow velocity is an important variable for discharge estimation and research on sediment dynamics. Given the influence of the latter on rating curves (stage-discharge relations), and the relative scarcity of direct streamflow measurements, surface velocity measurements can offer important information for, e.g., flood warning, hydropower, and hydrological science and engineering in general. With the growing amount of sensing and computing power in the hands of more outdoorsy individuals, and the advances in image processing techniques, there is now a tremendous potential to obtain hydrologically relevant data from motivated citizens. This is the main focus of the interdisciplinary "WeSenseIt" project, a citizen observatory of water. In this subproject, we investigate the feasibility of stream flow surface velocity measurements from movie clips taken by (smartphone-) cameras. First results from movie-clip derived velocity information will be shown and compared to reference measurements.

  16. Measurement-based perturbation theory and differential equation parameter estimation for high-precision high-resolution reconstruction of the Earth's gravitational field from satellite tracking measurements

    CERN Document Server

    Xu, Peiliang

    2016-01-01

    The numerical integration method has been routinely used to produce global standard gravitational models from satellite tracking measurements of CHAMP/GRACE types. It is implemented by solving the differential equations of the partial derivatives of a satellite orbit with respect to the unknown harmonic coefficients under the conditions of zero initial values. From the mathematical point of view, satellite gravimetry from satellite tracking is the problem of estimating unknown parameters in the Newton's nonlinear differential equations from satellite tracking measurements. We prove that zero initial values for the partial derivatives are incorrect mathematically and not permitted physically. The numerical integration method, as currently implemented and used in satellite gravimetry and statistics, is groundless. We use three different methods to derive new local solutions to the Newton's nonlinear governing differential equations of motion with a nominal reference orbit. Bearing in mind that satellite orbits ...

  17. Measurement of Poloidal Velocity on the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ronald E. Bell and Russell Feder

    2010-06-04

    A diagnostic suite has been developed to measure impurity poloidal flow using charge exchange recombination spectroscopy on the National Spherical Torus Experiment. Toroidal and poloidal viewing systems measure all quantities required to determine the radial electric field. Two sets of up/down symmetric poloidal views are used to measure both active emission in the plane of the neutral heating beams and background emission in a radial plane away from the neutral beams. Differential velocity measurements isolate the line-integrated poloidal velocity from apparent flows due to the energy-dependent chargeexchange cross section. Six f/1.8 spectrometers measure 276 spectra to obtain 75 active and 63 background channels every 10 ms. Local measurements from a similar midplane toroidal viewing system are mapped into two dimensions to allow the inversion of poloidal line-integrated measurements to obtain local poloidal velocity profiles. Radial resolution after inversion is 0.6-1.8 cm from the plasma edge to the center.

  18. Investigating the deformation of upper crustal faults at the N-Chilean convergent plate boundary at different scales using high-resolution topography datasets and creepmeter measurements

    Science.gov (United States)

    Ewiak, O.; Victor, P.; Ziegenhagen, T.; Oncken, O.

    2012-04-01

    The Chilean convergent plate boundary is one of the tectonically most active regions on earth and prone to large megathrust earthquakes as e. g. the 2010 Mw 8.8 Maule earthquake which ruptured a mature seismic gap in south-central Chile. In northern Chile historical data suggests the existence of a seismic gap between Arica and Mejillones Peninsula (MP), which has not ruptured since 1877. Further south, the 1995 Mw 8.0 Antofagasta earthquake ruptured the subduction interface between MP and Taltal. In this study we investigate the deformation at four active upper plate faults (dip-slip and strike-slip) located above the coupling zone of the subduction interface. The target faults (Mejillones Fault - MF, Salar del Carmen Fault - SCF, Cerro Fortuna Fault - CFF, Chomache Fault - CF) are situated in forearc segments, which are in different stages of the megathrust seismic cycle. The main question of this study is how strain is accumulated in the overriding plate, what is the response of the target faults to the megathrust seismic cycle and what are the mechanisms / processes involved. The hyper arid conditions of the Atacama desert and the extremely low erosion rates enable us to investigate geomorphic markers, e .g. fault scarps and knickpoints, which serve as a record for upper crustal deformation and fault activity about ten thousands years into the past. Fault scarp data has been acquired with Differential-GPS by measuring high-resolution topographic profiles perpendicular to the fault scarps and along incised gullies. The topographic data show clear variations between the target faults which possibly result from their position within the forearc. The surveyed faults, e. g. the SCF, exhibit clear along strike variations in the morphology of surface ruptures attributed to seismic events and can be subdivided into individual segments. The data allows us to distinguish single, composite and multiple fault scarps and thus to detect differences in fault growth initiated

  19. High resolution digital delay timer

    Science.gov (United States)

    Martin, Albert D.

    1988-01-01

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay (20) provides a first output signal (24) at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits (26, 28) latch the high resolution data (24) to form a first synchronizing data set (60). A selected time interval has been preset to internal counters (142, 146, 154) and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses (32, 34) count down the counters to generate an internal pulse delayed by an interval which is functionally related to the preset time interval. A second LCD (184) corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD (74) to generate a second set of synchronizing data (76) which is complementary with the first set of synchronizing data (60) for presentation to logic circuits (64). The logic circuits (64) further delay the internal output signal (72) to obtain a proper phase relationship of an output signal (80) with the internal pulses (32, 34). The final delayed output signal (80) thereafter enables the output pulse generator (82) to produce the desired output pulse (84) at the preset time delay interval following input of the trigger pulse (10, 12).

  20. High Resolution Orientation Imaging Microscopy

    Science.gov (United States)

    2012-05-02

    carbon distribution as it relates to the presence of Bainite phase (with small tetragonality) interspersed among the cubic ferrite. An example of the...preferentially segregate. The view offered by these high resolution methods differs from what has been considered before: grains thought to be Bainite

  1. High-Resolution Instrumentation Radar.

    Science.gov (United States)

    1986-09-30

    30 September 1986 Los Angeles Air Force Station 13. NUMBER OF PAGES Los Angeles, Calif. 90009-2960 36 74. MONITORING AGENCY NAME & ADDRESS(If...TREE PLMUT ",-20 -CUTLIASS DumpER SED AN... TREE TRUNK, -0 - MERC BUMPER f - 40 H!-I -50 iI Fig. 7. High-Resolution Instrumentation Radar View of

  2. Turbulence Measurements with the CIRES Tethered Lifting System during CASES-99: Calibration and Spectral Analysis of Temperature and Velocity.

    Science.gov (United States)

    Frehlich, Rod; Meillier, Yannick; Jensen, Michael L.; Balsley, Ben

    2003-10-01

    Finescale temperature and velocity measurements with multiple vertically spaced cold-wire and hot-wire sensors on the Cooperative Institute for Research in the Environmental Sciences (CIRES) tethered lifting system (TLS) were produced during the Cooperative Atmosphere-Surface Exchange Study-1999 (CASES-99). The various calibration methods are presented as well as algorithms to extract high-resolution estimates of the energy dissipation rate and the temperature structure constant C2T. The instrumentation is capable of measurements of 10-7 m2 s-3 and C2T 10-6 K2 m-2/3.

  3. Velocity measurement by coherent x-ray heterodyning

    Energy Technology Data Exchange (ETDEWEB)

    Lhermitte, Julien R. M.; Rogers, Michael C.; Manet, Sabine; Sutton, Mark

    2017-01-01

    We present a small-angle coherent x-ray scattering technique used for measuring flow velocities in slow moving materials. The technique is an extension of X-ray Photon Correlation Spectroscopy (XPCS): It involves mixing the scattering from moving tracer particles with a static reference that heterodynes the signal. This acts to elongate temporal effects caused by flow in homodyne measurements, allowing for a more robust measurement of flow properties. Using coherent x-ray heterodyning, velocities ranging from 0.1 to 10 μm/s were measured for a viscous fluid pushed through a rectangular channel. We describe experimental protocols and theory for making these Poiseuille flow profile measurements and also develop the relevant theory for using heterodyne XPCS to measure velocities in uniform and Couette flows.

  4. Velocity measurement by coherent x-ray heterodyning.

    Science.gov (United States)

    Lhermitte, Julien R M; Rogers, Michael C; Manet, Sabine; Sutton, Mark

    2017-01-01

    We present a small-angle coherent x-ray scattering technique used for measuring flow velocities in slow moving materials. The technique is an extension of X-ray Photon Correlation Spectroscopy (XPCS): It involves mixing the scattering from moving tracer particles with a static reference that heterodynes the signal. This acts to elongate temporal effects caused by flow in homodyne measurements, allowing for a more robust measurement of flow properties. Using coherent x-ray heterodyning, velocities ranging from 0.1 to 10 μm/s were measured for a viscous fluid pushed through a rectangular channel. We describe experimental protocols and theory for making these Poiseuille flow profile measurements and also develop the relevant theory for using heterodyne XPCS to measure velocities in uniform and Couette flows.

  5. Direct Ejecta Velocity Measurements of Tycho's Supernova Remnant

    CERN Document Server

    Sato, Toshiki

    2016-01-01

    We present the first direct ejecta velocity measurements of Tycho's supernova remnant (SNR). Chandra's high angular resolution images reveal a patchy structure of radial velocities in the ejecta that can be separated into distinct redshifted, blueshifted, and low velocity ejecta clumps or blobs. The typical velocities of the redshifted and blueshifted blobs are <~ 7,800 km/s and <~ 5,000 km/s, respectively. The highest velocity blobs are located near the center, while the low velocity ones appear near the edge as expected for a generally spherical expansion. Systematic uncertainty on the velocity measurements from gain calibration was assessed by carrying out joint fits of individual blobs with both the ACIS-I and ACIS-S detectors. We identified an annular region (~3.3'-3.5'), where the surface brightness in the Si, S, and Fe K lines reaches a peak while the line width reaches a minimum value. These minimum line widths correspond to ion temperatures of ~1 MeV for each of the three species, in excellent ...

  6. Near-wall velocity measurements by Particle-Shadow-Tracking

    CERN Document Server

    Lancien, Pierre; Métivier, François; 10.1007/s00348-007-0260-z

    2009-01-01

    We report a new method to measure the velocity of a fluid in the vicinity of a wall. The method, that we call Particle-Shadow Tracking (PST), simply consists in seeding the fluid with a small number of fine tracer particles of density close to that of the fluid. The position of each particle and of its shadow on the wall are then tracked simultaneously, allowing one to accurately determine the distance separating tracers from the wall and therefore to extract the velocity field. We present an application of the method to the determination of the velocity profile inside a laminar density current flowing along an inclined plane.

  7. Measurement of velocity field in parametrically excited solitary waves

    CERN Document Server

    Gordillo, Leonardo

    2014-01-01

    Paramerically excited solitary waves emerge as localized structures in high-aspect-ratio free surfaces subject to vertical vibrations. Herein, we provide the first experimental characterization of the hydrodynamics of thess waves using Particle Image Velocimetry. We show that the underlying velocity field of parametrically excited solitary waves is mainly composed by an oscillatory velocity field. Our results confirm the accuracy of Hamiltonian models with added dissipation in describing this field. Remarkably, our measurements also uncover the onset of a streaming velocity field which is shown to be as important as other crucial nonlinear terms in the current theory. The observed streaming pattern is particularly interesting due to the presence of oscillatory meniscii.

  8. Progress toward high resolution EUV spectroscopy

    Science.gov (United States)

    Korendyke, C.; Doschek, G. A.; Warren, H.; Young, P. R.; Chua, D.; Hassler, D. M.; Landi, E.; Davila, J. M.; Klimchuck, J.; Tun, S.; DeForest, C.; Mariska, J. T.; Solar C Spectroscopy Working Group; LEMUR; EUVST Development Team

    2013-07-01

    HIgh resolution EUV spectroscopy is a critical instrumental technique to understand fundamental physical processes in the high temperature solar atmosphere. Spectroscopic observations are used to measure differential emission measure, line of sight and turbulent flows, plasma densities and emission measures. Spatially resolved, spectra of these emission lines with adequate cadence will provide the necessary clues linking small scale structures with large scale, energetic solar phenomena. The necessary observations to determine underlying physical processes and to provide comprehensive temperature coverage of the solar atmosphere above the chromosphere will be obtained by the proposed EUVST instrument for Solar C. This instrument and its design will be discussed in this paper. Progress on the VEry high Resolution Imaging Spectrograph (VERIS) sounding rocket instrument presently under development at the Naval Research Laboratory will also be discussed.

  9. High Resolution ground penetrating radar (GPR) measurements at the laboratory scale to model porosity and permeability in the Miami Limestone in South Florida.

    Science.gov (United States)

    Mount, G. J.; Comas, X.

    2015-12-01

    Subsurface water flow within the Biscayne aquifer is controlled by the heterogeneous distribution of porosity and permeability in the karst Miami Limestone and the presence of numerous dissolution and mega-porous features. The dissolution features and other high porosity areas can create preferential flow paths and direct recharge to the aquifer, which may not be accurately conceptualized in groundwater flow models. As hydrologic conditions are undergoing restoration in the Everglades, understanding the distribution of these high porosity areas within the subsurface would create a better understanding of subsurface flow. This research utilizes ground penetrating radar to estimate the spatial variability of porosity and dielectric permittivity of the Miami Limestone at centimeter scale resolution at the laboratory scale. High frequency GPR antennas were used to measure changes in electromagnetic wave velocity through limestone samples under varying volumetric water contents. The Complex Refractive Index Model (CRIM) was then applied in order to estimate porosity and dielectric permittivity of the solid phase of the limestone. Porosity estimates ranged from 45.2-66.0% from the CRIM model and correspond well with estimates of porosity from analytical and digital image techniques. Dielectric permittivity values of the limestone solid phase ranged from 7.0 and 13.0, which are similar to values in the literature. This research demonstrates the ability of GPR to identify the cm scale spatial variability of aquifer properties that influence subsurface water flow which could have implications for groundwater flow models in the Biscayne and potentially other shallow karst aquifers.

  10. Near-wall velocity profile measurement for nanofluids

    OpenAIRE

    Anoop Kanjirakat; Reza Sadr

    2016-01-01

    We perform near-wall velocity measurements of a SiO2–water nanofluid inside a microchannel. Nanoparticle image velocimetry measurements at three visible depths within 500 nm of the wall are conducted. We evaluate the optical properties of the nanofluid and their effect on the measurement technique. The results indicate that the small effect of the nanoparticles on the optical properties of the suspension have a negligible effect on the measurement technique. Our measurements show an increase ...

  11. Digital technique for the simultaneous measurement of velocity and temperature.

    Science.gov (United States)

    Keffer, J F; Budny, R S; Kawall, J G

    1978-09-01

    A computer-oriented, hot-wire anemometer technique for the simultaneous measurement of velocity and temperature in heated turbulent flows is described. This technique involves conversion of analogue anemometer voltage signals into digital forms and processing of these latter on a digital computer, in accordance with the anemometer response equations, to obtain instantaneous temperature and velocity. The technique was tested with a heated plane jet and found to be satisfactory.

  12. Measurements of electron drift velocity in pure isobutane

    Energy Technology Data Exchange (ETDEWEB)

    Vivaldini, Tulio C.; Lima, Iara B.; Goncalves, Josemary A.C.; Botelho, Suzana; Tobias, Carmen C.B., E-mail: ccbueno@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Ridenti, Marco A.; Pascholati, Paulo R. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Fisica. Lab. do Acelerador Linear; Fonte, Paulo; Mangiarotti, Alessio [Universidade de Coimbra (Portugal). Dept de Fisica. Lab. de Instrumentacao e Fisica Experimental de Particulas

    2009-07-01

    In this work we report on preliminary results related to the dependence of the electron drift velocity for pure isobutane as a function of reduced electric field (E/N) in the range from 100 Td up to 216 Td. The measurements of electron drift velocity were based on the Pulsed Townsend technique. In order to validate the technique and analyzing non-uniformity effects, results for nitrogen are also presented and compared with a numerical simulation of the Bolsig+ code. (author)

  13. Source detection and high-resolution localization using microphone arrays for UGS: results of the NATO TG25 experiment measurements (Bourges, October 2002)

    Science.gov (United States)

    Hengy, Sebastien; Naz, Pierre; Gounon, Patrick

    2003-09-01

    This paper presents different ways to process acoustic data in order to localize targets.Beamforming and the MUSIC high resolution method have been tested for different propagation conditions during a NATO experimental campaign. This campaign,organized by DG /DCE/ETBS,has involved 6 countries in October 2002 in Bourges, France). Different localization methods were used to get the position of moving sources on a 4 kilometres circuit.The I.S.L. (French-German research institute of Saint Louis)has deployed a network of arrays nearby the circuit to test those localization techniques in different propagation conditions (day/night,early morning,...).Variance and mean error of the localization are compared for the different techniques used.

  14. Analysis of the horizontal two-dimensional near-surface structure of a winter tornadic vortex using high-resolution in situ wind and pressure measurements

    Science.gov (United States)

    Kato, Ryohei; Kusunoki, Kenichi; Sato, Eiichi; Mashiko, Wataru; Inoue, Hanako Y.; Fujiwara, Chusei; Arai, Ken-ichiro; Nishihashi, Masahide; Saito, Sadao; Hayashi, Syugo; Suzuki, Hiroto

    2015-06-01

    The horizontal two-dimensional near-surface structure of a tornadic vortex within a winter storm was analyzed. The tornadic vortex was observed on 10 December 2012 by the high-resolution in situ observational linear array of wind and pressure sensors (LAWPS) system in conjunction with a high-resolution Doppler radar. The 0.1 s maximum wind speed and pressure deficit near the ground were recorded as 35.3 m s-1 and -3.8 hPa, respectively. The horizontal two-dimensional distributions of the tornadic vortex wind and pressure were retrieved by the LAWPS data, which provided unprecedented observational detail on the following important features of the near-surface structure of the tornadic vortex. Asymmetric convergent inflow toward the vortex center existed. Total wind speed was strong to the right and rear side of the translational direction of the vortex and weak in the forward part of the vortex possibly because of the strong convergent inflow in that region. The tangential wind speed profile of the vortex was better approximated using a modified Rankine vortex rather than the Rankine vortex both at 5 m above ground level (agl) and 100 m agl, and other vortex models (Burgers-Rott vortex and Wood-White vortex) were also compared. The cyclostrophic wind balance was violated in the core radius R0 and outside the core radius in the forward sector; however, it was held with a relatively high accuracy of approximately 14% outside the core of the vortex in the rearward sector (from 2 R0 to 5 R0) near the ground.

  15. Velocity Measurements of Turbulent Wake Flow Over a Circular Cylinder

    Science.gov (United States)

    Shih, Chang-Lung; Chen, Wei-Cheng; Chang, Keh-Chin; Wang, Muh-Rong

    2016-06-01

    There are two general concerns in the velocity measurements of turbulence. One is the temporal characteristics which governs the turbulent mixing process. Turbulence is rotational and is characterized by high levels of fluctuating vorticity. In order to obtain the information of vorticity dynamics, the spatial characteristics is the other concern. These varying needs can be satisfied by using a variety of diagnostic techniques such as invasive physical probes and non-invasive optical instruments. Probe techniques for the turbulent measurements are inherently simple and less expensive than optical methods. However, the presence of a physical probe may alter the flow field, and velocity measurements usually become questionable when probing recirculation zones. The non-invasive optical methods are mostly made of the foreign particles (or seeding) instead of the fluid flow and are, thus, of indirect method. The difference between the velocities of fluid and foreign particles is always an issue to be discussed particularly in the measurements of complicated turbulent flows. Velocity measurements of the turbulent wake flow over a circular cylinder will be made by using two invasive instruments, namely, a cross-type hot-wire anemometry (HWA) and a split-fiber hot-film anemometry (HFA), and a non-invasive optical instrument, namely, particle image velocimetry (PIV) in this study. Comparison results show that all three employed diagnostic techniques yield similar measurements in the mean velocity while somewhat deviated results in the root-mean-squared velocity, particularly for the PIV measurements. It is demonstrated that HFA possesses more capability than HWA in the flow measurements of wake flow. Wake width is determined in terms of either the flatness factor or shear-induced vorticity. It is demonstrated that flow data obtained with the three employed diagnostic techniques are capable of yielding accurate determination of wake width.

  16. Using embedded fibers to measure explosive detonation velocities

    Energy Technology Data Exchange (ETDEWEB)

    Podsednik, Jason W.; Parks, Shawn Michael; Navarro, Rudolfo J.

    2012-07-01

    Single-mode fibers were cleverly embedded into fixtures holding nitromethane, and used in conjunction with a photonic Doppler velocimeter (PDV) to measure the associated detonation velocity. These measurements have aided us in our understanding of energetic materials and enhanced our diagnostic capabilities.

  17. Measurement of Critical Impact Velocity of Copper in Tension

    Institute of Scientific and Technical Information of China (English)

    HU Jin-Wei; JIN Yang-Hui; CHEN Da-Nian; WU Shan-Xing; WANG Huan-Ran; MA Dong-Fang

    2008-01-01

    @@ Critical impact velocity (CIV) of oxygen-free high-conductivity (OFHC) copper is experimentally measured with a novel facility in a gas gun system.The results are compared with the theoretical predictions using the typical constitutive relations,and the measured CIV value is much lower than the predictions.

  18. Estimating Radar Velocity using Direction of Arrival Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Horndt, Volker [General Atomics Aeronautical Systems, Inc., San Diego, CA (United States); Bickel, Douglas Lloyd [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Naething, Richard M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-09-01

    Direction of Arrival (DOA) measurements, as with a monopulse antenna, can be compared against Doppler measurements in a Synthetic Aperture Radar ( SAR ) image to determine an aircraft's forward velocity as well as its crab angle, to assist the aircraft's navigation as well as improving high - performance SAR image formation and spatial calibration.

  19. Particle velocity measurements with macroscopic fluorescence imaging in lymph tissue mimicking microfluidic phantoms

    Science.gov (United States)

    Hennessy, Ricky; Koo, Chiwan; Ton, Phuc; Han, Arum; Righetti, Raffaella; Maitland, Kristen C.

    2011-03-01

    Ultrasound poroelastography can quantify structural and mechanical properties of tissues such as stiffness, compressibility, and fluid flow rate. This novel ultrasound technique is being explored to detect tissue changes associated with lymphatic disease. We have constructed a macroscopic fluorescence imaging system to validate ultrasonic fluid flow measurements and to provide high resolution imaging of microfluidic phantoms. The optical imaging system is composed of a white light source, excitation and emission filters, and a camera with a zoom lens. The field of view can be adjusted from 100 mm x 75 mm to 10 mm x 7.5 mm. The microfluidic device is made of polydimethylsiloxane (PDMS) and has 9 channels, each 40 μm deep with widths ranging from 30 μm to 200 μm. A syringe pump was used to propel water containing 15 μm diameter fluorescent microspheres through the microchannels, with flow rates ranging from 0.5 μl/min to 10 μl/min. Video was captured at a rate of 25 frames/sec. The velocity of the microspheres in the microchannels was calculated using an algorithm that tracked the movement of the fluorescent microspheres. The imaging system was able to measure particle velocities ranging from 0.2 mm/sec to 10 mm/sec. The range of flow velocities of interest in lymph vessels is between 1 mm/sec to 10 mm/sec; therefore our imaging system is sufficient to measure particle velocity in phantoms modeling lymphatic flow.

  20. Laboratory Measurements of Velocity and Attenuation in Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Zimmer, M A; Berge, P A; Bonner, B P; Prasad, M

    2004-06-08

    Laboratory measurements are required to establish relationships between the physical properties of unconsolidated sediments and P- and S-wave propagation through them. Previous work has either focused on measurements of compressional wave properties at depths greater than 500 m for oil industry applications or on measurements of dynamic shear properties at pressures corresponding to depths of less than 50 m for geotechnical applications. Therefore, the effects of lithology, fluid saturation, and compaction on impedance and P- and S-wave velocities of shallow soils are largely unknown. We describe two state-of-the-art laboratory experiments. One setup allows us to measure ultrasonic P-wave velocities at very low pressures in unconsolidated sediments (up to 0.1 MPa). The other experiment allows P- and S-wave velocity measurements at low to medium pressures (up to 20 MPa). We summarize the main velocity and attenuation results on sands and sand - clay mixtures under partially saturated and fully saturated conditions in two ranges of pressures (0 - 0.1 MPa and 0.1 - 20 MPa) representative of the top few meters and the top 1 km, respectively. Under hydrostatic pressures of 0.1 to 20 MPa, our measurements demonstrate a P- and S-wave velocity-dependence in dry sands around a fourth root (0.23 -0.26) with the pressure dependence for S-waves being slightly lower. The P- velocity-dependence in wet sands lies around 0.4. The Vp-Vs and the Qp-Qs ratios together can be useful tools to distinguish between different lithologies and between pressure and saturation effects. These experimental velocities at the frequency of measurement (200 kHz) are slightly higher that Gassmann's static result. For low pressures under uniaxial stress, Vp and Vs were a few hundred meters per second with velocities showing a strong dependence on packing, clay content, and microstructure. We provide a typical shallow soil scenario in a clean sand environment and reconstruct the velocity profile

  1. High-Resolution Spectroscopy of the Lunar Sodium Exosphere

    Science.gov (United States)

    Mierkiewicz, E. J.; Oliversen, R. J.; Roesler, F. L.; Lupie, O. L.

    2014-01-01

    We have applied high-resolution Fabry-Perot spectroscopy to the study of the lunar sodium exosphere for the study of exospheric effective temperature and velocity variations. Observing from the National Solar Observatory McMath-Pierce Telescope, we used a dual-etalon Fabry-Perot spectrometer with a resolving power of 180,000 to measure line widths and Doppler shifts of the sodium D2 (5889.95 Å) emission line. Our field of view was 360 km, and measurements were made in equatorial and polar regions from 500 km to 3500 km off the limb. Data were obtained from full moon to 3 days following full moon (waning phase) in March 2009. Measured Doppler line widths within 1100 km of the sunlit east and south lunar limbs for observations between 5 and 40 deg lunar phase imply effective temperatures ranging between 3260 +/- 190 and 1000 +/- 135 K. Preliminary line center analysis indicates velocity displacements between different locations off the lunar limb ranging between 100 and 600 m/s from the lunar rest velocity with a precision of +/-20 to +/-50 m/s depending on brightness. Based on the success of these exploratory observations, an extensive program has been initiated that is expected to constrain lunar atmospheric and surface-process modeling and help quantify source and escape mechanisms.

  2. High-resolution spectroscopy of the lunar sodium exosphere

    Science.gov (United States)

    Mierkiewicz, E. J.; Oliversen, R. J.; Roesler, F. L.; Lupie, O. L.

    2014-06-01

    We have applied high-resolution Fabry-Perot spectroscopy to the study of the lunar sodium exosphere for the study of exospheric effective temperature and velocity variations. Observing from the National Solar Observatory McMath-Pierce Telescope, we used a dual-etalon Fabry-Perot spectrometer with a resolving power of 180,000 to measure line widths and Doppler shifts of the sodium D2 (5889.95 Å) emission line. Our field of view was 360 km, and measurements were made in equatorial and polar regions from 500 km to 3500 km off the limb. Data were obtained from full moon to 3 days following full moon (waning phase) in March 2009. Measured Doppler line widths within 1100 km of the sunlit east and south lunar limbs for observations between 5 and 40° lunar phase imply effective temperatures ranging between 3260 ± 190 and 1000 ± 135 K. Preliminary line center analysis indicates velocity displacements between different locations off the lunar limb ranging between 100 and 600 m/s from the lunar rest velocity with a precision of ±20 to ±50 m/s depending on brightness. Based on the success of these exploratory observations, an extensive program has been initiated that is expected to constrain lunar atmospheric and surface-process modeling and help quantify source and escape mechanisms.

  3. Signal processing method for shear wave velocity measurement

    Institute of Scientific and Technical Information of China (English)

    Hou Xingmin; Qu Shuying; Shi Xiangdong

    2007-01-01

    Soil shear wave velocity (SWV) is an important parameter in geotechnical engineering. To measure the soil SWV, three methods are generally used in China, including the single-hole method, cross-hole method and the surface-wave technique. An optimized approach based on a correlation function for single-hole SWV measurement is presented in this paper. In this approach, inherent inconsistencies of the artificial methods such as negative velocities, and too-large and too-small velocities, are eliminated from the single-hole method, and the efficiency of data processing is improved. In addition, verification using the cross-hole method of upper measuring points shows that the proposed optimized approach yields high precision in signal processing.

  4. Sound field separation with sound pressure and particle velocity measurements

    DEFF Research Database (Denmark)

    Fernandez Grande, Efren; Jacobsen, Finn; Leclère, Quentin

    2012-01-01

    separation techniques make it possible to distinguish between outgoing and incoming waves from the two sides, and thus NAH can be applied. In this paper, a separation method based on the measurement of the particle velocity in two layers and another method based on the measurement of the pressure...... and the velocity in a single layer are proposed. The two methods use an equivalent source formulation with separate transfer matrices for the outgoing and incoming waves, so that the sound from the two sides of the array can be modeled independently. A weighting scheme is proposed to account for the distance...... pressure-velocity method, although it requires an additional measurement surface. On the whole, the separation methods can be useful when the disturbance of the incoming field is significant. Otherwise the direct reconstruction is more accurate and straightforward. © 2012 Acoustical Society of America....

  5. Velocity of detonation (VOD measurement techniques - practical approach

    Directory of Open Access Journals (Sweden)

    Aruna Dhanraj Tete

    2013-06-01

    Full Text Available Velocity of Detonation (VOD is an important measure characteristics parameter of explosive material. The performance of explosive invariably depends on the velocity of detonation. The power/ strength of explosive to cause fragmentation of the solid structure determine the efficiency of the Blast performed. It is an established fact that measuring velocity of detonation gives a good indication of the strength and hence the performance of the explosive. In this survey various VOD measurement techniques such as electric, nonelectric and fibre optic have been discussed. To aid the discussion some commercially available VOD meter comparison are also presented. After review of the existing units available commercially and study of their respective merits and demerits, feature of an ideal system is proposed. 

  6. Sensors for Using Times of Flight to Measure Flow Velocities

    Science.gov (United States)

    Fralick, Gutave; Wrbanek, John D.; Hwang, Danny; Turso, James

    2006-01-01

    Thin-film sensors for measuring flow velocities in terms of times of flight are undergoing development. These sensors are very small and can be mounted flush with surfaces of airfoils, ducts, and other objects along which one might need to measure flows. Alternatively or in addition, these sensors can be mounted on small struts protruding from such surfaces for acquiring velocity measurements at various distances from the surfaces for the purpose of obtaining boundary-layer flow-velocity profiles. These sensors are related to, but not the same as, hot-wire anemometers. Each sensor includes a thin-film, electrically conductive loop, along which an electric current is made to flow to heat the loop to a temperature above that of the surrounding fluid. Instantaneous voltage fluctuations in segments of the loop are measured by means of electrical taps placed at intervals along the loop. These voltage fluctuations are caused by local fluctuations in electrical resistance that are, in turn, caused by local temperature fluctuations that are, in turn, caused by fluctuations in flow-induced cooling and, hence, in flow velocity. The differential voltage as a function of time, measured at each pair of taps, is subjected to cross-correlation processing with the corresponding quantities measured at other pairs of taps at different locations on the loop. The cross-correlations yield the times taken by elements of fluid to travel between the pairs of taps. Then the component of velocity along the line between any two pairs of taps is calculated simply as the distance between the pairs of taps divided by the travel time. Unlike in the case of hot-wire anemometers, there is no need to obtain calibration data on voltage fluctuations versus velocity fluctuations because, at least in principle, the correlation times are independent of the calibration data.

  7. Detailed Measurement of Horizontal Groundwater Velocities Without a Borehole

    Science.gov (United States)

    Bakker, M.; Calje, R.; Van der Made, K. J.; Schaars, F.

    2014-12-01

    A new methodology has been developed to measure horizontal groundwater velocities in unconsolidated aquifers. Groundwater velocities are measured with a heat tracer experiment. Temperature is measured along fiber optic cables using a Distributed Temperature Sensing (DTS) system. Fiber optic cables and a separate heating cable are pushed into the ground to depths of tens of meters. The groundwater is heated with the heating cable and the response is measured along several nearby fiber optic cables. The measured temperature responses are used to estimate the distribution of the magnitude and direction of the horizontal groundwater velocity over the entire depth of the cables. The methodology has been applied in a phreatic aquifer in the dune area along the Dutch coast. Significant variations of groundwater velocities with depth were observed even though the dune sand is relatively homogeneous. Major advantages of the new methodology are that the fiber optic cables are in direct contact with the groundwater and that the cables and installation are relatively cheap. No expensive boreholes are needed and consequently measurements are not affected by movement and mixing of water inside a borehole.

  8. Optic-microwave mixing velocimeter for superhigh velocity measurement

    Energy Technology Data Exchange (ETDEWEB)

    Weng Jidong; Wang Xiang; Tao Tianjiong; Liu Cangli; Tan Hua [Laboratory for Shock Waves and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, Mianyang, Sichuan 621900 (China)

    2011-12-15

    The phenomenon that a light beam reflected off a moving object experiences a Doppler shift in its frequency underlies practical interferometric techniques for remote velocity measurements, such as velocity interferometer system for any reflector (VISAR), displacement interferometer system for any reflector (DISAR), and photonic Doppler velocimetry (PDV). While VISAR velocimeters are often bewildered by the fringe loss upon high-acceleration dynamic process diagnosis, the optic-fiber velocimeters such as DISAR and PDV, on the other hand, are puzzled by high velocity measurement over 10 km/s, due to the demand for the high bandwidth digitizer. Here, we describe a new optic-microwave mixing velocimeter (OMV) for super-high velocity measurements. By using currently available commercial microwave products, we have constructed a simple, compact, and reliable OMV device, and have successfully obtained, with a digitizer of bandwidth 6 GH only, the precise velocity history of an aluminum flyer plate being accelerated up to 11.2 km/s in a three stage gas-gun experiment.

  9. Achieving sensitive, high-resolution laser spectroscopy at CRIS

    Energy Technology Data Exchange (ETDEWEB)

    Groote, R. P. de [Instituut voor Kern- en Stralingsfysica, KU Leuven (Belgium); Lynch, K. M., E-mail: kara.marie.lynch@cern.ch [EP Department, CERN, ISOLDE (Switzerland); Wilkins, S. G. [The University of Manchester, School of Physics and Astronomy (United Kingdom); Collaboration: the CRIS collaboration

    2017-11-15

    The Collinear Resonance Ionization Spectroscopy (CRIS) experiment, located at the ISOLDE facility, has recently performed high-resolution laser spectroscopy, with linewidths down to 20 MHz. In this article, we present the modifications to the beam line and the newly-installed laser systems that have made sensitive, high-resolution measurements possible. Highlights of recent experimental campaigns are presented.

  10. High-resolution X-ray diffraction studies of multilayers

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Hornstrup, Allan; Schnopper, H. W.

    1988-01-01

    High-resolution X-ray diffraction studies of the perfection of state-of-the-art multilayers are presented. Data were obtained using a triple-axis perfect-crystal X-ray diffractometer. Measurements reveal large-scale figure errors in the substrate. A high-resolution triple-axis set up is required...

  11. High-resolution measurement, line identification, and spectral modeling of the K{beta} spectrum of heliumlike argon emitted by a laser-produced plasma using a gas-puff target

    Energy Technology Data Exchange (ETDEWEB)

    Skobelev, I.Y.; Faenov, A.Y.; Dyakin, V.M. [Multicharged Ion Spectra Data Center, VNIIFTRI, Mendeleevo, 141570 (Russia); Fiedorowicz, H.; Bartnik, A.; Szczurek, M. [Institute of Optoelectronics, Military University of Technology, 01-489 Warsaw (Poland); Beiersdorfer, P.; Nilsen, J.; Osterheld, A.L. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

    1997-03-01

    We present an analysis of the spectrum of satellite transitions to the He-{beta} line in ArXVII. High-resolution measurements of the spectra from laser-heated Ar-gas-puff targets are made with spectral resolution of 10000 and spatial resolution of better than 50 {mu}m. These are compared with tokamak measurements. Several different lines are identified in the spectra and the spectral analysis is used to determine the plasma parameters in the gas-puff laser-produced plasma. The data complement those from tokamak measurements to provide more complete information on the satellite spectra. {copyright} {ital 1997} {ital The American Physical Society}

  12. High-resolution traction force microscopy.

    Science.gov (United States)

    Plotnikov, Sergey V; Sabass, Benedikt; Schwarz, Ulrich S; Waterman, Clare M

    2014-01-01

    Cellular forces generated by the actomyosin cytoskeleton and transmitted to the extracellular matrix (ECM) through discrete, integrin-based protein assemblies, that is, focal adhesions, are critical to developmental morphogenesis and tissue homeostasis, as well as disease progression in cancer. However, quantitative mapping of these forces has been difficult since there has been no experimental technique to visualize nanonewton forces at submicrometer spatial resolution. Here, we provide detailed protocols for measuring cellular forces exerted on two-dimensional elastic substrates with a high-resolution traction force microscopy (TFM) method. We describe fabrication of polyacrylamide substrates labeled with multiple colors of fiducial markers, functionalization of the substrates with ECM proteins, setting up the experiment, and imaging procedures. In addition, we provide the theoretical background of traction reconstruction and experimental considerations important to design a high-resolution TFM experiment. We describe the implementation of a new algorithm for processing of images of fiducial markers that are taken below the surface of the substrate, which significantly improves data quality. We demonstrate the application of the algorithm and explain how to choose a regularization parameter for suppression of the measurement error. A brief discussion of different ways to visualize and analyze the results serves to illustrate possible uses of high-resolution TFM in biomedical research. © 2014 Elsevier Inc. All rights reserved.

  13. A refined TALDICE-1a age scale from 55 to 112 ka before present for the Talos Dome ice core based on high-resolution methane measurements

    Directory of Open Access Journals (Sweden)

    S. Schüpbach

    2011-09-01

    Full Text Available A precise synchronization of different climate records is indispensable for a correct dynamical interpretation of paleoclimatic data. A chronology for the TALDICE ice core from the Ross Sea sector of East Antarctica has recently been presented based on methane synchronization with Greenland and the EDC ice cores and δ18Oice synchronization with EDC in the bottom part (TALDICE-1. Using new high-resolution methane data obtained with a continuous flow analysis technique, we present a refined age scale for the age interval from 55–112 thousand years (ka before present, where TALDICE is synchronized with EDC. New and more precise tie points reduce the uncertainties of the age scale from up to 1900 yr in TALDICE-1 to below 1100 yr over most of the refined interval and shift the Talos Dome dating to significantly younger ages during the onset of Marine Isotope Stage 3. Thus, discussions of climate dynamics at sub-millennial time scales are now possible back to 110 ka, in particular during the inception of the last ice age. Calcium data of EDC and TALDICE are compared to show the impact of the refinement to the synchronization of the two ice cores not only for the gas but also for the ice age scale.

  14. A refined TALDICE-1a age scale from 55 to 112 ka before present for the Talos Dome ice core based on high-resolution methane measurements

    Directory of Open Access Journals (Sweden)

    S. Schüpbach

    2011-04-01

    Full Text Available A precise synchronization of different climate records is indispensable for a correct dynamical interpretation of paleoclimatic data. A chronology for the TALDICE ice core from the Ross Sea sector of East Antarctica has recently been presented based on methane synchronization with Greenland and the EDC ice cores and δ18Oice synchronization with EDC in the bottom part (TALDICE-1. By the use of new high-resolution methane data, obtained with a continuous flow analysis technique, we present a refined age scale for the age interval from 55–112 ka before present where TALDICE is synchronized with EDC. New and more precise tie points reduce the uncertainties of the age scale from up to 2000 yr in TALDICE-1 to below 1000 yr over most of the refined interval. Thus, discussions of climate dynamics at sub-millennial time scales are now possible back to 110 ka, in particular during the inception of the last ice age. Calcium data of EDC and TALDICE are compared to show the impact of the refinement to the synchronization of the two ice cores not only for the gas but also for the ice age scale.

  15. Measuring of the maximum measurable velocity for dual-frequency laser interferometer

    Institute of Scientific and Technical Information of China (English)

    Zhiping Zhang; Zhaogu Cheng; Zhaoyu Qin; Jianqiang Zhu

    2007-01-01

    There is an increasing demand on the measurable velocity of laser interferometer in manufacturing technologies. The maximum measurable velocity is limited by frequency difference of laser source, optical configuration, and electronics bandwidth. An experimental setup based on free falling movement has been demonstrated to measure the maximum easurable velocity for interferometers. Measurement results show that the maximum measurable velocity is less than its theoretical value. Moreover, the effect of kinds of factors upon the measurement results is analyzed, and the results can offer a reference for industrial applications.

  16. Velocity and rotation measurements in acoustically levitated droplets

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Abhishek [University of Central Florida, Orlando, FL 32816 (United States); Basu, Saptarshi [Indian Institute of Science, Bangalore 560012 (India); Kumar, Ranganathan, E-mail: ranganathan.kumar@ucf.edu [University of Central Florida, Orlando, FL 32816 (United States)

    2012-10-01

    The velocity scale inside an acoustically levitated droplet depends on the levitator and liquid properties. Using Particle Imaging Velocimetry (PIV), detailed velocity measurements have been made in a levitated droplet of different diameters and viscosity. The maximum velocity and rotation are normalized using frequency and amplitude of acoustic levitator, and droplet viscosity. The non-dimensional data are fitted for micrometer- and millimeter-sized droplets levitated in different levitators for different viscosity fluids. It is also shown that the rotational speed of nanosilica droplets at an advanced stage of vaporization compares well with that predicted by exponentially fitted parameters. -- Highlights: ► Demonstrates the importance of rotation in a levitated droplet that leads to controlled morphology. ► Provides detailed measurements of Particle Image Velocimetry inside levitated droplets. ► Shows variation of vortex strength with the droplet diameter and viscosity of the liquid.

  17. Investigation by high resolution electron spectroscopy of the helium-like 3lnl' Rydberg series in double capture processes at low collision velocity: auto transfer to Rydberg states and electron stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Bordenave-Montesquieu, A.; Moretto-Capelle, P.; Gonzalez, A.; Benhenni, M. (Toulouse-3 Univ., 31 (France)); Bachau, H.; Sanchez, I. (Bordeaux-1 Univ., 33 - Talence (France). Lab. des Collisions Atomiques)

    1994-09-28

    A high resolution electron spectrometry of the (3lnl') Ryberg series populated in N[sup 7+] + He and Ne[sup 10+] + He collisions at 10 q keV, 10[sup o] allows us to observe, for the first time by this method, two post-collisional effects. First, it is found with nitrogen ions that, when n increases from n = 4 to 9, the L-distribution peaks more and more on the high angular momentum states. This is qualitatively understood as a Stark deformation of the Rydberg orbit by the Coulomb field of the receding ion. Also, in the n range where the double capture process populates symmetrical 4l4l' states (n>9), an enhancement of the intensities of the 3lnl' Rydberg lines is observed for both collisonal systems. This is thought to be a signature of the so-called auto transfer to Rydberg states effect. The transfer of population from the 3l4l' to the 3lnl' states is found to be favoured against a direct autoionization of these 4l4l' states into the n = 2 continuum. These experimental findings together with preliminary spectroscopic calculations concerning the configuration interaction of the Ne[sup 8+] (4l4l') states with the Ne[sup 8+](3lnl') Rydberg series are also discussed within the context of the electron stabilization which follows a double capture. (Author).

  18. Wind Velocity Decreasing Effects of Windbreak Fence for Snowfall Measurement

    Directory of Open Access Journals (Sweden)

    Ki-Pyo You

    2014-01-01

    Full Text Available Meteorological observatories use measuring boards on even ground in open areas to measure the amount of snowfall. In order to measure the amount of snowfall, areas unaffected by wind should be found. This study tried to determine the internal wind flow inside a windbreak fence, identifying an area unaffected by wind in order to measure the snowfall. We performed a computational fluid dynamics analysis and wind tunnel test, conducted field measurements of the type and height of the windbreak fence, and analyzed the wind flow inside the fence. The results showed that a double windbreak fence was better than a single windbreak fence for decreasing wind velocity. The double fence (width 4 m, height 60 cm, and fixed on the bottom has the greatest wind velocity decrease rate at the central part of octagonal windbreak.

  19. Intraglottal velocity and pressure measurements in a hemilarynx model.

    Science.gov (United States)

    Oren, Liran; Gutmark, Ephraim; Khosla, Sid

    2015-02-01

    Determining the mechanisms of self-sustained oscillation of the vocal folds requires characterization of the pressures produced by intraglottal aerodynamics. Because most of the intraglottal aerodynamic forces cannot be measured in a tissue model of the larynx, current understanding of vocal fold vibration mechanism is derived from mechanical, analytical, and computational models. Previous studies have computed intraglottal pressures from measured intraglottal velocity fields and intraglottal geometry; however, this technique for determining pressures is not yet validated. In this study, intraglottal pressure measurements taken in a hemilarynx model are compared with pressure values that are computed from simultaneous velocity measurements. The results showed that significant negative pressure formed near the superior aspect of the folds during closing, which agrees with previous measurements in other hemilarynx models. Intraglottal velocity measurements show that the flow near the superior aspect separates from the glottal wall during closing and may develop into a vortex, which further augments the magnitude of negative pressure. Intraglottal pressure distributions, computed by solving the pressure Poisson equation, showed good agreement with pressure measurements. The match between the pressure computations and its measurements validates the current technique, which was previously used to estimate intraglottal pressure distribution in a full larynx model.

  20. Evaluation of temporal bone pneumatization on high resolution CT (HRCT) measurements of the temporal bone in normal and otitis media group and their correlation to measurements of internal auditory meatus, vestibular or cochlear aqueduct

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Miyako

    1988-07-01

    High resolution CT axial scans were made at the three levels of the temoral bone 91 cases. These cases consisted of 109 sides of normal pneumatization (NR group) and 73 of poor pneumatization resulted by chronic otitis (OM group). NR group included sensorineural hearing loss cases and/or sudden deafness on the side. Three levels of continuous slicing were chosen at the internal auditory meatus, the vestibular and the cochlear aqueduct, respectively. In each slice two sagittal and two horizontal measurements were done on the outer contour of the temporal bone. At the proper level, diameter as well as length of the internal acoustic meatus, the vestibular or the cochlear aqueduct were measured. Measurements of the temporal bone showed statistically significant difference between NR and OM groups. Correlation of both diameter and length of the internal auditory meatus to the temporal bone measurements were statistically significant. Neither of measurements on the vestibular or the cochlear aqueduct showed any significant correlation to that of the temporal bone.

  1. Precise Measurement of Drift Velocities in Active-Target Detectors

    Science.gov (United States)

    Jensen, Louis

    2016-09-01

    Nuclear experiments with radioactive beams are needed to improve our understanding of nuclei structure far from stability. Radioactive beams typically have low beam rates, but active-target detectors can compensate for these low beam rates. In active-target detectors that are also Time-Projection Chambers (TPC), ionized electrons drift through an electric fieldto a detection device to imagethe trajectory of charged-particle ionization tracks within the chamber's gas volume. The measurement of the ionized electrons' drift velocity is crucial for the accurate imaging of these tracks. In order to measure this drift velocity, we will use a UV laser and photo-sensitive foil in a the ND-Cubedetector we are developing, periodically releasingelectrons from the foil at a known timesand a known distance from the electron detector, thereby precisely measuring the drift velocity in situ. We have surveyed several materials to find a material that will work well with typical solid-state UV lasers on the market. We plan to determine the best material and thickness of the foil to maximize the number of photoelectrons. The precision that will be afforded by this measurement of the drift velocity will allow us to eliminate a source of systematic uncertainty.

  2. Improved Measurement of Ejection Velocities From Craters Formed in Sand

    Science.gov (United States)

    Cintala, Mark J.; Byers, Terry; Cardenas, Francisco; Montes, Roland; Potter, Elliot E.

    2014-01-01

    A typical impact crater is formed by two major processes: compression of the target (essentially equivalent to a footprint in soil) and ejection of material. The Ejection-Velocity Measurement System (EVMS) in the Experimental Impact Laboratory has been used to study ejection velocities from impact craters formed in sand since the late 1990s. The original system used an early-generation Charge-Coupled Device (CCD) camera; custom-written software; and a complex, multicomponent optical system to direct laser light for illumination. Unfortunately, the electronic equipment was overtaken by age, and the software became obsolete in light of improved computer hardware.

  3. An inexpensive instrument for measuring wave exposure and water velocity

    Science.gov (United States)

    Figurski, J.D.; Malone, D.; Lacy, J.R.; Denny, M.

    2011-01-01

    Ocean waves drive a wide variety of nearshore physical processes, structuring entire ecosystems through their direct and indirect effects on the settlement, behavior, and survivorship of marine organisms. However, wave exposure remains difficult and expensive to measure. Here, we report on an inexpensive and easily constructed instrument for measuring wave-induced water velocities. The underwater relative swell kinetics instrument (URSKI) is a subsurface float tethered by a short (<1 m) line to the seafloor. Contained within the float is an accelerometer that records the tilt of the float in response to passing waves. During two field trials totaling 358 h, we confirmed the accuracy and precision of URSKI measurements through comparison to velocities measured by an in situ acoustic Doppler velocimeter and those predicted by a standard swell model, and we evaluated how the dimensions of the devices, its buoyancy, and sampling frequency can be modified for use in a variety of environments.

  4. Depth-encoded dual beam phase-resolved Doppler OCT for Doppler-angle-independent flow velocity measurement

    Science.gov (United States)

    Qian, Jie; Cheng, Wei; Cao, Zhaoyuan; Chen, Xinjian; Mo, Jianhua

    2017-02-01

    Phase-resolved Doppler optical coherence tomography (PR-D-OCT) is a functional OCT imaging technique that can provide high-speed and high-resolution depth-resolved measurement on flow in biological materials. However, a common problem with conventional PR-D-OCT is that this technique often measures the flow motion projected onto the OCT beam path. In other words, it needs the projection angle to extract the absolute velocity from PR-D-OCT measurement. In this paper, we proposed a novel dual-beam PR-D-OCT method to measure absolute flow velocity without separate measurement on the projection angle. Two parallel light beams are created in sample arm and focused into the sample at two different incident angles. The images produced by these two beams are encoded to different depths in single B-scan. Then the Doppler signals picked up by the two beams together with the incident angle difference can be used to calculate the absolute velocity. We validated our approach in vitro on an artificial flow phantom with our home-built 1060 nm swept source OCT. Experimental results demonstrated that our method can provide an accurate measurement of absolute flow velocity with independency on the projection angle.

  5. Mean velocity, turbulence intensity and turbulence convection velocity measurements for a convergent nozzle in a free jet wind tunnel

    Science.gov (United States)

    Mccolgan, C. J.; Larson, R. S.

    1978-01-01

    The effect of light on the mean flow and turbulence properties of a 0.056 m circular jet were determined in a free jet wind tunnel. The nozzle exit velocity was 122 m/sec, and the wind tunnel velocity was set at 0, 12, 37, and 61 m/sec. Measurements of flow properties including mean velocity, turbulence intensity and spectra, and eddy convection velocity were carried out using two linearized hot wire anemometers. Normalization factors were determined for the mean velocity and turbulence convection velocity.

  6. Particle Velocity Measurement for Spherical Wave in Solid

    Institute of Scientific and Technical Information of China (English)

    ZHENG Xue-feng; WANG Zhan-jiang; LIN Jun-de; SHEN Jun-yi

    2006-01-01

    An experimental technique for research on spherical divergent wave propagation in a solid has been developed,in which the source of generating spherical wave is a center initiating explosive charge designed in a mini-spherical shape with yield equivalent to 0.125 g and 0. 486 g TNT and a set of circular electromagnetic particle velocity gages is used to record the particle velocity histories. By using the circular electromagnetic particle velocity gages, the signal outputs not only are unattenuated due to the geometrical divergence, but also represent the average of the measured dynamic states of the medium over a circle on the wavefront. The distinctive features of this technique are very useful for the study of spherical divergent wave propagation in a solid, especially in an inhomogeneous solid, and the corresponding material dynamics.Many experimental measurements were conducted in polymethylmethacrylate (PMMA) and granite by means of the technique, and the reproducibility of tests was shown to be good. The measurement technique of the circular electromagnetic particle velocity gages is also suitable to the case of cylindrical wave.

  7. Characterization of spatially resolved high resolution x-ray spectrometers for high energy density physics and light source experiments.

    Science.gov (United States)

    Hill, K W; Bitter, M; Delgado-Aparacio, L; Efthimion, P; Pablant, N A; Lu, J; Beiersdorfer, P; Chen, H; Magee, E

    2014-11-01

    A high resolution 1D imaging x-ray spectrometer concept comprising a spherically bent crystal and a 2D pixelated detector is being optimized for diagnostics of small sources such as high energy density physics (HEDP) and synchrotron radiation or x-ray free electron laser experiments. This instrument is used on tokamak experiments for Doppler measurements of ion temperature and plasma flow velocity profiles. Laboratory measurements demonstrate a resolving power, E/ΔE of order 10,000 and spatial resolution better than 10 μm. Initial tests of the high resolution instrument on HEDP plasmas are being performed.

  8. High resolved velocity measurements using Laser Cantilever Anemometry

    Science.gov (United States)

    Puczylowski, Jaroslaw; Hölling, Michael; Peinke, Joachim

    2016-11-01

    We have developed a new anemometer, namely the 2d-LCA (2d-Laser-Cantilever-Anemometer), that is capable of performing high resolved velocity measurements in fluids. The anemometer uses a micostructured cantilever made of silicon as a sensing element. The specific shape and the small dimensions (about 150µm) of the cantilever allow for precise measurements of two velocity component at a temporal resolution of about 150kHz. The angular acceptance range is 180° in total. The 2d-LCA is a simple to use alternative to x-wires and can be used in many areas of operation including measurements in liquids or in particle-laden flows. Unlike hot-wires, the resolution power of the 2d-LCA does not decrease with increasing flow velocity, making it particularly suitable for measurements in high-speed flows. In the recent past new cantilever designs were implemented with the goal to further improve the angular resolution and increase the stability. In addition, we have designed more robust cantilevers for measurements in rough environments such as offshore areas. Successful comparative measurements with hot-wires have been carried out in order to assess the performance of the 2d-LCA.

  9. High resolution melting: a useful field-deployable method to measure dhfr and dhps drug resistance in both highly and lowly endemic Plasmodium populations.

    Science.gov (United States)

    Ndiaye, Yaye Dié; Diédhiou, Cyrille K; Bei, Amy K; Dieye, Baba; Mbaye, Aminata; Mze, Nasserdine Papa; Daniels, Rachel F; Ndiaye, Ibrahima M; Déme, Awa B; Gaye, Amy; Sy, Mouhamad; Ndiaye, Tolla; Badiane, Aida S; Ndiaye, Mouhamadou; Premji, Zul; Wirth, Dyann F; Mboup, Souleymane; Krogstad, Donald; Volkman, Sarah K; Ahouidi, Ambroise D; Ndiaye, Daouda

    2017-04-19

    Emergence and spread of drug resistance to every anti-malarial used to date, creates an urgent need for development of sensitive, specific and field-deployable molecular tools for detection and surveillance of validated drug resistance markers. Such tools would allow early detection of mutations in resistance loci. The aim of this study was to compare common population signatures and drug resistance marker frequencies between two populations with different levels of malaria endemicity and history of anti-malarial drug use: Tanzania and Sénégal. This was accomplished by implementing a high resolution melting assay to study molecular markers of drug resistance as compared to polymerase chain reaction-restriction fragment length polymorphism (PCR/RFLP) methodology. Fifty blood samples were collected each from a lowly malaria endemic site (Sénégal), and a highly malaria endemic site (Tanzania) from patients presenting with uncomplicated Plasmodium falciparum malaria at clinic. Data representing the DHFR were derived using both PCR-RFLP and HRM assay; while genotyping data representing the DHPS were evaluated in Senegal and Tanzania using HRM. Msp genotyping analysis was used to characterize the multiplicity of infection in both countries. A high prevalence of samples harbouring mutant DHFR alleles was observed in both population using both genotyping techniques. HRM was better able to detect mixed alleles compared to PCR/RFLP for DHFR codon 51 in Tanzania; and only HRM was able to detect mixed infections from Senegal. A high prevalence of mutant alleles in DHFR (codons 51, 59, 108) and DHPS (codon 437) were found among samples from Sénégal while no mutations were observed at DHPS codons 540 and 581, from both countries. Overall, the frequency of samples harbouring either a single DHFR mutation (S108N) or double mutation in DHFR (C59R/S108N) was greater in Sénégal compared to Tanzania. Here the results demonstrate that HRM is a rapid, sensitive, and field

  10. Dwarf Galaxies in the Coma Cluster: I. Velocity Dispersion Measurements

    CERN Document Server

    Kourkchi, E; Carter, D; Karick, A M; Mármol-Queraltó, E; Chiboucas, K; Tully, R B; Mobasher, B; Guzmán, R; Matković, A; Gruel, N

    2011-01-01

    We present the study of a large sample of early-type dwarf galaxies in the Coma cluster observed with DEIMOS on the Keck II to determine their internal velocity dispersion. We focus on a subsample of 41 member dwarf elliptical galaxies for which the velocity dispersion can be reliably measured, 26 of which were studied for the first time. The magnitude range of our sample is $-21measurement of the velocity dispersion and their error estimates. The measurements were performed using {\\it pPXF (penalised PiXel Fitting)} and using the Calcium triplet absorption lines. We use Monte Carlo bootstrapping to study various sources of uncertainty in our measurements, namely statistical uncertainty, template mismatch and other systematics. We find that the main source of uncertainty is the template mismatch effect which is reduced by using templates with a range of spectral types. Combining our measurements with those from the literature, we study the Faber-Jackson...

  11. A clear and measurable signature of modified gravity in the galaxy velocity field

    CERN Document Server

    Hellwing, Wojciech A; Frenk, Carlos S; Li, Baojiu; Cole, Shaun

    2014-01-01

    The velocity field of dark matter and galaxies reflects the continued action of gravity throughout cosmic history. We show that the low-order moments of the pairwise velocity distribution, $v_{12}$, are a powerful diagnostic of the laws of gravity on cosmological scales. In particular, the projected line-of-sight galaxy pairwise velocity dispersion, $\\sigma_{12}(r)$, is very sensitive to the presence of modified gravity. Using a set of high-resolution N-body simulations we compute the pairwise velocity distribution and its projected line-of-sight dispersion for a class of modified gravity theories: the chameleon $f(R)$ gravity and Galileon gravity (cubic and quartic). The velocities of dark matter halos with a wide range of masses exhibit deviations from General Relativity at the 5 to 10 $\\sigma$ level. We examine strategies for detecting these deviations in galaxy redshift and peculiar velocity surveys. If detected, this signature would be a smoking gun for modified gravity.

  12. Clear and measurable signature of modified gravity in the galaxy velocity field.

    Science.gov (United States)

    Hellwing, Wojciech A; Barreira, Alexandre; Frenk, Carlos S; Li, Baojiu; Cole, Shaun

    2014-06-06

    The velocity field of dark matter and galaxies reflects the continued action of gravity throughout cosmic history. We show that the low-order moments of the pairwise velocity distribution v_{12} are a powerful diagnostic of the laws of gravity on cosmological scales. In particular, the projected line-of-sight galaxy pairwise velocity dispersion σ_{12}(r) is very sensitive to the presence of modified gravity. Using a set of high-resolution N-body simulations, we compute the pairwise velocity distribution and its projected line-of-sight dispersion for a class of modified gravity theories: the chameleon f(R) gravity and Galileon gravity (cubic and quartic). The velocities of dark matter halos with a wide range of masses would exhibit deviations from general relativity at the (5-10)σ level. We examine strategies for detecting these deviations in galaxy redshift and peculiar velocity surveys. If detected, this signature would be a "smoking gun" for modified gravity.

  13. Research on the photoelectric measuring method of warhead fragment velocity

    Science.gov (United States)

    Liu, Ji; Yu, Lixia; Zhang, Bin; Liu, Xiaoyan

    2016-09-01

    The velocity of warhead fragment is the key criteria to determine its mutilation efficiency. But owing to the small size, larger quantity, irregular shape, high speed, arbitrary direction, large dispersion of warhead fragment and adverse environment, the test of fragment velocity parameter is very difficult. The paper designed an optoelectronic system to measure the average velocity of warhead fragments accurately. The apparatus included two parallel laser screens spaced apart at a known fixed distance for providing time measurement between start and stop signals. The large effective screen area was composed of laser source, retro-reflector and large area photo-diode. Whenever a moving fragment interrupted two optical screens, the system would generate a target signal. Due to partial obscuration of the incident energy and the poor test condition of the explosion, fragment target signal is easily disturbed. Therefore, fragments signal processing technology has become a key technology of the system. The noise of signal was reduced by employing wavelet decomposition and reconstruction. The time of fragment passing though the target was obtained by adopting peak detection algorithm. Based on the method of search peak in different width scale and waveform trend by using optima wavelet, the problem of rolling waveform was solved. Lots of fragments experiments of the different types of the warheads were conducted. Experimental results show that: warhead fragments capture rate of system is better than 98%, which can give velocity of each fragment in the density of less than 20 pieces per m2.

  14. Investigation of gravity waves using horizontally resolved radial velocity measurements

    Directory of Open Access Journals (Sweden)

    G. Stober

    2013-06-01

    Full Text Available The Middle Atmosphere Alomar Radar System (MAARSY on the island Andøya in Northern Norway (69.3° N, 16.0° E observes polar mesospheric summer echoes (PMSE. These echoes are used as tracers of atmospheric dynamics to investigate the horizontal wind variability at high temporal and spatial resolution. MAARSY has the capability of a pulse-to-pulse beam steering allowing for systematic scanning experiments to study the horizontal structure of the backscatterers as well as to measure the radial velocities for each beam direction. Here we present a method to retrieve gravity wave parameters from these horizontally resolved radial wind variations by applying velocity azimuth display and volume velocity processing. Based on the observations a detailed comparison of the two wind analysis techniques is carried out in order to determine the zonal and meridional wind as well as to measure first order inhomogeneities. Further, we demonstrate the possibility to resolve the horizontal wave properties, e.g. horizontal wavelength, phase velocity and propagation direction. The robustness of the estimated gravity wave parameters is tested by a simple atmospheric model.

  15. Velocity measurements in jets with application to noise source modeling

    Science.gov (United States)

    Morris, Philip J.; Zaman, K. B. M. Q.

    2010-02-01

    This paper describes an experimental investigation of the statistical properties of turbulent velocity fluctuations in an axisymmetric jet. The focus is on those properties that are relevant to the prediction of noise. Measurements are performed using two single hot-wire anemometers as well as a two-component anemometer. Two-point cross correlations of the axial velocity fluctuations and of the fluctuations in the square of the axial velocity fluctuations are presented. Several reference locations in the jet are used including points on the jet lip and centerline. The scales of the turbulence and the convection velocity are determined, both in an overall sense as well as a function of frequency. The relationship between the second and fourth order correlations is developed and compared with the experimental data. The implications of the use of dimensional as well as non-dimensional correlations are considered. Finally, a comparison is made between the length scales deduced from the flow measurements and a RANS CFD calculation.

  16. Investigation of gravity waves using horizontally resolved radial velocity measurements

    Science.gov (United States)

    Stober, G.; Sommer, S.; Rapp, M.; Latteck, R.

    2013-10-01

    The Middle Atmosphere Alomar Radar System (MAARSY) on the island of Andøya in Northern Norway (69.3° N, 16.0° E) observes polar mesospheric summer echoes (PMSE). These echoes are used as tracers of atmospheric dynamics to investigate the horizontal wind variability at high temporal and spatial resolution. MAARSY has the capability of pulse-to-pulse beam steering allowing for systematic scanning experiments to study the horizontal structure of the backscatterers as well as to measure the radial velocities for each beam direction. Here we present a method to retrieve gravity wave parameters from these horizontally resolved radial wind variations by applying velocity azimuth display and volume velocity processing. Based on the observations a detailed comparison of the two wind analysis techniques is carried out in order to determine the zonal and meridional wind as well as to measure first-order inhomogeneities. Further, we demonstrate the possibility to resolve the horizontal wave properties, e.g., horizontal wavelength, phase velocity and propagation direction. The robustness of the estimated gravity wave parameters is tested by a simple atmospheric model.

  17. Investigation of gravity waves using horizontally resolved radial velocity measurements

    Directory of Open Access Journals (Sweden)

    G. Stober

    2013-10-01

    Full Text Available The Middle Atmosphere Alomar Radar System (MAARSY on the island of Andøya in Northern Norway (69.3° N, 16.0° E observes polar mesospheric summer echoes (PMSE. These echoes are used as tracers of atmospheric dynamics to investigate the horizontal wind variability at high temporal and spatial resolution. MAARSY has the capability of pulse-to-pulse beam steering allowing for systematic scanning experiments to study the horizontal structure of the backscatterers as well as to measure the radial velocities for each beam direction. Here we present a method to retrieve gravity wave parameters from these horizontally resolved radial wind variations by applying velocity azimuth display and volume velocity processing. Based on the observations a detailed comparison of the two wind analysis techniques is carried out in order to determine the zonal and meridional wind as well as to measure first-order inhomogeneities. Further, we demonstrate the possibility to resolve the horizontal wave properties, e.g., horizontal wavelength, phase velocity and propagation direction. The robustness of the estimated gravity wave parameters is tested by a simple atmospheric model.

  18. Faulting mechanism of the Campania–Lucania 1980 earthquake, Italy, from high-resolution, 3D velocity structure, aftershock relocation, fault-plane solutions, and post-seismic deformation modeling

    Directory of Open Access Journals (Sweden)

    Roberto Scarpa

    2011-06-01

    Full Text Available

    This study performs a detailed reconstruction of the rupture mechanism of the 1980 Campania–Lucania (southern Italy earthquake. This is achieved by relocation of the main event through computation of fault-plane solutions of the aftershocks, P-wave velocity inversion, and analysis of post-seismic ground deformation, which provide an overall picture of the faulting mechanism. All of these data are in favor of a complex rupture mechanism, as already identified by many studies, which consists of three separate events. The present study defines a graben-like rupture, with the first event rupturing a (>20-km-long segment of a large, high-angle, NE-dipping, SE-NW-striking, normal fault. The two successive ruptures occurred separately, the first along the southern segment, and the second along the northern segment, of a complementary SW-dipping, normal fault. This mechanism is well evidenced by the revised location of the hypocenter of the main event, and the location of the aftershocks and their fault-plane solutions, as well as by the underlying three-dimensional P-wave velocity structure. The model proposed by Amoruso et al. [2005a] that was based on the inversion of co-seismic vertical displacement data is confirmed by the present analyses, as it satisfies all of the available experimental observations, and better constrains the location and fault-plane solutions of the aftershocks, the velocity discontinuities, and the rupture observations at the surface. This conclusion is also supported by analyses of the post-seismic data.

  19. Flow velocity measurement with the nonlinear acoustic wave scattering

    Science.gov (United States)

    Didenkulov, Igor; Pronchatov-Rubtsov, Nikolay

    2015-10-01

    A problem of noninvasive measurement of liquid flow velocity arises in many practical applications. To this end the most often approach is the use of the linear Doppler technique. The Doppler frequency shift of signal scattered from the inhomogeneities distributed in a liquid relatively to the emitted frequency is proportional to the sound frequency and velocities of inhomogeneities. In the case of very slow flow one needs to use very high frequency sound. This approach fails in media with strong sound attenuation because acoustic wave attenuation increases with frequency and there is limit in increasing sound intensity, i.e. the cavitation threshold. Another approach which is considered in this paper is based on the method using the difference frequency Doppler Effect for flows with bubbles. This method is based on simultaneous action of two high-frequency primary acoustic waves with closed frequencies on bubbles and registration of the scattered by bubbles acoustic field at the difference frequency. The use of this method is interesting since the scattered difference frequency wave has much lower attenuation in a liquid. The theoretical consideration of the method is given in the paper. The experimental examples confirming the theoretical equations, as well as the ability of the method to be applied in medical diagnostics and in technical applications on measurement of flow velocities in liquids with strong sound attenuation is described. It is shown that the Doppler spectrum form depends on bubble concentration velocity distribution in the primary acoustic beams crossing zone that allows one to measure the flow velocity distribution.

  20. Flow velocity measurement with the nonlinear acoustic wave scattering

    Energy Technology Data Exchange (ETDEWEB)

    Didenkulov, Igor, E-mail: din@appl.sci-nnov.ru [Institute of Applied Physics, 46 Ulyanov str., Nizhny Novgorod, 603950 (Russian Federation); Lobachevsky State University of Nizhny Novgorod, 23 Gagarin ave., Nizhny Novgorod, 603950 (Russian Federation); Pronchatov-Rubtsov, Nikolay, E-mail: nikvas@rf.unn.ru [Lobachevsky State University of Nizhny Novgorod, 23 Gagarin ave., Nizhny Novgorod, 603950 (Russian Federation)

    2015-10-28

    A problem of noninvasive measurement of liquid flow velocity arises in many practical applications. To this end the most often approach is the use of the linear Doppler technique. The Doppler frequency shift of signal scattered from the inhomogeneities distributed in a liquid relatively to the emitted frequency is proportional to the sound frequency and velocities of inhomogeneities. In the case of very slow flow one needs to use very high frequency sound. This approach fails in media with strong sound attenuation because acoustic wave attenuation increases with frequency and there is limit in increasing sound intensity, i.e. the cavitation threshold. Another approach which is considered in this paper is based on the method using the difference frequency Doppler Effect for flows with bubbles. This method is based on simultaneous action of two high-frequency primary acoustic waves with closed frequencies on bubbles and registration of the scattered by bubbles acoustic field at the difference frequency. The use of this method is interesting since the scattered difference frequency wave has much lower attenuation in a liquid. The theoretical consideration of the method is given in the paper. The experimental examples confirming the theoretical equations, as well as the ability of the method to be applied in medical diagnostics and in technical applications on measurement of flow velocities in liquids with strong sound attenuation is described. It is shown that the Doppler spectrum form depends on bubble concentration velocity distribution in the primary acoustic beams crossing zone that allows one to measure the flow velocity distribution.

  1. High-resolution land topography

    Science.gov (United States)

    Massonnet, Didier; Elachi, Charles

    2006-11-01

    After a description of the background, methods of production and some scientific uses of high-resolution land topography, we present the current status and the prospect of radar interferometry, regarded as one of the best techniques for obtaining the most global and the most accurate topographic maps. After introducing briefly the theoretical aspects of radar interferometry - principles, limits of operation and various capabilities -, we will focus on the topographic applications that resulted in an almost global topographic map of the earth: the SRTM map. After introducing the Interferometric Cartwheel system, we will build on its expected performances to discuss the scientific prospects of refining a global topographic map to sub-metric accuracy. We also show how other fields of sciences such as hydrology may benefit from the products generated by interferometric radar systems. To cite this article: D. Massonnet, C. Elachi, C. R. Geoscience 338 (2006).

  2. Measurement uncertainty budget of an interferometric flow velocity sensor

    Science.gov (United States)

    Bermuske, Mike; Büttner, Lars; Czarske, Jürgen

    2017-06-01

    Flow rate measurements are a common topic for process monitoring in chemical engineering and food industry. To achieve the requested low uncertainties of 0:1% for flow rate measurements, a precise measurement of the shear layers of such flows is necessary. The Laser Doppler Velocimeter (LDV) is an established method for measuring local flow velocities. For exact estimation of the flow rate, the flow profile in the shear layer is of importance. For standard LDV the axial resolution and therefore the number of measurement points in the shear layer is defined by the length of the measurement volume. A decrease of this length is accompanied by a larger fringe distance variation along the measurement axis which results in a rise of the measurement uncertainty for the flow velocity (uncertainty relation between spatial resolution and velocity uncertainty). As a unique advantage, the laser Doppler profile sensor (LDV-PS) overcomes this problem by using two fan-like fringe systems to obtain the position of the measured particles along the measurement axis and therefore achieve a high spatial resolution while it still offers a low velocity uncertainty. With this technique, the flow rate can be estimated with one order of magnitude lower uncertainty, down to 0: