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Sample records for range seismic measurements

  1. Upper limit on a stochastic background of gravitational waves from seismic measurements in the range 0.05-1 Hz.

    Science.gov (United States)

    Coughlin, Michael; Harms, Jan

    2014-03-14

    In this Letter, we present an upper limit of ΩGWgravitational-wave (GW) background integrated over a year in the frequency range 0.05-1 Hz, which improves current upper limits from high-precision laboratory experiments by about 9 orders of magnitude. The limit is obtained using the response of Earth itself to GWs via a free-surface effect described more than 40 years ago by Dyson. The response was measured by a global network of broadband seismometers selected to maximize the sensitivity.

  2. SEG Advances in Rotational Seismic Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Pierson, Robert; Laughlin, Darren; Brune, Bob

    2016-10-17

    Significant advancements in the development of sensors to enable rotational seismic measurements have been achieved. Prototypes are available now to support experiments that help validate the utility of rotational seismic measurements.

  3. Nevada Test Site seismic: telemetry measurements

    Energy Technology Data Exchange (ETDEWEB)

    Albright, J N; Parker, L E; Horton, E H

    1983-08-01

    The feasibility and limitations of surface-to-tunnel seismic telemetry at the Nevada Test Site were explored through field measurements using current technology. Range functions for signaling were determined through analysis of monofrequency seismic signals injected into the earth at various sites as far as 70 km (43 mi) from installations of seismometers in the G-Tunnel complex of Rainier Mesa. Transmitted signal power at 16, 24, and 32 Hz was measured at two locations in G-Tunnel separated by 670 m (2200 ft). Transmissions from 58 surface sites distributed primarily along three azimuths from G-Tunnel were studied. The G-Tunnel noise environment was monitored over the 20-day duration of the field tests. Noise-power probability functions were calculated for 20-s and 280-s seismic-record populations. Signaling rates were calculated for signals transmitted from superior transmitter sites to G-Tunnel. A detection threshold of 13 dB re 1 nm/sup 2/ displacement power at 95% reliability was demanded. Consideration of field results suggests that even for the frequency range used in this study, substantially higher signaling rates are likely to be obtained in future work in view of the present lack of information relevant to hardware-siting criteria and the seismic propagation paths at the Nevada Test Site. 12 references.

  4. Advances in Rotational Seismic Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Pierson, Robert [Applied Technology Associates, Albuquerque, NM (United States); Laughlin, Darren [Applied Technology Associates, Albuquerque, NM (United States); Brune, Robert [Applied Technology Associates, Albuquerque, NM (United States)

    2016-10-19

    Rotational motion is increasingly understood to be a significant part of seismic wave motion. Rotations can be important in earthquake strong motion and in Induced Seismicity Monitoring. Rotational seismic data can also enable shear selectivity and improve wavefield sampling for vertical geophones in 3D surveys, among other applications. However, sensor technology has been a limiting factor to date. The US Department of Energy (DOE) and Applied Technology Associates (ATA) are funding a multi-year project that is now entering Phase 2 to develop and deploy a new generation of rotational sensors for validation of rotational seismic applications. Initial focus is on induced seismicity monitoring, particularly for Enhanced Geothermal Systems (EGS) with fracturing. The sensors employ Magnetohydrodynamic (MHD) principles with broadband response, improved noise floors, robustness, and repeatability. This paper presents a summary of Phase 1 results and Phase 2 status.

  5. Stress-Release Seismic Source for Seismic Velocity Measurement in Mines

    Science.gov (United States)

    Swanson, P. L.; Clark, C.; Richardson, J.; Martin, L.; Zahl, E.; Etter, A.

    2014-12-01

    Accurate seismic event locations are needed to delineate roles of mine geometry, stress and geologic structures in developing rockburst conditions. Accurate absolute locations are challenging in mine environments with rapid changes in seismic velocity due to sharp contrasts between individual layers and large time-dependent velocity gradients attending excavations. Periodic use of controlled seismic sources can help constrain the velocity in this continually evolving propagation medium comprising the miners' workplace. With a view to constructing realistic velocity models in environments in which use of explosives is problematic, a seismic source was developed subject to the following design constraints: (i) suitable for use in highly disturbed zones surrounding mine openings, (ii) able to produce usable signals over km-scale distances in the frequency range of typical coal mine seismic events (~10-100 Hz), (iii) repeatable, (iv) portable, (v) non-disruptive to mining operations, and (vi) safe for use in potentially explosive gaseous environments. Designs of the compressed load column seismic source (CLCSS), which generates a stress, or load, drop normal to the surface of mine openings, and the fiber-optic based source-initiation timer are presented. Tests were conducted in a coal mine at a depth of 500 m (1700 ft) and signals were recorded on the surface with a 72-ch (14 Hz) exploration seismograph for load drops of 150-470 kN (16-48 tons). Signal-to-noise ratios of unfiltered signals ranged from ~200 immediately above the source (500 m (1700 ft)) to ~8 at the farthest extent of the array (slant distance of ~800 m (2600 ft)), suggesting the potential for use over longer range. Results are compared with signals produced by weight drop and sledge hammer sources, indicating the superior waveform quality for first-arrival measurements with the CLCSS seismic source.

  6. Seismic switch for strong motion measurement

    Energy Technology Data Exchange (ETDEWEB)

    Harben, Philip E. (Oakley, CA); Rodgers, Peter W. (Santa Barbara, CA); Ewert, Daniel W. (Patterson, CA)

    1995-01-01

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

  7. Laboratory measurements of seismic velocity anisotropy of salt diapirs: Implications for wellbore stability and seismic processing

    Science.gov (United States)

    Vargas-Meleza, Liliana; Healy, David

    2013-04-01

    A set of ten evaporite samples collected from outcrops in a single diapiric province in Cape Breton Island (Canada) have been tested for seismic velocity anisotropy using three methods: 1) conventional ultrasonic pulse transmission method, where velocities are found from the travel times and the known dimensions of the samples. In order to obtain the entire suite of elastic constants, both P- and S-wave velocity measurements were taken in three different directions of cuboid rock samples. Velocities have been measured under dry, ambient conditions of temperature and pressure in halite-, gypsum- and anhydrite-dominated samples; 2) optical microscopy and scanning electron microscopy on thin sections to define the spatial distribution of minerals, their crystallographic preferred orientations (CPO); and 3) a numerical 'rock-recipe' approach based on Tatham et al. (2008) to calculate seismic velocity anisotropy using arbitrary composites of evaporite minerals and different CPOs. These three methods are then compared to understand the controlling factors of the anisotropic elastic properties. The elasticity data are used to guide geomechanical modeling for wellbore stability and to provide insights for the seismic data processing and seismic imaging of salt diapirs. Reference Tatham, D.J., Lloyd, G.E., Butler, R.W.H. and Casey, M, 2008, Amphibole and lower crustal seismic properties: Earth and Planetary Science Letters, 267, 118-128.

  8. Considering the ranges of uncertainties in the New Probabilistic Seismic Hazard Assessment of Germany - Version 2016

    Science.gov (United States)

    Grunthal, Gottfried; Stromeyer, Dietrich; Bosse, Christian; Cotton, Fabrice; Bindi, Dino

    2017-04-01

    The seismic load parameters for the upcoming National Annex to the Eurocode 8 result from the reassessment of the seismic hazard supported by the German Institution for Civil Engineering . This 2016 version of hazard assessment for Germany as target area was based on a comprehensive involvement of all accessible uncertainties in models and parameters into the approach and the provision of a rational framework for facilitating the uncertainties in a transparent way. The developed seismic hazard model represents significant improvements; i.e. it is based on updated and extended databases, comprehensive ranges of models, robust methods and a selection of a set of ground motion prediction equations of their latest generation. The output specifications were designed according to the user oriented needs as suggested by two review teams supervising the entire project. In particular, seismic load parameters were calculated for rock conditions with a vS30 of 800 ms-1 for three hazard levels (10%, 5% and 2% probability of occurrence or exceedance within 50 years) in form of, e.g., uniform hazard spectra (UHS) based on 19 sprectral periods in the range of 0.01 - 3s, seismic hazard maps for spectral response accelerations for different spectral periods or for macroseismic intensities. The developed hazard model consists of a logic tree with 4040 end branches and essential innovations employed to capture epistemic uncertainties and aleatory variabilities. The computation scheme enables the sound calculation of the mean and any quantile of required seismic load parameters. Mean, median and 84th percentiles of load parameters were provided together with the full calculation model to clearly illustrate the uncertainties of such a probabilistic assessment for a region of a low-to-moderate level of seismicity. The regional variations of these uncertainties (e.g. ratios between the mean and median hazard estimations) were analyzed and discussed.

  9. Ambient seismic noise interferometry in Hawai'i reveals long-range observability of volcanic tremor

    Science.gov (United States)

    Ballmer, Silke; Wolfe, Cecily; Okubo, Paul G.; Haney, Matt; Thurber, Clifford H.

    2013-01-01

    The use of seismic noise interferometry to retrieve Green's functions and the analysis of volcanic tremor are both useful in studying volcano dynamics. Whereas seismic noise interferometry allows long-range extraction of interpretable signals from a relatively weak noise wavefield, the characterization of volcanic tremor often requires a dense seismic array close to the source. We here show that standard processing of seismic noise interferometry yields volcanic tremor signals observable over large distances exceeding 50 km. Our study comprises 2.5 yr of data from the U.S. Geological Survey Hawaiian Volcano Observatory short period seismic network. Examining more than 700 station pairs, we find anomalous and temporally coherent signals that obscure the Green's functions. The time windows and frequency bands of these anomalous signals correspond well with the characteristics of previously studied volcanic tremor sources at Pu'u 'Ō'ō and Halema'uma'u craters. We use the derived noise cross-correlation functions to perform a grid-search for source location, confirming that these signals are surface waves originating from the known tremor sources. A grid-search with only distant stations verifies that useful tremor signals can indeed be recovered far from the source. Our results suggest that the specific data processing in seismic noise interferometry—typically used for Green's function retrieval—can aid in the study of both the wavefield and source location of volcanic tremor over large distances. In view of using the derived Green's functions to image heterogeneity and study temporal velocity changes at volcanic regions, however, our results illustrate how care should be taken when contamination by tremor may be present.

  10. Measurements of Superattenuator seismic isolation by Virgo interferometer

    NARCIS (Netherlands)

    Acernese, F.; Bulten, H.J.; Rabeling, D.S.; van den Brand, J.F.J.; Bauer, Th. S.; Beker, M.G.; Li, T.G.F.; van der Putten, S.

    2010-01-01

    Each mirror of the interferometric gravitational wave antenna Virgo is attached to a Superattenuator, a chain of mechanical filters designed to suppress seismic vibrations, starting from a few Hz. The filter chain attenuation has been measured by exciting its suspension point with sinuisodal forces

  11. Radar range measurements in the atmosphere.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2013-02-01

    The earths atmosphere affects the velocity of propagation of microwave signals. This imparts a range error to radar range measurements that assume the typical simplistic model for propagation velocity. This range error is a function of atmospheric constituents, such as water vapor, as well as the geometry of the radar data collection, notably altitude and range. Models are presented for calculating atmospheric effects on radar range measurements, and compared against more elaborate atmospheric models.

  12. Characterization of Unstable Rock Slopes Through Passive Seismic Measurements

    Science.gov (United States)

    Kleinbrod, U.; Burjanek, J.; Fäh, D.

    2014-12-01

    Catastrophic rock slope failures have high social impact, causing significant damage to infrastructure and many casualties throughout the world each year. Both detection and characterization of rock instabilities are therefore of key importance. An analysis of ambient vibrations of unstable rock slopes might be a new alternative to the already existing methods, e.g. geotechnical displacement measurements. Systematic measurements have been performed recently in Switzerland to study the seismic response of potential rockslides concerning a broad class of slope failure mechanisms and material conditions. Small aperture seismic arrays were deployed at sites of interest for a short period of time (several hours) in order to record ambient vibrations. Each measurement setup included a reference station, which was installed on a stable part close to the instability. Recorded ground motion is highly directional in the unstable parts of the rock slope, and significantly amplified with respect to stable areas. These effects are strongest at certain frequencies, which were identified as eigenfrequencies of the unstable rock mass. In most cases the directions of maximum amplification are perpendicular to open cracks and in good agreement with the deformation directions obtained by geodetic measurements. Such unique signatures might improve our understanding of slope structure and stability. Thus we link observed vibration characteristics with available results of detailed geological characterization. This is supported by numerical modeling of seismic wave propagation in fractured media with complex topography.For example, a potential relation between eigenfrequencies and unstable rock mass volume is investigated.

  13. In situ seismic measurements in claystone at Tournemire (France)

    Science.gov (United States)

    Zillmer, M.; Marthelot, J.-M.; Gélis, C.; Cabrera, J.; Druivenga, G.

    2014-12-01

    Compressional and shear wave seismic measurements were performed in an old railway tunnel and in galleries excavated in a 250-m-thick Toarcian claystone formation in the Tournemire experimental station (France). Three component (3C) geophones and three orthogonal orientations of the vibroseismic force source were used. Additionally, vertical seismic profiling (VSP) measurements were recorded with a 3C borehole geophone, a hydrophone and a microphone in a 159 m deep borehole (ID180) in the tunnel. The seismic data show that Toarcian claystone has strong transverse isotropy (TI) with a vertical symmetry axis. The qP, SH and qSV wave propagation velocities in horizontal directions-the plane of isotropy of the TI medium-are measured as 3550, 1850 and 1290 m s-1, respectively. The zero-offset VSP reveals that only one shear wave propagates in the vertical (depth) direction and the P- and S-wave velocities are 3100 and 1375 m s-1, respectively. Four elastic moduli of the TI medium are determined from the seismic velocities and from the bulk density of 2.53 g cm-3: c11 = 31.9 GPa, c33 = 24.3 GPa, c44 = 4.5 GPa and c66 = 8.7 GPa. A walkaway VSP with the borehole geophone at 50 m depth in borehole ID180 and shot points in the galleries leads to oblique seismic ray paths which allow us to determine the fifth elastic modulus of the TI medium to c13 = 16 GPa. The tube wave recorded by a hydrophone in the water filled lower part of the borehole propagates with 1350 m s-1, which confirms the estimate of the elastic constant c66. The analysis of body wave and surface wave data from a seismic experiment in Galerie Est shows reflections from several fracture zones in the gallery floor. The thickness of the excavation damaged zone (EDZ) in the floor of Galerie Est is estimated to 0.7 m.

  14. Integration of HVSR measures and stratigraphic constraints for seismic microzonation studies: the case of Oliveri (ME)

    Science.gov (United States)

    Di Stefano, P.; Luzio, D.; Renda, P.; Martorana, R.; Capizzi, P.; D'Alessandro, A.; Messina, N.; Napoli, G.; Todaro, S.; Zarcone, G.

    2014-04-01

    Because of its high seismic hazard the urban area of Oliveri has been subject of first level seismic microzonation. The town develops on a large coastal plain made of mixed fluvial/marine sediments, overlapping a complexly deformed substrate. In order to identify points on the area probably suffering relevant site effects and define a preliminary Vs subsurface model for the first level of microzonation, we performed 23 HVSR measurements. A clustering technique of continuous signals has been used to optimize the calculation of the HVSR curves. 42 reliable peaks of the H/V spectra in the frequency range 0.6-10 Hz have been identified. A second clustering technique has been applied to the set of 42 vectors, containing Cartesian coordinates, central frequency and amplitude of each peak to identify subsets which can be attributed to continuous spatial phenomena. The algorithm has identified three main clusters that cover significant parts of the territory of Oliveri. The HVSR data inversion has been constrained by stratigraphic data of a borehole. To map the trend of the roof of the seismic bedrock, from the complete set of model parameters only the depth of the seismic interface that generates peaks fitting those belonging to two clusters characterized by lower frequency has been extracted. The reconstructed trend of the top of the seismic bedrock highlight its deepening below the mouth of the Elicona Torrent, thus suggesting the possible presence of a buried paleo-valley.

  15. Compact ranges in antenna and RCS measurements

    Science.gov (United States)

    Audone, B.

    1989-09-01

    With the increased complexity and extended frequency range of operation model measurements and far field test ranges are no longer suitable to satisfy the demand of accurate testing. Moreover plane wave test conditions are required for Radar Cross Section (RCS) measurements which represent a key point in stealth technology. Compact ranges represent the best test facilities available presently since they allow for indoor measurements under far field conditions in real time without any calculation effort. Several types of compact ranges are described and compared discussing their relevant advantages with regard to RCS and antenna measurements. In parallel to measuring systems sophisticated computer models were developed with such a high level of accuracy that it is questionable whether experiments give better results than theory. Tests performed on simple structures show the correlation between experimental results and theoretical ones derived on the basis of GTD computer codes.

  16. Review of sensors for low frequency seismic vibration measurement

    CERN Document Server

    Collette, C; Janssens, S; Artoos, K; Guinchard, M; Hauviller, C

    2011-01-01

    The objective of this report is to review the main different types of sensors used to measure seismic vibrations at low frequencies. After some basic background preliminaries, the main different types of relative measurements are first reviewed. Then, the following inertial sensors are treated: geophones, accelerometers and broadband seismometers. For each of these sensors, the basic working principle is explained, along with the main performances limitations. Each section ends with a tentative comparison of some commercial products, far from being exhaustive, but hopefully representative of the average characteristics of each family of sensors. The report finishes with a brief discussion on the modelling and measurement of the sensor noise

  17. Seismic imaging of the shallow subsurface with high frequency seismic measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kaelin, Bruno [Univ. of California, Berkeley, CA (United States). Dept. of Geology and Geophysics

    1998-07-01

    Elastic wave propagation in highly heterogeneous media is investigated and theoretical calculations and field measurements are presented. In the first part the dynamic composite elastic medium (DYCEM) theory is derived for one-dimensional stratified media. A self-consistent method using the scattering functions of the individual layers is formulated, which allows the calculation of phase velocity, attenuation and waveform. In the second part the DYCEM theory has been generalized for three-dimensional inclusions. The specific case of spherical inclusions is calculated with the exact scattering functions and compared with several low frequency approximations. In the third part log and VSP data of partially water saturated tuffs in the Yucca Mountain region of Nevada are analyzed. The anomalous slow seismic velocities can be explained by combining self-consistent theories for pores and cracks. The fourth part analyzes an air injection experiment in a shallow fractured limestone, which has shown large effects on the amplitude, but small effects on the travel time of the transmitted seismic waves. The large amplitude decrease during the experiment is mainly due to the impedance contrast between the small velocities of gas-water mixtures inside the fracture and the formation. The slow velocities inside the fracture allow an estimation of aperture and gas concentration profiles.

  18. Upper Mississippi embayment shallow seismic velocities measured in situ

    Science.gov (United States)

    Liu, Huaibao P.; Hu, Y.; Dorman, J.; Chang, T.-S.; Chiu, J.-M.

    1997-01-01

    for shallow sediment obtained from reflection, refraction, crosshole and downhole techniques have been obtained for sites at the northern end of the embayment basin. The present borehole data, however, are measured from sites representative of large areas in the Mississippi embayment. Therefore, they fill a gap in information needed for modeling the response of the embayment to destructive seismic shaking.

  19. ATTENUATION OF SEISMIC WAVES IN THE LITHOSPHERE OF THE NORTHERN PART OF THE BASIN AND RANGE PROVINCE

    Directory of Open Access Journals (Sweden)

    А. А. Dobrynina

    2013-01-01

    Full Text Available This paper presents results of the study of attenuation of seismic waves in the lithosphere and upper mantle of the northern part of the Basin and Range Province (BRP (Fig. 1. In this study, the coda-wave method [Aki, Chouet, 1975] is applied to process data collected in the seismic experiment conducted in 1988–1989, PASSCAL Basin and Range Passive Seismic Experiment [Owens, Randall, 1989], including records of 66 earthquakes and explosions (Mb=1.1–5.0 which occurred in BRP (Fig. 2.The effective seismic quality factor by the coda is calculated using the single-backscattering model [Aki, Chouet, 1975]. The QC values are calculated for 18 values of the lapse time window W from 10 to 95 sec with the step of 5 sec at six (6 central frequencies (0.3, 0.75, 1.5, 3.0, 6.0, and 12.0 Hz. In total, 7776 individual measurements of QC were done. It is observed that the quality factor QC is strongly dependent on the frequency and the lapse time window W: QC increases from 12±6 to 359±17 for the central frequencies of 0.3 and 12.0 Hz when the lapse time window is W=10 sec and from 87±6 to 1177±87 for the same frequencies when W=95 sec (Fig. 6. On the basis of the QС values obtained for all the lapse time windows W empirical relationships of quality factors and frequencies are calculated according to [Mitchell, 1981], and values of quality factor Q0 at reference frequency f0 (f0=1 Hz and frequency parameter n (which is close to 1 and varies depending on the heterogeneity of the medium [Aki, 1981] are obtained. In this study, Q0 varies from 60±8 to 222±17, the frequency parameter ranges from 0.57±0.04 to 0.84±0.05, and the attenuation coefficient δ varies from 0.015 to 0.004 km–1, depending on W (Fig. 8; similar values of attenuation parameters are typical of regions with high tectonic activity [Mak et al., 2004].In the single-backscattering model, the dependence of the attenuation parameters from the lapse time window can be explained in terms

  20. The Global Detection Capability of the IMS Seismic Network in 2013 Inferred from Ambient Seismic Noise Measurements

    Science.gov (United States)

    Gaebler, P. J.; Ceranna, L.

    2016-12-01

    All nuclear explosions - on the Earth's surface, underground, underwater or in the atmosphere - are banned by the Comprehensive Nuclear-Test-Ban Treaty (CTBT). As part of this treaty, a verification regime was put into place to detect, locate and characterize nuclear explosion testings at any time, by anyone and everywhere on the Earth. The International Monitoring System (IMS) plays a key role in the verification regime of the CTBT. Out of the different monitoring techniques used in the IMS, the seismic waveform approach is the most effective technology for monitoring nuclear underground testing and to identify and characterize potential nuclear events. This study introduces a method of seismic threshold monitoring to assess an upper magnitude limit of a potential seismic event in a certain given geographical region. The method is based on ambient seismic background noise measurements at the individual IMS seismic stations as well as on global distance correction terms for body wave magnitudes, which are calculated using the seismic reflectivity method. From our investigations we conclude that a global detection threshold of around mb 4.0 can be achieved using only stations from the primary seismic network, a clear latitudinal dependence for the detection thresholdcan be observed between northern and southern hemisphere. Including the seismic stations being part of the auxiliary seismic IMS network results in a slight improvement of global detection capability. However, including wave arrivals from distances greater than 120 degrees, mainly PKP-wave arrivals, leads to a significant improvement in average global detection capability. In special this leads to an improvement of the detection threshold on the southern hemisphere. We further investigate the dependence of the detection capability on spatial (latitude and longitude) and temporal (time) parameters, as well as on parameters such as source type and percentage of operational IMS stations.

  1. Deep crustal structure of the Cascade Range and surrounding regions from seismic refraction and magnetotelluric data

    Science.gov (United States)

    Stanley, W.D.; Mooney, W.D.; Fuis, G.S.

    1990-01-01

    Several regional seismic refraction and magnetotelluric (MT) profiles have been completed across the Cascade Range and surrounding geologic provinces in California, Oregon, and Washington. Analysis of three MT and two seismic refraction profiles in Oregon and a coincident MT and refraction profile in northern California show a high degree of correlation between resistivity and velocity models. The main feature that is evident in both data sets is a highly conductive (2-20 ohm m) zone that occurs at depths of 6-20 km and largely within a midcrustal velocity layer of 6.4-6.6 km/s, overlying a lower crust with velocities of 7.0-7.4 km/s. Accretionary structures in the southern Washington Cascades have been shown to be related to stress release in the area of Mount St. Helens. In order to explain the similar structures in the MT and refraction models for Oregon and California, a model is proposed involving the effects of metamorphic zonation to produce the velocity structure, combined with metamorphically produced fluids and partial melt to produce the deep conductor. -from Authors

  2. Mechanical monolithic sensor for low-frequency seismic noise measurement

    Science.gov (United States)

    Acernese, Fausto; De Rosa, Rosario; Giordano, Gerardo; Romano, Rocco; Barone, Fabrizio

    2007-04-01

    This paper describes a new low-frequency seismic sensor for geophysical applications. The instrument is basically a monolithic tunable folded pendulum with an interferometric readout system, that can be configured as seismometer or as accelerometer. The monolithic mechanical design and the introduction of a laser interferometric technique for the readout implementation make it a very sensitive and compact instrument with a very good immunity to environmental noises. The theoretical sensitivity curve is calculated considering the brownian noise, the readout noise and the data acquisition noise. Preliminary tests on the mechanical performances of the monolithic structure and on the optical readout have been performed. Interesting result is the measured resonant frequency of the instrument of ~ 150mHz obtained with a rough tuning, demonstrating the feasibility of a resonant frequency of the order of 5mHz with a more refined tuning. The transfer function of the folded pendulum in open loop configuration is calculated measuring the resonant frequency and the quality factor for several step responses. Then a PID controller is added to implement the closed loop configuration. The mechanics of the seismic sensor, the optical scheme of the readout system, the theoretical predictions and the preliminary experimental performances as accelerometer are discussed in detail, together with the foreseen further improvements.

  3. Interpretation of a 3D Seismic-Reflection Volume in the Basin and Range, Hawthorne, Nevada

    Science.gov (United States)

    Louie, J. N.; Kell, A. M.; Pullammanappallil, S.; Oldow, J. S.; Sabin, A.; Lazaro, M.

    2009-12-01

    A collaborative effort by the Great Basin Center for Geothermal Energy at the University of Nevada, Reno, and Optim Inc. of Reno has interpreted a 3d seismic data set recorded by the U.S. Navy Geothermal Programs Office (GPO) at the Hawthorne Army Depot, Nevada. The 3d survey incorporated about 20 NNW-striking lines covering an area of approximately 3 by 10 km. The survey covered an alluvial area below the eastern flank of the Wassuk Range. In the reflection volume the most prominent events are interpreted to be the base of Quaternary alluvium, the Quaternary Wassuk Range-front normal fault zone, and sequences of intercalated Tertiary volcanic flows and sediments. Such a data set is rare in the Basin and Range. Our interpretation reveals structural and stratigraphic details that form a basis for rapid development of the geothermal-energy resources underlying the Depot. We interpret a map of the time-elevation of the Wassuk Range fault and its associated splays and basin-ward step faults. The range-front fault is the deepest, and its isochron map provides essentially a map of "economic basement" under the prospect area. There are three faults that are the most readily picked through vertical sections. The fault reflections show an uncertainty in the time-depth that we can interpret for them of 50 to 200 ms, due to the over-migrated appearance of the processing contractor’s prestack time-migrated data set. Proper assessment of velocities for mitigating the migration artifacts through prestack depth migration is not possible from this data set alone, as the offsets are not long enough for sufficiently deep velocity tomography. The three faults we interpreted appear as gradients in potential-field maps. In addition, the southern boundary of a major Tertiary graben may be seen within the volume as the northward termination of the strong reflections from older Tertiary volcanics. Using a transparent volume view across the survey gives a view of the volcanics in full

  4. Long-range correlations and trends in Colombian seismic time series

    CERN Document Server

    Martin-Montoya, L A; Quimbay, C J

    2014-01-01

    We detect long-range correlations and trends in time series extracted from the data of seismic events occurred since 1973 until 2011 in a rectangular region that contain mainly all the continental part of Colombia. The long-range correlations are detected by the calculation of the Hurst exponents for the time series of interevent intervals, separation distances, depth differences and magnitude differences. By using a geometrical modification of the classical R/S method that has been developed to detect long-range correlations in short time series, we find the existence of persistence for all the time series considered. We find also, by using the DFA until the third order, that the time series of interevent intervals, separation distances and depth differences are influenced by quadratic trends, while the time series of magnitude differences is influenced by a linear trend. Finally, for the time series of interevent intervals, we present an analysis of the Hurst exponent as a function of the time and the minim...

  5. Noncontact Measurement and Detection of Instantaneous Seismic Attributes Based on Complementary Ensemble Empirical Mode Decomposition

    Directory of Open Access Journals (Sweden)

    Yaping Huang

    2017-10-01

    Full Text Available Hilbert–Huang transform (HHT is a popular method to analyze nonlinear and non-stationary data. It has been widely used in geophysical prospecting. This paper analyzes the mode mixing problems of empirical mode decomposition (EMD and introduces the noncontact measurement and detection of instantaneous seismic attributes using complementary ensemble empirical mode decomposition (CEEMD. Numerical simulation testing indicates that the CEEMD can effectively solve the mode mixing problems of EMD and can provide stronger anti-noise ability. The decomposed results of the synthetic seismic record show that CEEMD has a better ability to decompose seismic signals. Then, CEEMD is applied to extract instantaneous seismic attributes of 3D seismic data in a real-world coal mine in Inner Mongolia, China. The detection results demonstrate that instantaneous seismic attributes extracted by CEEMD are helpful to effectively identify the undulations of the top interfaces of limestone.

  6. Bridge seismic retrofit measures considering subduction zone earthquakes.

    Science.gov (United States)

    2015-07-01

    Over the years, earthquakes have exposed the vulnerability of reinforced concrete structures under : seismic loads. The recent occurrence of highly devastating earthquakes near instrumented regions, e.g. 2010 Maule, Chile : and 2011 Tohoku, Japan, ha...

  7. Ultrasonic range measurements on the human body

    NARCIS (Netherlands)

    Weenk, D.; van Beijnum, Bernhard J.F.; Droog, Adriaan; Hermens, Hermanus J.; Veltink, Petrus H.

    2013-01-01

    Ambulatory range estimation on the human body is important for the assessment of the performance of upper- and lower limb tasks outside a laboratory. In this paper an ultrasound sensor for estimating ranges on the human body is presented and validated during gait. The distance between the feet is

  8. Mantle seismic anisotropy beneath NE China and implications for the lithospheric delamination hypothesis beneath the southern Great Xing'an range

    Science.gov (United States)

    Chen, Haichao; Niu, Fenglin; Obayashi, Masayuki; Grand, Stephen P.; Kawakatsu, Hitoshi; John Chen, Y.; Ning, Jieyuan; Tanaka, Satoru

    2017-08-01

    We measured shear wave splitting from SKS data recorded by the transcontinental NECESSArray in NE China to constrain lithosphere deformation and sublithospheric flows beneath the area. We selected several hundreds of high quality SKS/SKKS waveforms from 32 teleseismic earthquakes occurring between 09/01/2009 and 08/31/2011 recorded by 125 broadband stations. These stations cover a variety of tectonic terranes, including the Songliao basin, the Changbaishan mountain range and Zhangguancai range in the east, the Great Xing'an range in the west and the Yanshan orogenic belt in the southwest. We assumed each station is underlaid by a single anisotropic layer and employed a signal-to-noise ratio (SNR) weighted multi-event stacking method to estimate the two splitting parameters (the fast polarization direction φ, and delay time, δt) that gives the best fit to all the SKS/SKKS waveforms recorded at each station. Overall, the measured fast polarization direction lies more or less along the NW-SE direction, which significantly differs from the absolute plate motion direction, but is roughly consistent with the regional extension direction. This suggests that lithosphere deformation is likely the general cause of the observed seismic anisotropy. The most complicated anisotropic structure is observed beneath the southern Great Xing'an range and southwest Songliao basin. The observed large variations in splitting parameters and the seismic tomographic images of the area are consistent with ongoing lithospheric delamination beneath this region.

  9. Crustal composition in the Hidaka Metamorphic Belt estimated from seismic velocity by laboratory measurements

    Science.gov (United States)

    Yamauchi, K.; Ishikawa, M.; Sato, H.; Iwasaki, T.; Toyoshima, T.

    2015-12-01

    To understand the dynamics of the lithosphere in subduction systems, the knowledge of rock composition is significant. However, rock composition of the overriding plate is still poorly understood. To estimate rock composition of the lithosphere, it is an effective method to compare the elastic wave velocities measured under the high pressure and temperature condition with the seismic velocities obtained by active source experiment and earthquake observation. Due to an arc-arc collision in central Hokkaido, middle to lower crust is exposed along the Hidaka Metamorphic Belt (HMB), providing exceptional opportunities to study crust composition of an island arc. Across the HMB, P-wave velocity model has been constructed by refraction/wide-angle reflection seismic profiling (Iwasaki et al., 2004). Furthermore, because of the interpretation of the crustal structure (Ito, 2000), we can follow a continuous pass from the surface to the middle-lower crust. We corrected representative rock samples from HMB and measured ultrasonic P-wave (Vp) and S-wave velocities (Vs) under the pressure up to 1.0 GPa in a temperature range from 25 to 400 °C. For example, the Vp values measured at 25 °C and 0.5 GPa are 5.88 km/s for the granite (74.29 wt.% SiO2), 6.02-6.34 km/s for the tonalites (66.31-68.92 wt.% SiO2), 6.34 km/s for the gneiss (64.69 wt.% SiO2), 6.41-7.05 km/s for the amphibolites (50.06-51.13 wt.% SiO2), and 7.42 km/s for the mafic granulite (50.94 wt.% SiO2). And, Vp of tonalites showed a correlation with SiO2 (wt.%). Comparing with the velocity profiles across the HMB (Iwasaki et al., 2004), we estimate that the lower to middle crust consists of amphibolite and tonalite, and the estimated acoustic impedance contrast between them suggests an existence of a clear reflective boundary, which accords well to the obtained seismic reflection profile (Iwasaki et al., 2014). And, we can obtain the same tendency from comparing measured Vp/Vs ratio and Vp/Vs ratio structure model

  10. An Interpretation of Results from Seismic Measurements on SLIAÈ Airport

    Directory of Open Access Journals (Sweden)

    Pandula Blažej

    2004-12-01

    Full Text Available A knowledge obtained during the survey of runways and examination of the airport asphalt pavement structure by non-destructive methods is presented in this paper. The theoretical problem and the problem of application of selected geophysical methods for the determination of real conditions of the runway are solved. From the geological-engineering aspect is determined the disturbance of the rock environment. A possible complex approach to the evaluation of of disturbance of runway subgrade by seismic and seismo-acoustic methods is also presented.

  11. Kinematics of active deformation across the Western Kunlun mountain range (Xinjiang, China), and potential seismic hazards within the southern Tarim Basin

    DEFF Research Database (Denmark)

    Guilbaud, Christelle; Simoes, Martine; Barrier, Laurie

    2017-01-01

    The Western Kunlun mountain range is a slowly converging intra-continental orogen where deformation rates are too low to be properly quantified from geodetic techniques. This region has recorded little seismicity, but the recent July 2015 (Mw 6.4) Pishan earthquake shows that this mountain range...... remains seismic. To quantify the rate of active deformation and the potential for major earthquakes in this region, we combine a structural and quantitative morphological analysis of the Yecheng-Pishan fold, along the topographic mountain front in the epicentral area. Using a seismic profile, we derive...

  12. New insights of seismic disturbances due to wind turbines - long and short term measurements in SW Germany

    Science.gov (United States)

    Zieger, Toni; Ritter, Joachim

    2017-04-01

    Within the scope of the project "TremAc", we present new insights of ground motion disturbances due to wind turbines (WTs) in the vicinity of the town of Landau, SW Germany. The main goal of this project, which is funded by the German Federal Ministry for Economic Affairs and Energy, is the detection of influences from WTs on human health and buildings in an interdisciplinary way. The interaction between WTs, humans, infrastructure (incl.seismic stations) becomes more and more an important role with the increase of installed WTs. We present averaged one hour long PSD-spectra in a frequency range from 0.5 Hz to 7 Hz depending on the wind speed before and after the installation of characteristic WTs, especially for seismic borehole stations, during one month measurements. The results show a clear increase of the ground motion and a related disturbance of the seismic recordings. The station threshold for signal detection below 2 Hz is reduced after the installation of a new wind farm in the area around Landau. This effect occurs even up to distances to the WTs of more than 5 kilometers. The increasing noise level depends also clearly on wind speed, which indicate also the WT origin related with the signals. Using short-term measurements during few hours, we are able to determine the maximum of the PSD values for different discrete frequencies as function of distance to the next WT and to fit a power-law decay curve proportional to 1/rb to the data. In this way we can differentiate between near- and far-field effects of the seismic wave propagation of WTs. A clear frequency dependent decay can be observed, for which high frequencies are more attenuated than lower frequencies, probably due to scattering processes. The new results will help for a better understanding of WTs as a seismic noise source and their interaction with nearby seismic stations and other infrastructure. Seismic data were provided by "Erdbebendienst Südwest", "Federal Institute for Geosciences and

  13. New inferences from spectral seismic energy measurement of a link between regional seismicity and volcanic activity at Mt. Etna, Italy

    Science.gov (United States)

    Ortiz, R.; Falsaperla, S.; Marrero, J. M.; Messina, A.

    2009-04-01

    The existence of a relationship between regional seismicity and changes in volcanic activity has been the subject of several studies in the last years. Generally, activity in basaltic volcanoes such as Villarica (Chile) and Tungurahua (Ecuador) shows very little changes after the occurrence of regional earthquakes. In a few cases volcanic activity has changed before the occurrence of regional earthquakes, such as observed at Teide, Tenerife, in 2004 and 2005 (Tárraga et al., 2006). In this paper we explore the possible link between regional seismicity and changes in volcanic activity at Mt. Etna in 2006 and 2007. On 24 November, 2006 at 4:37:40 GMT an earthquake of magnitude 4.7 stroke the eastern coast of Sicily. The epicenter was localized 50 km SE of the south coast of the island, and at about 160 km from the summit craters of Mt. Etna. The SSEM (Spectral Seismic Energy Measurement) of the seismic signal at stations at 1 km and 6 km from the craters highlights that four hours before this earthquake the energy associated with volcanic tremor increased, reached a maximum, and finally became steady when the earthquake occurred. Conversely, neither before nor after the earthquake, the SSEM of stations located between 80 km and 120 km from the epicentre and outside the volcano edifice showed changes. On 5 September, 2007 at 21:24:13 GMT an earthquake of magnitude 3.2 and 7.9 km depth stroke the Lipari Island, at the north of Sicily. About 38 hours before the earthquake occurrence, there was an episode of lava fountain lasting 20 hours at Etna volcano. The SSEM of the seismic signal recorded during the lava fountain at a station located at 6 km from the craters highlights changes heralding this earthquake ten hours before its occurrence using the FFM method (e.g., Voight, 1988; Ortiz et al., 2003). A change in volcanic activity - with the onset of ash emission and Strombolian explosions - was observed a couple of hours before the occurrence of the regional

  14. Seismic anisotropy inferred from direct S-wave-derived splitting measurements and its geodynamic implications beneath southeastern Tibetan Plateau

    Science.gov (United States)

    Kant Tiwari, Ashwani; Singh, Arun; Eken, Tuna; Singh, Chandrani

    2017-04-01

    The present study deals with detecting seismic anisotropy parameters beneath southeastern Tibet near Namcha Barwa Mountain using the splitting of direct S waves. We employ the reference station technique to remove the effects of source-side anisotropy. Seismic anisotropy parameters, splitting time delays, and fast polarization directions are estimated through analyses of a total of 501 splitting measurements obtained from direct S waves from 25 earthquakes ( ≥ 5.5 magnitude) that were recorded at 42 stations of the Namcha Barwa seismic network. We observe a large variation in time delays ranging from 0.64 to 1.68 s, but in most cases, it is more than 1 s, which suggests a highly anisotropic lithospheric mantle in the region. A comparison between direct S- and SKS-derived splitting parameters shows a close similarity, although some discrepancies exist where null or negligible anisotropy has been reported earlier using SKS. The seismic stations with hitherto null or negligible anisotropy are now supplemented with new measurements with clear anisotropic signatures. Our analyses indicate a sharp change in lateral variations of fast polarization directions (FPDs) from consistent SSW-ENE or W-E to NW-SE direction at the southeastern edge of Tibet. Comparison of the FPDs with Global Positioning System (GPS) measurements, absolute plate motion (APM) directions, and surface geological features indicates that the observed anisotropy and hence inferred deformation patterns are not only due to asthenospheric dynamics but are a combination of lithospheric deformation and sub-lithospheric (asthenospheric) mantle dynamics. Direct S-wave-based station-averaged splitting measurements with increased back-azimuths tend to fill the coverage gaps left in SKS measurements.

  15. Ultrasonic Measurements of Unconsolidated Saline Sediments During Freeze/Thaw Cycles: The Seismic Properties of Cryopeg Environments

    Science.gov (United States)

    Dou, S.; Ajo Franklin, J. B.

    2013-12-01

    Saline permafrost and cryopegs (hypersaline unfrozen layers/zones within permafrost) are widespread in the Arctic coastal area as a result of marine transgression and regression in recent geological history. Owing to the freezing-point depression effect of soluble salts, they contain more unfrozen water than non-saline frozen sediments when subjected to the same permafrost temperatures (e.g., from 0 to -15 °C). Mapping subsurface cryopeg structure remains a challenging geophysical task due to the poor penetration of GPR in highly conductive fluids and related limitations for lower frequency EM techniques. Seismic profiling, particularly surface wave characterization, provides one possible approach to delineate the extent of cryopeg bodies. However, interpretation of such surveys is currently limited by the sparse database of measurements examining the seismic properties of unconsolidated materials saturated with saline fluids at sub-zero temperatures. We present the results of experiments examining seismic velocity in the ultrasonic range for both synthetic and natural permafrost sediments during freeze/thaw cycles; in these experiments, use of a range of brine salinities allows us to evaluate the properties of cryopeg sediments at in-situ conditions, a prerequisite for quantitative interpretation of seismic imaging results. Because of the abundant unfrozen water and less developed inter-granular ice structure, the seismic properties of saline permafrost typically falls between frozen and unfrozen soils. We conducted ultrasonic measurements of a freeze-thaw cycle on 20-30 Ottawa sand (grain size 590-840 μm) as well as natural mineral soils from the Barrow Environmental Observatory (BEO) saturated with brines of different salinities (0-2.5 M NaCl). For each salinity, seismic properties were measured using the ultrasonic (~1 MHz) pulse-transmission method in the temperature range from 20 to -30 °C. Similar to sediments saturated with low salinity fluids, seismic

  16. Seismic survey in southeastern Socorro Island: Background noise measurements, seismic events, and T phases

    Energy Technology Data Exchange (ETDEWEB)

    Valenzuela, Raul W [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, D.F. (Mexico); Galindo, Marta [Comprehensive Nuclear-Test-Ban Treaty Organization, IMS, Vienna (Austria); Pacheco, Javier F; Iglesias, Arturo; Teran, Luis F [Instituto de Geofisica, Universidad Nacional Autonoma de Mexico, D.F. (Mexico); Barreda, Jose L; Coba, Carlos [Facultad de Ingenieria, Benemerita Universidad Autonoma de Puebla, Puebla (Mexico)

    2005-01-15

    We carried out a seismic survey and installed five portable, broadband seismometers in the southeastern corner of Socorro Island during June 1999. Power spectral densities for all five sites were relatively noisy when compared to reference curves around the world. Power spectral densities remain constant regardless of the time of day, or the day of the week. Cultural noise at the island is very small. Quiet and noisy sites were identified to determine the best location of the T phase station to be installed jointly by the Universidad Nacional Autonoma de Mexico and the Comprehensive Nuclear-Test-Ban Treaty Organization. During the survey six earthquakes were recorded at epicentral distances between 42 km and 2202 km, with magnitudes between 2.8 and 7.0. Two small earthquakes (M{sub c} = 2.8 and 3.3) occurred on the Clarion Fracture Zone. The four largest and more distant earthquakes produced T waves. One T wave from an epicenter near the coast of Guatemala had a duration of about 100 s and a frequency content between 2 and 8 Hz, with maximum amplitude at about 4.75 Hz. The Tehuacan earthquake of June 15, 1999 (M{sub w} = 7.0) produced arrivals of P {yields} T and S {yields} T waves, with energy between 2 Hz and 3.75 Hz. The earthquake occurred inland within the subducted Cocos plate at a depth of 60 km; a significant portion of the path was continental. Seismic P and S waves probably propagated upward in the subducted slab, and were converted to acoustic energy at the continental slope. Total duration of the T phase is close to 500 s and reaches its maximum amplitude about 200 s after the P {yields} T arrival. The T wave contains energy at frequencies between 2 and 10 Hz and reaches its maximum amplitude at about 2.5 Hz. T phases were also recorded from two earthquakes in Guerrero, Mexico and in the Rivera Fracture Zone. [Spanish] En junio de 1999 instalamos cinco sismometros portatiles de banda ancha en el sureste de la Isla Socorro. Se encontro que las densidades

  17. Measuring the Dynamic Soil Response During Repeated Wheeling Using Seismic Methods

    DEFF Research Database (Denmark)

    Keller, Thomas; Carizzon, Marco; Berisso, Feto Esimo

    2013-01-01

    seismic measurements could be used to assess the dynamic soil behavior during repeated loading. Moreover, we aimed at linking the velocity of P-waves, Vp, to traditionally measured soil properties associated with soil compaction, namely bulk density (ρb) and penetrometer resistance. A wheeling experiment...

  18. Measurements of Seismic Anisotropy in Synthetic Rocks with Controlled Crack Geometry and Different Crack Densities

    Science.gov (United States)

    Ding, Pinbo; Di, Bangrang; Wang, Ding; Wei, Jianxin; Li, Xiangyang

    2017-05-01

    Seismic anisotropy can help to extract azimuthal information for predicting crack alignment, but the accurate evaluation of cracked reservoir requires knowledge of degree of crack development, which is achieved through determining the crack density from seismic or VSP data. In this research we study the dependence of seismic anisotropy on crack density, using synthetic rocks with controlled crack geometries. A set of four synthetic rocks containing different crack densities is used in laboratory measurements. The crack thickness is 0.06 mm and the crack diameter is 3 mm in all the cracked rocks, while the crack densities are 0.00, 0.0243, 0.0486, and 0.0729. P and S wave velocities are measured by an ultrasonic investigation system at 0.5 MHz while the rocks are saturated with water. The measurements show the impact of crack density on the P and S wave velocities. Our results are compared to the theoretical prediction of Chapman (J App Geophys 54:191-202, 2003) and Hudson (Geophys J R Astron Soc 64:133-150, 1981). The comparison shows that measured velocities and theoretical results are in good quantitative agreement in all three cracked rocks, although Chapman's model fits the experimental results better. The measured anisotropy of the P and S wave in the four synthetic rocks shows that seismic anisotropy is directly proportional to increasing crack density, as predicted by several theoretical models. The laboratory measurements indicate that it would be effective to use seismic anisotropy to determine the crack density and estimate the intensity of crack density in seismology and seismic exploration.

  19. High speed high dynamic range high accuracy measurement system

    Science.gov (United States)

    Deibele, Craig E.; Curry, Douglas E.; Dickson, Richard W.; Xie, Zaipeng

    2016-11-29

    A measuring system includes an input that emulates a bandpass filter with no signal reflections. A directional coupler connected to the input passes the filtered input to electrically isolated measuring circuits. Each of the measuring circuits includes an amplifier that amplifies the signal through logarithmic functions. The output of the measuring system is an accurate high dynamic range measurement.

  20. Measuring the seismic velocity in the top 15 km of Earth's inner core

    Science.gov (United States)

    Godwin, Harriet; Waszek, Lauren; Deuss, Arwen

    2018-01-01

    We present seismic observations of the uppermost layer of the inner core. This was formed most recently, thus its seismic features are related to current solidification processes. Previous studies have only constrained the east-west hemispherical seismic velocity structure in the Earth's inner core at depths greater than 15 km below the inner core boundary. The properties of shallower structure have not yet been determined, because the seismic waves PKIKP and PKiKP used for differential travel time analysis arrive close together and start to interfere. Here, we present a method to make differential travel time measurements for waves that turn in the top 15 km of the inner core, and measure the corresponding seismic velocity anomalies. We achieve this by generating synthetic seismograms to model the overlapping signals of the inner core phase PKIKP and the inner core boundary phase PKiKP. We then use a waveform comparison to attribute different parts of the signal to each phase. By measuring the same parts of the signal in both observed and synthetic data, we are able to calculate differential travel time residuals. We apply our method to data with ray paths which traverse the Pacific hemisphere boundary. We generate a velocity model for this region, finding lower velocity for deeper, more easterly ray paths. Forward modelling suggests that this region contains either a high velocity upper layer, or variation in the location of the hemisphere boundary with depth and/or latitude. Our study presents the first direct seismic observation of the uppermost 15 km of the inner core, opening new possibilities for further investigating the inner core boundary region.

  1. The influence of construction measurement and structure storey on seismic performance of masonry structure

    Science.gov (United States)

    Sun, Baitao; Zhao, Hexian; Yan, Peilei

    2017-08-01

    The damage of masonry structures in earthquakes is generally more severe than other structures. Through the analysis of two typical earthquake damage buildings in the Wenchuan earthquake in Xuankou middle school, we found that the number of storeys and the construction measures had great influence on the seismic performance of masonry structures. This paper takes a teachers’ dormitory in Xuankou middle school as an example, selected the structure arrangement and storey number as two independent variables to design working conditions. Finally we researched on the seismic performance difference of masonry structure under two variables by finite element analysis method.

  2. Measurements of translation, rotation and strain: new approaches to seismic processing and inversion

    NARCIS (Netherlands)

    Bernauer, M.; Fichtner, A.; Igel, H.

    2012-01-01

    We propose a novel approach to seismic tomography based on the joint processing of translation, strain and rotation measurements. Our concept is based on the apparent S and P velocities, defined as the ratios of displacement velocity and rotation amplitude, and displacement velocity and

  3. 3-D Characterization of Seismic Properties at the Smart Weapons Test Range, YPG

    National Research Council Canada - National Science Library

    Miller, Richard

    2001-01-01

    The Smart Weapons Test Range (SWTR) lies within the Yuma Proving Ground (YPG), Arizona. SWTR is a new facility constructed specifically for the development and testing of futuristic intelligent battlefield sensor networks...

  4. Volcanic plume height measured by seismic waves based on a mechanical model

    Science.gov (United States)

    Prejean, Stephanie G.; Brodsky, Emily E.

    2011-01-01

    In August 2008 an unmonitored, largely unstudied Aleutian volcano, Kasatochi, erupted catastrophically. Here we use seismic data to infer the height of large eruptive columns such as those of Kasatochi based on a combination of existing fluid and solid mechanical models. In so doing, we propose a connection between a common, observable, short-period seismic wave amplitude to the physics of an eruptive column. To construct a combined model, we estimate the mass ejection rate of material from the vent on the basis of the plume height, assuming that the height is controlled by thermal buoyancy for a continuous plume. Using the estimated mass ejection rate, we then derive the equivalent vertical force on the Earth through a momentum balance. Finally, we calculate the far-field surface waves resulting from the vertical force. The model performs well for recent eruptions of Kasatochi and Augustine volcanoes if v, the velocity of material exiting the vent, is 120-230 m s-1. The consistency between the seismically inferred and measured plume heights indicates that in these cases the far-field ~1 s seismic energy radiated by fluctuating flow in the volcanic jet during the eruption is a useful indicator of overall mass ejection rates. Thus, use of the model holds promise for characterizing eruptions and evaluating ash hazards to aircraft in real time on the basis of far-field short-period seismic data. This study emphasizes the need for better measurements of eruptive plume heights and a more detailed understanding of the full spectrum of seismic energy radiated coeruptively.

  5. Pile volume measurement by range imaging camera in indoor environment

    Directory of Open Access Journals (Sweden)

    C. Altuntas

    2014-06-01

    Full Text Available Range imaging (RIM camera is recent technology in 3D location measurement. The new study areas have been emerged in measurement and data processing together with RIM camera. It has low-cost and fast measurement technique compared to the current measurement techniques. However its measurement accuracy varies according to effects resulting from the device and the environment. The direct sunlight is affect measurement accuracy of the camera. Thus, RIM camera should be used for indoor measurement. In this study gravel pile volume was measured by SwissRanger SR4000 camera. The measured volume is acquired as different 8.13% from the known.

  6. Discrete filtering techniques applied to sequential GPS range measurements

    Science.gov (United States)

    Vangraas, Frank

    1987-01-01

    The basic navigation solution is described for position and velocity based on range and delta range (Doppler) measurements from NAVSTAR Global Positioning System satellites. The application of discrete filtering techniques is examined to reduce the white noise distortions on the sequential range measurements. A second order (position and velocity states) Kalman filter is implemented to obtain smoothed estimates of range by filtering the dynamics of the signal from each satellite separately. Test results using a simulated GPS receiver show a steady-state noise reduction, the input noise variance divided by the output noise variance, of a factor of four. Recommendations for further noise reduction based on higher order Kalman filters or additional delta range measurements are included.

  7. Comparison of methods of measuring active cervical range of motion.

    Science.gov (United States)

    Whitcroft, Katherine L; Massouh, Laura; Amirfeyz, Rouin; Bannister, Gordon

    2010-09-01

    Experimental study. Cervical range of motion (CROM) was measured using different clinical methods. To compare the reliability and accuracy of visual estimation, tape measurement, and the universal goniometer (UG) with that of the CROM goniometer in measuring active CROM in healthy volunteers. The secondary objective was to identify the single neck movement that best represents overall range of motion. Neck movement is affected by pathology in the spine and shoulder. A reliable and accurate measurement of neck movement is required to quantify injury, recovery, and disability. Various methods of measuring neck movement have been described of which radiography remains the accepted reference standard. However, radiography is impractical for routine clinical assessment. Visual estimation, tape measurement, and the UG are convenient alternatives. To date, the accuracy and reliability of these methods have not been compared in healthy subjects, and the single neck movement that best reflects overall range has not yet been identified. Active cervical flexion, extension, right and left lateral flexion and rotation were measured in 100 healthy volunteers. Visual estimation, tape measurement between fixed landmarks, and the UG aligned on fixed and anatomic landmarks were compared with the CROM goniometer, which was used as the reference standard. Compared with the CROM goniometer, the UG aligned on fixed landmarks was the most accurate method, followed by the UG on anatomic landmarks. The reliability of the UG was between substantial and perfect. Visual estimation was reproducible but measured range of movement inaccurately. Tape measurement was inaccurate. Extension best reflected overall range. The UG aligned on a fixed landmark is most reliable method of measuring neck movement clinically. Where range must be quickly assessed, extension should be measured.

  8. Method for determining the position of seismic streamers in a reflection seismic measuring system. Fremgangsmaate til posisjonsbestemmelse av minst to seismiske kabler i et refleksjonsseismisk maalesystem

    Energy Technology Data Exchange (ETDEWEB)

    Langeland, J.Aa.; Aasheim, S.; Nordmoen, B.; Vigen, E.

    1993-08-02

    The invention deals with a method for determining the position of at least two seismic streamers in a reflection seismic measuring system. Hydroacoustic distance measurements are used which are taken by means of acoustic transceivers provided in vessels, buoys, floats, seismic sources and in the seismic streamers. Absolute reference positions are determined by means of position determining equipment provided in at least two locations, for instance on a vessel or a float. The acoustic transceivers and the position determining equipment form a three-dimensional structure. According to the method the position determination takes place by trilateration between the acoustic transceivers and the determination of at least two reference positions. Therefore, there is no dependency on compass bearings or optical visibility, and high redundancy is obtained. The method is particularly suited for application in connection with three-dimensional marine seismic surveys. The method may be integrated with suitable surface navigation systems in order to find the reference positions and provide absolute positions at any point within a marginal error of 5 to 10 m. 9 figs.

  9. High Precision Ranging and Range-Rate Measurements over Free-Space-Laser Communication Link

    Science.gov (United States)

    Yang, Guangning; Lu, Wei; Krainak, Michael; Sun, Xiaoli

    2016-01-01

    We present a high-precision ranging and range-rate measurement system via an optical-ranging or combined ranging-communication link. A complete bench-top optical communication system was built. It included a ground terminal and a space terminal. Ranging and range rate tests were conducted in two configurations. In the communication configuration with 622 data rate, we achieved a two-way range-rate error of 2 microns/s, or a modified Allan deviation of 9 x 10 (exp -15) with 10 second averaging time. Ranging and range-rate as a function of Bit Error Rate of the communication link is reported. They are not sensitive to the link error rate. In the single-frequency amplitude modulation mode, we report a two-way range rate error of 0.8 microns/s, or a modified Allan deviation of 2.6 x 10 (exp -15) with 10 second averaging time. We identified the major noise sources in the current system as the transmitter modulation injected noise and receiver electronics generated noise. A new improved system will be constructed to further improve the system performance for both operating modes.

  10. A quantum inspired model of radar range and range-rate measurements with applications to weak value measurements

    Science.gov (United States)

    Escalante, George

    2017-05-01

    Weak Value Measurements (WVMs) with pre- and post-selected quantum mechanical ensembles were proposed by Aharonov, Albert, and Vaidman in 1988 and have found numerous applications in both theoretical and applied physics. In the field of precision metrology, WVM techniques have been demonstrated and proven valuable as a means to shift, amplify, and detect signals and to make precise measurements of small effects in both quantum and classical systems, including: particle spin, the Spin-Hall effect of light, optical beam deflections, frequency shifts, field gradients, and many others. In principal, WVM amplification techniques are also possible in radar and could be a valuable tool for precision measurements. However, relatively limited research has been done in this area. This article presents a quantum-inspired model of radar range and range-rate measurements of arbitrary strength, including standard and pre- and post-selected measurements. The model is used to extend WVM amplification theory to radar, with the receive filter performing the post-selection role. It is shown that the description of range and range-rate measurements based on the quantum-mechanical measurement model and formalism produces the same results as the conventional approach used in radar based on signal processing and filtering of the reflected signal at the radar receiver. Numerical simulation results using simple point scatterrer configurations are presented, applying the quantum-inspired model of radar range and range-rate measurements that occur in the weak measurement regime. Potential applications and benefits of the quantum inspired approach to radar measurements are presented, including improved range and Doppler measurement resolution.

  11. A story about estimation of a random field of boulders from incomplete seismic measurements

    DEFF Research Database (Denmark)

    Ditlevsen, Ove Dalager

    2005-01-01

    This paper reports on the statistical interpretation of seismic diffraction measurements of boulder locations. The measurements are made in a corridor along the planned tunnel line for the later realized bored tunnel through the till deposits under the East Channel of the Great Belt in Denmark...... graphical registrations on seismograms do not make a proper interpretation possible without detailed knowledge about the joint distribution of the primary dimensions of the boulders. Therefore separate measurements were made of the dimensions of boulders deposited visibly on the cliff beaches of the Great...... and measured. These direct observations on site confirmed that the prediction was quite good....

  12. Smartphone photography utilized to measure wrist range of motion.

    Science.gov (United States)

    Wagner, Eric R; Conti Mica, Megan; Shin, Alexander Y

    2018-02-01

    The purpose was to determine if smartphone photography is a reliable tool in measuring wrist movement. Smartphones were used to take digital photos of both wrists in 32 normal participants (64 wrists) at extremes of wrist motion. The smartphone measurements were compared with clinical goniometry measurements. There was a very high correlation between the clinical goniometry and smartphone measurements, as the concordance coefficients were high for radial deviation, ulnar deviation, wrist extension and wrist flexion. The Pearson coefficients also demonstrated the high precision of the smartphone measurements. The Bland-Altman plots demonstrated 29-31 of 32 smartphone measurements were within the 95% confidence interval of the clinical measurements for all positions of the wrists. There was high reliability between the photography taken by the volunteer and researcher, as well as high inter-observer reliability. Smartphone digital photography is a reliable and accurate tool for measuring wrist range of motion. II.

  13. Underground earth strain and seismic radiation measurements with a laser interferometer and a dense small-aperture seismic array

    Directory of Open Access Journals (Sweden)

    M. Abril

    1997-06-01

    Full Text Available This paper describes two geophysical instruments, installed in the underground physics laboratories of Gran Sasso (LNGS-INFN, located in the seismic zone of the Central Apennines, Italy. These instruments monitor strain and seismic radiation with very high sensitivity: one is a 90 m-long laser interferometer, sensitivity 3 x 10-12, frequency response 10-7-10-2 Hz, and has been operating since 1994. The other is a small-aperture seismic array composed of 21 three-component short period (Mark L4C-3D and 3 broadband (Guralp CMG-3ESP seismometers. This dense array will be in operation at the beginning of 1998.

  14. Effective seismic acceleration measurements for low-cost Structural Health Monitoring

    Science.gov (United States)

    Pentaris, Fragkiskos; Makris, John P.

    2015-04-01

    There is increasing demand on cost effective Structural Health Monitoring systems for buildings as well as important and/or critical constructions. The front end for all these systems is the accelerometer. We present a comparative study of two low cost MEMS accelaration sensors against a very sensitive, high dynamic range strong motion accelerometer of force balance type but much more expensive. A real experiment was realized by deploying the three sesnors in a reinforced concrete building of the premises of TEI of Crete at Chania Crete, an earthquake prone region. The analysis of the collected accelararion data from many seismic events indicates that all sensors are able to efficiently reveal the seismic response of the construction in terms of PSD. Furthermore, it is shown that coherence diagrams between excitation and response of the building under study, depict structural characteristics but also the seismic energy distribution. This work is supported by the Archimedes III Program of the Ministry of Education of Greece, through the Operational Program "Educational and Lifelong Learning", in the framework of the project entitled "Interdisciplinary Multi-Scale Research of Earthquake Physics and Seismotectonics at the front of the Hellenic Arc (IMPACT-ARC)" and is co-financed by the European Union (European Social Fund) and Greek national funds.

  15. Small Device For Short-Range Antenna Measurements Using Optics

    DEFF Research Database (Denmark)

    Yanakiev, Boyan Radkov; Nielsen, Jesper Ødum; Christensen, Morten

    2011-01-01

    This paper gives a practical solution for implementing an antenna radiation pattern measurement device using optical fibers. It is suitable for anechoic chambers as well as short range channel sounding. The device is optimized for small size and provides a cheap and easy way to make optical antenna...

  16. Measuring the relativistic perigee advance with satellite laser ranging

    CERN Document Server

    Iorio, L; Pavlis, E C

    2002-01-01

    The pericentric advance of a test body by a central mass is one of the classical tests of general relativity. Today, this effect is measured with radar ranging by the perihelion shift of Mercury and other planets in the gravitational field of the Sun, with a relative accuracy of the order of 10 sup - sup 2 -10 sup - sup 3. In this paper, we explore the possibility of a measurement of the pericentric advance in the gravitational field of Earth by analysing the laser-ranged data of some orbiting, or proposed, laser-ranged geodetic satellites. Such a measurement of the perigee advance would place limits on hypothetical, very weak, Yukawa-type components of the gravitational interaction with a finite range of the order of 10 sup 4 km. Thus, we show that, at the present level of knowledge of the orbital perturbations, the relative accuracy, achievable with suitably combined orbital elements of LAGEOS and LAGEOS II, is of the order of 10 sup - sup 3. With the corresponding measured value of (2 + 2 gamma - beta)/3, ...

  17. Ion range measurements using fluorescent nuclear track detectors

    DEFF Research Database (Denmark)

    Klimpki, G.; Osinga, J.-M.; Herrmann, R.

    2013-01-01

    Fluorescent nuclear track detectors (FNTDs) show excellent detection properties for heavy charged particles and have, therefore, been investigated in this study in terms of their potential for in-vivo range measurements. We irradiated FNTDs with protons as well as with C, Mg, S, Fe and Xe ion beams...

  18. Absolute stress measurements at the rangely anticline, Northwestern Colorado

    Science.gov (United States)

    de la Cruz, R. V.; Raleigh, C.B.

    1972-01-01

    Five different methods of measuring absolute state of stress in rocks in situ were used at sites near Rangely, Colorado, and the results compared. For near-surface measurements, overcoring of the borehole-deformation gage is the most convenient and rapid means of obtaining reliable values for the magnitude and direction of the state of stress in rocks in situ. The magnitudes and directions of the principal stresses are compared to the geologic features of the different areas of measurement. The in situ stresses are consistent in orientation with the stress direction inferred from the earthquake focal-plane solutions and existing joint patterns but inconsistent with stress directions likely to have produced the Rangely anticline. ?? 1972.

  19. Reliability of three measures of ankle dorsiflexion range of motion.

    Science.gov (United States)

    Konor, Megan M; Morton, Sam; Eckerson, Joan M; Grindstaff, Terry L

    2012-06-01

    A variety of methods exist to measure ankle dorsiflexion range of motion (ROM). Few studies have examined the reliability of a novice rater. The purpose of this study was to determine the reliability of ankle ROM measurements using three different techniques in a novice rater. Twenty healthy subjects (mean±SD, age=24±3 years, height=173.2±8.1 cm, mass=72.6±15.2 kg) participated in this study. Ankle dorsiflexion ROM measures were obtained in a weight-bearing lunge position using a standard goniometer, digital inclinometer, and a tape measure using the distance-to-wall technique. All measures were obtained three times per side, with 10 minutes of rest between the first and second set of measures. Intrarater reliability was determined using an intraclass correlation coefficient (ICC(2,3)) and associated 95% confidence intervals (CI). Standard error of measurement (SEM) and the minimal detectable change (MDC) for each measurement technique were also calculated. The within-session intrarater reliability (ICC(2,3)) estimates for each measure are as follows: tape measure (right 0.98, left 0.99), digital inclinometer (right 0.96; left 0.97), and goniometer (right 0.85; left 0.96). The SEM for the tape measure method ranged from 0.4-0.6 cm and the MDC was between 1.1-1.5 cm. The SEM for the inclinometer was between 1.3-1.4° and the MDC was 3.7-3.8°. The SEM for the goniometer ranged from 1.8-2.8° with an MDC of 5.0-7.7°. The results indicate that reliable measures of weight-bearing ankle dorsiflexion ROM can be obtained from a novice rater. All three techniques had good reliability and low measurement error, with the distance-to-wall technique using a tape measure and inclinometer methods resulting in higher reliability coefficients (ICC(2,3)=0.96 to 0.99) and a lower SEM compared to the goniometer (ICC(2,3)=0.85 to 0.96). 2b.

  20. Entanglement-enhanced lidars for simultaneous range and velocity measurements

    Science.gov (United States)

    Zhuang, Quntao; Zhang, Zheshen; Shapiro, Jeffrey H.

    2017-10-01

    Lidar is a well-known optical technology for measuring a target's range and radial velocity. We describe two lidar systems that use entanglement between transmitted signals and retained idlers to obtain significant quantum enhancements in simultaneous measurements of these parameters. The first entanglement-enhanced lidar circumvents the Arthurs-Kelly uncertainty relation for simultaneous measurements of range and radial velocity from the detection of a single photon returned from the target. This performance presumes there is no extraneous (background) light, but is robust to the round-trip loss incurred by the signal photons. The second entanglement-enhanced lidar—which requires a lossless, noiseless environment—realizes Heisenberg-limited accuracies for both its range and radial-velocity measurements, i.e., their root-mean-square estimation errors are both proportional to 1 /M when M signal photons are transmitted. These two lidars derive their entanglement-based enhancements from the use of a unitary transformation that takes a signal-idler photon pair with frequencies ωS and ωI and converts it to a signal-idler photon pair whose frequencies are (ωS+ωI)/2 and (ωS-ωI)/2 . Insight into how this transformation provides its benefits is provided through an analogy to continuous-variable superdense coding.

  1. Range-limited centrality measures in complex networks

    Science.gov (United States)

    Ercsey-Ravasz, Mária; Lichtenwalter, Ryan N.; Chawla, Nitesh V.; Toroczkai, Zoltán

    2012-06-01

    Here we present a range-limited approach to centrality measures in both nonweighted and weighted directed complex networks. We introduce an efficient method that generates for every node and every edge its betweenness centrality based on shortest paths of lengths not longer than ℓ=1,...,L in the case of nonweighted networks, and for weighted networks the corresponding quantities based on minimum weight paths with path weights not larger than wℓ=ℓΔ, ℓ=1,2...,L=R/Δ. These measures provide a systematic description on the positioning importance of a node (edge) with respect to its network neighborhoods one step out, two steps out, etc., up to and including the whole network. They are more informative than traditional centrality measures, as network transport typically happens on all length scales, from transport to nearest neighbors to the farthest reaches of the network. We show that range-limited centralities obey universal scaling laws for large nonweighted networks. As the computation of traditional centrality measures is costly, this scaling behavior can be exploited to efficiently estimate centralities of nodes and edges for all ranges, including the traditional ones. The scaling behavior can also be exploited to show that the ranking top list of nodes (edges) based on their range-limited centralities quickly freezes as a function of the range, and hence the diameter-range top list can be efficiently predicted. We also show how to estimate the typical largest node-to-node distance for a network of N nodes, exploiting the afore-mentioned scaling behavior. These observations were made on model networks and on a large social network inferred from cell-phone trace logs (˜5.5×106 nodes and ˜2.7×107 edges). Finally, we apply these concepts to efficiently detect the vulnerability backbone of a network (defined as the smallest percolating cluster of the highest betweenness nodes and edges) and illustrate the importance of weight-based centrality measures in

  2. Mode-locked laser autocollimator with an expanded measurement range.

    Science.gov (United States)

    Chen, Yuan-Liu; Shimizu, Yuki; Kudo, Yukitoshi; Ito, So; Gao, Wei

    2016-07-11

    A mode-locked laser is employed as the light source of a laser autocollimator, instead of the conventionally employed single-wavelength laser, for an expanded range of tilt angle measurement. A group of the spatially separated diffracted beams from a diffraction grating are focused by a collimator objective to form an array of light spots on the focal plane of the collimator objective where a light position-sensing photodiode is located for detecting the linear displacement of the light spot array corresponding to the tilt angle of the reflector. A prototype mode-locked femtosecond laser autocollimator is designed and constructed for achieving a measurement range of 11000 arc-seconds.

  3. Monitoring methane emission of mud volcanoes by seismic tremor measurements: a pilot study

    Directory of Open Access Journals (Sweden)

    D. Albarello

    2012-12-01

    Full Text Available A new approach for estimating methane emission at mud volcanoes is here proposed based on measurements of the seismic tremor on their surface. Data obtained at the Dashgil mud volcano in Azerbaijan reveal the presence of energy bursts characterized by well-determined features (i.e. waveforms, spectra and polarization properties that can be associated with bubbling at depth. Counting such events provides a possible tool for monitoring gas production in the reservoir, thus minimizing logistic troubles and representing a cheap and effective alternative to more complex approaches. Specifically, we model the energy bursts as the effect of resonant gas bubbles at depth. This modelling allows to estimate the dimension of the bubbles and, consequently, the gas outflow from the main conduit in the assumption that all emissions from depth occur by bubble uprising. The application of this model to seismic events detected at the Dashgil mud volcano during three sessions of measurements carried out in 2006 and 2007 provides gas flux estimates that are in line with those provided by independent measurements at the same structure. This encouraging result suggests that the one here proposed could be considered a new promising, cheap and easy to apply tool for gas flux measurements in bubbling gas seepage areas.

  4. An Observability Metric for Underwater Vehicle Localization Using Range Measurements

    Science.gov (United States)

    Arrichiello, Filippo; Antonelli, Gianluca; Aguiar, Antonio Pedro; Pascoal, Antonio

    2013-01-01

    The paper addresses observability issues related to the general problem of single and multiple Autonomous Underwater Vehicle (AUV) localization using only range measurements. While an AUV is submerged, localization devices, such as Global Navigation Satellite Systems, are ineffective, due to the attenuation of electromagnetic waves. AUV localization based on dead reckoning techniques and the use of affordable motion sensor units is also not practical, due to divergence caused by sensor bias and drift. For these reasons, localization systems often build on trilateration algorithms that rely on the measurements of the ranges between an AUV and a set of fixed transponders using acoustic devices. Still, such solutions are often expensive, require cumbersome calibration procedures and only allow for AUV localization in an area that is defined by the geometrical arrangement of the transponders. A viable alternative for AUV localization that has recently come to the fore exploits the use of complementary information on the distance from the AUV to a single transponder, together with information provided by on-board resident motion sensors, such as, for example, depth, velocity and acceleration measurements. This concept can be extended to address the problem of relative localization between two AUVs equipped with acoustic sensors for inter-vehicle range measurements. Motivated by these developments, in this paper, we show that both the problems of absolute localization of a single vehicle and the relative localization of multiple vehicles can be treated using the same mathematical framework, and tailoring concepts of observability derived for nonlinear systems, we analyze how the performance in localization depends on the types of motion imparted to the AUVs. For this effect, we propose a well-defined observability metric and validate its usefulness, both in simulation and by carrying out experimental tests with a real marine vehicle during which the performance of an

  5. An Observability Metric for Underwater Vehicle Localization Using Range Measurements

    Directory of Open Access Journals (Sweden)

    Filippo Arrichiello

    2013-11-01

    Full Text Available The paper addresses observability issues related to the general problem of single and multiple Autonomous Underwater Vehicle (AUV localization using only range measurements. While an AUV is submerged, localization devices, such as Global Navigation Satellite Systems, are ineffective, due to the attenuation of electromagnetic waves. AUV localization based on dead reckoning techniques and the use of affordable motion sensor units is also not practical, due to divergence caused by sensor bias and drift. For these reasons, localization systems often build on trilateration algorithms that rely on the measurements of the ranges between an AUV and a set of fixed transponders using acoustic devices. Still, such solutions are often expensive, require cumbersome calibration procedures and only allow for AUV localization in an area that is defined by the geometrical arrangement of the transponders. A viable alternative for AUV localization that has recently come to the fore exploits the use of complementary information on the distance from the AUV to a single transponder, together with information provided by on-board resident motion sensors, such as, for example, depth, velocity and acceleration measurements. This concept can be extended to address the problem of relative localization between two AUVs equipped with acoustic sensors for inter-vehicle range measurements. Motivated by these developments, in this paper, we show that both the problems of absolute localization of a single vehicle and the relative localization of multiple vehicles can be treated using the same mathematical framework, and tailoring concepts of observability derived for nonlinear systems, we analyze how the performance in localization depends on the types of motion imparted to the AUVs. For this effect, we propose a well-defined observability metric and validate its usefulness, both in simulation and by carrying out experimental tests with a real marine vehicle during which the

  6. Use of moment independent importance measures in the framework of seismic fragility analysis

    OpenAIRE

    Zentner, I.; Borgonovo, E.; Pellegri, A.; Tarantola, S.

    2010-01-01

    In the nuclear industry, the seismic probabilistic risk assessment (PRA) has become the most commonly used methodology for evaluating the seismic risk of nuclear plants. In this framework, fragility curves express the conditional probability of failure of a structure or component for a given seismic input motion parameter value. The failure probability of a component due to a seismic event is obtained by integrating the conditional probability of failure (fragility) with respect to s...

  7. Optical measurements of long-range protein vibrations

    Science.gov (United States)

    Acbas, Gheorghe; Niessen, Katherine A.; Snell, Edward H.; Markelz, A. G.

    2014-01-01

    Protein biological function depends on structural flexibility and change. From cellular communication through membrane ion channels to oxygen uptake and delivery by haemoglobin, structural changes are critical. It has been suggested that vibrations that extend through the protein play a crucial role in controlling these structural changes. While nature may utilize such long-range vibrations for optimization of biological processes, bench-top characterization of these extended structural motions for engineered biochemistry has been elusive. Here we show the first optical observation of long-range protein vibrational modes. This is achieved by orientation-sensitive terahertz near-field microscopy measurements of chicken egg white lysozyme single crystals. Underdamped modes are found to exist for frequencies >10 cm-1. The existence of these persisting motions indicates that damping and intermode coupling are weaker than previously assumed. The methodology developed permits protein engineering based on dynamical network optimization.

  8. Measurement of individual loudness functions by trisection of loudness ranges.

    Science.gov (United States)

    Villchur, Edgar; Killion, Mead C

    2008-10-01

    Loudness-balance measurements with monaurally impaired subjects have shown that the shape of the loudness versus sound-pressure curve among hearing-impaired persons varies significantly. But the effectiveness of adjusting the compression characteristics of wide-dynamic-range compression hearing aids-the compression ratios, the variation of compression ratio with level, and the threshold of compression-to restore normal loudness growth for the individual patient has never been properly tested; individual loudness measurements have been too uncertain to permit meaningful individual adjustments. Recent investigators have reported standard deviations of such measurements in normal-hearing subjects of 6.4 dB and 7.8 dB. This investigation describes a method of measuring loudness function with a standard deviation in normal-hearing subjects of the order of 1 dB, both significantly lower than that of previous methods and sufficiently accurate for individual-subject adjustments. Each of nine normal-hearing subjects-seven of them inexperienced and one a 9-year-old was asked to make three successive loudness trisections within an amplitude range of 40 to 80 dB SPL, providing six points from which to plot a loudness-function curve between these limits. The individual and average curves were validated as accurate loudness functions by comparing them to the curve defined by the equation of loudness versus amplitude in current Standards. In a second validation experiment, the loudness functions of masked ears measured by trisection were compared to the loudness function of those ears measured by loudness balance between masked and unmasked ears. The difference between a loudness function based on the average of subject trisections and the loudness function defined by the ANSI Standard loudness equation was -1.92 dB at the lowest trisection level and +0.05 dB at the highest level. The standard deviations of subject responses were 1.63 dB for the lowest trisection level and 0.68 d

  9. Radioscience and seismic measurements for the INSIGHT mission about interior of Mars.

    Science.gov (United States)

    Dehant, Véronique; Asmar, Sami; Folkner, William; Lognonné, Philippe; Banerdt, Bruce; Smrekar, Suzanne; Rivoldini, Attilio; Christensen, Ulrich; Giardini, Domenico; Pike, Tom; Clinton, John; Garcia, Raphael; Johnson, Catherine; Kobayashi, Naoki; Knapmeyer-Endrun, Brigitte; Mimoun, David; Mocquet, Antoine; Panning, Mark; Tromp, Jeroen; Weber, Renee

    2015-04-01

    We shall use the X-band radio link of the future 2016 InSIGHT (Interior exploration using Seismic Investigations, Geodesy, and Heat Transport) lander on the surface of Mars with the objective to better determine the rotation and interior structure of Mars. This X-band radio link consists in two-way Doppler measurements from a direct radio-link between the Martian lander and deep space tracking stations on the Earth. On the basis of these measurements, it will be possible to monitor the lander position relative to the Earth and in turn to improve the determination of the Mars' orientation and rotation parameters (MOP), i.e. the rotation rate variations (or Length of Days LOD), the precession rate and the nutations of the rotation axis. As these MOP parameters are related to the interior of the planet, we further discuss the expected improvement in our knowledge of Mars' interior in synergy with the seismic data, which include the tidal data. We will show in particular how to determine the state, size, and composition of the Martian core. These parameters are very important for understanding the evolution of Mars.

  10. Estimating the 2008 Quetame (Colombia) earthquake source parameters from seismic data and InSAR measurements

    Science.gov (United States)

    Dicelis, Gabriel; Assumpção, Marcelo; Kellogg, James; Pedraza, Patricia; Dias, Fábio

    2016-12-01

    Seismic waveforms and geodetic measurements (InSAR) were used to determine the location, focal mechanism and coseismic surface displacements of the Mw 5.9 earthquake which struck the center of Colombia on May 24, 2008. We determined the focal mechanism of the main event using teleseismic P wave arrivals and regional waveform inversion for the moment tensor. We relocated the best set of aftershocks (30 events) with magnitudes larger than 2.0 recorded from May to June 2008 by a temporary local network as well as by stations of the Colombia national network. We successfully estimated coseismic deformation using SAR interferometry, despite distortion in some areas of the interferogram by atmospheric noise. The deformation was compared to synthetic data for rectangular dislocations in an elastic half-space. Nine source parameters (strike, dip, length, width, strike-slip deformation, dip-slip deformation, latitude shift, longitude shift, and minimum depth) were inverted to fit the observed changes in line-of-sight (LOS) toward the satellite four derived parameters were also estimated (rake, average slip, maximum depth and seismic moment). The aftershock relocation, the focal mechanism and the coseismic dislocation model agree with a right-lateral strike-slip fault with nodal planes oriented NE-SW and NW-SE. We use the results of the waveform inversion, radar interferometry and aftershock relocations to identify the high-angle NE-SW nodal plane as the primary fault. The inferred subsurface rupture length is roughly 11 km, which is consistent with the 12 km long distribution of aftershocks. This coseismic model can provide insights on earthquake mechanisms and seismic hazard assessments for the area, including the 8 million residents of Colombia's nearby capital city Bogota. The 2008 Quetame earthquake appears to be associated with the northeastward "escape" of the North Andean block, and it may help to illuminate how margin-parallel shear slip is partitioned in the

  11. Mobile seismic exploration

    Energy Technology Data Exchange (ETDEWEB)

    Dräbenstedt, A., E-mail: a.draebenstedt@polytec.de, E-mail: rembe@iei.tu-clausthal.de, E-mail: ulrich.polom@liag-hannover.de; Seyfried, V. [Research & Development, Polytec GmbH, Waldbronn (Germany); Cao, X.; Rembe, C., E-mail: a.draebenstedt@polytec.de, E-mail: rembe@iei.tu-clausthal.de, E-mail: ulrich.polom@liag-hannover.de [Institute of Electrical Information Technology, TU Clausthal, Clausthal-Zellerfeld (Germany); Polom, U., E-mail: a.draebenstedt@polytec.de, E-mail: rembe@iei.tu-clausthal.de, E-mail: ulrich.polom@liag-hannover.de [Leibniz Institute of Applied Geophysics, Hannover (Germany); Pätzold, F.; Hecker, P. [Institute of Flight Guidance, TU Braunschweig, Braunschweig (Germany); Zeller, T. [Clausthaler Umwelttechnik Institut CUTEC, Clausthal-Zellerfeld (Germany)

    2016-06-28

    Laser-Doppler-Vibrometry (LDV) is an established technique to measure vibrations in technical systems with picometer vibration-amplitude resolution. Especially good sensitivity and resolution can be achieved at an infrared wavelength of 1550 nm. High-resolution vibration measurements are possible over more than 100 m distance. This advancement of the LDV technique enables new applications. The detection of seismic waves is an application which has not been investigated so far because seismic waves outside laboratory scales are usually analyzed at low frequencies between approximately 1 Hz and 250 Hz and require velocity resolutions in the range below 1 nm/s/√Hz. Thermal displacements and air turbulence have critical influences to LDV measurements at this low-frequency range leading to noise levels of several 100 nm/√Hz. Commonly seismic waves are measured with highly sensitive inertial sensors (geophones or Micro Electro-Mechanical Sensors (MEMS)). Approaching a laser geophone based on LDV technique is the topic of this paper. We have assembled an actively vibration-isolated optical table in a minivan which provides a hole in its underbody. The laser-beam of an infrared LDV assembled on the optical table impinges the ground below the car through the hole. A reference geophone has detected remaining vibrations on the table. We present the results from the first successful experimental demonstration of contactless detection of seismic waves from a movable vehicle with a LDV as laser geophone.

  12. Seismic bearing

    Science.gov (United States)

    Power, Dennis

    2009-05-01

    Textron Systems (Textron) has been using geophones for target detection for many years. This sensing capability was utilized for detection and classification purposes only. Recently Textron has been evaluating multiaxis geophones to calculate bearings and track targets more specifically personnel. This capability will not only aid the system in locating personnel in bearing space or cartesian space but also enhance detection and reduce false alarms. Textron has been involved in the testing and evaluation of several sensors at multiple sites. One of the challenges of calculating seismic bearing is an adequate signal to noise ratio. The sensor signal to noise ratio is a function of sensor coupling to the ground, seismic propagation and range to target. The goals of testing at multiple sites are to gain a good understanding of the maximum and minimum ranges for bearing and detection and to exploit that information to tailor sensor system emplacement to achieve desired performance. Test sites include 10A Site Devens, MA, McKenna Airfield Ft. Benning, GA and Yuma Proving Ground Yuma, AZ. Geophone sensors evaluated include a 28 Hz triax spike, a 15 Hz triax spike and a hybrid triax spike consisting of a 10 Hz vertical geophone and two 28 Hz horizontal geophones. The algorithm uses raw seismic data to calculate the bearings. All evaluated sensors have triaxial geophone configuration mounted to a spike housing/fixture. The suite of sensors also compares various types of geophones to evaluate benefits in lower bandwidth. The data products of these tests include raw geophone signals, seismic features, seismic bearings, seismic detection and GPS position truth data. The analyses produce Probability of Detection vs range, bearing accuracy vs range, and seismic feature level vs range. These analysis products are compared across test sites and sensor types.

  13. Measuring Systems for Thermometer Calibration in Low-Temperature Range

    Science.gov (United States)

    Szmyrka-Grzebyk, A.; Lipiński, L.; Manuszkiewicz, H.; Kowal, A.; Grykałowska, A.; Jancewicz, D.

    2011-12-01

    The national temperature standard for the low-temperature range between 13.8033 K and 273.16 K has been established in Poland at the Institute of Low Temperature and Structure Research (INTiBS). The standard consists of sealed cells for realization of six fixed points of the International Temperature Scale of 1990 (ITS-90) in the low-temperature range, an adiabatic cryostat and Isotech water and mercury triple-point baths, capsule standard resistance thermometers (CSPRT), and AC and DC bridges with standard resistors for thermometers resistance measurements. INTiBS calibrates CSPRTs at the low-temperature fixed points with uncertainties less than 1 mK. In lower temperature range—between 2.5 K and about 25 K — rhodium-iron (RhFe) resistance thermometers are calibrated by comparison with a standard which participated in the EURAMET.T-K1.1 comparison. INTiBS offers a calibration service for industrial platinum resistance thermometers and for digital thermometers between 77 K and 273 K. These types of thermometers may be calibrated at INTiBS also in a higher temperature range up to 550°C. The Laboratory of Temperature Standard at INTiBS acquired an accreditation from the Polish Centre for Accreditation. A management system according to EN ISO/IEC 17025:2005 was established at the Laboratory and presented on EURAMET QSM Forum.

  14. Proton range verification in homogeneous materials through acoustic measurements

    Science.gov (United States)

    Nie, Wei; Jones, Kevin C.; Petro, Scott; Kassaee, Alireza; Sehgal, Chandra M.; Avery, Stephen

    2018-01-01

    Clinical proton beam quality assurance (QA) requires a simple and accurate method to measure the proton beam Bragg peak (BP) depth. Protoacoustics, the measurement of the pressure waves emitted by thermal expansion resulting from proton dose deposition, may be used to obtain the depth of the BP in a phantom by measuring the time-of-flight of the pressure wave. Rectangular and cylindrical phantoms of different materials (aluminum, lead, and polyethylene) were used for protoacoustic studies. Four different methods for analyzing the protoacoustic signals are compared. Data analysis shows that, for Methods 1 and 2, plastic phantoms have better accuracy than metallic ones because of the lower speed of sound. Method 3 does not require characterizing the speed of sound in the material, but it results in the largest error. Method 4 exhibits minimal error, less than 3 mm (with an uncertainty  ⩽1.5 mm) for all the materials and geometries. Psuedospectral wave-equation simulations (k-Wave MATLAB toolbox) are used to understand the origin of acoustic reflections within the phantom. The presented simulations and experiments show that protoacoustic measurements may provide a low cost and simple QA procedure for proton beam range verification as long as the proper phantoms and calculation methods are used.

  15. Geophysical interpretation of satellite laser ranging measurements of crustal movement in California

    Science.gov (United States)

    Cohen, S. C.

    1984-01-01

    As determined by satellite laser ranging the rate of contraction of a 900 kilometer baseline between sites located near Quincy in northern California and San Diego in southern California is about 61 to 65 mm/yr with a formal uncertainty of about 10 mm/yr. The measured changes in baseline length are a manifestation of the relative motion between the North America and Pacific tectonic plates. This long baseline result is compared to measurements made by more conventional means on shorter baselines. Additional information based on seismicity, geology, and theoretical modelling is also analyzed. Deformation lying within a few tens of kilometers about the major faults in southern California accounts for most, but not all of the observed motion. Further motion is attributable to a broader scale deformation in southern California. Data suggesting crustal movements north of the Garlock fault, in and near the southern Sierra Nevada and local motion at an observatory are also critically reviewed. The best estimates of overall motion indicated by ground observations lie between 40 and 60 mm/yr. This lies within one or two standard deviations of that deduced by satellite ranging but the possibility of some unresolved deficit cannot be dismissed. The long time scale RM2 plate tectonic model of Minster and Jordan predicts a contraction between 47 and 53 mm/yr depending on the extension rate of the Basin and Range. Thus the ground based observations, satellite laser ranging (SLR) results, and RM2 rates differ at about the 10 mm/yr level and are consistent with one another within the data and model uncertainties.

  16. Broadband Measurement of Aerosol Extinction in the Visible Range

    Science.gov (United States)

    He, Quanfu; Bluvshtein, Nir; Segev, Lior; Flores, Michel; Rudich, Yinon; Washenfelder, Rebecca; Brown, Steven

    2017-04-01

    Atmospheric aerosols influence the Earth's radiative budget directly by scattering and absorbing incoming solar radiation. Aerosol direct forcing remains one of the largest uncertainties in quantifying the role that aerosols play in the Earth's radiative budget. The optical properties of aerosols vary as a function of wavelength, but few measurements reported the wavelength dependence of aerosol extinction cross section and complex refractive indices, particularly in the blue and visible spectral range. There is also currently a large gap in our knowledge of how the optical properties evolve as a function of atmospheric aging in the visible spectrum. In this study, we constructed a new and novel laboratory instrument to measure aerosol extinction as a function of wavelength, using cavity enhanced spectroscopy with a white light source. This broadband cavity enhanced spectroscopy (BBCES) covers the 395-700 nm spectral region using a broadband light source and a grating spectrometer with charge-coupled device detector (CCD). We evaluated this BBCES by measuring extinction cross section for aerosols that are pure scattering, slightly absorbing and strongly absorbing atomized from standard materials. We also retrieved the refractive indices from the measured extinction cross sections. Secondary organic aerosols from biogenic and anthropogenic precursors were "aged" to differential time scales (1 to 10 days) in an Oxidation Flow Reactor (OFR) under the combined influence of OH, O3 and UV light. The new BBCES was used to online measure the extinction cross sections of the SOA. This talk will provide a comprehensive understanding of aerosol optical properties alerting during aging process in the 395 - 700 nm spectrum.

  17. Picosecond X-ray streak camera dynamic range measurement

    Energy Technology Data Exchange (ETDEWEB)

    Zuber, C., E-mail: celine.zuber@cea.fr; Bazzoli, S.; Brunel, P.; Gontier, D.; Raimbourg, J.; Rubbelynck, C.; Trosseille, C. [CEA, DAM, DIF, F-91297 Arpajon (France); Fronty, J.-P.; Goulmy, C. [Photonis SAS, Avenue Roger Roncier, BP 520, 19106 Brive Cedex (France)

    2016-09-15

    Streak cameras are widely used to record the spatio-temporal evolution of laser-induced plasma. A prototype of picosecond X-ray streak camera has been developed and tested by Commissariat à l’Énergie Atomique et aux Énergies Alternatives to answer the Laser MegaJoule specific needs. The dynamic range of this instrument is measured with picosecond X-ray pulses generated by the interaction of a laser beam and a copper target. The required value of 100 is reached only in the configurations combining the slowest sweeping speed and optimization of the streak tube electron throughput by an appropriate choice of high voltages applied to its electrodes.

  18. Tunnel and Subsurface Void Detection and Range to Target Measurement

    Energy Technology Data Exchange (ETDEWEB)

    Phillip B. West

    2009-06-01

    Engineers and technicians at the Idaho National Laboratory invented, designed, built and tested a device capable of detecting and measuring the distance to, an underground void, or tunnel. Preliminary tests demonstrated positive detection of, and range to, a void thru as much as 30 meters of top-soil earth. Device uses acoustic driving point impedance principles pioneered by the Laboratory for well-bore physical properties logging. Data receipts recorded by the device indicates constructive-destructive interference patterns characteristic of acoustic wave reflection from a downward step-change in impedance mismatch. Prototype tests demonstrated that interference patterns in receipt waves could depict the patterns indicative of specific distances. A tool with this capability can quickly (in seconds) indicate the presence and depth/distance of a void or tunnel. Using such a device, border security and military personnel can identify threats of intrusion or weapons caches in most all soil conditions including moist and rocky.

  19. Principal component analysis of geoelectrical signals measured in the seismically active area of Basilicata Region (southern Italy

    Directory of Open Access Journals (Sweden)

    L. Telesca

    2004-01-01

    Full Text Available Geoelectrical fluctuations are the end product of several geophysical phenomena. In particular geoelectrical signals measured in seismically active areas can be attributed to stress and strain changes, associated with earthquakes. The complexity of this problem has suggested the development of advanced statistical methods to investigate the heterogeneous nature of these fluctuations. In this paper we analysed the time dynamics of short-term variability of geoelectrical field measured at Giuliano station, located in Basilicata Region, one of the most seismically active areas of southern Italy. We applied the principal component analysis (PCA. The analysis has shown earthquake precursory patterns in the daily variation of the principal components, revealing that the PCA approach is promising for monitoring seismic areas.

  20. Measurement of Acoustic-to-Seismic Conversion Using T-wave Signals Recorded at Ascension Island and Diego Garcia

    Science.gov (United States)

    Pulli, J. J.; Kofford, A. S.; Newman, K. R.; Krumhansl, P. A.

    2012-12-01

    T-wave signals from sub-sea earthquakes are often recorded on coastal or island seismic stations (Linehan, 1940; Okal, 2008). The physical process of the acoustic-to-seismic conversion is poorly understood but likely depends on factors such as seafloor relief and sediment thickness at the location where the interaction occurs. Quantification of the conversion process is necessary to understand and interpret the seismic recordings, and allow for the calculation of in-water acoustic levels from these recordings where no in-water sensor recordings are available. Applications for this knowledge would include the calculation of in-water explosion yields and seismic airgun source levels. Here we present the measurement of the acoustic-to-seismic transfer functions at Ascension Island and Diego Garcia using hydroacoustic data from the International Monitoring System and broadband seismic data from the Global Seismic Network. For Ascension Island, a volcanic island formed above magmatic plumes, we used T-wave signals from earthquakes on the Central Mid-Atlantic Ridge and associated fracture zones. For Diego Garcia, an atoll of carbonate sequences and no volcanism, we used T-wave signals from earthquakes along the Sumatran Subduction Zone, the Indian Ocean Ridges, and the Chagos Arch. The methodology is based on the smoothed cross-spectra over a frequency band that is common to the acoustic and seismic recordings, typically 2-18 Hz. Preliminary results indicate that at 5 Hz the acoustic-to-seismic conversion is 2-4 times more efficient at Ascension Island than at Diego Garcia (124 nm/s/Pa vs. 51 nm/s/Pa, respectively), but nearly equal at 10 Hz (20 nm/s/Pa). At 15 Hz the conversion is more efficient at Diego Garcia (13 nm/s/Pa vs. 8 nm/s/Pa at Ascension). We also investigate the azimuthal variance of this transfer function, as well as the differences between the three components of seismic motion. As a verification of the methodology, we use the equivalent time domain

  1. Carbon monoxide degassing from seismic fault zones in the Basin and Range province, west of Beijing, China

    Science.gov (United States)

    Sun, Yutao; Zhou, Xiaocheng; Zheng, Guodong; Li, Jing; Shi, Hongyu; Guo, Zhengfu; Du, Jianguo

    2017-11-01

    Degassing of carbon monoxide (CO), which plays a significant role in the contribution of deep carbon to the atmosphere, commonly occurs within active fault zones. CO degassing from soil to the atmosphere in the Basin and Range province, west of Beijing (BRPB), China, was investigated by in-situ field measurements in the active fault zones. The measured concentrations of CO in soil gas in the BRPB ranged from 0.29 × 10-6 to 1.1 × 10-6 with a mean value of 0.6 × 10-6, which is approximately twice as large as that in the atmosphere. Net fluxes of CO degassing ranged from -48.6 mg m-2 d-1 to 12.03 mg m-2 d-1. The diffusion of CO from soil to the atmosphere in the BRPB was estimated to be at least 7.6 × 103 ton/a, which is comparable to the corresponding result of about 1.2 × 104 ton/a for CO2. CO concentrations were spatially heterogeneous with clearly higher concentrations along the NE-SW trending in the BRPB. These elevated values of CO concentrations were also coincident with the region with low-velocity and high conductivity in deep mantle, and high Poisson's ratio in the crust, thereby suggesting that CO degassing from the soil might be linked to upwelling of the asthenospheric mantle. Other sources of CO in the soil gas are suggested to be dominated by chemical reactions between deep fluids and carbonate minerals (e.g., dolomite, limestone, and siderite) in country rocks. Biogenic processes may also contribute to the CO in soil gas. The spatial distribution patterns of CO concentrations are coincident with the stress field, suggesting that the concentrations of CO could be a potential indicator for crustal stress field and, hence is potential useful for earthquake monitoring in the BRPB.

  2. CENTIMETER COSMO-SKYMED RANGE MEASUREMENTS FOR MONITORING GROUND DISPLACEMENTS

    Directory of Open Access Journals (Sweden)

    F. Fratarcangeli

    2016-06-01

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

  3. Assessing the small-strain soil stiffness for offshore wind turbines based on in situ seismic measurements

    NARCIS (Netherlands)

    Versteijlen, W.G.; Van Dalen, K.N.; Metrikine, A.; Hamre, L.

    2014-01-01

    In this contribution, in situ seismic measurements are used to derive the small-strain shear modulus of soil as input for two soil-structure interaction (SSI) models to assess the initial soil stiffness for offshore wind turbine foundations. This stiffness has a defining influence on the first

  4. Geophysical and transport properties of reservoir rocks. Final report for task 4: Measurements and analysis of seismic properties

    Energy Technology Data Exchange (ETDEWEB)

    Cook, N.G.W.

    1993-05-01

    The principal objective of research on the seismic properties of reservoir rocks is to develop a basic understanding of the effects of rock microstructure and its contained pore fluids on seismic velocities and attenuation. Ultimately, this knowledge would be used to extract reservoir properties information such as the porosity, permeability, clay content, fluid saturation, and fluid type from borehole, cross-borehole, and surface seismic measurements to improve the planning and control of oil and gas recovery. This thesis presents laboratory ultrasonic measurements for three granular materials and attempts to relate the microstructural properties and the properties of the pore fluids to P- and S-wave velocities and attenuation. These experimental results show that artificial porous materials with sintered grains and a sandstone with partially cemented grains exhibit complexities in P- and S-wave attenuation that cannot be adequately explained by existing micromechanical theories. It is likely that some of the complexity observed in the seismic attenuation is controlled by details of the rock microstructure, such as the grain contact area and grain shape, and by the arrangement of the grain packing. To examine these effects, a numerical method was developed for analyzing wave propagation in a grain packing. The method is based on a dynamic boundary integral equation and incorporates generalized stiffness boundary conditions between individual grains to account for viscous losses and grain contact scattering.

  5. Design and implementation of a low-cost multichannel seismic noise recorder for array measurements

    Science.gov (United States)

    Soler-Llorens, Juan Luis; Juan Giner-Caturla, Jose; Molina-Palacios, Sergio; Galiana-Merino, Juan Jose; Rosa-Herranz, Julio; Agea-Medina, Noelia

    2017-04-01

    Soil characterization is the starting point for seismic hazard studies. Currently, the methods based on ambient noise measurements are very used because they are non-invasive methods and relatively easy to implement in urban areas. Among these methods, the analysis of array measurements provides the dispersion curve and subsequently the shear-wave velocity profile associated to the site under study. In this case, we need several sensors recording simultaneously and a data acquisition system with one channel by sensor, what can become the complete equipment unaffordable for small research groups. In this work, we have designed and implemented a low-cost multichannel ambient noise recorder for array measurements. The complete system is based on Arduino, an open source electronic development platform, which allows recording 12 differential input channels simultaneously. Besides, it is complemented with a conditioning circuit that includes an anti-aliasing filter and a selectable gain between 0 and 40dB. The data acquisition is set up through a user-friendly graphical user interface. It is important to note that the electronic scheme as well as the programming code are open hardware and software, respectively, so it allows other researchers to suite the system to their particular requirements. The developed equipment has been tested at several sites around the province of Alicante (southeast of Spain), where the soil characteristics are well-known from previous studies. Array measurements have been taken and after that, the recorded data have been analysed using the frequency-wavenumber (f-k) and the extended spatial autocorrelation (ESAC) methods. The comparison of the obtained dispersion curves with the ones obtained in previous studies shows the suitability of the implemented low-cost system for array measurements.

  6. Fusing range measurements from ultrasonic beacons and a laser range finder for localization of a mobile robot.

    Science.gov (United States)

    Ko, Nak Yong; Kuc, Tae-Yong

    2015-05-11

    This paper proposes a method for mobile robot localization in a partially unknown indoor environment. The method fuses two types of range measurements: the range from the robot to the beacons measured by ultrasonic sensors and the range from the robot to the walls surrounding the robot measured by a laser range finder (LRF). For the fusion, the unscented Kalman filter (UKF) is utilized. Because finding the Jacobian matrix is not feasible for range measurement using an LRF, UKF has an advantage in this situation over the extended KF. The locations of the beacons and range data from the beacons are available, whereas the correspondence of the range data to the beacon is not given. Therefore, the proposed method also deals with the problem of data association to determine which beacon corresponds to the given range data. The proposed approach is evaluated using different sets of design parameter values and is compared with the method that uses only an LRF or ultrasonic beacons. Comparative analysis shows that even though ultrasonic beacons are sparsely populated, have a large error and have a slow update rate, they improve the localization performance when fused with the LRF measurement. In addition, proper adjustment of the UKF design parameters is crucial for full utilization of the UKF approach for sensor fusion. This study contributes to the derivation of a UKF-based design methodology to fuse two exteroceptive measurements that are complementary to each other in localization.

  7. Brittleness estimation from seismic measurements in unconventional reservoirs: Application to the Barnett shale

    Science.gov (United States)

    Perez Altimar, Roderick

    Brittleness is a key characteristic for effective reservoir stimulation and is mainly controlled by mineralogy in unconventional reservoirs. Unfortunately, there is no universally accepted means of predicting brittleness from measures made in wells or from surface seismic data. Brittleness indices (BI) are based on mineralogy, while brittleness average estimations are based on Young's modulus and Poisson's ratio. I evaluate two of the more popular brittleness estimation techniques and apply them to a Barnett Shale seismic survey in order to estimate its geomechanical properties. Using specialized logging tools such as elemental capture tool, density, and P- and S wave sonic logs calibrated to previous core descriptions and laboratory measurements, I create a survey-specific BI template in Young's modulus versus Poisson's ratio or alternatively lambdarho versus murho space. I use this template to predict BI from elastic parameters computed from surface seismic data, providing a continuous estimate of BI estimate in the Barnett Shale survey. Extracting lambdarho-murho values from microseismic event locations, I compute brittleness index from the template and find that most microsemic events occur in the more brittle part of the reservoir. My template is validated through a suite of microseismic experiments that shows most events occurring in brittle zones, fewer events in the ductile shale, and fewer events still in the limestone fracture barriers. Estimated ultimate recovery (EUR) is an estimate of the expected total production of oil and/or gas for the economic life of a well and is widely used in the evaluation of resource play reserves. In the literature it is possible to find several approaches for forecasting purposes and economic analyses. However, the extension to newer infill wells is somewhat challenging because production forecasts in unconventional reservoirs are a function of both completion effectiveness and reservoir quality. For shale gas reservoirs

  8. Extending the range of turbidity measurement using polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Justin S.

    2017-11-21

    Turbidity measurements are obtained by directing a polarized optical beam to a scattering sample. Scattered portions of the beam are measured in orthogonal polarization states to determine a scattering minimum and a scattering maximum. These values are used to determine a degree of polarization of the scattered portions of the beam, and concentrations of scattering materials or turbidity can be estimated using the degree of polarization. Typically, linear polarizations are used, and scattering is measured along an axis that orthogonal to the direction of propagation of the polarized optical beam.

  9. A low-power tool for measuring acceleration, pressure, and temperature (APT) with wide dynamic range and bandwidth

    Science.gov (United States)

    Heesemann, Martin; Davis, Earl E.; Paros, Jerome; Johnson, Greg; Meldrum, Robert; Scherwath, Martin; Mihaly, Steven

    2017-04-01

    We present a new tool that facilitates the study of inter-related geodetic, geodynamic, seismic, and oceanographic phenomena. It incorporates a temperature compensated tri-axial accelerometer developed by Quartz Seismic Sensors, Inc., a pressure sensor built by Paroscientific Inc., and a low-power, high-precision frequency counter developed by Bennest Enterprises Ltd. and built by RBR, Ltd. The sensors are housed in a 7 cm o.d. titanium pressure case designed for use to full ocean depths (withstands more than 20 km of water pressure). Sampling intervals are programmable from 0.08 s to 1 hr; standard memory can store up to 130 million samples; total power consumption is roughly 115 mW when operating continuously and proportionately lower when operating intermittently (e.g., 2 mW average at 1 sample per min). Serial and USB communications protocols allow a variety of autonomous and cable-connection options. Measurement precision of the order of 10-8 of full scale (e.g., pressure equivalent to 4000 m water depth, acceleration = +/- 3 g) allows observations of pressure and acceleration variations of 0.4 Pa and 0.3 μm s-2. Long-term variations in vertical acceleration are sensitive to displacement through the gravity gradient down to a level of roughly 2 cm, and variations in horizontal acceleration are sensitive to tilt down to a level of 0.03 μrad. With the large dynamic ranges, high sensitivities and broad bandwidth (6 Hz to DC), ground motion associated with microseisms, strong and weak seismic ground motion, tidal loading, and slow and rapid geodynamic deformation - all normally studied using disparate instruments - can be observed with a single tool. Installation in the marine environment is accomplished by pushing the tool roughly 1 m vertically below the seafloor with a submersible or remotely operated vehicle, with no profile remaining above the seafloor to cause current-induced noise. The weight of the tool is designed to match the sediment it displaces to

  10. Intensity autocorrelation measurements of frequency combs in the terahertz range

    Science.gov (United States)

    Benea-Chelmus, Ileana-Cristina; Rösch, Markus; Scalari, Giacomo; Beck, Mattias; Faist, Jérôme

    2017-09-01

    We report on direct measurements of the emission character of quantum cascade laser based frequency combs, using intensity autocorrelation. Our implementation is based on fast electro-optic sampling, with a detection spectral bandwidth matching the emission bandwidth of the comb laser, around 2.5 THz. We find the output of these frequency combs to be continuous even in the locked regime, but accompanied by a strong intensity modulation. Moreover, with our record temporal resolution of only few hundreds of femtoseconds, we can resolve correlated intensity modulation occurring on time scales as short as the gain recovery time, about 4 ps. By direct comparison with pulsed terahertz light originating from a photoconductive emitter, we demonstrate the peculiar emission pattern of these lasers. The measurement technique is self-referenced and ultrafast, and requires no reconstruction. It will be of significant importance in future measurements of ultrashort pulses from quantum cascade lasers.

  11. Silicon device performance measurements to support temperature range enhancement

    Science.gov (United States)

    Johnson, R. Wayne; Askew, Ray; Bromstead, James; Weir, Bennett

    1991-01-01

    The results of the NPN bipolar transistor (BJT) (2N6023) breakdown voltage measurements were analyzed. Switching measurements were made on the NPN BJT, the insulated gate bipolar transistor (IGBT) (TA9796) and the N-channel metal oxide semiconductor field effect transistor (MOSFET) (RFH75N05E). Efforts were also made to build a H-bridge inverter. Also discussed are the plans that have been made to do life testing on the devices, to build an inductive switching test circuit and to build a dc/dc switched mode converter.

  12. Offshore wind profiling using light detection and ranging measurements

    DEFF Research Database (Denmark)

    Pena Diaz, Alfredo; Hasager, Charlotte Bay; Gryning, Sven-Erik

    2009-01-01

    The advantages and limitations of the ZephlR (R), a continuous-wave, focused light detection and ranging (LiDAR) wind profiler, to observe offshore winds and turbulence characteristics were tested during a 6 month campaign at the tronsformer/platform of Hams Rev, the world's largest wind form......-derived friction velocities and roughness lengths were compared to Charnock's sea roughness model. These overage values were found to be close to the model, although the scatter of the individual estimations of sea roughness length was large. Copyright (C) 2008 John Wiley & Sons, Ltd....

  13. Measurements of Capture Efficiency of Range Hoods in Homes

    DEFF Research Database (Denmark)

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

    2015-01-01

    mapped the pollution distribution in the room, and showed that the pollutants escape more at the sides of the cooktop. These preliminary results suggest that more measurements should be conducted investigating the capture efficiency at different pollutant source temperature, size and location...

  14. Seismic Studies

    Energy Technology Data Exchange (ETDEWEB)

    R. Quittmeyer

    2006-09-25

    This technical work plan (TWP) describes the efforts to develop and confirm seismic ground motion inputs used for preclosure design and probabilistic safety 'analyses and to assess the postclosure performance of a repository at Yucca Mountain, Nevada. As part of the effort to develop seismic inputs, the TWP covers testing and analyses that provide the technical basis for inputs to the seismic ground-motion site-response model. The TWP also addresses preparation of a seismic methodology report for submission to the U.S. Nuclear Regulatory Commission (NRC). The activities discussed in this TWP are planned for fiscal years (FY) 2006 through 2008. Some of the work enhances the technical basis for previously developed seismic inputs and reduces uncertainties and conservatism used in previous analyses and modeling. These activities support the defense of a license application. Other activities provide new results that will support development of the preclosure, safety case; these results directly support and will be included in the license application. Table 1 indicates which activities support the license application and which support licensing defense. The activities are listed in Section 1.2; the methods and approaches used to implement them are discussed in more detail in Section 2.2. Technical and performance objectives of this work scope are: (1) For annual ground motion exceedance probabilities appropriate for preclosure design analyses, provide site-specific seismic design acceleration response spectra for a range of damping values; strain-compatible soil properties; peak motions, strains, and curvatures as a function of depth; and time histories (acceleration, velocity, and displacement). Provide seismic design inputs for the waste emplacement level and for surface sites. Results should be consistent with the probabilistic seismic hazard analysis (PSHA) for Yucca Mountain and reflect, as appropriate, available knowledge on the limits to extreme ground

  15. Robust Long-Range Optical Tracking for Tunneling Measurement Tasks

    Science.gov (United States)

    Mossel, Annette; Gerstweiler, Georg; Vonach, Emanuel; Chmelina, Klaus; Kaufmann, Hannes

    2013-04-01

    Over the last years, automation for tunnel construction and mining activities increased rapidly. To allow for enhanced tunneling measurement, monitoring of workers and remote control of machines, systems are required that are capable of real-time positioning of several static as well as moving targets. Such a system must provide continuous and precise 3D position estimation in large volumes and must be capable to be installed and work correctly during on-going tunneling or mining tasks. Tracking systems are a fundamental component of a VR system to determine the 3D-position and orientation of a target in 3D space. Infrared optical tracking systems use infrared light to track several static or moving targets simultaneously with low latency in small tracking volumes. To benefit from the capabilities of infrared optical tracking, a system is proposed to track static as well as moving optical targets in large tracking volumes with a maximum depth extend of 70 meters. Our system needs a minimal hardware setup consisting out of two high quality machine vision cameras, which are mounted on both walls of the tunnel, and a standard (portable) workstation for data processing. Targets are equipped with infrared LEDs and can be either carried by workers or attached to a machine. The two cameras form a stereo rig and face into the measurement volume to allow for continuous tracking. Using image processing techniques, the LEDs of the target(s) are detected in both 2D camera images and are back-projected into 3D using projective reconstruction algorithms. Thereby, the 3D position estimate of the target is determined. Using image filtering techniques, fitting methods based on target's geometric constraints and prediction heuristics, the system allows for unique target identification during calibration and tracking even in environments with heavy interferences such as vibrations, tunnel illumination or machine lights. We extensively tested the system to (1) determine optimal

  16. Soil radon measurements as potential tracer of seismic and volcanic activity at Etna

    Science.gov (United States)

    Neri, Marco; Giammanco, Salvatore; Galli, Gianfranco; Ferrera, Elisabetta

    2014-05-01

    Radon is a radioactive noble gas present in all rocks of the Earth. It's used by the scientific community as a tracer of natural phenomena related to outgassing from the soil along faults, fractures and crustal discontinuity. Recently, radon has also been used on active volcanoes such as Etna, both as a precursor of volcanic phenomena as well as in the study of the dynamics of faults. The Istituto Nazionale di Geofisica e Vulcanologia (INGV) performs discrete and continuous measurements of radon from soil at Etna since 2002. First studies concerned measurements of radon and thoron emissions from soil carried out on the E and SW flanks of Etna, in zones characterized by the presence of numerous seismogenic and aseismic faults. The statistical treatment of the geochemical data allowed recognizing anomaly thresholds, producing distribution maps that highlighted a significant spatial correlation between soil gas anomalies and tectonic lineaments. These studies confirmed that mapping the distribution of radon and thoron in soil gas can reveal hidden faults buried by recent soil cover. INGV permanent radon monitoring network was installed in July 2005. First results were obtained during the July 2006 eruption. The radon signal recorded at Torre del Filosofo (TdF, ~2950 m asl) was compared with volcanic tremor and thermal radiance data. The onset of explosive activity and a lava fountaining episode were preceded by some hours with increases in radon activity and more gradual increases in volcanic tremor. After 2006, Etna produced dozens of paroxysmal episodes from a new vent opened on the eastern flank of the Southeast Crater (summit area), that have built up a new, huge pyroclastic cone. In many cases we observed increase in radon activity some hours before the eruptive events. These observations suggest that radon emissions from the TdF zone are sensitive to the local geodynamic pressure induced by magma dynamics in the conduit systems. Other promising results were

  17. Crustal Seismic Attenuation in Germany Measured with Acoustic Radiative Transfer Theory

    Science.gov (United States)

    Gaebler, Peter J.; Eulenfeld, Tom; Wegler, Ulrich

    2017-04-01

    This work is carried out in the context of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). As part of this treaty a verification regime was introduced to detect, locate and characterize nuclear explosion testings. The study of seismology can provide essential information in the form of broadband waveform recordings for the identification and verification of these critical events. A profound knowledge of the Earth's subsurface between source and receiver is required for a detailed description of the seismic wave field. In addition to underground parameters such as seismic velocity or anisotropy, information about seismic attenuation values of the medium are required. Goal of this study is the creation of a comprehensive model of crustal seismic attenuation in Germany and adjacent areas. Over 20 years of earthquake data from the German Central Seismological Observatory data archive is used to estimate the spatial dependent distribution of seismic intrinsic and scattering attenuation of S-waves for frequencies between 0.5 and 20 Hz. The attenuation models are estimated by fitting synthetic seismogram envelopes calculated with acoustic radiative transfer theory to observed seismogram envelopes. This theory describes the propagation of seismic S-energy under the assumption of multiple isotropic scattering, the crustal structure of the scattering medium is hereby represented by a half-space model. We present preliminary results of the spatial distribution of intrinsic attenuation represented by the absorption path length, as well as of scattering attenuation in terms of the mean free path and compare the outcomes to results from previous studies. Furthermore catalog magnitudes are compared to moment magnitudes estimated during the inversion process. Additionally site amplification factors of the stations are presented.

  18. A Sparse Bayesian Imaging Technique for Efficient Recovery of Reservoir Channels With Time-Lapse Seismic Measurements

    KAUST Repository

    Sana, Furrukh

    2016-06-01

    Subsurface reservoir flow channels are characterized by high-permeability values and serve as preferred pathways for fluid propagation. Accurate estimation of their geophysical structures is thus of great importance for the oil industry. The ensemble Kalman filter (EnKF) is a widely used statistical technique for estimating subsurface reservoir model parameters. However, accurate reconstruction of the subsurface geological features with the EnKF is challenging because of the limited measurements available from the wells and the smoothing effects imposed by the \\\\ell _{2} -norm nature of its update step. A new EnKF scheme based on sparse domain representation was introduced by Sana et al. (2015) to incorporate useful prior structural information in the estimation process for efficient recovery of subsurface channels. In this paper, we extend this work in two ways: 1) investigate the effects of incorporating time-lapse seismic data on the channel reconstruction; and 2) explore a Bayesian sparse reconstruction algorithm with the potential ability to reduce the computational requirements. Numerical results suggest that the performance of the new sparse Bayesian based EnKF scheme is enhanced with the availability of seismic measurements, leading to further improvement in the recovery of flow channels structures. The sparse Bayesian approach further provides a computationally efficient framework for enforcing a sparse solution, especially with the possibility of using high sparsity rates through the inclusion of seismic data.

  19. Peru Subduction Experiment (PERUSE) Preliminary results of Gravity measurements, Earthquake locations and Regional Seismicity in Southern Peru

    Science.gov (United States)

    Foote, E. J.; Davis, P. M.; Guy, R.; Lukac, M. L.; Feng, H. S.; Clayton, R. W.; Phillips, K. E.; Skinner, S.; Audin, L.; Tavera, H.; Aguilar, V.

    2009-12-01

    The Peru Subduction Experiment (PERUSE) is a collaborative project developed by UCLA, Caltech, French L’Institut de Recherche pour le Développement (IRD) and Instituto Geofisico del Peru (IGP) to improve geophysical models of the Andean Orogenic Belt and to image the subduction process in Southern Peru. One area of particular interest is where the Nazca Plate transitions from a normally subducting slab at an angle of about 30 degrees to a shallow subducting slab beneath the South American Plate. The PERUSE project, which started in the summer of 2008, consists of a linear array of 50 broadband seismic stations that are evenly spaced about 6 kilometers apart. They are aligned perpendicular to the coast of Peru, from Mollendo to Juliaca. Caltech will deploy 50 more stations by the end of 2009. Their line will run perpendicular to the current line, from Juliaca to Cusco. By the end of 2010, a third linear array will be installed north of and perpendicular to Caltech’s line in the Altiplano. Preliminary results from gravity measurements indicate that the crustal root of the Andes dips approximately 20 degrees on both sides of the range, and extends to a depth of approximately 70km. This also agrees well with the receiver function results, which show that the crust thickens from the coast of Mollendo through the Altiplano to Juliaca to a depth about 70km (Phillips et al, Fall AGU 2009). Teleseismic studies also indicate that the crustal thickness varies laterally below southern Peru. We are developing a heterogeneous model from the topographic and gravity data, teleseismic events, and the receiver function results to accurately locate earthquakes in the area of interest and to provide a better crustal model of the region.

  20. Long-range measurement system using ultrasonic range sensor with high-power transmitter array in air.

    Science.gov (United States)

    Kumar, Sahdev; Furuhashi, Hideo

    2017-02-01

    A long-range measurement system comprising an ultrasonic range sensor with a high-power ultrasonic transmitter array in air was investigated. The system is simple in construction and can be used under adverse conditions such as fog, rain, darkness, and smoke. However, due to ultrasonic waves are well absorbed by air molecules, the measurable range is limited to a few meters. Therefore, we developed a high-power ultrasonic transmitter array consisting of 144 transmitting elements. All elements are arranged in the form of a 12×12 array pattern. The sound pressure level at 5m from the transmitter array was >30dB higher than that of a single element. A measuring range of over 25m was achieved using this transmitter array in conjunction with a receiver array having 32 receiving elements. The characteristics of the transmitter array and range sensor system are discussed by comparing simulation and experimental results. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Measured Response of Local, Mid-range and Far-range Discontinuities of Large Metal Groundplanes using Time Domain Techniques

    Directory of Open Access Journals (Sweden)

    T. Schrader

    2005-01-01

    Full Text Available This work describes a method to detect and to quantify any local or mid-range discontinuity on extended flat metal planes. Often these planes are used for antenna calibration (open area test site - OATS or the plane could be the ground of a semi-anechoic chamber used in Electromagnetic Compatibility (EMC testing. The measurement uncertainty of antenna calibration or EMC testing depends on the groundplane's quality, which can be accessed using this method. A vector network analyzer with time-domain option is used to determine the complex-valued input scattering parameter S11,F of an aperture antenna in a monostatic setup. S11,F contains the information desired about the discontinuities and is measured in the frequency domain with high dynamic range. But only after a linear filtering utilizing the Chirp-Z-Transform the obtained time-domain signal S11,T evidence of local and mid-range discontinuities.

  2. Evolution of a giant debris flow in the transitional mountainous region between the Tibetan Plateau and the Qinling Mountain range, Western China: Constraints from broadband seismic records

    Science.gov (United States)

    Huang, Xinghui; Li, Zhengyuan; Yu, Dan; Xu, Qiang; Fan, Junyi; Hao, Zhen; Niu, Yanping

    2017-10-01

    The catastrophic Sanyanyu and Luojiayu debris flows, which were induced by heavy rainfall, occurred at approximately midnight, August 7th, 2010 (Beijing time, UTC + 8) and claimed 1,765 lives. Most seismic stations located within 150 km did not detect the debris flows except for the closest seismic station, ZHQ, indicating that the seismic signals generated by the debris flows decayed rapidly. We analyzed broadband seismic signals from the ZHQ seismic station, beginning approximately 20 min before the outbreak of the Sanyanyu debris flow, to rebuild its evolution processes. Seismic signals can detect development of the Sanyanyu debris flow approximately 20 min after a heavy rain started falling in its initiation area; this time was characterized by a gradual increase in seismic amplitude accompanied by a series of spike signals that were probably generated by rock collapses within the catchment. The frequency contents and the characteristics of seismic signals before and after 23:33:15 (T1) are distinctively different, which we interpret as being generated by a large quantity of flowing material entering the main channel, marking the formation of the Sanyanyu debris flow. We attribute seismic amplitude increases between 23:33:15 (T1) and 23:34:26 (T2) and between 23:35:40 (T3) and 23:36:49 (T4) to entrainment of the deposit material after initiation of the debris flow and to its flow through a colluvial deposit area, respectively. The main frequency band broadening of seismic signals after 23:37:30 (T5) is believed to have been induced by impacts between the flowing material and check dams.

  3. Characterization of magnetized ore bodies based on three-component borehole magnetic and directional borehole seismic measurements

    Science.gov (United States)

    Virgil, Christopher; Neuhaus, Martin; Hördt, Andreas; Giese, Rüdiger; Krüger, Kay; Jurczyk, Andreas; Juhlin, Christopher; Juhojuntti, Niklas

    2016-04-01

    In the last decades magnetic prospecting using total field data was used with great success for localization and characterization of ferromagnetic ore bodies. Especially borehole magnetic measurements reveal important constraints on the extent and depth of potential mining targets. However, due to the inherent ambiguity of the interpretation of magnetic data, the resulting models of the distribution of magnetized material, such as iron ore bodies, are not entirely reliable. Variations in derived parameters like volume and estimated ore content of the expected body have significant impact on the economic efficiency of a planned mine. An important improvement is the introduction of three-component borehole magnetic sondes. Modern tools comprise orientation modules which allow the continuous determination of the tool's heading regardless of the well inclination and independent of the magnetic field. Using the heading information the recorded three-component magnetic data can be transferred from the internal tool's frame to the geographic reference frame. The vector information yields a more detailed and reliable description of the ore bodies compared to total field or horizontal and vertical field data. Nevertheless complementary information to constrain the model is still advisable. The most important supplementary information for the interpretation of magnetic data is the knowledge of the structural environment of the target regions. By discriminating dissimilar rock units, a geometrical starting model can be derived, constraining the magnetic interpretation and leading to a more robust estimation of the rock magnetizations distribution. The most common approach to reveal the lithological setting rests upon seismic measurements. However, for deep drilling targets surface seismic and VSP lack the required spatial resolution of 10s of meters. A better resolution is achieved by using directed sources and receivers inside the borehole. Here we present the application of

  4. Geotechnical Parameters from Seismic Measurements: Two Field Examples from Egypt and Saudi Arabia

    KAUST Repository

    Khalil, Mohamed H.

    2016-03-18

    © 2016 EEGS. Geotechnical parameters were used to determine subsurface rock quality for construction purposes. We summarize the mathematical relationships used to calculate the geotechnical parameters from P- and S-wave velocities and density values. These relationships are applied to two field examples; the first is a regional seismic study in Egypt and the second is a 2-D seismic profile recorded in Saudi Arabia. Results from both field examples are used to determine the subsurface rock quality and locate zones that should be avoided during construction. We suggest combining all geotechnical parameters into one map using a normalized-weighted relation, which helps to locate the zones with high versus low rock quality for engineering purposes.

  5. Study of Behavior and Measurement of Seismic Resistant Connections in Light Structural Frame Out of Aspen

    Directory of Open Access Journals (Sweden)

    Mohammad Shamsian

    2012-06-01

    Full Text Available Earthquake is the major Natural disaster in Iran which once a while causes widespread death and financial losses. Constructional system and materials used in them, most often accelerate these damages, so these are considered principal reasons of the events. Countries that have regions of high seismicity, conducted research on constructional systems, materials, and methods of improving their resistance to earthquake. These research efforts have found simple solution of the problem in wood and its proper combinations with other constructional materials. In this research, regarding such target, two subjects were studied. A model of light framed one story single-family residential house in Iran was constructed to determine its dynamical behavior. The model was constructed in one- third scale of a unit with 54 square meters in base. Foundation anchorage in model was made by metal angle pieces, which were bolted to lower plank. These types of connectors could easily be fabricated in metal working shops in Iran. The rest of joints in model were made with bolts and common nails. To see the behavior of the model, its natural frequency, acceleration at different points, lateral movements (displacement, and also response of joints to tensile and compressive forces (developed due to lateral dynamical loading on a shaking table were measured and analyzed. Results have shown that with respect to Fast Fourier Transformation spectra, ratio of maximum acceleration in roof to bottom of model, in sinusoidal acceleration test, the natural frequency of model is ten HZ (fn = 10 Hz, since 10 Hz frequency has the highest amplitude. This result had contingency with data of sinusoidal acceleration records with 10 HZ frequency and 0.64 g as well. Therefore, stiffness of model structure would be 78,250 Kg/cm. In addition, results of several sinusoidal acceleration tests for determining delay damping, has shown on the average 0.039 for this quantity. Brief results of

  6. Range Measurements of keV Hydrogen Ions in Solid Oxygen and Carbon Monoxide

    DEFF Research Database (Denmark)

    Schou, Jørgen; Sørensen, H.; Andersen, H.H.

    1984-01-01

    Ranges of 1.3–3.5 keV/atom hydrogen and deuterium molecular ions have been measured by a thin-film reflection method. The technique, used here for range measurements in solid oxygen and carbon monoxide targets, is identical to the one used previously for range measurements in hydrogen and nitrogen....... The main aim was to look for phase-effects, i.e. gas-solid differences in the stopping processes. While measured ranges in solid oxygen were in agreement with known gas data, the ranges in solid carbon monoxide were up to 50% larger than those calculated from gas-stopping data. The latter result agrees...

  7. Communication system features dual mode range acquisition plus time delay measurement

    Science.gov (United States)

    Atwood, S. W.; Kline, A. W., Jr.; Welter, N. E.

    1968-01-01

    Communication system combines range acquisition system and time measurement system for tracking high velocity aircraft and spacecraft. The range acquisition system uses a pseudonoise code to determine range and the time measurement system reduces uncontrolled phase variations in the demodulated signal.

  8. Assessment of Damage in Seismically Excited RC-Structures from a Single Measured Response

    DEFF Research Database (Denmark)

    Skjærbæk, P. S.; Nielsen, Søren R.K.; Cakmak, A. S.

    A method has been developed for the localization of structural damage of substructures of seismically excited RC-structures using only the ground surface acceleration time series and a single response time series. From the response, the smoothed two lowest eigenfrequencies are estimated. The dist......A method has been developed for the localization of structural damage of substructures of seismically excited RC-structures using only the ground surface acceleration time series and a single response time series. From the response, the smoothed two lowest eigenfrequencies are estimated...... by a sequence of substructures, where two new substructures are introduced at each level, so that the smoothed eigenfrequencies are reproduced at each level. The method is applied to simulated data of a 1-bay, 2-storey RC-frame and a 1-bay, 4-storey RC-frame generated by a finite element programme developed...... for RC-frames which also admits an estimation of local damage. Based on the response time series calculated by the finite element programme, the corresponding local damages are next calculated by the present method. The method is investigated at different intensities of the earthquake and upon comparison...

  9. Assessment of Damage in Seismically Excited RC-Structures from a Single Measured Response

    DEFF Research Database (Denmark)

    Skjærbæk, P. S.; Nielsen, Søren R. K.; Cakmak, A. S.

    1996-01-01

    A method has been developed for the localization of structural damage of substructures of seismically excited RC-structures using only the ground surface acceleration time series and a single response time series. From the response, the smoothed two lowest eigenfrequencies are estimated. The dist......A method has been developed for the localization of structural damage of substructures of seismically excited RC-structures using only the ground surface acceleration time series and a single response time series. From the response, the smoothed two lowest eigenfrequencies are estimated...... by a sequence of substructures, where two new substructures are introduced at each level, so that the smoothed eigenfrequencies are reproduced at each level. The method is applied to simulated data of a 1-bay, 2-storey RC-frame and a 1-bay, 4-storey RC-frame generated by a finite element programme developed...... for RC-frames which also admits an estimation of local damage. Based on the response time series calculated by the finite element programme, the corresponding local damages are next calculated by the present method. The method is investigated at different intensities of the earthquake and upon comparison...

  10. Weightbearing and nonweightbearing ankle dorsiflexion range of motion: are we measuring the same thing?

    Science.gov (United States)

    Rabin, Alon; Kozol, Zvi

    2012-01-01

    Ankle dorsiflexion range of motion has been measured in weightbearing and nonweightbearing conditions. The different measurement conditions may contribute to inconsistent conclusions regarding the role of ankle dorsiflexion in several pathologic conditions. The purpose of this study was to examine the relationship between ankle dorsiflexion range of motion as measured in weightbearing and nonweightbearing conditions. We compared ankle dorsiflexion range of motion as measured in a weightbearing versus a nonweightbearing position in 43 healthy volunteers. Measurements were taken separately by two examiners. Weightbearing and nonweightbearing ankle dorsiflexion measurements produced significantly different results (P dorsiflexion measurements produce significantly different results and only a moderate correlation, suggesting that these two measurements should not be used interchangeably as measures of ankle dorsiflexion range of motion.

  11. Imaging Seismic Reflections

    NARCIS (Netherlands)

    op 't Root, T.J.P.M.; Op 't Root, Timotheus Johannes Petrus Maria

    2011-01-01

    The goal of reflection seismic imaging is making images of the Earth subsurface using surface measurements of reflected seismic waves. Besides the position and orientation of subsurface reflecting interfaces it is a challenge to recover the size or amplitude of the discontinuities. We investigate

  12. Reliability of digital compass goniometer in knee joint range of motion measurement.

    Science.gov (United States)

    Yaikwawongs, Nammond; Limpaphayom, Noppachart; Wilairatana, Vajara

    2009-04-01

    To compare the reliability of range of motion measurement in the knee joint using a digital compass goniometer combined with inclinometer with standard range of motion measurement from roentgenographic picture. Range of flexion and extension of the knee joint in volunteer participants was measured by the newly developed digital compass goniometer combined with inclinometer (DCG). The results were compared with range of knee joint motion obtained from standard roentgenographic picture by intraclass correlation coefficient. Range of motion of knee joint measured by DCG correlated very well with the data obtained from standard knee roentgenographic picture. The intraclass correlation coefficient equals 0.973. The digital compass goniometer was a reliable tool to measure knee joint range of motion in flexion and extension plane.

  13. Optimizing measurement geometry for seismic near-surface full waveform inversion

    Science.gov (United States)

    Nuber, André; Manukyan, Edgar; Maurer, Hansruedi

    2017-09-01

    Full waveform inversion (FWI) is an increasingly popular tool for analysing seismic data. Current practise is to record seismic data sets that are suitable for reflection processing, that is, a very dense spatial sampling and a high fold are required. Using tools from optimized experimental design (ED), we demonstrate that such a dense sampling is not necessary for FWI purposes. With a simple noise-free acoustic example, we show that only a few suitably selected source positions are required for computing high-quality images. A second, more extensive study includes elastic FWI with noise-contaminated data and free-surface boundary conditions on a typical near-surface setup, where surface waves play a crucial role. The study reveals that it is sufficient to employ a receiver spacing in the order of the minimum shear wavelength expected. Furthermore, we show that horizontally oriented sources and multicomponent receivers are the preferred option for 2-D elastic FWI, and we found that with a small amount of carefully selected source positions, similarly good results can be achieved, as if as many sources as receivers would have been employed. For the sake of simplicity, we assume in our simulations that the full data information content is available, but data pre-processing and the presence of coloured noise may impose restrictions. Our ED procedure requires an a priori subsurface model as input, but tests indicate that a relatively crude approximation to the true model is adequate. A further pre-requisite of our ED algorithm is that a suitable inversion strategy exists that accounts for the non-linearity of the FWI problem. Here, we assume that such a strategy is available. For the sake of simplicity, we consider only 2-D FWI experiments in this study, but our ED algorithm is sufficiently general and flexible, such that it can be adapted to other configurations, such as crosshole, vertical seismic profiling or 3-D surface setups, also including larger scale

  14. Insights into induced earthquakes and aftershock activity with in-situ measurements of seismic velocity variations in an active underground mine

    Science.gov (United States)

    Brenguier, F.; Olivier, G.; Campillo, M.; Roux, P.; Shapiro, N.; Lynch, R.

    2015-12-01

    The behaviour of the crust shortly after large earthquakes has been the subject of numerous studies, but many co- and post-seismic processes remain poorly understood. Damage and healing of the bulk rock mass, post-seismic deformation and the mechanisms of earthquake triggering are still not well understood. These processes are important to properly model and understand the behaviour of faults and earthquake cycles.In this presentation, we will show how in-situ measurements of seismic velocity variations have given new insights into these co- and post-seismic processes. An experiment was performed where a blast was detonated in a tunnel in an underground mine, while seismic velocity variations were accurately (0.005 %) measured with ambient seismic noise correlations. Additionally, aftershock activity was examined and the influence of the removal of a piece of solid rock was estimated with elastic static stress modelling. The majority of the aftershocks were delayed with respect to the passing of the dynamic waves from the blast, while the locations of the aftershocks appeared clustered and not homogeneously spread around the blast location. A significant velocity drop is visible during the time of the blast, which is interpreted as co-seismic damage and plastic deformation. These non-elastic effects are healed by the confining stresses over a period of 5 days until the seismic velocity converges to a new baseline level. The instantaneous weakening and gradual healing observed from the velocity variations are qualitatively similar to results reported in laboratory studies. The change in the baseline level of the seismic velocity before and after the blast indicate a change in the static stress that is comparable to the results of elastic static stress modelling. The differences between the elastic model predictions and the seismic velocity variations could be due to zones of fractured rock, indicated by the spatial clustering of the aftershocks, that are not

  15. Seismic Measurement of the Locations of the Base of Convection Zone and Helium Ionization Zone for Stars in the Kepler Seismic LEGACY Sample

    Science.gov (United States)

    Verma, Kuldeep; Raodeo, Keyuri; Antia, H. M.; Mazumdar, Anwesh; Basu, Sarbani; Lund, Mikkel N.; Silva Aguirre, Víctor

    2017-03-01

    Acoustic glitches are regions inside a star where the sound speed or its derivatives change abruptly. These leave a small characteristic oscillatory signature in the stellar oscillation frequencies. With the precision achieved by Kepler seismic data, it is now possible to extract these small amplitude oscillatory signatures, and infer the locations of the glitches. We perform glitch analysis for all the 66 stars in the Kepler seismic LEGACY sample to derive the locations of the base of the envelope convection zone (CZ) and the helium ionization zone. The signature from helium ionization zone is found to be robust for all stars in the sample, whereas the CZ signature is found to be weak and problematic, particularly for relatively massive stars with large errorbars on the oscillation frequencies. We demonstrate that the helium glitch signature can be used to constrain the properties of the helium ionization layers and the helium abundance.

  16. Program to perform research on use of lidar for range resolved turbulence measurements

    Science.gov (United States)

    Moskowitz, Warren P.; Garner, Richard C.

    1989-11-01

    The design of a lidar system capable of measuring remotely range resolved atmospheric turbulence is presented. The connection between the measured quantities and the accepted turbulence strength parameter (C sub n)-sq is developed theoretically. Simulations of an operating system were made, and the results provide a measure of system capability. A typical value for (C sub n)-sq of 10(exp -16) m to the -2/3 power at 3 km vertical range is measurable with a 200 m range resolution.

  17. Upper Mantle Seismic Anisotropy in the Southwest Indian Ocean from SKS-splitting measurements: Plate, Plume and Ridges signatures

    Science.gov (United States)

    Scholz, J. R.; Barruol, G.; Fontaine, F. R.; Montagner, J. P.; Stutzmann, E.; Sigloch, K.; Mazzullo, A.

    2016-12-01

    We present results of upper mantle seismic anisotropy in the Southwest Indian Ocean, a region influenced by the effects of absolute plate motion of the African Plate, of mid-ocean ridge spreading of the Central and Southwest Indian Ridges, and of potential plume-lithosphere and plume-ridge interactions. Data analyzed in this study were recorded by 20 terrestrial and 57 ocean-bottom three-component seismometers installed in the frame of the RHUM-RUM project (Réunion Hotspot and Upper Mantle - Réunions Unterer Mantel, www.rhum-rum.net). Broadband land stations were installed at the Îles Eparses (5), Madagascar (5) and La Réunion Island (10), and recorded for about two years. Broadband and wideband ocean-bottom instruments were deployed around the La Réunion Island and along the Central and Southwest Indian Ridges (deployment: R/V Marion Dufresne, 2012, MD192 - recovery: R/V Meteor, 2013, M101), and recorded for 8 to 13 months. Measurements of upper mantle anisotropy measurements are based on the effect of SKS-splitting and performed using the `SplitLab' toolbox. To our results we integrate findings of former seismic anisotropy studies (SKS-splitting measurements and fundamental mode Rayleigh wave tomography). We interpret the overall picture in terms of the existence - or lack - of a mantle plume signature around the La Réunion hotspot, of a physical plume-ridge interaction and of the general upper mantle flow geometry in the Southwest Indian Ocean.

  18. Micromachined silicon seismic accelerometer development

    Energy Technology Data Exchange (ETDEWEB)

    Barron, C.C.; Fleming, J.G.; Montague, S. [and others

    1996-08-01

    Batch-fabricated silicon seismic transducers could revolutionize the discipline of seismic monitoring by providing inexpensive, easily deployable sensor arrays. Our ultimate goal is to fabricate seismic sensors with sensitivity and noise performance comparable to short-period seismometers in common use. We expect several phases of development will be required to accomplish that level of performance. Traditional silicon micromachining techniques are not ideally suited to the simultaneous fabrication of a large proof mass and soft suspension, such as one needs to achieve the extreme sensitivities required for seismic measurements. We have therefore developed a novel {open_quotes}mold{close_quotes} micromachining technology that promises to make larger proof masses (in the 1-10 mg range) possible. We have successfully integrated this micromolding capability with our surface-micromachining process, which enables the formation of soft suspension springs. Our calculations indicate that devices made in this new integrated technology will resolve down to at least sub-{mu}G signals, and may even approach the 10{sup -10} G/{radical}Hz acceleration levels found in the low-earth-noise model.

  19. Investigating the temporal fluctuations in geoelectrical and geochemical signals Jointly measured in a seismic area of Southern Apennine chain (Italy

    Directory of Open Access Journals (Sweden)

    S. Piscitelli

    2001-06-01

    Full Text Available We analyse geoelectrical and geochemical time series jointly measured by means of a multiparametric automatic station close to an anomalous fluid emission in Val d'Agri (Basilicata, Southern Italy. In the investigated are some destructive seismic events occurred in past and recent years. We analysed the temporal fluctuations of the signals by spectral tools. We detected scaling behaviours in the power spectra of the time series recorded, that are typical fingerprints of fractional Brownian motions. The estimated values of the spectral indices reveal the presence of antipersistent behaviour in the time dynamics of all geoelectrical and geochemical data recorded. This work intends to improve our knowledge of the inner time dynamics of geophysical non-seismometric parameters.

  20. Laboratory Constraints on Basal Seismicity

    Science.gov (United States)

    Zoet, L.; Ikari, M.; Carpenter, B. M.; Scuderi, M.; Alley, R. B.; Anandakrishnan, S.; Marone, C.

    2016-12-01

    Basal seismicity has been observed across a continuum of glacier morphologies and bed conditions, ranging from ice streams to alpine glaciers, and from hard to deformable beds. Passive seismicity provides a non-invasive method for observing basal processes and investigating ice-earth interactions in glaciated regions, offering the opportunity to characterize the bed (e.g. till stiffness, shear modulus, changes in subglacial hydrology) over glaciated regions. While analysis of glacial seismicity continues to be a widely-used method for studying ice-earth phenomena, the underlying mechanics that control glacial seismicity remain speculative. We have performed a series of experiments using a biaxial shearing apparatus that simulates glacier slip by shearing debris-laden ice over bedrock. By modifying and controlling the apparatus stiffness and frictional rheologic stiffness, we generated a range of stick-slip behaviors during shearing. Our data provide the first experimental insights into unstable glacier slip to be compared with field seismological observations. We found that our laboratory icequakes approximate several seismological field observations of glacier slip, such as dynamic slip distance, stress drop, velocity, and acceleration. Furthermore, the stress drop and peak slip velocity of laboratory ice-quakes are comparable with laboratory stick-slip on fault gouge. We found that once a critical sliding velocity was exceeded a transition from stable to unstable slip occurred as predicted by rate-and-state friction. Our results demonstrate that: (1) characteristics of basal glacial seismicity determined by traditional seismologic analysis techniques are corroborated by our laboratory measurements, (2) both icequakes and earthquakes on tectonic faults are controlled by similar physical mechanisms, and (3) slip behavior in glaciers can be accurately predicted by rate-and-state friction laws, which are traditionally used to describe rock friction.

  1. Enhanced Strain Measurement Range of an FBG Sensor Embedded in Seven-Wire Steel Strands

    Directory of Open Access Journals (Sweden)

    Jae-Min Kim

    2017-07-01

    Full Text Available FBG sensors offer many advantages, such as a lack of sensitivity to electromagnetic waves, small size, high durability, and high sensitivity. However, their maximum strain measurement range is lower than the yield strain range (about 1.0% of steel strands when embedded in steel strands. This study proposes a new FBG sensing technique in which an FBG sensor is recoated with polyimide and protected by a polyimide tube in an effort to enhance the maximum strain measurement range of FBG sensors embedded in strands. The validation test results showed that the proposed FBG sensing technique has a maximum strain measurement range of 1.73% on average, which is 1.73 times higher than the yield strain of the strands. It was confirmed that recoating the FBG sensor with polyimide and protecting the FBG sensor using a polyimide tube could effectively enhance the maximum strain measurement range of FBG sensors embedded in strands.

  2. Seismic noise limit for ground-based performance measurements of an inertial sensor using a torsion balance

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Z B; Liu, L; Tu, H B; Bai, Y Z; Luo, J, E-mail: zhouzb@mail.hust.edu.c [School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2010-09-07

    A torsion balance, which is sensitive to force or torque, has been employed to investigate the residual disturbances of high-precision inertial sensors for the LISA Pathfinder and LISA missions. These experiments are inevitably disturbed by the seismic noise. In this paper, the impact of the seismic noise is theoretically analysed, and the corresponding experimental result is consistent with theoretical estimation. Finally, the seismic noise limit for the ground-based torsion balance experiments for performance investigation of an inertial sensor for the LISA mission is discussed. The results show that the local seismic noise should be carefully considered for further experiments with higher resolution.

  3. Correction of motion measurement errors beyond the range resolution of a synthetic aperture radar

    Science.gov (United States)

    Doerry, Armin W [Albuquerque, NM; Heard, Freddie E [Albuquerque, NM; Cordaro, J Thomas [Albuquerque, NM

    2008-06-24

    Motion measurement errors that extend beyond the range resolution of a synthetic aperture radar (SAR) can be corrected by effectively decreasing the range resolution of the SAR in order to permit measurement of the error. Range profiles can be compared across the slow-time dimension of the input data in order to estimate the error. Once the error has been determined, appropriate frequency and phase correction can be applied to the uncompressed input data, after which range and azimuth compression can be performed to produce a desired SAR image.

  4. Advanced Seismic While Drilling System

    Energy Technology Data Exchange (ETDEWEB)

    Robert Radtke; John Fontenot; David Glowka; Robert Stokes; Jeffery Sutherland; Ron Evans; Jim Musser

    2008-06-30

    A breakthrough has been discovered for controlling seismic sources to generate selectable low frequencies. Conventional seismic sources, including sparkers, rotary mechanical, hydraulic, air guns, and explosives, by their very nature produce high-frequencies. This is counter to the need for long signal transmission through rock. The patent pending SeismicPULSER{trademark} methodology has been developed for controlling otherwise high-frequency seismic sources to generate selectable low-frequency peak spectra applicable to many seismic applications. Specifically, we have demonstrated the application of a low-frequency sparker source which can be incorporated into a drill bit for Drill Bit Seismic While Drilling (SWD). To create the methodology of a controllable low-frequency sparker seismic source, it was necessary to learn how to maximize sparker efficiencies to couple to, and transmit through, rock with the study of sparker designs and mechanisms for (a) coupling the sparker-generated gas bubble expansion and contraction to the rock, (b) the effects of fluid properties and dynamics, (c) linear and non-linear acoustics, and (d) imparted force directionality. After extensive seismic modeling, the design of high-efficiency sparkers, laboratory high frequency sparker testing, and field tests were performed at the University of Texas Devine seismic test site. The conclusion of the field test was that extremely high power levels would be required to have the range required for deep, 15,000+ ft, high-temperature, high-pressure (HTHP) wells. Thereafter, more modeling and laboratory testing led to the discovery of a method to control a sparker that could generate low frequencies required for deep wells. The low frequency sparker was successfully tested at the Department of Energy Rocky Mountain Oilfield Test Center (DOE RMOTC) field test site in Casper, Wyoming. An 8-in diameter by 26-ft long SeismicPULSER{trademark} drill string tool was designed and manufactured by TII

  5. Climate services for adapting landslide hazard prevention measures in the Vrancea Seismic Region

    Science.gov (United States)

    Micu, Dana; Balteanu, Dan; Jurchescu, Marta; Sima, Mihaela; Micu, Mihai

    2014-05-01

    The Vrancea Seismic Region is covering an area of about 8 000 km2 in the Romanian Curvature Carpathians and Subcarpathians and it is considered one of Europe's most intensely multi-hazard-affected areas. Due to its geomorphic traits (heterogeneous morphostructural units of flysch mountains and molasse hills and depressions), the area is strongly impacted by extreme hydro-meteorological events which are potentially enhancing the numerous damages inflicted to a dense network of human settlements. An a priori knowledge of future climate change is a useful climate service for local authorities to develop regional adapting strategies and adequate prevention/preparedness frameworks. This paper aims at integrating the results of the high-resolution climate projections over the 21st century (within the FP7 ECLISE project) into the regional landslide hazard assessment. The requirements of users (Civil Protection, Land management, local authorities) for this area refer to reliable and high-resolution spatial data on landslide and flood hazard for short and medium-term risk management strategies. An insight into the future behavior of climate variability in the Vrancea Seismic Region, based on future climate projections of three regional models, under three RCPs (2.6, 4.5, 8.6), suggests a clear warming, both annually and seasonally and a rather limited annual precipitation decrease, but with a strong change of seasonality. A landslide inventory of 2485 cases (shallow and medium seated earth, debris and rock slides and earth and debris flows) was obtained based on large scale geomorphological mapping and aerial photos support (GeoEye, DigitalGlobe; provided by GoogleEarth and BingMaps). The landslides are uniformly distributed across the area, being considered representative for the entire morphostructural environment. Landslide susceptibility map was obtained using multivariate statistical analysis (logistic regression), while a relative landslide hazard index was computed

  6. Permafrost Active Layer Seismic Interferometry Experiment (PALSIE).

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Knox, Hunter Anne [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); James, Stephanie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lee, Rebekah [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cole, Chris [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-01-01

    We present findings from a novel field experiment conducted at Poker Flat Research Range in Fairbanks, Alaska that was designed to monitor changes in active layer thickness in real time. Results are derived primarily from seismic data streaming from seven Nanometric Trillium Posthole seismometers directly buried in the upper section of the permafrost. The data were evaluated using two analysis methods: Horizontal to Vertical Spectral Ratio (HVSR) and ambient noise seismic interferometry. Results from the HVSR conclusively illustrated the method's effectiveness at determining the active layer's thickness with a single station. Investigations with the multi-station method (ambient noise seismic interferometry) are continuing at the University of Florida and have not yet conclusively determined active layer thickness changes. Further work continues with the Bureau of Land Management (BLM) to determine if the ground based measurements can constrain satellite imagery, which provide measurements on a much larger spatial scale.

  7. Estimation of reservoir fluid saturation from 4D seismic data: effects of noise on seismic amplitude and impedance attributes

    Science.gov (United States)

    Souza, Rafael; Lumley, David; Shragge, Jeffrey

    2017-02-01

    Time-lapse (4D) seismic data sets have proven to be extremely useful for reservoir monitoring. Seismic-derived impedance estimates are commonly used as a 4D attribute to constrain updates to reservoir fluid flow models. However, 4D seismic estimates of P-wave impedance can contain significant errors associated with the effects of seismic noise and the inherent instability of inverse methods. These errors may compromise the geological accuracy of the reservoir model leading to incorrect reservoir model property updates and incorrect reservoir fluid flow predictions. To evaluate such errors and uncertainties we study two time-lapse scenarios based on 1D and 3D reservoir model examples, thereby exploring a number of inverse theory concepts associated with the instability and error of coloured inversion operators and their dependence on seismic noise levels. In the 1D example, we show that inverted band-limited impedance changes have a smaller root-mean-square (RMS) error in comparison to their absolute broadband counterpart for signal-to-noise ratios 10 and 5 while for signal-to-noise ratio (S/N)  =  3 both inversion methods present similarly high errors. In the 3D example we use an oilfield benchmark case based on the Namorado Field in Campos Basin, Brazil. We introduce a histogram similarity measure to quantify the impact of seismic noise on maps of 4D seismic amplitude and impedance changes as a function of S/N levels, which indicate that amplitudes are less sensitive to 4D seismic noise than impedances. The RMS errors in the estimates of water saturation changes derived from 4D seismic amplitudes are also smaller than for 4D seismic impedances, over a wide range of typical seismic noise levels. These results quantitatively demonstrate that seismic amplitudes can be more accurate and robust than seismic impedances for quantifying water saturation changes with 4D seismic data, and emphasize that seismic amplitudes may be more reliable to update fluid flow

  8. Engineering geological zonation of a complex landslide system through seismic ambient noise measurements at the Selmun Promontory (Malta)

    Science.gov (United States)

    Iannucci, Roberto; Martino, Salvatore; Paciello, Antonella; D'Amico, Sebastiano; Galea, Pauline

    2018-01-01

    The cliff slope of the Selmun Promontory, located in the Northern part of the island of Malta (Central Mediterranean Sea) close to the coastline, is involved in a landslide process as exhibited by the large block-size talus at its bottom. The landslide process is related to the geological succession outcropping in the Selmun area, characterised by the over-position of a grained limestone on a plastic clay, that induces a lateral spreading phenomenon associated with detachment and collapse of different-size rock blocks. The landslide process shapes a typical landscape with a stable plateau of stiff limestone bordered by an unstable cliff slope. The ruins of Għajn Ħadid Tower, the first of the thirteen watchtowers built in 1658 by the Grand Master Martin de Redin, stand out on the Selmun Promontory. The conservation of this important heritage site, already damaged by an earthquake which struck the Maltese Archipelago on October 12th 1856, is currently threatened by a progressive retreat of the landslide process towards the inland plateau area. During 2015 and 2016, field surveys were carried out to derive an engineering geological model of the Selmun Promontory. After a high-resolution geomechanical survey, the spatial distribution of the joints affecting the limestone was obtained. At the same time, 116 single-station noise measurements were carried out to cover the inland and edge plateau zones as well as the clayey slope area. The obtained 1-hour time histories were analysed through the horizontal to vertical spectral ratio (HVSR) technique, as well as polarity and ellipticity analysis of particle motion to define the local seismic response in zones having different stability conditions, i.e. related to the presence of unstable rock blocks characterised by different vibrational modes. The results obtained confirm the suitability of passive seismic geophysical techniques for zoning landslide hazard in case of rock slopes and demonstrate the relevance of

  9. Coherent change detection and interferometric ISAR measurements in the folded compact range

    Energy Technology Data Exchange (ETDEWEB)

    Sorensen, K.W.

    1996-08-01

    A folded compact range configuration has been developed ant the Sandia National Laboratories` compact range antenna and radar-cross- section measurement facility as a means of performing indoor, environmentally-controlled, far-field simulations of synthetic aperture radar (SAR) measurements of distributed target samples (i.e. gravel, sand, etc.). The folded compact range configuration has previously been used to perform coherent-change-detection (CCD) measurements, which allow disturbances to distributed targets on the order of fractions of a wavelength to be detected. This report describes follow-on CCD measurements of other distributed target samples, and also investigates the sensitivity of the CCD measurement process to changes in the relative spatial location of the SAR sensor between observations of the target. Additionally, this report describes the theoretical and practical aspects of performing interferometric inverse-synthetic-aperture-radar (IFISAR) measurements in the folded compact range environment. IFISAR measurements provide resolution of the relative heights of targets with accuracies on the order of a wavelength. Several examples are given of digital height maps that have been generated from measurements performed at the folded compact range facility.

  10. Multipath error in range rate measurement by PLL-transponder/GRARR/TDRS

    Science.gov (United States)

    Sohn, S. J.

    1970-01-01

    Range rate errors due to specular and diffuse multipath are calculated for a tracking and data relay satellite (TDRS) using an S band Goddard range and range rate (GRARR) system modified with a phase-locked loop transponder. Carrier signal processing in the coherent turn-around transponder and the GRARR reciever is taken into account. The root-mean-square (rms) range rate error was computed for the GRARR Doppler extractor and N-cycle count range rate measurement. Curves of worst-case range rate error are presented as a function of grazing angle at the reflection point. At very low grazing angles specular scattering predominates over diffuse scattering as expected, whereas for grazing angles greater than approximately 15 deg, the diffuse multipath predominates. The range rate errors at different low orbit altutudes peaked between 5 and 10 deg grazing angles.

  11. Optimal frequency range for medical radar measurements of human heartbeats using body-contact radar.

    Science.gov (United States)

    Brovoll, Sverre; Aardal, Øyvind; Paichard, Yoann; Berger, Tor; Lande, Tor Sverre; Hamran, Svein-Erik

    2013-01-01

    In this paper the optimal frequency range for heartbeat measurements using body-contact radar is experimentally evaluated. A Body-contact radar senses electromagnetic waves that have penetrated the human body, but the range of frequencies that can be used are limited by the electric properties of the human tissue. The optimal frequency range is an important property needed for the design of body-contact radar systems for heartbeat measurements. In this study heartbeats are measured using three different antennas at discrete frequencies from 0.1 - 10 GHz, and the strength of the received heartbeat signal is calculated. To characterize the antennas, when in contact with the body, two port S-parameters(†) are measured for the antennas using a pork rib as a phantom for the human body. The results shows that frequencies up to 2.5 GHz can be used for heartbeat measurements with body-contact radar.

  12. Measurement of dragging of inertial frames and gravitomagnetic field using laser-ranged satellites.

    Science.gov (United States)

    Ciufolini, I.; Lucchesi, D.; Vespe, F.; Mandiello, A.

    1996-05-01

    By analysing the observations of the orbits of the laser-ranged satellites LAGEOS and LAGEOS II, using the program GEODYN, the authors have obtained the first direct measurement of the Lense-Thirring effect, or dragging of inertial frames and the first direct experimental evidence for the gravitomagnetic field. The accuracy of their measurement is of about 30%.

  13. Expanding the dynamic measurement range for polymeric nanoparticle pH sensors

    DEFF Research Database (Denmark)

    Sun, Honghao; Almdal, Kristoffer; Andresen, Thomas Lars

    2011-01-01

    Conventional optical nanoparticle pH sensors that are designed for ratiometric measurements in cells have been based on utilizing one sensor fluorophore and one reference fluorophore in each nanoparticle, which results in a relatively narrow dynamic measurement range. This results in substantial...

  14. Variation in measurements of range of motion : a study in reflex sympathetic dystrophy patients

    NARCIS (Netherlands)

    Geertzen, J.H.B.; Dijkstra, P.U.; Stewart, R.E; Groothoff, J.W.; ten Duis, H J; Eisma, W.H.

    1998-01-01

    Objective: To quantify the amount of variation attributed to different sources of variation in measurement results of upper extremity range of motion, and to estimate the smallest detectable difference (SDD) between measurements in reflex sympathetic dystrophy (RSD) patients. Design: Two observers

  15. Permeability and seismic velocity and their anisotropy across the Alpine Fault, New Zealand: An insight from laboratory measurements on core from the Deep Fault Drilling Project phase 1 (DFDP-1)

    Science.gov (United States)

    Allen, M. J.; Tatham, D.; Faulkner, D. R.; Mariani, E.; Boulton, C.

    2017-08-01

    The Alpine Fault, a transpressional plate boundary between the Australian and Pacific plates, is known to rupture quasiperiodically with large magnitude earthquakes (Mw 8). The hydraulic and elastic properties of fault zones are thought to vary over the seismic cycle, influencing the nature and style of earthquake rupture and associated processes. We present a suite of laboratory permeability and P (Vp) and S (Vs) wave velocity measurements performed on fault lithologies recovered during the first phase of the Deep Fault Drilling Project (DFDP-1), which sampled principal slip zone (PSZ) gouges, cataclasites, and fractured ultramylonites, with all recovered lithologies overprinted by abundant secondary mineralization, recording enhanced fluid-rock interaction. Core material was tested in three orthogonal directions, orientated relative to the down-core axis and, when present, foliation. Measurements were conducted with pore pressure (H2O) held at 5 MPa over an effective pressure (Peff) range of 5-105 MPa. Permeabilities and seismic velocities decrease with proximity to the PSZ with permeabilities ranging from 10-17 to 10-21 m2 and Vp and Vs ranging from 4400 to 5900 m/s in the ultramylonites/cataclasites and 3900 to 4200 m/s at the PSZ. In comparison with intact country rock protoliths, the highly variable cataclastic structures and secondary phyllosilicates and carbonates have resulted in an overall reduction in permeability and seismic wave velocity, as well as a reduction in anisotropy within the fault core. These results concur with other similar studies on other mature, tectonic faults in their interseismic period.

  16. Clinical measurement of range of motion. Review of goniometry emphasizing reliability and validity.

    Science.gov (United States)

    Gajdosik, R L; Bohannon, R W

    1987-12-01

    Clinical measurement of range of motion is a fundamental evaluation procedure with ubiquitous application in physical therapy. Objective measurements of ROM and correct interpretation of the measurement results can have a substantial impact on the development of the scientific basis of therapeutic interventions. The purpose of this article is to review the related literature on the reliability and validity of goniometric measurements of the extremities. Special emphasis is placed on how the reliability of goniometry is influenced by instrumentation and procedures, differences among joint actions and body regions, passive versus active measurements, intratester versus intertester measurements, and different patient types. Our discussion of validity encourages objective interpretation of the meaning of ROM measurements in light of the purposes and the limitations of goniometry. We conclude that clinicians should adopt standardized methods of testing and should interpret and report goniometric results as ROM measurements only, not as measurements of factors that may affect ROM.

  17. Simultaneous measurement of spectra at multiple ranges using a single spectrometer.

    Science.gov (United States)

    Lienert, Barry; Porter, John; Sharma, Shiv K

    2009-08-20

    We have designed and built an instrument having the capability to measure and display spectra at multiple ranges near simultaneously in real time. An excitation laser beam is oriented parallel to and offset from the axis of the light collection optics. The image of the laser beam is then displaced with range. Multiple optical fibers collect the displaced images at different ranges. The output ends of these fibers are positioned vertically along the input slit of a spectrometer that disperses the light from each fiber along different rows of the spectrometer's two-dimensional detector array. The detector array rows then give an immediate visual comparison of spectra at different ranges. A small prototype of this system covering a range from 3 to 13 m has been built. It has been successfully tested using containers holding two distinct fluorescent dyes. Numerical simulations indicate that the technique can be extended to longer-range systems.

  18. Near Field HF Antenna Pattern Measurement Method Using an Antenna Pattern Range

    Science.gov (United States)

    2015-12-01

    TECHNICAL REPORT 3006 December 2015 Near-Field HF Antenna Pattern Measurement Method Using an Antenna Pattern Range Ani Siripuram Michael Daly...link budget. This report focuses on computing absolute gain for HF antennas measured on the APR. Recent research efforts by SSC Pacific’s Applied...Electromagnetics Branch (Code 52250) show that the APR extends to accurate measurement of normalized far-field radiation patterns of HF antennas. The

  19. Accuracy and Reliability of Visual Inspection and Smartphone Applications for Measuring Finger Range of Motion.

    Science.gov (United States)

    Lee, Hannah H; St Louis, Kwesi; Fowler, John R

    2018-01-08

    Measurement of finger range of motion is critical in clinical settings, especially for outcome analysis, clinical decision making, and rehabilitation/disability assessment. Although goniometer measurement is clinically considered the gold standard, its accuracy compared with the true radiographic measurements of the joint angles remains questionable. The authors compared 3 smartphone applications and visual inspection measurements of the finger joints with the radiographic measurements and determined interrater reliability for these measurement tools. A finger was held in place using an aluminum-alloy splint, and a fluoroscopic image was acquired by a mini C-arm. An independent observer measured each joint flexion angle of the fluoroscopic image using a universal handheld goniometer, and this was used as the reference. Finger joint flexion angles were then independently measured by 3 observers using 3 different smartphone applications. In addition, visual inspection was used to estimate the flexion angles of finger joints. The results of this study suggest that all 3 smartphone measurement tools, as well as visual inspection, agree and correlate well with the reference fluoroscopic image measurement. Average differences between the fluoroscopic image measurements with the measured angles using the tools studied ranged from 9.4° to 12.2°. The mean correlation coefficients for each smartphone application exceeded 0.7. Overall interrater reliabilities were similar, with the interclass correlation coefficient being greater than 0.9 for all of the measurement tools. These data suggest that new smartphone applications hold promise for providing accurate and reliable measures of range of motion. [Orthopedics. 201x; xx(x):xx-xx.]. Copyright 2018, SLACK Incorporated.

  20. An impedance bridge measuring the capacitance ratio in the high frequency range up to 1 MHz

    Science.gov (United States)

    Bee Kim, Dan; Kew Lee, Hyung; Kim, Wan-Seop

    2017-02-01

    This paper describes a 2-terminal-pair impedance bridge, measuring the capacitance ratio in the high frequency range up to 1 MHz. The bridge was configured with two voltage sources and a phase control unit which enabled the bridge balance by synchronizing the voltage sources with an enhanced phase resolution. Without employing the transformers such as inductive voltage divider, injection and detection transformers, etc, the bridge system is quite simple to set up, and the balance procedure is quick and easy. Using this dual-source coaxial bridge, the 1:1 and 10:1 capacitance ratios were measured with 1 pF-1 nF capacitors in the frequency range from 1 kHz to 1 MHz. The measurement values obtained by the dual-source bridge were then compared with reference values measured using a commercial precision capacitance bridge of AH2700A, the Z-matrix method developed by ourselves, and the 4-terminal-pair coaxial bridge by the Czech Metrological Institute. All the measurements agreed within the reference uncertainty range of an order of 10-6-10-5, proving the bridge ability as a trustworthy tool for measuring the capacitance ratio in the high frequency range.

  1. Propagation Loss Measurements at 400 Hertz in the BIFI Range Using a Towed Source.

    Science.gov (United States)

    1971-01-27

    series using the BIFI Range (Reference 1) located between Block Island, Rhode Island and Fishers Island, New York. Three types of acoustic tests were... Colossus theoretical predictions (Reference 7). The agreement is fairly good; it is apparent, howev er, that the Colossus predictions do not take into...given in reference 11. - Propagation loss was measured as a function of range and the results compared to the Colossus predictions’ (reference 7). The

  2. Seismic site response of unstable steep slope using noise measurements: the case study of Xemxija Bay area, Malta

    National Research Council Canada - National Science Library

    F. Panzera; S. D'Amico; A. Lotteri; P. Galea; G. Lombardo

    2012-01-01

    ... to the landslide body existing in the area. Experimental spectral ratios were also calculated after rotating the horizontal components of the seismic signal, and a direct estimate of the polarization angle was also performed in order...

  3. Varying the item format improved the range of measurement in patient-reported outcome measures assessing physical function

    DEFF Research Database (Denmark)

    Liegl, Gregor; Gandek, Barbara; Fischer, H. Felix

    2017-01-01

    Background: Physical function (PF) is a core patient-reported outcome domain in clinical trials in rheumatic diseases. Frequently used PF measures have ceiling effects, leading to large sample size requirements and low sensitivity to change. In most of these instruments, the response category...... easy, increases the range of precise measurement of self-reported PF. Methods: Three five-item PF short forms were constructed from the Patient-Reported Outcomes Measurement Information System (PROMIS®) wave 1 data. All forms included the same physical activities but varied in item stem and response...... precision between the short forms using different item formats. Results: Sufficient unidimensionality of all short-form items and the original PF item bank was supported. Compared to formats A and B, format C increased the range of reliable measurement by about 0.5 standard deviations on the positive side...

  4. Long-Range Channel Measurements on Small Terminal Antennas Using Optics

    DEFF Research Database (Denmark)

    Yanakiev, Boyan; Nielsen, Jesper Ødum; Christensen, Morten

    2012-01-01

    In this paper, details are given on a novel measurement device for radio propagation-channel measurements. To avoid measurement errors due to the conductive cables on small terminal antennas, as well as to improve the handling of the prototypes under investigation, an optical measurement device has...... been developed. It utilizes thin, light, and flexible glass fibers as opposed to heavy, stiff, and conductive coaxial cables. This paper looks at the various system parameters such as overall gain, noise figure, and dynamic range and compares the solution to other methods. An estimate of the device...

  5. Seismic Catalogue and Seismic Network in Haiti

    Science.gov (United States)

    Belizaire, D.; Benito, B.; Carreño, E.; Meneses, C.; Huerfano, V.; Polanco, E.; McCormack, D.

    2013-05-01

    The destructive earthquake occurred on January 10, 2010 in Haiti, highlighted the lack of preparedness of the country to address seismic phenomena. At the moment of the earthquake, there was no seismic network operating in the country, and only a partial control of the past seismicity was possible, due to the absence of a national catalogue. After the 2010 earthquake, some advances began towards the installation of a national network and the elaboration of a seismic catalogue providing the necessary input for seismic Hazard Studies. This paper presents the state of the works carried out covering both aspects. First, a seismic catalogue has been built, compiling data of historical and instrumental events occurred in the Hispaniola Island and surroundings, in the frame of the SISMO-HAITI project, supported by the Technical University of Madrid (UPM) and Developed in cooperation with the Observatoire National de l'Environnement et de la Vulnérabilité of Haiti (ONEV). Data from different agencies all over the world were gathered, being relevant the role of the Dominican Republic and Puerto Rico seismological services which provides local data of their national networks. Almost 30000 events recorded in the area from 1551 till 2011 were compiled in a first catalogue, among them 7700 events with Mw ranges between 4.0 and 8.3. Since different magnitude scale were given by the different agencies (Ms, mb, MD, ML), this first catalogue was affected by important heterogeneity in the size parameter. Then it was homogenized to moment magnitude Mw using the empirical equations developed by Bonzoni et al (2011) for the eastern Caribbean. At present, this is the most exhaustive catalogue of the country, although it is difficult to assess its degree of completeness. Regarding the seismic network, 3 stations were installed just after the 2010 earthquake by the Canadian Government. The data were sent by telemetry thought the Canadian System CARINA. In 2012, the Spanish IGN together

  6. Accurate Measurement of First Metatarsophalangeal Range of Motion in Patients With Hallux Rigidus.

    Science.gov (United States)

    Vulcano, Ettore; Tracey, Joseph A; Myerson, Mark S

    2016-05-01

    The reliability of range of motion (ROM) measurements has not been established for the hallux metatarsophalangeal (MTP) joint in patients with hallux rigidus. The aim of the present study was to prospectively assess the clinical versus radiographic difference in ROM of the arthritic hallux MTP joint. One hundred consecutive patients who presented with any grade of hallux rigidus were included in this prospective study to determine the hallux MTP range of motion. Clinical range of motion using a goniometer and radiographic range of motion on dynamic x-rays was recorded. The mean difference between clinical and radiographic dorsiflexion was 13 degrees (P dorsiflexion was equal to or less than radiographically measured dorsiflexion. The difference was significantly greater in patients with a clinical dorsiflexion of less than 30 degrees than in patients with 30 degrees or more. Radiographic measurement of hallux dorsiflexion had an excellent intra- and interobserver reliability. We describe a reliable, reproducible, and straightforward method of measuring hallux MTP ROM that improved upon measuring clinical ROM. Level II, prospective comparative study. © The Author(s) 2015.

  7. Seismic site response of unstable steep slope using noise measurements: the case study of Xemxija Bay area, Malta

    Directory of Open Access Journals (Sweden)

    F. Panzera

    2012-11-01

    Full Text Available Landslide phenomena involve the northern coast of Malta, affecting in particular the urban area of Xemxija. Limestones overlying a clayey formation represent the shallower lithotypes that characterize the surficial geology of this area, where lateral spreading phenomena and rockfalls take place.

    Ambient noise records, processed through spectral ratio techniques, were analysed in order to characterize the dynamic behavior of the rock masses affected by the presence of fractures linked to the landslide body existing in the area. Experimental spectral ratios were also calculated after rotating the horizontal components of the seismic signal, and a direct estimate of the polarization angle was also performed in order to investigate the existence of directional effects in the ground motion.

    The results of the morphologic survey confirmed the existence of large cliff-parallel fractures that cause cliff-edge and unstable boulder collapses. Such phenomena appear connected to the presence, inside the clay formation, of a sliding surface that was identified through the interpretation of the noise measurement data. The boundaries of the landslide area appear quite well defined by the pronounced polarization effects, trending in the northeastern direction, observed in the fractured zone and in the landslide body in particular.

  8. GRAIL Refinements to Lunar Seismic Structure

    Science.gov (United States)

    Weber, Renee; Gernero, Edward; Lin, Pei-Ying; Thorne, Michael; Schmerr, Nicholas; Han, Shin-Chan

    2012-01-01

    The present ]day internal structure of the Moon provides insight not only into its own formation and evolution, but also that of all rocky planetary bodies. The most direct way to probe a planet fs interior structure is through seismology. As part of the Apollo lunar missions, four seismometers were deployed on the nearside surface of the Moon between the years 1969 and 1972. These instruments operated continuously until 1977, forming the only substantial extraterrestrial seismic data set in existence. These data have been used to constrain various aspects of the seismic velocity and density structure of the Moon. Typical 1-D models recognize a 30-60 km thick crust overlying a nearly constant ]velocity mantle, and extend to a depth of approximately 1000 km, below which the lack of penetrating moonquake ray ]paths precludes the seismic determination of deeper structure. Previously, the lack of observed moonquakes from the far side of the Moon has been used to infer the presence of a highly attenuating (possibly molten) core. Indirect geophysical measurements such as moment of inertia, magnetic induction, lunar laser ranging, and elemental abundances of mare basalts also place varying constraints on core size and state. In combination with seismic studies, these indirect measurements have been used to arrive at a commonly accepted model of the Moon's deepest interior that includes a solid inner and fluid outer core, overlain by a partial melt boundary layer. We recently applied modern array seismology techniques to the Apollo data and revealed detailed core structure, including the first direct confirmation of the presence of a solid inner core. Our study focused on the identification of core ]reflected phases in deep moonquake seismograms. The resulting model of the Moon fs innermost structure was found to be consistent with the commonly accepted model. However, the modeled layer radii may vary by tens of kilometers, as is expected when accounting for uncertainties

  9. Human-Induced Effects on RSS Ranging Measurements for Cooperative Positioning

    OpenAIRE

    Francescantonio Della Rosa; Mauro Pelosi; Jari Nurmi

    2012-01-01

    We present experimental evaluations of human-induced perturbations on received-signal-strength-(RSS-) based ranging measurements for cooperative mobile positioning. To the best of our knowledge, this work is the first attempt to gain insight and understand the impact of both body loss and hand grip on the RSS for enhancing proximity measurements among neighbouring devices in cooperative scenarios. Our main contribution is represented by experimental investigations. Analysis of the errors intr...

  10. Intersatellite laser ranging with homodyne optical phase locking for Space Advanced Gravity Measurements mission.

    Science.gov (United States)

    Yeh, Hsien-Chi; Yan, Qi-Zhong; Liang, Yu-Rong; Wang, Ying; Luo, Jun

    2011-04-01

    In this paper, we present the scheme and the preliminary results of an intersatellite laser ranging system that is designed for the Earth's gravity recovery mission proposed in China, called Space Advanced Gravity Measurements (SAGM). The proposed intersatellite distance is about 100 km and the precision of inter-satellite range monitoring is 10 nm/Hz(1/2) at 0.1 Hz. To meet the needs, we designed a transponder-type intersatellite laser ranging system by using a homodyne optical phase locking technique, which is different from the heterodyne optical phase-locked loop used in GRACE follow-on mission. Since an ultrastable oscillator is unnecessary in the homodyne phase-locked loop, the measurement error caused by the frequency instability of the ultrastable oscillator need not be taken into account. In the preliminary study, a heterodyne interferometer with 10-m baseline (measurement arm-length) was built up to demonstrate the validity of the measurement scheme. The measurement results show that a resolution of displacement measurement of about 3.2 nm had been achieved. © 2011 American Institute of Physics

  11. Evaluation of Soil Loss and Erosion Control Measures on Ranges and Range Structures at Installations in Temperate Climates

    Science.gov (United States)

    2006-06-01

    classified as discontinu- ous loess on bedrock and are finely textured silty clays and silty loams (Noble et al. 1990). The first visit to Camp...challenge as vegetation reestablishment is diffi- cult on the remaining eroded nutrient -poor soil. Investigations of newly constructed embankments as in...concentrations through range monitoring. Camp Atterbury Soils The soils in this area are classified as discontinuous loess on bedrock. Soil surveys completed

  12. Acoustic absorption measurement of human hair and skin within the audible frequency range.

    Science.gov (United States)

    Katz, B F

    2000-11-01

    Utilizing the two-microphone impedance tube method, the acoustic absorption of human skin and hair is measured in the frequency range 1-6 kHz. Various locations on a number of human subjects are measured to determine if the presence of bone or an air pocket affects the acoustic absorption of human skin. The absorption coefficient of human hair is also measured. Additional techniques are utilized to minimize errors due to sample mounting methods. Techniques are employed to minimize potential errors in sensor and sample locations. The results of these measurements are compared to relevant historical papers on similar investigations. Results for skin measurements compare well with previous work. Measured hair absorption data do not agree with previous work in the area but do coincide with expected trends, which previous works do not.

  13. An extended set-value observer for position estimation using single range measurements

    DEFF Research Database (Denmark)

    Marcal, Jose; Jouffroy, Jerome; Fossen, Thor I.

    of transponders. The knowledge of the bearing of the vehicle and the range measurements from a single location can provide a solution which is sensitive to the trajectory that the vehicle is following, since there is no complete constraint on the position estimate with a single beacon. In this paper...

  14. Polymeric pH nanosensor with extended measurement range bearing octaarginine as cell penetrating peptide

    DEFF Research Database (Denmark)

    Ke, Peng; Sun, Honghao; Liu, Mingxing

    2016-01-01

    A synthetic peptide octaarginine which mimics human immunodeficiency virus-1, Tat protein is used as cell penetrating moiety for new pH nanosensors which demonstrate enhanced cellular uptake and expanded measurement range from pH 3.9 to pH 7.3 by simultaneously incorporating two complemental p...

  15. Spin motion determination of the Envisat satellite through laser ranging measurements from a single pass measured by a single station

    Science.gov (United States)

    Pittet, Jean-Noël; Šilha, Jiří; Schildknecht, Thomas

    2018-02-01

    The Satellite Laser Ranging (SLR) technology is used to accurately determine the position of space objects equipped with so-called retro-reflectors or retro-reflector arrays (RRA). This type of measurement allows to measure the range to the spacecraft with high precision, which leads to determination of very accurate orbits for these targets. Non-active spacecraft, which are not attitude controlled any longer, tend to start to spin or tumble under influence of the external and internal torques and forces. If the return signal is measured for a non-spherical non-active rotating object, the signal in the range residuals with respect to the reference orbit is more complex. For rotating objects the return signal shows an oscillating pattern or patterns caused by the RRA moving around the satellite's centre of mass. This behaviour is projected onto the radial component measured by the SLR. In our work, we demonstrate how the SLR ranging technique from one sensor to a satellite equipped with a RRA can be used to precisely determine its spin motion during one passage. Multiple SLR measurements of one target over time allow to accurately monitor spin motion changes which can be further used for attitude predictions. We show our solutions of the spin motion determined for the non-active ESA satellite Envisat obtained from measurements acquired during years 2013-2015 by the Zimmerwald SLR station, Switzerland. All the necessary parameters are defined for our own so-called point-like model which describes the motion of a point in space around the satellite centre of mass.

  16. The value of forage measurement information in rangeland management. [implementation of satellite data in range management

    Science.gov (United States)

    Lietzke, K. R.

    1975-01-01

    An economic model and simulation are developed to estimate the potential social benefit arising from the use of alternative measurement systems in rangeland management. In order to estimate these benefits, it was necessary to model three separate systems: the range environment, the rangeland manager, and the information system which links the two. The rancher's decision-making behavior is modeled according to sound economic principles. Results indicate substantial potential benefits, particularly when used in assisting management of government-operated ranges; possible annual benefits in this area range from $20 to $46 million, depending upon the system capabilities assumed. Possible annual benefit in privately-managed stocker operations range from $2.8 to $49.5 million, depending upon where actual rancher capabilities lie and what system capabilities are assumed.

  17. High-resolution and wide range displacement measurement based on planar grating

    Science.gov (United States)

    Lin, Jie; Guan, Jian; Wen, Feng; Tan, Jiubin

    2017-12-01

    High/ultra-precision motion measurements for precision translation stages are highly desired in modern manufacturing systems and instruments. In this work, we introduce a wide range three-axis grating encoder with nanometric resolution, which can measure the x-, y- and z-axial translational motions of a stage simultaneously. The grating encoder is composed of a reflective-type planar scale grating with a period of 8 μm and an optical reading head. A planar reference grating, which is the same as the planar scale grating except the length and width, is employed in the optical reading head. The x- and y- directional ±1st order diffractive beams of the planar scale grating interfere with the corresponding diffractive beams of the planar reference grating, forming the measurement signals. The x- and y- directional ±1st order diffractive beams of the two planar gratings propagate against their original incident path, working as the autocollimatic diffractive beams. Therefore, the z-axial measurement range of the proposed grating encoder is greatly enhanced. The x- and y- axial measurement ranges depend on the size of the planar scale grating. To make the grating encoder more compact, a double grating beam-splitting (DGBS) unit and two diffractive optical elements (DOEs) are introduced. The experimental results indicate that the z-axial displacement resolution is as high as 4 nm with an electronic data division card of 80 segments developed by our lab.

  18. Improving the Dynamic Emissivity Measurement Above 1000 K by Extending the Spectral Range

    Science.gov (United States)

    Urban, D.; Krenek, S.; Anhalt, K.; Taubert, D. R.

    2018-01-01

    To improve the dynamic emissivity measurement, which is based on the laser-flash method, an array spectrometer is characterized regarding its spectral radiance responsivity for a spectrally resolved emissivity measurement above 1000 K in the wavelength range between 550 nm and 1100 nm. Influences like dark signals, the nonlinearity of the detector, the size-of-source effect, wavelength calibration and the spectral radiance responsivity of the system are investigated to obtain an uncertainty budget for the spectral radiance and emissivity measurements. Uncertainties for the spectral radiance of lower than a relative 2 % are achieved for wavelengths longer than 550 nm. Finally, the spectral emissivity of a graphite sample was determined in the temperature range between 1000 K and 1700 K, and the experimental data show a good repeatability and agreement with literature data.

  19. LUMOS - A Sensitive and Reliable Optode System for Measuring Dissolved Oxygen in the Nanomolar Range

    DEFF Research Database (Denmark)

    Lehner, Philipp; Larndorfer, Christoph; Garcia-Robledo, Emilio

    2015-01-01

    Most commercially available optical oxygen sensors target the measuring range of 300 to 2 mu mol L-1. However these are not suitable for investigating the nanomolar range which is relevant for many important environmental situations. We therefore developed a miniaturized phase fluorimeter based...... measurement system called the LUMOS (Luminescence Measuring Oxygen Sensor). It consists of a readout device and specialized "sensing chemistry" that relies on commercially available components. The sensor material is based on palladium(II)-5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorphenyl)-porphyrin embedded...... for read out of less sensitive optical oxygen sensors based on the same or similar indicator dyes, for example for monitoring oxygen at physiological conditions. The presented sensor system exhibits lower noise, higher resolution and higher sensitivity than the electrochemical STOX sensor previously used...

  20. Comparison of seismic sources for shallow seismic: sledgehammer and pyrotechnics

    Directory of Open Access Journals (Sweden)

    Brom Aleksander

    2015-10-01

    Full Text Available The pyrotechnic materials are one of the types of the explosives materials which produce thermal, luminous or sound effects, gas, smoke and their combination as a result of a self-sustaining chemical reaction. Therefore, pyrotechnics can be used as a seismic source that is designed to release accumulated energy in a form of seismic wave recorded by tremor sensors (geophones after its passage through the rock mass. The aim of this paper was to determine the utility of pyrotechnics for shallow seismic engineering. The work presented comparing the conventional method of seismic wave excitation for seismic refraction method like plate and hammer and activating of firecrackers on the surface. The energy released by various sources and frequency spectra was compared for the two types of sources. The obtained results did not determine which sources gave the better results but showed very interesting aspects of using pyrotechnics in seismic measurements for example the use of pyrotechnic materials in MASW.

  1. Comparison of seismic sources for shallow seismic: sledgehammer and pyrotechnics

    Science.gov (United States)

    Brom, Aleksander; Stan-Kłeczek, Iwona

    2015-10-01

    The pyrotechnic materials are one of the types of the explosives materials which produce thermal, luminous or sound effects, gas, smoke and their combination as a result of a self-sustaining chemical reaction. Therefore, pyrotechnics can be used as a seismic source that is designed to release accumulated energy in a form of seismic wave recorded by tremor sensors (geophones) after its passage through the rock mass. The aim of this paper was to determine the utility of pyrotechnics for shallow seismic engineering. The work presented comparing the conventional method of seismic wave excitation for seismic refraction method like plate and hammer and activating of firecrackers on the surface. The energy released by various sources and frequency spectra was compared for the two types of sources. The obtained results did not determine which sources gave the better results but showed very interesting aspects of using pyrotechnics in seismic measurements for example the use of pyrotechnic materials in MASW.

  2. LUMOS - A Sensitive and Reliable Optode System for Measuring Dissolved Oxygen in the Nanomolar Range

    Science.gov (United States)

    Lehner, Philipp; Larndorfer, Christoph; Garcia-Robledo, Emilio; Larsen, Morten; Borisov, Sergey M.; Revsbech, Niels-Peter; Glud, Ronnie N.; Canfield, Donald E.; Klimant, Ingo

    2015-01-01

    Most commercially available optical oxygen sensors target the measuring range of 300 to 2 μmol L-1. However these are not suitable for investigating the nanomolar range which is relevant for many important environmental situations. We therefore developed a miniaturized phase fluorimeter based measurement system called the LUMOS (Luminescence Measuring Oxygen Sensor). It consists of a readout device and specialized “sensing chemistry” that relies on commercially available components. The sensor material is based on palladium(II)-5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorphenyl)-porphyrin embedded in a Hyflon AD 60 polymer matrix and has a KSV of 6.25 x 10-3 ppmv-1. The applicable measurement range is from 1000 nM down to a detection limit of 0.5 nM. A second sensor material based on the platinum(II) analogue of the porphyrin is spectrally compatible with the readout device and has a measurement range of 20 μM down to 10 nM. The LUMOS device is a dedicated system optimized for a high signal to noise ratio, but in principle any phase flourimeter can be adapted to act as a readout device for the highly sensitive and robust sensing chemistry. Vise versa, the LUMOS fluorimeter can be used for read out of less sensitive optical oxygen sensors based on the same or similar indicator dyes, for example for monitoring oxygen at physiological conditions. The presented sensor system exhibits lower noise, higher resolution and higher sensitivity than the electrochemical STOX sensor previously used to measure nanomolar oxygen concentrations. Oxygen contamination in common sample containers has been investigated and microbial or enzymatic oxygen consumption at nanomolar concentrations is presented. PMID:26029920

  3. Comparing range data across the slow-time dimension to correct motion measurement errors beyond the range resolution of a synthetic aperture radar

    Science.gov (United States)

    Doerry, Armin W.; Heard, Freddie E.; Cordaro, J. Thomas

    2010-08-17

    Motion measurement errors that extend beyond the range resolution of a synthetic aperture radar (SAR) can be corrected by effectively decreasing the range resolution of the SAR in order to permit measurement of the error. Range profiles can be compared across the slow-time dimension of the input data in order to estimate the error. Once the error has been determined, appropriate frequency and phase correction can be applied to the uncompressed input data, after which range and azimuth compression can be performed to produce a desired SAR image.

  4. Knee range of motion: reliability and agreement of 3 measurement methods.

    Science.gov (United States)

    Peters, Paul G; Herbenick, Michael A; Anloague, Philip A; Markert, Ronald J; Rubino, L Joseph

    2011-12-01

    We conducted a study to compare 3 methods of measuring knee range of motion: visual estimation by physicians, hand goniometry by physical therapists, and radiographic goniometry. We hypothesized that reliability would be high within and across all techniques. We found intrarater and interrater reliability to be satisfactory for visual estimation, hand goniometry, and radiographic goniometry. Interrater reliability across methods did not agree satisfactorily. Between-methods differences in estimating knee range of motion may result from variations in technique among physicians and physical therapists.

  5. Fluorescent Protein Based FRET Pairs with Improved Dynamic Range for Fluorescence Lifetime Measurements

    Science.gov (United States)

    George Abraham, Bobin; Sarkisyan, Karen S.; Mishin, Alexander S.; Santala, Ville; Tkachenko, Nikolai V.; Karp, Matti

    2015-01-01

    Fluorescence Resonance Energy Transfer (FRET) using fluorescent protein variants is widely used to study biochemical processes in living cells. FRET detection by fluorescence lifetime measurements is the most direct and robust method to measure FRET. The traditional cyan-yellow fluorescent protein based FRET pairs are getting replaced by green-red fluorescent protein variants. The green-red pair enables excitation at a longer wavelength which reduces cellular autofluorescence and phototoxicity while monitoring FRET. Despite the advances in FRET based sensors, the low FRET efficiency and dynamic range still complicates their use in cell biology and high throughput screening. In this paper, we utilized the higher lifetime of NowGFP and screened red fluorescent protein variants to develop FRET pairs with high dynamic range and FRET efficiency. The FRET variations were analyzed by proteolytic activity and detected by steady-state and time-resolved measurements. Based on the results, NowGFP-tdTomato and NowGFP-mRuby2 have shown high potentials as FRET pairs with large fluorescence lifetime dynamic range. The in vitro measurements revealed that the NowGFP-tdTomato has the highest Förster radius for any fluorescent protein based FRET pairs yet used in biological studies. The developed FRET pairs will be useful for designing FRET based sensors and studies employing Fluorescence Lifetime Imaging Microscopy (FLIM). PMID:26237400

  6. Fluorescent Protein Based FRET Pairs with Improved Dynamic Range for Fluorescence Lifetime Measurements.

    Directory of Open Access Journals (Sweden)

    Bobin George Abraham

    Full Text Available Fluorescence Resonance Energy Transfer (FRET using fluorescent protein variants is widely used to study biochemical processes in living cells. FRET detection by fluorescence lifetime measurements is the most direct and robust method to measure FRET. The traditional cyan-yellow fluorescent protein based FRET pairs are getting replaced by green-red fluorescent protein variants. The green-red pair enables excitation at a longer wavelength which reduces cellular autofluorescence and phototoxicity while monitoring FRET. Despite the advances in FRET based sensors, the low FRET efficiency and dynamic range still complicates their use in cell biology and high throughput screening. In this paper, we utilized the higher lifetime of NowGFP and screened red fluorescent protein variants to develop FRET pairs with high dynamic range and FRET efficiency. The FRET variations were analyzed by proteolytic activity and detected by steady-state and time-resolved measurements. Based on the results, NowGFP-tdTomato and NowGFP-mRuby2 have shown high potentials as FRET pairs with large fluorescence lifetime dynamic range. The in vitro measurements revealed that the NowGFP-tdTomato has the highest Förster radius for any fluorescent protein based FRET pairs yet used in biological studies. The developed FRET pairs will be useful for designing FRET based sensors and studies employing Fluorescence Lifetime Imaging Microscopy (FLIM.

  7. Fluorescent Protein Based FRET Pairs with Improved Dynamic Range for Fluorescence Lifetime Measurements.

    Science.gov (United States)

    George Abraham, Bobin; Sarkisyan, Karen S; Mishin, Alexander S; Santala, Ville; Tkachenko, Nikolai V; Karp, Matti

    2015-01-01

    Fluorescence Resonance Energy Transfer (FRET) using fluorescent protein variants is widely used to study biochemical processes in living cells. FRET detection by fluorescence lifetime measurements is the most direct and robust method to measure FRET. The traditional cyan-yellow fluorescent protein based FRET pairs are getting replaced by green-red fluorescent protein variants. The green-red pair enables excitation at a longer wavelength which reduces cellular autofluorescence and phototoxicity while monitoring FRET. Despite the advances in FRET based sensors, the low FRET efficiency and dynamic range still complicates their use in cell biology and high throughput screening. In this paper, we utilized the higher lifetime of NowGFP and screened red fluorescent protein variants to develop FRET pairs with high dynamic range and FRET efficiency. The FRET variations were analyzed by proteolytic activity and detected by steady-state and time-resolved measurements. Based on the results, NowGFP-tdTomato and NowGFP-mRuby2 have shown high potentials as FRET pairs with large fluorescence lifetime dynamic range. The in vitro measurements revealed that the NowGFP-tdTomato has the highest Förster radius for any fluorescent protein based FRET pairs yet used in biological studies. The developed FRET pairs will be useful for designing FRET based sensors and studies employing Fluorescence Lifetime Imaging Microscopy (FLIM).

  8. Spatiotemporal treadmill gait measurements using a laser range scanner: feasibility study of the healthy young adults.

    Science.gov (United States)

    Tanabe, S; Ii, T; Koyama, S; Saitoh, E; Itoh, N; Ohtsuka, K; Katoh, Y; Shimizu, A; Tomita, Y

    2017-04-01

    Spatio-temporal parameters are typically used for gait analysis. Although these parameters are measured by sophisticated systems such as 3D motion capture system or optoelectronic bars, these systems cannot be deployed easily because of their high costs, large space requirements and elaborate set-up. The purpose of this study is to develope a system for measuring spatiotemporal gait parameters using a laser range scanner during treadmill gait. To calculate accurate spatiotemporal parameters, the differences between the laser range scanner measured values and the reference values obtained from a 3D motion capture system were investigated in thirty subjects. From measurements in time and position at foot contact/off, adjustments to compensate for the differences in time and position were derived. Then, to determine the validity of the proposed system, values from the proposed system and the reference system were compared in four additional subjects. The results indicate that the data from the laser range scanner demonstrate certain differences in time and position compared with reference values. However, when compensation values were introduced, each spatiotemporal parameter correlated well with the reference values. This newer system is smaller, is easier to deploy and requires less training than the 3D motion capture system.

  9. Seismic damage diagnosis of a masonry building using short-term damping measurements

    Science.gov (United States)

    Kouris, Leonidas Alexandros S.; Penna, Andrea; Magenes, Guido

    2017-04-01

    It is of considerable importance to perform dynamic identification and detect damage in existing structures. This paper describes a new and practical method for damage diagnosis of masonry buildings requiring minimum computational effort. The method is based on the relative variation of modal damping and validated against experimental data from a full scale two storey shake table test. The experiment involves a building subjected to uniaxial vibrations of progressively increasing intensity at the facilities of EUCENTRE laboratory (Pavia, Italy) up to a near collapse damage state. Five time-histories are applied scaling the Montenegro (1979) accelerogram. These strong motion tests are preceded by random vibration tests (RVT's) which are used to perform modal analysis. Two deterministic methods are applied: the single degree of freedom (SDOF) assumption together with the peak-picking method in the discrete frequency domain and the Eigen realisation algorithm with data correlations (ERA-DC) in the discrete time domain. Regarding the former procedure, some improvements are incorporated to locate rigorously the natural frequencies and estimate the modal damping. The progressive evolution of the modal damping is used as a key indicator to characterise damage on the building. Modal damping is connected to the structural mass and stiffness. A square integrated but only with two components expression for proportional (classical) damping is proposed to fit better with the experimental measurements of modal damping ratios. Using this Rayleigh order formulation the contribution of each of the damping components is evaluated. The stiffness component coefficient is proposed as an effective index to detect damage and quantify its intensity.

  10. Is goniometry suitable for measuring ankle range of motion in female ballet dancers? An initial comparison with radiographic measurement.

    Science.gov (United States)

    Russell, Jeffrey A; Shave, Ruth M; Kruse, David W; Nevill, Alan M; Koutedakis, Yiannis; Wyon, Matthew A

    2011-06-01

    Female ballet dancers require extreme ankle motion to attain the demi-plié (weight-bearing full dorsiflexion [DF]) and en pointe (weight-bearing full plantar flexion [PF]) positions of ballet. However, techniques for assessing this amount of motion have not yet received sufficient scientific scrutiny. Therefore, the purpose of this study was to examine possible differences between weight-bearing goniometric and radiographic ankle range of motion measurements in female ballet dancers. Ankle range of motion in 8 experienced female ballet dancers was assessed by goniometry and 2 radiographic measurement methods. The latter were performed on 3 mediolateral x-rays, in demi-plié, neutral, and en pointe positions; one of them used the same landmarks as goniometry. DF values were not significantly different among the methods, but PF values were (P ballet dancers and suggest that goniometry may not be ideal for assessing ankle range of motion in these individuals. Therefore, further research is needed to standardize how DF and PF are measured in ballet dancers. Diagnostic, Level I.

  11. Electron probe microanalysis (EPMA) measurement of thin-film thickness in the nanometre range.

    Science.gov (United States)

    Procop, M; Radtke, M; Krumrey, M; Hasche, K; Schädlich, S; Frank, W

    2002-10-01

    The thickness of thin films of platinum and nickel on fused silica and silicon substrates has been determined by EPMA using the commercial software STRATAGEM for calculation of film thickness. Film thickness ranged in the order 10 nm. An attempt was made to estimate the confidence range of the method by comparison with results from other methods of analysis. The data show that in addition to the uncertainty of the spectral intensity measurement and the complicated fitting routine, systematic deviation caused by the underlying model should be added. The scattering in the results from other methods does not enable specification of a range of uncertainty, but deviations from the real thickness are estimated to be less than 20%.

  12. A Non-Contact Measurement System for the Range of Motion of the Hand

    Directory of Open Access Journals (Sweden)

    Trieu Pham

    2015-07-01

    Full Text Available An accurate and standardised tool to measure the active range of motion (ROM of the hand is essential to any progressive assessment scenario in hand therapy practice. Goniometers are widely used in clinical settings for measuring the ROM of the hand. However, such measurements have limitations with regard to inter-rater and intra-rater reliability and involve direct physical contact with the hand, possibly increasing the risk of transmitting infections. The system proposed in this paper is the first non-contact measurement system utilising Intel Perceptual Technology and a Senz3D Camera for measuring phalangeal joint angles. To enhance the accuracy of the system, we developed a new approach to achieve the total active movement without measuring three joint angles individually. An equation between the actual spacial position and measurement value of the proximal inter-phalangeal joint was established through the measurement values of the total active movement, so that its actual position can be inferred. Verified by computer simulations, experimental results demonstrated a significant improvement in the calculation of the total active movement and successfully recovered the actual position of the proximal inter-phalangeal joint angles. A trial that was conducted to examine the clinical applicability of the system involving 40 healthy subjects confirmed the practicability and consistency in the proposed system. The time efficiency conveyed a stronger argument for this system to replace the current practice of using goniometers.

  13. Measuring finite-range phase coherence in an optical lattice using Talbot interferometry

    Science.gov (United States)

    Santra, Bodhaditya; Baals, Christian; Labouvie, Ralf; Bhattacherjee, Aranya B.; Pelster, Axel; Ott, Herwig

    2017-06-01

    One of the important goals of present research is to control and manipulate coherence in a broad variety of systems, such as semiconductor spintronics, biological photosynthetic systems, superconducting qubits and complex atomic networks. Over the past decades, interferometry of atoms and molecules has proven to be a powerful tool to explore coherence. Here we demonstrate a near-field interferometer based on the Talbot effect, which allows us to measure finite-range phase coherence of ultracold atoms in an optical lattice. We apply this interferometer to study the build-up of phase coherence after a quantum quench of a Bose-Einstein condensate residing in a one-dimensional optical lattice. Our technique of measuring finite-range phase coherence is generic, easy to adopt and can be applied in practically all lattice experiments without further modifications.

  14. Wide-range dynamic strain measurements based on K-BOTDA and frequency-agile technique

    Science.gov (United States)

    Zhou, Dengwang; Dong, Yongkang; Wang, Benzhang; Zhang, Hongying; Lu, Zhiwei

    2017-04-01

    We propose and demonstrate a novel fast Brillouin optical time-domain analysis system using the coefficient K spectrum which is defined as the ratio of phase-shift and gain of Brillouin amplification, where K features linear response, immune to the variation of pump power and a wide measure range. For a 30ns-square pump pulse, the frequency span of K spectrum can reach up to 200MHz. In dynamic strain experiment, a multi-slope assisted K-BOTDA with the measured strain of 5358.3μɛ and the vibration frequency of 6.01Hz and 12.05Hz are demonstrated.

  15. [Measurement of the knee range of motion: standard goniometer or smartphone?].

    Science.gov (United States)

    Rwakabayiza, Sylvia; Pereira, Luis Carlos; Lécureux, Estelle; Jolles-Haeberli, Brigitte

    2013-12-18

    Universal standard goniometer is an essential tool to measure articulations' range of motion (ROM). In this time of technological advances and increasing use of smartphones, new measurement's tools appear as specific smartphone applications. This article compares the iOS application "Knee Goniometer" with universal standard goniometer to assess knee ROM. To our knowledge, this is the first study that uses a goniometer application in a clinical context. The purpose of this study is to determine if this application could be used in clinical practice.

  16. Human-Induced Effects on RSS Ranging Measurements for Cooperative Positioning

    DEFF Research Database (Denmark)

    Della Rosa, Francescantonio; Pelosi, Mauro; Nurmi, Jari

    2012-01-01

    We present experimental evaluations of human-induced perturbations on received-signal-strength-(RSS-) based ranging measurements for cooperative mobile positioning. To the best of our knowledge, this work is the first attempt to gain insight and understand the impact of both body loss and hand grip...... on the RSS for enhancing proximity measurements among neighbouring devices in cooperative scenarios. Our main contribution is represented by experimental investigations. Analysis of the errors introduced in the distance estimation using path-loss-based methods has been carried out. Moreover, the exploitation...

  17. Repeatability of Contour Method Residual Stress Measurements for a Range of Material, Process, and Geometry (Preprint)

    Science.gov (United States)

    2017-09-19

    titanium, and nickel, reflecting key industrial alloys . The set of conditions also includes a range of geometry, including plate, disk, and...for measurements. 2.2.3. Titanium Electron Beam Welded Plate Titanium alloy electron beam (EB) welded plate specimens were fabricated using one...right to use , modify, reproduce, release, perform, display, or disclose the work. 14. ABSTRACT (Maximum 200 words) This paper examines precision of

  18. Measurement of the short-range attractive force between Ge plates using a torsion balance

    OpenAIRE

    Kim, W. J.; Sushkov, A. O.; Dalvit, D. A. R.; Lamoreaux, S. K.

    2008-01-01

    We have measured the short-range attractive force between crystalline Ge plates, and found contributions from both the Casimir force and an electrical force possibly generated by surface patch potentials. Using a model of surface patch effects that generates an additional force due to a distance dependence of the apparent contact potential, the electrical force was parameterized using data at distances where the Casimir force is relatively small. Extrapolating this model, to provide a correct...

  19. Validity and reliability of using photography for measuring knee range of motion: a methodological study

    OpenAIRE

    Adie Sam; Ko Victoria; Naylor Justine M; Gaskin Clive; Walker Richard; Harris Ian A; Mittal Rajat

    2011-01-01

    Abstract Background The clinimetric properties of knee goniometry are essential to appreciate in light of its extensive use in the orthopaedic and rehabilitative communities. Intra-observer reliability is thought to be satisfactory, but the validity and inter-rater reliability of knee goniometry often demonstrate unacceptable levels of variation. This study tests the validity and reliability of measuring knee range of motion using goniometry and photographic records. Methods Design: Methodolo...

  20. Seismic Creep

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Seismic creep is the constant or periodic movement on a fault as contrasted with the sudden erupture associated with an earthquake. It is a usually slow deformation...

  1. Quantitative analysis of impact-induced seismic signals by numerical modeling

    Science.gov (United States)

    Güldemeister, Nicole; Wünnemann, Kai

    2017-11-01

    We quantify the seismicity of impact events using a combined numerical and experimental approach. The objectives of this work are (1) the calibration of the numerical model by utilizing real-time measurements of the elastic wave velocity and pressure amplitudes in laboratory impact experiments; (2) the determination of seismic parameters, such as quality factor Q and seismic efficiency k, for materials of different porosity and water saturation by a systematic parameter study employing the calibrated numerical model. By means of ;numerical experiments; we found that the seismic efficiency k decreases slightly with porosity from k = 3.4 × 10-3 for nonporous quartzite to k = 2.6 × 10-3 for 25% porous sandstone. If pores are completely or partly filled with water, we determined a seismic efficiency of k = 8.2 × 10-5, which is approximately two orders of magnitude lower than in the nonporous case. By measuring the attenuation of the seismic wave with distance in our numerical experiments we determined the seismic quality factor Q to range between ∼35 for the solid quartzite and 80 for the porous dry targets. For water saturated target materials, Q is much lower, seismic efficiency into seismic magnitudes we show that the seismic magnitude of an impact event is about one order of magnitude smaller considering a water saturated target in comparison to a solid or porous target. Obtained seismic magnitudes decrease linearly with distance to the point of impact and are consistent with empirical data for distances closer to the point of impact. The seismic magnitude decreases more rapidly with distance for a water saturated material compared to a dry material.

  2. Comparison of linear gain and wide dynamic range compression hearing aid circuits II: aided loudness measures.

    Science.gov (United States)

    Jenstad, L M; Pumford, J; Seewald, R C; Cornelisse, L E

    2000-02-01

    The goal of this study was to test the theoretical advantages of a single-channel wide dynamic range compression (WDRC) circuit fitted using the DSL method for increased dynamic range and normalized loudness growth. Ten adolescents and young adults with moderate to severe sensorineural hearing loss were fitted monaurally with the Siemens Viva 2 Pro behind-the-ear instrument set to DSL 4.0 targets for both linear gain and WDRC processing. Threshold, upper limit of comfort and loudness growth were measured in the unaided, linear gain and WDRC conditions for warble tones, environmental sounds and speech. Twelve adult listeners with normal hearing also were tested monaurally in the unaided condition to provide normative data for comparison purposes. The WDRC hearing aid provided a greater input dynamic range than the linear circuit for all stimuli. The dynamic range was normalized for more subjects with the WDRC than the linear hearing aid. In addition, exponential loudness growth functions fitted to the loudness growth data showed that, on average, loudness growth was more normalized with the WDRC hearing aid fitted to DSL[i/o] targets than the linear hearing aid fitted to DSL[i/o] targets. WDRC processing, fitted using the DSL[i/o] method, has potential applications in hearing aid fittings for listeners with moderate to severe hearing loss because it provides an audible, comfortable and tolerable amplified signal across a wider range of inputs than linear gain processing, without the need for volume control adjustments.

  3. Reliability of speaking and maximum voice range measures in screening for dysphonia.

    Science.gov (United States)

    Ma, Estella; Robertson, Jennie; Radford, Claire; Vagne, Sarah; El-Halabi, Ruba; Yiu, Edwin

    2007-07-01

    Speech range profile (SRP) is a graphical display of frequency-intensity occurring interactions during functional speech activity. Few studies have suggested the potential clinical applications of SRP. However, these studies are limited to qualitative case comparisons and vocally healthy participants. The present study aimed to examine the effects of voice disorders on speaking and maximum voice ranges in a group of vocally untrained women. It also aimed to examine whether voice limit measures derived from SRP were as sensitive as those derived from voice range profile (VRP) in distinguishing dysphonic from healthy voices. Ninety dysphonic women with laryngeal pathologies and 35 women with normal voices, who served as controls, participated in this study. Each subject recorded a VRP for her physiological vocal limits. In addition, each subject read aloud the "North Wind and the Sun" passage to record SRP. All the recordings were captured and analyzed by Soundswell's computerized real-time phonetogram Phog 1.0 (Hitech Development AB, Täby, Sweden). The SRPs and the VRPs were compared between the two groups of subjects. Univariate analysis results demonstrated that individual SRP measures were less sensitive than the corresponding VRP measures in discriminating dysphonic from normal voices. However, stepwise logistic regression analyses revealed that the combination of only two SRP measures was almost as effective as a combination of three VRP measures in predicting the presence of dysphonia (overall prediction accuracy: 93.6% for SRP vs 96.0% for VRP). These results suggest that in a busy clinic where quick voice screening results are desirable, SRP can be an acceptable alternate procedure to VRP.

  4. Measurement of soil water potential over an extended range by polymer tensiometers: comparison with other instruments

    Science.gov (United States)

    van der Ploeg, M. J.; Gooren, H. P.; Hoogendam, R. C.; Bakker, G.; Huiskes, C.; Koopal, L. K.; Kruidhof, H.; de Rooij, G. H.

    2007-12-01

    In water scarce areas, plant growth and productivity can be severely hampered by irregular precipitation and overall water shortage. Root water uptake is mainly driven by matric potential gradients, but measurement of soil water matric potential is limited by the measurement range of water-filled tensiometers (-0.085 MPa). Other measurement techniques indirectly measure soil water potential by converting soil water content with the use of the water retention curve. In dry soils, the water content measurements may become insensitive to small variations, and consequently this conversion may lead to large errors. We developed a polymer tensiometer (POT) that is able to measure matric potentials down to -2.0 MPa. The POT consists of a solid ceramic, a stainless steel cup and a pressure transducer. The ceramic consist of a support layer and a membrane with 2 nm pore-size to prevent polymer leakage. Between the ceramic membrane and the pressure transducer a tiny chamber is located, which contains the polymer solution. The polymer's osmotic potential strongly reduces the total water potential inside the polymer tensiometer, which causes build-up of osmotic pressure. Hence, the water in the polymer tensiometer will cavitate at a much lower matric potential than the nearly pure water in a conventional tensiometer. Direct observation of the potential of soil water at different locations in the root-system will yield knowledge about the ability of a plant to take up the water under conditions of water shortage or salinity stress. With this knowledge it will be possible to adjust existing unsaturated flow models accounting for root water uptake. We tested 8 POTs in an experimental setup, where we compared matric potential measurements to TDR water content measurements, matric potentials derived from measured water contents, and matric potentials measured by water-filled tensiometers. The experimental setup consisted of two evaporation boxes, one filled with sand (97.6% sand, 1

  5. Dynamic Data Filtering of Long-Range Doppler LiDAR Wind Speed Measurements

    Directory of Open Access Journals (Sweden)

    Hauke Beck

    2017-06-01

    Full Text Available Doppler LiDARs have become flexible and versatile remote sensing devices for wind energy applications. The possibility to measure radial wind speed components contemporaneously at multiple distances is an advantage with respect to meteorological masts. However, these measurements must be filtered due to the measurement geometry, hard targets and atmospheric conditions. To ensure a maximum data availability while producing low measurement errors, we introduce a dynamic data filter approach that conditionally decouples the dependency of data availability with increasing range. The new filter approach is based on the assumption of self-similarity, that has not been used so far for LiDAR data filtering. We tested the accuracy of the dynamic data filter approach together with other commonly used filter approaches, from research and industry applications. This has been done with data from a long-range pulsed LiDAR installed at the offshore wind farm ‘alpha ventus’. There, an ultrasonic anemometer located approximately 2.8 km from the LiDAR was used as reference. The analysis of around 1.5 weeks of data shows, that the error of mean radial velocity can be minimised for wake and free stream conditions.

  6. Average Neutron Total Cross Sections in the Unresolved Energy Range From ORELA High Resolutio Transmission Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Derrien, H

    2004-05-27

    Average values of the neutron total cross sections of {sup 233}U, {sup 235}U, {sup 238}U, and {sup 239}Pu have been obtained in the unresolved resonance energy range from high-resolution transmission measurements performed at ORELA in the past two decades. The cross sections were generated by correcting the effective total cross sections for the self-shielding effects due to the resonance structure of the data. The self-shielding factors were found by calculating the effective and true cross sections with the computer code SAMMY for the same Doppler and resolution conditions as for the transmission measurements, using an appropriate set of resonance parameters. Our results are compared to results of previous measurements and to the current ENDF/B-VI data.

  7. Measurements and correlations of turbulent burning velocities over wide ranges of fuels and elevated pressures

    KAUST Repository

    Bradley, Derek

    2013-01-01

    The implosion technique has been used to extend measurements of turbulent burning velocities over greater ranges of fuels and pressures. Measurements have been made up to 3.5 MPa and at strain rate Markstein numbers as low as 23. The implosion technique, with spark ignition at two opposite wall positions within a fan-stirred spherical bomb is capable of measuring turbulent burning velocities, at higher pressures than is possible with central ignition. Pressure records and schlieren high speed photography define the rate of burning and the smoothed area of the flame front. The first aim of the study was to extend the previous measurements with ethanol and propane-air, with further measurements over wider ranges of fuels and equivalence ratios with mixtures of hydrogen, methane, 10% hydrogen-90% methane, toluene, and i-octane, with air. The second aim was to study further the low turbulence regime in which turbulent burning co-exists with laminar flame instabilities. Correlations are presented of turbulent burning velocity normalised by the effective rms turbulent velocity acting on the flame front, ut=u0k , with the Karlovitz stretch factor, K, for different strain rate Markstein numbers, a decrease in which increases ut=u0k . Experimental correlations are presented for the present measurements, combined with previous ones. Different burning regimes are also identified, extending from that of mixed turbulence/laminar instability at low values of K to that at high values of K, in which ut=u0k is gradually reduced due to increasing localised flame extinctions. © 2012 The Combustion Institute.

  8. Feasibility of RACT for 3D dose measurement and range verification in a water phantom.

    Science.gov (United States)

    Alsanea, Fahed; Moskvin, Vadim; Stantz, Keith M

    2015-02-01

    The objective of this study is to establish the feasibility of using radiation-induced acoustics to measure the range and Bragg peak dose from a pulsed proton beam. Simulation studies implementing a prototype scanner design based on computed tomographic methods were performed to investigate the sensitivity to proton range and integral dose. Derived from thermodynamic wave equation, the pressure signals generated from the dose deposited from a pulsed proton beam with a 1 cm lateral beam width and a range of 16, 20, and 27 cm in water using Monte Carlo methods were simulated. The resulting dosimetric images were reconstructed implementing a 3D filtered backprojection algorithm and the pressure signals acquired from a 71-transducer array with a cylindrical geometry (30 × 40 cm) rotated over 2π about its central axis. Dependencies on the detector bandwidth and proton beam pulse width were performed, after which, different noise levels were added to the detector signals (using 1 μs pulse width and a 0.5 MHz cutoff frequency/hydrophone) to investigate the statistical and systematic errors in the proton range (at 20 cm) and Bragg peak dose (of 1 cGy). The reconstructed radioacoustic computed tomographic image intensity was shown to be linearly correlated to the dose within the Bragg peak. And, based on noise dependent studies, a detector sensitivity of 38 mPa was necessary to determine the proton range to within 1.0 mm (full-width at half-maximum) (systematic error ionizing radiation-induced acoustics can be used to verify dose distribution and proton range with centi-Gray sensitivity. Realizing this technology into the clinic has the potential to significantly impact beam commissioning, treatment verification during particle beam therapy and image guided techniques.

  9. Seismic processing in the inverse data space

    NARCIS (Netherlands)

    Berkhout, A.J.

    2006-01-01

    Until now, seismic processing has been carried out by applying inverse filters in the forward data space. Because the acquired data of a seismic survey is always discrete, seismic measurements in the forward data space can be arranged conveniently in a data matrix (P). Each column in the data matrix

  10. Seismic hazard estimation of northern Iran using smoothed seismicity

    Science.gov (United States)

    Khoshnevis, Naeem; Taborda, Ricardo; Azizzadeh-Roodpish, Shima; Cramer, Chris H.

    2017-07-01

    This article presents a seismic hazard assessment for northern Iran, where a smoothed seismicity approach has been used in combination with an updated seismic catalog and a ground motion prediction equation recently found to yield good fit with data. We evaluate the hazard over a geographical area including the seismic zones of Azerbaijan, the Alborz Mountain Range, and Kopeh-Dagh, as well as parts of other neighboring seismic zones that fall within our region of interest. In the chosen approach, seismic events are not assigned to specific faults but assumed to be potential seismogenic sources distributed within regular grid cells. After performing the corresponding magnitude conversions, we decluster both historical and instrumental seismicity catalogs to obtain earthquake rates based on the number of events within each cell, and smooth the results to account for the uncertainty in the spatial distribution of future earthquakes. Seismicity parameters are computed for each seismic zone separately, and for the entire region of interest as a single uniform seismotectonic region. In the analysis, we consider uncertainties in the ground motion prediction equation, the seismicity parameters, and combine the resulting models using a logic tree. The results are presented in terms of expected peak ground acceleration (PGA) maps and hazard curves at selected locations, considering exceedance probabilities of 2 and 10% in 50 years for rock site conditions. According to our results, the highest levels of hazard are observed west of the North Tabriz and east of the North Alborz faults, where expected PGA values are between about 0.5 and 1 g for 10 and 2% probability of exceedance in 50 years, respectively. We analyze our results in light of similar estimates available in the literature and offer our perspective on the differences observed. We find our results to be helpful in understanding seismic hazard for northern Iran, but recognize that additional efforts are necessary to

  11. Sensitivity of physiological emotional measures to odors depends on the product and the pleasantness ranges used

    Directory of Open Access Journals (Sweden)

    Aline Marie Pichon

    2015-12-01

    Full Text Available Emotions are characterized by synchronized changes in several components of an organism. Among them, physiological variations provide energy support for the expression of approach/avoid action tendencies induced by relevant stimuli, while self-reported subjective pleasantness feelings integrate all other emotional components and are plastic.Consequently, emotional responses evoked by odors should be highly differentiated when they are linked to different functions of olfaction (e.g., avoiding environmental hazards. As this differentiation has been observed for contrasted odors (very pleasant or unpleasant, we questioned whether subjective and physiological emotional response indicators could still disentangle subtle affective variations when no clear functional distinction is made (mildly pleasant or unpleasant fragrances. Here, we compared the sensitivity of behavioral and physiological (respiration, skin conductance, facial electromyography (EMG, and heart rate indicators in differentiating odor-elicited emotions in two situations: when a wide range of odor families was presented (e.g., fruity, animal, covering different functional meanings; or in response to a restricted range of products in one particular family (fragrances. Results show clear differences in physiological indicators to odors that display a wide range of reported pleasantness, but these differences almost entirely vanish when fragrances are used even though their subjective pleasantness still differed. Taken together, these results provide valuable information concerning the ability of classic verbal and psychophysiological measures to investigate subtle differences in emotional reactions to a restricted range of similar olfactory stimuli.

  12. Validation of a photography-based goniometry method for measuring joint range of motion.

    Science.gov (United States)

    Blonna, Davide; Zarkadas, Peter C; Fitzsimmons, James S; O'Driscoll, Shawn W

    2012-01-01

    A critical component of evaluating the outcomes after surgery to restore lost elbow motion is the range of motion (ROM) of the elbow. This study examined if digital photography-based goniometry is as accurate and reliable as clinical goniometry for measuring elbow ROM. Instrument validity and reliability for photography-based goniometry were evaluated for a consecutive series of 50 elbow contractures by 4 observers with different levels of elbow experience. Goniometric ROM measurements were taken with the elbows in full extension and full flexion directly in the clinic (once) and from digital photographs (twice in a blinded random manner). Instrument validity for photography-based goniometry was extremely high (intraclass correlation coefficient: extension = 0.98, flexion = 0.96). For extension and flexion measurements by the expert surgeon, systematic error was negligible (0° and 1°, respectively). Limits of agreement were 7° (95% confidence interval [CI], 5° to 9°) and -7° (95% CI, -5° to -9°) for extension and 8° (95% CI, 6° to 10°) and -7° (95% CI, -5° to -9°) for flexion. Interobserver reliability for photography-based goniometry was better than that for clinical goniometry. The least experienced observer's photographic goniometry measurements were closer to the reference measurements than the clinical goniometry measurements. Photography-based goniometry is accurate and reliable for measuring elbow ROM. The photography-based method relied less on observer expertise than clinical goniometry. This validates an objective measure of patient outcome without requiring doctor-patient contact at a tertiary care center, where most contracture surgeries are done. Copyright © 2012 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Mosby, Inc. All rights reserved.

  13. CFD comparison with centrifugal compressor measurements on a wide operating range

    Directory of Open Access Journals (Sweden)

    Arnou D.

    2013-04-01

    Full Text Available Centrifugal compressors are widely used in industrial applications thanks to their high efficiency. They are able to provide a wide operating range before reaching the flow barrier or surge limits. Performances and range are described by compressor maps obtained experimentally. After a description of performance test rig, this article compares measured centrifugal compressor performances with computational fluid dynamics results. These computations are performed at steady conditions with R134a refrigerant as fluid. Navier-Stokes equations, coupled with k-ε turbulence model, are solved by the commercial software ANSYS-CFX by means of volume finite method. Input conditions are varied in order to calculate several speed lines. Theoretical isentropic efficiency and theoretical surge line are finally compared to experimental data.

  14. Calibration Standards for Surface Topography Measuring Systems down to Nanometric Range

    DEFF Research Database (Denmark)

    Trumpold, H.; De Chiffre, Leonardo; Andreasen, Jan Lasson

    geometry of basic bodies for compression and injection moulding of plastic negatives with different step height, sinusoidal-, triangular and arcuate profiles covering Pt-values from 0.05 µm up to 100 µm and PSm values from 0.8 µm up to 800 µm. For active calibration in Z-direction a small size vertical...... and for the calibration of filters. Existing ISO standards on calibration specimens are inadequate and limited in that they only cover contacting instruments and only partially the measuring ranges for these instruments. The whole range of non-contacting instruments are not covered despite their increasing use...... compression and injection moulded plastic negatives and Ni-negatives have been made from which again Ni-positives were produced. The replication processes showed negligible deviations from the Pt and Pa values compared to the primary standards. An important prerequisite is the cleanliness of the surfaces...

  15. Range Resolved CO2 Atmospheric Backscattering Measurements Using Fiber Lasers and RZPN Code Modulation

    Science.gov (United States)

    Burris, John

    2011-01-01

    We report the use of a return-to- zero (RZPN) pseudo noise modulation technique for making range resolved measurements of CO2 within the planetary boundary layer (PBL) using commercial, off-the-shelf, components. Conventional, range resolved, DIAL measurements require laser pulse widths that are significantly shorter than the desired spatial resolution and necessitate using pulses whose temporal spacing is such that scattered returns from only a single pulse are observed by the receiver at any one time (for the PBL pulse separations must be greater than approximately 20 microseconds). This imposes significant operational limitations when using currently available fiber lasers because of the resulting low duty cycle (less than approximately 0.0005) and consequent low average laser output power. The RZPN modulation technique enables a fiber laser to operate at much higher duty cycles (approaching 0.04) thereby more effectively utilizing the amplifier's output. This increases the counts received by approximately two orders of magnitude. Our approach involves employing two distributed feedback lasers (DFB), each modulated by a different RPZN code, whose outputs are then amplified by a CW fiber amplifier. One laser is tuned to a CO2 absorption line; the other operates offline thereby permitting the simultaneous acquisition of both on and offline signals using independent RZPN codes. This minimizes the impact of atmospheric turbulence on the measurement. The on and offline signals are retrieved by deconvolving the return signal using the appropriate kernels.

  16. Testing accuracy of long-range ultrasonic sensors for olive tree canopy measurements.

    Science.gov (United States)

    Gamarra-Diezma, Juan Luis; Miranda-Fuentes, Antonio; Llorens, Jordi; Cuenca, Andrés; Blanco-Roldán, Gregorio L; Rodríguez-Lizana, Antonio

    2015-01-28

    Ultrasonic sensors are often used to adjust spray volume by allowing the calculation of the crown volume of tree crops. The special conditions of the olive tree require the use of long-range sensors, which are less accurate and faster than the most commonly used sensors. The main objectives of the study were to determine the suitability of the sensor in terms of sound cone determination, angle errors, crosstalk errors and field measurements. Different laboratory tests were performed to check the suitability of a commercial long-range ultrasonic sensor, as were the experimental determination of the sound cone diameter at several distances for several target materials, the determination of the influence of the angle of incidence of the sound wave on the target and distance on the accuracy of measurements for several materials and the determination of the importance of the errors due to interference between sensors for different sensor spacings and distances for two different materials. Furthermore, sensor accuracy was tested under real field conditions. The results show that the studied sensor is appropriate for olive trees because the sound cone is narrower for an olive tree than for the other studied materials, the olive tree canopy does not have a large influence on the sensor accuracy with respect to distance and angle, the interference errors are insignificant for high sensor spacings and the sensor's field distance measurements were deemed sufficiently accurate.

  17. Improving detection range, signal-to-noise ratio, and measurement time through hyperentanglement

    Science.gov (United States)

    Smith, James F.

    2017-07-01

    An atmospheric imaging system based on quantum hyperentanglement has been developed. Hyper-entanglement can increase the maximum detection range of the system by more than a factor of 10, improve the signal-to-noise ratio (SNR) by more than a factor of 10,000, and decrease measurement time. Hyperentanglement refers to entanglement in more than one degree of freedom. A design for creating states hyperentangled in the degrees of freedom polarization, energy-time, orbital angular momentum (OAM), and the radial quantum number is examined. The design helps reduce propagation loss. Figures of merit related to generation and detection efficiencies, the SNR, signal to interference ratio, the measurement time, and phase estimation are provided in closed form. A formula describing how hyperentanglement greatly improves the maximum detection range of the system is derived. Hermite-Gaussian modes, Laguerre-Gaussian (LG) modes, OAM dependence of the LG modes, and mode conversion are discussed. Bell state generation and Bell state measurement, i.e., the ability to distinguish the various Bell states, is discussed. Mathematical and circuit representations of Bell state generation and the Bell state analyzer are provided. Signatures for unique detection of the various Bell states are developed. The formalism permits random noise and entangled or nonentangled sources of interference to be modeled.

  18. Effects of Surface Geology on Seismic Ground Motion Deduced from Ambient-Noise Measurements in the Town of Avellino, Irpinia Region (Italy)

    Science.gov (United States)

    Maresca, R.; Nardone, L.; Pasquale, G.; Pinto, F.; Bianco, F.

    2012-07-01

    The effects of surface geology on ground motion provide an important tool in seismic hazard studies. It is well known that the presence of soft sediments can cause amplification of the ground motion at the surface, particularly when there is a sharp impedance contrast at shallow depth. The town of Avellino is located in an area characterised by high seismicity in Italy, about 30 km from the epicentre of the 23 November 1980, Irpinia earthquake ( M = 6.9). No earthquake recordings are available in the area. The local geology is characterised by strong heterogeneity, with impedance contrasts at depth. We present the results from seismic noise measurements carried out in the urban area of Avellino to evaluate the effects of local geology on the seismic ground motion. We computed the horizontal-to-vertical (H/V) noise spectral ratios at 16 selected sites in this urban area for which drilling data are available within the first 40 m of depth. A Rayleigh wave inversion technique using the peak frequencies of the noise H/V spectral ratios is then presented for estimating Vs models, assuming that the thicknesses of the shallow soil layers are known. The results show a good correspondence between experimental and theoretical peak frequencies, which are interpreted in terms of sediment resonance. For one site, which is characterised by a broad peak in the horizontal-to-vertical spectral-ratio curve, simple one-dimensional modelling is not representative of the resonance effects. Consistent variations in peak amplitudes are seen among the sites. A site classification based on shear-wave velocity characteristics, in terms of Vs30, cannot explain these data. The differences observed are better correlated to the impedance contrast between the sediments and basement. A more detailed investigation of the physical parameters of the subsoil structure, together with earthquake data, are desirable for future research, to confirm these data in terms of site response.

  19. Seismic evidence of crustal heterogeneity beneath the northwestern Deccan volcanic province of India from joint inversion of Rayleigh wave dispersion measurements and P receiver functions

    Science.gov (United States)

    Deshpande, Akshaya; Mohan, Gollapally

    2017-04-01

    The northwestern Deccan volcanic province (NWDVP) of India, encompassing the Saurashtra peninsula and the adjoining Gulf of Cambay, is investigated through joint inversion of surface wave dispersion measurements and teleseis- mic P receiver functions, to estimate the crustal and shallow upper mantle shear wave velocity (Vs) structure. The Mw ˜ 7.7 Bhuj earthquake and the post Bhuj regional events, recorded during the period 2001-2010 at 7 stations along 37 source-receiver paths were used along with 35 teleseismic events. A joint curve fitting inversion technique is applied to obtain a best fit for the fundamental mode Rayleigh wave group velocity dispersion curves for time periods 5-50 s and high quality crustal P wave receiver functions obtained at each station. Significant crustal heterogeneity is observed within the study region with the average crustal Vs ranging from 3.5 km/s to 3.8 km/s with the paths cutting across the Gulf of Cambay exhibiting large reduction in shear wave velocities. Utilizing the average crustal Vs ≈ 3.66 km/s estimated for Saurashtra, together with the average crustal P wave velocity (Vp) ≈ 6.54 km/s derived independently through deep seismic sounding studies, yields a bulk Vp/Vs ratio of 1.786 or an equivalent crustal Poisson's ratio of 0.271. A major contribution to the high Poisson's ratio comes from the 12 to 16 km thick lower crustal layers with shear velocities ranging from 3.8 km/s to 4.19 km/s suggesting widespread magmatic underplating due to emplacement of mafic cumulates in the lower crust. The shallow uppermost mantle shear velocities are in the range 4.2-4.5 km/s averaging 4.36 km/ s, which is less than that observed for the Indian shield, indicating the effects of residual thermal anomaly. The variation in the crustal Vs, high Poisson's ratios and low upper mantle shear velocities reflect the thermal and compositional effects of the Deccan volcanism which are manifested in terms of pervasive presence of mafic dykes

  20. Spatial wavefield gradient-based seismic wavefield separation

    Science.gov (United States)

    Van Renterghem, C.; Schmelzbach, C.; Sollberger, D.; Robertsson, J. OA

    2018-03-01

    Measurements of the horizontal and vertical components of particle motion combined with estimates of the spatial gradients of the seismic wavefield enable seismic data to be acquired and processed using single dedicated multicomponent stations (e.g. rotational sensors) and/or small receiver groups instead of large receiver arrays. Here, we present seismic wavefield decomposition techniques that use spatial wavefield gradient data to separate land and ocean bottom data into their upgoing/downgoing and P/S constituents. Our method is based on the elastodynamic representation theorem with the derived filters requiring local measurements of the wavefield and its spatial gradients only. We demonstrate with synthetic data and a land seismic field data example that combining translational measurements with spatial wavefield gradient estimates allows separating seismic data recorded either at the Earth's free-surface or at the sea bottom into upgoing/downgoing and P/S wavefield constituents for typical incidence angle ranges of body waves. A key finding is that the filter application only requires knowledge of the elastic properties exactly at the recording locations and is valid for a wide elastic property range.

  1. Feasibility of RACT for 3D dose measurement and range verification in a water phantom

    Energy Technology Data Exchange (ETDEWEB)

    Alsanea, Fahed [School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907-2051 (United States); Moskvin, Vadim [Radiation Oncology, Indiana University School of Medicine, 535 Barnhill Drive, RT 041, Indianapolis, Indiana 46202-5289 (United States); Stantz, Keith M., E-mail: kstantz@purdue.edu [School of Health Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, Indiana 47907-2051 and Radiology and Imaging Sciences, Indiana University School of Medicine, 950 West Walnut Street, Indianapolis, Indiana 46202-5289 (United States)

    2015-02-15

    Purpose: The objective of this study is to establish the feasibility of using radiation-induced acoustics to measure the range and Bragg peak dose from a pulsed proton beam. Simulation studies implementing a prototype scanner design based on computed tomographic methods were performed to investigate the sensitivity to proton range and integral dose. Methods: Derived from thermodynamic wave equation, the pressure signals generated from the dose deposited from a pulsed proton beam with a 1 cm lateral beam width and a range of 16, 20, and 27 cm in water using Monte Carlo methods were simulated. The resulting dosimetric images were reconstructed implementing a 3D filtered backprojection algorithm and the pressure signals acquired from a 71-transducer array with a cylindrical geometry (30 × 40 cm) rotated over 2π about its central axis. Dependencies on the detector bandwidth and proton beam pulse width were performed, after which, different noise levels were added to the detector signals (using 1 μs pulse width and a 0.5 MHz cutoff frequency/hydrophone) to investigate the statistical and systematic errors in the proton range (at 20 cm) and Bragg peak dose (of 1 cGy). Results: The reconstructed radioacoustic computed tomographic image intensity was shown to be linearly correlated to the dose within the Bragg peak. And, based on noise dependent studies, a detector sensitivity of 38 mPa was necessary to determine the proton range to within 1.0 mm (full-width at half-maximum) (systematic error < 150 μm) for a 1 cGy Bragg peak dose, where the integral dose within the Bragg peak was measured to within 2%. For existing hydrophone detector sensitivities, a Bragg peak dose of 1.6 cGy is possible. Conclusions: This study demonstrates that computed tomographic scanner based on ionizing radiation-induced acoustics can be used to verify dose distribution and proton range with centi-Gray sensitivity. Realizing this technology into the clinic has the potential to significantly

  2. Measurement based scenario analysis of short-range distribution system planning

    DEFF Research Database (Denmark)

    Chen, Peiyuan; Bak-Jensen, Birgitte; Chen, Zhe

    2009-01-01

    feasible scenarios are performed based on a local distribution system at Støvring in Denmark. Simulation results provide more accurate and insightful information for the decision-maker when using the probabilistic analysis than using the worst-case analysis, so that a better planning can be achieved.......This paper focuses on short-range distribution system planning using a probabilistic approach. Empirical probabilistic distributions of load demand and distributed generations are derived from the historical measurement data and incorporated into the system planning. Simulations with various...

  3. Frequency Comb Driven Raman Transitions in the THz Range: High Precision Isotope Shift Measurements in Ca+

    DEFF Research Database (Denmark)

    Meyer, Steffen

    2017-01-01

    to picoseconds in the previous experiments. For the broad spectrum, the additional effect of group delay dispersion (GDD) has to be taken into account, since the Raman process relies on the coherent interaction of all frequency components of the spectrum, with GDD influencing the relative phase which leads......This thesis presents for the first time the experimental implementation of coherent Raman oscillations with a femtosecond frequency comb for transition frequencies in the THz range. The technique has been successfully demonstrated before to drive Raman transitions between hyperfine structure states...... to destructive interference. Therefore, GDD is compensated using a prism compressor and it is shown quantitatively that the measured GDD matches the theoretically predicted effect on the total Raman Rabi frequency. For the measurements and compensation of GDD, the techniques of interferometric autocorrelation...

  4. Human-Induced Effects on RSS Ranging Measurements for Cooperative Positioning

    Directory of Open Access Journals (Sweden)

    Francescantonio Della Rosa

    2012-01-01

    Full Text Available We present experimental evaluations of human-induced perturbations on received-signal-strength-(RSS- based ranging measurements for cooperative mobile positioning. To the best of our knowledge, this work is the first attempt to gain insight and understand the impact of both body loss and hand grip on the RSS for enhancing proximity measurements among neighbouring devices in cooperative scenarios. Our main contribution is represented by experimental investigations. Analysis of the errors introduced in the distance estimation using path-loss-based methods has been carried out. Moreover, the exploitation of human-induced perturbations for enhancing the final positioning accuracy through cooperative schemes has been assessed. It has been proved that the effect of cooperation is very limited if human factors are not taken into account when performing experimental activities.

  5. The validity and reliability of a new instrumented device for measuring ankle dorsiflexion range of motion.

    Science.gov (United States)

    Calatayud, Joaquin; Martin, Fernando; Gargallo, Pedro; García-Redondo, Jessica; Colado, Juan Carlos; Marín, Pedro J

    2015-04-01

    A restriction in ankle dorsiflexion range of motion (ROM) has been linked to several clinical manifestations such as metatarsalgia, heel pain, nerve entrapment, ankle joint equinus, patellar and ankle injuries. The purpose of the present study was to examine the validity and reliability of the Leg Motion system for measuring ankle dorsiflexion ROM. Descriptive repeated-measures study. Twenty-six healthy male university students were recruited to test the reliability of the Leg Motion system, which is a portable tool used for assessment of ankle dorsiflexion during the weight-bearing lunge test. The participants were tested two times separated by two weeks and measurements were performed at the same time of the day by the same single rater. To test the validity of the Leg Motion system, other maximal ankle dorsiflexion ROM assessments (goniometer, inclinometer and measuring tape) were measured in a single session (i.e., the first test session) during the weight-bearing lunge position using a standard goniometer, a digital inclinometer and a measuring tape measure with the ability to measure to the nearest 0.1 cm. Paired t-tests showed the absence of significant differences between right and left limb measurements of dorsiflexion in all tests. Mean values ± standard deviations were as follows: Leg Motion test (left 11.6cm±3.9; right 11.9cm ±4.0), tape measure (left 11.6cm±4.0; right 11.8cm±4.2), goniometer (left 40.6º±5.2; right 40.6º±5.2), and digital inclinometer (left 40.0º±5.8; right 39.9º±5.6). The Leg Motion composite values (i.e., average of the two legs) showed a significant (pMotion system as a valid, portable, and easy to use alternative to the weight-bearing lunge test to assess ankle dorsiflexion ROM in healthy participants. 2b.

  6. Multiscale seismic characterization of marine sediments by using a wavelet-based approach

    Science.gov (United States)

    Ker, Stephan; Le Gonidec, Yves; Gibert, Dominique

    2015-04-01

    We propose a wavelet-based method to characterize acoustic impedance discontinuities from a multiscale analysis of reflected seismic waves. This method is developed in the framework of the wavelet response (WR) where dilated wavelets are used to sound a complex seismic reflector defined by a multiscale impedance structure. In the context of seismic imaging, we use the WR as a multiscale seismic attributes, in particular ridge functions which contain most of the information that quantifies the complex geometry of the reflector. We extend this approach by considering its application to analyse seismic data acquired with broadband but frequency limited source signals. The band-pass filter related to such actual sources distort the WR: in order to remove these effects, we develop an original processing based on fractional derivatives of Lévy alpha-stable distributions in the formalism of the continuous wavelet transform (CWT). We demonstrate that the CWT of a seismic trace involving such a finite frequency bandwidth can be made equivalent to the CWT of the impulse response of the subsurface and is defined for a reduced range of dilations, controlled by the seismic source signal. In this dilation range, the multiscale seismic attributes are corrected from distortions and we can thus merge multiresolution seismic sources to increase the frequency range of the mutliscale analysis. As a first demonstration, we perform the source-correction with the high and very high resolution seismic sources of the SYSIF deep-towed seismic device and we show that both can now be perfectly merged into an equivalent seismic source with an improved frequency bandwidth (220-2200 Hz). Such multiresolution seismic data fusion allows reconstructing the acoustic impedance of the subseabed based on the inverse wavelet transform properties extended to the source-corrected WR. We illustrate the potential of this approach with deep-water seismic data acquired during the ERIG3D cruise and we compare

  7. Finite-frequency wave propagation through outer rise fault zones and seismic measurements of upper mantle hydration

    Science.gov (United States)

    Miller, Nathaniel; Lizarralde, Daniel

    2016-01-01

    Effects of serpentine-filled fault zones on seismic wave propagation in the upper mantle at the outer rise of subduction zones are evaluated using acoustic wave propagation models. Modeled wave speeds depend on azimuth, with slowest speeds in the fault-normal direction. Propagation is fastest along faults, but, for fault widths on the order of the seismic wavelength, apparent wave speeds in this direction depend on frequency. For the 5–12 Hz Pn arrivals used in tomographic studies, joint-parallel wavefronts are slowed by joints. This delay can account for the slowing seen in tomographic images of the outer rise upper mantle. At the Middle America Trench, confining serpentine to fault zones, as opposed to a uniform distribution, reduces estimates of bulk upper mantle hydration from ~3.5 wt % to as low as 0.33 wt % H2O.

  8. The 1995-99 measurements of the Lense-Thirring effect using laser-ranged satellites

    Science.gov (United States)

    Ciufolini, Ignazio

    2000-06-01

    In general relativity a current of mass-energy, such as a spinning body, gives rise to peculiar phenomena on bodies, particles and clocks in its vicinity, which are not predicted by the Newtonian gravitational theory; one of these phenomena is the Lense-Thirring effect on particles orbiting a spinning central body. In this paper we first review the method used to measure the Lense-Thirring effect, by analysing the orbits of the two laser-ranged satellites LAGEOS and LAGEOS II, that has provided a direct measurements of this effect; we then report on these detections of the Lense-Thirring effect, obtained by analysing the nodes of LAGEOS and LAGEOS II and the perigee of LAGEOS II with the orbital programs GEODYN-SOLVE, using the Earth gravitational models JGM-3 and EGM-96 and this new method. The first detection was obtained in 1995, the most accurate measurements were obtained in 1998 using EGM-96, with about 20-30% accuracy. Finally, we briefly review the proposed LARES experiment to measure the Lense-Thirring effect with an accuracy of about 2-3% and to provide other basic tests of general relativity and gravitation.

  9. Development of a Coherent Differential Absorption Lidar for Range Resolved Atmospheric CO2 Measurements

    Science.gov (United States)

    Yu, Jirong; Petros, Mulgueta; Chen, Songsheng; Bai, Yingxin; Petzar, Paul J.; Trieu, Bo. C.; Koch, Grady J.; Beyon, Jeffery J.; Singh, Upendra N.

    2010-01-01

    A pulsed, 2-m coherent Differential Absorption Lidar (DIAL) / Integrated Path Differential Absorption (IPDA) transceiver, developed under the Laser Risk Reduction Program (LRRP) at NASA, is integrated into a fully functional lidar instrument. This instrument will measure atmospheric CO2 profiles (by DIAL) initially from a ground platform, and then be prepared for aircraft installation to measure the atmospheric CO2 column densities in the atmospheric boundary layer (ABL) and lower troposphere. The airborne prototype CO2 lidar can measure atmospheric CO2 column density in a range bin of 1km with better than 1.5% precision at horizontal resolution of less than 50km. It can provide the image of the pooling of CO2 in lowlying areas and performs nighttime mass balance measurements at landscape scale. This sensor is unique in its capability to study the vertical ABL-free troposphere exchange of CO2 directly. It will allow the investigators to pursue subsequent in science-driven deployments, and provides a unique tool for Active Sensing of CO2 Emissions over Night, Days, and Seasons (ASCENDS) validation that was strongly advocated in the recent ASCENDS Workshop.

  10. seismic-py: Reading seismic data with Python

    Directory of Open Access Journals (Sweden)

    2008-08-01

    Full Text Available The field of seismic exploration of the Earth has changed
    dramatically over the last half a century. The Society of Exploration
    Geophysicists (SEG has worked to create standards to store the vast
    amounts of seismic data in a way that will be portable across computer
    architectures. However, it has been impossible to predict the needs of the
    immense range of seismic data acquisition systems. As a result, vendors have
    had to bend the rules to accommodate the needs of new instruments and
    experiment types. For low level access to seismic data, there is need for a
    standard open source library to allow access to a wide range of vendor data
    files that can handle all of the variations. A new seismic software package,
    seismic-py, provides an infrastructure for creating and managing drivers for
    each particular format. Drivers can be derived from one of the known formats
    and altered to handle any slight variations. Alternatively drivers can be
    developed from scratch for formats that are very different from any previously
    defined format. Python has been the key to making driver development easy
    and efficient to implement. The goal of seismic-py is to be the base system
    that will power a wide range of experimentation with seismic data and at the
    same time provide clear documentation for the historical record of seismic
    data formats.

  11. Measurement of peak impact loads differ between accelerometers - Effects of system operating range and sampling rate.

    Science.gov (United States)

    Ziebart, Christina; Giangregorio, Lora M; Gibbs, Jenna C; Levine, Iris C; Tung, James; Laing, Andrew C

    2017-06-14

    A wide variety of accelerometer systems, with differing sensor characteristics, are used to detect impact loading during physical activities. The study examined the effects of system characteristics on measured peak impact loading during a variety of activities by comparing outputs from three separate accelerometer systems, and by assessing the influence of simulated reductions in operating range and sampling rate. Twelve healthy young adults performed seven tasks (vertical jump, box drop, heel drop, and bilateral single leg and lateral jumps) while simultaneously wearing three tri-axial accelerometers including a criterion standard laboratory-grade unit (Endevco 7267A) and two systems primarily used for activity-monitoring (ActiGraph GT3X+, GCDC X6-2mini). Peak acceleration (gmax) was compared across accelerometers, and errors resulting from down-sampling (from 640 to 100Hz) and range-limiting (to ±6g) the criterion standard output were characterized. The Actigraph activity-monitoring accelerometer underestimated gmax by an average of 30.2%; underestimation by the X6-2mini was not significant. Underestimation error was greater for tasks with greater impact magnitudes. gmax was underestimated when the criterion standard signal was down-sampled (by an average of 11%), range limited (by 11%), and by combined down-sampling and range-limiting (by 18%). These effects explained 89% of the variance in gmax error for the Actigraph system. This study illustrates that both the type and intensity of activity should be considered when selecting an accelerometer for characterizing impact events. In addition, caution may be warranted when comparing impact magnitudes from studies that use different accelerometers, and when comparing accelerometer outputs to osteogenic impact thresholds proposed in literature. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  12. Measurements of pulse rate using long-range imaging photoplethysmography and sunlight illumination outdoors

    Science.gov (United States)

    Blackford, Ethan B.; Estepp, Justin R.

    2017-02-01

    Imaging photoplethysmography, a method using imagers to record absorption variations caused by microvascular blood volume pulsations, shows promise as a non-contact cardiovascular sensing technology. The first long-range imaging photoplethysmography measurements at distances of 25, 50, and 100 meters from the participant was recently demonstrated. Degraded signal quality was observed with increasing imager-to-subject distances. The degradation in signal quality was hypothesized to be largely attributable to inadequate light return to the image sensor with increasing lens focal length. To test this hypothesis, a follow-up evaluation with 27 participants was conducted outdoors with natural sunlight illumination resulting in 5-33 times the illumination intensity. Video was recorded from cameras equipped with ultra-telephoto lenses and positioned at distances of 25, 50, 100, and 150 meters. The brighter illumination allowed high-definition video recordings at increased frame rates of 60fps, shorter exposure times, and lower ISO settings, leading to higher quality image formation than the previous indoor evaluation. Results were compared to simultaneous reference measurements from electrocardiography. Compared to the previous indoor study, we observed lower overall error in pulse rate measurement with the same pattern of degradation in signal quality with respect to increasing distance. This effect was corroborated by the signal-to-noise ratio of the blood volume pulse signal which also showed decreasing quality with respect to increasing distance. Finally, a popular chrominance-based method was compared to a blind source separation approach; while comparable in measurement of signal-to-noise ratio, we observed higher overall error in pulse rate measurement using the chrominance method in this data.

  13. At Home Photography-Based Method for Measuring Wrist Range of Motion.

    Science.gov (United States)

    Trehan, Samir K; Rancy, Schneider K; Johnsen, Parker H; Hillstrom, Howard J; Lee, Steve K; Wolfe, Scott W

    2017-11-01

    Purpose  To determine the reliability of wrist range of motion (WROM) measurements based on digital photographs taken by patients at home compared with traditional measurements done in the office with a goniometer. Methods  Sixty-nine postoperative patients were enrolled in this study at least 3 months postoperatively. Active and passive wrist flexion/extension and radial/ulnar deviation were recorded by one of the two attending surgeons with a 1-degree resolution goniometer at the last postoperative office visit. Patients were provided an illustrated instruction sheet detailing how to take digital photographic images at home in six wrist positions (active and passive flexion/extension, and radial/ulnar deviation). Wrist position was measured from digital images by both the attending surgeons in a randomized, blinded fashion on two separate occasions greater than 2 weeks apart using the same goniometer. Reliability analysis was performed using the intraclass correlation coefficient to assess agreement between clinical and photography-based goniometry, as well as intra- and interobserver agreement. Results  Out of 69 enrolled patients, 30 (43%) patients sent digital images. Of the 180 digital photographs, only 9 (5%) were missing or deemed inadequate for WROM measurements. Agreement between clinical and photography-based measurements was "almost perfect" for passive wrist flexion/extension and "substantial" for active wrist flexion/extension and radial/ulnar deviation. Inter- and intraobserver agreement for the attending surgeons was "almost perfect" for all measurements. Discussion  This study validates a photography-based goniometry protocol allowing accurate and reliable WROM measurements without direct physician contact. Passive WROM was more accurately measured from photographs than active WROM. This study builds on previous photography-based goniometry literature by validating a protocol in which patients or their families take and submit their own

  14. Measurement of the extreme ankle range of motion required by female ballet dancers.

    Science.gov (United States)

    Russell, Jeffrey A; Kruse, David W; Nevill, Alan M; Koutedakis, Yiannis; Wyon, Matthew A

    2010-12-01

    Female ballet dancers require extreme ankle motion, especially plantar flexion, but research about measuring such motion is lacking. The purposes of this study were to determine in a sample of ballet dancers whether non-weight-bearing ankle range of motion is significantly different from the weight-bearing equivalent and whether inclinometric plantar flexion measurement is a suitable substitute for standard plantar flexion goniometry. Fifteen female ballet dancers (5 university, 5 vocational, and 5 professional dancers; age 21 ± 3.0 years) volunteered. Subjects received 5 assessments on 1 ankle: non-weight-bearing goniometry dorsiflexion (NDF) and plantar flexion (NPF), weight-bearing goniometry in the ballet positions demi-plié (WDF) and en pointe (WPF), and non-weight-bearing plantar flexion inclinometry (IPF). Mean NDF was significantly lower than WDF (17° ± 1.3° vs 30° ± 1.8°, P ballet proficiency. The authors conclude that assessment of extreme ankle motion in female ballet dancers is challenging, and goniometry and inclinometry appear to measure plantar flexion differently.

  15. Accelerated ice-sheet mass loss in Antarctica from 18-year satellite laser ranging measurements

    Directory of Open Access Journals (Sweden)

    Shuanggen Jin

    2016-02-01

    Full Text Available Accurate estimate of the ice-sheet mass balance in Antarctic is very difficult due to complex ice sheet condition and sparse in situ measurements. In this paper, the low-degree gravity field coefficients of up to degree and order 5 derived from Satellite Laser Ranging (SLR measurements are used to determine the ice mass variations in Antarctica for the period 1993–2011. Results show that the ice mass is losing with -36±13 Gt/y in Antarctica, -42±11 Gt/y in the West Antarctica and 6±10 Gt/y in the East Antarctica from 1993 to 2011. The ice mass variations from the SLR 5×5 have a good agreement with the GRACE 5×5, GRACE 5×5 (1&2 and GRACE (60×60 for the entire continent since 2003, but degree 5 from SLR is not sufficient to quantify ice losses in West and East Antarctica, respectively. The rate of ice loss in Antarctica is -28±17 Gt/y for 1993-2002 and -55±17 Gt/y for 2003-2011, indicating significant accelerated ice mass losses since 2003. Furthermore, the results from SLR are comparable with GRACE measurements.

  16. Accurate Measurements of Aerosol Hygroscopic Growth over a Wide Range in Relative Humidity.

    Science.gov (United States)

    Rovelli, Grazia; Miles, Rachael E H; Reid, Jonathan P; Clegg, Simon L

    2016-06-30

    Using a comparative evaporation kinetics approach, we describe a new and accurate method for determining the equilibrium hygroscopic growth of aerosol droplets. The time-evolving size of an aqueous droplet, as it evaporates to a steady size and composition that is in equilibrium with the gas phase relative humidity, is used to determine the time-dependent mass flux of water, yielding information on the vapor pressure of water above the droplet surface at every instant in time. Accurate characterization of the gas phase relative humidity is provided from a control measurement of the evaporation profile of a droplet of know equilibrium properties, either a pure water droplet or a sodium chloride droplet. In combination, and by comparison with simulations that account for both the heat and mass transport governing the droplet evaporation kinetics, these measurements allow accurate retrieval of the equilibrium properties of the solution droplet (i.e., the variations with water activity in the mass fraction of solute, diameter growth factor, osmotic coefficient or number of water molecules per solute molecule). Hygroscopicity measurements can be made over a wide range in water activity (from >0.99 to, in principle, 0.9 and ∼±1% below 80% RH, and maximum uncertainties in diameter growth factor of ±0.7%. For all of the inorganic systems examined, the time-dependent data are consistent with large values of the mass accommodation (or evaporation) coefficient (>0.1).

  17. Realization of High Dynamic Range Imaging in the GLORIA Network and Its Effect on Astronomical Measurement

    Directory of Open Access Journals (Sweden)

    Stanislav Vítek

    2016-01-01

    Full Text Available Citizen science project GLORIA (GLObal Robotic-telescopes Intelligent Array is a first free- and open-access network of robotic telescopes in the world. It provides a web-based environment where users can do research in astronomy by observing with robotic telescopes and/or by analyzing data that other users have acquired with GLORIA or from other free-access databases. Network of 17 telescopes allows users to control selected telescopes in real time or schedule any more demanding observation. This paper deals with new opportunity that GLORIA project provides to teachers and students of various levels of education. At the moment, there are prepared educational materials related to events like Sun eclipse (measuring local atmosphere changes, Aurora Borealis (calculation of Northern Lights height, or transit of Venus (measurement of the Earth-Sun distance. Student should be able to learn principles of CCD imaging, spectral analysis, basic calibration like dark frames subtraction, or advanced methods of noise suppression. Every user of the network can design his own experiment. We propose advanced experiment aimed at obtaining astronomical image data with high dynamic range. We also introduce methods of objective image quality evaluation in order to discover how HDR methods are affecting astronomical measurements.

  18. Seismic Data Gathering and Validation

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, Justin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-02-01

    Three recent earthquakes in the last seven years have exceeded their design basis earthquake values (so it is implied that damage to SSC’s should have occurred). These seismic events were recorded at North Anna (August 2011, detailed information provided in [Virginia Electric and Power Company Memo]), Fukushima Daichii and Daini (March 2011 [TEPCO 1]), and Kaswazaki-Kariwa (2007, [TEPCO 2]). However, seismic walk downs at some of these plants indicate that very little damage occurred to safety class systems and components due to the seismic motion. This report presents seismic data gathered for two of the three events mentioned above and recommends a path for using that data for two purposes. One purpose is to determine what margins exist in current industry standard seismic soil-structure interaction (SSI) tools. The second purpose is the use the data to validated seismic site response tools and SSI tools. The gathered data represents free field soil and in-structure acceleration time histories data. Gathered data also includes elastic and dynamic soil properties and structural drawings. Gathering data and comparing with existing models has potential to identify areas of uncertainty that should be removed from current seismic analysis and SPRA approaches. Removing uncertainty (to the extent possible) from SPRA’s will allow NPP owners to make decisions on where to reduce risk. Once a realistic understanding of seismic response is established for a nuclear power plant (NPP) then decisions on needed protective measures, such as SI, can be made.

  19. Respiration rate of stream insects measured in situ along a large altitude range

    DEFF Research Database (Denmark)

    Rostgaard, S.; Jacobsen, D.

    2005-01-01

    conditions in streams from 400 to 3800 m above sea level in tropical Ecuador. Mean active respiration rates of the animals at 3800 m were approximately half of those at 400 m. Trichoptera showed a slightly larger difference in respiration with altitude than Ephemeroptera. Comparative respiration measurements...... at 100 and 50% oxygen saturation indicated that highland animals reduced their oxygen uptake more than their counterparts in the lowland when oxygen availability decreased. The temperature response of respiration calculated between the insect assemblages at different altitudes showed a mean assemblage Q...... to temperature in tropical streams is probably due to full acclimatization of the component species to stable and narrow temperature ranges. Adaptations to the low oxygen availability at high altitude probably consist of a suite of genetic physiological and behavioural features....

  20. OPO DIAL lidar for remote measurements of atmospheric gases in the IR range

    Science.gov (United States)

    Romanovskii, O. A.; Kharchenko, O. V.; Shumskii, V. K.; Sadovnikov, S. A.; Yakovlev, S. V.

    2016-05-01

    Applicability of a KTA crystal-based laser system with optical parametric oscillators (OPO) generation to lidar sounding of the atmosphere in the spectral range 3-4 μm is studied in this work. A technique developed for lidar sounding of trace atmospheric gases (TAG) is based on differential absorption lidar (DIAL) method and differential optical absorption spectroscopy (DOAS). The new technique uses broadband radiation and a CCD detector, which ensures measurement of backscattering signals with simultaneous altitude and wavelength resolution. The DIAL-DOAS technique is tested to estimate its efficiency for lidar sounding of atmospheric trace gases. The numerical simulation performed shows that a KTA-based OPO laser is a promising source of radiation for remote DIAL-DOAS sounding of the TAGs under study along surface tropospheric paths. The laser system design provides a possibility of narrowing the laser line within the 0.01-5 cm-1 limits. This possible improvement along with a small step of laser line tuning and the presence of absorption lines of other atmospheric gases, including atmospheric pollutants, in the spectral range under study make this laser a unique instrument for atmospheric sounding.

  1. Seismic Symphonies

    Science.gov (United States)

    Strinna, Elisa; Ferrari, Graziano

    2015-04-01

    The project started in 2008 as a sound installation, a collaboration between an artist, a barrel organ builder and a seismologist. The work differs from other attempts of sound transposition of seismic records. In this case seismic frequencies are not converted automatically into the "sound of the earthquake." However, it has been studied a musical translation system that, based on the organ tonal scale, generates a totally unexpected sequence of sounds which is intended to evoke the emotions aroused by the earthquake. The symphonies proposed in the project have somewhat peculiar origins: they in fact come to life from the translation of graphic tracks into a sound track. The graphic tracks in question are made up by copies of seismograms recorded during some earthquakes that have taken place around the world. Seismograms are translated into music by a sculpture-instrument, half a seismograph and half a barrel organ. The organ plays through holes practiced on paper. Adapting the documents to the instrument score, holes have been drilled on the waves' peaks. The organ covers about three tonal scales, starting from heavy and deep sounds it reaches up to high and jarring notes. The translation of the seismic records is based on a criterion that does match the highest sounds to larger amplitudes with lower ones to minors. Translating the seismogram in the organ score, the larger the amplitude of recorded waves, the more the seismogram covers the full tonal scale played by the barrel organ and the notes arouse an intense emotional response in the listener. Elisa Strinna's Seismic Symphonies installation becomes an unprecedented tool for emotional involvement, through which can be revived the memory of the greatest disasters of over a century of seismic history of the Earth. A bridge between art and science. Seismic Symphonies is also a symbolic inversion: the instrument of the organ is most commonly used in churches, and its sounds are derived from the heavens and

  2. Design Optimization for the Measurement Accuracy Improvement of a Large Range Nanopositioning Stage

    Directory of Open Access Journals (Sweden)

    Marta Torralba

    2016-01-01

    Full Text Available Both an accurate machine design and an adequate metrology loop definition are critical factors when precision positioning represents a key issue for the final system performance. This article discusses the error budget methodology as an advantageous technique to improve the measurement accuracy of a 2D-long range stage during its design phase. The nanopositioning platform NanoPla is here presented. Its specifications, e.g., XY-travel range of 50 mm × 50 mm and sub-micrometric accuracy; and some novel designed solutions, e.g., a three-layer and two-stage architecture are described. Once defined the prototype, an error analysis is performed to propose improvement design features. Then, the metrology loop of the system is mathematically modelled to define the propagation of the different sources. Several simplifications and design hypothesis are justified and validated, including the assumption of rigid body behavior, which is demonstrated after a finite element analysis verification. The different error sources and their estimated contributions are enumerated in order to conclude with the final error values obtained from the error budget. The measurement deviations obtained demonstrate the important influence of the working environmental conditions, the flatness error of the plane mirror reflectors and the accurate manufacture and assembly of the components forming the metrological loop. Thus, a temperature control of ±0.1 °C results in an acceptable maximum positioning error for the developed NanoPla stage, i.e., 41 nm, 36 nm and 48 nm in X-, Y- and Z-axis, respectively.

  3. Higher measured than modeled ozone production at increased NOx levels in the Colorado Front Range

    Science.gov (United States)

    Baier, Bianca C.; Brune, William H.; Miller, David O.; Blake, Donald; Long, Russell; Wisthaler, Armin; Cantrell, Christopher; Fried, Alan; Heikes, Brian; Brown, Steven; McDuffie, Erin; Flocke, Frank; Apel, Eric; Kaser, Lisa; Weinheimer, Andrew

    2017-09-01

    Chemical models must correctly calculate the ozone formation rate, P(O3), to accurately predict ozone levels and to test mitigation strategies. However, air quality models can have large uncertainties in P(O3) calculations, which can create uncertainties in ozone forecasts, especially during the summertime when P(O3) is high. One way to test mechanisms is to compare modeled P(O3) to direct measurements. During summer 2014, the Measurement of Ozone Production Sensor (MOPS) directly measured net P(O3) in Golden, CO, approximately 25 km west of Denver along the Colorado Front Range. Net P(O3) was compared to rates calculated by a photochemical box model that was constrained by measurements of other chemical species and that used a lumped chemical mechanism and a more explicit one. Median observed P(O3) was up to a factor of 2 higher than that modeled during early morning hours when nitric oxide (NO) levels were high and was similar to modeled P(O3) for the rest of the day. While all interferences and offsets in this new method are not fully understood, simulations of these possible uncertainties cannot explain the observed P(O3) behavior. Modeled and measured P(O3) and peroxy radical (HO2 and RO2) discrepancies observed here are similar to those presented in prior studies. While a missing atmospheric organic peroxy radical source from volatile organic compounds co-emitted with NO could be one plausible solution to the P(O3) discrepancy, such a source has not been identified and does not fully explain the peroxy radical model-data mismatch. If the MOPS accurately depicts atmospheric P(O3), then these results would imply that P(O3) in Golden, CO, would be NOx-sensitive for more of the day than what is calculated by models, extending the NOx-sensitive P(O3) regime from the afternoon further into the morning. These results could affect ozone reduction strategies for the region surrounding Golden and possibly other areas that do not comply with national ozone regulations

  4. Higher measured than modeled ozone production at increased NOx levels in the Colorado Front Range

    Directory of Open Access Journals (Sweden)

    B. C. Baier

    2017-09-01

    Full Text Available Chemical models must correctly calculate the ozone formation rate, P(O3, to accurately predict ozone levels and to test mitigation strategies. However, air quality models can have large uncertainties in P(O3 calculations, which can create uncertainties in ozone forecasts, especially during the summertime when P(O3 is high. One way to test mechanisms is to compare modeled P(O3 to direct measurements. During summer 2014, the Measurement of Ozone Production Sensor (MOPS directly measured net P(O3 in Golden, CO, approximately 25 km west of Denver along the Colorado Front Range. Net P(O3 was compared to rates calculated by a photochemical box model that was constrained by measurements of other chemical species and that used a lumped chemical mechanism and a more explicit one. Median observed P(O3 was up to a factor of 2 higher than that modeled during early morning hours when nitric oxide (NO levels were high and was similar to modeled P(O3 for the rest of the day. While all interferences and offsets in this new method are not fully understood, simulations of these possible uncertainties cannot explain the observed P(O3 behavior. Modeled and measured P(O3 and peroxy radical (HO2 and RO2 discrepancies observed here are similar to those presented in prior studies. While a missing atmospheric organic peroxy radical source from volatile organic compounds co-emitted with NO could be one plausible solution to the P(O3 discrepancy, such a source has not been identified and does not fully explain the peroxy radical model–data mismatch. If the MOPS accurately depicts atmospheric P(O3, then these results would imply that P(O3 in Golden, CO, would be NOx-sensitive for more of the day than what is calculated by models, extending the NOx-sensitive P(O3 regime from the afternoon further into the morning. These results could affect ozone reduction strategies for the region surrounding Golden and possibly other areas that do not comply with national ozone

  5. Objective Measurement of Fusional Vergence Ranges and Heterophoria in Infants and Preschool Children

    Science.gov (United States)

    Sreenivasan, Vidhyapriya; Babinsky, Erin E.; Wu, Yifei; Candy, T. Rowan

    2016-01-01

    Purpose Binocular alignment typically includes motor fusion compensating for heterophoria. This study evaluated heterophoria and then accommodation and vergence responses during measurement of fusional ranges in infants and preschoolers. Methods Purkinje image eye tracking and eccentric photorefraction (MCS PowerRefractor) were used to record the eye alignment and accommodation of uncorrected infants (n = 17; 3–5 months old), preschoolers (n = 19; 2.5–5 years), and naïve functionally emmetropic adults (n = 14; 20–32 years; spherical equivalent [SE], +1 to −1 diopters [D]). Heterophoria was derived from the difference between monocular and binocular alignments while participants viewed naturalistic images at 80 cm. The presence or absence of fusion was then assessed after base-in (BI) and base-out (BO) prisms (2–40 prism diopters [pd]) were introduced. Results Mean (±SD) SE refractions were hyperopic in infants (+2.4 ± 1.2 D) and preschoolers (+1.1 ± 0.6 D). The average exophoria was similar (P = 0.11) across groups (Infants, −0.79 ± 2.5 pd; Preschool, −2.43 ± 2.0 pd; Adults, −1.0 ± 2.7 pd). Mean fusional vergence range also was similar (P = 0.1) for BI (Infants, 11.2 ± 2.5 pd; Preschool, 8.8 ± 2.8 pd; Adults, 11.8 ± 5.2 pd) and BO (Infants, 14 ± 6.6 pd; Preschool, 15.3 ± 8.3 pd; Adults, 20 ± 9.2 pd). Maximum change in accommodation to the highest fusible prism was positive (increased accommodation) for BO (Infants, 1.69 ± 1.4 D; Preschool, 1.35 ± 1.6 D; Adults, 1.22 ± 1.0 D) and negative for BI (Infants, −0.96 ± 1.0 D; Preschool, −0.78 ± 0.6 D; Adults, −0.62 ± 0.3 D), with a similar magnitude across groups (BO, P = 0.6; BI, P = 0.4). Conclusions Despite typical uncorrected hyperopia, infants and preschoolers exhibited small exophorias at 80 cm, similar to adults. All participants demonstrated substantial fusional ranges, providing evidence that even 3- to 5-month-old infants can respond to a large range of image disparities

  6. Outlier Detection in GNSS Pseudo-Range/Doppler Measurements for Robust Localization.

    Science.gov (United States)

    Zair, Salim; Le Hégarat-Mascle, Sylvie; Seignez, Emmanuel

    2016-04-22

    In urban areas or space-constrained environments with obstacles, vehicle localization using Global Navigation Satellite System (GNSS) data is hindered by Non-Line Of Sight (NLOS) and multipath receptions. These phenomena induce faulty data that disrupt the precise localization of the GNSS receiver. In this study, we detect the outliers among the observations, Pseudo-Range (PR) and/or Doppler measurements, and we evaluate how discarding them improves the localization. We specify a contrario modeling for GNSS raw data to derive an algorithm that partitions the dataset between inliers and outliers. Then, only the inlier data are considered in the localization process performed either through a classical Particle Filter (PF) or a Rao-Blackwellization (RB) approach. Both localization algorithms exclusively use GNSS data, but they differ by the way Doppler measurements are processed. An experiment has been performed with a GPS receiver aboard a vehicle. Results show that the proposed algorithms are able to detect the 'outliers' in the raw data while being robust to non-Gaussian noise and to intermittent satellite blockage. We compare the performance results achieved either estimating only PR outliers or estimating both PR and Doppler outliers. The best localization is achieved using the RB approach coupled with PR-Doppler outlier estimation.

  7. Reliability assessment of measuring active wrist pronation and supination range of motion with a smartphone.

    Science.gov (United States)

    Santos, C; Pauchard, N; Guilloteau, A

    2017-10-01

    This study aimed to improve clinical examination techniques by determining the reliability of different methods to evaluate forearm movements. Two methods using the iPhone™ 5 and its gyroscope application (alone [I5] or attached to a selfie stick [ISS]) were compared with two conventional measurement devices (a plastic goniometer with a hand-held pencil [HHP] and a bubble goniometer [BG]) to evaluate the active range of movement (AROM) of the wrist during pronation and supination. Two independent groups of subjects took part in this prospective single-center diagnostic study: 20 healthy subjects and 20 patients. The four evaluation methods had high intra-observer consistency after three measurements (intra-class correlation coefficient [ICC] [3, 1] of 0.916 for the HHP; 0.944 for ISS; 0.925 for BG; 0.933 for I5) and excellent inter-observer reliability (ICC [2, k] of 0.926 for HHP; 0.934 for ISS; 0.899 for BG; 0.894 for I5), with an agreement of plus or minus 2°. When these devices are used with rigorous methodology, they are reliable for the goniometric evaluation of AROM of wrist pronation and supination. Copyright © 2017 SFCM. Published by Elsevier Masson SAS. All rights reserved.

  8. Outlier Detection in GNSS Pseudo-Range/Doppler Measurements for Robust Localization

    Directory of Open Access Journals (Sweden)

    Salim Zair

    2016-04-01

    Full Text Available In urban areas or space-constrained environments with obstacles, vehicle localization using Global Navigation Satellite System (GNSS data is hindered by Non-Line Of Sight (NLOS and multipath receptions. These phenomena induce faulty data that disrupt the precise localization of the GNSS receiver. In this study, we detect the outliers among the observations, Pseudo-Range (PR and/or Doppler measurements, and we evaluate how discarding them improves the localization. We specify a contrario modeling for GNSS raw data to derive an algorithm that partitions the dataset between inliers and outliers. Then, only the inlier data are considered in the localization process performed either through a classical Particle Filter (PF or a Rao-Blackwellization (RB approach. Both localization algorithms exclusively use GNSS data, but they differ by the way Doppler measurements are processed. An experiment has been performed with a GPS receiver aboard a vehicle. Results show that the proposed algorithms are able to detect the ‘outliers’ in the raw data while being robust to non-Gaussian noise and to intermittent satellite blockage. We compare the performance results achieved either estimating only PR outliers or estimating both PR and Doppler outliers. The best localization is achieved using the RB approach coupled with PR-Doppler outlier estimation.

  9. Prototype system for proton beam range measurement based on gamma electron vertex imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Han Rim [Neutron Utilization Technology Division, Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057 (Korea, Republic of); Kim, Sung Hun; Park, Jong Hoon [Department of Nuclear Engineering, Hanyang University, Seongdong-gu, Seoul 04763 (Korea, Republic of); Jung, Won Gyun [Heavy-ion Clinical Research Division, Korean Institute of Radiological & Medical Sciences, Seoul 01812 (Korea, Republic of); Lim, Hansang [Department of Electronics Convergence Engineering, Kwangwoon University, Seoul 01897 (Korea, Republic of); Kim, Chan Hyeong, E-mail: chkim@hanyang.ac.kr [Department of Nuclear Engineering, Hanyang University, Seongdong-gu, Seoul 04763 (Korea, Republic of)

    2017-06-11

    In proton therapy, for both therapeutic effectiveness and patient safety, it is very important to accurately measure the proton dose distribution, especially the range of the proton beam. For this purpose, recently we proposed a new imaging method named gamma electron vertex imaging (GEVI), in which the prompt gammas emitting from the nuclear reactions of the proton beam in the patient are converted to electrons, and then the converted electrons are tracked to determine the vertices of the prompt gammas, thereby producing a 2D image of the vertices. In the present study, we developed a prototype GEVI system, including dedicated signal processing and data acquisition systems, which consists of a beryllium plate (= electron converter) to convert the prompt gammas to electrons, two double-sided silicon strip detectors (= hodoscopes) to determine the trajectories of those converted electrons, and a plastic scintillation detector (= calorimeter) to measure their kinetic energies. The system uses triple coincidence logic and multiple energy windows to select only the events from prompt gammas. The detectors of the prototype GEVI system were evaluated for electronic noise level, energy resolution, and time resolution. Finally, the imaging capability of the GEVI system was tested by imaging a {sup 90}Sr beta source, a {sup 60}Co gamma source, and a 45-MeV proton beam in a PMMA phantom. The overall results of the present study generally show that the prototype GEVI system can image the vertices of the prompt gammas produced by the proton nuclear interactions.

  10. Validity and reliability of using photography for measuring knee range of motion: a methodological study.

    Science.gov (United States)

    Naylor, Justine M; Ko, Victoria; Adie, Sam; Gaskin, Clive; Walker, Richard; Harris, Ian A; Mittal, Rajat

    2011-04-18

    The clinimetric properties of knee goniometry are essential to appreciate in light of its extensive use in the orthopaedic and rehabilitative communities. Intra-observer reliability is thought to be satisfactory, but the validity and inter-rater reliability of knee goniometry often demonstrate unacceptable levels of variation. This study tests the validity and reliability of measuring knee range of motion using goniometry and photographic records. Methodology study assessing the validity and reliability of one method ('Marker Method') which uses a skin marker over the greater trochanter and another method ('Line of Femur Method') which requires estimation of the line of femur. Radiology and orthopaedic departments of two teaching hospitals. 31 volunteers (13 arthritic and 18 healthy subjects). Knee range of motion was measured radiographically and photographically using a goniometer. Three assessors were assessed for reliability and validity. Agreement between methods and within raters was assessed using concordance correlation coefficient (CCCs). Agreement between raters was assessed using intra-class correlation coefficients (ICCs). 95% limits of agreement for the mean difference for all paired comparisons were computed. Validity (referenced to radiographs): Each method for all 3 raters yielded very high CCCs for flexion (0.975 to 0.988), and moderate to substantial CCCs for extension angles (0.478 to 0.678). The mean differences and 95% limits of agreement were narrower for flexion than they were for extension. Intra-rater reliability: For flexion and extension, very high CCCs were attained for all 3 raters for both methods with slightly greater CCCs seen for flexion (CCCs varied from 0.981 to 0.998). Inter-rater reliability: For both methods, very high ICCs (min to max: 0.891 to 0.995) were obtained for flexion and extension. Slightly higher coefficients were obtained for flexion compared to extension, and with the Marker compared to the Line of Femur Method

  11. Cloud cover detection combining high dynamic range sky images and ceilometer measurements

    Science.gov (United States)

    Román, R.; Cazorla, A.; Toledano, C.; Olmo, F. J.; Cachorro, V. E.; de Frutos, A.; Alados-Arboledas, L.

    2017-11-01

    This paper presents a new algorithm for cloud detection based on high dynamic range images from a sky camera and ceilometer measurements. The algorithm is also able to detect the obstruction of the sun. This algorithm, called CPC (Camera Plus Ceilometer), is based on the assumption that under cloud-free conditions the sky field must show symmetry. The symmetry criteria are applied depending on ceilometer measurements of the cloud base height. CPC algorithm is applied in two Spanish locations (Granada and Valladolid). The performance of CPC retrieving the sun conditions (obstructed or unobstructed) is analyzed in detail using as reference pyranometer measurements at Granada. CPC retrievals are in agreement with those derived from the reference pyranometer in 85% of the cases (it seems that this agreement does not depend on aerosol size or optical depth). The agreement percentage goes down to only 48% when another algorithm, based on Red-Blue Ratio (RBR), is applied to the sky camera images. The retrieved cloud cover at Granada and Valladolid is compared with that registered by trained meteorological observers. CPC cloud cover is in agreement with the reference showing a slight overestimation and a mean absolute error around 1 okta. A major advantage of the CPC algorithm with respect to the RBR method is that the determined cloud cover is independent of aerosol properties. The RBR algorithm overestimates cloud cover for coarse aerosols and high loads. Cloud cover obtained only from ceilometer shows similar results than CPC algorithm; but the horizontal distribution cannot be obtained. In addition, it has been observed that under quick and strong changes on cloud cover ceilometers retrieve a cloud cover fitting worse with the real cloud cover.

  12. Seismic risk assessment and application in the central United States

    Science.gov (United States)

    Wang, Z.

    2011-01-01

    Seismic risk is a somewhat subjective, but important, concept in earthquake engineering and other related decision-making. Another important concept that is closely related to seismic risk is seismic hazard. Although seismic hazard and seismic risk have often been used interchangeably, they are fundamentally different: seismic hazard describes the natural phenomenon or physical property of an earthquake, whereas seismic risk describes the probability of loss or damage that could be caused by a seismic hazard. The distinction between seismic hazard and seismic risk is of practical significance because measures for seismic hazard mitigation may differ from those for seismic risk reduction. Seismic risk assessment is a complicated process and starts with seismic hazard assessment. Although probabilistic seismic hazard analysis (PSHA) is the most widely used method for seismic hazard assessment, recent studies have found that PSHA is not scientifically valid. Use of PSHA will lead to (1) artifact estimates of seismic risk, (2) misleading use of the annual probability of exccedance (i.e., the probability of exceedance in one year) as a frequency (per year), and (3) numerical creation of extremely high ground motion. An alternative approach, which is similar to those used for flood and wind hazard assessments, has been proposed. ?? 2011 ASCE.

  13. Expected Seismicity and the Seismic Noise Environment of Europa

    Science.gov (United States)

    Panning, Mark P.; Stähler, Simon C.; Huang, Hsin-Hua; Vance, Steven D.; Kedar, Sharon; Tsai, Victor C.; Pike, William T.; Lorenz, Ralph D.

    2018-01-01

    Seismic data will be a vital geophysical constraint on internal structure of Europa if we land instruments on the surface. Quantifying expected seismic activity on Europa both in terms of large, recognizable signals and ambient background noise is important for understanding dynamics of the moon, as well as interpretation of potential future data. Seismic energy sources will likely include cracking in the ice shell and turbulent motion in the oceans. We define a range of models of seismic activity in Europa's ice shell by assuming each model follows a Gutenberg-Richter relationship with varying parameters. A range of cumulative seismic moment release between 1016 and 1018 Nm/yr is defined by scaling tidal dissipation energy to tectonic events on the Earth's moon. Random catalogs are generated and used to create synthetic continuous noise records through numerical wave propagation in thermodynamically self-consistent models of the interior structure of Europa. Spectral characteristics of the noise are calculated by determining probabilistic power spectral densities of the synthetic records. While the range of seismicity models predicts noise levels that vary by 80 dB, we show that most noise estimates are below the self-noise floor of high-frequency geophones but may be recorded by more sensitive instruments. The largest expected signals exceed background noise by ˜50 dB. Noise records may allow for constraints on interior structure through autocorrelation. Models of seismic noise generated by pressure variations at the base of the ice shell due to turbulent motions in the subsurface ocean may also generate observable seismic noise.

  14. High Voltage Seismic Generator

    Science.gov (United States)

    Bogacz, Adrian; Pala, Damian; Knafel, Marcin

    2015-04-01

    This contribution describes the preliminary result of annual cooperation of three student research groups from AGH UST in Krakow, Poland. The aim of this cooperation was to develop and construct a high voltage seismic wave generator. Constructed device uses a high-energy electrical discharge to generate seismic wave in ground. This type of device can be applied in several different methods of seismic measurement, but because of its limited power it is mainly dedicated for engineering geophysics. The source operates on a basic physical principles. The energy is stored in capacitor bank, which is charged by two stage low to high voltage converter. Stored energy is then released in very short time through high voltage thyristor in spark gap. The whole appliance is powered from li-ion battery and controlled by ATmega microcontroller. It is possible to construct larger and more powerful device. In this contribution the structure of device with technical specifications is resented. As a part of the investigation the prototype was built and series of experiments conducted. System parameter was measured, on this basis specification of elements for the final device were chosen. First stage of the project was successful. It was possible to efficiently generate seismic waves with constructed device. Then the field test was conducted. Spark gap wasplaced in shallowborehole(0.5 m) filled with salt water. Geophones were placed on the ground in straight line. The comparison of signal registered with hammer source and sparker source was made. The results of the test measurements are presented and discussed. Analysis of the collected data shows that characteristic of generated seismic signal is very promising, thus confirms possibility of practical application of the new high voltage generator. The biggest advantage of presented device after signal characteristics is its size which is 0.5 x 0.25 x 0.2 m and weight approximately 7 kg. This features with small li-ion battery makes

  15. Comparison of linear gain and wide dynamic range compression hearing aid circuits: aided speech perception measures.

    Science.gov (United States)

    Jenstad, L M; Seewald, R C; Cornelisse, L E; Shantz, J

    1999-04-01

    The goal of this study was to test the theoretical advantages of a single-channel wide dynamic range compression (WDRC) circuit for speech intelligibility and loudness comfort for five speech spectra. Twelve adolescents and young adults with moderate to severe hearing loss were fitted with the Siemens Viva 2 Pro behind-the-ear instrument set to DSL 4.0 targets for both linear gain and WDRC processing. Speech intelligibility was measured in the unaided, linear gain and WDRC conditions using two tasks in quiet: nonsense words and sentences. The items were digitally filtered to represent five speech spectra: average speech at 4 m, average speech at 1 m, own voice at ear level, classroom at 1 m, and shouted speech at 1 m. The subjects also rated the loudness of each hearing aid/speech spectrum combination using a categorical rating scale. Both the linear gain and WDRC settings provided improved speech recognition relative to the unaided condition, and the two circuits resulted in equivalent performance for average speech input levels. On average, the WDRC aid resulted in high and uniform speech recognition scores across the five spectra. In contrast, the linear gain aid resulted in a lower recognition score for soft speech and shouted speech relative to that obtained with an average speech level. Analysis of individual speech recognition benefit scores revealed that 11 out of 12 subjects had equal or greater performance with the WDRC processing than the linear processing. Subjective loudness ratings in the linear gain condition were compatible with decreased sensation level for soft speech and loudness discomfort for shouted speech. WDRC processing has potential applications in hearing aid fittings for listeners with moderate to severe hearing loss because it provides a consistently audible and comfortable signal across a wide range of listening conditions in quiet without the need for volume control adjustments.

  16. 40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specification

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Test Concentration Ranges, Number of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specification Pollutant Concentration range...

  17. MeV-range velocity-space tomography from gamma-ray and neutron emission spectrometry measurements at JET

    DEFF Research Database (Denmark)

    Salewski, Mirko; Nocente, M.; Jacobsen, Asger Schou

    2017-01-01

    We demonstrate the measurement of a 2D MeV-range ion velocity distribution function by velocity-space tomography at JET. Deuterium ions were accelerated into the MeV-range by third harmonic ion cyclotron resonance heating. We made measurements with three neutron emission spectrometers and a high-...

  18. Seismic Prediction While Drilling (SPWD): Seismic exploration ahead of the drill bit using phased array sources

    Science.gov (United States)

    Jaksch, Katrin; Giese, Rüdiger; Kopf, Matthias

    2010-05-01

    maximize the energy of the seismic source in order to reach a sufficient exploration range. The next step for focusing is to use the method of phased array. Dependent of the seismic wave velocities of the surrounding rock, the distance of the actuators to each other and the used frequencies the signal phases for each actuator can be determined. Since one year several measurements with the prototype have been realized under defined conditions at a test site in a mine. The test site consists of a rock block surrounded from three galleries with a dimension of about 100 by 200 meters. For testing the prototype two horizontal boreholes were drilled. They are directed to one of the gallery to get a strong reflector. The quality of the data of the borehole seismics in amplitude and frequency spectra show overall a good signal-to-noise ratio and correlate strongly with the fracture density along the borehole and are associated with a lower signal-to-noise ratio. Additionally, the geophones of the prototype show reflections from ahead and rearward in the seismic data. In particular, the reflections from the gallery ahead are used for the calibration of focusing. The direct seismic wave field indicates distinct compression and shear waves. The analysis of several seismic measurements with a focus on the direct seismic waves shows that the phased array technology explicit can influence the directional characteristics of the radiated seimic waves. The amplitudes of the seismic waves can be enhanced up to three times more in the desired direction and simultaneously be attenuated in the reverse direction. A major step for the directional investigation in boreholes has accomplished. But the focusing of the seismic waves has to be improved to maximize the energy in the desired direction in more measurements by calibrating the initiating seismic signals of the sources. A next step this year is the development of a wireline prototype for application in vertical boreholes with depths not

  19. Mobile Robot Self-Localization by Matching Range Maps Using a Hausdorff Measure

    Science.gov (United States)

    Olson, C. F.

    1997-01-01

    This paper examines techniques for a mobile robot to perform self-localization in natural terrain by comparing a dense range map computed from stereo imagery to a range map in a known frame of reference.

  20. An intercomparison of POLARIS measurement results from the DTU-ESA Facility and from the ESTEC Near-Field Range

    DEFF Research Database (Denmark)

    Pivnenko, Sergey; Breinbjerg, Olav

    This report documents an intercomparison of measurement results of the POLARIS antenna from measurement at the DTU-ESA Spherical Near-Field Antenna Test Facility in August 2011 and from measurement at the ESTEC Near-Field Range in the fall 2012. The comparison was carried out at the DTU-ESA Facil......This report documents an intercomparison of measurement results of the POLARIS antenna from measurement at the DTU-ESA Spherical Near-Field Antenna Test Facility in August 2011 and from measurement at the ESTEC Near-Field Range in the fall 2012. The comparison was carried out at the DTU...

  1. Measurement of a wide-range of X-ray doses using specialty doped silica fibres

    Science.gov (United States)

    Abdul Sani, S. F.; Hammond, R.; Jafari, S. M.; Wahab, Norfadira; Amouzad Mahdiraji, G.; Siti Shafiqah, A. S.; Abdul Rashid, H. A.; Maah, M. J.; Aldousari, H.; Alkhorayef, M.; Alzimami, M.; Bradley, D. A.

    2017-08-01

    Using six types of tailor-made doped optical fibres, we carry out thermoluminescent (TL) studies of X-rays, investigating the TL yield for doses from 20 mGy through to 50 Gy. Dosimetric parameters were investigated for nominal 8 wt% Ge doped fibres that in two cases were co-doped, using B in one case and Br in the other. A comparative measurement of surface analysis has also been made for non-annealed and annealed capillary fibres, use being made of X-ray Photoelectron Spectroscopy (XPS) analysis. Comparison was made with the conventional TL phosphor LiF in the form of the proprietary product TLD-100, including dose response and glow curves investigated for X-rays generated at 60 kVp over a dose range from 2 cGy to 50 Gy. The energy response of the fibres was also performed for X-rays generated at peak accelerating potentials of 80 kVp, 140 kVp, 250 kVp and 6 MV photons for an absorbed dose of 2 Gy. Present results show the samples to be suitable for use as TL dosimeters, with good linearity of response and a simple glow curve (simple trap) distribution. It has been established that the TL performance of an irradiated fibre is not only influenced by radiation parameters such as energy, dose-rate and total dose but also the type of fibre.

  2. Airborne Dust Cloud Measurements at the INL National Security Test Range

    Energy Technology Data Exchange (ETDEWEB)

    Michael L. Abbott; Norm Stanley; Larry Radke; Charles Smeltzer

    2007-09-01

    On July 11, 2007, a surface, high-explosive test (<20,000 lb TNT-equivalent) was carried out at the National Security Test Range (NSTR) on the Idaho National Laboratory (INL) Site. Aircraft-mounted rapid response (1-sec) particulate monitors were used to measure airborne PM-10 concentrations directly in the dust cloud and to develop a PM-10 emission factor that could be used for subsequent tests at the NSTR. The blast produced a mushroom-like dust cloud that rose approximately 2,500–3,000 ft above ground level, which quickly dissipated (within 5 miles of the source). In general, the cloud was smaller and less persistence than expected, or that might occur in other areas, likely due to the coarse sand and subsurface conditions that characterize the immediate NSTR area. Maximum short time-averaged (1-sec) PM-10 concentrations at the center of the cloud immediately after the event reached 421 µg m-3 but were rapidly reduced (by atmospheric dispersion and fallout) to near background levels (~10 µg m-3) after about 15 minutes. This occurred well within the INL Site boundary, about 8 km (5 miles) from the NSTR source. These findings demonstrate that maximum concentrations in ambient air beyond the INL Site boundary (closest is 11.2 km from NSTR) from these types of tests would be well within the 150 µg m-3 24-hour National Ambient Air Quality Standards for PM-10. Aircraft measurements and geostatistical techniques were used to successfully quantify the initial volume (1.64E+9 m3 or 1.64 km3) and mass (250 kg) of the PM-10 dust cloud, and a PM-10 emission factor (20 kg m-3 crater soil volume) was developed for this specific type of event at NSTR. The 250 kg of PM-10 mass estimated from this experiment is almost seven-times higher than the 36 kg estimated for the environmental assessment (DOE-ID 2007) using available Environmental Protection Agency (EPA 1995) emission factors. This experiment demonstrated that advanced aircraft-mounted instruments operated by

  3. Spatial/temporal patterns of Quaternary faulting in the southern limb of the Yellowstone-Snake River Plain seismic parabola, northeastern Basin and Range margin

    Energy Technology Data Exchange (ETDEWEB)

    McCalpin, J.P. (GEO-HAZ Consultants, Estes Park, CO (United States))

    1993-04-01

    During the period 1986--1991, 11 backhoe trenches were excavated across six Quaternary faults on the northeastern margin of the Basin and Range province. These faults comprise the southern limb of a parabola of Quaternary faults and historic moderate-magnitude earthquakes which is roughly symmetrical about the Snake River Plain, and heads at the Yellowstone hot spot. Fifteen Holocene paleoseismic events have been bracketed by radiocarbon or thermoluminescence ages. On the six central faults, the latest rupture event occurred in a relatively short time interval between 3 ka and 6 ka. The period between 6 ka and the end of the latest glaciation (ca. 15 ka) was a period of relative tectonic quiescence on the central faults, but not on the two end faults with higher slip rates (Wasatch and Teton faults). Southward-younging of events in the 3--6 ka period may indicate that temporally-clustered faulting was initiated at the Yellowstone hot spot. Faults at the same latitude, such as the Star Valley-Grey's River pair of faults, or the East Cache-Bear Lake-Rock Creek system of faults, show nearly identical timing of latest rupture events within the pairs or systems. Faults at common latitudes probably sole into the same master decollement, and thus are linked mechanically like dominoes. The timing of latest ruptures indicates that faulting on the westernmost fault preceded faulting on successively more eastern faults by a few hundred years. This timing suggests that slip on the westernmost faults mechanically unloaded the system, causing tectonic instabilities farther east.

  4. Validity and reliability of using photography for measuring knee range of motion: a methodological study

    Directory of Open Access Journals (Sweden)

    Adie Sam

    2011-04-01

    Full Text Available Abstract Background The clinimetric properties of knee goniometry are essential to appreciate in light of its extensive use in the orthopaedic and rehabilitative communities. Intra-observer reliability is thought to be satisfactory, but the validity and inter-rater reliability of knee goniometry often demonstrate unacceptable levels of variation. This study tests the validity and reliability of measuring knee range of motion using goniometry and photographic records. Methods Design: Methodology study assessing the validity and reliability of one method ('Marker Method' which uses a skin marker over the greater trochanter and another method ('Line of Femur Method' which requires estimation of the line of femur. Setting: Radiology and orthopaedic departments of two teaching hospitals. Participants: 31 volunteers (13 arthritic and 18 healthy subjects. Knee range of motion was measured radiographically and photographically using a goniometer. Three assessors were assessed for reliability and validity. Main outcomes: Agreement between methods and within raters was assessed using concordance correlation coefficient (CCCs. Agreement between raters was assessed using intra-class correlation coefficients (ICCs. 95% limits of agreement for the mean difference for all paired comparisons were computed. Results Validity (referenced to radiographs: Each method for all 3 raters yielded very high CCCs for flexion (0.975 to 0.988, and moderate to substantial CCCs for extension angles (0.478 to 0.678. The mean differences and 95% limits of agreement were narrower for flexion than they were for extension. Intra-rater reliability: For flexion and extension, very high CCCs were attained for all 3 raters for both methods with slightly greater CCCs seen for flexion (CCCs varied from 0.981 to 0.998. Inter-rater reliability: For both methods, very high ICCs (min to max: 0.891 to 0.995 were obtained for flexion and extension. Slightly higher coefficients were obtained

  5. Statistical seismo-ionospheric precursors of M7.0+ earthquakes in Circum-Pacific seismic belt by GPS TEC measurements

    Science.gov (United States)

    Li, Wang; Yue, Jianping; Guo, Jinyun; Yang, Yang; Zou, Bin; Shen, Yi; Zhang, Kefei

    2018-03-01

    The Circum-Pacific seismic belt is the region heavily affected by earthquakes in the world. The relationship between earthquake (e.g., the geographic location, occurrence time, magnitude, and focal depth) and ionospheric anomalies in the belt was investigated using 100 M7.0+ earthquakes during 2006-2015. The ground-based GPS measurements and global ionosphere map (GIM) data were used for the analyses of the ionospheric variations preceding the earthquakes. The results indicated that the occurrence rate of total electron content (TEC) anomalies was proportional to the magnitude and inversely proportional to the focal depth to a certain degree, and the occurrence frequency of anomalies had a rising trend with the days getting close to the main shock. The occurrence rate of TEC anomalies in the Southern hemisphere was larger than that in the Northern hemisphere. Besides, the spatial characteristics of TEC anomalies showed that the anomalies in low-middle latitudes did not coincide with the epicenter, sometimes the anomalies were also observed in the corresponding conjugated region. However, the TEC anomalies in the high latitude usually appeared around the epicenter and within the seismogenic zone while no TEC anomalies appeared in the conjugated area. These results may have potential applications to the earthquake prediction in the Circum-Pacific seismic belt.

  6. Photon Pressure Force on Space Debris TOPEX/Poseidon Measured by Satellite Laser Ranging

    Science.gov (United States)

    Kucharski, D.; Kirchner, G.; Bennett, J. C.; Lachut, M.; Sośnica, K.; Koshkin, N.; Shakun, L.; Koidl, F.; Steindorfer, M.; Wang, P.; Fan, C.; Han, X.; Grunwaldt, L.; Wilkinson, M.; Rodríguez, J.; Bianco, G.; Vespe, F.; Catalán, M.; Salmins, K.; del Pino, J. R.; Lim, H.-C.; Park, E.; Moore, C.; Lejba, P.; Suchodolski, T.

    2017-10-01

    The (TOPography EXperiment) TOPEX/Poseidon (T/P) altimetry mission operated for 13 years before the satellite was decommissioned in January 2006, becoming a large space debris object at an altitude of 1,340 km. Since the end of the mission, the interaction of T/P with the space environment has driven the satellite's spin dynamics. Satellite laser ranging (SLR) measurements collected from June 2014 to October 2016 allow for the satellite spin axis orientation to be determined with an accuracy of 1.7°. The spin axis coincides with the platform yaw axis (formerly pointing in the nadir direction) about which the body rotates in a counterclockwise direction. The combined photometric and SLR data collected over the 11 year time span indicates that T/P has continuously gained rotational energy at an average rate of 2.87 J/d and spins with a period of 10.73 s as of 19 October 2016. The satellite attitude model shows a variation of the cross-sectional area in the Sun direction between 8.2 m2 and 34 m2. The direct solar radiation pressure is the main factor responsible for the spin-up of the body, and the exerted photon force varies from 65 μN to 228 μN around the mean value of 138.6 μN. Including realistic surface force modeling in orbit propagation algorithms will improve the prediction accuracy, giving better conjunction warnings for scenarios like the recent close approach reported by the ILRS Space Debris Study Group—an approximate 400 m flyby between T/P and Jason-2 on 20 June 2017.

  7. Inflammatory challenge increases measures of oxidative stress in a free-ranging, long-lived mammal.

    Science.gov (United States)

    Schneeberger, Karin; Czirják, Gábor Á; Voigt, Christian C

    2013-12-15

    Oxidative stress - the imbalance between reactive oxygen species (ROS) and neutralising antioxidants - has been under debate as the main cause of ageing in aerobial organisms. The level of ROS should increase during infection as part of the activation of an immune response, leading to oxidative damage to proteins, lipids and DNA. Yet, it is unknown how long-lived organisms, especially mammals, cope with oxidative stress. Bats are known to carry a variety of zoonotic pathogens and at the same time are, despite their high mass-specific basal metabolic rate, unusually long lived, which may be partly the result of low oxidative damage of organs. Here, we asked whether an immune challenge causes oxidative stress in free-ranging bats, measuring two oxidative stress markers. We injected 20 short-tailed fruit bats (Carollia perspicillata) with bacterially derived lipopolysaccharide (LPS) and 20 individuals with phosphate-buffered saline solution (PBS) as a control. Individuals injected with LPS showed an immune reaction by increased white blood cell count after 24 h, whereas there was no significant change in leukocyte count in control animals. The biological antioxidant potential (BAP) remained the same in both groups, but reactive oxygen metabolites (ROMs) increased after treatment with LPS, indicating a significant increase in oxidative stress in animals when mounting an immune reaction toward the inflammatory challenge. Control individuals did not show a change in oxidative stress markers. We conclude that in a long-lived mammal, even high concentrations of antioxidants do not immediately neutralise free radicals produced during a cellular immune response. Thus, fighting an infection may lead to oxidative stress in bats.

  8. Detailed seismic intensity in Morioka area; Moriokashi ni okeru shosai shindo bunpu

    Energy Technology Data Exchange (ETDEWEB)

    Saito, T.; Yamamoto, H.; Settai, H. [Iwate University, Iwate (Japan). Faculty of Engineering; Yamada, T. [Obayashi Road Construction Co. Ltd., Tokyo (Japan)

    1996-10-01

    To reveal a seismic intensity distribution in individual areas, a large-scale detailed seismic intensity survey was conducted in Morioka City through questionnaire, as to the Hokkaido Toho-oki (HE) earthquake occurred on October 4, 1994 with a record of seismic intensity 4 at Morioka, and the Sanriku Haruka-oki (SH) earthquake occurred on December 28, 1994 with a record of seismic intensity 5 at Morioka. A relationship was also examined between the seismic intensity distribution and the properties of shallow basement in Morioka City. The range of seismic intensity was from 2.9 to 4.6 and the difference was 1.7 in the case of HE earthquake, and the range was from 3.1 to 5.0 and the difference was 1.9 in the case of SH earthquake. There were large differences in the seismic intensity at individual points. Morioka City has different geological structures in individual areas. There were differences in the S-wave velocity in the surface layer ranging from 150 to 600 m/sec, which were measured using a plate hammering seismic source at 76 areas in Morioka City. These properties of surface layers were in harmony with the seismic intensity distribution obtained from the questionnaire. For the observation of short frequency microtremors at about 490 points in the city, areas with large amplitudes, mean maximum amplitudes of vertical motion components more than 0.1 mkine were distributed in north-western region and a part of southern region. 4 refs., 9 figs., 1 tab.

  9. Updated Colombian Seismic Hazard Map

    Science.gov (United States)

    Eraso, J.; Arcila, M.; Romero, J.; Dimate, C.; Bermúdez, M. L.; Alvarado, C.

    2013-05-01

    possible to determinate environments and scenarios where the seismic hazard is a function of distance and magnitude and also the principal seismic sources that contribute to the seismic hazard at each site (dissagregation). This project was conducted by the Servicio Geológico Colombiano (Colombian Geological Survey) and the Universidad Nacional de Colombia (National University of Colombia), with the collaboration of national and foreign experts and the National System of Prevention and Attention of Disaster (SNPAD). It is important to stand out that this new seismic hazard map was used in the updated national building code (NSR-10). A new process is ongoing in order to improve and present the Seismic Hazard Map in terms of intensity. This require new knowledge in site effects, in both local and regional scales, checking the existing and develop new acceleration to intensity relationships, in order to obtain results more understandable and useful for a wider range of users, not only in the engineering field, but also all the risk assessment and management institutions, research and general community.

  10. Wildlife speed cameras: measuring animal travel speed and day range using camera traps

    NARCIS (Netherlands)

    Rowcliffe, J.M.; Jansen, P.A.; Kays, R.; Kranstauber, B.; Carbone, C.

    2016-01-01

    Travel speed (average speed of travel while active) and day range (average speed over the daily activity cycle) are behavioural metrics that influence processes including energy use, foraging success, disease transmission and human-wildlife interactions, and which can therefore be applied to a range

  11. Investigation of hopped frequency waveforms for range and velocity measurements of radar targets

    CSIR Research Space (South Africa)

    Kathree, U

    2015-10-01

    Full Text Available In the field of radar, High Range Resolution (HRR) profiles are often used to improve target tracking accuracy in range and to allow the radar system to produce an image of an object using techniques such as inverse synthetic aperture radar (ISAR...

  12. Determination of plant growth rate and growth temperature range from measurement of physiological parameters

    Science.gov (United States)

    R. S. Criddle; B. N. Smith; L. D. Hansen; J. N. Church

    2001-01-01

    Many factors influence species range and diversity, but temperature and temperature variability are always major global determinants, irrespective of local constraints. On a global scale, the ranges of many taxa have been observed to increase and their diversity decrease with increasing latitude. On a local scale, gradients in species distribution are observable with...

  13. SourceURL:file://localhost/Users/socquet/Auboulot/congres/socquetAGU2014.doc Geodetic coupling in the North Chile - South Peru seismic gap: new insights from GPS measurements in Peru

    Science.gov (United States)

    Socquet, A.; Cotte, N.; Norabuena, E. O.; Quiroz, W.; Jara, J.; Pina-Valdes, J.; Chlieh, M.; Carrizo, D.; Bejar Pizarro, M.; Metois, M.

    2014-12-01

    SourceURL:file://localhost/Users/socquet/Auboulot/congres/socquetAGU2014.doc The subduction zone at the latitude of the Central Andes did not experience a Mw>8.5 earthquake since the 19thcentury, and forms a ~500km long seismic gap in North Chile - South Peru. Understanding the factors that limit the extent of seismic ruptures is crucial for risk mitigation and for understanding physical processes that govern the behavior of seismogenic faults. It appears crucial to evaluate interseismic coupling and its spatial variation in seismic gaps to assess seismic potential. Recent geodetic studies combining continuous and campaign GPS measurements as well as InSAR measurements showed that the subduction interface in north Chile, was accumulating interseismic elastic strain, likely to rebound into a large megathrust Earthquake. A Mw8.2 earthquake occurred on the 1st of April 2014 in this seismic gap, in front of Pisagua (North Chile), ~150 km south of the Chile-Peru Border. In spite of its already large magnitude, that earthquake was smaller expected in the area, and has most probably increased the stress in the unbroken segments at both edges. Most of accumulated strain remains to be relaxed in the North Chile-South Peru seismic gap. Here we propose to present a first assessment of the interseismic loading in the South Peru part of the seismic gap, at the northern extremity of Pisagua Earthquake, where it is poorly known. In south Peru, over an area of 500 x 250 km, 33 campaign markers have been installed and measured in June 2012. This network has been partially remeasured in June 2013 and April 2014 (after Mw8.2 Pisagua Eaquake). These measurements provide us with an estimate of the Pre-Pisagua-Earthquake coupling, and the co-seismic static displacements. These displacements are combined together with the ones of previous studies that occurred in North Chile and provide a unique and dense velocity field spreading through the Chile Peru border. In particular this provides

  14. Evaluation of knee range of motion: Correlation between measurements using a universal goniometer and a smartphone goniometric application.

    Science.gov (United States)

    Dos Santos, Rafael Aparecido; Derhon, Viviane; Brandalize, Michelle; Brandalize, Danielle; Rossi, Luciano Pavan

    2017-07-01

    Goniometers are commonly used to measure range of motion in the musculoskeletal system. Recently smartphone goniometry applications have become available to clinicians. Compare angular measures using a universal goniometer and a smartphone application. Thirty four healthy women with at least 20° of limited range of motion regarding knee extension were recruited. Knee flexion angles of the dominant limb were measured with a universal goniometer and the ROM(©) goniometric application for the smartphone. Three trained examiners compared the two assessment tools. Strong correlations were found between the measures of the universal goniometer and smartphone application (Pearson's correlation and interclass correlation coefficient > 0.93). The measurements with both devices demonstrated low dispersion and little variation. Measurements obtained using the smartphone goniometric application analyzed are as reliable as those of a universal goniometer. This application is therefore a useful tool for the evaluation of knee range of motion. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Seismic investigations for high resolution exploration ahead and around boreholes

    Science.gov (United States)

    Jaksch, Katrin; Giese, Ruediger; Kopf, Matthias

    2013-04-01

    Deep reservoirs usually will be explored with a surface seismic survey often in combination with borehole seismic measurements like VSP or SWD which can improve the velocity model of the underground. Reservoirs especially in geothermal fields are often characterized by small-scale structures. Additionally, with depth the need for exploration methods with a high resolution increases because standard methods like borehole seismic measurements cannot improve their resolution with depth. To localize structures with more accuracy methods with higher resolution in the range of meters are necessary. Within the project SPWD - Seismic Prediction While Drilling a new exploration method will be developed. With an implementation of seismic sources and receivers in one device an exploration method ahead and around the borehole will be enabled. Also, a high resolution independent from the depth will be achieved. Therefore active and powerful seismic sources are necessary to reach an acceptable penetration depth. Step by step seismic borehole devices were developed, which can be used under different conditions. Every borehole device contains four seismic sources and several three-component geophones. A small distance between actuators and geophones allows detecting also the high frequency content of the wave field reflected at geological structures. Also, exploration with a high resolution is possible. A first borehole device was developed for basic conditions in horizontal boreholes without special terms to temperature or pressure. In a mine first methodical measurements for the initiated wave field were performed. Therefor an existing seismic test area at the research and education mine of the TU Bergakademie Freiberg was extended with boreholes. In the seismic test area, consisting of a dense geophone array with three-component geophone anchors, two horizontal and one vertical borehole was drilled. To achieve a radiation pattern in predefined directions by constructive

  16. Precise Gravity Measurements for Lunar Laser Ranging at Apache Point Observatory

    Science.gov (United States)

    Crossley, D. J.; Murphy, T.; Boy, J.; De Linage, C.; Wheeler, R. D.; Krauterbluth, K.

    2012-12-01

    Lunar Laser Ranging (LLR) at Apache Point Observatory began in 2006 under the APOLLO project using a 3.5 m telescope on a 2780 m summit in New Mexico. Recent improvements in the technical operations are producing uncertainties at the few-mm level in the 1.5 x 10^13 cm separation of the solar orbits of the Earth and Moon. This level of sensitivity permits a number of important aspects of gravitational theory to be tested. Among these is the Equivalence Principle that determines the universality of free fall, tests of the time variation of the Gravitational Constant G, deviations from the inverse square law, and preferred frame effects. In 2009 APOLLO installed a superconducting gravimeter (SG) on the concrete pier under the main telescope to further constrain the deformation of the site as part of an initiative to improve all aspects of the modeling process. We have analyzed more than 3 years of high quality SG data that provides unmatched accuracy in determining the local tidal gravimetric factors for the solid Earth and ocean tide loading. With on-site gravity we have direct measurements of signals such as polar motion, and can compute global atmospheric and hydrological loading for the site using GLDAS and local hydrology models that are compared with the SG observations. We also compare the SG residuals with satellite estimates of seasonal ground gravity variations from the GRACE mission. Apache Point is visited regularly by a team from the National Geospatial-Intelligence Agency to provide absolute gravity values for the calibration of the SG and to determine secular gravity changes. Nearby GPS location P027 provides continuous position information from the Plate Boundary Observatory of Earthscope that is used to correlate gravity/height variations at the site. Unusual aspects of the data processing include corrections for the telescope azimuth that appear as small offsets at the 1 μGal level and can be removed by correlating the azimuth data with the SG

  17. A hydrogel based nanosensor with an unprecedented broad sensitivity range for pH measurements in cellular compartments

    DEFF Research Database (Denmark)

    Zhang, M.; Søndergaard, Rikke Vicki; Ek, Pramod Kumar

    2015-01-01

    Optical pH nanosensors have been applied for monitoring intracellular pH in real-time for about two decades. However, the pH sensitivity range of most nanosensors is too narrow, and measurements that are on the borderline of this range may not be correct. Furthermore, ratiometric measurements...... of acidic intracellular pH (pH nanosensors. In this paper we successfully developed a multiple sensor, a fluorophore based nanosensor, with an unprecedented broad measurement range from pH 1.4 to 7.0. In this nanosensor, three p......H-sensitive fluorophores (difluoro-Oregon Green, Oregon Green 488, and fluorescein) and one pH-insensitive fluorophore (Alexa 568) were covalently incorporated into a nanoparticle hydrogel matrix. With this broad range quadruple-labelled nanosensor all physiological relevant pH levels in living cells can be measured...

  18. Submillimeter-Wave Polarimetric Compact Ranges for Scale-Model Radar Measurements

    National Research Council Canada - National Science Library

    Coulombe, Michael J; Waldman, Jerry; Giles, R. H; Gatesman, Andrew J; Goyette, Thomas M; Nixon, William

    2002-01-01

    .... A dielectric material fabrication and characterization capability has also been developed to fabricate custom anechoic materials for the ranges as well as scaled dielectric parts for the models and clutter scenes...

  19. Shear-wave velocity profile and seismic input derived from ambient vibration array measurements: the case study of downtown L'Aquila

    Science.gov (United States)

    Di Giulio, Giuseppe; Gaudiosi, Iolanda; Cara, Fabrizio; Milana, Giuliano; Tallini, Marco

    2014-08-01

    Downtown L'Aquila suffered severe damage (VIII-IX EMS98 intensity) during the 2009 April 6 Mw 6.3 earthquake. The city is settled on a top flat hill, with a shear-wave velocity profile characterized by a reversal of velocity at a depth of the order of 50-100 m, corresponding to the contact between calcareous breccia and lacustrine deposits. In the southern sector of downtown, a thin unit of superficial red soils causes a further shallow impedance contrast that may have influenced the damage distribution during the 2009 earthquake. In this paper, the main features of ambient seismic vibrations have been studied in the entire city centre by using array measurements. We deployed six 2-D arrays of seismic stations and 1-D array of vertical geophones. The 2-D arrays recorded ambient noise, whereas the 1-D array recorded signals produced by active sources. Surface-wave dispersion curves have been measured by array methods and have been inverted through a neighbourhood algorithm, jointly with the H/V ambient noise spectral ratios related to Rayleigh waves ellipticity. We obtained shear-wave velocity (Vs) profiles representative of the southern and northern sectors of downtown L'Aquila. The theoretical 1-D transfer functions for the estimated Vs profiles have been compared to the available empirical transfer functions computed from aftershock data analysis, revealing a general good agreement. Then, the Vs profiles have been used as input for a deconvolution analysis aimed at deriving the ground motion at bedrock level. The deconvolution has been performed by means of EERA and STRATA codes, two tools commonly employed in the geotechnical engineering community to perform equivalent-linear site response studies. The waveform at the bedrock level has been obtained deconvolving the 2009 main shock recorded at a strong motion station installed in downtown. Finally, this deconvolved waveform has been used as seismic input for evaluating synthetic time-histories in a strong

  20. Infrasound Generation from the HH Seismic Hammer.

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Kyle Richard

    2014-10-01

    The HH Seismic hammer is a large, "weight-drop" source for active source seismic experiments. This system provides a repetitive source that can be stacked for subsurface imaging and exploration studies. Although the seismic hammer was designed for seismological studies it was surmised that it might produce energy in the infrasonic frequency range due to the ground motion generated by the 13 metric ton drop mass. This study demonstrates that the seismic hammer generates a consistent acoustic source that could be used for in-situ sensor characterization, array evaluation and surface-air coupling studies for source characterization.

  1. Validation of an in-vivo proton beam range check method in an anthropomorphic pelvic phantom using dose measurements.

    Science.gov (United States)

    Bentefour, El H; Tang, Shikui; Cascio, Ethan W; Testa, Mauro; Samuel, Deepak; Prieels, Damien; Gottschalk, Bernard; Lu, Hsiao-Ming

    2015-04-01

    In-vivo dosimetry and beam range verification in proton therapy could play significant role in proton treatment validation and improvements. In-vivo beam range verification, in particular, could enable new treatment techniques one of which could be the use of anterior fields for prostate treatment instead of opposed lateral fields as in current practice. This paper reports validation study of an in-vivo range verification method which can reduce the range uncertainty to submillimeter levels and potentially allow for in-vivo dosimetry. An anthropomorphic pelvic phantom is used to validate the clinical potential of the time-resolved dose method for range verification in the case of prostrate treatment using range modulated anterior proton beams. The method uses a 3 × 4 matrix of 1 mm diodes mounted in water balloon which are read by an ADC system at 100 kHz. The method is first validated against beam range measurements by dose extinction measurements. The validation is first completed in water phantom and then in pelvic phantom for both open field and treatment field configurations. Later, the beam range results are compared with the water equivalent path length (WEPL) values computed from the treatment planning system XIO. Beam range measurements from both time-resolved dose method and the dose extinction method agree with submillimeter precision in water phantom. For the pelvic phantom, when discarding two of the diodes that show sign of significant range mixing, the two methods agree with ±1 mm. Only a dose of 7 mGy is sufficient to achieve this result. The comparison to the computed WEPL by the treatment planning system (XIO) shows that XIO underestimates the protons beam range. Quantifying the exact XIO range underestimation depends on the strategy used to evaluate the WEPL results. To our best evaluation, XIO underestimates the treatment beam range between a minimum of 1.7% and maximum of 4.1%. Time-resolved dose measurement method satisfies the two basic

  2. Gasgeochemical indicators seismic activity

    Science.gov (United States)

    Obzhirov, Anatoly

    2017-10-01

    Laboratory of Gasgeochemistry of POI FEB RAS is studying gas distribution in lithosphere, hydrosphere and atmosphere from 1977 years. Method consist is sampling from its in expedition, take gas from samples of sediment, water and atmosphere to use method degassing and analysis gas in chromatograph, to measure CH4, C2-C4, O2, N2, H2, He and some time Rn. Gas is using like indicators to search oil-gas deposits, gas hydrate, mapping zones faults, to determine seismic activity, to calculate green house gas (CH4, CO2). The next geological, geophysics and hydro-acoustics characteristics assist which help to explain to form methane bubbles fluxes and gas hydrate in the Okhotsk Sea. The methane fluxes are mostly located in the zones faults and it increase in period seismic activity.

  3. Multicomponent ensemble models to forecast induced seismicity

    Science.gov (United States)

    Király-Proag, E.; Gischig, V.; Zechar, J. D.; Wiemer, S.

    2018-01-01

    In recent years, human-induced seismicity has become a more and more relevant topic due to its economic and social implications. Several models and approaches have been developed to explain underlying physical processes or forecast induced seismicity. They range from simple statistical models to coupled numerical models incorporating complex physics. We advocate the need for forecast testing as currently the best method for ascertaining if models are capable to reasonably accounting for key physical governing processes—or not. Moreover, operational forecast models are of great interest to help on-site decision-making in projects entailing induced earthquakes. We previously introduced a standardized framework following the guidelines of the Collaboratory for the Study of Earthquake Predictability, the Induced Seismicity Test Bench, to test, validate, and rank induced seismicity models. In this study, we describe how to construct multicomponent ensemble models based on Bayesian weightings that deliver more accurate forecasts than individual models in the case of Basel 2006 and Soultz-sous-Forêts 2004 enhanced geothermal stimulation projects. For this, we examine five calibrated variants of two significantly different model groups: (1) Shapiro and Smoothed Seismicity based on the seismogenic index, simple modified Omori-law-type seismicity decay, and temporally weighted smoothed seismicity; (2) Hydraulics and Seismicity based on numerically modelled pore pressure evolution that triggers seismicity using the Mohr-Coulomb failure criterion. We also demonstrate how the individual and ensemble models would perform as part of an operational Adaptive Traffic Light System. Investigating seismicity forecasts based on a range of potential injection scenarios, we use forecast periods of different durations to compute the occurrence probabilities of seismic events M ≥ 3. We show that in the case of the Basel 2006 geothermal stimulation the models forecast hazardous levels

  4. Light detection and ranging measurements of wake dynamics. Part II: two-dimensional scanning

    DEFF Research Database (Denmark)

    Trujillo, Juan-José; Bingöl, Ferhat; Larsen, Gunner Chr.

    2011-01-01

    A nacelle-mounted lidar system pointing downstream has been used to measure wind turbine wake dynamics. The new measurement and data analysis techniques allow estimation of quasi-instantaneous wind fields in planes perpendicular to the rotor axis. A newly developed wake tracking procedure deliver...

  5. Inter and intra-rater reliability of mobile device goniometer in measuring lumbar flexion range of motion.

    Science.gov (United States)

    Bedekar, Nilima; Suryawanshi, Mayuri; Rairikar, Savita; Sancheti, Parag; Shyam, Ashok

    2014-01-01

    Evaluation of range of motion (ROM) is integral part of assessment of musculoskeletal system. This is required in health fitness and pathological conditions; also it is used as an objective outcome measure. Several methods are described to check spinal flexion range of motion. Different methods for measuring spine ranges have their advantages and disadvantages. Hence, a new device was introduced in this study using the method of dual inclinometer to measure lumbar spine flexion range of motion (ROM). To determine Intra and Inter-rater reliability of mobile device goniometer in measuring lumbar flexion range of motion. iPod mobile device with goniometer software was used. The part being measure i.e the back of the subject was suitably exposed. Subject was standing with feet shoulder width apart. Spinous process of second sacral vertebra S2 and T12 were located, these were used as the reference points and readings were taken. Three readings were taken for each: inter-rater reliability as well as the intra-rater reliability. Sufficient rest was given between each flexion movement. Intra-rater reliability using ICC was r=0.920 and inter-rater r=0.812 at CI 95%. Validity r=0.95. Mobile device goniometer has high intra-rater reliability. The inter-rater reliability was moderate. This device can be used to assess range of motion of spine flexion, representing uni-planar movement.

  6. Sensitivity analysis of nacelle lidar free stream wind speed measurements to wind-induction reconstruction model and lidar range configuration

    DEFF Research Database (Denmark)

    Svensson, Elin; Borraccino, Antoine; Meyer Forsting, Alexander Raul

    The sensitivity of nacelle lidar wind speed measurements to wind-induction models and lidar range configurations is studied using experimental data from the Nørrekær Enge (NKE) measurement campaign and simulated lidar data from Reynold-Averaged Navier Stokes (RANS) aerodynamic computational fluid...

  7. Aerial low-frequency hearing in captive and free-ranging harbour seals (Phoca vitulina) measured using auditory brainstem responses

    NARCIS (Netherlands)

    Lucke, K.; Hastie, Gordon D.; Ternes, Kerstin; McConnell, Bernie; Moss, Simon; Russell, Deborah J.F.; Weber, Heike; Janik, Vincent M.

    2016-01-01

    The hearing sensitivity of 18 free-ranging and 10 captive harbour seals (Phoca vitulina) to aerial sounds was measured in the presence of typical environmental noise through auditory brainstem response measurements. A focus was put on the comparative hearing sensitivity at low frequencies. Low-

  8. High dynamic range isotope ratio measurements using an analog electron multiplier

    Czech Academy of Sciences Publication Activity Database

    Williams, P.; Lorinčík, Jan; Franzreb, K.; Herwig, R.

    2013-01-01

    Roč. 45, č. 1 (2013), s. 549-552 ISSN 0142-2421 R&D Projects: GA MŠk ME 894 Institutional support: RVO:67985882 Keywords : Isotope ratios * electron multiplier * dynamic range Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.393, year: 2013

  9. Reliability and Validity of Electro-Goniometric Range of Motion Measurements in Patients with Hand and Wrist Limitations.

    Science.gov (United States)

    Bashardoust Tajali, Siamak; MacDermid, Joy C; Grewal, Ruby; Young, Chris

    2016-01-01

    Cross-sectional reliability and validity study. 1. To determine intrarater, interrater and inter instrument reliabilities and validity of two digital electro goniometry to measure active wrist/finger range of motions (ROMs) in patients with limited motion. 2. To determine intrarater and interrater reliabilities of digital goniometry to measure torques of PIP passive flexion of the index finger in patients with limited motion. The study was designed in a randomized block plan on 44 patients (24 women, 20 men) with limited wrist or hand motions. Two experienced raters measured active wrist ROMs, and active and passive index PIP flexion using two digital goniometers. All measures were repeated by one rater 2-5 days after the initial measurements. The reliability measures were analyzed using Intraclass Correlation Coefficients (ICCs) and the construct validity was determined by correlation coefficients analysis between sub measures of scores; patient rated pain and function (PRWE) and quick Disabilities of the Arm, Shoulder and Hand (quick DASH) scores. The intrarater, interrater and inter instrument reliabilities were high in most ROM measures (range 0.64-0.97) for both types of electro-goniometers. The 95% limit of agreements and Bland and Altman plots did not show progressive changes. There was a significant difference in force application between the raters when performing passive ROM measures for PIP index, but the same rater produced consistent force. Most of the NK and J-Tech ROM measures were moderately correlated with the patient rated pain and function scores (range 0.32-0.63).

  10. Detection of Porous and Permeable Formations: From Laboratory Measurements to Seismic Measurements Détection des formations poreuses et perméables : des mesures de laboratoire aux mesures sismiques

    Directory of Open Access Journals (Sweden)

    Mari J.L.

    2012-09-01

    Full Text Available We present a seismic processing method which shows that it is possible to extract new attributes from seismic sections, leading to a better understanding of the distribution of the porous and permeable bodies. The attributes are also used to detect the impermeable layers. The methodology is based on laboratory experiments which have shown that a formation permeability indicator can be obtained via the computation of 4 input data: P-wave frequency and attenuation, porosity and specific surface. The procedure has been firstly conducted in acoustic logging to estimate permeability of porous layers and to detect water inflows [Mari et al. (2011 Phys. Chem. Earth 36, 17, 1438-1449]. In seismic, the processing is performed in order to measure these parameters. The analytic signal is used to compute the instantaneous frequency and attenuation (Q factor. The porosity and specific surface are computed from seismic impedances obtained by acoustic inversion of the migrated seismic sections. The input parameters are used to compute a new index named Ik-Seis factor (Indicator (I of permeability (k from acoustic or seismic (Seis data. The potential of the proposed procedure is demonstrated via a field case, both in full waveform acoustic logging and in seismic surveying. The example shows that the Ik-Seis factor can be used to map both the distribution of the permeable bodies in the carbonate formations and the non permeable shaly layers associated with the Callovo-Oxfordian claystone. Dans le but d’avoir une meilleure comprehension de la distribution des corps poreux et permeables d’une formation geologique, nous montrons que de nouveaux attributs peuvent etre extraits des donnees sismiques. Les attributs peuvent etre egalement utilises pour detecter les niveaux impermeables. La methodologie est basee sur des mesures experimentales effectuees en laboratoire, qui ont montre qu’un indicateur de permeabilite peut etre obtenu a partir de quatre grandeurs

  11. Lichenometric age measured on rock-falls related to historic seismicity affecting Lorca and its surroundings (Murcia, SE Spain); Datacion mediante liquenometria de los desprendimientos rocosos asociados a la sismicidad historica en Lorca (Murcia, SE de Espana)

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Lopez, R.; Martin-Gonzalez, F.; Martinez-Diaz, J. J.; Rodriguez-Pascua, M. A.

    2012-11-01

    During the earthquake at Lorca (Murcia, SE Spain) in 2011 (5.2 Mw, 4km depth) several rock-falls occurred, mobilizing an estimated volume of close to 2,000 m3. All these rock-falls took place within the Estancias and La Tercia mountain ranges, the topography of which is composed of Tortonian calcarenitic sandstones with steep scarps more than 30 m in height. We have conducted a lichenometric study to obtain the age of the ancient rock-falls within the Las Estancias Range. We have assumed an annual growth rate of 0.24 mm for lichen species classified as calcicolous and related to warm climatic conditions. Our aim was to corroborate the hypothesis that seismic events triggered these massive rock-falls. The city of Lorca had experienced two nearfield historic earthquakes (1674 EMS VIII and 1818 EMS VI) and one far-field tremor during the great Lisbon earthquake in 1755 (EMS VI). Results obtained here indicate that the earthquakes of 1674 and 2011 were quite similar, except that the 1674 one mobilised a greater quantity and twenty times the volume of blocks mobilised during the 2011 earthquake. Therefore, we conclude that the size of the earthquake of 1674 was possibly between 6.0 < M < 6.8, assuming similar focal and seismotectonic conditions to those of the instrumentally measured earthquake of 2011. (Author) 34 refs.

  12. Ultrasonic Measurement of Body Fat as a Means of Assessing Body Condition in Free-Ranging Raccoons (Procyon lotor

    Directory of Open Access Journals (Sweden)

    Elizabeth M. Stringer

    2010-01-01

    Full Text Available Assessment of body condition of free-ranging animals is important when evaluating population health and fitness. The following study used body condition scoring, ultrasound, and dissected physical measurement to assess fat stores in free-ranging raccoons (Procyon lotor. Measurements were taken of subcutaneous fat at interscapular, thoracolumbar, and lumbosacral paraspinal and ventral midline sites. These measurements were examined in relationship to body condition scores and body weight. The ultrasound technique accurately measured the subcutaneous fat of raccoons when compared to dissected physical measurement and yielded data that strongly correlated with both body condition score and body weight, with the ventral midline measurement most strongly correlated. This noninvasive method may be useful in conjunction with body condition score and body weight when assessing the nutritional status of raccoons and potentially other small carnivore species.

  13. Comparison of the measurement of heart rate in adult free-range chickens (Gallus domesticus) by auscultation and electrocardiography.

    Science.gov (United States)

    Smith, C F; Gavaghan, B J; McSweeney, D; Powell, V; Lisle, A

    2014-12-01

    To compare the heart rates of adult free-range chickens (Gallus domesticus) measured by auscultation with a stethoscope with those measured simultaneously using electrocardiography (ECG). With each bird in a standing position, estimation of the heart rate was performed by placing a mark on paper for every 4 beats for roosters and 8 beats for hens as detected by auscultation over 30 s, while simultaneous ECG was performed. Heart rates measured by auscultation showed a high correlation (r = 0.97) with those measured by ECG. There was a high correlation between the heart rates of adult free-range chickens measured by auscultation with a stethoscope and those measured simultaneously using ECG. © 2014 Australian Veterinary Association.

  14. Excitation Mechanisms for Jovian Seismic Modes

    Science.gov (United States)

    Markham, Stephen; Stevenson, David J.

    2017-10-01

    Recent (2011) results from the Nice Observatory indicate the existence of global seismic modes on Jupiter in the frequency range between 0.7 and 1.5mHz with amplitudes of tens of cm/s. Currently, the driving force behind these modes is a mystery; the measured amplitudes were much larger than anticipated based on theory analogous to helioseismology (that is, turbulent convection as a source of stochastic excitation). One of the most promising hypotheses is that these modes are driven by Jovian storms. This work constructs a framework to analytically model the expected equilibrium normal mode amplitudes arising from convective columns in storms. We also place rough constraints of Jupiter's seismic modal quality factor. Using this model, neither meteor strikes, turbulent convection, nor water storms can feasibly excite the order of magnitude of observed amplitudes. Next we speculate about the potential role of rock storms deeper in Jupiter's atmosphere, because the rock storms' expected energy scales make them promising candidates to be the chief source of excitation for Jovian seismic modes, based on simple scaling arguments. Finally we suggest a predicted power spectrum for frequencies which have not yet been observed based on our findings, and supply some commentary on potential applications to Juno, Saturn, and future missions to Uranus and Neptune.

  15. Factors affecting seismic response of submarine slopes

    Directory of Open Access Journals (Sweden)

    G. Biscontin

    2006-01-01

    Full Text Available The response of submerged slopes on the continental shelf to seismic or storm loading has become an important element in the risk assessment for offshore structures and 'local' tsunami hazards worldwide. The geological profile of these slopes typically includes normally consolidated to lightly overconsolidated soft cohesive soils with layer thickness ranging from a few meters to hundreds of meters. The factor of safety obtained from pseudo-static analyses is not always a useful measure for evaluating the slope response, since values less than one do not necessarily imply slope failure with large movements of the soil mass. This paper addresses the relative importance of different factors affecting the response of submerged slopes during seismic loading. The analyses use a dynamic finite element code which includes a constitutive law describing the anisotropic stress-strain-strength behavior of normally consolidated to lightly overconsolidated clays. The model also incorporates anisotropic hardening to describe the effect of different shear strain and stress histories as well as bounding surface principles to provide realistic descriptions of the accumulation of the plastic strains and excess pore pressure during successive loading cycles. The paper presents results from parametric site response analyses on slope geometry and layering, soil material parameters, and input ground motion characteristics. The predicted maximum shear strains, permanent deformations, displacement time histories and maximum excess pore pressure development provide insight of slope performance during a seismic event.

  16. Microwave-range shielding effectiveness measurements using a dual vibrating intrinsic reverberation chamber

    NARCIS (Netherlands)

    Leferink, Frank Bernardus Johannes; Serra, Ramiro; Schipper, H.

    2012-01-01

    Reverberation chambers create a statistical uniformly distributed field which is very useful for reliable electromagnetic interference measurements. Another advantage of these chambers is the high field strength which can be generated compared to conventional test setups. A reverberation chamber

  17. Assessment of health status by molecular measures in adults ranging from middle-aged to old

    DEFF Research Database (Denmark)

    Waaijer, M. E. C.; Westendorp, R. G. J.; Goldeck, D.

    2017-01-01

    substitution test and 15-picture learning test) with age and with cardiovascular or metabolic disease as a measure of the health status. These associations with age and health status were also tested for molecular measures (C reactive protein (CRP), numbers of senescent p16INK4a positive cells in the epidermis...... disease, as was epidermal p16INK4a positivity. All associations with cardiovascular or metabolic disease attenuated when adjusting for age. In conclusion, in middle-aged to old persons, the molecular measures tested here were more weakly associated with age and health status than functional capacity...... and dermis and putative immunosenescence (presence of CD57+ T cells)). All functional capacity measures were associated with age. CRP and epidermal p16INK4a positivity were also associated with age, but with smaller estimates. Grip strength and the Stroop test were associated with cardiovascular or metabolic...

  18. Validity and reliability of range of motion measured on smartphone (mROM)

    OpenAIRE

    Cuesta-Vargas, Antonio

    2014-01-01

    Background: Nowadays, as internet-based communication is advancing rapidly, it is getting more and more interesting to adapt clinical examination of patients to remote communication. The use of smartphone photographic is presented as a method for studying the measurement of shoulders joint ROM. Objective: To investigate the reliability of smartphone photographic measurements of upper limbs abduction angle through mRom app compared to inertial sensors as the criterion standard. Methods: ...

  19. Fluorescent Protein Based FRET Pairs with Improved Dynamic Range for Fluorescence Lifetime Measurements

    OpenAIRE

    Bobin George Abraham; Karen S Sarkisyan; Mishin, Alexander S.; Ville Santala; Tkachenko, Nikolai V.; Matti Karp

    2015-01-01

    Fluorescence Resonance Energy Transfer (FRET) using fluorescent protein variants is widely used to study biochemical processes in living cells. FRET detection by fluorescence lifetime measurements is the most direct and robust method to measure FRET. The traditional cyan-yellow fluorescent protein based FRET pairs are getting replaced by green-red fluorescent protein variants. The green-red pair enables excitation at a longer wavelength which reduces cellular autofluorescence and phototoxicit...

  20. Close Range Photogrammetry for Direct Multiple Feature Positioning Measurement without Targets

    OpenAIRE

    Gorka Kortaberria; Aitor Olarra; Alberto Tellaeche; Rikardo Minguez

    2017-01-01

    The main objective of this study is to present a new method to carry out measurements so as to improve the positioning verification step in the wind hub part dimensional validation process. This enhancement will speed up the measuring procedures for these types of parts. An industrial photogrammetry based system was applied to take advantage of its results, and new functions were added to existing capabilities. In addition to a new development based on photogrammetry modelling and image proce...

  1. New measurements of high-momentum nucleons and short-range structures in nuclei

    CERN Document Server

    Fomin, N; Asaturyan, R; Benmokhtar, F; Boeglin, W; Bosted, P; Bruell, A; Bukhari, M H S; Chudakov, E; Clasie, B; Connell, S H; Dalton, M M; Daniel, A; Day, D B; Dutta, D; Ent, R; Fassi, L El; Fenker, H; Filippone, B W; Garrow, K; Gaskell, D; Hill, C; Holt, R J; Horn, T; Jones, M K; Jourdan, J; Kalantarians, N; Keppel, C E; Kiselev, D; Kotulla, M; Lindgren, R; Lung, A F; Malace, S; Markowitz, P; McKee, P; Meekins, D G; Mkrtchyan, H; Navasardyan, T; Niculescu, G; Opper, A K; Perdrisat, C; Potterveld, D H; Punjabi, V; Qian, X; Reimer, P E; Roche, J; Rodriguez, V M; Rondon, O; Schulte, E; Seely, J; Segbefia, E; Slifer, K; Smith, G R; Solvignon, P; Tadevosyan, V; Tajima, S; Tang, L; Testa, G; Trojer, R; Tvaskis, V; Vulcan, W F; Wasko, C; Wesselmann, F R; Wood, S A; Wright, J; Zheng, X

    2011-01-01

    We present new, high-Q^2 measurements of inclusive electron scattering from high-momentum nucleons in nuclei. This yields an improved extraction of the strength of two-nucleon correlations for several nuclei, including light nuclei where clustering effects can, for the first time, be examined. The data extend to the kinematic regime where three-nucleon correlations are expected to dominate and we observe significantly greater strength in this region than previous measurements.

  2. Measured electric field intensities near electric cloud discharges detected by the Kennedy Space Center's Lightning Detection and Ranging System, LDAR

    Science.gov (United States)

    Poehler, H. A.

    1977-01-01

    For a summer thunderstorm, for which simultaneous, airborne electric field measurements and Lightning Detection and Ranging (LDAR) System data was available, measurements were coordinated to present a picture of the electric field intensity near cloud electrical discharges detected by the LDAR System. Radar precipitation echos from NOAA's 10 cm weather radar and measured airborne electric field intensities were superimposed on LDAR PPI plots to present a coordinated data picture of thunderstorm activity.

  3. Direct measurement of additional Ar-H2O vibration-rotation-tunneling bands in the millimeter-submillimeter range

    Science.gov (United States)

    Zou, Luyao; Widicus Weaver, Susanna L.

    2016-06-01

    Three new weak bands of the Ar-H2O vibration-rotation-tunneling spectrum have been measured in the millimeter wavelength range. These bands were predicted from combination differences based on previously measured bands in the submillimeter region. Two previously reported submillimeter bands were also remeasured with higher frequency resolution. These new measurements allow us to obtain accurate information on the Coriolis interaction between the 101 and 110 states. Here we report these results and the associated improved molecular constants.

  4. What range of trait levels can the Autism-Spectrum Quotient (AQ) measure reliably? An item response theory analysis.

    Science.gov (United States)

    Murray, Aja Louise; Booth, Tom; McKenzie, Karen; Kuenssberg, Renate

    2016-06-01

    It has previously been noted that inventories measuring traits that originated in a psychopathological paradigm can often reliably measure only a very narrow range of trait levels that are near and above clinical cutoffs. Much recent work has, however, suggested that autism spectrum disorder traits are on a continuum of severity that extends well into the nonclinical range. This implies a need for inventories that can capture individual differences in autistic traits from very high levels all the way to the opposite end of the continuum. The Autism-Spectrum Quotient (AQ) was developed based on a closely related rationale, but there has, to date, been no direct test of the range of trait levels that the AQ can reliably measure. To assess this, we fit a bifactor item response theory model to the AQ. Results suggested that AQ measures moderately low to moderately high levels of a general autistic trait with good measurement precision. The reliable range of measurement was significantly improved by scoring the instrument using its 4-point response scale, rather than dichotomizing responses. These results support the use of the AQ in nonclinical samples, but suggest that items measuring very low and very high levels of autistic traits would be beneficial additions to the inventory. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  5. A hydrogel based nanosensor with an unprecedented broad sensitivity range for pH measurements in cellular compartments.

    Science.gov (United States)

    Zhang, M; Søndergaard, R V; Kumar, E K P; Henriksen, J R; Cui, D; Hammershøj, P; Clausen, M H; Andresen, T L

    2015-11-07

    Optical pH nanosensors have been applied for monitoring intracellular pH in real-time for about two decades. However, the pH sensitivity range of most nanosensors is too narrow, and measurements that are on the borderline of this range may not be correct. Furthermore, ratiometric measurements of acidic intracellular pH (pH pH 1.4 to 7.0. In this nanosensor, three pH-sensitive fluorophores (difluoro-Oregon Green, Oregon Green 488, and fluorescein) and one pH-insensitive fluorophore (Alexa 568) were covalently incorporated into a nanoparticle hydrogel matrix. With this broad range quadruple-labelled nanosensor all physiological relevant pH levels in living cells can be measured without being too close to the limits of its pH-range. The nanosensor exhibits no susceptibility to interference by other intracellular ions at physiological concentrations. Due to its positive surface charge it is spontaneously internalized by HeLa cells and localizes to the lysosomes where the mean pH was measured at 4.6. This quadruple-labelled nanosensor performs accurate measurements of fluctuations of lysosomal pH in both directions, which was shown by treatment with the V-ATPase inhibitor bafilomycin A1 or its substrate ATP in HeLa cells. These measurements indicate that this novel quadruple-labelled nanosensor is a promising new tool for measuring the pH of acidic compartments in living cells.

  6. Methane emission from free-ranging sheep: a comparison of two measurement methods

    Science.gov (United States)

    Leuning, R.; Baker, S. K.; Jamie, I. M.; Hsu, C. H.; Klein, L.; Denmead, O. T.; Griffith, D. W. T.

    Methane emissions from a flock of 14, 1-year old sheep grazing on a grass and legume pasture were measured using a micrometeorological mass-balance method and a sulphur hexaflouride (SF 6) tracer technique. The former measured the mean emission, over 45 min intervals, from all the sheep within a fenced 24 m×24 m enclosure, from the enrichment of methane (CH 4) in air as it passed over the sheep. The tracer technique measured emissions from a subset of 7 individual animals over 24 h periods from measurements of CH 4 and SF 6 concentrations in air exhaled by the sheep, and from the known rate of release of SF 6 from small permeation tubes placed in the animals' rumens. Both methods gave highly similar results for 4 out of 5 days. When the species composition of dietary intake was steady during the last two days of measurement, the mean emission rate from the mass-balance method was 11.9±1.5 (SEM) g CH 4 sheep -1 d -1, while the rate from the tracer technique was 11.7±0.4 (SEM) g CH 4 sheep -1 d -1. These rates are for sheep with mean live mass of 27 kg, with a measured dry matter intake of 508 g sheep -1 d -1 and pasture dry matter digestibility of 69.5%. There was close agreement between these measurements and estimates from algorithms used to predict methane emissions from sheep for the Australian National Greenhouse Gas Inventory.

  7. Measurement of Ion Motional Heating Rates over a Range of Trap Frequencies and Temperatures

    CERN Document Server

    Bruzewicz, C D; Chiaverini, J

    2014-01-01

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

  8. Close Range Photogrammetry for Direct Multiple Feature Positioning Measurement without Targets

    Directory of Open Access Journals (Sweden)

    Gorka Kortaberria

    2017-01-01

    Full Text Available The main objective of this study is to present a new method to carry out measurements so as to improve the positioning verification step in the wind hub part dimensional validation process. This enhancement will speed up the measuring procedures for these types of parts. An industrial photogrammetry based system was applied to take advantage of its results, and new functions were added to existing capabilities. In addition to a new development based on photogrammetry modelling and image processing, a measuring procedure was defined based on optical and vision system considerations. A validation against a certified procedure by means of a laser-tracker has also been established obtaining deviations of ±0.125 μm/m.

  9. Comparison of repeated measurements of methane production in sheep over 5 years and a range of measurement protocols.

    Science.gov (United States)

    Robinson, D L; Goopy, J P; Hegarty, R S; Oddy, V H

    2015-10-01

    Emissions of 710 ewes at pasture were measured for 1 h (between 09:00-16:30 h) in batches of 15 sheep in portable accumulation chambers (PAC) after an overnight fast continuing until 2 h before measurement, when the sheep had access to baled hay for 1 h. The test was used to identify a group of 104 low emitters (I-Low) and a group of 103 high emitters (I-Hi) for methane emissions adjusted for liveweight (CHawt). The 207 ewes selected at the initial study were remeasured in 5 repeat tests from 2009 through 2014 at another location. The first repeat used the original measurement protocol. Two modified protocols, each used in 2 yr, drafted unfasted sheep on the morning of the test into a yard or holding paddock until measurement. Emissions of the I-Hi sheep were higher (102-112%) than I-Low sheep in all subsequent PAC tests, with statistical significance ( sheep were measured in respiration chambers (RC); 10 high (Hi-10) and 10 low (Low-10) sheep were chosen, representing extremes (top and bottom 6.25%) for methane yield (MY; g CH/kg DMI). The Hi-10 group emitted 14% more methane (adjusted for feed intake) in a follow-up RC test, but Low-10 and Hi-10 sheep differed in only 1 of the 5 PAC tests, when Hi-10 sheep emitted less CHawt than Low-10 sheep ( = 0.002) and tended to eat less in the feeding opportunity ( = 0.085). Compared with their weight on good pasture, Low-10 sheep were proportionately lighter than Hi-10 sheep in the relatively poor pasture conditions of the initial test. Sheep identified as low emitters by PAC tests using the initial protocol did not produce less CH (mg/min) when fed a fixed level of intake in RC. Correlations between estimates of an animal's CHawt measured in PAC and CH adjusted for feed intake in RC were quite low ( = 0-19%) and significant ( sheep. With moderate repeatability over the 5 yr, PAC tests of CHawt could be a viable way to select for reduced emissions of grazing sheep. As well as exploiting any variation in MY, selecting for

  10. 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.

  11. Characterization of short-pulse oscillators by means of a high-dynamic-range autocorrelation measurement.

    Science.gov (United States)

    Braun, A; Rudd, J V; Cheng, H; Mourou, G; Kopf, D; Jung, I D; Weingarten, K J; Keller, U

    1995-09-15

    A high-dynamic-range autocorrelation technique was used to characterize the temporal pulse shape of ultrashort laser pulses produced from four separate oscillators. These lasers included two Kerr-lens mode-locked Ti:sapphire oscillators as well as a Nd:glass and a Ti:sapphire oscillator, each passively mode locked by an antiresonant Fabry-Perot semiconductor saturable absorber. It was shown that the Nd:glass oscillator supported a pulse that was temporally clean over 8 orders of magnitude.

  12. Response of Hydrothermal System to Stress Transients at Lassen Volcanic Center, California inferred from Seismic Interferometry with Ambient Noise

    Science.gov (United States)

    Taira, T.; Brenguier, F.

    2016-12-01

    Time-lapse monitoring of seismic velocity at volcanic areas can provide unique insight into the property of hydrothermal and magmatic fluids and their temporal variability. We established a quasi real-time velocity monitoring system by using seismic interferometry with ambient noise to explore the temporal evolution of velocity in the Lassen Volcanic Center, northern California. Our monitoring system finds temporal variability of seismic velocity in response to stress changes imparted by an earthquake and by seasonal environmental changes. Dynamic stress changes from a magnitude 5.7 local earthquake induced a 0.1% velocity reduction at a depth of about 1 km. The seismic velocity susceptibility defined as ratio of seismic velocity change to dynamic stress change is estimated to be about 0.006 MPa-1, which suggests the Lassen hydrothermal system is marked by high-pressurized hydrothermal fluid. By combining geodetic measurements, our observation shows that the long-term seismic velocity fluctuation closely tracks snow-induced vertical deformation without time delay, which is most consistent with an hydrologic load model (either elastic or poroelastic response) in which surface loading drives hydrothermal fluid diffusion that leads to an increase of opening of cracks and subsequently reductions of seismic velocity. We infer that heated-hydrothermal fluid in a vapor-dominated zone at a depth of 2-4 km range is responsible for the long-term variation in seismic velocity.

  13. A measurement of auroral electrons in the 1–10 MeV range

    NARCIS (Netherlands)

    Gils, J.N. van; Beek, H.F. van; Fetter, L.D. de; Hendrickx, R.V.

    Particle fluxes have been measured by means of shielded Geiger-Müller telescopes mounted m a rocket, which was launched from ESRANGE(Kiruna) into a diffuse aurora. The analysis of the dependence of the counting rates on altitude indicates that a weak flux of energetic electrons, 1–10 MeV, has been

  14. Quantifying uncertainty of measuring gully morphological evolution with close-range digital photogrammetry

    Science.gov (United States)

    Measurement of geomorphic change may be of interest to researchers and practitioners in a variety of fields including geology, geomorphology, hydrology, engineering, and soil science. Landscapes are often represented by digital elevation models. Surface models generated of the same landscape over a ...

  15. Probabilistic Seismic Hazard Analysis for Yemen

    Directory of Open Access Journals (Sweden)

    Rakesh Mohindra

    2012-01-01

    Full Text Available A stochastic-event probabilistic seismic hazard model, which can be used further for estimates of seismic loss and seismic risk analysis, has been developed for the territory of Yemen. An updated composite earthquake catalogue has been compiled using the databases from two basic sources and several research publications. The spatial distribution of earthquakes from the catalogue was used to define and characterize the regional earthquake source zones for Yemen. To capture all possible scenarios in the seismic hazard model, a stochastic event set has been created consisting of 15,986 events generated from 1,583 fault segments in the delineated seismic source zones. Distribution of horizontal peak ground acceleration (PGA was calculated for all stochastic events considering epistemic uncertainty in ground-motion modeling using three suitable ground motion-prediction relationships, which were applied with equal weight. The probabilistic seismic hazard maps were created showing PGA and MSK seismic intensity at 10% and 50% probability of exceedance in 50 years, considering local soil site conditions. The resulting PGA for 10% probability of exceedance in 50 years (return period 475 years ranges from 0.2 g to 0.3 g in western Yemen and generally is less than 0.05 g across central and eastern Yemen. The largest contributors to Yemen’s seismic hazard are the events from the West Arabian Shield seismic zone.

  16. Correlation between seismicity and barometric tidal exalting

    Directory of Open Access Journals (Sweden)

    D. N. Arabelos

    2008-10-01

    Full Text Available Changes of barometric pressure in the area of Thessaloniki in Northern Greece were studied by analyzing a sample of 31 years of hourly measurements. The results of this analysis on the periodicities of tidal components are expressed in terms of amplitude and phases variability. An earlier investigation revealed a detectable correlation between the exalting of the amplitude parameters of the tidal waves with strong seismic events. A problem of this work was that we had compared the tidal parameters resulting from the analysis of data covering the period of one year with instantaneous seismic events, although the earthquake is the final result of a tectonic process of the upper lithosphere. Consequently, in order to increase the resolution of our method we had analyzed our data in groups of 3-months extent and the resulted amplitudes were compared with seismicity index for corresponding time periods. A stronger correlation was found in the last case. However, the estimation of tidal parameters in this case was restricted to short period (from one day down to eight hours constituents. Therefore, a new analysis was performed, retaining the one-year length of each data block but shifting the one year window by steps of three months from the beginning to the end of the 31 years period. This way, we are able to estimate again tidal parameters ranging from periods of one year (Sa down to eight hours (M3. The resulting correlation between these tidal parameters with a cumulative seismicity index for corresponding time intervals was remarkably increased.

  17. Non-destructive testing principles and accurate evaluation of the hydraulic measure impact range using the DC method

    Science.gov (United States)

    Qiu, Liming; Shen, Rongxi; Song, Dazhao; Wang, Enyuan; Liu, Zhentang; Niu, Yue; Jia, Haishan; Xia, Shankui; Zheng, Xiangxin

    2017-12-01

    An accurate and non-destructive evaluation method for the hydraulic measure impact range in coal seams is urgently needed. Aiming at the application demands, a theoretical study and field test are presented using the direct current (DC) method to evaluate the impact range of coal seam hydraulic measures. We firstly analyzed the law of the apparent resistivity response of an abnormal conductive zone in a coal seam, and then investigated the principle of non-destructive testing of the coal seam hydraulic measure impact range using the DC method, and used an accurate evaluation method based on the apparent resistivity cloud chart. Finally, taking hydraulic fracturing and hydraulic flushing as examples, field experiments were carried out in coal mines to evaluate the impact ranges. The results showed that: (1) in the process of hydraulic fracturing, coal conductivity was enhanced by high-pressure water in the coal seam, and after hydraulic fracturing, the boundary of the apparent resistivity decrease area was the boundary impact range. (2) In the process of hydraulic flushing, coal conductivity was reduced by holes and cracks in the coal seam, and after hydraulic flushing, the boundary of the apparent resistivity increase area was the boundary impact range. (3) After the implementation of the hydraulic measures, there may be some blind zones in the coal seam; in hydraulic fracturing blind zones, the apparent resistivity increased or stayed constant, while in hydraulic flushing blind zones, the apparent resistivity decreased or stayed constant. The DC method realized a comprehensive and non-destructive evaluation of the impact range of the hydraulic measures, and greatly reduced the time and cost of evaluation.

  18. Reliability of two goniometric methods of measuring active inversion and eversion range of motion at the ankle

    Directory of Open Access Journals (Sweden)

    Refshauge Kathryn M

    2006-07-01

    Full Text Available Abstract Background Active inversion and eversion ankle range of motion (ROM is widely used to evaluate treatment effect, however the error associated with the available measurement protocols is unknown. This study aimed to establish the reliability of goniometry as used in clinical practice. Methods 30 subjects (60 ankles with a wide variety of ankle conditions participated in this study. Three observers, with different skill levels, measured active inversion and eversion ankle ROM three times on each of two days. Measurements were performed with subjects positioned (a sitting and (b prone. Intra-class correlation coefficients (ICC[2,1] were calculated to determine intra- and inter-observer reliability. Results Within session intra-observer reliability ranged from ICC[2,1] 0.82 to 0.96 and between session intra-observer reliability ranged from ICC[2,1] 0.42 to 0.80. Reliability was similar for the sitting and the prone positions, however, between sessions, inversion measurements were more reliable than eversion measurements. Within session inter-observer measurements in sitting were more reliable than in prone and inversion measurements were more reliable than eversion measurements. Conclusion Our findings show that ankle inversion and eversion ROM can be measured with high to very high reliability by the same observer within sessions and with low to moderate reliability by different observers within a session. The reliability of measures made by the same observer between sessions varies depending on the direction, being low to moderate for eversion measurements and moderate to high for inversion measurements in both positions.

  19. Reliability of two goniometric methods of measuring active inversion and eversion range of motion at the ankle.

    Science.gov (United States)

    Menadue, Collette; Raymond, Jacqueline; Kilbreath, Sharon L; Refshauge, Kathryn M; Adams, Roger

    2006-07-28

    Active inversion and eversion ankle range of motion (ROM) is widely used to evaluate treatment effect, however the error associated with the available measurement protocols is unknown. This study aimed to establish the reliability of goniometry as used in clinical practice. 30 subjects (60 ankles) with a wide variety of ankle conditions participated in this study. Three observers, with different skill levels, measured active inversion and eversion ankle ROM three times on each of two days. Measurements were performed with subjects positioned (a) sitting and (b) prone. Intra-class correlation coefficients (ICC[2,1]) were calculated to determine intra- and inter-observer reliability. Within session intra-observer reliability ranged from ICC[2,1] 0.82 to 0.96 and between session intra-observer reliability ranged from ICC[2,1] 0.42 to 0.80. Reliability was similar for the sitting and the prone positions, however, between sessions, inversion measurements were more reliable than eversion measurements. Within session inter-observer measurements in sitting were more reliable than in prone and inversion measurements were more reliable than eversion measurements. Our findings show that ankle inversion and eversion ROM can be measured with high to very high reliability by the same observer within sessions and with low to moderate reliability by different observers within a session. The reliability of measures made by the same observer between sessions varies depending on the direction, being low to moderate for eversion measurements and moderate to high for inversion measurements in both positions.

  20. Application of bridge continuous shape measurement system based on optical fiber sensing technology in bridge post-seismic detection

    Science.gov (United States)

    Yang, Yan; Liu, Fang; Fu, Jinghua; Yang, Dandan

    2017-04-01

    Bridge shape is the important indicator to estimate the safety of the bridge. A bridge shape measurement system based on fiber optic gyroscope is builded up to survey the continuous shape of bridge. This measurement system comprises angular velocity sensor, linear velocity sensor, position sensor and etc. The bridge shape survey using the leveling measurement and bridge continuous shape measurement system was carried out after the earthquake. By comparing the data before and after the earthquake, the numerical values of the two method were similar. The experimental results show that the proposed system is an effective measurement method.

  1. Measuring Pulse Rate Variability using Long-Range, Non-Contact Imaging Photoplethysmography

    Science.gov (United States)

    2016-08-20

    Photoplethysmography (PPG), first pioneered in the 1930’s, is a low cost , noninvasive method of detecting changes in blood volume using variations in...glasses, piercings, and use of skin or beauty products were recorded but not otherwise used for analysis or screening purposes. C. Experimental Design...and Lei Wang. A review of non-contact, low- cost physiological information measurement based on photoplethysmographic imaging. Annu. Int. Conf. IEEE

  2. Measurement of long-range particle correlations in small systems with the ATLAS detector

    CERN Document Server

    Milov, Alexander; The ATLAS collaboration

    2016-01-01

    Study of particle correlations is an important instrument to understand the nature of relativistic heavy ion collisions. Using a wealth of new data available from the recent heavy ion runs of Large Hadron Collider at CERN it becomes possible to study particle correlations in different collisions systems under the same conditions. The results of several recent measurement performed by the ATLAS experiment are reviewed in this proceeding. Measurements are performed in various techniques in $pp$, $p+$Pb and PbPb collisions at the energies $\\sqrt{s_{_{\\rm{NN}}}}$, $\\sqrt{s}$ from 2.76 to 13 TeV. The results are compared between the systems having the same charged particle multiplicities in the final state, but different initial geometries. Results for multiplicity correlations, two-particle and muti-particle correlations measured in different techniques are presented and discussed. The goal of these comparison is to make further steps in understanding the nature of fluctuations observed in the small collisions sy...

  3. Angstrom-range optical path-length measurement with a high-speed scanning heterodyne optical interferometer.

    Science.gov (United States)

    Riza, Nabeel A; Arain, Muzammil A

    2003-05-01

    A highly accurate method of optical path-length measurement is introduced by use of a scanning heterodyne optical interferometer with no moving parts. The instrument has demonstrated the potential to measure optical path length at angstrom resolution over continuous thickness in the micrometer range. This optical path length can be used to calculate the thickness of any material if the refractive index is known or to measure the refractive index of the material if the thickness is known. The instrument uses a single acousto-optic device in an in-line ultra-stable reflective geometry to implement rapid scanning in the microsecond domain for thickness measurements of the test medium.

  4. RTX Correction Accuracy and Real-Time Data Processing of the New Integrated SeismoGeodetic System with Real-Time Acceleration and Displacement Measurements for Earthquake Characterization Based on High-Rate Seismic and GPS Data

    Science.gov (United States)

    Zimakov, L. G.; Raczka, J.; Barrientos, S. E.

    2016-12-01

    We will discuss and show the results obtained from an integrated SeismoGeodetic System, model SG160-09, installed in the Chile (Chilean National Network), Italy (University of Naples Network), and California. The SG160-09 provides the user high rate GNSS and accelerometer data, full epoch-by-epoch measurement integrity and the ability to create combined GNSS and accelerometer high-rate (200Hz) displacement time series in real-time. The SG160-09 combines seismic recording with GNSS geodetic measurement in a single compact, ruggedized case. The system includes a low-power, 220-channel GNSS receiver powered by the latest Trimble-precise Maxwell™6 technology and supports tracking GPS, GLONASS and Galileo signals. The receiver incorporates on-board GNSS point positioning using Real-Time Precise Point Positioning (PPP) technology with satellite clock and orbit corrections delivered over IP networks. The seismic recording includes an ANSS Class A, force balance accelerometer with the latest, low power, 24-bit A/D converter, producing high-resolution seismic data. The SG160-09 processor acquires and packetizes both seismic and geodetic data and transmits it to the central station using an advanced, error-correction protocol providing data integrity between the field and the processing center. The SG160-09 has been installed in three seismic stations in different geographic locations with different Trimble global reference stations coverage The hardware includes the SG160-09 system, external Zephyr Geodetic-2 GNSS antenna, both radio and high-speed Internet communication media. Both acceleration and displacement data was transmitted in real-time to the centralized Data Acquisition Centers for real-time data processing. Command/Control of the field station and real-time GNSS position correction are provided via the Pivot platform. Data from the SG160-09 system was used for seismic event characterization along with data from traditional seismic and geodetic stations

  5. Airborne Gravity Measurements using a Helicopter with Special Emphases on Delineating Local Gravity Anomalies Mainly for Detecting Active Seismic Faults (Invited)

    Science.gov (United States)

    Segawa, J.

    2010-12-01

    The first aerial gravity measurement in Japan started in 1998 using a Japanese airborne gravimeter ‘ Segawa-TKeiki airborne gravimeter Model FGA-1’. We lay emphasis on the measurement of detailed gravity structures at the land-to-sea border areas and mountainous areas. This is the reason why we use a helicopter and make surveys at low altitude and low speed. We have so far made measurement at twelve sites and the total flight amounts to 20,000km. The accuracy of measurement is 1.5 mgal and half-wavelength resolution is 1.5 km. The Japanese type gravimeter consists of a servo-accelerometer type gravity sensor, a horizontal platform controlled by an optical fiber gyro, GPS positioning system, and a data processing system. Helicopter movement has to be precisely monitored three-dimensionally to calculate the vehicle’s acceleration noises. The necessary accuracy of positioning of the vehicle must be better than 10 cm in positioning error. Our helicopter gravity measurement has a special target in Japan to investigate active seismic faults located across land-to-sea borderlines. In Japan, it is generally thought that gravity over most of the country has already been measured by the governmental surveys, leaving the land-sea border lines and mountainous zones unsurveyed as difficult-to-access areas. In addition the use of airplane or helicopter in Japan appeared disadvantageous because of the narrowness of the Japanese Islands. Under such situations the author thought there still remained a particular as well as unique need for aerial gravity measurement in Japan, i.e. the need for detailed and seamless knowledge of gravity structures across land-to-sea border lines to elucidate complicated crustal structures of the Japanese Islands as well as distribution of active seismic faults for disaster prevention. The results of gravity measurements we have conducted so far include those of 12 sites. In the following the brief logs of our measurements are listed. 1)April

  6. Radar measurements of surface deformation in the sub mm-range

    Science.gov (United States)

    Peters, Gerhard; Hort, Matthias; Gerst, Alexander; Scharff, Lea

    2016-04-01

    A portable low power Doppler radar at 24 GHz is used for volcano eruption observations since more than a decade (e.g. Hort and Seyfried, 1998, doi: 10.1029/97GL03482; Seyfried and Hort, 1999, doi: 10.1007/s004450050256; Vöge et al., 2005, doi: 10.1029/2005 EO510001, Vöge and Hort, 2009, doi: 10.1109/TGRS. 2008.2002693, Gerst et al., 2013, doi: 10.1002/jgrb.50234; Scharff et al, 2015, doi: 10.1130/G36705.1) The typical radar products are range resolved Doppler spectra containing information on the reflectivity, radial velocity and its distribution of ejected particles. Here we present the analysis of the phase of radar signals for the detection of comparably slow and small deformations of the solid surface which may occur for example prior to an eruption [Hort et al., 2010, AGU Fall meeting, Abstract V32B-03]. While the phase analysis of weather radar echoes from ground targets is established for estimating the atmospheric refractivity [Besson and du Châtelet, 2013, http://dx.doi.org/ 10.1175/ JTECH-D-12-00167.1], we consider here the variability of the atmosphere as a source of uncertainty. We describe the implementation of this technique in a dedicated compact low power FMCW system. Observations at Stromboli suggest an expansion of the vent prior to the eruption on the order of millimeter which is on the same oder as reported by [Noferini et al., 2009, doi: 10.1109/IGARSS. 2009. 5416901] and in case of Santiaguito volcano we were able to observe the post eruptive subsidence of the volcanic dome. We suggest further to resolve the range/refractivity ambiguity by using a dual frequency radar with sufficient frequency separation for utilizing the frequency dependence of refractivity.

  7. A simple and wide-range refractive index measuring approach by using a sub-micron grating

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chun-Wei; Wu, Chun-Che; Lin, Shih-Chieh [Department of Power Mechanical Engineering, National Tsing Hua University, 101 Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China)

    2015-04-13

    This paper presents the design and simulation results of a high-precision low-cost refractometer that demonstrates the main advantage of a wide measurement range (1 ≤ n ≤ 2). The proposed design is based on the diffractive properties of sub-micron gratings and Snell's Law. The precision and uncertainty factors of the proposed system were tested and analyzed, revealing that the proposed refractometer demonstrates a wide measurement range with sensitivity of 10{sup −4}.

  8. Mine layout, geological features and seismic hazard.

    CSIR Research Space (South Africa)

    Van Aswegen, G

    1993-01-01

    Full Text Available of seismic radiated energies or seismic moments. It is considered the most comprehensive measure, since it reconstructs the dimension, i.e. a number of degrees of freedom, and the divergence of motion trajectories in those directions. The more negative....2.2. Static circular-crack model........................................................................................55 6.2.3. Asperity model...........................................................................................................55 6...

  9. Light detection and ranging measurements of wake dynamics Part I: One-dimensional Scanning

    DEFF Research Database (Denmark)

    Bingöl, Ferhat; Mann, Jakob; Larsen, Gunner Chr.

    2010-01-01

    of the wake meandering, as well as the instantaneous wake expansion expressed in a meandering frame of reference. The experiment was conducted primarily to test the simple hypothesis that the wake deficit is advected passively by the larger-than-rotor-size eddies in the atmospheric flow, and that the wake...... at the same time widens gradually, primarily because of mixing caused by small-scale atmospheric eddies. In this first paper, we focus on our new measurement technique, and test if the wake meandering follows the wind direction fluctuations, i.e. if it is advected passively in the lateral direction...

  10. Shock initiation of nano-Al/Teflon: High dynamic range pyrometry measurements

    Science.gov (United States)

    Wang, Jue; Bassett, Will P.; Dlott, Dana D.

    2017-02-01

    Laser-launched flyer plates (25 μm thick Cu) were used to impact-initiate reactive materials consisting of 40 nm Al particles embedded in TeflonAF polymer (Al/Teflon) on sapphire substrates at a stoichiometric concentration (2.3:1 Teflon:Al), as well as one-half and one-fourth that concentration. A high dynamic range emission spectrometer was used to time and spectrally resolve the emitted light and to determine graybody temperature histories with nanosecond time resolution. At 0.5 km s-1, first light emission was observed from Teflon, but at 0.6 km s-1, the emission from Al/Teflon became much more intense, so we assigned the impact threshold for Al/Teflon reactions to be 0.6 (±0.1) km s-1. The flyer plates produced a 7 ns duration steady shock drive. Emission from shocked Al/Teflon above threshold consisted of two bursts. At the higher impact velocities, the first burst started 15 ns after impact, peaked at 25 ns, and persisted for 75 ns. The second burst started at a few hundred nanoseconds and lasted until 2 μs. The 15 ns start time was exactly the time the flyer plate velocity dropped to zero after impact with sapphire. The first burst was associated with shock-triggered reactions and the second, occurring at ambient pressure, was associated with combustion of leftover material that did not react during shock. The emission spectrum was found to be a good fit to a graybody at all times, allowing temperature histories to be extracted. At 25 ns, the temperature at 0.7 km s-1 and the one-fourth Al load was 3800 K. Those temperatures increased significantly with impact velocity, up to 4600 K, but did not increase as much with Al load. A steady combustion process at 2800 (±100) K was observed in the microsecond range. The minimal dependence on Al loading indicates that these peak temperatures arise primarily from Al nanoparticles reacting almost independently, since the presence of nearby heat sources had little influence on the peak temperatures.

  11. Measurements of cnidae from sea anemones (Cnidaria: Actiniaria, III: ranges and other measures of statistical dispersion, their interrelations and taxonomic relevance

    Directory of Open Access Journals (Sweden)

    R. B. Williams

    2000-03-01

    Full Text Available This is the third of a series of papers examining the taxonomic relevance of some statistical treatments of measurements of cnidae from sea anemones (Actiniaria. Some cnida lengths from fresh tissue samples (column ectoderm, tentacles or acontia from Nematostella vectensis, Haliplanella lineata, Sagartia elegans, Metridium senile, Cereus pedunculatus, Sagartia troglodytes, Anthopleura thallia, Urticina eques and Sagartiogeton lacerates were measured. Five measures of statistical dispersion (sample standard deviation, coefficient of variation, observed sample range, standard range, and 99% probable maximum value of the standard range were calculated, and their interrelations and potential applications were appraised. It has long been the convention to use the largest and smallest cnida sizes (observed sample range from tissue samples in attempts to establish differences between actiniarian taxa. However, such data do not reflect the true extremes of a population range. In the present study, the 99% probable maximum value of the standard range for a standard abundance of 1,000 gave the greatest and, therefore, the most cautious estimate of a population range of cnida sizes for a species. This maximum standard range is the only measure of dispersion of cnida sizes that may be used validly to demonstrate that anemone specimens are of different species, and then only if there is no overlap between the extreme cnida sizes being compared. However, partial or complete overlaps of cnida size extremes do not necessarily indicate that specimens are conspecific; other taxonomic characters must also be considered. Coefficients of variation may provide valuable clues as to the homogeneity or heterogeneity of samples of cnida measurements. This paper should be read in conjunction with the first two in this series, which address the taxonomic relevance of differences between mean cnida sizes (Williams, 1996, Sci. Mar., 60: 339-351; 1998, Sci. Mar., 62: 361-372.

  12. Design, Manufacture and Testing of Capacitive Pressure Sensors for Low-Pressure Measurement Ranges

    Directory of Open Access Journals (Sweden)

    Vasileios Mitrakos

    2017-02-01

    Full Text Available This article presents the design, manufacture and testing of a capacitive pressure sensor with a high, tunable performance to low compressive loads (<10 kPa and a resolution of less than 0.5 kPa. Such a performance is required for the monitoring of treatment efficacy delivered by compression garments to treat or prevent medical conditions such as deep vein thrombosis, leg ulcers, varicose veins or hypertrophic scars. Current commercial sensors used in such medical applications have been found to be either impractical, costly or of insufficient resolution. A microstructured elastomer film of a polydimethylsiloxane (PDMS blend with a tunable Young’s modulus was used as the force-sensing dielectric medium. The resulting 18 mm × 18 mm parallel-plate capacitive pressure sensor was characterised in the range of 0.8 to 6.5 kPa. The microstructuring of the surface morphology of the elastomer film combined with the tuning of the Young’s modulus of the PDMS blend is demonstrated to enhance the sensor performance achieving a 0.25 kPa pressure resolution and a 10 pF capacitive change under 6.5 kPa compressive load. The resulting sensor holds good potential for the targeted medical application.

  13. Analysis of the properties of targets used in digital close-range photogrammetric measurement

    Science.gov (United States)

    Clarke, Timothy A.

    1994-10-01

    It is common to use some form of targeting in close range photogrammetry as there are seldom enough points on the surface of an object with sufficient contrast. Targets which have been used include: light emitting diodes; black circles on a white background; retro-reflective film; projected laser beams; projected `white light' slides; feature encoded targets; and color targets. This paper discusses the characteristics of targets. In particular the established retro- reflective target and the promising projected laser target are considered as they both offer high signal-to-noise ratios together with optimum target sizes. The performance of the targets are analyzed by use of laboratory tests, for example: (1) a retro-reflective target was placed on a rotating mount with the center of the target located on the axis of rotation and the target monitored by a CCD camera under varying conditions; and (2) a laser target was analyzed by experiments which were designed to indicate the effect of speckle by moving a flat object in a direction perpendicular to the laser beam.

  14. Nanocomposite-Based Microstructured Piezoresistive Pressure Sensors for Low-Pressure Measurement Range

    Directory of Open Access Journals (Sweden)

    Vasileios Mitrakos

    2018-01-01

    Full Text Available Piezoresistive pressure sensors capable of detecting ranges of low compressive stresses have been successfully fabricated and characterised. The 5.5 × 5 × 1.6 mm3 sensors consist of a planar aluminium top electrode and a microstructured bottom electrode containing a two-by-two array of truncated pyramids with a piezoresistive composite layer sandwiched in-between. The responses of two different piezocomposite materials, a Multiwalled Carbon Nanotube (MWCNT-elastomer composite and a Quantum Tunneling Composite (QTC, have been characterised as a function of applied pressure and effective contact area. The MWCNT piezoresistive composite-based sensor was able to detect pressures as low as 200 kPa. The QTC-based sensor was capable of detecting pressures as low as 50 kPa depending on the contact area of the bottom electrode. Such sensors could find useful applications requiring the detection of small compressive loads such as those encountered in haptic sensing or robotics.

  15. The concurrent validity and reliability of the Leg Motion system for measuring ankle dorsiflexion range of motion in older adults

    OpenAIRE

    Romero Morales, Carlos; Calvo Lobo, C?sar; Rodr?guez Sanz, David; Sanz Corbal?n, Irene; Ruiz Ruiz, Beatriz; L?pez L?pez, Daniel

    2017-01-01

    Background New reliable devices for range of motion (ROM) measures in older adults are necessary to improve knowledge about the functional capability in this population. Dorsiflexion ROM limitation is associated with ankle injuries, foot pain, lower limb disorders, loss of balance, gait control disorders and fall risk in older adults. The aim of the present study was to assess the validity and reliability of the Leg Motion device for measuring ankle dorsiflexion ROM in older adults. Methods A...

  16. Reliability and Validity of Electro-Goniometric Range of Motion Measurements in Patients with Hand and Wrist Limitations

    OpenAIRE

    Bashardoust Tajali, Siamak; MacDermid, Joy C.; Grewal, Ruby; Young, Chris

    2016-01-01

    Study Design: Cross-sectional reliability and validity study. Purpose: 1. To determine intrarater, interrater and inter instrument reliabilities and validity of two digital electro goniometry to measure active wrist/finger range of motions (ROMs) in patients with limited motion. 2. To determine intrarater and interrater reliabilities of digital goniometry to measure torques of PIP passive flexion of the index finger in patients with limited motion. Methods: The study was designed in a randomi...

  17. Geophysical surveys and velocimetric measures in the Cerreto di Spoleto (Perugia) area, aiming at a seismic microzoning; Indagini geofisiche e misure velocimetriche finalizzate alla microzonazione sismica dell'area di Cerreto di Spoleto (Perugia)

    Energy Technology Data Exchange (ETDEWEB)

    Bongiovanni, G.; Martino, S.; Paciello, A.; Verrubbi, V. [ENEA, Div. Caratterizzazione dell' Ambiente e del Territorio, Centro Ricerche Csaccia, S. Maria di Galeria, Rome (Italy)

    2001-07-01

    Geophysical prospectings and velocimetric measures, aiming at the seismic microzoning of Cerreto di Spoleto area, are presented. Starting from the data obtained by previous geological-geomechanical surveys, seismic-refraction prospectings were carried on in order to obtain a dynamic characterisation and a geometrical description both of soil and rock materials. The velocimetric measures were performed by temporary free-field arrays, recording both environmental noise and small-magnitude seismic events. The analysis of the obtained records is still in progress, in order to evaluate the local seismic wave amplification. [Italian] Vengono illustrate le indagini geofisiche e le misure velocimetriche condotte nell'area di Cerreto di Spoleto (PG) per la microzonazione sismica. In particolare, sulla base dei dati geologici e geomeccanici precedentemente acquisiti, sono state effettuate indagini di sismica a rifrazione che hanno portato alla caratterizzazione dinamica dei litotipi ed alla definizione delle loro geometrie. Le misure velometriche sono state condotte installando array temporanei in free-field per la registrazione di rumore ambientale ed eventi sismici di piccola magnitudo. E' in corso l'elaborazione delle registrazioni ottenute, finalizzata all'analisi degli effetti di amplificazione sismica locale.

  18. Systematic Study of Acquisition Electronics with a High Dynamic Range for a Beam Loss Measurement System

    CERN Document Server

    Venturini, G G; Effinger, E; Emery, J; Zamantzas, C

    2009-01-01

    A discrete components design for a current digitizer based on the current-to-frequency converter (CFC) principle is currently under development at CERN. The design targets at higher current inputs than similar designs, with a maximum equal to 100mA and a minimum of 1nA, as required by the ionization chamber that will be employed in the Proton Synchrotron and Booster accelerators as well as in the LINAC 4. It allows the acquisition of currents of both polarities without requiring any configuration and provides fractional counts through an ADC to increase resolution. Several architectural choices are considered for the front-end circuit, including charge balance integrators, dual-integrator input stages, integrators with switchable-capacitor. Design approach and measurements are discussed in this article.

  19. Reliability and validity of a weight-bearing measure of ankle dorsiflexion range of motion.

    Science.gov (United States)

    Chisholm, Martin D; Birmingham, Trevor B; Brown, Janet; Macdermid, Joy; Chesworth, Bert M

    2012-01-01

    To examine reliability and validity of the Lunge Test (LT) of dorsiflexion range of motion and determine the impact of different approaches to obtain a score on these parameters. Fifty-three patients with ankle injury/dysfunction provided initial assessment data for cross-sectional convergent and known-groups validity analysis with the Pearson coefficient (r) and paired t-test, respectively; data after 4-8 weeks of treatment for longitudinal validity analysis with coefficient r; and data 3 days later for test-retest reliability using the intra-class correlation coefficient (ICC) and minimal detectable change (MDC). LT scores were determined for the affected leg only (LTAff) and for the difference between the two limbs (LTDiff). Two strategies were used to calculate LT scores: a single series and the mean of three series of lunges. LTs were correlated with the Lower Extremity Functional Scale and Global Foot and Ankle Scale. Reliability coefficients were high (ICC=0.93-0.99). The MDC=1.0/1.5 cm, LTAff/LTDiff, respectively. Cross-sectional validity was confirmed for LTDiff (r=-0.40 to -0.50). Between-limb differences (p<0.05) supported known-groups validity. Longitudinal validity was supported for both LT change scores (r=0.39-0.63). The number of series of lunges used did not impact results. A single series of lunges produces a reliable LT score. From a validity perspective, clinicians should use LTDiff on initial assessment and either LT to assess change.

  20. Romanian Educational Seismic Network Project

    Science.gov (United States)

    Tataru, Dragos; Ionescu, Constantin; Zaharia, Bogdan; Grecu, Bogdan; Tibu, Speranta; Popa, Mihaela; Borleanu, Felix; Toma, Dragos; Brisan, Nicoleta; Georgescu, Emil-Sever; Dobre, Daniela; Dragomir, Claudiu-Sorin

    2013-04-01

    will be installed in several schools in the most important seismic areas (Vrancea, Dobrogea), vulnerable cities (Bucharest, Ploiesti, Iasi) or high populated places (Cluj, Sibiu, Timisoara, Zalău). All the elements of the seismic station are especially designed for educational purposes and can be operated independently by the students and teachers themselves. The first stage of ROEDUSEIS project was centered on the work of achievement of educational materials for all levels of pre-university education (kindergarten, primary, secondary and high school). A study of necessity preceded the achievement of educational materials. This was done through a set of questionnaires for teachers and students sent to participating schools. Their responses formed a feedback instrument for properly materials editing. The topics covered within educational materials include: seismicity (general principles, characteristics of Romanian seismicity, historical local events), structure of the Earth, measuring of earthquakes, seismic hazard and risk.

  1. Application of seismic refraction tomography for subsurface imaging ...

    African Journals Online (AJOL)

    Seismic refraction tomography involves the measurement of the travel times of seismic refracted raypaths in order to define an image of seismic velocity in the intervening ground. This technique was used to estimate the depth to the fresh basement, estimate thickness of the weathered basement and to determine the ...

  2. Dual sightline measurements of MeV range deuterons with neutron and gamma-ray spectroscopy at JET

    DEFF Research Database (Denmark)

    Eriksson, J.; Nocente, M.; Binda, F.

    2015-01-01

    Observations made in a JET experiment aimed at accelerating deuterons to the MeV range by third harmonic radio-frequency (RF) heating coupled into a deuterium beam are reported. Measurements are based on a set of advanced neutron and gamma-ray spectrometers that, for the first time, observe the p...

  3. Reliability of the spin-T cervical goniometer in measuring cervical range of motion in an asymptomatic Indian population.

    Science.gov (United States)

    Agarwal, Shabnam; Allison, Garry T; Singer, Kevin P

    2005-09-01

    To examine the intratester reliability of the Spin-T goniometer, a cervical range of motion device, in a normal Indian population. Subjects comprised 30 healthy adults with mean age of 34 years (range, 18-65 years). The subjects were stabilized in the sitting position and the Spin-T goniometer mounted on the head of the subject. The study design was a within-subject repeated intratester reliability trial conducted for cervical range of motion in 6 directions of movement. Three measurements were taken in each direction (flexion, extension lateral flexion, and lateral rotation) per participant. Reliability coefficients, intraclass correlation coefficients, and 95% confidence interval were derived from repeated-measures analysis of variance (ANOVA). Where differences in ANOVA were detected, a paired t test was conducted and the typical error values and coefficient of variance were calculated. All repeated measures showed high intraclass correlation coefficients (all >0.96, P goniometer proved to be a reliable measuring instrument for cervical range of movement in an Indian population. The use of a laser pointer fixed to the instrument ensured a consistent neutral start position.

  4. Synthesis and Characterization of a Micelle-Based pH Nanosensor with an Unprecedented Broad Measurement Range

    DEFF Research Database (Denmark)

    Ek, Pramod Kumar; Feldborg, Lise N.; Almdal, Kristoffer

    2013-01-01

    ) carboxyfluorescein and a reference fluorophore Alexa 633 to the PAEMA shell region of the micelles. Fluorescence measurements show that these pH nanosensors are sensitive in a surprisingly broad pH range of 3.4–8.0, which is hypothesized to be due to small differences in the individual fluorophores’ local...

  5. Reproducibility of range of motion and muscle strength measurements in patients with hip osteoarthritis – an interrater study

    DEFF Research Database (Denmark)

    Poulsen, Erik; Christensen, Henrik Wulff; Penny, Jeannette Østergaard

    2012-01-01

    ABSTRACT: BACKGROUND: Assessment of range of motion (ROM) and muscle strength is fundamental in the clinical diagnosis of hip osteoarthritis (OA) but reproducibility of these measurements has mostly involved clinicians from secondary care and has rarely reported agreement parameters. Therefore, t...

  6. Linear viscoelasticity of emulsions : II. Measurements of the linear viscoelastic behavior of emulsions in the kilohertz range

    NARCIS (Netherlands)

    Oosterbroek, M.; Mellema, J.; Lopulissa, J.S.

    1981-01-01

    Linear viscoelasticity of emulsions in shear deformation in the kilohertz range is demonstrated experimentally. In order to avoid complications due to inertia effects, emulsions with small droplet sizes are studied. The preliminary measurements are interpreted as being the result of droplet

  7. Relative Orbital Element Estimation and Observability Analysis for Formation Flying Satellites using Inter-Satellite Range Measurements Only

    NARCIS (Netherlands)

    Maessen, D.C.; Gill, E.K.A.

    2010-01-01

    This paper investigates to what extent the relative orbital elements of two satellites flying in formation can be estimated making use of inter-satellite range measurements only. Since the determination of relative orbital elements does not require the orientation of the relative orbit with respect

  8. Muon momentum measurement in ICARUS-T600 LAr-TPC via multiple scattering in few-GeV range

    Science.gov (United States)

    Antonello, M.; Baibussinov, B.; Bellini, V.; Benetti, P.; Boffelli, F.; Bubak, A.; Calligarich, E.; Centro, S.; Cervi, T.; Cesana, A.; Cieslik, K.; Cocco, A. G.; Dabrowska, A.; Dermenev, A.; Falcone, A.; Farnese, C.; Fava, A.; Ferrari, A.; Gibin, D.; Gninenko, S.; Guglielmi, A.; Haranczyk, M.; Holeczek, J.; Janik, M.; Kirsanov, M.; Kisiel, J.; Kochanek, I.; Lagoda, J.; Menegolli, A.; Meng, G.; Montanari, C.; Otwinowski, S.; Picchi, P.; Pietropaolo, F.; Plonski, P.; Rappoldi, A.; Raselli, G. L.; Rossella, M.; Rubbia, C.; Sala, P.; Scaramelli, A.; Sergiampietri, F.; Spanu, M.; Stefan, D.; Sulej, R.; Szarska, M.; Terrani, M.; Torti, M.; Tortorici, F.; Varanini, F.; Ventura, S.; Vignoli, C.; Wang, H.; Yang, X.; Zalewska, A.; Zani, A.; Zaremba, K.

    2017-04-01

    The measurement of muon momentum by Multiple Coulomb Scattering is a crucial ingredient to the reconstruction of νμ CC events in the ICARUS-T600 liquid argon TPC in absence of magnetic field, as in the search for sterile neutrinos at Fermilab where ICARUS will be exposed to ~ 1 GeV Booster neutrino beam. A sample of ~ 1000 stopping muons produced by charged current interactions of CNGS νμ in the surrounding rock at the INFN Gran Sasso underground Laboratory provides an ideal benchmark in the few-GeV range since their momentum can be directly and independently obtained by the calorimetric measurement. Stopping muon momentum in the 0.5-4.5 GeV/c range has been reconstructed via Multiple Coulomb Scattering with resolution ranging from 10 to 25% depending on muon energy, track length and uniformity of the electric field in the drift volume.

  9. Long Range Weather Prediction III: Miniaturized Distributed Sensors for Global Atmospheric Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Teller, E; Leith, C; Canavan, G; Wood, L

    2001-11-13

    impacts of weather involve continuing costs of the order of 1% of GDP, a large fraction of which could be retrieved if high-fidelity predictions of two weeks forward applicability were available. These {approx}$10{sup 2} B annual savings dwarf the <$1 B costs of operating a rational, long-range weather prediction system of the type proposed.

  10. Pose and Shape Reconstruction of a Noncooperative Spacecraft Using Camera and Range Measurements

    Directory of Open Access Journals (Sweden)

    Renato Volpe

    2017-01-01

    Full Text Available Recent interest in on-orbit proximity operations has pushed towards the development of autonomous GNC strategies. In this sense, optical navigation enables a wide variety of possibilities as it can provide information not only about the kinematic state but also about the shape of the observed object. Various mission architectures have been either tested in space or studied on Earth. The present study deals with on-orbit relative pose and shape estimation with the use of a monocular camera and a distance sensor. The goal is to develop a filter which estimates an observed satellite’s relative position, velocity, attitude, and angular velocity, along with its shape, with the measurements obtained by a camera and a distance sensor mounted on board a chaser which is on a relative trajectory around the target. The filter’s efficiency is proved with a simulation on a virtual target object. The results of the simulation, even though relevant to a simplified scenario, show that the estimation process is successful and can be considered a promising strategy for a correct and safe docking maneuver.

  11. Micromachined silicon seismic transducers

    Energy Technology Data Exchange (ETDEWEB)

    Barron, C.C.; Fleming, J.G.; Sniegowski, J.J.; Armour, D.L.; Fleming, R.P.

    1995-08-01

    Batch-fabricated silicon seismic transducers could revolutionize the discipline of CTBT monitoring by providing inexpensive, easily depolyable sensor arrays. Although our goal is to fabricate seismic sensors that provide the same performance level as the current state-of-the-art ``macro`` systems, if necessary one could deploy a larger number of these small sensors at closer proximity to the location being monitored in order to compensate for lower performance. We have chosen a modified pendulum design and are manufacturing prototypes in two different silicon micromachining fabrication technologies. The first set of prototypes, fabricated in our advanced surface- micromachining technology, are currently being packaged for testing in servo circuits -- we anticipate that these devices, which have masses in the 1--10 {mu}g range, will resolve sub-mG signals. Concurrently, we are developing a novel ``mold`` micromachining technology that promises to make proof masses in the 1--10 mg range possible -- our calculations indicate that devices made in this new technology will resolve down to at least sub-{mu}G signals, and may even approach to 10{sup {minus}10} G/{radical}Hz acceleration levels found in the low-earth-noise model.

  12. American marten respond to seismic lines in northern Canada at two spatial scales.

    Science.gov (United States)

    Tigner, Jesse; Bayne, Erin M; Boutin, Stan

    2015-01-01

    Development of hydrocarbon resources across northwest Canada has spurred economic prosperity and generated concerns over impacts to biodiversity. To balance these interests, numerous jurisdictions have adopted management thresholds that allow for limited energy development but minimize undesirable impacts to wildlife. Used for exploration, seismic lines are the most abundant linear feature in the boreal forest and exist at a variety of widths and recovery states. We used American marten (Martes americana) as a model species to measure how line attributes influence species' response to seismic lines, and asked whether responses to individual lines trigger population impacts. Marten response to seismic lines was strongly influenced by line width and recovery state. Compared to forest interiors, marten used open seismic lines ≥ 3 m wide less often, but used open lines ≤ 2 m wide and partially recovered lines ≥ 6 m wide similarly. Marten response to individual line types appeared to trigger population impacts. The probability of occurrence at the home range scale declined with increasing seismic line density, and the inclusion of behavioral response to line density calculations improved model fit. In our top performing model, we excluded seismic lines ≤ 2 m from our calculation of line density, and the probability of occurrence declined > 80% between home ranges with the lowest and highest line densities. Models that excluded seismic lines did not strongly explain occurrence. We show how wildlife-derived metrics can inform regulatory guidelines to increase the likelihood those guidelines meet intended management objectives. With respect to marten, not all seismic lines constitute disturbances, but avoidance of certain line types scales to population impacts. This approach provides the ecological context required to understand cause and effect relationships among socio-economic and ecological conservation goals.

  13. Signal processing and analysis for copper layer thickness measurement within a large variation range in the CMP process

    Science.gov (United States)

    Li, Hongkai; Zhao, Qian; Lu, Xinchun; Luo, Jianbin

    2017-11-01

    In the copper (Cu) chemical mechanical planarization (CMP) process, accurate determination of a process reaching the end point is of great importance. Based on the eddy current technology, the in situ thickness measurement of the Cu layer is feasible. Previous research studies focus on the application of the eddy current method to the metal layer thickness measurement or endpoint detection. In this paper, an in situ measurement system, which is independently developed by using the eddy current method, is applied to the actual Cu CMP process. A series of experiments are done for further analyzing the dynamic response characteristic of the output signal within different thickness variation ranges. In this study, the voltage difference of the output signal is used to represent the thickness of the Cu layer, and we can extract the voltage difference variations from the output signal fast by using the proposed data processing algorithm. The results show that the voltage difference decreases as thickness decreases in the conventional measurement range and the sensitivity increases at the same time. However, it is also found that there exists a thickness threshold, and the correlation is negative, when the thickness is more than the threshold. Furthermore, it is possible that the in situ measurement system can be used within a larger Cu layer thickness variation range by creating two calibration tables.

  14. Neck range of motion measurements using a new three-dimensional motion analysis system: validity and repeatability.

    Science.gov (United States)

    Inokuchi, Haruhi; Tojima, Michio; Mano, Hiroshi; Ishikawa, Yuki; Ogata, Naoshi; Haga, Nobuhiko

    2015-12-01

    Neck movement is important for many activities of daily living (ADL). Neck disorders, such as cervical spondylosis and whiplash can limit neck movement and ADL. The cervical range of motion (CROM) device has been recently used to measure neck range of motion (ROM); however, this measurement includes trunk motion, and therefore does not represent a pure neck ROM measurement. The authors aimed to develop a new method to establish pure neck ROM measurements during flexion, extension, lateral bending, and rotation using a three-dimensional motion analysis system, VICON. Twelve healthy participants were recruited and neck ROMs during flexion, extension, lateral bending, and rotation were measured using VICON and the CROM device. Test-retest repeatability was assessed using interclass correlation coefficients (ICCs), standard error of measurement (SEM), and minimal detectable change (MDC). Validity between two measurements was evaluated using a determination coefficient and Pearson's correlation coefficient. ICCs of neck ROM measured using VICON and the CROM device were all at substantial or almost perfect levels [VICON: ICC(1,2) = 0.786-0.962, the CROM device: ICC(1,2) = 0.736-0.950]. Both SEMs and MDCs were low in all measurement directions (VICON: SEM = 1.3°-4.5°, MDC = 3.6°-12.5°; the CROM device: SEM = 2.2°-3.9°, MDC = 6.1°-10.7°). Determination coefficients (R(2)s) and Pearson's correlation coefficients (rs) between the two measurement methods were high (R(2) = 0.607-0.745, r = 0.779-0.863). VICON is a useful system to measure neck ROMs and evaluate the efficacy of interventions, such as surgery or physiotherapeutic exercise.

  15. A Multi-hop Topology Control Based on Inter-node Range Measurement for Wireless Sensor Networks Node Localization

    Directory of Open Access Journals (Sweden)

    Ali Husein ALASIRY

    2011-10-01

    Full Text Available In centralized range-based localization techniques, sufficiency of inter-node range information received by the base station strongly affects node position estimation results. Successful data aggregation is influenced by link stability of each connection of routes, especially in a multi-hop topology model. In general, measuring the inter-node range is only performed for position determination purposes. This research introduces the use of inter-node range measurement information for link selection in a multi-hop route composition in order to increase the rate of data aggregation. Due to irregularity problems of wireless media, two areas of node communication have been considered. The regular communication area is the area in which other nodes are able to perform symmetrical communication to the node without failure. The irregular area is the area in which other nodes are seldom able to communicate. Due to its instability, some existing methods tried to avoid the irregular area completely. The proposed method, named Virtual Boundaries (VBs prioritizes these areas. The regular communication area’s nodes have high priority to be selected as link vertices; however, when there is no link candidate inside this area, nodes within the irregular area will be selected with respect to their range to the parent node. This technique resulted in a more robust multi-hop topology that can reduce isolated node numbers and increase the percentage of data collected by the base station accordingly.

  16. Assessing the small-strain soil stiffness for offshore wind turbines based on in situ seismic measurements

    NARCIS (Netherlands)

    Versteijlen, W.G.; Van Dalen, K.N.; Metrikine, A.V.; Hamre, L.

    2014-01-01

    The fundamental natural frequency as measured on installed offshore wind turbines is significantly higher than its designed value, and it is expected that the explanation for this can be found in the currently adopted modeling of soil-structure interaction. The small-strain soil stiffness is an

  17. Detection of ULF geomagnetic signals associated with seismic events in Central Mexico using Discrete Wavelet Transform

    Directory of Open Access Journals (Sweden)

    O. Chavez

    2010-12-01

    Full Text Available The geomagnetic observatory of Juriquilla Mexico, located at longitude –100.45° and latitude 20.70°, and 1946 m a.s.l., has been operational since June 2004 compiling geomagnetic field measurements with a three component fluxgate magnetometer. In this paper, the results of the analysis of these measurements in relation to important seismic activity in the period of 2007 to 2009 are presented. For this purpose, we used superposed epochs of Discrete Wavelet Transform of filtered signals for the three components of the geomagnetic field during relative seismic calm, and it was compared with seismic events of magnitudes greater than Ms > 5.5, which have occurred in Mexico. The analysed epochs consisted of 18 h of observations for a dataset corresponding to 18 different earthquakes (EQs. The time series were processed for a period of 9 h prior to and 9 h after each seismic event. This data processing was compared with the same number of observations during a seismic calm. The proposed methodology proved to be an efficient tool to detect signals associated with seismic activity, especially when the seismic events occur in a distance (D from the observatory to the EQ, such that the ratio D/ρ < 1.8 where ρ is the earthquake radius preparation zone. The methodology presented herein shows important anomalies in the Ultra Low Frequency Range (ULF; 0.005–1 Hz, primarily for 0.25 to 0.5 Hz. Furthermore, the time variance (σ2 increases prior to, during and after the seismic event in relation to the coefficient D1 obtained, principally in the Bx (N-S and By (E-W geomagnetic components. Therefore, this paper proposes and develops a new methodology to extract the abnormal signals of the geomagnetic anomalies related to different stages of the EQs.

  18. Polymeric nanosensors for measuring the full dynamic pH range of endosomes and lysosomes in mammalian cells

    DEFF Research Database (Denmark)

    Sun, Honghao; Andresen, Thomas Lars; Benjaminsen, Rikke Vicki

    2009-01-01

    as pH sensitive dyes, which gave a dynamic pH measurement range from 4.1-7.5. Thus, the sensors cover the pH range of almost all intracellular compartments in mammalian cells. Both neutral and cationic polyacrylamide particles were synthesized where (3-acrylamidopropyl) trimethylammonium chloride...... was used to introduce a net positive charge in the cationic particles. It was found that the positively charged particle sensors were internalized spontaneously by HepG2 cancer cells. These new pH nanosensors are potential tools in time resolved quantification of pH in the endocytic pathway of living cells....

  19. SU-F-T-184: 3D Range-Modulator for Scanned Particle Therapy: Development, Monte Carlo Simulations and Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Simeonov, Y; Penchev, P; Ringbaek, T Printz [University of Applied Sciences, Institute of Medical Physics and Radiation Protection, Giessen (Germany); Brons, S [Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg (Germany); Weber, U [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Zink, K [University of Applied Sciences, Institute of Medical Physics and Radiation Protection, Giessen (Germany); University Hospital Giessen-Marburg, Marburg (Germany)

    2016-06-15

    Purpose: Active raster scanning in particle therapy results in highly conformal dose distributions. Treatment time, however, is relatively high due to the large number of different iso-energy layers used. By using only one energy and the so called 3D range-modulator irradiation times of a few seconds only can be achieved, thus making delivery of homogeneous dose to moving targets (e.g. lung cancer) more reliable. Methods: A 3D range-modulator consisting of many pins with base area of 2.25 mm2 and different lengths was developed and manufactured with rapid prototyping technique. The form of the 3D range-modulator was optimised for a spherical target volume with 5 cm diameter placed at 25 cm in a water phantom. Monte Carlo simulations using the FLUKA package were carried out to evaluate the modulating effect of the 3D range-modulator and simulate the resulting dose distribution. The fine and complicated contour form of the 3D range-modulator was taken into account by a specially programmed user routine. Additionally FLUKA was extended with the capability of intensity modulated scanning. To verify the simulation results dose measurements were carried out at the Heidelberg Ion Therapy Center (HIT) with a 400.41 MeV 12C beam. Results: The high resolution measurements show that the 3D range-modulator is capable of producing homogeneous 3D conformal dose distributions, simultaneously reducing significantly irradiation time. Measured dose is in very good agreement with the previously conducted FLUKA simulations, where slight differences were traced back to minor manufacturing deviations from the perfect optimised form. Conclusion: Combined with the advantages of very short treatment time the 3D range-modulator could be an alternative to treat small to medium sized tumours (e.g. lung metastasis) with the same conformity as full raster-scanning treatment. Further simulations and measurements of more complex cases will be conducted to investigate the full potential of the 3D

  20. Seismic behaviour of geotechnical structures

    Directory of Open Access Journals (Sweden)

    F. Vinale

    2002-06-01

    Full Text Available This paper deals with some fundamental considerations regarding the behaviour of geotechnical structures under seismic loading. First a complete definition of the earthquake disaster risk is provided, followed by the importance of performing site-specific hazard analysis. Then some suggestions are provided in regard to adequate assessment of soil parameters, a crucial point to properly analyze the seismic behaviour of geotechnical structures. The core of the paper is centered on a critical review of the analysis methods available for studying geotechnical structures under seismic loadings. All of the available methods can be classified into three main classes, including the pseudo-static, pseudo-dynamic and dynamic approaches, each of which is reviewed for applicability. A more advanced analysis procedure, suitable for a so-called performance-based design approach, is also described in the paper. Finally, the seismic behaviour of the El Infiernillo Dam was investigated. It was shown that coupled elastoplastic dynamic analyses disclose some of the important features of dam behaviour under seismic loading, confirmed by comparing analytical computation and experimental measurements on the dam body during and after a past earthquake.

  1. A Proposal for an Out-of-Range Glycemic Population Health Safety Measure for Older Adults With Diabetes.

    Science.gov (United States)

    Pogach, Leonard; Tseng, Chin-Lin; Soroka, Orysya; Maney, Miriam; Aron, David

    2017-04-01

    To evaluate patient-level glycemic control and facility variation of a proposed out-of-range (OOR) measure (overtreatment [OT] [HbA1c 9% (75 mmol/mol)]) compared with the standard measure (SM) (HbA1c 75 years. The 47.4% of patients 65-75 years met the OOR measure (33.4% OT, 14% UT), and 65.7% met the SM. For patients aged >75 years, rates were 48.1% for OOR (39.2% OT; 8.9% UT) and 73.2% for SM. Facility-level rates for OOR for patients aged 65-75 years ranged from 33.7 to 60.4% (median 47.4%), with a strong inverse correlation (ρ = -0.41) between SM and OOR performance rankings. Among the best-performing 20% facilities on the SM, 14 of 28 ranked in the worst-performing 20% on the OOR measure; 12 of 27 of the worst-performing 20% facilities on the SM ranked in the best-performing 20% on the OOR measure. Facility rankings that are based on an SM (potential benefits) and OOR measure (potential risks) differ substantially. An OOR for high-risk populations can focus quality improvement on individual patient evaluation to reduce the risk for short-term harms. © 2017 by the American Diabetes Association.

  2. Tilted Magnetic Levitation Enables Measurement of the Complete Range of Densities of Materials with Low Magnetic Permeability.

    Science.gov (United States)

    Nemiroski, Alex; Soh, Siowling; Kwok, Sen Wai; Yu, Hai-Dong; Whitesides, George M

    2016-02-03

    Magnetic levitation (MagLev) of diamagnetic or weakly paramagnetic materials suspended in a paramagnetic solution in a magnetic field gradient provides a simple method to measure the density of small samples of solids or liquids. One major limitation of this method, thus far, has been an inability to measure or manipulate materials outside of a narrow range of densities (0.8 g/cm(3) levitated magnetically. Tilting the MagLev device relative to the gravitational vector enables the magnetic force to be decreased (relative to the magnetic force) along the axis of measurement. This approach enables many practical measurements over the entire range of densities observed in matter at ambient conditions-from air bubbles (ρ ≈ 0) to osmium and iridium (ρ ≈ 23 g/cm(3)). The ability to levitate, simultaneously, objects with a broad range of different densities provides an operationally simple method that may find application to forensic science (e.g., for identifying the composition of miscellaneous objects or powders), industrial manufacturing (e.g., for quality control of parts), or resource-limited settings (e.g., for identifying and separating small particles of metals and alloys).

  3. Seismic potential in Italy from integration and comparison of seismic and geodetic strain rates

    Science.gov (United States)

    Angelica, Carmelo; Bonforte, Alessandro; Distefano, Giovanni; Serpelloni, Enrico; Gresta, Stefano

    2013-11-01

    Seismological and geodetic data provide key information about the kinematics and active tectonics of plate margins. Focal solutions enable the determining of the directions in which the current tectonic stress acts when fault rupturing occurs; GPS measurements provide information on the crustal velocity field and on current interseismic strain rates. The comparison of the strain rates resulting from the two datasets provides further insight into how large an area is affected by aseismic deformation, which is a valuable indicator for seismic hazard mitigation and estimation of the seismic potential. In this work, we investigate both seismic and geodetic strain rates and the combined field resulting from the joint inversion of the geodetic and seismic datasets, providing a picture of the overall deformation field and its variation during the last decades. In this way, we try to give an overview of the seismic potential distribution across the Apennines and southern Italy, as a qualitative analysis of space-time variations in the released seismic strain rate, compared to the space-time distribution of the cumulated geodetic strain rate. The results show a variable distribution of the seismic efficiency over Italy. The Southern Apennines shows the greatest seismic potential, highlighting a significantly lower seismicity in the last two decades over an area affected by the highest total strain rates. The Messina Straits and eastern Sicily have a significant seismic potential, together with the Calabrian arc (from the Tindari-Letojanni and central Aeolian islands to the Mt. Pollino area), as a result of seismic gaps with respect to the combined strain rates in the investigated period. This long gap highlights the longer recurrence periods for the strongest earthquakes on this area. The central-northern Apennines and off-shore northern Sicily, show a lower seismic potential than central-southern Apennines, probably due to the more recent seismicity affecting these areas.

  4. Robotization in Seismic Acquisition

    NARCIS (Netherlands)

    Blacquière, G.; Berkhout, A.J.

    2013-01-01

    The amount of sources and detectors in the seismic method follows "Moore’s Law of seismic data acquisition", i.e., it increases approximately by a factor of 10 every 10 years. Therefore automation is unavoidable, leading to robotization of seismic data acquisition. Recently, we introduced a new

  5. Next generation seismic fragility curves for California bridges incorporating the evolution in seismic design philosophy

    Science.gov (United States)

    Ramanathan, Karthik Narayan

    Quantitative and qualitative assessment of the seismic risk to highway bridges is crucial in pre-earthquake planning, and post-earthquake response of transportation systems. Such assessments provide valuable knowledge about a number of principal effects of earthquakes such as traffic disruption of the overall highway system, impact on the regions’ economy and post-earthquake response and recovery, and more recently serve as measures to quantify resilience. Unlike previous work, this study captures unique bridge design attributes specific to California bridge classes along with their evolution over three significant design eras, separated by the historic 1971 San Fernando and 1989 Loma Prieta earthquakes (these events affected changes in bridge seismic design philosophy). This research developed next-generation fragility curves for four multispan concrete bridge classes by synthesizing new knowledge and emerging modeling capabilities, and by closely coordinating new and ongoing national research initiatives with expertise from bridge designers. A multi-phase framework was developed for generating fragility curves, which provides decision makers with essential tools for emergency response, design, planning, policy support, and maximizing investments in bridge retrofit. This framework encompasses generational changes in bridge design and construction details. Parameterized high-fidelity three-dimensional nonlinear analytical models are developed for the portfolios of bridge classes within different design eras. These models incorporate a wide range of geometric and material uncertainties, and their responses are characterized under seismic loadings. Fragility curves were then developed considering the vulnerability of multiple components and thereby help to quantify the performance of highway bridge networks and to study the impact of seismic design principles on the performance within a bridge class. This not only leads to the development of fragility relations

  6. S3 HMBC hetero: Spin-State-Selective HMBC for accurate measurement of long-range heteronuclear coupling constants

    Science.gov (United States)

    Hoeck, Casper; Gotfredsen, Charlotte H.; Sørensen, Ole W.

    2017-02-01

    A novel method, Spin-State-Selective (S3) HMBC hetero, for accurate measurement of heteronuclear coupling constants is introduced. The method extends the S3 HMBC technique for measurement of homonuclear coupling constants by appending a pulse sequence element that interchanges the polarization in 13C-1H methine pairs. This amounts to converting the spin-state selectivity from 1H spin states to 13C spin states in the spectra of long-range coupled 1H spins, allowing convenient measurement of heteronuclear coupling constants similar to other S3 or E.COSY-type methods. As usual in this type of techniques, the accuracy of coupling constant measurement is independent of the size of the coupling constant of interest. The merits of the new method are demonstrated by application to vinyl acetate, the alkaloid strychnine, and the carbohydrate methyl β-maltoside.

  7. Measuring Relativistic effects in the field of the Earth with Laser Ranged Satellites and the LARASE research program

    Science.gov (United States)

    Lucchesi, David; Anselmo, Luciano; Bassan, Massimo; Magnafico, Carmelo; Pardini, Carmen; Peron, Roberto; Pucacco, Giuseppe; Stanga, Ruggero; Visco, Massimo

    2017-04-01

    The main goal of the LARASE (LAser RAnged Satellites Experiment) research program is to obtain refined tests of Einstein's theory of General Relativity (GR) by means of very precise measurements of the round-trip time among a number of ground stations of the International Laser Ranging Service (ILRS) network and a set of geodetic satellites. These measurements are guaranteed by means of the powerful and precise Satellite Laser Ranging (SLR) technique. In particular, a big effort of LARASE is dedicated to improve the dynamical models of the LAGEOS, LAGEOS II and LARES satellites, with the objective to obtain a more precise and accurate determination of their orbit. These activities contribute to reach a final error budget that should be robust and reliable in the evaluation of the main systematic errors sources that come to play a major role in masking the relativistic precession on the orbit of these laser-ranged satellites. These error sources may be of gravitational and non-gravitational origin. It is important to stress that a more accurate and precise orbit determination, based on more reliable dynamical models, represents a fundamental prerequisite in order to reach a sub-mm precision in the root-mean-square of the SLR range residuals and, consequently, to gather benefits in the fields of geophysics and space geodesy, such as stations coordinates knowledge, geocenter determination and the realization of the Earth's reference frame. The results reached over the last year will be presented in terms of the improvements achieved in the dynamical model, in the orbit determination and, finally, in the measurement of the relativistic precessions that act on the orbit of the satellites considered.

  8. Comparative study on three highly sensitive absorption measurement techniques characterizing lithium niobate over its entire transparent spectral range.

    Science.gov (United States)

    Leidinger, M; Fieberg, S; Waasem, N; Kühnemann, F; Buse, K; Breunig, I

    2015-08-24

    We employ three highly sensitive spectrometers: a photoacoustic spectrometer, a photothermal common-path interferometer and a whispering-gallery-resonator-based absorption spectrometer, for a comparative study of measuring the absorption coefficient of nominally transparent undoped, congruently grown lithium niobate for ordinarily and extraordinarily polarized light in the wavelength range from 390 to 3800 nm. The absorption coefficient ranges from below 10(-4) cm(-1) up to 2 cm(-1). Furthermore, we measure the absorption at the Urbach tail as well as the multiphonon edge of the material by a standard grating spectrometer and a Fourier-transform infrared spectrometer, providing for the first time an absorption spectrum of the whole transparency window of lithium niobate. The absorption coefficients obtained by the three highly sensitive and independent methods show good agreement.

  9. Measurement of cervical range of motion (CROM) by electronic CROM goniometer: a test of reliability and validity.

    Science.gov (United States)

    Law, Ellis Yuk Hung; Chiu, Thomas Tai-Wing

    2013-01-01

    To investigate the reliability and validity of the Electronic Cervical Range of Motion (CROM) Goniometer in measurement of cervical spine mobility in adults with and without neck pain. A cross-sectional reliability study was conducted on 54 subjects (26 neck pain and 26 non-neck pain) aged from 20-70 years old. The Numerical Pain Rating Scale and Chinese version of Northwick Park Neck Pain Questionnaire were used to assess neck pain severity and disability respectively. The CROM was measured in sitting position except left to right rotation was measured in supine lying. All the cervical active movements were measured by using the Electronic CROM Goniometer from ARCON TM Functional Capacity Evaluation (FCE) systems. The intra-tester and inter-tester reliability were high in both normal and chronic neck pain groups with ICC coefficients ranged from 0.75-*0.92. There was significant difference in the total CROM between the normal (374.7°) and chronic neck pain group (292.6°). The ACRON cervical goniometer was found to be reliable for measuring cervical mobility in 3 planes for both normal and patient subjects. Construct validity of the goniometer was supported as the test's result documented significant difference in CROM between the control and the neck pain groups.

  10. Reliability and responsiveness of a goniometric device for measuring the range of motion in the dart-throwing motion plane.

    Science.gov (United States)

    Kasubuchi, Kenji; Dohi, Yoshihiro; Fujita, Hiroyuki; Fukumoto, Takahiko

    2018-02-26

    Dart-throwing motion (DTM) is an important component of wrist function and, consequently, has the potential to become an evaluation tool in rehabilitation. However, no measurement method is currently available to reliably measure range of motion (ROM) of the wrist in the DTM plane. To determine the reliability and responsiveness of a goniometric device to measure wrist ROM in the DTM plane. ROM of the wrist in the DTM plane was measured in 70 healthy participants. The intra-class correlation coefficient (ICC) was used to evaluate the relative reliability of measurement, and a Bland-Altman analysis conducted to establish its absolute reliability, including the 95% limits of agreement (95% LOA). The standard error of the measurement (SEM) and minimal detectable change at the 95% confidence level (MDC 95 ) were calculated as measures of responsiveness. The intra-rater ICC was 0.87, and an inter-rater ICC of 0.71. There was no evidence of a fixed or proportional bias. For intra- and inter-rater reliability, 95% LOA ranged from -13.83 to 11.12 and from -17.75 to 16.19, respectively. The SEM and MDC 95 were 4.5° and 12.4°, respectively, for intra-rater reliability, and 6.0° and 16.6°, respectively, for inter-rater reliability. The ROM of the wrist in the DTM plane was measured with fair-to-good reliability and responsiveness and, therefore, has the potential to become an evaluation tool for rehabilitation.

  11. Airborne Measurements of CO2 Column Concentration and Range Using a Pulsed Direct-Detection IPDA Lidar

    Science.gov (United States)

    Abshire, James B.; Ramanathan, Anand; Riris, Haris; Mao, Jianping; Allan, Graham R.; Hasselbrack, William E.; Weaver, Clark J.; Browell, Edward V.

    2013-01-01

    We have previously demonstrated a pulsed direct detection IPDA lidar to measure range and the column concentration of atmospheric CO2. The lidar measures the atmospheric backscatter profiles and samples the shape of the 1,572.33 nm CO2 absorption line. We participated in the ASCENDS science flights on the NASA DC-8 aircraft during August 2011 and report here lidar measurements made on four flights over a variety of surface and cloud conditions near the US. These included over a stratus cloud deck over the Pacific Ocean, to a dry lake bed surrounded by mountains in Nevada, to a desert area with a coal-fired power plant, and from the Rocky Mountains to Iowa, with segments with both cumulus and cirrus clouds. Most flights were to altitudes >12 km and had 5-6 altitude steps. Analyses show the retrievals of lidar range, CO2 column absorption, and CO2 mixing ratio worked well when measuring over topography with rapidly changing height and reflectivity, through thin clouds, between cumulus clouds, and to stratus cloud tops. The retrievals shows the decrease in column CO2 due to growing vegetation when flying over Iowa cropland as well as a sudden increase in CO2 concentration near a coal-fired power plant. For regions where the CO2 concentration was relatively constant, the measured CO2 absorption lineshape (averaged for 50 s) matched the predicted shapes to better than 1% RMS error. For 10 s averaging, the scatter in the retrievals was typically 2-3 ppm and was limited by the received signal photon count. Retrievals were made using atmospheric parameters from both an atmospheric model and from in situ temperature and pressure from the aircraft. The retrievals had no free parameters and did not use empirical adjustments, and >70% of the measurements passed screening and were used in analysis. The differences between the lidar-measured retrievals and in situ measured average CO2 column concentrations were 6 km.

  12. Infrasonic and seismic signals from earthquakes and explosions observed with Plostina seismo-acoustic array

    Science.gov (United States)

    Ghica, D.; Ionescu, C.

    2012-04-01

    Plostina seismo-acoustic array has been recently deployed by the National Institute for Earth Physics in the central part of Romania, near the Vrancea epicentral area. The array has a 2.5 km aperture and consists of 7 seismic sites (PLOR) and 7 collocated infrasound instruments (IPLOR). The array is being used to assess the importance of collocated seismic and acoustic sensors for the purposes of (1) seismic monitoring of the local and regional events, and (2) acoustic measurement, consisting of detection of the infrasound events (explosions, mine and quarry blasts, earthquakes, aircraft etc.). This paper focuses on characterization of infrasonic and seismic signals from the earthquakes and explosions (accidental and mining type). Two Vrancea earthquakes with magnitude above 5.0 were selected to this study: one occurred on 1st of May 2011 (MD = 5.3, h = 146 km), and the other one, on 4th October 2011 (MD = 5.2, h = 142 km). The infrasonic signals from the earthquakes have the appearance of the vertical component of seismic signals. Because the mechanism of the infrasonic wave formation is the coupling of seismic waves with the atmosphere, trace velocity values for such signals are compatible with the characteristics of the various seismic phases observed with PLOR array. The study evaluates and characterizes, as well, infrasound and seismic data recorded from the explosion caused by the military accident produced at Evangelos Florakis Naval Base, in Cyprus, on 11th July 2011. Additionally, seismo-acoustic signals presumed to be related to strong mine and quarry blasts were investigated. Ground truth of mine observations provides validation of this interpretation. The combined seismo-acoustic analysis uses two types of detectors for signal identification: one is the automatic detector DFX-PMCC, applied for infrasound detection and characterization, while the other one, which is used for seismic data, is based on array processing techniques (beamforming and frequency

  13. A Comparison of Antenna Measurements in a Near-Field Range and a Newly Renovated Short-Tapered Chamber

    Science.gov (United States)

    2016-09-01

    Research Laboratory’s (ARL) near-field range (NFR) and tapered anechoic chamber, which has been newly renovated with absorber material . ARL would like...SUPPLEMENTARY NOTES 14. ABSTRACT This study was undertaken to quantify and compare electromagnetic device (i.e., antenna) measurements using the US Army...to know the performance levels with the NFR and the newly renovated, slightly different absorber layout configuration laid out and designed by the

  14. Seismic imaging of a thermohaline staircase in the western tropical North Atlantic

    Directory of Open Access Journals (Sweden)

    I. Fer

    2010-07-01

    Full Text Available Multichannel seismic data acquired in the Lesser Antilles in the western tropical North Atlantic indicate that the seismic reflection method has imaged an oceanic thermohaline staircase. Synthetic acoustic modeling using measured density and sound speed profiles corroborates inferences from the seismic data. In a small portion of the seismic image, laterally coherent, uniform layers are present at depths ranging from 550–700 m and have a separation of ~20 m, with thicknesses increasing with depth. The reflection coefficient, a measure of the acoustic impedance contrasts across these reflective interfaces, is one order of magnitude greater than background noise. Hydrography sampled in previous surveys suggests that the layers are a permanent feature of the region. Spectral analysis of layer horizons in the thermohaline staircase indicates that internal wave activity is anomalously low, suggesting weak internal wave-induced turbulence. Results from two independent measurements, the application of a finescale parameterization to observed high-resolution velocity profiles and direct measurements of turbulent dissipation rate, confirm these low levels of turbulence. The lack of internal wave-induced turbulence may allow for the maintenance of the staircase or may be due to suppression by the double-diffusive convection within the staircase. Our observations show the potential for seismic oceanography to contribute to an improved understanding of occurrence rates and the geographical distribution of thermohaline staircases, and should thereby improve estimates of vertical mixing rates ascribable to salt fingering in the global ocean.

  15. Wireless acquisition of multi-channel seismic data using the Seismobile system

    Science.gov (United States)

    Isakow, Zbigniew

    2017-11-01

    This paper describes the wireless acquisition of multi-channel seismic data using a specialized mobile system, Seismobile, designed for subsoil diagnostics for transportation routes. The paper presents examples of multi-channel seismic records obtained during system tests in a configuration with 96 channels (4 landstreamers of 24-channel) and various seismic sources. Seismic waves were generated at the same point using different sources: a 5-kg hammer, a Gisco's source with a 90-kg pile-driver, and two other the pile-drivers of 45 and 70 kg. Particular attention is paid to the synchronization of source timing, the measurement of geometry by autonomous GPS systems, and the repeatability of triggering measurements constrained by an accelerometer identifying the seismic waveform. The tests were designed to the registration, reliability, and range of the wireless transmission of survey signals. The effectiveness of the automatic numbering of measuring modules was tested as the system components were arranged and fixed to the streamers. After measurements were completed, the accuracy and speed of data downloading from the internal memory (SDHC 32GB WiFi) was determined. Additionally, the functionality of automatic battery recharging, the maximum survey duration, and the reliability of battery discharge signalling were assessed.

  16. The Seismic Alert System of Mexico (SASMEX): Performance and Evolution

    Science.gov (United States)

    Espinosa Aranda, J.

    2013-05-01

    Originally the Seismic Alert System of Mexico (SASMEX) was proposed to integrate the Seismic Alert System of Mexico City (SAS), operating since 1991, with the Seismic Alert System of Oaxaca City (SASO), in services since 2003. And today, after the intense big earthquake activity observed in our world during 2010 and 2011, local governments of Mexico City, Oaxaca Estate, and the Mexican Ministry of the Interior have been promoting the expansion of this technological EEW development. Until 2012 SASMEX better coverage includes 48 new field seismic sensors (FS) deployed over the seismic region of Jalisco, Colima, Michoacan and Puebla, with someone enhancements over Guerrero and Oaxaca, to reach 97 FS. During 2013, 35 new FS has been proposed to SASMEX enhancements covering the Chiapas and Veracruz seismic regions. The SASMEX, with the support of the Mexico Valley Broadcasters Association (ARVM) since 1993, automatically issue Public and Preventive earthquake early warning signals in the Cities of Mexico, Toluca, Acapulco, Chilpancingo, and Oaxaca. The seismic warning range in each case is seated in accordance with local Civil Protection Authorities: Public Alert, if they expect strong earthquake effects, and Preventive Alert one, the effect could be moderated. Now the SASMEX warning time opportunity could be different to the 60 sec. average typically generated when SAS warned earthquake effects coming from Guerrero to Mexico City valley. Mexican EEW issued today reach: 16 Public and 62 Preventive Alert in Mexico City; 25 Public and 19 Preventive Alerts in Oaxaca City; also 14 Public and 4 Preventive Alerts in Acapulco; 14 Public and 5 Preventive Alerts in Chilpancingo. The earthquakes events registered by SASMEX FS until now reach 3448. With the support of private and Federal telecommunications infrastructure like, TELMEX, Federal Electric Commission, and the Mexican Security Ministry, it was developed a redundant communication system with pads to link the different

  17. Mathematical Model and Calibration Experiment of a Large Measurement Range Flexible Joints 6-UPUR Six-Axis Force Sensor

    Directory of Open Access Journals (Sweden)

    Yanzhi Zhao

    2016-08-01

    Full Text Available Nowadays improving the accuracy and enlarging the measuring range of six-axis force sensors for wider applications in aircraft landing, rocket thrust, and spacecraft docking testing experiments has become an urgent objective. However, it is still difficult to achieve high accuracy and large measuring range with traditional parallel six-axis force sensors due to the influence of the gap and friction of the joints. Therefore, to overcome the mentioned limitations, this paper proposed a 6-Universal-Prismatic-Universal-Revolute (UPUR joints parallel mechanism with flexible joints to develop a large measurement range six-axis force sensor. The structural characteristics of the sensor are analyzed in comparison with traditional parallel sensor based on the Stewart platform. The force transfer relation of the sensor is deduced, and the force Jacobian matrix is obtained using screw theory in two cases of the ideal state and the state of flexibility of each flexible joint is considered. The prototype and loading calibration system are designed and developed. The K value method and least squares method are used to process experimental data, and in errors of kind Ι and kind II linearity are obtained. The experimental results show that the calibration error of the K value method is more than 13.4%, and the calibration error of the least squares method is 2.67%. The experimental results prove the feasibility of the sensor and the correctness of the theoretical analysis which are expected to be adopted in practical applications.

  18. Performance Analysis of ToA-Based Positioning Algorithms for Static and Dynamic Targets with Low Ranging Measurements.

    Science.gov (United States)

    Ferreira, André G; Fernandes, Duarte; Catarino, André P; Monteiro, João L

    2017-08-19

    Indoor Positioning Systems (IPSs) for emergency responders is a challenging field attracting researchers worldwide. When compared with traditional indoor positioning solutions, the IPSs for emergency responders stand out as they have to operate in harsh and unstructured environments. From the various technologies available for the localization process, ultra-wide band (UWB) is a promising technology for such systems due to its robust signaling in harsh environments, through-wall propagation and high-resolution ranging. However, during emergency responders' missions, the availability of UWB signals is generally low (the nodes have to be deployed as the emergency responders enter a building) and can be affected by the non-line-of-sight (NLOS) conditions. In this paper, the performance of four typical distance-based positioning algorithms (Analytical, Least Squares, Taylor Series, and Extended Kalman Filter methods) with only three ranging measurements is assessed based on a COTS UWB transceiver. These algorithms are compared based on accuracy, precision and root mean square error (RMSE). The algorithms were evaluated under two environments with different propagation conditions (an atrium and a lab), for static and mobile devices, and under the human body's influence. A NLOS identification and error mitigation algorithm was also used to improve the ranging measurements. The results show that the Extended Kalman Filter outperforms the other algorithms in almost every scenario, but it is affected by the low measurement rate of the UWB system.

  19. The Value of Motion: Patient-Reported Outcome Measures Are Correlated With Range of Motion in Total Ankle Replacement.

    Science.gov (United States)

    Dekker, Travis J; Hamid, Kamran S; Federer, Andrew E; Steele, John R; Easley, Mark E; Nunley, James A; Adams, Samuel B

    2017-12-01

    The proposed benefit of total ankle replacement (TAR) over ankle fusion is preserved ankle motion, thus we hypothesized that an increase in range of motion (ROM) is positively correlated with validated patient-reported outcome measures (PROMs) in individuals receiving TAR. Patients undergoing TAR at a single academic medical center between 2007 and 2013 were evaluated in this study. In addition to a minimum of 2-year follow-up, complete preoperative and postoperative outcome measures for the Foot and Ankle Disability Index (FADI), Short Musculoskeletal Function Assessment (SMFA) Bother and Function Indices, Visual Analog Scale (VAS), and 36-Item Short Form Health Survey (SF-36) were requisite for inclusion. Standardized weightbearing maximum dorsiflexion and plantarflexion sagittal radiographs were obtained and previously described ankle and foot measurements were performed to determine ankle ROM. Eighty-eight patients met inclusion criteria (33 INBONE, 18 Salto-Talaris, 37 STAR). Mean time to final ROM radiographs was 43.8 months (range 24-89 months). All aforementioned PROMs improved between preoperative evaluation and most recent follow-up (  P dorsiflexion was positively associated with FADI, SF-36 MCS, and SMFA Function (  P motion was positively correlated with multiple PROMs. Disease-specific and generic health-related quality of life PROMs demonstrated improvement postoperatively in all domains when evaluating final total range of motion. Patients who undergo TAR for end-stage osteoarthritis with improvement in ROM demonstrate a direct correlation with improved patient-centric metrics and outcome scores. Level III: Retrospective comparative study.

  20. AcquisitionFootprintAttenuationDrivenbySeismicAttributes

    Directory of Open Access Journals (Sweden)

    Cuellar-Urbano Mayra

    2014-04-01

    Full Text Available Acquisition footprint, one of the major problems that PEMEX faces in seismic imaging, is noise highly correlated to the geometric array of sources and receivers used for onshore and offshore seismic acquisitions. It prevails in spite of measures taken during acquisition and data processing. This pattern, throughout the image, is easily confused with geological features and misguides seismic attribute computation. In this work, we use seismic data from PEMEX Exploración y Producción to show the conditioning process for removing random and coherent noise using linear filters. Geometric attributes used in a workflow were computed for obtaining an acquisition footprint noise model and adaptively subtract it from the seismic data.

  1. A wide-frequency range AC magnetometer to measure the specific absorption rate in nanoparticles for magnetic hyperthermia

    Energy Technology Data Exchange (ETDEWEB)

    Garaio, E., E-mail: eneko.garayo@ehu.es [Elektrizitatea eta Elektronika Saila, UPV/EHU, P.K. 644, Bilbao (Spain); Collantes, J.M. [Elektrizitatea eta Elektronika Saila, UPV/EHU, P.K. 644, Bilbao (Spain); Garcia, J.A. [Fisika Aplikatua II Saila, UPV/EHU, P.K. 644, Bilbao (Spain); Plazaola, F. [Elektrizitatea eta Elektronika Saila, UPV/EHU, P.K. 644, Bilbao (Spain); Mornet, S. [Institut de Chimie de la Matière Condensée de Bordeaux, UPR 9048 CNRS / Université de Bordeaux, Bordeaux (France); Couillaud, F. [Résonance Magnétique des Systèmes Biologiques, UMR 5536 CNRS / Université de Bordeaux, Bordeaux (France); Sandre, O., E-mail: olivier.sandre@enscbp.fr [Laboratoire de Chimie des Polymères Organiques, UMR 5629 CNRS / Université de Bordeaux, Bordeaux (France)

    2014-11-15

    Measurement of specific absorption rate (SAR) of magnetic nanoparticles is crucial to assert their potential for magnetic hyperthermia. To perform this task, calorimetric methods are widely used. However, those methods are not very accurate and are difficult to standardize. In this paper, we present AC magnetometry results performed with a lab-made magnetometer that is able to obtain dynamic hysteresis-loops in the AC magnetic field frequency range from 50 kHz to 1 MHz and intensities up to 24 kA m{sup −1}. In this work, SAR values of maghemite nanoparticles dispersed in water are measured by AC magnetometry. The so-obtained values are compared with the SAR measured by calorimetric methods. Both measurements, by calorimetry and magnetometry, are in good agreement. Therefore, the presented AC magnetometer is a suitable way to obtain SAR values of magnetic nanoparticles. - Highlights: • We propose AC magnetometry as a method to measure the specific absorption rate (SAR) of magnetic nanoparticles suitable for magnetic hyperthermia therapy. • We have built a lab-made AC magnetometer, which is able to measure magnetic dynamic hysteresis-loops of nanoparticle dispersions. • The device works with AC magnetic field intensities up to 24 kA m{sup −1} in a frequency range from 75 kHz to 1 MHz. • The SAR values of maghemite nanoparticles around 12 nm in magnetic diameter dispersed in water are measured by the lab-made magnetometer and different calorimetric methods. • Although all methods are in good agreement, several factors (probe location, thermal inertia, losses, etc.) make calorimetric method less accurate than AC magnetometry.

  2. Seismic Recording Characterization of the Makanchi Observatory

    National Research Council Canada - National Science Library

    Komarov, Igor

    1998-01-01

    ...: The contractor shall perform three primary tasks as described in the proposal. The contractor shall characterize seismic noise and measure the power spectral densities of the ambient ground noise at Makanchi...

  3. First evidence for correlations between electron fluxes measured by NOAA-POES satellites and large seismic events

    Energy Technology Data Exchange (ETDEWEB)

    Battiston, Roberto [Dipartimento di Fisica and INFN-Trento Center for Fundamental Physics and Applications (TIPFA), Povo (Italy); Vitale, Vincenzo [Istituto Nazionale di Fisica Nucleare, sez. Perugia and ASI Science Data Center, Frascati (Italy)

    2013-10-15

    We present the result for the search of correlations between the precipitation of low energy electrons (E>0.3MeV) trapped within the Van Allen Belts and earthquakes with magnitude above 5 Richter scale. We used the electron data measured by the NOAA POES 15,16,17 and 18 satellites collected during a period of 13 years, corresponding to about 18 thousands M>5 earthquakes registered in the NEIC catalog of the U.S. Geological Survey. We defined Particle Burst (PB) the fluctuations of electrons counting rate having a probability <1% to be a background fluctuation. Within a time window of ±36 hours, we observe a clear correlation peak at −1.25±0.25 hours. This result is obtained using data driven algorithms independent from specific modelling of the lithosphere-ionosphere coupling and adding the data collected by each POES satellite. The significance of the observed correlation peak is 5.7 s.d. corresponding to a probability of 1.210{sup −6} of being a statistical fluctuation. The observed correlation involves about 1.410{sup −3} of the earthquakes in that period of time. It provides the first statistically convincing evidence for the existence of a detectable coupling mechanism between the lithosphere and the magnetosphere having well defined time characteristics.

  4. Seismic risk perception test

    Science.gov (United States)

    Crescimbene, Massimo; La Longa, Federica; Camassi, Romano; Pino, Nicola Alessandro

    2013-04-01

    The perception of risks involves the process of collecting, selecting and interpreting signals about uncertain impacts of events, activities or technologies. In the natural sciences the term risk seems to be clearly defined, it means the probability distribution of adverse effects, but the everyday use of risk has different connotations (Renn, 2008). The two terms, hazards and risks, are often used interchangeably by the public. Knowledge, experience, values, attitudes and feelings all influence the thinking and judgement of people about the seriousness and acceptability of risks. Within the social sciences however the terminology of 'risk perception' has become the conventional standard (Slovic, 1987). The mental models and other psychological mechanisms which people use to judge risks (such as cognitive heuristics and risk images) are internalized through social and cultural learning and constantly moderated (reinforced, modified, amplified or attenuated) by media reports, peer influences and other communication processes (Morgan et al., 2001). Yet, a theory of risk perception that offers an integrative, as well as empirically valid, approach to understanding and explaining risk perception is still missing". To understand the perception of risk is necessary to consider several areas: social, psychological, cultural, and their interactions. Among the various research in an international context on the perception of natural hazards, it seemed promising the approach with the method of semantic differential (Osgood, C.E., Suci, G., & Tannenbaum, P. 1957, The measurement of meaning. Urbana, IL: University of Illinois Press). The test on seismic risk perception has been constructed by the method of the semantic differential. To compare opposite adjectives or terms has been used a Likert's scale to seven point. The test consists of an informative part and six sections respectively dedicated to: hazard; vulnerability (home and workplace); exposed value (with reference to

  5. Short-range lidar measurement of top fruit tree canopies for pesticide applications research in the United Kingdom

    Science.gov (United States)

    Walklate, Peter J.; Richardson, G. M.; Baker, D. E.; Richards, P. A.; Cross, J. V.

    1997-07-01

    This paper presents the measurements of dwarf and semi-dwarf Cox apple trees with a tractor-mounted LIDAR (light detecting and ranging). An analysis is presented which derives structural parameters of the canopy for use in pesticide spraying research by considering the number flux of LIDAR scans intercepted by the crop in a known spatial segment. LIDAR measurements of the crop area normalized by the horizontal projected area of the crop are compared with measurements derived from a destructive sampling method. The distributions of local crop area density and crop interception probability are also presented. Crop area density distribution can be used to estimate the deposition distribution of spray by utilizing a suitable transport and deposition model. Alternatively, crop interception probability distribution can be used as a first order estimate of the spray deposition distribution by making an analogy between light and spray transmission.

  6. [Research on the range of motion measurement system for spine based on LabVIEW image processing technology].

    Science.gov (United States)

    Li, Xiaofang; Deng, Linhong; Lu, Hu; He, Bin

    2014-08-01

    A measurement system based on the image processing technology and developed by LabVIEW was designed to quickly obtain the range of motion (ROM) of spine. NI-Vision module was used to pre-process the original images and calculate the angles of marked needles in order to get ROM data. Six human cadaveric thoracic spine segments T7-T10 were selected to carry out 6 kinds of loads, including left/right lateral bending, flexion, extension, cis/counterclockwise torsion. The system was used to measure the ROM of segment T8-T9 under the loads from 1 Nm to 5 Nm. The experimental results showed that the system is able to measure the ROM of the spine accurately and quickly, which provides a simple and reliable tool for spine biomechanics investigators.

  7. Ground motion simulations for seismic stations in southern and eastern Romania and seismic hazard assessment

    Science.gov (United States)

    Pavel, Florin; Vacareanu, Radu

    2017-09-01

    This research focuses on the evaluation of soil conditions for seismic stations in southern and eastern Romania, their influence on stochastic finite-fault simulations, and the impact of using them on the seismic hazard assessment. First, the horizontal-to-vertical spectral ratios (HVSR) are evaluated using ground motions recorded in 32 seismic stations during small magnitude ( M W ≤ 6.0) Vrancea seismic events. Most of the seismic stations situated in the southern part of Romania exhibit multiple HVSR peaks over a broad period range. However, only the seismic stations in the eastern-most part of Romania have clear short-period predominant periods. Subsequently, stochastic finite-fault simulations are performed in order to evaluate the influence of the soil conditions on the ground motion amplitudes. The analyses show that the earthquake magnitude has a larger influence on the computed ground motion amplitudes for the short- and medium-period range, while the longer-period spectral ordinates tend to be influenced more by the soil conditions. Next, the impact of the previously evaluated soil conditions on the seismic hazard results for Romania is also investigated. The results reveal a significant impact of the soil conditions on the seismic hazard levels, especially for the sites characterized by long-period amplifications (sites situated mostly in southern Romania), and a less significant influence in the case of sites which have clear short predominant periods.

  8. Earth gravity field modeling and relativistic measurements with laser-ranged satellites and the LARASE research program

    Science.gov (United States)

    Pucacco, Giuseppe; Lucchesi, David; Anselmo, Luciano; Bassan, Massimo; Magnafico, Carmelo; Pardini, Carmen; Peron, Roberto; Stanga, Ruggero; Visco, Massimo

    2017-04-01

    The importance of General Relativity (GR) for space geodesy — and for geodesy in general — is well known since several decades and it has been confirmed by a number of very significant results. For instance, GR plays a fundamental role for the following very notable techniques: Satellite-and-Lunar Laser Ranging (SLR/LLR), Very Long Baseline Interferometry (VLBI), Doppler Orbitography and Radio-positioning Integrated by Satellite (DORIS), and Global Navigation Satellite Systems (GNSS). Each of these techniques is intimately and closely related with both GR and geodesy, i.e. they are linked in a loop where benefits in one field provide positive improvements in the other ones. A common ingredient for a suitable and reliable use of each of these techniques is represented by the knowledge of the Earth's gravitational field, both in its static and temporal dependence. Spaceborne gravimetry, with the inclusion of accelerometers and gradiometers on board dedicated satellites, together with microwave links between satellites and GPS measurements, have allowed a huge improvement in the determination of the Earth's geopotential during the last 15 years. In the near future, further improvements are expected in this knowledge thanks to the inclusion of laser inter-satellite link and the possibility to compare frequency and atomic standards by a direct use of atomic clocks, both on the Earth's surface and in space. Such results will be also important for the possibility to further improve the GR tests and measurements in the field of the Earth with laser-ranged satellites in order to compare the predictions of Einstein's theory with those of other (proposed) relativistic theories for the interpretation of the gravitational interaction. Within the present paper we describe the state of the art of such measurements with geodetic satellites, as the two LAGEOS and LARES, and we discuss the effective impact of the systematic errors of gravitational origin on the measurement of

  9. Entropy measures, entropy estimators, and their performance in quantifying complex dynamics: Effects of artifacts, nonstationarity, and long-range correlations

    Science.gov (United States)

    Xiong, Wanting; Faes, Luca; Ivanov, Plamen Ch.

    2017-06-01

    Entropy measures are widely applied to quantify the complexity of dynamical systems in diverse fields. However, the practical application of entropy methods is challenging, due to the variety of entropy measures and estimators and the complexity of real-world time series, including nonstationarities and long-range correlations (LRC). We conduct a systematic study on the performance, bias, and limitations of three basic measures (entropy, conditional entropy, information storage) and three traditionally used estimators (linear, kernel, nearest neighbor). We investigate the dependence of entropy measures on estimator- and process-specific parameters, and we show the effects of three types of nonstationarities due to artifacts (trends, spikes, local variance change) in simulations of stochastic autoregressive processes. We also analyze the impact of LRC on the theoretical and estimated values of entropy measures. Finally, we apply entropy methods on heart rate variability data from subjects in different physiological states and clinical conditions. We find that entropy measures can only differentiate changes of specific types in cardiac dynamics and that appropriate preprocessing is vital for correct estimation and interpretation. Demonstrating the limitations of entropy methods and shedding light on how to mitigate bias and provide correct interpretations of results, this work can serve as a comprehensive reference for the application of entropy methods and the evaluation of existing studies.

  10. Critical current measurements of high-temperature superconducting short samples at a wide range of temperatures and magnetic fields.

    Science.gov (United States)

    Ma, Hongjun; Liu, Huajun; Liu, Fang; Zhang, Huahui; Ci, Lu; Shi, Yi; Lei, Lei

    2018-01-01

    High-Temperature Superconductors (HTS) are potential materials for high-field magnets, low-loss transmission cables, and Superconducting Magnetic Energy Storage (SMES) due to their high upper critical magnetic field (H c2 ) and critical temperature (T c ). The critical current (I c ) of HTS, which is one of the most important parameters for superconductor application, depends strongly on the magnetic fields and temperatures. A new I c measurement system that can carry out accurate I c measurement for HTS short samples with various temperatures (4.2-80 K), magnetic fields (0-14 T), and angles of the magnetic field (0°-90°) has been developed. The I c measurement system mainly consists of a measurement holder, temperature-control system, background magnet, test cryostat, data acquisition system, and DC power supply. The accuracy of temperature control is better than ±0.1 K over the 20-80 K range and ±0.05 K when measured below 20 K. The maximum current is over 1000 A with a measurement uncertainty of 1%. The system had been successfully used for YBa 2 Cu 3 O 7-x (YBCO) tapes I c determination with different temperatures and magnetic fields.

  11. Current Practices of Measuring and Reference Range Reporting of Free and Total Testosterone in the United States.

    Science.gov (United States)

    Le, Margaret; Flores, David; May, Danica; Gourley, Eric; Nangia, Ajay K

    2016-05-01

    The evaluation and management of male hypogonadism should be based on symptoms and on serum testosterone levels. Diagnostically this relies on accurate testing and reference values. Our objective was to define the distribution of reference values and assays for free and total testosterone by clinical laboratories in the United States. Upper and lower reference values, assay methodology and source of published reference ranges were obtained from laboratories across the country. A standardized survey was reviewed with laboratory staff via telephone. Descriptive statistics were used to tabulate results. We surveyed a total of 120 laboratories in 47 states. Total testosterone was measured in house at 73% of laboratories. At the remaining laboratories studies were sent to larger centralized reference facilities. The mean ± SD lower reference value of total testosterone was 231 ± 46 ng/dl (range 160 to 300) and the mean upper limit was 850 ± 141 ng/dl (range 726 to 1,130). Only 9% of laboratories where in-house total testosterone testing was performed created a reference range unique to their region. Others validated the instrument recommended reference values in a small number of internal test samples. For free testosterone 82% of laboratories sent testing to larger centralized reference laboratories where equilibrium dialysis and/or liquid chromatography with mass spectrometry was done. The remaining laboratories used published algorithms to calculate serum free testosterone. Reference ranges for testosterone assays vary significantly among laboratories. The ranges are predominantly defined by limited population studies of men with unknown medical and reproductive histories. These poorly defined and variable reference values, especially the lower limit, affect how clinicians determine treatment. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  12. Long-range weight functions in fundamental measure theory of the non-uniform hard-sphere fluid.

    Science.gov (United States)

    Hansen-Goos, Hendrik

    2016-06-22

    We introduce long-range weight functions to the framework of fundamental measure theory (FMT) of the non-uniform, single-component hard-sphere fluid. While the range of the usual weight functions is equal to the hard-sphere radius R, the modified weight functions have range 3R. Based on the augmented FMT, we calculate the radial distribution function g(r) up to second order in the density within Percus' test particle theory. Consistency of the compressibility and virial routes on this level allows us to determine the free parameter γ of the theory. As a side result, we obtain a value for the fourth virial coefficient B 4 which deviates by only 0.01% from the exact result. The augmented FMT is tested for the dense fluid by comparing results for g(r) calculated via the test particle route to existing results from molecular dynamics simulations. The agreement at large distances (r  >  6R) is significantly improved when the FMT with long-range weight functions is used. In order to improve agreement close to contact (r  =  2R) we construct a free energy which is based on the accurate Carnahan-Starling equation of state, rather than the Percus-Yevick compressibility equation underlying standard FMT.

  13. Upper Mantle Seismic Anisotropy Patterns around the La Réunion Hotspot deduced from SKS-splitting measurements: Plate, Plume and Ridges signatures

    Science.gov (United States)

    Scholz, John-Robert; Barruol, Guilhem; Fontaine, Fabrice R.; Mazzullo, Alessandro; Montagner, Jean-Paul; Stutzmann, Eléonore; Sigloch, Karin

    2017-04-01

    We present results of upper mantle seismic anisotropy in the Southwest Indian Ocean around the hotspot of La Réunion, deduced from SKS splitting measurements using the 'SplitLab' toolbox. Data analysed in this study were recorded by 20 terrestrial and 57 ocean-bottom three-component seismometers installed in the framework of the RHUM-RUM project (www.rhum-rum.net). Broad-band and wide-band ocean-bottom instruments were deployed around the La Réunion Island and along the Central and Southwest Indian Ridges (deployment: R/V Marion Dufresne, 2012, MD192 - recovery: R/V Meteor, 2013, M101), and recorded for 8 to 13 months. We discuss the anisotropy signatures that are potentially induced by the absolute motion of the African Plate, by the spreading of the Central and Southwest Indian Mid-Ocean Ridges (CIR & SWIR), and by the interaction of the ascending plume with the overlying lithosphere and the neighbouring CIR and SWIR. The observed pattern displays a ridge-parallel anisotropy beneath the SWIR that suggests an along-axis upper mantle flow controlled by the thick and cold lithosphere on both sides of the ridge. We furthermore observe a coherent regional anisotropy pattern between La Réunion and the CIR. Both body and surface wave analysis suggest that this dominant flow is located at asthenospheric depths and could be consistent with a preserved feeding of the ridge by the mantle upwelling associated with the Réunion hotspot, as first proposed by Morgan (1978). Finally, we quantitatively compare the azimuthal anisotropy derived from SKS splitting with those from surface wave data.

  14. Airborne Measurements of CO2 Column Concentration and Range Using a Pulsed Direct-Detection IPDA Lidar

    Directory of Open Access Journals (Sweden)

    James B. Abshire

    2013-12-01

    Full Text Available We have previously demonstrated a pulsed direct detection IPDA lidar to measure range and the column concentration of atmospheric CO2. The lidar measures the atmospheric backscatter profiles and samples the shape of the 1,572.33 nm CO2 absorption line. We participated in the ASCENDS science flights on the NASA DC-8 aircraft during August 2011 and report here lidar measurements made on four flights over a variety of surface and cloud conditions near the US. These included over a stratus cloud deck over the Pacific Ocean, to a dry lake bed surrounded by mountains in Nevada, to a desert area with a coal-fired power plant, and from the Rocky Mountains to Iowa, with segments with both cumulus and cirrus clouds. Most flights were to altitudes >12 km and had 5–6 altitude steps. Analyses show the retrievals of lidar range, CO2 column absorption, and CO2 mixing ratio worked well when measuring over topography with rapidly changing height and reflectivity, through thin clouds, between cumulus clouds, and to stratus cloud tops. The retrievals shows the decrease in column CO2 due to growing vegetation when flying over Iowa cropland as well as a sudden increase in CO2 concentration near a coal-fired power plant. For regions where the CO2 concentration was relatively constant, the measured CO2 absorption lineshape (averaged for 50 s matched the predicted shapes to better than 1% RMS error. For 10 s averaging, the scatter in the retrievals was typically 2–3 ppm and was limited by the received signal photon count. Retrievals were made using atmospheric parameters from both an atmospheric model and from in situ temperature and pressure from the aircraft. The retrievals had no free parameters and did not use empirical adjustments, and >70% of the measurements passed screening and were used in analysis. The differences between the lidar-measured retrievals and in situ measured average CO2 column concentrations were <1.4 ppm for flight measurement altitudes >6

  15. The concurrent validity and reliability of the Leg Motion system for measuring ankle dorsiflexion range of motion in older adults.

    Science.gov (United States)

    Romero Morales, Carlos; Calvo Lobo, César; Rodríguez Sanz, David; Sanz Corbalán, Irene; Ruiz Ruiz, Beatriz; López López, Daniel

    2017-01-01

    New reliable devices for range of motion (ROM) measures in older adults are necessary to improve knowledge about the functional capability in this population. Dorsiflexion ROM limitation is associated with ankle injuries, foot pain, lower limb disorders, loss of balance, gait control disorders and fall risk in older adults. The aim of the present study was to assess the validity and reliability of the Leg Motion device for measuring ankle dorsiflexion ROM in older adults. Adescriptive repeated-measures study was designed to test the reliability of Leg Motion in thirty-three healthy elderly patients older than 65 years. The subjects had to meet the following inclusion and exclusion criteria in their medical records: older than 65 years; no lower extremity injury for at least one year prior to evaluation (meniscopathy, or fractures) and any chronic injuries (e.g., osteoarthritis); no previous hip, knee or ankle surgery; no neuropathic alterations and no cognitive conditions (e.g., Alzheimer's disease or dementia). Participants were recruited through the person responsible for the physiotherapist area from a nursing center. The subjects were evaluated in two different sessions at the same time of day, and there was a break of two weeks between sessions. To test the validity of the Leg Motion system, the participants were measured in a weight-bearing lunge position using a classic goniometer with 1° increments, a smartphone with an inclinometer standard app (iPhone 5S®) with 1° increments and a measuring tape that could measure 0.1 cm. All testing was performed while the patients were barefoot. The researcher had ten years of experience as a physiotherapist using goniometer, tape measure and inclinometer devices. Mean values and standard deviations were as follows: Leg Motion (right 5.15 ± 3.08; left 5.19 ± 2.98), tape measure (right 5.12 ± 3.08; left 5.12 ± 2.80), goniometer (right 45.87° ± 4.98; left 44.50° ± 5.54) and inclinometer app (right

  16. The concurrent validity and reliability of the Leg Motion system for measuring ankle dorsiflexion range of motion in older adults

    Directory of Open Access Journals (Sweden)

    Carlos Romero Morales

    2017-01-01

    Full Text Available Background New reliable devices for range of motion (ROM measures in older adults are necessary to improve knowledge about the functional capability in this population. Dorsiflexion ROM limitation is associated with ankle injuries, foot pain, lower limb disorders, loss of balance, gait control disorders and fall risk in older adults. The aim of the present study was to assess the validity and reliability of the Leg Motion device for measuring ankle dorsiflexion ROM in older adults. Methods Adescriptive repeated-measures study was designed to test the reliability of Leg Motion in thirty-three healthy elderly patients older than 65 years. The subjects had to meet the following inclusion and exclusion criteria in their medical records: older than 65 years; no lower extremity injury for at least one year prior to evaluation (meniscopathy, or fractures and any chronic injuries (e.g., osteoarthritis; no previous hip, knee or ankle surgery; no neuropathic alterations and no cognitive conditions (e.g., Alzheimer’s disease or dementia. Participants were recruited through the person responsible for the physiotherapist area from a nursing center. The subjects were evaluated in two different sessions at the same time of day, and there was a break of two weeks between sessions. To test the validity of the Leg Motion system, the participants were measured in a weight-bearing lunge position using a classic goniometer with 1° increments, a smartphone with an inclinometer standard app (iPhone 5S® with 1° increments and a measuring tape that could measure 0.1 cm. All testing was performed while the patients were barefoot. The researcher had ten years of experience as a physiotherapist using goniometer, tape measure and inclinometer devices. Results Mean values and standard deviations were as follows: Leg Motion (right 5.15 ± 3.08; left 5.19 ± 2.98, tape measure (right 5.12 ± 3.08; left 5.12 ± 2.80, goniometer (right 45.87° ± 4.98; left 44

  17. Validity and intra-rater reliability of an android phone application to measure cervical range-of-motion.

    Science.gov (United States)

    Quek, June; Brauer, Sandra G; Treleaven, Julia; Pua, Yong-Hao; Mentiplay, Benjamin; Clark, Ross Allan

    2014-04-17

    Concurrent validity and intra-rater reliability using a customized Android phone application to measure cervical-spine range-of-motion (ROM) has not been previously validated against a gold-standard three-dimensional motion analysis (3DMA) system. Twenty-one healthy individuals (age:31 ± 9.1 years, male:11) participated, with 16 re-examined for intra-rater reliability 1-7 days later. An Android phone was fixed on a helmet, which was then securely fastened on the participant's head. Cervical-spine ROM in flexion, extension, lateral flexion and rotation were performed in sitting with concurrent measurements obtained from both a 3DMA system and the phone.The phone demonstrated moderate to excellent (ICC = 0.53-0.98, Spearman ρ = 0.52-0.98) concurrent validity for ROM measurements in cervical flexion, extension, lateral-flexion and rotation. However, cervical rotation demonstrated both proportional and fixed bias. Excellent intra-rater reliability was demonstrated for cervical flexion, extension and lateral flexion (ICC = 0.82-0.90), but poor for right- and left-rotation (ICC = 0.05-0.33) using the phone. Possible reasons for the outcome are that flexion, extension and lateral-flexion measurements are detected by gravity-dependent accelerometers while rotation measurements are detected by the magnetometer which can be adversely affected by surrounding magnetic fields. The results of this study demonstrate that the tested Android phone application is valid and reliable to measure ROM of the cervical-spine in flexion, extension and lateral-flexion but not in rotation likely due to magnetic interference. The clinical implication of this study is that therapists should be mindful of the plane of measurement when using the Android phone to measure ROM of the cervical-spine.

  18. Beam-based measurements of long-range transverse wakefields in the Compact Linear Collider main-linac accelerating structure

    Directory of Open Access Journals (Sweden)

    Hao Zha

    2016-01-01

    Full Text Available The baseline design of CLIC (Compact Linear Collider uses X-band accelerating structures for its main linacs. In order to maintain beam stability in multibunch operation, long-range transverse wakefields must be suppressed by 2 orders of magnitude between successive bunches, which are separated in time by 0.5 ns. Such strong wakefield suppression is achieved by equipping every accelerating structure cell with four damping waveguides terminated with individual rf loads. A beam-based experiment to directly measure the effectiveness of this long-range transverse wakefield and benchmark simulations was made in the FACET test facility at SLAC using a prototype CLIC accelerating structure. The experiment showed good agreement with the simulations and a strong suppression of the wakefields with an unprecedented minimum resolution of 0.1  V/(pC mm m.

  19. Measurement of the Range Component Directional Signature in a DRIFT-II Detector using 252Cf Neutrons

    CERN Document Server

    Burgos, S; Forbes, J; Ghag, C; Gold, M; Hagemann, C; Kudryavtsev, V A; Lawson, T B; Loomba, D; Majewski, P; Muna, D; Murphy, A St J; Nicklin, G G; Paling, S M; Petkov, A; Plank, S J S; Robinson, M; Sanghi, N; Snowden-Ifft, D P; Spooner, N J C; Turk, J; Tziaferi, E

    2008-01-01

    The DRIFT collaboration utilizes low pressure gaseous detectors to search for WIMP dark matter with directional signatures. A 252Cf neutron source was placed on each of the principal axes of a DRIFT detector in order to test its ability to measure directional signatures from the three components of very low energy (~keV/amu) recoil ranges. A high trigger threshold and the event selection procedure ensured that only sulfur recoils were analyzed. Sulfur recoils produced in the CS2 target gas by the 252Cf source closely match those expected from massive WIMP induced sulfur recoils. For each orientation of the source a directional signal from the range components was observed, indicating that the detector is directional along all 3 axes. An analysis of these results yields an optimal orientation for DRIFT detectors when searching for a directional signature from WIMPs. Additional energy dependent information is provided to aid in understanding this effect.

  20. Measurements of the conduction of heat in water vapor, nitrogen and mixtures of these gases in an extended temperature range

    Science.gov (United States)

    Frohn, A.; Westerdorf, M.

    Experimental and analytical results are presented from trials with heat conduction in water vapor, nitrogen, and mixtures of the two in a cylindrical heat transfer cell. The pressures examined ranged from 100-0.01 mbar, corresponding to Knudsen numbers of 0.01-100. Formulations are defined for the continuum conditions, the free molecule conditions, the transition region, and the momentum equation solution. Experimentation with an instrumented configuration of an inner and outer cylinder over the temperature range 300-725 K is described, noting the use of a vacuum around the inner, gas-filled container in order to measure the radiative heat losses. The results are useful for predicting heat transfer in high altitude flight or among small droplets in natural fogs, cooling towers, and combustion chambers.

  1. Validity and test-retest reliability of manual goniometers for measuring passive hip range of motion in femoroacetabular impingement patients.

    Directory of Open Access Journals (Sweden)

    Nussbaumer Silvio

    2010-08-01

    Full Text Available Abstract Background The aims of this study were to evaluate the construct validity (known group, concurrent validity (criterion based and test-retest (intra-rater reliability of manual goniometers to measure passive hip range of motion (ROM in femoroacetabular impingement patients and healthy controls. Methods Passive hip flexion, abduction, adduction, internal and external rotation ROMs were simultaneously measured with a conventional goniometer and an electromagnetic tracking system (ETS on two different testing sessions. A total of 15 patients and 15 sex- and age-matched healthy controls participated in the study. Results The goniometer provided greater hip ROM values compared to the ETS (range 2.0-18.9 degrees; P P Conclusions The present study suggests that goniometer-based assessments considerably overestimate hip joint ROM by measuring intersegmental angles (e.g., thigh flexion on trunk for hip flexion rather than true hip ROM. It is likely that uncontrolled pelvic rotation and tilt due to difficulties in placing the goniometer properly and in performing the anatomically correct ROM contribute to the overrating of the arc of these motions. Nevertheless, conventional manual goniometers can be used with confidence for longitudinal assessments in the clinic.

  2. Intra-examiner reliability of measurements of ankle range of motion using a modified inclinometer: a pilot study

    Science.gov (United States)

    Tavares, Patricia; Landsman, Victoria; Wiltshire, Leslie

    2017-01-01

    A modified inclinometer was designed for measuring total ankle range of motion (ROM) in the standing position for a large future study. The purpose of this pilot study was to assess the intra-examiner reliability of this new device in order to see if the examiner would be able to produce equally reliable measurements with this instrument as with a routinely used goniometer. Nineteen young healthy individuals took part in the pilot. The same examiner took the ROM measurements using both devices twice on the same day and one further time 2 or 3 days later. Test-retest reliability was measured using the intraclass correlation coefficient (ICC). The ICC values were 0.86 (95% CI=[0.67; 0.94]) and 0.83 (95% CI=[0.61; 0.93]) for the measurements taken with the goniometer on the same day and for those on two different days. The corresponding values for the modified inclinometer were 0.88 (95% CI=[0.72;0.95]) and 0.81 (95% CI=[0.57; 0.92]). Both instruments were found to have very good test-retest reliability. PMID:28928495

  3. Validity of an Alternate Hand Behind Back Shoulder Range of Motion Measurement in Patients With Shoulder Pain and Movement Dysfunction.

    Science.gov (United States)

    Satpute, Kiran H; Hall, Toby; Adanani, Aditi

    2018-02-23

    The purpose of this study was to determine the criterion-related validity of a novel method of measuring hand behind back (HBB) shoulder range of motion (ROM) for evaluating pain and disability in people with shoulder pain and movement impairment. This cross-sectional study design evaluated shoulder ROM, pain, fear-avoidance beliefs, and disability in 60 people (aged 35-70 years, 31 male) with chronic unilateral shoulder dysfunction (mean duration 15.73 weeks). Shoulder HBB ROM was measured with a bubble inclinometer in a manner that did not require the patient to disrobe. Correlations were sought between HBB ROM and other shoulder movements, as well as scores recorded on the Shoulder Pain and Disability Index (SPADI), visual analogue scale for pain, Fear Avoidance Beliefs Questionnaire (FABQ), and duration of symptoms. Restriction of HBB movement was significantly correlated with SPADI total disability score (r = 0.39, P shoulder movements. These findings suggest that this novel method of measuring HBB ROM could be used as a functional outcome measure in the evaluation of patients with shoulder disorders. This method could be considered as an additional or alternative where there are challenges in measuring HBB because of restrictions in undressing a patient, such as for cultural reasons. Copyright © 2018. Published by Elsevier Inc.

  4. Micro-Viscometer for Measuring Shear-Varying Blood Viscosity over a Wide-Ranging Shear Rate

    Science.gov (United States)

    Kim, Byung Jun; Lee, Seung Yeob; Jee, Solkeun; Atajanov, Arslan; Yang, Sung

    2017-01-01

    In this study, a micro-viscometer is developed for measuring shear-varying blood viscosity over a wide-ranging shear rate. The micro-viscometer consists of 10 microfluidic channel arrays, each of which has a different micro-channel width. The proposed design enables the retrieval of 10 different shear rates from a single flow rate, thereby enabling the measurement of shear-varying blood viscosity with a fixed flow rate condition. For this purpose, an optimal design that guarantees accurate viscosity measurement is selected from a parametric study. The functionality of the micro-viscometer is verified by both numerical and experimental studies. The proposed micro-viscometer shows 6.8% (numerical) and 5.3% (experimental) in relative error when compared to the result from a standard rotational viscometer. Moreover, a reliability test is performed by repeated measurement (N = 7), and the result shows 2.69 ± 2.19% for the mean relative error. Accurate viscosity measurements are performed on blood samples with variations in the hematocrit (35%, 45%, and 55%), which significantly influences blood viscosity. Since the blood viscosity correlated with various physical parameters of the blood, the micro-viscometer is anticipated to be a significant advancement for realization of blood on a chip. PMID:28632151

  5. Measures of range of motion and strength among healthy women with differing quality of lower extremity movement during the lateral step-down test

    National Research Council Canada - National Science Library

    Rabin, Alon; Kozol, Zvi

    2010-01-01

    Cross-sectional. To determine the association between hip and ankle range-of-motion measures, as well as measures of hip muscle strength, with measures of quality of lower extremity movement, as assessed visually...

  6. Impact of blood volume changes within the human skin on the diffuse reflectance measurements in visible and NIR spectral ranges

    Science.gov (United States)

    Zherebtsov, Evgeny; Bykov, Alexander; Popov, Alexey; Doronin, Alexander; Meglinski, Igor

    2017-03-01

    We consider changes in the volume of blood and oxygen saturation caused by a pulse wave and their influence on the diffuse reflectance spectra in the visible/NIR spectral range. CUDA-based Monte-Carlo model was used for routine simulation of detector depth sensitivity (sampling volume) and skin spectra, and their variations associated with physiological changes in the human skin. The results presented in the form of animated graphs of sampling volume changes for scaling of the parameters of the main human skin layers related to the results of experimental measurements are of particular interest for pulse oximetry, photoplethysmography, Doppler flowmetry, reflectance spectroscopy.

  7. Excited state absorption measurement in the 900-1250 nm wavelength range for bismuth-doped silicate fibers.

    Science.gov (United States)

    Yoo, Seongwoo; Kalita, Mridu P; Nilsson, Johan; Sahu, Jayanta

    2009-02-15

    The feasibility of direct laser diode pumping of Bi-doped fiber lasers at the wavelengths of 915 and 975 nm was examined by measuring excited state absorption in Bi-doped silicate fibers for the wavelength range of 900-1250 nm. When the Bi-doped fibers were pumped at 1047 nm a strong excited state absorption was found at 915 and 975 nm, whereas no significant excited state absorption was observed in the 1080 nm pumping band nor in the emission band, approximately 1160 nm, of Bi-doped fiber lasers.

  8. Seismic microzoning in the metropolitan area of Port - au-Prince - complexity of the subsoil

    Science.gov (United States)

    Gilles, R.; Bertil, D.; Belvaux, M.; Roulle, A.; Noury, G.; Prepetit, C.; Jean-Philippe, J.

    2013-12-01

    The magnitude 7.3 earthquake that struck Haiti in January 12, 2010 has caused a lot of damages in surrounding areas epicenter. These damages are due to a lack of knowledge of the Haitian subsoil. To overcome this problem, the LNBTP, the BME and BRGM have agreed to implement a project of seismic microzonation of the metropolitan area of Port-au-Prince which is financed by the Fund for the reconstruction of the country. The seismic microzonation is an important tool for knowledge of seismic risk. It is based on a collection of geological, geotechnical, geophysical and measures and recognition and the campaign of numerous sites. It describes a class of specific soils with associated spectral response. The objective of the microzoning is to identify and map the homogeneous zones of lithology, topography, liquefaction and ground movements. The zoning of lithological sites effect is to identify and map areas with geological and geomechanical consistent and homogeneous seismic response; the objective is to provide, in each area, seismic movements adapted to the ground. This zoning is done in about five steps: 1- Cross-analysis of geological, geotechnical and geophysical information; 2- Such information comprise the existing data collected and the data acquired during the project; 3- Identification of homogeneous areas. 4- Definition of one or more columns of representative soils associated with each zone; 5 - Possible consolidation of area to get the final seismic zoning. 27 zones types were considered for the study of sites effects after the analysis of all geological, geotechnical and geophysical data. For example, for the formation of Delmas, there are 5 areas with soil classes ranging from D to C. Soil columns described in the metropolitan area of Port-au-Prince are processed with the CyberQuake software, which is developed at the BRGM by Modaressi et al. in 1997, to calculate their response to seismic rock solicitation. The seismic motion is determined by 4

  9. Validity of clinical outcome measures to evaluate ankle range of motion during the weight-bearing lunge test.

    Science.gov (United States)

    Hall, Emily A; Docherty, Carrie L

    2017-07-01

    To determine the concurrent validity of standard clinical outcome measures compared to laboratory outcome measure while performing the weight-bearing lunge test (WBLT). Cross-sectional study. Fifty participants performed the WBLT to determine dorsiflexion ROM using four different measurement techniques: dorsiflexion angle with digital inclinometer at 15cm distal to the tibial tuberosity (°), dorsiflexion angle with inclinometer at tibial tuberosity (°), maximum lunge distance (cm), and dorsiflexion angle using a 2D motion capture system (°). Outcome measures were recorded concurrently during each trial. To establish concurrent validity, Pearson product-moment correlation coefficients (r) were conducted, comparing each dependent variable to the 2D motion capture analysis (identified as the reference standard). A higher correlation indicates strong concurrent validity. There was a high correlation between each measurement technique and the reference standard. Specifically the correlation between the inclinometer placement at 15cm below the tibial tuberosity (44.9°±5.5°) and the motion capture angle (27.0°±6.0°) was r=0.76 (p=0.001), between the inclinometer placement at the tibial tuberosity angle (39.0°±4.6°) and the motion capture angle was r=0.71 (p=0.001), and between the distance from the wall clinical measure (10.3±3.0cm) to the motion capture angle was r=0.74 (p=0.001). This study determined that the clinical measures used during the WBLT have a high correlation with the reference standard for assessing dorsiflexion range of motion. Therefore, obtaining maximum lunge distance and inclinometer angles are both valid assessments during the weight-bearing lunge test. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  10. Reliability of knee joint range of motion and circumference measurements after total knee arthroplasty: does tester experience matter?

    DEFF Research Database (Denmark)

    Jakobsen, Thomas Linding; Christensen, Malene; Christensen, Stine Sommer

    2010-01-01

    BACKGROUND AND PURPOSE: Two of the most utilized outcome measures to assess knee joint range of motion (ROM) and intra-articular effusion are goniometry and circumference, respectively. Neither goniometry nor circumference of the knee joint have been examined for both intra-tester and inter......-tester in patients with total knee arthroplasty (TKA). The purpose of this study was to determine the intra-tester and inter-tester reliability of active and passive knee joint ROM and circumference in patients with TKA when administered by physiotherapists (testers) with different clinical experience. METHOD......: The design was an intra-tester, inter-tester and intra-day reliability study. Nineteen outpatients (10 females) having received a TKA were examined by an inexperienced and an experienced physiotherapist. Following a standardized protocol, active and passive knee joint ROM and circumference measurements were...

  11. Distributed vibration sensing on optical fibre: field testing in borehole seismic applications

    Science.gov (United States)

    Frignet, B.; Hartog, A. H.; Mackie, D.; Kotov, O. I.; Liokumovich, L. B.

    2014-05-01

    We describe the measurement of seismic waves in a borehole using distributed vibration sensing conveyed on wireline cable. The optical measurement is compared directly with the results of a multi-level borehole seismic survey with conventional electrical accelerometers.

  12. Seismic data are rich in information about subsurface formations and fluids

    Energy Technology Data Exchange (ETDEWEB)

    Farfour, Mohammed; Yoon, Wang Jung; Kim, Dongshin [Geophysical Prospecting Lab, Energy & Resources Eng., Dept., Chonnam National University, Gwangju (Korea, Republic of); Lee, Jeong-Hwan [Petroleum Engineering Lab, Energy & Resources Eng., Dept., Chonnam National University, Gwangju (Korea, Republic of)

    2016-06-08

    Seismic attributes are defined as any measured or computed information derived from seismic data. Throughout the last decades extensive work has been done in developing variety of mathematical approaches to extract maximum information from seismic data. Nevertheless, geoscientists found that seismic is still mature and rich in information. In this paper a new seismic attribute is introduced. Instantaneous energy seismic attribute is an amplitude based attribute that has the potential to emphasize anomalous amplitude associated with hydrocarbons. Promising results have been obtained from applying the attribute on seismic section traversing hydrocarbon filled sand from Alberta, Canada.

  13. A study on the measurement of wrist motion range using the iPhone 4 gyroscope application.

    Science.gov (United States)

    Kim, Tae Seob; Park, David Dae Hwan; Lee, Young Bae; Han, Dong Gil; Shim, Jeong Su; Lee, Young Jig; Kim, Peter Chan Woo

    2014-08-01

    Measuring the range of motion (ROM) of the wrist is an important physical examination conducted in the Department of Hand Surgery for the purpose of evaluation, diagnosis, prognosis, and treatment of patients. The most common method for performing this task is by using a universal goniometer. This study was performed using 52 healthy participants to compare wrist ROM measurement using a universal goniometer and the iPhone 4 Gyroscope application. Participants did not have previous wrist illnesses and their measured values for wrist motion were compared in each direction. Normal values for wrist ROM are 73 degrees of flexion, 71 degrees of extension, 19 degrees of radial deviation, 33 degrees of ulnar deviation, 140 degrees of supination, and 60 degrees of pronation.The average measurement values obtained using the goniometer were 74.2 (5.1) degrees for flexion, 71.1 (4.9) degrees for extension, 19.7 (3.0) degrees for radial deviation, 34.0 (3.7) degrees for ulnar deviation, 140.8 (5.6) degrees for supination, and 61.1 (4.7) degrees for pronation. The average measurement values obtained using the iPhone 4 Gyroscope application were 73.7 (5.5) degrees for flexion, 70.8 (5.1) degrees for extension, 19.5 (3.0) degrees for radial deviation, 33.7 (3.9) degrees for ulnar deviation, 140.4 (5.7) degrees for supination, and 60.8 (4.9) degrees for pronation. The differences between the measurement values by the Gyroscope application and average value were 0.7 degrees for flexion, -0.2 degrees for extension, 0.5 degrees for radial deviation, 0.7 degrees for ulnar deviation, 0.4 degrees for supination, and 0.8 degrees for pronation. The differences in average value were not statistically significant. The authors introduced a new method of measuring the range of wrist motion using the iPhone 4 Gyroscope application that is simpler to use and can be performed by the patient outside a clinical setting.

  14. Simultaneous seismic and magnetic measurements in the Low-Noise Underground Laboratory (LSBB) of Rustrel, France, during the 2001 January 26 Indian earthquake

    Science.gov (United States)

    Gaffet, S.; Guglielmi, Y.; Virieux, J.; Waysand, G.; Chwala, A.; Stolz, R.; Emblanch, C.; Auguste, M.; Boyer, D.; Cavaillou, A.

    2003-12-01

    Since the decommission of the underground launching control room of the ground-based component of the French nuclear missile system, the whole installation has been turned into a cross-disciplinary underground laboratory. The LSBB is a unique low-noise underground laboratory because of its initial military conception and its location in the regional park of Luberon far from large cities, industry and heavy traffic. The deepest point is 500 m below the surface. At this depth a huge and non-conventional shielded cylindrical capsule is installed with no μ-metal, 1268 m3 in volume, with a residual electromagnetic noise lower than 2 fT Hz-1/2 above 10 Hz. As a result, fluctuations of the Earth's magnetic field under 10 Hz can be recorded at a very low-noise level with a low-Tc SQUID 3-D magnetometer. Taking advantage of the main gallery topology, a broad-band underground seismic array has been deployed since 2001. An analysis of data recorded simultaneously by the seismic underground array and by the magnetometer sensors during the Indian earthquake of 2001 January 26 is presented. Evidence of a magnetic field perturbation induced by the seismic waves at teleseismic distance (6250 km) is supported by a polarization analysis of seismic and magnetic signals. Spectral analysis shows specific frequency bands of perturbation related to physical processes such as ground water flow acceleration within the mountain structure.

  15. Measuring seismicity diversity and anomalies using point process models: case studies before and after the 2016 Kumamoto earthquakes in Kyushu, Japan

    Science.gov (United States)

    Kumazawa, Takao; Ogata, Yosihiko; Tsuruoka, Hiroshi

    2017-12-01

    This paper reviews seismic activity in and around the Kumamoto region before and after the April 16, 2016, Kumamoto earthquake of M7.3 using statistical models such as stationary, two-stage, and non-stationary epidemic-type aftershock sequence (ETAS) models to examine seismicity anomalies. Our findings are summarized as follows. First, most of the earthquake clusters before April 2016 are explained by the stationary ETAS model, except for a few clusters of swarm activity, one of which was remotely induced by the 2011 Tohoku-Oki earthquake (M9). The non-stationary ETAS model describes changes in the rate of background seismicity of swarm activity. Second, we revealed seismic quiescence relative to the stationary ETAS model in the foreshock sequence from the M6.5 earthquake on April 14, 2016, and further in the aftershock activity of the 2000 M5.0 earthquake that occurred in the shallower extension of the M6.5 foreshock zone. Thirdly, the main-fault and two off-fault aftershock clusters of the M7.3 mainshock show different features, caused by static triggering effects of the mainshock and/or effects induced by fault weakening. Finally, the b-value increased stepwise over time during the entire period of foreshocks and aftershocks, the reason of which is explained.

  16. Hydrologic modulation of seismicity in western China 1991-2014

    Science.gov (United States)

    Randolph-Flagg, Noah; Day, Jesse; Manga, Michael; Bürgmann, Roland

    2015-04-01

    Hydrologic loading, changes in pore fluid pressures, solid earth tides, and stresses due to thermoelastic expansion have all been proposed to modulate seismicity in a range of tectonic and climatic settings. Seismicity from 1991-2014 (24,892 events) in western China, between 20° and 60° N and between 105° and 70° E, appears to be seasonally modulated with 50% more shallow events in the spring and fall than the summer and winter. We show that this modulation is statistically significant using Schuster tests, analysis of variance tests, and the multifrequential periodogram approach on complete catalogs, a catalog of repeating earthquakes (Schaff and Richards, JGR, 2011), and declustered catalogs. Leveraging the tectonic and climatic heterogeneity in our study region, we compare each of the proposed causes of modulation to observations. We find that the spatial variation of modulation correlates best with spatial variation in hydrologic loading as measured by the GRACE satellites.

  17. Directions of seismic anisotropy in laboratory models of mantle plumes

    Science.gov (United States)

    Druken, K. A.; Kincaid, C.; Griffiths, R. W.

    2013-07-01

    recent expansion in global seismic anisotropy data provides important new insights about the style of mantle convection. Interpretations of these geophysical measurements rely on complex relationships between mineral physics, seismology, and mantle dynamics. We report on 3-D laboratory experiments using finite strain markers evolving in time-dependent, viscous flow fields to quantify the range in expected anisotropy patterns within buoyant plumes surfacing in a variety of tectonic settings. A surprising result is that laboratory proxies for the olivine fast axis overwhelmingly align tangential to radial outflow in plumes well before reaching the surface. These remarkably robust, and ancient, anisotropy patterns evolve differently in stagnant, translational, and divergent plate tectonic settings and are essentially orthogonal to patterns typically referenced when prospecting for plume signals in seismic data. Results suggest a fundamental change in the mineral physics-seismology-circulation relationship used in accepting or rejecting a plume model.

  18. Using strain rates to forecast seismic hazards

    Science.gov (United States)

    Evans, Eileen

    2017-01-01

    One essential component in forecasting seismic hazards is observing the gradual accumulation of tectonic strain accumulation along faults before this strain is suddenly released as earthquakes. Typically, seismic hazard models are based on geologic estimates of slip rates along faults and historical records of seismic activity, neither of which records actively accumulating strain. But this strain can be estimated by geodesy: the precise measurement of tiny position changes of Earth’s surface, obtained from GPS, interferometric synthetic aperture radar (InSAR), or a variety of other instruments.

  19. Atmospheric-Seismic Effect of Chelyabinsk Meteoroid

    Science.gov (United States)

    Chernogor, L. F.

    2017-06-01

    Purpose: The parameters of the shock-wave source in the atmosphere and seismic oscillations that this source caused are investigated Design/methodology/approach: The atmospheric and seismic processes caused by the passage and explosion of Chelyabinsk meteoroid on February 15, 2013 have been modelled. The model results are compared with the observation results obtained at several seismic stations. Findings: The shock-wave impact duration is shown to be equal to approximately 97 s, and the time delays of the shockwave at the sites of destruction relative to its generation time at altitudes of 23÷53 km are shown to be equal to 77÷295 s in the distance range interval of 23÷84 km. The length of the area destructed by the shock with the access pressure of no less than 0.7 kPa is determined to be equal to 125÷130 km, and its width to 16÷60 km at various parts of the meteoroid path. The regression relation between the duration of the seismic signal and the length of the seismic wave path has been determined. The characteristic scale time of seismic source impact is equal to approximately 40 s. In the 20÷50 -s period range of seismic oscillations, the dependence of the group speed on period is established. The attenuation depth of seismic waves is estimated to be approximately 10÷20 Mm in the frequency range of 0.25÷3.0 Hz, and the Earth’s crust speed to 5.7÷7.0 μm/s. Conclusions: The model and estimation results are in good agreement with the observations.

  20. A comparison of two stretching modalities on lower-limb range of motion measurements in recreational dancers.

    Science.gov (United States)

    Wyon, Matthew; Felton, Lee; Galloway, Shaun

    2009-10-01

    Most stretching techniques are designed to place a "stress" on the musculoskeletal unit that will increase its resting length and range of motion (ROM). Twenty-four adolescent dancers participated in a 6-week intervention program that compared low-intensity stretching (Microstretching) with moderate-intensity static stretching on active and passive ranges of motion. Microstretching is a new modality that reduces the possibility of the parasympathetic system being activated. Repeated measures analysis indicated changes in ROM over the intervention period (p active ROM than the static stretch group (p stretching increases the compliance of any given muscle and therefore increases the range of motion. One main finding of the present study was that throughout a 6-week training program very-low-intensity stretching had a greater positive effect on lower-limb ROM than moderate-intensity static stretching. The most interesting aspect of the study was the greater increase in active ROM compared to passive ROM by the Microstretching group. This suggests that adaptation has occurred within the muscle itself to a greater extent than in structures of the hip joint. Practical application for this technique suggests it is beneficial as a postexercise modality that potentially has a restorative component.

  1. Precise Measurement of the $\\bar{p}p$ Total Cross-Section in the ISR Energy Range

    CERN Multimedia

    2002-01-01

    The major aim of this experiment is the precise measurement of the antiproton-proton total cross-section in the ISR energy range, using the total-rate method. The proton-proton total cross-section is remeasured with the same method and the same apparatus, and a precision of 0.5\\% is expected for both cross-sections. The total-rate method consists in the simultaneous measurement of the total interaction rate and the ISR luminosity. This is done with a set of scintillation-counter hodoscopes covering over 99.99\\% of the solid angle, which are sensitive to over 95\\% of all interactions. In addition to these detectors, small-angle drift-tube hodoscopes are used to measure the differential elastic cross-section as a function of the momentum transfert t. The total cross-section can be measured independently by extrapolating this differential cross-section to the forward direction and invoking the optical theorem. A study of the general features of charged-particle production is performed using finely divided scinti...

  2. Borehole prototype for seismic high-resolution exploration

    Science.gov (United States)

    Giese, Rüdiger; Jaksch, Katrin; Krauß, Felix; Krüger, Kay; Groh, Marco; Jurczyk, Andreas

    2014-05-01

    Target reservoirs for the exploitation of hydrocarbons or hot water for geothermal energy supply can comprise small layered structures, for instance thin layers or faults. The resolution of 2D and 3D surface seismic methods is often not sufficient to determine and locate these structures. Borehole seismic methods like vertical seismic profiling (VSP) and seismic while drilling (SWD) use either receivers or sources within the borehole. Thus, the distance to the target horizon is reduced and higher resolution images of the geological structures can be achieved. Even these methods are limited in their resolution capabilities with increasing target depth. To localize structures more accuracy methods with higher resolution in the range of meters are necessary. The project SPWD -- Seismic Prediction While Drilling aims at s the development of a borehole prototype which combines seismic sources and receivers in one device to improve the seismic resolution. Within SPWD such a prototype has been designed, manufactured and tested. The SPWD-wireline prototype is divided into three main parts. The upper section comprises the electronic unit. The middle section includes the upper receiver, the upper clamping unit as well as the source unit and the lower clamping unit. The lower section consists of the lower receiver unit and the hydraulic unit. The total length of the prototype is nearly seven meters and its weight is about 750 kg. For focusing the seismic waves in predefined directions of the borehole axis the method of phased array is used. The source unit is equipped with four magnetostrictive vibrators. Each can be controlled independently to get a common wave front in the desired direction of exploration. Source signal frequencies up to 5000 Hz are used, which allows resolutions up to one meter. In May and September 2013 field tests with the SPWD-wireline prototype have been carried out at the KTB Deep Crustal Lab in Windischeschenbach (Bavaria). The aim was to proof the

  3. Optimal Sensor Placement for Multiple Target Positioning with Range-Only Measurements in Two-Dimensional Scenarios

    Directory of Open Access Journals (Sweden)

    Joaquin Aranda

    2013-08-01

    Full Text Available The problem of determining the optimal geometric configuration of a sensor network that will maximize the range-related information available for multiple target positioning is of key importance in a multitude of application scenarios. In this paper, a set of sensors that measures the distances between the targets and each of the receivers is considered, assuming that the range measurements are corrupted by white Gaussian noise, in order to search for the formation that maximizes the accuracy of the target estimates. Using tools from estimation theory and convex optimization, the problem is converted into that of maximizing, by proper choice of the sensor positions, a convex combination of the logarithms of the determinants of the Fisher Information Matrices corresponding to each of the targets in order to determine the sensor configuration that yields the minimum possible covariance of any unbiased target estimator. Analytical and numerical solutions are well defined and it is shown that the optimal configuration of the sensors depends explicitly on the constraints imposed on the sensor configuration, the target positions, and the probabilistic distributions that define the prior uncertainty in each of the target positions. Simulation examples illustrate the key results derived.

  4. Multispectral measurement of contrast in tissue-mimicking phantoms in near-infrared spectral range of 650 to 1600 nm.

    Science.gov (United States)

    Salo, Daniel; Zhang, Hairong; Kim, David M; Berezin, Mikhail Y

    2014-08-01

    In order to identify the optimal imaging conditions for the highest spatial contrast in biological tissue, we explored the properties of a tissue-mimicking phantom as a function of the wavelengths in a broad range of near-infrared spectra (650 to 1600 nm). Our customized multispectral hardware, which featured a scanning transmission microscope and imaging spectrographs equipped with silicon and InGaAs charge-coupled diode array detectors, allowed for direct comparison of the Michelson contrast obtained from a phantom composed of a honeycomb grid, Intralipid, and India ink. The measured contrast depended on the size of the grid, luminance, and the wavelength of measurements. We demonstrated that at low thickness of the phantom, a reasonable contrast of the objects can be achieved at any wavelength between 700 and 1400 nm and between 1500 and 1600 nm. At larger thicknesses, such contrast can be achieved mostly between 1200 and 1350 nm. These results suggest that distinguishing biological features in deep tissue and developing contrast agents for in vivo may benefit from imaging in this spectral range.

  5. Evaluation of EIT systems and algorithms for handling full void fraction range in two-phase flow measurement

    Science.gov (United States)

    Jia, Jiabin; Wang, Mi; Faraj, Yousef

    2015-01-01

    In the aqueous-based two-phase flow, if the void fraction of dispersed phase exceeds 0.25, conventional electrical impedance tomography (EIT) produces a considerable error due to the linear approximation of the sensitivity back-projection (SBP) method, which limits the EIT’s wider application in the process industry. In this paper, an EIT sensing system which is able to handle full void fraction range in two-phase flow is reported. This EIT system employs a voltage source, conducts true mutual impedance measurement and reconstructs an online image with the modified sensitivity back-projection (MSBP) algorithm. The capability of the Maxwell relationship to convey full void fraction is investigated. The limitation of the linear sensitivity back-projection method is analysed. The MSBP algorithm is used to derive relative conductivity change in the evaluation. A series of static and dynamic experiments demonstrating the mean void fraction obtained using this EIT system has a good agreement with reference void fractions over the range from 0 to 1. The combination of the new EIT system and MSBP algorithm would significantly extend the applications of EIT in industrial process measurement.

  6. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Joel Walls; M.T. Taner; Naum Derzhi; Gary Mavko; Jack Dvorkin

    2003-12-01

    We have developed and tested technology for a new type of direct hydrocarbon detection. The method uses inelastic rock properties to greatly enhance the sensitivity of surface seismic methods to the presence of oil and gas saturation. These methods include use of energy absorption, dispersion, and attenuation (Q) along with traditional seismic attributes like velocity, impedance, and AVO. Our approach is to combine three elements: (1) a synthesis of the latest rock physics understanding of how rock inelasticity is related to rock type, pore fluid types, and pore microstructure, (2) synthetic seismic modeling that will help identify the relative contributions of scattering and intrinsic inelasticity to apparent Q attributes, and (3) robust algorithms that extract relative wave attenuation attributes from seismic data. This project provides: (1) Additional petrophysical insight from acquired data; (2) Increased understanding of rock and fluid properties; (3) New techniques to measure reservoir properties that are not currently available; and (4) Provide tools to more accurately describe the reservoir and predict oil location and volumes. These methodologies will improve the industry's ability to predict and quantify oil and gas saturation distribution, and to apply this information through geologic models to enhance reservoir simulation. We have applied for two separate patents relating to work that was completed as part of this project.

  7. Analyses of seismic activities and hazards in Laos: A seismicity approach

    Directory of Open Access Journals (Sweden)

    Santi Pailoplee Punya Charusiri

    2017-01-01

    Full Text Available The seismic activities and hazards in People’s Democratic Republic Laos were analyzed using the most up-to-date seismicity data. Both the a- and b-values of the frequency-magnitude distribution model, including the return period of earthquake magnitude in the range of 5.0 - 6.0 Mw, were evaluated spatially in a region that ex­tends 300 km from Laos. Six seismic source zones with different seismic activities were found. Based on these seismic source zones and a suitable attenuation model, seismic hazards were then analyzed in both deterministic and probabilistic scenarios. The deterministic map showed a possible maximum ground shaking up to 0.4 g in Northern Laos, whereas the ground shaking calculated from the probabilistic ap­proach was 90, 70 - 90, and 20 - 40%, respectively, and was higher in the northern part. From these seismic activities and hazard analyses, Laos can be clearly separated into the three hazard zones of north­western, northeastern and southern Laos with a high, medium and low earthquake hazard, respectively. Therefore, effective mitigation plans to reduce the impact of seismic hazards should be formulated and in particular for a number of major prov­inces located in the northern part of Laos.

  8. Use of the t-distribution to construct seismic hazard curves for seismic probabilistic safety assessments

    Energy Technology Data Exchange (ETDEWEB)

    Yee, Eric [KEPCO International Nuclear Graduate School, Dept. of Nuclear Power Plant Engineering, Ulsan (Korea, Republic of)

    2017-03-15

    Seismic probabilistic safety assessments are used to help understand the impact potential seismic events can have on the operation of a nuclear power plant. An important component to seismic probabilistic safety assessment is the seismic hazard curve which shows the frequency of seismic events. However, these hazard curves are estimated assuming a normal distribution of the seismic events. This may not be a strong assumption given the number of recorded events at each source-to-site distance. The use of a normal distribution makes the calculations significantly easier but may underestimate or overestimate the more rare events, which is of concern to nuclear power plants. This paper shows a preliminary exploration into the effect of using a distribution that perhaps more represents the distribution of events, such as the t-distribution to describe data. The integration of a probability distribution with potentially larger tails basically pushes the hazard curves outward, suggesting a different range of frequencies for use in seismic probabilistic safety assessments. Therefore the use of a more realistic distribution results in an increase in the frequency calculations suggesting rare events are less rare than thought in terms of seismic probabilistic safety assessment. However, the opposite was observed with the ground motion prediction equation considered.

  9. A risk-mitigation approach to the management of induced seismicity

    Science.gov (United States)

    Bommer, Julian J.; Crowley, Helen; Pinho, Rui

    2015-04-01

    Earthquakes may be induced by a wide range of anthropogenic activities such as mining, fluid injection and extraction, and hydraulic fracturing. In recent years, the increased occurrence of induced seismicity and the impact of some of these earthquakes on the built environment have heightened both public concern and regulatory scrutiny, motivating the need for a framework for the management of induced seismicity. Efforts to develop systems to enable control of seismicity have not yet resulted in solutions that can be applied with confidence in most cases. The more rational approach proposed herein is based on applying the same risk quantification and mitigation measures that are applied to the hazard from natural seismicity. This framework allows informed decision-making regarding the conduct of anthropogenic activities that may cause earthquakes. The consequent risk, if related to non-structural damage (when re-location is not an option), can be addressed by appropriate financial compensation. If the risk poses a threat to life and limb, then it may be reduced through the application of strengthening measures in the built environment—the cost of which can be balanced against the economic benefits of the activity in question—rather than attempting to ensure that some threshold on earthquake magnitude or ground-shaking amplitude is not exceeded. However, because of the specific characteristics of induced earthquakes—which may occur in regions with little or no natural seismicity—the procedures used in standard earthquake engineering need adaptation and modification for application to induced seismicity.

  10. Seismic data filtering using non-local means algorithm based on structure tensor

    Science.gov (United States)

    Yang, Shuai; Chen, Anqing; Chen, Hongde

    2017-05-01

    Non-Local means algorithm is a new and effective filtering method. It calculates weights of all similar neighborhoods' center points relative to filtering point within searching range by Gaussian weighted Euclidean distance between neighborhoods, then gets filtering point's value by weighted average to complete the filtering operation. In this paper, geometric distance of neighborhood's center point is taken into account in the distance measure calculation, making the non-local means algorithm more reasonable. Furthermore, in order to better protect the geometry structure information of seismic data, we introduce structure tensor that can depict the local geometrical features of seismic data. The coherence measure, which reflects image local contrast, is extracted from the structure tensor, is integrated into the non-local means algorithm to participate in the weight calculation, the control factor of geometry structure similarity is added to form a non-local means filtering algorithm based on structure tensor. The experimental results prove that the algorithm can effectively restrain noise, with strong anti-noise and amplitude preservation effect, improving PSNR and protecting structure information of seismic image. The method has been successfully applied in seismic data processing, indicating that it is a new and effective technique to conduct the structure-preserved filtering of seismic data.

  11. Seismic data filtering using non-local means algorithm based on structure tensor

    Directory of Open Access Journals (Sweden)

    Yang Shuai

    2017-05-01

    Full Text Available Non-Local means algorithm is a new and effective filtering method. It calculates weights of all similar neighborhoods’ center points relative to filtering point within searching range by Gaussian weighted Euclidean distance between neighborhoods, then gets filtering point’s value by weighted average to complete the filtering operation. In this paper, geometric distance of neighborhood’s center point is taken into account in the distance measure calculation, making the non-local means algorithm more reasonable. Furthermore, in order to better protect the geometry structure information of seismic data, we introduce structure tensor that can depict the local geometrical features of seismic data. The coherence measure, which reflects image local contrast, is extracted from the structure tensor, is integrated into the non-local means algorithm to participate in the weight calculation, the control factor of geometry structure similarity is added to form a non-local means filtering algorithm based on structure tensor. The experimental results prove that the algorithm can effectively restrain noise, with strong anti-noise and amplitude preservation effect, improving PSNR and protecting structure information of seismic image. The method has been successfully applied in seismic data processing, indicating that it is a new and effective technique to conduct the structure-preserved filtering of seismic data.

  12. Instrument Correction and Dynamic Site Profile Validation at the Central United States Seismic Observatory, New Madrid Seismic Zone

    Science.gov (United States)

    Brengman, C.; Woolery, E. W.; Wang, Z.; Carpenter, S.

    2016-12-01

    The Central United States Seismic Observatory (CUSSO) is a vertical seismic array located in southwestern Kentucky within the New Madrid seismic zone. It is intended to describe the effects of local geology, including thick sediment overburden, on seismic-wave propagation, particularly strong-motion. The three-borehole array at CUSSO is composed of seismic sensors placed on the surface, and in the bedrock at various depths within the 585 m thick sediment overburden. The array's deep borehole provided a unique opportunity in the northern Mississippi embayment for the direct geological description and geophysical measurement of the complete late Cretaceous-Quaternary sediment column. A seven layer, intra-sediment velocity model is interpreted from the complex, inhomogeneous stratigraphy. The S- and P-wave sediment velocities range between 160 and 875 m/s and between 1000 and 2300 m/s, respectively, with bedrock velocities of 1452 and 3775 m/s, respectively. Cross-correlation and direct comparisons were used to filter out the instrument response and determine the instrument orientation, making CUSSO data ready for analysis, and making CUSSO a viable calibration site for other free-field sensors in the area. The corrected bedrock motions were numerically propagated through the CUSSO soil profile (transfer function) and compared, in terms of both peak acceleration and amplitude spectra, to the recorded surface observations. Initial observations reveal a complex spectral mix of amplification and de-amplification across the array, indicating the site effect in this deep sediment setting is not simply generated by the shallowest layers.

  13. Radiological Assessment of the Sacrofemoral Angle: A Novel Method to Measure the Range of Hip Joint Flexion.

    Science.gov (United States)

    Wei, Xian-Zhao; Xu, Xi-Ming; Wang, Fei; Li, Ming; Wang, Zi-Min

    2015-09-05

    A quantitative and accurate measurement of the range of hip joint flexion (RHF) is necessarily required in the evaluation of disordered or artificial hip joint function. This study aimed to assess a novel method to measure RHF more accurately and objectively. Lateral radiographs were taken of 31 supine men with hip joints extended or flexed. Relevant angles were measured directly from the radiographs. The change in the sacrofemoral angle (SFA) (the angle formed between the axis of the femur and the line tangent to the upper endplate of S1) from hip joint extension to hip joint flexion, was proposed as the RHF. The validity of this method was assessed via concomitant measurements of changes in the femur-horizontal angle (between the axis of the femur and the horizontal line) and the sacrum-horizontal angle (SHA) (between the line tangent to the upper endplate of S1 and the horizontal line), the difference of which should equal the change in the SFA. The mean change in the SFA was 112.5 ± 7.4°, and was independent of participant age, height, weight, or body mass index. The mean changes in the femur-horizontal and SHAs were 123.0 ± 6.4° and 11.4 ± 3.0°, respectively. This confirmed that the change of SFA between hip joint extension and hip joint flexion was equal to the difference between the changes in the femur-horizontal and SHAs. Using the SFA, to evaluate RHF could prevent compromised measurements due to the movements of pelvis and lumbar spine during hip flexion, and is, therefore, a more accurate and objective method with reasonable reliability and validity.

  14. Reliability of knee joint range of motion and circumference measurements after total knee arthroplasty: does tester experience matter?

    Science.gov (United States)

    Jakobsen, Thomas Linding; Christensen, Malene; Christensen, Stine Sommer; Olsen, Marie; Bandholm, Thomas

    2010-09-01

    Two of the most utilized outcome measures to assess knee joint range of motion (ROM) and intra-articular effusion are goniometry and circumference, respectively. Neither goniometry nor circumference of the knee joint have been examined for both intra-tester and inter-tester in patients with total knee arthroplasty (TKA). The purpose of this study was to determine the intra-tester and inter-tester reliability of active and passive knee joint ROM and circumference in patients with TKA when administered by physiotherapists (testers) with different clinical experience. The design was an intra-tester, inter-tester and intra-day reliability study. Nineteen outpatients (10 females) having received a TKA were examined by an inexperienced and an experienced physiotherapist. Following a standardized protocol, active and passive knee joint ROM and circumference measurements were obtained using a universal goniometer and a tape measure, respectively. To establish reliability, intraclass correlation coefficients (ICC(2,1)) and smallest real difference (SRD) were calculated. The knee joint ROM and circumference measurements were generally reliable (ICC > 0.8) within and between physiotherapists (except passive knee extension). Changes in knee joint ROM of more than 6.6 degrees and 10 degrees (except active knee flexion) and knee joint circumference of more than 1.0 cm and 1.63 cm represent a real clinical improvement (SRD) or deterioration for a single individual within and between physiotherapists, respectively. Generally, the experienced tester recorded larger knee joint ROM and lower circumference values than that of the inexperienced tester. In clinical practice, we suggest that repeated knee goniometric and circumferential measurements should be recorded by the same physiotherapist in individual patients with TKA. Tester experience appears not to influence the degree of reliability. (c) 2009 John Wiley & Sons, Ltd.

  15. Seismic Imaging and Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lianjie [Los Alamos National Laboratory

    2012-07-09

    I give an overview of LANL's capability in seismic imaging and monitoring. I present some seismic imaging and monitoring results, including imaging of complex structures, subsalt imaging of Gulf of Mexico, fault/fracture zone imaging for geothermal exploration at the Jemez pueblo, time-lapse imaging of a walkway vertical seismic profiling data for monitoring CO{sub 2} inject at SACROC, and microseismic event locations for monitoring CO{sub 2} injection at Aneth. These examples demonstrate LANL's high-resolution and high-fidelity seismic imaging and monitoring capabilities.

  16. Seismotectonics and seismic Hazard map of Tunisia

    Science.gov (United States)

    Soumaya, Abdelkader; Ben Ayed, Noureddine; Khayati Ammar, Hayet; Kadri, Ali; Zargouni, Fouad; Ghanmi, Mohamed

    2016-04-01

    One natural hazard in Tunisia is caused by earthquakes and one way to measure the shaking risk is the probabilistic seismic-hazard map. The study of seismic hazard and risk assessment in Tunisia started in 1990 within the framework of the National Program for Assessment of Earthquake Risk. Because earthquakes are random events characterized by specific uncertainties, we used a probabilistic method to build the seismic hazard map of Tunisia. Probabilities were derived from the available seismic data and from results of neotectonic, geophysical and geological studies on the main active domains of Tunisia. This map displays earthquake ground motions for various probability levels across Tunisia and it is used in seismic provisions of building codes, insurance rate structures, risk assessment and other public management activities. The product is a seismotectonic map of Tunisia summarizing the available datasets (e.g., active fault, focal mechanism, instrumental and historical seismicity, peak ground acceleration). In addition, we elaborate some thematic seismic hazard maps that represent an important tool for the social and economic development.

  17. Seismotectonic and Seismic Hazard Map of Tunisia

    Science.gov (United States)

    Soumaya, A.; Ben Ayed, N.; Khayati Ammar, H.; Tayech, M.; Ghanmi, M.

    2016-12-01

    One natural hazard in Tunisia is caused by earthquakes and one way to measure the shaking risk is the probabilistic seismic-hazard map. The study of seismic hazard and risk assessment in Tunisia started in 1990 within the framework of the National Program for Assessment of Earthquake Risk. Because earthquakes are random events characterized by specific uncertainties, we used a probabilistic method to build the seismic hazard map of Tunisia. Probabilities were derived from the available seismic data and from results of neotectonic, geophysical and geological studies on the main active domains of Tunisia. This map displays earthquake ground motions for various probability levels across Tunisia and it is used in seismic provisions of building codes, insurance rate structures, risk assessment and other public management activities. The product is a seismotectonic map of Tunisia summarizing the available datasets (e.g., active fault, focal mechanism, instrumental and historical seismicity, peak ground acceleration). In addition, we elaborate some thematic seismic hazard maps that represent an important tool for the social and economic development.

  18. Wide range instantaneous temperature measurements of convective fluid flows by using a schlieren system based in color images

    Science.gov (United States)

    Martínez-González, A.; Moreno-Hernández, D.; Monzón-Hernández, D.; León-Rodríguez, M.

    2017-06-01

    In the schlieren method, the deflection of light by the presence of an inhomogeneous medium is proportional to the gradient of its refractive index. Such deflection, in a schlieren system, is represented by light intensity variations on the observation plane. Then, for a digital camera, the intensity level registered by each pixel depends mainly on the variation of the medium refractive index and the status of the digital camera settings. Therefore, in this study, we regulate the intensity value of each pixel by controlling the camera settings such as exposure time, gamma and gain values in order to calibrate the image obtained to the actual temperature values of a particular medium. In our approach, we use a color digital camera. The images obtained with a color digital camera can be separated on three different color-channels. Each channel corresponds to red, green, and blue color, moreover, each one has its own sensitivity. The differences in sensitivity allow us to obtain a range of temperature values for each color channel. Thus, high, medium and low sensitivity correspond to green, blue, and red color channel respectively. Therefore, by adding up the temperature contribution of each color channel we obtain a wide range of temperature values. Hence, the basic idea in our approach to measure temperature, using a schlieren system, is to relate the intensity level of each pixel in a schlieren image to the corresponding knife-edge position measured at the exit focal plane of the system. Our approach was applied to the measurement of instantaneous temperature fields of the air convection caused by a heated rectangular metal plate and a candle flame. We found that for the metal plate temperature measurements only the green and blue color-channels were required to sense the entire phenomena. On the other hand, for the candle case, the three color-channels were needed to obtain a complete measurement of temperature. In our study, the candle temperature was took as

  19. Measurement of changes in glacier extent in the Rimo glacier, a sub-range of the Karakoram Range, determined from Landsat imagery

    Directory of Open Access Journals (Sweden)

    Prashant Kumar

    2014-01-01

    Full Text Available Accurate estimation of the spatiotemporal surface dynamics is very important for natural resource planning. This paper discusses a novel approach for the study of the surface patterns of a particular glacier Rimo located at 35°21′21″N77°22′05″E, about 20 km northeast of the snout of Siachen. Change detection in multiple images of the same location taken at different time intervals are of widely circulated use due to a large number of applications in various disciplines such as climate change, remote sensing and so on. The proposed technique uses image processing to derive regression models of selected glacier segments, these models are then used to measure area under the curve to estimate the surface area changes of the glacier. The surface area changes thus obtained have also been validated by standard method of pixel counting. With the rise in the global warming, the net change in the surface area of the concerned glacier is estimated using statistical analysis from 1998 to 2011. The results obtained show a fair degree of accuracy as compared to the standard method of pixel counting. We also discuss important pre-processing methods used in extracting the final concerned region of interest from a large satellite imagery of fairly average resolution.

  20. Normal ranges of right ventricular systolic and diastolic strain measures in children: a systematic review and meta-analysis.

    Science.gov (United States)

    Levy, Philip T; Sanchez Mejia, Aura A; Machefsky, Aliza; Fowler, Susan; Holland, Mark R; Singh, Gautam K

    2014-05-01

    Establishment of the range of normal values and associated variations of two-dimensional (2D) speckle-tracking echocardiography (STE)-derived right ventricular (RV) strain is a prerequisite for its routine clinical application in children. The objectives of this study were to perform a meta-analysis of normal ranges of RV longitudinal strain measurements derived by 2D STE in children and to identify confounders that may contribute to differences in reported measures. A systematic review was conducted in PubMed, Embase, Scopus, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov. Search hedges were created to cover the concepts of pediatrics, STE, and the right heart ventricle. Two investigators independently identified and included studies if they reported the 2D STE-derived RV strain measure RV peak global longitudinal strain, peak global longitudinal systolic strain rate, peak global longitudinal early diastolic strain rate, peak global longitudinal late diastolic strain rate, or segmental longitudinal strain at the apical, middle, and basal ventricular levels in healthy children. Quality and reporting of the studies were assessed. The weighted mean was estimated using random effects with 95% confidence intervals (CIs), heterogeneity was assessed using Cochran's Q statistic and the inconsistency index (I(2)), and publication bias was evaluated using funnel plots and Egger's test. Effects of demographic, clinical, equipment, and software variables were assessed in a metaregression. The search identified 226 children from 10 studies. The reported normal mean values of peak global longitudinal strain among the studies varied from -20.80% to -34.10% (mean, -29.03%; 95% CI, -31.52% to -26.54%), peak global longitudinal systolic strain rate varied from -1.30 to -2.40 sec(-1) (mean, -1.88 sec(-1); 95% CI, -2.10 to -1.59 sec(-1)), peak global longitudinal early diastolic strain rate ranged from 1.7 to 2.69 sec(-1) (mean, 2.34 sec(-1); 95% CI, 2

  1. Time-dependent seismic tomography

    Science.gov (United States)

    Julian, B.R.; Foulger, G.R.

    2010-01-01

    Of methods for measuring temporal changes in seismic-wave speeds in the Earth, seismic tomography is among those that offer the highest spatial resolution. 3-D tomographic methods are commonly applied in this context by inverting seismic wave arrival time data sets from different epochs independently and assuming that differences in the derived structures represent real temporal variations. This assumption is dangerous because the results of independent inversions would differ even if the structure in the Earth did not change, due to observational errors and differences in the seismic ray distributions. The latter effect may be especially severe when data sets include earthquake swarms or aftershock sequences, and may produce the appearance of correlation between structural changes and seismicity when the wave speeds are actually temporally invariant. A better approach, which makes it possible to assess what changes are truly required by the data, is to invert multiple data sets simultaneously, minimizing the difference between models for different epochs as well as the rms arrival-time residuals. This problem leads, in the case of two epochs, to a system of normal equations whose order is twice as great as for a single epoch. The direct solution of this system would require twice as much memory and four times as much computational effort as would independent inversions. We present an algorithm, tomo4d, that takes advantage of the structure and sparseness of the system to obtain the solution with essentially no more effort than independent inversions require. No claim to original US government works Journal compilation ?? 2010 RAS.

  2. A new faces scale in pain measurement: a test of bias from current mood, trait affectivity, and scale range.

    Science.gov (United States)

    Elfering, Achim; Grebner, Simone

    2012-01-01

    Faces pain rating scales used among children have been criticized to confound affective states with pain when smiling faces are included. This experimental study is an attempt to examine the possible confounding of affective states with pain when smiling faces are used as part of a faces scale. The meaning of the faces was tested to depend on current mood, current pain, trait affectivity, and inclusion versus exclusion of smiling faces. Sixty-four participants made 6,720 two-categorical pain judgments on faces with different mouth curvature. In multilevel regression analysis, current level of pain and negative trait affectivity biased faces' meaning only when the smiling faces were excluded from the scale. In adults, the new full range faces pain scale including a midpoint neutral face and smiling faces was more robust than the restricted scale. The faces scale that was tested in this study is not applicable for patient measurement but it is an interesting tool for psychological research.

  3. Measurement of performance of thermoacoustic heat pump in a -3 to 160 °C temperature range

    Science.gov (United States)

    Kikuchi, Ryo; Tsuda, Kenichiro; Bassem, Mohamed Mehdi; Ueda, Yuki

    2015-11-01

    A thermoacoustic heat pump was constructed and tested. It was composed of a looped tube, a straight tube, and a regenerator. The looped tube contained the regenerator and was connected to the straight tube. The tubes were filled with nitrogen. When an acoustic wave was input to the tubes, a temperature difference formed along the regenerator. Our experiments showed that this heat pump could work as both a cooler and a heater. This heat pump achieved -39 °C as a cooler and 270 °C as a heater. Using antifreeze liquid and oil as heat media, the cooling and heating performance of the heat pump was measured within the temperature range from -3 to 160 °C.

  4. Blackbody Sources for the Range 100 K to 3500 K for Precision Measurements in Radiometry and Radiation Thermometry

    Science.gov (United States)

    Sapritsky, V. I.; Khlevnoy, B. B.; Khromchenko, V. B.; Ogarev, S. A.; Morozova, S. P.; Lisiansky, B. E.; Samoylov, M. L.; Shapoval, V. I.; Sudarev, K. A.

    2003-09-01

    The paper presents a detailed review of precision blackbodies that are low-, medium-, and high-temperature range sources developed at VNIIOFI during the past 30 years. Low-temperature blackbodies were developed for calibration facilities of spaceborne instruments. Medium-temperature blackbodies are used for radiance temperature and IR radiometric measurements. The high-temperature pyrolitic graphite blackbodies BB3200 and BB3500 were developed for world-leading metrology centers as NIST (USA), PTB (Germany), NPL (Great Britain), VNIIOFI (Russia), CNAM (France) and others for the realization and dissemination of radiometric and radiation temperature scales. The latest modification of the high-temperature blackbody BB3500MP, the large-aperture version (with an opening of up to 16 mm) of the famous BB3500, suitable for holding large fixed-point cells with high-temperature TiC-C and ZrC-C eutectics, is under development.

  5. Scenario based seismic hazard assessment and its application to the seismic verification of relevant buildings

    Science.gov (United States)

    Romanelli, Fabio; Vaccari, Franco; Altin, Giorgio; Panza, Giuliano

    2016-04-01

    The procedure we developed, and applied to a few relevant cases, leads to the seismic verification of a building by: a) use of a scenario based neodeterministic approach (NDSHA) for the calculation of the seismic input, and b) control of the numerical modeling of an existing building, using free vibration measurements of the real structure. The key point of this approach is the strict collaboration, from the seismic input definition to the monitoring of the response of the building in the calculation phase, of the seismologist and the civil engineer. The vibrometry study allows the engineer to adjust the computational model in the direction suggested by the experimental result of a physical measurement. Once the model has been calibrated by vibrometric analysis, one can select in the design spectrum the proper range of periods of interest for the structure. Then, the realistic values of spectral acceleration, which include the appropriate amplification obtained through the modeling of a "scenario" input to be applied to the final model, can be selected. Generally, but not necessarily, the "scenario" spectra lead to higher accelerations than those deduced by taking the spectra from the national codes (i.e. NTC 2008, for Italy). The task of the verifier engineer is to act so that the solution of the verification is conservative and realistic. We show some examples of the application of the procedure to some relevant (e.g. schools) buildings of the Trieste Province. The adoption of the scenario input has given in most of the cases an increase of critical elements that have to be taken into account in the design of reinforcements. However, the higher cost associated with the increase of elements to reinforce is reasonable, especially considering the important reduction of the risk level.

  6. Application of the Two-Step Filter to Process Ranging Measurements for Relative Navigation in an Elliptical Orbit

    Science.gov (United States)

    Garrison, James L.; Axelrad, Penina

    1997-01-01

    This estimator breaks a nonlinear estimation problem into a set of over determined 'first step' states which are linear in the observations and 'second step' states which are ultimately the states of interest. Linear estimation methods are applied to filter the observations and produce the optimal first step state estimate. The 'second step' states are obtained through iterative nonlinear parameter estimation considering the first step states as observations. It has been shown that this process exactly minimizes the least squares cost function for static problems and provides a better solution than the iterated extended Kalman filter (EKF) for dynamic problems. The two step filter is applied in this paper to process range and range rate measurements between the two spacecraft. Details of the application of the two step estimator to this problem will be given, highlighting the use of a test for ill-conditioned covariance estimates that can result from the first order covariance propagation. A comparison will be made between the performance of the two step filter and the IEKF.

  7. 2D and 3D seismic measurements to evaluate the collapse risk of an important prehistoric cave in soft carbonate rock

    Science.gov (United States)

    Leucci, Giovanni; De Giorgi, Lara

    2015-02-01

    The southern part of the Apulia region (the Salento peninsula) has been the site of at least fifteen collapse events due to sinkholes in the last twenty years. The majority of these occurred in "soft" carbonate rocks (calcarenites). Man-made and/or natural cavities are sometimes assets of historical and archaeological significance. This paper provides a methodology for the evaluation of sinkhole hazard in "soft" carbonate rocks, combining seismic and mine engineering methods.Acase study of a natural cavity which is called Grotta delle Veneri is illustrated. For this example the approach was: i) 2D and 3D seismic methods to study the physical-mechanical characteristics of the rock mass that constitutes the roof of the cave; and ii) scaled span empirical analysis in order to evaluate the instability of the crown pillar's caves.

  8. Measurement of near-surface seismic compressional wave velocities using refraction tomography at a proposed construction site on the Presidio of Monterey, California

    Science.gov (United States)

    Powers, Michael H.; Burton, Bethany L.

    2012-01-01

    The U.S. Army Corps of Engineers is determining the feasibility of constructing a new barracks building on the U.S. Army Presidio of Monterey in Monterey, California. Due to the presence of an endangered orchid in the proposed area, invasive techniques such as exploratory drill holes are prohibited. To aid in determining the feasibility, budget, and design of this building, a compressional-wave seismic refraction survey was proposed by the U.S. Geological Survey as an alternative means of investigating the depth to competent bedrock. Two sub-parallel profiles were acquired along an existing foot path and a fence line to minimize impacts on the endangered flora. The compressional-wave seismic refraction tomography data for both profiles indicate that no competent rock classified as non-rippable or marginally rippable exists within the top 30 feet beneath the ground surface.

  9. Seismic strengthening of RC buildings

    OpenAIRE

    TSIONIS Georgios; APOSTOLSKA ROBERTA; TAUCER Fabio

    2014-01-01

    A literature review on the seismic strengthening of reinforced concrete buildings, using steel bracings, infills and shear walls, is presented. Extensive experimental testing and numerical analyses of elements and structures have demonstrated the feasibility and effectiveness of all three measures for the increase of global strength and stiffness. In certain cases, they provide additional energy dissipation and help reducing irregularities. The selection of the most appropriate technique i...

  10. Comparison of geodetic and seismic strain rates in Greece by using a uniform processing approach to campaign GPS measurements over the interval 1994-2000

    Science.gov (United States)

    Rontogianni, Sofia

    2010-12-01

    In this study we rigorously combine 18 old campaign GPS data sets from Greece covering the period 1994-2000. Although the majority of these old datasets have been analyzed and reported previously, it has not been possible to combine them into a single velocity field and apply strain analysis. Here a uniform, final coordinate solution is given by reprocessing 43 global, long-running International GNSS Service (IGS) sites together with 280 local sites. The 221 daily SINEX files are then combined in a least squares approach and the geodetic horizontal velocity field in ITRF2000 and Europe-fixed reference frame is derived. Two methods are used to compute the geodetic strain rates: (i) discrete estimates within contiguous polygons, and (ii) a continuous curvature surface fitted to the velocity field. The seismic hazard potential can be determined by comparing the geodetic and seismic strain rates. The published 300 year earthquake catalogue best describes the major active tectonic features at the scale of geodetic strain determination. The geodetic strain appears larger than the seismic strain for the majority of the region, suggesting that accumulated strain has not yet been released by earthquakes. The geodetic field is consistent with the detailed constraints implied by the observed orientations of faulting as these are given in the 300-year catalogue. We have shown that with the GPS dataset used in this work and following this processing scheme reasonable results can be obtained comparable with more recent studies, CGPS data and by recent earthquake activity.

  11. Measurements and Monte Carlo calculations with the extended-range Bonner sphere spectrometer at high-energy mixed fields

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00406842; Bay, Aurelio; Silari, Marco; Aroua, Abbas

    The use of spectrometry to provide information for neutron radiation protection has become an increasingly important activity over recent years. The need for spectral data arises because neither area survey instruments nor personal dosimeters give the correct dose equivalent results at all neutron energies. It is important therefore to know the spectra of the fields in which these devices are used. One of the systems most commonly employed in neutron spectrometry and dosimetry is the Bonner Sphere Spectrometers (BSS). The extended- range BSS that was used for this work, consists of 7 spheres with an overall response to neutrons up to 2 GeV. A 3He detector is used as a thermal counter in the centre of each sphere. In the context of this thesis the BSS was calibrated in monoenergetic neutron fields at low and intermediate energies. It was also used for measurements in several high energy mixed fields. These measurements have led to the calculation of neutron yields and spectral fluences from unshielded targets....

  12. Measurement and Modeling of Short and Medium Range Order in Amorphous Ta2O5 Thin Films

    Science.gov (United States)

    Shyam, Badri; Stone, Kevin H.; Bassiri, Riccardo; Fejer, Martin M.; Toney, Michael F.; Mehta, Apurva

    2016-08-01

    Amorphous films and coatings are rapidly growing in importance. Yet, there is a dearth of high-quality structural data on sub-micron films. Not understanding how these materials assemble at atomic scale limits fundamental insights needed to improve their performance. Here, we use grazing-incidence x-ray total scattering measurements to examine the atomic structure of the top 50-100 nm of Ta2O5 films; mirror coatings that show high promise to significantly improve the sensitivity of the next generation of gravitational-wave detectors. Our measurements show noticeable changes well into medium range, not only between crystalline and amorphous, but also between as-deposited, annealed and doped amorphous films. It is a further challenge to quickly translate the structural information into insights into mechanisms of packing and disorder. Here, we illustrate a modeling approach that allows translation of observed structural features to a physically intuitive packing of a primary structural unit based on a kinked Ta-O-Ta backbone. Our modeling illustrates how Ta-O-Ta units link to form longer 1D chains and even 2D ribbons, and how doping and annealing influences formation of 2D order. We also find that all the amorphousTa2O5 films studied in here are not just poorly crystalline but appear to lack true 3D order.

  13. Site effects in the Amatrice municipality through dense seismic network and detailed geological-geophysical survey

    Science.gov (United States)

    Cultrera, Giovanna; Cardinali, Mauro; de Franco, Roberto; Gallipoli, Maria Rosaria; Pacor, Francesca; Pergalani, Floriana; Milana, Giuliano; Moscatelli, Massimiliano

    2017-04-01

    After the first mainshock of the 2016 Central Italy seismic sequence, several Italian Institutions (under the umbrella of the Italian Center for Seismic Microzonation; http://www.centromicrozonazionesismica.it) conducted a preparatory survey to seismic microzonation of the Amatrice municipality, badly affected by the Mw 6.0 Amatrice earthquake of August 24. Despite the difficulties due to the heavily damaged investigated area and the winter weather condition, a large amount of different data were gathered in a very short time: (i) geological and geomorphological surveys (field trip and photo-geological interpretation), (ii) geophysical measurements (noise single-station and arrays, geoelectric, seismic refraction, MASW), and (iii) continuous seismic recordings from temporary network. In particular, 35 seismic stations were installed from half-September to early-December in an area of 170 km2, equipped with both velocimeter and accelerometer. They recorded thousands of earthquakes, including the Mw 6.5 of October 30, 2016; the continuous data will be organized in the EIDA repository (http://www.orfeus-eu.org/data/eida) through the INGV EIDA-node. The sites selection was performed according to the following criteria: representativeness of the geological conditions of 26 hamlets that experienced a damage level greater than VII MCS degree, optimization of the network geometry for array analysis, redundancy of bedrock reference sites, safety and accessibility. The photo-geology and the field investigations allowed the realization of a detailed geological-technical map of the area, characterized by peculiar features, namely the distinction between bedrock and Quaternary deposits (alluvial deposits and terraces, alluvial fans, landslides) and morpho-structural features (faults, folds, bedding attitude). Preliminary results allowed also the evaluation of the velocity models that show surface shear wave velocities (Vs) ranging from 200 m/s to 600 m/s. Data analysis of

  14. Airborne Light Detection and Ranging (LiDAR for Individual Tree Stem Location, Height, and Biomass Measurements

    Directory of Open Access Journals (Sweden)

    Michael G. Wing

    2011-11-01

    Full Text Available Light Detection and Ranging (LiDAR remote sensing has demonstrated potential in measuring forest biomass. We assessed the ability of LiDAR to accurately estimate forest total above ground biomass (TAGB on an individual stem basis in a conifer forest in the US Pacific Northwest region using three different computer software programs and compared results to field measurements. Software programs included FUSION, TreeVaW, and watershed segmentation. To assess the accuracy of LiDAR TAGB estimation, stem counts and heights were analyzed. Differences between actual tree locations and LiDAR-derived tree locations using FUSION, TreeVaW, and watershed segmentation were 2.05 m (SD 1.67, 2.19 m (SD 1.83, and 2.31 m (SD 1.94, respectively, in forested plots. Tree height differences from field measured heights for FUSION, TreeVaW, and watershed segmentation were −0.09 m (SD 2.43, 0.28 m (SD 1.86, and 0.22 m (2.45 in forested plots; and 0.56 m (SD 1.07 m, 0.28 m (SD 1.69 m, and 1.17 m (SD 0.68 m, respectively, in a plot containing young conifers. The TAGB comparisons included feature totals per plot, mean biomass per feature by plot, and total biomass by plot for each extraction method. Overall, LiDAR TAGB estimations resulted in FUSION and TreeVaW underestimating by 25 and 31% respectively, and watershed segmentation overestimating by approximately 10%. LiDAR TAGB underestimation occurred in 66% and overestimation occurred in 34% of the plot comparisons.

  15. Quantitative assessments of mantle flow models against seismic observations: Influence of uncertainties in mineralogical parameters

    Science.gov (United States)

    Schuberth, Bernhard S. A.

    2017-04-01

    synthetic traveltime data can then be compared - on statistical grounds - to the traveltime variations observed on Earth. Here, we now investigate the influence of uncertainties in the various input parameters that enter our modelling. This is especially important for the material properties at high pressure and high temperature entering the mineralogical models. In particular, this concerns uncertainties that arise from relating measurements in the laboratory to Earth properties on a global scale. As one example, we will address the question on the influence of anelasticity on the variance of global synthetic traveltime residuals. Owing to the differences in seismic frequency content between laboratory measurements (MHz to GHz) and the Earth (mHz to Hz), the seismic velocities given in the mineralogical models need to be adjusted; that is, corrected for dispersion due to anelastic effects. This correction will increase the sensitivity of the seismic velocities to temperature variations. The magnitude of this increase depends on absolute temperature, frequency, the frequency dependence of attenuation and the activation enthalpy of the dissipative process. Especially the latter two are poorly known for mantle minerals and our results indicate that variations in activation enthalpy potentially produce the largest differences in temperature sensitivity with respect to the purely elastic case. We will present new wave propagation simulations and corresponding statistical analyses of traveltime measurements for different synthetic seismic models spanning the possible range of anelastic velocity conversions (while being based on the same mantle circulation model).

  16. Seismic behaviour of cable-stayed bridges : design, analysis and seismic devices

    OpenAIRE

    Cámara Casado, Alfredo

    2011-01-01

    The social and economical importance of long-span bridges is extremely large; cablestayed bridges currently span distances ranging from 200 to even more than 1000 m, representing key points along infrastructure networks and requiring an outstanding knowledge of their seismic response. The objective of the study is three-fold; (i) to discern how project decisions affect the seismic behaviour of cable-stayed bridges;(ii) to shed light on appropriate analysis strategies in order to address th...

  17. A global database of seismically and non-seismically triggered landslides for 2D/3D numerical modeling

    Science.gov (United States)

    Domej, Gisela; Bourdeau, Céline; Lenti, Luca; Pluta, Kacper

    2017-04-01

    Landsliding is a worldwide common phenomenon. Every year, and ranging in size from very small to enormous, landslides cause all too often loss of life and disastrous damage to infrastructure, property and the environment. One main reason for more frequent catastrophes is the growth of population on the Earth which entails extending urbanization to areas at risk. Landslides are triggered by a variety and combination of causes, among which the role of water and seismic activity appear to have the most serious consequences. In this regard, seismic shaking is of particular interest since topographic elevation as well as the landslide mass itself can trap waves and hence amplify incoming surface waves - a phenomenon known as "site effects". Research on the topic of landsliding due to seismic and non-seismic activity is extensive and a broad spectrum of methods for modeling slope deformation is available. Those methods range from pseudo-static and rigid-block based models to numerical models. The majority is limited to 2D modeling since more sophisticated approaches in 3D are still under development or calibration. However, the effect of lateral confinement as well as the mechanical properties of the adjacent bedrock might be of great importance because they may enhance the focusing of trapped waves in the landslide mass. A database was created to study 3D landslide geometries. It currently contains 277 distinct seismically and non-seismically triggered landslides spread all around the globe whose rupture bodies were measured in all available details. Therefore a specific methodology was developed to maintain predefined standards, to keep the bias as low as possible and to set up a query tool to explore the database. Besides geometry, additional information such as location, date, triggering factors, material, sliding mechanisms, event chronology, consequences, related literature, among other things are stored for every case. The aim of the database is to enable

  18. Multidimensional seismic data reconstruction using tensor analysis

    Science.gov (United States)

    Kreimer, Nadia

    Exploration seismology utilizes the seismic wavefield for prospecting oil and gas. The seismic reflection experiment consists on deploying sources and receivers in the surface of an area of interest. When the sources are activated, the receivers measure the wavefield that is reflected from different subsurface interfaces and store the information as time-series called traces or seismograms. The seismic data depend on two source coordinates, two receiver coordinates and time (a 5D volume). Obstacles in the field, logistical and economical factors constrain seismic data acquisition. Therefore, the wavefield sampling is incomplete in the four spatial dimensions. Seismic data undergoes different processes. In particular, the reconstruction process is responsible for correcting sampling irregularities of the seismic wavefield. This thesis focuses on the development of new methodologies for the reconstruction of multidimensional seismic data. This thesis examines techniques based on tensor algebra and proposes three methods that exploit the tensor nature of the seismic data. The fully sampled volume is low-rank in the frequency-space domain. The rank increases when we have missing traces and/or noise. The methods proposed perform rank reduction on frequency slices of the 4D spatial volume. The first method employs the Higher-Order Singular Value Decomposition (HOSVD) immersed in an iterative algorithm that reinserts weighted observations. The second method uses a sequential truncated SVD on the unfoldings of the tensor slices (SEQ-SVD). The third method formulates the rank reduction problem as a convex optimization problem. The measure of the rank is replaced by the nuclear norm of the tensor and the alternating direction method of multipliers (ADMM) minimizes the cost function. All three methods have the interesting property that they are robust to curvature of the reflections, unlike many reconstruction methods. Finally, we present a comparison between the methods

  19. Single-station seismic noise measures, microgravity, and 3D electrical tomographies to assess the sinkhole susceptibility: the "Il Piano" area (Elba Island - Italy) case study

    Science.gov (United States)

    Pazzi, Veronica; Di Filippo, Michele; Di Nezza, Maria; Carlà, Tommaso; Bardi, Federica; Marini, Federico; Fontanelli, Katia; Intrieri, Emanuele; Fanti, Riccardo

    2017-04-01

    Sudden subsurface collapse, cavities, and surface depressions, regardless of shape and origin, as well as doline are currently indicate by means of the term "sinkhole". This phenomenon can be classified according to a large variety of different schemes, depending on the dominant formation processes (soluble rocks karstic processes, acidic groundwater circulation, anthropogenic caves, bedrock poor geomechanical properties), and on the geological scenario behind the development of the phenomenon. Considering that generally sinkholes are densely clustered in "sinkhole prone areas", detection, forecasting, early warning, and effective monitoring are key aspects in sinkhole susceptibility assessment and risk mitigation. Nevertheless, techniques developed specifically for sinkhole detection, forecasting and monitoring are missing, probably because of a general lack of sinkhole risk awareness, and an intrinsic difficulties involved in detecting precursory sinkhole deformations before collapse. In this framework, integration of different indirect/non-invasive geophysical methods is the best practice approach. In this paper we present the results of an integrated geophysical survey at "Il Piano" (Elba Island - Italy), where at least nine sinkholes occurred between 2008 and 2014. 120 single-station seismic noise measures, 17 3D electrical tomographies (min area 140.3 m2, max area 10,188.9 m2; min electrode spacing 2 m, max electrode spacing 5 m), 964 measurement of microgravity spaced in a grid of 6 m to 8 m were carried out at the study area. The most likely origin for these sinkholes was considered related to sediment net erosion from the alluvium, caused by downward water circulation between aquifers. Therefore, the goals of the study were: i) obtaining a suitable geological and hydrogeological model of the area; ii) detecting possible cavities which could evolve in sinkholes, and finally iii) assess the sinkhole susceptibility of the area. Among the results of the

  20. Rigid-plastic seismic design of reinforced concrete structures

    DEFF Research Database (Denmark)

    Costa, Joao Domingues; Bento, R.; Levtchitch, V.

    2007-01-01

    In this paper a new seismic design procedure for Reinforced Concrete (R/C) structures is proposed-the Rigid-Plastic Seismic Design (RPSD) method. This is a design procedure based on Non-Linear Time-History Analysis (NLTHA) for systems expected to perform in the non-linear range during a lifetime ...

  1. Application of seismic refraction methods in groundwater studies in ...

    African Journals Online (AJOL)

    Calabar, the Cross River State capital, is underlain by Benin Formation. The formation is partly marine, partly deltaic and partly fluviolacustrine in origin. Seismic refraction surveys in the area show that the aquiferous zone has seismic wave velocity of 700-800ms while the non aquiferous zone has velocity ranging from ...

  2. Wide Dynamic Range Multiband Infrared Radiometer for In-Fire Measurements of Wildland Fire Radiant Flux Density

    Science.gov (United States)

    Kremens, R.; Dickinson, M. B.; Hardy, C.; Skowronski, N.; Ellicott, E. A.; Schroeder, W.

    2016-12-01

    We have developed a wide dynamic range (24-bit) data acquisition system for collection of radiant flux density (FRFD) data from wildland fires. The data collection subsystem was designed as an Arduino `shield' and incorporates a 24-bit analog-to-digital converter, precision voltage reference, real time clock, microSD card interface, audible annuciator and interface for various digital communication interfaces (RS232, I2C, SPI, etc.). The complete radiometer system consists of our custom-designed `shield', a commercially available Arduino MEGA computer circuit board and a thermopile sensor -amplifier daughter board. Software design and development is greatly assisted by the availability of a library of public-domain, user-implemented software. The daughter board houses a 5-band radiometer using thermopiles designed for this experiment (Dexter Research Corp., Dexter, MI) to allow determination of the total FRFD from the fire (using a wide band thermopile with a KRS-5 window, 0.1 - 30 um), the FRFD as would be received by an orbital asset like MODIS (3.95 um center wavelength (CWL) and 10.95 CWL, corresponding to MODIS bands 21/22 and 31, respectively) and wider bandpass (0.1-5.5 um and 8-14 um) corresponding to the FRFD recorded by `MWIR' and `LWIR' imaging systems. We required a very wide dynamic range system in order to be able to record the flux density from `cold' ground before the fire, through the `hot' flaming combustion stage, to the `cool' phase after passage of the fire front. The recording dynamic range required (with reasonable resolution at the lowest temperatures) is on the order of 106, which is not currently available in commercial instrumentation at a price point, size or feature set that is suitable for wildland fire investigations. The entire unit, along with rechargeable battery power supply is housed in a fireproof aluminum chassis box, which is then mounted on a mast at a height of 5 - 7 m above the fireground floor. We will report initial

  3. A study on seismicity and seismic hazard for Karnataka State

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 121; Issue 2. A study on seismicity and seismic hazard for Karnataka State. T G Sitharam Naveen ... This paper presents a detailed study on the seismic pattern of the state of Karnataka and also quantifies the seismic hazard for the entire state. In the present work, ...

  4. Delineation of seismic source zones based on seismicity parameters ...

    Indian Academy of Sciences (India)

    The delineation of seismic source zones plays an important role in the evaluation of seismic hazard. In most of the studies the seismic source delineation is done based on geological features. In the present study, an attempt has been made to delineate seismic source zones in the study area (south India) based on the ...

  5. SEISMIC ATTENUATION FOR RESERVOIR CHARACTERIZATION

    Energy Technology Data Exchange (ETDEWEB)

    Joel Walls; M.T. Taner; Gary Mavko; Jack Dvorkin

    2002-01-01

    In Section 1 of this first report we will describe the work we are doing to collect and analyze rock physics data for the purpose of modeling seismic attenuation from other measurable quantities such as porosity, water saturation, clay content and net stress. This work and other empirical methods to be presented later, will form the basis for ''Q pseudo-well modeling'' that is a key part of this project. In Section 2 of this report, we will show the fundamentals of a new method to extract Q, dispersion, and attenuation from field seismic data. The method is called Gabor-Morlet time-frequency decomposition. This technique has a number of advantages including greater stability and better time resolution than spectral ratio methods.

  6. Seismic detection of sonic booms.

    Science.gov (United States)

    Cates, Joseph E; Sturtevant, Bradford

    2002-01-01

    The pressure signals from a sonic boom will produce a small, but detectable, ground motion. The extensive seismic network in southern California, consisting of over 200 sites covering over 50000 square kilometers, is used to map primary and secondary sonic boom carpets. Data from the network is used to analyze three supersonic overflights in the western United States. The results are compared to ray-tracing computations using a realistic model of the stratified atmospheric at the time of the measurements. The results show sonic boom ground exposure under the real atmosphere is much larger than previously expected or predicted by ray tracing alone. Finally, seismic observations are used to draw some inferences on the origin of a set of "mystery booms" recorded in 1992-1993 in southern California.

  7. Seismic Observations in the Taipei Metropolitan Area Using the Downhole Network

    Directory of Open Access Journals (Sweden)

    Win-Gee Huang

    2010-01-01

    Full Text Available Underlain by soft soils, the Taipei Metropolitan Area (TMA experienced major damage due to ground-motion amplification during the Hualien earthquake of 1986, the Chi-Chi earthquake of 1999, the Hualien earthquake of 2002 and the Taitung earthquake of 2003. To study how a local site can substantially change the characteristics of seismic waves as they pass through soft deposits below the free surface, two complementary downhole seismic arrays have been operated in the TMA, since 1991 and 2008. The accelerometer downhole array is composed of eight boreholes at depths in excess of 300 meters. The downhole array velocity sensor collocated with accelerometer composed of four boreholes at depths up to 90 meters. The integrated seismic network monitors potential earthquakes originating from faults in and around the TMA and provides wide-dynamic range measurement of data ranging in amplitude from seismic background noise levels to damage levels as a result of shaking. The data sets can be used to address on the response of soft-soil deposits to ground motions. One of the major considerations is the nonlinear response of soft soil deposits at different levels of excitation. The collocated acceloerometer and velocity sensors at boreholes give the necessary data for studies of non-linearity to be acquired. Such measurements in anticipation of future large, damaging earthquakes will be of special importance for the mitigation of earthquake losses.

  8. Evaluation of long-range transport potential of selected brominated flame retardants with measured 1-octanol-air partition coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Jeong; Kwon, Jung Hwan [Div. of Environmental Science and Ecological Engineering, Korea University, Seoul (Korea, Republic of)

    2016-10-15

    Various alternative flame retardants are used in many countries since polybrominated diphenyl ethers (PBDEs) were classified as persistent organic pollutants (POPs). However, difficulties in the evaluation of the long-range transport potential (LRTP) of the alternatives are related to the lack of information on their physicochemical properties, which govern their environmental fates and transport. Based on the simulation of LRTP using OECD P{sub OV} and LRTP Screening Tool, five alternative brominated flame retardants (BFRs) (hexabromobenzene [HBB], 2,3,4,5,6-pentabromotoluene [PBT], 2,3,4,5,6-pentabromoethylbenzene [PBEB], 2-ethylhexyl 2,3,4,5-tetrabromobenzoate [TBB], and 1,2,4,5-tetrabromo-3,6-dimethylbenzene [TBX]), and 3 PBDEs (BDE-28, BDE-47, and BDE-99) were chosen to perform a refined assessment. This was done using an experimentally measured 1-octanol–air partition coefficient (K{sub OA}) for the calculation of the air–water partition coefficient (K{sub AW}) required for the model. The four selected alternative BFRs (HBB, PBT, PBEB, TBX) have K{sub OA} values close to the in silico estimation used in the screening evaluation. On the other hand, the measured K{sub OA} value for TBB was two orders of magnitude lower than the estimated value used in the screening simulation. The refined simulation showed that characteristic travel distance (CTD) and transfer efficiency (TE) for HBB, PBT, PBEB, and TBX were greater than those for BDE-28, whereas CTD and TE for TBB were lower than those for BDE-28. This suggested that TBB has a lower LRTP than BDE-28, considering the refined partition coefficients.

  9. Identification of seismic precursors before large earthquakes: Decelerating and accelerating seismic patterns

    Science.gov (United States)

    Papadimitriou, Panayotis

    2008-04-01

    A useful way of understanding both seismotectonic processes and earthquake prediction research is to conceive seismic patterns as a function of space and time. The present work investigates seismic precursors before the occurrence of an earthquake. It does so by means of a methodology designed to study spatiotemporal characteristics of seismicity in a selected area. This methodology is based on two phenomena: the decelerating moment release (DMR) and the accelerating moment release (AMR), as they occur within a period ranging from several months to a few years before the oncoming event. The combination of these two seismic sequences leads to the proposed decelerating-accelerating moment release (DAMR) earthquake sequence, which appears as the last stage of loading in the earthquake cycle. This seismic activity appears as a foreshock sequence and can be supported by the stress accumulation model (SAM). The DAMR earthquake sequence constitutes a double seismic precursor identified in space and time before the occurrence of an earthquake and can be used to improve seismic hazard assessment research. In this study, the developed methodology is applied to the data of the 1989 Loma Prieta (California), the 1995 Kobe (Japan), and the 2003 Lefkada (Greece) earthquakes. The last part of this study focuses on the application of the methodology to the Ionian Sea (western Greece) and forecasts two earthquakes in that area.

  10. Evaluation of Spatial Resolution for Heavy Ion CT System Based on the Measurement of Residual Range Distribution With HIMAC

    Science.gov (United States)

    Muraishi, H.; Nishimura, K.; Abe, S.; Satoh, H.; Hara, S.; Hara, H.; Takahashi, Y.; Mogaki, T.; Kawai, R.; Yokoyama, K.; Yasuda, N.; Tomida, T.; Ohno, Y.; Kanai, T.

    2009-10-01

    We report experimental results from a heavy ion CT system based on the measurement of residual range distribution using an X-ray intensifying screen and a charged coupled device (CCD) camera system. This technique was first investigated by Zygmanski (2000) for proton beams, and they reported that the spatial resolution was significantly degraded by multiple Coulomb scattering (MCS) effects in the irradiated medium. Experiments were done on the spatial resolution phantom by using helium and carbon beams accelerated up to 120 MeV/u and 230 MeV/u by the Heavy Ion Medical Accelerator in Chiba (HIMAC), installed in the National Institute of Radiological Sciences (NIRS) in Japan, using a high performance intensified CCD (ICCD) camera. We show that the MCS blurring effect can be significantly reduced in the reconstructed image by using a carbon beam with this technique. Our results suggest that heavier particles such as carbon would be more useful if this technique is envisioned as a clinical tool to obtain data that would aid proton and/or heavy ion treatment planning.

  11. Uncertainties in forces extracted from non-contact atomic force microscopy measurements by fitting of long-range background forces

    Directory of Open Access Journals (Sweden)

    Adam Sweetman

    2014-04-01

    Full Text Available In principle, non-contact atomic force microscopy (NC-AFM now readily allows for the measurement of forces with sub-nanonewton precision on the atomic scale. In practice, however, the extraction of the often desired ‘short-range’ force from the experimental observable (frequency shift is often far from trivial. In most cases there is a significant contribution to the total tip–sample force due to non-site-specific van der Waals and electrostatic forces. Typically, the contribution from these forces must be removed before the results of the experiment can be successfully interpreted, often by comparison to density functional theory calculations. In this paper we compare the ‘on-minus-off’ method for extracting site-specific forces to a commonly used extrapolation method modelling the long-range forces using a simple power law. By examining the behaviour of the fitting method in the case of two radically different interaction potentials we show that significant uncertainties in the final extracted forces may result from use of the extrapolation method.

  12. Fault structure, stress, or pressure control of the seismicity in shale? Insights from a controlled experiment of fluid-induced fault reactivation

    Science.gov (United States)

    De Barros, Louis; Daniel, Guillaume; Guglielmi, Yves; Rivet, Diane; Caron, Hervé; Payre, Xavier; Bergery, Guillaume; Henry, Pierre; Castilla, Raymi; Dick, Pierre; Barbieri, Ernesto; Gourlay, Maxime

    2016-06-01

    Clay formations are present in reservoirs and earthquake faults, but questions remain on their mechanical behavior, as they can vary from ductile (aseismic) to brittle (seismic). An experiment, at a scale of 10 m, aims to reactivate a natural fault by fluid pressure in shale materials. The injection area was surrounded by a dense monitoring network comprising pressure, deformation, and seismicity sensors, in a well-characterized geological setting. Thirty-two microseismic events were recorded during several injection phases in five different locations within the fault zone. Their computed magnitude ranged between -4.3 and -3.7. Their spatiotemporal distribution, compared with the measured displacement at the injection points, shows that most of the deformation induced by the injection is aseismic. Whether the seismicity is controlled by the fault architecture, mineralogy of fracture filling, fluid, and/or stress state is then discussed. The fault damage zone architecture and mineralogy are of crucial importance, as seismic slip mainly localizes on the sealed-with-calcite fractures which predominate in the fault damage zone. As no seismicity is observed in the close vicinity of the injection areas, the presence of fluid seems to prevent seismic slips. The fault core acts as an impermeable hydraulic barrier that favors fluid confinement and pressurization. Therefore, the seismic behavior seems to be strongly sensitive to the structural heterogeneity (including permeability) of the fault zone, which leads to a heterogeneous stress response to the pressurized volume.

  13. Ozone sonde measurements aboard long-range boundary-layer pressurized balloons over the western Mediterranean basin

    Science.gov (United States)

    Gheusi, François; Barret, Brice; Verdier, Nicolas; Dulac, François; Durand, Pierre; Jambert, Corinne

    ChArMEx (http://charmex.lsce.ipsl.fr), including TRAQA in 2012 (launch base at Martigues, France) and ADRIMED (launch base at Sant Lluís, Minorca Island, Spain) and SAFMED (launch base at Levant Island off Hyères, France) in 2013. Complementary radiosoundings -- including ozone -- were also launched from these sites. BLPB drifting altitudes were in the range 0.25-3.2 km. The longest flight lasted more than 32 hours and covered more than 1000 km between Minorca and the limit of the authorized area south of Malta. Those quasi-Lagrangian measurements allow an evaluation of the ozone production/destruction rate as a function of the solar radiation (also measured onboard, as well as standard weather variables) that will be helpful to test chemistry-transport models.

  14. Seismic imaging in laboratory trough laser Doppler vibrometry

    Science.gov (United States)

    Brito, Daniel; Poydenot, Valier; Garambois, Stéphane; Diaz, Julien; Bordes, Clarisse; Rolando, Jean-Paul

    2016-04-01

    Mimic near-surface seismic field measurements at a small scale, in the laboratory, under a well-controlled environment, may lead to a better understanding of wave propagation in complex media such as in geological materials. Laboratory experiments can help in particular to constrain and refine theoretical and numerical modelling of physical phenomena occurring during seismic propagation, in order to make a better use of the complete set of measurements recorded in the field. We have developed a laser Doppler vibrometer (laser interferometry) platform designed to measure non-contact seismic displacements (or velocities) of a surface. This technology enables to measure displacements as small as a tenth of a nanometer on a wide range of frequencies, from a few tenths to a few megahertz. Our experimental set-up is particularly suited to provide high-density spatial and temporal records of displacements on the edge of any vibrating material. We will show in particular a study of MHz wave propagation (excited by piezoelectric transducers) in cylindrical cores of typical diameter size around 10 cm. The laser vibrometer measurements will be first validated in homogeneous materials cylinders by comparing the measurements to a direct numerical simulation. Special attention will be given to the comparison of experimental versus numerical amplitudes of displacements. In a second step, we will conduct the same type of study through heterogeneous carbonate cores, possibly fractured. Tomographic images of velocity in 2D slices of the carbonate core will be derived based upon on the time of first arrival. Preliminary attempts of tomographic attenuation maps will also be presented based on the amplitudes of first arrivals. Experimental records will be confronted to direct numerical simulations and tomographic images will be compared to x-ray scanner imaging of the cylindrical cores.

  15. Experiments on Seismic Metamaterials: Molding Surface Waves

    Science.gov (United States)

    Brûlé, S.; Javelaud, E. H.; Enoch, S.; Guenneau, S.

    2014-04-01

    Materials engineered at the micro- and nanometer scales have had a tremendous and lasting impact in photonics and phononics. At much larger scales, natural soils civil engineered at decimeter to meter scales may interact with seismic waves when the global properties of the medium are modified, or alternatively thanks to a seismic metamaterial constituted of a mesh of vertical empty inclusions bored in the initial soil. Here, we show the experimental results of a seismic test carried out using seismic waves generated by a monochromatic vibrocompaction probe. Measurements of the particles' velocities show a modification of the seismic energy distribution in the presence of the metamaterial in agreement with numerical simulations using an approximate plate model. For complex natural materials such as soils, this large-scale experiment was needed to show the practical feasibility of seismic metamaterials and to stress their importance for applications in civil engineering. We anticipate this experiment to be a starting point for smart devices for anthropic and natural vibrations.

  16. Prediction of subsurface fracture in mining zone of Papua using passive seismic tomography based on Fresnel zone

    Energy Technology Data Exchange (ETDEWEB)

    Setiadi, Herlan; Nurhandoko, Bagus Endar B.; Wely, Woen [WISFIR Lab., Physics of Complex System, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung 40132 (Indonesia); Riyanto, Erwin [PT Freeport Indonesia, Tembagapura, Indonesia herlansetiadi@yahoo.com (Indonesia)

    2015-04-16

    Fracture prediction in a block cave of underground mine is very important to monitor the structure of the fracture that can be harmful to the mining activities. Many methods can be used to obtain such information, such as TDR (Time Domain Relectometry) and open hole. Both of them have limitations in range measurement. Passive seismic tomography is one of the subsurface imaging method. It has advantage in terms of measurements, cost, and rich of rock physical information. This passive seismic tomography studies using Fresnel zone to model the wavepath by using frequency parameter. Fresnel zone was developed by Nurhandoko in 2000. The result of this study is tomography of P and S wave velocity which can predict position of fracture. The study also attempted to use sum of the wavefronts to obtain position and time of seismic event occurence. Fresnel zone tomography and the summation wavefront can predict location of geological structure of mine area as well.

  17. The forecast of mining-induced seismicity and the consequent risk of damage to the excavation in the area of seismic event

    Directory of Open Access Journals (Sweden)

    Jan Drzewiecki

    2017-01-01

    Full Text Available The Central Mining Institute has developed a method for forecasting the amount of seismic energy created by tremors induced by mining operations. The results of geophysical measurements of S wave velocity anomalies in a rock mass or the results of analytic calculations of the values of pressure on the horizon of the elastic layers are used in the process of calculating the energy. The calculation program which has been developed and adopted has been modified over recent years and it now enables not only the prediction of the energy of dynamic phenomena induced by mining but also the forecasting of the devastating range of seismic shock. The results obtained from this calculation, usually presented in a more readable graphic form, are useful for the macroscopic evaluation of locations that are potential sources of seismic energy. Forecasting of the maximum energy of seismic shock without prior knowledge of the location of the shock's source, does not allow shock attenuation that results from, for example, a distance of tremor source from the excavation which will be affected by seismic energy, to be taken into consideration. The phenomena of energy dissipation, which is taken into account in the forecasts, create a new quality of assessment of threat to the excavation. The paper presents the principle of a method of forecasting the seismic energy of a shock and the risk of damage to the excavation as a result of the impact of its energy wave. The solution assumes that the source of the energy shock is a resilient layer in which the sum of the gravitational stresses, resulting from natural disturbances and those induced by the conducted or planned mining exploitation, is estimated. The proposed solution assumes a spherical model for the tremor source, for which seismic energy is forecasted as a function of the longwall advance and the elementary value of seismic energy destroying the excavation. Subsequently, the following are calculated for the

  18. Seismic Tomography of the South Carpathian System

    Science.gov (United States)

    Stuart, G. W.; Ren, Y.; Dando, B. D.; Houseman, G.; Ionescu, C.; Hegedus, E.; Radovanovic, S.; South Carpathian Project Working Group

    2010-12-01

    The South Carpathian Mountain Range is an enigmatic system, which includes one of the most seismically active regions in Europe today. That region, Vrancea in the SE Carpathians, is well studied and its deep structure may be geologically unique, but the mantle structures beneath the western part of the South Carpathian Range are not well resolved by previous tomographic studies. The South Carpathian Project (SCP) is a major temporary deployment (2009-2011) of seismic broadband systems extending across the eastern Pannonian Basin and the South Carpathian Mountains. In this project we aim to map the upper mantle structure in central Europe with the objective of testing geodynamic models of the process that produced extension in the Pannonian, synchronous with convergence and uplift in the Carpathians. Here, we describe initial results of finite-frequency tomography using body waves to image the mantle of the region. We have selected teleseismic earthquakes with magnitude greater than 5.9, which occurred between 2005 and 2010. The data were recorded on 57 temporary stations deployed in the South Carpathian Project, 56 temporary stations deployed in the earlier Carpathian Basins Project (CBP), and 41 permanent broadband stations. The differential travel times are measured in high, intermediate and low frequencies (0.5-2.0 Hz, 0.1-0.5 Hz and 0.03-0.1 Hz for both P-wave, 0.1-0.5 Hz, 0.05-0.1 Hz and 0.02-0.05 Hz for S-wave), and are inverted to produce P and S-wave velocity maps at different depths in the mantle. An extensive zone of high seismic velocities is located in the Mantle Transition zone beneath the Pannonian Basin, and is related to down-welling associated with an earlier phase of continental convergence in the Pannonian region. These results will be used in conjunction with 3D geodynamical modelling to help understand the geological evolution of this region. SCP working group: G. Houseman, G. Stuart, Y. Ren, B. Dando, P. Lorinczi, School of Earth and

  19. Long term continuous radon monitoring in a seismically active area

    CERN Document Server

    Piersanti, A; Galli, G

    2015-01-01

    We present the results of a long term, continuous radon monitoring experiment started in April 2010 in a seismically active area, affected during the 2010-2013 data acquisition time window by an intense micro seismic activity and by several small seismic events. We employed both correlation and cross-correlation analyses in order to investigate possible relationship existing between the collected radon data, seismic events and meteorological parameters. Our results do not support the feasibility of a robust one-to-one association between the small magnitude earthquakes characterizing the local seismic activity and single radon measurement anomalies, but evidence significant correlation patterns between the spatio-temporal variations of seismic moment release and soil radon emanations, the latter being anyway dominantly modulated by meteorological parameters variations.

  20. METHODOLOGY OF SYSTEM APPROACHE TO SEISMIC RISK ASSESSMENT AND REDUCTION

    Directory of Open Access Journals (Sweden)

    A. D. Abakarov

    2016-01-01

    Full Text Available Abstract. Ensuring of urban areas seismic safety is a task which do not require delay. But it cannot be solved by separate parts. It is essential that all components of the seismic hazard must be grouped together in one problem based on the system approach. In the present paper is presented not only the main flowchart of systems approach to ensuring the territory seismic safety but also the flowcharts of components of each main unit. They cover the whole package of measures for a full assessment of territory seismic hazard, seismic risk and its reduction.The proposed methodology can be carried out for design and implementation of regional territory seismic safety programs. 

  1. Fibular taping does not influence ankle dorsiflexion range of motion or balance measures in individuals with chronic ankle instability.

    Science.gov (United States)

    Wheeler, Todd J; Basnett, Curtis R; Hanish, Michael J; Miriovsky, Daniel J; Danielson, Erin L; Barr, J B; Threlkeld, A Joseph; Grindstaff, Terry L

    2013-11-01

    To determine the effects of fibular taping on ankle dorsiflexion range of motion (ROM) and dynamic balance in individuals with chronic ankle instability (CAI). Single-blind, randomized crossover. Twenty-three individuals (age=23.4 ± 2.5 years, height=171.6 ± 12.4 cm, mass=71.5±13.1 kg) with CAI were allocated to either a fibular taping intervention or sham taping intervention (tape applied without tension) over the course of two visits. Weight-bearing ankle dorsiflexion ROM and components of the Star Excursion Balance Test (SEBT) were measured before and after intervention. There was not a significant change in ankle dorsiflexion ROM when comparing the taping interventions (F1,43=1.03, P=.32), but both interventions resulted in a small increase (F1,43=8.07, P=.007) in dorsiflexion ROM (pre=36.7° ± 6.9°, post=37.7° ± 6.2°). This increase in ROM did not exceed the established minimal detectable change for dorsiflexion ROM. Fibular taping with tension produced an increase (F1,41=5.84, P=.02) (pre=69.0 ± 9.1%, post=70.6±8.6%) in posterolateral reach distance when compared to taping without tension (pre=72.7 ± 11.0%, post=71.4 ± 9.6%), but this increase did not exceed the established minimal detectable change. There was not a significant change in dynamic balance between groups for the anterior (F1,41=2.33, P=.14) and posteromedial (F1,41=.41, P=.53) reach directions. Although small changes in ankle dorsiflexion ROM and posterolateral reach distances were observed, these changes did not exceed established minimal detectable change values for these measures. These results suggest that the benefits of fibular taping are not related to an increase in ankle dorsiflexion ROM or dynamic balance. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  2. Seismic response of linear accelerators

    CERN Document Server

    Collette, C; Guinchard, M; Hauviller, C

    2010-01-01

    This paper is divided into two parts. The first part presents recent measurements of ground motion in the LHC tunnel at CERN. From these measurements, an update of the ground motion model currently used in accelerator simulations is presented. It contains new features like a model of the lateral motion and the technical noise. In the second part, it is shown how this model can be used to evaluate the seismic response of a linear accelerator in the frequency domain. Then, the approach is validated numerically on a regular lattice, taking the dynamic behavior of the machine alignment stage and the mechanical stabilization of the quadrupoles into account.

  3. Seismic response of linear accelerators

    Directory of Open Access Journals (Sweden)

    C. Collette

    2010-07-01

    Full Text Available This paper is divided into two parts. The first part presents recent measurements of ground motion in the LHC tunnel at CERN. From these measurements, an update of the ground motion model currently used in accelerator simulations is presented. It contains new features like a model of the lateral motion and the technical noise. In the second part, it is shown how this model can be used to evaluate the seismic response of a linear accelerator in the frequency domain. Then, the approach is validated numerically on a regular lattice, taking the dynamic behavior of the machine alignment stage and the mechanical stabilization of the quadrupoles into account.

  4. Wide range of body composition measures are associated with cognitive function in community-dwelling older adults.

    Science.gov (United States)

    Won, Huiloo; Abdul Manaf, Zahara; Mat Ludin, Arimi Fitri; Shahar, Suzana

    2017-04-01

    Studies of the association between body composition, both body fat and body muscle, and cognitive function are rarely reported. The aim of the present study was to determine the association between a wide range of body composition measures with cognitive function in older adults. A total of 2322 Malaysian older adults aged 60 years and older were recruited using multistage random sampling in a population-based cross-sectional study. Out of 2322 older adults recruited, 2309 (48% men) completed assessments on cognitive function and body composition. Cognitive functions were assessed using the Malay version of the Mini-Mental State Examination, the Bahasa Malaysia version of Montreal Cognitive Assessment, Digit Span Test, Digit Symbol Test and Rey Auditory Verbal Learning Test. Body composition included body mass index, mid-upper arm circumference, waist circumference, calf circumference, waist-to-hip ratio, percentage body fat and skeletal muscle mass. The association between body composition and cognitive functions was analyzed using multiple linear regression. After adjustment for age, education years, hypertension, hypercholesterolemia, diabetes mellitus, depression, smoking status and alcohol consumption, we found that calf circumference appeared as a significant predictor for all cognitive tests among both men and women (P < 0.05), except for the Rey Auditory Verbal Learning Test. Waist-to-hip ratio was detected as a significant predictor for all cognitive tests among women (P < 0.05), but was only a significant predictor for the Bahasa Malaysia version of Montreal Cognitive Assessment among men (P < 0.05). These results suggest that there is a need to maintain muscle mass and lower adipose tissue among older adults for optimal cognitive function. Geriatr Gerontol Int 2017; 17: 554-560. © 2016 Japan Geriatrics Society.

  5. New comprehensive standard seismic noise models and 3D seismic noise variation for Morocco territory, North Africa, obtained using seismic broadband stations

    Science.gov (United States)

    El Fellah, Younes; El-Aal, Abd El-Aziz Khairy Abd; Harnafi, Mimoun; Villaseñor, Antonio

    2017-05-01

    In the current work, we constructed new comprehensive standard seismic noise models and 3D temporal-spatial seismic noise level cubes for Morocco in north-west Africa to be used for seismological and engineering purposes. Indeed, the original global standard seismic noise models published by Peterson (1993) and their following updates by Astiz and Creager (1995), Ekström (2001) and Berger et al. (2003) had no contributing seismic stations deployed in North Africa. Consequently, this preliminary study was conducted to shed light on seismic noise levels specific to north-west Africa. For this purpose, 23 broadband seismic stations recently installed in different structural domains throughout Morocco are used to study the nature and characteristics of seismic noise and to create seismic noise models for Morocco. Continuous data recorded during 2009, 2010 and 2011 were processed and analysed to construct these new noise models and 3D noise levels from all stations. We compared the Peterson new high-noise model (NHNM) and low-noise model (NLNM) with the Moroccan high-noise model (MHNM) and low-noise model (MLNM). These new noise models are comparable to the United States Geological Survey (USGS) models in the short period band; however, in the period range 1.2 s to 1000 s for MLNM and 10 s to 1000 s for MHNM display significant variations. This variation is attributed to differences in the nature of seismic noise sources that dominate Morocco in these period bands. The results of this study have a new perception about permanent seismic noise models for this spectacular region and can be considered a significant contribution because it supplements the Peterson models and can also be used to site future permanent seismic stations in Morocco.

  6. BUILDING 341 Seismic Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Halle, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-06-15

    The Seismic Evaluation of Building 341 located at Lawrence Livermore National Laboratory in Livermore, California has been completed. The subject building consists of a main building, Increment 1, and two smaller additions; Increments 2 and 3.

  7. Seismic Creep, USA Images

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Seismic creep is the constant or periodic movement on a fault as contrasted with the sudden rupture associated with an earthquake. It is a usually slow deformation...

  8. Seismic Consequence Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    M. Gross

    2004-10-25

    The primary purpose of this model report is to develop abstractions for the response of engineered barrier system (EBS) components to seismic hazards at a geologic repository at Yucca Mountain, Nevada, and to define the methodology for using these abstractions in a seismic scenario class for the Total System Performance Assessment - License Application (TSPA-LA). A secondary purpose of this model report is to provide information for criticality studies related to seismic hazards. The seismic hazards addressed herein are vibratory ground motion, fault displacement, and rockfall due to ground motion. The EBS components are the drip shield, the waste package, and the fuel cladding. The requirements for development of the abstractions and the associated algorithms for the seismic scenario class are defined in ''Technical Work Plan For: Regulatory Integration Modeling of Drift Degradation, Waste Package and Drip Shield Vibratory Motion and Seismic Consequences'' (BSC 2004 [DIRS 171520]). The development of these abstractions will provide a more complete representation of flow into and transport from the EBS under disruptive events. The results from this development will also address portions of integrated subissue ENG2, Mechanical Disruption of Engineered Barriers, including the acceptance criteria for this subissue defined in Section 2.2.1.3.2.3 of the ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274]).

  9. Monitoring the tidal response of a sea levee with ambient seismic noise

    Science.gov (United States)

    Planès, Thomas; Rittgers, Justin B.; Mooney, Michael A.; Kanning, Wim; Draganov, Deyan

    2017-03-01

    Internal erosion, a major cause of failure of earthen dams and levees, is often difficult to detect at early stages using traditional visual inspection. The passive seismic-interferometry technique could enable the early detection of internal changes taking place within these structures. We test this technique on a portion of the sea levee of Colijnsplaat, Netherlands, which presents signs of concentrated seepage in the form of sandboils. Applying seismic interferometry to ambient noise collected over a 12-hour period, we retrieve surface waves propagating along the levee. We identify the contribution of two dominant ambient seismic noise sources: the traffic on the Zeeland bridge and a nearby wind turbine. Here, the sea-wave action does not constitute a suitable noise source for seismic interferometry. Using the retrieved surface waves, we compute time-lapse variations of the surface-wave group velocities during the 12-hour tidal cycle for different frequency bands, i.e., for different depth ranges. The estimated group-velocity variations correlate with variations in on-site pore-water pressure measurements that respond to tidal loading. We present lateral profiles of these group-velocity variations along a 180-meter section of the levee, at four different depth ranges (0m-40m). On these profiles, we observe some spatially localized relative group-velocity variations of up to 5% that might be related to concentrated seepage.

  10. Seismically induced landslides: current research by the US Geological Survey.

    Science.gov (United States)

    Harp, E.L.; Wilson, R.C.; Keefer, D.K.; Wieczorek, G.F.

    1986-01-01

    We have produced a regional seismic slope-stability map and a probabilistic prediction of landslide distribution from a postulated earthquake. For liquefaction-induced landslides, in situ measurements of seismically induced pore-water pressures have been used to establish an elastic model of pore pressure generation. -from Authors

  11. A SEISMIC DESIGN OF NUCLEAR REACTOR BUILDING STRUCTURES APPLYING SEISMIC ISOLATION SYSTEM IN A HIGH SEISMICITY REGION –A FEASIBILITY CASE STUDY IN JAPAN-

    Directory of Open Access Journals (Sweden)

    TETSUO KUBO

    2014-10-01

    Full Text Available A feasibility study on the seismic design of nuclear reactor buildings with application of a seismic isolation system is introduced. After the Hyogo-ken Nanbu earthquake in Japan of 1995, seismic isolation technologies have been widely employed for commercial buildings. Having become a mature technology, seismic isolation systems can be applied to NPP facilities in areas of high seismicity. Two reactor buildings are discussed, representing the PWR and BWR buildings in Japan, and the application of seismic isolation systems is discussed. The isolation system employing rubber bearings with a lead plug positioned (LRB is examined. Through a series of seismic response analyses using the so-named standard design earthquake motions covering the design basis earthquake motions obtained for NPP sites in Japan, the responses of the seismic isolated reactor buildings are evaluated. It is revealed that for the building structures examined herein: (1 the responses of both isolated buildings and isolating LRBs fulfill the specified design criteria; (2 the responses obtained for the isolating LRBs first reach the ultimate condition when intensity of motion is 2.0 to 2.5 times as large as that of the design-basis; and (3 the responses of isolated reactor building fall below the range of the prescribed criteria.

  12. Enso-like cyclicity In Late Pleistocene varve thickness measurements from two alpine lakes, Wind River Range, Wyoming, USA

    Science.gov (United States)

    Dahms, D. E.; Noren, A. J.; Geiss, C. E.; Dorale, J. A.; Myrbo, A.

    2011-12-01

    Spectral analyses of varve thickness measurements in sediment cores from two moraine-dammed lakes in the Wind River Range of Wyoming, USA, reveal a 2.8-to-8-yr cyclicity consistent with that expressed by ENSO. The lakes [Louis Lake (42.596°N,108.846°W, 2610 m and nearby Fiddlers Lake 42.6312°N, 108.8786°W, 2868 m] and hold the possibility of longer records of mid-continental climate change even into the last interglacial. Nine macrofossil-based 14C ages (AMS) combined with varve thicknesses indicate the lakes were deep enough during the LGM to form and preserve varves and that the minimum age for the lacustrine sediments here is ~20 kyrs. The ENSO signal is most robust in the Louis Lake varves, displaying high spectral power across the entire band of frequencies associated with ENSO. Analysis of the Fiddlers Lake varves yield predictably less significant results, a consequence of the different geomorphic settings of these two lakes. Specifically, (1) Louis Lake has a large catchment and receives surface water input from a stream, which has delivered a large quantity of sediment to the lake margin and deposited a substantial delta. In this setting, variations in precipitation appear closely linked to sediment delivery to the lake, and are reflected in sediment distributions, while (2) Fiddlers Lake is located in a small re-entrant basin with a relatively insignificant catchment area and fed almost entirely by groundwater and direct rain/snow events, with little surface runoff; (3) the deeper water of Louis Lake aids in the formation and preservation of varves, while (4) lake level fluctuations in the shallower Fiddlers Lake directly affect varve creation and preservation (the onset of glaciation in the Fiddlers Lake core is represented by thick sediment packages that eventually thin to varves by ~1m up-core). The significant ENSO-like periodicities in the the varved sediments in these lakes suggests that the effects of ENSO forcing were felt far into the western

  13. Fluorescent sensors for the basic metabolic panel enable measurement with a smart phone device over the physiological range.

    Science.gov (United States)

    Awqatty, Becker; Samaddar, Shayak; Cash, Kevin J; Clark, Heather A; Dubach, J Matthew

    2014-10-21

    The advanced functionality of portable devices such as smart phones provides the necessary hardware to potentially perform complex diagnostic measurements in any setting. Recent research and development have utilized cameras and data acquisition properties of smart phones to create diagnostic approaches for a variety of diseases or pollutants. However, in concentration measurements, such as blood glucose, the performance of handheld diagnostic devices depends largely on the sensing mechanism. To expand measurements to multiple components, often necessary in medical tests, with a single diagnostic device, robust platform based sensors are needed. Here, we developed a suite of dual wavelength fluorescent sensors with response characteristics necessary to measure each component of a basic metabolic panel, a common clinical measurement. Furthermore, the response of these sensors could be measured with a simple optical setup to convert a smart phone into a fluorescence measurement instrument. This approach could be used as a mobile basic metabolic panel measurement system for point of care diagnostics.

  14. Close Range Photogrammetry in Space - Measuring the On-Orbit Clearance between Hardware on the International Space Station

    Science.gov (United States)

    Liddle, Donn

    2017-01-01

    When photogrammetrists read an article entitled "Photogrammetry in Space" they immediately think of terrestrial mapping using satellite imagery. However in the last 19 years the roll of close range photogrammetry in support of the manned space flight program has grown exponentially. Management and engineers have repeatedly entrusted the safety of the vehicles and their crews to the results of photogrammetric analysis. In February 2010, the Node 3 module was attached to the port side Common Berthing Mechanism (CBM) of the International Space Station (ISS). Since this was not the location at which the module was originally designed to be located on the ISS, coolant lines containing liquid ammonia, were installed externally from the US Lab to Node 3 during a spacewalk. During mission preparation I had developed a plan and a set of procedures to have the astronauts acquire stereo imagery of these coolant lines at the conclusion of the spacewalk to enable us to map their as-installed location relative to the rest of the space station. Unfortunately, the actual installation of the coolant lines took longer than expected and in an effort to wrap up the spacewalk on time, the mission director made a real-time call to drop the photography. My efforts to reschedule the photography on a later spacewalk never materialized, so rather than having an as-installed model for the location of coolant lines, the master ISS CAD database continued to display an as-designed model of the coolant lines. Fast forward to the summer of 2015, the ISS program planned to berth a Japanese cargo module to the nadir Common Berthing Mechanism (CBM), immediately adjacent to the Node 3 module. A CAD based clearance analysis revealed a negative four inch clearance between the ammonia lines and a thruster nozzle on the port side of the cargo vehicle. Recognizing that the model of the ammonia line used in the clearance analysis was "as-designed" rather than "as-installed", I was asked to determine the

  15. A meta-analysis of echocardiographic measurements of the left heart for the development of normative reference ranges in a large international cohort

    DEFF Research Database (Denmark)

    Møgelvang, Rasmus

    2014-01-01

    AIM: To develop age-, sex-, and ethnic-appropriate normative reference ranges for standard echocardiographic measurements of the left heart by combining echocardiographic measurements obtained from adult volunteers without clinical cardiovascular disease or significant cardiovascular risk factors......, from multiple studies around the world. METHODS AND RESULTS: The Echocardiographic Normal Ranges Meta-Analysis of the Left heart (EchoNoRMAL) collaboration was established and population-based data sets of echocardiographic measurements combined to perform an individual person data meta-analysis. Data...... and 95th centile of each measurement against age. CONCLUSION: This unique data set represents a large, multi-ethnic cohort of subjects resident in a wide range of countries. The resultant reference ranges will have wide applicability for normative data based on age, sex, and ethnicity....

  16. Seismic Device UVS 1504, possibilities of its Utilization

    Directory of Open Access Journals (Sweden)

    Leššo Igor

    1996-09-01

    Full Text Available Department of Mining and Geotechnics for many years deals with questions of the technical seismicity. In the paper are given possibilities of utilizing the UVS 1504 device and results obtained from the measurement of seismic effects of blasting as well as others sources of bursts. The measurements showed that this device enables to measure parameters and to evaluate measured data quickly, reliably, and with a very high precision. The device enables evaluating individual time degrees of blasts, determining the law of attenuation of the seismic waves, and precise determination of the maximum charge permissible for futher advance of the blasting in given conditions.

  17. Characteristics and reference ranges of Insulin-Like Growth Factor-I measured with a commercially available immunoassay in 724 healthy adult Caucasians

    DEFF Research Database (Denmark)

    Andreassen, Mikkel; Nielsen, Kaspar Renÿ; Kristensen, Lars Østergaard

    2009-01-01

    BACKGROUND AND OBJECTIVE: Measurements of Insulin-Like Growth Factor-I (IGF-I) play a pivotal role in the evaluation of the growth hormone-IGF-I axis. Due to assay variation IGF-I reference ranges are assay specific. We provide serum IGF-I reference ranges for adult men and women obtained...

  18. Innovations in seismic sensors driven by the search for gravitational waves

    NARCIS (Netherlands)

    Beker, Mark; Campman, Xander; Van Oven, Jules; Walk, Wim; Levell, Jack; Tang, Zijian; Danilouchkine, Mike; Smit, Dirk; Van Den Brand, Johannes; Koley, Soumen; Bader, Maria

    2016-01-01

    An example is provided of how technology from a seemingly far-removed field of science has found its way into seismic surveying equipment. In order to achieve affordable dense sampling to remove adverse seismic-noise effects from gravitational-wave measurements, autonomous, integrated seismic nodes

  19. Seismic hazard in the Nation's breadbasket

    Science.gov (United States)

    Boyd, Oliver; Haller, Kathleen; Luco, Nicolas; Moschetti, Morgan P.; Mueller, Charles; Petersen, Mark D.; Rezaeian, Sanaz; Rubinstein, Justin L.

    2015-01-01

    The USGS National Seismic Hazard Maps were updated in 2014 and included several important changes for the central United States (CUS). Background seismicity sources were improved using a new moment-magnitude-based catalog; a new adaptive, nearest-neighbor smoothing kernel was implemented; and maximum magnitudes for background sources were updated. Areal source zones developed by the Central and Eastern United States Seismic Source Characterization for Nuclear Facilities project were simplified and adopted. The weighting scheme for ground motion models was updated, giving more weight to models with a faster attenuation with distance compared to the previous maps. Overall, hazard changes (2% probability of exceedance in 50 years, across a range of ground-motion frequencies) were smaller than 10% in most of the CUS relative to the 2008 USGS maps despite new ground motion models and their assigned logic tree weights that reduced the probabilistic ground motions by 5–20%.

  20. SEISMIC MODELING ENGINES PHASE 1 FINAL REPORT

    Energy Technology Data Exchange (ETDEWEB)

    BRUCE P. MARION

    2006-02-09

    Seismic modeling is a core component of petroleum exploration and production today. Potential applications include modeling the influence of dip on anisotropic migration; source/receiver placement in deviated-well three-dimensional surveys for vertical seismic profiling (VSP); and the generation of realistic data sets for testing contractor-supplied migration algorithms or for interpreting AVO (amplitude variation with offset) responses. This project was designed to extend the use of a finite-difference modeling package, developed at Lawrence Berkeley Laboratories, to the advanced applications needed by industry. The approach included a realistic, easy-to-use 2-D modeling package for the desktop of the practicing geophysicist. The feasibility of providing a wide-ranging set of seismic modeling engines was fully demonstrated in Phase I. The technical focus was on adding variable gridding in both the horizontal and vertical directions, incorporating attenuation, improving absorbing boundary conditions and adding the optional coefficient finite difference methods.

  1. Kinematics and Dynamics of the Kivu Rift System from Seismic Anisotropy, Seismicity, and Structural Analyses

    Science.gov (United States)

    Zal, H. J.; Wood, D. A.; Ebinger, C. J.; Scholz, C. A.; d'Oreye, N.; Carn, S. A.; Rutagarama, U.

    2014-12-01

    The westward-tilted Kivu rift in East Africa is bounded by the ~100 km-long, seismically active West Kivu border fault, and dammed at its northern end by flows from the Virunga Volcanic Province. Earlier work delineated faults along the basin margins, but little was known of active faults beneath Lake Kivu, and the lithospheric structure was unexplored. The aims of this study are to determine the kinematics of normal faults and their relation to pre-existing basement structures; to examine the locations of earthquakes with respect to faults in order to delineate zones of active faulting; to evaluate models for the modification of lithosphere by extension and mantle plume processes using seismic shear wave splitting measurements; and to evaluate the role of volcanic loading within the Virunga volcanic province on the evolution of the Kivu basin. We determine rift fault and volcanic fissure locations and orientations using merged high-resolution CHIRP bathymetric and Space Radar Topography Mission data. The majority of faults in the northern sector strike NNE, whereas NE faults are equally important in the southern basin, marking the Kivu-Rusizi accommodation zone. Seismic data was acquired from an 8-station array deployed between March 2012 and April 2013. Although the majority of earthquakes beneath the rift (excluding the active volcanoes) occur at depths of 8-20 km, unusually shallow earthquakes (2-4 km) are located along submerged faults within the East Kivu basin and suggest high pore pressures within the upper crust. Using simple elastic plate flexure model calculations we estimate the maximum deflection of the plate to be ~7 km, using an effective elastic thickness of ~7.5 km. We propose that the rapid subsidence of the ~400 m deep northern Kivu basin occurred in response to volcanic construction. We evaluate models for the modification of lithosphere using shear wave splitting measurements. Splitting results with backazimuths ranging